NORIKO TANAKA, TAKUHITO TADA, MASAHIRO TOKUNAGA et al. Small-bowel Obstruction due to Pouch-type Internal Hernia through a Defect in the Broad Ligament of the Uterus Diagnosed with Multidetector Computed Tomography: A Case Report. Osaka City Medical Journal. 2017, 63, 111-115

Small-bowel Obstruction due to Pouch-type Internal Hernia through a Defect in the Broad Ligament of

the Uterus Diagnosed with Multidetector Computed Tomography: A Case Report

NORIKO TANAKA, TAKUHITO TADA, MASAHIRO TOKUNAGA,

MASARU MAKIHARA, TAKESHI SUNAMI, SATOSHI DOISHITA,

and TOHRU TAKESHITA

Citation Osaka City Medical Journal. Issue Date 2017-12

Type Journal Article Textversion Publisher

Right © Osaka City Medical Association. https://osakashi-igakukai.com/.

Placed on: Osaka City University Repository

Introduction　 Small-bowel obstruction (SBO) caused by internal hernia (IH) is uncommon, with a reported

incidence of up to 5.8% of all cases of SBO1). Furthermore, IH through a defect in the broad

ligament of the uterus, defined as a protrusion of an abdominal viscus through or into a defect in the

supporting structures of the uterus, is rare. Based on the degree of the defect, they can be classified

into two types, fenestra-type and pouch-type2).

　 Because of its post-processing techniques, multidetector computed tomography (MDCT) is

currently the first-line imaging modality for diagnosing various types of IH3-10). These post-processing

techniques include maximum-intensity and minimum-intensity projection, variable thickness

viewing, and volume and surface rendering, in addition to standard reformatting methods such as

sagittal, coronal, oblique, and curved reformatting11).

　 For fenestra-type IH, MDCT findings have been presented in several reports7-10). However, reports

of pouch-type IH are extremely rare. Here, we describe a case of SBO caused by pouch-type IH, for

Small-bowel Obstruction due to Pouch-type Internal Hernia through a Defect in the Broad Ligament of the Uterus Diagnosed

with Multidetector Computed Tomography: A Case Report

NORIKO TANAKA1), TAKUHITO TADA1), MASAHIRO TOKUNAGA1), MASARU MAKIHARA1),

TAKESHI SUNAMI2), SATOSHI DOISHITA3), and TOHRU TAKESHITA4)

Departments of Radiology1) and Surgery2), Izumi Municipal Hospital; Department of Diagnostic and Interventional Radiology3), Osaka City University Graduate School of Medicine; and Department of Radiology4),

Osaka Prefectural Medical Center for Respiratory and Allergic Diseases

Abstract　 Small-bowel obstruction due to internal hernia through a defect in the broad ligament of the uterus

is rare, and its clinical diagnosis is usually difficult because of the lack of specific symptoms. This

report presents a case of small-bowel obstruction due to pouch-type internal-hernia through a defect

in the broad ligament, for which multidetector computed tomography proved useful for preoperative

diagnosis. A herniated small-bowel loop appearing as a “sac-like mass” was considered diagnostic for

distinguishing the pouch-type internal hernia from the fenestra-type internal hernia.

Key Words: Small-bowel obstruction; Internal hernia; Pouch-type; Fenestra-type;

Multidetector computed tomography

Received November 10, 2016; accepted April 18, 2017.Correspondence to: Noriko Tanaka, MD.

Department of Radiology, Izumi Municipal Hospital, Fuchucho 4-10-10, Izumi, Osaka, 594-0071, JapanTel: +81-725-41-1331;　Fax: +81-725-43-3350E-mail: mqfwk775@ybb.ne.jp

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Osaka City Med. J. Vol. 63, 111-115, 2017

which a preoperative diagnosis was obtained using MDCT.

Case Report　 A 49-year-old woman was admitted to our institution with a complaint of severe lower abdominal

pain that started during the morning. Before onset of pain, she had suffered from constipation and

nausea for 4 days and 3 days, respectively. She did not have vomiting or the diarrhea. She had been

in good health prior to admission except for an appendectomy due to appendicitis at the age of 22

years. She was gravida 2, para 2, and had a history of two normal vaginal deliveries.

　 Physical examination revealed abdominal distention with tenderness in the left pelvis, without

bowel sounds. No fever was noted. Laboratory test results were within normal limits, including no

leukocytosis (white blood cells, 5100/μL; neutrophils, 70.1%), and negative C-reactive protein (0.03

mg/dL). Abdominal radiography showed multiple dilated small-bowel loops (not shown). Contrast-

enhanced CT of the abdomen and pelvis was immediately performed using a 16-row MDCT scanner

(Aquilion 16, TOSHIBA, Tokyo, Japan). MDCT showed multiple dilated fluid-filled loops of the

proximal small-bowel and collapsed distal ileum, which was consistent with mechanical SBO.

　 In the pelvic cavity, encapsulated small-bowel with air-fluid was observed as a “sac-like mass” on

the left side of the uterus (Figs. 1, 2, and 3). Within this sac-like mass, crowded mesenteric fat tissue

and vessels were seen as a radial form converging toward the ventral side. Proximal and distal

transition points were identified on the ventral side of the sac-like mass, adjacent to one another,

suggestive of closed-loop SBO (Figs. 1 and 2). At the apex of the sac-like mass, a band-like structure

between the uterus and the left ovary corresponding to the left fallopian tube was stretched and

displaced ventrally (Figs. 1 and 2). Widening of the distance between the uterus and the left ovary

was also noted (Fig. 2). Based on these MDCT findings, a diagnosis of SBO due to IH through a

defect in the left broad ligament, and in particular the pouch-type, was made.

　 Subseqently, emergency surgery was performed. During surgery, the adhesion was not identified

in abdominal cavity. A moderate quantity of yellow serous ascites was identified. Dilatation of

Figure 1. Contrast-enhanced axial MDCT image shows a sac-like cluster of dilated small-bowel with air-fluid level (white arrows) on the left side of the uterus. The left fallopian tube (black arrows) is observed as a band-like structure. MDCT, multidetector computed tomography.

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Tanaka et al

the proximal small-bowel was observed. A 10-cm long ileal loop, which was 30-cm proximal from

the terminal ileum, had herniated through an 8-mm aperture in the anterior leaf of the left broad

ligament (Fig. 4), and was entrapped between the anterior and posterior leaves of the broad ligament

located in the parametrial tissue. Because the entrapped bowel loop could not be liberated, the hernial

orifice was enlarged by a diameter of 7-mm. Then, traction and repositioning of the entrapped bowel

loop were performed. The herniated bowel loop had initially appeared congested, but its color and

peristalsis improved rapidly. No bowel resection was required and the defect was closed to prevent

relapse. The postoperative course was uneventful, and the patient was discharged on postoperative

day 10.

Figure 2. Contrast-enhanced coronal MDCT images are presented from the ventral side a) to the dorsal side c).a) The small-bowel loops with mesenteric fat tissue and vessels (open arrow) have herniated into a defect in the left

broad ligament.b) The herniated small-bowel loops (white arrows) are observed as a “sac-like mass” on the left side of the uterus (U).

The left fallopian tube (black arrows) is stretched and displaced superiorly.c) Widening of the distance between the uterus (U) and the left ovary (white arrowhead) is also noted.MDCT, multidetector computed tomography.

Figure 3. Contrast-enhanced reformatted sagittal MDCT image clearly depicts the encapsulation of the herniated small-bowel loop, as a “sac-like mass” (white arrows). MDCT, multidetector computed tomography.

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Small-bowel Obstruction due to Pouch-type Internal Hernia through a Defect in the Broad Ligament of the Uterus

Discussion　 IH through a defect in the broad ligament is rare, accounting for only 4%-7% of all cases of

IH7-10). According to a report by Baron12), the first case of this type of IH was reported in 1861 during

an autopsy by Quain. Since then, approximately 200 cases have been reported in the English and

Japanese medical literature including both the fenestra-type and the pouch-type13,14). The fenestra-

type is defined as herniation of an abdominal viscus through a full-thickness defect in the broad

ligament. This type involves both the anterior and posterior leaves of the broad ligament, with

no hernial sac. Thus, the herniated viscus is located outside the parametrial tissue, in the pelvic

peritoneum. On the other hand, the pouch-type is defined as herniation of an abdominal viscus

through a defect in only one leaf in the broad ligament. With this type, either the anterior or the

posterior leaf is involved. The hernia sac is the broad ligament itself. The herniated viscus enters

the parametrial tissue and gets trapped in it.

　 MDCT has proven to be useful in the preoperative diagnosis of various types of IH3-10). Its findings

of fenestra-type IH through a defect in the broad ligament have been reported as follows7-10): 1)

mechanical SBO with a double transition zone (closed-loop SBO) located lateral to the uterus; 2)

a cluster of dilated fluid-filled small-bowel loops in the pelvic cavity; 3) displacement of the uterus

to the contralateral side, displacement of the ipsilateral fallopian tube ventrally, and displacement

of the rectosigmoid colon dorsolaterally by the herniated small-bowel loops; and 4) widening of the

distance between the uterus and ipsilateral ovary. These findings were also observed in the present

pouch-type case, with the exception that no displacement of the uterus or rectosigmoid colon by the

herniated small-bowel loops was recognized.

　 In this case, the most impressive finding was that the herniated small-bowel loop appeared as

a sac-like mass. Such an appearance is only seen when the herniated small-bowel loops lie within

a small enclosed space6). In the present case, this finding indicated that the hernial sac was lying

within the broad ligament itself and that the contents were trapped in the parametrial tissue. This

finding was considered diagnostic for distinguishing pouch-type IH from fenestra-type IH.

　 Differential diagnoses for IH through a defect in the broad ligament may indicate sigmoid

Figure 4. Intraoperative photographs are presented.a) An ileal loop, which was 30-cm proximal from the terminal ileum, has herniated through an aperture in the anterior

leaf of the left broad ligament (BL).b) The defect in the anterior leaf of the left BL is seen. This defect was enlarged by a diameter of 7-mm for traction

and repositioning of the entrapped bowel loop.

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Tanaka et al

mesocolon hernia, IH through a peritoneal defect in the pouch of Douglas, and internal supravesical

hernia15-16). The key to differentiating these hernias is to identify the hernial orifice: the orifice of

sigmoid mesocolon hernia is located in the sigmoid mesocolon itself or near the root of the sigmoid

mesocolon, whereas that of IH through a peritoneal defect in the pouch of Douglas is located in the

pelvic floor, and that of supravesical hernia is the supravesical fossa. Furthermore, when a patient

has a history of abdominal or pelvic surgery, SBO due to a fibrous band around the uterus should be

considered among the differential diagnoses.

　 In conclusion, we encountered a case of SBO due to pouch-type IH through a defect in the broad

ligament. During preoperative diagnosis, MDCT provided several useful findings suggesting this

extremely rare disease. A herniated small-bowel loop appearing as a “sac-like mass” was considered

the diagnostic key for distinguishing pouch-type IH from fenestra-type IH. Therefore when clinical

manifestations and abdominal radiography suggest SBO, MDCT is recommended.

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Small-bowel Obstruction due to Pouch-type Internal Hernia through a Defect in the Broad Ligament of the Uterus