Subcutaneous closure versus no subcutaneous closure after non-caesarean surgical procedures

Most surgical procedures involve a cut in the skin that allows the surgeon to gain access to the surgical site. Most surgical wounds are closed fully at the end of the procedure, and this review focuses on these. The human body has multiple layers of tissues, and the skin is the outermost of these layers. The loose connective tissue just beneath the skin is called subcutaneous tissue, and this generally contains fat. There is uncertainty about closure of subcutaneous tissue after surgery: some surgeons advocate closure of subcutaneous tissue, as they consider this closes dead space and leads to a decrease in wound complications; others consider closure of subcutaneous tissue to be an unnecessary step that increases operating time and involves the use of additional suture material without offering any benefit.

To compare the benefits (such as decreased wound-related complications) and consequences (such as increased operating time) of subcutaneous closure compared with no subcutaneous closure in participants undergoing non-caesarean surgical procedures.

In August 2013 we searched the following databases: Cochrane Wounds Group Specialised Register (searched 29 August, 2013); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 7); Ovid MEDLINE (1946 to August Week 3 2013); Ovid MEDLINE (In-Process & Other Non-Indexed Citations August 28, 2013); Ovid EMBASE (1974 to 2013 Week 34); and EBSCO CINAHL (1982 to 23 August 2013). We did not restrict studies with respect to language, date of publication or study setting.

We included only randomised controlled trials (RCTs) comparing subcutaneous closure with no subcutaneous closure irrespective of the nature of the suture material(s) or whether continuous or interrupted sutures were used. We included all RCTs in the analysis, regardless of language, publication status, publication year, or sample size.

Two review authors independently identified the trials and extracted data. We calculated the risk ratio (RR) with 95% confidence intervals (CI) for comparing binary (dichotomous) outcomes between the groups and calculated the mean difference (MD) with 95% CI for continuous outcomes. We performed meta-analysis using the fixed-effect model and random-effects model. We performed intention-to-treat analysis whenever possible.

Eight RCTs met the inclusion criteria. Six of the trials provided data for this review and all of these were at high risk of bias. Six trials randomised a total of 815 participants to subcutaneous closure (410 participants) or no subcutaneous closure (405 participants). Overall, 7.7% of participants (63/815 of participants) developed superficial surgical site infections and there was no clear evidence of a difference between the two intervention groups (RR 0.84; 95% CI 0.53 to 1.33; very low quality evidence). Only two trials reported superficial wound dehiscence, with 7.9% (17/215) of participants developing the problem. It is not clear whether the lack of reporting of this outcome in other trials was because it did not occur, or was not measured. There was no clear evidence of a between-group difference in the proportion of participants who developed superficial wound dehiscence in the trials that reported this outcome (RR 0.56; 95% CI 0.22 to 1.41; very low quality evidence). Only one trial reported deep wound dehiscence, which occurred in 8.3% (5/60) of participants. There was no clear evidence of a difference in the proportion of participants who developed deep wound dehiscence between the two groups (RR 0.25; 95% CI 0.03 to 2.11; very low quality evidence). Three trials reported the length of hospital stay and found no significant difference between groups (MD 0.10 days; 95% CI -0.45 to 0.64; very low quality evidence). We do not know whether this review reveals a lack of effect or lack of evidence of effect. The confidence intervals for these outcomes were wide, and significant benefits or harms from subcutaneous closure cannot be ruled out. In addition, none of the trials assessed the impact of subcutaneous closure on quality of life, long-term patient outcomes (the follow-up period in the trials varied between one week and two months after surgery) or financial implications to the healthcare provider.

There is currently evidence of very low quality which is insufficient to support or refute subcutaneous closure after non-caesarean operations. The use of subcutaneous closure has the potential to affect patient outcomes and utilisation of healthcare resources. Further well-designed trials at low risk of bias are necessary.