Standardization and reproducibility of sonographic stomach position grades in fetuses with congenital diaphragmatic hernia

Abstract

Objectives The purpose of this study was to evaluate the reproducibility of stomach position grading in congenital diaphragmatic hernia (CDH) as proposed by Cordier et al and Basta et al after standardization of the methods at our center. Methods We collected sonographic images from 23 fetuses with left‐sided CDH at our center from 2010 to 2018. Nine operators (one maternal fetal medicine expert and eight sonographers) reviewed the selected images and graded the stomach position according to the methods of Cordier et al and Basta et al. We assessed the interoperator agreement with Fleiss's kappa statistics. Results Overall agreement amongst all operators was moderate for both methods proposed by Cordier et al (k = 0.60, SE 0.07, 95% CI 0.47‐0.73, P < .0001) and Basta et al (k = 0.60, SE 0.06, 95% CI 0.47‐0.73, P < .0001). Interoperator agreement was moderate for grade 3 with the method by Cordier et al (k = 0.45, SE 0.09, 95% CI 0.27‐0.64, P < .0001) and fair for grade 4 with the method by Basta et al (k = 0.33, SE 0.08, 95% CI 0.18‐0.49 P < .0001). Conclusions Our study demonstrates a fair to moderate interoperator agreement of the stomach position grading methods proposed in the literature after standardization of the methods at our center. Further multicenter studies are needed to confirm our results.

Interrater agreement for sonographic stomach position classification in fetal diaphragmatic hernia across the North American Fetal Therapy Network

“…lowest for "retrocardiac" stomach position (κ = 0.33, 95% CI: 0.18-0.49, p < 0.0001) followed by "mid to posterior" left chest position (κ = 0.52, 95% CI: 0.35-0.69, p < 0.0001) as defined by Basta et al 8 Similarly, fair to moderate inter-operator agreement was also demonstrated for grades 3 (κ = 0.45, 95% CI: 0.27-0.64, p < 0.0001) and 4 (κ = 0.48, 95% CI: 0.30-0.65, p < 0.0001) stomach position, as described by Cordier et al 9 in this series. 13 These findings highlight a potential ambiguity within this stomach classification system and support the need for more precise definitions of these positions for both classifications. 8,9 To help address these ambiguities, we recommend that the AV valves be used as the critical landmark for establishment of stomach position, and that sonographers divide the fetal chest transversely at the AV valves on the four-chamber view of the heart to help classify stomach position.…”

“…The poor interrater agreement between experts for stomach position classification particularly for “mid to posterior” left chest and “retrocardiac” stomach position has also been demonstrated by Ibirogba et al. , 13 in a single center series, which included eight sonographers and an MFM specialist, evaluating stomach position in 23 cases of left CDH. They found that inter‐operator agreement was lowest for “retrocardiac” stomach position ( κ = 0.33, 95% CI: 0.18–0.49, p < 0.0001) followed by “mid to posterior” left chest position ( κ = 0.52, 95% CI: 0.35–0.69, p < 0.0001) as defined by Basta et al 8 .…”

Prenatal stomach position and volume in relation to postnatal outcomes in left‐sided congenital diaphragmatic hernia

“…US1, ultrasound scan ≤24 weeks gestational age (GA); US2, ultrasound scan 24–30 weeks GA; US3 ultrasound scan ≥30 weeks GA. Prenatal liver position “up”: liver intrathoracic. CDH severity: combination of O/E LHR and liver position according to Jani et al 16 …”

“…Liver position “up”: liver intrathoracic. CDH severity: combination of O/E LHR and liver position according to Jani et al 16 …”

“…It was shown that the prenatal SP is a potential marker for postnatal survival, the need for postnatal patch repair, need for extracorporeal membrane oxygenation (ECMO), and need for prolonged respiratory support 12,14 . Moderate to almost perfect inter‐ and intraobserver agreement for the determination of prenatal SP has been shown by different groups, which might support its clinical applicability 12,16 …”