Randomised-controlled feasibility trial on abdominal wall closure techniques in patients undergoing relaparotomy (ReLap study; DRKS00013001)

The 6:1 short stitch SL-WL-ratio: short term closure results of transverse and midline incisions in elective and emergency operations

AIM

To analyze laparotomy closure quality (suture/wound length ratio; SL/WL) and short term complications (surgical site occurrence; SSO) of conventional midline and transverse abdominal incisions in elective and emergency laparotomies with a longterm, absorbent, elastic suture material.

METHOD

Prospective, monocentric, non-randomized, controlled cohort study on short stitches with a longterm resorbable, elastic suture (poly-4-hydroxybutyrate, [p-4OHB]) aiming at a 6:1 SL/WL-ratio in midline and transverse, primary and secondary laparotomies for elective and emergency surgeries.

RESULTS

We included 351 patients (♂: 208; ♀: 143) with midline (n = 194), transverse (n = 103), and a combined midline/transverse L-shaped (n = 54) incisions. There was no quality difference in short stitches between elective (n = 296) and emergency (n = 55) operations. Average SL/WL-ratio was significantly higher for midline than transverse incisions (6.62 ± 2.5 vs 4.3 ± 1.51, p < 0.001). Results in the first 150 patients showed a reduced SL/WL-ratio to the following 200 suture closures (SL/WL-ratio: 5.64 ± 2.5 vs 6.1 ± 2.3; p < 0.001). SL/WL-ratio varied insignificantly among the six surgeons participating while results were steadily improving over time. Clinically, superficial surgical site infections (SSI, CDC-A1/2) were encountered in 8%, while 4,3% were related to intraabdominal complications (CDC-A3). An abdominal wall dehiscence (AWD) occurred in 22/351 patients (6,3%)-twice as common in emergency than elective surgery (12,7 vs 5,1%)-necessitating an abdominal revision in 86,3% of cases.

CONCLUSION

We could show that a short stitch 6:1 SL/WL-ratio with a 2-0 single, ultra-long term, absorbent, elastic suture material can be performed in only 43% of cases (85% > 4:1 SL/WL-ratio), significantly better in midline than transverse incisions. Transverse incisions should preferably be closed in two layers to achieve a sufficient SL/WL-ratio equivalent to the median incision.

CLINICAL TRIALS

GOV IDENTIFIER

NCT01938222.

Small bites versus large bites during fascial closure of midline laparotomies: a systematic review and meta-analysis

PURPOSE

Incisional ventral hernias (IVH) are common after laparotomies, with up to 20% incidence in 12 months, increasing up to 60% at 3-5 years. Although Small Bites (SB) is the standard technique for fascial closure in laparotomies, its adoption in the United States is limited, and Large Bites (LB) is still commonly performed. We aim to assess the effectiveness of SB regarding IVH.

METHODS

We searched for RCTs and observational studies on Cochrane, EMBASE, and PubMed from inception to May 2023. We selected patients ≥ 18 years old, undergoing midline laparotomies, comparing SB and LB for IVH, surgical site infections (SSI), fascial dehiscence, hospital stay, and closure duration. We used RevMan 5.4. and RStudio for statistics. Heterogeneity was assessed with I2 statistics, and random effect was used if I2 > 25%.

RESULTS

1687 studies were screened, 45 reviewed, and 6 studies selected, including 3 RCTs and 3351 patients (49% received SB and 51% LB). SB showed fewer IVH (RR 0.54; 95% CI 0.39-0.74; P < 0.001) and SSI (RR 0.68; 95% CI 0.53-0.86; P = 0.002), shorter hospital stay (MD -1.36 days; 95% CI -2.35, -0.38; P = 0.007), and longer closure duration (MD 4.78 min; 95% CI 3.21-6.35; P < 0.001). No differences were seen regarding fascial dehiscence.

CONCLUSION

SB technique has lower incidence of IVH at 1-year follow-up, less SSI, shorter hospital stay, and longer fascial closure duration when compared to the LB. SB should be the technique of choice during midline laparotomies.

Effect of Metformin on HIF-1α Signaling and Postoperative Adhesion Formation

BACKGROUND

Peritoneal adhesion formation is common after abdominal surgery and results in severe complications. Tissue hypoxia is one of the main drivers of peritoneal adhesions. Thus, we determined the clinical role of hypoxia-inducible factor (HIF)-1 signaling in peritoneal adhesions and investigated whether the biguanide antidiabetic drug metformin shows HIF-inhibitory effects and could be repurposed to prevent adhesion formation.

STUDY DESIGN

As part of the ReLap study (DRKS00013001), adhesive tissue from patients undergoing relaparotomy was harvested and graded using the adhesion grade score. HIF-1 signaling activity within tissue biopsies was determined and correlated with adhesion severity. The effect of metformin on HIF-1 activity was analyzed by quantification of HIF target gene expression and HIF-1 protein stabilization in human mesothelial cells and murine fibroblast under normoxia and hypoxia. Mice were treated with vehicle or metformin 3 days before and until 7 days after induction of peritoneal adhesions; alternatively, metformin treatment was discontinued 48 hours before induction of peritoneal adhesions.

RESULTS

HIF-1 signaling activity correlated with adhesion severity in patient biopsies. Metformin significantly mitigated HIF-1 activity in vitro and in vivo. Oral treatment with metformin markedly prevented adhesion formation in mice even when the treatment was discontinued 48 hours before surgery. Although metformin treatment did not alter macrophage polarization, metformin reduced proinflammatory leucocyte infiltration and attenuated hypoxia-induced profibrogenic expression patterns and myofibroblast activation.

CONCLUSIONS

Metformin mitigates adhesion formation by inhibiting HIF-1-dependent (myo)fibroblast activation, conferring an antiadhesive microenvironment after abdominal surgery. Repurposing the clinically approved drug metformin might be useful to prevent or treat postoperative adhesions.

Wound complications after primary and repeated midline, transverse and modified Makuuchi incision: A single-center experience in 696 patients

There are 3 main types of incisions in major open, elective abdominal surgery: the midline incision (MI), the transverse incision (TI) and the modified Makuuchi incision (MMI). This study aimed to compare these approaches regarding wound complications and hernias, with a special focus on suture material and previous laparotomies.Patients who underwent elective abdominal surgery between 2015 and 2016 were retrospectively analyzed. Uni- and multivariate analyses were computed using stepwise binary and multifactorial regression models.In total, 696 patients (406 MI, 137 TI and 153 MMI) were included. No relevant differences were observed for patient characteristics (e.g., sex, age, body mass index [BMI], American Society of Anesthesiologists [ASA] score). Fewer wound complications (TI 22.6% vs MI 33.5% vs MMI 32.7%, P = .04) occurred in the TI group. However, regarding the endpoints surgical site infection (SSI), fascial dehiscence and incisional hernia, no risk factor after MI, TI, and MMI could be detected in statistical analysis. There was no difference regarding the occurrence of fascial dehiscence (P = .58) or incisional hernia (P = .97) between MI, TI, and MMI. In cases of relaparotomies, the incidence of fascial dehiscence (P = .2) or incisional hernia (P = .58) did not significantly differ between the MI, TI, or MMI as well as between primary and reincision of each type. On the other hand, the time to first appearance of a hernia after MMI is significantly shorter (P = .03) than after MI or TI, even after previous laparotomy (P = .003).In comparing the 3 most common types of abdominal incisions and ignoring the type of operative procedure performed, TI seems to be the least complicated approach. However, because the incidence of fascial dehiscence and incisional hernia is not relevantly increased, the stability of the abdominal wall is apparently not affected by relaparotomy, even by repeated MIs, TIs, and MMIs. Therefore, the type of laparotomy, especially a relaparotomy, can be chosen based on the surgeon's preference and planned procedure without worrying about increased wound complications.

Standard of Care and Outcomes of Primary Laparotomy Versus Laparotomy in Patients with Prior Open Abdominal Surgery (ReLap Study; DRKS00013001)

BACKGROUND

Patients undergoing relaparotomy are generally underrepresented in trials, despite how common the procedure is in clinical practice. The aim of this trial was to determine standard of care and gain evidence of intra- and postoperative outcomes for patients undergoing relaparotomy compared to primary laparotomy.

METHODS

In this single-center controlled clinical trial, adult patients scheduled for elective abdominal surgery via relaparotomy or primary laparotomy were consecutively screened for eligibility. The perioperative course was monitored prospectively in five study visits during hospital stay and one study visit 1 year after surgery. Intraoperative standards, short and long-term outcomes were statistically explored at a level of significance of 5%.

RESULTS

A total of 131 patients with relaparotomy and 50 patients with primary laparotomy were analyzed. In the relaparotomy group, the access to the abdomen took longer (23.5 min vs. 8.8 min; p = < 0.001) and the peritoneal adhesion index was higher (10.8 vs. 0.4; p = < 0.001). Inadvertent enterotomies were more frequent in the relaparotomy group (relaparotomy 0.3 versus primary laparotomy: 0.0; p = 0.002). The overall comprehensive complication index and rates of surgical site infection and wound dehiscence with evisceration were not different between the two groups. At long-term follow-up, rates of incisional hernia did not differ (relaparotomy: n = 12/104 (11.5%); primary laparotomy: n = 7/35 (20.0%); p = 0.208).

DISCUSSION

In this first prospective comparison of relaparotomy with primary laparotomy, inadvertent enterotomies were more frequent in the relaparotomy group. However, contrary to previous retrospective studies, the risk of complications and incisional hernias was not increased compared to primary laparotomy.

TRIAL REGISTRATION

Deutsches Register Klinischer Studien ( www.germanctr.de ): DRKS00013001.