U-CaVIT Versus Standard of Care for Prevention of Atonic Postpartum Hemorrhage After Cesarean Section in High-risk Women.

This pilot study aims to assess performance, safety and feasibility of U-CaVIT method (Uro-Catheter Vacuum Induced Tamponade), using the Rüsch® Brillant Silicone Balloon Catheter, an urological catheter, for the prevention of atonic PPH in high-risk women undergoing cesarean delivery. The U-CaVIT method has been implemented at the Department of Obstetrics at university hospital of Zurich (USZ) due to temporary supply issues with the Bakri® Balloon Catheter. The Rüsch® Balloon Catheter is used in case of uterine atony when standard first-line uterotonic treatments have failed or in some cases as add-on therapy in non-atonic PPH. In the meantime, the use of U-CaVIT has become standard practice at the USZ for the treatment of atonic PPH, appearing to be user-friendly, clinically effective according to treating physicians, well tolerated by the treated women and cost-saving compared to the previously used Bakri® Balloon.

Postpartum hemorrhage (PPH) is the main reason for maternal peripartum mortality and morbidity. It poses a significant burden not just in developing countries but also in industrialized nations, where an upward trend in PPH-related problems is being observed. According to the WHO, PPH is defined as blood loss of 500 mL or more within 24 hours after delivery, and it causes about 30% of maternal deaths worldwide. The internationally observed trend towards increased PPH-related morbidity and mortality is disturbing and demands new strategies in the prevention and treatment of PPH. The underlying causes of PPH are uterine atony (Tonus), trauma (Trauma), placental disorders (Tissue), and coagulopathy/hemorrhagic diathesis (Thrombin) as well as disorder of the coagulation system which itself aggravates bleeding. Among these, uterine atony, which prevents mechanical hemostasis, is thought to be responsible for 60-80% of PPH cases and remains one of the most frequent causes of postpartum hysterectomy. Therapy of uterine atony is based on the use of uterotonic drugs, nonsurgical approaches (e.g., uterine massage, intrauterine tamponade with an intrauterine balloon, vacuum device, or packing) as well as surgical therapies (e.g., repair of a deep laceration or tear in the uterus, cervix, or vagina; uterine artery ligation; curettage; uterine compression sutures; hysterectomy). A reasoned and sequential treatment approach is based on a multistage strategy that starts from less invasive interventions proceeding to more invasive methods. The strategic goal is to prevent severe PPH by implementing a minimally invasive, effective and low-cost method at an early stage of PPH or even before PPH might occur in high-risk patients, who inherently have an increased bleeding risk following a cesarean section. This would result in an enormous benefit to the patient in terms of morbidity and mortality as well as a consistent and judicious approach in the use of resources. In an atonic uterus, vessels are not constricted and hemorrhage ensues, prompting first-line therapy. When medical management alone is deemed unsuccessful, balloon tamponade is currently the next treatment option added to control uterine atony. A balloon is placed within the uterus and inflated with sterile saline solution to put sustained pressure on the uterus from the inside. The Bakri® Balloon (Cook Medical) is currently the most commonly described intrauterine tamponade balloon device in the literature. By applying external pressure to the uterine walls for 12-24 hours, the uterus may then involute and regain normal tone. Although tamponade has been demonstrated to be effective in controlling hemorrhage in 87% (95% CI 84-90%) of atony-related cases, the mechanism of action of using outward pressure to control bleeding from uterine atony is counterintuitive if the ultimate goal is uterine contraction. Recently, intrauterine vacuum devices have been introduced, offering a new mechanism for achie trial.show_full_description

Inclusion Criteria: * Signed informed consent * Maternal age ≥18 years * Gestational age ≥30+0 weeks of pregnancy at day of delivery * Vital pregnancy * Delivery mode: planned cesarean delivery * High-risk patient for PPH specified by the presence of at least one of the following characteristics: Previous PPH, obesity (BMI ≥30 kg/m2), high parity (patient who has had ≥4 previous births (live or stillborn) at ≥20 weeks of gestation), very advanced maternal age ≥45 years, multiple gestation, polyhydramnios (defined as amniotic fluid index \> 25 cm or deepest amniotic fluid pocket \> 8 cm) at admission to delivery, suspected fetal macrosomia (estimated fetal weight ≥ 4500g) Exclusion Criteria: * Insufficient language skills in German or English to understand and sign informed consent * Participation in another interventional study * Emergency cesarean section (incl. patients undergoing cesarean after failed vaginal delivery) * Subjects who change their delivery plan from vaginal to cesarean section in the course of hospitalization * Women with regular and painful contractions and women who do not have time for sufficient consideration * Clinical situations in which vacuum-induced uterine tamponade is unlikely to be effective or is contraindicated: * Uterine or vaginal anomalies (genital tract congenital anomalies) * Cesarean section due to placenta previa or suspected placenta accreta spectrum * Suspected uterine rupture * Injuries of the cervix or vagina * Submucous or intramural uterine fibroids which are buldging into the uterine cavity * Deep endometriosis \[16, 17\] * Planned atony-prophylaxis with oxytocin due to contraindication for carbetocin * Previous MMC-repair (myelomeningocele-repair) * Clinical diagnosis of chorioamnionitis, sepsis * Known allergy to silicone * Known and proven diagnosis of bleeding disorder or thrombophilia * Known thrombocytopenia during second half of pregnancy with thrombocytes \< 100 G/L * Known anemia during second half of pregnancy with Hb\<80