CT EVALUATION OF PARARECTAL VARICES

Purpose: This study was undertaken to determine the prevalence of para rectal varices on CT scan in patients with portal hypertension and to see if dilatation of the inferior mesenteric vein (IMV) or the presenc e of pararectal varices on CT correlates with rectal varices noted on colonoscopy. Method: We reviewed 83 consecutive CT scans of the abdome n and pelvis performed in patients with portal hypertension. The size and prevalence of pararectal varices were determined. Correlation with colonoscopic and endoscopic reports was performed. The diameter of th e IMV was compared in those patients with pararectal varices with that in those patients without, as was the presence of esophageal varices. Results: Twenty patients (24%) had CT evidence of pararectal varices, ranging from 5 to 11 mm in diameter (mean 7.8 mm). Colonoscopic corre lation was available in 30 patients. Of these, 6 of 30 (20%) had parar ectal varices on CT and no rectal varices on colonoscopy, 3 of 30 (10% ) had pararectal varices on CT and rectal varices on colonoscopy, and 3 of 30 (10%) had net pararectal varices on CT but did have rectal var ices on colonoscopy. Endoscopic correlation (available in 48 patients) demonstrated esophageal varices in 88% of patients with rectal or par arectal varices and in 66% of patients without rectal or pararectal va rices (p = 0.170). The lMV was significantly larger in patients with p ararectal varices (mean diameter 7.5 mm, SD 2.3) as compared with thos e without (mean diameter 5.8 mm, SD 2.0) (p = 0.014). However, in pati ents with colonoscopically proven rectal varices, only two of six (33% ) had an IMV diameter of greater than or equal to 7 mm. Conclusion: in clusion of the pelvis on CT scans of patients with portal hypertension can yield further information about the presence and extent of parare ctal venous collaterals, which may be of particular importance in thos e patients requiring pelvic surgery. The presence of pararectal varice s on CT and the diameter of the IMV do not correlate with the presence of rectal varices on colonoscopy. Decompression of portal hypertensio n by rectal and pararectal varices does not result ina decreased incid ence of esophageal varices.