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Use of the stomach as an esophageal substitute

Arnulf H. Holscher and J. Rudiger Siewert

HISTORY

The use of the stomach as an esophageal substitute was introduced by Kirschner in 1920 as a nonresectional operative bypass. His operation consisted of skeletonization of the greater curvature of the stomach, and the mobilized stomach was then brought subcutaneously up to the divided cervical esophagus. The application of this procedure using either the orthotopic or the retrosternal route after esophagectomy and the standardization of this method was largely due to the work of Ong, Nakayama, and Akiyama.

PRINCIPLES AND JUSTIFICATION

The reconstruction of intestinal transit after esophagectomy is normally made using stomach or colon. The small bowel is used much less frequently for complete substitution of the esophagus. Small bowel interposition does have a place, however, for partial esophageal replacement of both proximal and distal esophagus. Gastric interposition is the simplest form of esophageal replacement. Furthermore, as it guarantees good long-term functional results, it has become the method of first choice as an esophageal substitute, especially after esophagectomy for cancer. Only when the stomach is not available because of previous operations or in benign esophageal diseases iscolonic interposition used. An important question to be answered in planning an esophageal replacement is where to site the esophagoenteral anastomosis. If intrathoracic anastomoses are performed, they should be carried out near the apex of the pleura. Anastomotic leakage is less likely to occur with intrathoracic anastomosis than with cervical anastomosis, but the consequences of such a leak are much more serious. With regard to oncologic radicality (remaining esophagus) and long-term results, both types of anastomosis are similar.

Finally, the site for the esophageal substitute must be chosen. Antesternal subcutaneous placement is usually not indicated. This leaves the posterior and anterior mediastinal routes available. Swallowing, at least in the early postoperative phase, is more normal when the interposition is in the posterior mediastinum. One should also note that the distance through the posterior mediastinum is the shortest. If an intrathoracic anastomosis is performed in the upper thorax, the gastric conduit can only be placed in the posterior mediastinum. In case of cervical anastomoses, both routes are possible. The posterior mediastinal route should be avoided for reconstruction if a high risk for local recurrence exists, especially after R1 or R2 resection. If a postoperative radiotherapy of the former tumor site is planned, the anterior mediastinum should be preferred for reconstruction in order to avoid radiation damage of the gastric conduit.

PREOPERATIVE ASSESSMENT AND PREPARATION

The stomach may be used as an esophageal substitute only if it has not previously been operated on. After gastric resections, the length will be insufficient, and after vagotomy procedures, the vascularization is doubtful. If lesser procedures (such as suturing of a bleeding ulcer or closure of a perforation) have been performed, then a transposition of the stomach may be possible, but the vascularity should be checked at the beginning of the operation. A preoperative gastroscopy should be carried out to exclude any mucosal pathology and to confirm the borders of the esophageal tumor. If the cancer is infiltrating the cardia or the subcardial area, the safety margin between the lower edge of the tumor and the resection line of the gastric tube may not be sufficient. Lymph node metastases to the lesser curvature (compartment I according to the classification in gastric cancer) and the celiac trunk (compartment II) should be detected by preoperative endoscopic ultrasonography.

In all cases, the colon should be prepared by bowel lavage and colonoscopy so that it may be used if the stomach should prove unusable.

Anesthesia

The type of anesthesia used depends more on the type of esophagectomy than on the method of reconstruction. If an intrathoracic anastomosis is to be performed, a doublelumen endotracheal tube should be used.

Anatomical points

1. A knowledge of the arterial blood supply of the stomach is essential for its use as an esophageal substitute. The arterial supply of the stomach originates from the celiac trunk. This vessel has a short stem that immediately divides into three branches. The left gastric artery runs in a cranial ventral direction, covered by the peritoneum of the posterior wall of the lesser sac. Subcardially, it turns to the lesser curvature in an aborad direction, where it supplies the anterior and posterior gastric wall by small branches. The left gastric artery has anastomoses with the right gastric artery, which originates from the common hepatic artery and approaches from the region of the pylorus. By these means, an arterial ring along the lesser curvature is completed, with its strongest inflow being from the left gastric artery.

The second vessel of the celiac trunk is the splenic artery, which runs along the upper border of the pancreas behind the posterior wall of the omental bursa to the hilum of the spleen. At the splenic hilum, the short gastric vessels originate; they proceed to the fundus and the cranial third of the greater curvature of the stomach. The left gastroepiploic artery arises from the splenic artery and runs through the gastrocolic ligament parallel to the greater curvature of the stomach in a caudad direction. This artery gives gastric branches to both walls of the stomach and epiploic branches to the greater omentum. It anastomoses with the right gastroepiploic artery, which comes from the region of the pylorus. Thus, the greater curvature also has a vascular ring, with its strongest supply being from the right gastroepiploic artery. This artery has a number of anatomical variations, which may be relevant to gastric interposition.

The third vessel of the celiac trunk, the common hepatic artery, turns to the right, in the direction of the hepatoduodenal ligament of the small omentum. There it divides into the hepatic and gastroduodenal arteries. The hepatic artery runs through the hepatoduodenal ligament to the liver and usually gives rise to the right gastric artery, which proceeds to the lesser curvature of the stomach. The right gastric artery may also originate from the gastroduodenal artery. The gastroduodenal artery runs posterior to the superior part of the duodenum distal to the pylorus and comes out caudad to the duodenum, where it divides into the right gastroepiploic and superior pancreaticoduodenal arteries. All gastric arteries anastomose between themselves directly or indirectly by intramural or extramural branches. Therefore, the ligation of two or even three gastric arteries preserves the blood supply of the stomach under normal circumstances.

The veins of the stomach lead the blood to the portal vein. With only minor exceptions they correspond in their courses to the our gastric arteries. From the gastric fundus, the short gastric veins run through the gastrosplenic ligament to the splenic vein. The left gastroepiploic vein from the greater curvature also proceeds in this direction to the left side. It reaches the splenic vein through the gastrosplenic ligament.

The right gastroepiploic vein accompanies its artery to the area of the pylorus. At this point, the vein turns in a posterior direction and flows into the superior mesenteric vein. At the lesser curvature, a venous arch runs along both arteries (coronary or left gastric vein). This vein flows near the right gastric artery into the portal vein or splenic vein within the hepatoduodenal ligament. At the cardia, the venous arch follows the left gastric artery up to the area of the celiac trunk. (See Figure 30.1 a through d.)

OPERATION (OPEN TECHNIQUE)

The laparoscopic technique for preparation of the gastric conduit is described in Chapter 35, “Thoracoscopic and laparoscopic esophagectomy.”

Position of patient

1. The patient lies in a supine position with the head turned to the right to provide a free approach to the left side of the neck. A rolled-up towel or a sandbag is placed behind the shoulders to facilitate the approach to the anterior mediastinum, and under the lumbar region to facilitate access to the stomach. (See Figure 30.2.)

Incision

1. The abdomen is opened by a transverse incision extended by an upper midline incision in the direction of the xiphoid process. This ensures a good view of the epigastric area. (See Figure 30.3.)

Preparation of the stomach

Skeletonization of the stomach begins along the greater curvature outside the gastroepiploic arch. It is performed stepwise in the direction of the fundus. Although the supply to the stomach from the right gastroepiploic artery shows variations (as illustrated in Figure 30.1), it is sufficient in nearly all cases to guarantee a blood supply to the gastric tube. After division of the left gastroepiploic artery, the preparation of the upper third of the gastric fundus may be performed close to the stomach wall.

1. In an aborad direction, the preparation must be done very carefully outside the gastroepiploic arch to the origin of the right gastroepiploic artery from the gastroduodenal artery (see Figure 30.4.)
   
2. Maintaining the venous drainage via the right gastroepiploic vein is also important (see Figure 30.5.)

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