Internal hernia with small bowel obstruction caused by Meckel's diverticulum: A case report

Abstract

We report a case of small bowel obstruction (SBO) caused by internal hernia from Meckel's diverticulum (MD). Abdominal CT scan showed an abnormal dilated blind-ending structure in continuity with the distal ileum in the right lower quadrant, suggesting Meckel's diverticulum. MPR images revealed a “double beak-sign” at the point of MD and a collapsed closed loop with mesenteric vessels converging to the diverticulum. Since the patient has no prior history of abdominal surgery, the diagnosis of internal hernia caused by Meckel's diverticulum was considered. On laparoscopic exploration, an abnormal orifice for internal hernia created by adhesion from the tip of Meckel's diverticulum to the adjacent mesentery was revealed, confirming the diagnosis. The patient was discharged after 7 days without postoperative complications. MD-associated internal hernia is a rare cause of small bowel obstruction and should be considered to avoid delay in treatment. Multidetector Computed Tomography (MDCT) is the first-line imaging modality of choice and may offer some suggestive imaging features to make an accurate preoperative diagnosis.

Introduction

Internal hernia caused by Meckel's diverticulum is relatively rare. This condition is a surgery emergency because of the possibility of strangulation and ischemia of the herniated loops. An accurate diagnosis is imperative for proper treatment. However, clinical diagnosis of internal hernia caused by MD is difficult because of their nonspecific signs and symptoms [[1], [2], [3], [4], [5], [6], [7]]. This report describes a case of small bowel obstruction (SBO) caused by an internal hernia from the adhesion of a Meckel's diverticulum to adjacent mesentery, which was diagnosed by MDCT and confirmed during laparoscopic surgery.

Case-report

A 42-year-old male presented to the emergency department with intermittent abdominal pain, nausea, and vomiting over the past 24 hours. Physical examination revealed abdominal distension, tenderness in the right lower quadrant, and hyperactive bowel sounds. Laboratory tests showed no abnormalities. A plain abdominal film revealed multiple air-fluid levels, indicating a small bowel obstruction. Abdominal CT scan showed widespread dilatation of small intestinal loops with fluid accumulation. An abnormal dilated blind-ending structure in continuity with the distal ileum was seen in the right lower quadrant, suggesting Meckel's diverticulum (Fig. 1). This structure raised the possibility of MD-related SBO because it was located at the transitional point between the dilated and collapsed loops. On closer inspection of MPR images, CT scan revealed a “double beak- sign” at the point of MD and a collapsed closed-loop with mesenteric vessels converging to the diverticulum (Fig. 2). A diagnosis of closed-loop obstruction due to Meckel's diverticulum was established. Since the patient has no prior history of abdominal surgery, the diagnosis of internal hernia caused by Meckel's diverticulum was considered. No signs of necrosis or ischemia were observed on CT.

Fig. 1.

CT appearance of Meckel's diverticulum. Axial CT image (A) shows Meckel's diverticulum (asterisk) as a dilated blind-ending structure in the right lower quadrant. Sagittal MPR image (B) shows the continuity between the diverticulum (asterisk) and distal ileum.

Fig. 2.

Closed-loop obstruction. Axial image (A) shows a “double beak sign” (arrow) at the point of Meckel's diverticulum (asterisk). MPR image (B) shows a closed loop (arrows) with mesenteric vessels converging (circle) to the Meckel's diverticulum (asterisk).

Laparoscopic exploration confirmed the presence of a Meckel's diverticulum 60 cm from the ileocecal valve. The tip of the diverticulum was adhered to the adjacent mesentery, forming a narrow ring through which a small bowel loop herniated and became obstructed (Fig. 3). Surgical intervention included adhesiolysis and resection of the Meckel's diverticulum, allowing for the release of the obstructed bowel. The herniated loop was manually reduced and the patient recovered without complications, being discharged after 7 days.

Fig. 3.

Laparoscopic exploration confirmed the diagnosis of internal hernia caused by Meckel's diverticulum. The tip of the diverticulum (arrow) was adhered to the adjacent mesentery, forming a narrow ring through which a small bowel loop (asterisk) herniated and became obstructed.

Discussion

Meckel diverticulum is the most common congenital anomaly of the gastrointestinal tract, resulting from improper closure and absorption of the omphalomesenteric duct. Classically, its features are described by “the rule of 2s” as 2 feet from the ileocecal valve, 2 inches in diameter, and 2 inches long. Meckel's diverticulum occurs in about 2 to 3% of the population, with equal frequency in both sexes. In the majority of patients, Meckel diverticulum is asymptomatic and usually detected due to its complications including gastrointestinal bleeding, diverticulitis, perforation, neoplasm, and intestinal obstruction. Small bowel obstruction due to Meckel's diverticulum-related internal hernia is relatively rare [8].

There are several mechanisms for SBO secondary to a MD-associated internal hernia. First, bowel loops may cause hernia through a defect in the mesentery of a Meckel's diverticulum [3]. Second, a mesodiverticular band, an embryologic remnant of the vitelline circulation, extends from Meckel's diverticulum to the adjacent mesentery, creating a narrow opening through which bowel loops may herniate and become obstructed [6,9,10]. Third, as seen in this case, repeated inflammation can cause adhesion between the tip of Meckel's diverticulum and adjacent mesentery, forming an abnormal orifice for internal hernia.

CT is the primary imaging method used to evaluate patients with SBO. It helps determine whether there is an obstruction, its location, cause, and any associated complications. Since clinical diagnosis of internal hernia with SBO can be challenging, abdominal CT plays a crucial role in making an accurate and prompt diagnosis. Some key CT findings of internal hernia include the clustering of the intestine in a sac-like appearance in case of intramesenteric or pouch-type hernia, the presence of a closed loop or a cluster of small bowel loops in an abnormal location, converging mesenteric vessels at the hernia orifice, abnormal displacement of surrounding structures around the hernia orifice or hernia sac [11,12].

However, the radiology literature rarely discusses CT features of Meckel's diverticulum-related internal hernia, making it challenging for radiologists to diagnose accurately. Identifying Meckel's diverticulum is crucial for diagnosing MD-related internal hernia. On CT scans, Meckel's diverticulum can look like a normal bowel loop in uncomplicated cases, or it may be hard to be identified due to other conditions such as intussusception, volvulus, diverticulitis, foreign body impaction, or small bowel obstruction. High-resolution MDCT scans with multiplanar reconstruction images can clearly show Meckel's diverticulum. Typically, Meckel's diverticulum appears as a blind-end tubular segment or diverticular sac that arises from the antimesenteric side of the distal ileum and contains fluid, enterolith, or fecal-like content [13]. Like another type of internal hernia, small bowel obstruction caused by MD-related internal hernia is a closed-loop obstruction. Moreover, as seen in this case, herniated loops and their mesenteric vessels will converge to the point of Meckel's diverticulum because this diverticulum forms the hernial orifice. Therefore, CT findings of closed loop obstruction with ileal loops and mesenteric vessels of the obstructed loop converging to Meckel's diverticulum may be suggestive of making an accurate diagnosis.

Conclusion

The presence of Meckel's diverticulum can sometimes lead to internal hernia, which is an uncommon cause of acute abdominal pain. It is important to consider this possibility in patients with symptoms of intestinal obstruction, particularly if they do not have previous abdominal surgery. MDCT is usually the primary imaging method of choice and can provide some suggestive imaging features to make an accurate preoperative diagnosis.

Patient consent

I confirm that written informed consent has been obtained from the involved patient and they have given approval for this information to be published in this case report.