Sonography of subfascial hematoma after cesarean delivery.

Subfascial hematoma is an important complication of cesarean delivery that has received little attention in the radiologic literature. It results from extraperitoneal hemorrhage within the prevesical space, posterior to the rectus muscles and transversalis fascia but anterior to the peritoneum and umbilicovesical fascia. Subfascial hematomas were found in 12 (38%) of 32 patients referred for sonographic evaluation of a fever or a fall in hemoglobin that occurred after a cesarean delivery. In all cases, sonography revealed cystic or complex masses of various sizes anterior to the bladder. The use of high-frequency, short-focus transducers often was necessary to recognize these superficial abnormalities. Seven of the 12 patients had concomitant bladder-flap hematomas between the lower uterine segment and posterior bladder margin. Of the five remaining patients with isolated subfascial hematomas, the sonograms on four were misinterpreted as showing bladder-flap hematomas. The other was diagnosed correctly. Distinction of subfascial hematomas from bladder-flap hematomas and superficial-wound hematomas must be made if surgical evacuation is contemplated.