Palliative Pelvic Exenteration: Patient Selection and Results

Introduction

Total pelvic exenteration is a radical extirpative procedure designed to treat pelvic malignancy that has invaded more than one of the hollow organs of the genitourinary or gastrointestinal tracts. The early experience with exenterative surgery focused on cervical and rectal cancer [1-5]. The biologic characteristics of these tumors (ie, central pelvic growth in a locally advanced pattern without distant disease) permit the consideration of radical, extensive pelvic surgery. Other extensive or recurrent tumors that may be amenable to exenterative surgery are vaginal squamous- and clear-cell carcinoma; squamous-cell carcinoma of the vulva; endometrial carcinoma; leiomyosarcomas of the vagina, cervix, and uterus; melanoma of the vagina or vulva; and Bartholin gland tumors [6]. Less favorable cancers are ovarian, prostate, and bladder carcinomas, because of their tendency toward widespread hematogenous metastases in the presence of limited primary tumor growth.

Bulky pelvic malignancy is notorious for the production of disabling symptoms. Pain, infection, bleeding, obstruction, and fistula formation are the most serious consequences of uncontrolled local tumor growth. The goal of treatment in the initial widespread application of pelvic exenterative surgery was palliation of these symptoms in patients who had either failed to respond to or were not candidates for conventional therapy [1]. Institutional operative mortality as high as 33% was reported in these early series. Morbidity was also significant, and postoperative recovery was often long and arduous.

Nevertheless, the operation was considered beneficial with regard to relieving symptoms in patients with limited options. As reported by Brunschwig: "Because of the advanced stage of their disease, it is not to be anticipated that many, if any, of these patients will survive for very prolonged periods....On the other hand, of those surviving at this writing, not one has expressed the feeling that they would have preferred to have remained as they were and not to have had the operation [1]."

As more of these procedures were performed and longer follow-up was reported, it became apparent that some carefully selected patients were long-term survivors after pelvic exenteration. Five-year survival rates after radical pelvic surgery for gynecologic malignancy approached 60%7-10 and were as high as 50% [11-14] for some patients with locally advanced primary colorectal cancer.

Despite favorable results in some patients, the recognized morbidity and mortality associated with exenterative surgery added to the controversy surrounding its use as a palliative procedure, and strict guidelines were established to select those patients who were most likely to benefit from this procedure. These criteria include an exhaustive preoperative and operative evaluation to ensure the absence of extrapelvic spread of disease, as well as to assess pelvic bones, muscles, major nerves, and blood vessels for extent of cancer involvement. An assessment of the patient's underlying physical and psychiatric condition, with consideration of malnutrition, sepsis, obesity, advanced age, or inadequate cardiopulmonary reserve, also should be carried out before the final decision about whether to perform a palliative pelvic exenteration is made [15]. As with many technically demanding procedures, a learning curve has been identified for radical pelvic surgery. The literature following the institutional experience with pelvic exenteration over the past 47 years has demonstrated a dramatic decrease in mortality associated with this surgery. Since the early 1970s, reports of operative mortality of less than 5% have been published, and these types of statistics are becoming more common in the current literature [15-18].

Thus, although the value of radical pelvic surgery for the palliation of symptoms caused by pelvic malignancy continues to be a controversial issue [19], several institutions are reporting good results, with improvements in quality of life and reasonable associated operative morbidity and mortality. In this article, we will explore the definition of palliation in the context of radical pelvic surgery and the process of selecting appropriate patients for this type of surgery, as well as the expected results.

Three Definitions of Pelvic Exenteration

Radical pelvic surgery for palliation of local symptoms have been defined in three ways in the literature. The most obvious definition is based on intent. If an operation is embarked upon with the foreknowledge that all of the tumor cannot be removed, the objective of the operation is not cure, but rather palliation of the symptoms of local tumor growth. This definition may include patients with minimal distant metastases associated with uncontrolled local symptoms.

A second use of the term "palliative pelvic exenteration" relates to patients who undergo an operation with curative intent but intraoperatively have either known gross or microscopic disease left behind. This group includes patients who, after extensive operative dissection, are discovered to have invasion of the bony sacrum or pelvic sidewall.

A third definition found in the literature describes patients who have locally recurrent or persistent disease after having failed primary surgical, radiation, or chemotherapy for their pelvic malignancy. This includes patients who have a local recurrence after curative resection of a rectal cancer or recurrent cervical cancer after standard radiation or surgical treatment. These patients then undergo radical pelvic surgery as a form of salvage therapy and are often said to have undergone palliative pelvic exenteration following discovery and evaluation of locoregional pelvic recurrent disease.

All three of these definitions will be incorporated in the following discussion on patient selection and results.

Patient Selection

Virtually all patients who present for consideration of palliative pelvic exenteration have local symptoms. In general, asymptomatic tumors identified on screening evaluation are recognized earlier, are smaller, and are more amenable to standard local therapy, and rarely require radical pelvic surgery for initial local control. Most patients with bulky disease present with symptoms of pain often associated with gastrointestinal or urinary obstruction, fistulas, infection, or bleeding. These symptoms can often lead to severe disability and diminished quality of life.

All treatment options, including surgery, radiation therapy, and chemotherapy, must be considered in a multimod- ality approach. In general, chemotherapy has minimal impact on bulky pelvic disease [20]. It remains a last resort for patients who are not surgical candidates, and can be used alone or in combination with radiotherapy. Patients with severely disabling symptoms, however, rarely benefit from chemotherapy. Chemotherapy also is a difficult option for treating patients with localized pelvic sepsis secondary to complications of pelvic tumor.

In the palliative setting, radiotherapy can be used only in patients who have not been previously treated with pelvic radiation. Most patients with recurrent disease or bulky initial disease will have undergone pelvic radiation in the initial course of treatment. However, in individuals who are eligible for palliative radiation, symptoms of pain, tenesmus, bleeding, and discharge may have an initial favorable response to this treatment. Arnott reported a 75% response rate for the treatment of pain and a 60% response rate for the treatment of pelvic drainage in a select group of patients [21].

The duration of response to palliative radiation is usually quite limited, ranging from 3 to 6 months [22]. An enterocutaneous fistula, on the other hand, is rarely improved by radiotherapy and, indeed, may develop as a side effect of this treatment. In the palliative setting, radiation therapy is most appropriate for patients who have failed other attempts at local control and whose underlying medical condition or disease extent limits their anticipated life expectancy to a few months.