Multi-institutional Experience of Minimally Invasive Inguinal Lymph Node Dissection (milnd) for Melanoma

Objective: The most frequent site of spread of melanoma is to the regional lymph nodes. Operative intervention remains the mainstay of treatment and necessary for cure. Unfortunately, lymph node dissection is associated with significant morbidity. Three prospective trials report complications in over 50% of patients undergoing inguinal lymph node dissection; these include wound infections, wound dehiscence, seromas, venous thrombotic events and life long lymphedema. Minimally invasive lymph node dissection (MILND) is a recently described alternative approach to traditional, open inguinal lymphadenectomy (OIL).
Technique: We report the first 13 MILD cases performed for melanoma by two surgeons at two tertiary academic centers using similar techniques. These are compared with 28 OIL cases performed by the same two surgeons. MILD is accomplished using a 3 port technique: 1 camera port 3 cm from the apex of the femoral triangle and 2 working ports 3 cm from the medial and lateral border of triangle. The initial anterior dissection is either done with insufflation at 25 mm Hg or with a balloon dissector. The anatomical borders are the same as the open procedure: inguinal ligament superiorly, sartorius laterally and adductor longus medially. The anterior dissection occurs just above Scarpa’s fascia. After medial and lateral fascial dissection the saphenous vein is ligated distally and at the sapheno-femoral junction, the specimen is removed en bloc in an endo bag. A 10 Fr JP drain is placed through one of the trocar sites and the other two incisions are closed.
Results: There were no significant differences in patient age, gender, BMI or smoking status between MILD and OIL. MILD required a longer operative time (236 vs. 138 min p=0.0005). In this small study the wound dehiscence (0% vs. 11%, p=0.12), hospital readmission (7% vs. 20%, p=0.32) and hospital length of stay (1 vs. 2 days, p=0.06) were all lower in the MILND group, but none of these reached statistical significance. With a median follow up of only 3 months in the MILD cohort we could not assess regional control, however the lymph node retrieval was higher (11 vs. 8 p=0.03) for MILD than OIL.
Conclusions: MILND is a novel technique for treating metastatic nodal disease to the inguinal basin in patients with melanoma. Our early experience suggests it is safe with a non-significant reduction in wound complications and hospital length of stay when compared to the conventional open approach. In terms of the number of lymph nodes retrieved, the oncological adequacy of MILND appears to be at least as good as OIL with increased lymph node retrieval in the MILND group. Although these results are promising, long term outcomes are unknown. Our short term success should be further validated in prospective trials.