Bariatric operations: Late complications with acute presentations

INTRODUCTION — The number of bariatric surgical operations performed in the United States has been steadily increasing. The complications following surgical treatment of severe obesity vary based upon the procedure performed and can be as high as 40 percent [1,2]. Early complications (defined as occurring within 30 days of the surgery) are usually treated by the operating surgeon. However, complications that arise months or years after the surgery may present to local emergency rooms away from bariatric centers and need to be treated by providers who do not perform bariatric surgery (eg, general surgeons).

This topic will review the major late complications of bariatric surgery, defined as occurring after 30 days, that present acutely. Early (<30 days) complications and late complications that present subacutely or chronically are discussed elsewhere:

●(See "Bariatric operations: Early (fewer than 30 days) morbidity and mortality".)

●(See "Bariatric operations: Late complications with subacute presentations".)

A description of bariatric procedures, indications and preoperative management, and outcomes are reviewed in separate topics.

●(See "Bariatric procedures for the management of severe obesity: Descriptions".)

●(See "Bariatric surgery for management of obesity: Indications and preoperative preparation".)

●(See "Outcomes of bariatric surgery".)

●(See "Laparoscopic Roux-en-Y gastric bypass".)

●(See "Laparoscopic sleeve gastrectomy".)

ACUTE PRESENTATIONS OF BARIATRIC COMPLICATIONS — Patients with a complication from bariatric surgery typically present acutely with abdominal pain and one or more alarming signs:

●Tachycardia (≥110 beats per minute)

●Fever ≥38°C

●Hypotension

●Respiratory distress with tachypnea and hypoxia

●Decreased urine output

In the early postoperative period, the combination of fever, tachycardia, and tachypnea is the best predictor of an anastomotic leak or staple line leak after sleeve gastrectomy and Roux-en-Y gastric bypass. (See "Bariatric operations: Early (fewer than 30 days) morbidity and mortality", section on 'Gastrointestinal leak'.)

However, the presentation of a late complication may be more atypical and insidious, sometimes only with abdominal pain. Nevertheless, such patients should also be promptly evaluated with laboratory work and imaging to exclude an intra-abdominal complication. (See 'Evaluation' below.)

Following bariatric surgery, persistent nausea and vomiting is indicative of possible internal hernia, volvulus, gastrointestinal stenosis, intestinal ischemia, or marginal ulcer. The most common clinical presentation of internal hernia after gastric bypass is acute-onset, persistent crampy/colicky abdominal pain, mostly located in the epigastrium [3]. (See 'Intestinal obstructions' below.)

The late bleeding complications of bariatric surgery are typically intraluminal (gastrointestinal) rather than intraperitoneal (extraluminal). Any signs of intestinal bleeding, such as hematemesis, melena, and hematochezia, after bariatric surgery predict intra-abdominal complications. (See 'Bleeding complications' below.)

EVALUATION — Patients presenting with a suspected complication from bariatric surgery should undergo a standard evaluation in the emergency department including a history and physical examination, laboratory work, and imaging studies. Endoscopic evaluation may be indicated in select patients.

Laboratory evaluation — A complete blood count, serum electrolytes, serum albumin, liver and renal function tests, C-reactive protein, procalcitonin, serum lactate levels, and blood gas analysis should be performed to assess late complications following bariatric surgery in the emergency setting [4].

Imaging — Contrast-enhanced computed tomography (CT) with oral contrast provides the best assessment of acute abdomen after bariatric surgery [4]. Point-of-care ultrasound is useful in the evaluation of gallbladder pathology, acute appendicitis, free fluid, or intestinal distention. Women who are pregnant may be evaluated with ultrasound or magnetic resonance imaging (MRI).

Endoscopy — Endoscopic evaluation may be performed in stable patients suspected of staple line leak, gastric fistula, delayed gastrojejunal anastomotic leakage, marginal or stomal ulceration, gastrogastric fistula, gastrojejunal anastomotic stricture, and intraluminal bleeding after sleeve gastrectomy and gastric bypass [4]. (See "Gastrointestinal endoscopy in patients who have undergone bariatric surgery".)

BLEEDING COMPLICATIONS — Intraperitoneal (extraluminal) bleeding is a rare, late (>30 days) complication of bariatric surgery [4]. Thus, most late bleeding complications of bariatric surgery occur intraluminally (ie, gastrointestinal bleeding).

Bleeding after gastric bypass — Patients with a history of Roux-en-Y gastric bypass (RYGB) can bleed from the gastrojejunostomy (marginal ulcer), the excluded stomach, or the duodenum.

Marginal ulcers — Marginal ulcers have been reported in 0.6 to 16 percent of patients undergoing RYGB [5-8]. Marginal ulcers occur near the gastrojejunostomy and result from acid injuring the jejunum, or they can be associated with a gastrogastric [6] or, rarely, gastrocolic fistula [9].

Causes of early (in 1 to 10 months) marginal ulcers include [5,10,11]:

●Poor tissue perfusion due to tension or ischemia at the anastomosis

●Presence of foreign material, such as staples or nonabsorbable suture

Causes of late (after 10 months) marginal ulcers include [12,13]:

●Excess acid exposure in the gastric pouch due to gastrogastric fistulas

●Nonsteroidal anti-inflammatory drug use

●Helicobacter pylori infection

●Smoking

●Diabetes

Patients with marginal ulcers can present with nausea, abdominal pain, gastrointestinal bleeding, stomal stenosis, or perforation. The diagnosis of a marginal ulcer is established by upper endoscopy. (See "Gastrointestinal endoscopy in patients who have undergone bariatric surgery", section on 'Gastrojejunal ulceration and bleeding'.)

The mainstay of medical therapy for marginal ulcers is high-dose proton pump inhibitors (PPIs) for three to six months [14]. There is no consensus on the formulation or dose of therapy [15]. Some authors recommend the use of soluble PPIs, or opening capsules, to enhance absorption in RYGB patients [16]. In addition to PPIs twice a day, we recommend adding sucralfate 1 gram four times a day for a minimum of three months prior to considering revisional operations. (See "Overview of the treatment of bleeding peptic ulcers", section on 'Pharmacologic therapy'.)

Additionally, nonsteroidal anti-inflammatory drugs should be discontinued, and patients should be encouraged to stop smoking. An upper gastrointestinal series or a CT scan with oral contrast should be performed to rule out a gastrogastric fistula.

The prevalence of H. pylori infection in patients undergoing weight loss surgery is high, and a significant proportion of them have postoperative foregut symptoms. Observational studies have shown that patients with H. pylori colonization have a higher incidence of marginal ulcer formation [10,17-19]. Furthermore, in one study, preoperative testing and treatment of H. pylori significantly reduced the incidence of postoperative marginal ulcers (2.4 versus 6.8 percent in unscreened patients) [20]. (See "Indications and diagnostic tests for Helicobacter pylori infection in adults" and "Treatment regimens for Helicobacter pylori in adults".)

Although medical management of marginal ulcers is successful in 56 to 100 percent of patients [6,7], surgery may be indicated when persistent pain or recurrent bleeding occurs despite maximal medical therapy. There are no established algorithms for the management of recalcitrant marginal ulcer; available surgical options include gastrojejunostomy revision, vagotomy, conversion to sleeve gastrectomy, subtotal/total gastrectomy, and reversal to normal anatomy [21]. Emergency surgery is required to treated perforated marginal ulcer as discussed in the perforation section below. (See 'Perforated marginal ulcer' below.)

A bleeding marginal ulcer is managed similarly to any other bleeding ulcer in the upper digestive tract [22] (see "Overview of the treatment of bleeding peptic ulcers"):

●In hemodynamically stable patients, upper endoscopy can both diagnose and stop the bleeding.

●Angiographic embolization is an alternative to endoscopic treatment if the latter is not available or unsuccessful.

●Surgical exploration is reserved for bleeding that is persistent or recurrent despite endoscopic and angiographic therapies, or when the patient becomes unstable.

Excluded stomach or duodenal bleeding — After RYGB, bleeding can also occur from an ulcer in the excluded stomach or duodenum [23,24]. Endoscopic access to those parts of the upper gastrointestinal tract is more challenging given the altered anatomy (figure 1) [25].

In elective situations when the patient is stable, the bleeding can be localized and controlled either by an experienced endoscopist going through the Roux limb, then the biliopancreatic limb, with double-balloon enteroscopy [26], or by vascular interventional radiology [27]. In emergency situations when the patient is unstable, access to the remnant stomach or duodenum is best gained expeditiously by creating a surgical gastrotomy. (See "ERCP in patients with Roux-en-Y anatomy".)

Bleeding after sleeve gastrectomy — During sleeve gastrectomy, bleeding can occur from the gastric or short gastric vessels during dissection of the greater curve. Most of the early (<30 days) postoperative bleeding problems associated with sleeve gastrectomy occur from the staple line after transection of the stomach, which are discussed elsewhere. (See "Bariatric operations: Early (fewer than 30 days) morbidity and mortality", section on 'Hemorrhage' and "Laparoscopic sleeve gastrectomy", section on 'Bleeding'.)

Late (>30 days) bleeding complications after sleeve gastrectomy occur from gastric ulcers within the gastric sleeve, which are treated like any other bleeding ulcer. Endoscopy or angiography is used to both diagnose and treat the bleeding. Surgery is reserved for refractory bleeding, especially from ulcers >2 cm in diameter. (See "Overview of the treatment of bleeding peptic ulcers".)

INTESTINAL OBSTRUCTIONS — After bariatric surgery, the stomach or intestines can become obstructed at the anastomosis (eg, stomal stenosis after Roux-en-Y gastric bypass [RYGB]), conduit (eg, sleeve stenosis after sleeve gastrectomy), or small bowel (eg, small bowel obstruction from adhesions or internal hernia, intussusception, or bezoar).

Stomal stenosis — Stomal (anastomotic) stenosis has been described in 3 to 27 percent of patients who have undergone gastric bypass [28,29]. The risk factors include the size of the circular stapler, the original size of the anastomosis, whether the Roux limb is antecolic or retrocolic, and chronic marginal ulcer [30,31].

A stomal stenosis manifests clinically when the anastomosis narrows to a diameter of <10 mm [32]. Patients typically present several weeks after surgery with nausea, vomiting, dysphagia, gastroesophageal reflux, and eventually an inability to tolerate oral intake, including liquids [32,33]. The diagnosis is usually established by endoscopy (when a standard upper endoscope cannot pass easily into the jejunum) or with an upper gastrointestinal series (picture 1).

Endoscopic balloon dilation is usually successful [34-37]. The stoma should be dilated to a diameter of approximately 15 mm; further dilation to 20 mm may reduce the restrictive effect of gastric bypass. The gastrojejunal anastomosis should not be dilated by >3 to 4 mm at a time, and, as such, most patients will need two to three endoscopic procedures to reach a 15 mm anastomosis [32,38]. The complication rate for dilation is approximately 3 percent [38]. Careful communication between the endoscopist and the surgeon regarding the details of the original operation is important to minimize the risk of endoscopic complications.

Stenotic stomas refractory to repeated dilation have been treated with lumen-apposing stents [39,40]. Patients with a chronic stenosis that is refractory to endoscopic treatments (rare) require a surgical revision of the gastrojejunal anastomosis after a delay of a few months to allow the gastric pouch to dilate.

Sleeve stenosis — Gastric obstruction occurs in 0.4 to 2 percent of patients after sleeve gastrectomy, usually within six weeks of the surgery [41]. Narrowing or stenosis of the sleeve stomach can create gastric outlet obstruction [42]. The presentation varies depending on the severity of the obstruction and can include dysphagia, vomiting, dehydration, and the inability to tolerate an oral diet [43]. Sleeve stenosis occurs most commonly at the incisura angularis [44]. (See "Imaging studies after bariatric surgery", section on 'Stricture or stenosis of the SG'.)

Sleeve stenosis can be anatomical or functional. Anatomical stenosis occurs at the level of the incisura angularis due to using a bougie that is too small and/or stapling too close to the incisura [41]. Anatomical stenosis can be easily diagnosed by upper endoscopy. Functional stenosis can be caused by either a localized twist of the gastric tube (type 1) or a spiral staple line that winds around the stomach (type 2) [45]. A functional stenosis is best diagnosed by CT since it usually does not allow the passage of an endoscope.

Management of stenosis primarily consists of endoscopic dilation with or without stent placement, which is successful in 69 to 94 percent of patients [46-48]. If the area of stenosis is severe, helical, or too long, surgical intervention may be necessary with conversion to a RYGB (most common), gastric stricturoplasty, or resection with gastrogastrostomy. (See "Laparoscopic sleeve gastrectomy", section on 'Stricture'.)

Small bowel obstruction — Small bowel obstruction (SBO) can occur at any time after RYGB, with a lifetime incidence of 6 to 9.6 percent [49,50]. Early postoperative SBO is usually caused by technical problems such as kinking of the Roux limb; late SBO is most often caused by herniation of small intestine through one of the mesenteric defects (ie, internal hernias; 54 percent) or adhesions (14 percent) [51]. Other causes of late SBO include incisional hernia, intussusception (typically at the jejunojejunal anastomosis), or bezoar.

●Internal hernia – Potential spaces that are created during a RYGB and can cause SBO include (figure 2):

•A mesenteric defect at the jejunojejunostomy

•A space between the transverse mesocolon and Roux limb mesentery (ie, Petersen defect)

•A defect in the transverse mesocolon in patients with a retrocolic Roux limb (see "Laparoscopic Roux-en-Y gastric bypass", section on 'Antecolic versus retrocolic passage of the Roux limb')

Internal hernias have been described in 12 percent of patients after RYGB without routine closure of the mesenteric defects [52]. To reduce the incidence of internal hernias, all mesenteric defects should be closed with nonabsorbable sutures [4]. In a multicenter trial, 2507 patients were randomly assigned to undergo laparoscopic RYGB with or without mesenteric defect closure [53]. Compared with nonclosure, mesenteric closure significantly decreased the incidence of reoperation due to small bowel obstruction (6 versus 10 percent at three years) but increased early postoperative complications due to kinking of the jejunojejunostomy (4.3 versus 2.8 percent). In another study, the small bowel obstruction rate was reduced from 6 to 3 percent when all such defects were routinely closed [54].

The majority of internal hernias after laparoscopic gastric bypass occurred through the transverse mesocolon defect (44 of 66 in one study) [55]. The use of an antecolic Roux limb can, in theory, reduce the risk of internal hernia formation by eliminating the transverse mesocolic defect. A 2016 meta-analysis found that the use of an antecolic Roux limb, as opposed to a retrocolic Roux limb, was associated with lower rates of postoperative internal hernia (1.3 versus 2.3 percent) and small bowel obstruction (1.4 versus 5.2 percent) [50]. However, the two techniques have not been directly compared with each other in randomized trials.

Internal hernias can be difficult to detect radiographically because they are intermittent. Several studies have shown that the "mesenteric swirl" sign on CT scan is the best indicator of an internal hernia following RYGB [56,57]. The mesenteric swirl sign shows a swirled appearance of mesenteric vessels or fat at the root of the mesentery (image 1). The mesenteric swirl sign has high sensitivity (78 to 100 percent) and specificity (80 to 90 percent) and can be easily recognized by experienced radiologists with high interobserver agreement [58]. (See "Imaging studies after bariatric surgery", section on 'Internal hernia'.)

●Intussusception – Jejunojejunal intussusception after RYGB is a rare (0.1 to 0.64 percent) but potentially catastrophic complication [59,60]. Typical patients are females who have lost a significant amount of weight [60]. Most patients present acutely with abdominal pain ranging from 25 to 52 months after bypass [61]. Most intussusceptions after RYGB occur at the jejunojejunostomy site and are retrograde (antiperistaltic). A jejunojejunostomy length greater than 60 mm may be associated with the occurrence of intussusception [62]. Intussusception is best diagnosed by CT scan [63].

Most patients require surgical intervention, but the best surgical treatment is debated. Resection and revision of the jejunojejunostomy is mandatory in the presence of ischemic or nonreducible small bowel [61]. Less acute patients can be managed with laparoscopic reduction and enteropexy after reduction [62]. Imbrication of the jejunojejunal anastomosis has also been proposed as a method to reduce recurrences [64]. Nevertheless, patients are least likely to recur after resection of the invaginated segment. In a systematic review that included 74 studies and 191 patients, 107 required surgery and 34 percent underwent resection [60].

●Bezoar – After bariatric surgery, bezoar is another rare cause of small bowel obstruction. Bezoars form because of a small gastric pouch, decreased gastric motility and acidity, as well as narrow stomas at the gastrojejunostomy and jejunojejunostomy anastomoses [65].

Treatments include chemical dissolution (with Coca-Cola or papain) or endoscopic removal for bezoars in the stomach or surgery for bezoars in the small bowel [66]. Small bowel bezoars can either be milked into the cecum or retrieved via an enterotomy. Dietary counseling is required to prevent recurrence. (See "Gastric bezoars".)

Patients with SBO can present with vague, intermittent, crampy, and sharp abdominal pain usually unrelated to eating. Patients rarely vomit due to the small size of the gastric pouch. Symptomatic patients should undergo CT scan. Those who are diagnosed with SBO due to internal hernia by CT scan should undergo urgent surgical exploration to reduce the hernia. An uncorrected SBO due to internal hernia could lead to bowel strangulation, which may necessitate extensive bowel resection and can result in short bowel syndrome. SBO due to internal hernia is likely a closed loop obstruction, which has a higher perforation risk.

If the CT scan is inconclusive but patients continue to have symptoms suggestive of SBO, they should be explored laparoscopically to exclude an internal hernia or another cause of an SBO. Surgical exploration should begin at the ileocecal valve where the small bowel is decompressed and thus easier to manipulate laparoscopically [4]. All three potential mesenteric defects should be inspected. If an internal hernia is found, it should be reduced and the defect closed with permanent sutures. A bowel resection should be performed when there is clear evidence of ischemia or infarction. If no internal hernia is found, the entire small bowel should be inspected for other causes of SBO (eg, adhesions).

PERFORATIONS — After Roux-Y gastric bypass (RYGB), perforation can occur at the gastrojejunostomy (marginal ulcer), jejunojejunostomy, or excluded portion of the gastrointestinal tract (remnant stomach or duodenum).

Perforated marginal ulcer — One to 16 percent of patients develop a marginal ulcer at or near the gastrojejunostomy after RYGB. Untreated or refractory marginal ulcers can perforate in 0.83 percent of patients at 27.5±8.5 months after RYGB [11,67,68]. Patients with a perforated marginal ulcer typically present with peritonitis, and the diagnosis is usually made on CT scan. (See 'Marginal ulcers' above.)

Perforated marginal ulcers are treated like other peptic ulcers. In a systematic review of 26 studies (610 patients), laparoscopic repair with an omental patch is most commonly performed (58 percent) followed by open repair (18 percent) and nonoperative treatment (20 percent) [11]. Anastomotic revision may be necessary in some patients but is associated with more complications and longer hospital stay [68]. If a gastrogastric fistula is found, it may be divided and an omental or jejunal interposition performed. Drainage and feeding tubes may be placed at the surgeon's discretion.

In unstable patients, damage control surgery with an open abdomen may be required [69]. Recurrent marginal ulcer can occur in about a quarter of patients after surgical repair or revision [68].

Gastric remnant perforation — Gastric remnant distension is a rare (0.14 percent) but potentially lethal complication following RYGB [70,71]. The gastric remnant is a blind pouch and may become distended if paralytic ileus or distal mechanical obstruction occurs postoperatively. Iatrogenic injury to vagal fibers along the lesser curvature may also contribute, possibly by leading to impaired emptying of the bypassed stomach.

Clinical features include pain, hiccups, left upper quadrant tympany, shoulder pain, abdominal distension, tachycardia, or shortness of breath. Radiographic assessment may demonstrate a large gastric air bubble.

Treatment of gastric remnant distention consists of image-guided percutaneous gastrostomy [72,73] or, failing that, operative (laparoscopic) decompression with a gastrostomy tube [70].

Progressive distension can ultimately lead to rupture, spillage of massive gastric contents, and subsequent severe peritonitis [74]. The combination of the large size of inoculum (liters) and the injurious contents (acid, bile, pancreatic enzymes, and bacteria) makes this complication much more serious than leakage occurring at the gastrojejunostomy. Alternatively, an ulcer in the remnant stomach or duodenum can perforate [75,76].

Immediate operative exploration and decompression are required if perforation is suspected. The surgical treatment for a perforated gastric remnant is not standardized [75]. Options include suture oversew with omental patch, remnant gastrectomy, and ulcer excision with bypass reversal. The jejunojejunostomy should be checked to exclude mechanical outflow obstruction of the remnant [4].

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Bariatric surgery".)

SUMMARY AND RECOMMENDATIONS

●Early versus late complications of bariatric surgery – Early complications (defined as occurring within 30 days of the surgery) are usually treated by the operating surgeon. However, complications that arise months or years after the surgery may present to local emergency rooms away from bariatric centers and need to be treated by providers who do not perform bariatric surgery (eg, general surgeons). (See 'Introduction' above.)

●Bleeding complications – The late bleeding complications of bariatric surgery are typically intraluminal (gastrointestinal) rather than intraperitoneal (extraluminal). Patients with a history of Roux-en-Y gastric bypass (RYGB) can bleed from the gastrojejunostomy (marginal ulcer), the excluded stomach, or the duodenum. Patients with a history of sleeve gastrectomy may bleed from gastric ulcers within the gastric sleeve. (See 'Bleeding complications' above.)

●Obstructive complications – After bariatric surgery, the stomach or intestines can obstruct at the anastomosis (eg, stomal stenosis after gastric bypass), conduit (eg, sleeve stenosis after sleeve gastrectomy), or small bowel (eg, small bowel obstruction from adhesions or internal hernia, intussusception, or bezoar). (See 'Intestinal obstructions' above.)

●Perforations – After RYGB, perforation can occur at the gastrojejunostomy (marginal ulcer), jejunojejunostomy, or excluded portion of the gastrointestinal tract (remnant stomach or duodenum). (See 'Perforations' above.)