Maternal hypotension during fetoscopic surgery: incidence and its impact on fetal survival outcomes

Real-time fetal monitoring using photoacoustic measurement of placental oxygen saturation in a rabbit hypoxia model

INTRODUCTION

Ensuring adequate fetal oxygenation is an essential aim of fetal monitoring. The purpose of this study was to establish a basic technique for real-time measurement of blood oxygen saturation of the placenta by photoacoustic (PA) technique as a new fetal monitoring method.

METHODS

The hypoxia model established in our previous study was applied to 7 pregnant rabbits. Three phases were induced: normal phase, hypoxia phase, and recovery phase. Three methods were simultaneously used for real-time fetal monitoring: fetal heat rate (FHR) monitoring, oxygen saturation (SO2) measurement by near-infrared spectroscopy (SNO2), and placenta SO2 measured by PA technique (SplO2). The maternal hypoxia was assessed by skin SO2 measured by PA technique (SsO2), and arterial blood SO2 by blood gas analysis (SaO2).

RESULTS

The average of SplO2 in normal phase was 52.6 ± 13.9 %. The averages of SNO2, SSO2, and SplO2 in the seven rabbits changed in parallel from the normal phase to hypoxia phase. In the recovery phase, the SplO2 rose in parallel with recovery of SaO2. There was lag in increase of the FHR compared to the change in the other values. In the detailed analysis of PA signals from the labyrinth and decidua, a unique change in oxygen saturation was seen in one case.

DISCUSSION

Results of this study showed that sensitivity of our novel PA technique in detecting tissue hypoxia was similar to near-infrared spectroscopy (NIRS). As an advantage, unlike NIRS, monitoring with PA technique was unaffected by ischemia and surface changes in oxygen saturation because of its higher spatial resolution. We conclude that PA technique provides more accurate information about fetal blood placenta than NIRS. Ultrasound imaging, combined with oxygen saturation monitoring by PA technique, would improve fetal monitoring and fetal diagnosis in the future.

Single fetal demise following fetoscopic ablation for twin-to-twin transfusion syndrome-cohort study, systematic review, and meta-analysis

BACKGROUND

Several studies have assessed preoperative and operative factors associated with fetal demise after laser for TTTS, yet these findings are not completely conclusive.

OBJECTIVE

This study aimed to identify risk factors for single fetal demise (recipient and donor twins) after fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome.

STUDY DESIGN

We searched PubMed, Scopus, and Web of Science systematically from the inception of the database to June 2020. We conducted a systemic review on studies investigating risk factors for fetal demise (donor and/or recipient) after fetoscopic laser photocoagulation in monochorionic pregnancies complicated with twin-to-twin transfusion syndrome. Initially, we investigated the cohort of women with twin-to-twin transfusion syndrome that underwent fetoscopic laser photocoagulation at our 2 high-volume fetal centers between 2012 and 2020 to identify risk factors for donor demise and recipient demise. Furthermore, we conducted a systematic review of the literature to better characterize these factors. Among studies that met the entry criteria, multiple preoperative and operative factors were tabulated. The random-effect model was used to pool the standardized mean differences or odds ratios and corresponding 95% confidence intervals. Heterogeneity was assessed using the I² value.

RESULTS

A total of 514 pregnancies with twin-to-twin transfusion syndrome managed with fetoscopic laser photocoagulation were included in the final analysis. Following the logistic regression, factors that remained significant for donor demise were selective fetal growth restriction (odds ratio, 1.9; 95% confidence interval, 1.3-2.8; P=.001) and umbilical artery blood flow with absent or reversed end-diastolic velocity of the donor (odds ratio, 2.06; 95% confidence interval, 1.2-3.4; P=.004). A significant factor associated with recipient demise was absent or reversed a-wave in the ductus venosus of the recipient (odds ratio, 1.74; 95% confidence interval, 1.07-3.13; P=.04). Data from 23 studies and our current cohort were included. A total of 4892 pregnancies with twin-to-twin transfusion syndrome managed with fetoscopic laser photocoagulation were analyzed for risk factors for donor demise, and 4594 pregnancies with twin-to-twin transfusion syndrome were analyzed for recipient demise. Among studies, the overall incidence rates ranged from 10.9% to 35.8% for donor demise and 7.3% to 24.5% for recipient demise. Significant risk factors for donor demise were intertwin estimated fetal weight discordance of >25% (odds ratio, 1.86; 95% confidence interval, 1.44-2.4; I², 0.0%), selective fetal growth restriction (odds ratio, 1.78; 95% confidence interval, 1.4-2.27; I², 0.0%), twin-to-twin transfusion syndrome stage III (odds ratio, 2.18; 95% confidence interval, 1.53-3.12; I², 0.0%), umbilical artery blood flow with absent or reversed end-diastolic velocity of the donor (odds ratio, 2.31; 95% confidence interval, 1.9-2.8; I², 23.7%), absent or reversed a-wave in the ductus venosus of the donor (odds ratio, 1.83; 95% confidence interval, 1.45-2.3; I², 0.0%), and presence of arterioarterial anastomoses (odds ratio, 2.81; 95% confidence interval, 1.35-5.85; I², 90.7%). Sequential selective coagulation was protective against donor demise (odds ratio, 0.31; 95% confidence interval, 0.16-0.58; I², 0.0%). Significant risk factors for recipient demise were twin-to-twin transfusion syndrome stage IV (odds ratio, 2.18; 95% confidence interval, 1.01-4.6; I², 16.5%), umbilical artery blood flow with absent or reversed end-diastolic velocity of the recipient (odds ratio, 2.68; 95% confidence interval, 1.91-3.74; I², 0.0%), absent or reversed a-wave in the ductus venosus of the recipient (odds ratio, 2.37; 95% confidence interval, 1.55-3.64; I², 60.2%), and middle cerebral artery peak systolic velocity of >1.5 multiple of the median (odds ratio, 3.06; 95% confidence interval, 1.36-6.88; I², 0.0%).

CONCLUSION

Abnormal blood flow patterns represented by abnormal Doppler studies and low fetal weight were associated with single fetal demise in women with twin-to-twin transfusion syndrome undergoing laser therapy. Although sequential selective coagulation was protective against donor demise, the presence of arterioarterial anastomoses was considerably associated with donor demise. This meta-analysis extensively investigated the association of a wide range of preoperative and operative factors with fetal demise. These findings may be important inpatient counseling, in further understanding the disease, and perhaps in improving surgical techniques.

Seguridad de la anestesia neuroaxial en mujeres con embarazo gemelar y síndrome de transfusión feto-fetal, sometidas a fotocoagulación láser. Estudio de cohorte retrospectiva

Objetivo: describir las características clínicas y la frecuencia de complicaciones maternas, fetales y neonatales, según técnica de anestesia neuroaxial (AN) en mujeres con síndrome de transfusión feto-fetal (STFF) tratadas con fotocoagulación láser (FL). Materiales y métodos: estudio de cohorte retrospectiva descriptivo. Se incluyeron gestantes con STFF tratadas con FL y AN en la Fundación Valle del Lili, Cali (Colombia) entre 2013-2017. Se excluyeron pacientes con STFF estadio-V de Quintero. Se usó estadística descriptiva. El protocolo fue aprobado por el Comité de Ética de la institución. Resultados: 32 participantes cumplieron con los criterios de inclusión y de exclusión. La población estuvo constituida por mujeres jóvenes, multíparas. En el 87,5% de los casos se realizó intervención de urgencia. El 43,7% presentaba el estadio-III de Quintero y en el 56,2 % de las gestantes se utilizó anestesia epidural. Las variables hemodinámicas maternas exhibieron un comportamiento similar, acorde al momento de la cirugía y la técnica neuoraxial implementada. El 65,6 % de las gestantes presentó hipotensión sostenida y el 9,3 % desarrolló edema pulmonar. El 65,6 % de las pacientes experimentó parto pretérmino y el 18,7 % ruptura prematura de membranas. Se registraron 14 muertes fetales y cinco neonatales. No se registraron casos de mortalidad materna. Conclusiones: en pacientes con STFF que requieren FL, el uso de la anestesia epidural, espinal o combinada probablemente se asocia con un comportamiento similar al de las variables hemodinámicas maternas, durante los momentos de la cirugía. Los profesionales que brindan atención a estas gestantes deben estar alerta ante la frecuente aparición de complicaciones maternas, fetales y neonatales. Se requieren estudios prospectivos que evalúen la seguridad y la efectividad de las diferentes técnicas de anestesia neuroaxial en pacientes con STFF.

Anesthesia for predelivery procedures: ex-utero intrapartum treatment/intrauterine transfusion/surgery of the fetus

PURPOSE OF REVIEW

The aim of this study was to review the current literature on anesthesia for predelivery procedures and to summarize recent findings on anesthesiological methods used.

RECENT FINDINGS

Ex-utero intrapartum treatment (EXIT)-procedures are performed to secure the newborn's oxygenation in case of severe airway obstruction due to multiple conditions. A key feature of EXIT is continued intactness of the maternofetal circulation by uterine relaxation achieved by general anesthesia with high doses of anesthetic gases. A dose reduction may be achieved by combining inhaled anesthesia with propofol. After intrauterine transfusion the anesthesia team needs to be prepared for a potential need of emergency cesarean section. Temporary fetal endoluminal tracheal occlusion and laser coagulation for twin-to-twin transfusion syndrome may be either performed in monitored anesthesia care or neuraxial anesthesia. Neuraxial anesthesia also is a method of choice for fetal valvuloplasty and amniotic band release. Fetal myelomenigocele repair requires general anesthesia with tocolysis.

SUMMARY

Predelivery procedures require a differentiated anesthesia approach depending on the invasiveness of the intervention. Anesthesia ranges from monitored care to neuraxial anesthesia and general anesthesia. Depending on the procedure uterine relaxation and fetal immobilization are crucial for technical success. Interdisciplinary consultation optimizes the anesthesia plan for complex procedures.

Outcome reporting across randomized trials and observational studies evaluating treatments for twin-twin transfusion syndrome: systematic review

OBJECTIVE

Twin-twin transfusion syndrome (TTTS) is associated with significant mortality and morbidity. Potential treatments for the condition require robust evaluation. The aim of this study was to evaluate outcome reporting across observational studies and randomized controlled trials assessing treatments for TTTS.

METHODS

Cochrane Central Register of Controlled Trials, EMBASE and MEDLINE were searched from inception to August 2016. Observational studies and randomized controlled trials reporting outcome following treatment for TTTS in monochorionic-diamniotic twin pregnancy and monochorionic-triamniotic or dichorionic-triamniotic triplet pregnancy were included. Outcome reporting was systematically extracted and categorized.

RESULTS

Six randomized trials and 94 observational studies were included, reporting data from 20 071 maternal participants and 3199 children. Six different treatments were evaluated. Included studies reported 62 different outcomes, including six fetal, seven offspring mortality, 25 neonatal, six early childhood and 18 maternal/operative outcomes. Outcomes were reported inconsistently across trials. For example, when considering offspring mortality, 31 (31%) studies reported live birth, 31 (31%) reported intrauterine death, 49 (49%) reported neonatal mortality and 17 (17%) reported perinatal mortality. Four (4%) studies reported respiratory distress syndrome. Only 19 (19%) studies were designed for long-term follow-up and 11 (11%) of these reported cerebral palsy.

CONCLUSIONS

Studies evaluating treatments for TTTS have often neglected to report clinically important outcomes, especially neonatal morbidity outcomes, and most are not designed for long-term follow-up. The development of a core outcome set could help standardize outcome collection and reporting in TTTS studies. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

[Epidural anesthesia for fetoscopy : Retrospective analysis of a one-year cohort]

BACKGROUND

The introduction of routine prenatal screening using ultrasound has led to a substantial increase in diagnoses of fetal disorders that are amenable to intrauterine treatment. While an ultrasound guided insertion of small bore cannulas can be performed under local anesthesia, insertion of a fetoscope usually requires anesthetic management for the mother and the fetus. Additionally, the fetus' intrauterine position may have to be manipulated in order to enable access. Such manoeuvres depend on relaxation of the mother's abdominal wall. General anesthesia has been the preferred method, but it involves substantial risks both to the mother and possibly the fetus, especially when combined with aggressive uterine relaxation. Epidural anesthesia (EA) may provide an alternative. Only little systematic data on the efficacy, requirements or untoward effects of epidural anesthesia for fetoscopy exists in the literature, yet a high rate of arterial hypotension following EA has been reported. We therefore aimed to assess the hemodynamic reaction to EA in a mixed population of pregnant women undergoing fetoscopy for a variety of fetal conditions and performed a retrospective analysis of a one-year cohort in a single university hospital.

METHODS

The local ethics committee approved this retrospective analysis and waived patient consent (local study identifier 304/14). We extracted anesthesiologic and hemodynamic data from the anesthesia charts of 23 consecutive cases of elective fetoscopic procedures requiring anesthesia between May 2011 and 2012 at a German university medical centre.

RESULTS

Twenty-three cases of fetoscopy were included in this study. Indications for fetoscopy were congenital diaphragmatic hernia (n = 9), aortic valve stenosis (n = 8), and feto-fetal transfusion syndrome (n = 6). Median gestational age was 26 (8, interquartile range) weeks. Lumbar epidural catheters were injected with a median dose of 0.09 (0.02, interquartile range) ml ropivacaine 0.75% per cm maternal height. In 11 patients, EA was titrated to a sufficient height whereas 12 patients received a single dose with a median volume of 0.08 (0.02) ml/cm maternal height. After injection, systolic arterial pressure did not change significantly, mean arterial pressure dropped from 93 (14) mm Hg to 88 (15) mm Hg (p = 0.03). Heart rate fell from 96 (29) to 89 (20) beats per minute (p = 0.02). At incision, neither blood pressure nor heart rate changed significantly. For hemodynamic support during the procedure, cafedrine/theodrenaline (Akrinor™) was injected in five patients (median dose in these patients 0.5 (1.5) ml). One patient carrying a fetus with a poor prognosis and who underwent two separate procedures demanded additional sedation, for which we chose remifentanil. Another patient was hypotensive after intravenous administration of the tocolytic drug atosiban. A stable hemodynamic condition was quickly restored in this patient with administration of cafedrine/theodrenaline and i. v. fluids. All procedures were performed without conversion to general anaesthesia.

CONCLUSION

This retrospective study demonstrates that fetoscopic procedures under EA in the range of indications treated in our institution can be performed safely. EA was associated with stable hemodynamic conditions in this mixed cohort of pregnant women. EA appears thus to be a suitable technique for fetoscopy, avoiding the risks inherent to general anesthesia in pregnant women.

Anaesthesia for foetoscopic Laser ablation- a retrospective study

Background and Aims:

Twin pregnancy with monochorionic placenta may be associated with arteriovenous vascular anastomosis of the placental vessels resulting in twin-to-twin transfusion syndrome (TTTS) and twin reversed arterial perfusion syndrome (TRAP). Foetoscopic LASER ablation (FLA) is the treatment of choice in reducing foetal mortality related to this.

Methods:

A retrospective review of medical records of 41 FLA procedures for TTTS and TRAP were analysed for anaesthetic management. Thirty-four patients received subarachnoid block, three combined spinal-epidural block, three general anaesthesia and one local anaesthesia with sedation. Nitroglycerine 5 mg patch was used for tocolysis 1 h before the procedure and continued for 24–48 h postoperatively.

Results:

Bupivacaine was used in 34 patients, and ropivacaine in three patients. Mean dose of bupivacaine 0.5% was 2.43 ± 0.32 ml and ropivacaine 0.75% was 2.85 ± 0.19 ml. The mean duration of surgery was 117.07 ± 28 min. Mild hypotension occurred in all patients under spinal anaesthesia and was treated with vasopressors. The foetal outcome among all 41 patients were 13 delivered live twins, 15 had a single live baby with intrauterine death of other twin baby. In 12 patients, both babies were intrauterine death. One patient was lost for follow-up.

Conclusion:

Foetoscopic procedures can be done under central neuraxial block, however occasionally general anaesthesia may be required.