Perioperative management - Gastric bypass, laparoscopic

Surgical measures, like all other therapeutic approaches for treating obesity, are not a cure for the cause, as the actual cause of obesity is complex and still largely unknown. They are considered in developed countries according to guidelines for patients with a BMI ≥ 35 kg/m² with serious comorbidities, such as diabetes mellitus, or a BMI ≥ 40 kg/m², and in whom conservative treatment measures have demonstrably not been successful.

When choosing the procedure, the following parameters should be considered:

• the patient's initial weight (BMI)
• the expected weight loss (EWL)
• compliance
• the age
• a possible desire for children in women
• comorbidities (especially diabetes mellitus)
• the surgical risk

Further factors to consider are:

• gender
• profession
• eating habits

• wasting diseases
• Pregnancy
• lack of compliance
• Diseases of the stomach and duodenum

Since bleedings in the remnant stomach cannot be treated endoscopically, there is a contraindication for patients

• with lifelong medication for blood thinning (Marcumar or ASA)
• with chronic need for pain medication (ulcerogenic)

Risk evaluation has a high priority in obesity surgery. It includes, in addition to the standard diagnostics (ECG, chest X-ray, laboratory), always a pulmonary function test and an assessment of the nutritional status. The endoscopic evaluation of the stomach is particularly important in resective procedures, such as gastric bypass. In contrast, the radiological examination provides additional information in only about 5% of patients. Routine polysomnography is standard in US clinics, as between 77 and 88% of patients there have sleep apnea.

The preparation of the patient begins already before inpatient admission with physical conditioning: smoking ban, liquid diet at least 2 days before admission (ideally 2 weeks) and discontinuation of medications that can increase the risk (Metformin, oral anticoagulants etc.)
Bowel preparation is also recommended when performing gastric bypass. General hygienic requirements in the preparation do not differ significantly from other procedures. Intertriginous skin fold affections and acute-inflammatory leg ulcers or diabetes-related changes in the lower extremity are particularly to be noted. The pharmacological thrombosis prophylaxis begins on the day of surgery and is dosed according to body weight.

The informed consent must be particularly comprehensive, as it involves an elective procedure. This includes, in addition to capturing the general surgical risks in laparoscopy and conversion to laparotomy, the capturing of specific risks. This includes the presentation of intraoperative risks, short- and long-term consequences, up to transfusion and mortality risk. Currently, there is no standardized informed consent for the procedure.

An example of comprehensive informed consent can be found here.