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

Fantastic niches and where to find them: the current diagnosis and management of uterine niche

Background

Caesarean section (CS) scar niche is a well recognised complication of caesarean delivery and is defined as an indentation at the site of the CS scar with a depth of at least 2mm.

Objectives

To review systematically the medical literature regarding the current diagnosis and management of uterine niche

Materials and methods

We carried out a systematic review using MeSH terms ‘niche’ OR ‘sacculation’ OR ‘caesarean scar defect’ OR ‘caesarean section scar’ OR ‘uterine defect’ OR ‘isthmocele.’ Articles included were peer-reviewed and in English language.

Main outcome measures

Prevalence, symptoms, diagnosis, pathophysiology and management of uterine niche.

Results

CS scar niche is common and, in a subgroup, produces a range of symptoms including post-menstrual bleeding, dyspareunia and subfertility. It may be linked to use of locked sutures during CS closure. Niche repair can be achieved laparoscopically or hysteroscopically and appears to improve symptoms, although solid conclusions regarding fertility outcomes cannot be drawn.

Conclusions

CS scar niche is associated with a range of symptoms. Repair may aid subfertile patients and those with post-menstrual spotting. The presence of a niche is probably irrelevant in the absence of symptoms.

What is new?

LNG-IUS and surgical repair appear to improve symptoms in those with a niche.

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.

Captive uterus syndrome: An unrecognized complication of cesarean sections?

Cesarean sections are a common surgical procedure at risk of complications including adhesions and chronic pelvic pain. This case series presents 10 cases of patients presenting with chronic pelvic pain following a cesarean section which were found upon surgical exploration to have developed adhesions between the abdominal wall and the uterus. When they first consulted, patients were evaluated clinically with a questionnaire and physical exam, and with ultrasonography to evaluate pelvic anatomy when necessary. The evaluation was completed with diagnostic laparoscopy which revealed atypical post-cesarean adhesions which were treated by adhesion lysis or hysterectomy. Surgical protocols of the cesarean sections were retrieved and analysed for potential adhesion risk factors. Patients presented with chronic pelvic pain that appeared in the early post-operative period. Physical exam revealed a subinvoluted uterus with a high fixed cervix. Ultrasound examination revealed clues of adhesions manifested by points of traction and an irregular uterine border. No other diagnosis such as endometriosis, pelvic inflammatory disease, ovarian or bowel anomalies were identified during surgery. After laparoscopic adhesion lysis or hysterectomy, all patients who were treated noted a complete resolution of the pain that lasted during a follow-up of at least 5 years. These findings suggest that adhesions that create traction and fix the uterus to the abdominal wall following caesarian section can be the cause of severe chronic pelvic pain. In the presence of such pain, clinicians should suspect the presence of adhesions and investigate and treat patients accordingly.

Evidence-Based Cesarean Delivery for the Nonobstetrician

Cesarean delivery (CD) is one of the most common major surgeries performed in the United States and worldwide. Surgical techniques evaluated in well-designed randomized controlled trials (RCTs) that demonstrate maternal benefit should be incorporated into practice. The objective of this review is to provide a summary of surgical techniques of the procedure and review the evidence basis for them for the nonobstetrician. The following techniques with the strongest evidence should be commonly performed, when feasible: (1) prophylactic antibiotics with a single dose of ampicillin or first-generation cephalosporin prior to skin incision; (2) postpartum hemorrhage prevention with oxytocin infusion of 10 to 40 IU in 1 L crystalloid over 4 to 8 hours; (3) low transverse skin incision; (4) blunt or sharp subcutaneous and fascial expansion; (5) blunt, cephalad-caudad uterine incision expansion; (6) spontaneous placental removal; (7) blunt-tip needle usage during closure; (8) subcutaneous suture closure (running or interrupted) if thickness is ≥2 cm; and (9) skin closure with suture. Although the number of RCTs designed to optimize maternal and neonatal outcomes of this common procedure is encouraging, further work is needed to minimize surgical morbidity. Optimal methods for postpartum hemorrhage prevention, adhesion prevention, and venous thromboembolism prophylaxis remain ongoing areas of active research, with outcomes that could markedly improve maternal morbidity and mortality. If evidence of a surgical technique appears preferred over another, clinicians should be comfortable adopting the evidence-based technique when performing and teaching CD.

Variables influencing the integrity of lower uterine segment in post-cesarean pregnancy

BACKGROUND

There is significant increase in proportion of cases with previous cesarean delivery requiring obstetric care. The available literature fails to provide uniform opinion on each woman's characteristics to identify risk of uterine rupture while planning trial of labor after cesarean.

OBJECTIVE

To study the association of abnormal lower uterine segment with some of the present and previous obstetric variables including patient characteristics and surgical techniques at previous cesarean operation.

MATERIALS AND METHODS

Consenting consecutive 96 post-cesarean singleton pregnancies admitting after 36 weeks gestation at the same facility from July 2011 to December 2012 for repeat cesarean, were studied. Only the cases with cephalic presentation and vertex as presenting part, having no placenta previa, polyhydramnios, uterine anomaly or fibroid and those who had previous one lower segment cesarean were recruited. Based on the intra-operative finding the lower uterine segment (LUS) was categorized into those having a normal and abnormal (grades 2-4) LUS. Sonographic assessment of LUS thickness and any abnormalities if any were noted. The findings of abnormal LUS (direct observation at surgery and sonographic impression within a week before surgery) were looked for association with some of the present and previous obstetric variables including patient characteristics and surgical techniques at previous cesarean operation using Student t, Chi square or Fisher's exact test for analysis as appropriate. Receiver operating curve analysis was used to determine the optimal cut off value for prediction of LUS integrity by ultrasound.

RESULTS

Of the women recruited for the study, 36 were admitted in early labor and ultrasound evaluation of LUS was performed in 48 of the remaining 60 women admitted antenatal for elective cesarean delivery. There were 38 abnormal LUS (39.6%) with 22 of them (57.9%) graded as 'thinned out LUS'. The incidence of scar dehiscence (grade 3, cases 5) was 5.2% of 96 cases and there were no cases of scar rupture. Proportion of cases with abnormal LUS was significantly high when primary cesarean was done in preterm (p = 0.02); it was a single layer uterine closure (p = 0.02), and inter-cesarean interval was 54 months (p = 0.01). Abnormal LUS was also seen to be associated with maternal age beyond 35 years (p = 0.2), when cesarean was performed in labor (p = 0.5), following 18 h of rupture of membranes (p = 0.75), for a baby weight more than 3 kg (p = 0.4), and different suture materials (polyglactin 910 and chromic catgut) were used to close uterus at primary cesarean delivery (p = 0.1), and also if they had post-partum fever (p = 0.3). Ultrasound measurement of LUS by abdominal scan correlated with the intra-operative LUS grading and a thickness of more than 3.2 mm within a week before delivery and was seen to be the safe cut off above which most of the women had a normal LUS (sensitivity 92.3%, specificity 81.1%).

CONCLUSION

Factors at primary cesarean operation significantly influence the state of LUS at term in subsequent pregnancy .

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 closure with unlocked suture in cesarean section: Safety and Quality

Objective: Comparing locked and unlocked uterine closure techniques in terms of bleeding control and uterine incision healing.

Methods: The patients undergoing cesarean section in Sifa University Hospital between May - October 2012 were accepted to this prospective controlled study. Primarily, safety was evaluated. The hemoglobin count (HC) and serum creatine kinase (CK) levels of the patients in the locked (n = 47) and unlocked (n = 35) groups were measured just before and 24 hours after operation. Hemoglobin deficit, increase in CK and the additional hemostatic sutures were compared. Secondly, uterine scar healing was evaluated three months later. Scar thickness, niche and percentage of thinning of the scar region of the locked (n = 27) and unlocked (n = 32) groups were calculated and compared.

Results: The hemoglobin deficit was similar in two groups. CK rise was less in the unlocked group but it was not significant (P = 0.082). Unlocked group needed more additional sutures (P = 0.016). The thickness of the niche and the percentage of thinning of the scar region were significantly less in the unlocked group (P= 0.002, P=0.000).

Conclusions: Unlocked uterine closure technique is safe and has less damage to the myometrium.

Emergency cesarean delivery: special precautions

An emergent cesarean delivery is performed to immediately intervene to improve maternal or fetal outcome for such indications as fetal distress, prolapsed cord, maternal hemorrhage from previa or trauma, uterine rupture, and complete placental abruption. It is paramount to reduce morbidity and mortality by preparing health care providers for special precautions.

A randomized comparative study on modified Joel-Cohen incision versus Pfannenstiel incision for cesarean section

OBJECTIVE

Pfanennstiel incision is the most commonly used incision for cesarean section, but may not be the best. This study compared the modified Joel-Cohen incision with the Pfannenstiel incision to evaluate whether techniques to open the abdomen might influence operative time, and maternal and neonatal outcomes.

MATERIAL AND METHODS

In a randomized comparative trial, 302 women with gestational age >34 weeks, requiring cesarean section, were randomly assigned to either modified Joel-Cohen incision or Pfannenstiel incision for entry into the peritoneal cavity. The primary outcome measure was total time required for performing operation and secondary outcome measures were baby extraction time, number of haemostatic procedures used in the abdominal wall, postoperative morbidity, postoperative hospital stay and neonatal outcome.

RESULTS

Mean total operative time was significantly less in the modified Joel-Cohen group as compared to the Pfannenstiel group (29.81 vs 32.67 min, p<0.0001, 95%CI=2.253 to 3.467). Time taken to deliver the baby and haemostatic procedures required during operation were also significantly less in the modified Joel-Cohen group as compared to the Pfannenstiel group. Requirement of strong analgesics was higher in the Pfannenstiel group (53.64% vs 21.85%, p<0.0001). There was no statically significant difference in the incidence of postoperative wound complications but postoperative stay in hospital was significantly less in the modified Joel-Cohen group (p=0.002). Neonatal outcomes were similar in both groups.

CONCLUSION

The modified Joel-Cohen incision for entry into peritoneal cavity during cesarean section is associated with reduced mean total operative and baby extraction times with less postoperative pain and shorter hospital stay, which may be beneficial and cost effective.

Dehiscent scar in the lower uterine segment after Caesarean section and IVF infertility treatment: a case report

AIMS

Caesarean section is the most common obstetric operation associated with short and long term risks, one of which is uterine scar dehiscence. In this case report we describe four cases of in vitro fertilization and embryo transfer (IVF+ET) treatment where the embryo was transferred into the uterus with known scar dehiscence in the lower uterine segment after a previous Caesarean section (SC).

METHODS

All transfers of embryos were ultrasound guided directly into the middle of uterine cavity. All resulting pregnancies continued without problems related to the dehiscent scar and babies were delivered in the third trimester by elective/emergency SC.

RESULTS

Our cases suggest that IVF+ET can be offered as an infertility treatment option despite a dehiscent scar in the lower uterine segment after previous SC.

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.

Techniques and materials for skin closure in caesarean section

BACKGROUND

Caesarean section is a common operation with no agreed upon standard regarding certain operative techniques or materials to use. With regard to skin closure, the skin incision can be re-approximated by a subcuticular suture immediately below the skin layer, by an interrupted suture, or by staples. A great variety of materials and techniques are used for skin closure after caesarean section and there is a need to identify which provide the best outcomes for women.

OBJECTIVES

To compare the effects of skin closure techniques and materials on maternal and operative outcomes after caesarean section.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (10 January 2012).

SELECTION CRITERIA

All randomized trials comparing different skin closure materials in caesareans were selected. Two review authors independently abstracted the data.

DATA COLLECTION AND ANALYSIS

We identified 19 trials and included 11, but only eight trials contributed data. Three trials were not randomized controlled trials; two were ongoing; one study was terminated and the results were not available for review; one is awaiting classification; and one did not compare skin closure materials, but rather suture to suture and drain placement.

MAIN RESULTS

The two methods of skin closure for caesarean that have been most often compared are non-absorbable staples and absorbable subcutaneous sutures. Compared with absorbable subcutaneous sutures, non-absorbable staples are associated with similar incidences of wound infection. Other important secondary outcomes, such as wound complications, were also similar between the groups in women with Pfannenstiel incisions. However, it is important to note, that for both of these outcomes (wound infection and wound complication), staples may have a differential effect depending on the type of skin incision, i.e., Pfannenstiel or vertical. Compared with absorbable subcutaneous sutures, non-absorbable staples are associated with an increased risk of skin separation, and therefore, reclosure. However, skin separation was variably defined across trials, and most staples were removed before four days postpartum.

AUTHORS' CONCLUSIONS

There is currently no conclusive evidence about how the skin should be closed after caesarean section. Staples are associated with similar outcomes in terms of wound infection, pain and cosmesis compared with sutures, and these two are the most commonly studied methods for skin closure after caesarean section. If staples are removed on day three, there is an increased incidence of skin separation and the need for reclosure compared with absorbable sutures.

Techniques and materials for skin closure in caesarean section

BACKGROUND

Caesarean section is a common operation with no agreed upon standard regarding certain operative techniques or materials to use. With regard to skin closure, the skin incision can be re-approximated by a subcuticular suture immediately below the skin layer, by an interrupted suture, or by staples. A great variety of materials and techniques are used for skin closure after caesarean section and there is a need to identify which provide the best outcomes for women.

OBJECTIVES

To compare the effects of skin closure techniques and materials on maternal and operative outcomes after caesarean section.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (10 January 2012).

SELECTION CRITERIA

All randomized trials comparing different skin closure materials in caesareans were selected. Two review authors independently extracted the data.

DATA COLLECTION AND ANALYSIS

We identified 18 trials and included 10, but only eight trials contributed data. Three trials were not randomized controlled trials; three were ongoing; and one did not compare skin closure materials, but rather suture to suture and drain placement.

MAIN RESULTS

The two methods of skin closure for caesarean that have been most often compared are non-absorbable staples and absorbable subcutaneous sutures. Compared with absorbable subcutaneous sutures, non-absorbable staples are associated with similar incidences of wound infection. Other important secondary outcomes, such as wound complications, were also similar between the groups in women with Pfannenstiel incisions. However, it is important to note, that for both of these outcomes (wound infection and wound complication), staples may have a differential effect depending on the type of skin incision, i.e., Pfannenstiel or vertical. Compared with absorbable subcutaneous sutures, non-absorbable staples are associated with an increased risk of skin separation, and therefore, reclosure. However, skin separation was variably defined across trials, and most staples were removed before four days postpartum.

AUTHORS' CONCLUSIONS

There is currently no conclusive evidence about how the skin should be closed after caesarean section. Staples are associated with similar outcomes in terms of wound infection, pain and cosmesis compared with sutures, and these two are the most commonly studied methods for skin closure after caesarean section. If staples are removed on day three, there is an increased incidence of skin separation and the need for reclosure compared with absorbable sutures.

Uterine closure in cesarean delivery: a new technique

Fear of scar rupture is one of risks involved in a post caesarean pregnancy. This had led to an increased rate of repeat cesarean delivery in today's times. Closure of the uterine incision is a key step in cesarean section, and it is imperative that an optimal surgical technique be employed for closing a uterine scar. This technique should be able to withstand the stress of subsequent labor. In the existing techniques of uterine closure, single or double layer, correct approximation of the cut margins, that is, decidua-to-decidua, myometrium to myometrium, serosa to serosa is not guaranteed. Also, there are high chances of inter surgeon variability. It was felt that if a suturing technique which ensures correct approximation of all the layers mentioned above with nil or minimal possibility of inter operator variability existed, there will not be any thinning of lower segment caesarean section (LSCS). Further, a scarred uterus repaired in this manner will be able to withstand the stress of labor in future. We hereby report a new technique for uterine closure devised by us, which incorporates a continuous modified mattress suture technique as a modification of the existing surgical technique of uterine closure.

Unforeseen consequences of the increasing rate of cesarean deliveries: early placenta accreta and cesarean scar pregnancy. A review

This review concentrates on 2 consequences of cesarean deliveries that may occur in a subsequent pregnancy. They are the pathologically adherent placenta and the cesarean scar pregnancy. We explored their clinical and diagnostic as well as therapeutic similarities. We reviewed the literature concerning the occurrence of early placenta accreta and cesarean section scar pregnancy. The review resulted in several conclusions: (1) the diagnosis of placenta accreta and cesarean scar pregnancy is difficult; (2) transvaginal ultrasound seems to be the best diagnostic tool to establish the diagnosis; (3) an early and correct diagnosis may prevent some of their complications; (4) curettage and systemic methotrexate therapy and embolization as single treatments should be avoided if possible; and (5) in the case of cesarean scar pregnancy, local methotrexate- and hysteroscopic-directed procedures had the lowest complication rates.

Adhesion prevention in patients with multiple cesarean deliveries

Adhesion formation is a well-known complication of abdominal surgery. Although one third of all deliveries in the United States are by cesarean delivery (CD), little is known about adhesions in the obstetric setting. Various surgical techniques for reducing adhesion formation following CD have been investigated. The relative benefits of peritoneal closure and single-layer uterine closure are areas of continued research and debate. Adhesion prevention products are also becoming more commonplace in gynecologic surgery. Two membrane/adhesion barriers have been approved in the United States. A barrier consisting of oxidized regenerated cellulose (Interceed absorbable adhesion barrier) has been shown to reduce adhesions during microsurgery. Its use may be limited following CD because complete hemostasis is crucial to its efficacy. Seprafilm adhesion barrier, composed of hyaluronic acid and carboxymethylcellulose, is approved for use in abdominal or pelvic laparotomy. Preliminary data suggest that it may be effective for reducing adhesions following CD. This article discusses what is currently known about adhesion prevention in the obstetric population and highlights the paucity of level I evidence available to clinicians in this setting.

New and underutilised technologies to reduce maternal mortality and morbidity: what progress have we made since Bellagio 2003?

In 2003, maternal health experts met in Bellagio, to consider new and underutilised technologies vital to pregnancy-related health services in low-resource settings. Five years later, we examine what progress has been made and what new opportunities may be on the horizon. Based on a review of literature and consultation with experts, we consider technologies addressing the five leading causes of maternal mortality: postpartum haemorrhage, eclampsia, obstructed labour, puerperal sepsis, and unsafe abortion (pregnancy termination and miscarriage). In addition, we consider technologies related to obstetric fistula, which has received more attention in recent years.

The CORONIS Trial. International study of caesarean section surgical techniques: a randomised fractional, factorial trial

BACKGROUND

Caesarean section is one of the most commonly performed operations on women throughout the world. Rates have increased in recent years - about 20-25% in many developed countries. Rates in other parts of the world vary widely.A variety of surgical techniques for all elements of the caesarean section operation are in use. Many have not yet been rigorously evaluated in randomised controlled trials, and it is not known whether any are associated with better outcomes for women and babies. Because huge numbers of women undergo caesarean section, even small differences in post-operative morbidity rates between techniques could translate into improved health for substantial numbers of women, and significant cost savings.

DESIGN

CORONIS is a multicentre, fractional, factorial randomised controlled trial and will be conducted in centres in Argentina, Ghana, India, Kenya, Pakistan and Sudan. Women are eligible if they are undergoing their first or second caesarean section through a transverse abdominal incision. Five comparisons will be carried out in one trial, using a 2 x 2 x 2 x 2 x 2 fractional factorial design. This design has rarely been used, but is appropriate for the evaluation of several procedures which will be used together in clinical practice. The interventions are:* Blunt versus sharp abdominal entry* Exteriorisation of the uterus for repair versus intra-abdominal repair* Single versus double layer closure of the uterus* Closure versus non-closure of the peritoneum (pelvic and parietal)* Chromic catgut versus Polyglactin-910 for uterine repairThe primary outcome is death or maternal infectious morbidity (one or more of the following: antibiotic use for maternal febrile morbidity during postnatal hospital stay, antibiotic use for endometritis, wound infection or peritonitis) or further operative procedures; or blood transfusion. The sample size required is 15,000 women in total; at least 7,586 women in each comparison.

DISCUSSION

Improvements in health from optimising caesarean section techniques are likely to be more significant in developing countries, because the rates of postoperative morbidity in these countries tend to be higher. More women could therefore benefit from improvements in techniques.

TRIAL REGISTRATION

The CORONIS Trial is registered in the Current Controlled Trials registry. ISCRTN31089967.