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Laparoscopic Roux-en-Y gastric bypass

Laparoscopic Roux-en-Y gastric bypass
Literature review current through: Jan 2024.
This topic last updated: Dec 02, 2022.

INTRODUCTION — Laparoscopic Roux-en-Y gastric bypass (LRYGB), as a bariatric procedure, was first described by Alan Wittgrove in 1994 [1]. Over the ensuing decades, the technique of LRYGB as well as perioperative care of patients have been gradually improved and refined [2]. Consequently, the mortality rate associated with the RYGB has decreased from 2.6 percent at the turn of the century [3] to 0.09 percent in contemporary practices [4].

LRYGB remains the gold standard against which other bariatric procedures are measured. LRYGB induces more weight loss than adjustable gastric banding [5] and more durable weight loss than sleeve gastrectomy [6], causes lower morbidity and mortality than biliopancreatic diversion/duodenal switch and the single-anastomosis duodenal ileal bypass [7], and has proven efficacy that is sometimes matched but not surpassed by newer procedures such as the one-anastomosis gastric bypass (also known as the mini-gastric bypass), intragastric balloon, and vagal stimulation [8-10]. (See "Bariatric procedures for the management of severe obesity: Descriptions".)

The indications, preoperative workup, techniques, postoperative care, and outcomes of LRYGB are discussed here. Other bariatric procedures along with their perioperative management are discussed in other topics, including:

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

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

(See "Bariatric surgery: Postoperative nutritional management".)

(See "Outcomes of bariatric surgery".)

(See "Laparoscopic sleeve gastrectomy".)

(See "Intragastric balloon therapy for weight loss".)

MECHANISM OF ACTION — The Roux-en-Y gastric bypass (RYGB) works by restricting the amount of food one ingests (restriction), by limiting the amount of nutrients absorbed from the ingested food (malabsorption), and by altering the hormonal response to food. By bypassing the duodenum and excluding the distal stomach, ghrelin levels are lowered, which decreases hunger; leptin levels increase, which increases satiety; and glucagon-like peptide-1 levels increase, which decreases appetite and the desire for food intake [11].

INDICATIONS — The indications for laparoscopic Roux-en-Y gastric bypass (LRYGB) are the same as for all endorsed bariatric procedures. (See "Bariatric surgery for management of obesity: Indications and preoperative preparation", section on 'Indications'.)

Patients who are eligible by these criteria should undergo a multidisciplinary evaluation by a registered dietitian, a psychologist, a bariatrician, and a bariatric surgeon. Good candidates for bariatric surgery may then choose from the procedures offered by their surgeons. (See "Bariatric surgery for management of obesity: Indications and preoperative preparation", section on 'Preoperative assessment'.)

While all commonly performed bariatric procedures will produce substantial and sustained weight loss, physiologic or anatomic reasons to favor or avoid RYGB include:

RYGB has better efficacy against insulin resistance than most other bariatric procedures. It may be preferred in patients with uncontrolled type 2 diabetes, nonalcoholic fatty liver disease, metabolic syndrome, or polycystic ovarian syndrome. These conditions are attributable to insulin resistance. Additionally, while sleeve gastrectomy (SG) and RYGB are equally effective in improving diabetes in the short term, RYGB is associated with better long-term control of diabetes and lower rates of relapse [12]. (See "Outcomes of bariatric surgery", section on 'Diabetes mellitus'.)

Patients with Barrett's esophagus, severe/complicated gastroesophageal reflux disease (GERD), or bile reflux may be better candidates for RYGB than for SG. (See 'Preoperative workup' below and "Laparoscopic sleeve gastrectomy", section on 'Indications'.)

Because RYGB involves two gastrointestinal anastomoses, it may be riskier for patients who chronically take glucocorticoid or nonsteroidal anti-inflammatory medications because of the risk of leaks or marginal ulceration. Crohn disease, in particular, is a relative contraindication for RYGB due to the potential for strictures and leaks at the anastomoses [13]. Patients who have obesity and are candidates for a renal or liver transplant may be better suited for an SG because of their need for anti-inflammatory or antirejection medication [14]. (See "Laparoscopic sleeve gastrectomy", section on 'Indications'.)

PREOPERATIVE PREPARATIONS

Preoperative workup — Details of the general preoperative workup for all bariatric patients are discussed separately. (See "Bariatric surgery for management of obesity: Indications and preoperative preparation", section on 'Preoperative assessment'.)

In addition, patients who are symptomatic from foregut diseases should undergo esophagogastroduodenoscopy (EGD) before undergoing a laparoscopic Roux-en-Y gastric bypass (LRYGB):

An EGD should be performed in patients with current or a history of peptic ulcer disease to ensure that there is no residual or active disease in the remnant stomach. The remnant stomach and the duodenum will not be accessible to standard endoscopic examination after RYGB.

Patients with severe gastroesophageal reflux disease (GERD) should undergo preoperative EGD to rule out Barrett's esophagus or severe dysplasia, which should be addressed before bariatric surgery. For areas that have access to an advanced endoscopist who can perform a submucosal resection of the diseased esophagus, a sleeve gastrectomy (SG) may still be an option as these entities can be treated without esophageal resection. For those patients who do not have this option, the findings of Barrett's esophagus or severe dysplasia should encourage them to choose RYGB over SG. (See 'Indications' above and "Laparoscopic sleeve gastrectomy", section on 'Indications'.)

However, routine EGD before RYGB is probably not necessary [15]. Identification of foregut abnormalities such as esophagitis or hiatal hernia by EGD does not usually alter the timing or operative plans of bariatric surgery.

Preoperative weight loss — Most surgeons will prescribe a low-calorie liquid diet for a period of one to four weeks prior to surgery to help reduce any stiffness and the size of the liver [16]. A soft, mobile liver will be easier to retract, enabling better exposure of the gastroesophageal junction. Mandatory weight loss prior to offering surgery, however, is not necessary and often only serves to delay treatment. (See "Bariatric surgery for management of obesity: Indications and preoperative preparation", section on 'Preoperative weight loss'.)

TECHNIQUE

Premedications — Hospitals should utilize an enhanced recovery after surgery (ERAS) protocol for bariatric procedures as it has been shown to reduce opioid use, postoperative nausea/vomiting, and length of stay without negatively affecting the morbidity and mortality rate [17,18]. There are many variants of an ERAS protocol, but the tenets of a protocol include prophylaxis against infection, venous thromboembolic events (VTEs), postoperative nausea/vomiting (PONV), marginal ulcers, and difficulty with pain control.

Infection prophylaxis – On the day of surgery, antibiotic prophylaxis should be given within one hour prior to the skin incision (table 1).

VTE prophylaxis For VTE prophylaxis, sequential compression devices (SCDs) should be placed for all patients undergoing bariatric surgery. The decision to add chemoprophylaxis is controversial and left to the individual surgeon's discretion. In general, high-volume surgeons with short operative times (ie, <90 minutes) do not routinely use chemoprophylaxis. Others routinely use chemoprophylaxis, most commonly low-molecular-weight heparin [19]. Chemoprophylaxis should be given well before induction of anesthesia, which is the time when VTE formation begins [20]. There is no role for inferior vena cava (IVC) filters in bariatric patients unless there is a history of VTEs despite adequate anticoagulation [21]. (See "Bariatric operations: Early (fewer than 30 days) morbidity and mortality", section on 'Venous thromboembolism'.)

Marginal ulcer prophylaxis A proton-pump inhibitor is given preoperatively and typically continued for one to three months after surgery.

PONV prophylaxis Antinausea medication is typically given prior to induction and surgery. This would include a scopolamine patch and/or intravenous medications. (See "Postoperative nausea and vomiting", section on 'Prevention'.)

Pain control Intravenous and sometimes oral pain medication is started prior to induction and surgery. A long-acting local anesthetic or a laparoscopically guided transverse abdominis plane block with long-acting local anesthetic is given. (See "Measures to prevent prolonged postoperative ileus", section on 'Multimodal analgesia'.)

Anesthesia — General endotracheal anesthesia is required for laparoscopic Roux-en-Y gastric bypass (LRYGB). Intubating patients with obesity can be difficult, so every precaution should be taken. A "ramp" that elevates the patient's torso can allow some body fat to fall away from the head and neck area (figure 1). (See "Anesthesia for the patient with obesity", section on 'Preoxygenation and apneic oxygenation'.)

Positioning — The patient should be placed supine with both arms abducted to almost 90° while secured to the table with two leg straps and a footplate to prevent sliding when the patient is placed in the steep reverse Trendelenburg position. An inflatable mat (eg, HoverMatt) can be placed underneath the patient to facilitate moving the patient after surgery.

A urinary catheter can be placed at the discretion of the surgeon depending on the expected length of the procedure. An orogastric tube should be placed to decompress the stomach so the stomach will be easier to manipulate. The surgeon must remember to remove the orogastric tube prior to stapling across the stomach to create the gastric pouch. (See 'Formation of the gastric pouch' below.)

Typically, the surgeon will stand on the patient's right side and the first assistant on the patient's left side. To perform the procedure ergonomically in an abdomen made taller by the pneumoperitoneum, the surgeon should stand on one or two step stools so that their shoulders are relaxed and the forearms can operate at a ≥90° angle from the upper arms.

Pneumoperitoneum and trocar placement — The pneumoperitoneum can be established with one of three safe methods: Veress needle, the open Hasson trocar, and the optical trocar technique. Due to extensive subcutaneous tissue present, the Hasson technique will require a larger incision in patients with obesity. (See "Abdominal access techniques used in laparoscopic surgery", section on 'Initial port placement'.)

Many bariatric surgeons favor the use of a combination of the Veress needle and the optical trocar technique. First, a Veress needle is placed inferior to the left costal margin at the midclavicular line (Palmer's point). Proper needle placement is assured by a pressure reading of <10 mmHg [22]. Carbon dioxide is insufflated via the Veress needle to a pressure of 15 mmHg. The Veress needle is then removed, and an optical viewing trocar is placed through a 5 to 15 mm skin incision in the left upper quadrant. After the port is placed, the peritoneum is inspected laparoscopically to exclude any injury caused by either the Veress needle or the optical trocar. Placing the patient in a 10 to 15° reverse Trendelenburg position may allow the subcutaneous and intra-abdominal fat to be displaced away from the upper quadrant, allowing easier initial access to the peritoneal cavity.

After pneumoperitoneum has been established, additional trocars are inserted under laparoscopic vision:

If only one assistant is available, five trocars are typically required:

The surgeon operates through two trocars in the patient's right upper quadrant.

The camera trocar is placed in the midline, 20 to 25 cm from the xiphoid and cephalad to the umbilicus.

One trocar is used for a liver retractor. That trocar is placed through a 5 mm subxiphoid incision if a Nathanson-type retractor is used.

The first assistant works through a left upper quadrant trocar.

If a second assistant is available, the second assistant will usually hold the camera. The first assistant will then use two operating trocars in the left upper quadrant to help with retraction and exposure. A second assistant may be necessary in patients with a lot of intra-abdominal fat to help with retraction.

Since reaching the gastroesophageal (GE) junction is imperative, working trocars should generally not be placed farther than 15 to 20 cm from the xiphoid, measured after abdominal insufflation. Standard laparoscopic equipment is 38 cm long, but bariatric ones are available that are 43 cm long. Laparoscopic staplers also come in longer lengths to accommodate patients with obesity.

In patients who are very large or with a lot of truncal obesity, an extra working trocar for the surgeon may be added in the right upper quadrant. This way, the surgeon can reach the GE junction by using the more cephalad two trocars and reach the small intestine through the two more caudal trocars.

In patients with a previous abdominoplasty or who are very short in stature, the pneumoperitoneum may not yield a large enough working space. In such patients, trocars need to be placed further apart to avoid having instruments interfere with one another. Additional trocars may also be needed for retraction.

Surgical steps — The basic tenets of an LRYGB are to create a 30 mL gastric pouch from the proximal stomach, anastomose it to a Roux limb that is 75 to 150 cm in length, and connect the Roux limb to the biliopancreatic (BP) limb to create a common channel (figure 2). The BP limb is typically 50 to 150 cm in length, and the combined lengths of the Roux limb and the BP limb are a total of 200 cm. It is generally accepted that the common channel (from the jejunojejunal [JJ] anastomosis to the cecum) must be >200 cm to permit sufficient absorption of nutrients to prevent malnutrition. (See 'Bypass length' below.)

These tenets can be achieved in many different ways, each with its own merits and perils. The description below is the author's preferred technique of a retrocolic, antegastric Roux limb with a linear-stapled gastrojejunal (GJ) anastomosis. Other variations in techniques will be addressed in a subsequent section. (See 'Variations in technique' below.)

Division of the falciform ligament — This is done to improve visualization of the upper abdomen and to allow easy passage of the right upper quadrant instruments to the GE junction. Also, at this time, any adhesions to the anterior abdominal wall should be divided to allow full mobilization of the small intestine, omentum, and transverse colon.

Making the retrocolic passageway — The next step is to gain entry into the lesser sac via the gastrocolic omentum. The stomach is retracted superiorly, and the omentum is retracted inferiorly. The gastrocolic omentum is then opened using an electrosurgical device. After the lesser sac is entered, the transverse mesocolon is identified and an opening is made using the electrosurgical device. This opening allows access to the infracolic portion of the abdomen through the lesser sac. This opening can be found on the infracolic side of the transverse mesocolon by retracting the omentum and transverse colon cephalad.

Formation of the jejunojejunal anastomosis — With this same retraction, the ligament of Treitz can be seen at the left base of the transverse mesocolon where the duodenum exits the retroperitoneal space. From the ligament of Treitz, 50 to 150 cm of jejunum is measured. At this point, the jejunum is divided using an endoscopic linear stapler with a closed stapler height of 1.0 to 2.5 mm. The jejunum proximal to this division becomes the BP limb, and the jejunum distal to this division becomes the Roux limb (also referred to as the alimentary limb). The BP limb is labeled with a clip or a stitch to help identify it and prevent the Roux limb from being anastomosed to itself, also known as a Roux-en-O loop. The mesentery is further divided using a 45 mm endoscopic linear stapler with a 1 mm closed stapler height to allow further mobilization of the Roux limb to reach the GE junction without tension. The mesentery should be divided perpendicular to the intestine to avoid ischemia of the Roux or BP limb. Careful attention should also be paid to avoid stapling too close to the base of the mesentery, which may cause ischemia to the entire small bowel. The use of fluorescence imaging can assist with preventing ischemia to the bowel.

Seventy-five to 150 cm of small bowel is then measured to be used as the Roux limb. At the desired length, the distal end of the Roux limb is placed next to the BP limb to construct a side-to-side JJ anastomosis. The bowel loops are first held together with a stay suture, which is also used to provide countertraction. Enterotomies are then made in both the BP and the Roux limbs. A 60 to 90 mm linear stapler with a 1.0 to 2.5 mm closed staple height is placed through the enterotomies and fired to create the anastomosis. The resulting common enterotomy is closed by sewing in a running over-and-over fashion or with a linear stapler. At least two antiobstruction stitches are placed to suture the Roux limb to the BP limb just proximal to the JJ anastomosis. The Roux limb is then placed into the lesser sac through the opening in the transverse mesocolon, making sure that the Roux limb is not twisted when doing so.

The transverse colon and omentum are then retracted caudally so that the Roux limb can be seen in the lesser sac. The Roux limb is then brought to the GE junction for the GJ anastomosis.

Formation of the gastric pouch — The patient is placed in a moderate-to-steep reverse Trendelenburg position. A 30 mL pouch has a dimension of approximately 3 x 3 x 3 cm. This can be measured using laparoscopic instruments, rulers placed in the abdomen, or a 30 mL balloon deployed in the proximal stomach as a guide.

When creating the pouch, some surgeons spare the perigastric neurovascular bundle containing vagal fibers, while others divide it routinely. In theory, sparing the vagal nerve fibers may allow better peristalsis of the BP limb and normal emptying of both the gastric remnant and the gallbladder. Normal gallbladder emptying may help prevent gallstone formation. Dividing the vagal fibers may help prevent peptic ulcer disease in the gastric remnant and the duodenum, both difficult areas to survey after RYGB. A single-institution, retrospective study of 773 patients suggested that transecting the perigastric neurovascular bundle was associated with more leaks, bleeding, and abscess formation but no difference in weight loss or diabetes control [23].

After entering the retrogastric space, the surgeon should fully mobilize the angle of His by dividing the cardia's attachments to the overlying diaphragm. Complete mobilization of the fundus, especially a large one, will ensure that a too large gastric pouch is not created. The gastric vascular pedicle is also visualized, and blood supply to the gastric pouch should be preserved.

The stomach is then divided into a gastric pouch and a gastric remnant using a stapling device with 1.0 to 2.5 mm closed staple heights after the anesthesia provider has removed all tubes and probes from the patient's mouth. Failure to do so would risk dividing the tubes or probes and leaving the distal ends in the gastric remnant.

After making the gastric pouch, the surgeon may divide more retrogastric attachments to decrease the tension on the anastomosis and to allow better visualization of the gastric tissue. Overly aggressive mobilization, however, could devascularize the gastric pouch and lead to complications such as leak or stenosis.

Gastrojejunal anastomosis — We prefer to create the GJ anastomosis with the linear-stapled technique, which involves the use of a linear stapler device and some hand-sewing. The anastomosis is created in two layers.

First, a posterior row of sutures is placed to connect the Roux limb to the gastric pouch. Next, enterotomies are made in both the Roux limb and the gastric pouch. Then, approximately 20 to 25 mm of a linear stapler with 1.0 to 2.5 mm closed staple heights is placed in the enterotomies, and the stapler is fired, creating the inner layer of the anastomosis. The common enterotomy is then closed by hand-sewing with sutures. At this point, some surgeons will place a bougie or endoscope through the anastomosis to calibrate the anastomosis and prevent it from being too narrow. After that, an anterior row of sutures is placed to complete the anastomosis. The author recommends using long-lasting absorbable sutures.

Intraoperative leak test — After creating the GJ anastomosis, the author prefers to perform an intraoperative leak test. Methods of such testing are described separately. (See 'Leak testing' below.)

Closing of potential internal hernia sites — After the GJ anastomosis has been created and tested, potential internal hernia sites are closed. A number of randomized trials found that routine closure of the mesenteric defects reduced the rate of internal hernia at two years (4.5 versus 8 percent), five years (6.5 versus 15.5 percent), and 10 years (8 versus 15 percent) without adverse effects [24,25].

For a retrocolic Roux limb, there are three potential hernia sites (figure 3): between the Roux limb mesentery and the transverse mesocolon (ie, Petersen defect), the opening in the transverse mesocolon, and the mesentery of the JJ anastomosis. All should be closed with permanent sutures. The Petersen defect and the mesenteric defect at the JJ anastomosis are closed with pursestring sutures; closure by running or interrupted linear sutures may reopen after significant weight loss. At the transverse mesocolic defect, the mesocolon is sutured to the Roux limb in several areas.

For antecolic Roux limbs, there are two potential internal hernia sites: the JJ anastomosis mesenteric defect and the space between the Roux limb and the transverse mesocolon. The JJ anastomosis defect should be closed with a pursestring suture. Some surgeons argue that the other defect is a large space and that while internal herniation may occur, an obstruction is less likely. Others have reported this space to be a potential site for incarceration and argued that it should be closed with a running suture or several interrupted ones [26].

Closure — The pneumoperitoneum is evacuated actively. Trocar incisions that are greater than 10 mm are closed at the fascia level [27]. Because of the large amount of subcutaneous tissue in patients with obesity, a transfascial suturing device can be used. At this point, and under laparoscopic guidance, long-acting local anesthetic is given to assist with postoperative pain control if not already performed by the anesthesia provider under ultrasound guidance. A drain is only placed in revision operations and when there is concern about the integrity of the GJ anastomosis. The drain can potentially identify a leak and/or help control a small leak.

VARIATIONS IN TECHNIQUE

Antecolic versus retrocolic passage of the Roux limb — For the Roux limb to reach the gastroesophageal (GE) junction from the infracolic abdomen, it must pass either in front of or behind the transverse colon. For the antecolic approach, the omentum should be divided up to the transverse colon to allow the Roux limb a shorter path to reach the gastric pouch. For the retrocolic approach, a defect is made in the transverse mesocolon for the Roux limb. (See 'Making the retrocolic passageway' above.)

The antecolic Roux limb is faster to create but takes a longer course, which may predispose to ischemia or leak. The retrocolic approach is more time consuming and technically challenging but takes a shorter route to the GE junction and thus has less ischemia risk.

Another potential disadvantage of the retrocolic approach is that it creates more potential internal hernia sites than the antecolic approach (figure 3). In large retrospective series, the retrocolic approach was associated with more internal herniations leading to bowel obstructions than the antecolic approach [28-30]. However, the difference was reduced when potential hernia sites were routinely closed [31].

Since there have been no randomized trials comparing the two approaches, the choice between an antecolic and a retrocolic Roux limb is left to the surgeon's discretion. Surgeons should be familiar with both techniques, however, as at times anatomy may dictate which approach should be used. As an example, in situations where the small bowel mesentery is foreshortened and the Roux limb will not reach the GE junction without tension, a retrocolic approach may be indicated. Conversely, previous adhesions in the lesser sac from ulcer disease, pancreatitis, or previous transverse colon resection may make entry into that space difficult, in which case an antecolic approach is preferable.

Bypass length — The optimal length of an intestinal bypass that maximizes weight loss and minimizes side effects is debated. A Roux limb of 75 to 150 cm is most commonly used [32].

Some surgeons advocate including the length of the biliopancreatic (BP) limb in calculating the total bypassed intestinal length [32]. In other words, if one creates a 75 cm BP limb and a 100 cm Roux limb, they should report a 175 cm bypass. A meta-analysis of large retrospective studies concluded that the optimal length of bypass is a combined Roux limb and BP limb length up to 200 cm [33]. There is some evidence that a longer BP limb provides a better glucagon-like peptide-1 response, resulting in better glucose control and less weight recidivism [34].

The fact that patients have variable lengths of small bowel has led some surgeons to perform laparoscopic Roux-en-Y gastric bypass (LRYGB) based on the length of the common channel, rather than that of the Roux limb. As an example, they will measure back 200 cm of the small bowel from the cecum and create the Roux limb from there. That approach, however, has not been proven superior to standard LRYGB [32].

Patients with body mass index (BMI) >50 kg/m2 may benefit from a longer Roux limb. However, in a randomized trial of patients with BMI between 50 and 60 kg/m2 undergoing LRYGB, a common channel of 150 cm resulted in similar weight loss compared with a Roux limb of 150 cm (BMI reduction of 17.2 versus 17.8 kg/m2) but worse metabolic outcomes in some cases, including liver failure and protein-calorie malnutrition [35].

Other gastrojejunal anastomosis techniques — Three techniques are most commonly used to construct the gastrojejunal (GJ) anastomosis in LRYGB: the linear-stapled technique, the hand-sewn technique, and the circular-stapled technique.

The linear-stapled anastomosis, which is our preferred technique, has been described in detail above (see 'Gastrojejunal anastomosis' above). Compared with the circular-stapled technique, the linear-stapled technique can be more technically challenging and the anastomosis diameter can be more varied because the surgeon, rather than the stapler, determines the size of the anastomosis. However, the linear-stapled technique does not require an experienced assistant or enlargement of one of the trocar sites to accommodate the circular stapler, which is 25 mm in diameter.

The hand-sewn technique is similar to the linear-stapled technique, except that no stapler is used. A posterior row of sutures is first placed to approximate the gastric pouch and the Roux limb. Enterotomies of approximately 1.5 to 2 cm are then made in the gastric pouch and the Roux limb. The inner layer of the anastomosis is then hand-sewn; some surgeons prefer to use a bougie to control the size of the anastomosis during this step. Finally, the anterior row of sutures is placed.

The advantages of the hand-sewn technique are that it can be done by a single surgeon, it does not require an experienced assistant, it does not require the size of the trocars to be increased, and it can be adapted to difficult anatomic situations that preclude the use of a stapler. The disadvantages are that it is technically most challenging and that the surgeon estimates the anastomosis diameter.

The circular-stapled anastomosis uses an end-to-end-anastomosis (EEA) stapler to create the anastomosis by connecting the anvil in the gastric pouch and the stapler device in the Roux limb.

There are two ways to place the anvil into the gastric pouch. One way is by attaching the anvil to a specially designed orogastric tube and inserting both through the mouth (figure 4). After making a small hole in the gastric pouch, the orogastric tube can be pulled into the peritoneum with the anvil trailing. Once the anvil is well seated in the gastric pouch, the orogastric tube can be cut from the anvil and removed.

The second way is to place the anvil in the stomach before the gastric pouch is created. To accomplish that, a gastrotomy is made in the distal stomach. Through the gastrotomy, the anvil is introduced along with a sharp instrument, which is used to puncture through the stomach in the area of the gastric pouch. The anvil is then pulled through the opening made by the sharp instrument. The gastrotomy in the distal stomach is closed after the gastric pouch is created.

After the anvil is positioned in the gastric pouch, the circular stapler is introduced into an opening created in the Roux limb and deployed so that the integrated trocar pierces the Roux limb wall and protrudes toward the anvil. The anvil is then connected to the integrated trocar and the EEA stapler is fired, creating a circular anastomosis. Many surgeons will buttress the anastomosis with a few Lembert sutures after stapling.

The circular-stapled technique is technically easier to perform because it does not require sewing and it assures a uniform size of anastomosis determined by the stapler. The circular-stapled technique also has several disadvantages. First, it requires enlargement of one of the laparoscopic trocar sites to >2 cm in order to accommodate the circular stapler. In retrospective comparative studies, this was associated with a higher incidence of wound infection [36]. The second disadvantage is that the circular-stapled technique has been associated with a higher incidence of anastomotic stenosis, especially when a 21 mm EEA stapler is used [37,38]. EEA staplers used in upper gastrointestinal surgery generally have a luminal size of 21 or 25 mm. The third disadvantage is that this technique requires an experienced assistant because the surgeon cannot operate the EEA stapler and control the anvil at the same time. (See 'Stomal stenosis' below.)

The three GJ anastomotic techniques have been compared in retrospective series and meta-analyses but not randomized trials. There were no differences among the techniques in terms of leak rate, bleeding rate, length of surgery, or amount of weight loss. One study demonstrated that the circular-stapled technique had the highest stenosis rate, followed by the hand-sewn technique and the linear-stapled technique [37].

The choice of techniques is largely determined by surgeon training and preference. However, a good bariatric surgeon will be able to perform any of the techniques as situations may call for a particular technique. For the hand-sewn technique, robotic assistance may help overcome some of the technical challenges.

Banded gastric bypass — Some surgeons have advocated placing a band (silastic ring) around the gastric pouch during the initial RYGB procedure. Although there have been no randomized trials comparing banded RYGB with standard RYGB, several prospective comparative studies have associated banded RYGB with less weight recidivism and more weight loss, especially after the first year following bariatric surgery [39,40]. Banded RYGB, however, was also associated with more mild complications such as dysphagia as well as vomiting and severe complications such as band eroding through the stomach wall. Thus, banded RYGB has not gained universal acceptance among bariatric surgeons.

Leak testing — Intraoperative and postoperative leak testing of the GJ anastomosis is another area of controversy among bariatric surgeons. Available data are not sufficient to recommend either the method or the timing of a leak test. Although most leaks occur after postoperative day 7, many bariatric surgeons will perform some form of leak test prior to that.

Several methods of leak test after RYGB have been described, including (see 'Intraoperative leak test' above):

A leak test can be done with methylene blue. If the test is done intraoperatively, the anesthesia provider carefully places an orogastric tube under the guidance of the surgeon to avoid perforating the newly formed anastomosis. When the orogastric tube is positioned in the gastric pouch, 60 mL of methylene blue mixed with saline is injected through the orogastric tube while the surgeon watches for extravasation (blue staining). Gauze pads can be placed behind the gastric pouch to detect posterior leaks. If the test is done postoperatively, the patient will swallow the same amount of methylene blue solution; a drain needs to be placed near the GJ anastomosis to detect the leak.

An endoscopic leak test is done intraoperatively and is also capable of identifying any intraluminal bleeding at the anastomosis. If an endoscope is used to calibrate the GJ anastomosis, it is already in position for the leak test. The distal Roux limb is occluded with either a fired stapler or a laparoscopic instrument. The GJ anastomosis is submerged under saline, and the endoscope is slowly withdrawn while insufflating air. Bubbles at the anastomosis would indicate a leak.

A barium swallow, while not routinely used, is typically done on the first postoperative day before oral feeding is started. Besides detecting leak, a swallow study can also exclude delayed emptying of the gastric pouch caused by an early anastomotic stenosis.

None of the tests described above has a distinct advantage over another. Thus, the decision about leak testing rests with the surgeon. Many surgeons do not routinely perform leak tests unless there are clinical reasons. Because radiologic studies, including computed tomography (CT) scans, have a reported positive predictive value of only approximately 67 percent [41], a negative leak test should not preclude surgical exploration in the face of strong clinical suspicion for a leak. (See 'Leak' below.)

POSTOPERATIVE CARE

Feeding — If a leak test is not routinely done, patients can start water intake on the night after surgery, but at the rate of only 1 to 2 oz/hour to ensure that liquids pass through the new anastomosis easily. On the first postoperative day, they can be started on a clear liquid diet and advanced to a full liquid diet on the same day, moving up to 4 to 6 oz/hour. The goal would be at least 60 oz of fluid daily.

If a leak test is routinely done, it is typically performed on the first postoperative day before oral intake is started. If the test is negative for a leak or stenosis, oral intake is started with <1 oz of water every hour. If water is tolerated, the patient can be advanced to a clear liquid diet on postoperative day 1, with the rate increased 1 oz every 15 minutes. If the clear liquid diet is tolerated, the patient is advanced to a full liquid diet for lunch on postoperative day 2. A full liquid diet contains necessary protein supplements that will enable the patient to take in 60 grams of protein daily.

Patients can be discharged home when they tolerate the full liquid diet and their pain is controlled with oral medications. After discharge, the patient is continued on a full liquid diet for two weeks or until the first postoperative visit. After that, patients can be advanced to a pureed or soft mechanical diet. Patients should be reminded to stay hydrated by drinking at least 60 oz. of water daily. (See "Bariatric surgery: Postoperative nutritional management", section on 'Diet and texture progression'.)

Monitoring and nursing — Prophylaxis against venous thromboembolic events (VTEs) should continue after surgery. Specifically, patients should ambulate on the night of surgery, sequential compression devices (SCDs) should be worn, and chemoprophylaxis should be continued starting from the night after surgery. Extended chemoprophylaxis is not routinely required even in high-risk patients, though it is left up to the discretion of surgeon.

Patients should be continuously monitored for their respiratory and cardiovascular status after surgery. In the postoperative period, early ambulation, aggressive pulmonary toilet, deep breathing exercises, and incentive spirometry should be routine. For patients with obstructive sleep apnea (OSA), there is no contraindication to the use of continuous positive airway pressure (CPAP) devices even immediately after surgery. Patients should be placed on telemetry so their heart rate and oxygenation can be continuously monitored.

Antibiotic prophylaxis should be continued for 24 hours. A proton pump inhibitor (PPI) should be given intravenously until the patient is tolerating oral intake. In general, PPI therapy should be continued for one to three months after surgery to prevent marginal ulcers. The patient should be provided with multimodal pain medications with the exception of nonsteroidal anti-inflammatory drugs (NSAIDs), which should be avoided due to the risk of gastric ulcers. Patients should be given antiemetics to prevent nausea and vomiting as vomiting may disrupt the newly formed gastrojejunal anastomosis. If a Foley catheter has been inserted, it should be removed on postoperative day 1 unless it is needed for monitoring of volume status. Intravenous fluids should be continued until the patient is tolerating oral intake well.

Supplements and discharge medications — Nutritional supplementation should begin as soon as oral intake is tolerated. Because of the restrictive and malabsorptive effects from the RYGB, patients will require supplementation with multivitamins (MVIs), iron, and calcium citrate. Iron supplementation should be at least 40 mg per day in the elemental form. Calcium supplementation should be in the form of calcium citrate for better absorption. (See "Bariatric surgery: Postoperative nutritional management".)

The patient's regular medications can be restarted when the patient is tolerating oral intake. Patients should schedule a follow-up appointment with their primary care provider or a bariatrician in four to six weeks after surgery to help adjust their regular medications. For the first month after surgery, all medications should be in a liquid form, a dissolvable capsule, or crushed. Medications that are sustained, slow released, or enteric coated should be avoided because they may not be absorbed adequately.

OUTCOMES

Weight loss — Success with any bariatric procedure is first and foremost measured by weight loss. At two years, the expected weight loss from a Roux-en-Y gastric bypass (RYGB) is approximately 70 to 75 percent of that in excess of a patient's ideal body weight, which is roughly equal to 35 to 40 percent total body weight loss. (See "Outcomes of bariatric surgery", section on 'RYGB and SG'.)

A bariatric procedure's durability is also important. At five years after RYGB, the sustained weight loss is approximately 60 to 70 percent of the excess weight or 35 percent of total body weight [4]. Weight regain may be a result of both physiologic and mechanical changes. Mechanically, gastric pouch enlargement, gastrogastric fistula formation, and gastrojejunal anastomosis widening to greater than 20 mm may all cause or contribute to weight regain. Physiologically, ghrelin increase or leptin and glucagon-like peptide-1 decrease may predispose to weight regain [42]. (See "Outcomes of bariatric surgery", section on 'Durable weight loss'.)

In a single-center prospective observational study from the United States, 418 patients who underwent RYGB, 417 patients who sought but did not undergo surgery (most for insurance reasons), and 321 control patients with obesity were followed long-term with follow-up rates exceeding 90 percent [43]. At 12 years, patients who underwent surgery lost 45 kg, compared with 2.9 kg for those who sought but did not receive surgery and 0 kg for controls. Ninety-three, 70, and 40 percent of patients maintained 10, 20, and 30 percent total body weight loss, respectively, at 12 years. The mean percentage weight loss was virtually unchanged between 6 and 12 years (28 and 26.9 percent) for those who underwent surgery, attesting to the durability of RYGB.

In a multicenter longitudinal study of approximately 1400 adults who underwent RYGB, the median maximum weight loss was 37.4 percent (25th to 75th percentile, 31.6 to 43.3 percent) of total body weight, which occurred at a median of two years after surgery (25th to 75th percentile, 1.0 to 3.2 years) [44]. The rate of weight regain was highest during the first year after achieving maximum weight loss and decreased over time, but weight regain continued throughout the follow-up period (median 6.6 years, 25th to 75th percentile, 5.9 to 7.0 years). The median rate of weight regain was 9.5 percent of the maximum weight lost (25th to 75th percentile, 4.7 to 17.2 percent) one year after reaching the lowest weight, 22.5 percent (25th to 75th percentile, 12.9 to 34.5 percent) three years after reaching the lowest weight, and 26.8 percent (25th to 75th percentile, 16.7 to 41.5 percent) five years after reaching the lowest weight. Among a number of indices examined, weight regain expressed as percentage of maximum weight lost was the best predictor of most patient-important clinical outcomes, including diabetes, hypertension, and hyperlipidemia remission.

Diabetes mellitus — The improvement in type 2 diabetes mellitus (T2DM) is one of the most significant benefits of RYGB. Bypassing the distal stomach, duodenum, and proximal jejunum seems to have a positive effect on glucose control via improved insulin sensitivity and decreased insulin resistance in patients with obesity. (See "Outcomes of bariatric surgery", section on 'Diabetes mellitus'.)

In the Surgical Therapy And Medications Potentially Eradicate Diabetes Efficiently (STAMPEDE) trial, 80 percent of diabetic patients maintained glucose control (hemoglobin A1c [HbA1c] <7 percent) after RYGB compared with 0 percent of patients treated medically at three years [45]. Among those who had some improvement in their glucose control, 24 percent who underwent RYGB relapsed (indicated by elevated HbA1c) versus 80 percent treated medically.

In the 12 year follow-up study after RYGB cited above, the remission rates of T2DM after RYGB were 75 percent at 2 years, 62 percent at 6 years, and 51 percent at 12 years [43]. The incidence of new-onset diabetes among patients who underwent surgery was 91 to 92 percent lower than that of patients who did not undergo surgery.

Weight loss alone may not be the only reason for better glucose control after RYGB. However, in a study of 22 patients with obesity with T2DM, the benefits of matched (but not randomized) weight loss (18 percent) induced by gastric bypass or diet alone on multiorgan insulin sensitivity, beta cell function, 24 hour plasma glucose and insulin profiles, and body composition were nearly identical [46]. This suggests that improvement in blood glucose control in persons with T2DM is primarily driven by weight loss, however it is achieved. Nevertheless, the difficulty in adhering to lifestyle modifications over time often renders RYGB far more effective than diet therapy for most patients with obesity with T2DM.

Hyperlipidemia — In the STAMPEDE trial, triglyceride levels were 46 percent lower at three years after RYGB compared with 21 percent lower in patients treated medically [45]. Database and large retrospective studies have also shown resolution of hyperlipidemia after RYGB [47].

Obstructive sleep apnea — Obstructive sleep apnea (OSA) can be improved by weight loss. In large retrospective studies, bariatric surgery resulted in more weight loss and was more effective against OSA in patients with obesity both by objective parameters (eg, apnea-hypopnea index) and subjective parameters (eg, quality of sleep) [48]. In a prospective comparative study, more patients who underwent RYGB achieved remission of OSA than those treated with lifestyle intervention (66 versus 40 percent), with most of the benefit attributed to superior weight loss (30 versus 8 percent) [49].

Gastroesophageal reflux disease — Gastroesophageal reflux disease (GERD) is another common complication of obesity. In large retrospective database studies, RYGB reduced the prevalence of GERD symptoms by almost 50 percent; up to 45 percent of patients also achieved a normalization of their esophageal pH; these benefits were sustained for at least three years [50]. RYGB is superior to sleeve gastrectomy and adjustable gastric banding in improving GERD [51]. As such, patients with severe, uncontrolled GERD or Barrett's esophagus should be offered RYGB rather than sleeve gastrectomy. (See 'Preoperative workup' above.)

Other medical comorbidities — Additionally, RYGB has been associated with improvement in other obesity-related medical conditions, including:

Blood pressure control (see "Outcomes of bariatric surgery", section on 'Hypertension')

Nonalcoholic fatty liver disease (see "Outcomes of bariatric surgery", section on 'Nonalcoholic fatty liver disease')

Chronic renal dysfunction (see "Outcomes of bariatric surgery", section on 'Renal disorders')

Arthritis and physical function (see "Outcomes of bariatric surgery", section on 'Joint pain and physical activities')

Long-term survival (see "Outcomes of bariatric surgery", section on 'Long-term survival')

Those studies are discussed separately because they also enrolled patients who underwent bariatric procedures other than RYGB.

COMPLICATIONS

Mortality — The 30 day mortality rate associated with laparoscopic Roux-en-Y gastric bypass (LRYGB) and other major bariatric procedures has decreased from 2.6 percent at the turn of the century [3] to 0.09 to 0.12 percent in contemporary practices [4]. However, the mortality rate for patients >65 years can be as high as 4 percent depending on patients' preoperative health status and the procedure [4]. As a part of the informed consent process, bariatric surgeons should frankly and accurately counsel patients about their risk of dying from the procedure using data from large database studies.

Morbidity

Leak — A postoperative gastrointestinal leak is a rare (0 to 5 percent) but serious complication of LRYGB [4].

The danger to the patient's life is not the leak itself but not recognizing a leak in a timely fashion and treating it aggressively. In a review of 140 bariatric procedures that resulted in a malpractice claim, the most commonly litigated procedure was RYGB (76 percent) [52]. The most common alleged reason for the claim was delay in diagnosis or management of a complication in the postoperative period (47 percent), most commonly an anastomotic leak (45 percent).

The diagnosis and treatment of anastomotic leak after bariatric surgery is discussed separately. (See "Bariatric operations: Early (fewer than 30 days) morbidity and mortality", section on 'Gastrointestinal leak'.)

Stomal stenosis — A stomal (anastomotic) stenosis is defined clinically as the inability to swallow liquids and usually occurs if the anastomosis narrows to a diameter of <10 mm. Stomal stenosis occurs in 6 to 17 percent of patients undergoing LRYGB, typically in the early postoperative period. The diagnosis and treatment of stomal stenosis after RYGB is discussed separately. (See "Bariatric operations: Late complications with acute presentations", section on 'Stomal stenosis'.)

Marginal ulcers — Marginal ulcers are ulcers that develop near the gastrojejunal (GJ) anastomosis. They have been reported in 0.6 to 16 percent of patients after RYGB. The diagnosis and treatment of marginal ulcers is discussed separately. (See "Bariatric operations: Late complications with acute presentations", section on 'Marginal ulcers'.)

Gastrogastric fistula — A gastrogastric (GG) fistula is a channel that develops between the gastric pouch and the excluded stomach remnant, allowing ingested food to enter the bypassed foregut (stomach and duodenum). GG fistulas occur in approximately 1 to 2 percent of patients after RYGB and most commonly cause marginal ulcers or weight regain. The diagnosis and treatment of GG fistulas is discussed separately. (See "Bariatric operations: Late complications with subacute presentations", section on 'Gastrogastric fistula'.)

Dumping syndrome — After RYGB, approximately 50 percent of patients will experience symptoms of flushing, crampy diarrhea, palpitations, and diaphoresis after ingesting a meal rich in simple carbohydrates. This "dumping syndrome" may contribute to weight loss by encouraging patients to replace simple sugar with high-fiber, complex carbohydrate-rich, and protein-rich food items.

In a descriptive cohort study, self-reported complaints suggestive of early and late dumping of moderate-to-severe intensity were present in 18.8 and 11.7 percent of 351 patients at a mean of 2.3 years after RYGB [53]. These complaints were associated with markedly reduced health-related quality of life. Dumping syndrome after bariatric surgery is further discussed separately. (See "Bariatric operations: Late complications with subacute presentations", section on 'Dumping syndrome'.)

Hypoglycemia — More severe forms of low blood glucose can also occur independent of recent food ingestion. It is estimated to occur at least once in up to 44.2 percent of patients [54]. They can be debilitating due to an exaggerated insulin response (hyperinsulinemia) or from an increase in glucagon-like peptide-1. There is no true consensus on how best to treat this. Some have advocated for reversing the RYGB [55] or using continuous enteral feeding through the excluded stomach [56]. The data only report small case series. Pancreatectomy has also been considered but is a highly morbid procedure.

Internal hernia, small bowel obstruction — Small bowel obstructions (SBOs) can occur at any time after RYGB, with a lifetime incidence of approximately 3 to 5 percent [28,57]. Patients can present acutely with a bowel obstruction or with chronic acute abdominal pain usually unrelated to eating. Once diagnosed by imaging, SBO is treated surgically. (See "Bariatric operations: Late complications with acute presentations", section on 'Small bowel obstruction'.)

Post-RYGB SBO is most commonly caused by bowel herniation through a mesenteric defect created by the surgery (ie, internal hernia). Internal hernias associated with RYGB and their complications are discussed separately. (See 'Antecolic versus retrocolic passage of the Roux limb' above and "Bariatric operations: Late complications with acute presentations", section on 'Small bowel obstruction'.)

Psychosocial impairment — Some patients experience psychosocial impairments following bariatric surgery, leading to alcoholism, substance abuse, and even self-injurious behaviors or suicide. The risk of suicide is higher after bariatric surgery [58]. Thus, bariatric providers need to be vigilant about potential psychosocial complications of bariatric surgery and counsel or refer patients as appropriate. (See "Outcomes of bariatric surgery", section on 'Psychosocial impact'.)

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

Mechanisms of action – The Roux-en-Y gastric bypass (RYGB) works by restricting the amount of food one ingests (restriction), by limiting the amount of nutrients absorbed from the ingested food (malabsorption), and by affecting the amount of hormones that improve insulin sensitivity, hunger control, and hunger satisfaction. (See 'Mechanism of action' above.)

Indications for RYGB – The indications for laparoscopic RYGB are the same as for all accepted bariatric procedures. (See "Bariatric surgery for management of obesity: Indications and preoperative preparation", section on 'Indications'.)

RYGB may be preferred in patients with uncontrolled type 2 diabetes, nonalcoholic fatty liver disease, metabolic syndrome, or polycystic ovarian syndrome because it treats insulin resistance better than other bariatric procedures. (See 'Indications' above.)

Crohn disease is a relative contraindication for RYGB due to the potential for strictures and leaks at the anastomoses. Patients who take glucocorticoid or nonsteroidal anti-inflammatory drugs chronically (transplant patients) may be at higher risks of developing marginal ulcers after RYGB. (See 'Indications' above.)

Preoperative workup – In addition to routine preoperative workup, patients who are symptomatic from foregut diseases should undergo esophagogastroduodenoscopy (EGD) before undergoing an RYGB. Patients with Barrett's esophagus or severe/complicated gastroesophageal reflux disease (GERD) are better candidates for RYGB than for sleeve gastrectomy. (See 'Preoperative workup' above.)

Outcomes – At two years, the expected weight loss from an RYGB is approximately 35 to 40 percent total body weight. At five years after RYGB, the sustained weight loss is approximately 30 percent total body weight. RYGB also improves obesity-related medical conditions, including type 2 diabetes mellitus, hypertension, hyperlipidemia, obstructive sleep apnea, and GERD, among others. (See 'Outcomes' above.)

Complications – The 30 day mortality rate associated with RYGB and other major bariatric procedures is 0.09 to 0.12 percent in contemporary practices. Serious morbidities include anastomotic leak, stomal stenosis, marginal ulcer, gastrogastric fistula, internal hernia, hypoglycemia, and small bowel obstruction, among others. Early diagnosis and treatment of complications is paramount to good patient outcomes. (See 'Complications' above and "Bariatric operations: Early (fewer than 30 days) morbidity and mortality".)

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Topic 109434 Version 14.0

References

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