Both interrupted and continuous 5–0 nylon sutures used to close facial wounds from Mohs micrographic surgery (MMS) produced equivalent cosmetic outcomes at all examined time points in a large, randomized trial published in Dermatologic Surgery (Aug. 2015; 41(8):919–928).
A total of 105 individuals with facial defects from MMS surgery were enrolled, and 101 of them completed assessment at all time points. All studied scars were at least 4 cm in length. Participants who were randomly selected had half of their scar sutured with interrupted 5–0 nylon stitches, and the other half sutured with running 5–0 nylon stitches.
Unblinded scar evaluation was done at one week, eight weeks, and six months by the principal investigator. Blinded photographic assessments were done at one week and six months by both a plastic surgeon and a general dermatologist using three different scar assessment scales.
First of a series of studies The study was the first of a series of studies undertaken by senior author Dr. David Zloty (left), clinical associate professor, Department of Dermatology and Skin Science, University of British
Columbia, Vancouver, and his colleagues in order to test commonly-accepted ideas about skin surgery that may be insufficiently supported. “There are concepts that everybody believes to be true, but when you look at the evidence it is either non-existent, weak, or of poor quality,” said Dr. Zloty. “One of the biggest ones was the idea that interrupted sutures were going to give a better long term final cosmetic result compared to a running suture, especially on a facial site.”
In contrast to this common wisdom, the trial found no statistical difference in cosmetic outcomes between the two suturing techniques at any time point, by any assessor, on any of three different scar assessment scales.
“We were very happy with the findings because we enrolled a large number of patients which allowed for a very high degree of statistical power,” said Dr. Zloty. A statistician from the University of British Columbia was employed to look at the data and to ensure enough patients were enrolled so that the study had the statistical power to answer the questions the investigators were asking, he said.
The data also showed no difference in outcome from different types of reconstruction, whether side-to-side closure, rotation flap, or transposition flap. “We also looked at sites,” said Dr. Zloty. “Were there different sites where you are better off using interrupted versus running?” Again, because of the numbers and the power of the analysis, there was no perceived difference in cosmetic outcome—forehead, cheek, lip, or nose. “That was also quite exciting for us,” Dr.Zloty said, “because some people were saying that you could use running [sutures], maybe, on the lateral cheek but you certainly would not want to use them on the nose.
Findings a boon to surgeons Dr. Zloty there has long been debate about experience and how those with more experience might have better use and handling of instruments and better suture handling to deal with the limitations of running sutures and still obtain great results.
Conversely, an inexperienced practitioner using running sutures may get a compromised cosmetic result. However, that did not seem to be case. “We were able actually to separate my repairs—and I had 18 years of experience at that time—vs. my fellow’s repairs. She just had one year. And again, we did not find any difference," said Dr. Zloty.
“This is the largest, randomized clinical trial looking to answer this question. There is nothing else in the literature that we were aware of that was this large, this well powered, this robust statistically in a randomized, prospective, blinded fashion,” Dr. Zloty said. “I think our results as we have outlined are very strong and I think the results are very valid.”
Finding no difference in cosmetic outcomes between the two suturing techniques is a boon to surgeons, said Dr. Zloty, who noted that there are a number of advantages to using running sutures compared to interrupted. “One, you probably use less suture material. With interrupted you may go through more suture, and if you are paying for these sutures there can be a cost saving using the running suture compared to interrupted.”
Potentially more important though, he said, is the saving of time. The additional motions needed to tie and cut the additional knots, as well as reload the suture material can add significant time to a procedure.
However, Dr. Zloty cautions that this study focused entirely on facial scars of at least 4 cm, so the findings cannot be generalized to other sites on the body or to short scars. “I personally use running [sutures]” even when operating on patients with benign nevi who are concerned about the cosmetic effects, said Dr. Zloty. “Those cosmetic results have been excellent. So my own bias has been that even for shorter scars, or shorter wounds on the face, running will still give you at least equivalent if not better results than interrupted. But that is my own personal bias, not supported by the data from our study.”
Originially published in The Chronicle of Skin & Allergy (Oct/Nov. 2015; 27(7):8)