Suprapubic Bladder Catheterization

Anatomy and Physiology

The urinary bladder is a hollow organ made of muscle designed to store and evacuate urine from the human body. A typical urinary bladder holds between 300 and 500 ml. The bladder is divided into the fundus, body, apex, and neck. The urinary bladder is located behind the pubic bone in the extraperitoneal space. The extraperitoneal space anterior to the bladder is referred to as the prevesical space or space of Retzius. The space is named after Anders Retzius (1796-1860), the Swedish anatomist who first described this area.

The abdominal wall just above the pubis comprises the rectus muscle bellies lateral and the linea alba in the midline. Below the arcuate line, the aponeuroses of the external oblique, internal oblique, and transversal muscles run anterior to the rectus muscle. It is through this area that open access to the dome of the bladder is obtained. The dome or cephalad covers most of the bladder with the perineum. The urinary bladder is supported below by the pelvic diaphragm. Suprapubic drainage tubes commonly exit via a midline site, but off-center (through the rectus) is also acceptable, depending on the patient’s body habitus.

Indications

The most common indication for suprapubic tube placement is for urinary retention when urethral catheterization is not feasible. This can include severe benign prostatic hyperplasia, false urethral passages, morbid obesity, urethral strictures, bladder neck contracture, and genital malignancy. Urogenital trauma causing urethral disruption and severe damage are common indications. Suprapubic tube placement for the long-term diversion of urine in cases of neurogenic bladder is also sometimes indicated.[4][5]

Contraindications

Contraindications to suprapubic cystotomy are relatively few, depending on the utilized approach. Percutaneous approaches are contraindicated in a nondistended bladder and the setting of bladder malignancy. The former places the patient at substantial risk of inadvertent bowel or vascular injury. Relative contraindications for suprapubic cystotomy, whether open or percutaneous, include active skin infection, coagulopathy, osteomyelitis of the pubis, and orthopedic hardware of the pubic symphysis.

Equipment

Equipment utilized for the placement of a suprapubic catheter varies by technique. Typically, standard Foley catheters are used for drainage catheters. The open technique utilizes standard surgical instrumentation, including a small self-retaining retractor such as a Weitlander retractor and a dissolvable suture for closure of the cystostomy. The Percutaneous (Seldinger) technique requires a large-bore needle, a guide wire, and an away catheter insertion sheath. These are commercially available as an all-in-one kit. Percutaneous approaches are often performed under vision with a rigid or flexible cystoscope. Finally, a specialized retractor called a Lousley prostatic retractor can assist in an open tube placement. Portable ultrasound devices are also helpful in confirming tube location. 

Personnel

A urologist, a surgeon specializing in the genitourinary system, performs suprapubic catheterization. Other practitioners who may perform this procedure include general surgeons, gynecologists, urogynecologists, emergency providers such as emergency room physicians, and trauma surgeons.

Preparation

Depending on the situation, suprapubic catheterization can be performed with a local or general anesthetic. The lower abdomen is shaved and prepped with standard surgical prep. If the technique involves entrance via the urethra, the genitals are prepped and draped accordingly. If rigid cystoscopy is required, the patient should be positioned in dorsal lithotomy. Flexible cystoscopy can easily be performed supine in most cases. The patient should always be placed in a Trendelenburg position to help minimize the risk of bowel injury. Having an abdominal ultrasound or computed tomography scan is helpful, especially in patients with prior abdominal surgical procedures, to make certain there are no bowel loops between the distended bladder and the abdominal wall that could be inadvertently injured during suprapubic tube placement.

Technique or Treatment

Several techniques for placing a suprapubic catheter are well described. Two categories exist: open technique and percutaneous technique. Variations of each exist, and many are hybrid techniques.

Open cystotomy involves a small, typically transverse incision roughly 2 fingerbreadths above the pubic symphysis. The bladder is ideally filled prior, which aids in identifying the bladder. The rectus fascia is opened, allowing access to the preperitoneal space. The bladder is identified, and dissolvable stay stitches are placed on either side of the intended cystotomy. A small cystotomy is then made, and the drainage tube is placed. The tube is secured to the bladder with a dissolvable purse-string stitch. The facial layers and skin are then closed around the tube, which is finally secured to the skin with a temporary stitch.

The Percutaneous Seldinger technique is also fairly common. Distention of the urinary bladder is imperative for this approach. This can be done physiologically (urinary retention) or with a cystoscope. The cystoscopic examination allows direct visualization of the puncture needle but is not required. A large bore needle is inserted in an area roughly 2 fingerbreadths above the pubis until urine returns. Sterile saline can be added to the bladder at this point if necessary. X-ray guidance is also optional, as contrast can be added to better visualize the urinary bladder. A guide wire is then advanced through the needle into the urinary bladder. (Note: A 0.035-inch guidewire comfortably fits in an 18 gauge or larger bore needle.) This tract is then dilated mechanically with dilators or balloon dilators to accommodate a pull-away sheath. The suprapubic catheter is then passed into the bladder via the access sheath, which is removed after the catheter balloon is inflated. The catheter is then secured. Cystoscopic confirmation of placement is recommended when feasible. 

The curved Lowsley prostatic retractor can be utilized for a modified open approach. This specialized instrument is passed from the urethra into the urinary bladder. Urethral access to the bladder is necessary for this technique to be used. Upward pressure is applied, bringing the curved instrument tip and bladder dome close to the abdominal wall. Except in very obese individuals, the tip of the Lowsley retractor is palpable through the skin of the lower abdomen. A suprapubic cutdown is then performed, exposing the retractor tip. The urinary catheter is then attached to the Lowsley prostatic retractor, which is pulled back into the bladder, taking the catheter tip with it. The balloon on the suprapubic tube is inflated, and the catheter is released from the Lowsley by twisting and opening its jaws. The jaws are then closed, and the Lowsley is removed. Occasionally, the tip of the catheter is in the bladder, but the balloon is inflated just outside. For this reason, a cystoscopy is recommended after placement to ensure proper positioning.[6] 

Trocar kits are also available for direct puncture into the urinary bladder. These are used less frequently as they can increase the risk of injury to adjacent organs. Several kits are available for the percutaneous technique, which is the most common approach.

Complications

Early complications of the operation include inadvertent bowel injury, bleeding, vascular injury, obstruction of the tube, and failure to enter the bladder during the initial procedure. Bowel injury can be limited with the use of preoperative imaging as well as intra-operative ultrasound. Other late complications include refractory hematuria, urosepsis, wound infection, bladder stones, tube calcification or malfunction, and loss of the cystotomy tract. In patients with a chronic obstruction such as benign prostatic hyperplasia, decompression of the bladder can result in post-obstructive diuresis. This is defined as urine output greater than 200 mL per hour for 2 or more hours. This brisk diuresis is a physiologic response to the volume expansion that occurs when a chronic obstruction is relieved.[7] Another late complication is chronic irritation of the bladder secondary to the tube. This is considered a risk factor for squamous cell carcinoma of the bladder. Finally, while not a surgical complication in the true sense of the term, body image alteration can later become a patient concern.[8][9]

Clinical Significance

Suprapubic catheters provide an alternate method to drain the urinary bladder. These are commonly utilized to manage bladder dysfunction and urinary retention not amenable to urethral catheterization. Like all urinary catheters, they have risks and benefits. Current literature is mixed concerning the risk of urinary tract infection. Some studies have suggested that limiting genital contact with the catheter may decrease symptomatic infection rates. However, other series have not supported this conclusion. Urethral catheters have obvious limitations on a patient's sexual function, making suprapubic tubes potentially more appealing to those sexually active. Access to catheter exchange is a common consideration when choosing bladder drainage. Suprapubic tubes allow for more convenient tube exchanges based on their location. Furthermore, chronic urethral catheters carry the risk of urethral erosion over time, particularly in males. Urinary incontinence is often a consideration when considering bladder catheterization. It is important to note that urinary incontinence by the way to the urethra can occur despite suprapubic drainage. This is of particular concern when skin breakdown from bladder incontinence is present. Leakage around the suprapubic tube can also occur. This may indicate either tube blockage or bladder spasms.

Suprapubic catheters can be placed for certain surgical procedures. These can provide stable bladder drainage before and after complex urethral reconstructions. Additionally, they can be combined with a urethral catheter to provide continuous irrigation. Irrigation inflow can be instilled through a suprapubic catheter and outflow through the urethral catheter or vice versa. Usually, the larger diameter tube is used for outflow. In patients undergoing bladder, prostate, or urethral surgery, these tubes can be a valuable tool to maintain adequate urinary drainage.

Enhancing Healthcare Team Outcomes

Suprapubic catheterization is sometimes needed when drainage via the urethra is not possible. While a urologist usually performs the procedure, the nurse is usually in charge of monitoring the catheter and the urine output. Nurses need to know the potential complications of this procedure, such as bowel injury, and must regularly examine the abdomen. In addition, the patient needs to be monitored for signs and symptoms of a urinary tract infection. Patients who are confused may pull and try to remove their suprapubic or urethral catheters. Techniques and methods to secure catheters from such attempts are well described elsewhere.[10] Finally, a common problem with suprapubic catheterization is leakage at the skin site, and hence, the nurse should monitor this area for signs of incontinence.[11][12]