Step 1: Surgical Anatomy
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Surgery of the stomach and duodenum requires an understanding of both the blood supply of the stomach and duodenum and the anatomical relationships to the pancreas and spleen. ( Figure 15-1 )
Figure 15-1
Step 2: Preoperative Considerations
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The most common indications for antrectomy or distal gastrectomy are duodenal ulcer disease, gastric ulcer, and benign gastric tumors. Relative contraindications include cirrhosis, extensive scarring of the proximal duodenum, and previous surgery on the proximal duodenum.
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When performed in combination with a truncal vagotomy, antrectomy is the gold standard in reducing acid secretion and recurrence when compared to vagotomy, pyloroplasty, and highly selective vagotomy. However, the low recurrence rates must be weighed against the postgastrectomy and postvagotomy complications that occur in approximately 20% of patients. In the H. pylori era, antrectomy is performed infrequently in patients with peptic ulcer disease.
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Antrectomy with Billroth I reconstruction (gastroduodenostomy) is the most physiologic gastric resection as it restores the normal continuity. Combined with vagotomy, antrectomy allows for retention of 50% of the stomach with the lowest recurrence rate of all ulcer procedures. ( Figure 15-2 )
Figure 15-2
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In the malnourished patient, especially female, antrectomy leaves enough of a gastric reservoir to allow for maintenance of adequate postoperative nutrition. Constructing the gastroduodenal anastomosis to approximate the size of the pylorus usually delays gastric emptying and reduces problems with postgastrectomy dumping.
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The patient’s nutritional status must be adequately assessed. Preoperative labs should include prealbumin and albumin levels.
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In the acute setting, electrolytes must be corrected. When chronic nausea and vomiting is present, alkalosis must be corrected and potassium levels restored.
Step 3: Operative Steps
1.
Incision
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An upper midline incision works well to provide adequate exposure to the stomach. This incision can be extended to the xiphoid to gain access to the esophageal hiatus for vagotomy. In patients with a barrel-shaped chest, a subcostal incision may provide slightly better access to the foregut. However, dividing the muscle results in more potential wound problems and more dissection time.
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Once the peritoneum is entered, the falciform ligament should be divided to allow for upward retraction of the left lateral lobe of the liver.
2.
Dissection
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The first step of antrectomy for ulcer disease is to evaluate the duodenum for possible resection and the possibility of a difficult duodenal stump closure. This determination is difficult by inspection alone. A marked fibrotic or edematous anterior duodenal wall suggests that duodenal closure will be difficult. Extensive edema or fibrosis of the pylorus, pancreas, and hepatoduodenal ligaments is a relative contraindication to antrectomy.
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Extensive duodenal mobilization is a necessity for a Billroth I reconstruction. The peritoneum along the lateral border of the second portion of the duodenum is incised and a Kocher maneuver performed. Typically, the duodenum can be retracted medially with the left hand, and the peritoneal attachments are swept away with the blunt finger or gauze. Again, the middle colic vessels course over the second portion of the duodenum and may be encountered suddenly. The hepatic flexure should be directed caudally and medially to identify the middle colic vessels early. ( Figure 15-3 )
Figure 15-3
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The avascular hepatogastric ligament is incised to the right of the lesser curve. This maneuver allows for passage of the left forefinger behind the antrum, emerging posterior to the gastroepiploic arcade along the greater curvature. The omentum is elevated off of the transverse mesocolon and opened, thus avoiding injury to the middle colic vessels. ( Figure 15-4 ) The branches of the gastroepiploic arcade going to the greater curve are sequentially divided with clamps and ties. This dissection is continued along the greater curve until a point that is approximately halfway from the pylorus and the diaphragm. ( Figure 15-5 ) The distal segment of the gastroepiploic arcade is dissected off of the antrum. Care should be taken as the fragile veins near the origin of the right gastroepiploic vessels can be easily torn. During this dissection, the congenital attachments of the pancreas to the back wall of the antrum can be taken down to completely mobilize the distal half of the greater curve.
Figure 15-4
Figure 15-5
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A site along the lesser curve is identified just proximal to the third prominent vein. This point is roughly halfway between the esophagogastric junction and the pylorus and is a good estimation of the upper extent of antral mucosa. A hemostat is inserted between the lesser curve and the adjacent vascular bundle in this area. The left gastric vessels are divided between two clamps. ( Figure 15-6 ) Ligatures of 0 silk or polyglactin 910 are used to control the cut ends of the vessels. Preferably, at least a 1-cm stump of gastric artery is left beyond each tie. There may be additional small gastric veins that require additional ties.
Figure 15-6
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The omentum is retracted upward, and the posterior wall of the stomach is freed up from the capsule of the pancreas. Any adhesions encountered should be taken down sharply. If a posterior ulcer is present, there may be erosion into the capsule of the pancreas. The attachments can be broken up with the thumb and forefinger, leaving the ulcer crater on the capsule of the pancreas. ( Figure 15-7 ) All gastric ulcers should be biopsied to rule out the presence of malignancy.
Figure 15-7
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At this point, extensive mobilization of the duodenum and stomach is ensured. No commitment to resection has been made. Once it appears feasible to perform an antrectomy, the surgeon proceeds with division of the stomach and duodenum.
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Combined with a complete vagotomy, no more than half of the stomach needs to be removed. The stomach may be divided with the single firing of a linear stapler typically 90 mm in length, with either 3.5- or 4.8-mm staple heights. This technique sets things up better for a stapled gastrointestinal anastomosis. ( Figure 15-8 ) For a hand-sewn reconstruction, longitudinal serrated visceral clamps are placed at 90-degree angles to the greater curve for a distance of about 3 to 4 cm. The amount of tissue in the clamp should correspond to the desired size of anastomotic opening for the gastroduodenostomy or gastrojejunostomy. The gastric wall is divided between the clamps. A linear stapler is used to divide the remaining portion of the stomach on the lesser curve side. ( Figure 15-9 ) An additional Allen clamp is placed distal to the stapler, and the stomach divided flush with the stapler. The cut end of the stomach may be cauterized for hemostasis. It is preferable to use absorbable staple-line reinforcement to minimize bleeding. An interrupted layer of 4-0 silk or polyglactin can be used to invert the staple line of the gastric pouch using a Lembert suture. When a stapling device is not used or available, the lesser curve is divided between two Allen clamps. A 3-0 polyglactin suture is used to close the gastric pouch in layers, starting on the lesser curve side. The suture needle is passed back and forth just deep to the Allen clamp to make a running horizontal mattress stitch. When the base of the Allen clamp is reached, the same suture is run back to the lesser curve using a running, locked suture and tied to its point of origin. The mucosa is then inverted with an interrupted, Lembert layer of 4-0 silk or polyglactin. ( Figure 15-10ABC )
