Saturday, February 2, 2008

Laparoscopic pelvic and paraaortic lymphadenectomy in gynecologic cancers

INTRODUCTION — In 1989, Dargent used the laparoscope to perform limited pelvic lymphadenectomy on women with cervical cancer [1]. Subsequently, additional observational studies have established the feasibility, oncologic validity, and safety of laparoscopic pelvic and paraaortic node dissection in women with a variety of gynecologic cancers [2-10].
General advantages of the laparoscopic approach are a decrease in operative time, less blood loss, shorter hospital stay, and reduction in total cost. The only randomized trial evaluating different approaches to pelvic lymphadenectomy compared laparoscopic to extraperitoneal or transperitoneal lymphadenectomy [11]. The three techniques had similar complication rates, the laparoscopic approach took longer (75 versus 54 and 63 minutes, respectively) and fewer lymph nodes were resected (30 versus 35 and 36, respectively), but recovery was faster (hospitalization 3.1 versus 3.2 and 5.6 days, respectively) [11].
The benefits of laparoscopy are most meaningful if subsequent laparotomy for treatment of the gynecologic malignancy is also avoided. As an example: Enhanced staging of cervical carcinoma: Laparoscopic lymphadenectomy provides better information than imaging studies [12]. Node-negative women may be treated by laparoscopic or vaginal radical hysterectomy performed either simultaneously (based upon frozen section results [13]) or secondarily after routine pathologic examination of the pelvic nodes [8,9,14-17]. Node-positive women are generally considered for radiotherapy and/or chemotherapy. Knowledge of periaortic node positivity allows for individualization of the radiation field. (See "Laparoscopic approach to hysterectomy").
Laparoscopic staging of cervical carcinoma is also useful when radical trachelectomy is planned. Stage I and some stage II endometrial cancers can be staged and then treated by total hysterectomy, bilateral salpingo-oophorectomy (BSO), and pelvic lymphadenectomy using only a laparoscopic approach or the hysterectomy-BSO can be done vaginally [18-22]. (See "Laparoscopic approach to hysterectomy").
Laparoscopic sentinel node mapping in women with early stage cervical [23-30] or endometrial cancer [31,32] is also being studied and appears promising, but requires further investigation [33]. Laparoscopy has been used for second look operations in ovarian cancer for a number of years; however, its value for staging ovarian cancer has not been established. (See "Initial surgical management and follow-up of epithelial ovarian cancer" section on Laparoscopic approach).
Laparoscopic staging has also been used for interval staging of women with pelvic malignancies who were incompletely staged at initial surgery [34].
PREOPERATIVE PREPARATION — It is important that the bowel be collapsed during the laparoscopic lymphadenectomy so that proper exposure can be obtained. This is particularly important if the patient is obese and paraaortic lymphadenectomy is planned. Therefore, we place our patients on a clear liquid diet the day before the surgical procedure and evacuate the bowel using magnesium citrate or Go-Lytely.
OPERATIVE APPROACH — The patient is positioned in a dorsal lithotomy position using stirrups to support the legs (show picture 1). There should be minimal external hip rotation and no part of the leg should receive excessive pressure from the stirrups. It is helpful to have adjustable stirrups that allow for conversion from the low lithotomy to a leg-flexed position for vaginal surgery. The arms are tucked at the side, an endotracheal tube is positioned, and a Foley catheter is placed in the bladder.
The principles of laparoscopic surgery are the same as those of laparotomy: there must be adequate exposure, identification of the anatomy, and removal of the appropriate tissue.
Trocar placement — The first trocar is inserted into the umbilicus if the patient has not had a previous midline incision. If there is a midline scar, then the left upper quadrant is insufflated and a 5 mm trocar inserted. The left upper quadrant approach for patients with previous midline incisions allows the laparoscope to be placed away from possible adhesions that can then be dissected from the umbilicus before placing a second, 10 mm trocar.
Additional trocars are then positioned in the right and left lower quadrants and in the suprapubic area (show picture 2). A laparoscope in the suprapubic port site can help with packing the bowel or in dissecting adhesions from around the umbilical port.
Exposure — The bowel is carefully packed into the upper abdomen so that adequate exposure of the paraaortic area and pelvis can be obtained. Sponges or minilaparotomy packs can be placed around loops of bowel to aid in exposure and to blot small amounts of blood.
Lymphadenectomy — The lymphadenectomies are best performed by the surgeon on the side opposite the side of dissection (eg, the surgeon on the patient's right side dissects the left pelvic lymph nodes). For endometrial cancer, a partial lymphadenectomy (lymph node sampling) is performed: the lymph nodes removed are those medial to the external iliac and superior to the obturator nerve. For cervical cancer, a complete lymphadenectomy is performed, including the lymph nodes between the iliac vessels and the psoas muscle, and the obturator space is dissected in its entirety.
Paraaortic nodes — The paraaortic lymphadenectomy is usually performed first. The landmarks are usually the reflection of the duodenum and inferior mesenteric vessel superiorly and the psoas muscles laterally. The ureter must be identified and placed on traction by the assistant to keep it out of the operative field. Both the right- and left-sided aortic lymph nodes are sampled. Variations in vascular anatomy are not uncommon in this area; awareness of these variants and cautious dissection is advised to avoid vascular complications [35].
The peritoneum is incised between the sigmoid mesentery and the mesentery of the cecum (show picture 3). The paraaortic lymph node chain is isolated and dissected using either monopolar surgery, bipolar surgery, harmonic scalpel, or the argon beam coagulator (show picture 4A-G).
Common iliac nodes — The proximal common iliac lymph nodes are dissected through a retroperitoneal incision extending from the paraaortic lymph nodes down to the middle common iliac lymph nodes (show picture 5). The remaining common iliac lymph nodes are dissected through the incision for the pelvic lymphadenectomy.
Pelvic nodes — The pelvic lymph nodes are exposed by dividing the round ligaments and retracting the obliterated umbilical artery medially, thus opening the entire lateral pelvic space (show picture 6A-C).
The disease (cervical or endometrial cancer) and clinical circumstances determine the extent of the pelvic lymphadenectomy, as discussed above. To perform pelvic lymph node sampling, the lymph nodes are removed medial to the external iliac and anterior to the obturator nerve (show picture 7A-E). For a complete lymphadenectomy, the lymph nodes are also removed from between the iliac vessels and the psoas muscle, and from the obturator fossa (show picture 8A-E).
Closure — All port sites 10 mm or larger should have the fascia and peritoneal layers closed to prevent herniation of bowel. Smaller peritoneal incisions are left open. Several instruments are available that pass the suture through the skin incision lateral to the port and back up on the opposite side to create a one layer closure. A local anesthetic is injected around the port sites to decrease postoperative pain. Drains are not used.
POSTOPERATIVE MANAGEMENT — Patients are given liquids the day of surgery and the diet is advanced rapidly. Early ambulation is encouraged. The patient's progress is usually rapid with discharge within one or two days.
COMPLICATIONS — The complication rate in large case series varies from 1 to 12 percent [36].
Adynamic ileus is unusual after laparoscopic surgery. Abdominal distention, worsening of pain, or vomiting must be taken seriously as these symptoms could be due to a bowel injury. The carbon dioxide used for insufflation should be absorbed within hours, so any free air on x-ray of the abdomen is highly suspicious of perforation. Vascular and urinary tract injuries can also occur. (See "Overview of gynecologic laparoscopic surgery" section on Complications).
Complications of laparoscopy for malignant disease are higher than for benign disease, and include port site metastasis [37]. The rate depends upon the type of case, whether there had been previous pelvic surgery or adhesive disease (eg, endometriosis, pelvic inflammatory disease), and the experience of the surgeon.
Data on complication rates from laparoscopic lymphadenectomy are inadequate due to small sample sizes, lack of adjustment for a learning curve, and confounding by combinations of and differences in procedures [38-40]. Postoperative complications of wound infection, ileus, and fever occur, but at lower rates than after laparotomy. Herniation of omentum or bowel into the trocar sites is a complication unique to laparoscopy and occurred in 0.17 percent of 3560 laparoscopic operations in one series [41]. In another study of 19 cases of postlaparoscopy herniation from 11 institutions, no patient had a hernia through a port site smaller than 10 cm; therefore, it is recommended that all port sites greater than 10 mm be closed [42]. Conversion to open laparotomy is necessary in fewer than 10 percent of cases [36,43,44]. The most common reasons are obesity, bleeding, adhesions and intraperitoneal disease [39,44]. A series including 1000 patients reported postoperative lymphocyst formation in 7 percent; significant vascular, bowel, or urinary tract injury occurred in fewer than 1 percent of patients [36].
The skills to manage gynecologic malignancies by laparoscopic techniques are acquired through a commitment on the surgeon's part to learn the technique. It requires up-to-date equipment and a team familiar with the procedures. Hands-on experience in an animal laboratory and proctored learning in the operating suite are highly recommended.
SUMMARY AND RECOMMENDATIONS The advantages of the laparoscopic approach to lymphadenectomy are a decrease in operative time, less blood loss, shorter hospital stay, and reduction in total cost. These benefits are most meaningful if subsequent laparotomy for treatment of the gynecologic malignancy is also avoided. Laparoscopic lymphadenectomy is most commonly used for enhanced staging of cervical cancer and for staging endometrial cancer. The skills to manage gynecologic malignancies by laparoscopic techniques require up-to-date equipment, hands-on experience in an animal laboratory, proctored learning, and an operating team familiar with the procedures. We suggest placing patients on a clear liquid diet the day before the surgical procedure and evacuating the bowel using magnesium citrate or Go-Lytely. This collapses the bowel, making it less likely to obstruct the operative field. All port sites 10 mm or larger should have the fascia and peritoneal layers closed to prevent herniation of bowel.

No comments: