Validation Of The Ultrasonographic Quantitative Scoring System For Cesarean Scar Pregnancy

Background:Cesarean scar pregnancy(CSP)refers to a special type of pregnancy with the gestational sac implanted in the previous cesarean section scar.With the increase of cesarean section rate and the implement of two-child policy,the incidence of CSP has been increasing rapidly in china.Because of the special location of the gestational sac,CSP often accompany with severe complication such as placenta accrete spectrum disorders,massive bleeding and uterine rupture.At present,there are various treatment modalities for CSP,but no universal consensus has been obtained.In the previous study of our team,an ultrasonographic quantitative scoring system had been established to evaluate the severity of CSP,and different treatments were suggested according to the severity.However,the ultrasonographic quantitative scoring system has not been validated or applied clinically.Objectives:1.To retrospectively evaluate the effect of ultrasonographic quantitative scoring system in evaluating the severity of CSP and predicting prognosis of patients.2.To further prospectively validate the ultrasonographic quantitative scoring system.Materials and Methods:1.We retrospectively collected clinical records of 372 women who were diagnosed with CSP and treated by evacuation following uterine artery chemoembolization(UACE)in the Second Affiliated Hospital of Army Medical University of China between January 1,2009 and May 31,2015.All patients were scored by the ultrasonographic quantitative scoring system,and were divided into low-risk group(0-4 points),medium-risk group(5-7 points)and high-risk group(8-10 points)according to the different score.The prognosis of the three groups of patients and the consistency between the actual treatment and the predicted treatment were compared,and the predictive efficacy of the ultrasonographic quantitative scoring system on the severity and the prognosis was analyzed.2.A prospective analysis of 183 patients diagnosed with CSP between April 1,2018 and June 30,2019 was performed.All patients treated by evacuation,followed by uterine artery embolization(UAE)and successive laparoscopic local resection as salvage treatments if necessary.A score was computed based on clinical and ultrasonographic parameters included in the ultrasonographic quantitative scoring system.Treatment indicated by the scoring system was compared with actual treatment received.Receiver operating characteristic(ROC)curves were used to identify cut-off scores for salvage treatment.Statistical analysisIBM SPSS 22.0 was used for statistical analysis.Statistical methods including univariate analysis and ROC curve analysis were adopted,and Kappa consistency test was employed.Results:1.In the retrospective analysis of 372 CSP patients,there were 208 patients in the low-risk group,138 patients in the medium-risk group and 26 patients in the high-risk group.The proportion of intraoperative bleeding more than 50 ml,the size of the mass formed after treatment,the time for mass to disappear,and the probability of pregnancy after treatment in the high-risk group were significantly lower than those in the low-risk group and the medium-risk group.Comparison among three groups,the two factors of probability of mass formation after treatment and the time to menstrual recovery in the three groups was: high-risk group > medium-risk group > low-risk group.2.Among 138 patients in the medium-risk group,136 recovered after UACE combined with evacuation,and 2 needed further treatment.The prediction accuracy of treatment modality was 98.5%(136/138).In the high-risk group,15 patients recovered after UACE followed by evacuation,and 11 patients were further treated,with a prediction accuracy of 42.3%(11/26).3.Of the 183 CSP patients in the prospectively study,108 recovered after evacuation,57 required UAE,and 18 eventually underwent laparoscopic surgery.The factors included in the ultrasonographic quantitative scoring system were significant differences among the three groups of patients with different treatment methods,including: number of cesarean section,maximum diameter of the gestational sac,thickness of remnant myometrium of the lower uterine segment,positive fetal heart,grading of blood around the gestational sac,and type of CSP.4.183 patients were evaluated by ultrasonographic quantitative scoring system.Among 97 women scoring 0–4,89(91.8%)were treated by evacuation only.Of 69 women scoring between 5–7,44(63.8%)needed UAE following evacuation.Of 17 women scoring 8–10,10 women(58.8%)underwent laparoscopic surgery.A cut-off of 4.145 was obtained by ROC curve for prediction of any salvage treatment;this was comparable to the scale's conventional cut-off of 4.The cut-off score for women requiring laparoscopic surgery was 6.580,which was lower than 8 obtained in the scale's initial validation.Conclusion:The ultrasonographic quantitative scoring system can effectively assess the severity and prognosis of CSP.The overall performance of the ultrasonographic quantitative scoring system is moderate,but it has a good predictive ability in recognizing patients needing only evacuation before recovery.The ultrasonographic quantitative scoring system provides the basis for the hierarchical individualized treatment of CSP.