Emily J Hotton1,2, Mary Alvarez3,4, Erik Lenguerrand5, Julia Wade4, Natalie S Blencowe6,7, Tim J Draycott3, Joanna F Crofts3. 1. Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS10 5NB, UK. Emily.hotton@nhs.net. 2. Women & Children's Directorate, North Bristol NHS Trust, Bristol, UK. Emily.hotton@nhs.net. 3. Women & Children's Directorate, North Bristol NHS Trust, Bristol, UK. 4. Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK. 5. Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS10 5NB, UK. 6. Centre for Surgical Research - Population Health Sciences, University of Bristol, Bristol, UK. 7. NIHR Bristol Biomedical Research Centre, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
Abstract
BACKGROUND: The Odon Device™ is a new device for assisted vaginal birth that employs an air cuff around the fetal head for traction. Assisted vaginal birth (AVB) is a vital health intervention that can result in better outcomes for mothers and their babies when complications arise in the second stage of labour. Unfortunately, instruments for AVB (forceps and ventouse) are often not used in settings where there is most clinical need often due to lack of training and resources, resulting in maternal and neonatal morbidity and mortality which could have been prevented. This is often due to a lack of trained operators as well as difficulties in the sterilisation and maintenance of AVB devices. This novel, single use device has the potential to mitigate these difficulties as it is single use and is potentially simpler to use than forceps and ventouse. All the studies of the Odon Device to date (pre-clinical, preliminary developmental and clinical) suggest that the Odon Device does not present a higher risk to mothers or babies compared to current standard care, and recruitment to intrapartum research exploring the device is feasible and acceptable to women. The first study in which the Odon Device was used in clinically indicated conditions (the ASSIST Study) reported a lower efficacy than those reported with established devices. The reasons need to be explored, specifically focussing on learning curve, the technique of the doctors using this new device and potential modifications to device design. A follow-on clinical study to further investigate the efficacy and safety of the Odon Device in its indicated use, the ASSIST II Study, is therefore being undertaken. METHODS: The primary feasibility outcome is study feasibility (recruitment and retention rates) whilst the primary clinical outcome successful vaginal birth completed with the Odon Device. Key secondary feasibility outcomes include participant withdrawal, compliance in data collection and acceptability of the device to women and operators. Secondary clinical outcomes include maternal, neonatal and device outcomes. Safety data will be reviewed following every birth exploring maternal, neonatal and device risks. Using A'Hern approach for sample size calculation, we aim to recruit 104 women requiring an assisted vaginal birth for a recognised clinical indication. Assuming an AVB success rate of 65% or more, a one-sided alpha risk of 5% and power of 90%. DISCUSSION: The data from the ASSIST II Study will provide the information required regarding acceptability, recruitment, outcome data collection, device design, technique of device use and operator learning curve in order to design a future randomised controlled trial of the Odon Device versus current modes of assisted vaginal birth. TRIAL REGISTRATION: ISRCTN registration: 38829082 (prospectively registered July 26, 2019).
BACKGROUND: The Odon Device™ is a new device for assisted vaginal birth that employs an air cuff around the fetal head for traction. Assisted vaginal birth (AVB) is a vital health intervention that can result in better outcomes for mothers and their babies when complications arise in the second stage of labour. Unfortunately, instruments for AVB (forceps and ventouse) are often not used in settings where there is most clinical need often due to lack of training and resources, resulting in maternal and neonatal morbidity and mortality which could have been prevented. This is often due to a lack of trained operators as well as difficulties in the sterilisation and maintenance of AVB devices. This novel, single use device has the potential to mitigate these difficulties as it is single use and is potentially simpler to use than forceps and ventouse. All the studies of the Odon Device to date (pre-clinical, preliminary developmental and clinical) suggest that the Odon Device does not present a higher risk to mothers or babies compared to current standard care, and recruitment to intrapartum research exploring the device is feasible and acceptable to women. The first study in which the Odon Device was used in clinically indicated conditions (the ASSIST Study) reported a lower efficacy than those reported with established devices. The reasons need to be explored, specifically focussing on learning curve, the technique of the doctors using this new device and potential modifications to device design. A follow-on clinical study to further investigate the efficacy and safety of the Odon Device in its indicated use, the ASSIST II Study, is therefore being undertaken. METHODS: The primary feasibility outcome is study feasibility (recruitment and retention rates) whilst the primary clinical outcome successful vaginal birth completed with the Odon Device. Key secondary feasibility outcomes include participant withdrawal, compliance in data collection and acceptability of the device to women and operators. Secondary clinical outcomes include maternal, neonatal and device outcomes. Safety data will be reviewed following every birth exploring maternal, neonatal and device risks. Using A'Hern approach for sample size calculation, we aim to recruit 104 women requiring an assisted vaginal birth for a recognised clinical indication. Assuming an AVB success rate of 65% or more, a one-sided alpha risk of 5% and power of 90%. DISCUSSION: The data from the ASSIST II Study will provide the information required regarding acceptability, recruitment, outcome data collection, device design, technique of device use and operator learning curve in order to design a future randomised controlled trial of the Odon Device versus current modes of assisted vaginal birth. TRIAL REGISTRATION: ISRCTN registration: 38829082 (prospectively registered July 26, 2019).
Authors: N Mottet; A Bourtembourg; A Eckman-Lacroix; O Forner; C Mougey; J P Metz; R Ramanah; D Riethmuller Journal: Gynecol Obstet Fertil Senol Date: 2020-03-14
Authors: Stephen O'Brien; Emily J Hotton; Erik Lenguerrand; Julia Wade; Cathy Winter; Tim J Draycott; Joanna F Crofts Journal: Trials Date: 2019-03-05 Impact factor: 2.279
Authors: Emily J Hotton; Erik Lenguerrand; Mary Alvarez; Stephen O'Brien; Tim J Draycott; Joanna F Crofts Journal: Am J Obstet Gynecol Date: 2020-12-13 Impact factor: 8.661
Authors: Emily J Hotton; Natalie S Blencowe; Nichola Bale; Erik Lenguerrand; Tim J Draycott; Joanna F Crofts; Julia Wade Journal: BMJ Open Date: 2022-08-04 Impact factor: 3.006