Antrectomy (distal gastrectomy) is a procedure in which the portion of the stomach distal to the antrum is excised. Gastrectomies are further defined by the type of reconstruction used to reestablish gastrointestinal (GI) continuity. A Billroth I procedure is a gastroduodenostomy, which can be fashioned end-to-end or end-to-side. A Billroth II or gastrojejunostomy reconstruction is usually fashioned end-to-side.  Alternatively, a Roux-en-Y gastrojejunostomy can be performed and is the focus of this topic.
In a prospective randomized trial comparing Billroth II and Roux-en-Y anastomosis after partial gastrectomy plus vagotomy for duodenal ulcers after an average follow-up of 15 years, the latter was found to be significantly better.  Although patients who had a Billroth II anastomosis had significantly more frequent chronic fundic gastritis and intestinal metaplasia of the remnant stomach, those who had Roux-en-Y reconstruction were significantly more asymptomatic and were more likely to have normal esophageal and gastric histology.
The incidence and prevalence of gastric ulcers, particularly perforated ulcers necessitating surgical intervention, fell dramatically after the 1970s, when antacids were discovered.  Currently, Helicobacter pylori infection and nonsteroidal anti-inflammatory drug (NSAID) use are the most common etiologic factors for ulcer disease.
A review analyzing hospitalization trends between 1993 and 2006 revealed an overall decrease in the prevalence of ulcer disease in the United States, with duodenal ulcers showing a steeper decline than gastric ulcers.  Overall inpatient mortality has also decreased. There has been a significant rise in the use of therapeutic endoscopy and a concurrent fall in the use of definitive surgery, which remains the therapy of choice for complications such as perforation or persistent bleeding.
Antrectomy is indicated in the treatment of gastric ulcers that are (a) refractory to medical therapy; (b) complicated by perforation,  bleeding, or obstruction; or (c) recurrent after adequate treatment of H pylori. Ulcer location and pathophysiology (see the image below) dictate the appropriate intervention, which does not always involve surgery.
Type I ulcers lie along the lesser curvature at or around the incisura. Type II ulcers involve the lesser curvature as well as the duodenum. Type III ulcers are prepyloric, whereas type IV ulcers are located proximally on the lesser curvature. Type V ulcers can be located anywhere in the stomach but are associated with NSAID use.
Types I, IV, and V ulcers represent a state of underprotection from acid, whereas types II and III ulcers are sequelae of acid hypersecretion. These are best treated with antrectomy. Removal of the antrum allows pathologic examination of antral/prepyloric ulcers to rule out carcinoma, and it decreases the rate of ulcer recurrence by removing the gastrin-secreting G cells. Truncal vagotomy or highly selective vagotomy is almost always performed simultaneously to decrease the likelihood of ulcer recurrence. This procedure will not be described here.
Antrectomy is also the procedure of choice for benign or small, well-differentiated tumors of the distal stomach. As with any GI neoplasm, lymphadenectomy is mandatory in such cases.
With proper patient selection, there should remain few relative contraindications to the procedure. Prior duodenal surgery precludes a Billroth I reconstruction, as does a “woody,” inflamed, or ulcerated duodenum, which makes a secure anastomosis unlikely. Poor nutritional status impairs healing and may contribute to postoperative complications such as anastomotic leaks.
Patient education and consent
Patients should be counseled preoperatively about the common postoperative complications and how they may recognized, avoided, and alleviated. Often, lifestyle modification alone can prevent reoperation. Emphasizing the importance of postoperative follow-up tests and imaging specific to the patient's condition is also important.
Upper gastrointestinal (GI) endoscopy is performed for patients with ulcer disease in order to determine the extent of disease and to obtain biopsies for ruling out carcinoma. Identification of ulcer location can determine the level of resection. In patients with carcinoma of the stomach, endoscopic ultrasonography is often used in conjunction with computed tomography to determine extent and resectability, and has the added advantage of providing biopsy specimens.
In cases of ulcer disease caused by H pylori, repeat testing should be done to document the refractory nature of the disease.
GI anastomosis (GIA) and end-to-end anastomosis (EEA) staplers are used in creating the anastomoses.
General endotracheal anesthesia is administered.
The patient is placed in a supine position. Reverse Trendelenburg may improve exposure.
Monitoring and follow-up
Closed suction drains are usually not indicated, except in the case of perforated ulcers. Similarly, postoperative antibiotics are not indicated in elective cases. Nasogastric tubes may be left in place for decompression and are usually removed by postoperative day 2. A clear diet is initiated soon thereafter. A contrast swallow study to confirm anastomotic integrity is optional before the start of oral feedings. In some cases, dependent on underlying disease, parenteral nutrition may be necessary to supplement oral intake.
Upper GI endoscopy, or esophagogastroduodenoscopy (EGD), is used routinely to screen for recurrent ulcer disease; it is also used diagnostically and potentially therapeutically in the event of a complication. In addition to surveillance for signs of recurrent ulcer disease, EGD has the added advantage of being therapeutic in the event of a postoperative complication such as stricture or bleeding. Patients undergoing resection for carcinoma undergo annual screening postoperatively.
Although the preference of the author is for a two-layer handsewn anastomosis, staplers are often used in the creation of the anastomosis after an antrectomy. There are no differences between these two approaches with respect to morbidity. The staplers used for antrectomy and reconstruction are of the gastrointestinal (GI) anastomosis (GIA) and end-to-end anastomosis (EEA) types.
An upper midline incision is made, extending from the xiphoid to the umbilicus. This incision may be extended inferiorly as needed to increase exposure. A self-retaining retractor may be used to increase exposure.
Upon entry into the abdomen, a thorough exploration is undertaken to assess the extent of disease and, in the case of gastric carcinoma, to confirm resectability. The gastrocolic ligament is identified and opened at the anticipated area of resection along the greater curvature. A Penrose drain may be placed around the stomach at this point.
Division of the omentum is then continued medially toward the duodenum, staying close to the greater curvature, or extended to include the omentum in the case of surgery for ulcer disease or carcinoma, respectively. 
The Billroth I (gastroduodenostomy) reconstruction would proceed at this stage to preparation of the duodenum with the Kocher maneuver, followed by resection of the distal stomach and end-to-end or end-to-side anastomosis.
The author prefers a Roux-en-Y Billroth II (gastrojejunostomy) reconstruction, the operative steps of which are described in the following section.
The duodenum is mobilized with the Kocher maneuver and dissected circumferentially.  The right gastroepiploic artery and vein are identified along the greater curvature, ligated, and cut. Next, the right gastric artery is identified and divided along the lesser curvature. The duodenum is then divided 2 cm distal to the pylorus with a linear cutting stapler. Oversewing the duodenal stump is optional and is carried out in an interrupted fashion with absorbable suture.
The stomach is then transected with a transverse anastomosis (TA) stapler after further dissection along the greater and lesser curvature. Although the location or extent of ulcer disease sometimes guides the exact area of transection, the standard antrectomy involves removal of the distal third of the stomach, with the landmarks being the incisura on the lesser curvature and the third branch of the right gastroepiploic artery along the greater curvature (see the image below). 
The first or second loop of jejunum that easily reaches the area of transection is mobilized. After careful inspection of the jejunal arcades in the mesentery, a suitable area is chosen. The vessels of the mesentery are then divided between clamps and cut. Suture ligatures may be required for larger vessels. The jejunum is then transected with a linear TA stapler.
Stay sutures are placed on the proximal divided end. This limb is left open while attention is turned to creation of the gastrojejunostomy. The distal cut end of jejunum is isoperistaltic and thus used to create the gastrojejunostomy. This limb is brought up to the area of the stomach in a retrocolic fashion through a suitable incision made in the transverse mesocolon.
The jejunum is incised on the antimesenteric border with an electrocautery device. Stay sutures are placed at the corners. A matching incision is made in the posterior wall of the stomach 5 cm proximal to the staple line, starting at the greater curvature. The gastrojejunostomy is fashioned end-to-side in a single layer with absorbable 3-0 suture.
The posterior wall sutures are full-thickness interrupted mattress sutures, with knots placed intraluminally. The anterior wall is then completed with a single layer of extramucosal stitches after the placement of a gastric tube under direct vision. Alternatively, the gastrojejunostomy can be created with an end-to-end anastomosis stapler fired through a separate smaller gastrotomy that is later closed in an interrupted fashion.
The Y limb of the anastomosis is then completed by suturing or stapling the previously transected proximal jejunal loop in an end-to-side fashion to the distal jejunum at least 40 cm aborally to the gastrojejunostomy. This distance is important in the prevention of postoperative bile reflux symptoms. At this point, care is taken to reapproximate the opening in the mesentery and to inspect the anastomosis for hemostasis. The abdomen is then closed in the usual fashion (see the image below).
Complications of procedure
Complications after antrectomy can occur at any point. The most common complications and steps to avoid them are discussed here.
Anastomotic leaks that present in the first few days postoperatively represent technical errors and should be managed by reoperation. Although reoperation is also warranted in cases of brisk, difficult-to-control bleeding, endoscopic approaches are usually attempted initially in the hemodynamically stable patient.
Patients with anastomotic leaks present with tachycardia, fever, or a change in the effluent of closed suction drains. Radiographic studies using water-soluble oral contrast are helpful in the diagnosis. Closed suction or gastric drainage tubes may increase the healing rate of anastomotic leaks by diverting flow across the healing tissue. Percutaneous drains may be placed minimally invasively if large collections are seen on imaging.
Patients are kept NPO, and parenteral alimentation is used adjunctively. Although some success has been seen with the use of endoscopically placed stents across anastomoses, large leaks, worsening of sepsis, and prolonged time to healing warrant reoperation.
Risk factors associated with anastomotic leak include malnutrition, smoking, steroids, and the use of alcohol or tobacco. Identification and elimination of these risk factors preoperatively may decrease the leak rate. Intraoperative factors that contribute to increased leak rates include long operative time and gross spillage. 
Gastric outlet obstruction
Anastomotic edema or hematoma can cause early outlet obstruction and manifests as vomiting and early satiety. This diagnosis is usually made clinically or on endoscopy. No treatment is necessary, because the condition resolves over time.  In contrast, a late presentation of these symptoms could represent anastomotic stricture from scarring, cancer recurrence, or external adhesions. Endoscopic dilation is used initially, but in cases of cancer recurrence or strictures refractory to dilation, anastomotic revision becomes mandatory.
Recurrent ulcer disease
Antral tissue may be present up to 0.5 cm past the pylorus.  Retained antral tissue may cause symptoms of gastritis or recurrent ulcer disease. This complication is prevented by performing a sufficient resection at the level of the duodenum. Incomplete vagotomy may also explain recurrent ulcer disease. Zollinger-Ellison syndrome must also be ruled out in the case of recurrent or multiple intractable ulcers. 
Postoperative pancreatitis may be caused by edema and in this instance is usually self-limiting. However, if dissection was difficult or encroached on the pancreas, ductal injury must be suspected. Hemorrhagic and necrotizing pancreatitis carry a much higher morbidity and mortality. 
Duodenal stump blowout
Duodenal stump leak or blowout is a severe complication that presents early with peritonitis and varying degrees of sepsis. This complication is most common in cases where the duodenum is chronically ulcerated or edematous; it always warrants reexploration. A thorough washout of the right upper quadrant is followed by definitive repair. In some cases, primary closure reinforced with a patch of omentum may suffice, but this should not be attempted if the duodenum still appears friable and is difficult to reapproximate.
Tube duodenostomy is recommended in this situation. Duodenal stump blowout can be prevented by placement of a tube duodenostomy or distal tube jejunostomy at the time of the initial operation if the integrity of the tissues or the anastomosis is in question.  Alternatively, the Bancroft closure can be used during the initial operation (see the image below).
A Bancroft closure involves transection of the stomach above the pylorus followed by dissection and removal of the mucosal layer of the stomach and duodenum. The duodenal closure is then reinforced by invaginating the duodenum within the submucosal and muscularis layers of the stomach.
Dumping syndrome is a common complication after distal gastrectomy. The early stage is characterized by cramping abdominal pain and diarrhea following meals secondary to the hyperosmotic load delivered to the small intestine. Late dumping is caused by hyperinsulinemia and presents with hypoglycemic symptoms such as lightheadedness and diaphoresis.
Dumping is more prevalent in Billroth II than in Billroth I reconstruction, with a frequency between 7% and 29%,  and is treated conservatively by consuming high-protein, high-fiber, low-carbohydrate meals and by avoiding having liquids with meals. Octreotide is often used with good results. Surgical revision is rarely necessary and is carried out by either an antiperistaltic jejunal interposition or conversion to a Roux-en-Y reconstruction.
Atrophic gastritis is more common with Billroth II than with Roux-en-Y and Billroth I reconstructions and results from enterogastric reflux. As previously discussed, this complication can be minimized by fashioning an appropriately long Roux limb. Conversion of a Billroth II to a Roux reconstruction can alleviate symptoms related to gastritis.
Afferent loop syndrome
Afferent loop syndrome is caused by a closed loop obstruction of the afferent limb of a Billroth II reconstruction and manifests as epigastric pain, nausea, and feeling of fullness followed by projectile vomiting. The most common causes are adhesions, stasis, internal hernias, and volvulus. Closure of the mesocolon and retrocolic position of the loop at the time of initial operation can minimize this complication. Revision to a shorter afferent loop or conversion to a Roux-en-Y reconstruction usually results in symptom resolution.
Efferent loop syndrome
Efferent loop syndrome presents with nausea, vomiting, and abdominal pain from a partial obstruction. Common causes include adhesions and intussusception at the gastrojejunostomy or jejunojejunostomy.
Roux stasis syndrome
Roux stasis syndrome is unique to patients with Roux-en-Y gastrojejunostomies and manifests with symptoms similar to afferent loop syndrome. It is thought to be secondary to aperistalsis of the Roux limb and may be relieved by promotility agents such as erythromycin or metoclopramide.