39

Inguinal Node Dissection

Kenneth W. Angermeier; Rene Sotelo; David S. Sharp

Questions

1.Efforts designed to improve the accuracy of dynamic sentinel lymph node biopsy include all of the following EXCEPT:

a.use of an ultrasensitive gamma ray detection probe.

b.routine inguinal exploration in the absence of radiotracer visualization.

c.extended pathologic analysis of excised lymph nodes.

d.intraoperative palpation of the wound for abnormal nodes.

e.preoperative inguinal ultrasonography with fine-needle aspiration of any abnormal-appearing nodes.

2.When compared with the standard groin dissection, the modified groin dissection has all of the following features EXCEPT:

a.The node dissection excludes regions lateral to the femoral artery and caudad to the fossa ovalis.

b.The saphenous vein is preserved.

c.The transposition of the sartorius muscle is eliminated.

d.The required incision is longer.

e.Decreased morbidity.

3.Which of the following statements regarding radical ilioinguinal lymphadenectomy is TRUE?

a.The fascia lata remains intact.

b.The saphenous vein may be preserved in the setting of low-volume disease.

c.Rotation of the gracilis muscle is performed to cover the exposed femoral vessels.

d.The femoral nerve is visualized superior to the iliacus fascia.

e.A laparoscopic approach has not been reported.

4.A pelvic node dissection for male penile cancer should include all of the following areas EXCEPT:

a.distal common iliac nodes.

b.para-aortic and paracaval node dissection.

c.external iliac nodes.

d.obturator group of nodes.

e.a and b

5.Which of the following measures may help prevent lymphedema after a radical ilioinguinal node dissection?

a.Preservation of Colles fascia in the flap dissection

b.Low-dose heparin in the perioperative period

c.A 6-week delay between treatment of the primary tumor and the node dissection

d.Postoperative bed rest and elastic stockings

e.Obliteration of dead space during wound closure

Answers

1.a. Use of an ultrasensitive gamma ray detection probe. Techniques reported to increase the accuracy of dynamic sentinel lymph node biopsy include preoperative inguinal ultrasonography with needle biopsy of any suspicious nodes, routine inguinal exploration even in the absence of radiotracer visualization, intraoperative palpation of the wound for abnormal nodes, and extended pathologic analysis of any excised lymph nodes.

2.d. The required incision is longer. The modified groin dissection differs from the standard dissection in that (1) the skin incision is shorter; (2) the node dissection is limited, excluding regions lateral to the femoral artery and caudad to the fossa ovalis; (3) the saphenous veins are preserved; and (4) the transposition of the sartorius muscles is eliminated.

3.b. The saphenous vein may be preserved in the setting of low-volume disease. In a radical inguinal lymphadenectomy, the fascia lata is divided longitudinally, and the sartorius muscle is rotated to cover the femoral vessels. The femoral nerve is usually not seen because it lies beneath the iliacus fascia lateral to the femoral artery. In the setting of low-volume nodal disease, it is acceptable to spare the saphenous vein, if feasible, to attempt decreasing the risk of lower-extremity complications.

4.b. Para-aortic and paracaval node dissection. The pelvic lymphadenectomy

includes the distal common iliac, external iliac, and obturator groups of nodes. No further therapeutic benefit is gained from proximal iliac or paraaortic node dissection.

5.d. Postoperative bed rest and elastic stockings. Efforts to minimize lymphedema during the initial postoperative period include applying thighhigh elastic wraps or stockings and elevating the foot of the bed.

Chapter review

1.Penile cancer is not a unilateral disease and may metastasize to either groin regardless of location of the primary lesion.

2.Immediate resection of clinically occult lymph node metastases in patients with penile cancer results in improved survival when compared to waiting until metastatic lymph nodes become palpable before performing a groin dissection.

3.A radical groin dissection may be therapeutic and on occasion is used for palliation.

4.Penile cancer does not metastasize to the pelvic nodes without involvement of the inguinal nodes.

5.Twenty percent of patients with nonpalpable inguinal nodes harbor occult metastases.

6.Dynamic sentinel node biopsy has a false-negative rate of 5% to 15%. With the use of stage and grade, the false-negative rate is 20%.

7.The lymphatics drain to the groin beneath Camper fascia. When this fascia is included in the skin flaps, the dissection is less likely to compromise the overlying skin.

8.A transverse incision is least likely to compromise blood flow to the skin flaps.

9.The modified groin dissection differs from the standard dissection in that

(1) the skin incision is shorter; (2) the node dissection is limited, excluding regions lateral to the femoral artery and caudad to the fossa ovalis; (3) the saphenous veins are preserved; and (4) the transposition of the sartorius muscles is eliminated.

10.The pelvic lymphadenectomy when indicated includes the distal common iliac, external iliac, and obturator groups of nodes. No further therapeutic benefit is gained from proximal iliac or para-aortic node dissection.