Difficult Foley Catheterization

Anatomy and Physiology

A comprehensive understanding of normal and abnormal anatomy in both males and females improves the success of urinary catheterization. The male and female urethra each contain 4 distinct tissue layers. From the innermost to the outermost, these layers include:

• Mucosa (inner epithelial lining)
• Spongy submucosa (rich with vasculature)
• Smooth muscle layer
• Outer fibroelastic connective tissue layer [2]

Anatomy of the Female Urethra

The female urethra measures approximately 5 cm in length and lacks the natural curvature characteristic of the male urethra.[4] The distal one-third drains to the inguinal lymph nodes and contains stratified squamous epithelium, whereas the proximal two-thirds drains to the pelvic lymph nodes and consists of transitional epithelium (urothelium).[4] Unlike the male urethra, the female urethra has no distinct anatomical segments.

Estrogen stimulation increases blood flow and tissue elasticity within the urethral and vaginal tissues.[5] Declining estrogen levels during menopause thin the vaginal and urethral tissues, contributing to atrophic vaginitis. These tissue changes may cause tenderness or inflammation, making urethral exposure during catheterization more uncomfortable. Atrophic vaginitis may also cause the urethral meatus to retract inward into an anterior position, reducing visualization and making catheterization with a standard, non-curved catheter from the conventional supine frog-leg position more challenging.[2]

Obesity presents an additional obstacle to direct visualization of the female urethra during catheterization. Adequate exposure of the urethral meatus in patients with obesity may require assistance to retract the abdominal pannus along with additional lighting.

Pelvic organ prolapse

Pelvic organ or urethral prolapse further complicates urinary catheterization. Pelvic organ prolapse occurs more frequently in multiparous White and Hispanic women older than 50 years and develops when the fascial and muscular supports of the bladder, urethra, rectum, vaginal vault, or uterus become weakened by neuromuscular trauma, hormonal changes, obesity, smoking, connective tissue disorders, and other environmental or genetic factors. Prolapse may obscure the urethral meatus, compress the urethral lumen and contribute to urinary retention, while also altering the expected location and appearance of normal anatomy.

Anatomy of the Male Urethra

The male urethra forms a fibromuscular tube measuring approximately 20 cm in length and terminates in a urethral meatus measuring 22 to 24 French.[6] The urethra extends through the corpus spongiosum of the penis, traverses the prostate gland, and enters the bladder. From distal to proximal, the urethral anatomy includes the urethral meatus, navicular fossa, penile urethra, bulbar urethra, membranous urethra, and prostatic urethra. Viewed in the sagittal plane, the male urethra assumes an "S"-shaped curvature. Gentle traction on the penis straightens this curvature and facilitates smoother passage of a urinary catheter.

The most common sites of urethral narrowing include the fossa navicularis, where strictures often develop secondary to instrumentation, infection, or irritation; the bulbar urethra, where trauma, instrumentation, infection, or idiopathic causes commonly produce strictures; and the bladder neck, where prior radiation therapy, instrumentation, or surgery frequently causes narrowing. Benign prostatic hyperplasia may compress the prostatic urethra. Additional anatomic variations that may complicate catheterization include hypospadias, duplicated urethras, urethral diverticula, and neuroectodermal anomalies.

Urethral duplication occurs in several sagittal plane configurations and may be complete or incomplete. In affected patients, the ventral meatus most commonly communicates with the urinary bladder and should serve as the catheterization site when urinary drainage becomes necessary.

Hypospadias represents the most common congenital anatomical variant of the penis and develops when hormonal signaling abnormalities disrupt normal urethral tubularization during fetal development.[7] The urethral meatus may open anywhere along the glans, penile shaft, scrotum, or perineum, creating challenges during catheter placement. Dorsal pits, also known as neuroectodermal dimples, frequently accompany urethral duplication and hypospadias.[7] These blind-ending, epithelial-lined false urethras may resemble an obstructed urethra during catheterization despite lacking communication with the urinary tract.[7]

As the urethra approaches the prostate, a 30-degree ventral turn directs the lumen toward the bladder. This "J"-shaped configuration increases susceptibility to iatrogenic injury during catheterization and instrumentation, predisposing patients to strictures, bleeding, and stenosis. False passages most commonly develop at this location when excessive force advances a catheter without accounting for the changing urethral angle. Excessive pressure may damage or perforate the superficial urethral layers, and continued advancement can elevate a flap of urothelium, creating a false passage.

Nurses and physicians should obtain detailed information regarding previous catheterization attempts, including the type and size of each catheter used, the depth of insertion before resistance occurred, evidence of trauma, eg, blood on the catheter or at the urethral meatus, and whether balloon inflation may have occurred within the urethra rather than the urinary bladder.[8]

Physiology of Difficult Catheterizations of Males

Phimosis

Phimosis develops in uncircumcised boys and men when the foreskin cannot be retracted below the glans penis. Pathological phimosis features scarring of the preputial tissue resulting from chronic inflammation and commonly occurs in men with diabetes. Physiologic phimosis, more frequently observed in young boys, involves healthy tissue beneath a tight foreskin and commonly results from adherence between the glans and preputial tissue.[9] Gradual, gentle foreskin retraction often leads to spontaneous resolution, although topical corticosteroid therapy may sometimes be required. Persistent physiologic phimosis or pathological phimosis associated with symptoms generally responds to a dorsal slit procedure or circumcision.

Buried Penis

A buried penis may make identification of the urethral meatus challenging, particularly when phimosis also exists. Management requires only sufficient exposure of the glans to visualize the urethral meatus, which frequently can be achieved by applying firm pressure around the base of the penis. (Please refer to the Technique section for more information on additional management techniques.)

Meatal Stenosis and Fossa Navicularis Strictures

Distal penile anatomy frequently presents obstacles to successful catheterization. Meatal stenosis, urethral strictures, phimosis, hypospadias, and dorsal pits may all interfere with catheter passage. Recent reviews identify lichen sclerosus as the most common cause of distal urethral obstruction.[10] Although the precise etiology remains uncertain, proposed mechanisms include autoimmunity, skin injury, viral infection, and inflammation of the glands of Littre.[10][11] Lichen sclerosus produces chronic inflammation that progresses to tissue thickening, scarring, and obliteration of the normal architecture of the prepuce, glans, and urethral meatus, a condition known as balanitis xerotica obliterans.[10] The inflammatory process may also extend proximally along the penile urethra.[10]

Strictures

Urethral strictures represent the most common cause of difficult catheterization. Luminal narrowing creates resistance during catheter advancement and often causes anxiety for both the clinician and the patient. Various instruments and procedural techniques described in subsequent sections may successfully overcome this resistance. Infection, inflammation, trauma, instrumentation, and previous urethral reconstruction procedures, including genital gender-affirming penile construction, urethral lengthening, and vaginectomy, all contribute to stricture formation.

Damage to the urethral lumen from inflammation, trauma, or surgery disrupts the epithelial layers and alters normal tissue planes. Loss of urothelial integrity produces replacement cells that may lack the durability of native urothelium. Once the urothelial barrier becomes compromised, urine may extravasate into the surrounding corpus spongiosum. The resulting inflammatory response, known as spongiofibrosis, promotes progressive formation and coalescence of fibrotic plaques that ultimately develop into urethral strictures.[12] Strictures vary in length, depth, location, luminal caliber, and tissue density, yet each characteristic may contribute to difficult catheterization.

The penile urethra

The penile, or pendulous, urethra comprises most of the urethral length and commonly becomes difficult to traverse because of strictures or false passages. Strictures in this segment most often result from aggressive instrumentation or inflammation and frequently occur in patients with a history of surgery, trauma, sexually transmitted infections, urologic instrumentation, or urinary tract infections.

The bulbar urethra

The bulbar urethra is the most common site of urethral strictures, primarily due to iatrogenic injury from catheterization or trauma, eg, saddle injuries that compress the urethra against the pelvic bones. Local anatomy contributes substantially to this risk. The "J"-shaped configuration of the deep bulbar urethra immediately distal to the external urethral sphincter allows blindly advanced instruments or catheters to continue in a straight path, potentially damaging or perforating the posterior urethral wall and creating a false passage. Subsequent healing follows the same spongiofibrosis pathway responsible for other urethral strictures.

The membranous urethra

The membranous urethra contains the external urethral sphincter. Aggressive treatment of strictures in this region carries a substantial risk of urinary incontinence, which may prove difficult to manage. Trauma, pelvic radiation therapy, and instrumentation, including transurethral resection of the prostate, represent common causes of injury in this segment.

The prostatic urethra

The prostatic urethra passes through the prostatic lobes, which commonly undergo hyperplastic enlargement with advancing age. Approximately 50% of men between 50 and 60 years of age develop some degree of benign prostatic hyperplasia, and enlargement of the median lobe may progressively compress the urethra, creating narrowing and resistance during catheterization. Repeated passage of instruments during lithotripsy, cystoscopy, and other urologic procedures may also produce microvascular injury within the prostatic urethra, leading to fibrosis and subsequent stricture formation.

The Bladder Neck

Bladder neck contracture represents the most common iatrogenic cause of difficult Foley catheterization involving the proximal urethra after prostate surgery or pelvic radiation therapy.[13] Contracture elevates the bladder neck and reduces tissue compliance. Forceful advancement of a urinary catheter or instrument into this elevated, poorly compliant tissue without appropriate anterior angulation increases the risk of undermining the bladder.

Physiology of Difficult Catheterizations of Females

Although the female urethra has a relatively short length and pathological strictures occur less frequently than in males, anatomical variations and physiological changes associated with menopause and pelvic organ prolapse may significantly complicate urethral catheterization. Lichen sclerosus, tissue atrophy, pelvic organ prolapse, and body habitus all contribute to difficult catheterization in female patients.

Menopause and atrophy of the anterior urethra

The female vulvovaginal tissues contain estrogen receptors that support lubrication and preserve normal tissue architecture. The precise mechanisms remain incompletely understood, but declining estrogen levels during menopause promote progressive tissue atrophy. Reduced estrogen stimulation diminishes the fullness, elasticity, and structural support of elastic fibers, collagen, and smooth muscle. As these changes develop, the urethral meatus commonly retracts superiorly and inward, making direct visualization and urethral catheterization more difficult.

Indications

The first step in addressing a difficult Foley catheterization problem involves reviewing the indications for Foley catheterization.[2] A thorough clinical history and physical examination focused on identifying urethral trauma are essential when evaluating a patient for urinary catheterization, because attempts at Foley placement can worsen outcomes despite the intention to provide clinical benefit. In many situations, close monitoring of urinary output may provide sufficient information and help avoid the need for an indwelling catheter.[14]

A urinary catheter may be placed to relieve acute or chronic urinary retention, obtain urine specimens for analysis, dilate urethral strictures, splint the urethra after surgery, perform continuous bladder infusions, manage hematuria, drain the bladder following an injury, maintain hygiene in an immobile patient, and decompress a neurogenic bladder.[8][15] Urinary decompression also plays an important role in many critical care settings to ensure accurate measurement of urinary output and during prolonged surgical procedures that require bladder emptying.

Foley catheters may be appropriate for urine measurement and collection only when fluid status or urinary output cannot be assessed through alternative methods. Admission to an ICU alone does not automatically justify Foley catheter placement. Patients who can void with acceptable postvoid residual volumes and who are not being treated for urinary tract sepsis or infection generally do not require catheterization.[15] Acute heart failure patients provide another example in which clinicians must carefully weigh the risks and benefits of urinary catheterization.

In challenging cases, avoiding extensive urologic instrumentation for Foley catheter placement may be prudent unless catheterization becomes absolutely necessary.[2]

Contraindications

Acute traumatic injury to the urethra is a contraindication to urinary catheterization without direct visualization. Clinical signs correlating with injuries, eg, blood at the urethral meatus and a high-riding prostate, suggest urethral injury, and an attempt at Foley catheterization should only be made under direct visualization with the aid of a cystoscope or after retrograde urethrography.

The absence of urethral blood or a high-riding prostate does not provide sufficient evidence to definitively exclude a urethral injury. Clinical judgment remains essential when evaluating the patient’s injury severity and mechanism to determine whether a traumatic urethral injury remains likely or possible. When uncertainty persists, a retrograde urethrogram should be performed.

Equipment

Reviewing the patient’s urologic history and understanding the relevant anatomic considerations when evaluating difficult urinary catheterizations allow clinicians to select the most appropriate specialized adjunctive tools to facilitate successful catheter placement. Because difficult catheterizations can occur in various clinical settings, maintaining at least 1 fully stocked, mobile urologic emergency cart with supplies commonly required for urinary catheter placement is recommended. Since multiple urologic emergencies may occur simultaneously, 2 separate, fully stocked carts are recommended. Each cart should contain many of the following items.

Basic Supplies

Although many supplies commonly used for Foley catheterization come prepackaged in sterile kits, additional materials should remain available to support safe urinary catheterization using aseptic technique. Commonly used supplies include an ample supply of sterile lubricant, sterile drapes, sterile preparation solutions (with at least 2 different types available in case of allergies), sterile gloves, additional sterile water for irrigation, personal protective equipment, irrigation sets, Toomey syringes, and lidocaine jelly.

A range of urinary catheters in different sizes should also be readily accessible. Because some patients may have allergies to silicone or latex, both silicone and non-silicone catheters in various sizes should be available. Guide wires (0.035 inch) and 18-gauge angiocaths should also be included among the available supplies.

Foley Catheter Kit

Foley catheters are small, flexible tubes inserted into the urethra to drain urine from the bladder. The circumference of a Foley catheter is measured in French, where each French equals 0.33 mm. Eyelets near the end of the catheter drain urine, while a balloon just distal to the eyelets is inflated to keep the Foley in place. Foley catheters can be made with latex, plastic, or silicone. Some additional coatings for antimicrobial protection are available as well, but have limited proven efficacy.[16]

Some catheters have wider eyelets or ringed reinforcements to allow bladder irrigation to clear clots and debris. The catheter material and design determine the overall stiffness of the Foley. For example, vinyl and silicone catheters are generally more rigid than latex products. The standard Foley catheter is a 2-way catheter with 2 ports: a larger port for draining urine and the other for inflating the balloon. Most 3-way catheters are generally larger (at least 20 French) and have an additional small-caliber port through which sterile fluid can be instilled to flush the bladder continuously. These catheters are commonly used for management of significant hematuria.

Coude Catheter

Coude catheters contain a slight bend near the tip that helps guide the catheter beyond obstructions within the bulbar and prostatic urethra. This curvature can also assist with advancing the catheter into an anteriorly retracted female urethral meatus. The shape of the Coude catheter follows the natural curvature of the male bulbar and prostatic urethra, reducing the risk of urethral trauma or creation of a false passage compared with a straight-tip catheter.[17] The olive-tip Coude catheter features a curved tip and a small bulb that further assist in navigating around obstructions. The Tiemann-tip catheter has a similar design but features a slightly longer, more flexible, and thinner tip.

Councill-Tip Foley Catheters and the "Blitz" Technique

Councill-tip Foley catheters contain an opening at the catheter tip. These catheters may be used with a stylet to provide additional rigidity during catheterization with filiforms, or advanced over a guide wire. A makeshift Councill-tip equivalent can be created using the "Blitz Technique," which employs an 18-gauge angiocatheter to form a hole at the distal end of the Foley catheter.[2][18][19]

After removal of the needle, the remaining plastic sleeve from the angiocatheter stays within the newly created opening and readily accommodates a 0.035-inch guide wire but not a 0.038" guide wire.[19] After removal of the plastic sleeve, the Foley catheter can then be advanced over the 0.035-inch guide wire until reaching the bladder.[19] An 0.035-inch guide wire passes easily through an 18-gauge angiocatheter sleeve.[2][18][19]

Ureteric Catheters 

Ureteric catheters are small-caliber, flexible, open-tipped catheters designed to pass into the ureters up to the kidneys. They can also be used in the urethra to traverse narrow strictures. A ureteric catheter may bypass a stricture while avoiding additional trauma or the creation of a false passage, and is generally designed to pass over a guide wire. Their primary disadvantage is that they lack sufficient stiffness to insert easily and are generally too small to drain bladders effectively. The "Liss" technique, in which a guide wire is inserted into the ureteral catheter to stiffen it, can overcome this problem.[2][20]

Urology Instruments

Filiforms and followers 

When sounds are too large to be passed, filiforms and followers may be used. Filiforms are small, flexible tubes used to maneuver past strictures and stenosis. They range from 2 to 6 French and come with straight, coude, or spiral tips. Filiforms are used with a follower, a stiff plastic tube ranging from 10 to 24 French with a "male" screw tip, offered in straight or coude (curved) tip, and used for sequential dilation of the urethra.

With a filiform in place, the tip of the follower can be screwed into the distal "female" end of the filiform and then advanced into the bladder. When the follower reaches the bladder, a hole at its end allows urine to drain, confirming appropriate positioning within the bladder. The instrument is then removed until the end of the filiform is visualized externally, the follower is unscrewed, and the next larger-sized follower is selected. The procedure is repeated until adequate dilation is achieved. Filiforms and followers are generally reusable, but some sets are disposable. They have largely been supplanted by guide wire-based urethral sounds, which are generally preferred. Urologists should nevertheless be familiar with their use. 

A "male" screw-tip catheter guide can be passed through a Councill-tip catheter and then screwed into the distal "female" end of the filiform to facilitate passage. This is somewhat awkward but effective. Be sure the catheter guide can be easily extracted from the Foley, along with the filiform, once the catheter is positioned in the bladder. Blowing up the Foley balloon once the catheter is in the bladder can help prevent inadvertent removal of the Foley during this process. The internal lumen of the catheter should be well lubricated to facilitate easy removal of the catheter guide once the catheter is in place.

Additionally, the following recommendations should be kept in mind:

• Filiforms come in different lengths and stiffness with various tips. If the first filiform won't pass, clinicians should try another with a tip of a different shape.
• Ensure the filiform is not too short relative to the expected urethral length.
• If multiple filiforms won't pass, leave several in place and try another. The initial filiforms may fill any false passages, allowing subsequent filiforms to pass.
• Avoid pressing or pushing too hard, as this will only cause a new false passage and additional bleeding.
• While usually passed blindly, filiforms can be introduced around a flexible cystoscope if necessary.

Guide Wires 

Guide wires provide valuable assistance in obtaining and maintaining access to the bladder. Optimal use involves cystoscopic visualization to confirm successful passage into the bladder; however, blind passage of soft guide wires may also be performed. Blind advancement of a guide wire generally carries a low risk because the wire typically either enters the bladder or encounters an obstruction, causing it to reverse direction and eventually protrude from the urethral meatus.

When this occurs, another attempt at blind passage may be performed. Although cystoscopic passage remains the preferred approach, the blind passage technique can be performed safely by non-urologists with minimal equipment and without waiting for a cystoscope, light source, or urologist to become available at the bedside.[2] An open-ended catheter (5 French) may also be used when needed to increase the stiffness of the guide wire shaft.

Multiple guide wire types are available, each with varying characteristics, including stiffness, coatings, tip flexibility, lubricity, diameter, and tip angulation. Stiffer guide wires provide improved support during dilation procedures, whereas more flexible wires or wires with angled tips may facilitate navigation beyond strictured segments of the urinary tract.[21] Urologic guide wires frequently contain hydrophilic coatings and are manufactured with different stiffness profiles. These wires are designed to bypass or overcome obstructions while maintaining a flexible tip that reduces the risk of urothelial trauma.[21] An 0.035-inch wire size is generally recommended because this size allows the "Blitz" technique to be performed easily.

Urethral Sounds and Dilators

When urethral strictures are encountered and transurethral catheterization remains necessary, gentle dilation with sounds or dilators may be performed. Although these devices can be used interchangeably in some situations, sounds are specifically intended for use within the urethra, whereas dilators were originally designed for cervical and uterine dilation. Dilators do not contain holes or openings and are not designed for passage over guide wires. They are most commonly used for strictures involving the fossa navicularis, urethral meatal stenosis, and female urethral strictures.

Urethral sounds consist of graduated, straight or curved, plastic or metal rods with tapered tips that can be passed blindly or advanced over a guide wire to dilate the urethra sequentially. In complex cases, using a guide wire with a sound, eg, a Heyman or Goodwin sound specifically designed for wire passage, is generally recommended. This approach helps reduce the risk of creating false passages, minimizes urethral trauma, facilitates safe stricture dilation, and supports successful Foley catheter placement.

General Dilation Technique with Sounds

The use of dilators or sounds for treatment of urethral strictures involves a relatively straightforward technique. The clinician first identifies a tight, scarred, narrowed segment of the urethra. A lubricious 0.035-inch guide wire may then be advanced through the narrowed lumen and into the bladder. A well-lubricated, small French-size sound is subsequently passed over the guide wire and advanced into the bladder. Although the use of a guide wire remains optional, the technique is highly recommended. Successful passage of the instrument beyond the stricture can be confirmed by gently rotating the curved sound from side to side, as this maneuver can only be performed when the tip has entered the bladder. After the sound is removed, the tip should release a few drops of urine. The next larger French-size sound is then introduced, and the process is repeated.

The luminal diameter of the strictured segment gradually increases through radial expansion produced by progressively larger sounds. Each sound should remain in place for at least 20 seconds to allow adequate time for optimal radial dilation of the urethra. Sequential dilation continues until the desired French size is achieved.[22] The final dilation size typically measures 2 French sizes larger than the intended catheter. For placement of a standard 16 French catheter, the dilation should reach at least 18 French and may require 20 French in some cases. Maintaining the guide wire in position facilitates catheter placement using a Councill-tip or similar catheter designed to pass directly over the wire.

Although this technique appears relatively simple, the procedure can cause significant discomfort and may result in serious injury if performed improperly or without gentle technique. Small French-size sounds used without guide wires pose a particular risk because they can easily perforate the urethral wall, resulting in the formation of a false passage and bleeding.

Multiple sound variations exist, including McCrea, Van Buren (solid metal), and Goodwin (metal with a lumen that allows passage of a wire) sounds. These instruments are available in graduated sizes ranging from 8 to 32 French, and some extend to 40 French. Many sounds feature a curved end designed to follow the J-shaped configuration of the prostatic urethra. Female dilators are generally straight due to the shorter length and the lack of curvature of the female urethra.[23] 

Some common sounds and their characteristics include: 

• Bougie-a-boules or "bougies": These instruments are slim metal rods with an olive-shaped, slightly tapered tip or head and a slightly flattened handle. They come in sizes from 8 to 40 French and are about 10 inches long. They are most often used to measure or calibrate the urethral lumen and to dilate it. For active dilation, other instruments are usually preferred as the effective tip is quite short, and the slim metal rod can bend.

• Dittel sounds: Solid metal straight sounds with a slightly tapered tip. The back end or handle is wide and flat, like the Van Buren sounds.

• Goodwin sounds: Very similar to the standard Van Buren dilators with a gentle curve; Goodwin sounds have a small hole running from the very tapered tip to the end of the handle. Goodwin sounds are designed to be passed over a guide wire and should never be used alone, as their narrow tip could easily create false passages. However, when used over a guidewire placed in the bladder, they can easily and effectively open even tough strictures as they are superior dilators. Being metal, they are reusable but can be challenging to clean and sterilize due to the small, long hole through their center.

• Guyon sounds: Solid, reusable metal sounds with a flattened handle area and a continuous curve at the tip. The curve starts posteriorly and immediately begins a gradual, continuous turn anterior to the tip, roughly 90 degrees from the original shaft.

• Hegar dilators: A set of 8 metal sounds, each with a different size on either end, totaling 16 graduated sizes. These sounds are hollow steel, with no holes or openings. They are slightly curved, forming an elongated S shape, and about 8 inches long. Being short, they are typically used only for meatal and fossa navicularis strictures as well as female urethral strictures. Hegar dilators are sized in mm, not French size. One end is 1 mm larger than the other.

• Heyman sounds: A set of 4 to 8 curved sounds with a small central hole designed to fit over a guide wire or similar guide. Very similar to the Goodwin sounds described above, except Heyman sounds are usually disposable and have a wider proximal tip, while Goodwin Sounds are metal, reusable, and have a smaller, tighter tip with a more gradual taper, making them better dilators. Heyman sounds are usually disposable, while Goodwin's are metal and reusable. Disposable sets of Heyman sounds are commercially available, but they tend to be expensive.

• McCrea dilators: Very similar to the Van Buren sounds, these dilators are shorter with a gentle curve at the tip. McCrea dilators are intended for female patients and children.

• Pratt dilators: These solid metal dilators are 11 inches long and have an elongated S-shape, with a 15-degree angle at about 1 inch from each tip. Pratt dilators are longer and heavier than Hegar dilators. Pratt dilators are double-ended, with one end being 2 French sizes larger than the other. Size ranges from 13 to 43 French. 

• Rosebud sounds: Thin, metal, 12-inch-long sounds with a cylindrical tip, in varying sizes.

• Van Buren sounds: These sounds are J-shaped, solid metal, with a flat head at one end, indicating the direction of the curved tip. The curve is about 70 degrees and located 1.5 inches from the tip. These sounds range from 8 to 30 French in size and are 10.5 inches to 12 inches long. They are reusable and represent the classic "blind" metal urethral sound.

Urethral Balloon Dilators

Balloon dilators can be used for short urethral strictures (less than 1.5 cm in length) and are now frequently offered with paclitaxel drug coatings.[24][25][26][27][28][29] Paclitaxel is a microtubule inhibitor with antifibrotic and antiproliferative properties that significantly reduce stricture recurrences.[30]

Urethral balloon dilators are flexible tubes with very strong balloons of varying lengths (usually 4 cm or 10 cm) that can be inflated slowly under pressure at the stricture site to provide effective radial dilatation without the tearing and shearing forces produced by sounds and dilators.[31] Each balloon dilator is disposable and has a maximum pressure recommendation, often up to 20 atmospheres. Many are designed to pass over a guide wire. Positioning the balloon exactly at the stricture site can be challenging, and the maximum balloon pressure is limited. They can be used for both male and female urethral strictures. The balloons and inflation mechanism are disposable, but can be expensive to use. Some strictures may be too tough and fail to dilate even with the maximum allowable pressure.

Flexible Cystoscopy

For bedside urinary catheter placement, flexible cystoscopes can provide direct visualization of the urethra and confirm the location, source, and nature of the catheterization problem.[32][33] Cystoscopy also allows visualization of the correct urethral lumen, which can then be traversed by a guide wire. The flexible cystoscope has a flexible fiberoptic cable with an eyepiece or camera on one end, along with a port through which irrigation and guide wires can be passed. 

Cystoscopy may optionally have a video camera and monitor. The cystoscope requires a light source and irrigation fluid to distend the urethra and provide optimal visualization. The flexible cystoscope's tip is controlled by a knob or lever near the eyepiece and can be manipulated to maneuver the instrument throughout the lower urinary tract. A guide wire can be placed alongside or through the instrument under direct vision to facilitate introduction into the urethral lumen and bladder.

Suprapubic Percutaneous Urinary Kits

When access to the bladder via the urethra cannot be safely completed, or when a urethral stricture repair is being considered, a suprapubic tube (SPT) may be placed.[34] A variety of kits are available for placing suprapubic catheters at the bedside. Such kits commonly include a procedural tray, the suprapubic tray, a needle introducer (usually 14 Fr), some plastic dilators, a guide wire, a Councill-tip catheter stylet, a collection bag, and a pre-filled catheter balloon inflation syringe.[34] Sutures to secure the catheter, different catheter sizes and types (Councill-tip is preferred), longer guide wires, spinal needles (18-gauge or larger), and local anesthetic may be included but are often omitted and may be needed.[34] Imaging guidance is suggested.

Personnel

Physicians and nurses are trained in the routine placement of urinary catheters. But when a Foley catheter is not easily placed, additional assistance may be needed to achieve optimal urethral exposure, improve patient positioning, obtain supplies, administer analgesics, or pass additional instruments. Dedicated nurse-led difficult-catheterization teams are recommended when feasible, as their concentrated expertise yields better results with fewer complications.[35][36]

Preparation

Preparation for catheterization begins with a comprehensive clinical and urologic history to clarify the indication for catheter placement and determine the underlying cause of difficulty obtaining urethral access to the bladder. The location of a potential urethral obstruction, including the fossa navicularis, meatus, or bulbous urethra, can often be estimated based on findings from previous unsuccessful catheterization attempts. The physician should reassess the indication for urinary catheterization and determine whether placement remains absolutely necessary. A Foley catheter can often be avoided in patients who can void spontaneously, adequately empty the bladder, and require catheterization only for monitoring fluid output.

When appropriate, analgesic medication should be provided to reduce discomfort during instrumentation. The patient’s bed should be adjusted to a height that allows comfortable access for the clinician, and the patient should be positioned on the same side of the bed as the provider. Additional hospital staff should be available to assist with examination and positioning of obese patients, and adequate lighting should be ensured. A Trendelenburg position may provide additional benefit in certain cases, particularly among morbidly obese female patients.

Additional precautions are necessary for patients with limited mobility or those who have recently undergone surgery to ensure safe positioning and adequate urethral exposure. Adequate lighting should remain available throughout the procedure. When space permits, a sterile table should be prepared for instruments and catheter kits to support maintenance of aseptic technique. Additional considerations may include use of a bed equipped with stirrups to optimize leg positioning or a bed capable of Trendelenburg positioning to improve direct visualization. When difficult catheterization is anticipated, adequate supplies should be prepared in advance, including additional catheters, guide wires, angiocaths, sterile drapes, lubricant, and necessary instruments.

Technique or Treatment

Techniques to ensure proper urinary catheter placement must account for anatomic variations and differ when approaching male and female patients.

In women, the primary difficulty commonly encountered in catheter placement is identifying and cannulating the urethral meatus, which can be retracted or stenosed in cases of atrophic vaginitis or obscured by obesity, pelvic organ prolapse, or scarring related to prior surgeries or radiation therapy. Similarly, identifying and cannulating the urethral meatus can be difficult in men with penile edema, buried penis, phimosis, meatal stenosis, and fossa navicularis strictures.[2] 

When encountering a patient who has just experienced unsuccessful Foley placement, recognizing the discomfort and distress that further urinary catheterization attempts will have on them is essential. Recognizing the patient's discomfort, explaining the reasons and necessity for the catheter, reviewing the procedure, answering any questions, and reassuring them that adequate analgesia will be provided before further instrumentation are all critically important steps to minimize further pain and discomfort.

Some patients will need to be positioned with special care. For example, in patients with significant congestive heart failure (CHF), a reverse Trendelenburg position (lying flat with the bed tilted 15 to 30 degrees with the head up) is preferred to minimize CHF exacerbations.

Female Urinary Catheter Placement

For female patients, proper positioning and retraction create the best opportunity for direct visualization and intubation of the urethral meatus. The patient should be in a supine, frog-leg position with the head of the bed slightly lower than the feet. If a frog-leg position is impossible due to comorbid conditions or recent surgery, visualization can be improved by an alternative technique. One leg is bent at the knees and abducted at the thigh, with the heel drawn towards the pelvis. It may be necessary to recruit assistance to retract a large abdominal or suprapubic pannus and provide focused lighting to visualize the urethral meatus.

When atrophic vaginitis or vaginal contraction is present, the urethra commonly retracts posteriorly and anteriorly, making it difficult to view directly. If the meatus cannot be visualized, a small catheter, particularly one with a coude tip, can be slid over a finger placed in the vagina with gentle manual pressure maintained against the anterior vaginal wall. The urethral meatus will feel like a buttonhole on the anterior midline of the vagina, allowing catheter introduction. In rare cases, access to the vagina and urethral meatus may actually be easier from behind, with the patient lying on her back or side.[2]

A soft guidewire, often with an angled tip, can be placed into an anteriorly retracted urethral meatus if needed. In cases with a stenosed and retracted meatus, a firmer, smaller caliber catheter (usually silicone or vinyl) can often be placed more easily than a larger, softer one. A coude tip catheter is recommended for this purpose. Using a catheter guide to stiffen the Foley catheter is sometimes helpful as well. 

In addition to obscuring direct visualization of the urethral meatus, anterior prolapse can cause an inferior angulation of the urethra at the bladder neck. This can cause kinking of the catheter. To pass a catheter in such cases, placing a finger into the vagina to elevate the prolapsing bladder or placing a pessary can help align the urethra and bladder neck for direct intubation with a urinary catheter. In some cases, where the urethra is retracted anteriorly or obscured by prolapse, the patient may need to be placed prone for easier access.

Male Urinary Catheter Placement

Male patients should be placed in the supine position, and the penis should be prepped using an aseptic technique. 

Phimosis

If the urethral meatus is obscured by tight phimosis, gentle downward pressure can be placed on the suprapubic fat adjacent to the base of the penile shaft to expose the urethral meatus. If the phimosis remains unrelieved by gentle pressure to retract the foreskin, carefully placing a hemostat into the preputial opening and gently spreading it can often allow for adequate exposure of the meatus sufficient to allow for catheter introduction. The entire glans of the penis does not need to be exposed; just enough so the meatus can be visualized.

An alternate technique involves grasping the foreskin on the right and left sides and then pulling them outwards. This will tend to extend and separate the lips of the phimotic foreskin, which may allow visualization of the urethral meatus. A coude-tipped catheter can sometimes be introduced into the distal urethra through the phimosis and enter the meatus solely by touch, as the anatomical location of the opening in the glans is known to be slightly below the midline. Rarely, when all of these techniques fail, and the phimosis is particularly tight, a dorsal slit procedure in the prepuce may be required under local anesthesia at the bedside to expose the meatus. A dorsal penile nerve block will provide satisfactory anesthesia to allow for this instrumentation at the bedside.

Buried or hidden penis

In a buried or hidden penis, eg, from edema, anasarca, or lymphedema, exposure of the urethral meatus can often be achieved through downward pressure along the lateral edges of the base of the penile shaft with a hand on either side. If this allows visualization of the urethral meatus, an assistant can introduce the Foley catheter. In cases where this does not provide sufficient visualization, a blind attempt to pass a catheter or a guidewire may be successful.

The most reliable method for ensuring entry of a guide wire or catheter into the urethral meatus is direct visualization. This can be done with the assistance of a flexible cystoscope or ureteroscope placed into the preputial opening. Once the meatal opening is found, it can be catheterized with an 0.035-inch guide wire, after which the cystoscope or ureteroscope is removed. A Councill-tip Foley catheter is then passed over the wire and into the bladder.

Another technique utilizes a laryngoscope to directly visualize the glans.[37] This has the advantage of allowing direct catheterization of the urethral meatus with a Foley catheter under direct vision rather than requiring a guide wire.[37]

Meatal stenosis and fossa navicularis strictures

The next area of possible difficulty in catheterization in a male will be encountered at the urethral meatus and fossa navicularis, areas which may be strictured due to prior instrumentation, lichen sclerosis, or chronic irritation. If the meatus is visualized and narrowed, gentle dilation can often allow for the introduction of the urinary catheter. Dilation of the urethral meatus can be achieved using graduated meatal dilators, male urethral sounds, or even female dilators. Liberal use of lubricating jelly with lidocaine provides adequate analgesia for meatal dilation if performed slowly and gently.

Starting with the dilator's largest available caliber, place it carefully into the meatus and gently advance it into the fossa navicularis and distal penile urethra. Hold in place for 20 seconds to gently dilate the tissue without tearing it. If placing a dilator is difficult, confirming the urethral path with a soft guidewire or a pediatric dilator can help direct the instrument properly into the urethral lumen. Sometimes, a tear duct probe or similarly small-sized dilator is needed to initiate the process.

Continue gradual dilation with sequentially larger dilators until the urethra is calibrated to 2 French sizes larger than the desired catheter. The Foley catheter is then placed using gentle traction on the penis and slowly advancing the catheter into the bladder. Urology consultation may be necessary if unable to place a catheter after reasonable attempts at gentle meatal or fossa navicularis dilation have been attempted.[38]

Standard Placement Technique 

Difficulties in placing a urethral catheter once beyond the fossa navicularis may arise from urethral stricture disease, prostate cancer, an elevated bladder neck, bladder neck contractures, or anatomic disturbances caused by recent instrumentation, false passages, radiation therapy, trauma, or surgery. Benign prostatic hyperplasia is not generally a cause for difficult catheterization, as the enlarged prostatic lobes are easily bypassed by catheters. Proper technique with either a standard or a coude-tip catheter will generally bypass most obstructions. Standard placement in males consists of the following techniques:

• The penis should be held under gentle traction at a 90-degree angle to the body with the clinician's nondominant hand to straighten the urethra. A 4 x 4 gauze pad can help maintain a firm grip on the penis.

• A Toomey syringe filled with 20 mL of sterile lubricant, 2% lidocaine jelly, or a mixture of both can optionally be injected directly into the male urethra. This will help separate the urethral walls, provide generous lubrication, and possibly provide some additional analgesia.

• A well-lubricated 16 French catheter is then placed using the dominant hand and gentle pressure.

• As the catheter advances into the bulbous urethra, the penis should be gently pulled inferiorly towards the feet to straighten the passage as much as possible.

• A gentle twisting back-and-forth motion on the catheter will sometimes help, but extreme pressure should be avoided as it will only cause false passage formation and bleeding.

• Placing gentle upward pressure on the perineum can help direct the catheter anteriorly when the bladder neck may be elevated.

• If the catheter still does not pass easily, attention should be paid to identifying the point of obstruction, which is most commonly in the pendulous urethra or at the bladder neck, and the Foley should be removed.

• If the catheter passes into the bladder, it should be advanced to the hub before inflating the balloon. This minimizes the risk of inadvertent balloon inflation inside the prostate or urethra.[1]

• The final step is always to make sure the foreskin has been replaced to avoid any risk of paraphimosis.

Alternative Techniques Following Standard Placement Failure

In patients where standard placement of a urinary catheter has failed, alternative placement techniques in males consist of the following:

• A 16 or 18 French coude catheter should then be gently inserted into the urethra with the curve facing anteriorly toward the ceiling.[39] (Smaller catheters are generally too soft and floppy, while larger catheters become increasingly difficult to pass. Size 16 French is a good compromise.)

• Patients after transurethral resection will often have a hollowed-out prostatic urethra with an elevated bladder neck. Regular Foley catheters will often get stuck, creating a hole in the posterior prostatic fossa, but a coude catheter, with its elevated tip facing anteriorly, can often penetrate the correct lumen without additional trauma. Coude catheters, with their curved tips, can often bypass obstructions that standard Foley catheters cannot, simply by gentle rotation.

• Another technique involves using normal saline under mild manual pressure to dilate the proximal urethra and facilitate catheter passage.[40] The Foley catheter is introduced to the point of obstruction, then retracted 2-3 cm. With the Foley in place, the subcoronal urethra is gently compressed by hand around the catheter to create a seal. A 60 cc syringe containing normal saline is then inserted into the open port of the Foley catheter and gently injected, producing a retrograde flow. This will fill and enlarge the urethral lumen, lateralize and straighten any urethral flaps or folds, and create a passage between obstructing prostatic lobes.[40] With retrograde irrigation maintained by an assistant, the catheter can now usually be advanced. If the patient develops significant pain or the obstruction remains, the procedure should be abandoned.[40]

• If still unable to pass the catheter, an attempt with a smaller-caliber (12 Fr) silicone Foley catheter may be successful due to its smaller size and greater rigidity, which may help it resist recoil.[2] This rigidity can be further increased by inserting an 0.035-inch guide wire into the catheter up to but not beyond the tip (the "Liss" technique).[2][20] Silicone catheters also have the advantage of a relatively large lumen, which allows reasonable bladder drainage considering the small overall diameter. This step may be attempted before using a coude catheter, depending on the clinical situation and urological history.

• An initial attempt at passing a soft 0.035-inch guide wire directly into the urethra is quite safe and highly beneficial when successful, as it gives clear, protected access to the bladder.[2][19][41][42][43][44][45] A hydrophilic guidewire with a soft straight or angled tip is placed into the urethra and gently advanced.[2][39] The soft tip can often be passed beyond obstructions and into the bladder. Any obstruction will either be bypassed by the guide wire or the wire will reverse direction and pass back out through the urethral meatus.[2][39] If the guide wire can pass into the bladder, a Councill-tip catheter or sequential urethral dilators can be advanced over the wire.[2][39][41][46] A guide wire can be successfully passed in 80% of patients who fail passage of both a coude and a 12 French silicone catheter. This can then be followed by dilators and a Councill-tip catheter.

• If a urinary catheter does not easily pass over a guide wire into the bladder, additional blind attempts may cause additional trauma, and dilation will likely be required. Cystoscopic visualization can be helpful in such situations, but it will require removal of the catheter. Retrograde urethrography performed with the catheter in place can help identify the problem and allow a guide wire to bypass it, but may cause significant delays and is not absolutely required in most cases.[2][15]

• In rare cases where even flexible cystoscopy has failed, rigid ureteroscopy together with the Seldinger technique has been successfully used to place a Foley catheter in select patients with difficult transurethral access.[47]

Many clinical environments have designated catheterization teams for catheter placements and guidelines for when urologic consultation is recommended.[35][36] Such measures are highly recommended when feasible, as nurse-led difficult urinary catheter teams maintain and concentrate their expertise and experience while achieving high success rates, often greater than 90%.[35][36] They also reduce the incidence of iatrogenic injuries, decrease the rate of catheter-related urinary tract infections through strict adherence to protocols, and significantly reduce the need for urological consultations.[35][36] 

After the unsuccessful placement of a catheter with the above techniques, a urologic consultation is typically recommended. Successful catheter placement may be achieved after passing a guide wire, either with direct visual guidance from a flexible cystoscope or with a simple blind passage. Sequential dilation of strictures in the urethra or at the bladder neck may be required.[2][41]

Retrograde Urethrography Assisted Catheterizations

In difficult situations, a retrograde urethrogram and fluoroscopic guidance can be of help.[48] In a recent study, almost 70% of otherwise intractable cases were successfully catheterized with the assistance of retrograde urethrography.[48] This is not a perfect solution, as there are logistical problems, radiation exposure, and delays in obtaining imaging, especially in the middle of the night, but it can be helpful in select cases.[48] 

The technique involves using an 18 French 3-way catheter with a hole at the tip to place a guide wire. The irrigation port is connected to diluted contrast material 1:2. The guide wire is advanced under fluoroscopic guidance.[48] If the catheter cannot be directly advanced, the guide wire is left in place, and cystoscopy, balloon dilators, or appropriate sounds are used for dilation as previously described.

Flexible cystoscopy

Flexible cystoscopy is recommended when standard passage techniques have failed, including an unsuccessful blind passage of a guide wire. The use of a flexible cystoscope permits the identification of any obstructions or false passages, which can often be bypassed under direct vision with a guide wire, which can then be advanced directly into the bladder.[32] If a urethral stricture is encountered, a guide wire may be directed through the narrowed lumen into the bladder, allowing sequential dilation with Heyman or Goodwin sounds or alternatively with a high-pressure balloon dilator.

Dilation should be continued until at least 2 French sizes larger than the minimum acceptable desired final Foley catheter size. Patients with a known stricture or false passage should be catheterized cautiously, preferably with the use of a guide wire to avoid creating or exacerbating any existing false passages and further traumatizing the urethra.[49] A coude catheter is usually preferred in these patients as the tip can be angled away from the injured area.

When using a flexible cystoscope, the patient is prepped in a sterile manner, and the lower extremities are covered with a sterile drape. The cystoscope is assembled and lubricated. With direct vision, the cystoscope is maintained in the center of the urethral lumen to avoid trauma to the urethra. If a false passage is encountered, angling the cystoscope anteriorly towards the ceiling will frequently bypass the damaged urothelium.

A guide wire should be placed through the narrowed lumen if a stricture is encountered, rather than attempting to force the cystoscope through the narrowed lumen. Once the wire is in place, the cystoscope is removed, and a Heyman or Goodwin sound is placed over the wire and advanced gently into the bladder. Sequential dilation then continues as above. A high-pressure balloon dilator may also be used.

Direct vision video-assisted Foley catheters 

Direct vision video-assisted Foley catheters have been developed to facilitate placement in difficult patient situations. These catheters are designed to be used with an integrated fiberoptic video system and monitor. Direct vision video-assisted Foley catheters are used with lighting and allow irrigation through a side port. The irrigation port can also be used to advance a guide wire. The image is very similar to a flexible cystoscope, although the tip cannot be adjusted and lacks the maneuverability and angulation potential of a cystoscope.[1] The catheter is only designed for viewing the urethra to facilitate Foley catheterization and does not replace a cystoscope.

One significant advantage is that nurses and specialized catheterization teams can use direct-vision video-assisted Foley catheters without a physician present.[50] These catheters have been shown to be helpful, particularly initially in difficult Foley catheterization situations, but they are not inexpensive. Direct-vision video-assisted Foley catheters are most suitable for larger tertiary care institutions, where they can serve multiple areas, eg, the emergency department, operating room, and inpatient floors. 

"Soft" dilation

"Soft" dilation refers to the technique of leaving a small French-size catheter in place, as in a very strictured urethra, for 24 to 48 hours and then replacing it with the next larger Foley. Just leaving a catheter in the urethra for 24 to 48 hours will gently dilate the strictures, allowing easy replacement with a slightly larger catheter. This is then replaced again in another 24 to 48 hours, and the process is repeated until the optimal French-size Foley is successfully placed. While soft dilation takes time and may be inconvenient, this technique is a very safe, painless, and effective way of dilating a strictured urethra.

Follow-up and self-dilation

Follow-up care and self-dilation after successful catheterization depend largely on the nature, severity, and location of the stricture or obstruction. For most patients with significant strictures, the final Foley catheter size generally ranges from 16 to 20 French. If the catheter does not reach the optimal size, the "soft" dilation technique described above may be used. The initial catheter is typically left in place for 10 to 14 days before removal, although this duration may be extended to 4 or even 6 weeks when clinically necessary. After catheter removal, the patient is instructed on self-intermittent catheterization.

A catheter size, usually ranging from 14 French to 20 French, and catheter material, eg, soft latex or stiff vinyl, are selected based on the patient’s needs. The patient begins daily self-catheterization for at least 1 week to ensure proper understanding and performance of the technique. During each catheterization, the catheter should remain in place for approximately 20 to 30 seconds. The frequency of catheterization is then gradually reduced, transitioning from daily to twice-weekly for 6 weeks, then weekly for 6 weeks, twice-monthly for 6 weeks, and finally monthly.[22]

Maintaining monthly catheterizations helps confirm that the stricture has not recurred. If the patient experiences difficulty advancing the catheter at any point, the schedule should be adjusted to the earlier, more frequent catheterization interval, and the process repeated.

Suprapubic tube placement

Suprapubic tube placement is the treatment of last resort when all other methods of gaining access to the bladder through the urethra have failed.[51] If a wire cannot be passed through the lumen of a urethral stricture or bladder neck contracture, the patient will most likely require suprapubic catheter placement to decompress the bladder. In the United States, about 15% of all men with acute urinary retention due to urethral strictures will be treated with suprapubic tubes.[51] Nationwide, the trend to go directly to a suprapubic tube appears to be increasing, with younger patients and those with public insurance enjoying a higher incidence.[51]

Finally, if significant instrumentation was required to achieve urinary catheterization, antibiotic use should be considered. If a male patient is uncircumcised, returning the foreskin to the anatomic position following catheterization is mandatory to avoid paraphimosis. For male patients, the catheter should be fully inserted "to the hub" before inflating the Foley balloon. The balloon should be inflated slowly to ensure it is not malpositioned in the prostatic urethra. A bladder ultrasound or flexible cystoscopy should be used to verify the final catheter position if there is any doubt about its location.

Recommend Algorithm and Summary for Difficult Male Foley Catheterization 

The following is a summary of the recommended protocol for difficult male Foley catheterizations:

• The clinician should first confirm that Foley catheterization remains indicated and absolutely necessary. Significant and painful urologic instrumentation should be avoided when catheter placement addresses only a minor or temporary condition, as unnecessary manipulation may result in long-term complications from permanent urethral scarring and stricture formation.
• When appropriate and safe, the patient should receive premedication for pain before undergoing painful catheter manipulations.
• The clinician should use the patient’s history and information from previous catheterization attempts to determine the likely location and nature of the obstruction or difficulty.
• When a buried penis contributes to the challenge, use of a laryngoscope or flexible cystoscope should be considered. If the stricture occurs in a very distal location, the problem can often be managed relatively easily with blind Van Buren sounds or Hegar dilators, typically without requiring guide wires or cystoscopy.
• The clinician should consider instilling 20 mL of sterile lubricant, 2% lidocaine jelly, or a combination of both directly into the urethra using a Toomey syringe. This approach is recommended.
• If the obstruction involves the penile urethra or a more proximal location, gentle advancement of a straight or Coude catheter, using proper technique and adequate lubrication, should be considered. A 16- or 18-French Coude catheter is typically attempted initially. If unsuccessful, a smaller catheter, such as a 12 French silicone catheter, is generally the next option. A direct-vision, video-assisted Foley catheter may be used when available.
• If these measures fail, passage of a guide wire followed by placement of a Councill-tip Foley catheter generally represents the next step. When catheter passage is successful, the catheter should be advanced into the hub before inflating the balloon.
• If a guide wire passes successfully but the catheter cannot be advanced, or if all previous attempts fail while catheterization remains necessary, a urology consultation should be obtained for further management.
• The urology team will typically reassess the indication for catheterization and often begin by attempting standard or Coude Foley catheter insertion. Even when this attempt fails, the outcome provides the urologist with valuable information regarding the location and characteristics of the obstruction.
• The next step generally involves placement of a guide wire, either blindly or with cystoscopic guidance. Alternatively, a retrograde urethrography-assisted technique may be attempted.
• Blind urethral dilation without guide wire assistance is generally no longer recommended, except for extremely distal strictures involving the meatus or fossa navicularis.
• After successful guide wire placement, Heyman or Goodwin sounds can be used for sequential dilation of the stricture, typically reaching at least 2 French sizes larger than the intended Foley catheter. Urethral balloon dilators may also be used for gentle dilation of urethral strictures.
• A Councill-tip catheter or a standard Foley catheter modified using the "Blitz" technique, which involves placement of a guide wire through the catheter tip, can then be advanced over the wire into the bladder.[19]
• When only a very small catheter can initially be inserted, the "soft" dilation technique may be used. This approach involves replacing the Foley catheter every 24 to 48 hours with the next larger catheter size.
• If cystoscopic evaluation reveals no visible opening or lumen and the guide wire cannot be passed, placement of a suprapubic tube should be considered.
• After completion of all procedures, the foreskin should be returned to its original position to prevent complications.[2][39][52][53][54]

Complications

Difficult catheterizations and repeated unsuccessful attempts at Foley placement cause patients substantial pain, anxiety, and possible long-term complications. Instrumentation and trauma to the urethra can increase the risk of postinstrumentation infection. If continued pressure is applied against resistance during urinary catheterization, the catheter can create a false passage, undermine the bladder neck, or perforate the urethra or bladder. Trauma to the urethra, prostate, or bladder neck can lead to hematuria, infection, and scarring.

In the setting of prior surgeries or radiation, rectal perforation has also been seen. In poorly mobile or immunocompromised patients, trauma from unsuccessful catheterizations can contribute to urinary tract infections, Fournier gangrene, or periurethral abscess formation. In the longer term, urethral trauma from instrumentation may lead to permanent or long-lasting urethral stricture disease.

Patients who are confused, have dementia, or have a brain injury may seek to remove their Foley catheters traumatically by pulling on them. If the balloons are removed intact, this will obviously cause significant traumatic injury to the urethra with bleeding, pain, possible infection, and the potential development of further scarring and strictures. If the balloon is not intact, pieces are missing, or the catheter has been discarded and cannot be found for examination, a cystoscopy is recommended to ensure that no balloon fragments remain in the bladder, where they can calcify and form bladder stones.

Clinical Significance

The urinary bladder functions to store urine at low pressure and facilitate voluntary voiding at socially appropriate intervals. When a patient cannot effectively empty the bladder or requires immediate urinary drainage, placement of a urinary catheter becomes necessary. Although most urinary catheterizations proceed without difficulty, complications associated with catheter placement can cause significant distress and contribute to both short-term and long-term adverse outcomes. Ensuring optimal patient care requires physicians to confidently evaluate the cause of difficult catheterization and select interventions with the greatest likelihood of achieving successful catheter placement.

Reviews of urology consultations for difficult Foley catheterization have demonstrated that fewer than 20% of cases were considered difficult by the urology service.[55] Patients with a history of difficult or traumatic catheter placement, as well as those who underwent multiple catheterization attempts before urology consultation, were more likely to be classified as difficult cases by urology.[55] Additional risk factors include obesity with a high BMI, previous urethral stricture disease, prior surgery for benign prostatic hyperplasia (BPH), radical prostatectomy, and the presence of genitourinary implants.[3][55] These findings highlight the importance of improving healthcare personnel education, particularly among nursing staff, to reduce morbidity associated with failed Foley catheterization attempts and decrease the need for urology consultations in many situations.

Healthcare Team Care Coordination and Education

Clear communication with the patient and treatment team relieves distress and improves outcomes when a difficult catheterization is encountered.

A 2-person indwelling urinary catheterization team was found to decrease the incidence of catheter-associated urinary tract infections (CAUTIs) in a 2017 study.[56] A team of emergency room leaders, infection prevention members, nursing, and research specialists was created to evaluate a process of indwelling catheterization that would start with a safety time-out, much like a preprocedural/surgical time-out, to assess pertinent history, physical exam findings, appropriateness of the catheterization, and would include a review of the insertion techniques to educate and familiarize the entire team.

After a time-out, one physician would perform the insertion while the other monitored for a compromise in sterility. This approach had a significant positive impact on the CAUTI rate at this institution. This time-out approach can be applied to all patients requiring catheterization, whether as a formal time-out or a personal checklist reviewed before catheterization. This time-out could address 40% or more of cases in which a urology consult would have been unnecessary and help intercept inappropriate techniques, tools, and staff performing the catheterization.[56]

The "flipped classroom" approach to nursing education, in which students view online lectures and read current review articles before class, has proven successful in improving nursing knowledge and skills related to Foley catheterization.[57]

Improving healthcare team education and skilled nursing catheterization teams

Prospective analyses of Foley placement problems reported that urologic consultations for difficult Foley catheterizations were unnecessary in 41% to 70% of cases, as no specialized urologic instrumentation was required for successful placement.[46][58] (These numbers did not include instances in which a urology nurse was called and successfully placed the catheter using only standard equipment and supplies.) Complications from prior attempts at catheterizations occurred in 37%, including significant urethral trauma in 32%. Most consultations for difficult Foley placement occurred between 5 PM and 6:30 AM. The mean time from the initial attempt at Foley catheterization to urology consultation was 262 minutes, and the average patient had about 3 attempts before urology was involved. Nonurologist physicians frequently did not attempt catheterization due to lack of training, inexperience, or "not feeling comfortable."[46]

Even physicians do not always receive adequate training or supervision for Foley catheterization. In a study conducted at a tertiary care academic teaching center, 76% of interns reported that their practical training in Foley placement was either inadequate or nonexistent, and over half were not supervised during their first attempt at catheter placement in a real patient.[59] 

Successful programs to improve urinary catheterization outcomes with fewer injuries and reduced catheter-associated urinary tract infections (CAUTIs) included education for general nursing staff, medical students, and resident staff on urethral anatomy and proper Foley placement techniques.[35][60][61] In addition to improved undergraduate education, mandatory training on an annual or biannual basis for all clinical staff is recommended to enhance skills and patient outcomes.[62] Improved education for physicians (particularly in rehab, emergency room, and hospital medicine) as well as nurses should focus on various placement techniques, different types of Foley catheters, and the optimal management of difficult catheterization. A targeted 1-hour educational session for nurses and residents on urinary catheter placement has been shown to reduce the incidence of unsuccessful catheterization attempts and eliminate the need for many urology consultations.[63]

Utilizing a difficult Foley placement algorithm and implementing a skilled nursing catheterization team has greatly decreased the incidence of preventable urinary trauma.[64] The need for urological consultations for catheter placement dropped from 53% (before implementation) to about 12% afterward, and patient outcomes, including CAUTIs, improved.[64] Even just providing a few nurses with more extensive training and improved skills in Foley placement has also been shown to be helpful.[35]

Enhancing Healthcare Team Outcomes

Urinary catheterization is a common procedure performed to relieve urinary retention, monitor urine output, obtain sterile urine specimens, manage selected urologic conditions, and support perioperative or critically ill patients. Difficult Foley catheterization often results from anatomic variations, urethral strictures, prior surgery or radiation, benign prostatic obstruction, trauma, obesity, or pelvic organ prolapse. Repeated unsuccessful insertion attempts increase the risk of urethral trauma, false passage formation, catheter-associated urinary tract infections, hematuria, bladder injury, urethral stricture disease, and prolonged hospitalization. Appropriate patient selection, careful assessment of indications and contraindications, thorough genitourinary evaluation, and systematic use of evidence-based catheterization techniques, adjunctive devices, and timely urologic consultation improve procedural success while minimizing avoidable complications.

Interprofessional collaboration strengthens the safety and effectiveness of urinary catheterization through coordinated assessment, communication, and adherence to standardized protocols. Physicians, primary care clinicians, emergency physicians, hospitalists, and advanced practitioners determine the necessity of catheterization, evaluate complex anatomy, perform difficult catheterizations, and coordinate referrals when advanced interventions are required. Nurses perform ongoing assessment, maintain sterile insertion technique, monitor catheter function, identify early complications, reinforce patient education, and participate in specialized catheterization teams. Pharmacists optimize analgesic and antimicrobial therapy when indicated, while urologists provide advanced procedural management for complex cases. Shared decision-making, standardized safety time-outs, continuous staff education, and structured follow-up reduce unnecessary catheterization, prevent complications, improve patient-centered outcomes, and promote high-quality systems-based care.

Nursing, Allied Health, and Interprofessional Team Interventions

An interprofessional approach to care helps patients feel more comfortable and better understand the purpose of urinary catheterization. Foley catheter placement may represent an unexpected, frightening, and intimidating experience. Patients who require catheterization beyond hospitalization often experience significant distress and embarrassment. Comprehensive patient education, particularly from nursing staff, enables patients to understand the indication for the catheter, the limitations associated with its use, and the principles of safe catheter management after discharge.

Education regarding catheter care remains essential, especially for patients who must manage a Foley catheter and drainage bag at home. All members of the healthcare team should consistently reinforce key instructions, including maintaining tension-free catheter suspension with a leg strap, keeping the drainage bag below bladder level, performing hand hygiene before handling or changing the catheter, and replacing chronic indwelling catheters every 1 month. When prolonged urinary drainage appears likely, clinicians should consider replacing a urethral Foley catheter with a suprapubic tube.

Optimal patient care depends on every member of the healthcare team understanding and actively supporting the established care plan. Consistent communication throughout catheter placement and the postcatheterization period promotes patient confidence and recovery. The ordering clinician should clearly communicate the indication for Foley catheter placement and define the anticipated duration of catheterization. Once the clinical indication no longer exists, prompt catheter removal should follow without unnecessary delay.

Many healthcare professionals possess the fundamental skills required for Foley catheter placement. Nurse practitioner-led and nurse-led catheterization teams have demonstrated success in managing difficult catheterizations while reducing urethral trauma and the need for urology consultations.[35][36] When difficult catheterization occurs, the healthcare team should conduct a structured debriefing to review the clinical assessment, identify technical challenges, and reinforce best practices. Team members seeking additional procedural experience should receive supervised training from experienced clinicians to strengthen technical competence and improve patient outcomes.

Failed urinary catheterization attempts may leave healthcare professionals feeling embarrassed or discouraged because Foley placement often carries the perception of being a straightforward procedure.[65] Multiple patient-specific anatomical and clinical factors can substantially complicate catheterization, and unsuccessful attempts occur even among experienced clinicians. Every member of the healthcare team should recognize personal limitations and seek assistance when appropriate. Following an unsuccessful attempt, clinicians should promptly evaluate the cause of failure or request additional expertise before repeating the procedure, thereby minimizing the risk of urethral trauma and long-term complications.

Prevention of Inappropriate Foley Catheter Self-Extractions by Patients

Patients with dementia, brain injury, or acute confusion may attempt to remove Foley catheters without first deflating the balloon. Such events frequently cause severe pain, lower urinary tract injury, permanent scarring, and the need for catheter replacement. Traditional strategies, including physical restraints, continuous observation, or sedation, consume substantial healthcare resources, expose patients to additional risks, and often provide limited effectiveness.

A nursing-driven protocol has demonstrated safe and effective prevention of inappropriate Foley catheter self-extraction with excellent clinical outcomes. Development of this protocol in collaboration with nursing staff allows immediate implementation of practical preventive measures without waiting for physician orders. Although initially designed for intensive care units, rehabilitation units, and recovery areas, the protocol applies to any inpatient setting caring for patients with Foley catheters.[66] Please see StatPearls' companion resource, "Prevention of Inappropriate Self-Extraction of Foley Catheters," for further information. 

Upon admission to a nursing unit, nurses should identify every patient with a Foley catheter that does not require immediate removal. The initial nursing assessment should evaluate each patient's risk for inappropriate self-extraction of the catheter. Any identified risk should be communicated during nursing handoff to ensure continuity of care. Patients recovering from anesthesia, individuals with preexisting dementia or confusion, and those with brain injuries or stroke face the highest risk, particularly when previous episodes of catheter self-removal have occurred. Alert and oriented patients generally present minimal risk but may still require reminders to bring the drainage bag when getting out of bed.

When nursing assessment identifies a patient as being at risk, or even potentially at risk, for inappropriate catheter self-extraction, the following preventive interventions should begin immediately:

• Nursing staff should position the catheter tubing and drainage tubing beneath the patient's thigh to reduce accessibility.
• Securing the catheter and tubing directly to the skin while allowing sufficient slack for mobility further limits the patient's ability to grasp the device.
• Additional barriers, including diapers, shorts, mesh undergarments, wide elastic wraps, pajamas, absorbent pads, or thigh-high stockings, provide multiple protective layers between the patient's hands and the catheter.
• Placing a small straight catheter over the outer garments or protective coverings creates a harmless decoy that confused patients may grasp instead of the indwelling Foley catheter, reducing the likelihood of traumatic self-extraction.