As with other disciplines, in dermatosurgery innovation is giving rise to improved treatment outcomes. High-quality and guideline-based treatment of surgical patients must not be limited to the actual surgical procedure and its challenges with respect to surgical technique and reconstructive defect closure. In order to ensure the success of a surgical procedure, a number of perioperative aspects have to be considered.
When considering novelties in the surgical procedure itself, at least 3 aspects should be mentioned: anaesthesia, imaging and surgical technique.
Regarding anaesthesia, there is a paucity of data that directly compare outcomes, complications, and costs between general and local anaesthesia in cutaneous surgery. 
Given the relative risks of procedures performed under general anaesthesia and the consistently comparable outcomes with significantly lower costs of procedures performed under local anaesthesia, it has been recently suggested that local anaesthetic techniques should be used whenever possible.
However, careful consideration of the individual needs and comfort level of the patient should still be given when choosing anaesthesia.
Imaging techniques is another area that is receiving increasing attention. 
For example, frozen histological sections are routinely used for intraoperative margin assessment during Mohs surgery, although fluorescence confocal microscopy (FCM) is a new tool that offers a promising and faster alternative. 
High levels of accuracy for FCM vs. frozen section have been demonstrated in intraoperative margin assessment for basal cell carcinoma (BCC) during Mohs surgery. 
Even if at present some technical issues may hinder prevent the widespread use of FMC, new devices have the potential to overcome these limitations.
Rapid lump examination is another new technique that allows for rapid 3-dimensional visualisation of surgical margins for detection of residual BCC, and holds potential to speed up histologic examination during micrographic Mohs surgery. 
The technique has good sensitivity and specificity compared to traditionally-stained frozen sections.
Several refinements in surgical technique have also been reported in recent years.
One example is the use of functional surgery for in situ or minimally invasive nail melanoma, which has now been demonstrated to be the technique of choice over amputation. 
Another example is modified shave surgery combined with the nail window technique, which is now preferred for longitudinal melanonychia as it is associated with limited postoperative nail dystrophy and low rates of recurrence of pigmentation. 
Despite the large number of dermatological procedures performed, there is still limited information about surgical site infections (SSI) in the absence of antibiotic prophylaxis.
A recent analysis found that the risk of acquiring an SSI is increased in surgeries on the ear, in larger wounds and in defects closed with flaps or healed by secondary intention. 
In Mohs micrographic surgery, retrospective assessment of postoperative complications has shown that immunosuppression places patients at higher risk for postoperative complications, including SSI and wound dehiscence. 
A model was recently established for predicting SSI in dermatological surgery which shows that about 8 patients should be treated with antibiotic prophylaxis in order to avoid one infection. 
Mohs micrographic surgery is an important and effective treatment modality for cutaneous melanoma.
A recent prospective, multicentre, cohort study of 562 melanomas treated with MMS reported that the procedure with melanoma antigen recognised by T cells 1 immunostaining safely provides tissue conservation and same-day reconstruction of histologically verified tumour-free margins. 
Moreover, when comprehensive margin evaluation is not applied, initial surgical margins of at least 10 mm for primary trunk/extremity and 12 mm for head/neck melanomas should be used to achieve histologically negative margins 97% of the time.
A large study on over 70,000 patients also demonstrated that Mohs surgery may provide an alternative approach to traditional wide margin excision for appropriately selected cases of AJCC-8 stage I melanoma without compromising patient survival. 
An analysis of the SEER database reported that declining surgery, especially among the elderly, is associated with poorer survival outcomes, highlighting the need to provide better patient education and support for optimal management. 
In squamous cell carcinoma, Mohs surgery is also a highly effective treatment considering long-term outcomes and may mitigate factors typically considered at high risk such as T-stage. 
Tumour invasion beyond subcutaneous fat and poor histologic differentiation may carry a greater risk of poor outcomes than other factors in high risk disease.
Mohs surgery alone still provides excellent marginal control with low rates of local recurrence, nodal metastasis and disease-specific death.
In dermatofibrosarcoma protuberans, several risk factors for local recurrence have recently been identified following Mohs micrographic surgery, the most important of which is fibrosarcomatous changes, associated with a 13-fold increased risk, in addition to tumour size >5 cm. 
Thus, clinicians should be aware of these features in addition to emphasising intensive self-examination.
Another recent study found that fibrosarcomatous change was associated with a 20-fold increased risk of recurrence along with positive resection margins. 
These studies underline that follow-up should be proactive and individualised based on the patient, tumour and histopathological findings.
In atypical fibroxanthoma, a systematic review and meta-analysis has suggested that recurrence rates are similar between Mohs micrographic surgery and wide local excision techniques and that timing of recurrence is similar regardless of surgical technique employed. 
Locke MC, Davis JC2, Brothers RJ, et al. Assessing the outcomes, risks, and costs of local versus general anesthesia: A review with implications for cutaneous surgery. J Am Acad Dermatol. 2018 May;78(5):983-8.
Longo C, Pampena R, Bombonato C, et al. Diagnostic accuracy of ex ivo fluorescence confocal microscopy in Mohs surgery of basal cell carcinomas: A prospective study on 753 margins. Br J Dermatol. 2019 Jun;180(6):1473-80.
Zhou Y, Chen W, Liu ZR, et al. Modified shave surgery combined with nail window technique for the treatment of longitudinal melanonychia: Evaluation of the method on a series of 67 cases. J Am Acad Dermatol. 2019 Sep;81(3):717-22.
Presented by: Prof. Kristian Reich, Translational Research in Inflammatory Skin Diseases, Institute for Health Services Research in Dermatology and Nursing, University Medical Center Hamburg-Eppendorf, and Skinflammation® Center, Hamburg, Germany