Surgical staging including lymph node dissection is the cornerstone of treatment of early-stage endometrial and ovarian malignancies. In 1988, surgical staging replaced clinical staging for endometrial cancer, due to inherent underreporting of metastatic disease distribution in the clinical staging system. Comprehensive staging guides treatment planning for subsequent chemotherapy and/or radiation therapy. In the setting of advanced or recurrent disease, lymph node dissection may be undertaken for the purpose of removing bulky tumor. Although cervical cancer is staged clinically, lymph node dissection plays a role in the management of early-stage tumors.
The lymphatic drainage of the uterus, tubes, and ovaries follows the blood supply of these organs and includes the pelvic lymph node basins as well as the aortic lymph nodes (Figure 28-1). Depending on the site of malignancy and the clinical indications, lymph node dissection may be undertaken in some or all of these basins, either unilaterally or bilaterally.
Pelvic and aortic lymph node basins. (Redrawn, with permission, from Chi DS, Bristow RE, Gallup DG. Surgical principles in gynecologic oncology. In: Barakat RR, Markman M, Randall ME, eds. Principles and Practice of Gynecologic Oncology. Baltimore, MD: Lippincott Williams & Wilkins; 2009:270.)
PELVIC LYMPH NODE DISSECTION
Box 28-1 Master Surgeon's Corner
Adequate exposure and identifi cation of anatomic structures are crucial to avoid injury to adjacent structures of the pelvic sidewall.
Proper development of the paravesical and pararectal spaces is an essential step prior to beginning the process of removing lymph nodes.
Appropriate use of hemostatic clips and vesselsealing devices (ie, limiting the use of monopolar cautery and blunt dissection) may reduce the risk of lymphorrhea.
Indications and Historical Perspective
There is a generalized lack of standardization in the technique of pelvic lymphadenectomy in gynecologic cancer that is apparent in both the literature and surgical practice. With the exception of sentinel lymph node mapping, the total number of lymph nodes removed is most often used as a surrogate for the radicality and completeness of the procedure. Cibula and Abu-Rustum1 recently attempted to clarify and standardize the terminology and anatomic basis for the procedure, proposing a new anatomically based classification system for pelvic lymphadenectomy. In this system, a complete systematic lymphadenectomy or "type III dissection" includes the removal of all fatty lymphatic tissue from the predicted areas of high incidence of lymph nodes with metastatic involvement. This comprehensive procedure is described later in this chapter and includes dissection of the 5 main anatomic regions of the pelvic lymphatic drainage: external iliac, obturator, internal iliac, common iliac, and presacral lymph nodes. In certain circumstances, more limited dissection may be indicated, such as sentinel lymph node biopsy, excision of only bulky nodes, or lymph node sampling.