Negative-pressure wound therapy after stoma reversal in colorectal surgery: a randomized controlled trial

Background

Stoma-reversal surgery is associated with high postoperative morbidity, including wound complications and surgical-site infections (SSIs). This study aims to assess whether the application of negative-pressure wound therapy (NPWT) can improve wound healing compared with conventional wound dressing.

Methods

This was a single-centre, superiority, open-label, parallel, individually randomized controlled trial. Patients undergoing stoma reversal were randomized (1 : 1) to receive NPWT or conventional wound dressing. The primary endpoint of the study was the rate of wound complications and SSIs after stoma closure. The secondary endpoints were postoperative wound pain, rate of wound healing after 30 days from stoma closure, and wound aesthetic satisfaction.

Results

Between June 2019 and January 2021, 50 patients were allocated to the NPWT group (all received NPWT, 49 were analysed); 50 patients were allocated to the conventional wound dressing group (48 received the treatment, 45 were analysed). No significant difference was found in wound-complication rate (10 per cent NPWT versus 16 per cent controls; odds ratio 0.61 (95 per cent c.i. 0.18 to 2.10), P = 0.542) and incisional SSI rate (8 per cent NPWT versus 7 per cent controls; odds ratio 1.24 (95 per cent c.i. 0.26 to 5.99), P = 1.000). The NPWT group showed less pain, higher aesthetic satisfaction (P < 0.0001), and a higher proportion of wound healing (92 versus 78 per cent; P = 0.081) compared with the control group.

Conclusion

NPWT does not reduce the incidence of SSI after stoma-reversal surgery compared with conventional wound dressing. However, NPWT improved the healing of uninfected wounds, reduced wound pain and led to better aesthetic outcomes.

Registration number: NCT037812016 (clinicaltrials.gov).

Cell autonomous commitment to an endodermal fate and behaviour by activation of Nodal signalling

In vertebrates the endoderm germ layer gives rise to most tissues of the digestive tract and controls head and heart morphogenesis. The induction of endoderm development relies on extracellular signals related to Nodals and propagated intracellularly by TGFβ type I receptors ALK4/Taram-A. It is unclear, however, whether Nodal/ALK4/Taram-A signalling is involved only in the specification of endodermal precursors or plays a more comprehensive role in the activation of the endodermal program leading to the irreversible commitment of cells to the endodermal fate. Using cell transplantation experiments in zebrafish, we show that marginal cells become committed to endoderm at the onset of gastrulation and that commitment to endoderm can be reached by intracellular activation of the Nodal pathway induced by expression of an activated form of the taram-A receptor, Tar*. In a manner similar to endoderm progenitors, Tar*-activated blastomeres translocate from their initial site of implantation in the blastoderm to reach the surface of their migration substratum, the yolk syncitial layer, where they join endogenous endodermal derivatives during gastrulation and differentiate according to their anteroposterior position. We demonstrate that Nodal/Tar*-induced commitment does not rely on a secondary signal released by Tar*-expressing cells or a signal released by endogenous endoderm since Tar*-expressing wild-type cells can restore endoderm derivatives when transplanted into the endoderm-deficient mutant casanova. Likewise, the YSL does not appear essential for the maintenance of endodermal identity during gastrulation once the Nodal pathway has been activated. Thus, our results demonstrate that the activation of Nodal signalling is sufficient to commit cells both to an endodermal fate and behaviour. Wild-type endoderm implantation into casanova embryos rescues, in a non-autonomous fashion, the defective fusion of the two heart primordia in the midline, highlighting the importance of endoderm for normal heart morphogenesis.