Inguinal lymphadenectomy for penile cancer has both staging and therapeutic values. The presence of nodal involvement and node density are the most important prognostic factors for recurrence and death; ≥7 nodes per groin is considered the quality standard. Dr. Gaya-Sopena notes that among cN0 patients (80%), 20-25% of patients will harbor occult metastases. For patients with cN+ disease (20%), in the patients with palpable nodes, approximately 70% will actually have metastatic involvement. Among cN+ patients, around 70-80% have no distant metastases and cure can be attained.
According to the EAU guidelines, a modified inguinal lymphadenectomy (or dynamic sentinel node biopsy) should be performed for cN0 patients with >T1G2 disease. Furthermore, among cN1/cN2 patients a radical inguinal lymphadenectomy should be performed; cN3 patients should have a radical lymphadenectomy if they have a response to neoadjuvant chemotherapy. Despite these guidelines, there is low adoption rate for inguinal lymphadenectomy at the population level. According to Dr. Gaya-Sopena, this may be secondary to (i) low experience in management of the disease secondary to the rarity of penile carcinoma, (ii) old fashion beliefs “if you can’t cure it, primum non nocere”, and (iii) there is a high morbidity for open (modified or radical) inguinal lymphadenectomy with a 70-75% total complication rate, including 30-35% Clavien ≥3. There are several ways to solve this issue, namely centralization and minimally invasive (laparoscopic or robotic) approaches.
Dr. Gaya-Sopena cautions that those adopting minimally invasive techniques for inguinal lymphadenectomy must adhere to the gold-standard open oncological principles. These include (i) dissecting lymph tissue from the same anatomic limits, (ii) the same oncologic indications (cN0 or cN1-2), and (iii) performing a modified or radical inguinal lymphadenectomy depending on the clinical indication.
The key steps to a robotic inguinal lymphadenectomy are as follows:
- Making space in the groin: first, a 2-cm incision is made at the inferior vertex of the femoral triangle, followed by blunt dissection with the index finger, and gas insufflation (5 mmHg) with an Air-Seal device
- Trocar placement: trocars should always be placed outside the femoral triangle to avoid clutching/clashing of the instruments. Trocars with a balloon are very useful for avoiding unnecessary length of the trocar inside the reduced space
There are several retrospective case series comparing laparoscopic and robotic inguinal lymphadenectomy to historical open series’ noting decreased major complication rate and decreased lymphedema rates. In the only report comparing laparoscopic (n=7) to robotic (n=27) inguinal lymphadenectomy there were no differences in lymph node yield, length of stay, or complications.1 However, based on the largest reported robotic experience to date from India2 (n=40), there are still complications after robotic inguinal lymphadenectomy: lymphocele (13.7%), lymphedema (7.8%), and cellulitis (7.8%). Wound infection (3.9%) and skin necrosis (1.9%) were rare. In his personal experience, Dr. Gaya-Sopena has performed 51 groin dissections robotically with a median surgical time of 95 min per groin and median lymph node count of 8, with 18 groins having lymphorrhea and 4 patients having lymphedema.
Dr. Gaya-Sopena concluded his presentation with several take-home messages:
- Minimally invasive inguinal lymphadenectomy is a safe technique with the same oncological principles and indications as the open procedure – the major contraindication is cN3 disease
- The same number of nodes removed is achievable, with no increased risk of local recurrence or port-site metastases
- Minimally invasive procedures are associated with less number of minor and major complications
- There is still a high rate of lymphocele and lymphedema and we must continue to search for additional solutions
- In some urology departments, minimally invasive inguinal lymphadenectomy is the gold-standard procedure
Written By: Zachary Klaassen, MD, MSc – Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, Twitter: @zklaassen_md at the 16th Meeting of the European Section of Oncological Urology, #ESOU19, January 18-20, 2019, Prague, Czech Republic
- Russell CM, Salami SS, Nieman A, et al. Minimally invasive inguinal lymphadenectomy in the management of penile carcinoma. Urology 2017 Aug;106:113-118.
- Singh A, Jaipuria J, Goel A, et al. Comparing outcomes of robotic and open inguinal lymph node dissection in patients with carcinoma of the penis. J Urol 2018 Jun;199(6):1518-1525.