Indication for Pelvic Nodal Dissection

Transperitoneal pelvic lymph node dissection typically is performed in gynecologic oncology centers as a staging procedure or as a part of surgical management of cervical and endometrial cancers. In early cervical cancer, pelvic nodal dissection is performed at the time of radical hysterectomy. It is our policy to start with the nodal dissection, in order to select patients for a radical procedure; the patient with positive nodes on frozen section does not benefit from completion of a radical hysterectomy.

The technique of sentinel node dissection is gaining popularity in gynecologic oncology. Removal of a single targeted node from a node-bearing area can be accomplished with minimally invasive technique. Moreover, the identification of minute lymphatic channels located deep in the pelvis is facilitated with magnification, as provided by the laparoscope (Fig. 35-1). Initial attempts at sentinel node detection involved blue dye injection only, with marginal success; subsequently, combined isotope and blue dye mapping improved the detection rate up to 90%. A sentinel node may be found in an unusual area, such as in the region of the common iliac or aorta. Of note, the sentinel node technique does not apply to obviously diseased nodes in which lymphatic flow is blocked, which would make uptake of markers impossible.

FIGURE 35-1 Sentinel node identification using blue dye.

Many centers (including ours) consider a positive sentinel node in early cervical cancer as a contraindication for an upfront radical extirpation; rather, it as an indication for aortic nodal dissection and possible definitive chemoradiation therapy. Further pelvic dissection in such a circumstance is not advised because it could increase the risk for a radiation-induced complication. On the other hand, the finding of a negative sentinel node does not necessarily eliminate the need for a pelvic dissection.

In endometrial carcinoma, the performance of a lymph node dissection is not indicated in low-risk patients, is controversial in intermediate-risk patients, and is mandatory in high-risk patients. In the future, pelvic sentinel node sampling could be used as a compromise between performing no dissection versus a full dissection in the intermediate-risk patient. If a patient with endometrial cancer has a positive pelvic sentinel node, then an aortic node dissection or sampling should be performed.

Indications for Aortic Dissection

Aortic node dissection is a component of most gynecologic oncology procedures, for both primary and recurrent gynecologic malignancy, including adnexal cancers. It is controversial in early endometrial cancer but routinely performed by most gynecologic oncologists in the case of positive pelvic nodes or in the high-risk patient (e.g., stage IB G3 endometrioid, or pathologic type 2). In early cervical cancer, some investigators advise routine aortic dissection, whereas others perform aortic dissections only if the patient has positive pelvic nodes. In advanced cervical cancer, the concept of surgical staging is not widely accepted, although an aortic dissection may prevent the node-negative patient from undergoing para-aortic irradiation and may prevent the node-positive patient from an unnecessary primary procedure or exenteration for pelvic recurrence. An aortic nodal dissection generally is reserved for the patient who has no uptake in the aortic nodes on positron emission tomography (PET).

Indications for Laparoscopic Aortic Dissection

The laparoscopic approach to aortic dissection is the preferred approach if (1) the staging procedure is the only goal of the operation, as in the case of advanced cervical cancer; (2) an early adnexal malignancy has inadequate staging; or (3) the dissection is part of the evaluation before a pelvic exenteration. If simple or radical hysterectomy is feasible, then most stage I uterine cancers can be managed using a minimally invasive approach. As a consequence, aortic dissection may be part of the comprehensive surgical management of early gynecologic malignancy. In some cases, open surgical management of the primary disease is required to remove bulky disease. The laparoscopic management of early ovarian cancer is controversial because it is crucial to avoid tumor rupture and contamination of the abdominal wall. If ovarian tumor size is greater than 5 cm, then extraction through a port incision is not recommended.

Choice of Approach: Transperitoneal versus Extraperitoneal

The main benefits of the extraperitoneal approach are (1) better surgical ergonomics, with easy access to the left infrarenal area and an absence of bowel loops in the way; and (2) a reduction of postoperative adhesions, which has been demonstrated in an experimental study in our laboratory. As a consequence, the patient who is a possible candidate for extended-field radiation may benefit from the extraperitoneal approach. In addition, patients presenting with advanced cervical cancer or with high-risk endometrial cancer may benefit from an extraperitoneal approach.

If the technical conditions are not optimal (e.g., as in obese patients), then it is advisable to try an extraperitoneal approach. If the extraperitoneal approach fails in this situation, then the transperitoneal route can be used. The opposite strategy is not possible because the development of the extraperitoneal space requires an intact peritoneum. In addition, the extraperitoneal route is preferred if the patient’s history suggests the presence of extensive intraperitoneal adhesions.

Considering the improved surgical ergonomics with the extraperitoneal approach, we have favored the extraperitoneal route, even when a transperitoneal procedure is possible. If a reassessment of adnexal malignancy or a hysterectomy is required, then a “combined” approach is used. The first step is a diagnostic transperitoneal laparoscopy. An extraperitoneal aortic dissection (with common iliac and, when indicated, pelvic dissections) is then performed. Finally, the transperitoneal view is reestablished, the trocars used for the extraperitoneal approach are pushed into the peritoneal cavity, and the transperitoneal steps of the operation are performed.

Contraindications

If the patient will not benefit from the pathologic staging of a pelvic malignancy, then laparoscopic staging is not indicated. For example, an elderly patient who is not a candidate for extended-field radiation therapy with concomitant chemotherapy will not benefit from surgical aortic staging. Additionally, a patient with distant metastases identified at the time of PET imaging, or a patient with nodal metastases identified with computed tomography (CT) and then cytologically confirmed, will not benefit from laparoscopic staging.

A relative contraindication is the presence of bulky nodes that are difficult to remove through the laparoscope. Abdominal wall seeding, or spillage of cancer cells in the retroperitoneal space, is a concern in such a case. Although surgical debulking of enlarged nodes is an acceptable procedure, the benefit of such a procedure has never been demonstrated in a randomized trial. In addition, the dissection of fixed nodes may harm large vessels, leading to an emergency laparotomy for vascular repair. Our policy is to laparoscopically remove a diseased node up to 3 cm in diameter, so long as the node may be separated from the associated large vessel without breaking the nodal capsule.