Vacuum extractor in the fight against intra- and postnatal fetal mortality

The introduction of obstetric forceps into practice did not satisfy obstetricians, since their use can cause severe damage to the birth canal and the head of the fetus, even if the head is located in the wide part or in the exit of the small pelvis, not to mention the imposition of high forceps, which is dangerous for both the mother and for the fetus.

Vacuum extractor AVE-1 in obstetric practice

Recently, a vacuum extractor has become more widely used in obstetric practice. However, the assessment of its application has not yet been given to the proper extent, which prompted us to share our experience.

Experience of using a vacuum extractor

The idea of creating a vacuum apparatus was put forward about 150 years ago (McKay, Zeman, Simpson, etc.). However, the method received wide application only after the creation of Finderle (Yugoslavia, 1952) and, independently of him, Malmstrm (Sweden, 1953) of more advanced models of vacuum extractors.

Investigating the Vacuum Extractors of Biomedical Devices of Different Materials and Pressures on the Fetal Head during Delivery

Operative delivery requires the use of a vacuum extractor; obstetricians can choose the appropriate vacuum extractor to make the delivery process smoother and safer. However, there is no biomechanical literature focused on the imposed effects of a vacuum extractor prepared with different materials and vacuum pressure on the fetal head during the process of delivery. Therefore, we first established and performed the finite element analytical model to explore the influences of vacuum extractors manufactured from different materials on the fetal head under various extractive pressures. The model of the vacuum extractor was designed as a hemispherical shape, and the material of the vacuum extractor was composed of silicone rubber and stainless steel for comparison. Four different vacuum pressures (500 cm H2O, 600 cm H2O, 700 cm H2O, and 800 cm H2O) were applied as the factors for investigation. The reaction force on the fetal head, von Mises stress of vacuum extractor, and von Mises stress on the skull of fetal head were measured and analyzed to evaluate the effects. The results revealed that subtle divergent influences of different vacuum pressures were observed, and the stainless-steel vacuum extractor induced a larger reaction force (358.04–361.37 N), accompanied with stress (13.547–13.675 MPa), on the fetal head than non-metallic or relatively softer materials. The results provide a reliable basis for selecting proper vacuum extractor during operative delivery to avoid obstetrical complications, such as scalp scratch, cephalohematoma and even intracerebral hemorrhage.

Vacuum Extractor Versus Manual Head Extraction During Cesarean Section

Background: For multifactorial reasons, the rate of cesarean deliveries increased clearly over a decade; decreased in vaginal births after cesarean (VBAC), multiple gestation, maternal obesity, pre-term labor, gestational diabetes or hypertension, increased number of high-risk expectant mothers and the obstetrical medico-legal environment. Delivering the fetal head at cesarean section can also be a lengthy operation and can result in maternal or fetal Complications. The vacuum extractor allows for the application of traction on the fetal head. In this study we aim to compare the safety (for mother and infant) and efficacy of delivery of the fetal head in cesarean section using vacuum extractor with the manual extraction. Methods: This study was conducted on 60 pregnant women undergoing cesarean section. All patients were between 37 and 42 weeks of pregnancy with signs of healthy fetus and were divided into 2 groups; Group I- 30 patients subjected to vacuum extraction at the cesarean section, Group II- 30 patients subjected to the conventional cesarean method. The result: The BMI of women in group I was 27.90 ± 0.96 and in group II was 28.0 ± 0.98. The gestational age of the babies in Group I and II were 39.0 ± 1.02 and 39.0 ± 0.98 weeks. U-D interval for Group I and Group II were 48.40 ± 17.63 and 73.87 ± 16.76 days respectively. The estimated blood loss in group I and group II were 478.0 ± 59.62 and 464.7 ± 52.57 respectively. The birth weight of the babies delivered in Group I and Group II were 4253.33 ± 118.72 and 4246.67 ± 135.58 KG respectively. The five minutes Apgar score for Group I and Group II were 8.50 ± 0.68 and 8.57 ± 0.57. Conclusion: The use of the vacuum extractor at cesarean section may be a safe and effective method to facilitate delivery of the large fetal head and cesarean section delivery can be simplified by this technique.

Effects of Attraction of Vacuum Extractors of Different Materials and Pressures on the Fetal Head During Delivery

PurposeIn some cases where operative deliveries are required with vacuum extractor, and obstetricians could choose the vacuum extractor to facilitate the process smoother and safer. However, there is no related biomechanical literature about the influences of vacuum extractors fabricated from different materials and pressures of vacuum on the fetal head. Hence, we utilized the finite element method to investigate the influences of vacuum extractors manufactured from different materials on the fetal head under various extractive pressures.MethodsFirst, the finite element analysis models of vacuum extractor and fetal head were established. The vacuum extractor model was designed as a hemispherical shape and we compared silicone rubber and stainless steel for the materials of vacuum extractor. Subsequently, four different vacuum pressures were applied as the factors for investigation—500-cm H2O, 600-cm H2O, 700-cm H2O, and 800-cm H2O. Finally, we observed and analyzed the reactive force on the fetal head, von Mises stress of vacuum extractor, and von Mises stress on the skull of fetal head to evaluate the influences of vacuum extractors of different materials under different pressures. ResultsThe results demonstrated that different vacuum pressures had only a slight difference of influences on the fetal head. The use of stainless-steel vacuum extractors caused a relatively larger reactive force (358.04–361.37 N) and stress (13.547–13.675 MPa) on the fetal head. ConclusionsNon-metallic or relatively softer materials could be selected when using a vacuum extractor for operative delivery to avoid complications such as scalp scratch, and even cephalohematoma and intracerebral hemorrhage.

Evaluation of Suzor forceps training by studying obstetric anal sphincter injuries: a retrospective study

Background Instrumental deliveries are an unavoidable part of obstetric practice. Dedicated training is needed for each instrument. To identify when a trainee resident can be entrusted with instrumental deliveries by Suzor forceps by studying obstetric anal sphincter injuries. Methods A French retrospective observational study of obstetric anal sphincter injuries due to Suzor forceps deliveries performed by trainee residents was conducted from November 2008 to November 2016 at Limoges University Hospital. Perineal lesion risk factors were studied. Sequential use of a vacuum extractor and then forceps was also analyzed. Results Twenty-one residents performed 1530 instrumental deliveries, which included 1164 (76.1%) using forceps and 89 (5.8%) with sequential use of a vacuum extractor and then forceps. Third and fourth degree perineal tears were diagnosed in 82 patients (6.5%). Residents caused fewer obstetric anal sphincter injuries after 23.82 (+/− 0.8) deliveries by forceps (p = 0.0041), or after 2.36 (+/− 0.7) semesters of obstetrical experience (p = 0.0007). No obese patient (body mass index> 30) presented obstetric anal sphincter injuries (p = 0.0013). There were significantly fewer obstetric anal sphincter injuries after performance of episiotomy (p < 0.0001), and more lesions in the case of the occipito-sacral position (p = 0.028). Analysis of sequential instrumentation did not find any additional associated risk. Conclusion Training in the use of Suzor forceps requires extended mentoring in order to reduce obstetric anal sphincter injuries. A stable level of competence was found after the execution of at least 24 forceps deliveries or after 3 semesters (18 months) of obstetrical experience.

Which technique is better to place a manoeuvrable vacuum extractor cup on the flexion point? Vacca vs. Bird technique

ObjectivesThe purpose of this study is to compare the vacuum extractor cup application technique described by Bird vs. the technique described by Vacca on a simulation model.MethodsSix obstetricians participated in the study. Each obstetrician performed eight vacuum assisted deliveries using the Bird technique and eight vacuum assisted deliveries using the Vacca 5-Steps technique.ResultsA total of 96 vacuum assisted deliveries were performed. The mean distance from the centre of the cup to the flexion point was 1.78±0.96 cm for the Bird technique and 1.05±0.60 cm for the Vacca technique (p<0.001). The lateral distance (over the parietal bone) was 1.16±0.69 cm for the Bird technique and 0.66±0.52 cm for the Vacca technique (p<0.001). The vertical distance (towards the frontal or occipital bone) was 1.12±1.02 cm for the Bird technique and 0.67±0.55 cm for the Vacca technique (p=0.009). In occipito anterior positions, there were no significant differences between both techniques.ConclusionsThe Vacca technique was better in transverse and posterior positions.

« Vous êtes toujours là? Ma souris m’a lâché » : cris, chuchotements et objets de l’écrivain dans le roman Vacuum de Christian Mistral

Le roman Vacuum (2003) de Christian Mistral se fait l’écho à notre époque de deux obsessions majeures : celle de la technologie et celle de se dire. Nous allons montrer que dans ce texte, qui a pris d’abord la forme d’un journal (éponyme) en ligne, l’utilisation du dispositif informatique (outil de communication privilégié en ce début de nouveau millénaire) et la manipulation de la matière du journal (support de l’œuvre à venir) sont le mobile d’un régime émotionnel chez le narrateur – un écrivain abandonné par sa muse qui raconte et commente son quotidien alors que son livre en chantier tarde à se concrétiser. Dans l’attente des mots justes et dociles, cet exutoire, vacuum extractor est salutaire : convié dans son « Bunker » où l’ordinateur, Memory Babe, a pris la place d’une vieille Underwood, le lecteur apprend la complicité de la nouvelle machine, l’épuisement de cette magie et le changement de destin du livre qui peine à mûrir.