In this study, our results showed that absorbable suture can safely and effectively be used to close the mesenteric defect (Peterson’s space). In our experiment we also found that the mesenteric defect was completely closed in the absorbable and non-absorbable (Group D non-absorbable polyester suture) sutures groups, as well as the glue group but not in the prolene group (Group B, non-absorbable prolene suture) when the rats were sacrificed 8 weeks after surgery. The mesenteric defect in the control group was still opened with almost no adhesion in the Peterson’s space.
Many materials are used to close mesenteric defects, including various non-absorbable sutures, stapler, biological glue, hernia mesh, hernia clips and so on [4, 6, 8, 15-17]. Some surgeons are accustomed to closing the mesenteric defects using prolene sutures because of its non-absorbability and smoothness, but our experiment results indicated that adhesion in prolene group was minimum, and importantly, we found gaps formed between the suture and mesentery along the suture line likely indicating that using prolene sutures may not be safe to close the mesenteric defect probably because of the light tissue response and little adhesion. Moreover, this situation is likely exacerbated by the weight loss and decrease in mesentery fat that occurs after bariatric surgery. Using another non-absorbable suture (4-0 Polyester suture) we found a complete closure and adhesion of the mesenteric defect although the suture was still present.
Non-absorbable sutures (prolene) may lead to some small gap formation between the suture and the mesentery due to the decrease of mesenteric fat following weight loss in gastric bypass, which may also be a potential risk for postoperative internal hernia formation. We want to emphasize that IH may still occurred after operation irrespective of the suture material due to improper suture technique.
Biological glue can also be used to close mesenteric defect based on findings in this study. However, the use of glue was associated with surrounding tissue and intestinal adhesion in the area glue applied. The average adhesion score in the glue group was the highest among all groups. Therefore, it is feasible to use the glue to close the mesenteric defect, but the risk of intestinal and surrounding tissue adhesion is high, likely because it is difficult to control the amount of glue during application. However, Mark Magdy et al closed Petersen’s space using bioabsorbable mesh with fibrin glue fixation with a good result [16].
It is unknown about whether absorbable suture can be effectively and safely used to close mesenteric defects. The purpose of this study was to try to explore this problem. The results of absorbable suture group showed a complete closure of the mesentery defect with the sutures completely absorbed leaving a smooth plane along the sutured line. There were no visible bowel adhesions or internal herniation. This indicates that absorbable sutures are safe and effective in closing mesenteric defects. Gumbs et al [18] analyzed 152 patients in whom laparoscopic Roux-en-y gastric bypass (LRYGB) was performed. They recorded jejunojejunal anastomotic obstruction occurred in 7 patients due to small intestine adhesion which was attributed to the Dacron suture. Their study therefore indicated that non absorbable suture is not a good selection to close the jejunojejunal mesenteric leaves defect.
No matter what suture is used, the closure of the mesenteric defect ultimately depends on the adhesion between mesentery. Comparing all methods used in our experiment, applying absorbable suture to close the mesenteric defect is safe, effective, and feasible. Moreover, the absorbable suture may be superior to the non-absorbable suture and glue to close the mesenteric defect, because it did not cause extra adhesions of intestine or formed small gap between the suture and the mesentery due to a complete absorption 8 weeks after surgery.
Here we need to emphasize that different absorbable sutures require different time of absorption. The absorbable time of the absorbable suture used in our experiment is about 2 months, so it is unknown if other absorbable sutures (shorter or longer absorbable time) could be safely used in closing mesenteric defect. We think a suture with too short absorbable time (one or two weeks) may not be suitable for closing mesenteric defects, because adhesions between mesentery may not formed or not be firm in such a short period of time.
Limitations
The obvious shortcoming of this study is the use of animal model to perform the experiment which cannot completely represent humans, and absence of internal hernia in any group may be due to the small number of rats and short follow up, so long term results need to be further studied. Although we have used absorbable sutures to close the mesenteric defect in dozens of patients with radical gastrectomy and no IH was found after more than one year of follow-up, large clinical trial of multi-center study is needed to clarify the safety and effectiveness of absorbable sutures used to close mesenteric defects.