An antrectomy is the surgical removal of the antrum, the lower portion of the stomach responsible for producing most of the body’s gastrin, a hormone that drives acid secretion. Surgeons have used this procedure for decades to treat conditions where excess acid or antral disease is the root problem, from stubborn peptic ulcers to certain tumors. Though powerful proton-pump inhibitor drugs have reduced the number of antrectomies performed for ulcer disease, the operation remains a key tool in cancer surgery and a handful of other situations where medication alone falls short.
What the Antrum Does and Why Removing It Matters
The antrum sits at the bottom of the stomach, just before the pylorus (the muscular valve that controls emptying into the small intestine). It is home to specialized G cells that act as sensors, detecting proteins from food and physical stretching of the stomach wall, then responding by releasing gastrin into the bloodstream.1PubMed Central. Mechanosensitive ion channel Piezo1 is expressed in antral G cells of murine stomach Gastrin tells the acid-producing cells higher up in the stomach to ramp up hydrochloric acid output. It also helps regulate stomach motility, the rhythmic churning that breaks food down mechanically.
Removing the antrum therefore accomplishes two things at once. It eliminates the main source of gastrin, which sharply reduces acid production. And it removes the pyloric mechanism, which changes how quickly food leaves the stomach. Both of these effects are intentional when the goal is to stop acid from damaging the lining of the stomach or duodenum, but they also set the stage for some of the side effects discussed later.
When Surgeons Recommend an Antrectomy
The classic indication was a duodenal ulcer that kept coming back despite medical treatment. Before effective acid-suppressing drugs existed, cutting away the gastrin-producing tissue was one of the most reliable ways to cure recurrent ulcers. That role has shrunk considerably with the advent of proton-pump inhibitors and the recognition that most ulcers are caused by the bacterium H. pylori, which can be eradicated with antibiotics. Still, some ulcers prove refractory or cause life-threatening bleeding or perforation, and antrectomy remains an option in those emergencies.
Beyond ulcer disease, antrectomy is performed for tumors and other masses in the antrum, pylorus, or duodenal bulb. Neuroendocrine tumors of the gastric antrum are one example where an antrectomy (sometimes combined with resection of part of the duodenum) can be curative.2Journal of Medical Insight. Open antrectomy and duodenal resection for neuroendocrine tumor Distal gastric cancer is another major reason: when a tumor sits in the lower stomach, a distal gastrectomy that includes the antrum is standard oncologic practice.
Combining Antrectomy with Vagotomy
For peptic ulcer disease, antrectomy was rarely done alone. Surgeons typically paired it with a truncal vagotomy, which cuts the vagus nerve branches supplying the stomach to further reduce acid secretion. A prospective randomized trial comparing three surgical strategies for chronic duodenal ulcer found that truncal vagotomy with antrectomy had no ulcer recurrences, outperforming both proximal gastric vagotomy and truncal vagotomy with a simple drainage procedure.3Annals of Surgery. Proximal Gastric Vagotomy, Truncal Vagotomy with Drainage, and Truncal Vagotomy with Antrectomy for Chronic Duodenal Ulcer: A Prospective, Randomized Controlled Trial That same trial did note one death after vagotomy with antrectomy, reflecting the reality that the more tissue you remove and the more nerve you cut, the lower the recurrence rate but the higher the operative risk.
This trade-off defined ulcer surgery for decades. Less invasive options like vagotomy with drainage carried lower immediate risk but higher recurrence. Adding antrectomy essentially eliminated recurrences but introduced a bigger physiological disruption. Today, these combinations are uncommon because drug therapy handles most ulcers, but understanding them matters for anyone who has already had one of these operations or is facing one in an emergency setting.
Reconstruction After Antrectomy
Once the antrum is removed, the remaining stomach needs to be reconnected to the intestinal tract. The choice of reconstruction has real consequences for how you eat, how you feel, and what complications you face in the years ahead. Three main options have stood the test of time.
Billroth I
This is the most anatomically straightforward approach: the remaining stomach is sewn directly to the duodenum. It preserves the normal route food takes through the digestive system, which tends to produce fewer metabolic disruptions. Billroth I is a popular reconstruction after distal gastrectomy for gastric cancer.4PubMed Central. A simple method for tension-free Billroth I anastomosis after gastrectomy for gastric cancer The main limitation is that the connection can be under physical tension if a lot of stomach was removed, because the duodenum is relatively fixed in place. Surgeons have developed techniques to reduce that tension, but when the remaining stomach is too small, a Billroth I simply isn’t feasible.
Billroth II
Here the duodenal stump is closed off, and the remaining stomach is connected to a loop of the jejunum (the next segment of small intestine). This avoids the tension problem entirely, because the jejunum can be brought up to meet the stomach regardless of how much was removed. It is considered the workhorse reconstruction when resection is extensive.5Annals of Surgical Treatment and Research. Comparison of gastric-jejunum pouch anastomosis and Billroth-II reconstructions after distal gastrectomy: a propensity score matching analysis The downside is that it reroutes food away from the duodenum, which changes the normal sequence of digestion and can lead to bile washing back into the stomach remnant, a phenomenon called bile reflux gastritis. It also creates a blind loop of intestine (the afferent loop) that can occasionally become partially obstructed, causing episodes of nausea and vomiting of bile-stained fluid without food mixed in.6Surgery. Afferent loop syndrome
Roux-en-Y
The Roux-en-Y reconstruction divides the jejunum and brings the downstream end up to the stomach while reattaching the upstream end lower down. The key advantage is that bile drains away from the stomach rather than toward it. Combining antrectomy with a Roux-en-Y has been shown to prevent postoperative bile reflux gastritis and spare patients the need for revision surgery on that account.7British Journal of Surgery. Combined antrectomy and Roux-en-Y anastomosis in the surgical treatment of recurrent peptic ulceration A comparison between Roux-en-Y and Billroth I (gastroduodenostomy) after antrectomy found that although Roux-en-Y was very effective at preventing bile reflux, gastric emptying rates were similar between the two approaches.8PubMed. Primary Roux-Y gastrojejunostomy versus gastroduodenostomy after antrectomy and selective vagotomy
How Reconstruction Affects Long-Term Quality of Life
Randomized trials comparing Billroth I and Roux-en-Y after distal gastrectomy for gastric cancer have tracked patients for years and found consistent differences. In one trial, patients who received Roux-en-Y reconstruction reported less reflux and less upper abdominal pain at one year compared with Billroth I patients, along with slightly higher overall health scores.9Scientific Reports. Comparison of quality of life between Billroth-І and Roux-en-Y anastomosis after distal gastrectomy for gastric cancer: A randomized controlled trial A longer follow-up of the same cohort confirmed that these advantages persisted through five years: the Roux-en-Y group consistently reported milder reflux and epigastric pain, with no difference in cancer survival between the two groups.10PubMed Central. Comparison of long-term quality of life between Billroth-I and Roux-en-Y anastomosis after distal gastrectomy for gastric cancer: a randomized controlled trial A separate study looking at total gastrectomy with pouch reconstruction found that it produced dumping and heartburn rates comparable to distal resection, while total gastrectomy without a pouch fared worse on both counts.11PubMed. Reconstruction after gastrectomy and quality of life
The practical takeaway is that the type of reconstruction matters for everyday comfort after surgery, sometimes more than the extent of the resection itself. If you or someone you know is facing a distal gastrectomy, asking the surgeon about the reconstruction plan is worth doing.
Postgastrectomy Syndromes
Roughly one in five patients who undergo gastric surgery develop some form of postgastrectomy syndrome, a catch-all term for the digestive problems that arise when the stomach’s normal anatomy and nerve supply are disrupted. These syndromes stem from three interrelated changes: the stomach can no longer store as much food, its mechanical churning is weakened, and food empties into the intestine too quickly or in an uncontrolled way.
The most familiar of these is dumping syndrome, where a rush of poorly processed food and concentrated sugars hits the small intestine. Early dumping happens within half an hour of eating and causes bloating, cramping, nausea, and sometimes a rapid heartbeat. Late dumping occurs one to three hours later when the body overshoots its insulin response to the sugar load, producing lightheadedness and sweating from low blood sugar. Both forms are managed mainly by changing eating habits: smaller, more frequent meals with less sugar and more protein and fat to slow gastric emptying.
Bile reflux gastritis, as noted above, is a particular concern after Billroth II reconstruction. And afferent loop syndrome, though uncommon, can produce dramatic symptoms when the blind intestinal loop becomes kinked or narrowed.12Surgery. Afferent loop syndrome
Duodenal Stump Leakage
When a Billroth II or Roux-en-Y reconstruction is used, the duodenal stump is closed off as a dead end. If that closure fails, digestive juices leak into the abdominal cavity, an event that can cause serious infection and sometimes requires reoperation. Risk factors identified in large surgical series include higher body mass index, elevated inflammatory markers before surgery, and significant underlying health problems. One study found that patients with substantial comorbidity burdens had a significantly higher rate of leaks, and that Billroth II reconstruction itself was a risk factor compared with other approaches.13Bratislava Medical Journal. Factors Affecting Duodenal Stump Leakage After Gastrectomy Another analysis identified high BMI, elevated C-reactive protein, and failure to reinforce the duodenal stump as independent predictors.14PubMed Central. Risk Factors for Duodenal Stump Leakage after Laparoscopic Gastrectomy for Gastric Cancer Whether reinforcement sutures genuinely help remains somewhat debated, with one of those studies finding a clear benefit and the other finding no significant difference based on closure method. The discrepancy likely reflects differences in patient populations and surgical technique.
Retained Antrum Syndrome
This is a rare but instructive complication. During a Billroth II gastrectomy, if a small cuff of antral tissue is accidentally left behind on the duodenal stump, its G cells keep producing gastrin. Normally the antrum’s acid output would suppress gastrin release through a feedback loop, but the retained fragment sits downstream in an alkaline environment, so the feedback never kicks in. The result is persistent high gastrin levels and recurrent ulcers that puzzle clinicians until the retained tissue is identified.15PubMed. Retained gastric antrum syndrome diagnosed by [99mTc] pertechnetate scintiphotography in man: hormonal and radioisotopic study of two cases The syndrome is diagnosed using a nuclear medicine scan and treated by removing the leftover fragment. It serves as a good reminder of how precisely the antrum needs to be cleared.
Nutritional and Metabolic Consequences
Removing part of the stomach changes nutrient absorption in several ways, some obvious and some subtle.
Iron deficiency is one of the most common long-term problems. The stomach’s acid environment helps convert dietary iron into a form the body can absorb. After antrectomy, lower acid output combined with faster emptying of the stomach remnant reduces the time and acidity available for this conversion. When borderline dietary intake or chronic low-grade blood loss is also present, frank anemia can develop.16PubMed Central. Iron-deficiency anemia after partial gastrectomy Periodic blood work and iron supplementation are standard follow-up measures.
Bone health is another concern. Animal research has shown that antrectomy reduces calcium and magnesium absorption from the intestine, apparently because the loss of gastrin disrupts mineral handling. Over several months, antrectomized rats developed measurably lower bone mineral content compared with controls, even though their blood calcium levels stayed normal: the body maintained calcium in the blood at the expense of the skeleton.17Bone and Mineral. Disturbances of mineral and bone metabolism following gastric antrectomy in the rat Interestingly, a separate rat study found that antrectomy produced less bone loss than total gastrectomy or fundectomy, suggesting the antrum’s contribution to bone metabolism, while real, is smaller than that of the stomach as a whole.18PubMed. Osteopenia after gastrectomy, fundectomy or antrectomy: an experimental study in the rat In clinical practice, vitamin D and calcium supplementation are routinely recommended after any significant gastric resection.
Weight loss is almost universal after gastrectomy. Part of the explanation involves ghrelin, a hunger-signaling hormone produced mainly by the stomach. In mice, gastrectomy reduced circulating ghrelin by about 80%, and the animals weighed roughly 15% less than controls. Injecting ghrelin partially reversed the weight loss and fat loss but did not restore bone mass.19Gut. Ghrelin treatment reverses the reduction in weight gain and body fat in gastrectomised mice Whether antrectomy alone produces a ghrelin drop as large as total gastrectomy is uncertain, since much of the stomach’s ghrelin comes from the fundus rather than the antrum. But patients who undergo distal gastrectomy that includes the antrum do consistently lose weight, and adequate caloric intake often requires deliberate dietary adjustments after surgery.
Antrectomy in the Context of Sleeve Gastrectomy
Sleeve gastrectomy, the most commonly performed bariatric (weight-loss) operation worldwide, involves removing roughly 80% of the stomach to create a narrow tube. Whether to include or spare the antrum during a sleeve has become a genuine controversy. A retrospective cohort comparing antrum-resecting and antrum-preserving sleeve gastrectomy found that the antrectomy group had a significantly higher complication rate: complications occurred in about 10% of the antrectomy group versus roughly 1% in the antrum-preserving group, and every leak in the study occurred in patients whose antrum was removed.20Saudi Journal of Gastroenterology. Patient-reported outcomes after antrum resection versus antrum preservation in laparoscopic sleeve gastrectomy patients: A retrospective cohort study After adjusting for confounders, preserving the antrum was associated with substantially lower odds of complications.
The reasoning is mechanical as much as metabolic. The antrum has a thicker, more muscular wall than the upper stomach, and its preservation may help maintain the pumping action that prevents stasis and leak at the staple line. In bariatric surgery, at least, the trend appears to be moving toward keeping the antrum intact unless there is a specific oncologic reason to remove it.
Living with a Partial Stomach
People who have had an antrectomy can live full, active lives, but certain adjustments become permanent. Eating smaller meals more frequently prevents the discomfort of overloading a reduced stomach. Chewing thoroughly helps compensate for the loss of the stomach’s mechanical mixing. Some foods, particularly high-sugar liquids, may trigger dumping symptoms and are best limited or paired with protein. Alcohol tolerance often drops because the stomach’s reduced capacity and faster emptying accelerate absorption.
On the monitoring side, periodic checks for iron, vitamin B12, calcium, and vitamin D are important. B12 deficiency can develop slowly because the stomach produces intrinsic factor, a protein needed for B12 absorption lower in the intestine. After partial gastrectomy, intrinsic factor output may be reduced enough that oral B12 supplements or injections become necessary years down the line. Bone density screening is also worth discussing with your doctor, given the absorptive changes described earlier.
Psychologically, adapting to a new relationship with food takes time. Many patients describe a period of frustration as they learn what they can eat comfortably and how to manage social meals. Support groups and dietitians who specialize in post-gastrectomy nutrition can make a meaningful difference in that transition.