Gastrointestinal Radiol 17:79-80 (1992)
Gastrointestinal
Radiology ~c~ Springer-Verlag N e w York Inc. 1992
Patulous Rectum Extension into the Ischiorectal Fossa: CT Findings Jacov Bar-Ziv I and Albert Solomon 2 Department of Radiology, Hadassa Medical Center, Jerusalem; and 2 Division of Imaging, Tel-Aviv Medical Center and the Tel-Aviv University Sackler School of Medicine, Tel-Aviv, Israel
Abstract. Protrusion of the rectum with egress into the ischiorectal fossa was present on computed tomography (CT) in three elderly women. CT demonstration of such rectal redundancy in elderly women will avoid unnecessary bowel damage in the case of misguided clinical assessment of rectal pathology. Key words: fossa.
Rectum,
protrusion - - Ischiorectal
Hernias, particularly esophageal and inguinal, are regularly noted in computed tomographic (CT) scans of the abdomen and pelvis. Reference to a patulous rectum with protrusion of the redundant rectum into the ischiorectal fossa seems to have escaped attention in the literature. In the last 2 years three patients with such patulous rectums have come to our attention in the course of unrelated CT investigations.
Discussion The anatomy of the ischiorectal fossa is such that a potential gap exists between the sling attachment of the levator ani muscle and the obturator fascia. Normally, the levator ani arises from the pubic bone in front, the ischial spine behind, and the obturator fascia between these points. A potential gap occurs when the levator ani arises from a tendinous sling, which is attached only to bone in front and behind, and not to fascia at all. A hiatus then exists between this sling and the obturator fascia [1]. In parous women of advanced age the muscle fibers of the pelvic floor are subject to stretching and weakening. Lateral bulging of the rectum between the stretched weakened levator sling and the adjoining deep part of the external anal sphincter muscle would find easy egress to the immediately adjoining ischiorectal fossa (Fig. 1). The patulous rectum may be mistakenly identified as the rarely occurring perineal hernia [2]. The
Methods and Materials CT scans were performed with the Elscint 2400. One-centimeter-thick sections with 1-cm spacing at a scanning time of 2.1 s were obtained for both abdominal and pelvic regions. Each patient received 600-800 ml of an oral solution of 3% Telabrix (meglamine-ioxitalamate) at least 1 h prior to the examination. Intravenous contrast material was used routinely, unless contraindicated by a clinical history.
Address offprint requests to: Albert Solomon, M.D., Division of Imaging, Tel-Aviv Medical Center, Ichilov Hospital, 64 239 TelAviv, Israel
Fig. 1. Axial CT, prone view in a 74-year-old women, demonstrates redundant patulous rectum in the right ischiorectal fossa. Note associated subcutaneous neurofibromatous mass.
80
J. Bar-Ziv and A. Solomon: The Redundant Rectum
Fig. 2. CT in an 83-year-old woman demonstrates patulous rectum in the right ischiorectal fossa. Fig. 3. CT in an 81-year-old woman shows rectal content in the left ischiorectal fossa.
latter hernia may follow surgical procedures, such as perineal prostatectomy, abdominoperineal resection, or perineal exenteration for advanced pelvic cancer. Extremely more rarely, a perineal hernia may occur as a primary hernia. More common manifestations of a relaxed vaginal outlet due to childbirth are cystocoeles or rectocoeles. Palpating a patulous rectum in the region of the ischiorectal fossa may give rise to the misguided diagnosis of a cyst, lipoma, hematoma [3], or even rectal prolapse. As the correct surgical approach avoids the unnecessary risk of bowel damage, the complementary CT examination has much to offer the attendant physician. Segmental axial CT scans of the pelvis enable one to view the direction and continuity of the lateral bulge and descending extrusion of the rectum as
it finds its egress into the adjoining ischiorectal fossa (Figs. 2 and 3).
References 1. Lee McGregor A. The ischio-rectal fossa. In: Lee McGregor A, ed. A synopsis of surgical anatomy. Bristol: John Wright & Sons, 1957:96-99 2. Moschovitz AV. Perineal hernia. Surg Gynecol Obstet 1918;26:514-520 3. Hubbard AM, Egelhoff JC. Posterior perineal hernia presenting as a gluteal mass. Pediatr Radiol 1989;19:246
Received: February 26, 1991: accepted: March 29, 1991
Gastrointestinal
Radiology ~c~ Springer-Verlag N e w York Inc. 1992
Patulous Rectum Extension into the Ischiorectal Fossa: CT Findings Jacov Bar-Ziv I and Albert Solomon 2 Department of Radiology, Hadassa Medical Center, Jerusalem; and 2 Division of Imaging, Tel-Aviv Medical Center and the Tel-Aviv University Sackler School of Medicine, Tel-Aviv, Israel
Abstract. Protrusion of the rectum with egress into the ischiorectal fossa was present on computed tomography (CT) in three elderly women. CT demonstration of such rectal redundancy in elderly women will avoid unnecessary bowel damage in the case of misguided clinical assessment of rectal pathology. Key words: fossa.
Rectum,
protrusion - - Ischiorectal
Hernias, particularly esophageal and inguinal, are regularly noted in computed tomographic (CT) scans of the abdomen and pelvis. Reference to a patulous rectum with protrusion of the redundant rectum into the ischiorectal fossa seems to have escaped attention in the literature. In the last 2 years three patients with such patulous rectums have come to our attention in the course of unrelated CT investigations.
Discussion The anatomy of the ischiorectal fossa is such that a potential gap exists between the sling attachment of the levator ani muscle and the obturator fascia. Normally, the levator ani arises from the pubic bone in front, the ischial spine behind, and the obturator fascia between these points. A potential gap occurs when the levator ani arises from a tendinous sling, which is attached only to bone in front and behind, and not to fascia at all. A hiatus then exists between this sling and the obturator fascia [1]. In parous women of advanced age the muscle fibers of the pelvic floor are subject to stretching and weakening. Lateral bulging of the rectum between the stretched weakened levator sling and the adjoining deep part of the external anal sphincter muscle would find easy egress to the immediately adjoining ischiorectal fossa (Fig. 1). The patulous rectum may be mistakenly identified as the rarely occurring perineal hernia [2]. The
Methods and Materials CT scans were performed with the Elscint 2400. One-centimeter-thick sections with 1-cm spacing at a scanning time of 2.1 s were obtained for both abdominal and pelvic regions. Each patient received 600-800 ml of an oral solution of 3% Telabrix (meglamine-ioxitalamate) at least 1 h prior to the examination. Intravenous contrast material was used routinely, unless contraindicated by a clinical history.
Address offprint requests to: Albert Solomon, M.D., Division of Imaging, Tel-Aviv Medical Center, Ichilov Hospital, 64 239 TelAviv, Israel
Fig. 1. Axial CT, prone view in a 74-year-old women, demonstrates redundant patulous rectum in the right ischiorectal fossa. Note associated subcutaneous neurofibromatous mass.
80
J. Bar-Ziv and A. Solomon: The Redundant Rectum
Fig. 2. CT in an 83-year-old woman demonstrates patulous rectum in the right ischiorectal fossa. Fig. 3. CT in an 81-year-old woman shows rectal content in the left ischiorectal fossa.
latter hernia may follow surgical procedures, such as perineal prostatectomy, abdominoperineal resection, or perineal exenteration for advanced pelvic cancer. Extremely more rarely, a perineal hernia may occur as a primary hernia. More common manifestations of a relaxed vaginal outlet due to childbirth are cystocoeles or rectocoeles. Palpating a patulous rectum in the region of the ischiorectal fossa may give rise to the misguided diagnosis of a cyst, lipoma, hematoma [3], or even rectal prolapse. As the correct surgical approach avoids the unnecessary risk of bowel damage, the complementary CT examination has much to offer the attendant physician. Segmental axial CT scans of the pelvis enable one to view the direction and continuity of the lateral bulge and descending extrusion of the rectum as
it finds its egress into the adjoining ischiorectal fossa (Figs. 2 and 3).
References 1. Lee McGregor A. The ischio-rectal fossa. In: Lee McGregor A, ed. A synopsis of surgical anatomy. Bristol: John Wright & Sons, 1957:96-99 2. Moschovitz AV. Perineal hernia. Surg Gynecol Obstet 1918;26:514-520 3. Hubbard AM, Egelhoff JC. Posterior perineal hernia presenting as a gluteal mass. Pediatr Radiol 1989;19:246
Received: February 26, 1991: accepted: March 29, 1991
