For bariatric surgery, the patient is required to be evaluated by an interprofessional team before being a surgical candidate. This includes a nutritionist, a psychiatric specialist, surgical team and the primary care physician.

For the operative portion, the following personnel are required; an anesthesiologist, experienced metabolic surgeon, scrub nurse, and first assistant. 

Preoperatively all patients should receive upper endoscopy. There is increasing evidence for the use of an “ultra-low” preoperative carbohydrate diet to shrink the liver allowing for better exposure and favorable outcomes.[7]

The patient will be given preoperative antibiotics 30 minutes prior to incision as well as VTE prophylaxis.  The hair on the abdomen is removed with clippers in the preoperative area. The patient is placed on the operating table and secured in the supine position with the arms extended. After induction of anesthesia, an orogastric tube is positioned within the stomach.

There are many ways to perform a laparoscopic sleeve gastrectomy, and an example is provided below. Different techniques and the data to support them will also be discussed in each section.

 1) Entrance and set up

Entrance into the abdomen begins in the left upper quadrant and the technique utilized is at the surgeon's discretion. The abdomen is insufflated to a pressure of 15 mmHg, and the abdomen is visually explored with a laparoscope. Trocar placement will be as follows:

• 5mm trocar in the left upper quadrant, anterior axillary line (assistant port)
• 5mm trocar in the left upper paramedian midclavicular line (camera port)
• 5mm trocar in the right upper paramedic midclavicular line 
• 15mm trocar placed at or just superior and to the right of the umbilicus (should be parallel with the lesser curvature of the stomach)
• Liver retractor placed in the subxiphoid area
• The two 5mm ports on the left side will be used by the assistant, the two right sided ports (15mm and 5mm right paramedian) will be used by the primary surgeon. Once all ports are in, and liver is retracted, the patient is placed in reverse Trendelenburg.  

2) Mobilization of the greater curvature

Dissection begins by dividing the greater omentum 5 cm proximal to the pylorus near the incisor angularis.  The gastroepiploic vessels are divided using an energy device along the greater curvature toward the short gastric vessels. Division of the short gastric vessels should be done with a bipolar cautery device.  This dissection is continued to completely divide the gastrophrenic ligament and mobilize the angle of His to identify the left crus of the diaphragm.  

• Length from the pylorus - there is debate on the starting point for the first staple load in terms of distance from the pylorus. Distances from 2-6cm are practiced today and the amount of retained antrum determines its clinical significance. With a distance of 2 cm, more antrum is resected, and the gastric remnant is relatively smaller. This, in theory, will produce an increase in excess weight loss but may lead to more complications from the increase in distal intragastric pressure. Studies comparing 2cm distance and 4-6cm distance have shown mixed results. One showed equal outcomes when considering weight loss and complications[8], and the other demonstrated increased weight loss without an increase in complications for the 2cm length.[9] The opinion of the international consensus conference was to start the resection at least 3cm from the pylorus.   

3) Identification and repair of a hiatal hernia

After exposing the left crura of the diaphragm, one should determine if a hiatal hernia is present.  If so it is recommended to reduce the sac and repair the hernia with crural approximation utilizing interrupted sutures posterior to the esophagus.  

4) Posterior mobilization

The omentum has been separated from the greater curvature allowing access into the lesser sac. The stomach is grasped and lifted anteriorly to expose its posterior wall. All adhesions to the lesser sac are taken down up until the most medial aspect of the stomach at the lesser curvature.  

5) Bougie placement

The orogastric tube is removed and a 32 to 40 French Bougie is placed under laparoscopic visualization and is directed to a point distal to the divided omental attachments.

• Size of bougie - the thought behind choosing a size of bougie to create the sleeve gastrectomy around stems on two outcomes, proximal staple line leaks, and percent estimated weight loss. Historically it was shown that with smaller french bougie this would lead to an increase in leak rate and weight loss. A meta-analysis in 2013 has shown that there is a leak rate reduction of 66% when using a bougie of 40 French or higher without a statistically significant alteration in the effectiveness of weight loss.[10] This would suggest a larger size bougie would be beneficial in terms of leaks, but it did not address other complications, and its impact on them and further studies are needed. In the Fifth International Consensus Conference, it was recommended that a large bougie should be used (median was 36French).[11]

6) Creation of a stapled sleeve gastrectomy

A 60mm long endoscopic stapler is used for this. Firing is begun at a point approximately 5 cm proximal to the pylorus along the bougie and with an angle that is parallel to the lesser curvature. One must ensure that the stapler is encompassing equal lengths of the anterior and posterior stomach to avoid “spiraling” of the sleeve. The staple lines are sequentially fired along the bougie toward the angle of His and divide the fundus at a distance of .5 to 2 cm lateral to the esophagus. The remaining cardia will be inverted at the GE junction utilizing interrupted Lembert sutures. The amputated stomach is then removed through the 15mm port.  

• Reinforcement of staple line - the main objectives of reinforcement of the staple line are to reduce the staple line leak and hemorrhage rates. There are many techniques to do this and are of two main categories, oversewing and buttressing. In a recent meta-analysis in 2016, when comparing reinforcement to no reinforcement, there was no statistically significant difference in leak rate however it did show a decrease in overall complications including staple line bleeding. When comparing oversewing to buttressing, sewing revealed weaker benefits with longer operative times and a higher complication rate.[12]  There is further research needed to determine the best method of reinforcement, but in the latest consensus, most experts are using a buttress technique.[11]

• Staple height - on average the wall thickness of the antrum, body, and funds are 3.1, 2.4, and 1.7mm respectively.[13] The goal is to use a stapler with tall enough staples to accommodate the thicker antrum as opposed to the thinner fundus.  Some have advocated superior results using taller staple height distally and shortener staple height proximally when approaching the fundus.[14]

7) Endoscopy

A flexible endoscope is carefully inserted into the esophagus and the staple line is visualized for integrity and hemostasis. The remaining stomach may be submerged in irrigation fluid and then insufflated with the endoscope to check for a staple line leak.  

• Intraoperative leak test - this is up to the surgeons' discretion as it has had inconsistent results. A multicenter retrospective analysis in 2017 demonstrated a poor sensitivity of intraoperative leak test to predict postoperative leaks.  They demonstrated that the intraoperative leak test was negative in 91% of patients who eventually developed a staple line leak.[15]

8) Closure 

A fascial closure is done at the 15mm port site and skin closure done at all sites.

Currently, the 30-day morbidity and mortality of a laparoscopic sleeve gastrectomy in the literature ranges from 0-17.5% and 0-1.2% respectively.[16] 

As with many operations, complications can be divided into early and late.

Early:

Hemorrhage

The reported incidence is between 1 and 6% postoperatively and can be intraluminal or intraabdominal.[17] Extraluminal bleeding are typically from the staple line, spleen, liver, or abdominal wall. This is treated with reoperation at the surgeon's discretion. For intraluminal bleeding, the patient may present with melena or hematemesis with a concomitant hematocrit drop. This may be treated by endoscopic means and more rarely surgical intervention. 

There is some evidence to support reinforcement of the staple line to prevent bleeding. There has been more successful outcomes when comparing buttressing materials as opposed to staple line suture reinforcement.  There is still controversy in this area, and a definitive conclusion has not yet been made.[18]

Leak 

The incidence of postoperative leak in laparoscopic sleeve gastrectomy is between 2 and 3%.[19] The cause of leak in sleeve gastrectomy patients is increased pressure relayed on the staple line in the setting of relative ischemia. This is typically located just below the GE junction where there is relative ischemia due to the dependence on the sacrificed short gastric vessels.  Increase in pressure may be due to a distal narrowing caused by a small caliber bougie, stricturing, or technical error of firing the stapler too close to the incisura angularis is. There has been mixed results and opinions on whether staple line reinforcement can decrease postoperative leak rate and further studies are needed.  It has been demonstrated that a larger bougie size will decrease the incidence of leak in sleeve gastrectomy patients.

Patients may be asymptomatic but frequently present with fever, tachycardia, and tachypnea with elevated heart rate being the first sign. The diagnostic test of choice is a CT scan with oral and IV contrast which demonstrates a relatively high sensitivity and specificity. An UGI contrast series has a high specificity, but a low sensitivity and thus is not recommended as first-line diagnostic imaging. 

Leaks should be classified as either acute (<5 days postoperatively) or chronic (>4 weeks postoperatively). In the acute, unstable patient, exploration with drainage of the leak and placement of a distal feeding tube is the management of choice.  In the chronic patient, operative management is less successful. If they are unstable, the patient will require an operation as described for an acute leak. For a chronic leak/fistula in a stable patient, treatment is conservative utilizing drainage of abscess if present, antibiotics, NPO, TPN, and endoluminal stenting.  Most chronic fistulae/leaks will close within the range of 4 weeks to 3 months.[20]

Late: 

Stricture 

This complication has an incidence of up to 4 percent and may present acutely secondary to edema or more often chronically. The common symptoms are dysphagia, nausea and vomiting and the most common location is at the incisura angularis. In the acute setting, this is likely secondary to edema or kinking due to technical issues.  The diagnostic image of choice is an UGI contrast study.  Treatment of the acute stricture is conservative and only require surgery in the setting of nonresolution.  Patients who present with chronic strictures should undergo endoscopic balloon dilations and may require multiple interventions for long-term improvement.  Failure of endoscopic management will require surgical intervention with either a laparoscopic seromyotomy or conversion to a gastric bypass procedure.[21]

Gastroesophageal Reflux

Severe GERD is a relative contra indication to sleeve gastrectomy.  There have been conflicting results in the literature, but many have advocated development or worsening of reflux symptoms.  First line therapy are PPIs, but if the patient has severe symptoms and is refractory to medical treatment, they may require conversion to a Roux-en-Y gastric bypass.[22]

Nutritional Deficiencies 

All bariatric procedures harbor nutrient deficiencies and are largely prevented by routine testing and daily supplementation. There is data to show a decreased incidence of nutrient deficiency when compared to gastric bypass patient with the exception of folate.[22]

Laparoscopic sleeve gastrectomy has become the most popular weight loss procedure in the United States over the last two decades.  Long-term data is now available on the outcomes of sleeve gastrectomy, and it is very promising. The average excess weight loss after five years in a laparoscopic sleeve gastrectomy is reported to be around 60%, and resolution of comorbidities are excellent.  A meta-analysis in 2017 compared midterm and long-term results between sleeve gastrectomy and roux-en-y gastric bypass.  The conclusion was that in the midterm (3-5 years postoperatively) the two surgeries had similar results in terms of excess weight loss and resolution or improvement of comorbidities. The long-term data demonstrated that gastric bypass eventually did have superior excess weight loss but the improvement in comorbidities remained the same between the two procedures.[23]

Management of obesity is with an interprofessional team to get the ideal results. Even though there are several types of bariatric procedures for weight loss, the key is patient education on the prevention of obesity. All healthcare workers including nurse practitioners should educate the patient on a healthy diet, regular exercise and maintaining a healthy weight. These preventive measures do work as long as the patient is compliant. More important these measures are virtually devoid of risks. Bariatric surgery does not cure obesity and the results are not always guaranteed. However, for those who do manage to lose weight with surgery, there is an added benefit of better glucose control, lowering of blood pressure and lipids. (Level II)