Phase 1 prospective evaluation of the oncological adequacy of robotic assisted video-endoscopic inguinal lymphadenectomy in patients with penile carcinoma.

OBJECTIVE To prospectively determine the oncological adequacy of robotic assisted video-endoscopic inguinal lymphadenectomy (RAVEIL). PATIENTS AND METHODS Patients with T1-3N0 penile cancer were enrolled into a prospective phase I trial at a tertiary care institution from March 2010 to January 2012. All patients underwent an initial RAVEIL approach. Verification of adequacy of dissection was performed by an independent surgeon via a separate open incision at the conclusion of the RAVEIL procedure. Out of 10 patients, if more than two superficial inguinal fields with ≥ 2 nodes or more than four with ≥ 1 node remained within the superficial dissection field, the study would not proceed to phase II. RESULTS Of 10 enrolled patients two had inguinal metastases and all positive nodes were detected by RAVEIL. The remaining eight patients had no metastases, with a mean of nine (range 5–21) left and nine (range 6–17) right nodes removed. One inguinal field RAVEIL was converted to an open dissection. The verifying surgeon confirmed that 18 of 19 inguinal fields (94.7% in nine patients) had an adequate dissection. Two benign nodes were found just beneath Scarpa’s fascia above the inguinal dissection field. Limitations of the study include an inability to determine decisively what specific wound complications were related to RAVEIL because of the protocol-specified creation of a small inguinal incision for verification of adequate dissection. CONCLUSIONS RAVEIL allowed adequate staging of disease in the inguinal region among patients with penile cancer at risk for inguinal metastases. Keywords: penile cancer, lymph nodes, robotic surgery, lymphadenectomy, squamous cell carcinoma, prospective study INTRODUCTION Inguinal lymphadenectomy (ILND) is the current standard of care for patients with penile squamous cell carcinoma and resectable inguinal lymph node metastasis. Because the presence and extent of inguinal metastasis dictate survival in patients with metastatic penile cancer [1–5], determining these features at the earliest possible time point maximizes the possibility of a surgical cure. Recent data suggest a survival advantage for patients who undergo prophylactic ILND and have positive nodes compared with those treated with surveillance and delayed dissection for positive nodes [6]. Furthermore, recent guidelines suggest strategies to select high risk patients most likely to benefit from ILND [7,8]. While prophylactic ILND seems to be preferable, it has disadvantages as well. The incidence of postoperative complications following ILND has been reported to approach 50% or even up to 75% [9–12]. Patients with comorbidities or locally advanced disease are at particular risk for postoperative morbidity [13]. Wound dehiscence and skin necrosis following ILND have also been reported [14–17]. More recently, complication rates among men with no palpable adenopathy have been reported to be decreasing in comparison with historical experience, but overall complication rates still range from 10% to 46% [18]. Alternative lymph node staging procedures have been proposed to reduce morbidity and complication rates. Dynamic sentinel lymph node biopsy with recent modifications has decreased false-negative findings to approximately 7%, and there is little morbidity associated with the procedure [19,20]. Another potential technique that could limit morbidity while sampling all the nearby superficial lymph nodes is endoscopic inguinal lymphadenectomy. The initial endoscopic inguinal lymphadenectomy technique for penile cancer was described by Bishoff and associates [21] and further developed by both Tobias-Machado and associates (who called their method video-endoscopic inguinal lymphadenectomy [VEIL]) and Sotelo et al. [22–24]. The first published study on the VEIL technique described a single patient with penile cancer who underwent a successful bilateral ILND [22]. A subsequent study of 10 patients who underwent bilateral ILND using standard lymphadenectomy on one side and the VEIL technique on the contralateral side was reported by the same centre [23]. Sotelo and colleagues reported a similar procedure in eight patients, with no intraoperative or wound-related complications [24]. A more recent development has been the incorporation of robotic assistance as an enabling tool for performing endoscopic/laparoscopic ILND; two case reports of robotic assisted lymph node dissection have been published on the subject [25,26]. We sought to prospectively evaluate the oncological adequacy of robotic assisted VEIL (RAVEIL) as a staging tool in patients with penile cancer at risk for inguinal metastasis. We assessed and confirmed that all the superficial first-echelon lymph nodes in the inguinal region would be successfully removed using RAVEIL.