A historically controlled, single-arm, multi-centre, prospective trial to evaluate the safety and efficacy of MonoMax suture material for abdominal wall closure after primary midline laparotomy. ISSAAC-Trial [NCT005725079]

Abdominal incision defect following AAA-surgery (AIDA): 2-year results of prophylactic onlay-mesh augmentation in a multicentre, double-blind, randomised controlled trial

The reported incidence of incisional hernia following repair of abdominal aortic aneurysm (AAA) via midline laparotomy is up to 69%. This prospective, multicenter, double-blind, randomised controlled trial was conducted at eleven hospitals in Germany. Patients aged 18 years or older undergoing elective AAA-repair via midline incision were randomly assigned using a computer-generated randomisation sequence to one of three groups for fascial closure: with long-term absorbable suture (MonoPlus^®, group I), long-term absorbable suture and onlay mesh reinforcement (group II) or extra long-term absorbable suture (MonoMax^®, group III). The primary endpoint was the incidence of incisional hernia within 24 months of follow-up, analysed by intention to treat. Physicians conducting the postoperative visits and the patients were blinded. Between February 2011 and July 2013, 104 patients (69.8 ± 7.7 years) were randomised, 99 of them received a study intervention. The rate of incisional hernia within 24 months was not significantly reduced with onlay mesh augmentation compared to primary suture (p = 0.290). Furthermore, the rate of incisional hernia did not differ significantly between fascial closure with slow and extra long-term absorbable suture (p = 0.111). Serious adverse events related to study intervention occurred in five patients (5.1%) from treatment groups II and III. Wound healing disorders were more frequently seen after onlay mesh implantation on the day of discharge (p = 0.010) and three (p = 0.009) and six (p = 0.023) months postoperatively. The existing evidence on prophylactic mesh augmentation in patients undergoing AAA-repair via midline laparotomy probably needs critical review. As the implementation of new RCTs is considered difficult due to the increasing number of endovascular AAA treated, registry studies could help to collect and evaluate data in cases of open AAA-repair. Comparisons between prophylactic mesh implantation and the small bite technique are also required. Trial registration: ClinicalTrials.gov Identifier: NCT01353443. Funding Sources: Aesculap AG, Tuttlingen, Germany.

MonoMax Suture: A New Long-Term Absorbable Monofilament Suture Made from Poly-4-Hydroxybutyrate

A long-term absorbable monofilament suture was developed using poly-4-hydroxybutyrate (P4HB) made from a biosynthetically produced homopolymer of the natural metabolite 4-hydroxybutyrate. The suture, called MonoMax, has prolonged strength retention. At 12 weeks, a size 3-0 MonoMax suture retains approximately 50% of its initial tensile strengthin vivoand is substantially degraded in one year with minimal tissue reaction. In contrast, PDS II monofilament suture (Ethicon, Inc., Somerville, NJ) has no residual strengthin vivoafter 12 weeks.In vivo, the MonoMax suture is hydrolyzed primarily by bulk hydrolysis, and is then degraded via the Krebs cycle. MonoMax is substantially more compliant than other monofilament sutures, and incorporates an element of elasticity. Its tensile modulus of 0.48 GPa is approximately one-third of the value of the PDS II fiber providing an exceptionally flexible and pliable fiber with excellent knot strength and security. These features are further enhanced by the fiber's elasticity, which also improves knot security and may help prevent wound dehiscence. Because of its performance advantages, this suture may find clinical utility in applications where prolonged strength retention, and greater flexibility are required, particularly in procedures like abdominal wall closure where wound dehiscence is still a significant post-surgical complication.

Evaluation of the safety and efficacy of MonoMax® suture material for abdominal wall closure after primary midline laparotomy-a controlled prospective multicentre trial: ISSAAC [NCT005725079]

Purpose

Different suture techniques and various suture materials are in use to close midline incisions after primary laparotomy. The ISSAAC study aimed to assess the safety and efficacy of the new ultra-long-term absorbable, elastic monofilament suture material MonoMax® for abdominal wall closure.

Methods

This is a single-arm, multicentre prospective study that included 150 patients undergoing a primary elective midline incision. The control group consists of 141 patients from the INSECT study who received MonoPlus® or PDS® for abdominal wall closure. The incidences of burst abdomen and wound infection until the day of discharge were defined as the primary composite endpoints. The rate of incisional hernias 1 year after surgery, the length of postoperative hospital stay and safety parameters served as secondary endpoints. The study has been registered under www.clinicaltrials.gov [NCT005725079].

Results

Eleven patients in the ISSAAC study [7.3%; 95% CI = (3.9; 13.1%)] experienced wound infection or burst abdomen until the day of discharge as compared to 16 [11.3%; 95% CI = (6.6; 17.8%)] patients in the INSECT control group (p = 0.31). The length of postoperative hospital stay was comparable in both study groups. One year after surgery, incisional hernias were observed in 21 ISSAAC patients (14.0%) in contrast to 30 hernias (21.3%) in the INSECT control group.

Conclusions

The ultra-long-term absorbable, elastic monofilament suture material MonoMax® is safe and efficient for abdominal wall closure.