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.

Since the gastric bypass is a procedure that can only be performed by means of laparoscopy or laparotomy, an intubation anesthesia or an intubation anesthesia with capnoperitoneum must be chosen for the operation.
In principle, an endoscopically assisted intubation must be possible in obese patients. Video laryngoscopy significantly facilitates intubation.

Ileus positioning
During the entire operation time, maximum relaxation is required to create a maximum range of action in the operating area, which is already restricted by abdominal and visceral fat. In addition, the anesthesiologist must note that due to the very upright positioning of the patient in an almost sitting position in anti-Trendelenburg position, possibly higher ventilation pressures, possibly PEEP ventilation, may be required.

Central venous catheter
Individually, in high-volume centers, the placement of a CVC can usually be dispensed with, as the placement of a CVC in extreme obesity has its own morbidity. In centers with low surgical frequency and longer operating times, a CVC is recommended. Furthermore, a central venous catheter postoperatively provides a secure access in the usually poor peripheral venous situation of the patients for the critical first 24-48 hours.
This CVC can also be placed "peripherally" in the brachial or radial veins to avoid the risk of pneumothorax.

Gastric tube
A gastric tube must be placed during the procedure and moved according to the surgeon's instructions during the creation of the upper anastomosis. This requires absolute coordination via the laparoscopy monitor, as the gastric tube must be carefully advanced over the anastomosis to be created without risking a perforation. After creation of the anastomosis, a leak test with methylene blue must be performed. Here too, close coordination with the surgeon is necessary. After the leak test, accidental suturing must be excluded by moving the tube. If necessary, the tube can be left in place above the anastomosis for up to 24 hours, but must then be removed to avoid pressure ulcerations in the small intestine. Usually, however, the gastric tube can be carefully removed after the leak test. Pulling too quickly must be avoided, as in the case of accidental suturing of the tube, it can lead to perforation or rupture of the anastomosis.

The patient is positioned in the reverse Trendelenburg position on the operating table approved for the patient's weight. These tables should also feature side extensions for very wide patients. The video monitors are placed over the patient's shoulders on the left and right. Both arms are extended outward. The legs are spread apart.

The surgeon's position in Europe is predominantly between the patient's abducted legs, which is ergonomically the most favorable (“French Position”). A camera assistant is required if no voice-controlled camera is used. A pneumatic liver retractor on the patient's right side holds the left liver lobe constant. The scrub nurse stands on the surgeon's left side.

• a basic laparoscopic set
• a Two-Step trocar with Verres needle or another access trocar
• two 5 mm trocars (if necessary in extra length)
• three 12 mm trocars (if necessary in extra length)
• if necessary, a 15mm trocar for the staple suturing devices.
• a dissection device (Ultracision® or LigaSure™)
• an HF device
• a selection of laparoscopic staple suturing devices (3-4 blue magazines for the stomach and two white magazines for the small intestine)
• two Babcock forceps or other atraumatic grasping forceps for measuring the small intestine
• two needle holders
• scissors and if necessary traumatic grasping instruments
• the use of a 30° optic is recommended
• high-volume insufflators
• holding arm for liver retractor

Postoperative Analgesia: 

Intravenously administered standard medications that do not carry ulcerogenic potential are generally sufficient.
Follow the link here to PROSPECT (Procedure Specific Postoperative Pain Management).
Follow the link here to the current guideline Treatment of acute perioperative and posttraumatic pain.

Medical Follow-up Care:

• Postoperative Monitoring: Since tachycardia is sometimes the only sign of significant problems in these patients, postoperative monitoring in a monitoring or intensive care unit is advisable.
• Bronchial Toilet: A high incidence of atelectasis and low oxygen saturation necessitates frequent bronchial toilet in this patient population.
• Gastrografin Swallow: On the 2nd postoperative day, a Gastrografin swallow can be performed. If there is no insufficiency or stenosis, the nasogastric tube can be removed, provided this has not already been done intraoperatively. Some centers do not perform routine X-ray examinations and others do not leave a gastric tube postoperatively, without observing negative effects.Vitamin Supplementation: Vitamin supplementation begins after the 3rd postoperative week. This consists of a daily dose of multivitamin tablets, 100 mg Vitamin B12 and calcium in the form of Tums.
• Iron Intake: In menstruating women, additional iron intake is recommended.
• Gallstones: If patients still have a gallbladder, the occurrence of gallstones can be reduced from almost 40% to 3% by administering certain bile acids during the first 6 postoperative months.
• Exercise: Since physical activity is a crucial factor for the long-term success of the surgery, patients are encouraged to engage in a lot of exercise at every follow-up examination. Running, cycling or aerobics should be done for at least 30 minutes 5 times a week.If there are no wound healing disorders, muscle-building weight training for the upper body can also be recommended after the 6th postoperative week. All patients undergo follow-up examinations at 3-month intervals during the first year so that appropriate dietary and exercise behavior can be checked.
• Follow-up Examinations: At least twice a year for an indefinite period.

Thrombosis Prophylaxis: 

In the absence of contraindications, due to the moderate thromboembolism risk (surgical procedure > 30min duration), in addition to physical measures, low-molecular-weight heparin should be administered in prophylactic, possibly weight- or disposition risk-adapted dosage until full mobilization is achieved. In addition, thigh-high compression stockings are to be worn by the patient.
Note: Renal function, HIT II (history, platelet count)
Follow the link here to the current guideline Prophylaxis of venous thromboembolism (VTE).

Mobilization: 

Start on the evening of the surgery; increasing mobilization is desired, but lifting objects over approx. 3 kg should be avoided until 6 weeks postoperatively.

Physiotherapy: 

If necessary, respiratory therapy for pneumonia prophylaxis

Diet Build-up: 

On the 2nd postoperative day, slow diet build-up with initially water ( < 30 ml/hr) is possible. Once the patient tolerates water in sips, the drinking amount is increased to up to 60 ml/hr, and he receives 60 ml of an enteral standard nutritional solution of his choice of flavor 3 times a day. Patients are instructed to avoid solid food until further notice. Carbohydrate-rich drinks are generally obsolete. Medications may only be taken in powder form or as a solution. Four weeks after the procedure, a gradual transition from soft to firmer food can finally be made. This should start with cooked chicken and fish. Meat may not be tolerated at all for some time. Patients are instructed to chew food for a long time and to take breaks between individual bites. When a feeling of fullness occurs, food intake should be stopped. 3 meals per day are to be observed; skipping a meal is to be avoided. Snacks should contain few calories if at all, such as plain popcorn, celery or carrots.

Bowel Regulation: 

In the immediate postoperative phase, patients may experience both constipation and diarrhea. These can usually be treated conservatively. Lactose intolerance may occasionally be unmasked. Crucial is the adequate fluid intake of the patients. Persistent diarrhea with severe bloating may be a sign of excessive oral fat intake. Occasionally, there is also a transient bacterial overgrowth of the intestine, which usually normalizes after returning to normal eating habits. Here, consistent follow-up care by a trained nutritional physician is advisable.

Inability to Work: 

Usually, discharge is possible on the 3rd-5th postoperative day, provided the drinking amount is sufficient.