Congenital mesenteric absence of mid-gut with ileal volvulus: a case report

Abstract

Background

Transmesenteric hernia caused by mesenteric defects are rare causes of intestinal obstruction in children. Here, we report a rare mesenteric defect, which was completely mesenteric in absence, with the defect extending from the mesenteric root to the ascending colon.

Case presentation

A 4-year-old Han Chinese boy presented to the surgical emergency department with a 1-day history of abdominal pain and vomiting. An X-ray examination of the abdomen revealed intestinal obstruction. The patient was diagnosed with intestinal obstruction and was advised to undergo laparoscopy. Laparoscopy revealed a large mesenteric defect, with the defect extending from the mesenteric root to the ascending colon, and a single mesenteric vessel supplied the small intestine. The single mesenteric vessel passed along the small intestine and crossed with the distal ileum, which trapped the distal ileum, leading to intestinal obstruction. During surgery, the distal ileum was transected and reanastomosed in front of the mesenteric vessel to relieve the intestinal obstruction, and the mesenteric defect was closed to prevent mesenteric hiatal hernia. There was no recurrence of intestinal obstruction during the follow-up.

Conclusions

A complete mesenteric defect with ileal volvulus is a rare cause of intestinal obstruction. Prompt exploration based on clinical signs is mandatory to establish the diagnosis and provide immediate therapy. This can reduce morbidity and mortality in this rare life-threatening disease.

Background

Transmesenteric hernias caused by mesenteric defects are rare causes of intestinal obstruction in children, with an incidence of 0.6–5.8% [1, 2]. These hernias were first described by Rokitansky in 1836. The absence of a sac characterizes transmesenteric hernias, which occur when an intestinal loop enters the mesenteric defect [3], leading to intestinal obstruction, strangulation, gangrene, or chronic symptoms secondary to intermittent herniation. Mortality rates can reach as high as 45% [4]. The size of mesenteric defects causing transmesenteric hernia varies from 2 to 7 cm [1]. However, the relationship between the size of the mesenteric defect and intestinal incarceration remains unclear. In most cases, the mesenteric defect size is smaller (2–3 cm), and bowel incarceration often results in rapid ischemia and necrosis [5]. While minor defects can cause vascular constriction and gangrene, larger defects are generally associated with volvulus formation [6]. Some literature has reported large mesenteric defects with diameters exceeding 10 cm [6, 7]. However, the mesenteric defects described in these reports were significantly smaller than the one observed in our case. This study presents a rare mesenteric defect characterized by the absence of the mesentery, with the defect extending from the mesenteric root to the ascending colon (Fig. 1).

Fig. 1

Complete absence of the mesentery, with the terminal ileum trapped by its mesenteric vessels (arrow)

Case presentation

A 4-year-old Han Chinese boy was brought to the surgical emergency department with a 1-day history of abdominal pain and vomiting. The patient had no history of prior surgeries. On physical examination, abdominal distension, tenderness in the lower right abdomen, and excessive bowel sounds were noted. The patient’s vital signs were normal, including body temperature (36.8 °C), heart rate (80 beats per minute), respiratory rate (20 breaths per minute), and blood pressure (110/70 mmHg).

Laboratory tests revealed an elevated white blood cell (WBC) count of 16.49 × 10⁹/L (reference range: 4–10 × 10⁹/L) and a neutrophil proportion of 89% (reference range: 23–64%), while C-reactive protein (CRP) levels remained within the normal range. Abdominal ultrasound suggested acute appendicitis with a suspected internal hernia (Fig. 2a), and an abdominal X-ray confirmed intestinal obstruction (Fig. 2b).

Fig. 2

Findings from plain radiography and ultrasound. a Abdominal ultrasound revealed a “whirlpool”-like rotation of the small intestine in the right lower quadrant (arrow), suggestive of a possible internal hernia. b An upright abdominal radiograph demonstrated air fluid levels in the bowel, consistent with a diagnosis of intestinal obstruction

Although the patient’s vital signs were within normal limits, their clinical presentation—including abdominal distension, tenderness in the lower right abdomen, and increased bowel sounds—along with radiographic evidence of intestinal obstruction and ultrasound findings suggestive of an internal hernia strongly indicated a potential surgical emergency. In pediatric patients, particularly young children, intestinal obstruction can progress rapidly, leading to severe complications such as bowel ischemia or perforation if not promptly managed. Bostancı SA et al. reported a mortality rate of 15.5% in a study on intestinal malrotation in children, attributing this to the rapid progression of complications and delays in medical intervention [8]. Given these concerns, laparoscopic exploration was recommended for this patient.

The decision to proceed with laparoscopy without computed tomography (CT) was based on clinical judgment, as the patient’s symptoms and signs warranted immediate intervention. In many cases of suspected intestinal obstruction in children—particularly when there is a high clinical suspicion of a surgical cause—early surgical consultation and intervention are advised to prevent clinical deterioration [8, 9].

Laparoscopy was performed and revealed a large mesenteric defect. Due to the extent of the defect, the procedure was converted to open surgery. Intraoperative findings showed the complete absence of the intestinal mesentery, including the jejunal, ileal, and ascending colonic mesentery. This resulted in a large defect surrounding the intestine (Fig. 1). However, the bowel had not entered the mesenteric defect to cause incarceration. The appendix appeared normal, ruling out appendicitis. A notable finding was the absence of fan-shaped mesenteric vessels along the defect. Instead, a single mesenteric vessel originated from the mesenteric root, supplying blood to the bowel. The terminal ileum, along with its vessels, crossed in an abnormal manner, resulting in volvulus and intestinal obstruction (arrow in Fig. 1). To address this, the terminal ileum was transected, and its ends were reanastomosed anterior to its vessels using 5–0 polydioxanone (PDS) sutures to correct the abnormal anatomy and relieve the obstruction (Fig. 3). The mesenteric defect was closed by suturing the surrounding tissue with 5–0 Prolene sutures to prevent future transmesenteric hernias (Fig. 4).

Fig. 3

The terminal ileum was transected and reanastomosed anterior to its mesenteric vessels (arrow) to relieve ileal volvulus and intestinal obstruction

Fig. 4

Closure of the mesenteric defect

Postoperatively, the patient began oral feeding on postoperative day 3. Follow-up ultrasound confirmed the resolution of intestinal obstruction. The patient was discharged on postoperative day 7. During a 1-year follow-up, there was no recurrence of intestinal obstruction.

Discussion and conclusions

Intestinal obstruction is a common condition in pediatric general surgery. Approximately 30–40% of acute abdominal diseases in neonates are caused by intestinal obstruction [10]. The causes of intestinal obstruction include postoperative adhesions, tumor compression, and hernias [11]. However, the etiology differs between adults and children. In adults, the leading causes of intestinal obstruction are sigmoid volvulus (25.6%), adhesions (23.1%), small-bowel volvulus (21.3%), and ileosigmoid knotting (8.5%) [12]. In children, intussusception and strangulated hernias are the primary causes of acute mechanical intestinal obstruction, accounting for 43.59% and 29.48% of cases, respectively, with anorectal malformations representing 17.95% [13]. Congenital malformations are a significant cause of intestinal obstruction in children, typically presenting in the neonatal period. These include conditions such as intestinal atresia (or stenosis), intestinal malrotation, congenital fibrous band compression, incarcerated hernias, annular pancreas, Hirschsprung’s disease, anorectal malformation, and jejunal duplication malformation [10].

Although mesenteric defects are congenital, their presentation in children is rare, with most case series reported in adults [6]. In pediatric reports, the typical presentation occurs in neonates with gangrene. Acute symptoms include bilious vomiting and abdominal distension, primarily seen in neonates and infants. Chronic presentations involve intermittent herniation of the bowel, leading to abdominal pain, distension, nausea, vomiting, and constipation [6]. The absence of symptoms until preschool age (3–6 years old) is exceptionally rare in children with congenital intestinal obstruction [14]. The present study reports a 4-year-old boy with a congenital mesenteric defect and ileal volvulus who did not exhibit symptoms of intestinal obstruction, such as abdominal pain or vomiting, before the age of 4 years. The reasons for this absence of symptoms may include the following: (1) The mesenteric defect did not lead to mesenteric hernia because it was large, allowing the bowel to pass through the defect without causing obstruction; (2) although the terminal ileum was trapped by its vessels, it did not lead to complete occlusion of the intestine; and (3) the patient resided in a rural area of China, where medical care might be limited, and the parents may not have recognized or reported subtle symptoms due to a lack of awareness. Delayed onset of symptoms in congenital mesenteric defects is rare, as most cases present earlier in life.

The mesenteric defect may be associated with abnormal development of the mesenteric blood vessels, leading to partial regression of the dorsal mesentery. Normally, mesenteric blood vessels are fan-shaped, supplying blood to the mesentery and bowel. However, in cases with mesenteric defects, the fan-shaped mesenteric vessels are often absent in the region of the defect, supporting this hypothesis. In the present patient, fan-shaped mesenteric vessels were completely absent, and a single vessel supplied blood to the bowel, which aligns with this theory. Furthermore, the distal ileum, along with its vessels, crossed abnormally, leading to entrapment of the distal ileum and intestinal obstruction. To the best of our knowledge, no similar case has been reported. However, similar vascular malformations are seen in type IIIb small-intestinal atresia, where a mesenteric defect exists between the proximal and distal segments of the atresia, with a single vessel supplying both ends. This results in the characteristic “apple peel” malformation seen in type IIIb [15]. Concurrent small intestinal atresia, mesenteric defects, and vascular malformations suggest that abnormal blood supply may play a role in the pathogenesis of both conditions [16], which could also explain the mesenteric defects observed in this patient.

Diagnosing intestinal obstruction caused by mesenteric defects prior to surgery is challenging [3]. The decision between conservative treatment and surgical exploration depends on the patient’s symptoms and clinical presentation. A varied presentation without a clear radiological diagnosis can lead to delays, increasing morbidity and mortality [6]. Common symptoms include abdominal pain, vomiting, distension, an abdominal mass, and shock, often caused by bowel incarceration within the mesenteric defect. Abdominal ultrasound and X-ray can help exclude other common causes of obstruction, such as intussusception, but they have low sensitivity for diagnosing mesenteric defects. Therefore, diagnostic imaging was not pursued in this case, and surgery was planned on the basis of the clinical signs alone [6]. Intraoperative exploration remains the most reliable method for diagnosing mesenteric defects [1, 3, 6]. Surgical exploration should be urgently performed in patients with worsening abdominal pain, peritonitis, abdominal mass, or shock. Exploration can be done via open incision or laparoscopy. While laparoscopy is commonly used for diagnosing acute abdominal conditions, its limitations in abdominal space can pose challenges in treatment, making open surgery the preferred approach in some cases [3].

In this study, laparoscopy was initially used for diagnosis but was converted to open surgery after identifying the large mesenteric defect. Surgical treatment for transmesenteric hernia aims to relieve obstruction and prevent bowel incarceration [1]. In this case, the bowel did not enter the mesenteric defect, preventing the development of a transmesenteric hernia. This may be due to the large size of the defect, which allowed the bowel to pass freely through the opening. The main cause of the intestinal obstruction was the abnormal crossing of the mesenteric vessels, which trapped the distal ileum, leading to volvulus. To relieve the obstruction, the distal ileum was transected and reanastomosed anterior to its mesenteric vessels. The mesenteric defect was then closed to prevent recurrence of transmesenteric hernia.

In conclusion, a complete mesenteric defect with ileal volvulus is a rare cause of intestinal obstruction. Prompt surgical exploration based on clinical signs is crucial for diagnosing and treating transmesenteric hernia. This timely intervention is vital for reducing the morbidity and mortality associated with this rare, life-threatening condition.