Risks of Weight Loss Surgery

Weight loss surgery should not be considered until you and your doctor have evaluated all other options. As with all surgeries, there are risks associated with this procedure. If complications occur during the operation, your doctor may choose to perform open surgery. Your doctor must determine if you are an appropriate surgical candidate.

Weight loss surgery is typically reserved for those individuals 100 pounds or more overweight (Body Mass Index [BMI] of 40 or higher) who have not responded to other less invasive therapies such as diet, exercise, medications, etc.

In certain circumstances, less morbidly obese patients (with BMIs between 35 and 40) may be considered for surgery (patients with high-risk co-morbid conditions and obesity-induced physical problems that are interfering with quality of life).

Important Considerations
Weight loss surgery should not be considered until you and your doctor have evaluated all other options. The proper approach to weight loss surgery requires discussion and careful consideration of the following with your doctor:

  1. These procedures are in no way to be considered as cosmetic surgery.
  2. The surgery does not involve the removal of adipose tissue (fat) by suction or excision.
  3. A decision to elect surgical treatment requires an assessment of the risk and benefit to the patient and the meticulous performance of the appropriate surgical procedure.
  4. These weight loss surgical procedures (approved in the United States) are not reversible.
  5. The success of weight loss surgery is dependent upon long-term lifestyle changes in diet and exercise.
  6. Problems may arise after surgery that may require revisions. Success of surgical treatment must begin with realistic goals and progress through the best possible use of well-designed and tested operations.

Complications and Risks
As with any surgery, there are operative, short-term, and long-term complications and risks associated with weight loss surgical procedures that should be discussed with your doctor.

The risks of this surgery depend in great part on your general medical condition. Each patient is different, and must be personally evaluated by a surgeon and possibly specialists, to determine the particular risks. Studies demonstrate that obesity is associated with higher surgical risks. As with all major abdominal surgical procedures, there are risks inherent to anesthesia and the surgical process, including the potential for respiratory, neurological, cardiovascular abnormalities, blood clot formation, hemorrhage, infection, and even death. The risks of obesity may cause these same anesthesia and surgical risks to be even higher.

Immediate postoperative problems may include: leakage of intestinal contents and fluids at the surgical sites, infection, respiratory complications, the need for cardiopulmonary, renal, and other intensive care support, re-operation, or even death.

Short-term complications from weight loss surgical procedures are possible. The following information is from the International Bariatric Surgery Registry (IBSR), Winter 2000-2001 Pooled Report 15. Gastrointestinal surgery for severe obesity. Proceedings of a National Institutes of Health Consensus Development Conference. March 25-27, 1991, Bethesda, MD. Am J Clin Nutr, 1992. 55(2 Suppl): p. 487S-619S. See also American Society of Bariatric Surgeons.

  Complications from gastric bypass within 30 days of surgical treatment for obesity of 10, 993 people. Total patients from IBSR 2000-2001 Winter Pooled Report 15(1) N % Minor:* Major:*
Minor:* other: drug skin problems, balloon dilatation, hemorrhoidectomy, gastroenteritis, undefined 165 1.50% 1.50% 0.00%
Minor:* atelectasis (46), hyperventilation (1), respiratory undefined (104) 151 1.37% 1.37% 0.00%
Minor:* wound site Seroma (80), wound infection (48) 128 1.17% 1.17% 0.00%
Minor:* Splenic injury 27 0.25% 0.25% 0.00%
Minor:* pleural effusion (11), pleuritis (2), pneumonitis (9), 22 0.20% 0.20% 0.00%
Minor:* dehydration 8 0.07% 0.07% 0.00%
Minor:* renal, urinary tract infection (4) 7 0.06% 0.06% 0.00%
Minor:* stoma too large (5), stoma too small (1) 6 0.05% 0.05% 0.00%
Minor:* ulcers: duodenal, gastric, stomal (jejunum or anastomoses) 5 0.05% 0.05% 0.00%
Minor:* hepatic, liver hematoma (1) 4 0.04% 0.04% 0.00%
Minor:* esophageal reflux, esophagitis (2) 3 0.03% 0.03% 0.00%
Minor:* hernia: incisional (1), ventral (1) 2 0.02% 0.02% 0.00%
Minor:* dumping syndrome (1), vitamin insufficiency (1) 2 0.02% 0.02% 0.00%
Major:* GI Leak (5 deaths) 33 0.30% 0.00% 0.30%
Major:* stoma obstruction (lumenal - 18); stoma stenosis (15) 33 0.30% 0.00% 0.30%
Major:* GI hemorrhage or GI bleeding; 7 due to ulcers, undefined (19) 26 0.24% 0.00% 0.24%
Major:* cardiac (4 deaths) 19 0.17% 0.00% 0.17%
Major: * pulmonary embolism (11 deaths) 19 0.17% 0.00% 0.17%
Major: * respiratory arrest or failure (4 deaths) 16 0.15% 0.00% 0.15%
Major:* wound dehiscence 13 0.12% 0.00% 0.12%
Major:* small bowel obstruction: Roux-en-y (4), common channel (2), enterostomy (1) undefined (6) 13 0.12% 0.00% 0.12%
Major:* Subphrenic / sub hepatic abscess; abdominal abscess (1) 11 0.10% 0.00% 0.10%
Major:* gastric dilatation (1 death) 11 0.10% 0.00% 0.10%
Major:* deep venous thrombosis (6), thrombophlebitis (2) 8 0.07% 0.00% 0.07%
Major:* staple line breakdown: linear gastric (3), window (1), enterostomy (3 - 2 deaths) 7 0.06% 0.00% 0.06%
Major:* pancreatitis (3); acute cholecystitis (2) 5 0.05% 0.00% 0.05%
Major:* neurologic (1 death) 4 0.04% 0.00% 0.04%
Major:* gastric fistula 3 0.03% 0.00% 0.03%
Major:* peritonitis (2 deaths) 2 0.02% 0.00% 0.02%
All Complications   6.87% 4.83% 2.04%
      Total:* Minor:* Major:*

Weight loss surgery involves some loss of absorptive function, therefore, the long-term consequences of potential nutrient deficiencies must be recognized and adequate monitoring must be performed, particularly with regard to vitamin B12, folate, and iron. Some patients may develop other gastrointestinal symptoms such as "dumping syndrome" or gallstones. Occasionally, patients may have postoperative mood changes or their pre-surgical depression symptoms may not be improved by the achieved weight loss. Thus, surveillance should include monitoring of indices of inadequate nutrition and modification of any preoperative disorders. The table below illustrates some of the complications that can occur following gastric bypass surgery.

Gastric Bypass Surgery Complications: 14-Year Follow-Up

Complications Number Percent
Vitamin B12 deficiency 239 39.9
Readmit for various reasons 229 38.2
Incisional hernia 143 23.9
Depression >142 23.7
Staple line failure 90 15.0
Gastritis 79 13.2
Cholecystitis 68 11.4
Anastomotic problems 59 9.8
Dehydration malnutrition 35 5.8
Dilated pouch 19 3.2

Data derived from source (Pories WJ (595)) and modified based on personal communications.

This information is taken from the Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: The Evidence Report published by the National Institutes of Health, National Heart, Lung, and Blood Institute in June 1998.

The intent of the guidelines is to provide the current scientific evidence on the most appropriate treatment strategies for the overweight and obese patient, and to report on the effects of such treatments in a way that constitutes evidence-based clinical guidelines for primary health care practitioners. The guidelines should also be useful for managed care organizations or other groups that define benefit plans for patients or handle health care resources. In addition, the systematic assessment of the literature should be a valuable resource to health care policy makers and clinical investigators.

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