Part 1 Continent Diversions: The New Gold Standards of Ileoanal Reservoir and Neobladder
C ontemporary surgical techniques have revolutionized the therapy of persons affected by severe colorectal or urinary bladder disease. Two approaches, ileoanal reservoir (IAR) and orthotopic bladder reconstruction (neobladder), have become the new "gold standards" of definitive care because their functional outcomes have been so positive and they preserve patients' native sphincters. This article examines these two innovations, their surgical construction, indications, contraindications, medical and surgical care issues, and nursing implications. Research to discern optimal surgical techniques, assess the long-term outcomes of these procedures, develop definitive diagnostic instruments for Crohn's disease, and ascertain the potential effects of medical treatments for conditions such as inflammatory bowel disease and bladder cancer is needed.
Until the last decade or so, persons affected by familial adenomatous polyposis (FAP), severe chronic ulcerative colitis (CUC), or cancer of the urinary bladder were faced with a difficult choice. They could undergo a traditional noncontinent fecal or urinary diversion or face even longer surgery and adaptation by the creation of a catheterizable continent fecal or urinary diversion. Although research suggests that quality of life can be good for persons with an ileostomy or ileal conduit (urostomy),1 both involve wearing an external appliance for life. The alternative to a continent ileostomy or urostomy eradicates the need for an external "bag" but involves more intricate surgery and necessitates multiple daily intubations. In addition, the "nipple valve" continence mechanisms of the various continent fecal and urinary pouches can deteriorate over time and require surgical revision or conversion to a traditional diversion.
Improved anesthetic techniques and surgical technology (especially stapling devices) have empowered surgeons to accomplish one of the noteworthy developments in elimination surgery - a move away from permanent incontinent stomas. Now, IAR and neobladder innovations have become the "gold standard" or treatment of choice.2,3 Many of these complex surgeries now can be performed laparoscopically, further shortening recovery time. The enormous advantage is that trans-anal defecation or transurethral urination is preserved with near normal continence. For many persons with life-threatening diagnoses, the worst of times has become the best of times.
The IAR should be distinguished from two other procedures - ie, the coloanal reservoir performed for rectal cancer and the straight ileoanal pull-through for the treatment of CUC or FAP. In the former restorative procedure, a neo-rectum is constructed using descending colon, making a colonic pouch. The pouch is attached to the anal canal similar to the IAR approach. Many adaptation issues that IAR patients face are not present with the coloanal pouch because the entire colon is not removed.4
The IAR differs from the straight ileoanal pull-through - the pull-through involves a proctocolectomy and direct attachment of the ileum to the rectum. The pull-through is associated with much poorer outcomes, prolonged severe diarrhea, and fecal incontinence.5
Epidemiology and Pathophysiology: FAP, CUC, and Bladder Cancer
The IAR is known by several names, including restorative proctocolectomy, Park's Pouch (after Sir Alan Parks who first published about the IAR), and ileal pouch anal anastomosis (IPAA), among others.3 The two common indications for use include FAP and CUC. The negative consequences of both disorders mandate a surgical curative approach. The IAR offers definitive cure and spares the person's natural sphincter, allowing near-normal continence.
Familial adenomatous polyposis is an inherited disorder in which the affected person's large intestine contains multiple polyps. The polyps have a virtually 100% chance of malignant degeneration. Familial polyposis occurs across the world at an incidence of 1:10,000 to 1:20,000 in the population.6,7 Conversely, CUC occurs mostly in the Scandinavian countries, Great Britain, and North America at a rate of 1 to 15 cases per 100,000 population or 1 in 160 people.8,9 Because of the substantially lower occurrence of FAP, not as many persons undergo IAR surgery for the disorder.
Ileoanal reservoir surgery is used in persons suffering from only one form of inflammatory bowel disease - CUC, a condition that affects the inner lining of the large intestine. The bleeding, pain, mucus, and other symptoms can be treated definitively if the diseased tissue is surgically removed - that is, by total colectomy. Chronic ulcerative colitis is also associated with a higher incidence of colon cancer development. About 5% of persons with ulcerative colitis develop colon cancer.10 The risk of malignant degeneration over time is eradicated when the entire large intestine is removed. Because CUC sufferers are often younger persons, the IAR offers eradication of a horrible disease state along with preservation of their native anal sphincters.
Ileoanal reservoir surgery is not performed in people with Crohn's disease because the disease potentially affects the entire gastro-intestinal tract, including the ileum. Some research suggests that complications (eg, anal complications) are associated with people who were later diagnosed with Crohn's disease.11 When people have indeterminate colitis (IC), it is not certain whether their disease is CUC or Crohn's.12 The challenge for future care is to develop better diagnostic tests to truly rule out Crohn's disease. Therefore, in a person with IC, the choice of pouch surgery as an option is left to the colorectal surgeon and the patient.3
Bladder cancer is the fourth most common cancer in men, the eighth most common cancer in women, and the sixth most common cause of cancer deaths in the US.13 The American Cancer Society estimates that in 2004, approximately 60,240 new cases of bladder cancer (44,640 men and 15,600 women) will be diagnosed in the US.13 Bladder cancer affects twice as many men as women. The incidence of bladder cancer rises dramatically with age among men and women in all populations. Rates among people 70 years old and older are about 15 to 20 times higher than those age 30 to 54 years.14 The disease is most often linked with cigarette smoking,15 which is known to increase a person's risk of bladder cancer by at least threefold. The length of time of smoking appears to be the most important predictor of that risk.16
Occupational exposures also contribute to bladder cancer, particularly a group of chemicals known as arylamines; therefore, occupations with exposure to arylamines, (dye workers, rubber workers, leather workers, truck drivers, painters, and aluminum workers) are at higher risk. Other risk factors include exposure to certain drugs like arsenic and cyclophosphamide, frequent urinary tract infections, and infections from the parasite, schistosomiasis.17
The most common histologic type of bladder tumor is the "transitional" cell or "urothelial" cell form. Eighty percent of bladder tumors are "superficial"; they do not invade the bladder wall. As long as it is superficial, the tumor can be controlled by periodic surveillance, instillation of intravesical chemotherapy, and/or transuretheral resection of the bladder tumor (TURBT).
Once cancer is found to have invaded the detrusor muscle, it is considered muscle-invasive disease. Unfortunately, 20% of patients already have muscle layer invasion at initial presentation.18 Because the risk of local and distant metastasis increases with muscle invasion, cystectomy is recommended.
The Ileoanal Reservoir
The IAR or IPAA is a surgical reconstruction of the distal intestinal tract in which the colon and proximal rectum are removed and a new rectum or ileal reservoir is made from segments of the terminal ileum and attached to the anal canal either by hand sewing or surgical stapling. In Stage I, the mucosa of the distal rectum and anal canal is usually removed (anal mucosectomy) but some surgeons do not routinely include this step. The pouch can be constructed in several forms: a J, W, or S pouch or a lateral (side-lying) pouch. The J pouch is the predominant approach because it has been associated with equally as good outcomes as other pouches and is the easiest from a surgical construction perspective. To protect all the anastomoses, a defunctioning loop ileostomy is performed.
Stage II is much simpler surgically because it entails closure of the diverting ileostomy.2,19 Stage II is completed 2 to 3 months following the initial stage. In persons who have severe colitis, are on high-dose steroid therapy, and nutritionally compromised, a three-stage procedure is usually considered.20
The major challenges for patient management in Stage I include maintaining fluid and electrolyte balance, managing the high-output diverting ileostomy, and strengthening the anal sphincter. In Stage II, the greatest care challenge is protecting the perianal skin from the frequent liquid stools the patient will pass and promoting adaptation of the reservoir.
Contraindications for the IAR procedure include Crohn's disease, poor anal sphincter function, advanced age, cancer of the lower third of the rectum, and previous abdominal or pelvic radiation. Candidates with serious mental health problems will likely be counseled not to consider this procedure because it involves two surgeries and a prolonged adaptation process.3 Another questionable candidate is the person who falls into the category of indeterminate colitis. Those persons should approach this option with caution.
Even though the IAR procedure avoids a permanent stoma and the quality of life in IAR patients is generally good to excellent,19,21 it does not restore "normal" defecation. After adaptation that may take up to a year, the recipient can usually experience 4 to 6 watery to pasty stools per day.22,23
Research questions related to aspects of the surgical technique of IAR construction continue to arise. The surgical technique has undergone modifications since its inception and questions remain as to what is "best": Type of pouch (J, S, W), method of anastomosis (hand sewn or stapled), inclusion or exclusion of anal mucosectomy, and the need for a diverting temporary ileostomy.24 Some surgeons do not use two stages; some use one procedure for the whole process without a loop ileostomy but do so in carefully selected patients.25
Technical issue decisions include whether to perform anal mucosectomy and whether to hand-sew or surgically staple the pouch to the anal sphincter. More and more surgeons are avoiding anal mucosectomy and are stapling the IAR pouch to the anal connection.26 Case reports suggest that anal mucosectomy is no guarantee that adenocarcinoma will not reoccur in the anal canal27 or that recurrent cancer in the pouch is a manifestation of small areas of residual rectal mucosa.28
Another surgical challenge is related to pouch failure. Failed IAR anastomoses are associated with fistula development, pelvic sepsis, and chronic pouchitis. Sepsis is the ultimate cause of failure in more than 50% of people who develop pouch complications.29 In the past, IARs were removed and a traditional ileostomy constructed. Because the surgery's complications and approaches to address them are better understood, research suggests that people who require re-operation and re-construction of the IPAA can anticipate good functional outcomes, provided the surgeons are well experienced.30
After IAR, bowel obstructions also can be problematic. They are usually severe and require surgery in almost half of the cases.31
The Orthotopic Neobladder
Neobladder, or orthotopic bladder reconstruction, involves the use of small intestine or small bowel-large bowel combination to create a low-pressure reservoir that attaches to the person's urinary sphincter. Although performed for other conditions, the most common indication for surgery is muscle-invasive bladder cancer requiring cystectomy.
The neobladder procedure involves lengthy (6 to 8 hours) surgery and a longer adaptation process. Patients are sited for a traditional ostomy in case the neobladder cannot be constructed and a "bail out" urostomy (eg, ileal conduit) is required. Neobladder also involves additional resections; in men, a cystoprostatectomy is performed; in women, a urethral-preserving anterior exenteration is performed. Initially, the neobladder was performed only on men. More recently, the procedure has been done on women. Research suggests that women and men have equally good daytime urinary continence. Complete nighttime urinary control and hypercontinence occur more frequently in women.32
Construction of the neobladder can be accomplished in several ways. Several versions in use include the Mainz, Studer, Kock-to-urethra pouch, and Hautmann.18,33 Whatever the chosen surgical technique, the criteria for a surgically constructed ideal bladder substitute are "low pressure, adequate volume, and a high compliance, as well as voluntary control of voiding without leakage or residual urine."33 These characteristics are crucial to protect the upper urinary tract from deterioration and to allow the patient to "feel" when the neobladder is full. The "ideal" characteristics are achieved by using small intestine, detubularizing its cylindrical shape and creating a spherical reservoir. Most surgical techniques use from 54 cm to 60 cm of ileum to create the pouch. To avoid malabsorption, the last 15 cm of terminal ileum are spared, as well as the ileocecal valve.
The ureters are anastomosed to the proximal part of the reservoir (called the afferent segment). The ureters are stented with 7 Fr or 8 Fr catheters to promote healing and drainage. A Foley catheter is placed from the reservoir into the urethra. Pelvic drains are placed to avoid build-up of fluids in the pelvic basin. One challenge facing surgeons is the size of the pelvis. Persons with a small narrow pelvis may not be neobladder candidates because space is inadequate to place and anastomose the reservoir.
Candidates for neobladder must have good life expectancy (longer than 1 to 2 years), adequate renal function (serum creatinine below 2.5 mg/dL), good fine motor skills, normal hepatic function, and intact cognitive status. In addition, they cannot have a history of compromised intestinal function, especially inflammatory bowel disease. Further, they may not be grossly obese or have a history of pelvic irradiation.34 Patients should be counseled to expect multiple drains postoperatively, including a urinary catheter, pelvic drains, and a mushroom catheter in the neobladder. A candidate must have an intact external striated sphincter muscle (intact rhabdosphincter continence mechanism) that will remain intact following surgery.35
The enormous advantage of the neobladder is the maintenance of the normal continence mechanism. In addition, no intubation of a continent stoma is necessary. Research suggests that patients' quality of life is significantly better with a continent urinary diversion than with an ileal conduit.36
Long-term research surveillance studies suggest that neobladder patient outcomes are generally good over years. Kulkarni et al37 examined the long-term results of 102 neobladder patients. Most patients had daytime (89%) continence and night-time (78%) continence. Only 36 required occasional clean intermittent catheterization.
Other authors attest to the efficacy of the neobladder in promoting quality of life for the patient with muscle-invasive bladder cancer. Kuczyk et al38 compared expensive time-consuming bladder preservation interventions (tumor resection, chemotherapy) with neobladder and concluded that the neobladder surgery should be given more weight because the functional outcomes are so positive.
Continue to Part 2