Esophageal Replacement

Patients with either benign or malignant disease are often treated by esophageal resection. Reestablishment of the continuity of the gastrointestinal tract must then be performed. This can be done by a variety of methods involving the stomach, jejunum, or colon.

The technique of "blind" or "blunt" esophagectomy was first performed by Denk in 1913, revised by Turner in 1931, and further updated by Orringer and Sloan in 1978 [55]. This technique, described in more detail shortly, allowed the surgeon, and the patient, to avoid an open thoracotomy. In addition, Orringer and Sloan placed the esophagogastric anastomosis in the neck. Ivor Lewis, in 1946, described the technique of transthoracic esophagectomy, followed by esopha-gogastrostomy via a right thoracotomy and laparotomy [55]. Among the many factors that determine the technique that will be used are the preference of the surgeon, the patient's general medical condition including prior surgical history, the location of the tumor, the choice and suitability for use of the esophageal substitute, and a history of prior radiation [55]. The two most important criteria in determining the actual surgery are the location of the tumor and the surgeon's preference.

Orringer and his colleagues popularized the transhiatal esophagec-tomy with an esophagogastric anastamosis in the neck [56]. This surgery avoids a thoracotomy and is usually performed for lesions in the lower third of the esophagus and/or the gastric cardia. An upper midline abdominal incision allows access to the stomach, which is then mobilized. The esophageal hiatus is opened. Some surgeons perform a pyloromyotomy to enhance emptying of the transposed stomach, once it is in the chest. After reaching into the mediastinum from below, the surgeon bluntly dissects the esophagus. A neck incision, usually on the left is then made, freeing up the esophagus, whereupon a short portion is delivered into the neck and out the incision. Care is taken to avoid injuring the left recurrent laryngeal nerve in the process. The remainder of the esophagus, including the tumor, is delivered through the esophageal hiatus into the abdomen. The stomach is then delivered through the mediastinal canal into the neck, where the primary anastomosis is performed. Besides avoiding a thoracotomy, the major advantage of this technique is that the cervical location of the anastomosis avoids the possibility of mediastinal soilage and mediastinitis in the case of leakage.

The Ivor Lewis technique is radically different [57]. It is the most frequently used technique for managing carcinomas of the middle to distal third of the esophagus. Initially performed as a two-stage procedure, it is now performed via simultaneous right thoracotomy and laparotomy. The abdomen is opened first, and in the absence of gross metastatic disease, the stomach is mobilized. A pyloromyotomy, or preferentially, a pyloroplasty, is performed. The esophageal hiatus is widened to allow delivery of the stomach into the chest. Following collapse of the left lung, the chest is opened, the esophagus mobilized, and the tumor-containing portion resected. The stomach is delivered into the chest and the proximal portion resected with wide margins if possible. The lesser curvature is resected to help form a tubular stomach that is then anastomosed to the esophageal remnant. This anastomosis is always performed above the level of the azygos vein, to help achieve adequate tumor margins and to aid in the reduction of gastroesophageal reflux.

The choices for benign disease are greatly influenced by the period of time during which the conduit must function. Unlike esophageal carcinoma, where patient survival is measured in months, or a few years, many patients with benign disease face decades of life with an esophageal substitute. Therefore, the colon has been advocated as the conduit of choice. Although the gastric pull-through is technically easier, many patients suffer from symptoms related to duodenogastric reflux and rapid gastric emptying, especially in the upright position [58]. As opposed to the stomach, the colon functions as a reservoir for the retained gastric antrum. The distal stomach, which remains in its normal subdiaphragmatic location, aids in a more normal and physiological emptying pattern [58]. This subdiaphragmatic location avoids the pressure gradient encountered when the stomach is placed in the thoracic compartment, where the pressure is relatively lower. This pressure gradient contributes to the development of duodenogastric reflux. The intra-abdominal portion of the colon is relatively collapsed by the positive pressure of the abdomen, further decreasing the possibility of reflux of contents into the native esophagus. Therefore, the development of a Barrett's esophagus is much less likely in patients with a colonic bypass [59,60]. Few if any long-term histological changes are encountered in the colon that has been used as an esophageal replacement [61].

Preoperative evaluation of the colon is required. The presence of diverticula does not preclude the use of the left colon for the construction of a conduit. Frank diverticulitis with pericolonic inflammation does limit the ability to transpose the colon into the chest. Vascular anatomy of the colon is also important in assessing the viability of the segment that is to be relocated.

The colon may be placed in the posterior mediastinum (Fig. 2.16A,B), or substernally (Fig. 2.17). The former placement allows better emptying of the cervical esophagus [58]. However, when adhesions prevent freeing up of the esophagus, the substernal route provides a viable alternative route. This procedure may require resection of portions of the manubrium, clavicle, and first rib to enlarge the thoracic inlet and avoid unnecessary compression of the colonic graft. Some authors prefer this route [62]. If a colonic segment is used in cases of esophageal carcinoma, the substernal route may avoid the complication of medi-astinal recurrence involving the bypass graft [62]. However, higher rates of complications are associated with the substernal or even subcutaneous route. For examples, there may be anastomotic leaks and poorer function [63,64]. The former may be secondary to lack of adequate support from the surrounding structures.

Another decision to be made is whether the colonic graft should be iso- or antiperistaltic (i.e., utilizing the right or left colon, respectively).

Figure 2.16. Mediastinal colonic interposition. Posteroanterior (A) and lateral (B) films of the chest show a barium-filled colon interposed between the esophagus and stomach traversing the posterior mediastinum.

Figure 2.16. Mediastinal colonic interposition. Posteroanterior (A) and lateral (B) films of the chest show a barium-filled colon interposed between the esophagus and stomach traversing the posterior mediastinum.

Figure 2.17. Retrosternal colonic interposition. Lateral film of the chest reveals the retro- or substernal course of a colonic interposition.

This choice is usually predicated on vascular anatomy, but the isoperistaltic alternative is preferred. Antiperistaltically placed colons may actually transport a barium bolus in a retrograde manner, leading to choking and possible aspiration [58]. The left colon's thicker wall and closer approximation in diameter to the esophageal remnant are additional reasons for its preferential use [60].

In the immediate postoperative period, single-contrast barium is used. Double-contrast studies with their need for effervescent granules are to be avoided to prevent excessively rapid overdistention of the lumen. An upright, delayed film is used to assess intrathoracic emptying. If a leak is suspected, water-soluble contrast should be used initially, and then barium if no leak is identified. The patient should be in the right posterior position on the fluoroscopy table with reverse Trendelenberg table tilt to help prevent possible aspiration [65]. The examination should be extended to include the proximal small bowel, since many problems may be encountered distal to the esophagogastric anastomosis [5].

Esophagogastric anastomoses have an angular appearance because the type usually used is end (esophagus) to side (gastric pull-through) (Fig. 2.18). There may be slight narrowing at the level of the anasto-

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