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Morbid Obesity Katherine Graw Lamond, MD, MS, and Anne O. Lidor, MD, MPH OVERVIEW Morbid obesity is becoming increasingly prevalent throughout the United States and other industrialized nations. Body mass index (BMI) is a calculated measurement that takes into account height and weight (BMI = weight [kg]/height [m]). More than 60% of adults in the United States are considered overweight (BMI ≥25), and more than 33% of Americans are obese (BMI ≥30). Almost one in three children and adolescents in the United States are also overweight (Table 1). The medical comorbidities of obesity are hazardous and include type 2 diabetes, obstructive sleep apnea, heart disease, and increased risk of stroke, gastroesophageal reflux disease (GERD), osteoarthritis, and liver disease. Medical therapies for weight reduction are largely unsuccessful at maintaining significant weight loss in the severely obese population. Bariatric surgery continues to be the only durable method to achieve sustained weight loss for many patients. Almost 150,000 bar- iatric procedures are performed in the United States annually. The two fundamental mechanisms of surgical weight loss are: 1, restric- tive; and 2, malabsorptive. Some of the procedures described have components of both. There are multiple theories surrounding the metabolic changes which occur following bariatric surgery. These changes can result in a near instant resolution of diabetes mellitus, as well as a change in set-point of body weight. These alterations may occur by hormonal influences and neuronal feedback loops which are made possible by surgery. The three most common operations include the laparoscopic Roux-en-Y gastric bypass, laparoscopic adjustable gastric band (LAGB), and vertical sleeve gastrectomy. All of these procedures assist with weight loss by restriction of calorie intake. The Roux-en-Y gastric bypass also causes malabsorption of food, which leads to weight loss. Duodenal switch with biliopancreatic diversion is a less com- monly performed malabsorptive and restrictive procedure. PATIENT SELECTION In 1991, the National Institute of Health issued a consensus statement regarding the effectiveness of bariatric surgery based on certain patient criteria. Insurance companies, including Medicare and Med- icaid, typically base their reimbursements on these indications. The indications include a BMI of 40 or more, or 35 or more with a sig- nificant obesity-related comorbidity. Patients must have documented attempts at weight loss that were unsuccessful, typically for a 6-month period. Finally, patients must also be cleared by a dietician and a mental health profession and have no other medical contraindica- tions for surgery. The American Society for Metabolic and Bariatric Surgery and the American College of Surgeons have produced guidelines of accreditation for both bariatric programs and hospitals. The policies insist that programs can provide excellent surgical technique and thorough postoperative care, follow-up, and specialty consultants. A multidisciplinary team approach has been shown to provide the best benefit for the evaluation of potential bariatric surgery cases. This team should include a dietician and a mental health professional familiar with bariatric surgery. Their purpose is to obtain a complete dietary and behavioral eating history, educate the patient on postop- erative dietary expectations, examine the social support structure, and ensure that any psychiatric or behavioral disorders are optimally controlled. At the Johns Hopkins Center for Bariatric Surgery, all patients are required to attend a multidisciplinary preoperative education seminar. Preoperative and postoperative participation in obesity and bariatric support groups is also encouraged. Age limits for surgery have expanded considerably over the last decade. Select centers, including Johns Hopkins, may offer surgery to adolescent patients and to patients over the age of 70 years. OPERATIVE PROCEDURES Most bariatric surgical procedures are now performed laparoscopi- cally, with a hospital stay of 48 hours or less. Open surgery may be necessary and planned for patients who undergo revision surgery, 104 Morbid obesity place clips in a region that interferes with the gastrojejunal anastomosis. The authors routinely bring the Roux limb of the jejunum up to the gastric pouch in an antecolic-antegastric orientation. This has been shown to reduce the incidence of internal hernia and is simpler to perform than the retrocolic-retrogastric approach. The gastrojejunostomy is performed by first suturing the side of the Roux limb to the gastric pouch staple line. A small enterotomy is performed proximal to the end of the Roux limb, and a similarly sized gastrotomy is made in the gastric pouch for insertion of the Endo- GIA blue 45-mm stapler. The stapler is fired with 30-mm of the cartridge to create an appropriately sized anastomosis. A stay suture is then placed on the lesser curve of the opening and is used to retract the anastomosis to expose the posterior staple line. This staple line is reinforced with a running 2-0 suture. Carefully, a blunt 32F bougie is then passed by the anesthesia or surgical team via the patient’s mouth through the gastrojejunal TABLE 1: Body mass index Classification Body mass index (kg/m2) Underweight ≤18.49 Normal range 18.5-24.9 Overweight ≥25.0 Obese ≥30.0 Obese class I 30.0-34.9 Obese class II (moderately obese) 35.0-39.9 Obese class III (severely obese) 40.0-49.9 Obese class IV (super obese) ≥50.0 FIGURE 1 Antecolic-antegastric Roux-en-Y gastric bypass. (Courtesy Corinne Sandone, Johns Hopkins University.) Roux limb (antecolic) Gastric pouch Jejunojejunostomy those with prior extensive abdominal operations, or patients with a high BMI (>70). Before surgery, all patients should receive appropriate antibiotics and subcutaneous unfractionated or low–molecular weight heparin within an hour of incision. Obese patients undergoing laparoscopic surgery have a significant risk of development of potentially life- threatening deep venous thrombosis. Patient positioning on the operative table is essential for safe placement of the patient in the steep reverse Trendelenburg’s posi- tion. This placement should include a footboard, secured arms and legs, and a split leg table if possible. Laparoscopic entry in a morbidly obese patient can be difficult. The authors have found that the safest way to enter is in the left upper quadrant with direct vision, with a device that allows visualization of the abdominal wall layers during entry with a 0-degree laparoscope (12-mm Visiport; Covidien, Norwalk, Conn). Laparoscopic Roux-en-Y Gastric Bypass Gastric bypass (Figure 1) is the most common bariatric procedure performed in the United States (60% to 70%). Numerous reports have shown achievement of durable long-term weight loss and remis- sion of metabolic disease with a reasonably low complication rate. The authors perform the procedure with five laparoscopic trocars (three 12-mm and two 5-mm) and a subxiphoid puncture for placement of a Nathanson liver retractor (Cook Medical, Bloomington, Ind). The jejunojejunal anastomosis is created first. The jejunum is divided approximately 40 cm distal to the ligament of Treitz with a 60-mm white stapler cartridge (Endo-GIA Universal XL; Covidien, Norwalk, Conn). The mesentery is divided with a gray stapler car- tridge and ultrasonic shears (AutoSonix XL; Covidien, Norwalk, Conn). The proximal biliopancreatic limb of jejunum is then anas- tomosed to the distal segment of jejunum 75 to 100 cm distal to the point of division. The authors perform this anastomosis in a side-to- side fashion with a white Endo-GIA stapler cartridge and complete it with a blue or tan tristaple Endo-GIA load and running suture. The mesenteric defect is then closed with a running permanent suture to help minimize the risk of internal hernia. Next, the patient is placed in steep reverse Trendelenburg’s posi- tion, and the gastric pouch is created. Dissection is performed at the angle of His, to expose the left crus, and at the gastrohepatic ligament, to gain access to the lesser sac. Division of the neurovascular bundle on the lesser curve side of the stomach, just distal to the left gastric artery and vein, is accomplished with a gray vascular cartridge. Mul- tiple 60-mm blue staple or tan tristaple cartridges are then used to transect the stomach up to the angle of His, creating a vertically oriented, 20-mL proximal gastric pouch. Any bleeding at the staple lines is controlled with clips or suture ligation. Care is taken not to tHe stoMACH 105 The band tubing is brought out through the left upper quadrant port and secured externally to the subcutaneous injection port. Man- ufacturer’s instructions must be followed, so as not to institute fluid or air into the band at this time. When securing the port to the fascia, a sufficient space must be cleared along the rectus sheath. After hemostasis has been achieved in the pocket, the port can be sutured or deployed into position while care is taken to leave the majority of the tubing intraabdominally. Finally, the port can be tested via Huber needle to ensure that the tube and band are functional and not kinked or malpositioned. The authors do not perform a band fill before 6 weeks after surgery so that the site heals appropriately. If manual palpation of the subcutaneous port is difficult, fluoroscopy can be of assistance to fill the band. In patients with very thick subcutaneous tissue, place- ment of the band at the costal margin may be advantageous, for better palpation of the port during fills. Bands are typically filled approximately six times during the first year after placement. Each fill volume is 0.5 to 1 mL, depending on the amount of restriction. The patients must be able to swallow liquid without difficulty before leaving the clinic. Laparoscopic Vertical Sleeve Gastrectomy Laparoscopic vertical sleeve gastrectomy (LVSG) is the most recently introduced of the bariatric surgery procedures (Figure 3). As mentioned previously, this procedure is primarily restrictive, as it removes the lateral aspect of the stomach to create a sleeve-like reservoir. The resection may also assist with weight loss by causing hormonally assisted satiety. The fundus produces the proappetite hormone ghrelin, and because the fundus is removed, these hormone levels are reduced after LVSG. Although this bariatric procedure is not reversible, it can be converted into a Roux-en-Y gastric bypass or duodenal switch if greater weight loss is desired. The LVSG is typically performed with one 5-mm, two 12-mm, and one 15-mm trocar. With the liver retracted with the Nathanson, FIGURE 2 Laparoscopic adjustable gastric band. (Courtesy Corinne Sandone, Johns Hopkins University.) anastomosis and into the Roux limb. The bougie can be seen through the opening formed after the stapler is removed. Another stay suture is placed at the halfway point of this opening. The stay sutures are then elevated, and a 60-mm blue staple or purple tristapler is used to close half of the opening. The remaining small defect is closed with a 2-0 vicryl running suture. For completion of the gastrojejunostomy, a running 2-0 suture is used to create a second layer across the entire anterior portion of the anastomosis. The resultant ostomy is approximately 12 mm in diam- eter. A leak test can be performed by clamping the Roux limb distal to the anastomosis and insufflating air via endoscope or orogastric tube, while the anastomosis is submerged in saline solution. Alterna- tively, a retrograde air leak test can be performed by puncturing the Roux limb with a large bore 14-gauge needle and placing the CO2 insufflator on low (3 L/min) to provide flow. This can be accom- plished via a tool similar to one used for laparoscopic gallbladder drainage. Once the retrograde leak test is performed, a stitch must be placed over the bowel entry point to avoid leakage. The mesenteric defects between the Roux limb mesentery and the transverse mesocolon (Petersen’s defect) is then closed to the level of the transverse colon. If desired, a drain can be placed adjacent to the gastric pouch. If clinically indicated, a Gastrografin swallow study is performed on postoperative day 1 or 2 to check for leakage or obstruction. Laparoscopic Adjustable Gastric Band The LAGB received United States Food and Drug Administration approval in 2002. Before this time, the LAGB was widely used in Europe. The band is adjustable via fluid injection into a subcutane- ous port to allow for tightening or loosening of the band. Advantages of the band include reversibility, lack of stapling, and ease of place- ment. The band requires an average of five to six adjustments in the first year after surgery, and its success requires patient compliance with return appointments and a diet and exercise regimen. Relative contraindications for band placement include the super obese (see Table 1), large paraesophageal hernia, prior gastric resection or Nissen fundoplication, and chronic inflammatory changes in the gastroesophageal junction. The LAGB procedure (Figure 2) is routinely performed via the pars flaccida technique, with two 12-mm trocars, one 5-mm trocar, and a 15-mm trocar for band insertion. The liver is retracted with a Nathanson retractor. Dissection is performed bluntly at the angle of His, freeing up attachments for later insertion of the band. The gas- trohepatic ligament adjacent to the lesser curve of the stomach is then divided with electrocautery. The right crus is identified, and the anterior peritoneal tissue is divided. If a hiatal hernia is identified, reinforcement of the hiatus is important, either anteriorly or poste- riorly, to discourage further herniation once the band has been placed. Two graspers are used to carefully dissect the plane of tissue posterior to the gastroesophageal junction to provide a tunnel for the LAGB. An articulating dissector such as the Realize Endoscopic Dissector (RED; Ethicon Endosurgery, Cincinnati, Ohio) is then placed from the right crus toward the angle of His. The RED is then flexed to create a right angle and locked into place. The adjustable band is placed into the abdomen through the 15-mm trocar in the left upper quadrant. The band is secured to the articulating dissector and brought around the stomach while the instrument is withdrawn. The band is then locked into place with approximately a 45-degree angle towards the patient’s left shoulder. A minimum of two sutures are then placed from the fundus to the proximal gastric tissue around the band to secure the band into place. This reduces the possibility of band migration or herniation. The authors use two 2-0 vicryl sutures to accomplish this. It is important to ensure that the balloon portion of the band has not been compromised while either placing the band or suturing it into position. 106 Morbid obesity The patient is then placed in steep reverse Trendelenburg’s posi- tion and the liver is retracted. If the sleeve gastrectomy portion has not been previously performed, then partial gastrectomy proceeds as described previously. The duodenum is then divided approximately 3 to 4 cm distal to the pylorus with a blue Endo-GIA 60-mm stapler. The Roux limb is directed in an antecolic fashion, and a side-to- side anastomosis is performed with the duodenum. An air leak or dye test can be performed to check for leaks at the stomach staple line and new duodenal-jejunal anastomosis. Finally, the mesenteric defect is then closed between the Roux limb mesentery and the transverse mesocolon. OUTCOMES AND COMPLICATIONS After all bariatric procedures, patients are seen in follow-up at 2 weeks to ensure that they are well hydrated, exercising, and without wound complications. They are then seen at 3, 6, 12, 18, and 24 months and annually thereafter to follow weight loss and nutritional issues. Patients are encouraged to meet with dieticians and remain with their support groups indefinitely. For 1 month after surgery, patients are all maintained on a high- protein puree consistency diet; they are gradually advanced to solid food. They also receive multivitamins, calcium, and vitamin B12 sup- plements. This is especially important for patients with gastric bypass and DS-BPD who are at higher risk for malabsorption and possible malnutrition. Supplemental iron is always considered for menstruat- ing women. the short gastric vessels are divided along the greater curve of the stomach. A LigaSure device (Covidien, Norwalk, Conn) is typically used to accomplish this. A 40F blunt tip bougie is placed in the stomach and directed along the lesser curve. The stomach is divided at the greater curvature, beginning 6 cm proximal to the pylorus. Green and blue staple loads are used adjacent to the 40F bougie and extending to the angle of His. The staple line is oversewn or an absorbable buttress material can be used with the staples to assist with hemostasis. To test the anastomosis, an endoscopic air test or liquid dye infused through an orogastric tube can be used. The partial gastrectomy specimen is removed through the 15-mm trocar site. Care should be taken to repair the fascial opening of this enlarged trocar site to prevent postoperative herniation. The authors typically place a drain in the left upper quadrant that is removed before discharge. As with Roux-en-Y gastric bypass, an UGI study is only performed if clinically indicated. Laparoscopic Duodenal Switch With Biliopancreatic Diversion The laparoscopic duodenal switch with biliopancreatic diversion (DS-BPD) is primarily a malabsorptive operation that involves pres- ervation of the pylorus and creation of a short, 100-cm ileal “common channel” (Figure 4). The DS-BPD is the least common bariatric procedure performed because of its surgical complexity and potential for extreme malabsorptive nutritional deficiencies. This procedure can be performed in a single operation, or in two stages if the patient has a high BMI (>70). The first stage is similar to LVSG. After approximately a 1-year period of weight loss, the patients can be converted to DS-BPD. This is performed by dividing the small bowel 250 cm from the ileocecal valve. The proximal end of bowel is then anastomosed to the distal ileum 100 cm from the cecum. FIGURE 4 Antecolic duodenal switch with biliopancreatic diversion. (Courtesy Corinne Sandone, Johns Hopkins University.) 150 cm 100 cm FIGURE 3 Creation of the gastric sleeve. (Courtesy Corinne Sandone, Johns Hopkins University.) tHe stoMACH 107 similar to an acute bowel obstruction or be chronic in nature and described as postprandial cramping pain. If there is even a slight suspicion of internal hernia, operative intervention is important to avoid bowel ischemia. In general, the results of weight-loss surgery are excellent, with most patients losing more than 50% of their excess weight and resolving comorbidities. Approximately 10% to 15% of patients either do not achieve significant weight loss or partially regain their weight after 2 to 3 years. Ideally, these patients respond to dietary counseling, although some may need operative revision or conver- sion to a more malabsorptive procedure, such as the DS-BPD. Unfortunately, no perfect method exists for choosing the best operation for each individual patient. Certainly, a multidisciplinary team approach is helpful in providing patient support throughout the preoperative and postoperative course. Reducing obesity-related diseases should be the major goal, not merely cosmetic improvement. Patients must understand that bariatric surgery is a tool to assist with weight loss, and it must be combined with drastic changes in dietary, exercise, and lifestyle habits. Su g g e S t e d Re a d i n g S ASMBS Clinical Issues Committee: Updated position statement on sleeve gastrectomy as a bariatric procedure, Surg Obs Relat Dis 8:e21, 2012. Adams TD, Gress RE, Smith SC, et al: Long-term mortality after gastric bypass surgery, N Engl J Med 357:753, 2007. Buchwald H, Avidor Y, Braunwald E, et al: Bariatric surgery: a systemic review and meta-analysis, JAMA 292:1724, 2004. Melton, G, Steele K, Schweitzer MA, et al: Suboptimal weight loss after gastric bypass surgery: correlation of demographics, comorbidities, and insur- ance status with outcomes, J Gastrointest Surg 12:250, 2008. Schweitzer MA, Lidor A, Magnuson TH: 251 consecutive laparoscopic gastric bypass operations using a 2-layer gastrojejunostomy technique with a zero leak rate, J Laparoendosc Adv Surg Tech 16:83, 2006. Weight loss after gastric bypass and DS-BPD occurs primarily in the first 12 to 18 months after surgery and averages approximately 70% and 80% excess weight loss (EWL), respectively. Gastric banding and sleeve gastrectomy typically have less EWL, typically 40% to 50% over a 2-year to 3-year period. One of the most important outcome measures after bariatric surgery is remission of obesity-related metabolic diseases, such as type 2 diabetes. More than 70% to 80% of patients with diabetes experience complete resolution after undergoing gastric bypass or DS-BPD. The restrictive operations have a 50% remission rate of diabetes. Hypertension, sleep apnea, hyperlipidemia, and fatty liver disease have similar remission rates. Overall complication rates after bariatric surgery are less than 15% in most reports. Like most surgeries, there are early and late complications for bariatric surgery. Early or perioperative complica- tions include bleeding, anastomotic leaking, and deep venous throm- bosis. The mortality rate is less than 1% and is usually attributable to a pulmonary emboli or sepsis from anastomotic leak. Typical symptoms such as anorexia and abdominal pain can be difficult to elicit from morbidly obese patients, so it is important to be prompted by unexplained persistent tachycardia. This should raise suspicion for possible staple line leak or pulmonary embolus and trigger a thor- ough workup. Vitamin B12, calcium, iron, vitamin D, and protein deficiencies are long-term complications that can occur within the first year after surgery. Rigorous monitoring of nutrition status is necessary. Vitamin B1 deficiency can also occur in patients with protracted vomiting after surgery and may present with extremity paresthesias and confu- sion. Lower extremity weakness and paresthesias can also be seen with vitamin B12 deficiency. Anastomotic stenosis and obstruction at the gastrojejunostomy in the first few months after surgery occur in less than 5% of patients after gastric bypass and can usually be managed with endoscopic dilation. Internal hernias are also a possible complication and can occur at any time after surgery. The symptoms of internal hernia can be n. If there is even a slight suspicion of internal hernia, operative intervention is important to avoid bowel ischemia. In general, the results of weight-loss surgery are excellent, with most patients losing more than 50% of their excess weight and resolving comorbidities. Approximately 10% to 15% of patients either do not achieve significant weight loss or partially regain their weight after 2 to 3 years. Ideally, these patients respond to dietary counseling, although some may need operative revision or conver- sion to a more malabsorptive procedure, such as the DS-BPD. Unfortunately, no perfect method exists for choosing the best operation for each individual patient. Certainly, a multidisciplinary team approach is helpful in providing patient support throughout the preoperative and postoperative course. Reducing obesity-related diseases should be the major goal, not merely cosmetic improvement. Patients must understand that bariatric surgery is a tool to assist with weight loss, and it must be combined with drastic changes in dietary, exercise, and lifestyle habits. Su g g e S t e d Re a d i n g S ASMBS Clinical Issues Committee: Updated position statement on sleeve gastrectomy as a bariatric procedure, Surg Obs Relat Dis 8:e21, 2012. Adams TD, Gress RE, Smith SC, et al: Long-term mortality after gastric bypass surgery, N Engl J Med 357:753, 2007. Buchwald H, Avidor Y, Braunwald E, et al: Bariatric surgery: a systemic review and meta-analysis, JAMA 292:1724, 2004. Melton, G, Steele K, Schweitzer MA, et al: Suboptimal weight loss after gastric bypass surgery: correlation of demographics, comorbidities, and insur- ance status with outcomes, J Gastrointest Surg 12:250, 2008. Schweitzer MA, Lidor A, Magnu