Manual epigastric compression during upper gastrointestinal examination of neonates: value in diagnosis of intestinal malrotation and volvulus

Fluoroscopic Diagnosis of Malrotation: Technique, Challenges, and Trouble Shooting

A fluoroscopic upper gastrointestinal series is the most commonly used investigation for the diagnosis of malrotation and midgut volvulus. However, both false positive and false negative results can occur causing diagnostic confusion. Several physiologic states and pathologic conditions can mimic fluoroscopic appearance of malrotation. Proper fluoroscopic technique is essential to maximize diagnostic accuracy. In this pictorial essay, we discuss common diagnostic challenges in the diagnosis of malrotation and strategies radiologists can use to clarify the diagnosis in equivocal cases.

Mimics of malrotation on pediatric upper gastrointestinal series: a pictorial review

Intestinal malrotation is a continuum of congenital anomalies due to lack of rotation or incomplete rotation of the fetal intestine around the superior mesenteric artery axis. The abnormal bowel fixation (by mesenteric bands) or absence of fixation of portions of the bowel increases the risk of bowel obstruction, acute or chronic volvulus, and bowel necrosis. The clinical presentation of patients with malrotation without, with intermittent, or with chronic volvulus can be problematic, with an important minority presenting late or having atypical or chronic symptoms, such as intermittent vomiting, abdominal pain, duodenal obstruction, or failure to thrive. The diagnosis is heavily reliant on imaging. Upper GI series remain the gold standard with the normal position of the duodenojejunal junction lateral to the left-sided pedicles of the vertebral body, at the level of the duodenal bulb on frontal views and posterior (retroperitoneal) on lateral views. However, a variety of conditions might influence the position of the duodenojejunal junction, potentially leading to a misdiagnosis of malrotation. Such conditions include improper technique, gastric over distension, splenomegaly, renal or retroperitoneal tumors, liver transplant, small bowel obstruction, the presence of properly or malpositioned enteric tubes, and scoliosis. All of these may cause the duodenojejunal junction to be displaced. We present a series of cases highlighting conditions that mimic malrotation without volvulus to increase the practicing radiologist awareness and help minimize interpretation errors.

Disorders of midgut rotation: making the correct diagnosis on UGI series in difficult cases

BACKGROUND

In some series of malrotation small numbers of children are described in whom the position of the duodenojejunal flexure was considered to be normal on straight anteroposterior (AP) view of an upper gastrointestinal (UGI) series.

OBJECTIVE

The purpose of this study was to illustrate children with disorders of midgut rotation in whom the diagnosis was difficult because on the straight AP view of the UGI series the duodenojejunal flexure was either not clearly depicted or was projected to the left of the midline close to its expected normal position at or close to the level of the duodenal cap.

MATERIALS AND METHODS

We reviewed 111 children with malrotation to determine the frequency that duodenojejunal flexure was not clearly depicted or was close to normal position.

RESULTS

Seven patients had close to normal position of duodenojejunal flexure on AP view. The correct diagnosis was made on initial UGI series in four patients based on other features on AP and lateral views. In two of the other three patients, a repeat UGI series facilitated the correct diagnosis. In the final patient, an abnormal position of a nasojejunal tube suggested the correct diagnosis.

CONCLUSION

Accurate diagnosis of anomalies of midgut rotation requires careful assessment of the entire duodenal sweep on both AP and lateral views to avoid false-negative interpretations.

Assessment of retromesenteric position of the third portion of the duodenum: an US feasibility study in 33 newborns

BACKGROUND

US can be used to assess bowel and does not require ionizing radiation or the administration of contrast material. Prior studies of the duodenum with US are limited.

OBJECTIVE

This study assesses the success rate of US demonstration of the third portion of the duodenum (D3) between the superior mesenteric artery (SMA) and the aorta in newborns to exclude malrotation based on embryologic and anatomic principles.

MATERIAL AND METHODS

Thirty-three newborns underwent US studies. The structures between the SMA and the aorta, including D3, were evaluated in axial and longitudinal planes. The length of time to acquire diagnostic images was recorded.

RESULTS

In both the axial and longitudinal planes, D3 was seen between the SMA and the aorta in all 33 infants, including some with abundant bowel gas. The mean length of time to acquire diagnostic images was 34 s.

CONCLUSION

Bedside US successfully illustrated the retromesenteric position of D3 in all 33 infants. Overlying gas-filled bowel was effectively effaced by graded compression. The short study duration indicates the practicality of the method. Further studies in broader patient populations and in correlation with other imaging and/or surgical findings is required to validate our technique.

The position of the duodenojejunal junction: the wrong horse to bet on in diagnosing or excluding malrotation

PURPOSE

The purpose of this communication is to highlight the shortcomings of all currently used imaging criteria in diagnosing or excluding malrotation and offer ultrasound demonstration of the 3(rd) portion of the duodenum (D3) between the AO and the SMA in transverse and sagittal plains as the most reliable diagnostic method.

BACKGROUND

Although UGI is currently considered to be the imaging modality of choice in diagnosis of malrotations, numerous publications indicate that in certain patients, false positives and negatives can be encountered.

MATERIALS AND METHODS

The material consists of more than 10 years experience in university settings, during which the author has used US as the definitive imaging modality for the work-up of malrotation. High resolution linear transducers (5-17 MHz) are the transducers of choice. Imaging plains: A. Transverse. With gradual grading compression, the following landmarks are illustrated in cehaplocaudad directions in the following order. The junction of splenic vein with the SMV portal vein. The cross sections of SMA and SMV that may either be situated in midline, or to the right or the left of the midline. Left renal vein crossing the spine from left to right between the AO and the SMA. The jejunal vein, often coming from left, transversing between the AO and the SMA. The transverse portion of the duodenum, D3, between the AO & the SMA. B. Sagittal. D3 between vertically oriented SMA-SMV and the AO. If SMA is not aligned with the AO by slight compression on the right or the left side of the abdomen, it will be aligned (depending on leftward or rightward position of SMA-SMV in axial plain). Vertical orientation of SMA and SMV if they have an anteroposterior orientation. C. Coronal. Side by side orientation of SMA and SMV if they don't have an anteroposterior orientation.

RESULTS

In overwhelming majority of cases, by illustrating a retromesenteric D3 malrotation and, therefore, midgut volvulus were excluded.

DISCUSSION

None of the current imaging criteria addresses the following most fundamental anatomic and embryologic facts regarding the gut rotation and fixation. In first trimester, the D3 is secured in retroperitoneal space after the embryologic journey comes to an end, making the duodenum immune of midgut volvulus. The surgical pathology of malrotation-midgut volvulus indicates that D3 is always Intraperitoneal and has not reached its final embryologic destination in retroperitoneal space. Demonstrating a retromesenteric D3, therefore, indicates that the embryologic journey is completed and the patient does not have malrotation. Excluding malrotation excludes the likelihood of midgut volvus.

CONCLUSION

The position of the DJJ, the configuration of the duodenal sweep, the orientation of the mesenteric vessels are all wrong horses to bet on because none of them addresses the fundamental anatomic and embryologic facts. Only the cross-sectional imaging, US, CT and MRI can prove that the D3 is retromesenteric, therefore, excluding malrotation and volvulus. Therefore, demonstrating a retromesenteric duodenum is the reference standard of imaging in the work-up of malrotation, not any other previously published criteria. The US imaging is the most acceptable imaging method for malrotation work-up, in the spirit of ALARA principle and "Image Gently" campaign.

Intestinal malrotation in children: a problem-solving approach to the upper gastrointestinal series

Intestinal malrotation, which is defined by a congenital abnormal position of the duodenojejunal junction, may lead to midgut volvulus, a potentially life-threatening complication. An evaluation for malrotation is part of every upper gastrointestinal (GI) tract examination in pediatric patients, particularly neonates and infants. Although the diagnosis of malrotation is often straightforward, the imaging features in approximately 15% of upper GI tract examinations are equivocal and lead to a false-positive or false-negative interpretation. The clinical manifestations and upper GI tract findings of malrotation in older children and adults are less specific than are those in younger patients, and for this reason diagnosis of the condition may be more difficult. Successful differentiation between a normal variant and malrotation requires the use of optimal techniques in acquiring and interpreting the upper GI series. Familiarity with the upper GI series appearance of both normal and abnormal anatomic variants allows the radiologist to increase both diagnostic accuracy and confidence in the diagnosis of malrotation.

Disorders of intestinal rotation and fixation ("malrotation")

Malrotation with volvulus is one of the true surgical emergencies of childhood. Prompt radiological diagnosis is often paramount to achieving a good outcome. An understanding of the normal and anomalous development of the midgut provides a basis for understanding the pathophysiology and the clinical presentation of malrotation and malrotation complicated by volvulus. In this essay, the radiologic findings of malrotation and volvulus are reviewed and illustrated with particular attention to the child with equivocal imaging findings.