Controversy: Mohs and Close

We read with great interest the dialogue between Dr. Mehta et al and Dr. Konda et al regarding the “Effectiveness of the Mohs and Close Technique in Increasing the Efficiency of a Mohs Micrographic Surgery.”^1,2 As Editor-in-Chief of the JDD, and a Mohs surgeon for over 30 years (DSS), and as a plastic surgeon with 30 years’ experience in reconstruction following Mohs surgery (RHG), we feel compelled to share our opinion on this issue. We invite others to comment and weigh in with their opinions on this controversial topic.In our opinion, the Mohs and Close Technique (MCT), ? extirpating a non-melanoma skin cancer with a planned elliptical excision, with pre-planned gross clinical margins and reconstructing the defect before the status of margins is known – is not Mohs Micrographic Surgery (MMS) with respect to the time-honored Mohs technique. Just because horizontal frozen sections are prepared on the premises in real time and the physician is functioning in the capacity of both surgeon and pathologist does not make this “one and done” procedure MMS. By definition, the Mohs technique is designed to spare as much normal skin as possible, while using specialized mapping and the microscope to trace the tumor to its roots. After debulking with a curette, a thin layer of tissue is excised – not a fusiform excision. When such an elliptical excision is performed, even one with 2mm borders, it is not tissue-sparing. More normal tissue is excised than what is needed. Although this may occur as part of the reconstruction, the repair of the wound is a separate and distinct procedure from MMS.In Mohs surgery, only after the horizontal frozen section slides are examined, clear margins are obtained, and one is certain that the patient is cured of the cancer, should a decision be made regarding reconstruction of the wound. In some cases, it is best to allow the defect to heal by secondary intention. This is even simpler and more cost effective than the preemptive simple or layered closure Mehta et al propose. Alternatively, the resultant defect can be reconstructed in the easiest way possible to achieve an optimal cosmetic result. Closing the defect prior to examining the slides defeats the purpose of Mohs; in fact, it is not Mohs. It puts the "cart before the horse.”Furthermore, it is humbling and never ceases to amaze us that, after so many years in practice, we still get surprised. Not infrequently, tumors that we thought would be easy to clear go on for several stages, with tumor extension in directions that are unpredictable. So why guess or gamble and be in such a hurry to repair the defect when the repair may be for naught.We also do not think that the MCT is any more efficient than MMS for the Mohs surgeon. For example, if it takes a Mohs surgeon 15 minutes to repair a given defect, it is the same 15 minutes whether it is done immediately after excision of the first stage of Mohs (before the tissue has been processed in the lab) or after the tissue is processed and the slides are read (about 30-60 minutes later). An efficient Mohs surgeon can multitask. So instead of spending 15 minutes repairing a defect when margin control is still not known, the 15 minutes can be spent taking the first stage on other patients, seeing post-op patients, or consulting on new patients. Whether the definitive repair is done before or after slides are read, there is no net savings of time for the Mohs surgeon. And only “13.66 minutes” saved for the patient seems negligible and hardly worth taking the risk that the margins might still be positive. In fact, if the margins are positive, it will cost the patient more time; they must be brought back to the treatment room, the sutures removed, and the closure opened before the next stage of Mohs can be performed. This can be very demoralizing to a patient – perceived as a form of failure in that what was done now has to be undone only to be done later!Furthermore, if the deep margin is positive, we find it difficult to understand how it is technically feasible to obtain an adequate second layer and be certain of its orientation without opening the entire repair. Any time a repair must be redone it seems that efficiency will be less, certainly not more, for both the surgeon and the patient.With all due respect, Mehta states that they have a “high volume” practice, treating up to 14 Mohs patients a day, and they are seeking maximal efficiency. It seems to us that if you want to put emphasis on individual attention and are truly interested in delivering the best patient care possible, it would behoove you to get another cryostat, hire a second histology technician, and perhaps even a second Mohs surgeon. In this way you can perform bonafide Mohs surgery, trace the tumor to its roots, and repair the resultant defect in the manner in which the tried-and-true technique of MMS was intended.