Endoscopic Subcutaneous Modified Inguinal Lymph Node Dissection for Squamous Cell Carcinoma of the Penis

The presence and extent of metastatic disease to the lymph nodes is the most important prognostic indicator of survival in patients with squamous cell carcinoma of the penis and has significant clinical application for cutaneous melanoma and vulvar cancer. Lymphadenectomy is often required in these disease processes for cancer staging and can also be curative when cancer is isolated to the penis and regional nodes. Serious, life-altering complications have been associated with inguinal lymph node dissection. Because of the substantial morbidity associated with inguinal lymphadenectomy, controversy surrounds the use of bilateral and prophylactic dissection.

In 2002, Dr. Ian M. Thompson conceived the idea of applying laparoscopic techniques in an endoscopic approach to the inguinal lymph nodes, with the hope of decreasing the morbidity associated with open surgery by preserving the continuity of the lymphatic and vascular supply to the overlying skin. Working together, we combined different techniques from subcutaneous endoscopic brow lift and saphenous vein harvest to formulate an approach using laparoscopic instruments for inguinal node dissection in staging penile cancer. The result of our work was the endoscopic subcutaneous modified inguinal lymphadenectomy (ESMIL) procedure, which mimics the same oncologic approach traditionally performed through an open incision.

We first explored the feasibility of this new procedure in several fresh cadaver studies; in 2003 a patient with T3, N1, M0 squamous cell carcinoma of the penis underwent the first ESMIL procedure. ^∗

∗ Bishoff JT, Basler JW, Teichman JM, Thompson IM. Endoscopic subcutaneous modified inguinal lymph node dissection (ESMIL) for squamous cell carcinoma of the penis. J Urol . 2003;169(Suppl 4): 78.

Since our initial report, others have used the technique with great success and have applied the same technique to other cancers requiring inguinal node dissection. In all of the series, there has been less skin necrosis, less lymph edema, and fewer infections than with open surgery.

Indications and Contraindications

ESMIL is indicated when traditional inguinal lymphadenectomy would be required for staging squamous cell carcinoma of the penis. Patients with nonpalpable nodes or small (<1 cm) mobile nodes at high risk for inguinal node involvement are considered good candidates for endoscopic node dissection. Patients with pTa and pT1 G1 penile tumors will have positive nodes approximately 10% of the time, when inguinal nodes are not enlarged. Fifty percent of patients with pT2 tumors and G3 tumors will demonstrate positive inguinal lymph nodes.

Both stage and grade are predictive of nodal involvement. Verrucous carcinoma and carcinoma in situ are both associated with a low risk for nodal metastasis. However, 70% of stage T2 cancers have positive nodes. G1 tumors have a 30% chance of spread to lymph nodes, whereas approximately 85% of patients with G3 tumors have inguinal node involvement. Because cross-drainage from the affected side to the contralateral side is a well-known occurrence, bilateral dissection is indicated in patients at high risk for metastatic disease (stage T2 or greater or G2 or G3 tumors).

Patients with large, fixed inguinal lymph nodes have a relative contraindication to ESMIL. In these patients it can be very difficult to dissect the superior aspect of fixed, matted lymph nodes with an endoscopic technique, and as a result they are better candidates for traditional open surgery.

Patient Preoperative Evaluation and Preparation

A complete metastatic evaluation should be performed before biopsy of the presenting penile lesion or partial penectomy when indicated. The presence of carcinoma of the penis is established with biopsy to determine the diagnosis, extent of invasion, presence of vascular invasion, and grade of the lesion before lymphadenectomy. Distant metastatic disease without lymph node involvement is rarely seen. However, distant metastatic spread to bone, brain, liver, and lung should be considered as part of the overall workup for penile cancer. Computed tomography of the pelvis and inguinal region can be helpful in determining the presence of large pelvic and inguinal nodes, especially in the obese patient.

Waist-high elastic stockings should be fitted and obtained before surgery. Preoperative intravenous antibiotics for skin flora coverage are given 60 minutes before the skin incision. A sterile preparation of the area is performed in the usual fashion.

Operating Room Configuration and Patient Positioning

The operating room is configured so that all of the staff can view the procedure. The surgeon’s monitor is placed on the contralateral side of the dissection, near the shoulder and arm of the patient. A second monitor is placed on the opposite side in the case of bilateral dissection or as needed for viewing by the entire team ( Fig. 15-1 ).

The patient is placed in a supine position, with the ipsilateral knee flexed and hip abducted. The foot on the side of dissection is secured to the contralateral leg for a unilateral dissection, or both feet are secured together in the case of a bilateral procedure. A pad placed under the bent knee will help maintain the correct position during the case ( Fig. 15-2 ).

Trocar Placement

Before the first trocar is placed, the limits of the dissection are marked on the skin to preserve the orientation once the skin is distorted from the insufflation used to create the working space. A line is drawn from the pubic tubercle to the anterior superior iliac crest. The width of the area of dissection is approximately 11 to 12 cm, and the length is 15 cm down the medial thigh and 20 cm on the lateral thigh ( Fig. 15-3 ).