The colon receives its blood supply from the superior mesenteric artery, inferior mesenteric artery, and internal iliac arteries (Fig. 85–2). The major arteries supplying the colon and rectum include the ileocolic, right colic, middle colic, left colic, sigmoid, superior hemorrhoidal, middle hemorrhoidal, and inferior hemorrhoidal arteries. These arteries anastomose one with the other to form the arc of Drummond and allow considerable leeway in mobilizing the colon. The middle colic artery arises from the first portion of the superior mesenteric artery and generally ascends the transverse mesocolon to the right of midline. The right colic artery usually arises just below the middle colic artery from the superior mesenteric artery and courses to the right colon. It may arise, however, from the ileocolic artery or directly from the middle colic artery. If it arises from the ileocolic artery, mobilization of the distal ascending colon is facilitated so that this portion of the colon can easily be brought into the deep pelvis. On occasion, however, it is necessary to sever the right colic artery at its origin to mobilize the distal portion of the ascending colon to the pelvis. This is particularly true if the right colic artery originates from the middle colic artery. The ileocolic artery is the terminal portion of the superior mesenteric artery and supplies the last 6 inches of ileum and ascending colon. The left colic artery arises from the inferior mesenteric artery, and then the inferior mesenteric artery gives off four to six sigmoid branches, the last of which becomes the superior hemorrhoidal artery. This anastomoses with the middle hemorrhoidal artery, a branch of the internal iliac artery, which in turn anastomoses with the inferior hemorrhoidal artery, the terminal branch of the internal pudendal artery. The middle sacral artery, which originates directly from the aorta, may supply the posterior aspect of the rectum.

Three weak points involving the vascular supply to the colon have been described. Sudeck’s critical point, which is located between the junction of the sigmoid and superior hemorrhoidal arteries, was thought to be a particularly tenuous anastomotic area such that if the colon were transected in this region, the anastomosis would heal with difficulty because the blood supply might be compromised. Similarly, the midpoints between the middle colic and right colic arteries and between the middle colic and left colic arteries also have somewhat tenuous anastomotic communications. Although anastomoses in these areas generally heal well, provided the principles of proper technique are adhered to, it is usually wise to select an area for the anastomosis to one side of these points.

The ascending colon is mobilized first by transecting the cecal and distal ileal fibrous attachments to the lateral abdominal wall and retroperitoneum described previously and then by detaching it from the lateral abdominal wall along the avascular line of Toldt. This is a bloodless plane, provided the colonic mesentery is not violated. The transverse colon is mobilized by dividing the gastrocolic omentum (along the avascular plane of its attachment to the colon), the hepatocolic ligament (which may have some small vessels coursing through it), and the phrenocolic ligament. The descending colon is mobilized, much like the right colon, by incising the avascular line of Toldt lateral to the colon. With these attachments taken down, there is considerable mobility of the colon. Further mobility is gained by isolating a pedicle of the intestinal segment on the basis of one of the major arterial vessels described earlier.

Selecting the Segment of Intestine

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The stomach, jejunum, ileum, and colon have unique properties, each of which has special advantages and disadvantages. The selection of the proper intestinal segment should be based on the patient’s condition, renal function, history of previous abdominal procedures, and type of diversion or substitution required. The stomach has been employed as a replacement for bladder, for augmentation cystoplasty, as a conduit, and for continent diversions (Bihrle et al, 1989; Abdel-Azim, 2003; DeFoor, 2003; Bissada, 2004). The advantage of the stomach over other intestinal segments for urinary intestinal diversion is that it is less permeable to urinary solutes, it has a net excretion of chloride and protons rather than a net absorption of them, and it produces less mucus. Urodynamically, it behaves like other intestinal segments. When it is used in urinary reconstruction, electrolyte imbalance rarely ensues in patients with normal renal function, although a hypochloremic metabolic alkalosis has been described. The incidence of bacteriuria has been reported to be as low as 25%, much less than the 60% to 80% incidence reported for ileal and colon segments. However, more recent data from our institution suggest that there is no difference in bacteriuria among any of the segments. The urine, which usually has a pH of 6 to 7, does not generally result in an increased incidence of peristomal skin problems. The authors have also noted that in bladder augmentation patients, there is little difference in urinary pH between gastric and ileal augmentations. Serum gastrin levels are generally normal or minimally elevated, depending on what portion of the stomach is used and how much (Leong, 1978; Adams et al, 1988). Although exclusion of the antrum from the gastrointestinal tract has not resulted in elevated serum gastrin levels and an ulcer diathesis clinically (Lim et al, 1983), antral exclusion experimentally results in elevated circulating gastrin levels, which may cause major intestinal ulcerative problems in the postoperative period (Tiffany et al, 1986).

Rarely, severe ulcerative complications have been reported in cases that have employed stomach for urinary reconstruction (Reinberg, 1992; Tainio, 2000). Long-term H2 or proton-pump inhibition should be considered for these patients. When the antral portion of stomach is employed, reconstitution is generally by a Billroth I anastomosis. Complications with Billroth I gastroduodenostomy are well documented. The antrum should not be employed if the fundus is available. Early complications of the use of portions of the stomach for reconstruction include gastric retention due to atony of the stomach or edema of the anastomosis; hemorrhage, most commonly originating from the anastomotic site; hiccups secondary to gastric distention; pancreatitis as a consequence of intraoperative injury; and duodenal leakage. Delayed complications include dumping syndrome, steatorrhea, small stomach syndrome, increased intestinal transit time, bilious vomiting, afferent loop syndrome, hypoproteinemia, and megaloblastic or iron deficiency anemia. Postoperative bowel obstruction occurs with an incidence of 10% (2 of 21 patients) (Leong, 1978). Gastroduodenal and gastroureteral leaks have also been reported, occasionally resulting in a fatal outcome (Leong, 1978).

The use of stomach for urinary intestinal diversion may be considered when the use of other intestinal segments in a patient with a decreased amount of intestine would result in serious nutritional problems. One advantage of using stomach segments in the patient with severe abdominal adhesions is that the area of the stomach is generally adhesion free and easily mobilized. Complications specific to the use of stomach include the hematuria-dysuria syndrome and severe metabolic alkalosis associated with respiratory distress in some patients (see “Metabolic Complications” later).

The jejunum is usually not employed for reconstruction of the urinary system because it may result in severe electrolyte imbalance. In general, diseases that would make the ileum inappropriate for use also make the jejunum inappropriate for use. Rarely, it is the only segment available. Under these circumstances, as distal a segment of jejunum as possible should be employed to minimize the electrolyte problems.

The ileum and colon are used most often for urinary tract reconstruction and have been employed in all types of reconstructive procedures. The ileum is mobile and of small diameter, has a constant blood supply, and serves well for ureteral replacement and the formation of conduits. Loss of significant portions of the ileum results in nutritional problems because of lack of vitamin B₁₂ absorption, diarrhea because of lack of bile salt reabsorption, and fat malabsorption. On occasion, the mesenteric fat is excessive, making mobility and anastomosis difficult. Also, the mesentery may be so short that it is difficult to mobilize the ileum into the deep pelvis. Postoperative bowel obstruction occurs in up to 10% of patients who have segments isolated from the ileum for urinary tract reconstruction (Varkarakis, 2006). As many as half of the obstructions occur in the early postoperative period (Schwarz and Jeffs, 1975).

The colon requires mobilization from its fixed positions to give it the mobility necessary for use in urinary reconstruction. It has a larger diameter than the ileum and is usually easily mobilized into any area of the abdomen or pelvis. In patients who have received pelvic irradiation, portions of the right, transverse, and descending colon may be used confidently with the knowledge that they have not been exposed to the radiation therapy. Removal of segments of colon from the enteric tract results in fewer nutritional problems than does removal of segments of ileum, provided the ileocecal valve is not violated. Should the ileocecal valve be used, diarrhea, excessive bacterial colonization of the ileum with malabsorption, and fluid and bicarbonate loss may occur. The incidence of postoperative bowel obstruction with colon is 4%, less than that occurring with ileum. Both ileal and colon segments result in the same type of electrolyte imbalance with similar frequencies. An antireflux ureterointestinal anastomosis by the submucosal tunnel technique is easier to perform with use of the colon. In general, ileum and colon are comparable and have few differences, which does not argue strongly for the selection of one over the other except under special circumstances.

Bowel Preparation

It has been a long-held tenet of elective intestinal surgery that bowel preparation is appropriate. The bacterial population in the stomach is relatively low, but in the remaining segments of the bowel including the jejunum, ileum, and colon, there are high bacterial counts. Early studies had suggested that bowel anastomoses in the patients whose intestinal tract had not been prepared before surgery had increased wound infection rates, increased intraperitoneal abscesses, and an anastomotic dehiscence rate greater than in those patients who have had proper bowel preparation before surgery (Irvin and Goligher, 1973; Dion et al, 1980). Other studies showed that mechanical preparation resulted in collapsed bowel at the time of surgery, which was shown to reduce the incidence of anastomotic leaks (Christensen and Kronborg, 1981). Studies have recently begun to question the widely held belief that bowel preparation is mandatory. In meta-analyses of randomized clinical trials of anastomotic leakage during colon and rectal surgery, researchers found that there was no support for the conclusion that bowel preparation reduces anastomotic leak rates and other complications (Guenaga et al, 2003; Slim, 2009). There are suggestions that mechanical bowel preparation may actually increase the rate of anastomotic leakage and wound complications (Guenaga et al, 2005).

In experimental animals, it has been shown that an anastomosis with vascular compromise at the anastomotic line, which would normally result in perforation, heals if the bowel has been properly prepared with antibiotics. Also, solid feces may place strain on the anastomosis in the early phase of healing and result in ischemia with subsequent perforation. Complications that result from bacterial contamination are a major cause of morbidity and mortality in patients undergoing urologic procedures. Infectious complications after radical cystectomy that are a direct result of fecal contamination may occur in 18% to 20% of patients who undergo radical cystectomy and include wound infections, peritonitis, intra-abdominal abscesses, wound dehiscence, anastomotic dehiscence, and systemic sepsis (Bracken et al, 1981). More recent series suggest that current management practices appear to have made a substantial improvement with perioperative infectious complications of 7% (Stein et al, 2004). In another contemporary series of radical cystectomy with continent or ileal loop urinary diversion in 167 patients, there was an infection complication rate of 7.2% (Mansson et al, 2003). A 5.2% rate of infectious complications was reported in another contemporary series (Cookson et al, 2003).

There are two aspects to bowel preparation, mechanical and antibiotic. Both methods attempt to reduce the complication rate from intestinal surgery. The mechanical preparation reduces the amount of feces, whereas the antibiotic preparation reduces the bacterial count. The bacterial flora in the bowel consists of aerobic organisms, the most common of which are Escherichia coli and Enterococcus faecalis, and anaerobic organisms, the most common of which are Bacteroides species and Clostridium species. The bacterial concentration ranges from 10 to 10⁵ organisms per gram of fecal content in the jejunum, 10⁵ to 10⁷ in the distal ileum, 10⁶ to 10⁸ in the ascending colon, and 10¹⁰ to 10¹² in the descending colon.

Mechanical Bowel Preparation

A mechanical bowel preparation reduces the total number of bacteria but not their concentration. Thus the same number of organisms is present per gram of fecal content (Nichols et al, 1972). Therefore spilling enteric contents during the procedure may be less likely with the mechanically prepared bowel because there is less of it to spill; however, once spilled, cubic centimeter for cubic centimeter, the inoculum is the same as if the bowel had not been prepared. Recent analysis has suggested, however, that there may in fact be an increase in bacterial contamination in patients who have undergone bowel preparation (Fa-Si-Oen et al, 2005).

Conventional bowel preparations commonly used in the past tended to exhaust the patient and exacerbate nutritional depletion because they generally required a 3-day preparation period of insufficient calorie intake (Table 85–1). The use of elemental diets has been advocated to clean the colon of feces while not compromising the nutritional status of the patient. Unfortunately, they have not proved useful because the elemental diets do not empty the colon of feces, and they do not reduce the bacterial flora (Arabi et al, 1978). In an attempt to reduce the time required for intestinal preparation and to obviate low-calorie intakes, whole-gut irrigation has been used. Originally, whole-gut irrigation was performed by placement of a nasogastric tube (NGT) into the stomach and infusion of 9 to 12 L of lactated Ringer solution or normal saline during a several-hour period. These fluids were subsequently replaced with 10% mannitol, which was equally successful in ridding the bowel of its fecal content; however, the mannitol served as a bacterial nutrient and thereby facilitated microbial growth (Hares and Alexander-Williams, 1982). These solutions have largely been replaced by a polyethylene glycol–electrolyte solution. Whole-gut irrigation may be exhausting to the patient and may, in fact, result in a fluid gain, particularly when either saline or mannitol is used. Whole-gut irrigation is contraindicated in patients with an unstable cardiovascular system, patients with cirrhosis, patients with severe renal disease, patients with congestive heart failure, or those with an obstructed bowel. Whole-gut irrigation has been found to be no more effective than conventional preparations in reducing wound infections and septic complications (Christensen and Kronborg, 1981), even though there is a reduction of aerobic flora compared with the conventional preparations (van den Bogaard et al, 1981). The advantages of the whole-gut irrigation are that it gives the patient dietary freedom, there is a short preparation time, and it eliminates the enema. Its disadvantages are that it may result in the patient’s exhaustion, it is rather rigorous, and it does result on occasion in fluid overload.

Table 85–1 Mechanical Bowel Preparation

The polyethylene glycol–electrolyte lavage solution (GoLYTELY or the more palatable NuLYTELY) is an effective lavage agent in preparing the gut for elective colon and rectal surgery, as well as for urologic surgery in which bowel is used. For the adult, 20 to 30 mL/min or approximately 1 to 1.5 L/hr for 3 hours is given either orally or through a small-caliber NGT placed into the stomach. If it is taken by mouth, it is better tolerated if the solution is chilled. The administration of GoLYTELY is stopped when the rectal effluent is clear and there is no particulate matter in it or when 4 L of fluid has been given. This preparation in the adult has been as effective as conventional preparations. The septic complications with its use are approximately 4%. An inadequate preparation occurs in 5% of the patients using this modality (Wolff et al, 1988). For children, even those younger than 1 year, GoLYTELY may be used at a rate of 20 to 40 mL/kg/hour and given until the rectal effluent is clear and free of particulate matter (Tuggle et al, 1987). Metoclopramide (Reglan), 10 mg, in adults is often given simultaneously to control nausea.

Bowel preparation can increase metabolic complications and cause electrolyte disturbances, which could affect surgical care. Caution must be exercised in elderly and debilitated patients receiving sodium phosphate preparation; the sodium phosphate preparation has been shown to cause significant derangements in potassium, calcium, and phosphorus levels in frail individuals (Beloosesky et al, 2003). Phosphate nephropathy has recently been recognized as a serious complication of oral sodium phosphate (OSP) bowel preparation (Markowitz, 2005). Caution should be used in prescribing OSP to patients with underlying renal insufficiency or treated with nephrotoxic medications. The only study in postsurgical complications comparing sodium phosphate with polyethylene glycol found no significant difference in complication rates (Oliveira et al, 1997). One study suggested that polyethylene glycol is better tolerated by elderly patients and causes less disruption in potassium and sodium levels (Seinela et al, 2003). Oral electrolyte solution rehydration may prevent some of the complications of bowel preparation (Tjandra and Tagkalidis, 2004).

A number of studies have questioned the efficacy of mechanical bowel preparation. Some have suggested that a limited mechanical bowel preparation is all that is necessary; others have questioned even the need for a mechanical bowel preparation. In one study, 2 L of polyethylene glycol plus metoclopramide was compared with the administration of 4 L of polyethylene glycol solution. There was no difference in surgical complication rate or the extent to which the bowel was clean (Grundel et al, 1997). In another study, when 4 L of polyethylene glycol was compared with 90 mL of sodium phosphate, there was no significant difference in surgical complication rate (Oliveira et al, 1997). Two meta-analyses have found that there is an increased anastomotic dehiscence rate with preoperative mechanical bowel preparation (Wille-Jorgensen et al, 2003; Bucher et al, 2005). Polyethylene glycol may be the agent responsible for the increased rate of complications, but other preparation strategies have not been adequately analyzed (Slim et al, 2004). A recent meta-analysis of randomized trials comparing mechanical bowel prep to no bowel prep before elective colorectal surgery found no difference between the groups for anastomotic leakage, abdominal abscess, or wound sepsis (Slim, 2009). No study has adequately addressed the issue of the need for debulking of the intestine before laparoscopic approaches to intestinal surgery. It is extremely important to note that in these studies, the administration of intravenous antibiotics was crucial in keeping the complication rate low. Moreover, it is important to note that in these studies there was limited exposure of the intestine as the patients underwent elective bowel resections, unlike urologic procedures in which long segments of the intestine are opened or interposed in a urinary tract that is normally free of fecal contents.

Antibiotic Bowel Preparation

There has been considerable recent controversy as to whether the addition of antibiotics in elective colon and small bowel surgery reduces mortality and morbidity significantly. The long-held practice of mechanical and oral antibiotic bowel preparation dates to the 1970s. In one study, the septic complication rate was reduced from 68% in the control group to 8% in the antibiotic group (Washington et al, 1974). Most series, however, report a lesser incidence of reduction in wound infection, generally from 35% without antibiotics to 9% with their use (Clarke et al, 1977). Others have suggested that the mortality rate drops from 9% to 3% with the use of antibiotics (Baum et al, 1981). It is clear that the use of antibiotics protects vulnerable bowel in that it may allow the tenuous anastomosis to survive. Other studies, however, have shown that without the use of oral antibiotics in mechanically prepared bowel in elective surgery, the septic complication rate is comparable with those studies using antibiotics and the rate of Clostridium difficile colitis was lower without oral antibiotics (Wren, 2005). In the presence of a bowel obstruction, however, oral antibiotics are of little value because they do little good in sterilizing the bowel. The disadvantages of antibiotics include postoperative increase in the incidence of diarrhea; pseudomembranous enterocolitis; theoretical increased incidence of tumor implantation at the suture line that is not germane to urologic surgery; monilial overgrowth resulting in stomatitis, thrush, and diarrhea; and, with prolonged use, malabsorption of protein, carbohydrate, and fat. The antibiotics most commonly used for bowel preparation include kanamycin, which is the best single agent; neomycin and erythromycin base; and neomycin and metronidazole (Table 85–2). With an appropriate antibiotic preparation, enteric organisms are reduced to 10² per gram of feces (Nichols et al, 1972). A contemporary randomized trial of patients undergoing elective colonic surgery found the lowest fecal bacterial concentrations when patients had preoperative mechanical bowel preparation, oral neomycin, and supplemental “synbiotic” treatment (to provide benign flora to the intestine). No difference in clinical infections was seen between patients prepared with or without oral antibiotic bowel preparation (Reddy, 2007).

Table 85–2 Antibiotic Bowel Preparation

Perioperative intravenous antibiotics appear to be the most important means of preventing infectious complications of intestinal surgery. Systemic antibiotics must be given before the operative event if they are to be effective. Ideally, antibiotics should be given between 1 and 2 hours before the start of surgery (Classen et al, 1992). They appear to be most effective against the anaerobic flora and apparently reduce the complications caused by these organisms (Dion et al, 1980). Perioperative systemic antibiotics, when added to the oral regimen, reduced the septic complication rate from 15% to 20% to half that rate in several series (Hares and Alexander-Williams, 1982; Gottrup et al, 1985). Other studies, however, have shown no effect of systemic cephalosporin, for example, in reducing septic complications (Wolff et al, 1988). If perioperative antibiotics are given, they should be effective against anaerobes because it is complications from these organisms against which perioperative antibiotics appear to be particularly effective. Third-generation cephalosporins have been advocated as an appropriate systemic antibiotic. Other recent studies support the use of both oral and systemic antibiotic prophylaxis before intestinal surgery (Lewis, 2002). It is clear that preoperative antibiotics reduce postoperative complications. Most agree that preoperative intravenous antibiotics are important, and many advocate discontinuing the use of oral antibiotics as the incidence of C. difficile diarrhea is increased and there appears to be no advantage provided preoperative intravenous antibiotics are given within an hour of the operative event (Wren et al, 2005).

It is the authors’ preference not to perform a vigorous mechanical bowel preparation allowing the patient a normal diet until one day preoperatively, at which time a clear liquid diet is begun and citrate of magnesia is taken as a cathartic. No oral antibiotic bowel preparation is performed; however, the patient is given intravenous antibiotics 1 hour before the incision.

Diarrhea and Pseudomembranous Enterocolitis

Antibiotic bowel preparations may result in diarrhea and pseudomembranous enterocolitis. Pseudomembranous enterocolitis is the more severe form of a spectrum of diarrhea. Clinically, this occurs after a bowel preparation in the postoperative period and is heralded by abdominal pain and diarrhea usually in the absence of fever or chills. As the symptoms and infection become more severe, systemic toxicity supervenes. These patients can develop a toxic megacolon, and if this occurs, the mortality may exceed 15% to 20%. Historically, pseudomembranous enterocolitis was thought to be due to staphylococcus, but there was, in fact, little evidence to support that organism as the etiologic agent. It is now clear that C. difficile plays a significant role in the majority of cases. C. difficile elaborates at least two toxins that cause diarrhea and enterocolitis. C. difficile does not invade the bowel, and it is not normally a significant inhabitant of the fecal flora. It is held in check by other bacteria that inhibit its growth. Thus antibiotics destroy the bacteria that inhibit the growth of C. difficile and thereby allow it to flourish. The toxin produces a diffuse inflammatory response with cream-colored plaque formation, erythema, and edema of the bowel wall. On microscopic examination, the villi appear to be intact and there is a polymorphonuclear leukocyte infiltrate of the submucosa (Bartlett, 2002).

As the disease progresses, large areas of mucosa may slough and areas of the bowel are denuded of their mucosa. The lesions may involve the colon, in which case it is called pseudomembranous enterocolitis, or the small bowel, in which case it is called pseudomembranous enteritis, or they may involve both. The diagnosis is suspected by the symptoms or endoscopy and confirmed by culture of the organism or identification of its toxin. Because culture takes a prolonged time, it is more expeditious and therefore clinically useful to confirm the diagnosis by identifying the toxin produced by C. difficile. Once the diagnosis has been made, treatment involves the administration of vancomycin or metronidazole and discontinuance of other antibiotics that the patient is receiving. Vancomycin or metronidazole is effective in most cases. Rarely, toxic megacolon supervenes, requiring subtotal colectomy as a lifesaving procedure (Chang, 1985).

Intestinal Anastomoses

Regardless of the type of anastomosis or the methods used to perform it, certain fundamental principles must be observed to minimize morbidity and mortality from intestinal surgery. In urologic procedures in which gut is used, the most common cause of mortality and morbidity within the immediate postoperative period relates to complications involving the bowel, either with the enteroenterostomy or with the segment interposed in the urinary tract. Therefore it cannot be overemphasized that great care must be taken and proper techniques used in handling bowel in urologic procedures. Unfortunately, the portion of the procedure that involves mobilization of the intestine and reanastomosis often follows a rather lengthy urologic endeavor and is performed when the surgical team is not fresh. Therefore the following principles should be so firmly ingrained in the surgeon that they are performed without the need to recall each one specifically.

The first principle of proper technique for intestinal anastomoses is adequate exposure. The intestine should be mobilized sufficiently so that the anastomosis may be performed without struggling for exposure. If possible, it is preferable to mobilize the intestine sufficiently so that the anastomosis can be performed on the anterior abdominal wall. The area of the anastomosis should be walled off from the rest of the abdominal cavity with Mikulicz pads. This is important so that any inadvertent enteric spills are not distributed throughout the abdominal cavity. The mesentery must be cleared from the bowel segments to be anastomosed for a suitable distance (usually 0.5 cm) from the intestinal clamps or staple line at the severed ends so that good serosal apposition may be achieved without interposed mesentery. Sufficient serosa must be exposed so that the seromuscular sutures or staples can be placed directly in the serosa without traversing the mesentery.

The second principle of performing a proper anastomosis is to maintain a good blood supply to the severed ends of the bowel. The blood supply may be compromised by construction of an anastomosis under tension, excessive dissection or mobilization of the bowel, excessive use of the electrocautery, and tying of the sutures so tight that the intervening tissue is strangulated. A cut margin of bowel that is pink and bleeds freely suggests that the blood supply has not been compromised; however, hemostasis must be ensured before beginning the anastomosis. The site of transection is selected at a point where the blood supply is adequate to both segments. The mesentery should be transilluminated so that the blood supply may be defined before transection of the bowel segment. In urologic surgery, the location of the transection is elective so that an area may be selected in which excellent arcades supply both sections of the transected segment. The area must be selected with an eye to how deep the mesenteric transection must be for proper segment mobility. After location of the appropriate area where the mesentery is to be transected, it is cleaned from the serosa, severed between mosquito clamps, and tied with 4-0 silk sutures. Alternatively, the mesentery may be transected with the LDS staple device (Covidien Surgical, Mansfield, MA), a bipolar cautery device, or ultrasonic shears.

The third principle involves prevention of local spillage of enteric contents. The best way of preventing spills is to operate on bowel properly prepared (i.e., devoid of feces and collapsed). Stripping of the enteric contents between the fingers both cephalad and caudad from the proposed transection site and application of a noncrushing occlusive clamp across the bowel make a spill even less likely. The clamp should prevent enteric contents from exiting the cut ends of the bowel without interference with the mesenteric blood supply. After linen-shod clamps are applied and the area is walled off, Allen clamps are applied to the bowel and the bowel is transected between the Allen clamps. An anastomotic staple device may be used to transect the bowel at this point in place of Allen clamps (see later). Local spills and local sepsis have an adverse effect on the healing anastomosis, and it is for this reason that noncrushing occlusion clamps, in addition to an adequate bowel preparation, are advisable. If a spill does occur, it should be caught in the Mikulicz pads if the bowel has been properly walled off as described previously. The isolated segment that is to be used in the reconstructive procedure should be irrigated thoroughly with copious amounts of normal saline. The segment should be walled off. The irrigant is placed in one end of the segment and caught in a kidney basin as it exits the other end. This should be continued until the efflux is clear. This procedure prevents local spills during the ureterointestinal anastomosis and other aspects of reconstruction.

The fourth principle, germane to all intestinal anastomoses, is that there should be an accurate apposition of serosa to serosa of the two segments of bowel to be anastomosed. The anastomosis should be watertight and performed without tension. The bowel must be handled gently with the use of noncrushing forceps. The anastomotic line should be inverted and not everted. There is considerable controversy about this issue in that an everted anastomosis has been shown to heal with few complications. It is clear that when marginal conditions occur, an inverted anastomosis is more likely to remain intact than is the everted anastomosis.

The fifth principle is not to tie the sutures so tight that the tissue is strangulated. Obviously, the sutures must bring the serosa of the two segments firmly together. Nonabsorbable sutures used for the anastomosis result in a stronger anastomotic line in the early healing phase compared with absorbable sutures, but the difference is minimal and probably not particularly significant.

The final principle involves realignment of the mesentery of the two segments of bowel to be joined. These should be parallel to each other and ensure that there is no twist on completion of the anastomosis.

Factors that significantly contribute to anastomotic breakdown include poor blood supply, local sepsis induced by fecal spillage, drains placed on an intra-abdominal anastomosis, and anastomosis performed in irradiated bowel. Poor blood supply and local sepsis cause ischemia. Drains placed on the anastomosis increase the likelihood of an anastomotic leak, and an anastomosis performed in irradiated bowel is more likely to result in an anastomotic failure than one performed in nonirradiated tissue. The importance of careful technique and adherence to these principles is emphasized by the fact that in one series of urinary intestinal diversion, 75% of the lethal complications that occurred in the postoperative period were related to the bowel. Eighty percent of these patients had received radiation before the intestinal surgery (Mansson et al, 1979).

Types of Anastomoses

Intestinal anastomoses may be performed with use of sutures or staples. Properly performed, both have similar complication rates (Catena, 2004). In selected circumstances, however, one method may have advantages over the other. Because there is a high rate of stones that form on surgical staples (Woodhouse, 2004), absorbable suture should be used for intestinal segments that are exposed to urine (e.g., suturing intestine to renal pelvis or bladder, closing the proximal end of a conduit [Costello and Johnson, 1984], and forming an intestinal pouch for urine).

Enteroenterostomy by a Two-Layer Suture Anastomosis

A 3-0 silk holding suture is placed on the mesenteric border just beneath the Allen clamps traversing both segments to be anastomosed, and a second suture is placed on the antimesenteric border similarly just beneath the Allen clamps (Fig. 85–3). It is important that the mesentery is cleaned sufficiently so that these sutures are placed in the serosa under direct vision. A row of silk sutures is placed 2 mm apart between the two holding sutures. This is accomplished by rotating the two Allen clamps away from each other, thus apposing the serosal surfaces. Sutures must traverse the muscularis but should not traverse the full thickness of the bowel. After all sutures have been placed, each is tied and the tails of all the sutures are cut, except those at each end; these are used as holding sutures. The Allen clamps are removed, and hemostasis is achieved, if necessary, with the light application of electrocautery. A 3-0 double-ended chromic intestinal suture is placed in the posterior suture line through all layers and tied to itself. Each end of the suture is then run in a locking fashion away from the midpoint until the mesenteric and antimesenteric borders are approached. As the lateral aspects of the bowel are approached, the suture is converted to a Connell suture (Fig. 85–4), which proceeds onto the anterior bowel wall. The sutures meet anteriorly in the midline and are tied together. The anterior serosa is then apposed with interrupted 3-0 silk sutures. The noncrushing occlusive clamps are removed, and the mesentery is closed with interrupted 3-0 silk sutures.

Figure 85–3 Two-layer suture anastomosis. A, Two holding sutures of 3-0 silk have been placed at the mesenteric and antimesenteric border, and the posterior wall is approximated with seromuscular sutures of 3-0 silk. B, A 3-0 intestinal chromic suture is placed through the full thickness of the bowel posteriorly, tied to itself, and run to the lateral borders with a continuous locking suture. At the lateral borders, it is converted to a Connell suture. C, The Connell suture brings the anterior margins together, inverting the suture line. The anastomosis is completed by placement of horizontal mattress seromuscular sutures of 3-0 silk over the anterior suture line (not depicted).

Figure 85–4 Connell suture. The suture traverses the bowel from serosa to mucosa and then from mucosa to serosa on the same side of the anastomosis. The suture is then placed on the opposite side of the anastomosis “outside in-inside out.” The sequence is repeated until the two segments are approximated.

Patency of the anastomosis is ensured by palpating the anastomosis with the thumb and forefinger and feeling an annulus of tissue around the fingers. This anastomotic technique is employed when the antrum pylorus is removed and intestinal continuity is restored by a Billroth I procedure. It is also the most secure of all the anastomoses and should be used when one is forced to do an anastomosis under less than ideal circumstances.

Enteroenterostomy by a Single-Layer Suture Anastomosis

The single-layer anastomosis for reapproximating bowel is an excellent technique with a low complication rate, that is, a 0.2% anastomotic leakage rate compared with an 8.4% anastomotic leakage rate for a stapled anastomosis in one large series (Leslie and Steele, 2003).

The mesenteries of the two segments of bowel to be anastomosed are aligned, and a 3-0 silk suture is passed through the seromuscular layers of both segments on the mesenteric side; a second suture is similarly placed on the antimesenteric side. The mesenteric suture is tied, and the antimesenteric suture is left untied. The Allen clamps are removed, and hemostasis is achieved with light electrocautery. The critical point of the anastomosis, where most leaks occur, is at the mesenteric border. Leaking generally occurs because the sutures are placed carelessly or the serosa has not been cleaned of mesentery sufficiently so that the sutures are placed through it under direct vision. Because this mesenteric border is the critical area, it is approached first. Two 3-0 silk sutures are placed through the full thickness of the bowel on either side of the mesenteric holding suture. These sutures are placed in such a way as to include more serosa than mucosa, thus causing inversion of the suture line (Fig. 85–5A). Some prefer to use a Gambee stitch at this point, which involves placing the suture through the full thickness of the bowel followed by traversing a small segment of mucosa of each segment of bowel before exiting through the full thickness of the bowel of the other segment (Fig. 85–5B). The two bowel sutures on the mesenteric border are tied, with care taken to invert the suture line, thus apposing serosa. Then 3-0 silk sutures are placed 2 mm apart, both on the anterior and posterior walls, inverting the suture line, thus apposing the serosa of the two bowel segments to each other. On approaching the antimesenteric holding suture, several sutures are placed before all are tied. A patent anastomosis is confirmed by feeling the annulus with the thumb and forefinger as described previously.

Figure 85–5 A, When it is properly placed, the suture through the intestine should include more serosa than mucosa. B, The Gambee stitch. The suture is placed through the full thickness of the bowel, the mucosa is traversed, and then the mirror image procedure is performed on the segment to be anastomosed.

End-to-Side Ileocolic Sutured Anastomosis

The transected end of the colon is closed in the following manner (Fig. 85–6). A 3-0 silk suture is placed beneath the Allen clamp on the mesenteric border, and a second suture is placed on the antimesenteric border. These are tied. A 3-0 chromic suture is placed beneath the clamp in a horizontal mattress fashion. Beginning at the mesenteric border, it is tied to itself and the horizontal mattress suture is placed until the antimesenteric border is reached, at which point the suture is again tied to itself. The clamp is removed, and an over-and-over suture is performed with the same chromic suture throughout the full thickness of the bowel until returning to the point of origin (i.e., the mesenteric border is approached). At this point, the suture is again tied to itself. The suture line is buried by approximating the serosa on each side with interrupted 3-0 silk sutures placed 2 mm apart. Our preference is to close the end of the colon similarly to the way one closes the proximal end of a conduit. After a 3-0 silk suture is placed through the serosa on the antimesenteric and mesenteric sides, the clamp is removed and a 3-0 chromic suture is placed through all layers at the mesenteric and antimesenteric end. A Connell suture is used—the two chromic sutures meet in the middle and are tied together. Seromuscular sutures of 3-0 silk are placed to appose the serosal margins.

Figure 85–6 Closure of the proximal end of the intestine. A, A 3-0 chromic suture is tied to itself at the antimesenteric border and placed beyond the intestinal clamp in a horizontal mattress fashion until the mesenteric border is reached. The suture is then tied to itself at this point. B, The intestinal clamp is removed, and an over-and-over suture through the full thickness of the bowel returns the chromic suture to its point of origin, where it is again tied to itself. C, Interrupted horizontal mattress seromuscular sutures of 3-0 silk invert the chromic suture line.

The mesenteries are aligned, and the ileal serosa is sutured with interrupted 3-0 silk sutures to the colonic serosa 2 mm below a taenia (Fig. 85–7). The taenia is incised the length of the diameter of the ileum adjacent to it. As described earlier for the two-layer anastomosis, a 3-0 double-ended intestinal chromic suture is placed through all layers of the colon and ileum in the midpoint of the posterior wall and run in a locking fashion laterally to either side of the incision in the taenia. At the most lateral border, the suture is converted to a Connell suture and the anterior wall is closed. Seromuscular sutures of 3-0 silk placed from ileum to colon bury the anterior suture line. The mesentery is reapproximated.

Figure 85–7 End-to-side anastomosis. A, The serosa of the ileum is sutured to the serosa of the colon 2 to 3 mm below a taenia. B, The taenia is opened for a distance sufficient to accommodate the diameter of the ileum. A 3-0 chromic suture is placed through all layers on the posterior wall, tied to itself, run in a locking fashion to both borders, and converted to a Connell suture laterally, thus completing the inversion anteriorly. C, The anterior margin of serosa is reapproximated with interrupted horizontal mattress sutures of 3-0 silk.

Ileocolonic End-to-End Sutured Anastomosis with Discrepant Bowel Sizes

A 3-0 silk suture is placed on the mesenteric border of the ileum and colon (Fig. 85–8). A second 3-0 silk suture is placed on the antimesenteric border of the colon immediately beneath the Allen clamp. The other end of the suture is placed on the antimesenteric border of the ileum at a distance proximal to the Allen clamp so that the serosal lengths between the two sutures of both ileal and colon segment are equal. Thus an equal amount of ileal serosa is applied to the length of colonic serosa bordering the severed end of bowel. In the seromuscular layers of ileum and colon, 3-0 silk sutures are placed 2 mm apart, thus apposing the serosa of the ileum to the colon. The Allen clamps are removed. Hemostasis is achieved, and the antimesenteric border of the ileum is incised to the level of the most proximal suture in the ileum. Thus the bowel lumens are now of identical size. With a 3-0 chromic double-ended intestinal suture, the posterior row is run in a locking fashion, laterally converting to a Connell suture, and the anterior row is completed. Seromuscular sutures of 3-0 silk bury the anterior suture line.