Managing the Patient With Orthotopic Bladder Substitution



Managing the Patient With Orthotopic Bladder Substitution


GIANLUCA GIANNARINI

URS E. STUDER



Orthotopic bladder substitution has become the preferred method of urinary diversion, usually following radical cystectomy for malignant disease, in both male and female patients, provided that certain criteria are satisfied (1). The goal of this type of lower urinary tract reconstruction is to substitute the original bladder in both location and function by creating a reservoir that provides a safe and continent means to store and void urine through the urethra. This allows patients to preserve their body image, avoiding the need for a stoma and to recover an almost completely normal and socially integrated lifestyle.

Several types of bladder substitution have been developed over the past decades, each with its own specific advantages and disadvantages. However, regardless of the type of bladder substitute, optimal outcomes are achieved when a lowpressure, high-compliance reservoir is made of detubularized and cross-folded bowel segments with a preserved sphincter competence and no mechanical/obstructive outlet resistance. Good long-term results with any bladder substitute are not only dependent on surgical technique but equally importantly on a thorough preoperative assessment, meticulous active postoperative management, and lifelong patient follow-up.


PREOPERATIVE MANAGEMENT


Patient Selection

A thorough preoperative assessment requires that the following factors be evaluated when determining candidacy for orthotopic bladder substitution (Table 77.1).








TABLE 77.1 SELECTION CRITERIA FOR ORTHOTOPIC BLADDER SUBSTITUTION







  • Patient agreement to lifelong follow-up



  • Preferably younger age (<70 years)



  • Adequate renal function (estimated glomerular filtration rate >50 mL/min)



  • Adequate liver function



  • No evidence of significant bowel disease



  • No severe stress urinary incontinence



  • No neurologic voiding disorders



  • No evidence of tumor in the distal urethra, paracollicular (male), or bladder neck region (female)



Patient Motivation and Mental Status

Perhaps the single most important factor contributing to a successful bladder substitute is patient motivation and willingness to comply with an indefinite follow-up. A thorough understanding of how one’s bladder substitute works is mandatory. Within this context, a dedicated specialized nurse can facilitate the preoperative assessment and postoperative education, as well as be a useful resource when patients have problems with their bladder substitute, by providing continuous and longterm educational reinforcement.

It is, however, the responsibility of the treating surgeon to thoroughly inform patients before surgery on all possible forms of urinary diversion and their relative benefits and risks should an orthotopic bladder substitution be not possible at the time of surgery. Alternative forms of urinary diversion to be discussed are continent cutaneous diversion, ureterosigmoidostomy, and incontinent cutaneous diversion (ileal conduit, ureterostomy, and percutaneous nephrostomy).

Patients should also be informed that the choice of a particular form of urinary diversion is primarily a quality-of-life decision with no or little impact on the course of the disease necessitating bladder substitution. Having this background in mind, patients are prepared to make a truly informed decision. Adequate intellectual skills and physical dexterity, should intermittent self-catheterization become necessary, are currently relative criteria. Recent data has, in fact, shown that in men, the need to self-catheterize is rare, provided the reservoir has no outlet obstruction or this is promptly treated when it occurs (2). The problem remains for female patients in whom urinary retention may occur in up to 50% within 5 years postoperatively (1).


Age

Chronologic age should not be a criterion for offering orthotopic bladder substitution. However, in general, elderly patients (particularly octogenarians) have prolonged recovery of urinary continence and increased risk of long-term urinary incontinence (particularly nighttime) as compared to their younger counterparts (3,4).


Renal Function

The most frequent postoperative complications are metabolic acidosis and electrolyte abnormalities. The type and severity of these disorders depend on type and length of bowel segment used, time of urine contact with bowel mucosa, and compensatory
renal reserve. An absolute contraindication to continent urinary diversion is a compromised renal function as a result of chronic renal failure or long-standing ureteral obstruction. Some patients with preexisting renal failure due to ureteral obstruction caused by their primary bladder cancer may recover sufficient renal function to allow for continent diversion once the obstruction is relieved. Placement of a percutaneous nephrostomy tube before surgery in these patients may provide a more accurate estimate of the true renal function. Currently, an estimated glomerular filtration rate of 50 mL/min is considered the lower limit so as to prevent the need for lifelong alkaline supplementation.


Liver Function

Adequate preoperative liver function is also mandatory. The continuous contact of urine with bladder substitute wall allows ammonium to shift through the bowel mucosa into circulation. A urinary tract infection caused by a urease-splitting organism will further increase this ammonium load. If baseline liver function is impaired, a hyperammonemia state will occur, which can lead to severe neurologic decompensation and eventual coma.


Bowel Function

Because bowel is needed for a bladder substitute, the impact of a prior bowel resection and diseased (e.g., Crohn disease) or irradiated bowel needs to be considered as it relates to malabsorption or diarrhea. The bowel segment used for the bladder substitute itself needs to be free of any pathology. Patients with compromised bowel function are better served by an ileal conduit.


Urinary Continence Status

Urinary incontinence, especially in female patients, may reflect a poorly functioning sphincter. These patients require preoperative urodynamic evaluation including a urethral pressure profile because this may identify an etiology and thereby potential treatment options. Severe stress urinary incontinence and neurologic voiding disorders are contraindications to an orthotopic bladder substitution.


Paracollicular and Bladder Neck Biopsy

Positive biopsies from the paracollicular region in the prostatic urethra or the bladder neck/proximal urethra in women indicate a high likelihood of a urethral recurrence. These patients should undergo a primary urethrectomy in conjunction with radical cystectomy and be considered for an alternative form of urinary diversion. Prostatic infiltration (superficial or stromal) proximal to the paracollicular region as well as carcinoma in situ and/or multifocal cancer of the bladder confer a higher risk of urethral recurrence but are not absolute contraindications for an orthotopic bladder substitution.


PREPARATION BEFORE SURGERY

The type of bowel preparation depends on the bowel segment used for the construction of the bladder substitute. If small bowel is used, a limited preparation with two enemas late in the afternoon before surgery is sufficient. Antegrade rinses and neomycin-erythromycin preparations are avoided. In addition, such preparations may increase the risk of fluid imbalances. In the elderly patient, this can produce cardiovascular instability due to intravascular volume depletion as well as potentially place the patient in a catabolic state prior to surgery. If large bowel is used, this must be freed from feces by antegrade irrigation or laxatives. A full mechanical bowel preparation is no longer required for colorectal surgery (5).

Subcutaneous deep venous thrombosis prophylaxis is started the evening before surgery and continued postoperatively. It is administered in the upper extremity so as to prevent a pelvic lymphocele. All patients receive perioperative antibiotic prophylaxis. Also, patients wear stockings and are taught appropriate exercises by a physiotherapist in order to prevent a deep venous thrombosis of the lower extremities or bronchopneumonia.


INTRAOPERATIVE MANAGEMENT

There are certain critical surgical steps that, if adhered to during radical cystectomy, will allow for optimal functional results of the bladder substitute.


Preservation of Pelvic Innervation

In general, nerve sparing should be performed on the non-tumor-bearing side and extensive resection on the tumorbearing side of the bladder (Fig. 77.1). It has been shown that attempted nerve sparing during radical cystectomy in bladder substitute patients does not only increase the chance to maintain erectile function but also have a positive impact on daytime and nighttime urinary continence (3).

For nerve-sparing cystectomy in men, the nerve fibers in the dorsomedial pedicles lateral to the seminal vesicles as well as the periprostatic neurovascular bundle have to be spared. The pelvic plexus can be preserved by sectioning the dorsomedial pedicle along its ventral aspect, anterolateral to the seminal vesicles, and terminating the dissection at the base of the prostate. A nerve-sparing prostatectomy must also be performed which requires a lateral approach with incision of the endopelvic and periprostatic fascia and bunching of Santorini plexus at the level of the prostate and not distal to it. The dorsolateral neurovascular bundle can be separated from the prostatic capsule. The prostatic apex needs to be approached laterally directly along the prostatic capsule, and the membranous urethra is delivered sharply out of the donut-shaped prostatic apex to avoid nerve damage on the dorsolateral side of the urethra (6).

For nerve-sparing cystectomy in women, the vaginal wall dissection at the cervical level is in the anteroventral plane of the vagina, that is, at the 2 or 10 o’clock position. An empty sponge-holding forceps in the vagina helps facilitate dissection along the whitish vaginal wall. It is important to remain in close contact with the whitish wall of the vagina, thereby ensuring that the paravaginal venous plexus is hemostatically controlled and resected with the dorsomedial bladder pedicle. The endopelvic fascia is only incised cephalad to the bladder neck to minimize damage to the sphincter, its innervation, and to the intrapelvic branch of the pudendal nerve, which also contributes to urethral innervation (7).







FIGURE 77.1 Dissection line for nerve sparing on the non-tumor-bearing side and for extensive resection on the tumor-bearing side of the bladder in male (A and B) and female (C and D) patients.


Atraumatic Dissection of the Urethra

To obtain a maximum length of competent urethra, sharp and atraumatic dissection of the urethra with minimal use of electrocautery at the prostatic apex in men is used with preservation of the distal puboprostatic ligaments, which cover the membranous urethra. In female patients, the endopelvic fascia is not incised at its deepest point but along the bladder neck. This, together with the preservation of the pubourethral ligaments, will allow for urethral stability and improved urinary continence.


Ureters

Ureters need to be resected at a safe oncologic distance from the bladder, allowing for removal of periureteral lymphatics that may harbor micrometastases. In addition, by removing the distal ureter, the risk of ureteral ischemia and subsequent stricture formation is decreased. Furthermore, when mobilizing the ureters, the periureteral tissue must be preserved in order to ensure good blood supply to the anastomotic area, again in order to prevent anastomotic strictures. The left ureter is transposed without tension to the right side of the abdomen retroperitoneally by crossing the aorta above the inferior mesenteric artery. An antireflux ureterointestinal anastomosis (8) or other antireflux mechanisms (9) are not required in lowpressure bladder substitutes, rather they may be detrimental to the renal function. A long, spatulated, end-to-side anastomosis according to the refluxing Nesbit technique using a water tight running suture should, instead, be performed. Traction on the anastomosis can be avoided by placing interrupted sutures between the periureteral tissue and the bowel wall. Although stenting of the ureterointestinal anastomosis apparently does not lower the stricture rate, it may improve the recovery of bowel function and decrease the risk of metabolic disturbances in the early postoperative period (10). If ureteral stents are placed, they should be passed through the bowel wall where their exit sites are covered with mesenteric fat, so as to prevent urine leakage once they are removed.

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Apr 24, 2020 | Posted by in UROLOGY | Comments Off on Managing the Patient With Orthotopic Bladder Substitution

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