INTRODUCTION — The number of bariatric surgical operations performed in the United States has steadily increased. It is estimated that 199,000 weight-loss surgeries were performed in 2020 [1]. Of those, 59 percent were sleeve gastrectomy, 21 percent were gastric bypass, 1.2 percent were adjustable gastric band, and 1.8 percent were biliopancreatic diversion with duodenal switch. The remaining 11 percent were revisional procedures.
Complications following the surgical treatment of severe obesity vary based upon the procedure performed and can be as high as 40 percent [2-4]. Due to the high surgical volume, improving the safety of these operations has become a high priority.
This topic will review the major late complications of bariatric surgery, defined as occurring after 30 days, that present subacutely or chronically. Early complications and late complications that present acutely are discussed in other topics:
●(See "Bariatric operations: Early (fewer than 30 days) morbidity and mortality".)
●(See "Bariatric operations: Late complications with acute presentations".)
Nutritional complications are discussed elsewhere. (See "Bariatric surgery: Postoperative nutritional management".)
A description of bariatric procedures, indications and preoperative management, medical outcomes, and individual bariatric operations can be found in other 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".)
COMPLICATIONS COMMON TO ALL PROCEDURES — Late complications that can occur after all bariatric procedures include cholelithiasis, incisional hernias, and change in bowel habits.
Cholelithiasis — Gallstones can develop after bariatric surgery due to an increased biliary cholesterol concentration following rapid weight loss, gallbladder hypomotility secondary to vagal nerve resection and a decreased cholecystokinin secretion, an increased secretion of calcium and biliary mucin, and a disturbed enterohepatic circulation of biliary salts [5,6]. After a mean follow-up of 29 months after a variety of bariatric operations, cholelithiasis develops in as many as 20.7 percent of patients, and 8.2 percent of patients become symptomatic, which is three times higher than in the general population [7]. Gallstones can develop after all bariatric operations [6]. (See "Gallstones: Epidemiology, risk factors and prevention".)
The decision to perform a cholecystectomy at the time of bariatric surgery is controversial. Some surgeons recommend performing cholecystectomy at the time of bariatric surgery if a patient has symptomatic gallstones preoperatively. The surgical opinion about asymptomatic gallstones is more divided, as studies have associated a greater number of complications (odds ratio 1.2, 95% CI 1.1-1.3), albeit not severe ones, with simultaneous cholecystectomy at the time of bariatric surgery [7,8].
The frequency of cholelithiasis can be reduced from 25 to 7 percent with a six-month course of ursodeoxycholic acid (UDCA; ursodiol, a synthetic bile salt) at 600 mg/day given prophylactically after weight-loss surgery [9]. A meta-analysis of 11 randomized trials found that UDCA significantly reduces the risk of both asymptomatic (odds ratio 0.29) and symptomatic gallstones (odds ratio 0.25) and the need for cholecystectomy (odds ratio 0.33) after bariatric surgery [10]. The adoption of a six-month course of prophylactic UDCA has been variable despite the evidence and society guidelines [11]. Some experts adopt it after Roux-en-Y gastric bypass (RYGB) but not sleeve gastrectomy (SG) because of the anatomical difficulties associated with the former if endoscopic treatment of gallstone disease is required.
Patients who develop choledocholithiasis (stones in the common bile duct) after gastric bypass can be challenging to treat with endoscopic retrograde cholangiopancreatography (ERCP) due to the Roux-en-Y configuration (figure 1) [12]. As a result, surgery or transhepatic percutaneous access may be required. This is discussed in detail elsewhere. (See "ERCP in patients with Roux-en-Y anatomy".)
Ventral incisional hernia — Severe obesity is associated with increased intra-abdominal pressure, and thus, a high risk of hernia development after any abdominal surgery. In a study of over 2161 patients undergoing bariatric surgery, ventral incisional hernias occurred in 2.4 percent at a follow-up of 28±25 months [13]. Patients are 10 times more likely to develop a hernia after open than laparoscopic surgery. Other risk factors include malnutrition, prior abdominal surgery, and a body mass index greater than 60 kg/m2.
Incisional hernias present with an enlarging bulge, pain, or obstructive symptoms. Many surgeons postpone a formal repair until significant weight loss occurs (>1 year). Indications for early surgical repair include significant pain, bowel obstruction, and rapid enlargement of the hernia. (See "Clinical features, diagnosis, and prevention of incisional hernias" and "Management of ventral hernias".)
The management of an existing ventral hernia in patients seeking bariatric surgery should be individualized [14,15]. There is some evidence that hernia repair and bariatric surgery may be performed concomitantly, although there are limited data addressing the safety of synthetic mesh placement [16]. For larger hernias not amenable to laparoscopic repair, most surgeons would delay hernia repair/abdominal wall reconstruction until after bariatric surgery and expected weight loss [17].
Change in bowel habits — Patients can expect some change in bowel habits after bariatric surgery, although significant alterations can negatively impact quality of life. In general, loose stool and diarrhea are more common after biliopancreatic diversion (BPD) and RYGB, while constipation is more common after restrictive procedures such as adjustable gastric banding [18,19]. The outcome of SG is variable [20].
In a study of 208 patients, BPD patients reported a higher frequency of bowel movements, more trouble with flatus and urgency, and increased need for keeping a diet compared with RYGB patients. However, general quality of life was improved over baseline after both procedures [21].
Changes in bowel habits after bariatric surgery may be transient. In another study, 573 patients who underwent all types of bariatric surgery reported worsened bowel function at two weeks after surgery. However, by three months, the reported bowel function was already better than the baseline, and the improvement was sustained to two years [22].
PROCEDURE-SPECIFIC COMPLICATIONS
Roux-en-Y gastric bypass — Roux-en-Y gastric bypass (RYGB) involves the creation of a small gastric pouch and an anastomosis to a Roux limb of jejunum that bypasses 75 to 150 cm of small bowel, thereby restricting food and limiting absorption (figure 1). This procedure is the second most common weight loss procedure performed after sleeve gastrectomy. The complications of RYGB are diverse and vary based upon the specific technique. (See "Laparoscopic Roux-en-Y gastric bypass".)
Dumping syndrome — Dumping syndrome is a common complication of esophageal or gastric surgery, including bariatric surgery. The surgically altered anatomy delivers undigested food rapidly into the intestine, thereby triggering a constellation of gastrointestinal and vasomotor symptoms [23].
In a Danish survey of 1429 patients who underwent gastric bypass, 9.4 and 6.6 percent reported experiencing moderate-to-severe symptoms indicative of early dumping and hypoglycemia, respectively [24]. In that cohort, the total prevalence of one or both types of symptoms was 12.6 percent (95% CI 10.9-14.4). Patients who were younger than 35 years of age or had a body mass index (BMI) <25 kg/m2 were more likely to be symptomatic than those who were older or had a higher BMI. Dumping may contribute to weight loss in part by causing patients to modify their eating habits. (See "Postgastrectomy complications", section on 'Dumping syndrome'.)
There are two types of dumping syndrome, early and late [23,25].
Early dumping syndrome — Early dumping syndrome has a rapid onset, usually within one hour of eating. It is the result of rapid emptying of food into the small bowel. Due to the hyperosmolality of the food, rapid fluid shifts from the plasma into the bowel occur, resulting in hypotension and a sympathetic nervous system response. Patients often present with gastrointestinal symptoms (abdominal pain, bloating, borborygmi, nausea, and diarrhea) and vasomotor symptoms (flushing; palpitations; perspiration; tachycardia; hypotension; fatigue; a desire to lie down; and, rarely, syncope) [26].
Patients should avoid foods high in simple sugar content and replace them with a diet consisting of high-fiber, complex carbohydrate, and protein-rich foods. Behavioral modification, such as small, frequent meals, slow eating, chewing well, and separating solid from liquid intake by 30 minutes, is also advocated. Usually, early dumping is self-limiting and resolves within 7 to 12 weeks [27].
Dietary supplements that increase the viscosity of food (such as guar gum, pectin, and glucomannan) or pharmacologic agents (such as acarbose) are a good second-line treatment for symptoms of dumping syndrome after dietary modification [23].
Postprandial hyperinsulinemic hypoglycemia — Previously referred to as "late dumping syndrome," postprandial hyperinsulinemic hypoglycemia (PHH) is a rare complication of bariatric surgery. It occurs in 0.1 to 0.3 percent of patients, most commonly after gastric bypass. Symptoms of PHH, including dizziness, fatigue, diaphoresis, and weakness, usually occur one to three hours after ingesting a carbohydrate-rich meal, typically months to years after surgery, and are associated with documented hypoglycemia [28]. The pathophysiology of PHH is not fully understood but likely includes alterations in multiple hormonal and glycemic patterns (eg, increase in incretin levels). (See "Hypoglycemia in adults without diabetes mellitus: Determining the etiology".)
Most patients with PHH can be managed with the same dietary modification suggested above for early dumping syndrome. Patients who are refractory to dietary modification can be treated with medications (eg, nifedipine, acarbose, diazoxide, or octreotide), gastrostomy tube feeding into the remnant stomach, or revisional bariatric surgery. Pancreatic resection has unproven benefit and should not be performed for PHH. (See "Evaluation of postprandial symptoms of hypoglycemia in adults without diabetes".)
Metabolic derangements — Metabolic and nutritional derangements are common in patients with severe obesity and can be exacerbated following bariatric surgery, making postoperative lifelong compliance with appropriate dietary choices and vitamin supplementation imperative. Decreased oral intake, as well as altered absorption of food from the stomach and small bowel, reduces absorption of various micronutrients, particularly iron, calcium, vitamin B12, thiamine, and folate.
Metabolic derangements that are most common after RYGB are presented here. Nutritional deficiencies are discussed in a separate topic. (See "Bariatric surgery: Postoperative nutritional management", section on 'Micronutrient management'.)
Nephrolithiasis and renal failure — RYGB has been linked to metabolic changes that can alter urine chemistry profiles, resulting in higher calcium oxalate supersaturation and urine oxalate, lower citrate, and lower volume. Consequently, patients have a higher risk of developing nephrolithiasis after RYGB (pooled relative risk 1.79, 95% CI 1.54-2.10) [29]. (See "Kidney stones in adults: Epidemiology and risk factors".)
While uncommon, increased absorption of calcium oxalate can also lead to deposition in the renal parenchyma, resulting in oxalate nephropathy and renal failure [30]. A retrospective review of 11 patients with oxalate nephropathy found that all were hypertensive, and nine had diabetes before the procedure [31]. Renal biopsies revealed diffuse tubular degenerative changes, abundant tubular calcium oxalate deposits, and varying degrees of tubulointerstitial scarring. Effective medical therapy is lacking [32], although anecdotal reports have shown that reversing the gastric bypass may help [33].
Metabolic bone changes and secondary hyperparathyroidism — Vitamin D deficiency and secondary hyperparathyroidism already exists in 60 to 84 percent and 42 to 49 percent of patients seeking bariatric surgery, respectively [34,35]. RYGB further exacerbates calcium deficiency and reduces bone mineral density by reducing dietary calcium intake, calcium absorption (from bypassing the proximal small intestine and reducing gastric acidity), and reducing mechanical loading (from weight loss) [36-39]. Reducing the bone mineral density of the skeletal system can increase the risk of fracture [40]. The increased risk of fractures varies from 25 percent to 2.6-fold, depending on studies [41-44]. Treatment options include calcium/vitamin D supplementation and exercise [45]. (See "Bariatric surgery: Postoperative nutritional management", section on 'Vitamin D' and "Bariatric surgery: Postoperative nutritional management", section on 'Calcium'.)
The prevalence of secondary hyperparathyroidism (SHPT) is high in patients with obesity before bariatric surgery, which is related to vitamin D deficiency. The prevalence of SHPT increased continually along with the time after bariatric surgery, especially in patients receiving single anastomosis gastric bypass, followed by RYGB [46]. A meta-analysis of nine studies found that the risk of SHPT after RYGB markedly increased after two years of follow-up (odds ratio 6.06, 95% CI 3.39-10.85) [47].
Hyperammonemic encephalopathy — Hyperammonemic encephalopathy has been reported in case reports of patients who are failing to thrive after complicated gastrointestinal surgeries that can include RYGB [48]. The underlying etiologies are incompletely understood but include both genetic (eg, proximal urea cycle disorders) and nongenetic causes (eg, splenorenal shunt). The typical clinical features include hypoalbuminemia, hypoglycemia, low plasma zinc level, and other nutritional deficiencies [49].
The key to diagnosis is the early assessment of plasma ammonia levels in such patients with normal hepatic function but characteristic symptoms of encephalopathy [50]. Once hyperammonemic encephalopathy is diagnosed, it can be treated with supportive and medical care to reduce ammonia levels. (See "Hepatic encephalopathy in adults: Treatment".)
Short bowel syndrome — RYGB and other bariatric procedures can be complicated by short bowel syndrome (SBS) that results from massive small bowel resections for internal hernias or bowel obstruction from adhesions [51]. In a retrospective review of 265 patients, 11 (4 percent) developed SBS following bariatric surgery, of which nine had prior primary or revisional RYGB [52].
Initial treatment consists of supportive measures such as total parenteral nutrition [53]; surgical options are lengthening of the common channel, enteral nutrition via gastrostomy into the gastric remnant, and restitution of normal anatomy if still possible [54]. In some cases, this complication may require intestinal transplantation [55]. (See "Pathophysiology of short bowel syndrome".)
Gastrogastric fistula — After RYGB, a gastrogastric fistula (GGF) is a channel that can develop between the gastric pouch and the excluded stomach remnant, allowing ingested food to enter the bypassed foregut (stomach and duodenum). GGF occurs in approximately 1 to 2 percent of patients after RYGB and most commonly causes marginal ulcers or weight regain [56].
Historically, gastric bypass surgeons stapled the stomach without completely dividing the gastric remnant from the pouch. The gastric pouch and gastric remnant stapled in continuity were associated with a 49 percent rate of GGF [57]. The introduction of complete transection of these two segments has decreased the rate of GGF to 0 to 3 percent (figure 2) [56,58].
When persistent marginal ulcers or significant weight regain are seen in a postgastric-bypass patient, particularly in the setting of recurrent or new-onset gastroesophageal reflux symptoms, an upper gastrointestinal series or a computed tomography (CT) scan with oral contrast should be performed to exclude a GGF as a cause. Alternatively, GGF can be diagnosed on flexible upper endoscopy [59].
Patients diagnosed with a GGF who also have either significant weight regain or persistent symptoms from marginal ulcers (eg, abdominal pain, stomal stenosis, or gastrointestinal bleeding) are candidates for repair of the GGF. Endoscopic techniques, including clipping, suturing, and stenting, have been used to treat GGF, but results are varied at best and recurrence rates are high [59,60].
We suggest surgical revision for patients with persistent pain, bleeding, or stenosis from a GGF. In preparation for dividing the GGF, the gastric pouch should be fully mobilized, and the path of the Roux limb should be outlined with an orogastric tube or endoscope. The GGF can be resected by stapling, in which case one must staple inside the previous staple line to avoid creating a blind pouch. Alternatively, the gastric remnant can be opened to allow the fistula to be accessed from the distal side. In some cases, either a redo gastrojejunostomy or a remnant gastrectomy may be required [61].
Failure to lose weight and weight regain — Failure to lose weight following RYGB is rare and is often due to maladaptive eating patterns during the early postoperative period. By contrast, significant late weight regain occurs in up to 20 percent of patients, especially those with BMI >50 kg/m2 at the time of the initial operation. It is often due to progressive noncompliant eating and other behavioral habits [62,63], development of a functional GGF, gradual enlargement of the gastric pouch, or dilatation of the gastrojejunal anastomosis.
●A GGF can cause weight regain by allowing food passage into the remnant stomach, thereby decreasing the restrictive effect of RYGB. The diagnosis and treatment of GGFs has been discussed above. (See 'Gastrogastric fistula' above.)
●Dilatation of the gastric pouch or the gastrojejunal anastomosis may be responsible for weight gain in other patients. The stretched pouch and/or the outlet are thought to arise from repeated overdistension due to excessive food intake. These patients usually do not benefit from the high-risk revisional surgery. However, less invasive endoscopic procedures aimed at suture reduction of the pouch size or tightening of the stoma may be successful [64,65]. (See "Gastrointestinal endoscopy in patients who have undergone bariatric surgery", section on 'Stoma/pouch enlargement'.)
Candy cane Roux syndrome — Candy cane Roux syndrome in patients who have undergone RYGB refers to an excessively long blind afferent Roux limb at the gastrojejunostomy causing postprandial pain often relieved by vomiting. It is believed that the blind afferent limb ("candy cane") acts as an obstructed loop when filled with food (often preferentially), and the distention of the loop causes pain until the food either spills into the Roux limb or is vomited back out (figure 3) [66].
Patients have been reported presenting as early as three months and as late as 11 years after their initial RYGB, typically with symptoms of postprandial epigastric pain, nausea, vomiting, and reflux or food regurgitation [67]. The diagnosis is confirmed by upper gastrointestinal contrast studies or endoscopy. On upper gastrointestinal series, the afferent limb fills before contrast spills into the Roux limb. On upper endoscopy, the afferent limb is usually the most direct outlet of the gastrojejunostomy [66].
The treatment is revisional bariatric surgery, most commonly laparoscopic resection of the afferent limb [68], which ranged in length from 3 to 22 cm in one study (mean of 7.6 cm) [66]. Symptoms resolve after revision surgery in most patients. Surgeons should minimize the length of the blind afferent loop left at the time of initial RYGB to prevent candy cane Roux syndrome.
Sleeve gastrectomy — Laparoscopic sleeve gastrectomy (SG) is a restrictive procedure initially developed as part of a staged approach to an RYGB for high-risk patients with class III obesity, but now typically performed as a standalone operation with good weight loss and resolution of obesity-related comorbidities. In 2013, SG surpassed RYGB as the most performed weight loss surgery in the United States [1].
SG involves creating a "sleeve" of stomach over a bougie and removes a large portion of the greater curvature of the stomach, leaving a small tube along the lesser curvature (figure 4). (See "Laparoscopic sleeve gastrectomy".)
Significant advantages of SG include low complication (3 to 24 percent) and mortality (0.39 percent) rates, the ease of performing the procedure, preservation of the pylorus, maintenance of physiological food passage, and avoidance of foreign material [69]. In a database study of over 38,000 patients, patients undergoing SG had fewer reinterventions (9.9 versus 15.6 percent) and complications (6.6 versus 9.6 percent) than patients undergoing RYGB in the first two years. At or after two years, revisions were slightly more common with SG than RYGB (0.6 versus 0.4 percent), primarily because of the higher incidence of gastroesophageal reflux disease (GERD) with SG [70].
The most common early (<30 days) complications of SG, including bleeding, narrowing or stenosis of the stoma, and leaks, are discussed in another topic. (See "Bariatric operations: Early (fewer than 30 days) morbidity and mortality", section on 'Gastrointestinal leak'.)
Late (>30 days) complications of SG include GERD and Barrett esophagus.
Acid reflux or Barrett esophagus — GERD is common among the population with obesity and may improve after bariatric surgery because of weight loss [71]. However, compared with RYGB, patients are more likely to develop de novo GERD after SG.
●A 2020 systematic review and meta-analysis of 46 studies found that 19 percent of patients had worsening reflux, and 23 percent developed de novo reflux after SG [72]. Additionally, 28 and 8 percent developed esophagitis and Barrett esophagus over the long term. Four percent of all patients required conversion to RYGB for severe reflux.
●A 2021 systematic review and meta-analysis of 10 studies reported an 11.6 percent (95% CI 8.1-16.4) prevalence of Barrett esophagus after SG over 6 months to 10 years follow-up [73]. Interestingly, the prevalence of Barrett esophagus did not correlate with that of GERD.
GERD after SG presents with classic symptoms such as burning pain, heartburn, and regurgitation (image 1). It can occur as an early or late complication. The first-line treatment is antireflux medical therapy. GERD unresponsive to antireflux medical therapy with no clear anatomic abnormalities, such as stoma stenosis or a hiatal hernia, can be effectively treated by conversion to RYGB [74,75]. (See "Medical management of gastroesophageal reflux disease in adults".)
Biliopancreatic diversion and duodenal switch — Biliopancreatic diversion (BPD) is a malabsorptive procedure that relies on limiting absorption of fats and starches to a relatively short segment of small intestine as well as decreasing the gastric reservoir size (figure 5). (See "Bariatric procedures for the management of severe obesity: Descriptions", section on 'Biliopancreatic diversion with duodenal switch'.)
BPD differs from jejunoileal bypass in that no intestinal limb is excluded from flow, thus avoiding creation of a blind loop (see 'Jejunoileal bypass' below). Excellent weight loss results with morbidity and mortality rates comparable to RYGB have been described by the few centers that perform BPD along with its duodenal switch variant (BPD-DS) (figure 6) [76,77].
BPD-DS has not become widespread because of the technical complexity of the procedure, with historically high surgical morbidity and mortality rates and concerns regarding the long-term nutritional outcomes [78], including significant protein-calorie malnutrition, anemia, metabolic bone disease, and deficiencies of fat-soluble vitamins [79-81].
Vitamin deficiency — BPD-DS is associated with a greater risk of vitamin D deficiency and secondary hyperparathyroidism because it induces more protein-calorie malnutrition than any other bariatric operation. In a five-year study of 1400 patients undergoing BPD-DS, vitamin D deficiency developed in up to 15 percent of patients at three years and secondary hyperparathyroidism in up to 68 percent of patients at five years [82]. Consequently, the risk of fracture due to lower bone mineral density is also increased the greatest after BPD-DS. In one study, the fracture risk after BPD-DS was increased by 60 percent compared with nonsurgical controls with obesity [41]. Due to the higher prevalence of metabolic bone disease, a higher dosage of supplementation and repletion of calcium and vitamin D is recommended after BPD-DS than after other bariatric operations [83]. (See "Bariatric surgery: Postoperative nutritional management", section on 'Vitamin D' and "Bariatric surgery: Postoperative nutritional management", section on 'Calcium'.)
Adjustable gastric banding — Adjustable gastric banding (AGB) is a purely restrictive procedure involving placement of an adjustable silicone device at the gastric cardia near the gastroesophageal junction, limiting the amount of food consumed. Restriction can be adjusted by injecting saline into a subcutaneous port connected to the band (figure 7). (See "Bariatric procedures for the management of severe obesity: Descriptions", section on 'Laparoscopic adjustable gastric banding'.)
AGB has the lowest mortality rate among all bariatric procedures (about 0.05 percent) [84]. The early (<30 days) complication rate is low (5 to 10 percent), but the late (>30 days) complication rate is high (>25 percent) [84-89]. Almost 50 percent of patients will need surgical revision or removal of the band [90]. Failed bands (due either to complications or inadequate weight loss) can generally be converted to other bariatric procedures such as RYGB, SG [91], one-anastomosis gastric bypass [92,93], or single-anastomosis duodenal switch [94].
Late complications of AGB include band erosion, band slippage or prolapse, port or tubing malfunction, leakage at the port site tubing or band, pouch or esophageal dilatation, esophagitis, and hiatal hernia [95].
Band erosion — Partial or complete band erosion through the gastric wall has been reported in 1 percent of AGB patients [96], and it is thought to occur as a result of either gastric wall ischemia from an excessively tight band, mechanical trauma related to the band buckle, or thermal trauma from electrosurgical energy sources used during band placement [97-99] (figure 8). Band erosion is a late complication that occurs at a mean of 22 months after surgery [97].
Clinical signs of band erosion include port site infection, failure of weight loss, or nausea and vomiting [100]. Epigastric pain and hematemesis can also signal erosion of the band into the left gastric artery [101]. This can happen when the lap band erodes into the posterior part of the stomach near the cardioesophageal junction. This complication can be avoided by careful placement during the initial surgery, ensuring not to include the ascending branch of the left gastric artery during band placement.
Band erosion can be diagnosed by endoscopy, and treatment involves removal of the band to avoid further complications. Band removal, along with repair of the gastric wall, is typically performed laparoscopically [102]. An intraoperative leak test is performed, and a drain is placed. Revision to another bariatric procedure should be delayed for at least two to three months.
Successful endoscopic removal has also been reported when the buckle of the band is visible endoscopically [103,104]. However, endoscopic band removal is more technically challenging. (See "Gastrointestinal endoscopy in patients who have undergone bariatric surgery", section on 'Band erosion'.)
Band slippage and gastric prolapse — In contemporary series, band slippage occurs at a rate of 5 to 8 percent [96,105,106]. The modern pars flaccida approach with anterior band fixation by gastrogastric sutures is specifically designed to prevent band slippage [107].
Band slippage involves prolapse of part of the stomach through the band, with varying degrees of gastric obstruction. The stomach usually prolapses in one of three configurations [108]:
●Anterior prolapse involves migration of the band cephalad, which creates an acute angle with the stomach pouch and esophagus, resulting in obstruction.
●Posterior gastric prolapse occurs when the stomach migrates cephalad, displacing the band caudally and creating a new pouch (figure 9).
●Symmetric prolapse, also referred to as symmetric pouch dilation, differs from anterior and posterior prolapse, which are asymmetric prolapses.
Gastric prolapse is characterized by food intolerance, epigastric pain, and acid reflux [106]. Diagnosis is confirmed with an abdominal plain film, CT, or an upper gastrointestinal series demonstrating either malposition of the band or dilatation and prolapse of the gastric pouch [109,110]. (See "Imaging studies after bariatric surgery", section on 'Band slippage and gastric prolapse'.)
A slipped band can sometimes be repositioned by deflation, but often the band needs to be replaced or removed surgically if removing the fluid from the band does not reposition it. Although surgical correction of a slipped band is usually not an emergency, it should be performed in a timely manner to avoid further complications such as aspiration or gastric strangulation. Revision to another bariatric procedure should be delayed until the inflammation has subsided to avoid complications at the staple lines.
In patients who present with acute onset epigastric pain, surgery is required urgently to exclude catastrophic complications such as gastric strangulation, ischemia, or volvulus [111,112]. (See "Bariatric operations: Late complications with acute presentations".)
Esophageal dilatation or esophagitis — Esophageal dilatation proximal to the band device has been reported in 6 percent of AGB patients [113,114]. This so-called "pseudoachalasia syndrome" may develop when the band is excessively inflated or in the setting of excessive amounts of food intake. Pouch dilatation has also been associated with a history of binge eating behavior [115].
Patients often present with food and saliva intolerance, reflux, and epigastric discomfort. The diagnosis can be confirmed with an upper gastrointestinal series. (See "Imaging studies after bariatric surgery", section on 'Esophageal dilation'.)
The initial treatment should be the removal of all the fluid from the band and behavioral diet modifications. This is usually successful in reversing esophageal dilatation [116]. The band should not be reinflated for at least eight weeks. However, persistent dilatation may require replacement of the band in a new location on the stomach or conversion to a RYGB.
Esophagitis and reflux are infrequent early complications following AGB [117]. Deflation of the band and acid suppression therapy are the mainstays of treatment. However, if intractable to medical therapy, band removal or conversion to other procedures such as RYGB may be necessary. (See "Medical management of gastroesophageal reflux disease in adults".)
Hiatal hernia — Hiatal hernia is often a preexisting but unrecognized condition in patients undergoing bariatric surgery [118]. This can lead to ongoing intractable reflux necessitating reoperation or band removal (image 2). Thus, a simple crural repair can be performed at the initial operation to avoid these complications [119]. A retrospective review of 1298 patients who underwent AGB alone and 520 patients who underwent AGB with concurrent hiatal hernia repair showed that the rate of reoperation was significantly reduced in patients who had hiatal repair at the time of AGB as compared with those who had AGB alone (1.7 versus 5.6 percent, respectively) [118]. (See "Imaging studies after bariatric surgery", section on 'Hiatus hernia' and "Hiatus hernia", section on 'Management'.)
Port malfunction or infection — Port malfunction results if the tubing disconnects, subcutaneous port flips, or leakage within the system occurs. Such problems lead to inability to titrate the instilled volume of saline in the system. The reported incidence of port and tubing malfunction ranges from 0.4 to 7 percent [120,121]. These problems usually become evident as an inability to access the port and maintain band volume, or with the development of weight gain. These complications require surgical repair or exchange of the hardware to attain band adjustability. (See "Imaging studies after bariatric surgery", section on 'Tubing migration or disconnection'.)
Port infection has been reported in 0.3 to 9 percent of AGB patients [87,122,123]. Because the port is a foreign body, port infection is treated with surgical removal, especially in association with band erosion. If an isolated port infection is found, the infected port is removed, and a new port is reimplanted once the infection clears.
Vertical banded gastroplasty — Vertical banded gastroplasty (VBG), also known as "stomach stapling," is a purely restrictive procedure involving the creation of a small proximal gastric pouch lined by a vertical staple line and a tight prosthetic mesh (figure 10) [124]. (See "Bariatric procedures for the management of severe obesity: Descriptions", section on 'Vertical banded gastroplasty'.)
The VBG has been largely supplanted by other bariatric procedures and is no longer performed, but patients who underwent VBG still present to bariatric surgeons today with complications including staple line disruption, stomal stenosis, band erosion, GERD, nausea/vomiting, marginal ulcers, and weight regain [125]. In long-term studies, up to 40 percent of patients require reoperation for complications (eg, vomiting), and up to 30 percent require another bariatric procedure [126-128]. VBG is more commonly converted to an RYGB or a BPD [129].
Staple line disruption — Disruption of the staple line results in a fistula to the fundus, which can lead to decreased restriction in the VBG [130,131]. This complication can occur in 27 to 31 percent of the patients and can be as high as 48 percent if assessed on routine postoperative endoscopy [132]. Staple line disruption typically leads to weight regain due to increased food consumption since patients can eat around their restriction without feeling full.
Obstruction — Stomal stenosis occurs in approximately 20 to 33 percent and can occur due to fibrosis in the stomach or by the band itself [127,133]. The resulting obstruction leads to food intolerance, reflux, and often weight regain due to dietary shifts to calorically dense liquids and softer foods. Staple line dehiscence, esophageal dilatation, and a fistula between the VBG pouch and occluded stomach have also been reported [3].
Stomal stenosis following VBG can initially be managed nonoperatively by endoscopic dilation, with surgery reserved for failures. However, dilation may be unsuccessful due to the rigid nature of the prosthetic band. A success rate of 68 percent for endoscopic dilation of stomal stenosis was described in one series [134]. Symptomatic relief following endoscopic dilation is often short lived, and surgical revision may be necessary when symptoms persist. Dense scarring also presents a significant operative risk when revision is required.
Erosion of mesh band — Band erosion is a frequent late complication of VBG occurring with an incidence of 1 to 7 percent and usually occurs one to three years after the surgery [132,135]. Patients generally present with abdominal pain and vomiting. Surgical removal is indicated if erosion is visualized by endoscopy.
Reflux — Gastroesophageal reflux after VBG presents with classic symptoms such as burning pain, heartburn, aspiration, and cough. It typically occurs as a late complication as a result of stomal stenosis and pouch dilatation [136]. GERD unresponsive to antireflux medical therapy often requires reversal of the VBG or conversion to RYGB. In a review of 25 patients undergoing a revision of a VBG for symptomatic reflux, esophagitis was present in 58 percent of patients and Barrett esophagus in 28 percent [136]. (See "Medical management of gastroesophageal reflux disease in adults".)
Vomiting — Recurrent vomiting occurs in approximately 8 to 21 percent of patients following VBG [126]. The etiology may be multifactorial, including maladaptive dietary patterns (such as eating too quickly or not chewing properly) as well as functional problems such as stomal stenosis, pouch dilatation, staple line disruption, or GERD. These patients will often become sweet eaters to ingest calories in a form that does not cause vomiting.
Not all patients with recurrent vomiting require an operative revision. Initial treatment should consist of dietary modification (ie, proper chewing, eating at a slower pace, and avoidance of problem foods that give recurrent vomiting) and radiologic and/or endoscopic evaluations for structural problems. Operative revision is required if the vomiting persists and leads to malnutrition and/or dehydration [127].
Jejunoileal bypass — Jejunoileal bypass (JIB) is a purely malabsorptive procedure that was popular in the 1960s and 1970s. The procedure produces significant weight loss by creating a surgical short bowel syndrome (figure 11). (See "Bariatric procedures for the management of severe obesity: Descriptions", section on 'Jejunoileal bypass'.)
JIB is no longer used today because of a 50 percent morbidity rate and a 10 percent mortality rate [137]. Over half of the patients who underwent JIB developed diarrhea and electrolyte imbalances [138], and these problems could persist more than five years after surgery. Patients who previously underwent JIB should be followed carefully for signs of complications, including arthritis, protein malnutrition, vitamin deficiencies, cirrhosis, nephrolithiasis with oxalate stones, and renal failure [139-142].
Renal failure — Increased absorption of calcium oxalate leads to deposition in the renal parenchyma, which can lead to postobstruction nephropathy and renal failure [143,144]. Conversion to a RYGB or reversal should be considered in patients with metabolic complications [145,146].
Cirrhosis — Hepatic abnormalities that may lead to cirrhosis can occur in up to 40 percent of patients and may persist or progress despite reversal in more than one-third of patients [147,148]. Progressive liver injury appears histologically as increasing steatosis, lobular lymphocytic inflammation, pericellular fibrosis, Mallory bodies, and deranged architecture, all features resembling those seen in alcoholic liver disease [149-151].
Some patients have progressed to decompensated cirrhosis requiring liver transplantation [152,153]. If not already performed, reversal of the jejunoileal bypass at the time of transplant should be considered. Reversal prior to transplant may not be feasible because of the risk of precipitating hepatic decompensation in patients with advanced liver disease. Patients who do not undergo reversal at the time of transplant should be monitored closely, with reversal performed in those who develop progressive liver injury [149,152,153].
REOPERATIONS — Evaluations of longer-term safety of bariatric operations most often center on rates of reoperation and reinterventions. In contemporary series, the reoperation rate following bariatric surgery generally ranges from 5 to 22.1 percent [4,154]. Roux-en-Y gastric bypass has higher rates of reoperations compared with sleeve gastrectomy in cohort studies [155,156] but not randomized trials [157,158]. The incidence of reoperations may also change with the length of follow-up [70].
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
●Common complications – Late (>30 days), nonacute complications that can occur after all bariatric procedures include cholelithiasis, ventral incisional hernias, and change in bowel habits. (See 'Complications common to all procedures' above.)
●Roux-en-Y gastric bypass – Late (>30 days), nonacute complications of Roux-en-Y gastric (RYGB) bypass include dumping syndrome (early and late), metabolic and nutritional derangements, gastrogastric fistulas (GGF), short bowel syndrome, and candy cane Roux syndrome. For patients with persistent pain, bleeding, or stenosis from a GGF, we suggest surgical revision rather than other treatments (Grade 2C). (See 'Roux-en-Y gastric bypass' above.)
●Sleeve gastrectomy – Late (>30 days), nonacute complications of sleeve gastrectomy (SG) include gastroesophageal reflux disease and Barrett esophagus. (See 'Sleeve gastrectomy' above.)
●Biliopancreatic diversion – Late (>30 days), nonacute complications of biliopancreatic diversion (BPD) with or without duodenal switch include significant protein-calorie malnutrition, anemia, metabolic bone disease, and deficiencies of fat-soluble vitamins (eg, vitamin D) and vitamin B12. (See 'Biliopancreatic diversion and duodenal switch' above.)
●Adjustable gastric banding – Late (>30 days), nonacute complications of adjustable gastric banding include band erosion, band slippage leading to gastric prolapse, port malfunction or infection, esophageal dilatation or esophagitis, and hiatal hernia. About half of these patients require revision surgery. (See 'Adjustable gastric banding' above.)
●Vertical banded gastroplasty – Although no longer performed, vertical banded gastroplasty complications include staple line disruption, stomal stenosis, band erosion, reflux, nausea/vomiting, marginal ulcers, and weight regain. About 40 percent of patients require revision surgery. (See 'Vertical banded gastroplasty' above.)
●Jejunoileal bypass – Jejunoileal bypass is no longer performed because of a high morbidity and mortality rate. However, patients who underwent this procedure can present years later with significant complications, including arthritis, protein malnutrition, vitamin deficiencies, cirrhosis, nephrolithiasis with oxalate stones, and renal failure. (See 'Jejunoileal bypass' above.)
●Reoperations – In contemporary series, the reoperation rate following bariatric surgery generally ranges from 5 to 22 percent. RYGB is associated with higher rates of reoperations compared with SG in cohort studies but not randomized trials. (See 'Reoperations' above.)
28 : ASMBS Position Statement on Postprandial Hyperinsulinemic Hypoglycemia after Bariatric Surgery.
35 : Prevalence of vitamin D depletion among morbidly obese patients seeking gastric bypass surgery.
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