| Background and objectives:Cesarean scar pregnancy(CSP)is a rare form of ectopic implantation that refers to the implantation of the myometrium at the site of a previous cesarean scar.The incidence of CSP represents 6.1% of all ectopic pregnancies with a history of at least one cesarean section.Early diagnosis and management of CSP is very important because a cesarean section scar has much fibrous tissue and a thin muscle wall,which reduces the contractility of the uterus.So caesarean scar pregnancy is potentially life threatening,if not managed early and properly,it could lead to catastrophic complications such as uncontrolled and massive vaginal bleeding and uterine rupture,which could require hysterectomy and results in subsequent loss of fertilityDue to the rare incidence of CSP worldwide,there is no consensus on the treatment of CSP at present.In recent years,a noninvasive therapy called high intensity focused ultrasound(HIFU)has been applied to many tumors including breast tumor,hepatocellular carcinoma,bone malignancy,pancreatic cancer,etc.The wave energy of ultrasound can p generate a temperature of 65°C to 100°C at the focal spot and induces cellular death and vascular obliteration in tissue In the present research,we studied HIFU ablation the pregnancied animal and it’s effect,then we used ultrasound-guided HIFU therapy to treat CSP patients and examined the efficacy and safety of HIFU treatment in CSP.Methods:1.Using High Intensity Focused ultrasound(HIFU)ablation the fetal and placenta tissues of pregnant rats,in order to provide experimental evidence for HIFU treatment of CSP.The fetal and placental tissues were irradiated by different energy HIFU,and the changes of ultrasonography and pathology were observed after irradiation.And to detect the expression of RIP3 and the change of iron staining and electron microscopy.2.From September 2011 to Feberary 2014,21 patients with CSP were treatedwith US-guided high intensity focused ultrasound ablation.The diagnosis of CSP was based on patient history of cesarean delivery,clinical manifestations,positive serumβ-HCG levels,physical examination and ultrasono-graphy findings.One hour before the therapy,patients were told drank water 500 ml,in order to be with proper filling of bladder.Then the HIFU system began the treatment and it’s treatment parameters adjusted by the gestational sac depth and size.The gestational sac/mass was in focal spot of ultrasound energy.The average therapeutic acoustic power was 800-1600 W,firing time 0.15 s,interval time between shots 0.18 s.No patients were lost to follow-up.Transvaginal color Doppler scanning were used to detect evidence of residual lesions,to assess changes in size with time.Serum β-hCG levels were determined beforethe intervention,on day 1,3 and 7 after the whole ultrasound treatment over,and then every week until recovery to normality.At the same time,the sizes of the retained gestational products were measured by transvaginal ultrasound.3.The study was designed as a retrospective cohort study.In total,43 patients were treated with HIFU(the HIFU group),and 72 patients were treated with UAE(the UAE group).Serum β-hCG levels were determined beforethe intervention,on day 1,3 and 7 after the whole treatment over,and then every week until recovery to normality At the same time,the sizes of the retained gestational products were measured by transvaginal ultrasound 。 In the study,we compared the treatment and recovery of the patients,including follow-up.Results :1.The 15 days fetus and placenta were irradiated by HIFU.The fetal heart and blood vessels were visible in the ultrasound scan before irradiation.The fetal blood was abundant in the placenta.After irradiation,the fetal rats were vaginal bleeding and the hemorrhagic changes of the placenta were seen.And the necrosis and hemorrhage of the irradiated area were observed by HE staining.Outside the irradiated area,the tissue swelling and infiltration of the inflammatory cells.Electron microscopic examination showed that nuclear shrinkage,heterochromosome aggregation and autophagosome were visible and the mitochondria and endoplasmic reticulum were expanded,swollen,dissolved and broken after HIFU irradiated.2.All of the patients were successfully treated.HIFU treatment was successful and the whole progress was in out-patient department.There was no serious complication.The complications were mainly pain,which were alleviated with symptomatic treatment.The average session in all patients was 3.4±1.1.The median(IQR)of serum β-hCG levels on days 1,3,7 and two weeks after HIFU treatment were 5889±3994(312–15306)mIU/mL,5939±5201(289–17905)mIU/mL,5629±6008(79–15021)mIU/mL and 5186±6665(2.1–19348)mIU/mL respectively.After HIFU ablation,gestational sacs/mass showed a similar change: the blood flow signals around the the mass or cyst increased at first and then decreased gradually some days later,at the same time the yolk sac or embryo gradually disappeared,remained a cystic area with echo free zone,which around poor blood flow,and then the cyst fell off from the previous cesarean scar,absorbed or discharged from the body,at last left the scar tissue,which detected by Color Doppler reflected no obvious blood flow signal.The mean time until normalization of serum-human chorionic gonadotrophin(β-HCG)was 5.3±2.2 weeks,and the mean time until CSP mass disappearance was 6.7±3.0 weeks.No-one was hospitalized.All 21 patients had recovered their normal menstruation at follow-up.There were two patients were pregnant 1/2-1years after treatment,and they gave birth to full term health newborns by Cesarean delivery.3.There were no significant differences in the age,gestational age,time since the last caesarean pregnancy,longest diameter of the sac/mass,myometrial thickness and serum β-hCG levels before the treatment in the two groups.In the UAE group,patients received anesthetics and were admitted to the hospital.23 patients presented with a low-grade fever,5 patients had limb soreness,11 patients had hip and pelvic pain,and 6 patients presented with lower abdominal pain,and in 3 patients,the pain was severe,which was relieved with medication.All of the patients received uterine curettage after the embolization procedure,and the blood loss during curettage was from 20 ml to 1000 ml.During the curettage,one patient experienced heavy bleeding(1000 ml)when the probe entered the cervix,and the patient underwent a transabdominal hysterectomy and blood transfusion.The average time to the restoration of the serum β-hCG levels to an undetectable level was 7.5±2.0 weeks,themass disappeared in an average of 6.9±2.9 weeks and the cost was 14156.9±3623.3Yuan.We found in the HIFU group that in some patients,the HCG increased in reactivity after the HIFU ablation and then decreased rapidly after 2-12 weeks.The average time to serum β-hCG restoration to an undetectable level was.5±2.0 weeks,the mass disappeared in an average of 7.7±2.7 weeks and the cost was 5142.5±1992.5 Yuan.The all treatment there was no need anesthetics,curettage or admitted to the hospital.Conclusion:1.HIFU can damage the fetus and destroy the placenta blood,so that the placenta degeneration,necrosis,inflammatory cell infiltration peripheral,which may be a method of termination of pregnancy.2.High-intensity focused ultrasound ablation may be a safe and feasible in the treatment of CSP.3.Compared with the UAE method,Ultrasound-guided HIFU ablation is a safe,inexpensive and feasible method for the treatment of CSP and causes little complications. |
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