Primary Wound Closure

Author(s): 
Laura Bolton, PhD, FAPWCA

Dear Readers:

Primary wound closure is an important step in the management of clean open wounds. Sutures or staples are 2 leading options for primary intention. Recent evidence is adding to our understanding of the risks and benefits of these 2 wound closure modalities, but we still have much to learn in order to choose the best material and closure techniques for specific wounds. This Evidence Corner reviews 2 studies on very different wounds. The results suggest that the choice of primary intention wound closure may depend on a wide array of variables in closure techniques, patients, and the type of wound being closed, as well as the measured outcomes.

 

Sutures or Staples For Closing Cardiovascular Surgery Wounds

Reference: Sanni A, Dunning J. Staples or sutures for chest and leg wounds following cardiovascular surgery. Interact Cardiovasc Thorac Surg. 2007;6(2):243–246. (Available at: http://icvts.ctsnetjournals.org/cgi/content/full/6/2/243. Accessed August 24, 2007).
Rationale: Sutures or staples offer different advantages as wound closure techniques.Their effects on wounds have been explored in randomized controlled trials sufficient to present a position on the best available evidence for minimizing infections in cardiovascular surgical wounds of the leg or chest.
Objective: Use a structured protocol to determine whether using sutures or staples for wound closure on closed cardiovascular surgical wounds of the leg and chest reduce wound infection rates.
Methods: The authors searched the MEDLINE reference database from 1960 to 2006 for experimental studies investigating the terms cardiac or thoracic related to coronary bypass graft or coronary artery bypass graft surgery (CABG) surgery combined with the terms suture, staple, skin closure, wound closure, or intracutaneous or transcutaneous. The search terms wound or infection were also used. Of 119 abstracts found, 9 were relevant to overall surgery, including 5 prospective, randomized, controlled trials (RCTs) relevant to wound closure of cardiovascular surgical wounds of the leg and chest.
Results: The only statistically significant differences in reported infection rates were a lower median number of infections with sutures than with staples for overall infections (1 study), and fewer superficial infections (1 study). One study reported a borderline reduction in infections in sutured versus stapled chest wounds (P = 0.06).Three studies reported no difference in infection rates between sutures and staples. In addition, there was a lower median wound discharge with sutures than staples (1 study), fewer leg and chest complications with sutures compared to staples (1 study), improved cosmetic results with Dexon continuous subcuticular sutures than with staples (1 study), and 3 studies reporting no difference on cosmetic results between sutures or staples. One study reported less time to close wounds with staples than with sutures.
Authors’ Conclusions: Three of 5 RCTs reported reduced complications using sutures as compared to staples to close cardiovascular wounds of the chest or leg.The other 2 RTCs found no difference between sutures and staples. Suture closure was concluded to be superior to staple closure for these wounds.

Staples Versus Sutures for Ileocolic Anastomoses

Reference: Choy P, Bissett I, Docherty J, Parry B, Merrie A. Stapled versus handsewn methods for ileocolic anastomoses. Cochrane Database Syst Rev. 2007;18(3):CD004320.
Rationale: Ileocolic anastomoses, often performed for right-sided colonic cancer or Crone’s disease,may be constructed using either a linear cutter stapler or sutures. RCTs on their safety or efficacy have been inadequately powered to detect small differences between outcomes achieved using these 2 techniques.
Objective: Compare outcomes of stapled versus sutured ileocolic anastomoses in a meta-analysis.
Methods: RCTs were identified in a search of trials with adult subjects comparing use of linear cutter stapler (isoperistaltic side-to-side or functional end-to-end) with any type of suturing technique. The MEDLINE, EMBASE, and relevant Cochrane databases were analyzed for differences between outcomes achieved using these techniques. Relevant results were extracted, and clinical outcomes associated with stapled or sutured ileocolic anastomoses were compared in the total group and also in a sub-group analysis for patients with cancer.
Results: Six trials (1 unpublished) with 357 stapled and 598 sutured ileocolic participants were included, with adequate allocation concealment in the 3 largest trials. Significantly fewer anastomotic leaks occurred in stapled (5/357) compared with sutured (36/598) anastomoses for the analysis of all patients (P = 0.02) and for the subgroup of 825 patients with cancer in 4 studies. There were no significant differences in the other outcomes measured: anastomotic time or hemorrhage, stricture, reoperation, mortality, intra-abdominal abscess, wound infection, or length of stay.
Authors’ Conclusions: Functional end-to-end ileocolic anastomosis is associated with fewer leaks if stapled rather than sutured.

Clinical Perspective

It is not easy to place this wound closure literature into clinical perspective because there are so many independent variables that can affect clinical outcomes, and the outcomes are measured in such diverse ways. Comparative infection rates associated with sutures or staples differed in the 2 different clinical wounds summarized here. Sanni et al reported that in external wounds exposed to drying conditions, closure with staples resulted in more infections and/or complications than closure with sutures. In contrast, Choy et al found that moist wounds of the gastrointestinal tract closed with sutures or staples did not differ in infection rates, though more leakage was seen in sutured than in stapled wounds. These differences in effects may be a result of independent variables, such as closure technique, composition of the suture or staple material, wound etiology and contamination status, local wound environment (dry or moist), patient condition, or combinations of these variables. As an example of varying suture composition and technique, slowly absorbed monofilament continuous sutures decrease hernias in midline abdominal fascial closure without increasing pain or dehiscence compared to interrupted nonabsorbable sutures, though surgeon preference often overrides this evidence.1 Wound etiology and clean or contaminated status influence clinical outcomes so strongly that primary wound closure is contraindicated following colon injury because it increases the likelihood of wound infection and associated dehiscence.2
In the cardiovascular surgery review by Sanni et al, it was difficult to compare clinical outcomes across studies because of differences in the measured clinical outcomes. For example, in the first review, 2 of 5 studies differentiated superficial from deep infection, 2 of 5 reported overall infection, and 2 of 5 differentiated leg from chest infections. Improving uniformity of infection outcomes reporting would clarify trends evident in the literature and improve the strength of meta-analysis conclusions. A meta-analysis investigating clinical outcomes of traumatic or surgical wounds found no statistically consistent differences between absorbable versus nonabsorbable sutures in wound infections, redness or swelling, dehiscence, or cosmetic results.3 Both structured reviews conclude that there is a need for large, methodologically sound, RCTs to inform clinical decisions about surgical closure. As a general conclusion, the richness of independent variables in the wound closure literature and variations in dependent variables (ie, outcomes) reported have left clinicians with a confusing array of evidence that is difficult to integrate into practice.

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