The association between unintended hysterotomy extensions with cesarean delivery and subsequent preterm birth.

BACKGROUND: An increased risk for preterm birth has been observed among individuals with a previous second stage cesarean delivery when compared with those with a previous vaginal delivery. One mechanism that may contribute to the increased risk for preterm birth following a second stage cesarean delivery is the increased risk for cervical injury because of extension of the uterine incision (hysterotomy) into the cervix. The contribution of hysterotomy extension to the rate of preterm birth in a subsequent pregnancy has not been investigated and may shed light on the mechanism underlying the observed relationship between the mode of delivery and subsequent preterm birth. OBJECTIVE: We aimed to quantify the association between unintended hysterotomy extension and preterm birth in a subsequent delivery. STUDY DESIGN: We performed a retrospective cohort study using electronic perinatal data collected from 2 university-affiliated obstetrical centers. The study included patients with a primary cesarean delivery of a term, singleton live birth and a subsequent singleton birth in the same catchment (2005-2021). The primary outcome was subsequent preterm birth <37 weeks' gestation; secondary outcomes included subsequent preterm birth at <34, <32, and <28 weeks' gestation. We assessed crude and adjusted associations between unintended hysterotomy extensions and subsequent preterm birth with log binomial regression models using rate ratios and 95% confidence intervals. Adjusted models included several characteristics of the primary cesarean delivery such as maternal age, length of active labor, indication for cesarean delivery, chorioamnionitis, and maternal comorbidity. RESULTS: A total 4797 patients met the study inclusion criteria. The overall rate of unintended hysterotomy extension in the primary cesarean delivery was 6.0% and the total rate of preterm birth in the subsequent pregnancy was 4.8%. Patients with an unintended hysterotomy extension were more likely to have a longer duration of active labor, chorioamnionitis, failed vacuum delivery attempt, second stage cesarean delivery, and persistent occiput posterior position of the fetal head in the primary cesarean delivery and higher rates of smoking in the subsequent pregnancy. Multivariable analyses that controlled for several confounders showed that a history of hysterotomy extension was not associated with a higher risk for preterm birth <37 weeks' gestation (adjusted rate ratio, 1.55; 95% confidence interval, 0.98-2.47), but it was associated with preterm birth <34 weeks' gestation (adjusted rate ratio, 2.49; 95% confidence interval, 1.06-5.42). CONCLUSION: Patients with a uterine incision extension have a 2.5 times higher rate of preterm birth <34 weeks' gestation when compared with patients who did not have this injury. This association was not observed for preterm birth <37 weeks' gestation. Future research should aim to replicate our analyses with incorporation of additional data to minimize the potential for residual confounding.

Length of hysterotomy for fetal spina bifida repair is associated with prematurity risk.

OBJECTIVE: To investigate whether prenatal repair of spina bifida aperta through mini-hysterotomy results in less prematurity, as compared to standard hysterotomy, when adjusting for known prematurity risks. METHODS: We performed a bi-centric, propensity score matched, controlled study, that is, adjusting for factors earlier reported to result in premature delivery or membrane rupture, in consecutive women having prenatal repair either through stapled hysterotomy or sutured mini-hysterotomy (≤3.5 cm). Matches were pairwise compared and cox-regression analysis was performed to define the hazard ratio of delivery <37 weeks. RESULTS: Of 346 meeting the MOMS-criteria, 78 comparable pairs were available for matched-controlled analysis. Mini-hysterotomy patients were younger and had a higher BMI. Mini-hysterotomy was associated with a 1.67-lower risk of delivery <37 weeks (hazard ratio: 0.60; 95% CI: 0.42-0.85; p = 0.004) and 1.72 for delivery <34 + 6 weeks (hazard ratio: 0.58; 95% CI: 0.34-0.97; p = 0.037). The rate of intact uterine scar at birth (mini-hysterotomy: 98.7% vs. hysterotomy: 90.4%; p = 0.070), the rate of reversal of hindbrain herniation within 1 week after surgery (88.9% vs. 97.4%; p = 0.180) and the rate of cerebrospinal fluid leakage (0% vs. 2.7%; p = 0.50) were comparable. CONCLUSION: Prenatal spina bidifa repair through mini-hysterotomy was associated with a later gestational age at delivery and a comparable intact uterus rate without apparent compromise in neuroprotection.

FIGO good practice recommendations on surgical techniques to improve safety and reduce complications during cesarean delivery.

FIGO is actively contributing to the global effort to reduce maternal morbidity, mortality, and disability worldwide. Cesarean delivery rates are increasing globally, without signs of slowing down. Bleeding associated with cesarean delivery has become an important cause of hemorrhage-related maternal deaths in many low- and middle-income countries. Correct surgical techniques to improve safety and reduce complications of cesarean delivery is of the utmost importance. This article presents FIGO's good practice recommendations for effective surgical techniques to reduce cesarean complications. Evidence-based information is included where data are available. An expanded WHO Surgical Safety Checklist for maternity cases is suggested. Different incision techniques through the layers of the abdominal wall with appropriate indications are discussed. Hysterotomy through a transverse incision is described, as are indications for low vertical and classical incisions. Important precautions when extracting the fetus are explained. Uterine closure includes a safe method ensuring adequate reapproximation of the upper segment if a vertical incision is made. The paper concludes with the management of two common bleeding problems following delivery of the placenta.

The amenorrhea as a protective factor for healing of hysterotomy - a retrospective analysis one year postpartum.

OBJECTIVES: The good healing of the hysterotomy after cesarean section is important for subsequent pregnancies. However, the factors which improve this healing have not been completely described, yet. In this study, we focused on factors which may affect healing of hysterotomy within one year after delivery, such as menstruation, breastfeeding, and the use of the contraception. MATERIAL AND METHODS: Following delivery, total of 540 women were invited for three consecutive visits at six weeks, six months, and 12 months postpartum. The presence of menstruation, frequency of breastfeeding and contraception use were recorded. The scar was evaluated by vaginal ultrasound as already described. The impact of menstruation, breastfeeding, and contraception method on presence of niche was evaluated. RESULTS: The presence of menstruation increased odds to have niche by 45% (CI 1.046-2.018, p = 0.026). Secondarily, our results demonstrated a statistically significant protective effect of breastfeeding on the incidence of niche with OR 0.703 (CI 0.517-0.955, p = 0.024). Breastfeeding decreases odds to have niche by 30%. Also, the use of gestagen contraception lowered the odds by 40% and intrauterine device (IUD) or combine oral contraceptive (COC) by 46.5%. The other possibly intervening factors were statistically controlled. CONCLUSIONS: Amenorrhea, breast-feeding and progesterone-contraceptive decreases the risk of uterine niche within one year follow up.

Unintended lower-segment hysterotomy extension at cesarean delivery and the risk for uterine rupture during a subsequent trial of labor.

OBJECTIVE: To evaluate the association between unintended uterine extension in cesarean delivery and uterine scar disruption (rupture or dehiscence) at the subsequent trial of labor after cesarean delivery (TOLAC). METHODS: This is a multicenter retrospective cohort study (2005-2021). Parturients with a singleton pregnancy who had unintended lower-segment uterine extension during the primary cesarean delivery (excluding T and J vertical extensions) were compared with patients who did not have an unintended uterine extension. We assessed the subsequent uterine scar disruption rate following the subsequent TOLAC and the rate of adverse maternal outcome. RESULTS: During the study period, 7199 patients underwent a trial of labor and were eligible for the study, of whom 1245 (17.3%) had a previous unintended uterine extension and 5954 (82.7%) did not. In univariate analysis, previous unintended uterine extension during the primary cesarean delivery was not significantly associated with uterine scar rupture in the following subsequent TOLAC. Nevertheless, it was associated with uterine scar dehiscence, higher rates of TOLAC failure, and a composite adverse maternal outcome. In multivariate analyses, only the association between previous unintended uterine extension and higher rates of TOLAC failure was confirmed. CONCLUSION: A history of unintended lower-segment uterine extension is not associated with an increased risk for uterine scar disruption following subsequent TOLAC.

Risk factors for shunting at 12 months following open fetal repair of spina bifida by mini-hysterotomy.

OBJECTIVES: Open spina bifida (OSB) is the most common neural tube defect. Prenatal repair reduces the need for ventriculoperitoneal shunting (VPS) due to hydrocephalus from 80-90% to 40-50%. We aimed to determine which variables work as risk factors for VPS at 12 months of age in our population. METHODS: Thirty-nine patients underwent prenatal repair of OSB by mini-hysterotomy. The main outcome was occurrence of VPS in the first 12 months of life. Logistic regression was used to estimate the odds ratios (OR) between prenatal variables and the need for shunting. RESULTS: VPS at 12 months occurred in 34.2% of the children. Larger ventricle size before surgery (62.5% ≥15 mm; 46.2% between 12 and 15 mm; 11.8% <12 mm; p=0.008), higher lesion level (80% >L2, vs. 17.9% ≤L3; p=0.002; OR, 18.4 [2.96-114.30]), and later gestational age at surgery (25.25 ± 1.18 vs. 24.37 ± 1.06 weeks; p=0.036; OR, 2.23 [1.05-4.74]) were related to increased need for shunting. In the multivariate analysis, larger ventricle size before surgery (≥15 mm vs. <12 mm; p=0.046; OR, 1.35 [1.01-1.82]) and higher lesion level (>L2 vs. ≤L3; p=0.004; OR, 39.52 [3.25-480.69]) were risk factors for shunting. CONCLUSIONS: Larger ventricle size before surgery (≥15 mm) and higher lesion level (>L2) are independent risk factors for VPS at 12 months of age in fetuses undergoing prenatal repair of OSB by mini-hysterotomy in the studied population.

Impact of Hysterotomy Closure Technique on Subsequent Cesarean Scar Defects Formation: A Systematic Review.

INTRODUCTION: The uterine caesarean scar defect, also known as uterine niche or isthmocele, is an irregularity in the anterior uterine wall at the site of a previous cesarean section scar. It is associated with obstetrical complications such as caesarean scar, ectopic pregnancy, uterine rupture, and the placenta accreta spectrum. Women with cesarean scar defects are frequently asymptomatic but may also experience abnormal vaginal bleeding, chronic pelvic pain, and infertility. METHODS: This systematic review aims to determine the best hysterotomy closure technique to prevent subsequent development of uterine scar defects. An electronic search in Medline, Embase, Cochrane Database of Systematic Reviews, ClinicalTrials.gov was performed from January 2001 until December 2020 for studies evaluating hysterotomy closure techniques. RESULTS: Our systematic search strategy identified 1,781 titles. Six studies fulfilled inclusion criteria and were included in the final analysis. The results supported the superiority of the double-layer closure over the single-layer closure. CONCLUSIONS: Hysterotomy closure with continuous running sutures in two layers represents a suitable option to prevent cesarean scar defect formation. Particularly, the first layer should include the decidua and the second layer should overlap the first.

Prior vertical uterine incision: Effect on subsequent pregnancy characteristics and outcomes.

OBJECTIVE: To examine characteristics and outcomes of cesarean delivery (CD) in women with a history of vertical hysterotomy. METHOD: This is a comparative study that retrospectively queried the National Inpatient Sample from October 2016 to December 2018. Pregnancy characteristics and surgical outcomes of CD among 18 575 women with prior vertical uterine incision were compared to 1 072 949 women with prior low-transverse incision, assessed by multivariable generalized estimating equation model and propensity score weighting. RESULTS: In a multivariable analysis, women who had prior vertical uterine incision were more likely to have placenta percreta (odds ratio [OR] 3.41, 95% confidence interval [CI] 1.87-6.20), pre-labor uterine rupture (OR 2.70, 95% CI 1.52-4.80), in-labor uterine rupture (OR 2.33, 95% CI 1.55-3.51), and extreme preterm delivery <28 weeks (OR 17.8, 95% CI 15.2-20.7) in the current pregnancy, compared to those who had prior low-transverse uterine incision. In a weighted model, prior vertical hysterotomy was associated with increased surgical morbidity in current CD compared to prior low-transverse hysterotomy (10.6% vs. 4.8%, OR 2.02, 95% CI 1.81-2.26), including hemorrhage (OR 1.99, 95% CI 1.74-2.27) and hysterectomy (OR 3.67, 95% CI 2.97-4.53). CONCLUSION: Prior vertical uterine incision at CD was associated with increased risk of placenta percreta, uterine rupture, particularly before labor, and adverse outcomes in the subsequent pregnancy.

Uterine rupture after previous caesarean section with hysterotomy above the lower uterine segment.

Background Spontaneous uterine rupture is a severe pregnancy complication. Several risk factors have been described, especially for women with a previous caesarean section. Method We reported two cases of uterine rupture (UR) occurring outside of labour in patients with a history of caesarean section (CS) due to placenta previa. Results: The current study evaluates how a higher hysterotomy, combined with some risk factors, can increase the prevalence of UR in the subsequent pregnancy. Conclusion This study supports that a careful evaluation of risk factors can identify patients who need a specific follow up to early diagnose and treat UR and thus improve the maternal-fetal outcome.

Knotless Barbed versus Conventional Suture for Closure of the Uterine Incision at Cesarean Delivery: A Systematic Review and Meta-analysis.

OBJECTIVE: To compare perioperative outcomes between knotless barbed sutures (KBSs) and conventional smooth sutures for uterine incision closure at cesarean section. DATA SOURCES: MEDLINE, EMBASE, Web of Sciences, Scopus, the Cochrane Library, and ClinicalTrials.gov were searched from the inception of the study to March 2021 without language restriction. The search terms were as follows: ["Stratafix" OR "Quill" OR "V-Loc" OR "Barbs" OR "barbed"] AND ["Cesarean" OR "Caesarean"] AND ["Suturing" OR "Suture" OR "Closure" OR "Repair"]. Moreover, these terms were combined to complete the search. METHODS OF STUDY SELECTION: Retrospective and randomized peer-reviewed studies comparing the use of KBSs and conventional sutures for uterine incision closure at cesarean section were included. The studies' quality was assessed by the Cochrane risk-of-bias tool. The primary outcome was the time of uterine incision closure in seconds. The secondary outcomes included total operating time (minutes), use of additional hemostatic sutures, rates of blood transfusion, and postoperative complications. TABULATION, INTEGRATION, AND RESULTS: Of 20 reports identified, 4 representing 3332 women (1473 with KBSs and 1859 with conventional sutures) were eligible. All studies were judged to be at low risk of bias. The uterine incision closure time was significantly lower in the KBS group (mean difference, -110.58; 95% confidence interval [CI], -127.37 to -93.79; p = .001). Furthermore, the rate of use of additional hemostatic sutures was significantly lower in the KBS group (odds ratio, 0.14; 95% CI, 0.07-0.26; p = .001). Total operative time, rates of blood transfusion, febrile morbidity, and length of postoperative stay were comparable. The incidence of postoperative ileus was significantly lower in the KBS group (odds ratio, 0.31; 95% CI, 0.11-0.89; p = .029). CONCLUSION: The use of KBSs for uterine incision closure was associated with decreased hysterotomy closure time and less frequent need for the placement of additional hemostatic sutures. Other perioperative outcomes were not affected, although the risk of postoperative ileus was reduced.

Desenlace fatal en embarazadas contagiadas con la COVID-19 / Fatal outcome wiht pregnant and COVID-19

Introducción: Múltiples han sido las muertes y contagios por el nuevo coronavirus. En medio de este contexto el contagio de la enfermedad en pacientes embarazadas ha sido bien documentado. Objetivo: Presentar los eventos ocurridos en embarazadas para transmitir la experiencia a quienes tratan estas pacientes. Presentación del caso: Se expone el caso de una gestante de 24 años, obesa, con embarazo de 25 semanas. Fue ingresada con neumonía por COVID-19 y evolución hacia la insuficiencia respiratoria grave que fallece durante la cesárea. Se recibió en el quirófano con hipoxemia e hipercapnia, taquicardia, cianosis, oliguria y ventilada a presión positiva con oxígeno al 100 %. Se conduce con ketamina, fentanilo y rocuronio. A los 35 min, y posterior a la histerotomía, presentó bradicardia progresiva, por lo que se inicia compresiones torácicas externas y tratamiento farmacológico. Se recuperó el ritmo sinusal a los 12 min, pero recidiva la parada en asistolia a los 20 min, con cianosis en esclavina. Se implementó compresiones y administración de epinefrina hasta fallecer 30 min después por no recuperación de ritmo y signos ciertos de la muerte. Conclusiones: La atención multidisciplinaria mejora las condiciones de tratamiento en todas las etapas. El manejo anestésico individualizado ofrece una estrategia invaluable en casos como estos, independientemente del resultado. El tromboembolismo pulmonar en la gestante es un riesgo latente y asociado a la COVID-19, incrementa, exponencialmente, su letalidad.

Introduction: Multiple deaths and infections due to the new coronavirus have occurred. In the midst of this context, the spread of the disease in pregnant patients has been well documented. Objective: Present the events that occurred in pregnant women, in order to share the experience with those who treat these patients. Presentation of the case: The case of a 24-year-old pregnant woman, obese, with a pregnancy of 25 weeks is presented. She was admitted with COVID-19 pneumonia and evolution towards severe respiratory failure led to her death during cesarean section. She was received in the operating room with hypoxemia and hypercapnia, tachycardia, cyanosis, oliguria and ventilated at positive pressure with 100% oxygen. She was treated with ketamine, fentanyl and rocuronium. At 35 min, and after hysterotomy, she presented progressive bradycardia, so external chest compressions and pharmacological treatment were initiated. The sinus rhythm was recovered at 12 min, but the asystole stop relapsed at 20 min, with cyanosis. Compressions and administration of epinephrine were implemented until death 30 minutes later due to non-recovery of rhythm and certain signs of death. Conclusions: Multidisciplinary care improves treatment conditions at all stages. Individualized anesthetic management offers an invaluable strategy in cases like these, regardless of the outcome. Pulmonary thromboembolism in pregnant women is a latent risk associated with COVID-19, exponentially increasing its lethality.

Opciones e indicaciones en el manejo del istmocele / Options and indications in the management of isthmocele

INTRODUCCIÓN: El istmocele es un defecto en la cicatrización del sitio de una histerotomía, que puede cursar con sangrado posmenstrual, dolor pélvico, dismenorrea, dispareunia e infertilidad secundaria. Esta patología ha ido incrementando su prevalencia dado el aumento de la tasa de cesáreas en todo el mundo. OBJETIVO: Se realizó una revisión sobre el istmocele y su manejo, presentando sus indicaciones específicas y las complicaciones asociadas a esta patología. MÉTODO: Se llevó a cabo una búsqueda en PubMed, Embase, Scopus y Google Scholar, en la que se encontraron 868 artículos, de los cuales se revisaron 30 al aplicar los criterios de inclusión y exclusión. DISCUSIÓN: El istmocele es cada vez más frecuente. Tiene una prevalencia cercana al 60% posterior a la realización de una cesárea y aumenta hasta valores del 100% con tres de ellas. Los métodos diagnósticos más utilizados son la ecografía transvaginal y la histerosonografía. Su abordaje es habitualmente quirúrgico, aunque existe la posibilidad de intentar tratamiento médico en algunos casos. CONCLUSIONES: Es necesario determinar el grosor miometrial para poder establecer un plan de manejo adecuado. Además, se ameritan estudios que realicen un seguimiento a largo plazo y que aporten mayor evidencia para la realización de cada procedimiento. Después de clasificar el tipo de defecto, el tratamiento quirúrgico del istmocele se debe ofrecer a pacientes sintomáticas y a aquellas con defectos grandes y que desean mantener la fertilidad.

INTRODUCTION: The isthmocele is a defect in the healing of the site of a hysterotomy, which can present with post-menstrual bleeding, pelvic pain, dysmenorrhea, dyspareunia and secondary infertility. This pathology has been increasing its prevalence given the increase in the rate of cesarean sections worldwide. OBJECTIVE: A review will be carried out of the isthmocele and its management, presenting its specific indications and the complications associated with this pathology. METHOD: A search was carried out in databases such as PubMed, Embase, Scopus and Google Scholar, finding a total of 868 articles, of which 30 of them were reviewed when applying the inclusion and exclusion criteria. DISCUSSION: Isthmocele is an increasingly frequent pathology, having a prevalence of 60% after performing a cesarean section and increasing to 100% with 3 of them. There are multiple diagnostic methods, mainly transvaginal ultrasound and sono-hysterosonography. The approach to this pathology is usually surgical, although there is the possibility of trying medical treatment in some cases. CONCLUSIONS: It is necessary to determine the myometrial thickness in order to establish an adequate management plan. Additionally, long-term follow-up studies are warranted and provide more evidence for the performance of each procedure. After classifying the type of defect, surgical treatment of the isthmocele should be offered to symptomatic patients or those with large defects and who desire future fertility.

Uterine externalization versus in situ repair of hysterotomy during cesarean delivery: a systematic review, equivalence meta-analysis, and trial sequential analysis.

BACKGROUND: Uterine positioning during hysterotomy repair is controversial, with both in situ and externalized approaches commonly performed. Despite many published trials, clinical equipoise remains. This meta-analysis and trial sequential analysis (TSA) summarizes studies comparing both techniques. METHODS: A systemic search for randomized controlled trials comparing in situ with externalized hysterotomy repair during cesarean delivery was performed. The primary outcomes were estimated blood loss (EBL) and surgical duration. Secondary outcomes were need for blood transfusion, incidence of endometritis, hospital length of stay, intra-operative hypotension, return of bowel function, intra-operative vomiting, intra-operative pain, and need for postoperative analgesia. Cochrane methodology was used to assess risk of bias. Data are presented as mean difference/standardized mean difference or odds ratio/risk difference with 95% confidence intervals (CI). RESULTS: Nineteen studies enrolling 20 739 patients were included. Estimated blood loss and surgical duration were equivalent between methods, with TSA confirming adequate information size for surgical duration but not EBL. In situ repair was associated with faster return of bowel function (MD -0.76 days; 95% CI -1.36 to -0.15; P=0.01) and a reduction in need for breakthrough postoperative analgesia (OR 0.44; 95% CI 0.28 to 0.68; P <0.01). CONCLUSIONS: This analysis revealed equivalence between methods for EBL and surgical duration. While the small reduction in EBL with externalized repair was not clinically or statistically significant, TSA analysis revealed an unmet information size, suggesting a potentially inconclusive result. In situ repair may be associated with less breakthrough postoperative analgesia requirement and faster return of bowel function.

A new technique for uterine incision closure at the time of cesarean section: does it make a difference?

The purpose of this study was to compare the short-term operative outcomes of three different surgical techniques for uterine incision closure during caesarean section (CS). This trial enrolled 120 patients scheduled for primary caesarean delivery. Patients were randomised into either classical double-layer uterine closure, purse-string double-layer uterine closure (Turan), or our new approach of uterine closure (double layer step up-step down technique). For short-term comparison, transvaginal ultrasonography was planned for all patients 6 weeks after surgery. Compared to group II and Group III, residual myometrial thickness was significantly thinner in group I (p < .001). The number of patients with uterine niche was 10 (50% of all scar defects) in group I whereas it was 4 (20%) in group II and 6 (30%) in group III. Operative time was significantly longer in group II (p < .001). This led to our conclusion that Turan technique and our new approach are associated with thicker myometrial thickness and less frequency of uterine scar defect than classical double-layer uterine incision closure; however, our approach takes less operative time. Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT04681378Impact statementWhat is already known on this subject? Many variations in CS technique have been studied. For example, single-layer uterine incision closure has been compared to double-layer uterine incision closure. Purse string double layer (Turan) has been also compared to the traditional double-layer technique. Double layer unlocked closure has been shown to result in a thicker residual myometrium and as a consequence can possibly lead to the decrease of niche development after a CS compared to single-layer closure with lower frequency of uterine scar defect with Turan technique.What do the results of this study add? Here we introduce a new uterine closure technique, which we have named double-layer step up-step down technique, as an alternative method. With this technique, the uterine incision contract more than with the traditional double layer technique and has similar results to the Turan technique; however, our approach takes less operative time.What are the implications of these findings for clinical practice and/or further research? These alternative techniques of uterine incision closure decrease the frequency of uterine niche that may be associated with many clinical problems such as ectopic pregnancy at the CS scar, placenta accreta, rupture of the uterus during a subsequent pregnancy. Future studies are needed to investigate the frequency of uterine rupture in a subsequent pregnancy following different uterine incision closure techniques.

Human Mesenchymal Stem Cell Sheets Improve Uterine Incision Repair in a Rodent Hysterotomy Model.

OBJECTIVE: The study aimed to assess the feasibility of creating and transplanting human umbilical cord mesenchymal stem cell sheets applied to a rat model of hysterotomy, and additionally to determine benefits of human umbilical cord mesenchymal stem cell sheet transplantation in reducing uterine fibrosis and scarring. STUDY DESIGN: Human umbilical cord mesenchymal stem cell sheets are generated by culturing human umbilical cord mesenchymal stem cells on thermo-responsive cell culture plates. The temperature-sensitive property of these culture dishes facilitates normal cell culture in a thin contiguous layer and allows for reliable recovery of intact stem cell sheets without use of destructive proteolytic enzymes.We developed a rat hysterotomy model using nude rats. The rat uterus has two distinct horns: one horn provided a control/untreated scarring site, while the second horn was the cell sheet transplantation site.On day 14 following surgery, complete uteri were harvested and subjected to histologic evaluations of all hysterotomy sites. RESULTS: The stem cell sheet culture process yielded human umbilical cord mesenchymal stem cell sheets with surface area of approximately 1 cm2.Mean myometrial thickness in the cell sheet-transplanted group was 274 µm compared with 191 µm in the control group (p = 0.02). Mean fibrotic surface area in the human umbilical cord mesenchymal stem cell sheet-transplanted group was 95,861 µm2 compared with 129,185 µm2 in the control group. Compared with control horn sites, cell sheet-transplanted horns exhibited significantly smaller fibrotic-to-normal myometrium ratios (0.18 vs. 0.27, respectively, p = 0.029). Mean number of fibroblasts in cell sheet-transplanted horns was significantly smaller than the control horns (483 vs. 716/mm2, respectively, p = 0.001). CONCLUSION: Human umbilical cord mesenchymal stem cell sheet transplantation is feasible in a rat model of hysterotomy. Furthermore, use of stem cell sheets reduces fibroblast infiltration and uterine scar fibrotic tissue formation during hysterotomy healing, potentially mitigating risks of uterine scar formation. KEY POINTS: · Stem cell sheet transplanted to hysterotomy promotes myometrial regeneration and reduced fibrotic tissue formation.. · This study demonstrates the feasibility of using human umbilical cord mesenchymal stem cell sheets..

Placental Location in Maternal-Fetal Surgery for Myelomeningocele.

INTRODUCTION: Uterine incision based on the placental location in open maternal-fetal surgery (OMFS) has never been evaluated in regard to maternal or fetal outcomes. OBJECTIVE: The aim of this study was to investigate whether an anterior placenta was associated with increased rates of intraoperative, perioperative, antepartum, obstetric, or neonatal complications in mothers and babies who underwent OMFS for fetal myelomeningocele (fMMC) closure. METHODS: Data from the international multicenter prospective registry of patients who underwent OMFS for fMMC closure (fMMC Consortium Registry, December 15, 2010-June 31, 2019) was used to compare fetal and maternal outcomes between anterior and posterior placental locations. RESULTS: The placental location for 623 patients was evenly distributed between anterior (51%) and posterior (49%) locations. Intraoperative fetal bradycardia (8.3% vs. 3.0%, p = 0.005) and performance of fetal resuscitation (3.6% vs. 1.0%, p = 0.034) occurred more frequently in cases with an anterior placenta when compared to those with a posterior placenta. Obstetric outcomes including membrane separation, placental abruption, and spontaneous rupture of membranes were not different among the 2 groups. However, thinning of the hysterotomy site (27.7% vs. 17.7%, p = 0.008) occurred more frequently in cases of an anterior placenta. Gestational age (GA) at delivery (p = 0.583) and length of stay in the neonatal intensive care unit (p = 0.655) were similar between the 2 groups. Fetal incision dehiscence and wound revision were not significantly different between groups. Critical clinical outcomes including fetal demise, perinatal death, and neonatal death were all infrequent occurrences and not associated with the placental location. CONCLUSIONS: An anterior placental location is associated with increased risk of intraoperative fetal resuscitation and increased thinning at the hysterotomy closure site. Individual institutional experiences may have varied, but the aggregate data from the fMMC Consortium did not show a significant impact on the GA at delivery or maternal or fetal clinical outcomes.

The Impact of Uterine Incision Closure Techniques on Post-cesarean Delivery Niche Formation and Size: Sonohysterographic Examination of Nonpregnant Women.

OBJECTIVE: To compare the prevalence and size of residual niche in the nongravid uterus following Cesarean delivery (CD) with different hysterotomy closure techniques (HCTs). METHODS: Saline infusion sonohysterogram (SIS) was performed in women after one prior CD, documenting the presence or absence of a postoperative niche and measuring its depth, width, length, and residual myometrial thickness. Women were grouped by HCT: Technique A (endometrium-free) and Technique B (routine non-endometrium-free). The primary outcome was the prevalence of a clinically significant niche, defined as a depth of >2 mm. HCT groups were compared using χ2 , T-test (ANOVA), and analyzed using logistic regression and two-sided test (P < .05). RESULTS: Forty-five women had SIS performed, 25 and 20 via Technique A and B, respectively. Technique groups varied by average interval time from CD to SIS (13.6 versus 74.5 months, P = 0.006) but were otherwise similar. Twenty niches were diagnosed, 85% of which were clinically significant, including five following Technique A, nine following Technique B with double-layer closure, and three following Technique B with single-layer (P = .018). The average niche depth was 2.4 mm and 4.9 mm among the two-layer subgroups following Techniques A and B, respectively (P = .005). A clinically significant niche development was six times higher with Technique B when compared to Technique A (OR 6.0, 95% CI 1.6-22.6, P = .008); this significance persisted after controlling for SIS interval on multivariate analysis (OR 4.4, 95% CI 1.1-18.3, P = .04). The average niche depth was 5.7 ± 2.9 mm following Technique B with single-layer. CONCLUSION: Hysterotomy closure techniques determine the prevalence of post-Cesarean delivery niche formation and size. Exclusion of the endometrium at uterine closure reduces the development of significant scar defects.