Blunt expansion of the low transverse uterine incision at cesarean delivery: a randomized comparison of 2 techniques

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.

Unintended uterine extension at the time of cesarean delivery - risk factors and associated adverse maternal and neonatal outcomes

OBJECTIVE

To identify risk factors, maternal and neonatal adverse outcomes related to unintended lower segment uterine extension during cesarean delivery (CD).

METHODS

A retrospective cohort analysis in a single, university-affiliated medical center between 1 January 2018 and 31 December 2019. All singleton pregnancies delivered by CD were included. Univariate and multivariate analyses were performed to identify maternal and obstetrical predictors for uterine extension during CD. For secondary outcomes, we assessed the correlation between uterine extension and any adverse maternal or neonatal outcome. Risk factors were analyzed using ROC statistics to measure their prediction performance for a uterine extension.

RESULTS

Overall, 1746 (19.3%) CDs were performed during the study period. Of them, 121 (6.9%) CDs were complicated by unintended uterine extension. There was no difference in maternal demographics and clinical data stratified by uterine extension at CD. Uterine extensions were significantly more common following induction of labor, intrapartum fever, premature rupture of membranes, a trial of labor after cesarean, advanced gestational age, emergent CD, and in particular CD during the second stage of labor (37.2% vs. 6.5%) and after failed vacuum extraction (6.6% vs. 1.1%), p < .05 for all. The incidence of postpartum hemorrhage and re-laparotomy did not differ between the groups. Most of the extensions were caudal-directed (40.4%), and were closed by a two-layer closure (92%). Mean extension size was 4.5 ± 1.7 cm. Using multivariable analysis, the only factor that remained significant was CD at the second stage of labor (adjusted odds ratio (aOR) 54.2, 95% CI 4.5-648.9, p = .002), with an area under the ROC curve 0.653 (95% CI 0.595-0.712, p < .001). Emergent CD, body mass index, birth weight, failed vacuum attempt, and trial of labor after cesarean were not significant. For secondary outcomes, an unintended uterine extension was associated with longer operation time, higher estimated blood loss, greater pre- to post-CD hemoglobin difference, increased blood products transfusion, puerperal fever, and longer hospital stay. No clinically significant neonatal adverse outcomes were observed.

CONCLUSIONS

In our cohort, second-stage CD was the strongest predictor for an unintended uterine extension. Following uterine extension, women had increased infectious and blood-loss morbidity.

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.

[The cesarean procedure: Guidelines for clinical practice from the French College of Obstetricians and Gynecologists]

OBJECTIVE

To identify procedures to reduce maternal morbidity during cesarean.

MATERIAL AND METHODS

The quality of evidence of the literature was assessed following the GRADE® method with questions formulated in the PICO format (Patients, Intervention, Comparison, Outcome) and outcomes defined a priori and classified according to their importance. An extensive bibliographic search was performed on PubMed, Cochrane and EMBASE databases. The quality of the evidence was assessed (high, moderate, low, very low) and a (i) strong or (ii) weak recommendations or (iii) no recommendation were formulated. The recommendations were reviewed in two rounds with external reviewers (Delphi survey) to select the consensus recommendations.

RESULTS

Of the 27 questions, there was agreement between the working group and the external reviewers on 26. The level of evidence of the literature was insufficient to provide a recommendation on 15 questions. Preventing hypothermia is recommended to increase maternal satisfaction and comfort (weak recommendation) and to reduce neonatal hypothermia (strong recommendation). The quality of the evidence of the literature did not allow to recommend the skin disinfectant to be used nor the relevance of a preoperative vaginal disinfection nor the choice between the use or nonuse of an indwelling bladder catheterization (if micturition takes place 1 hour before the cesarean section). The Misgav-Ladach technique or its analogues should be considered rather than the Pfannenstiel technique to reduce maternal morbidity (weak recommendation) bladder flap before uterine incision should not be performed routinely (weak recommendation), but a blunt (weak recommendation) and cephalad-caudad extension of uterine incision (weak recommendation) should be considered to reduce maternal morbidity. Antibiotic prophylaxis is recommended to reduce maternal infectious morbidity (strong recommendation) without recommendation on its type or the timing of administration (before incision or after cord clamping). The administration of carbetocin after cord clamping does not significantly decrease the incidence of blood loss>1000 ml, anemia, or blood transfusion compared with the administration of oxytocin. Thus, it is not recommended to use carbetocin rather than oxytocin in cesarean. It is recommended that systematic manual removal of the placenta not to be performed (weak recommendation). An antiemetic should be administered after cord clamping in women having a planned cesarean under locoregional anaesthesia to reduce intraoperative and postoperative nausea and vomiting (strong recommendation) with no recommendation regarding choice of use one or two antiemetics. The level of evidence of the literature was insufficient to provide any recommendation concerning single or double-layer closure of the uterine incision, or the uterine exteriorization. Closing the peritoneum (visceral or parietal) should not be considered (weak recommendation). The quality of the evidence of the literature was not sufficient to provide recommendation on systematic subcutaneous closure, including in obese or overweight patients, or the use of subcuticular suture in obese or overweight patients. The use of subcuticular suture in comparison with skin closure by staples was not considered as a recommendation due to the absence of a consensus in the external review rounds.

CONCLUSION

In case of cesarean, preventing hypothermia, administering antiemetic and antibiotic prophylaxis after cord clamping are the only strong recommendations. The Misgav-Ladach technique, the way of performing uterine incision (no systematic bladder flap, blunt cephalad-caudad extension), not performing routine manual removal of the placenta nor closure of the peritoneum are weak recommendations and may reduce maternal morbidity.

Comparison of intra operative hemorrhage by blunt and sharp expansion of uterine incision at cesarean section

Objectives:

To compare the effect of blunt and sharp incision of uterus at cesarean section on intra-operative haemorrhage.

Methods:

This trial was conducted at the Department of Obstetrics and Gynaecology, Pakistan Ordinance Factory Hospital, Wah Cantt from 14^th January to 13^th July 2012. Total 80 women planned for lower segment cesarean section through Pfannensteil incision were randomized to either blunt uterine incision (Group-A, n=40) or sharp uterine incision (Group-B, n=40). The fall in Haemoglobin and HCT was compared in two groups and analyzed with help of SPSS version 10.

Results:

Both groups were similar in terms of demographic features like age, parity, gestational age and indication for cesarean section. The participants in Group-A reveled significantly less drop of mean Hb concentration as compared to Group-B (1.47±1.08 and 1.95±0.85 respectively, P value 0.031). Similarly, the fall in mean HCT was significantly less in Group-A in comparison to Group-B (3.21±1.3 and 4.21±2.17 respectively, P-value 0.015)

Conclusion:

Blunt expansion of uterine incision during caesarean section is associated with less fall in Haemoglobin and HCT as compared to sharp expansion.

Is duration of passive second stage associated with a risk of hysterotomy extension during cesarean?

Objective

To assess obstetric factors associated with hysterotomy extension among women undergoing a second-stage cesarean.

Study design

This 5-year retrospective cohort study (2013–2017) included all women with second-stage cesarean deliveries of live-born singleton fetuses in cephalic presentation at term. It took place at a tertiary center that practices delayed pushing. We performed univariable and multivariable logistic regression to assess the maternal, obstetric, and neonatal factors associated with hysterotomy extension mentioned in the surgical report. Operative time, postpartum hemorrhage, and maternal complications were also studied.

Results

Of the 3350 intrapartum cesareans, 2637 were performed at term for singleton fetuses in cephalic presentation: 747 (28.3%) during the second stage of labor, 83 (11.1%) of which were complicated by a hysterotomy extension. The median duration of the passive phase of the second stage did not differ between women with and without an extension (164 min versus 160 min, P = 0.85). No other second-stage obstetric characteristics, i.e., duration of the active phase, fetal head station, or fetal malposition, were associated with the risk of extension. Factors significantly associated with extension were the surgeon’s experience and forceps use during the cesarean. Women with an extension, compared to women without one, had a longer median operative time (49 min versus 32 min, P<0.001) and higher rates of postpartum hemorrhage and blood transfusion (respectively, 30.1% versus 15.1%, p = 0.002 and 7.2% versus 2.4%, P = 0.03).

Conclusion

The risk of a hysterotomy extension does not appear to be associated with second-stage obstetric characteristics, including the duration of the passive phase of this stage. In our center, which practices delayed pushing, prolonging this passive phase beyond 2 hours does not increase the risk of hysterotomy extension in second-stage cesareans.

Transverse versus longitudinal blunt extension of the uterine incision during cesarean section in women with a uterine scar of previous cesarean delivery: A randomized controlled trial

OBJECTIVE

To compare two different blunt extension techniques of the lower segment transverse uterine incision at cesarean delivery in women with a uterine scar of previous cesarean delivery.

METHODS

Study design: Prospective single-blinded parallel multi-center randomized controlled trial involving 392 cases equally divided into two groups. Group one had their incision extended transversely, while group two had their incision extended longitudinally.

OUTCOME MEASURES

The primary outcome was the unintended extension of the uterine incision, while the secondary outcomes included the need for additional stitches to achieve hemostasis, the drop in hemoglobin level, uterine vessels injury, and the need for blood transfusion.

RESULTS

No significant difference between the transverse and longitudinal extension of the uterine incision during cesarean section as regards unintended uterine extension (P=0.860), uterine vessel injury (P=0.501), and cases requiring blood transfusion (P=0.814). Significantly lower drop in hemoglobin level (P≤0.001) and significantly less need for additional stitches (P≤0.001) in cases with the longitudinal extension of uterine incision.

CONCLUSION

In women with a uterine scar of previous cesarean delivery, the blunt longitudinal extension of the uterine incision in the lower segment cesarean section didn't differ from the blunt transverse extension as regards unintended uterine extension but is associated with less hemoglobin drop and less need for additional stitches as compared to transverse extension of the incision. Further studies are needed to assess the long-term complications of both techniques.

Cephalad-caudad versus transverse blunt expansion of the low transverse hysterotomy during cesarean delivery decreases maternal morbidity: a meta-analysis

OBJECTIVE

Cesarean delivery is the most prevalent surgical procedure worldwide, reaching approximately 29.7 million cases in 2015. It is directly associated with an increased risk of maternal and neonatal morbidity rates in the absence of malpresentation. Several techniques have been investigated, and there is evidence that cephalad-caudad expansion of the uterine incision might be associated with improved maternal outcomes compared with traditional transverse blunt expansion. The purpose of this meta-analysis was to evaluate the impact of cephalad-caudad expansion on adverse maternal outcomes, including intraoperative blood loss, risk of uterine vessel injury, and tearing of the lower uterine segment.

DATA SOURCES

We searched Medline, Scopus, the Cochrane Central Register of Controlled Trials, Google Scholar, and Clinicaltrials.gov databases from inception to January 2021.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials that assessed the impact of the cephalad-caudad blunt expansion of the low transverse uterine incision during cesarean delivery rather than those of transverse blunt expansion were selected for inclusion.

METHODS

Effect sizes were calculated with the Hartung-Knapp-Sidik-Jonkman random-effects model in R. Trial sequential analysis was performed to evaluate the adequacy of sample sizes.

RESULTS

Cephalad-caudad blunt expansion of the uterine incision was associated with a lower prevalence of unintended incision extension (relative risk, 0.62; 95% confidence interval, 0.45-0.86) and uterine vessel injury (relative risk, 0.55; 95% confidence interval 0.41-0.73). However, these complications were not accompanied by the increased need for additional suture placement (relative risk, 0.62; 95% confidence interval, 0.31-4.12) or transfusion rates (relative risk, 0.75; 95% confidence interval, 0.28-2.03). Similarly, the intraoperative duration was comparable with cases treated with transverse blunt expansion (mean difference = -0.45 minutes; 95% confidence interval -2.12 to 1.21) and the risk of intentional incision extension in the form of an inverted T (relative risk, 0.38; 95% confidence interval, 0.09-1.52). Trial sequential analysis revealed that the required sample size was reached in the unintended incision extension and uterine vessel injury outcomes.

CONCLUSION

The findings of our study suggested that cephalad-caudad blunt expansion of the uterine incision is superior to transverse expansion in terms of reducing unintended incision extension and uterine vessel injury.

Risk factors for uterine incision extension during cesarean delivery

Background: Unintentional extension of uterine incision is a known complication during cesarean delivery estimated to occur in 4-8% of cesarean deliveries. The aim of this study was to examine risk factors associated with unintentional uterine incision extension and to assess which of them are independent risk factors for this condition.Study design: We conducted a retrospective cohort study at a large public university tertiary referral center between 2003 and 2017. Included were women who underwent cesarean delivery during this time period. Demographic, medical, obstetrical and surgical data were collected. The primary outcome was the presence of uterine incision extension during cesarean delivery. Secondary outcomes included detection of risk factors associated with uterine incision extension. A multivariate analysis was additionally performed to identify general and labor related risk factors for unintentional extension of uterine incision among patients that underwent cesarean delivery during second stage of laborResults: During the study period, 25,879 cesarean deliveries performed in our medical center were assessed. Out of them, 731 (2.8%) cases of unintended uterine incision extension were identified. Women in this group had high rates of full cervical dilatation and increased maternal hemorrhage. Assessment of incision extension direction revealed that two-thirds of extensions were lateral, mostly unilateral. Median size of the extension was 2.7 ± 1.2 cm.Independent parameters associated with unintended uterine incision extension included nulliparity, vertex presentation, epidural anesthesia and cesarean section indication. Further analysis including cesarean deliveries performed during the second stage of labor revealed 397 (15.3%) cesarean deliveries in which incision extension was noted and 2205 (84.7%) cesarean deliveries without incision extension. Following multivariate analysis performed in women who underwent cesarean delivery during second stage of labor, two independent parameters associated with unintended uterine incision extension remained significant - past cesarean delivery and failed vacuum attempt.Conclusions: Vacuum extraction attempt and previous cesarean delivery are independent risk factors for uterine incision extension in women undergoing cesarean delivery during the second stage of labor. We also showed the majority of these extensions to be lateral.

External pop-out versus classic technique for delivery of the fetal head during elective cesarean section: A randomized clinical trial

OBJECTIVE

This study aims to compare two techniques (External pop-out versus classic technique) for delivery of the fetal head during elective cesarean section (CS).The potential clinical predictors associated with unintended uterine incision extension during fetal head delivery among women delivered by elective CS were also assessed.

METHODS

A randomized clinical trial conducted at a tertiary University hospital between February 2017 and January 2019. Participants were randomly assigned to the classic head delivery technique (group I) or external Pop-out (EPO) technique (group II). The primary outcome was the incidence of unintended uterine incision extension during elective CS. A logistic regression model was utilized to examine the association between patient's characteristics and the occurrence of unintended uterine incision extension.

RESULTS

Participants in both groups (455 women in each group) had similar demographic characteristics. The EPO group had a significantly lower incidence of uterine incision extension than the classic group (p = 0.006). The operative time was significantly shorter in the EPO group (p = 0.000), which was also significantly easier than the classic technique (p = 0.001). The high body mass index (p = 0.004), previous delivery by CS (p = 0.010), high birth weight (p = 0.001) and the classic technique for head delivery (p = 0.002) were significant predictors for uterine incision tears.

CONCLUSIONS

EPO technique is an easy technique for fetal head delivery during elective CS with a lower risk of uterine incision extension and shorter operative time.

Unintended hysterotomy extension during caesarean delivery: risk factors and maternal morbidity

We conducted an observational retrospective cohort study to evaluate the risk factors and the maternal morbidity associated with unintended extensions of the hysterotomy during caesarean delivery. We evaluated 2707 women who underwent low-transverse caesarean deliveries in 2011 at an academic, tertiary-care hospital. Hysterotomy extensions were identified through operative reports. Of the 2707 caesarean deliveries, 392 (14.5%) had an unintended hysterotomy extension. On the multivariable regression modelling, neonatal weight (OR 1.42; 95%CI 1.17-1.73), the arrest of labour [first-stage arrest (2.42; 1.73-3.38); second-stage arrest (5.54; 3.88-7.90)] and a non-reassuring foetal status (1.65; 1.20-2.25) were significantly associated with hysterotomy extensions. Hysterotomy extensions were significantly associated with an increased morbidity including an estimated blood loss >1200 millilitres (2.06; 1.41-3.02), a decline in postoperative haemoglobin ≥3.7 g/dL (2.07; 1.35-3.17), an evaluation for lower urinary tract injury (5.58; 3.17-9.81), and a longer operative time (8.11; 6.33-9.88). Based on these results, we conclude that unintended hysterotomy extensions significantly increase the maternal morbidity of caesarean deliveries. Impact statement What is already known on this subject? Maternal morbidity associated with caesarean delivery (CD) is significantly greater than that in vaginal delivery. Unintended extensions of the hysterotomy occur in approximately 4-8% of CDs and are more common after a prolonged second stage of labour. The morbidity associated with hysterotomy extensions has been incompletely evaluated. What do the results of this study add? We demonstrate a rate of hysterotomy extension in a general obstetric population of approximately 15%, which is higher than previously reported estimates, and represents a potential doubling of the rate of the unintended hysterotomy extensions in recent years. The most significant risk factor for a hysterotomy extension was a second-stage labour arrest with a fourfold increase in the frequency of extensions. A hysterotomy extension is a significant independent risk factor for an intraoperative haemorrhage, a drop in postoperative haemoglobin, an intraoperative evaluation for lower urinary tract injury, and longer CD operative times. What are the implications of these findings for clinical practice and/or further research? A second-stage arrest is a strong independent risk factor for a hysterotomy extension. Recent re-evaluations of the labour curve that extend the second stage of labour will likely increase the frequency of CDs performed after a prolonged second stage. In these scenarios, obstetricians should be prepared for an unintended hysterotomy extension and for the possibility of a longer procedure with the increased risks of blood loss and the need for evaluation of the lower urinary tract.

Blunt versus sharp uterine incision expansion during low transverse cesarean delivery: a metaanalysis

OBJECTIVE

We sought to review and update available evidence regarding outcomes after cesarean delivery (CD) using blunt vs sharp expansion of the uterine incision.

STUDY DESIGN

We queried the database of PubMed (US National Library of Medicine, 1946 through December 2013), the Cochrane Library Database of Systematic Reviews, ClinicalTrials.gov, and Web of Science. All relevant bibliographies were reviewed. Randomized controlled trials comparing blunt with sharp expansion of the lower segment during CD were evaluated for inclusion and methodological quality. The primary outcome was occurrence of unintended extensions. Secondary outcomes were drop in hematocrit or hemoglobin and estimated maternal blood loss, need for transfusion, operative time, use of uterotonics, rate of endometritis, and neonatal outcomes. Data extraction, analysis, and results were based on the preferred reporting items for systematic review and metaanalysis guidelines.

RESULTS

Six randomized controlled trials (2908 patients) were included. Blunt expansion technique was associated with lower drop in postoperative hematocrit (weighted mean difference [WMD], -1.07%; P = .05) and hemoglobin (WMD, -0.64 g/dL; P < .05), lower rate of unintended extensions (pooled relative risk, 0.47; P < .05), and a shorter operative time (WMD, -2 minutes; P < .05). Lower estimated blood loss was also observed but the difference was not significant (WMD, -88.07 mL; P > .05). There were no differences in the rates of blood transfusion, endometritis, use of uterotonics, and neonatal outcomes between both techniques.

CONCLUSION

Blunt expansion of uterine incision during CD is associated with less unintended extensions and favorable maternal outcomes. Although the drop in hemoglobin, hematocrit, and operative times were in favor of blunt expansion, the degree of reduction may not be clinically relevant.

[Clinical and pharmacological procedures for the prevention of postpartum haemorrhage in the third stage of labor]

OBJECTIVES

To describe the clinical and pharmacological procedures for the prevention of Postpartum Haemorrhage (PPH).

MATERIALS AND METHODS

We searched the Medline and the Cochrane Library (1st December 2004 to 1st March 2014) and we checked the international guidelines.

RESULTS

Vaginal birth: only the use of uterotonics reduces the incidence of PPH. Oxytocin is the treatment of choice if it is readily available (grade A). Oxytocin can be used either after the shoulders expulsion or rapidly after the placental delivery (grade B). A dose of 5 or 10IU must be administrated IV over at least 1minute or directly by an intramuscular injection (professional agreement) except in women with documented cardiovascular disease in which the duration of the IV perfusion should be over at least 5minutes (professional agreement). Mechanical procedures have no significant impact on PPH. The decision to use a collector bag is left to the medical team (professional agreement). A systematic complementary oxytocin perfusion is not recommended (professional agreement). Caesarean delivery: There is no evidence to recommend a particular type of caesarean technique to prevent PPH (professional agreement) but a lower uterine section is recommended (grade B). All types of incision expansion may be used (professional agreement). A controlled cord traction is associated with lower blood losses than manual removal of the placenta (grade B). A dose of 5 or 10IU can be injected (IV) over 1minute, and over 5minutes in women with cardiovascular disease (professional agreement). Carbetocin reduces the incidence of PPH but there is presently no inferiority study comparing oxytocin and carbetocin so that oxytocin remains the gold standard therapy to prevent PPH in C-section (professional agreement).

Surgical techniques for uterine incision and uterine closure at the time of caesarean section

BACKGROUND

Caesarean section is a common operation. Techniques vary depending on both the clinical situation and the preferences of the operator.

OBJECTIVES

To compare the effects of 1) different types of uterine incision, 2) methods of performing the uterine incision, 3) suture materials and technique of uterine closure (including single versus double layer closure of the uterine incision) on maternal health, infant health, and healthcare resource use.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 September 2013) and reference lists of all identified papers.

SELECTION CRITERIA

All published, unpublished, and ongoing randomised controlled trials comparing various types and closure of uterine incision during caesarean section.

DATA COLLECTION AND ANALYSIS

Two review authors evaluated trials for inclusion and methodological quality without consideration of their results according to the stated eligibility criteria and extracted data independently.

MAIN RESULTS

Our search strategy identified 60 studies for consideration, of which 27 randomised trials involving 17,808 women undergoing caesarean section were included in the review. Overall, the methodological quality of the trials was variable, with 12 of the 27 included trials adequately describing the randomisation sequence, with less than half describing adequately methods of allocation concealment, and only six trials indicating blinding of outcome assessors.Two trials compared auto-suture devices with traditional hysterotomy involving 300 women. No statistically significant difference in febrile morbidity between the stapler and conventional incision groups was apparent (risk ratio (RR) 0.92; 95% confidence interval (CI) 0.38 to 2.20).Five studies were included in the review that compared blunt versus sharp dissection when performing the uterine incision involving 2141 women. There were no statistically significant differences identified for the primary outcome febrile morbidity following blunt or sharp extension of the uterine incision (four studies; 1941 women; RR 0.86; 95% CI 0.70 to 1.05). Mean blood loss (two studies; 1145 women; average mean difference (MD) -55.00 mL; 95% CI -79.48 to -30.52), and the need for blood transfusion (two studies; 1345 women; RR 0.24; 95% CI 0.09 to 0.62) were significantly lower following blunt extension.A single trial compared transverse with cephalad-caudad blunt extension of the uterine incision, involving 811 women, and while mean blood loss was reported to be lower following transverse extension (one study; 811 women; MD 42.00 mL; 95% CI 1.31 to 82.69), the clinical significance of such a small volume difference is of uncertain clinical relevance. There were no other statistically significant differences identified for the limited outcomes reported.A single trial comparing chromic catgut with polygactin-910, involving 9544 women reported that catgut closure versus closure with polygactin was associated with a significant reduction in the need for blood transfusion (one study, 9544 women, RR 0.49, 95% CI 0.32 to 0.76) and a significant reduction in complications requiring re-laparotomy (one study, 9544 women, RR 0.58, 95% CI 0.37 to 0.89).Nineteen studies were identified comparing single layer with double layer closure of the uterus, with data contributed to the meta-analyses from 14 studies. There were no statistically significant differences identified for the primary outcome, febrile morbidity (nine studies; 13,890 women; RR 0.98; 95% CI 0.85 to 1.12). Although the meta-analysis suggested single layer closure was associated with a reduction in mean blood loss, heterogeneity is high and this limits the clinical applicability of the result. There were no differences identified in risk of blood transfusion (four studies; 13,571 women; average RR 0.86; 95% CI 0.63 to 1.17; Heterogeneity: Tau² = 0.15; I² = 49%), or other reported clinical outcomes.

AUTHORS' CONCLUSIONS

Caesarean section is a common procedure performed on women worldwide. There is increasing evidence that for many techniques, short-term maternal outcomes are equivalent. Until long-term health effects are known, surgeons should continue to use the techniques they prefer and currently use.

[Uterine artery pseudoaneurysm: an unusual cause of postpartum hemorrhage]

Uterine artery pseudoaneurysm is a rare complication of cesarean section. It can lead to severe postpartum hemorrhage. We report three cases of pseudoaneurysm diagnosed late after cesarean delivery, one followed by hemorrhagic shock. Ultrasound may point to the diagnosis, but arteriography of uterine arteries is decisive for the diagnosis. Selective artery embolization is recommended for treatment. Main advantages are complete occlusion of the pseudoaneurysm and fertility preservation.

Evidence-based surgery for cesarean delivery: an updated systematic review

The objective of our systematic review was to provide updated evidence-based guidance for surgical decisions during cesarean delivery (CD). We performed an English-language MEDLINE, PubMed, and COCHRANE search with the terms, cesarean section, cesarean delivery, cesarean, pregnancy, and randomized trials, plus each technical aspect of CD. Randomized control trials (RCTs) involving any aspect of CD technique from Jan. 1, 2005, to Sept. 1, 2012, were evaluated to update a previous systematic review. We also summarized Cochrane reviews, systematic reviews, and metaanalyses if they included additional RCTs since this review. We identified 73 RCTs, 10 metaanalyses and/or systematic reviews, and 12 Cochrane reviews during this time frame. Recommendations with high levels of certainty as defined by the US Preventive Services Task Force favor pre-skin incision prophylactic antibiotics, cephalad-caudad blunt uterine extension, spontaneous placental removal, surgeon preference on uterine exteriorization, single-layer uterine closure when future fertility is undesired, and suture closure of the subcutaneous tissue when thickness is 2 cm or greater and do not favor manual cervical dilation, subcutaneous drains, or supplemental oxygen for the reduction of morbidity from infection. The technical aspect of CD with high-quality, evidence-based recommendations should be adopted. Although 73 RCTs over the past 8 years is encouraging, additional well-designed, adequately powered trials on the specific technical aspects of CD are warranted.

Bladder Injury During Cesarean Delivery

Cesarean section is the most common surgery performed in the United States with over 30% of deliveries occurring via this route. This number is likely to increase given decreasing rates of vaginal birth after cesarean section (VBAC) and primary cesarean delivery on maternal request, which carries the inherent risk for intraoperative complications. Urologic injury is the most common injury at the time of either obstetric or gynecologic surgery, with the bladder being the most frequent organ damaged. Risk factors for bladder injury during cesarean section include previous cesarean delivery, adhesions, emergent cesarean delivery, and cesarean section performed at the time of the second stage of labor. Fortunately, most bladder injuries are recognized at the time of surgery, which is important, as quick recognition and repair are associated with a significant reduction in patient mortality. Although cesarean delivery is a cornerstone of obstetrics, there is a paucity of data in the literature either supporting or refuting specific techniques that are performed today. There is evidence to support double-layer closure of the hysterotomy, the routine use of adhesive barriers, and performing a Pfannenstiel skin incision versus a vertical midline subumbilical incision to decrease the risk for bladder injury during cesarean section. There is also no evidence that supports the creation of a bladder flap, although routinely performed during cesarean section, as a method to reduce the risk of bladder injury. Finally, more research is needed to determine if indwelling catheterization, exteriorization of the uterus, and methods to extend hysterotomy incision lead to bladder injury.

Blunt vs. sharp uterine expansion at lower segment cesarean section delivery: a systematic review with metaanalysis

OBJECTIVE

Blunt vs sharp expansion of the uterine incision at cesarean delivery has been investigated as a technique primarily to reduce intraoperative blood loss. The objective of this systematic review was to compare the effects of either intervention on maternal outcomes.

STUDY DESIGN

A systematic review with metaanalyses that used the DerSimonian and Laird random effects model was performed. The Cochrane Central Register of Controlled Trials (The Cochrane Library 2012, Issue 4), MEDLINE (1948-Apr 2012), EMBASE (1947-Apr 2012), and the reference lists/citation history of articles were searched. Only randomized controlled trials were included.

RESULTS

Four trials (1731 patients) were evaluated. Data from one recently completed trial (535 patients) were not yet available. Metaanalyses revealed a trend towards reduced maternal blood loss with blunt expansion of the uterine incision that was statistically significant when measured by surgeon's estimation of volume lost, but not by comparison of pre- and postoperative hematocrit and hemoglobin levels or a requirement for blood transfusion. There was a trend towards fewer unintended extensions in the blunt group and no difference in the incidence of endometritis.

CONCLUSION

Blunt dissection of the uterine incision at cesarean delivery appears to be superior to sharp dissection in minimizing maternal blood loss. However, this conclusion could change when data from a new unpublished large trial are available.

Evidence-based cesarean technique

PURPOSE OF REVIEW

Cesarean section is the most common surgical procedure performed on US women, and rates of cesarean delivery continue to increase.

RECENT FINDINGS

Recent studies on operative technique in cesarean section have contributed significantly to our knowledge of antibiotic prophylaxis, bladder flap formation, management of the uterine repair and closure of the peritoneum and skin. There is compelling evidence that antibiotics should be given prior to skin incision rather than the traditional administration after cord clamping. Additionally, evidence suggesting benefit to multiagent, extended-coverage regimens is mounting. Recent studies challenge the accepted practice of creating a bladder flap in cesarean section. Uterine repair can be safely accomplished either intra or extraabdominally but the debate over single versus double-layer closure continues. Nonclosure of the visceral peritoneum confers significant benefit, but recent evidence suggests that closure of the parietal layer may be advantageous with respect to future adhesions.

SUMMARY

It is imperative that all technical aspects in cesarean section continue to be challenged. Widely accepted aspects, including antibiotics administration at cord clamping and creation of a bladder flap, may not be best practice.

Cosmetic outcomes of various skin closure methods following cesarean delivery: a randomized trial

OBJECTIVE

The objective of the study was to compare scar quality associated with different types of wound closure methods after cesarean section (CS).

STUDY DESIGN

Patients were randomized to have skin closure following CS with either staples or 3 different types of subcuticular sutures. Scar quality was evaluated 2 and 6 months postoperatively. The Vancouver Scar Scale, the Patient and Observer Scar Assessment Scale (POSAS), and a visual analog scale were used as scar assessment tools.

RESULTS

Of the 180 patients who were recruited, 123 successfully completed the study. No difference in both subjective and objective scar rating was detected across groups at either 2 months or 6 months. In the overall study population, objective scores correlated with patient rating, and correlation was strongest between the observer and patient components of the POSAS (r = 0.48).

CONCLUSION

In women undergoing CS, stapled wounds and those closed with subcuticular sutures result in equivalent cosmetic appearance of the scar.

Surgical techniques for uterine incision and uterine closure at the time of caesarean section

BACKGROUND

Caesarean section is a common operation. Techniques vary depending on both the clinical situation and the preferences of the operator.

OBJECTIVES

To compare the effects of 1) different types of uterine incision, 2) methods of performing the uterine incision, 3) suture materials and technique of uterine closure (including single versus double layer closure of the uterine incision) on maternal health, infant health, and health care resource use.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (November 2007).

SELECTION CRITERIA

All published, unpublished, and ongoing randomised controlled trials comparing various types and closure of uterine incision during caesarean section.

DATA COLLECTION AND ANALYSIS

Two authors evaluated trials for inclusion and methodological quality without consideration of their results according to the stated eligibility criteria and extracted data independently.

MAIN RESULTS

We identified 30 studies, of which 15 (3972 women) were included. Ten trials compared single layer uterine closure with double layer uterine closure (2531 women), two trials compared blunt with sharp dissection at the time of the uterine incision (1241 women), and two trials compared auto-suture devices with traditional hysterotomy (300 women). Blunt dissection was associated with a reduction in mean blood loss at the time of the procedure when compared with sharp dissection of the uterine incision (one study, 945 women, mean difference (MD) -43.00, 95% confidence interval (CI) -66.12 to -19.88). There was no statistically significant difference related to need for blood transfusion (one study, 945 women, risk ratio (RR) 0.22, 95% CI 0.05 to 1.01). The use of an auto-suture instrument when compared with traditional methods of hysterotomy was associated with no difference in the amount of blood loss during the procedure (one study, 200 women, MD -87.00, 95% CI -175.09 to 1.09), but a statistically significant increase in the duration of the procedure (one study, 197 women, MD 3.30, 95% CI 0.02 to 6.62). Single layer closure compared with double layer closure was associated with a statistically significant reduction in mean blood loss (three studies, 527 women, MD -70.11, 95% CI -101.61 to -38.60); duration of the operative procedure (four studies, 645 women, MD -7.43, 95% CI -8.41 to -6.46); and presence of postoperative pain (one study, 158 women, RR 0.69, 95% CI 0.52 to 0.91).

AUTHORS' CONCLUSIONS

While caesarean section is a common procedure performed on women worldwide, there is little information available to inform the most appropriate surgical technique to adopt.