Complications Associated with Mohs Micrographic Surgery: Data from the Nationwide Prospective Cohort REGESMOHS
Verónica Ruiz-Salas 1 2 , Onofre Sanmartin-Jiménez 3 , Joan R Garcés 1 2 , Eva Vilarrasa 1 2 , Román Miñano-Medrano 4 , Begoña Escutia-Muñoz 5 , Ángeles Flórez-Menéndez 6 , Juan L Artola-Igarza 7 , Alberto Alfaro-Rubio 8 , Pedro Redondo 9 , Yolanda Delgado-Jiménez 10 11 , Julia Sánchez-Schmidt 12 , Irati Allende-Markixana 13 , Beatriz García Bracamonte 14 , Pablo de la Cueva-Dobao 15 , Cristina Ciudad 16 17 , Lucía Carnero-González 18 , Hugo Vázquez-Veiga 19 , Pedro Sánchez-Sambucety 20 , José Luis Estebaranz 4 , Rafael Botella-Estrada 5 , Beatriz González-Sixto 6 , Antonio Martorell 8 , Victoriano Morales-Gordillo 10 , Agustí Toll-Abelló 12 , Matías Mayor-Arenal 21 , Ricardo Suárez-Fernández 16 , Laura Sainz-Gaspar 19 , Miguel A Descalzo 22 , Ignacio Garcia-Doval 23 22 , REGESMOHS (Registro Español de Cirugía de Mohs)
Background: Large prospective studies on the safety of Mohs micrographic (MMS) surgery are scarce, and most focus on a single type of surgical adverse event. Mid-term scar alterations and functional loss have not been described.
Objectives: To describe the risk of MMS complications and the risk factors for them.
Methods: A nationwide prospective cohort collected all adverse events on consecutive patients in 22 specialised centres. We used multilevel mixed-effects logistic regression to find out factors associated with adverse events.
Results: 5,017 patients were included, with 14,421 patient-years of follow-up. 7.0% had some perioperative morbidity and 6.5% had mid-term and scar-related complications. The overall risk of complications was mainly associated with use of antiaggregant/anticoagulant and larger tumours, affecting deeper structures, not reaching a tumour-free border, and requiring complex repair.
Age and outpatient setting were not linked to the incidence of adverse events. Risk factors for haemorrhage (0.9%) were therapy with antiaggregant/anticoagulants, tumour size, duration of surgery, and unfinished surgery. Wound necrosis (1.9%) and dehiscence (1.0%) were associated with larger defects and complex closures. Immunosuppression was only associated with an increased risk of necrosis.
Surgeries reaching deeper structures, larger tumours and previous surgical treatments were associated with wound infection (0.9%). Aesthetic scar alterations (5.4%) were more common in younger patients, with larger tumours, in H-area, and in flap and complex closures.
Risk factors for functional scar alterations (1.7%) were the need for general anaesthesia, larger tumours that had received previous surgery, and flaps or complex closures.
Conclusions: MMS shows a low risk of complications. Most of the risk factors for complications were related to tumour size and depth, and the resulting need for complex surgery. Antiaggregant/anticoagulant intake was associated with a small increase in the risk of haemorrhage, that probably does not justify withdrawal. Age and outpatient setting were not linked to the risk of adverse events.