Adult Intestinal Malrotation with Atypical Presentation: A Case Report and Diagnostic Challenge

Introduction

A congenital defect known as small-bowel malrotation occurs when the fetal intestines fail to rotate completely or at all around the axis of the superior mesenteric artery during fetal development [1]. More specifically, the cecum is still linked to the right side of the abdominal wall by peritoneal fibrous bands known as Ladd’s bands, the duodenum runs down the right side of the abdomen, and the Treitz ligament fails to cross the mid-line to the left side [2]. About 1 in 500 live babies are affected by the disease. In 75–85% of these patients, the diagnosis is made in infancy. Adult midgut malrotation is extremely uncommon, with incidence estimates ranging from 0.0001% to 0.19%. In adults, there is a slight female predominance [3,4].

In older children and adults, the clinical presentation of malrotation is variable and often insidious. The most common symptom is abdominal pain. Vomiting is also frequently present, but not necessarily bilious, and abdominal pain and vomiting may be intermittent. Other less common presentations include failure to thrive, solid food intolerance, malabsorption, chronic diarrhea from protein-losing enteropathy, pancreatitis, peritonitis, biliary obstruction, motility disorders, and chylous ascites [5–7].

Chronic symptoms can frequently make a diagnosis challenging. Several modalities are employed for diagnosis, including barium tests, computed tomography scans, angiography, and emergency laparotomy [8]. Malrotation, regardless of the age of the patient and the presence of symptoms, is treated surgically with a Ladd procedure. This procedure begins with reduction of the volvulus, if present. Since the appendix ends up in the left middle to upper abdomen, an appendectomy is performed as well. If, after surgical reduction of a volvulus, the viability of the bowel is in question, the abdomen can be closed and the bowel reevaluated after 24–36 h. If frankly necrotic bowel is present, it is resected and stomas are created [9,10].

This report describes a case of congenital midgut malrotation presenting with small-bowel obstruction in an 18-year-old Saudi woman.

Case Report

The patient was an 18-year-old Saudi woman who did not smoke or drink, had 3 years of generalized, gradually intermittent abdominal pain 7/10 in severity that radiated to the back and was accompanied by nausea, non-bilious vomiting of a large amount without blood, and intermittent constipation. There was no history of fever, night sweats, weight loss, or fatigue. Her medical, surgical, and family histories were unremarkable, except for a history of episodic, recurrent, vague abdominal pain that occurred every few months over the previous several years. Physical examination revealed that the patient was unwell, morbidly obese (body mass index=43), vitally stable, and had a soft, lax abdomen with generalized pain. A rectal examination did not reveal any abnormality and the biochemical investigation was unremarkable. Normal mucosa was visible after a colonoscopy. A barium study and abdominal CT scan showed small-bowel loops at the right side of the abdomen, with the duodenojejunal junction at the right side or right paramedian level (Figure 1), the superior mesenteric artery (SMA) and vein (SMV) had an inverted relationship (Figure 2) and the cecum was observed in the left lumber region (Figure 3), anterior to the left kidney, opposing the upper border of 2nd lumbar vertebra. Collapsed large bowel loops were noted with minimal mucosal thickening. A few reactive para-aortic lymph nodes were enlarged. We decided to perform surgery after discussing the risks, advantages, and alternatives with the patient regarding diagnostic laparoscopy, potential exploratory laparotomy, and adhesiolysis. General anesthesia was administered in the operating room. A 12-mm port was placed supra-umbilically after pneumoperitoneum insufflation. A 5-mm right lumber and a second 5-mm left lower trocar were implanted. There was no segmental gangrene of the small intestine when the diagnostic laparoscopy was conducted in the small intestine. The cecum was on the left side, there were numerous adhesions, and the cecum was fixed. We attempted adhesiolysis, but the cecum was barely fixed, and due to the huge amount of fat, we decided to convert to an open exploratory laparotomy. An upper midline incision was made, carried through the fascia into the peritoneal cavity, adhesiolysis was performed, the cecum was mobilized, the small-bowel adhesion under the liver was released, and an appendectomy was performed. The abdominal incision was sutured layer by layer and a drain was inserted into the pelvis before closure. A second drain was inserted beneath the skin, which was subsequently sealed by a stepper. The wound was covered with a bandage. The patient was fasted for 6 h before beginning to take sips of water and a liquid diet as tolerated before starting a normal diet, and was managed with a double antibiotic regimen of ceftriaxone and metronidazole for 7 days. She is currently continuing her outpatient follow-up, with no complications. The patient followed up in the clinic 2 weeks after discharge. She had no abdominal pain, nausea, vomiting, or constipation, and was doing well.

Discussion

Intestinal malrotation is much more common in the pediatric population than in adults and is associated with higher morbidity and mortality rates [11,12]. Older age lowers the index of suspicion for congenital malrotation, and early assessments frequently miss the diagnosis [13]; to minimize the morbidity and mortality associated with intestinal malrotation, it is essential to take this into account when making a differential diagnosis for unexplained abdominal pain. A developmental defect that prevents the midgut from rotating 270 degrees counterclockwise is known as intestinal malrotation [14]. The cecum descends towards the right lower quadrant after the rotation, where it is attached to the abdominal wall by Ladd’s bands, and the duodenal-jejunal flexure is on the left side [15]. The duodeno-jejunal flexure typically has a right-side orientation in malrotation, and the ligament of Treitz that holds the peritoneum to the abdominal wall is absent. However, the Ladd’s bands are still connected to the cecum and the right abdominal wall, increasing the risk of entrapment and blockage of the small intestine. The colon, appendix, and cecum are all located on the left side of the body [13–16]. Adults with midgut malrotation can have a wide range of symptoms. Because it is rare, clinical diagnosis in adults and adolescents is challenging [4].

About 95% of midgut malrotation cases are detected in the first year of life [4,17]. However, Haqqani et al reported the case of a patient who presumably remained symptom-free for 80 years, until she finally presented with closed-loop small-bowel obstruction due to acute torsion around the axis of the SMA, and Gamblin et al reported a case of malrotation in an adult who presented with chronic vague abdominal pain [8,18]. However, our patient had recurrent symptoms with repeated visits to the ER and improved with conservative treatment. Our patient had symptoms of chronic malrotation, including constipation, nausea, vomiting, and intermittent abdominal pain. The compression caused by Ladd’s bands as they travel from the cecum and ascending colon to the right abdominal wall may be the cause of these persistent symptoms [8]. The upper gastrointestinal (UGI) series, which is often used in pediatrics, continues to be the current criterion standard for diagnosis of intestinal malrotation. However, CT scans for adult patients, particularly when combined with intravenous and oral contrast, have a higher diagnostic value, and some studies advise using CT as the primary option for adults with suspected malrotation [19–21]. The jejunum in patients with malrotation is continuously present in the right abdomen with 98.2% of patients, cecal ectopia was seen in 12% of patients, and only 8.4% of patients showed abnormal SMA/SMV relationships; our patient had all of these [19]. The Ladd procedure continues to be the standard management practice for adults and children according to most authors. Recently, neonates and adults with intestinal malrotation have been diagnosed and treated laparoscopically. Laparoscopic Ladd surgery has been proven to be safe, successful, and viable. Conversion to an open technique is typical due to the difficulties encountered [24–24]. Because our patient was morbidly obese and had multiple adhesions found during laparoscopic surgery, it was later converted to an open procedure. Depending on the severity of the presentation, patients undergoing surgery for malrotation have different outcomes. Acute volvulus has the highest mortality rate, ranging from 0% to 25%. Additionally, there is high postoperative morbidity (up to 60%) [25,26]. Our case patient had no complications.

Conclusions

Intestinal malrotation is commonly seen in pediatric populations but is rare in adults and can be extremely difficult to diagnose, but in our case, the finding in the CT scan help with diagnosis. Adults with a long history of vague or unexplained abdominal pain may need radiological studies to assess findings of intestinal malrotation such as an inverted relationship between the superior mesenteric artery and vein and left-sided cecum.