During operations surgeons make a cut (incision) in the skin to gain access to the surgical site. Incisions are closed with sutures (stitches), staples, tissue adhesives or tapes. Sutures can be continuous or interrupted. Continuous sutures are usually inserted underneath the skin surface using absorbable or non-absorbable suture material. Interrupted sutures involve the full thickness of the skin and are usually non-absorbable (but not always).
Impaired wound healing increases costs of health care and leads to poor cosmetic results. We investigated whether it is better to use continuous or interrupted sutures to close wounds after non-childbirth surgery by performing a thorough search of the medical literature for randomised controlled trials (RCTs) that compared these two methods of skin closure (in August 2013).
We identified five RCTs with a total of 827 participants. Seven hundred thirty participants (384 received continuous sutures and 346 interrupted sutures) provided data for this review. Participants had abdominal or groin operations.
The only outcomes reported were, superficial surgical site infection, superficial wound breakdown and length of hospital stay. No other important outcomes, including quality of life, long-term patient outcomes and use of healthcare resources, were reported.
Approximately 6% of participants developed superficial surgical site infection, but there was no significant difference between the two groups in the proportion of participants who developed these. Approximately 4% of participants developed superficial wound breakdown. The proportion of participants with this problem in the continuous suture group was approximately one-tenth of that in the interrupted suture group. Most wound breakdowns occurred in two trials that used absorbable sutures for continuous suturing and non-absorbable sutures for interrupted suturing. Non-absorbable sutures are removed seven to nine days after surgery, but absorbable sutures are not removed, and so support the wound for longer - which may account for the difference in distribution of this problem between groups. There was no significant difference between groups for length of hospital stay.
Superficial wound breakdown is reduced by continuous subcuticular suturing. However, the trials that contributed to this result had suture removal in only one group (interrupted sutures), which may have led to this observation. The number of participants included in this review was small and follow-up after surgery was short.
Quality of evidence
The overall quality of evidence was very low. Levels of bias across the studies were mostly high or unclear, so there may have been flaws in trial organisation that could produce erroneous results.
Further well-designed trials at low risk of bias are necessary.
Superficial wound dehiscence may be reduced by using continuous subcuticular sutures. However, there is uncertainty about this because of the quality of the evidence. Besides, the nature of the suture material used may have led to this observation, as the continuous suturing technique used suture material that did not need to be removed, whereas the comparator used interrupted (non-absorbable) sutures that did need to be removed. Differences in the methods of skin closure have the potential to affect patient outcomes and use of healthcare resources. Further well-designed trials at low risk of bias are necessary to determine which type of suturing is better.
Most surgical procedures involve a cut in the skin, allowing the surgeon to gain access to the surgical site. Most surgical wounds are closed fully at the end of the procedure; this review focuses on these closed wounds. There are many ways to close the surgical incision, for example, using sutures (stitches), staples, tissue adhesives or tapes. Skin sutures can be continuous or interrupted. In general, continuous sutures are usually subcuticular and can be absorbable or non-absorbable, while interrupted sutures are usually non-absorbable and involve the full thickness of the skin - although some surgeons do use absorbable interrupted sutures.
To compare the benefits and harms of continuous compared with interrupted skin closure techniques in participants undergoing non-obstetric surgery.
In August 2013 we searched the following databases: Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid Embase; and EBSCO CINAHL.
We included only randomised controlled trials (RCTs) that compared skin closure using continuous sutures with skin closure using interrupted sutures, irrespective of whether there were differences in the nature of the suture materials used in the two groups. We included all relevant RCTs in the analysis, irrespective of language of publication, 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 outcomes between the groups, and calculated the mean difference (MD) with 95% CI for comparing continuous outcomes. We performed meta-analysis using a fixed-effect model and a random-effects model. We performed intention-to-treat analysis whenever possible.
We included five RCTs with a total of 827 participants. Outcomes were available for 730 participants (384 participants randomised to continuous sutures and 346 participants to interrupted sutures). All the trials were of unclear or high risk of bias. The participants underwent abdominal or groin operations. The only outcomes reported in the trials were superficial surgical site infection, superficial wound dehiscence (breakdown) and length of hospital stay. Other important outcomes such as quality of life, long-term patient outcomes and use of healthcare resources were not reported in these trials.
Overall, 6.5% (39/602 participants, four trials) developed superficial surgical site infections. There was no significant difference between the groups in the proportion of participants who developed superficial surgical site infections (RR 0.73; 95% CI 0.40 to 1.33). A total of 23 participants (23/625 (3.7%), four trials) developed superficial wound dehiscence. Twenty-two of the 23 participants belonged to the interrupted suture group.The proportion of participants who developed superficial wound dehiscence was statistically significantly lower in the continuous suture group compared to the interrupted suture group (RR 0.08; 95% CI 0.02 to 0.35). Most of these wound dehiscences were reported in two recent trials in which the continuous skin suture groups received absorbable subcuticular sutures while the interrupted skin suture groups received non-absorbable transcutaneous sutures. The non-absorbable sutures were removed seven to nine days after surgery in the interrupted sutures groups whilst sutures in the comparator groups were not removed, being absorbable. The continuous suture technique with absorbable suture does not require suture removal and provides support for the wound for a longer period of time. This may have contributed to the difference between the two groups in the proportion of participants who developed superficial wound dehiscence. There was no significant difference in the length of the hospital stay between the two groups (MD -1.40 days; 95% CI -7.14 to 4.34).