Ultrasound evaluation of uterine healing after vaginal repair of cesarean section scar defect: An observational study

Ultrasound evaluation of uterine healing after vaginal repair of cesarean section scar defect: An observational study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Ultrasound evaluation of uterine healing after vaginal repair of cesarean section scar defect: An observational study Huayuan Qiao, Yizhi Wang, Huihui Chen, Xipeng Wang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4173497/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Many cesarean section scar defects (CSD) patients worry about thin thickness of the residual myometrium (TRM) and want to avoid uterine rupture in subsequent pregnancies. In addition, some blood flow indices could be possible predictive markers for impaired wound healing. To date, there is no method to dynamically assess the healing process in the uterine repair of CSD. To evaluate the association between uterine healing and uterine artery blood flow changes after vaginal repair of CSDs with two-dimensional power Doppler ultrasound and Doppler velocimetry. Methods A cohort prospective study (level of evidence II-2), run in University-affiliated hospitals: 98 women with CSDs underwent VR, between June 2021 and March 2022. During follow up 9 patients withdrew from the study. After vaginal repair, all patients were followed by traditional two-dimensional power Doppler ultrasound scanning and Doppler velocimetry preoperatively and at 2 days, 1 month and 3 months postoperatively. The size and location of the CSDs, TRM and Doppler velocimetry of the uterine arteries were evaluated. Results The thickness of the residual myometrium was significantly improved after vaginal repair (P < 0.05). However, it gradually became thinner over time. There was a significant (P < 0.05) progressive reduction in the uterine scar area from 82% on the second day in the first month to 67% in the third month. The pulsation index (PI), resistance index (RI), and systolic peak flow rate/diastolic flow rate (S/D) of the uterine artery showed little change after vaginal repair. The peak systolic velocity (PSV) value of the uterine artery significantly increased from 50.35 preoperatively to 53.92 on the second day after repair (p = 0.006). In total, 89 women had the symptom of postmenstrual spotting before repair, and 71.9% (64/89) of these patients returned to normal menstruation after repair. According to the preoperative duration of menstruation, the patients were divided into two groups (menstruation duration ≤ 7 days group and menstruation duration > 7 days group). The PSV values of the uterine artery in the first postoperative month were 53.32 ± 8.49 and 48.24 ± 7.35, respectively, and there was a significant difference between the two groups (p = 0.028). Conclusion The TRMs of CSD patients can be improved by vaginal repair. Traditional two-dimensional ultrasound and Doppler velocimetry can dynamically assess the healing process of the uterus after vaginal repair. Moreover, the PSV value in the first month after surgery may be a marker for predicting wound healing. cesarean section scar defect thickness of the residual myometrium uterine healing ultrasound vaginal repair Figures Figure 1 Figure 2 Figure 3 Capsule The peak systolic velocity value in the first month after the operation may be a marker for predicting cesarean section scar defect wound healing. Background Due to an increase in primary cesarean section (CS), the rate of CS has continued to rise worldwide. In China, although various intervention strategies have been implemented, the proportion of CSs climbed from 29% in 2008 to 35% in 2014 and up to 62% in the northeastern province of China[ 1 , 2 ]. It is well known that short- and long-term complications follow CS. Cesarean section scar defect (CSD), also termed ‘‘niche’’ by some authors[ 3 , 4 ], refers to the poor healing of the endometrium at the site of a previous cesarean incision on the anterior wall of the lower uterine segment, and the incidence of CSDs is approximately 24–84% after CS[ 5 , 6 ]. The most common symptoms are prolonged menstrual bleeding and postmenstrual spotting[ 7 ], as well as an increased risk for dysmenorrhea, dyspareunia, and chronic pelvic pain[ 8 , 9 ]. CSD has also been associated with lower thickness of the residual myometrium (TRM), which was assessed as the risk of uterine rupture in women with a prior cesarean section[ 10 , 11 ]. No special treatment is required for asymptomatic CSD. The treatment of symptomatic CSD includes hormone therapy and surgical treatment. Hormone treatment is reasonable for CSD patients who have no contraindications and no need for pregnancy[ 12 ]. If hormone treatment fails or there are some contraindications, surgery should be considered according to the signs and symptoms, including infertility, desire to retain the uterus and thin TRM. Surgical treatment usually includes hysteroscopic resection, laparoscopic repair, vaginal repair and robotic-assisted laparoscopic repair[ 8 , 13 – 15 ]. Most scholars recognize that reduced TRM is the limiting factor of hysteroscopic resection. Hysteroscopic surgery is not recommended for CSD patients with thin TRM or conception requirements. Hysteroscopic treatment will make the thickness of the myometrium weaker and not repair it. The repair and reconstruction of the lower segment of the uterus can only be achieved through laparoscopy or vaginal access[ 12 ]. Laparoscopy is widely performed in China because it is impossible to reach the defect by hand; in addition, there are high requirements for endoscopic suture skill of the operator. The results of laparoscopic repair are uneven. Furthermore, robotic-assisted surgery has not been carried out in many places due to its cost. Therefore, in our previous studies, vaginal surgery was carried out because it was minimally invasive and effective and achieved encouraging repair outcomes[ 14 , 16 – 18 ]. Many CSD patients worry about thin TRMs and want to avoid uterine rupture in subsequent pregnancies, so reconstructive suturing and uterine healing are especially significant in this operation. A previous study noted that the myometrial area of the scar after laparoscopic intracapsular myomectomy can be adequately monitored by two-dimensional ultrasound and Doppler velocimetry. In addition, some blood flow indices could be possible predictive markers for impaired wound healing[ 19 ]. To date, there is no method to dynamically assess the healing process in the uterine repair of CSD. Therefore, the aim of the present study was to dynamically evaluate uterine healing and uterine artery blood flow changes after vaginal repair of CSD with two-dimensional power Doppler ultrasound and Doppler velocimetry. Materials and methods Patients This study was conducted at the Department of Obstetrics and Gynecology, XinHua Hospital affiliated with Shanghai Jiao Tong University School of Medicine and was approved by the institutional ethics committee (XHEC-C-2021-0046-1). The 98 patients with CSDs enrolled in this prospective study received vaginal repair between June 2021 and March 2022. The study was conducted according to the Declaration of Helsinki. All patients were carefully informed and signed written informed consent to participate before enrollment in the study. Patient selection was based upon the following criteria: a history of CS and a diagnosis of CSD by transvaginal sonography (TVS) or magnetic resonance imaging (MRI), postmenstrual spotting after cesarean section, or TRM of some patients who desired pregnancy was less than 3.0 mm at preoperative MRI evaluation. The exclusion criteria were as follows: pregnancy, extension of the menstrual period before cesarean section, coagulation disorders, use of intrauterine devices, and endometrial disorder. Equipment and Evaluation All CSD patients were examined by abdominal combined with transvaginal Doppler ultrasound. The ultrasonic examination was performed by an ultrasonic expert to determine the size of the CSD, uterine healing and uterine artery blood flow. The size (the depth, length, width and TRM) and location of the niches were assessed and measured in two planes, sagittal and coronal[ 18 ] (Fig. 1 ). Two-dimensional power Doppler ultrasound was obtained preoperatively and 2 days, 1 month and 3 months postoperatively (Fig. 2 ). The ultrasonic Doppler ultrasound diagnostic instrument was a GE Voluson E8, and the abdominal probe frequency was 3.5 The transvaginal ultrasound probe frequency was 6.5 MHz. Uterine artery measurement procedure: The patient was placed in the supine position, and the uterine artery originated from the internal iliac artery and vertically crossed the external iliac artery outside the uterus and walked upward. During the examination, the external iliac artery was found at the groin first, and it was measured approximately 1 cm before the uterine artery crossed the external iliac artery to the bifurcation of the uterine artery. A 2-mm sample above each of the blood vessels of the uterine arteries was used. The sound beam blood flow angle was < 60°. More than 3 similar flow-velocity waveforms of satisfactory quality were obtained continuously. The instrument automatically calculated the pulsation index (PI), resistance index (RI), systolic peak flow rate/diastolic flow rate (S/D) and peak systolic velocity (PSV) of the uterine artery (Fig. 3 ). The bilateral average values were taken, and all data were recorded. Surgical Technique All CSD patients were managed by vaginal repair. All surgical procedures were performed by the same doctor. The complete surgical procedures have been described in detail in our previous publications[ 14 , 16 , 18 , 20 ], but the most important steps are summarized as follows. After anesthesia, the patient assumed the cystotomy position. After the perineum was sterilized, the surgeon opened the bladder cervical gap and then touched the smooth and moveable peritoneum. The peritoneum was opened, and the abdominal cavity was entered. After full exposure of the defect, under the guidance of the probe, the index finger was able to palpate and find the weakest point and determine the CSD site. Then, the scar tissue was cut completely with scissors. The myometrium was closed intermittently using 1–0 absorbable sutures double. The uterine peritoneum and anterior vaginal mucosal incision were sutured continuously using 1–0 absorbable sutures. Statistical Analysis The primary outcome measures were the duration of menstruation; TRM; and RI, PI, S/D, and PSV of the uterine artery. The data are expressed as the mean and standard deviation. Categorical data are expressed as frequencies and percentages. Student’s t test for paired samples was performed for paired data consisting of pre- and posttreatment parameters. Analysis of categorical variables was undertaken by the chi-squared test. Receiver operating characteristic (ROC) curves were plotted to identify the best predictors of nonreversal and to determine the cutoffs of the selected variables. The validity of the variables was measured by the area under the curve (AUROC). All analyses were performed using the statistical package SPSS 24.0 (SPSS Inc., Chicago, IL). A P value less than 0.05 was considered statistically significant. Results Patient characteristics Baseline characteristics are presented in Table 1 . During the study period, a total of 98 patients completed the study and follow-up. The mean age of our population was 33.18 ± 4.29 years (range 24–43 years). The primary preoperative size of the CSD was 7.48 ± 3.34 mm in length, 11.72 ± 8.05 mm in width, and 6.76 ± 2.50 mm in depth, and the TRM was 2.42 ± 0.98 mm. Prolonged menstrual bleeding was frequently encountered and was observed in 89 women in our series (90.81%). Twelve women presented with infertility. All vaginal repairs were successful, and there were no conversions to laparotomy or laparoscopy or other operative complications. Table 1 Patient baseline characteristics prior to surgery Variable Value (n = 98) Age (years) 33.18 ± 4.29 (24–43) Gravidity (n) 2.61 ± 1.44 (1–9) Number of cesarean deliveries (n) 1 57 (58.16) ≥2 41 (41.84) Intermenstrual bleeding 89 (90.81) Infertility 12 (12.24) Duration of postmenstrual spotting after cesarean delivery (days) 13.72 ± 4.73 (3–23) TVS findings before repair CSD length (mm) 7.48 ± 3.34 (3–22) CSD (mm) 11.72 ± 8.05 (3–15) CSD depth (mm) 6.76 ± 2.50 (2–15) TRM (mm) 2.42 ± 0.98 (1–6) CSD: cesarean section scar defect; TRM: thickness of the residual myometrium; TVS: transvaginal sonography Data are presented as the mean ± SD (range) or numbers (percentage). Postoperative US findings On the second day after surgery, the ultrasound pattern of the uterine scar in the lower segment of the anterior wall was represented by a strongly echoic area with an unclear heterogeneous muscular texture (Fig. 2 B). In the 1st to 3rd postoperative months, the image was transferred from a highly echoic area (Fig. 2 C) to a normal echo muscle texture (Fig. 2 D). However, we also found that the residual muscular layer showed a strong echo in the 3rd postoperative months, often indicating fibrosis, in some patients with poor prognosis (including postmenstrual spotting and thinner TRM after vaginal repair) (Fig. 2 E). This thickness was significantly increased (P < 0.001) compared with the values before repair (Table 2 ). TRMs after vaginal repair began to thicken significantly on the 2nd postoperative day. TRM on the 1st month after repair was 82% of the thickness on the 2nd day and 67% on the 3rd month. The progressive reduction in thickness of the ultrasound pattern of the residual myometrium was significant (P < 0.05). Table 2 TRM before surgery and on the second day and 1 and 3 months after surgery Group TRM (mm) P value Before surgery 2.40 ± 0.97 <0.001 On the second day 11.06 ± 1.98 Before surgery 2.45 ± 1.08 <0.001 At 1 month 9.09 ± 2.05 Before surgery 2.40 ± 1.00 <0.001 At 3 months 7.42 ± 2.68 TRM = thickness of the residual myometrium; Data are presented as the mean ± SD. The PI value, RI value and S/D value of the uterine artery showed little change before vaginal repair and on the 2nd day and 1 and 3 months after repair. The PSV value of the uterine artery increased from 50.35 on the preoperative day to 53.92 on the 2nd day after repair (Table 3 ). This difference was statistically significant (P 0.05). Table 3 PI, RI, S/D and PSV values before surgery and on the second day and 1 and 3 months after surgery Group PI P value RI P value S/D P value PSV P value Before surgery 2.37 ± 0.66 0.837 0.85 ± 0.10 0.088 6.32 ± 1.60 0.880 50.35 ± 10.08 0.006 On the second day 2.39 ± 0.66 0.82 ± 0.05 6.28 ± 2.00 53.92 ± 10.00 Before surgery 2.31 ± 0.40 0.187 0.86 ± 0.13 0.236 6.61 ± 1.61 0.482 50.38 ± 10.15 1.000 At 1 month 2.44 ± 0.70 0.83 ± 0.06 6.25 ± 1.72 50.38 ± 7.75 Before surgery 2.32 ± 0.40 0.347 0.85 ± 0.10 0.184 6.65 ± 1.60 0.172 49.13 ± 9.76 0.059 At 3 months 2.24 ± 0.55 0.83 ± 0.06 6.25 ± 1.72 52.30 ± 8.54 PI: pulsation index; RI: resistance index; S/D: systolic peak flow rate/diastolic flow rate; PSV: peak systolic velocity. Data are presented as the mean ± SD. Comparison of PI, RI, S/D and PSV values In this series, except for 9 patients, the other patients had the symptom of prolonged menstrual bleeding before repair. Therefore, according to the preoperative duration of menstruation at 3 months after surgery, we divided the 89 patients with abnormal menstruation into two groups: a group with no more than 7 days of menstruation and a group with more than 7 days of menstruation. We observed that among 89 patients with abnormal uterine bleeding, the rate of total symptom relief was 71.9% (64/89) after repair. In other words, 64 patients had menstruation for no more than 7 days, while 25 patients had menstruation for more than 7 days. The comparison of the PI value, RI value, S/D value and PSV value of the uterine artery before surgery and on the 2nd day and 1 and 3 months after surgery between the 2 groups is shown in Table 4 . The PSV values of the uterine artery in the 1st postoperative month were 53.32 ± 8.49 and 48.24 ± 7.35, respectively, and there was a significant difference between the 2 groups (p = 0.028). However, there was no significant difference between the 2 groups in the PI, RI, S/D and PSV values of the uterine artery on the day before repair, the 2nd day, and 3 months after surgery and the PI, RI, and S/D values on the 1st month after repair (p > 0.05). Table 4 Comparison of PI, RI, S/D and PSV values between the two groups Group Variable Menstruation duration ≤ 7 days (n = 64) Menstruation duration >7 days (n = 25) P value Before surgery PI 2.37 ± 0.51 2.31 ± 0.38 0.551 RI 0.83 ± 0.05 0.88 ± 0.16 0.137 S/D 6.49 ± 1.70 6.45 ± 1.56 0.908 PSV 49.30 ± 9.15 50.25 ± 10.85 0.704 On the second day after surgery PI 2.46 ± 0.77 2.30 ± 0.50 0.288 RI 0.83 ± 0.04 0.81 ± 0.07 0.309 S/D 6.19 ± 2.10 6.18 ± 1.68 0.969 PSV 53.79 ± 9.05 52.74 ± 11.90 0.692 At 1 month after surgery PI 2.52 ± 0.77 2.32 ± 0.37 0.216 RI 0.84 ± 0.06 0.84 ± 0.04 0.997 S/D 6.89 ± 1.67 6.51 ± 1.47 0.395 PSV 53.32 ± 8.49 48.24 ± 7.35 0.028 At 3 months after surgery PI 2.30 ± 0.52 2.09 ± 0.50 0.165 RI 0.84 ± 0.05 0.82 ± 0.06 0.123 S/D 6.45 ± 1.62 5.97 ± 1.70 0.335 PSV 52.02 ± 8.69 52.57 ± 7.68 0.815 PI: pulsation index; RI: resistance index; S/D: systolic peak flow rate/diastolic flow rate; PSV: peak systolic velocity. Data are presented as the mean ± SD. Through logistic regression, it was found that the PSV value in the 1st month after repair was related to the recovery of menstruation duration (P < 0.05). Therefore, ROC curves were drawn for the recovery of menstruation duration with the use of PSV values in the first month after repair. When determining the curves obtained from the relationships between PSV value and menstruation duration, the cutoff value was 49.02 (P = 0.029) with a sensitivity of 0.676 and a specificity of 0.684. The area under the curve was 0.683. Discussion Our study showed that the TRM can be significantly improved after vaginal repair and will gradually become thinner over time. The ultrasound pattern of the uterine scar was represented by a strongly echoic area and transferred to a highly echoic area, finally to the normal echo muscle texture at 3 months after surgery. Vaginal repair caused a change in the PSV value of the uterine artery, while the PI, RI and S/D values of the uterine artery showed little change. The progression and healing of injury is a complex process. Immediately after an injury, the cells at the break of the muscular layer necrosis and the hematoma began to fill in the fissure of ruptured muscle fibers[ 21 , 22 ]. At this time, a large number of inflammatory cells arrive at the injured site, and the inflammatory response starts rapidly, which is characterized by typical pain, swelling, redness and local temperature rise. Then, macrophages in circulation are recruited to play a role at the injury site. As the destruction stage gradually subsides, muscular layer healing enters the repair and remodeling stage. Repair and regeneration after injury are accompanied by two simultaneous processes of support and competition, the regeneration of muscle fibers and the formation of connective tissue scars[ 23 ]. Inflammatory cells form the early granulation tissue and compose a scaffold, and fibroblasts restore the framework by synthesizing proteins. With the continuous production of collagen, the regenerated muscle fiber matures, the scar tissue shrinks and recombines, and the function gradually recovers[ 24 , 25 ]. Gradually, the cross-linking and shortening of collagen fibers promotes the formation of tight and strong scars[ 19 ]. TRMs significantly increases after vaginal repair, which is consistent with our previous research results[ 14 , 17 , 18 , 20 ]. However, we found that TRMs gradually thin with the passage of time after surgery. During the third and final remodeling phases, newly regenerated muscle fibers are completed and the muscle reorganization leads to functional repair and a reduction in lesion size[ 26 ]. The thickness of the uterine scar gradually decreases. In the present study, the TRM on the 30th day after repair was 82% of the thickness on the second day and 67% on the 90th day. Within three months after surgery, the TRM was still significantly reduced, which was consistent with the pathophysiology of the healing process. In our previous study, we analyzed 121 patients with CSD, and the indices of the myometrium under ultrasound were stabilized 3 months after surgery[ 18 ]. It was further confirmed that the healing of the myometrium was a dynamic process and that the evaluation of postoperative efficacy should be based on three months after surgery. Injury after vaginal repair is caused by resecting defect tissue and closing the muscular layer edge with a good blood supply again. Excision of the defect tissue can result in the destruction of the muscle continuity structure and damage to the vascular system, which could lead to hematoma formation[ 26 ]. Next, the classic inflammatory reaction occurs and results in irreversible tissue damage and cell necrosis[ 26 ]. The regeneration reaction causes the optimal reconstruction of damaged tissue and high-quality muscle scarring, restoring normal muscle function[ 23 , 26 ]. Fibrous reactions lead to poor muscular reconstruction and inelastic scars. In this study, the uterine scar gradually evolved from a strong echoic area (the second day after the operation) to a highly echogenic area with an ill-defined heterogeneous myometrial texture (the first month after the operation) to a low (normal) echoic area, which is a normal healing process. However, fibrotic scars continue to show high echo areas, and there is a thinner TRM. Fibrosis indicates tissue dysfunction, which is characterized by changes in pain, inflammation and internal tissue stress. Some studies even suggest that fibrosis after injury may be the cause of recurrent muscle tears[ 27 , 28 ]. Such healing results could lead to progressive loss of muscular function and a higher risk of uterine rupture during subsequent pregnancy or delivery. After vascular repair, a complex angiogenesis process occurs. Vascularization or capillary regeneration of the injured area plays a very important role in injured muscle regeneration[ 23 , 29 , 30 ]. The reconstruction of a normal blood supply is the first sign of regeneration in the injured area and is also a necessary condition for the recovery of injured muscle morphology and function. New capillaries grow from the main blood vessel to the injured area and provide sufficient oxygen to the area[ 30 ]. Aerobic metabolism is the main energy pathway for muscle fiber growth. The arterioles in the injured area can expand and increase the blood flow to the injured area[ 26 ]. In our research, the PSV value of the uterine artery significantly increased from 50.35 on the first postoperative day to 53.92 on the 2nd day after repair, and the PSV value in the first postoperative month was significantly increased in the group with a menstruation duration of no more than 7 days. The change in PSV was reversible. There was no difference in PSV between the two groups at 3 months after the operation. The results showed that patients with good menstrual recovery (duration of menstruation no more than 7 days) had higher PSV values in the first month after surgery, which may be related to the higher blood flow rate of the uterus. More oxygen and nutrients were transported to support the growth of the myometrium and endometrium and to restore their normal function. However, the PSV between the two groups was almost the same in the third month after surgery, indicating that the change in blood flow was reversible. During this period, the PSV seemed to be stable regardless of whether the patient had a satisfactory duration of menstruation. Andrea Tinelli et al. prospectively evaluated vascular perfusion and healing of the myometrium after laparoscopic myomectomy using Doppler ultrasound and Doppler velocimetry in 149 women with uterine fibroids or leiomyomata[ 19 ]. They found that the PI and RI of the uterine arteries were reduced after laparoscopic myomectomy. However, in our study, except for PSV, the other blood flow parameters, such as the RI, PI and S/D value, did not change after surgery. Due to the formation of new blood vessels in the process of healing, the process is complex and phased[ 23 , 26 ]. We found that the PSV value changed during the dynamic observation of myometrial healing and may be related to the recovery of the menstrual period after surgery. The combined use of drugs that increase the blood flow velocity of the uterine artery may be a method to improve the healing of defects after surgery. The strengths of the study are summarized as follows. First, it involved prospectively collected data. Routine and dynamic ultrasound Doppler examinations were performed preoperatively and postoperatively. Second, this was the first study to use ultrasonic Doppler ultrasound and Doppler velocimetry to adequately monitor uterine scar healing after CSD vaginal repair. Third, only one professionally trained doctor measured the uterine artery blood flow and avoided measurement bias. The uniqueness of the surgical methods was a limitation of our study. The current study only analyzed the myometrial healing and uterine artery blood flow after vaginal repair. However, other types of CSD repair methods have not been studied. In addition, the subsequent pregnancy outcome has not been well studied. This work was a preliminary investigation, and further prospective and mega data population studies are needed. Conclusion The symptoms and TRMs of CSD patients can be improved by vaginal repair. Traditional two-dimensional ultrasound and Doppler velocimetry, which are safe, noninvasive methods to check the myometrium after vaginal repair, could dynamically assess the healing process of uterine CSDs after vaginal repair. Complete healing of the muscularis should occur at 3 months after the operation. Myometrial fibrosis may be an ultrasound pattern of poor scar healing. Moreover, the PSV value in the first month after the operation may be a marker for predicting wound healing. Further studies to assess the reliability of measurements of uterine healing using two-dimensional ultrasound and Doppler velocimetry in CSD women with vaginal repair may be justified. List of abbreviations cesarean section (CS) cesarean section scar defect (CSD) thickness of the remaining muscular layer (TRM) transvaginal sonography (TVS) magnetic resonance imaging (MRI) pulsation index (PI) resistance index (RI) systolic peak flow rate/diastolic flow rate (S/D) peak systolic velocity (PSV) Receiver operating characteristic (ROC) the area under the curve (AUROC) Declarations Ethics approval and consent to participate This study was conducted at the Department of Obstetrics and Gynecology, XinHua Hospital affiliated with Shanghai Jiao Tong University School of Medicine and was approved by the institutional ethics committee of XinHua Hospital affiliated with Shanghai Jiao Tong University School of Medicine (XHEC-C-2021-0046-1). The study was conducted according to the Declaration of Helsinki. All patients were carefully informed and signed written informed consent to participate before enrollment in the study. We confirm that all methods were performed in accordance with the relevant guidelines and regulations. Consent for publication Informed Consent for publication was obtained from all persons. Availability of data and materials The datasets generated and/or analyzed during the current study are not publicly available due personal privacy but are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no conflicts of interest and nothing to disclose. Funding This work was supported by grants from The Ministry of Science and Technology of China (2020YFC2002800). Author Contributions XP.W. developed the original design and performed the surgical procedures. HY.Q performed transvaginal sonography. The acquisition, analysis and interpretation of data were conducted by HH.C., HY.Q, and YZ.W. HY.Q. wrote the first draft of the report. XP.W. and HH.C reviewed and edited the report. 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Huard J, Li Y, Fu FH: Muscle injuries and repair: current trends in research . The Journal of bone and joint surgery American volume 2002, 84 (5):822-832. Goetsch SC, Hawke TJ, Gallardo TD, Richardson JA, Garry DJ: Transcriptional profiling and regulation of the extracellular matrix during muscle regeneration . Physiological genomics 2003, 14 (3):261-271. Smith C, Kruger MJ, Smith RM, Myburgh KH: The inflammatory response to skeletal muscle injury: illuminating complexities . Sports medicine 2008, 38 (11):947-969. Greco A, McNamara MT, Escher RM, Trifilio G, Parienti J: Spin-echo and STIR MR imaging of sports-related muscle injuries at 1.5 T . Journal of computer assisted tomography 1991, 15 (6):994-999. Kujala UM, Orava S, Jarvinen M: Hamstring injuries. Current trends in treatment and prevention . Sports medicine 1997, 23 (6):397-404. Jozsa L, Reffy A, Demel S, Szilagyi I: Alterations of oxygen and carbon dioxide tensions in crush-injured calf muscles of rat . Zeitschrift fur experimentelle Chirurgie 1980, 13 (2):91-94. Jarvinen M: Healing of a crush injury in rat striated muscle. 3. A micro-angiographical study of the effect of early mobilization and immobilization on capillary ingrowth . Acta pathologica et microbiologica Scandinavica Section A, Pathology 1976, 84 (1):85-94. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4173497","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":286593790,"identity":"a6da9c96-39a7-4f4f-8fa3-189685892dc8","order_by":0,"name":"Huayuan Qiao","email":"","orcid":"","institution":"Xin Hua Hospital affiliated with Shanghai Jiao Tong University School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Huayuan","middleName":"","lastName":"Qiao","suffix":""},{"id":286593791,"identity":"c927a05b-6f91-4e4b-872e-2b69cc57508f","order_by":1,"name":"Yizhi Wang","email":"","orcid":"","institution":"Xin Hua Hospital affiliated with Shanghai Jiao Tong University School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Yizhi","middleName":"","lastName":"Wang","suffix":""},{"id":286593792,"identity":"2f56abf8-0a93-47b3-b79e-b861fe3191e4","order_by":2,"name":"Huihui Chen","email":"","orcid":"","institution":"Xin Hua Hospital affiliated with Shanghai Jiao Tong University School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Huihui","middleName":"","lastName":"Chen","suffix":""},{"id":286593793,"identity":"f9b94c3f-4cf3-48fc-b611-49b21b2f70eb","order_by":3,"name":"Xipeng Wang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABBklEQVRIie3QMUvEMBTA8ZRApxxZGxT9Cq8UehQO76vkKNxUxPE2AwedhFvjF3Du5PxKwFuqXQveIAgu3tDD0RuMgqPpjcLlN2QI+Se8EOJ5/xZ8L7R+6WHCOFcHJ2Ee68X8VGg8+CmWnrDGTEDJgfvXj+adXW3OxvxORqOyZUAw6HeFI2ku55mGtyTTrwiifGZjqqi4vf87SbFIoQczq7oHKWObZApDOnIl7TYFCea66hrAWfnEAOVA0hWJ/Vsjob2JFTY4nEy7bRrYWeKqC/NALXImdL10ziJWRfLB9ptzaM36cw8XU86Xdb9zJFYYEYKERPJ3I1DO8xbtfxKOQwc9z/OO1Rd+cF5vPKDxkAAAAABJRU5ErkJggg==","orcid":"","institution":"Xin Hua Hospital affiliated with Shanghai Jiao Tong University School of Medicine","correspondingAuthor":true,"prefix":"","firstName":"Xipeng","middleName":"","lastName":"Wang","suffix":""}],"badges":[],"createdAt":"2024-03-27 05:02:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4173497/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4173497/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":54163912,"identity":"ded932d6-8ef7-43d0-a41a-7fd749af648c","added_by":"auto","created_at":"2024-04-05 13:16:05","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":47655,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic presentation of defect measurements.\u003c/p\u003e","description":"","filename":"Fig.1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4173497/v1/b4e38a0486763106c0e3a577.jpg"},{"id":54163909,"identity":"bbcd5dda-8769-4927-99a9-262de2c02f45","added_by":"auto","created_at":"2024-04-05 13:16:05","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":307718,"visible":true,"origin":"","legend":"\u003cp\u003eUltrasound pattern of the myometrium in the lower segment of the anterior wall.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eA. \u003c/strong\u003ePreoperative pattern;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eB.\u003c/strong\u003e Pattern 2 days postoperatively;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eC.\u003c/strong\u003e Pattern 1 month postoperatively;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eD.\u003c/strong\u003e Pattern 3 months postoperatively;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eE.\u003c/strong\u003e The fibrotic scar.\u003c/p\u003e","description":"","filename":"Fig.2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4173497/v1/141f3f286483656079f5bdac.jpg"},{"id":54163910,"identity":"7edfd22a-2c3d-4a33-8fdf-1d9424db5d34","added_by":"auto","created_at":"2024-04-05 13:16:05","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":157243,"visible":true,"origin":"","legend":"\u003cp\u003eWaveforms of the uterine arteries in CSD patients, including the PI, RI, S/D and PSV.\u003c/p\u003e","description":"","filename":"Fig.3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4173497/v1/7f8fb3bd4e6b1cb74788d265.jpg"},{"id":71197293,"identity":"1c5e5cd9-7a66-44c5-b5cb-d728c34c6b23","added_by":"auto","created_at":"2024-12-12 05:33:20","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1821109,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4173497/v1/4773d88f-6618-4fe1-a725-a7d44bb785b7.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Ultrasound evaluation of uterine healing after vaginal repair of cesarean section scar defect: An observational study","fulltext":[{"header":"Capsule","content":"\u003cp\u003eThe peak systolic velocity value in the first month after the operation may be a marker for predicting cesarean section scar defect wound healing.\u003c/p\u003e"},{"header":"Background","content":"\u003cp\u003eDue to an increase in primary cesarean section (CS), the rate of CS has continued to rise worldwide. In China, although various intervention strategies have been implemented, the proportion of CSs climbed from 29% in 2008 to 35% in 2014 and up to 62% in the northeastern province of China[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIt is well known that short- and long-term complications follow CS. Cesarean section scar defect (CSD), also termed \u0026lsquo;\u0026lsquo;niche\u0026rsquo;\u0026rsquo; by some authors[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], refers to the poor healing of the endometrium at the site of a previous cesarean incision on the anterior wall of the lower uterine segment, and the incidence of CSDs is approximately 24\u0026ndash;84% after CS[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe most common symptoms are prolonged menstrual bleeding and postmenstrual spotting[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], as well as an increased risk for dysmenorrhea, dyspareunia, and chronic pelvic pain[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. CSD has also been associated with lower thickness of the residual myometrium (TRM), which was assessed as the risk of uterine rupture in women with a prior cesarean section[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eNo special treatment is required for asymptomatic CSD. The treatment of symptomatic CSD includes hormone therapy and surgical treatment. Hormone treatment is reasonable for CSD patients who have no contraindications and no need for pregnancy[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. If hormone treatment fails or there are some contraindications, surgery should be considered according to the signs and symptoms, including infertility, desire to retain the uterus and thin TRM. Surgical treatment usually includes hysteroscopic resection, laparoscopic repair, vaginal repair and robotic-assisted laparoscopic repair[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan additionalcitationids=\"CR14\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMost scholars recognize that reduced TRM is the limiting factor of hysteroscopic resection. Hysteroscopic surgery is not recommended for CSD patients with thin TRM or conception requirements. Hysteroscopic treatment will make the thickness of the myometrium weaker and not repair it. The repair and reconstruction of the lower segment of the uterus can only be achieved through laparoscopy or vaginal access[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Laparoscopy is widely performed in China because it is impossible to reach the defect by hand; in addition, there are high requirements for endoscopic suture skill of the operator. The results of laparoscopic repair are uneven. Furthermore, robotic-assisted surgery has not been carried out in many places due to its cost. Therefore, in our previous studies, vaginal surgery was carried out because it was minimally invasive and effective and achieved encouraging repair outcomes[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan additionalcitationids=\"CR17\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMany CSD patients worry about thin TRMs and want to avoid uterine rupture in subsequent pregnancies, so reconstructive suturing and uterine healing are especially significant in this operation. A previous study noted that the myometrial area of the scar after laparoscopic intracapsular myomectomy can be adequately monitored by two-dimensional ultrasound and Doppler velocimetry. In addition, some blood flow indices could be possible predictive markers for impaired wound healing[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo date, there is no method to dynamically assess the healing process in the uterine repair of CSD. Therefore, the aim of the present study was to dynamically evaluate uterine healing and uterine artery blood flow changes after vaginal repair of CSD with two-dimensional power Doppler ultrasound and Doppler velocimetry.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n\u003ch2\u003ePatients\u003c/h2\u003e\n\u003cp\u003eThis study was conducted at the Department of Obstetrics and Gynecology, XinHua Hospital affiliated with Shanghai Jiao Tong University School of Medicine and was approved by the institutional ethics committee (XHEC-C-2021-0046-1). The 98 patients with CSDs enrolled in this prospective study received vaginal repair between June 2021 and March 2022. The study was conducted according to the Declaration of Helsinki. All patients were carefully informed and signed written informed consent to participate before enrollment in the study.\u003c/p\u003e\n\u003cp\u003ePatient selection was based upon the following criteria: a history of CS and a diagnosis of CSD by transvaginal sonography (TVS) or magnetic resonance imaging (MRI), postmenstrual spotting after cesarean section, or TRM of some patients who desired pregnancy was less than 3.0 mm at preoperative MRI evaluation. The exclusion criteria were as follows: pregnancy, extension of the menstrual period before cesarean section, coagulation disorders, use of intrauterine devices, and endometrial disorder.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n\u003ch2\u003eEquipment and Evaluation\u003c/h2\u003e\n\u003cp\u003eAll CSD patients were examined by abdominal combined with transvaginal Doppler ultrasound. The ultrasonic examination was performed by an ultrasonic expert to determine the size of the CSD, uterine healing and uterine artery blood flow. The size (the depth, length, width and TRM) and location of the niches were assessed and measured in two planes, sagittal and coronal[\u003cspan class=\"CitationRef\"\u003e18\u003c/span\u003e] (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). Two-dimensional power Doppler ultrasound was obtained preoperatively and 2 days, 1 month and 3 months postoperatively (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eThe ultrasonic Doppler ultrasound diagnostic instrument was a GE Voluson E8, and the abdominal probe frequency was 3.5 The transvaginal ultrasound probe frequency was 6.5 MHz. Uterine artery measurement procedure: The patient was placed in the supine position, and the uterine artery originated from the internal iliac artery and vertically crossed the external iliac artery outside the uterus and walked upward. During the examination, the external iliac artery was found at the groin first, and it was measured approximately 1 cm before the uterine artery crossed the external iliac artery to the bifurcation of the uterine artery. A 2-mm sample above each of the blood vessels of the uterine arteries was used. The sound beam blood flow angle was \u0026lt;\u0026thinsp;60\u0026deg;. More than 3 similar flow-velocity waveforms of satisfactory quality were obtained continuously. The instrument automatically calculated the pulsation index (PI), resistance index (RI), systolic peak flow rate/diastolic flow rate (S/D) and peak systolic velocity (PSV) of the uterine artery (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). The bilateral average values were taken, and all data were recorded.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\n\u003ch2\u003eSurgical Technique\u003c/h2\u003e\n\u003cp\u003eAll CSD patients were managed by vaginal repair. All surgical procedures were performed by the same doctor. The complete surgical procedures have been described in detail in our previous publications[\u003cspan class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e], but the most important steps are summarized as follows.\u003c/p\u003e\n\u003cp\u003eAfter anesthesia, the patient assumed the cystotomy position. After the perineum was sterilized, the surgeon opened the bladder cervical gap and then touched the smooth and moveable peritoneum. The peritoneum was opened, and the abdominal cavity was entered. After full exposure of the defect, under the guidance of the probe, the index finger was able to palpate and find the weakest point and determine the CSD site. Then, the scar tissue was cut completely with scissors. The myometrium was closed intermittently using 1\u0026ndash;0 absorbable sutures double. The uterine peritoneum and anterior vaginal mucosal incision were sutured continuously using 1\u0026ndash;0 absorbable sutures.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\n\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\n\u003cp\u003eThe primary outcome measures were the duration of menstruation; TRM; and RI, PI, S/D, and PSV of the uterine artery. The data are expressed as the mean and standard deviation. Categorical data are expressed as frequencies and percentages. Student\u0026rsquo;s t test for paired samples was performed for paired data consisting of pre- and posttreatment parameters. Analysis of categorical variables was undertaken by the chi-squared test. Receiver operating characteristic (ROC) curves were plotted to identify the best predictors of nonreversal and to determine the cutoffs of the selected variables. The validity of the variables was measured by the area under the curve (AUROC). All analyses were performed using the statistical package SPSS 24.0 (SPSS Inc., Chicago, IL). A P value less than 0.05 was considered statistically significant.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003ePatient characteristics\u003c/h2\u003e\n \u003cp\u003eBaseline characteristics are presented in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e. During the study period, a total of 98 patients completed the study and follow-up. The mean age of our population was 33.18\u0026thinsp;\u0026plusmn;\u0026thinsp;4.29 years (range 24\u0026ndash;43 years). The primary preoperative size of the CSD was 7.48\u0026thinsp;\u0026plusmn;\u0026thinsp;3.34 mm in length, 11.72\u0026thinsp;\u0026plusmn;\u0026thinsp;8.05 mm in width, and 6.76\u0026thinsp;\u0026plusmn;\u0026thinsp;2.50 mm in depth, and the TRM was 2.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.98 mm. Prolonged menstrual bleeding was frequently encountered and was observed in 89 women in our series (90.81%). Twelve women presented with infertility. All vaginal repairs were successful, and there were no conversions to laparotomy or laparoscopy or other operative complications.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003ePatient baseline characteristics prior to surgery\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eVariable\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eValue (n\u0026thinsp;=\u0026thinsp;98)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAge (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33.18\u0026thinsp;\u0026plusmn;\u0026thinsp;4.29 (24\u0026ndash;43)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGravidity (n)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.61\u0026thinsp;\u0026plusmn;\u0026thinsp;1.44 (1\u0026ndash;9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNumber of cesarean deliveries (n)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e57 (58.16)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026ge;2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e41 (41.84)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eIntermenstrual bleeding\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e89 (90.81)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eInfertility\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12 (12.24)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDuration of postmenstrual spotting after cesarean delivery (days)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.72\u0026thinsp;\u0026plusmn;\u0026thinsp;4.73 (3\u0026ndash;23)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTVS findings before repair\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCSD length (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.48\u0026thinsp;\u0026plusmn;\u0026thinsp;3.34 (3\u0026ndash;22)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCSD (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11.72\u0026thinsp;\u0026plusmn;\u0026thinsp;8.05 (3\u0026ndash;15)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCSD depth (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.76\u0026thinsp;\u0026plusmn;\u0026thinsp;2.50 (2\u0026ndash;15)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTRM (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.98 (1\u0026ndash;6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003eCSD: cesarean section scar defect; TRM: thickness of the residual myometrium; TVS: transvaginal sonography\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003eData are presented as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD (range) or numbers (percentage).\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\n \u003ch2\u003ePostoperative US findings\u003c/h2\u003e\n \u003cp\u003eOn the second day after surgery, the ultrasound pattern of the uterine scar in the lower segment of the anterior wall was represented by a strongly echoic area with an unclear heterogeneous muscular texture (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003eB). In the 1st to 3rd postoperative months, the image was transferred from a highly echoic area (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003eC) to a normal echo muscle texture (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003eD). However, we also found that the residual muscular layer showed a strong echo in the 3rd postoperative months, often indicating fibrosis, in some patients with poor prognosis (including postmenstrual spotting and thinner TRM after vaginal repair) (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003eE).\u003c/p\u003e\n \u003cp\u003eThis thickness was significantly increased (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) compared with the values before repair (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). TRMs after vaginal repair began to thicken significantly on the 2nd postoperative day. TRM on the 1st month after repair was 82% of the thickness on the 2nd day and 67% on the 3rd month. The progressive reduction in thickness of the ultrasound pattern of the residual myometrium was significant (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eTRM before surgery and on the second day and 1 and 3 months after surgery\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eTRM (mm)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBefore surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOn the second day\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e11.06\u0026thinsp;\u0026plusmn;\u0026thinsp;1.98\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBefore surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.45\u0026thinsp;\u0026plusmn;\u0026thinsp;1.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAt 1 month\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e9.09\u0026thinsp;\u0026plusmn;\u0026thinsp;2.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBefore surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.40\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAt 3 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7.42\u0026thinsp;\u0026plusmn;\u0026thinsp;2.68\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\"\u003eTRM\u0026thinsp;=\u0026thinsp;thickness of the residual myometrium; Data are presented as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eThe PI value, RI value and S/D value of the uterine artery showed little change before vaginal repair and on the 2nd day and 1 and 3 months after repair. The PSV value of the uterine artery increased from 50.35 on the preoperative day to 53.92 on the 2nd day after repair (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). This difference was statistically significant (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). However, there was no significant change in PSV values in the 1st and 3rd postoperative months (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab3\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003ePI, RI, S/D and PSV values before surgery and on the second day and 1 and 3 months after surgery\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePI\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eRI\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eS/D\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePSV\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBefore surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e0.837\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.85\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e0.088\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.32\u0026thinsp;\u0026plusmn;\u0026thinsp;1.60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e0.880\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50.35\u0026thinsp;\u0026plusmn;\u0026thinsp;10.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e0.006\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOn the second day\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.39\u0026thinsp;\u0026plusmn;\u0026thinsp;0.66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.28\u0026thinsp;\u0026plusmn;\u0026thinsp;2.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e53.92\u0026thinsp;\u0026plusmn;\u0026thinsp;10.00\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBefore surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e0.187\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.86\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e0.236\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.61\u0026thinsp;\u0026plusmn;\u0026thinsp;1.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e0.482\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50.38\u0026thinsp;\u0026plusmn;\u0026thinsp;10.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAt 1 month\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.25\u0026thinsp;\u0026plusmn;\u0026thinsp;1.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50.38\u0026thinsp;\u0026plusmn;\u0026thinsp;7.75\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBefore surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e0.347\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.85\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e0.184\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.65\u0026thinsp;\u0026plusmn;\u0026thinsp;1.60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e0.172\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e49.13\u0026thinsp;\u0026plusmn;\u0026thinsp;9.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" align=\"char\"\u003e\n \u003cp\u003e0.059\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAt 3 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.25\u0026thinsp;\u0026plusmn;\u0026thinsp;1.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e52.30\u0026thinsp;\u0026plusmn;\u0026thinsp;8.54\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"9\"\u003ePI: pulsation index; RI: resistance index; S/D: systolic peak flow rate/diastolic flow rate; PSV: peak systolic velocity. Data are presented as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e\n \u003ch2\u003eComparison of PI, RI, S/D and PSV values\u003c/h2\u003e\n \u003cp\u003eIn this series, except for 9 patients, the other patients had the symptom of prolonged menstrual bleeding before repair. Therefore, according to the preoperative duration of menstruation at 3 months after surgery, we divided the 89 patients with abnormal menstruation into two groups: a group with no more than 7 days of menstruation and a group with more than 7 days of menstruation. We observed that among 89 patients with abnormal uterine bleeding, the rate of total symptom relief was 71.9% (64/89) after repair. In other words, 64 patients had menstruation for no more than 7 days, while 25 patients had menstruation for more than 7 days. The comparison of the PI value, RI value, S/D value and PSV value of the uterine artery before surgery and on the 2nd day and 1 and 3 months after surgery between the 2 groups is shown in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e. The PSV values of the uterine artery in the 1st postoperative month were 53.32\u0026thinsp;\u0026plusmn;\u0026thinsp;8.49 and 48.24\u0026thinsp;\u0026plusmn;\u0026thinsp;7.35, respectively, and there was a significant difference between the 2 groups (p\u0026thinsp;=\u0026thinsp;0.028). However, there was no significant difference between the 2 groups in the PI, RI, S/D and PSV values of the uterine artery on the day before repair, the 2nd day, and 3 months after surgery and the PI, RI, and S/D values on the 1st month after repair (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab4\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComparison of PI, RI, S/D and PSV values between the two groups\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eVariable\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMenstruation duration\u0026thinsp;\u0026le;\u0026thinsp;7 days (n\u0026thinsp;=\u0026thinsp;64)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMenstruation duration \u0026gt;7 days (n\u0026thinsp;=\u0026thinsp;25)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBefore surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.551\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.137\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eS/D\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.49\u0026thinsp;\u0026plusmn;\u0026thinsp;1.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.45\u0026thinsp;\u0026plusmn;\u0026thinsp;1.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.908\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePSV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e49.30\u0026thinsp;\u0026plusmn;\u0026thinsp;9.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50.25\u0026thinsp;\u0026plusmn;\u0026thinsp;10.85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.704\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOn the second day after surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.288\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.81\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.309\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eS/D\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.19\u0026thinsp;\u0026plusmn;\u0026thinsp;2.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.18\u0026thinsp;\u0026plusmn;\u0026thinsp;1.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.969\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePSV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e53.79\u0026thinsp;\u0026plusmn;\u0026thinsp;9.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e52.74\u0026thinsp;\u0026plusmn;\u0026thinsp;11.90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.692\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAt 1 month after surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.52\u0026thinsp;\u0026plusmn;\u0026thinsp;0.77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.216\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.84\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.84\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.997\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eS/D\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.89\u0026thinsp;\u0026plusmn;\u0026thinsp;1.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.51\u0026thinsp;\u0026plusmn;\u0026thinsp;1.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.395\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePSV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e53.32\u0026thinsp;\u0026plusmn;\u0026thinsp;8.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e48.24\u0026thinsp;\u0026plusmn;\u0026thinsp;7.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.028\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAt 3 months after surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.165\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.84\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.123\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eS/D\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.45\u0026thinsp;\u0026plusmn;\u0026thinsp;1.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5.97\u0026thinsp;\u0026plusmn;\u0026thinsp;1.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.335\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePSV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e52.02\u0026thinsp;\u0026plusmn;\u0026thinsp;8.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e52.57\u0026thinsp;\u0026plusmn;\u0026thinsp;7.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.815\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\"\u003ePI: pulsation index; RI: resistance index; S/D: systolic peak flow rate/diastolic flow rate; PSV: peak systolic velocity. Data are presented as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eThrough logistic regression, it was found that the PSV value in the 1st month after repair was related to the recovery of menstruation duration (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Therefore, ROC curves were drawn for the recovery of menstruation duration with the use of PSV values in the first month after repair. When determining the curves obtained from the relationships between PSV value and menstruation duration, the cutoff value was 49.02 (P\u0026thinsp;=\u0026thinsp;0.029) with a sensitivity of 0.676 and a specificity of 0.684. The area under the curve was 0.683.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur study showed that the TRM can be significantly improved after vaginal repair and will gradually become thinner over time. The ultrasound pattern of the uterine scar was represented by a strongly echoic area and transferred to a highly echoic area, finally to the normal echo muscle texture at 3 months after surgery. Vaginal repair caused a change in the PSV value of the uterine artery, while the PI, RI and S/D values of the uterine artery showed little change.\u003c/p\u003e \u003cp\u003eThe progression and healing of injury is a complex process. Immediately after an injury, the cells at the break of the muscular layer necrosis and the hematoma began to fill in the fissure of ruptured muscle fibers[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. At this time, a large number of inflammatory cells arrive at the injured site, and the inflammatory response starts rapidly, which is characterized by typical pain, swelling, redness and local temperature rise. Then, macrophages in circulation are recruited to play a role at the injury site. As the destruction stage gradually subsides, muscular layer healing enters the repair and remodeling stage. Repair and regeneration after injury are accompanied by two simultaneous processes of support and competition, the regeneration of muscle fibers and the formation of connective tissue scars[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Inflammatory cells form the early granulation tissue and compose a scaffold, and fibroblasts restore the framework by synthesizing proteins. With the continuous production of collagen, the regenerated muscle fiber matures, the scar tissue shrinks and recombines, and the function gradually recovers[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Gradually, the cross-linking and shortening of collagen fibers promotes the formation of tight and strong scars[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTRMs significantly increases after vaginal repair, which is consistent with our previous research results[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. However, we found that TRMs gradually thin with the passage of time after surgery. During the third and final remodeling phases, newly regenerated muscle fibers are completed and the muscle reorganization leads to functional repair and a reduction in lesion size[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. The thickness of the uterine scar gradually decreases. In the present study, the TRM on the 30th day after repair was 82% of the thickness on the second day and 67% on the 90th day. Within three months after surgery, the TRM was still significantly reduced, which was consistent with the pathophysiology of the healing process. In our previous study, we analyzed 121 patients with CSD, and the indices of the myometrium under ultrasound were stabilized 3 months after surgery[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. It was further confirmed that the healing of the myometrium was a dynamic process and that the evaluation of postoperative efficacy should be based on three months after surgery.\u003c/p\u003e \u003cp\u003eInjury after vaginal repair is caused by resecting defect tissue and closing the muscular layer edge with a good blood supply again. Excision of the defect tissue can result in the destruction of the muscle continuity structure and damage to the vascular system, which could lead to hematoma formation[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Next, the classic inflammatory reaction occurs and results in irreversible tissue damage and cell necrosis[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. The regeneration reaction causes the optimal reconstruction of damaged tissue and high-quality muscle scarring, restoring normal muscle function[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Fibrous reactions lead to poor muscular reconstruction and inelastic scars. In this study, the uterine scar gradually evolved from a strong echoic area (the second day after the operation) to a highly echogenic area with an ill-defined heterogeneous myometrial texture (the first month after the operation) to a low (normal) echoic area, which is a normal healing process. However, fibrotic scars continue to show high echo areas, and there is a thinner TRM. Fibrosis indicates tissue dysfunction, which is characterized by changes in pain, inflammation and internal tissue stress. Some studies even suggest that fibrosis after injury may be the cause of recurrent muscle tears[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Such healing results could lead to progressive loss of muscular function and a higher risk of uterine rupture during subsequent pregnancy or delivery.\u003c/p\u003e \u003cp\u003eAfter vascular repair, a complex angiogenesis process occurs. Vascularization or capillary regeneration of the injured area plays a very important role in injured muscle regeneration[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. The reconstruction of a normal blood supply is the first sign of regeneration in the injured area and is also a necessary condition for the recovery of injured muscle morphology and function. New capillaries grow from the main blood vessel to the injured area and provide sufficient oxygen to the area[\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Aerobic metabolism is the main energy pathway for muscle fiber growth. The arterioles in the injured area can expand and increase the blood flow to the injured area[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. In our research, the PSV value of the uterine artery significantly increased from 50.35 on the first postoperative day to 53.92 on the 2nd day after repair, and the PSV value in the first postoperative month was significantly increased in the group with a menstruation duration of no more than 7 days. The change in PSV was reversible. There was no difference in PSV between the two groups at 3 months after the operation. The results showed that patients with good menstrual recovery (duration of menstruation no more than 7 days) had higher PSV values in the first month after surgery, which may be related to the higher blood flow rate of the uterus. More oxygen and nutrients were transported to support the growth of the myometrium and endometrium and to restore their normal function. However, the PSV between the two groups was almost the same in the third month after surgery, indicating that the change in blood flow was reversible. During this period, the PSV seemed to be stable regardless of whether the patient had a satisfactory duration of menstruation. Andrea Tinelli et al. prospectively evaluated vascular perfusion and healing of the myometrium after laparoscopic myomectomy using Doppler ultrasound and Doppler velocimetry in 149 women with uterine fibroids or leiomyomata[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. They found that the PI and RI of the uterine arteries were reduced after laparoscopic myomectomy. However, in our study, except for PSV, the other blood flow parameters, such as the RI, PI and S/D value, did not change after surgery. Due to the formation of new blood vessels in the process of healing, the process is complex and phased[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. We found that the PSV value changed during the dynamic observation of myometrial healing and may be related to the recovery of the menstrual period after surgery. The combined use of drugs that increase the blood flow velocity of the uterine artery may be a method to improve the healing of defects after surgery.\u003c/p\u003e \u003cp\u003eThe strengths of the study are summarized as follows. First, it involved prospectively collected data. Routine and dynamic ultrasound Doppler examinations were performed preoperatively and postoperatively. Second, this was the first study to use ultrasonic Doppler ultrasound and Doppler velocimetry to adequately monitor uterine scar healing after CSD vaginal repair. Third, only one professionally trained doctor measured the uterine artery blood flow and avoided measurement bias.\u003c/p\u003e \u003cp\u003eThe uniqueness of the surgical methods was a limitation of our study. The current study only analyzed the myometrial healing and uterine artery blood flow after vaginal repair. However, other types of CSD repair methods have not been studied. In addition, the subsequent pregnancy outcome has not been well studied. This work was a preliminary investigation, and further prospective and mega data population studies are needed.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe symptoms and TRMs of CSD patients can be improved by vaginal repair. Traditional two-dimensional ultrasound and Doppler velocimetry, which are safe, noninvasive methods to check the myometrium after vaginal repair, could dynamically assess the healing process of uterine CSDs after vaginal repair. Complete healing of the muscularis should occur at 3 months after the operation. Myometrial fibrosis may be an ultrasound pattern of poor scar healing. Moreover, the PSV value in the first month after the operation may be a marker for predicting wound healing. Further studies to assess the reliability of measurements of uterine healing using two-dimensional ultrasound and Doppler velocimetry in CSD women with vaginal repair may be justified.\u003c/p\u003e"},{"header":"List of abbreviations","content":"\u003cp\u003ecesarean section (CS)\u003c/p\u003e\n\u003cp\u003ecesarean section scar defect (CSD)\u003c/p\u003e\n\u003cp\u003ethickness of the remaining muscular layer (TRM)\u003c/p\u003e\n\u003cp\u003etransvaginal sonography (TVS)\u003c/p\u003e\n\u003cp\u003emagnetic resonance imaging (MRI)\u003c/p\u003e\n\u003cp\u003epulsation index (PI)\u003c/p\u003e\n\u003cp\u003eresistance index (RI)\u003c/p\u003e\n\u003cp\u003esystolic peak flow rate/diastolic flow rate (S/D)\u003c/p\u003e\n\u003cp\u003epeak systolic velocity (PSV)\u003c/p\u003e\n\u003cp\u003eReceiver operating characteristic (ROC)\u003c/p\u003e\n\u003cp\u003ethe area under the curve (AUROC)\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was conducted at the Department of Obstetrics and Gynecology, XinHua Hospital affiliated with Shanghai Jiao Tong University School of Medicine and was approved by the institutional ethics committee of XinHua Hospital affiliated with Shanghai Jiao Tong University School of Medicine (XHEC-C-2021-0046-1). The study was conducted according to the Declaration of Helsinki. All patients were carefully informed and signed written informed consent to participate before enrollment in the study. We confirm that all methods were performed in accordance with the relevant guidelines and regulations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInformed Consent for publication was obtained from all persons.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analyzed during the current study are not publicly available due personal privacy but are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no conflicts of interest and nothing to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by grants from The Ministry of Science and Technology of China (2020YFC2002800).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eXP.W. developed the original design and performed the surgical procedures. HY.Q performed transvaginal sonography. The acquisition, analysis and interpretation of data were conducted by HH.C., HY.Q, and YZ.W. HY.Q. wrote the first draft of the report. XP.W. and HH.C reviewed and edited the report. All authors contributed to the writing of the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank all of the patients, doctors and nurses who participated in this study. This study was supported by a grant from The Ministry of Science and Technology of China (2020YFC2002800).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eLiang J, Mu Y, Li X, Tang W, Wang Y, Liu Z, Huang X, Scherpbier RW, Guo S, Li M\u003cem\u003e et al\u003c/em\u003e: \u003cstrong\u003eRelaxation of the one child policy and trends in caesarean section rates and birth outcomes in China between 2012 and 2016: observational study of nearly seven million health facility births\u003c/strong\u003e. \u003cem\u003eBmj \u003c/em\u003e2018, \u003cstrong\u003e360\u003c/strong\u003e:k817.\u003c/li\u003e\n\u003cli\u003eBlustein J, Liu J: \u003cstrong\u003eTime to consider the risks of caesarean delivery for long term child health\u003c/strong\u003e. \u003cem\u003eBmj \u003c/em\u003e2015, \u003cstrong\u003e350\u003c/strong\u003e:h2410.\u003c/li\u003e\n\u003cli\u003eMonteagudo A, Carreno C, Timor-Tritsch IE: \u003cstrong\u003eSaline infusion sonohysterography in nonpregnant women with previous cesarean delivery: the \u0026quot;niche\u0026quot; in the scar\u003c/strong\u003e. \u003cem\u003eJournal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine \u003c/em\u003e2001, \u003cstrong\u003e20\u003c/strong\u003e(10):1105-1115.\u003c/li\u003e\n\u003cli\u003eBij de Vaate AJ, Brolmann HA, van der Voet LF, van der Slikke JW, Veersema S, Huirne JA: \u003cstrong\u003eUltrasound evaluation of the Cesarean scar: relation between a niche and postmenstrual spotting\u003c/strong\u003e. \u003cem\u003eUltrasound in obstetrics \u0026amp; gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology \u003c/em\u003e2011, \u003cstrong\u003e37\u003c/strong\u003e(1):93-99.\u003c/li\u003e\n\u003cli\u003eWozniak A, Pyra K, Tinto HR, Wozniak S: \u003cstrong\u003eUltrasonographic criteria of cesarean scar defect evaluation\u003c/strong\u003e. \u003cem\u003eJournal of ultrasonography \u003c/em\u003e2018, \u003cstrong\u003e18\u003c/strong\u003e(73):162-165.\u003c/li\u003e\n\u003cli\u003evan der Voet LF, Vervoort AJ, Veersema S, BijdeVaate AJ, Brolmann HA, Huirne JA: \u003cstrong\u003eMinimally invasive therapy for gynaecological symptoms related to a niche in the caesarean scar: a systematic review\u003c/strong\u003e. \u003cem\u003eBJOG : an international journal of obstetrics and gynaecology \u003c/em\u003e2014, \u003cstrong\u003e121\u003c/strong\u003e(2):145-156.\u003c/li\u003e\n\u003cli\u003evan der Voet LF, Bij de Vaate AM, Veersema S, Brolmann HA, Huirne JA: \u003cstrong\u003eLong-term complications of caesarean section. 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A micro-angiographical study of the effect of early mobilization and immobilization on capillary ingrowth\u003c/strong\u003e. \u003cem\u003eActa pathologica et microbiologica Scandinavica Section A, Pathology \u003c/em\u003e1976, \u003cstrong\u003e84\u003c/strong\u003e(1):85-94.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"cesarean section scar defect, thickness of the residual myometrium, uterine healing, ultrasound, vaginal repair","lastPublishedDoi":"10.21203/rs.3.rs-4173497/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4173497/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eMany cesarean section scar defects (CSD) patients worry about thin thickness of the residual myometrium (TRM) and want to avoid uterine rupture in subsequent pregnancies. In addition, some blood flow indices could be possible predictive markers for impaired wound healing. To date, there is no method to dynamically assess the healing process in the uterine repair of CSD. To evaluate the association between uterine healing and uterine artery blood flow changes after vaginal repair of CSDs with two-dimensional power Doppler ultrasound and Doppler velocimetry.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA cohort prospective study (level of evidence II-2), run in University-affiliated hospitals: 98 women with CSDs underwent VR, between June 2021 and March 2022. During follow up 9 patients withdrew from the study. After vaginal repair, all patients were followed by traditional two-dimensional power Doppler ultrasound scanning and Doppler velocimetry preoperatively and at 2 days, 1 month and 3 months postoperatively. The size and location of the CSDs, TRM and Doppler velocimetry of the uterine arteries were evaluated.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe thickness of the residual myometrium was significantly improved after vaginal repair (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). However, it gradually became thinner over time. There was a significant (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) progressive reduction in the uterine scar area from 82% on the second day in the first month to 67% in the third month. The pulsation index (PI), resistance index (RI), and systolic peak flow rate/diastolic flow rate (S/D) of the uterine artery showed little change after vaginal repair. The peak systolic velocity (PSV) value of the uterine artery significantly increased from 50.35 preoperatively to 53.92 on the second day after repair (p\u0026thinsp;=\u0026thinsp;0.006). In total, 89 women had the symptom of postmenstrual spotting before repair, and 71.9% (64/89) of these patients returned to normal menstruation after repair. According to the preoperative duration of menstruation, the patients were divided into two groups (menstruation duration\u0026thinsp;\u0026le;\u0026thinsp;7 days group and menstruation duration\u0026thinsp;\u0026gt;\u0026thinsp;7 days group). The PSV values of the uterine artery in the first postoperative month were 53.32\u0026thinsp;\u0026plusmn;\u0026thinsp;8.49 and 48.24\u0026thinsp;\u0026plusmn;\u0026thinsp;7.35, respectively, and there was a significant difference between the two groups (p\u0026thinsp;=\u0026thinsp;0.028).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThe TRMs of CSD patients can be improved by vaginal repair. Traditional two-dimensional ultrasound and Doppler velocimetry can dynamically assess the healing process of the uterus after vaginal repair. Moreover, the PSV value in the first month after surgery may be a marker for predicting wound healing.\u003c/p\u003e","manuscriptTitle":"Ultrasound evaluation of uterine healing after vaginal repair of cesarean section scar defect: An observational study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-04-05 13:16:00","doi":"10.21203/rs.3.rs-4173497/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"9cdb213d-1fd6-43f5-8e7d-f46b6aef7130","owner":[],"postedDate":"April 5th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-01-22T08:23:37+00:00","versionOfRecord":[],"versionCreatedAt":"2024-04-05 13:16:00","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4173497","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4173497","identity":"rs-4173497","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}