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

Abstract

Objective To evaluate inter‐rater agreement for sonographic classification of stomach position (as a surrogate for liver herniation) in fetal left congenital diaphragmatic hernia (LCDH) among: (i) fetal medicine specialists from the North American Fetal Therapy Network (NAFTNet) centers within and without the fetal endoscopic tracheal occlusion (FETO) consortium and in comparison to an expert external reviewer (ER1); and (iii) among two expert ERs (ER1 and ER2). Methods Forty‐eight physicians from 26 NAFTNet centers and 2 ERs were asked to assess 13 sonographic clips of isolated LCDH and classify stomach position as “intra‐abdominal,” “anterior left chest,” “mid to posterior left chest,” or “retro‐cardiac" based on the classification published by Basta et al.8 Interrater agreement was assessed by determining proportion of stomach position ratings concordant amongst NAFTNet participants and ER1. Agreement for stomach position between ERs was calculated using kappa statistics. Results Agreement for stomach position was 69% (39%–85%; n = 19) and 54% (23%–92%; n = 29) among FETO and non‐FETO NAFTNet participants, respectively, when compared to ER1. Most disagreement in stomach position was related to a discrepancy of one position. ERs were in agreement for stomach position in 5 of 13 cases (38.5%) and inter‐rater agreement was highest for “anterior” stomach position. Conclusion Interrater agreement for stomach position assessment in CDH was poor across NAFTNet and indeed amongst expert reviewers.

Survival in very preterm infants with congenital diaphragmatic hernia and association with prenatal imaging markers: A retrospective cohort study

“…Prenatal grading of stomach position has been shown to correlate with respiratory outcomes and survival in term left‐sided CDH infants 14,15,28 . Our results indicate that, also in very preterm born infants with left‐sided CDH, the survival rates are different based on stomach position grade, with lower survival rates for higher grades.…”

Diagnosis and management of congenital diaphragmatic hernia: a 2023 update from the Canadian Congenital Diaphragmatic Hernia Collaborative

“…Intrathoracic liver herniation may be challenging to recognise sonographically. As such, stomach position classification has been proposed as a surrogate,22–25 and has been shown to correlate with neonatal mortality and morbidity 23 24 26. Although promising in its simplicity, this prognosticator requires further prospective validation.…”

The grading of stomach position for postnatal outcomes in isolated left‐sided congenital diaphragmatic hernia: A systematic review and meta‐analysis

“…We then compared SP at level 1 versus level 2 + 3 considering that this would be easy in clinical practice. The reported inter‐rater agreement was highest for “anterior” SP, and there was no agreement seen for “mid‐posterior left chest” or “retro‐cardiac” assessments of SP 39 . Level 2 + 3 SP put the fetus at an increased risk of neonatal mortality when compared with level 1 SP.…”

“…The reported inter-rater agreement was highest for "anterior" SP, and there was no agreement seen for "mid-posterior left chest" or "retro-cardiac" assessments of SP. 39 Level 2 + 3 SP put the fetus at an increased risk of neonatal mortality when compared with level 1 SP. In fetuses with isolated left-sided CDH, a mid-thoracic or retrocardiac stomach seems to be a significant prognostic indicator.…”