Ileostomy, Colostomy, and Pouches

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CHAPTER 113 Ileostomy, Colostomy, and Pouches

Proctocolectomy and permanent ileostomy return most patients with chronic ulcerative colitis (UC) to excellent health and remove premalignant mucosa in patients with UC or familial adenomatous polyposis (FAP). Many of the inconveniences and dangers formerly associated with an ileal stoma have been eliminated by improved surgical techniques, a wider range of better stomal appliances, and more effective education of patients.¹

Between 1930 and 1950, the metabolic consequences of ileostomy became apparent, as did the frequent mechanical complications caused by ileostomy dysfunction. Better understanding of fluid, electrolyte, and blood replacement lessened the former problem, and newer techniques of ileostomy construction mitigated the second.^2,³ Before these advances, ileostomies were made by withdrawal of the intestine through the abdominal wall, the serosal surface of ileum then being sutured to the skin. Ileostomy dysfunction resulted from the serositis following exposure of the serosal surface to the stomal effluent. The mucosa of the ileum, however, is not susceptible to inflammation after a similar exposure, and a solution, therefore, became conceptually simple: evert the mucosal surface of the bud and suture the mucosa to the skin. This modification was described simultaneously early in the 1950s in the United Kingdom and United States and is commonly referred to as a Brooke ileostomy (Fig. 113-1).¹ Development of new ileostomy appliances quickly led to better acceptance by patients and, ultimately, to excellent long-term results.⁴ Enterostomal therapy was introduced in the 1960s as an additional allied health support, and ileostomy societies have blossomed in most countries, providing a lay component of support to patients with stomas.

Figure 113-1. Anatomy of the Brooke ileostomy. The mucosa is everted and sewn to the skin. Therefore no serosal surface is exposed to intestinal content.

Brooke ileostomies are incontinent by definition, and during the 1960s, Nils Kock, a Swedish surgeon, developed the first effective alternative to this incontinent ileostomy.⁵ The Kock pouch procedure featured an ileal pouch, a nipple valve, and an ileal conduit, which led to a cutaneous stoma that, because this ileostomy was continent and therefore an appliance was not needed, could be made flush with the skin. The Kock pouch was used in selected patients with chronic UC and FAP.⁶

Stimulated by patients’ poor acceptance of the ileostomy, surgeons explored other alternatives to the incontinent ileal stoma with its ever-present external appliance. The ileoanal pull-through operation was resurrected, with an important technical modification: the addition of an ileal reservoir.^7,⁸ This procedure offered the advantages of a normal exit for stool and preservation of the anal sphincters. Indeed, the use of this procedure in thousands of patients has revealed ileal pouch-anal anastomosis (IPAA) to be the procedure of choice in most patients requiring proctocolectomy for chronic UC or FAP.

Although the Brooke ileostomy had become the usual operation after a colectomy in the United Kingdom and the United States, ileorectostomy was standard in continental Europe and South America. Indeed, these different attitudes continue to influence approaches to the newer operations. This chapter details the pathophysiologic and clinical implications of colectomy per se and describes the options for control of enteric content. There are three surgical options after total colectomy in patients with chronic UC and FAP: proctocolectomy with the terminal Brooke ileostomy, IPAA, and ileorectostomy. The Kock pouch and IPAA are contraindicated in patients with Crohn’s disease, but the option of segmental colectomy is available.

PATHOPHYSIOLOGIC CONSEQUENCES OF PROCTOCOLECTOMY

FECAL OUTPUT AFTER PROCTOCOLECTOMY

After a colectomy with any type of ileostomy, the absence of the colon obviously prevents its reabsorption of electrolytes and water. Usually, this creates no major pathophysiologic disturbance, but some important principles should be remembered. A normal colon absorbs at least 1000 mL of water and 100 mEq of sodium chloride each day, and the healthy colon can increase absorption more than 5 L/day when presented with increased amounts of fluid.^9,¹⁰

Also, the colon has a greater capacity than the small intestine to conserve sodium chloride when a person is salt depleted. For example, under conditions of extremely low salt intake, sodium losses in normal stool can be reduced to 1 or 2 mEq/day, whereas patients with ileostomies have obligatory sodium losses of 30 to 40 mEq/day.¹¹^–¹³ The majority of patients adapt to these daily losses through minor changes in salt and water intake and physiologic compensation.¹⁴

Well-functioning conventional (Brooke) ileostomies discharge 300 to 800 g of material daily, 90% of which is water.^12,¹³ Continent ileostomies and IPAAs have similar volumes of effluent.¹⁵ Foods containing substantial unabsorbable residue increase the total ileostomy output by increasing the amount of solids discharged. Although many anecdotes are reported on the effect of foods on the volume and consistency of stomal effluents, the response to specific foods varies from one patient to another, and changes usually are minimal.¹⁶

FUNCTIONAL SEQUELAE

When oral intakes of sodium, chloride, and fluid are adequate, patients with ileostomies do not become depleted in volume or electrolytes; negative sodium balance, however, can follow periods of diminished oral intake, vomiting, or excess perspiration.¹⁷ In addition, chronic oliguria is to be anticipated, even with established ileostomies, because normal stools contain approximately 100 mL of water, whereas ileostomies lose 500 to 600 mL/day.¹⁴ Patients with ileostomies also have lower urinary Na⁺/K⁺ ratios because of compensatory renal conservation of sodium and water. These changes in the composition of urine presumably contribute to the increased frequency of urolithiasis (about 5%) in patients with ileostomies, whose stones are predominantly composed of urate or calcium salts¹⁸; these patients have relatively narrow tolerances for change in their volume and electrolyte status, and even minor changes potentially result in life-threatening electrolyte disturbances.¹⁹

When the terminal ileum is resected and a proximal ileostomy is constructed, there can be abnormalities of bile acid reabsorption, malabsorption of vitamin B₁₂ (see Chapters 64, 100, and 101), steatorrhea, and more than expected losses of fluid (1 L/day). These abnormalities usually do not follow a colectomy that is performed for chronic UC or FAP because the ileum, being free of disease, is preserved. Resection for Crohn’s colitis can require removal of additional diseased ileum with the possible consequences of malabsorption and even short bowl syndrome, depending on the length of small bowel removed (see Chapters 101, 103, and 111).

Colectomy also reduces the exposure of bile acids to the metabolic effects of the fecal flora, and after ileostomy, secondary bile acids largely disappear from bile; no metabolic consequences of significance have been recognized in this situation.^20,²¹ The flora of ileostomy effluents have quantitative (104 to 107 colony-forming units [CFUs] per 100 milliliters) and qualitative characteristics that are intermediate between those of feces and those of normal ileal contents, whereas the flora in an IPAA or Kock pouch are more similar to feces.²²^–²⁴

The principal pathophysiologic sequelae of colectomy with ileostomy are mainly the potential consequences of a salt-losing state; patients should be advised to use salt liberally and to increase their fluid intake, especially at times of stress, in hot weather, and after vigorous exercise. A balanced salt solution (Gatorade or Powerade) is a good source of balanced electrolytes. The limited ability of the small intestine to absorb sodium and water, however, means that stomal volumes also increase when the oral intake is increased.¹³

CLINICAL CONSEQUENCES OF PROCTOCOLECTOMY

After successful proctocolectomy, life expectancy is slightly below normal for the first few years owing to complications of the stoma and to intestinal obstruction; after ileorectostomy for FAP or chronic UC, particularly the former, cancer can develop in the retained rectum. In general, however, the long-term mortality rate in patients after proctocolectomy and conventional ileostomy is the same as for a matched normal population.²⁵ Ninety percent of patients with conventional ileostomies who responded to a survey rated the results of their operation excellent and claimed little inconvenience.⁴ Overall, there is no real difference in the reported quality of life of patients with conventional ileostomies, continent ileostomies, or an ileal pouch.²⁶ Almost all were able to lead normal lives and enjoy normal sexual relationships; a few patients avoided certain strenuous physical activities.

The metabolic consequences of a proctocolectomy per se should be the same regardless of whether a conventional ileostomy or an alternative procedure is performed. Patients in whom an ileostomy alternative achieves an excellent result have a better quality of life than do patients with a stoma because the former do not need to wear an ileostomy appliance. Indeed, when the Brooke ileostomy and IPAA were compared, patients with IPAA experienced significant advantages in performing daily activities and appeared to enjoy a better quality of life.²⁷ There are certain unique complications of the newer operations, however, including incontinence (Kock pouch), pelvic infections and sepsis, and pouchitis (IPAA), which are discussed later.

THE CONVENTIONAL BROOKE ILEOSTOMY

Major long-term complications relate to malfunctioning ileostomies, prestomal ileitis, and irritation of the peristomal skin. If the ileostomy was improperly constructed (a less-common problem with newer techniques), the stoma can become obstructed. Obstruction leads to cramping abdominal pain, increased ileal discharge (up to 4 L/day), and fluid and electrolyte depletion. Excessive ileal output arises, at least in part from increased intestinal secretion as the result of dilatation of the intestine proximal to the obstructed stoma. Stomal obstruction usually can be demonstrated by examining the stoma with the little finger or by endoscopy with a narrow endoscope. Radiologic studies reveal a dilated ileum proximal to the point of obstruction. Many obstructed ileostomies require reconstruction, and at operation, ulcerations often are found in the resected terminal ileum; the pathogenesis is unclear but probably relates in some way to the mechanical consequences of obstruction.

Prestomal ileitis is a much less common problem than is stomal obstruction. Patients with this complication exhibit the features of mechanical obstruction, and, in addition, they have signs of systemic toxicity (e.g., fever, tachycardia, anemia).^28,²⁹ In prestomal ileitis, the ileum has numerous punched-out ulcers, sometimes extending to the serosa. It is not clear whether prestomal ileitis has a different pathogenesis from the changes that follow simple mechanical obstruction of the stoma; both complications involve ileum that was normal histologically at the time of colectomy. Backwash ileitis, seen typically in chronic UC, does not predispose to either prestomal ileitis or obstruction. Conversely, patients who have had colectomy and ileostomy for Crohn’s disease experience problems with the ileal stoma more often, perhaps because transmural inflammation involves the new terminal ileum. In some instances, it is difficult to determine whether stomal dysfunction results from mechanical obstruction or recurrent Crohn’s disease.

Most people with an ileostomy lead a normal life and eat a normal diet; poorly digestible foods (e.g., nuts, corn, some fruits, lightly cooked vegetables) can obstruct the stoma and should be eaten in moderation and with careful chewing.⁴ Some patients experience continuing difficulties managing their ileostomy. These problems vary in severity, some being minor inconveniences and others being significant drawbacks to the success of the operation. Mechanical difficulties because of a poorly fitting stomal appliance can cause excoriation of the skin around the ileostomy and can even erode the stoma to produce a fistula. Some patients complain of unpleasant odors arising from the ileostomy bag, especially after eating certain foods, such as onions and beans. Because most odor arises from bacterial action on the contents of the appliance, however, the problem may be offset by frequent emptying of the appliance or by adding sodium benzoate or chlorine tablets to the appliance. Oral bismuth subgallate also controls odor, but doubts exist as to whether its long-term use is justified, because questions of neurotoxicity and encephalopathy have been raised.^30,³¹

A review of the long-term outcomes associated with ostomies has demonstrated a high rate of complications. The most common problems related to ostomies are skin irritation and parastomal hernias, both of which contribute to difficulty with appliance pouching, a term used by enterostomal therapists and referring to the fitting of an ostomy device. Several risk factors are associated with development of parastomal hernias, including obesity, malnutrition, chronic respiratory disorders that are associated with increased intra-abdominal pressure, chronic use of glucocorticoids or other immunosuppressive agents, malignancy, advanced age, and wound infection.³²^–³⁵ Several techniques have been described for parastomal hernia repair, including primary fascial repair, stoma relocation, and mesh repair; mesh repair achieves the best outcomes.³² The simplest approach, primary repair, is associated with very poor outcomes and up to 100% recurrence rates. Stoma relocation may be an effective approach when the initial stoma site is unsatisfactory, but parastomal hernias occur at the new site in up to 76% of patients.³⁵ The use of prosthetic mesh for parastomal hernia repair has significantly improved outcomes, with recurrence rates reported as low as 10%.^36,³⁷ To address the concerns of possible mesh infection and erosion of mesh into the bowel, the use of biologic materials, such as human acellular dermal matrix, has been reported, with results that are comparable to mesh in small series.³⁸

Trained stomal therapists and lay societies of ileostomy patients can help with numerous aspects of postoperative care. Education of the patient is best started before surgery; meetings with others who have undergone ileostomy and referral to specialized publications can allay many fears and uncertainties. The United Ostomy Associations of America (UOAA, P.O. Box 66, Fairview, TN 37062-0066; www.uoaa.org) publishes an excellent series of booklets dealing with all aspects of life for the ostomy patient. These materials also are of great help to patients and nursing staffs in the absence of a registered enterostomal therapist (wound ostomy and continence nurse [WOCN]). The location of a registered therapist can be obtained from the Wound Ostomy and Continence Nurses Society (WOCN Society National Office, 15000 Commerce Parkway, Suite C, Mt. Laurel, NJ 08054; www.wocn.org).

CONTINENT ILEOSTOMY (KOCK POUCH)

Clearly, one of the major (social) drawbacks to ileostomy could be eliminated if a continent stoma were possible. Nils Kock reasoned that a pouch and nipple valve constructed of terminal ileum could store ileal content internally until emptied voluntarily by the patient passing a large, soft catheter into the pouch several times daily, thereby obviating the need for an external appliance (Fig. 113-2). The first such operations were reported in 1969, and the results were promising; however, the nipple valve sometimes failed, usually because it slipped out of the pouch, resulting in incontinence.⁵ Techniques gradually improved, and the most recent approaches have been more successful, providing continence in most patients. In two series, more than 90% of patients were continent for gas and feces (i.e., never requiring an appliance).^34,³⁹

Figure 113-2. The continent ileostomy. The pouch is formed from a loop of ileum, folded on itself as a U, and sutured along the antimesenteric borders. The two limbs making up the pouch are then incised, exposing the mucosa, and the nipple valve is fashioned. The pouch is closed and positioned, as shown, underneath the abdominal wall. Note that the stoma is flush with the skin.

This high success rate, however, is achieved at the price of additional operations in most patients for nipple or pouch dysfunction, fistula, or stricture. Wasmuth and colleagues reported a 50% rate of reoperation by 14 years after continent ileostomy construction.⁴⁰ Furthermore, in a series reported by Lepisto, 59% of patients with a continent ileostomy required reoperation, with a total of 85 pouch reconstructions being performed: 42 patients had one reconstruction, nine had two reconstructions, three had three reconstructions, one had four reconstructions, and two had six reconstructions.⁴¹ Others have reported similar findings: patients generally did well after initial continent ileostomy construction, but a sizable minority required repeated surgical intervention either to salvage pouch function or remove the pouch.^42,⁴³

Despite requiring numerous reoperations, the majority of Kock pouch patients are satisfied with the outcomes of their functioning pouch. In a recent comparative study on quality of life in patients with standard ileostomies, ileal pouch, and Kock pouch, the Kock pouch patients did not fare significantly better or worse than those with a conventional ileostomy or IPAA; 56% of the continent ileostomy patients, however, did require reoperation to maintain function of the continent ileostomy.²⁶

The fundamental mechanical problem of the nipple valve design in the Kock pouch has prevented widespread acceptance of the procedure. Another continent ileostomy, the T pouch, has been developed to combat this problem ⁴⁴; its design prevents slippage of the intussusceptive nipple valve constructed in the traditional Kock pouch. In the T pouch, the valve mechanism is made by securing an isolated distal ileal segment into a serosal-lined trough formed by the base of two adjacent ileal segments. The high volume-low pressure reservoir is fashioned around this isolated valve segment. Once constructed, the distal end of the valve mechanism is brought up through the skin as a stoma. T pouches have been constructed in only a few patients, and the results are promising, but long-term follow-up is required to assess the structural integrity and clinical success of the new valve design. Given the wide acceptance of the IPAA, continent ileostomy operations are performed rarely and used mainly in patients who have had a proctocolectomy and ileostomy and who desire enteric continence.

ILEAL POUCH-ANAL ANASTOMOSIS

IPAA is now the procedure of choice for most patients who require proctocolectomy for chronic UC or FAP. IPAA is not considered suitable for patients with Crohn’s disease, although this recommendation now is being questioned.^45,⁴⁶ The operation has several major advantages: nearly all mucosal disease is removed in contrast to ileorectostomy; the normal route for elimination is maintained (a permanent stoma is not required); the anal sphincters are undisturbed; and the pelvic dissection, being less extensive than in cancer operations, should not endanger innervation of the sexual organs.

The general principle of ileoanal anastomosis was first described in 1947, and its revival was influenced by the success of pediatric surgeons in children with Hirschsprung’s disease.⁷ Early approaches used a straight pull-through and sutured the ileum directly to the anal verge.⁴⁷ Although results in children were encouraging, excessive stool frequency and anal seepage were unacceptable to many adult patients. Subsequently, the operation was modified to include one of several forms of ileal pouch. The basic surgical steps are as follows: a proctocolectomy is performed; the distal rectal mucosa is divided at the top of the anal canal, which leaves a small cuff of residual rectal and anal canal mucosa; an ileal pouch is fashioned and then stapled or sutured to the cuff of remaining rectal and anal canal tissue. A diverting ileostomy is usually required for two to three months until the anastomosis heals completely. At a second operation eight to 12 weeks later, the diverting ileostomy is closed.

The Mayo Clinic has acquired considerable experience with IPAA, having performed more than 2200 of these operations.⁴⁸^–⁵⁰ Although pouches of different configurations have been advocated by various surgical groups in the past, the pouch routinely used today is the J pouch because of its ease of construction and reliable function (Fig. 113-3).

Figure 113-3. The anatomy of the most commonly used type of ileal pouch, the J pouch. A pouch approximately 12 to 15 cm long is constructed by opening the common wall between the two limbs of the J formed from the distal terminal ileum. The apex is then anastomosed to the upper anal canal.

LONG-TERM RESULTS

IPAA is a complex operation and complications occur frequently. The overall morbidity rate still hovers between 25% and 30%.⁴⁹^–⁵¹ Failure, however, is rare, even in those who suffer a postoperative complication.

At the Mayo Clinic, overall pouch success rate was 92% in patients who had had their IPAA for up to 20 years.⁵² In this series of 1885 IPAA operations performed for UC over a 20-year period with a mean follow-up of 11 years, the overall rate of pouch success at 5, 10, 15 and 20 years was 96.3%, 93.3%, 92.4% and 92.1%, respectively. Over time, the mean daytime stool frequency increased from 5.7 times at one year to 6.4 times at 20 years; nighttime stool frequency also increased from 1.5 to 2.0. The incidence of frequent daytime fecal incontinence increased from 5% to 11% during the day (P < 0.001) and from 12% to 21% at night (P < 0.001). This series demonstrated that IPAA is a reliable surgical procedure for patients requiring proctocolectomy for UC and indeterminate colitis. Furthermore, it showed that the clinical and functional outcomes are excellent and durable.

When performed in centers that have experience with IPAA, the outcomes are very good; even more important, these centers understand the potential complications and their management in IPAA patients. Although it is not discussed any further here, the key to a successful outcome is a surgeon who performs the operation comfortably; the operation struggled through is the one fraught with complications and sometimes with failure.

Complications

Pelvic sepsis, an ominous development, occurs in 5% to 24% of patients after IPAA.^49,^50,^53,⁵⁴ Computed tomography (CT) is useful for demonstrating pelvic fluid collections or phlegmon. Patients with pelvic phlegmon usually respond to conservative treatment with broad-spectrum antibiotics and bowel rest, whereas patients with a pelvic abscess ideally should undergo CT-guided drainage, if technically feasible, or laparotomy and drainage (Fig. 113-4). The most commonly cited risk factor for pelvic sepsis is chronic or high-dose glucocorticoid use in the perioperative period.⁵⁵ Pelvic sepsis can, in the short-term, lead to pouch excision, which fortunately is rare; long-term functional results of the pouch are worse, however, and there is a higher rate of pouch loss compared with patients who did not experience pelvic sepsis.⁵²

Figure 113-4. Computed tomography (CT) scan showing a peripouch abscess (arrows) identified 8 days after surgery. This complication is best managed by placement of a percutaneous drain under CT guidance.

A diverting temporary ileostomy, while minimizing the impact of pelvic sepsis, is associated with a number of complications.⁵⁶ Closure of temporary ileostomies also may be associated with complications. Peritonitis occurred in 4% of patients and postoperative intestinal obstruction in 12% of patients. Proximal and distal serosal tears during stoma mobilization, in addition to anastomotic leaks, are important causes of peritonitis. If all extraperitoneal bowel (afferent and efferent limbs and the stoma itself) is resected, however, the chance of leaving an unrecognized perforation is nearly eliminated.

Almost all patients have a web-like stricture of the ileoanal anastomosis before ileostomy closure (Fig. 113-5). This stricture generally can be dilated digitally without difficulty, but narrowing can recur and is the most common indication for surgical intervention after an IPAA.⁵⁷ If the pouch retracts under anastomotic tension, heavy scarring can result in a long, fibrotic stricture. This type of stricture is manifested by increased straining to empty the pouch, a sensation of incomplete pouch evacuation, or a high stool frequency (more than 10 to 12 stools per day). Repeated anal dilation can prevent progression of the stricture.

Figure 113-5. Film from a water-soluble radiocontrast enema performed before ileostomy closure demonstrating a mild anastomotic narrowing (arrows). This stricture was dilated in the operating room before the ileostomy was closed.

Clinical Results

Following an IPAA, the average stool frequency is six stools during the day, with one stool at night.⁴⁸^–⁵⁰ ⁵⁴ Daytime and nocturnal stool frequency and the ability to discriminate flatus from stool remain relatively stable over time, whereas the need for stool bulking and hypomotility agents declines. The lower stool frequencies six months after surgery compared with the frequency in the early postoperative period are likely attributable to increased pouch capacity over time.

In the Mayo Clinic experience, major fecal incontinence (more than twice per week) occurs in 5% or less of patients during the day and 12% of patients during sleep.⁵⁰ In contrast, minor episodes of nocturnal incontinence occur in up to 30% of patients at least one year after the operation. A pad must be worn by 28% of patients for protection against seepage. Minor perianal skin irritation is reported by 63% of patients. Patients older than 50 years have a higher daytime stool frequency (eight per day) than do patients younger than 50 years (six per day). Men and women have similar stool frequencies postoperatively, but women have more episodes of fecal soilage during the day and night; this is thought to be related to a shorter average anal canal length in women. Seventy-eight percent of patients report excellent continence one year after surgery, which remains unchanged at 10 years; 20% experience minor incontinence; and 2% have poor control. Of patients with minor incontinence at one year, 40% remain unchanged, 40% improve, and 20% worsen by 10 years.⁵² Nocturnal fecal spotting increases during the 10-year period, but not significantly.

Pouchitis and Cuffitis

A wide range of reported incidences suggests that the level of clinical suspicion and the diagnostic criteria for pouchitis vary greatly.⁵⁸^–⁶⁰ An early experience in IPAA patients demonstrated that patients who have preoperative extraintestinal manifestations of UC had significantly higher rates of pouchitis than patients without such manifestations (39% with preoperative symptoms and 26% without).⁵⁸ A recent study by Hoda and colleagues, however, demonstrated that whereas extraintestinal manifestations might indicate a predisposition to episodes of acute pouchitis, they are not predictors of chronic pouchitis.⁶⁰ Furthermore, they report that patients at highest risk for developing chronic pouchitis suffered from postoperative complications, more specifically anastomotic and septic complications.

Other investigators have suggested that there is a biological predisposition for pouchitis and that better risk stratification can be obtained by the preoperative use of serum markers of IBD.⁶¹^–⁶³ In the study by Hui and colleagues, 63% of patients who went on to develop chronic pouchitis had a positive perinuclear-staining antineutrophil cytoplasmic antibody (pANCA) preoperatively, and only 17% had negative serologic results.⁶¹ There remain questions about these findings, because not all authors have demonstrated such a relationship.⁶⁴ Furthermore, although the serologic information is intriguing, it is unclear if it provides any information that would change surgical decision making before surgery, because the surgical options are limited.

As more surgeons have begun to perform a double stapled anastomosis, as opposed to a mucosectomy and hand-sewn anastomosis, there is a remnant cuff of rectal mucosa. This cuff of epithelial tissue can experience intermittent or chronic activity of UC, which has been termed cuffitis.⁶⁵ Cuffitis can cause symptoms similar to pouchitis. In a study of 61 IPAA patients with symptoms of pouchitis, 7% had cuffitis.⁶⁶

Most patients with apparent pouchitis or cuffitis have intermittent symptoms or respond well to therapy. In a few, however, symptoms are severe and persistent enough to lead to surgical removal of the pouch. Patients present with increased volumes of output, bleeding, discomfort from the pouch, and general symptoms similar to those of the initial disease. Fever, anemia, and dehydration as a result of diarrhea are variably present; fecal incontinence also is common. Extraintestinal dermatologic and rheumatologic manifestations are seen occasionally.⁵⁸

In a patient with pouchitis, endoscopy shows the pouch mucosa to be reddened, swollen, and often ulcerated. The mucosa is friable and bleeds readily from minor trauma during endoscopy; inflammatory changes usually are confined to the pouch but also can be seen in the adjacent ileum. Biopsy specimens show a range of acute and chronic inflammatory changes depending on severity, and a pouchitis disease activity index combining clinical, endoscopic, and histologic features has been developed (Table 113-1).⁵⁹ Gradual escalation of medical therapy for acute or chronic pouchitis is now the standard of care.⁶⁷ Exclusion of possible etiologies that may require specific treatment is essential before initiating treatment for pouchitis. The following points must be remembered: Patients with ileal pouches are not immune to superimposed specific enteric infections; stool culture and microscopy for parasites are appropriate.

Table 113-1 Pouchitis Disease Activity Index *

CRITERIA	SCORE
Clinical
Postoperative Stool Frequency
Usual	0
1 or 2 stools/day more than usual	1
≥3 stools/day more than usual	2
Rectal Bleeding
None or rare	0
Present daily	1
Fecal Urgency or Abdominal Cramps
None	0
Occasional	1
Usual	2
Fever (>100°F)
Absent	0
Present	1
Endoscopic
Edema	1
Granularity	1
Friability	1
Loss of vascular pattern	1
Mucoid exudate	1
Ulceration	1
Histologic
Polymorphonuclear Leukocyte Infiltration
None	0
Mild	1
Moderate + crypt abscess	2
Severe + crypt abscess	3
Percent of Mucosa That Is Ulcerated per Low-Power Field (Average)
<25	1
25-50	2
>50	3

The total score is the sum of the individual scores.

* Pouchitis is defined as a total score of 7 or greater.

Adapted from Sandborn WJ, Tremaine WJ, Batts KP, et al. Pouchitis after ileal pouch-anal anastomosis: A pouchitis disease activity index. Mayo Clin Proc 1994; 69:409.

Unsuspected Crohn’s disease in the pouch is always a major concern. The clinical features of the underlying colitis that led to the operation should be reviewed carefully, including gross and histologic examination of the resected bowel. A small but definite proportion of colitis falls into an unclassifiable group, and some patients with previously unrecognized Crohn’s disease present with pouchitis, which is actually a manifestation of (recurrent) Crohn’s disease. Surgically treatable problems such as an anastomotic stricture resulting in partial pouch outflow obstruction need to be looked for carefully and treated with dilation.

Pathogenesis

Acute, nonspecific inflammation of ileal pouches apparently reflects the propensity of the patient for IBD. Thus, pouchitis is much more common in patients with IBD than it is in patients with familial adenomatous polyposis (FAP). Still, patients operated on for FAP are not completely protected from pouchitis. The nonspecific pathologic features of pouchitis reflect the fact that pouchitis can result from different causes.

Histopathology of healthy and diseased pouches has shown that chronic inflammation is usual, even when the patient is asymptomatic.^68,⁶⁹ Villus architecture is distorted, and colonic metaplasia is present in biopsies from most pouches, even in the absence of severe acute inflammation. Thus, these changes are considered natural sequelae of the altered anatomy, just as the histologic changes of experimental and clinical blind-loop syndrome have been attributed to bacterial overgrowth.

Other possible causes of pouchitis have little support, including damage by bile acids or their bacterial metabolites and lack of short-chain fatty acids (SCFAs).⁵⁹ Normal colonic mucosa uses SCFAs as a source of nutrition, and some authors have proposed that IBD can result when the colon is deprived of SCFAs.⁷⁰ The clearest clinical experiment that tests this hypothesis is diversion colitis. Harig and coworkers proposed that diversion colitis is caused by deprivation of SCFAs,⁷¹ support for which is provided by the observation that diversion colitis improves in response to SCFA enemas. Ileal pouches contain high concentrations of SCFAs (≥100 mmol), however, and so a state of deprivation seems unlikely. Indeed, pouchitis has worsened or shown no predictable response to SCFA enemas.⁷² In a detailed evaluation of luminal factors, including fecal concentrations of bacteria, bile acids, and SCFAs, there were no differences between patients with or without pouchitis.⁵⁹ Alteration in butyrate metabolism has been linked to pouchitis.⁷³

At present, there is no definitive cause for pouchitis, but it most likely does involve an interaction between the pouch microenvironment and the patient’s underlying immune response to that environment. In the Mayo Clinic experience in patients who have had their IPAA for nearly 20 years, the rate of having at least one episode of pouchitis was 48% at 10 years, and it rose to 78% at 20 years.⁵² In this cohort, less than 5% of patients developed chronic pouchitis, and only 2% required pouch removal or permanent diversion.

Treatment

If diarrhea alone is the major complaint, treatment with simple antidiarrheal measures may be all that is required. For more severely symptomatic patients, a variety of empiric treatments have emerged. When the condition was first encountered in continent ileostomies, anecdotal evidence was that constant drainage would help, based on the assumption that stasis was an important predisposing factor.²³ Stasis should be a lesser factor after IPAA, although incomplete emptying (e.g., with the S pouch) or a persistent anastomotic stricture might need to be excluded. Metronidazole, 500 mg twice daily for 28 days, has been used often as a first line of treatment. The response to metronidazole or other broad-spectrum antibiotics usually is dramatic. Some patients relapse after initial therapy with antibiotics, and they require subsequent courses of treatment. In general, antibacterial agents with a spectrum of activity against anaerobes have been most successful in treating pouchitis.

When antibiotics are ineffective, treatment should consist of regimens that are effective in IBD: glucocorticoid enemas, aminosalicylates, mesalamine enemas, and even systemic glucocorticoids. In some cases of antibiotic resistant pouchitis, bismuth subsalicylate (Pepto-Bismol) 270 mg daily for three weeks is an effective treatment. Most patients unresponsive to antibiotics improve on one of these programs. Severe recurrent disease or major extraintestinal symptoms rarely require pouch removal.

Sequelae

Although the prevalence of chronic pouchitis is low, the possible consequences of chronic inflammation of the neorectum, especially dysplasia and malignant change, arouse concern. Morphologic and biochemical changes occur in the ileal mucosa of pouches, including villus blunting, chronic inflammatory infiltrates, variable transition to production of a colonic type of mucus (sulfomucins), and increased cellular proliferation.⁷⁴ Observations based on long-term follow-up (mean of 6.3 years) reveal three patterns of mucosal adaptation: approximately one half of the patients showed mild villus atrophy and minimal inflammation, slightly fewer had transient moderate or severe atrophy and inflammation with intervals of recovery, and approximately 10% had permanent subtotal or total villus atrophy with chronic inflammation.⁶⁸ In this study, three of eight patients developed low-grade dysplasia; in one patient it developed two years postoperatively. In patients having a double-stapled anastomosis, the remaining rectal cuff and anal canal transition zone tissue represent at-risk tissue. In one series of 225 patients with a stapled IPAA, 238 rectal cuff and anal canal biopsies were obtained; 202 (84.9%) had histologically confirmed chronic inflammation, 11 (4.6%) had acute inflammation, and 25 (10.5%) were read as normal.⁷⁵ Interestingly, 9 of the 11 patients with acute inflammation were asymptomatic.

Pouch Failure

Large series have reported failure rates between 2% and 12%, and in the Mayo clinic series, 8% of patients ultimately required pouch excision or construction of a permanent ileostomy.⁵² The most common causes of pouch failure, either alone or in combination, include pelvic sepsis, high stool volumes, Crohn’s disease, and uncontrollable fecal incontinence; pouchitis is the sole cause in 2% of all patients. Of the patients in whom the pouch fails, failure occurs within 1 year in 75%, by 2 years in 12%, and by 3 years in 12%. Fortunately, pouch failure is relatively uncommon. Early failures are almost always related to technical issues or complications related to the original operation, whereas late failures are more commonly related to chronic pouchitis or Crohn’s disease in the pouch.

Quality of Life

Often, quality of life is the deciding factor for patients choosing a particular operation for UC. Several studies that analyzed the outcome of surgery for UC have demonstrated that most patients are satisfied with the operation and have a normal lifestyle regardless of the procedure.

In one study of quality of life after a Brooke ileostomy or IPAA for UC and FAP, patients were highly satisfied with either operation (Brooke ileostomy, 93%; IPAA, 95%).²⁷ Daily activities (e.g., sexual life, participation in sports, social interaction, work, recreation, family relationships, travel), however, were more likely to be adversely affected with a Brooke ileostomy than by IPAA.

Sexual Dysfunction

Impotence and retrograde ejaculation developed in 1.5% and 4% of men, respectively. Dyspareunia developed in 7% of women postoperatively.^49,⁵⁰ Early studies of IPAA focused on physiologic assessment, but recent studies have concentrated on more multidomain quality-of-life assessments. A prospective evaluation of sexual function in patients with IPAA was performed using validated survey instruments, including the International Index of Erectile Function in men and the Female Sexual Function Index in women. Overall quality of life was assessed using the Short Inflammatory Bowel Disease Questionnaire. Preoperative scores were compared with scores at six and 12 months postoperatively. Of the 59 patients who completed the study, male sexual function and erectile function scores remained high 12 months after surgery and female sexual function improved 12 months after surgery. Quality of life significantly improved after IPAA in both men and women.⁷⁶ Others have reported similar improvements after IPAA.^77,⁷⁸

CONTROVERSIES

Double-Stapled versus Hand-Sewn Anastomosis

Much of the debate whether to staple the anastomosis or not has evolved because functional outcomes should be improved if the anal transition zone (ATZ) is preserved. In nonrandomized trials, a stapled anastomosis has been equated with better outcome, which in turn has been attributed to less injury of the anal sphincters; preservation of the ATZ and hence anal sensory discrimination; and preservation of the rectoanal inhibitory reflex.

To determine if stapled IPAA conferred any advantage over hand-sewn IPAA, we conducted a randomized study at the Mayo Clinic in which 41 patients were randomized to double-stapled (17 patients) or hand-sewn (15 patients) technique.⁷⁹ In the stapled group, 1.5 to 2.0 cm of ATZ was preserved, whereas complete mucosectomy was performed in the hand-sewn group. Overall, complications were the same in the two groups. Stool frequency and rates of fecal incontinence during the day and night were similar between the groups; however, fewer patients treated with the double-stapled technique had nocturnal incontinence.

Similar findings have been reported by other groups.⁸⁰ In a meta-analysis of more than 4000 patients, Silvestri and colleagues concluded that both techniques had similar early postoperative outcomes; stapled IPAA offered improved nocturnal continence, however, which was reflected in higher anorectal physiologic measurements.⁸¹

Role of Defunctioning Ileostomy

The most feared complication of IPAA is pelvic sepsis; therefore, a defunctioning ileostomy after pouch construction usually is performed to minimize its occurrence.⁸² In the literature, the reported rate of pelvic sepsis after IPAA varies between 0% and 25%. Although the incidence of pelvic sepsis is relatively low (6%) at the Mayo Clinic, when it occurs, it is responsible for a significant proportion of the failed pouches.^52,⁵⁷

Proponents of defunctioning ileostomies argue that diverting stomas allow the anal sphincter and ileal mucosa to recover before intestinal continuity is restored and that patients have a short-lived experience of a stoma to fully appreciate the ultimate benefit of IPAA. Use of a loop ileostomy does not appear to protect the patient fully from pelvic sepsis; however, its presence makes it easier to manage a patient with this complication. Supporters of a one-stage procedure believe that an IPAA can be performed without increased risk of pelvic sepsis.⁸³^–⁸⁷ A one-stage procedure avoids an ileostomy and a second hospitalization and operation, lowers the total cost, and results in a shorter hospital stay and perhaps a decreased incidence of small bowel obstruction.

In the large single-surgeon study reported by Sugerman and associates, there were no differences in the complication rates and functional outcomes of patients who had not had a diverting ileostomy compared with those who had a diverting ileostomy; there also was no relationship to glucocorticoid use.^83,⁸⁸ Whereas there might be no significant difference in the complication rate in patients without a diverting ileostomy, one study has suggested that the severity of complications was greater in patients without a protecting ileostomy.⁸⁹

Although it is our practice to perform a diverting ileostomy in all patients undergoing an IPAA, in properly selected patients who have uncomplicated procedures performed by experienced surgeons, a one-stage IPAA might be appropriate. The surgeon and patient care team must be attentive to the early signs of pelvic sepsis, aggressively investigate the possibility of a pouch leak, and intervene as needed.

ADDITIONAL ISSUES

Risk of Cancer

Patients with UC are at risk for developing adenocarcinoma of the colon, which increases with the duration of disease and extent of colonic involvement (see Chapters 112 and 123). Figures suggest that the risk of colon cancer for people with IBD increases by 0.5% to 1.0% yearly, eight to 10 years after diagnosis.⁹⁰ Any surgery that leaves behind diseased colonic mucosa puts the patient at risk for developing dysplasia or neoplasia in this residual tissue. The risk of developing a carcinoma in the residual colonic mucosa may be directly related to the amount of residual mucosa remaining in situ. Complete excision of the rectal mucosa during IPAA substantially decreases the risk of dysplasia. With the more commonly used stapled IPAA, however, a small amount of residual rectal and anal canal tissue is retained.

Early studies by Tsunoda and colleagues demonstrated the presence of dysplasia in mucosectomy specimens, which they believed supports the use of a mucosectomy and hand-sewn anastomosis.⁹¹ Even performing a mucosectomy, however, does not ensure that all rectal and at-risk anal canal mucosa is removed. In one study that evaluated anal canal specimens, islands (rests) of mucosa were present despite “complete” mucosal resection.⁹² In a study with long-term follow-up, however, the risk of dysplasia was quite low.⁹³ A cohort of 289 patients with stapled IPAAs was followed and had multiple biopsies of the rectal cuff and anal transition zone performed over a 10-year period. Dysplasia was identified in eight patients, including four with low-grade and four with high-grade dysplasia. No cancer in the ATZ was found during the study period. The authors concluded that ATZ dysplasia after stapled IPAA was infrequent and usually self-limiting. ATZ preservation did not lead to the development of cancer in the ATZ with a minimum of 10 years of follow-up, although long-term surveillance is recommended to monitor dysplasia.

Detection of neoplastic change in the pouch itself is another reason to perform follow-up in patients with IPAA. A subgroup of patients has been identified in whom the mucosa of the pelvic pouch develops severe villus atrophy.⁶⁸ These patients seem to have a significantly higher incidence of dysplasia compared with patients without villus atrophy (71% vs. 0%). The former group may be at greater risk for developing carcinoma and might require more intensive follow-up with regular pouch endoscopy and biopsy. Despite these findings, dysplasia in a pouch is a rare event. In group of 45 patients followed for a median of six years (one to 28 years), dysplasia of any type was found in 4% of pouch biopsies and there was no evidence of malignancy.⁹⁴

To date, there have been a small number of case reports of carcinomas arising in ileal pouches or in the region of the anastomosis.⁹⁵^–⁹⁸ Surprisingly, many of these cancers have arisen in patients who have undergone a complete mucosectomy with hand-sewn anastomosis. In a recent review, Branco and colleagues found that the occurrence of adenocarcinoma following IPAA for UC is an infrequent event.⁹⁹ Their conclusions were that post-IPAA cancer can occur following either mucosectomy or stapled anastomosis; that this malignancy can occur after IPAA performed for UC either with or without neoplasia; and that this complication is seen whether or not the initial cancer or dysplasia had involved the rectum. Given the known occurrence of dysplasia in pouch mucosa and the rare reports of cancers arising in pouches, routine clinical and endoscopic surveillance should be performed in patients after their IPAA.

Fertility and Pregnancy

Many patients with UC are in their childbearing years. Therefore, the impact of surgery on fertility is an important consideration when discussing surgery with a young woman. A number of studies have evaluated fertility and the course of a subsequent pregnancy after surgery.^100,¹⁰¹ Patients who have had a proctocolectomy and end ileostomy or Kock pouch can expect to have a normal pregnancy and delivery; however, these women often have temporary stoma or Kock pouch dysfunction.¹⁰² A similar disturbance of pouch function is seen in IPAA patients, in whom a slight increase in stool frequency, incontinence, and pad use is reported during the pregnancy.^100,¹⁰¹ Fortunately, this is temporary, and patients return to their baseline pouch function after the pregnancy. There is a reported higher rate of cesarean sections in IPAA patients, but there appears to be no contraindication to vaginal delivery, and the decision to proceed to a cesarean section should be based upon obstetric considerations.

Previous studies evaluated the course of pregnancies after IPAA, but the specific issue of fecundity after IPAA had not been considered. A Swedish population-based study, however, demonstrated a significant reduction in fecundity after IPAA.¹⁰³ More important, of the post-IPAA patients who became pregnant, 29% of pregnancies occurred only after in vitro fertilization compared with the expected 1% of all births in Sweden during the study period. The basis of this decreased fertility is unknown, but the authors hypothesize that changes in pelvic anatomy resulting from removal of the rectum and scarring from the pelvic dissection are major contributors to the problem. A case-control study comparing women with IPAAs and female controls who had previous abdominal surgery found that women who had an IPAA had significantly more infertility evaluations and need for infertility treatments.¹⁰⁴ Furthermore, an analysis of infertility treatments for post-IPAA women demonstrated that they suffered a reduction in the probability of conception rather than complete infertility. This reduction in fecundity is not seen in women who have undergone ileorectal anastomosis for FAP, which further the supports the idea that postoperative adhesions or altered pelvic anatomy contribute to this problem.¹⁰⁵

Given the growing evidence that IPAA reduces a woman’s fecundity, women need to be counseled regarding this prospect during the informed consent before IPAA. If this is a major concern in a young woman suffering from medically refractory UC, a subtotal colectomy and ileostomy to control the disease without disturbing the pelvic anatomy may be offered with a planned IPAA after completion of childbearing.

Ileal Pouch-Anal Anastomosis and Indeterminate Colitis

Among 1519 consecutive patients with UC undergoing IPAA between January 1981 and December 1995, 82 patients (5%) had features of indeterminate colitis, including unusual distribution of inflammation, deep linear ulcers, neural proliferation, transmural inflammation, fissures, and creeping fat.¹⁰⁶ We found that 12 (15%) of the 82 patients with indeterminate colitis eventually developed Crohn’s disease during follow-up, compared with only 26 (2%) of 1437 patients with UC. The probability of remaining free of Crohn’s disease at 10 years was 98% in patients with UC and 81% in the indeterminate colitis patients. After IPAA, patients with indeterminate colitis who did not develop Crohn’s disease experienced long-term outcomes nearly identical to those of patients with UC; that is, nearly 85% had functioning pouches 10 years after the operation. Crohn’s disease, however, regardless of whether it develops and is diagnosed after IPAA operations for UC or indeterminate colitis, is associated with poor long-term outcomes. Similar to our findings, other institutions have shown that although pouch complications are higher in patients with indeterminate colitis, the functional results after IPAA for indeterminate colitis are identical to those after UC.¹⁰⁷

Impact of Biological Medical Therapy

The inclusion of newer biological therapies, such as infliximab, in the treatment of UC has raised concerns regarding their impact on the surgical outcomes after IPAA. In a study by Selvasekar and colleagues, 47 UC patients received preoperative (IPAA) infliximab therapy and 254 did not.¹⁰⁸ Patients who received infliximab were statistically more likely to have postoperative infectious complications and pelvic abscesses. After multivariate adjustment for disease severity and other medication use, infliximab remained independently associated with an increased risk of ileal pouch-related and infectious complications. Another study of 85 patients with UC who received infliximab preoperatively found that they were at increased risk for postoperative septic complications as well as late complications compared with patients who did not receive infliximab.¹⁰⁹ The authors noted that patients who received infliximab were more likely to have undergone a three-stage IPAA, likely due to surgeon reluctance to perform an IPAA in the setting of preoperative infliximab administration.

Both of these studies are limited in their ability to draw any conclusion regarding the exact role of infliximab in the increased postoperative infection rate due to the retrospective nature of the analyses and possible selection bias. Most likely, patients who require infliximab for treatment of their UC represent a sicker and thus higher-risk group of patients at the time of surgery. Further prospective studies need to be performed to clarify this important issue.

As previously discussed, pelvic sepsis and abscess are devastating postoperative complications and are the leading risk factor for ileal pouch loss.⁵² Given the uncertainty about the role of biologic therapy contributing to this problem or the possibility of much sicker patients presenting for surgery, a three-stage approach in patients who have received preoperative infliximab may be considered.

ABDOMINAL COLECTOMY AND ILEORECTAL ANASTOMOSIS

The aim of a colectomy with an ileorectal anastomosis (IRA) is to extirpate most of the diseased colonic mucosa, thus reducing the risks of hemorrhage, megacolon and its complications, and malignant degeneration, while allowing the rectum to retain continence for stool and gas. The rationale for an IRA is that the operation avoids a permanent stoma, minimizes or eliminates injury to the pelvic nerves, and is easy to perform. Other operations, if they become necessary, are not precluded.¹¹⁰^–¹¹³ The rationale against the operation, however, is nearly as convincing. Subsequent proctectomy is required in 6% to 37% of patients, poor results have been reported in up to 50%, and the risk of developing carcinoma in the retained rectum approaches 17% after 27 years.^113,¹¹⁴

In a study by Pastore and colleagues, who reviewed the course of 48 patients with UC and 42 patients with Crohn’s disease who underwent an IRA, 84% of the UC and 91% of the Crohn’s disease patients reported an improvement in their quality of life.¹¹⁵ One patient with UC developed carcinoma of the rectal stump 11.5 years after the colectomy and IRA (cumulative probability of remaining free of cancer, 85.7% at 12 years).

In patients with Crohn’s disease and minimal or no rectal involvement, IRA with excision of the diseased colon is an appropriate operation. In addition, IRA, as a sphincter-saving procedure, continues to have a place in the surgical treatment of UC for high-risk or older patients who are not good candidates for IPAA and have relatively mild disease. It is also important that these patients understand the need for continued screening of the rectum because of possible development of a malignancy. The quality of life after IRA has been reported to be good; patient satisfaction is high, and an active, productive lifestyle can be preserved.^115,¹¹⁶

PATIENT SELECTION

Patients are candidates for IRA if the rectum is distensible, if the disease (UC, Crohn’s) involves the rectum only minimally, and if patients are willing to undergo follow-up screening for rectal cancer. Patients of any body habitus may undergo IRA. Although there is no maximum age that contraindicates an ileorectostomy, functional results related to poor sphincter function must be considered in older patients, especially in older female patients.

COMPLICATIONS

Operative mortality for elective IRA has been reported to vary between 2% and 8%.^116,¹¹⁷ In the series of UC patients reported by Leijonmarck and colleagues, complications occurred in seven of 43 patients (16%) undergoing an elective, one-stage procedure.¹¹⁶ There were two postoperative deaths (4%). Twenty-two patients (43%) had a functioning IRA at the time of follow-up, with a mean time of observation of 13 years. The cumulative probability of having the IRA in function at 10 years was 51%. The causes of total excision were recurrent inflammation in the retained rectum (N = 23), dysplasia (N = 3), and postoperative complications (N = 3). No rectal carcinoma occurred.