Technical aspects of the cesarean section

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.

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.