Robot-assisted laparoscopic transperitoneal deep pelvic lymphadenectomy for metastatic melanoma of the lower limb: initial report of four cases and outcomes at 1-year follow-up

Abstract

Current treatment for melanoma of the lower limb includes excision of the primary tumor with ilioinguinal lymphadenectomy in the case of lymph node metastases [1–4]. Robotic deep pelvic lymphadenectomy (RDPL) is a welldescribed procedure of staging and treatment of gynecologic and urologic malignancies. Herein we present our initial report of RDPL in malignant melanoma. To our knowledge only one report is present in literature [5], but no follow-up was performed. Clinical staging were performed using total body tomography. The patients were given cephalosporins and antithrombotic prophylaxis with low-weight heparins. The patients were placed on spreader bars in 30–35 Trendelenburg position. The Da Vinci robot (Intuitive Surgical, CA, USA) was docked in standard fashion, with the column positioned between the patient’s legs. Pneumoperitoneum to 20 mmHg was established with closed Veress needle insertion just above the umbilicus. A 12-mm port was placed above the umbilicus, two 8-mm robotic ports were placed just lateral to the medial umbilical ligaments 14–16 cm from the pubic symphysis and 10 cm from the midline. A third 8-mm robotic port was placed for robotic arm on the left side 10 cm lateral to the left-sided 8-mm robotic port. A 12-mm assistant port was placed in the right lower quadrant. After the intestinal bundle is replaced from the pelvis and adhesiolysis is performed, we first open the lateral leaf of the broad ligament. In the retroperitoneum, the first structure to be identified is the psoas muscle, and then ureter and iliac bifurcation are detected. The obturator nerve, the obturator muscle, and the whole course proximal to the internal iliac artery must be visualized. Lymphadenectomy then begins from the proximal side of the lateral external iliac nodes. The lymph node packet between the external iliac artery and the vein was dissected up to the bifurcation of the common iliac artery. After, excision of superficial and deep obturator lymph node chains and retro crural lymph nodes was performed. The packets were placed in 10-mm Endobags and the specimens were removed through the midline port site. The first patient was a 48-year-old woman, who initially underwent a wide local excision of a 1.3-cm melanoma over the right fibular head. Pathology revealed a nodulartype malignant pigmented melanoma (Clark IV, Breslow 2.75 mm; pT3b) with epithelioid cells (MART1-), with negative margins (no-brisk tumor). One month later, the patient was underwent radicalization of the previous excision and a biopsy of the sentinel lymph node. Two of three sentinel lymph nodes were positive for micrometastatic disease. Two months later a RDPL (ileo-crural inguinal/obturator) with deep inguinal groin lymph node dissection was performed, with removal of 18 negative lymph nodes. The second case concerned a pigmented melanoma of the right thigh with spindles cells (Clark IV, Breslow 1.93 mm; pT2a; no-brisk tumor; MART-1) in a 40 year-old patient. At radicalization and biopsy, micrometastatic disease was A. Pellegrino G. R. Damiani (&) Operative Unit of Gynecology and Obstetrics, Alessandro Manzoni Hospital, Lecco, Italy e-mail: damiani14@alice.it