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Research paper thumbnail of Impact of cannula size on recurrent twin–twin transfusion syndrome and twin anemia–polycythemia sequence after fetoscopic laser surgery

Ultrasound in Obstetrics & Gynecology, 2017

Objective The optimal outcome after fetoscopic laser surgery (FLS) for twin-twin transfusion synd... more Objective The optimal outcome after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) depends on the successful ablation of all placental anastomoses. The objective of this study was to determine the incidence of and risk factors for recurrent TTTS (rTTTS) or twin anemia-polycythemia sequence (TAPS) after FLS, focusing on the impact of cannula diameter. Methods This was a secondary analysis of data collected prospectively at two centers from 666 consecutive patients undergoing FLS for TTTS. The main outcomes were rTTTS and TAPS following FLS. Variables assessed included gestational age at intervention, stage of disease, recipient maximum vertical pocket, anterior placenta, number of anastomoses ablated, cannula diameter/operative scopes and use of the Solomon technique. Cannula diameter and corresponding scopes used were as follows: 8 Fr and 1.3 mm/0 • ; 9 Fr and 2.7 mm/0 • ; 10 Fr and 3 mm/0 • ; or 12 Fr and 3.3-3.7 mm/30-70 •. Cannula diameter was used as a surrogate for scopes during analysis. Multivariate logistic regression analysis was performed to identify risk factors associated with rTTTS or TAPS after FLS; 'center' was considered an independent variable to account for variations in practice. In a nested cohort of pregnancies in which both fetuses survived, placental dye injection was performed in 315 placentae. Multivariate logistic regression analysis was performed to evaluate variables associated with the presence of residual anastomoses.

Research paper thumbnail of OS019. External validation of the fullPIERS model in an existing dataset of women with severe pre-eclampsia, eclampsia or HELLP syndrome

Pregnancy Hypertension: An International Journal of Women's Cardiovascular Health, 2012

Research paper thumbnail of PP174. Timely prediction of maternal complications in pre-eclampsia analysis of the fullPIERS model

Pregnancy Hypertension: An International Journal of Women's Cardiovascular Health, 2012

Research paper thumbnail of Simulator training in fetoscopic laser surgery for TTTS: a pilot randomized controlled trial

Ultrasound in Obstetrics and Gynecology

To evaluate the effect of a newly developed training curriculum on performance of fetoscopic lase... more To evaluate the effect of a newly developed training curriculum on performance of fetoscopic laser surgery for twin-twin transfusion syndrome (TTTS) using an advanced high-fidelity simulator model. Ten novices were randomized to receive verbal instructions and skills training using the simulator (study group, n = 5) or no training (control group, n = 5). Both groups were evaluated with a pre-training test and post-training test. Assessment was performed by two independent observers and compromised a 52-item checklist for surgical performance (SP score), measurement of procedure time and number of anastomoses missed. Face validity and educational value of the simulator were assessed using a questionnaire. Eleven experts set the benchmark level of performance. Both groups showed an improvement in SP score compared to the pre-training test. The simulator-trained group significantly outperformed the control group with a median SP score of 28 (54%) in the pre-test and 46 (88%) in the pos...

Research paper thumbnail of Twenty-Five Years of Fetoscopic Laser Coagulation in Twin-Twin Transfusion Syndrome: A Systematic Review

Fetal Diagnosis and Therapy, 2015

Research paper thumbnail of Identification of essential steps in laser procedure for twin-twin transfusion syndrome using the Delphi methodology: SILICONE study

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2015

To determine, by expert consensus, the essential substeps of fetoscopic laser surgery (FLS) for t... more To determine, by expert consensus, the essential substeps of fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) that could be used to create an authority-based curriculum for training in this procedure among fetal medicine specialists. A Delphi survey was conducted among an international panel of experts (n = 98) in FLS. Experts rated the substeps of FLS on a five-point Likert-type scale to indicate whether they considered them to be essential, and were able to comment on each substep, using a dedicated online platform accessed by the invited tertiary care facilities that specialize in fetal therapy. Responses were returned to the panel until consensus was reached (Cronbach's α ≥ 0.80). All substeps that were rated ≥ 4 by 80% of the experts were included in the evaluation instrument. After the first iteration of the Delphi procedure, a response rate of 74% (73/98) was reached, and in the second and third iterations response rates of 90% (66/73) and 81% (59...

Research paper thumbnail of Is the Sequential Laser Technique for Twin-to-Twin Transfusion Syndrome Truly Superior to the Standard Selective Technique? A Meta-Analysis

Fetal diagnosis and therapy, Jan 16, 2014

Background and Objective: To investigate the efficacy of sequential laser coagulation in the trea... more Background and Objective: To investigate the efficacy of sequential laser coagulation in the treatment of twin-to-twin transfusion syndrome (TTTS). Data Sources: MEDLINE, EMBASE and the Cochrane Library were systematically searched for comparative studies on the efficacy of sequential versus standard selective laser coagulation for TTTS. The primary outcome measure in these studies was survival of at least one twin, both twins and fetal demise. Results: Three cohort studies comparing the selective laser treatment technique (n = 120) versus the sequential technique (n = 224) in 344 monochorionic twin pregnancies were included. Mean survival of at least one twin was 88% in the selective group versus 92% (p = 0.22) in the sequential group. Mean survival of both twins was lower in the selective group (52%) than in the sequential group (75%) (p = 0.002). Donor fetal demise decreased from 34% in the selective to 10% in the sequential group (p < 0.01), and recipient fetal demise decreas...

Research paper thumbnail of Intrauterine transfusion combined with partial exchange transfusion for twin anemia polycythemia sequence: Modeling a novel technique

Placenta, 2015

Introduction: Twin anemia-polycythemia sequence (TAPS) is a newly described disease in monochorio... more Introduction: Twin anemia-polycythemia sequence (TAPS) is a newly described disease in monochorionic twin pregnancies, characterized by large inter-twin hemoglobin differences. Optimal management for TAPS is not clear. One of the possible treatment modalities is intrauterine blood transfusion (IUT) in the donor with or without combination of partial exchange transfusion (PET) in the recipient. Methods: We applied a computational model simulation to illustrate the mechanism of IUT with and without PET in TAPS occurring after laser surgery for twinetwin transfusion syndrome (TTTS). Model simulations were performed with the representative anastomotic pattern as observed during laser intervention, and after placental dye injection. Results: The model was tested against different cases where IUT was combined with PET for the treatment of post-laser TAPS. Model simulations using the observed anastomotic pattern showed a significant reduction of hyperviscosity in the recipient after IUT/PET compared to IUT without PET. Discussion: In this model simulation we show that the addition of PET to IUT reduces the severity of polycythemia in the recipient. PET may thus be important to prevent complications of hyperviscosity. Conclusion: This model simulation shows the beneficial effect of PET for the recipient in TAPS cases treated with IUT.

Research paper thumbnail of Table of Contents

Research paper thumbnail of A worldwide survey of laser surgery for twin-twin transfusion syndrome

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2015

To evaluate differences between international fetal centers in their treatment of twin-twin trans... more To evaluate differences between international fetal centers in their treatment of twin-twin transfusion syndrome (TTTS) by fetoscopic placental laser coagulation. Fetal therapy centers worldwide were sent a web-based questionnaire. Participants were identified through networks and through scientific presentations and papers. Questions included physician and center demographics, treatment criteria, operative technique and instrumentation. Laser treatment was compared between low-volume (< 20 procedures/year) and high-volume (≥ 20 procedures/year) centers. Data were analyzed using descriptive statistics. Of 106 fetal therapy specialists approached, 76 (72%) from 64 centers in 25 countries responded. Of these, 48% (31/64) of centers and 63% (48/76) of operators performed fewer than 20 laser procedures annually. Comparison of low- and high-volume centers showed differences in technique, gestational age limits for treatment and geography. High-volume centers more often used the Solomo...

Research paper thumbnail of Continuous Non-Invasive Blood Pressure Monitoring, a Validation Study of Nexfin in a Pregnant Population

Hypertension in Pregnancy, 2009

To assess the accuracy of a non-invasive beat-to-beat continuous blood pressure monitoring device... more To assess the accuracy of a non-invasive beat-to-beat continuous blood pressure monitoring device (Nexfin) in pregnancy according to the International Protocol of the European Society of Hypertension. The validation was performed according to the International Protocol of the European Society of Hypertension. The test device (Nexfin, BMEYE, Amsterdam, the Netherlands) calculates beat to beat blood pressure from finger pulse wave analysis. Measurements of systolic and diastolic BP in 33 volunteers were obtained using the mercury sphygmomanometer and the Nexfin alternatingly. The device passed phase 1 as 30 systolic and 32 diastolic readings fell within 5 mmHg (25 required). In addition, the device also passed phase 2.1 as 68 systolic and 67 diastolic readings fell within 5 mmHg (65 required). Finally, it failed to pass phase 2.2 as 24 subjects for systolic and 23 for diastolic had at least 2/3 of their comparisons falling within 5 mmHg (22 required) but 6 subjects for systolic and 8 for diastolic had all three comparisons more than 5 mmHg different from the mercury readings (three allowed). The mean differences were 2.3 mmHg (SD 6.8) for SBP and 0.8 mmHg (SD 6.3) for DBP. The Nexfin device passed phase 1 and phase 2.1 but failed to pass phase 2.2. However, adaptation of the data to the more permissive AAMI (mean difference &lt;5 +/- 8 mmHg) and BHS (systolic grade B, diastolic grade A) protocols indicated adequate accuracy for application in research settings or for longitudinal within-patient tracking of blood pressure, given the possibility for continuous monitoring.

Research paper thumbnail of 156: A world-wide survey on laser surgery for twin-to-twin transfusion syndrome

American Journal of Obstetrics and Gynecology, 2014

Research paper thumbnail of Predicting complications in pre-eclampsia: external validation of the fullPIERS model using the PETRA trial dataset

European Journal of Obstetrics & Gynecology and Reproductive Biology, 2014

Therapeutics (J M Ansermino MBBCh, M J Douglas MD), and the CFRI Reproduction and Healthy Pregnan... more Therapeutics (J M Ansermino MBBCh, M J Douglas MD), and the CFRI Reproduction and Healthy Pregnancy Cluster (P Summary Background Pre-eclampsia is a leading cause of maternal deaths. These deaths mainly result from eclampsia, uncontrolled hypertension, or systemic inflammation. We developed and validated the fullPIERS model with the aim of identifying the risk of fatal or life-threatening complications in women with pre-eclampsia within 48 h of hospital admission for the disorder.

Research paper thumbnail of Impact of cannula size on recurrent twin–twin transfusion syndrome and twin anemia–polycythemia sequence after fetoscopic laser surgery

Ultrasound in Obstetrics & Gynecology, 2017

Objective The optimal outcome after fetoscopic laser surgery (FLS) for twin-twin transfusion synd... more Objective The optimal outcome after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) depends on the successful ablation of all placental anastomoses. The objective of this study was to determine the incidence of and risk factors for recurrent TTTS (rTTTS) or twin anemia-polycythemia sequence (TAPS) after FLS, focusing on the impact of cannula diameter. Methods This was a secondary analysis of data collected prospectively at two centers from 666 consecutive patients undergoing FLS for TTTS. The main outcomes were rTTTS and TAPS following FLS. Variables assessed included gestational age at intervention, stage of disease, recipient maximum vertical pocket, anterior placenta, number of anastomoses ablated, cannula diameter/operative scopes and use of the Solomon technique. Cannula diameter and corresponding scopes used were as follows: 8 Fr and 1.3 mm/0 • ; 9 Fr and 2.7 mm/0 • ; 10 Fr and 3 mm/0 • ; or 12 Fr and 3.3-3.7 mm/30-70 •. Cannula diameter was used as a surrogate for scopes during analysis. Multivariate logistic regression analysis was performed to identify risk factors associated with rTTTS or TAPS after FLS; 'center' was considered an independent variable to account for variations in practice. In a nested cohort of pregnancies in which both fetuses survived, placental dye injection was performed in 315 placentae. Multivariate logistic regression analysis was performed to evaluate variables associated with the presence of residual anastomoses.

Research paper thumbnail of OS019. External validation of the fullPIERS model in an existing dataset of women with severe pre-eclampsia, eclampsia or HELLP syndrome

Pregnancy Hypertension: An International Journal of Women's Cardiovascular Health, 2012

Research paper thumbnail of PP174. Timely prediction of maternal complications in pre-eclampsia analysis of the fullPIERS model

Pregnancy Hypertension: An International Journal of Women's Cardiovascular Health, 2012

Research paper thumbnail of Simulator training in fetoscopic laser surgery for TTTS: a pilot randomized controlled trial

Ultrasound in Obstetrics and Gynecology

To evaluate the effect of a newly developed training curriculum on performance of fetoscopic lase... more To evaluate the effect of a newly developed training curriculum on performance of fetoscopic laser surgery for twin-twin transfusion syndrome (TTTS) using an advanced high-fidelity simulator model. Ten novices were randomized to receive verbal instructions and skills training using the simulator (study group, n = 5) or no training (control group, n = 5). Both groups were evaluated with a pre-training test and post-training test. Assessment was performed by two independent observers and compromised a 52-item checklist for surgical performance (SP score), measurement of procedure time and number of anastomoses missed. Face validity and educational value of the simulator were assessed using a questionnaire. Eleven experts set the benchmark level of performance. Both groups showed an improvement in SP score compared to the pre-training test. The simulator-trained group significantly outperformed the control group with a median SP score of 28 (54%) in the pre-test and 46 (88%) in the pos...

Research paper thumbnail of Twenty-Five Years of Fetoscopic Laser Coagulation in Twin-Twin Transfusion Syndrome: A Systematic Review

Fetal Diagnosis and Therapy, 2015

Research paper thumbnail of Identification of essential steps in laser procedure for twin-twin transfusion syndrome using the Delphi methodology: SILICONE study

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2015

To determine, by expert consensus, the essential substeps of fetoscopic laser surgery (FLS) for t... more To determine, by expert consensus, the essential substeps of fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) that could be used to create an authority-based curriculum for training in this procedure among fetal medicine specialists. A Delphi survey was conducted among an international panel of experts (n = 98) in FLS. Experts rated the substeps of FLS on a five-point Likert-type scale to indicate whether they considered them to be essential, and were able to comment on each substep, using a dedicated online platform accessed by the invited tertiary care facilities that specialize in fetal therapy. Responses were returned to the panel until consensus was reached (Cronbach's α ≥ 0.80). All substeps that were rated ≥ 4 by 80% of the experts were included in the evaluation instrument. After the first iteration of the Delphi procedure, a response rate of 74% (73/98) was reached, and in the second and third iterations response rates of 90% (66/73) and 81% (59...

Research paper thumbnail of Is the Sequential Laser Technique for Twin-to-Twin Transfusion Syndrome Truly Superior to the Standard Selective Technique? A Meta-Analysis

Fetal diagnosis and therapy, Jan 16, 2014

Background and Objective: To investigate the efficacy of sequential laser coagulation in the trea... more Background and Objective: To investigate the efficacy of sequential laser coagulation in the treatment of twin-to-twin transfusion syndrome (TTTS). Data Sources: MEDLINE, EMBASE and the Cochrane Library were systematically searched for comparative studies on the efficacy of sequential versus standard selective laser coagulation for TTTS. The primary outcome measure in these studies was survival of at least one twin, both twins and fetal demise. Results: Three cohort studies comparing the selective laser treatment technique (n = 120) versus the sequential technique (n = 224) in 344 monochorionic twin pregnancies were included. Mean survival of at least one twin was 88% in the selective group versus 92% (p = 0.22) in the sequential group. Mean survival of both twins was lower in the selective group (52%) than in the sequential group (75%) (p = 0.002). Donor fetal demise decreased from 34% in the selective to 10% in the sequential group (p < 0.01), and recipient fetal demise decreas...

Research paper thumbnail of Intrauterine transfusion combined with partial exchange transfusion for twin anemia polycythemia sequence: Modeling a novel technique

Placenta, 2015

Introduction: Twin anemia-polycythemia sequence (TAPS) is a newly described disease in monochorio... more Introduction: Twin anemia-polycythemia sequence (TAPS) is a newly described disease in monochorionic twin pregnancies, characterized by large inter-twin hemoglobin differences. Optimal management for TAPS is not clear. One of the possible treatment modalities is intrauterine blood transfusion (IUT) in the donor with or without combination of partial exchange transfusion (PET) in the recipient. Methods: We applied a computational model simulation to illustrate the mechanism of IUT with and without PET in TAPS occurring after laser surgery for twinetwin transfusion syndrome (TTTS). Model simulations were performed with the representative anastomotic pattern as observed during laser intervention, and after placental dye injection. Results: The model was tested against different cases where IUT was combined with PET for the treatment of post-laser TAPS. Model simulations using the observed anastomotic pattern showed a significant reduction of hyperviscosity in the recipient after IUT/PET compared to IUT without PET. Discussion: In this model simulation we show that the addition of PET to IUT reduces the severity of polycythemia in the recipient. PET may thus be important to prevent complications of hyperviscosity. Conclusion: This model simulation shows the beneficial effect of PET for the recipient in TAPS cases treated with IUT.

Research paper thumbnail of Table of Contents

Research paper thumbnail of A worldwide survey of laser surgery for twin-twin transfusion syndrome

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2015

To evaluate differences between international fetal centers in their treatment of twin-twin trans... more To evaluate differences between international fetal centers in their treatment of twin-twin transfusion syndrome (TTTS) by fetoscopic placental laser coagulation. Fetal therapy centers worldwide were sent a web-based questionnaire. Participants were identified through networks and through scientific presentations and papers. Questions included physician and center demographics, treatment criteria, operative technique and instrumentation. Laser treatment was compared between low-volume (< 20 procedures/year) and high-volume (≥ 20 procedures/year) centers. Data were analyzed using descriptive statistics. Of 106 fetal therapy specialists approached, 76 (72%) from 64 centers in 25 countries responded. Of these, 48% (31/64) of centers and 63% (48/76) of operators performed fewer than 20 laser procedures annually. Comparison of low- and high-volume centers showed differences in technique, gestational age limits for treatment and geography. High-volume centers more often used the Solomo...

Research paper thumbnail of Continuous Non-Invasive Blood Pressure Monitoring, a Validation Study of Nexfin in a Pregnant Population

Hypertension in Pregnancy, 2009

To assess the accuracy of a non-invasive beat-to-beat continuous blood pressure monitoring device... more To assess the accuracy of a non-invasive beat-to-beat continuous blood pressure monitoring device (Nexfin) in pregnancy according to the International Protocol of the European Society of Hypertension. The validation was performed according to the International Protocol of the European Society of Hypertension. The test device (Nexfin, BMEYE, Amsterdam, the Netherlands) calculates beat to beat blood pressure from finger pulse wave analysis. Measurements of systolic and diastolic BP in 33 volunteers were obtained using the mercury sphygmomanometer and the Nexfin alternatingly. The device passed phase 1 as 30 systolic and 32 diastolic readings fell within 5 mmHg (25 required). In addition, the device also passed phase 2.1 as 68 systolic and 67 diastolic readings fell within 5 mmHg (65 required). Finally, it failed to pass phase 2.2 as 24 subjects for systolic and 23 for diastolic had at least 2/3 of their comparisons falling within 5 mmHg (22 required) but 6 subjects for systolic and 8 for diastolic had all three comparisons more than 5 mmHg different from the mercury readings (three allowed). The mean differences were 2.3 mmHg (SD 6.8) for SBP and 0.8 mmHg (SD 6.3) for DBP. The Nexfin device passed phase 1 and phase 2.1 but failed to pass phase 2.2. However, adaptation of the data to the more permissive AAMI (mean difference &lt;5 +/- 8 mmHg) and BHS (systolic grade B, diastolic grade A) protocols indicated adequate accuracy for application in research settings or for longitudinal within-patient tracking of blood pressure, given the possibility for continuous monitoring.

Research paper thumbnail of 156: A world-wide survey on laser surgery for twin-to-twin transfusion syndrome

American Journal of Obstetrics and Gynecology, 2014

Research paper thumbnail of Predicting complications in pre-eclampsia: external validation of the fullPIERS model using the PETRA trial dataset

European Journal of Obstetrics & Gynecology and Reproductive Biology, 2014

Therapeutics (J M Ansermino MBBCh, M J Douglas MD), and the CFRI Reproduction and Healthy Pregnan... more Therapeutics (J M Ansermino MBBCh, M J Douglas MD), and the CFRI Reproduction and Healthy Pregnancy Cluster (P Summary Background Pre-eclampsia is a leading cause of maternal deaths. These deaths mainly result from eclampsia, uncontrolled hypertension, or systemic inflammation. We developed and validated the fullPIERS model with the aim of identifying the risk of fatal or life-threatening complications in women with pre-eclampsia within 48 h of hospital admission for the disorder.