Controversy surrounding laparoscopic Y-shaped gastric bypass and methods to enhance weight loss results

Laparoscopic Y-type gastric bypass: Controversy

Laparoscopic Y-type gastric bypass (LRYGB) is touted by many scholars as the gold standard in bariatric surgery, but this is actually misleading, because there is currently no standard surgical procedure that most surgeons can follow.

The current LRYGB procedure is a significant improvement and transformation from the previous open abdominal surgery.

People are constantly discussing and debating, hoping to find an ideal surgical technique that will result in better surgical outcomes and fewer complications. Of course, this is also the goal of all surgical techniques.

In this chapter, we will explore some of the current controversies surrounding the LRYGB technique.

How to enhance weight loss results

Weight gain after gastric bypass surgery is due to enlargement of the anastomosis or gastric pouch.

We should know that many patients can achieve good postoperative results even with enlarged gastric pouches or anastomoses.

While some patients had successful surgeries with no enlargement of the stomach or anastomosis, their weight rebounded back to pre-operative levels.

Modified gastric bypass surgery, performed on patients with moderately enlarged gastric pouches in the hope of shrinking and further limiting gastric pouch expansion, is sometimes unsuccessful.

In this case, it is best to convert the standard proximal gastric bypass surgery into a distal gastric bypass surgery to slightly or moderately improve the weight loss effect.

Regarding the issue of poor long-term efficacy after gastric bypass surgery, some surgeons advocate reinforcing the gastric pouch and anastomosis to address this problem.

The reinforcement surgery can be performed using a silicone rubber band or a small section of the tensor fasciae latae muscle.

The latter can be used in both the gastric sac and the anastomosis.

Fobi et al. used a 5.5cm silicone rubber band for vertical gastric banding and combined it with gastric bypass surgery.

They reported follow-up results in the second and sixth years, with over 90% of patients losing more than 40% of their excess weight. However, the study did not include a control group, and the enhanced gastric pouch procedure was not without complications, such as erosion of the straps and poor food tolerance.

This procedure, which includes a reinforced gastric pouch, can also be performed laparoscopically.

Bessler et al. recently published the results of their randomized, prospective, double-blind study comparing the use of a polypropylene gastric bandage with and without one.

The two different surgical methods showed no difference in weight loss and complication rate within one year.

Sapala et al. suggested using a small gastric pouch to reduce anastomotic ulcers while enhancing weight loss, and the results showed that the effect of this procedure was almost the same as that of existing procedures.

To enhance the weight loss effect, surgeons have made countless attempts to improve the surgical procedure, including changing the size of the gastric pouch, the shape of the anastomosis, and the length of the Roux loop.

Further improvements include binding the gastric pouch or anastomosing to prevent gastric distension.

Most of these attempts at improvement are not well-known, and the analysis of their results is retrospective.

There are only a few prospective studies on the updating of various surgical techniques.

The main principle of surgical design and improvement is to avoid having to undergo corrective surgery due to failed weight loss, because corrective surgery is both time-consuming and risky, and the results of corrective surgery are usually not as good as those of the initial successful surgery.

Repair surgery should only be considered when absolutely necessary.

Unfortunately, we know very little about the different effects produced by variations in this technique.

Some surgical advancements have reduced the likelihood of needing a second, corrective surgery.

The initial gastric bypass surgery used a gastrojejunostomy, but due to the high incidence of alkaline reflux, doctors were forced to switch to the Roux-en-Y procedure; other changes were to staple the gastric pouch together instead of separating it in the gastric bypass surgery.

Recently, surgeons have begun to separate the two gastric pouches and make them independent of each other, which has significantly reduced the number of fistulas between the gastric pouch and the distal gastric remnant caused by stapler anastomosis failure.

To perform this surgery laparoscopically, the gastric sac needs to be separated from the distal gastric remnant when the gastric body is cut open to create the gastric sac. However, whether this will lead to intractable anastomotic ulcers requires further investigation.

Restricting food absorption is another way to enhance weight loss, which can be achieved through three pathways: ① lengthening the Roux loop or nutrient loop; ② shortening the length of the common passage; ③ increasing the length of the bile and pancreatic branches.

The specific methods have been described in previous chapters.

Besides passive diffusion, nutrients are difficult to absorb in the Roux loop of the intestine, which lacks bile and pancreatic juice.

The length of the Roux loop refers to the distance from the gastrojejunostomy to the anastomosis between the biliary-pancreatic loop and the Roux loop.

In routine gastrointestinal surgery, the minimum length of the Roux loop is 40 cm to reduce the risk of alkaline reflux gastritis.

Most of the time, the length of the Roux intestinal loop is around 75cm.

In gastric bypass surgery involving extended or long intestinal loops, the Roux loop can reach a length of 150 cm.

In distal gastric bypass surgery, the Roux loop and the bile-pancreatic loop are anastomosed proximally at a distance of 50-100 cm from the ileocecal valve.

While this is a good method for classifying patients, it does not take into account that the length of the small intestine can vary greatly depending on the BMI index.

Therefore, subtle differences in the length of the bypass small intestine may not be significant.