Amniotic fluid gamma-glutamyl transferase for prediction of biliary atresia in cases of non-visualisation of the fetal gallbladder: a retrospective study using a validated analytical platform and local reference range.

INTRODUCTION: The level of amniotic fluid gamma-glutamyl transferase (AFGGT) may help identify biliary atresia (BA) in cases of non-visualisation of the fetal gallbladder (NVFGB). This study aimed to validate a serum/plasma matrix-based gamma-glutamyl transferase (GGT) assay for amniotic fluid (AF) samples, establish a local gestational age-specific AFGGT reference range, and evaluate the efficacy of AFGGT for predicting fetal BA in pregnancies with NVFGB using the constructed reference range. METHODS: The analytical performance of a serum/plasma matrix-based GGT assay on AF samples was evaluated using a Cobas c502 analyser. Amniotic fluid gamma-glutamyl transferase levels in confirmed euploid singleton pregnancies (16+0 to 22+6 weeks of gestation) were determined using the same analyser to establish a local gestational age-specific reference range (the 2.5th to 97.5th percentiles). This local reference range was used to determine the positive predictive value (PPV) and negative predictive value (NPV) of AFGGT level <2.5th percentile for identifying fetal BA in euploid pregnancies with NVFGB. RESULTS: The serum/plasma matrix-based GGT assay was able to reliably and accurately determine GGT levels in AF samples. Using the constructed local gestational age-specific AFGGT reference range, the NPV and PPV of AFGGT level <2.5th percentile for predicting fetal BA in pregnancies with NVFGB were 100% and 25% (95% confidence interval=0, 53), respectively. CONCLUSION: In pregnancies with NVFGB, AFGGT level ≥2.5th percentile likely excludes fetal BA. Although AFGGT level <2.5th percentile is not diagnostic of fetal BA, fetuses with AFGGT below this level should be referred for early postnatal investigation.

Women with advanced pelvic organ prolapse and levator ani muscle avulsion would significantly benefit from mesh repair surgery.

OBJECTIVES: Mesh repair surgery for pelvic organ prolapse (POP) has been suspended in some countries owing to concerns about its associated complications. However, mesh repair has been shown to reduce the risk of prolapse recurrence after surgery. In view of this controversy, our aim was to assess the incidence of subjective and objective recurrence of POP following mesh repair surgery vs native-tissue repair in women with Stage-III or Stage-IV POP. METHODS: This was a prospective observational study of women who presented with Stage-III or Stage-IV POP and received primary prolapse surgery between 2013 and 2018. Transperineal ultrasound was performed before the operation and volumes were analyzed offline to assess the presence of levator ani muscle (LAM) avulsion. All women were counseled on either mesh repair or native-tissue reconstruction. The mesh-repair group was followed up for up to 5 years and the native-tissue-repair group for up to 2 years after the operation. Prolapse symptoms and POP quantification (POP-Q) staging were assessed at follow-up. Subjective recurrence of POP was defined as symptoms of prolapse (vaginal bulge sensation or dragging sensation) reported by the patient. Objective recurrence was defined as POP-Q ≥ Stage II. The subjective and objective recurrences of prolapse were compared between women with and those without mesh use. Multivariate regression analysis was used to identify risk factors for the recurrence of POP. RESULTS: A total of 154 Chinese women with Stage-III or Stage-IV prolapse were recruited. Of these, 104 (67.5%) underwent mesh repair (transabdominal in 57 women and transvaginal in 47 women) and 50 (32.5%) had native-tissue repair surgery. Ninety-five (61.7%) women had LAM avulsion. Both the subjective POP recurrence rate (4.8% vs 20.0%; P = 0.003) and the objective recurrence rate (20.2% vs 46.0%; P = 0.001) were significantly lower in the mesh-repair group than in the native-tissue-repair group. On multivariate logistic regression analysis, mesh repair was associated significantly with a reduced risk of subjective recurrence (odds ratio (OR), 0.20 (95% CI, 0.07-0.63)) and of objective recurrence (OR, 0.16 (95% CI, 0.07-0.55)) of prolapse. On subgroup analysis of women with LAM avulsion, mesh repair significantly reduced the risk of subjective recurrence (OR, 0.24 (95% CI, 0.07-0.87)) and objective recurrence (OR, 0.23 (95% CI, 0.09-0.57)) of POP. The incidence of mesh-related complications was low, and mesh exposure could be treated conservatively or by minor surgery. CONCLUSIONS: Mesh repair surgery, compared with native-tissue repair, was associated with a 5-fold reduction in the risk of subjective recurrence and a 6-fold reduction in the risk of objective recurrence of prolapse in women with Stage-III or Stage-IV POP. In women with concomitant LAM avulsion, mesh repair surgery was associated with a 4-fold reduction in both objective and subjective recurrence of POP. The rate of mesh-related complications was low, and mesh exposure could be treated conservatively or by minor surgery. The benefit of mesh surgery for these high-risk women appears to outweigh the risks of mesh complications, and it could be a treatment option for this group of women. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.