Vagotomy

Vagotomy decreases total acid secretion. Also, parietal cell response to gastrin and other stimulants decreases after vagotomy.

Truncal vagotomy requires complete transection of the anterior and posterior vagus nerve trunk and results in denervation of the stomach, liver, gallbladder, pancreas, small intestines, and proximal large intestine. Loss of the antropyloric mechanism results in gastric stasis, and a pyloroplasty, gastroduodenostomy, or gastrojejunostomy must be performed to improve gastric drainage. Gastrojejunostomy is the preferred choice for patients with gastric outlet obstruction or a severely diseased duodenum. Truncal vagotomy has the side effects of dumping or diarrhea in 10% of patients.

Highly selective vagotomy (HSV), also called parietal cell vagotomy or proximal gastric vagotomy, is a relatively safe procedure with minimal side effects that decreases total acid secretion by 75%. With HSV, the vagal nerve supply to the proximal 2/3 to 3/4 of the stomach (parietal cell location) is severed with preservation of the distal branches to the antrum and pylorus. The antropyloric mechanism remains intact and the innervation to remaining abdominal viscera is preserved, minimizing gastrointestinal side effects. This operation does not alter gastric emptying and therefore does not require a drainage procedure, gastric resection, or an anastomosis. Elective HSV may be a preferred treatment for refractory PUD in the absence of gastric outlet obstruction. However, overall elective HSV for treatment of PUD has largely been replaced by long-term PPI treatment. Also, patients with pyloric and prepyloric ulcers have higher ulcer recurrence rates after HSV than those with duodenal ulcers alone. In this setting, a truncal vagotomy with antrectomy may be preferable.

Radiography or CT studies following vagotomy may reveal multiple clips in the expected distribution of the vagus nerve and/or its branches.

Pyloroplasty

Pyloroplasty consists of reconstructing the pyloric channel to increase its diameter and improve gastric emptying. Following truncal vagotomy, impairment of gastric tone and interruption of the antropyloric mechanism result in gastric stasis, and a gastric drainage procedure is required. Pyloroplasty is relatively easy for the surgeon to perform, with less necessary dissection as compared with antrectomy. It also avoids surgical difficulties that may arise with a duodenal stump following antrectromy, and continuity of the GI tract is not altered.

Antrectomy

An antrectomy will remove the source of gastrin and prevent gastric stasis. When performed in combination with truncal vagotomy, antrectomy is the gold standard for reducing acid secretion, with the lowest recurrence rates when compared to vagotomy with pyloroplasty and HSV alone. Antral resection with vagotomy is the most definitive operation for treating ulcer disease. Ulcer recurrence following antrectomy is less than 1%, whereas following vagotomy and pyloroplasty, recurrence rates range from 4% to 27%, and recurrence rates following HSV range from 4% to 11%. However, low recurrence rates must be weighed against postgastrectomy and postvagotomy complications that occur in up to 20% of patients; these may include diarrhea, dumping, bile reflux gastritis, weight loss, and metabolic consequences. Also, there is increased morbidity and mortality risk with gastric resection as compared with HSV alone or vagotomy with pyloroplasty. Antrectomy with vagotomy may be most beneficial for patients with complicated PUD (e.g., patients with bleeding, obstruction, nonhealing, and/or recurrent ulcers).

Antrectomy typically leaves enough of a gastric remnant to allow for maintenance of adequate nutrition, but a bowel anastomosis is necessary. Antrectomy with Billroth I reconstruction (gastroduodenostomy) is the most physiologic anastomosis because it restores normal bowel continuity. Alternatively, a Billroth II reconstruction (gastrojejunostomy) may be performed. A loop of jejunum is brought up to the greater curvature side of the gastric remnant. The duodenal stump must be closed, and this may be technically challenging, especially if the duodenum is diseased.

Metabolic Problems

Anemia may be a consequence of gastric resection. Iron deficiency is the most common cause, but vitamin B ₁₂ or folate deficiency may also occur. Contributing factors may include malabsorption, inadequate oral intake, and chronic bleeding. Iron deficiency anemia may be related to rapid passage through the proximal jejunum, with resultant decreased iron absorption. Also, decreased acid and pepsin may limit the conversion of organic iron to inorganic iron (absorbable by the GI tract). Loss of intrinsic factor production in the stomach can lead to vitamin B ₁₂ deficiency.

Gastric surgery may also disturb calcium and vitamin D metabolism, resulting in metabolic bone disease. Calcium is absorbed in the duodenum, which is bypassed in a gastrojejunostomy. Also, fat malabsorption can occur because of bacterial overgrowth, insufficient mixing of food with digestive enzymes, or afferent loop syndrome. This can result in decreased absorption of fat-soluble vitamin D.

Postoperative Leak

Anastomotic leak or breakdown of a suture line can occur at any anastomosis in up to 5% of patients. Following a Billroth I procedure, leaks may occur at the gastroduodenal anastomosis. With a Billroth II, leaks may occur at the gastrojejunostomy or from the oversewn duodenal stump. With a Roux-en-Y reconstruction, leakage may also occur at these sites or, rarely, at the jejunojejunal anastomosis.

Water-soluble contrast should be used on UGIs if leakage is a concern. Extravasation of contrast material may be seen, with contrast opacifying a track or collection or coursing freely in the peritoneal cavity ( Fig. 35-4 ). A fistula may be seen with contrast opacifying another structure. Any postoperative drain should be carefully evaluated because opacification of a drain may be the only manifestation of a leak on UGI. CT may be necessary to determine the extent and location of collections and abscesses more definitively and to assess for leakage from the oversewn duodenum ( Fig. 35-5 ). Dehiscence of the duodenal stump suture line may be difficult to diagnose with imaging studies and can be a serious complication, resulting in leakage of bile and pancreatic sections into the peritoneal cavity. The duodenal stump may be difficult to opacify in retrograde fashion (anteperistaltic) on UGI. As a result, a fluoroscopic study that does not demonstrate an anastomotic leak following gastrojejunostomy does not exclude the presence of leakage, particularly from the oversewn duodenal stump. CT may reveal complex fluid or gas collections in the vicinity of the duodenal stump (see Fig. 35-5 ), in the subhepatic or peripancreatic space, or findings of peritonitis.

Anastomotic leak following Billroth II gastrojejunostomy.

This UGI image shows Billroth II anatomy. There are thickened folds in the anastomotic region secondary to postoperative edema in this recent postoperative patient. There is extravasation of contrast material from the gastrojejunal anastomosis, with the leak ( arrows ) extending toward an amorphous extraluminal contrast collection (C). J , jejunum; S, stomach remnant.

Duodenal stump leak after Billroth II.

A. Axial contrast-enhanced CT scan shows the stomach remnant (S) anastomosed to the jejunum (J) with a clip ( black arrow ) in the vicinity of the oversewn duodenal stump (D). There is a fluid collection containing gas anterior to the duodenal stump ( white arrows ). Also note foci of adjacent extraluminal gas. B. Supine UGI image show the Billroth II anatomy with a small amount of reflux in the afferent limb opacifying the duodenal stump (D). There is an amorphous collection ( arrows ) of contrast, confirming a duodenal stump leak.

Gastric Stasis

Stasis in a gastric remnant can result in postprandial bloating, vomiting, abdominal pain, and weight loss. Gastric stasis occurs without evidence of mechanical intestinal obstruction or anastomotic narrowing in up to 25% of patients, depending on the type of reconstruction that was performed. Ineffective gastric emptying, impaired bowel motility, and alkaline reflux gastritis can contribute to gastric stasis. UGI should reveal a patent anastomosis without obstruction. Nuclear medicine studies may be of benefit to assess gastric emptying. Severe gastric stasis may require surgical revision with repositioning of the anastomosis or total gastrectomy.

Roux Syndrome

Roux syndrome, or Roux stasis syndrome, may occur following distal gastrectomy with a Roux-en-Y gastrojejunostomy. With this syndrome, patients have an atonic stomach with delayed emptying of the gastric remnant and Roux limb without evidence of obstruction. This represents a motility abnormality rather than a mechanical problem. Patients may present with vomiting, epigastric pain, and weight loss.

On UGI, there is dilation of the gastric remnant with delayed emptying. The efferent limb is typically dilated, without evidence of mechanical obstruction. It is important to assess the anastomosis to make sure that an anastomotic stricture is not a contributing factor. A gastric emptying nuclear medicine scan may also show delayed solid and/or liquid emptying. GI motility testing shows abnormal motility in the Roux limb, with propulsive activity toward the stomach rather than away from the stomach. Promotility medications may be beneficial.

Obstruction

Gastric outlet or small bowel obstruction can be an early or late postoperative complication following ulcer surgery. Obstruction may be caused by postoperative edema or hematoma in the early postoperative course. In contrast, late postoperative obstruction can be caused by anastomotic strictures, with or without stomal ulcers, adhesive disease, or internal hernias. UGI may reveal an anastomotic stricture with gastric outlet obstruction ( Fig. 35-6 ). The patient should be positioned at fluoroscopy so that the anastomosis is viewed in profile, without overlapping structures, to optimally assess anastomotic width and height. Endoscopic treatment and balloon dilation of strictures may be beneficial in some patients.

Stomal stenosis following Billroth II.

This UGI image obtained with the patient drinking in the upright position shows stenosis of the gastrojejunal anastomosis ( arrow ). Also note the outpouchings adjacent to the anastomosis caused by postsurgical deformity and redundancy. There are no thickened, lobulated folds to suggest ulcers. J , jejunum; S, stomach remnant.

Bezoar Formation

A bezoar is a potential complication of subtotal gastrectomy. A bezoar may form in a gastric remnant as a result of decreased peristalsis and absence of gastric acid, especially when a vagotomy has been performed. Retained ingested material can coalesce to become a large masslike conglomerate. On UGI and CT, this appears as a large mottled mass within the gastric remnant. Contrast material and gas trapped within the interstices of the mass may help establish the correct diagnosis ( Fig. 35-7 ). Also, bezoars are usually mobile, allowing for distinction from a gastric tumor. A bezoar can lead to gastric outlet obstruction and occasionally small bowel obstruction if the bezoar passes into the jejunum. Bezoars may be successfully treated endoscopically, but surgical intervention may be necessary, especially with an associated obstruction.

Bezoar following Billroth I.

This supine UGI image shows a gastroduodenostomy. Also note clips from a prior vagotomy ( arrow ). There is a conglomerate mass in the gastric remnant, with contrast in the interstices consistent with a bezoar. Gastric atony and diminished gastric drainage contribute to bezoar formation. D, duodenum.

Dumping Syndrome

Dumping is a phenomenon caused by destruction or bypass of the pyloric sphincter (as with pyloroplasty or antrectomy) with rapid gastric emptying; however, other factors likely play a role. Patients with early dumping syndrome experience vasomotor and cardiovascular symptoms, including tachycardia, dizziness, diaphoresis, weakness, nausea, abdominal cramping, diarrhea, and the need to lie down after eating. Postprandial symptoms may be severe and disabling. High-carbohydrate food may precipitate the worst attacks. A rapid influx of sugars into the proximal jejunum may cause a strong osmotic effect, drawing fluid into the bowel.

Crampy abdominal pain and distention are not uncommon, and diarrhea often follows. Early dumping occurs 15 to 20 minutes after a meal in 5% to 50% of patients, depending on the specific operation. Clinically significant dumping occurs in 5% to 10% of patients after pyloroplasty or distal gastrectomy. Because of the abdominal pain associated with eating, patients tend to lose weight and become malnourished.

UGI in early dumping syndrome may reveal very rapid transit time with rapid opacification of the colon. Conservative therapy for dumping syndrome consists of dietary management; most patients improve with dietary changes over time. A somatostatin analogue may be beneficial. Surgical management may be necessary in a small percentage of patients, but the results of surgery for dumping symptoms are variable and unpredictable.

Late dumping, also called postprandial (reactive) hypoglycemia, occurs 2 to 4 hours after a meal and may have similar vasomotor symptoms, but does not typically have the associated GI symptoms. This can be alleviated by the administration of carbohydrates.

Stomal and Anastomotic Ulceration

Recurrent ulcers following gastric surgery for PUD occur at or near the anastomosis, usually on the duodenal or jejunal side of the anastomosis for a Billroth I or II procedure, respectively. In a Billroth II, the efferent loop is more commonly involved than the afferent loop. These ulcers are referred to as stomal, marginal, or postanastomotic ulcers; they occur primarily following inadequate gastric resection with a retained segment of antrum or because of a hypersecretory state or gastrinoma. In the setting of a Roux-en-Y gastrojejunostomy for PUD, a large gastric remnant predisposes to marginal ulcers.

UGI may reveal an ulcer crater with surrounding edema ( Fig. 35-8 ). Stomal ulcers may be difficult to diagnose on UGI studies because of opacification of overlapping structures, and it may be difficult to distinguish barium trapping in distorted folds and plication defects from an ulcer. A baseline postoperative comparison study may be most beneficial to make this distinction. Secondary signs of ulcers may include narrowing at the anastomosis with thickened, edematous, and masslike folds. UGI findings may be less reliable compared with endoscopy, but contrast studies are increasingly necessary when endoscopy is limited or difficult. If recurrent ulcers fail to respond to medical management, total gastrectomy may be necessary.

Billroth II with a recurrent ulcer.

This upright UGI image shows a gastrojejunostomy with edema in the vicinity of the anastomosis. The gastric remnant is dilated and contains a large amount of fluid and debris. There is a focal ulcer crater in the jejunum adjacent to the anastomosis ( arrows ) with surrounding edema and fold thickening. J, jejunum.

Jejunogastric Intussusception

Intussusception may occur in the vicinity of any anastomosis. Jejunogastric intussusception is a rare complication following gastrojejunostomy, with a reported incidence of 0.1%; the efferent loop intussuscepts into the stomach more often than the afferent loop. Prolapse may occur in an antegrade or retrograde direction. Retrograde migration of the jejunal segment into the gastric remnant can be acute, chronic, or intermittent and can result in partial or complete gastric outlet obstruction. On CT, the proximal jejunum, along with the adjacent mesenteric fat and vessels, can be seen within the lumen of the gastric remnant. On UGI, contrast can be seen outlining the jejunal folds within the gastric remnant, producing a coil spring appearance ( Fig. 35-9 ). A gastrojejunal intussusception may be manifested by narrowing of the distal gastric remnant with a coil spring filling defect in the adjacent proximal jejunum.

Jejunogastric intussusception following Billroth II.

A right lateral UGI image shows a dilated gastric remnant with a filling defect in the gastric remnant near the gastrojejunal anastomosis caused by retrograde migration of the jejunum into the stomach. Jejunal folds are seen within the gastric remnant ( arrows ). J, jejunum.

Afferent Loop Syndrome

Following gastrojejunostomy, the afferent loop (duodenal stump containing biliopancreatic secretions) may become dilated, which can lead to abdominal pain, nausea, vomiting, postprandial fullness, and, rarely, obstructive jaundice. This has been called afferent loop syndrome ; it occurs in less than 1% of patients. Afferent loop syndrome may be caused by blockage of this limb and may occur with adhesions, kinking or fibrosis near the anastomosis, internal hernias, or volvulus. Partial obstruction of the afferent loop results in luminal dilation with accumulation of biliary, pancreatic, and duodenal secretions. Acute complete obstruction may also occur. Afferent loop syndrome can also be due to preferential flow of ingested contents into the afferent limb (retrograde) rather than into the efferent limb.

Diagnosis of afferent loop syndrome caused by obstruction may be best made on CT. CT reveals a dilated, fluid-filled afferent loop ( Fig. 35-10 ) and may also reveal the cause of obstruction. On UGI, the obstructed afferent loop may not be opacified. The diagnosis may be inferred by the absence of opacification of the afferent limb and mass effect on the opacified efferent limb by the fluid-filled, unopacified afferent segment. However, lack of opacification of the afferent limb occurs in up to 20% of all patients following gastrojejunostomy, so lack of opacification by itself is not a reliable indicator of afferent loop syndrome. Afferent loop syndrome can also be due to preferential flow of ingested contents into a dilated afferent limb rather than the efferent limb, and this can be readily identified with UGI (see Fig. 35-10C ). In afferent loop syndrome, hepatobiliary scintigraphy reveals retention in the dilated biliopancreatic segment.

Afferent loop syndrome following Roux-en-Y gastrojejunostomy.

A, B. Axial-contrast enhanced CT images A. A small gastric remnant (S) is anastomosed to a jejunal Roux limb (J). B. There is a small bowel anastomosis in the left midabdomen ( white arrow ). The afferent limb is markedly dilated and fluid-filled, with distention of the duodenum (D). The efferent jejunal limb is decompressed ( black arrow ). C. Overhead radiograph following UGI shows a dilated gastric remnant (S) with reflux into the esophagus. There is preferential filling of a dilated afferent limb (A) and duodenum (D). Note contrast in the right colon from a prior study.

Bile Reflux Gastritis, Chronic Remnant Gastritis

A common complication following gastric surgery is chronic gastritis. Bile reflux gastritis occurs in 5% to 15% of patients following partial gastrectomy. Without an intact pylorus, chronic reflux of bile and pancreatic secretions into the gastric remnant can result in inflammatory change in the residual stomach. Following resection of the pylorus, most patients have bile in the stomach, with some degree of inflammation on endoscopic examination, and therefore many patients remain asymptomatic in the setting of bile reflux. However, a subset of patients will have bile reflux gastritis and present with nausea, bilious vomiting, and epigastric pain, possibly with excessive enterogastric reflux. There does not appear to be a strong correlation between the degree of inflammation and the degree of symptoms. The onset of pain is not associated with meals. The differential diagnosis may include afferent loop syndrome, obstruction, and gastric stasis, and UGI may help establish the diagnosis. UGI may reveal thickened gastric folds without associated obstruction ( Fig. 35-11 ). Ulcers may or may not be present in the perianastomotic region of the gastric remnant.

Bile reflux gastritis following Billroth II.

A supine double-contrast UGI image shows distal gastrectomy with gastrojejunostomy. There are thickening and lobulated folds in the gastric remnant caused by bile reflux gastritis.

Conversion to Roux-en-Y gastrojejunostomy with at least 45 cm of isoperistaltic jejunal loop between the gastric remnant and duodenum may help alleviate bile reflux gastritis by diverting bile and pancreatic secretions away from the gastric remnant.

Neoplasms After Surgery for Benign Ulcer Disease

Following partial gastrectomy for benign disorders, especially PUD, there is an increased risk of gastric remnant neoplasms. This occurs in the late postoperative course, with a 15- to 20-year latent period, at which point the relative risk increases twofold to fourfold. Malignant tumors most likely develop as a result of gradual progression from normal mucosa to intestinal metaplasia to dysplasia, and, subsequently, to cancer over time, presumably as a consequence of prolonged achlorhydria and chronic enterogastric reflux of bile and pancreatic secretions. Truncal vagotomy reduces gastric acid and may contribute to this process. Stump tumors involve the distal gastric remnant at or near the anastomosis. On UGI, stump tumors appear as infiltrating, plaquelike, polypoid, or ulcerative lesions in the gastric remnant near the anastomosis.