Figure 2.25. Delayed emptying of gastric pull-through. Upright chest film (A) reveals an air-fluid level above the right hemidiaphragm in a patient with a previous gastric pull-through. This represents delayed gastric emptying, presumably at the level of the pylorus. Upright film of the pyloric region (B) shows delayed emptying through a narrowed pylorus, located just at the level of the diaphragm.

patient in the upright position (Fig. 2.25B). Postoperative pyloric stenosis can readily be treated by dilatation [67].

Reflux into the esophageal remnant may be secondary to gastric atony and/or loss of the lower esophageal sphincter [71]. Duo-denogastric bile reflux into the interposed stomach may lead to the development of adenocarcinoma in that organ [93]. Barrett's esophagus with ulceration may also be seen. In at least one patient, this led to an esophagopericardial fistula with severe mediastinitis [94]. Reflux may also affect the colon when that organ is used as an esophageal substitute (see later).

The problems following colonic interposition are similar to those encountered with gastric pull-through procedures. Because the gastric antrum is preserved and maintained in its normal position, its contractions three times per minute aid in prompt emptying of the colonic reservoir [58]. The subdiaphragmatic portion of interposed colon is partially compressed by the relatively high (vs the chest) intraabdominal pressure (Fig. 2.26). This leads to a decreased rate of duo-denogastroesophageal reflux and subsequent decreased rates of esophagitis; also possible are stenoses or even Barrett's esophagus [58].

A finding similar to that seen in gastric pull-through is that of a pseu-dodiverticulum at the proximal esophagocolonic anastomosis secondary to an end-to-side technique (Fig. 2.27). The latter is employed because of a mismatch in size between the esophageal remnant and the interposed colon [95].

The colon often develops a peculiar mucosal pattern with redundant folds during the postoperative period. This can be seen in 20 to 50% of

Figure 2.26. Cologastric anastomosis following colonic interposition. Lateral film from an upper GI series shows the collapsed intra-abdominal segment of colon anastomosed to the anterior wall of the colon. This type of anastomosis is used in retro- or substernal placement of the interposed colon.
Figure 2.27. Esophagocolic blind pouch. Oblique film from an upper GI series shows a dilated esophageal remnant and a large blind-ending pouch or pseu-dodiverticulum, resulting from an end- (esophagus) to-side (interposed colon) anastomosis.

patients and has variably been called esophagization or jejunization [60,65,96]. In the colon the folds become longitudinally aligned and are slightly thicker than those seen in the native esophagus. Visible in the proximal portion of the transplanted colon, these folds become more marked with time from the original surgery. Tuszewski concluded that such changes are an adaption of the colonic mucosa to its new function, that primarily of transport, and not storage and water resorption [96]. The changes have been ascribed to postoperative edema or to an adaptation of the colonic mucosa due to its new function [65,96].

In the early postoperative period, the abnormality most commonly encountered is anastomotic narrowing [60]. Such changes may occur either proximally or distally and most often are related to postproce-dure edema (Fig. 2.28). Anastomatic stricture is usually self-limited, but when persistent is remediable by dilatation. A transient nodular appearance to the perianastomotic site is also most likely secondary to edema [60]. Stasis within the interposed segment was also seen, although less frequently. Slightly more than half the patients with stasis had narrowing of the distal colonic esophageal anastomosis.

Figure 2.28. Esophagocolic stricture. Oblique film from an upper GI series shows marked smooth narrowing at an esophagocolic anastomosis. This is the typical appearance for a benign stricture.

Leaks from the anastomoses are five times more frequently encountered at the proximal esophageal colon anastomosis than the distal one [60]. Only half these leaks seal spontaneously. Perforations of the colon have also been reported, as well as other cases of ischemic necrosis [60]. Aspiration was noted during the acute postoperative phase in slightly less than 10% of patients. A rare case of obstruction of the interposed colon due to an intrathoracic axial volvulus has also been reported [60].

During the late phase, aspiration and anastomotic strictures were equally observed (~15% of patients) [60]. The strictures were evenly distributed between the proximal and distal esophageal colonic anastomoses [60]. Gastric stasis has also been observed, but not as frequently as aspiration or strictures. Gastrocolic and gastrocolo-esophageal reflux is observed in slightly less than 10% of patients. This reflux may lead to ulceration. In one case, the ulcer penetrated into the aorta, resulting in an aortocolonic fistula [97].

Colonic stasis is occasionally secondary to a long, redundant intraabdominal portion of the colon, which may be acutely angulated just proximal to the cologastric anastomosis [60,95]. Diverticular disease

Figure 2.29. Carcinoma that developed in interposed colon. Film from a barium study reveals a colonic interposition. Annular constricting lesion in the midportion of the interposed colon represents a carcinoma.

[98] has been known to develop in the interposed colonic segment, as well as adenocarcinoma (Fig. 2.29) [55,93,99-101].

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