Prediction of Findings at Defecography in Patients with Genital Prolapse

Abstract

This study was designed to investigate the ability of defecography to identify abnormalities of the anterior and posterior compartments that might be associated with genital prolapse and require repair during prolapse surgery. Defecography is a technique that assesses the defecation process by recording the expulsion of a barium paste used as a substitute for feces. Study subjects were 82 patients with descensus uteri stages 2-4 who were enrolled in a trial comparing vaginal and abdominal prolapse surgery. All patients underwent a preoperative evaluation, including urogynecologic interview, physical examination, an assessment of genital prolapse using the Pelvic Organ Prolapse Quantification System (POP-Q), and a rectal examination. In addition, 1 to 3 weeks before surgery, study subjects completed a questionnaire about defecation and micturition symptoms. One to 3 months before surgery, defecography was performed according to standard techniques. The rectum is filled with barium paste, which is expelled while the patient is sitting on a radiolucent commode. The process of defecation is recorded on video. The results of defecography were analyzed by 2 physicians and were considered abnormal when an enterocele or rectal intussusception was identified. In this study, an enterocele was defined as a peritoneal sac that is herniated along the anterior rectal wall below the vaginal apex. A rectal intussusception was defined as the presence of a ring pocket formed by the rectal wall folding in toward the rectal lumen. The results of preoperative evaluation, including physical findings at pelvic examination, reported defecation and micturition symptoms, and patient history, were examined for their ability to predict the presence of abnormalities in defecography. Abnormal defecography results were seen in 26 (32%) of the 82 study subjects. Both an enterocele and rectal intussusception were found in 6 (7%) patients. Univariate analysis was performed of variables associated with the presence of rectocele or rectal intussusception, including details of the patient's medical history, results of genital prolapse assessment, and reported defecation and micturition symptoms. A history of pelvic surgery, the degree of genital prolapse as measured by POP-Q (Ap), and a history of constipation emerged as predictors of abnormal defecography. The results were similar after multivariate analysis. Using these 3 variables, the authors developed a model for predicting an abnormal defecography. With the model, a score is assigned to each variable and the total computed using the formula: 3 + 3 X history of abdominal or pelvic surgery + Ap (in centimeters) + 3 X constipation. As an example, for an imaginary patient with no history of pelvic surgery, with a rectocele descending to 1 cm above the hymen (Ap = -1 cm), who reports constipation, the formula would give a score of(3+3×0+-1+3×1). Table 1 shows the results from this series of patients using this model.