Prenatal diagnosis of megaduodenum using ultrasound: a case report

Idiopathic Megaduodenum in a Teenager: A Case Report

Megaduodenum is a rare clinical syndrome characterized by significant duodenal dilation, elongation, and hypertrophy. Given its rarity and nonspecific clinical manifestations, megaduodenum may be misdiagnosed, leading to delays in surgical care and increased morbidity. We describe a case of idiopathic megaduodenum in a teenage Caucasian female, who presented with a five-year history of halitosis, recurrent belching, bloating, nausea and vomiting, and postprandial epigastric abdominal pain. She was diagnosed with megaduodenum by dramatic findings on contrast radiography. She developed a duodenal volvulus necessitating emergency exploratory laparotomy, during which a duodenal plication and a side-to-side duodenojejunostomy were performed. Exploratory laparotomy and histopathological analysis were unrevealing of any definitive abnormalities to explain her megaduodenum. Postoperatively, she developed two early small bowel obstructions, both from subsequent adhesions requiring repeat laparotomy with adhesiolysis. She has subsequently recovered without incident. Diagnosis and accurate classification of megaduodenum requires surgical exploration with a full-thickness biopsy and subsequent histopathologic analysis to rule out obstructive or functional disorders of the duodenum. Treatment of megaduodenum depends on the underlying cause and degree of duodenal distention. It is crucial that clinicians are knowledgeable of the various surgical options, their indications, and the potential postoperative complications that may arise.

Ultrasound examination of the normal fetal duodenum

Objective

To use the fetal pylorus as a reference point to conveniently display the normal fetal duodenum by ultrasound.

Methods

This study was designed in cross-section. A total of 450 healthy singleton pregnant women at 19-39 weeks of gestation who underwent prenatal screening at our hospital from January 2019 to February 2020 were selected. They were divided into three groups according to gestational weeks: the 19-23 gestational weeks group, 29-32 gestational weeks group, and 34-39 gestational weeks group. The duodenal bulb was identified. Its movement and course were continuously and dynamically observed. The descending part of the duodenum was identified, and the duodenal course was traced.

Results

The fluid-filled in the fetal duodenum was discontinuous. The overall detection rates of the duodenum in the 19-23 gestational weeks group, 29-32 gestational weeks group, and the 34-39 gestational weeks group were 82.2%, 26.2%, and 13.8%, respectively. The detection rates of the bulbar, descending, horizontal, and ascending parts of the duodenum were 94.4%, 58.2%, 58.0%, and 52.0%, respectively. The anatomical structures of the duodenum as a whole and the pancreas were most easily recognized in the 19-23 gestational weeks group; while in the 34-39 gestational weeks group, the bulbar part had a maximum detection rate of 98.8%, and it had the longest filling time and the shortest examination time.

Conclusion

The pylorus is an ideal starting point for tracing the fetal duodenum. The overall detection rate of the fetal duodenum decreases with gestational age. The duodenal bulb is the most easily detected site.