Feasibility and safety study of a new device (Odón device) for assisted vaginal deliveries: study protocol

Exploring the reporting standards of RCTs involving invasive procedures for assisted vaginal birth: A systematic review

OBJECTIVE

Assisted vaginal birth (AVB) is a complex intervention involving medical devices, comprising multiple components. This complexity creates difficulties when designing and conducting randomised controlled trials (RCTs), in terms of describing, standardising and monitoring the intervention, and accounting for differing clinician expertise. This review examines the reporting standards of complex interventions involving a medical device, in the context of AVB RCTs.

STUDY DESIGN

Searches were undertaken from the start of indexing to March 2021, and limited to RCTs, feasibility and pilot studies including at least one device for AVB. RCTs were selected if they included participants having an AVB with any device, with or without a comparator group. Reporting details were assessed according to the Consolidating Standards of Reporting Trials extension for non-pharmacological treatments (CONSORT-NPT), focusing on intervention descriptions, standardization, adherence and clinician expertise. Screening of abstracts, full-text articles and data extraction was performed by two independent reviewers.

RESULTS

Of 4098 abstracts and 83 full-text articles, 39 papers were included, investigating 80 interventions. Twenty-seven different named devices were identified. Intervention descriptions were provided in 20 (55%) papers with varying levels of detail and with only one covering the entire procedure. Standardization of interventions was mentioned in 25 papers (64%). Only eight (21%) papers reported any form of adherence to the intended procedure. Some data regarding expertise were reported in 25 (64%) papers.

CONCLUSIONS

Despite some compliance with reporting standards, there is a lack of detail regarding intervention description, standardization, adherence and expertise in RCTs of AVB. This creates difficulties in understanding how intervention delivery was intended and what actually occurred. Clearer guidelines for the reporting of invasive procedures and devices are required.

The BD Odon Device™: an update of its current state

The BD Odon Device™ was designed as an alternative to conventional methods for assisting vaginal delivery, especially in low-resource settings. This a systematic review of published data concerning the BD Odon Device™ until March 2020 listed in Pubmed, Google Scholar, SCOPUS and Web of Science.Five studies testing the device were found, three in models and two in women with uncomplicated deliveries. According to their results, the device seems easy to use, safe, effective and requires simple and fast training, so it may become a good alternative to vacuum extractor or forceps, especially in places where there is less specialised staff, low-resources settings. The study protocol of the first study in complicated second stages has already been published. There is still few information about the BD Odon Device™ in scientific literature, however more research concerning the device is expected to take place in a near future.Impact StatementWhat is already known on this subject? The Odon Device^TM is a device under development that aims to be a useful tool to assist vaginal deliveries.What do the results of this study add? This is a review of the current state of the development of the Odon Device^TM. Further tests in humans are planned in the future in order to evaluate its safety and efficacy.What are the implications of these findings for clinical practice and/or further research? The Odon Device^TM may be a promising tool to assist vaginal deliveries, especially in low-resource countries and countries with high rates of C-section during second stage of labour, but further research is needed to evaluate its safety and efficacy.

Assessment of cerebral perfusion with contrast-enhanced ultrasound during constriction of the neck mimicking malposition of the BD Odon Device™: a study in newborn piglets

OBJECTIVE

The BD Odon Device™ is a new instrument for operative vaginal birth with potential for preventing maternal, fetal and newborn morbidity/mortality during a complicated second stage of labour. The device is a plastic sleeve with an air chamber inflated around the baby's head which is gently pulled through the birth canal. The aim was to monitor changes in cerebral circulation during constriction of the neck to evaluate a risk of potential malposition of the device.

DESIGN

Randomised prospective study.

POPULATION OR SAMPLE

Twelve newborn piglets.

METHODS

The anaesthetised piglets were exposed to hypoxia until base excess was -20 mmol/l and/or mean arterial blood pressure had decreased to 20 mmHg. At reoxygenation, an air chamber was inflated around the neck to 300 mmHg and the piglets randomised into three groups: 10 (n = 5), 5 (n = 5) or 2 (n = 2) minutes' occlusion. Cerebral perfusion was evaluated with transcranial contrast-enhanced ultrasound at four time-points, and analysed in the carotid arteries, basal ganglia, cortex and whole brain. Statistical analysis used ANOVA, linear mixed model, Kruskal-Wallis H-test.

MAIN OUTCOME MEASURES

Perfusion parameters; peak intensity, time to peak intensity, upslope, mean transit time, area under the curve.

RESULTS

The haemodynamic response was comparable between groups. Perfusion parameters showed a slight increase at end hypoxia followed by a decrease during occlusion, especially in the cortex (P = 0.00-0.2). After deflation, perfusion returned towards baseline values.

CONCLUSIONS

Simulation of malposition of the Odon Device was performed using a newborn hypoxic piglet model. Considerable compression of the neck vessels was applied, with only a moderate decrease in perfusion and with restoration of haemodynamics/cerebral perfusion after decompression.

TWEETABLE ABSTRACT

Malposition of Odon Device™ in a piglet model revealed a reversible decrease in cerebral perfusion during neck constriction.

Odon device for instrumental vaginal deliveries: results of a medical device pilot clinical study

Background

A prolonged and complicated second stage of labour is associated with serious perinatal complications. The Odon device is an innovation intended to perform instrumental vaginal delivery presently under development. We present an evaluation of the feasibility and safety of delivery with early prototypes of this device from an early terminated clinical study.

Methods

Hospital-based, multi-phased, open-label, pilot clinical study with no control group in tertiary hospitals in Argentina and South Africa. Multiparous and nulliparous women, with uncomplicated singleton pregnancies, were enrolled during the third trimester of pregnancy. Delivery with Odon device was attempted under non-emergency conditions during the second stage of labour. The feasibility outcome was delivery with the Odon device defined as successful expulsion of the fetal head after one-time application of the device.

Results

Of the 49 women enrolled, the Odon device was inserted successfully in 46 (93%), and successful Odon device delivery as defined above was achieved in 35 (71%) women. Vaginal, first and second degree perineal tears occurred in 29 (59%) women. Four women had cervical tears. No third or fourth degree perineal tears were observed. All neonates were born alive and vigorous. No adverse maternal or infant outcomes were observed at 6-weeks follow-up for all dyads, and at 1 year for the first 30 dyads.

Conclusions

Delivery using the Odon device is feasible. Observed genital tears could be due to the device or the process of delivery and assessment bias. Evaluating the effectiveness and safety of the further developed prototype of the BD Odon Device™ will require a randomized-controlled trial.

Trial registration

ANZCTR ACTRN12613000141741 Registered 06 February 2013. Retrospectively registered.

[Anal incontinence and obstetrical anal sphincter injuries, epidemiology and prevention]

Our main objectives were to identify risk factors, methods for early diagnosis, and prevention of obstetric anal sphincter injuries (OASIs), using a literature review. The main risk factors for OASIs are nulliparity, instrumental delivery, posterior presentation, median episiotomy, prolonged second phase of labor and fetal macrosomia. Asian origin, short ano-vulvar distance, ligamentous hyperlaxity, lack of expulsion control, non-visualization of the perineum or maneuvers for shoulder dystocia also appear to be risk factors. There is a risk of under-diagnosis of OASIs in the labor ward. Experience of the accoucheur is a protective factor. Secondary prevention is based on the training of birth professionals in recognition and repair of OASIs. Primary prevention of OASIs is based on training in the maneuvers of the second phase of labor; if possible, instrumental extractions should be avoided. Mediolateral episiotomy may have a preventive role in high-risk OASIs deliveries. A robust predictive model is still lacking to allow a selective use of episiotomy.

Prospective cohort study of a new vacuum delivery device to assist with complicated labour in low-resource settings

OBJECTIVES

Currently available vacuum devices used to assist women undergoing complicated labour are unsuitable for use in low-resource settings. The objective of this study was to evaluate the safety and feasibility of a new low-cost vacuum device, named Koohi Goth Vacuum Delivery System (KGVDS), designed for use in low-resource settings.

METHODS

A hospital-based, multicentre, prospective cohort study with no control group was conducted in Karachi, Pakistan. After training, KGVDS devices were made available for use by labour room staff at their discretion when instrumental delivery was indicated. Women to whom KGVDS was applied were followed from the start of labour until discharge. Feasibility was assessed in terms of successful expulsion of the foetal head following application of KGVDS and ease of use ratings. Safety was assessed by observing maternal and newborn post-delivery outcomes prior to discharge.

RESULTS

Koohi Goth Vacuum Delivery System was applied to 137 women requiring instrumental delivery, of whom 111 (81%; 95% CI = 74-88%) successfully expelled the foetal head assisted by KGVDS and 103 (75%) stated that they would agree to use KGVDS again. There were no serious maternal or neonatal injuries or infections related to KGVDS use. The mean score for 'ease of use' given by doctors and midwives using the device was 8 of 10.

CONCLUSIONS

Koohi Goth Vacuum Delivery System was feasible and safe to use for assisting complicated deliveries in low-resource hospitals in this initial evaluation. Our results indicate that this new device may have the potential to improve birth outcomes in settings where most mortality occurs and that further evaluations should be conducted.

Comparison of outcomes between operative vaginal deliveries and spontaneous vaginal deliveries in southeast Nigeria

OBJECTIVE

To evaluate the incidence of, indications for, and outcome of operative vaginal deliveries compared with spontaneous vaginal deliveries in southeast Nigeria.

METHODS

A retrospective cohort study was conducted involving cases of operative vaginal delivery performed at Ebonyi State University Teaching Hospital over a 10-year period. Data on the procedures were abstracted from the operation notes of the medical records of parturients.

RESULTS

An incidence of 4.7% (n = 461) was recorded. The most common indications for vacuum and forceps delivery were prolonged second stage of labor (44.9%) and poor maternal effort (27.8%). The only indication for destructive operation was intrauterine fetal death (3.7%). The risk ratio (RR) for hemorrhage/vulvar hematoma was 1.14 (95% confidence interval [CI], 0.53-2.48) for vacuum-assisted delivery and 5.49 (95% CI, 0.82-36.64) for forceps delivery. The RR for genital laceration was 1.21 (95% CI, 0.44-3.30) for vacuum-assisted delivery and 9.41 (95% CI, 1.33-66.65) for forceps delivery. The risk of fetal scalp bruises and caput succedaneum was higher for operative vaginal delivery than for spontaneous vaginal delivery, with no significant difference in maternal morbidity. The perinatal mortality rate was 0.9 per 1000 live births.

CONCLUSION

Operative vaginal delivery by experienced healthcare providers is associated with good obstetric outcomes with minimal risk.

Odon device: a promising tool to facilitate vaginal delivery and increase access to emergency care

The last innovation in operative vaginal delivery happened centuries ago with the invention of the forceps and the vacuum extractor. The World Health Organization Odon Device Research Group recently published a protocol for a feasibility and safety study for a new device (Odon device) which aims to revolutionize assisted vaginal delivery. This editorial discusses the device and its pathway to global use. Although preliminary results look promising, the rigorous three-phased WHO protocol needs completion before the device can be determined, based on the evidence, to be safe and effective.