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What GPs should know about lap banding |
 Introduction
Surgery for morbid obesity has been around for 50 years starting with jejunoileal bypass (a malabsorptive procedure) in the 1950s, followed by gastric bypass (malabsorptive-restrictive procedure) in the 1960s. Over the last 10 years gastric banding, a purely restrictive procedure done with a laparoscopic technique, has been developed. It is the least invasive procedure, creating a small pouch and a small stoma with a silicone band placed around the stomach above the lesser curvature.
By creating a smaller gastric pouch the lap band limits the amount of food that the stomach can hold at any time. The inflatable ring controls the flow of food from this smaller pouch to the rest of the digestive tract. The patient will feel comfortably full with a small amount of food and will continue to feel full for several hours thus reducing the urge to eat between meals.
One of the most important advantages of laparoscopic gastric banding (LAGB) compared with other gastric restrictive procedures is the possibility of stoma size adjustment without reoperation. Stoma diameter can be modified according to the patient’s need by inflation or deflation of the inflatable portion of the silicone band. This can be done as an outpatient procedure by injection or withdrawal of saline.
LAGB is now used commonly in continental Europe and in Australia. The US has only approved the procedure since June 2001.
Who should be referred?
LAGB is reserved for those who have a BMI of at least 35, who have complications of being obese such as metabolic complications, high cardiovascular risk, severe mechanical problems (such as arthritis in the knees), and psychosocial problems. The ideal candidate has exhausted all other avenues for weight loss including diet and exercise modifications, legitimate weight loss programs, weight loss medications, very low calorie diets, meal supplements etc. Obviously the surgical team needs to be thorough with informed consent of the benefits versus the risks of the procedure and to ensure the patient has a commitment to lifestyle modification that will make the procedure work long term. They also need to explain the long term medical follow up that is needed.
What are the results of such surgery?
The Swedish Obesity Subjects (SOS) intervention study began in 1987 and will continue until 2021. The main question posed is whether voluntary weight reduction will reduce total mortality in obese subjects.
Secondary aims of the study include the effects of weight loss on specific morbidity and mortality, cardiovascular risk factors, dietary habits, health related quality of life and health economics.
2010 operated patients (LAGB, vertical banded gastroplasty or gastric bypass) and 2037 conventionally treated controls are being followed over 20 years. So far the control group gained 1% in weight over 10 years while the operated patients have lost 16%. (1) It is too early to tell whether the beneficial effects on risk factors and cardiovascular system will reduce total mortality but the positive effects on health related quality of life and musculoskeletal pain is very clear.
Weight loss following lap banding has a major impact on type 2 diabetes, with resolution or remission of diabetes in two thirds of patients and improved blood glucose control for the remainder. In one study (2) obese subjects with impaired fasting glucose were all found to have normal fasting plasma glucose two years after surgery. In severely obese subjects without diabetes preoperatively and with a follow up of more than 3,000 patient years, there has not been a single case of type 2 diabetes developing.
Lap banding causes a substantial decrease in fasting triglycerides and rise in the HDL cholesterol to normal levels. There is a significant drop in both systolic and diastolic blood pressure, major improvements in sleep quality, and a reduction of daytime sleepiness, snoring, nocturnal choking and sleep apnoea. Asthma severity and symptoms improve following lap banding surgery, as does gastroesophageal reflux.
Patients with polycystic ovarian syndrome treated with LAGB have improved fertility rates. The band device can be adjusted in the event of a pregnancy to allow for increased nutritional demands. Many studies demonstrate major improvement in quality of life, body image and depression.
Overall there is now compelling evidence demonstrating the benefit of sustained weight loss on obesity comorbidity and quality of life following LAGB surgery.
What are the risks?
The early promise of a minimally invasive procedure that actively restricts intake and controls hunger was moderated by reports of high rates of gastric herniation through the band as well as the occasional erosion of the band through the stomach - both requiring open surgical repair. However a new surgical method for placement of the band has evolved. Higher placement of the band away from the body of the stomach has dramatically reduced the incidence of this complication from about 10-15% to 1.8%. (3) Overall in appropriately trained hands it is now considered a safe operation with low reported mortality rates (0-0.55%).
Post operative care and follow up
Adherence to a well structured postsurgical management plan is at least as important as the surgical technique and GPs and local dietitians, particularly in rural areas, may need to be involved. A properly placed and adjusted gastric band produces prolonged satiety after a small meal facilitating a major reduction in dietary intake leading to weight loss. The usual encouragement to increase activity levels, healthy food choices and behavioural changes are needed following this procedure and are vitally important for good long term results.
A dietitian may need to be involved to ensure adequate protein, complex carbohydrates, low fat and simple sugar foods. The food consumed needs to be solid so that it will not pass across the banded area and a
sense of satiety can occur and persist. The patient needs to eat slowly, eat three meals a day, not eat between meals, take no liquids with meals, use zero or low calorie drinks, exercise for at least 30 minutes a day, and be as active as possible.
At the completion of the surgical placement of the lap band, no additional saline is added for at least 5-7 weeks. Thereafter adjustments are made as required for further weight loss. Fluid can be removed if there is vomiting, heartburn or reflux.
Follow up should also involve assessment of the patient’s metabolic and nutritional status including fasting glucose, lipid profile, LFTs, iron, vitamin B12, folate, homocysteine (which may dangerously rise) and protein levels. GPs will need to become involved in the post operative management in partnership with and under the guidance of the surgical team.
Conclusion
LAGB may seem a rather drastic solution to a now common 21st century problem, but for those unfortunate morbidly obese people who have tried everything, who suffer and are at risk because of their morbid obesity; this operation is a safe and effective procedure. It can radically improve the quality of their lives and reduce the risk of life threatening or distressing disease. Cost is a major factor for consideration and waiting lists are growing. For some these are acceptable hurdles to get over. This is an operation that we are likely to hear more about in the future as the obesity epidemic soars out of control.
Medical Editors note: To find a list of gastric surgeons who perform lap banding go to www.professortrim.com/doctor_directory/surgeons.html
References
(1) Torgeson JS Swedish obese subjects - where is the study now? International Journal of Obesity volume 27, Supplement 1, May 2003 S19 Abstract
(2) Dixon JB, O’Brien P. Health outcomes of severely obese type 2 diabetic subjects 1 year after laparoscopic adjustable gastric banding. Diabetes Care 2002; 25:358-63 Abstract
(3) Dixon JB, O’Brien P. Changes in comorbidities and improvements in quality of life after LAP-BAND placement. American Journal of Surgery Vol 184 Suppl 2 S51-54 Dec 2002
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