Extent of Groin Dissection in Melanoma: A Mixed-Methods, Population-Based Study of Practice Patterns and Outcomes

Melanoma metastases to the groin are frequently managed by therapeutic lymph node dissection. Evidence is lacking regarding the extent of dissection required. Thus, we sought to describe practice patterns for the use of inguinal vs. ilioinguinal dissection, as well as the perioperative/oncologic outcomes of each procedure. A mixed-methods approach was employed to evaluate surgical practice patterns. A retrospective review of three multi-site databases was carried out, together with semi-structured interviews of melanoma surgeons. A total of 347 patients who underwent dissection were reviewed. The main indications stated for adding a "deep" ilioinguinal dissection were palpable or radiologically positive disease. There was no significant difference in complications, length of stay or lymphedema between patients having inguinal vs. ilioinguinal dissection, irrespective of method of diagnosis. There was also no significant difference in recurrence, cancer-specific survival or overall survival between groups. In conclusion, ilioinguinal dissection is a safe and well-tolerated procedure, with no significant added morbidity relative to an inguinal dissection. The indications for ilioinguinal dissection currently in use produce an appropriate deep node positivity rate and ilioinguinal dissection should continue to be used selectively. Randomized data are needed to clarify the impact of ilioinguinal dissection on regional control and survival.