Laparoscopic Roux-en-Y Gastric Bypass



Laparoscopic Roux-en-Y Gastric Bypass


Alfons Pomp

Mustafa Hussain





Indications/Contraindications

Obesity and obesity-related comorbidities, such as diabetes and heart disease, constitute a significant and increasing health problem. Currently, nearly two-thirds of the US population is overweight with one-third being classified as obese (BMI > 30 kg/m2). Unfortunately, public health campaigns, lifestyle modifications, and medical therapy have little effect on long-term weight loss. Weight loss induced by surgical therapy, however, appears to be both significant in magnitude as well as sustainable over a long period of time. Weight loss procedures are generally classified into restrictive or malabsorbtive. Mason and Ito are credited for employing the Roux-en-Y gastric bypass (combining restriction and malabsorption) for the treatment of morbid obesity. In 1996, Wittgrove reported on the first totally laparoscopic gastric bypass, which has generally been shown to have lower rates of wound and pulmonary complications than the open procedure. Laparoscopic Roux-en-Y gastric bypass is currently the most commonly performed bariatric procedure in the United States.

In 1991, the National Institutes of Health Consensus of Conference on Obesity stated that bariatric surgery is an effective and safe method of achieving sustained weight loss in morbidly obese individuals and that the benefit that results from weight loss after surgery outweighed the risk of the surgical procedures. The procedures are indicated for those individuals who are morbidly obese (BMI > 40 kg/m2) or with a BMI > 35 kg/m2 and a comorbidity that would resolve if the patient had significant weight loss, such as diabetes or obstructive sleep apnea. Recently, there has been increased interest in citing type 2 diabetes as a primary indication for those patients with BMI < 35 kg/m2. This is based on the observation of frequent diabetes resolution after gastric bypass in the morbidly obese and experimental evidence that there may be a weight-loss-independent function of gastric bypass that impacts blood glucose levels. Currently, gastric bypass is being performed in lower BMI patients only under IRB-approved protocols.

The NIH consensus also stated individuals who undergo surgery should be those who are not likely to lose weight by other means (e.g., failed prior nonsurgical techniques) and those who would comply with long-term follow-up. Many insurance companies require a medically supervised weight loss program of varying lengths of time before approving bariatric surgery. While commonplace, there is limited evidence that this appropriately selects patients for surgery and only prolongs the patient’s wait time. Patients should, however, meet with a nutritionist prior to surgery in order to optimize healthy eating habits and diet choices, as well as have reasonable expectation of diet postoperatively. Any vitamin or mineral deficiencies should be diagnosed preoperatively and optimized prior to surgery.

The patients should have reasonable expectations from the surgical procedure and desire significant weight loss. Generally, preoperative psychiatric evaluation is performed to ensure that patients are prepared for what can be a life-altering event and able to comply with the life-long follow-up that is necessary for best results. Patients with untreated or undiagnosed psychiatric disorders generally should not undergo bariatric surgery. In addition, the patients should be of appropriate surgical risk from a cardiopulmonary standpoint and have an abdomen that is amenable to the surgical procedure.

These guidelines generally apply to all bariatric procedures. Laparoscopic gastric bypass is appropriate for those who meet these criteria. Currently, no set criteria define which procedure is more preferable over another. However, operations that can be performed in a shorter period of time such as sleeve gastrectomy or adjustable gastric banding may be more appropriate in cases where minimizing time under anesthesia is a consideration. In diabetics, bypass maybe preferred, as there appears to be a greater frequency of resolution after this procedure. On the other hand, bypass may be less effective in super morbidly obese patients and biliopancreatic diversion might be more appropriate. Commonly, the choice of bariatric procedure is generally left to the patient.



Indications



  • BMI > 40 kg/m2


  • BMI > 35 kg/m2 with a comorbidity (e.g., diabetes, hypertension, obstructive sleep apnea.)


  • Failed attempts at nonsurgical weight loss



Contraindications



  • BMI < 35 kg/m2 (unless under IRB-approved protocol)


  • Inability to comply with postoperative follow-up


  • High anesthetic risk


  • Hostile abdomen: Extensive foregut surgery or extensive small-bowel adhesions


Preoperative Planning

A thorough history and physical examination should be obtained. History should include pertinent information regarding dietary habits and diet history. There should be documentation of attempts at nonsurgical means of weight loss. Generally, counseling by a registered dietician is warranted to establish this. Any preoperative vitamin or mineral deficiencies (e.g., vitamin D, iron) should be treated. Comorbidities should be elucidated and risk stratification and optimization should be undertaken before general anesthesia. This may include stress echocardiograms, pulmonary function tests, and sleep studies. Many patients present for operation with previously undiagnosed diabetes or sleep apnea. These and other newly diagnosed conditions should be optimized prior to surgery. Patients are assessed for hypercoagulable states and history of venous thromboembolism (VTE). Some patients, particularly super-super morbidly obese patients, may require a preoperative inferior vena cava (IVC) filter. Upper endoscopy should be performed to evaluate the stomach for pathology prior to bypass. If Helicobacter pylori is present, it should be treated prior to surgery to reduce the risk of postoperative ulcers and stricture. Notation of a hiatus hernia should be made; an upper GI series may be helpful for this. If significant hernia is present, it should be repaired at the time of surgery in order to prevent the creation of a large gastric pouch. Patients should not be active smokers, as this not only leads to postoperative pulmonary complications but also increases the risk
of later ulcer formation. Psychiatric evaluation should also be performed both to diagnose and optimize any pre-existing pathology and to assess patient’s ability to cope and comply with postsurgical life and follow-up.

Pertinent points in the physical examination include abdominal fat distribution. Patient’s who are “apple” shape or android tend to be more challenging to operate on than “pear” shape or gynecoid patients. Notation of prior abdominal surgery, scars, and hernias should be made. Skin folds should be examined for extensive fungal infection or cellulitis. Lower extremity edema, particularly asymmetric edema, may portend an underlying deep venous thrombosis (DVT), and this should be evaluated. The ability to ambulate and “clear a chair” should be assessed. Immobile patients are at significantly higher risk of postoperative complications.

Some surgeons require their patients to undergo a strict low-calorie, low-carbohydrate diet (e.g., Optifast) in the weeks leading up to surgery. The thinking here is not absolute weight loss per se, but the hopes it will reduce the size of the liver and amount of visceral fat. This makes access to the hiatus easier and safer and allows for easier manipulation of the mesentery. This may be particularly useful in higher BMI patients. Some surgeons also use this as a “test” to determine whether the patients have the willpower to comply with postoperative dietary restrictions. Generally, we do not feel that this is necessary or appropriate. Certainly patients should not be actively gaining weight in the weeks leading up to surgery, and such behavior should be discouraged.

Immediately prior to surgery all patients should receive appropriate antibiotic prophylaxis to limit wound infection. This is particularly the case when using transoral anvil and EEA stapling device. In addition, patients should have appropriate VTE prophylaxis. There have not been adequate studies to determine the best means of VTE prophylaxis in this patient population and it must be weighed against the risk of postoperative bleeding. There is unlikely to be such a study given the large number of patients required to measure differences. Generally, all patients should walk to the operating room if possible and ambulate hours after surgery. All patients should wear pneumatic compression devices prior, during, and after surgery while in bed. It is also generally recommend that some chemoprophylaxis be utilized. We administer 5,000 units of subcutaneous heparin prior to surgery and continue it every 12 or 8 hours. Low-molecular weight heparin administered in low doses may also be appropriate.


Preoperative Assessment



  • Nutritional assessment: Diet history, expectations after surgery, and optimization of nutritional deficiencies


  • Medical evaluation and optimization: Treat uncontrolled blood sugars, cardiac evaluation, assess for risk of VTE, diagnose and treat sleep apnea, and assess ambulatory status


  • Endoscopy: Evaluation of pre-existing pathology and treatment of H. pylori


  • Psychiatric: Diagnose and treat underlying psychiatric conditions if present. Assess for patient compliance and identify maladaptive behaviors


  • Abdominal assessment: Predict the likelihood of successfully completing a laparoscopic gastric bypass


  • Preoperative diet: Reduce liver size and intra-abdominal fat


  • Preoperative antibiotics and VTE prophylaxis as appropriate


Surgical Technique



  • Pertinent Anatomy: Surgeons undertaking laparoscopic gastric bypass should be well versed in foregut anatomy. Identification of the gastroesophageal junction and the anatomy of the angle of His is necessary to safely create the gastric pouch. The surgeon should be comfortable around the hiatus of the diaphragm and able to repair a hiatus hernia. The spleen lies at the superior extent of the dissection when creating the gastric pouch and may be injured during the process. The pancreas
    and splenic vessels run in the retroperitoneum behind the stomach. Injury here can result in bleeding or postoperative pancreatitis or fistula. Preservation of the left gastric artery and the lesser curve vasculature ensures blood supply to the gastric pouch. Identification of the ligament of Treitz is crucial in appropriately making the Roux-en-Y jejunal limbs. Generally, it can be located by its fixed attachment to the transverse colon mesentery. Often, the inferior mesenteric vein is seen just to the patient’s left of the fourth portion of the duodenum as it exits the transverse colon mesentery. Appropriately orienting the proximal and distal ends of the bowel is crucial when reconnecting bowel segments and creating the gastrojejunostomy.


  • Patient positioning and equipment: The operating room table should have the capability to withstand 800 lbs and should have split leg capabilities with right angle foot board attachments and have the ability to undergo steep reverse Trendelenburg. We prefer the Alphastar table (Maquet, Rastatt, Germany). Intubating the morbidly obese patient can be a challenge for the untrained anesthesiologist and having a dedicated bariatric team is ideal. Placing a “bump” or a “wedge” under the patient’s upper back can facilitate intubation and pull away flesh from the upper chest that can hinder manipulation of the patient’s airway. Once intubated, the patient should have all pressure points protected with foam padding. The arms should be out to the sides, just shy of 90 degrees. Care must be taken to assure that the arms are not hyperextended in both the cephalo-caudal and the anterior-posterior direction.



    • French Position: The patient is in split leg with all pressure points protected and each leg secured to boards with circumferential bandages or tape. The operating surgeon is between the legs. The first assistant stands to the patient’s right and is a dedicated camera driver and liver retractor. A second assistant is on the left and assists with retraction. The scrub technician stands on the patient’s left. A single high-definition screen should be positioned above the patient’s head at eye level. Alternatively, the surgeon can stand on the patient’s right with the camera driver between the legs.


    • American Position: The patient is supine with legs together. Right angle foot supports are still necessary for steep reverse Trendelenburg. The surgeon stands to the patient’s right and the first assistant on the left. The scrub technician stands on either the left or the right. Two high-definition screens are required over each of the patient’s shoulders. A second assistant is generally not required.


  • Trocar placement: Peritoneal access can be quite challenging in the obese patient. Several techniques have been described. We feel the safest method is to cut-down at the umbilicus. This site can serve as an optical port and all subsequent ports are placed under direct vision. Other techniques include the blind insertion of a Veress needle to establish pneumoperitoneum with blind placement of the first trocar and optical nonbladed trocar placement. If these techniques are used, it is generally recommended that they be placed in the left upper quadrant at the midclavicular line close to the costal margin. Our preferred trocar scheme is to have a 10-mm optical trocar in the umbilicus and a 10-mm optical trocar in the epigastrium which enters at the base of the falciform. A 12-mm trocar in the subxiphoid position is used for dissecting and stapling the gastric pouch and creation of the jejunojejunostomy. A second 12-mm trocar in the left upper quadrant is used for stapling the gastric pouch and is later expanded to introduce the EEA stapler to create the gastrojejunostomy. A 5-mm trocar in the left anterior axillary line is used by the second assistant and a 10-mm trocar in the right upper quadrant is used for a fan liver retractor and serves as an optical port during the creation of jejunojejunostomy. A fixed Nathanson or Genzyme liver retractor can be inserted through a separate 5-mm incision as an alternative.



    • Alternative techniques have been described and are valid and can be tailored to the surgeon’s preference and patient habitus. We have found this to be the most reproducible across a wide range of patient sizes and the most ergonomic. The abdomen should be insufflated to 15 mm Hg. At times 20 mm Hg may be necessary to enhance visualization.


Two insufflators are useful in maintaining pneumoperitoneum, especially if suction is used. The surgeon and anesthesia team should be aware of hemodynamic and respiratory alterations during insufflations.

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Jun 15, 2016 | Posted by in GASTOINESTINAL SURGERY | Comments Off on Laparoscopic Roux-en-Y Gastric Bypass

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