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Use of the stomach as an esophageal substitute

Benjamin knight

PRINCIPLES AND JUSTIFICATION

The colon as a viable conduit after esophageal resection hasbeen used for over a hundred years and was first described separately by Kelling and Vulliet. Its use gained favor over the next 30 years or so as a durable well-functioning substitute for the esophagus in benign and malignant disease. However, the stomach has become the favored conduit for most surgeons due to perceived lower rates of anastomotic complications and the technical ease of the operation.

The colon was routinely used to bypass the esophagus for palliation, but the advent of self-expanding metal stents means that this is rarely performed nowadays. As such, experience in colonic interposition has dwindled. Even so, the colon is considered a suitable replacement when the stomach is unusable as a conduit or has failed. With meticulous attention to detail, good long-term results using the colon as a conduit can be achieved with low mortality and morbidity and it should at least be considered as the primary conduit in the young and those with benign disease. Some believe the colon to be the conduit of choice in patients with benign esophageal disease and a long life expectancy.

Quality of life after esophagectomy is of paramount importance and is often overlooked, especially in the setting of malignant disease. Patients enjoy eating and want to do it without symptoms of fullness, pain, reflux, regurgitation, or aspiration. Therefore, the conduit must function well and have the capability of propelling food from the pharynx to the stomach. The colon is suited for this and, in experienced hands, colonic interposition has low rates of anastomotic complications and good long-term quality of life.

INDICATIONS

There are few absolute indications to use the colon as an esophageal substitute. If the stomach is unavailable due to previous surgery or a jejunal graft too short to bridge the gap, then perhaps the colon is the only option. Situations in which the colon might be used include: surgeon preference and expertise (rare today); restoration of gastrointestinal continuity after gastroesophageal resection for a long tumor extended well beyond the cardia; when it is deemed that the conduit must last over 10 years or so; when only the substernal route is available for reconnection—previous lung disease or thoracic sepsis may make the posterior mediastinal route impossible; and following vagal-sparing esophagectomy. Vagal-sparing esophagectomy is rarely performed these days and is reserved for benign disease. Functional results with a colonic interposition in this setting are very good, as the stomach and duodenum remain innervated.

CONTRAINDICATIONS

Severe intrinsic disease of the colon will preclude its use. Absolute contraindications include colorectal malignancy, polyposis coli, inflammatory bowel disease, severe diverticular disease, and inadequate blood supply due to atherosclerotic disease. The colon can still safely be used in mild diverticular disease with the right colon being used as opposed to the left. Scattered colonic polyps do not prohibit the colon as a graft, as these can be removed safely at colonoscopy prior to interposition. Patient factors such as extremes of age and cardiorespiratory fitness are relative contraindications. Often in these patients, the extra rigors of colonic dissection and interposition do not outweigh the benefit of needing a conduit to last more than a decade or so.

EMERGENCY VS. ELECTIVE

Colonic interposition requires meticulous surgical technique and is demanding on both the patient and surgeon. An experienced theater and anesthetic team is crucial, all of whom should be well briefed prior to surgery. There are times when an “unplanned” colonic interposition may be considered. This can occur if the gastric conduit has been deemed unsuitable intraoperatively—perhaps due to a damaged arcade, or tumor burden, or after gastric conduit necrosis. While feasible, we do not recommend an emergency colonic interposition. In this situation, it is far safer to deal with the immediate issue, and create a de-functioning esophagostomy in the left cervical region and place a feeding jejunostomy. In this way, the colon can be prepped prior to its use and the correct resources mobilized for a planned staged procedure.

ADVANTAGES OF THE COLON AS A CONDUIT

Increased incidence of duodenogastric reflux is common when transposing the stomach into the thoracic cavity. Excessive reflux and regurgitation lead to heartburn symptoms, dental decay, and silent aspiration, as well as the development of esophagitis and Barrett’s esophagus. Acid exposure at the anastomosis may also lead to stricture formation and dysphagia. As a consequence, studies have shown a significantly lower incidence of stricture formation when the colon is used compared with when the stomach is used. Patients also experience postprandial fullness and bloating with a gastric pull-up and this is probably due to the impaired reservoir function of the stomach. In colonic interposition, the remnant stomach remains in the abdomen and functions as an additional reservoir for gastric and biliary secretions. Not surprisingly, studies have shown better weight gain as a consequence of improved satisfaction and pleasure when eating 15 months postinterposition.

PATIENT PREPARATION

All patients should undergo endoscopic assessment of the colon prior to using the colon as a conduit to rule out occult malignancy, diverticular disease, colitis, or polyposis coli. Any scattered polyps can be excised and sent for histology and any worrying areas tattooed for future reference.

Mesenteric angiograms were used routinely to assess anatomical variations in blood supply and to identify atherosclerotic lesions, which might impede blood flow to the conduit. However, the invasive nature of angiography and its ability to predict clinical outcome has been called into question recently. In an angiographic series, McDermott et al. showed that only 65% of patients met angiographic criteria for colonic interposition. Despite this, there was no significant difference in ischemic complications and leak rate between those who underwent angiography and those who did not. As such, many centers have stopped routinely using angiography. High resolution computed tomography (CT) with arterial phase contrast is noninvasive and easy to perform and has superseded routine angiography.

Colonic blood supply is highly variable, with classic branches of the superior mesenteric artery only present 70% of the time. Attention should be given to the middle colic artery and the marginal artery arcade at the splenic flexure. Both of these areas have variable anatomy and the latter arcade is absent in 5% of patients. Multiple middle colic arteries make for a tenuous distal graft and difficult dissection. Similarly, an absent middle colic artery or middle colic artery originating from the coeliac trunk makes for dubious blood supply to the distal end of the graft and often precludes using the colon. Interruption of the marginal arcade at the splenic flexure is well reported on angiographic series, but, in practice, it rarely appears to be of clinical importance.

Cardiopulmonary fitness is assessed with lung function tests and echocardiogram or cardiopulmonary exercise testing. Smoking cessation is imperative and a planned, structured preoperative exercise program is desirable.

Prior to surgery, patients are fasted from solid food from 14:00 hours the day before surgery and given an osmotic electrolyte bowel preparation (ColonLYTELY or equivalent). Low molecular weight heparin is prescribed for the day of surgery. Intraoperatively, we use an enhanced recovery-based protocol with goal-directed fluid therapy, prophylactic antibiotics 6 hourly that continue for 3 days postoperatively, and pneumatic calf compression devices. Patients are prescribed a clear carbohydrate drink the night before and 2 hours prior to surgery to help prevent insulin resistance.

SURGICAL TECHNIQUE

The choice of colonic segment to be used is based on surgeon preference and experience, adequate vascular supply of the segment to be used, and any intrinsic colonic factors, which favor one segment over another. Of these, surgeon experience of one particular technique is probably of most importance.

There is no level-one evidence that favors the right, left, or transverse colon for interposition and data published are based mostly on personal series. For instance, in a combined analysis of results, a more reliable vascular supply of the inferior mesenteric artery has been shown with subsequent lower leak rates using the left colon (4.6% vs. 10.8%). However, similar leak rates and ischemic complications have also been reported whichever segment of colon is used. Whichever segment is chosen, it should be placed in an isoperistaltic fashion, as this allows a better functional outcome and lower rates of aspiration.

LEFT COLON

Standard esophageal mobilization is first performed either open (see Chapter 32, “Abdominal and right thoracic esophagectomy”) or thoracoscopically (see Chapter 35, “Thoracoscopic and laparoscopic esophagectomy”).

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