Surgical site occurrence after prophylactic use of mesh for prevention of incisional hernia in midline laparotomy: systematic review and meta-analysis of randomized clinical trials

BACKGROUND

The use of mesh is the standard for the prevention of incisional hernia (IH). However, the effect of surgical site occurrence (SSO) has never been compared. The aim of this meta-analysis was to evaluate the prevalence of SSO and measure its negative effect through the calculation of the number needed to treat for net effect (NNT net).

METHODS

A meta-analysis was performed according to the PRISMA guidelines. The primary objective was to determine the prevalence of SSO and IH, and the secondary objective was to determine the NNT net as a metric to measure the combined benefits and harms. Only published clinical trials were included. The risk of bias was analyzed, and the random effects model was used to determine statistical significance.

RESULTS

A total of 15 studies comparing 2344 patients were included. The incidence of IH was significantly lower in the mesh group than in the control group, with an OR of 0.29 (95% CI 0.16-0.49, p = 0.0001). The incidence of SSO was higher in the mesh group than in the control group, with an OR of 1.21 (95% CI 0.85-1.72, p = 0.0001) but without statistical significance. Therefore, the way to compare the benefits and risks of each of the studies was done with the calculation of the NNT net, which is the average number of patients who need to be treated to see the benefit exceeding the harm by one event, and the result was 5, which is the average number of patients who need to be treated to see the benefit exceeding the harm by one event.

CONCLUSION

The use of mesh reduces the prevalence of IH and it does not increases the prevalence of SSO, the NNT net determined that the use of mesh continues to be beneficial for the patient.

Synthetic mesh versus biological mesh to prevent incisional hernia after loop-ileostomy closure: a randomized feasibility trial

BACKGROUND

Incisional hernia is a frequent complication after loop-ileostomy closure, rationalizing hernia prevention. Biological meshes have been widely used in contaminated surgical sites instead of synthetic meshes in fear of mesh related complications. However, previous studies on meshes does not support this practice. The aim of Preloop trial was to study the safety and efficacy of synthetic mesh compared to a biological mesh in incisional hernia prevention after loop-ileostomy closure.

METHODS

The Preloop randomized, feasibility trial was conducted from April 2018 until November 2021 in four hospitals in Finland. The trial enrolled 102 patients with temporary loop-ileostomy after anterior resection for rectal cancer. The study patients were randomized 1:1 to receive either a light-weight synthetic polypropylene mesh (Parietene Macro™, Medtronic) (SM) or a biological mesh (Permacol™, Medtronic) (BM) to the retrorectus space at ileostomy closure. The primary end points were rate of surgical site infections (SSI) at 30-day follow-up and incisional hernia rate during 10 months' follow-up period.

RESULTS

Of 102 patients randomized, 97 received the intended allocation. At 30-day follow-up, 94 (97%) patients were evaluated. In the SM group, 1/46 (2%) had SSI. Uneventful recovery was reported in 38/46 (86%) in SM group. In the BM group, 2/48 (4%) had SSI (p > 0.90) and in 43/48 (90%) uneventful recovery was reported. The mesh was removed from one patient in both groups (p > 0.90).

CONCLUSIONS

Both a synthetic mesh and biological mesh were safe in terms of SSI after loop-ileostomy closure. Hernia prevention efficacy will be published after the study patients have completed the 10 months' follow-up.

Dehydrated Human Amniotic-Chorionic Membrane Reduces Incisional Hernia Formation in an Animal Model

BACKGROUND

Currently there are no standard of care treatment strategies for IH prevention (IHP). Dehydrated human amnion-chorion (dHACM) is a healing adjunct that elutes growth factors including several that have reduced IH in animal models. We therefore performed a double-blinded, prospective randomized controlled trial (RCT) to test the hypothesis that dHACM significantly reduces IH formation in a well-studied animal model of acute IH.

MATERIAL AND METHODS

Forty 16-week-old male Sprague-Dawley rats were randomized to one of four groups: No Treatment vs. dHACM Sheet (Group A), and Saline vs. dHACM Injection (Group B). Each animal underwent a 5-cm midline laparotomy which was incompletely closed with 5-0 plain gut sutures; this was performed by a surgeon blinded to treatment group (first blind). After 28 days, the primary endpoints of IH formation and hernia size were determined by study staff blinded to treatment (second blind). Secondary endpoints included healed fascia tensile strength as determined by tensiometry, systemic and local inflammatory markers as measured by ELISA, and fascial scar collagen I/III ratios per Western blotting.

RESULTS

In Group A, No Treatment developed IH at 87.5% vs. 62.5% for Sheet (P = 0.28). Hernias that formed in the Sheet group were significantly smaller (P = 0.036). In Group B, Injection and Saline yielded identical IH rates of 77.8%. Molecular characterization of fascial scar demonstrated non-inferior tensile strength, collagen I/III ratios, and inflammatory markers in dHACM-treated animals.

CONCLUSIONS

dHACM sheets significantly reduced the size of IH following laparotomy when compared to no treatment.

Prevention of incisional hernia with a reinforced tension line (RTL) versus primary suture only in midline laparotomies: 3-year follow-up in a randomized clinical trial

PURPOSE

Incisional hernia (IH) has an incidence of 10-23%, which can increase to 38% in specific risk groups. The objective of this study is to report the results at 3 years of follow-up of the use of the reinforced tension line (RTL) technique compared with primary suture only (PSO) closure in the prevention of IH in high-risk patients undergoing laparotomy.

METHODS

Open randomized controlled clinical trial. Included were patients older than 18 years who underwent midline laparotomy, emergency or scheduled, who were considered high risk, and who completed 3-year follow-up. The patients were randomized 1:1 to the RTL technique or to PSO. The objective was to report the incidence of IH and the complications associated with the closure method. Intention-to-treat analysis and Cox regression were performed.

RESULTS

A total of 124 patients were randomized; 51 patients from the RTL group and 53 patients from the PSO group finished the 3-year follow-up. The incidence of IH was higher in the PSO group (15/53, 28.3%) than the RTL group (5/51, 9.8%) (p = 0.016, OR 0.35, 95% CI 0.14-0.88, number needed to treat 5.4, log-rank test p = 0.017). The groups were similar in the rates of surgical site infection, hematoma, seroma, and postoperative pain during follow-up.

CONCLUSIONS

The RTL technique is useful in the prevention of IH when compared with PSO in high-risk midline laparotomy patients, and it is not associated with a higher percentage of complications.

TRIAL REGISTRATION

Local Committee CI-HRAEB-2013-020. March 13, 2013.

CLINICAL TRIALS

NCT02136628, retrospectively registered.

Elective and emergent laparotomy closure: The importance of protocolizing the technique

BACKGROUND

Incisional hernias are a frequent complication, and their prevention includes proper closure of the abdominal wall.

METHODS

A prospective study was conducted at a third-level hospital after the introduction of a midline laparotomy closure protocol. An objective measurement of the suture length to incision length ratio was made. and the postoperative results were analyzed.

RESULTS

127 patients were included and 34 of them (26.8%) had received a technically deficient closure. Incisional hernia was described in 20.5% of cases. An improvement in the quality of the abdominal wall closure was demonstrated over time.

CONCLUSION

The abdominal wall closure was deficient in nearly one- quarter of the laparotomies performed at a third-level medical center. A protocol improved the quality of the laparotomy closure.