Pelvic Exenteration
Kenneth D. Hatch
GENERAL PRINCIPLES
Definition
Pelvic exenteration refers to the radical resection of the uterus, tubes, ovaries, cervix, and vagina, along with the bladder and ureters, and portions of the rectosigmoid or anus. It is most often used in an attempt to cure a patient with localized recurrent or persistent cancer of the cervix following chemoradiation therapy. It is also indicated for persistent cancer of the endometrium, or cancer of the vulva and vagina. The disease must be localized to the pelvic structures and the patient is not a candidate for further curative radiation therapy. The patient must have biopsyproven cancer which has been reviewed and confirmed by the institution’s gynecologic oncology pathologist.
Differential Diagnosis
Radiation necrosis may mimic recurrent cervical cancer. The area where the cervical tumor was at initial presentation may cavitate and then form an inflammatory and fibrotic area around it. Anaerobic bacteria invade and give significant odor and further tissue destruction. Bladder and rectal fistulae may occur.
Give 2 weeks of metronidazole and ciprofloxacin and then perform an examination under anesthesia with cystoscopy and proctoscopy. Deep biopsies should be taken to get through the necrosis to the edge of viable tissue. This may require needle biopsies deep into the parametrium.
After the phase of radiation necrosis is passed (3 to 12 months), surveillance examinations may find an enlarged uterus. Uterine sarcoma should be considered. Needle biopsies as above may make the diagnosis.
A fluid-filled uterine cavity may mimic a recurrence. This occurs when the cervix is completely stenotic and some of the endometrium is still able to produce fluid. Needle aspiration is usually possible and the cytology or histology will guide further treatment.
Cancer of the endometrium can occur in this setting. A simple hysterectomy may result in a vesicovaginal fistula and the patient should be informed of this possible complication.
Anatomy
Total pelvic exenteration refers to removal of the uterus, tubes, ovaries, parametrium, bladder, rectum, anus, vagina, urethra, and a portion of the levator muscles (Fig. 23.1).
If the anus and lower rectum are spared for a low rectal anastomosis, it is called a supralevator total exenteration (Fig. 23.2).
Anterior exenteration refers to removal of the internal reproductive organs and the bladder, with or without the urethra (Fig. 23.3).
Posterior exenteration is removal of the uterus, tubes, ovaries, cervix, and a portion of the posterior vagina along with the rectum. It may be used for recurrent locally advanced cancer
of the cervix, vulva, or vagina which extends primarily to the rectum and/or anus.
Figure 23.1. A total pelvic exenteration is indicated for disease in the lower third of the posterior vagina. It includes resection of the levator muscles and the anus.
Figure 23.2. A supralevator total exenteration preserves the levators and anus along with a variable length of rectum. It may be performed when the disease does not extend to the lower vagina or rectum.
Figure 23.3. An anterior exenteration is performed for disease confined to the cervix and anterior vagina. Some posterior vagina can be removed but the rectum is preserved.
A posterior exenteration is rarely performed for the indications above. It is most often performed during primary debulking of ovarian cancers with deep infiltration of the rectosigmoid. In this instance, the anus is routinely preserved.
There is no “standard” exenteration. The choice of procedure is based upon the location of the cancer, difficulties that may arise during surgery, type, and location of previous radiotherapy, anatomy, and the patient’s postoperative goals and expectations.
The original pelvic exenteration performed by Brunswig at Memorial Sloan Kettering Cancer Center was a total pelvic exenteration with a perineal phase removing the entire vagina and anus.
An anterior exenteration has less morbidity and mortality with a higher overall survival in patients with central tumors 3 cm or less, no extension to the bladder or rectum, and recurrence after radiation therapy greater than 1 year.
A supralevator exenteration with low rectal anastomosis performed for larger lesions or spread to rectum and bladder has comparable survival to anterior exenteration.
The terminology of pelvic exenteration changed as the operations were tailored to remove the tumor and only those organs that were involved.
Nonoperative Management
When a patient has recurrent cancer after standard radiation, it is not possible to give more radiation therapy.
Chemotherapy is not curative.
IMAGING
The search for metastatic disease is imperative. The physical examination should include careful palpation of the peripheral lymph nodes and fine-needle aspiration (FNA) cytologic analysis if any suspicious nodes are found. Particular attention should be paid to the groin and supraclavicular nodes.
The use of imaging has decreased the number of “no go” explorations for pelvic exenteration. Lai and colleagues in Taipei evaluated the PET scan for the restaging of cervical carcinoma at the time of first recurrence. Forty patients had a PET scan, together with computed tomography (CT) or magnetic resonance imaging (MRI). PET was significantly superior to CT/MRI (sensitivity = 92% vs. 60%; p <0.0001) in identifying metastatic lesions. When compared with an earlier cohort of patients who did not undergo restaging with PET, there was a significantly better 2-year overall survival (72% vs. 36%; p = 0.02).
Husain et al. used FDG PET to determine metastatic disease prior to pelvic exenteration or radical resection in 27 patients with recurrent cervical or vaginal cancers. They found that FDG PET had a high sensitivity (100%) and a specificity of 73% in detecting sites of extrapelvic metastasis. PET/CT replaced CT scans for identification of metastasis outside the pelvis. The high sensitivity of the PET/CT scan for metastatic disease may allow the clinician to perform needle-guided biopsies or minimally invasive procedures to confirm the metastatic disease and avoid an abandoned exenteration attempt. On the other hand, the 70% to 80% specificity requires that patients undergo exploration if the minimally invasive techniques do not document metastatic disease.
Extension of the tumor to the pelvic sidewall is a contraindication to exenteration; however, this may be difficult for even the most experienced examiner to determine because of radiation fibrosis. MRI was evaluated for preoperative assessment of candidates for pelvic exenteration. Twenty-three patients were evaluated before pelvic exenteration for presence and location of the recurrent tumor. In four patients (17.4%), the MRI was falsely positive for pelvic sidewall infiltration and in one patient (4.3%), it was falsely negative on the sidewall disease. More experience with MRI is needed before being able to rely on it to exclude the patient from exenteration.
The role of PET/CT in detecting the extent of pelvic recurrence was recently addressed by Burger and colleagues from Memorial Sloan Kettering Cancer Center. Thirty-one patients had PET/CT prior to a pelvic exenteration. Two readers blindly read the PET/CT to determine invasion of bladder, rectum, vagina, and pelvic sidewall. Pelvic sidewall involvement was found in five patients at the time of surgery and it was correctly identified in three cases by one reader and four cases by the other. Both readers had one false-positive case for pelvic sidewall involvement. Thus PET/CT was not effective in accurately detecting pelvic sidewall disease.
PREOPERATIVE PLANNING
The patient must be counseled extensively concerning the seriousness of the operation. She should be prepared to spend several days in the intensive care unit and have a prolonged hospitalization of up to several weeks. She must understand that her sexual function will be permanently altered and that she may have one or two stomas.
There is no guarantee of cure. The most difficult subject to discuss is the possibility that she may have unresectable disease and that the procedure will need to be abandoned.
The woman’s medical condition should be made optimal. Serious comorbidities such as coronary artery disease, diabetes, and chronic pulmonary disease should be evaluated and optimized.
If the woman is severely malnourished, total parenteral nutrition (TPN) may be started in advance of surgery. She is taught incentive spirometry preoperatively.
The sites for stoma are marked by the ostomy team prior to surgery, and checked when the woman sits, stands, and lies down. Care is taken to avoid skin creases, scars, and the site where the woman normally wears her belt and elastic waistband.
A mechanical bowel preparation is given with intravenous fluids started at the same time to avoid dehydration. Patients may remain NPO (nothing by mouth) for extended periods postoperatively.
If the patient has not had TPN started prior to surgery, a central line can be placed in the operating room, and TPN started when the patient is stable from the blood loss and fluid shifts. Central lines with multiple ports facilitate postoperative fluid management. Four units of packed red blood cells (PRBC) are ordered.
SURGICAL MANAGEMENT
Positioning
The patient is placed in the low lithotomy position. This allows for two teams to operate when the vaginal and perineal portion of the operation is reached.
It allows for placement of the circular stapler through the anus to accomplish a low rectal anastomosis and vaginal reconstruction is easier.
Pneumatic compression devices are placed on the calves for DVT prophylaxis. A nasogastric tube is placed. Good venous access is necessary in case of rapid blood loss and an arterial line is placed. A central line is helpful for postoperative fluid shift management. When the operation is deemed a “go,” then the central line is placed.
PROCEDURES AND TECHNIQUES
Pelvic Exenteration
Exploration
A midline incision around the umbilicus is made. The upper abdomen is explored. If a paraaortic node dissection has not been done for past treatment or staging, then this should be performed.
The pelvis is inspected for any breakthrough of the tumor into the peritoneal cavity. This would be a contraindication to completing the exenteration.
The lateral pelvic retroperitoneal spaces are opened. Any enlarged lymph nodes are removed for frozen section. Pelvic node dissection is not mandatory. Extensive radiation fibrosis may preclude developing tissue planes between the nodes and vessels and lead to major bleeding. Such fibrotic nodes have a low risk of harboring metastatic disease.
The pararectal and paravesical spaces are developed on both sides and evaluated for the extent of disease. Biopsies can be taken of the pelvic sidewall to determine the presence or absence of cancer. Vaginal and rectal examination with a finger in the vagina and a finger in the rectum while the sterile abdominal hand is in the pararectal and paravesical space is very helpful in determining the resectability and later in the surgery assists in determining margins.
The Retzius space is opened next and if there is no fixation to the pubic arch the operation is declared a “go.”
More than one positive pelvic node, positive paraaortic nodes, peritoneal breakthrough of tumor, or tumor implants in the abdomen or pelvis should lead to abandonment of the operation.
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