Utility of sonographic assessment of the position of the third part of the duodenum using water instillation in intestinal malrotation: a single-center retrospective audit

Ultrasound as the first line investigation for midgut malrotation: a UK tertiary centre experience

AIM

To present the first 22-months experience of transitioning to an ultrasound-first pathway for suspected midgut malrotation.

MATERIALS AND METHODS

An "ultrasound-first" imaging pathway was initiated in October 2021. Twenty-two-months later, a search was undertaken of all <1-year-old patients with "bilious", "malrotation," or "volvulus" as the imaging indication. Reports and images from upper gastrointestinal fluoroscopy (UGI) and ultrasound were reviewed, and diagnoses and outcomes were documented.

RESULTS

The search yielded 101 eligible cases between October 2021 and July 2023. Of the patients, 63/101 (62%) had both ultrasound and UGI: 47/63 (75%) ultrasound first, 16/63 (25%) UGI first. Thirty-one per cent (31/101) had ultrasound only and 7/70 (10%) UGI only. The pathway diagnosed 7/8 (88%) infants with midgut malrotation with or without volvulus and one infant who had an inconclusive ultrasound examination with a suspected an internal hernia and who was found to have malrotation volvulus at surgery. Twenty-one infants who had confidently normal ultrasound examinations and who also had UGI all had a normal duodenojejunal flexure position. Ultrasound detected alternative pathology in eight children. Duodenal visualisation improved with time: 6/15 (40%) in the first 6 months to 23/34 (68%) after the first year.

CONCLUSION

The transition to ultrasound as the first diagnostic test for midgut malrotation can be done safely and effectively in a UK centre, which previously relied solely on UGI.

Diagnostic accuracy of upper gastrointestinal series in children with suspected intestinal malrotation

Intestinal malrotation (IM) results from an altered or incomplete rotation of the fetal midgut around the superior mesenteric artery axis. The abnormal anatomy of IM is associated with risk of acute midgut volvulus which can lead to catastrophic clinical consequences. The upper gastro-intestinal series (UGI) is addressed as the gold standard diagnosis procedure, but a variable failure degree has been described in literature. The aim of the study was to analyze the UGI exam and describe which features are the most reproducible and reliable in diagnosing IM. Medical records of patients surgically treated for suspected IM between 2007 and 2020 at a single pediatric tertiary care center were retrospectively reviewed. UGI inter-observer agreement and diagnostic accuracy were statistically calculated. Images obtained with antero-posterior (AP) projections were the most significant in terms of IM diagnosis. Duodenal-Jejunal Junction (DJJ) abnormal position resulted to be the most reliable parameter (Se = 0.88; Sp = 0.54) as well as the most readable, with an inter-reader agreement of 83% (k = 0.70, CI 0.49-0.90). The First Jejunal Loops (FJL), caecum altered position and duodenal dilatation could be considered additional data. Lateral projections demonstrated an overall low sensitivity (Se = 0.80) and specificity (Sp = 0.33) with a PPV of 0.85 and a NPV of 0.25. UGI on the sole AP projections ensures a good diagnostic accuracy. The position of the third portion of the duodenum on lateral views showed an overall low reliability, therefore it was not helpful but rather deceiving in diagnosing IM.

Ultrasound for malrotation and volvulus - point

Upper gastrointestinal series is considered the gold standard imaging test to evaluate for malrotation and midgut volvulus. US has been explored for this purpose in recent years and has been shown to be a good alternative because of its relatively good accuracy, fast learning curve for sonographers and radiologists, as well as convenience for children, clinical staff and radiologists in the neonatal intensive care unit. In this article we describe our experience and review the evidence supporting the use of emergency US primarily to diagnose midgut volvulus as well as its use as a problem-solving tool for the diagnosis of malrotation. The examination technique, normal and abnormal findings are described, with emphasis on the whirlpool and superior mesenteric artery cutoff signs to diagnose midgut volvulus.

Ultrasound for Midgut Malrotation and Midgut Volvulus: AJR Expert Panel Narrative Review

Midgut volvulus in association with malrotation is a pediatric surgical emergency. Prompt and accurate diagnosis is necessary to avoid bowel ischemia and necrosis, thereby reducing morbidity and mortality. Historically, the upper gastrointestinal (UGI) series has been the preferred imaging modality for the evaluation of both midgut malrotation and volvulus, although use of ultrasound (US) is increasing. In this narrative review, we describe the findings of midgut malrotation and volvulus on US, including practical tips for acquisition and interpretation; discuss the advantages and challenges of both imaging modalities; and propose a path and safeguards for possible transition to the use of US as the first-line modality for diagnosis, based on our experience in imaging children with midgut malrotation and volvulus.

Ultrasound imaging as the first line of investigation to diagnose intestinal malrotation in children: Safety and efficacy

BACKGROUND

Upper gastrointestinal contrast study is considered the gold standard investigation to diagnose intestinal malrotation and midgut volvulus which is potentially devastating condition. Ultrasound imaging is an alternative but has been considered unreliable due to significant false negative results. At our institution we have been using ultrasound imaging as the first line investigation to diagnose malrotation since 2008 with a preliminary study of 139 patients published in 2014. This is an ongoing audit of a further much larger cohort of patients to determine the efficacy and safety of ultrasound imaging in the diagnosis of intestinal malrotation.

MATERIALS AND METHODS

Following ethics approval, a retrospective analysis of a prospectively collected patient database undergoing ultrasound scans to exclude malrotation at our centre was performed from 2012 to 2019.

RESULTS

539 patients underwent ultrasound to assess for malrotation. The mean age of presentation was 365 days (median 30 days, mode 1 day). Malrotation was diagnosed in 17 with 5 having volvulus, with findings confirmed at surgery. 12 had equivocal findings and subsequent contrast studies ruled out malrotation. The remaining 510 patients with no evidence of malrotation were managed conservatively.

CONCLUSION

We have shown ultrasound to be a safe and effective tool to assess intestinal malrotation without exposure to ionizing radiation.

LEVEL OF EVIDENCE

Level IV.

Ultrasound for the diagnosis of malrotation and volvulus in children and adolescents: a systematic review and meta-analysis

CONTEXT

Despite the advantages of ultrasound (US), upper gastrointestinal contrast series (UGI) remains the first-line diagnostic modality in the diagnosis of midgut malrotation and volvulus in children.

OBJECTIVE

Evaluate the diagnostic accuracy of US in the diagnosis of malrotation with or without volvulus in children and adolescents aged 0-21 years, compared with the reference standard (diagnosis by surgery, UGI, CT, MRI, and clinical follow-up individually or as a composite).

DATA SOURCES

We searched the electronic databases Ovid-MEDLINE, Embase, Scopus, CINAHL, and the Cochrane library in October 2019 and updated on 18 August 2020.

STUDY SELECTION

Studies evaluating the diagnostic performance of US for diagnosis of midgut malrotation with or without volvulus in children (0-21 years).

DATA EXTRACTION AND SYNTHESIS

The data were extracted independently by two authors and a bivariate model was used for synthesis.

RESULTS

Meta-analysis of 17 cohort or cross-sectional studies and 2257 participants estimated a summary sensitivity of 94% (95% CI 89% to 97%) and summary specificity of 100% (95% CI 97% to 100%) (moderate certainty evidence) for the use of US for the diagnosis of malrotation with or without midgut volvulus compared with the reference standard. Subgroup analysis and meta-regression revealed better diagnostic accuracy in malrotation not complicated by volvulus, in the neonatal population and enteric fluid administration before US.

CONCLUSIONS

Moderate certainty evidence suggests excellent diagnostic accuracy and coupled with the advantages, a strong case exists for the use of abdominal US as the first-line diagnostic test for suspected midgut malrotation with or without volvulus in children and adolescents.

A unique sonographic presentation of prenatal volvulus associated with malrotation

This is a unique case of prenatal diagnosis of bowel malrotation suspected by an abnormal course of the duodenum. Early detection of volvulus was enabled, leading to timely intervention and a favorable outcome.

Untwisting the complexity of midgut malrotation and volvulus ultrasound

Abdominal US is emerging as an alternative to the upper gastrointestinal (GI) series as the preferred diagnostic imaging test for midgut malrotation complicated by volvulus. Unlike the upper GI series, US is free from ionizing radiation, does not require oral contrast agent, and can be performed portably and at times remotely from the interpreting radiologist, expediting diagnosis. Although some institutions do not have a standardized US protocol for midgut volvulus, many routinely use US in the setting of an infant or child with acute abdominal signs or symptoms to evaluate for common conditions such as hypertrophic pyloric stenosis, intussusception, necrotizing enterocolitis and appendicitis. Because these common conditions can overlap in age and clinical presentation with midgut volvulus, the aim of this pictorial essay is to provide instruction on the technique and diagnostic findings of midgut volvulus on US to ensure confident, accurate interpretation, and prompt treatment.

Diagnostic laparoscopy to exclude malrotation following inconclusive upper gastrointestinal contrast study in infants

PURPOSE

We report the use of diagnostic laparoscopy as an alternative to laparotomy in the investigation of infants with clinical features concerning for malrotation and inconclusive upper gastrointestinal contrast study.

METHOD

Case note review of all infants in whom laparoscopy was performed during 2016-2020 to investigate for possible malrotation.

RESULTS

Eight infants were identified. All presented with acute clinical features of malrotation (bilious vomit) without evidence of an alternate explanatory diagnosis. All underwent upper gastrointestinal contrast study, with three also undergoing abdominal ultrasound. The radiological examinations could not exclude malrotation and all proceeded to laparoscopy. At laparoscopy, the small intestine was run to exclude the presence of midgut volvulus. In six cases, normal rotation was confirmed and no abnormal pathology was found. Two proceeded to laparotomy and underwent correction of malrotation. All infants recovered without complication.

CONCLUSION

Laparoscopy is an excellent modality for further investigation of infants presenting acutely in whom intestinal malrotation cannot be formally excluded radiologically. The positive identification of the DJ flexure and cecum in correct anatomical sites, both fixed to the posterior abdominal wall, provides adequate reassurance of low risk of volvulus and avoids a full laparotomy. We recommend diagnostic laparoscopy in cases of inconclusive upper gastrointestinal contrast study.

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.

Selective duodenography for controlled first-pass bolus distention of the duodenum in neonates and young children with bile-stained vomiting

AIM

To compare "selective duodenograms" performed through nasogastric tubes advanced into the proximal duodenum against traditional contrast studies regarding visualisation of a first-pass bolus distention of the duodenum and frequency of inconclusive results.

MATERIALS AND METHODS

Retrospective comparison of "selective duodenograms" and traditional upper gastrointestinal contrast studies in neonates with bile-stained vomiting, regarding demonstration of the duodenal C-loop, first-pass bolus capture, degree of distention of the duodenum, and number of inconclusive studies. Statistical comparison was performed using the two-tailed Fishers exact and chi-squared tests.

RESULTS

There were 31 "selective duodenograms" and 70 traditional studies. The C-loop was demonstrated in 93% of traditional studies versus 100% in "selective duodenograms" and was demonstrated significantly more often during the first-pass (94% versus 73%; p=0.018) and more often with distention of the duodenum for "selective duodenography" (94% versus 56%, p<0.001). There were more inconclusive traditional studies (7% versus 3%; non-significant).

CONCLUSION

Emergency upper gastrointestinal tract studies performed in neonates using the "selective duodenogram" technique demonstrated the duodenum with 100% success, with significantly more frequent first-pass bolus visualisation and duodenal distention than traditional studies. The five (7%) inconclusive traditional studies, present a significant diagnostic conundrum in the emergency setting because emergency surgery must be contemplated without proof.

The efficiency of sonography in diagnosing volvulus in neonates with suspected intestinal malrotation

This study is to prospectively evaluate the efficiency of sonography for volvulus diagnosis in neonates with clinically suspected intestinal malrotation.A total of 83 patients with suspected intestinal malrotation who underwent detailed abdominal sonography and upper gastrointestinal contrast study were included. Malrotation was characterized by inversion of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in sonographic examination. The "whirlpool sign" of Color Doppler Sonography was recognized as a characteristic for malrotation with volvulus. The degrees of rotation of the SMV winding around SMA were also detected by sonography. Surgery was performed in patients with sonography diagnosed malrotation.A total of 39 patients were sonographically diagnosed as malrotation which was subsequently confirmed by surgery. The sensitivity and positive predictive value of the sonographic diagnosis were both 100% (39/39). The sensitivity, specificity and accuracy of "whirlpool sign" for the detection of midgut volvulus were 95.2% (20/21), 88.9% (16/18), and 92.3% (36/39), respectively. Greater degrees of rotation (equal or greater than 720°) showed higher risk (odds ratio, 5.0; P < .01) for intestinal necrosis occurrence.Sonography is more accurate in diagnosing suspected malrotation than upper gastrointestinal contrast study. Specific sonographic "whirlpool sign" related to volvulus may be used as a potential indicator for intestinal necrosis. In addition, sonography can exclude malrotation and may help the diagnosis of other diseases, such as annular pancreas and duodenal atresia.

Segmental volvulus in the neonate: A particular clinical entity

BACKGROUND

Complete intestinal volvulus is mainly related to congenital anomalies of the so-called intestinal malrotation, whereas segmental volvulus appears as a distinct entity, mostly observed during the perinatal period. Because these two situations are still lumped together, the aim of this study was to describe the particular condition of neonatal segmental volvulus.

STUDY DESIGN

We analyzed the circumstances of diagnosis and management of 17 consecutives neonates operated for segmental volvulus more than a 10-year period in a single institution. During the same period, 19 cases of neonatal complete midgut volvulus were operated.

RESULTS

Prenatal US exam anomalies were observed in 16/17 (94%) of segmental volvulus, significantly more frequently than in complete volvulus (p=0.003). Intestinal malposition was described peroperatively in all cases of complete volvulus, but also in 4/17 segmental volvulus (23%). Intestinal resection was performed in 88% of segmental volvulus when only one extensive intestinal necrosis was observed in complete volvulus. Parenteral nutrition was required in all patients with segmental volvulus with a median duration of 50days (range 5-251).

CONCLUSION

Segmental volvulus occurs mainly prenatally and leads to fetal ultrasound anomalies. This situation, despite a limited length of intestinal loss, is associated to significant postnatal morbidity.

TYPE OF THE STUDY

Treatment study.

LEVEL OF EVIDENCE

Level IV.

Usefulness of Sonography in Evaluating Children Suspected of Malrotation: Comparison With an Upper Gastrointestinal Contrast Study

OBJECTIVES

The purpose of this study was to prospectively evaluate the value of sonography in working up or ruling out malrotation by 3 sonographic features (inversion of the superior mesenteric artery and superior mesenteric vein, the whirlpool sign, and an intraperitoneal transverse duodenum) and comparing it with an upper gastrointestinal (GI) contrast study.

METHODS

A total of 70 pediatric patients who underwent detailed abdominal sonography to rule out intestinal malrotation were included. Twenty-three of them also underwent an upper GI contrast study. Surgery or clinical follow-up was taken as the reference standard. Statistical analysis was performed with the χ(2) test.

RESULTS

Twenty-three patients had a diagnosis of malrotation by surgical findings. With the combination of all 3 sonographic features, the sensitivity, specificity, and accuracy of sonography for determining malrotation were 100% (23 of 23), 97.8% (46 of 47), and 98.6% (69 of 70), respectively, whereas the sensitivity, specificity, and accuracy of the upper GI study were 40% (4 of 10), 64.3% (9 of 14), and 56.5% (13 of 23; P < .001). Combined anomalies in 2 patients and complications in 2 patients were also detected by sonography.

CONCLUSIONS

By combining inversion of the superior mesenteric artery and superior mesenteric vein, the whirlpool sign, and an intraperitoneal transverse duodenum, sonography might be more valuable for accurately working up or ruling out pediatric malrotation than an upper GI contrast study. In addition, sonography could provide extra information, such as combined anomalies and intestinal necrosis, to help management.