This retrospective study was conducted from January 2012 to August 2023 in West China Second University Hospital, a tertiary referral center for maternal and children’s health in Western China. The study was approved by the Ethics Committee of the West China Second University Hospital, Sichuan University. In our hospital, PPA is managed by multidisciplinary expertise, including experienced obstetricians, gynecologic oncologists, anesthesiologists, interventional radiologists, and surgical nurses. In our hospital, a cesarean hysterectomy was conducted to stop life-threatening hemorrhage only in case of severe PPA without an attempt to separate the placenta and in cases that had a failure of conservative management after removing the placenta.
Women with placenta previa and pathologically confirmed PAS who underwent hysterectomy during cesarean section after 28 weeks of gestation were included in the current study. Patients with twin pregnancies, severe prenatal uterine rupture before surgery, and who underwent relaparotomy for hysterectomy were excluded. Clinical and demographic characteristics were obtained from the electronic medical records.
A total of 199 women with PPA who received cesarean hysterectomy were included in the current study. PPA is a major cause of life-threatening PPH.4 The rate of PPH was extremely high in our study group. The median EBL of the study group was 3500 mL (2500, 5000) (interquartile range), and about 96.48% (192/199) of women were diagnosed with PPH which had EBL ≥ 1000 mL. In addition, there is no consensus on the severity classification of PPH. Therefore, the cases were divided into two similarly sized groups to investigate the potential risk factors of additional EBL in women with PPA who received cesarean hysterectomy. We defined Group 1 (G1) = EBL ≤ 3500 mL (n = 103), Group 2 (G2) = EBL > 3500 mL (n = 96). (Fig. 1)
Maternal information included demographic characteristics, obstetric history, perinatal complications, ultrasonic findings, and placental pathology. Perioperative outcomes included estimated blood loss (EBL), gestational age (GA) at delivery, intra-arterial balloons, surgical time, hysterectomy types, intraoperative consultation, cervical invasion of placenta, intraoperative bladder injury, infusion, blood products transfusion, and maternal postsurgical hospital stay. Neonatal outcomes included neonatal intensive care unit (NICU) admission and birth weight. The primary outcome was defined as an EBL > 3500 mL.
Placenta previa is defined as placenta implanting within the lower uterine segment, and the lower placental edge partially or entirely covers the cervical internal os.5 PAS is defined as three types of placenta adherenta, increta, and percreta, based on pathological examination of the hysterectomy specimens according to the International Federation of Gynecology and Obstetrics (FIGO) PAS classification. Placenta adherenta is where placental villi are attached directly to the superficial myometrium and extended absence of decidua. Placenta increta is where the villi penetrate into the uterine myometrium, and placenta percreta is defined as villous tissue within or breaching the uterine serosa.9
According to recent studies, the effectiveness of intraoperative internal iliac artery balloon occlusion in women with PAS was not reliable.10,11 Therefore, most of the women in our study who had bilateral internal iliac artery balloon occlusion were delivered before the year 2020. After 2020, prophylactic balloon occlusion of the internal iliac artery was not routinely conducted in our hospital, and prophylactic abdominal aortic balloon was performed in some severe cases of PPA at the multidisciplinary team’s discretion. Written informed consents were obtained from all women who received intra-arterial balloon catheters.
The procedure for balloon occlusion was as follows. For internal iliac arteries occlusion, under X-ray guidance, the catheters (low profile PTA dilatation catheter PTA5-35-80-8-6.0, Cook Medical Inc., Bloomington, USA) were inserted via the femoral arteries and placed at the anterior division of the internal iliac arteries. For abdominal aortic occlusion, the catheter (dilatation catheter AT75164, Bard Peripheral Vascular Inc., Arizona, USA) was inserted via the right femoral artery and placed in the abdominal aorta below the level of renal arteries. After the placement of catheters, cesarean delivery was conducted immediately, and the balloons were inflated after the cord was clamped. During the surgery, the abdominal aortic balloons were deflated every ten minutes, and oxygen saturation of the left great toe was monitored.
EBL was based on the amount of blood collected in the suction canister, excluding amniotic fluid and saline for irrigation. The number of laparotomy pads used during the surgery and blood on other surfaces were also calculated. The final EBL was confirmed by the judgment of surgeons, nurses, and anesthetists. The surgical time was defined as the duration between incision for cesarean and wound closure. The final decision of cesarean hysterectomy and the procedure of hysterectomy were made by experienced obstetricians and with consultation from gynecologic oncologists in some cases. Cervical invasion of the placenta was confirmed by laparotomic finding that part of the placenta penetrated the cervical canal or abnormally attached to the cervical tissue. If an intraoperative bladder injury occurred, urologists were consulted to repair the bladder.
The Kolmogorov–Smirnov test was performed to determine the normality of continuous variables. Non-normally distributed data were shown as median (interquartile range), and the Mann–Whitney U test was used for the analysis. Categorical variables are presented as number/proportion (%) and were analyzed by the chi-square test. A stepwise backward elimination multivariate logistic regression model was applied to ascertain independent risk factors of the primary outcome. All statistical analyses and data processing were conducted using SPSS 24.0 statistical software (IBM, Armonk, NY, USA). P < 0.05 was considered as statistically significant. Odds ratio (OR) and 95% confidence intervals (CI) are used to show the effect of potential risk factors.