The placement of the band creates a small pouch at the top of the stomach which holds approximately 50mls. This pouch ‘fills’ with food quickly and the passage of food from the top to the bottom of the stomach is slowed. As the upper part of the stomach believes it is ‘full’ the message to the brain is that the stomach is full and this sensation helps the person to eat smaller portions, eat less and therefore lose weight over time.

The band is inflated /adjusted via a small access port placed just under the skin subcutaneously. Radio opaque isotonic solution or saline is introduced into the band via the port. A specialized needle is used to avoid damage to the port membrane. There are many port designs and they may be placed in varying positions based on the surgeon’s preference. The port may be sutured in place. When fluid is introduced the band expands placing pressure around the outside of the stomach. This decreases the size of the passage in the stomach and restricts the movement of food.

Over a period of time, restriction is increased until patients feel they have reached a “sweet spot” where optimal weight loss can be reached with the minimal fluid required. This is an individual experience and timing cannot be predicted. There are approximately 7 - 8 adjustable bands on the market. The amount of fluid required and total content is varied.

• Body Mass Index above 40, or those who are 100 pounds (45 kg). or more over their estimated ideal weight according to the 1983 Metropolitan Life Insurance Tables or those between 30 to 40 with co-morbidities which may improve with weight loss (high blood pressure, diabetes, sleep apnea, and arthritis).
• Age between 18 and 55 years (although there are doctors who will work outside these ages).
• Failure of dietary or weight-loss drug therapy for more than one year
• History of obesity (generally 5 years or more).
• Comprehension of the risks and benefits of the procedure and willingness to comply with the substantial lifelong dietary restrictions required for long term success.
• Acceptable operative risk.

It is usually contraindicated for people with any of the following:

• If the surgery or treatment represents an unreasonable risk to the patient.
• Untreated glandular diseases such as hypothyroidism.
• Inflammatory diseases of the gastrointestinal tract such as ulcers, esophagitis or Crohn’s disease.
• Severe cardiopulmonary diseases or other conditions which may make them poor surgical candidates in general.
• An allergic reaction to materials contained in the band or who have exhibited a pain intolerance to implanted devices.
• Dependency on alcohol or drugs.
• Mentally retarded or emotionally unstable people.

Operative Planning for Laparoscopic Colectomy

No patient should undergo laparoscopic bowel surgery without a defined diagnosis. Colonoscopy, barium enemas, and computed tomography are all potentially useful in determining the diagnosis before operation; the choice of diagnostic modality should be governed by the patient’s initial presenting signs and symptoms. The distance from the tumor to the anal verge is readily measured in the course of colonoscopy, but such measurement does not always result in accurate identification of the corresponding segment of diseased bowel intraoperatively. Furthermore, with the exception of the ileocecal valve (which remains a constant and easily identifiable landmark), the general shape and curves of the colon are indistinct. Therefore, it is recommended that India ink tattooing be used to mark lesions located in segments of the bowel outside the area of the ileocecal valve, thereby facilitating intraoperative localization of the tumor.

Patients who have a history of severe cardiopulmonary disease, hepatic disease, coagulopathy, significant respiratory compromise, or a complex colonic disorder (e.g., obstruction, contained perforation, or colovesical fistula) should not be considered for laparoscopic colectomy, nor should patients who are known to have extensive intra-abdominal adhesions. Patients who have tumors larger than 8 to 10 cm in diameter are also unsuitable candidates for laparoscopic colectomy. Larger specimens inevitably require larger incisions for removal; accordingly, patients with large tumors would benefit from having an appropriately sized incision in place from the beginning of the operation.

Oncologic Outcomes

At present, there is a great deal of interest in the use of laparoscopy to resect colon cancers and to minimize the short-term morbidity associated with treatment of malignant diseases. There has been sufficient research into and experience with laparoscopic treatment of colorectal cancer to show that it is a feasible modality offering the same advantages as laparoscopic treatment of benign colonic disease. The heart of the current debate surrounding the application of laparoscopy to malignant colonic disease is the question of how a laparoscopic approach might affect long-term patterns of recurrence and survival.^[1]

Concerns regarding the efficacy of laparoscopic colectomy for cancer have centered on the completeness of the bowel and lymph node resections. As noted, multiple studies have shown no differences between laparoscopic colectomy and open colectomy with respect to proximal and distal margins of resection or the adequacy of lymph node dissection. Most of the concerns regarding the incidence and pattern of recurrence after laparoscopic treatment were generated early in surgeons’ experience with laparoscopic colectomy, and subsequent studies tended not to find substantial differences. However, further studies that include long-term follow-up to determine the adequacy of resection and the comparability of cure rates are needed to assess any changes in the long-term staging and survival patterns after laparoscopic colectomy.

Trocar Placement

When placing the trocars, we favor a Hasson technique, in which the initial 12 mm port is placed through the left upper quadrant rectus muscle under direct vision. The reason we have come to prefer this location is that in the right upper quadrant, the falciform ligament frequently complicates access to the abdominal cavity. The second, third, and fourth ports are then placed under direct vision. Initial studies reported injuries to major intra-abdominal vessels in the course of port placement, but we have not encountered this problem with our technique. In addition, we favor minimizing the number of 10/12 mm ports used because the larger incisions can be difficult to repair accurately and may be associated with bowel herniation. Bowel herniation has not been reported at 5 mm port sites. The port sizes and instrument sizes necessary for colonic dissection are predictable; thus, a standardized approach, as outlined (for more information, see the full chapter), can be established with little difficulty.

Reference: http://www.medscape.com/viewarticle/496510?rss