Laparoscopic Adjustable Gastric Banding

Ninh T. Nguyen

Brian R. Smith

Indications and Contraindications

In 1991, the National Institutes of Health Consensus Development Conference established the current indications for bariatric surgery which have remained in effect since that time. These guidelines recommend bariatric surgery for the following patients:

Acceptable operative risks, well-informed and motivated
Evaluated by a multidisciplinary team
Failure of established weight control programs
Body mass index (BMI) ≥ 40 or ≥ 35 with at least one high-risk, obesity-related comorbid condition

The prominent obesity-related comorbid conditions include hypertension, type 2 diabetes, dyslipidemia, obstructive sleep apnea, cardiomyopathy, and pseudotumor cerebri. Other common obesity-related comorbidities include gastroesophageal reflux, osteoarthritis, infertility, cholelithiasis, venous stasis, and urinary stress incontinence. With a large body of evidence supporting the efficacy of bariatric surgery in ameliorating the above comorbidities, debate over the role of bariatric surgery specifically to treat these conditions, more than the obesity, has begun. In February 2011, the FDA approved the expanded use of the Lap-Band (Allergan Inc., Irvine, CA, USA) for adults with obesity who have failed more conservative weight reduction alternatives and have a BMI of 30 to 40 with at least one obesity-related comorbid condition.

Relative contraindications to bariatric surgery include the following:

Alcohol or drug dependence
Ongoing smoking
Uncontrolled psychiatric disorders such as depression or schizophrenia
Untreated, severe underlying psychiatric disorders, specifically depression and schizophrenia.
Inability to comprehend the requirements for postoperative nutritional and behavioral changes
Unacceptable cardiorespiratory risk (American Society of Anesthesiologists class IV)
End-stage hepatic disease

The patients best suited for gastric band placement are those who have less weight to lose (BMI < 40), are willing to exercise regularly, and those willing to significantly change their eating habits. Patients who tend to take-in high-calorie foods or those who graze continuously throughout the day are less well suited to gastric banding, as are those unable to perform regular exercise to augment the dietary restriction or those who live far enough from their surgeon to preclude regular band adjustments.

Preoperative Planning

Patients preparing for laparoscopic adjustable gastric banding (LAGB) require both preoperative medical evaluation as well as optimization prior to surgery. Medical clearance requires a comprehensive and thorough review of the patient’s medical history, specifically looking for factors which can predict an adverse outcome. Independent predictors of surgical morbidity and mortality include age ≥45 years, male gender, BMI ≥50 kg/m², risk for pulmonary embolism, and hypertension. Collectively, these clinical findings can be used to calculate Obesity Surgery Mortality Risk Score which has been validated at multiple institutions. Patients with 0 or 1 comorbidity are considered low risk or class A with a 0.2% risk of mortality. Those in class B have two or three comorbidities and are at intermediate risk of 1.2%. Class C patients are highest risk and have four or five comorbidities with a corresponding mortality of 2.4%. BMI ≥ 50 kg/m² and cigarette smoking have also been shown to be associated with higher postoperative surgical morbidities. Basic preoperative work-up should include the following:

Comprehensive history and physical
12-lead EKG
Basic blood chemistries, lipid profile, and nutritional panel
Chest radiograph

The choice of operation for a particular patient must take into account several issues including patient’s preference, surgeon’s expertise, BMI, patient’s metabolic conditions, and other associated comorbidities. While gastric bypass is largely considered the most effective procedure at achieving long-term weight loss, it is also the most effective at reducing the metabolic derangements of obesity, including diabetes, hypertension, and dyslipidemia. However, these benefits come with a slightly higher overall mortality rate. For gastric bypass, average 30-day mortality is 0.16%, compared with that of LAGB placement at 0.06%. For this reason, high-risk patients, including older patients with more comorbidities, should be counseled with regards to the perioperative risks between gastric bypass and LAGB.

The benefit of preoperative weight loss prior to bariatric surgery has been debated. A recent randomized trial demonstrated that patients who achieve ≥5% excess body weight loss (EBWL) prior to surgery had significantly lower weight and BMI and a higher EBWL at 1 year. The success of preoperative weight loss is felt to predict patients with the discipline and willingness to follow a healthy lifestyle that will ultimately translate to sustained long-term weight loss. As a result, many surgeons will place patients on one of many available forms of preoperative weight loss diet for 2 to 4 weeks prior to surgery, with a goal of 5% to 10% EBWL. Many forms of commercial dietary programs are available for these purposes, often consisting of a high-protein, low-fat, low-carbohydrate, predominately liquid diet. An additional benefit of this preoperative liquid diet is decreased liver size and density which makes manipulation of the left lobe of the liver easier during surgery.

Surgical Procedure

All patients should receive routine deep venous thrombosis (DVT) chemoprophylaxis immediately prior to arrival in the operating room, as initial development of DVT is felt to occur intraoperatively in this high-risk population. In addition, sequential compression
device is placed prior to anesthetic induction. Routine preoperative antibiotic prophylaxis is also indicated. A second-generation cephalosporin is adequate but typically requires increased dosing in morbidly obese patients. There are two adjustable gastric bands currently on the market, including the Lap-Band™ (Allergan Inc., Irvine, CA, USA) and the Realize® Band (Ethicon Endo-Surgery, Cincinnati, OH, USA). Regardless of which band is implanted, it is advisable to have a second band available for backup at the time of surgery in the event that one is contaminated or damaged at the time of implantation. Each band also has a separately packaged replacement port available as a stand-alone when necessary.

Patient Positioning

Patient positioning is often dictated by surgeon’s preference. Some surgeons prefer the French or lithotomy position. The main advantage of this position is access in between the patient’s legs and inline trajectory of one’s laparoscopic instruments. This centers the surgeon over the operative field and improves posture while minimizing shoulder fatigue. However, this position can be difficult and time consuming and places patients at risk for nerve injury if not positioned properly. Most surgeons have evolved to a completely supine position with arms outstretched on and secured to arm boards. For LAGB placement, supine positioning is recommended. A footboard is also recommended to minimize patient slippage inferiorly during reverse Trendelenburg positioning, as is an upper thigh strap to minimize lateral slippage during rotation of the patient. All bolsters placed behind the patient’s neck and/or shoulders by anesthesia to facilitate endotracheal intubation should be removed prior to initiation of surgery. A Foley catheter is optional. Routine cardiac noninvasive monitoring is essential. Invasive monitoring, including arterial and central venous catheters, is not routinely indicated and is only utilized in selected cases where such additional monitoring is necessary.

Technique

Standard technique includes a five-trocar configuration (Fig. 31.1). Initial cannulation of the abdominal cavity with Veress needle is typically through the camera port, located

Only gold members can continue reading. Log In or Register to continue