Supplementary file 1. Surgical procedure of the superficial and deep groin dissection,
performed in the University Medical Hospital Groningen.
The surgical procedure is fully described in the Atlas of advanced operative surgery.9
Superficial groin dissection:
An ellipse-shaped incision of the skin is started cranially, 2cm medial from the superior iliac
anterior spine, slightly oblique to the midinguinal area, and then below Poupart ligament
vertically downward to the apex of the femoral triangle. The superficial dissection contains
the subcutaneous fat and lymphatic tissue underneath the skin ellipse, limited by the external
oblique fascia and inguinal ligament superiorly, the long adductor muscle medially, and the
Sartorius muscle laterally. The lymph nodes and adipose tissue are sharply dissected off the
external oblique aponeurosis in continuity with the fascia of the adductor muscle and
mobilized caudally and laterally. At the apex of the femoral triangle the saphenous vein is
dissected and the femoral vessels and nerve are identified. In selected cases it might be
possible to spare the saphenous vein, although in case of a macroscopic nodal involvement
the saphenous vein is transected. The superficial groin dissection is completed in front of the
femoral vessels and medially below Poupart ligament, without excision of the fatty tissue that
lies upon the external iliac fascia.
Deep groin dissection:
Two cm lateral from the iliacvessels, 3 cm vertical incision of the poupart ligament and the
retroperitoneal space openend. The ilio-obturator LND is performed in front of the external
iliac artery. The lateral border is the genitofemoral nerve. The medial border is the external
iliac vein, and the dissection is performed from the level of the internal iliac artery caudally.
The ureter is identified and the dissection is continued medially along the obturator nerve.
The deep nodes are almost exclusively medial to the femoral vessels and cephalad to the
fossa ovalis. The defect in pouparts ligament is closed with absorbable sutures. The origin of
the Sartorius muscle is dissected and is rotated medially to cover the neurovascular femoral
bundle and subsequently fixed with absorbable mattress surtures to the Poupart ligament and
the fascia of the adductor and vastus muscle groups. Two low-vacuum drains are placed, one
medial and one lateral, a suction drain of the pelvis is not required.