Prevention of internal hernia after RYGB surgery and intraoperative detection of anastomotic leakage

Prevention of internal hernia

Whether the surgery is performed via open surgery or laparoscopy, internal hernia is a complication of RYGB surgery.

Internal hernias can occur in one of three places: the transverse mesocolonic gap, Petersen's space, or other mesenteric gaps.

It was initially thought that laparoscopic surgery could reduce the probability of small bowel obstruction, but it has now been proven that this is not the case.

The incidence of internal hernias is relatively high with laparoscopic surgery, which is speculated to be due to the fact that this minimally invasive surgery results in fewer adhesions, leading to incomplete closure of the mesenteric incision.

Many surgeons who perform open surgery do not close the mesenteric incision. Therefore, the controversy lies in whether closing the mesenteric incision during laparoscopic gastric bypass surgery reduces the incidence of internal hernia. If so, what is the appropriate method to close the incision?

Closing these three mesenteric gaps by suturing has been shown to reduce the incidence of intraoperative hernia during LRYGB surgery, but it cannot completely eliminate this complication.

We compared the incidence of internal hernia in 246 patients who underwent laparoscopic retrocolic gastric bypass surgery. Of these 246 patients, 149 did not have the gap closed, while the other 97 underwent continuous suturing of the mesocolonic gap.

The incidence of internal hernia decreased but still occurred frequently, and there was no difference in the incidence of small bowel obstruction between the two groups (4.0% vs. 3.7%, P=0.70).

While suturing and reinforcement reduce the probability of internal hernia, it increases the risk of adhesions and obstruction caused by suturing. As a result, the overall complication rate and the risk of reoperation do not decrease; they are simply complications caused by different etiologies.

In addition, we observed patients who underwent a significant weight loss during their initial surgery and whose incisions were sutured during the operation, but still developed internal hernias within three years post-surgery.

According to literature reports, there is strong evidence that the best way to reduce the incidence of internal hernias is to choose the precolonial procedure, in which suturing the incision is not necessary.

Internal hernias can occur with any surgical procedure, including the anterior colonic procedure. However, the anterior colonic procedure does not have a gap in the mesentery, leaving a wider gap that allows the intestines to pass through smoothly. This may be why problems are less common with the anterior colonic procedure.

Narrow, constricted openings, such as the opening formed when the Roux loop passes through the colon, can greatly increase the likelihood of intussusception and obstruction.

For surgeons who use retrocolic procedures, the challenge is finding a way to repair weak areas of the mesentery so that retrocolic procedures, like other procedures, rarely result in internal hernias.

Intermittent or continuous sutures with absorbable or non-absorbable sutures can be used to repair weak areas of the mesentery.

Higa et al. have reported that using continuous absorbable sutures yields better results.

Our early experience was similar; the use of interrupted sutures or laparoscopic hernia repair screws did not reduce the incidence of internal hernias because weak areas remained between the suture knots.

We quickly adopted continuous suture technique, which, based on experience, yields the best results. We recommend using non-absorbable sutures for continuous suturing.

The additional use of fibrin glue may have a hemostatic and reinforcing effect on the suture, but apart from increasing the cost of the operation, it does not play a significant role in repairing weak areas of the mesentery.

Prevention of fistula after LRYGB surgery

Gastrointestinal fistula is a complication of LRYGB surgery and one of the important causes of postoperative complications and death.

Therefore, any method that can reduce the occurrence of this serious complication is highly welcomed by bariatric surgeons.

Methods to prevent this complication include improvements in anastomosis techniques, intraoperative testing and drainage placement, and postoperative imaging.

There are many methods for gastrojejunostomy today, including circular staplers, linear staplers, or manual suturing. Regardless of which method is chosen, there are supporters and opponents, and there is still controversy as to which method can reduce the incidence of fistula.

As long as the surgeon has good experience in laparoscopic suturing and performs the procedure carefully, the incidence of fistula is about the same regardless of the suturing technique used.

Early studies showed that anastomoses using only circular or linear staplers without suture reinforcement had a relatively higher risk of fistula development, while additional suture reinforcement did reduce the probability of gastrointestinal fistula.

Methods of suture reinforcement include dense reinforcement sutures along the stapled line to form a double-layer suture reinforcement, and simple single-layer sutures on the intestinal incision, into which a straight closure device is inserted for anastomosis to form a double-layer intestinal wall anastomosis.

Hand sewing can be done using single-layer or double-layer sewing methods, and the results are similar.

There is no data showing that absorbable sutures and non-absorbable sutures produce different results in the incidence of fistulas.

Reinforcing the sutures and anastomosis with fibrin glue or reinforcing felt strips can effectively reduce the occurrence of fistulas.

The experience of using fibrin glue to reduce anastomotic leakage has been reported in two series of studies, which compared previous results with those of our center and with those of other centers, but were not randomized clinical trials.

In addition, the use of fibrin glue or reinforcing felt strips significantly increases the cost of surgical materials.

It is too early to use fibrin adhesives unless prospective randomized trials demonstrate that the extra cost of using them is worthwhile.

Shikora et al. studied how reinforcing felt strips can reduce tension on sutures in animal models, and by comparing clinical cases after using reinforcing felt strips with cases that did not use reinforcing felt strips, they confirmed that the application of reinforcing felt strips can reduce the probability of suture fistulas.

This study has some limitations. The authors compared 250 of their most recent LRYGB surgeries with 100 earlier surgeries, but many of the earlier 100 surgeries were in the exploratory and learning stage of the procedure, so they are not very comparable.

Support bars also cost nearly $1,000 more per surgery.

From a health management perspective, the cost-effectiveness of each surgical instrument should be considered.

The effectiveness of reinforcing felt strips still needs further testing, and more research is needed before they can be widely used.

There is still considerable controversy regarding the intraoperative examination for suture leakage. The controversy revolves around two aspects: first, whether this examination is necessary; and second, if it is necessary, which detection method is better. Currently, intraoperative examination methods include: simple exploration, intraoperative esophagogastric endoscopy, and examination by instilling methylene blue or gas through a gastric tube.

The most sensitive examination method currently is intraoperative esophagogastric endoscopy, which involves injecting gas through a gastroscope, clamping the small intestine, and placing the sutures below the surface of the injected saline solution.

In a report by Champion et al. on 825 LRYGB procedures, 29 patients with suture-induced fistulas were found to have fistulas during the procedure. After suturing repair, only 3 patients (0.36%) developed fistulas postoperatively. Ramanathan et al. also obtained similar results. In 182 LRYGB procedures, 10% of patients were found to have fistulas during intraoperative esophagogastric endoscopy, but the postoperative fistula incidence was only 3.8%.

Critics of this examination method argue that injecting air under high pressure through a gastroscopy is an excessive procedure that leads to many false positives, and that the method is too complex and increases surgical costs.

However, some surgeons lack the skills to perform intraoperative gastroscopy, or worry that performing the gastroscopy themselves will draw criticism from gastroenterologists, so they find reasonable excuses to avoid this examination.

Schauer et al. reported a comparative trial of intraoperative gastroscopy and methylene blue, in which methylene blue was infused through a gastric tube placed in a gastric pouch to detect the presence of fistulas, but the method was not as sensitive as gastroscopy.

However, so far there have been no studies that directly compare the three methods of examining fistulas mentioned in the previous paragraph, nor have there been separate comparisons of which method, gastric tube inflation or gastroscopy, is more sensitive.