Bariatric surgery is highly sucessful in the majority of patients, however 15-20% of patients either fail to lose the appropriate weight or regain weight after several years.

The most common cause of failure is related to challenges in making the adjustments to a new life style and nutritional habits. Revisions may in some cases be necessay to correct the anatomy. All bariatric procedures have the risk of failure and revisions need to be tailored to the patients specific needs.

Gastric Bypass patients generally seek revision weight loss surgery for two reasons: 1) failure to lose adequate weight and/or weight regain, 2) medical complications (medical complications after gastric bypass may lead to failure). Failure after gastric bypass may be due to mechanical or metabolic reasons; the eating behaviors of a patient should be considered as well. In fact, the first step in assessing a patient who has failed to lose adequate weight after gastric bypass, is to look carefully at the patient's food consumption. The best way to analyze food intake is to simply start a detailed food diary. Patients are often shocked at how many calories they consume on a daily basis. While most people may think they have a good idea of their food consumption, it only takes tracking food intake in a food diary to get a true picture of how much we consume. When patients are not eating how they should, getting back on track is the next step.

There are a variety things that could happen next:

•  Some patients are able to return to the type of behavior they should be following, essentially getting back on track.

•  Some patients may not be successful at weight loss despite returning to proper dietary behaviors.

•  Other patients are never able to return to proper eating habits. This could mean a patient is non-compliant, but not necessarily.

There are mechanical reasons that may cause patients to resort to maladaptive eating behaviors. An example of this is a patient with an anastomotic stricture who slips into the "soft-calorie syndrome" due to the fact that soft foods are the only foods that the patient can tolerate without vomiting. Another point to consider is exactly what "compliance" is after gastric bypass. "Proper" eating after gastric bypass represents an entirely foreign eating pattern for the majority of humanity who have not had weight loss surgery. Some individuals are just not "wired" to live this type of lifestyle, even with the assistance of a small gastric pouch. A person's character, for better or worse, does not necessarily contribute to this problem.

Gastric Bypass may fail for the following mechanical reasons:

• gastro-gastric fistula

• pouch dilation

• anastomotic dilation

Conversion from gastric bypass to duodenal switch is the most definitive revision procedure for inadequate weight loss or weight regain after gastric bypass. This approach addresses the issues of metabolic failure and maladaptive eating as causes of failure. This conversion may be done laparoscopically in many cases. A potential concern with this operation is proper stomach function after surgery. The bypassed stomach is now brought back into use, and some patients may have had the nerves to the bypassed stomach cut during their original gastric bypass procedure. This is rarely a problem, as the nerves seem to grow back as the bypassed stomach "wakes up" and resumes working again. Sometimes it may not be safe to re-connect the gastric pouch to the bypassed stomach due to excessive scar tissue. If the patient has acceptable protein tolerance and satisfactory calcium metabolism, conversion to a Scopinaro-type Bilio-Pancreatic Diversion makes a very satisfactory option.

Medical issues complicating gastric bypass include marginal ulcer, stricture, and severe dumping syndrome. These conditions may often be treated conservatively, but when conservative treatment fails, revision surgery is indicated. Treatment for ulcer or stricture may involve resection of the ulcerated/strictured connection between the pouch and the intestine. Another approach is to convert to a Vertical Sleeve Gastrectomy-based procedure, as stricture and marginal ulcer are conditions that arise as a result of the intrinsic physiology of gastric bypass. This approach is favored for cases of severe dumping syndrome as well, as it is the inherent nature of the gastric bypass itself that results in the condition. Rarely, reversal of gastric bypass may be necessary to treat cases of malnutrition, including issues with vitamin and mineral malabsorption. Reversals for nutrient malabsorption may be accompanied by revision to a non-malabsorptive weight-loss procedure, allowing patients to stave off any weight re-gain that may otherwise result from the reversal of their malabsorption.

Sleeve gastrecctomy may also require revision. Generally they are designed to either enhance weight loss or correct any specific problem or complication such as strictures or severe acid reflux.

Several options exist when revising a sleeve gastrectomy:

Patients can be:

•  resleeved

•  converted to gastric bypass

•  converted to duodenal switch

•  the sleeve can also be banded.

It is important that patients understand that the majority of these treatments are still being investigated as to the safety and efficacy of outcomes.

Around 20% of LAP-BAND patients undergo some type of revision.

Revisions for gastric banding is often done to treat mechanical failure of the device, such as slippage. migration. port displacement and tubing dysruption.

Patients can also undergo revision for failure to lose weight.

Gastric banding can be converted to gastric bypass, BPD, DS and to sleeve gastrictomy.