Clinical evaluation of the effect for prophylactic balloon occlusion in pregnancies complicated with placenta accreta spectrum disorder: A systematic review and meta‐analysis
Bibliographic record
Abstract
Abstract Background Placenta accreta spectrum (PAS) disorder is a critical and severe obstetric condition associated with high risk of intraoperative massive hemorrhage and cesarean hysterectomy. Severe obstetric hemorrhage is currently one of the leading causes of maternal death worldwide. Prophylactic balloon occlusions, including prophylactic balloon occlusion of the abdominal aorta (PBOAA) and prophylactic balloon occlusion of the internal iliac arteries (PBOIIA), are the most common means of controlling hemorrhage in patients with PAS disorder, but their effectiveness is still debated. Objective A systematic review and meta‐analysis were conducted to evaluate the clinical effectiveness of prophylactic balloon occlusion during cesarean section (CS) in improving maternal outcomes for PAS patients. Search Strategy MEDLINE, EMBASE, OVID, PubMed and the Cochrane Library were systematically searched from the inception dates to June 2022, using the keywords “placenta accreta spectrum disorder/morbidly adherent placenta (placenta previa, placenta accreta, placenta increta, placenta percreta), balloon occlusion, internal iliac arteries, abdominal aorta, hemorrhage, hysterectomy, estimated blood loss (EBL), packed red blood cells (PRBCs)” to identify the systematic reviews or meta‐analyses. Selection Criteria All articles regarding PAS disorders and including the application of balloon occlusion were included in the screening. Data Collection and Analysis Two independent researchers performed the data extraction and assessed study quality. EBL volume and PRBC transfusion volume was regarded as the primary endpoints. Random and fixed effects models were used for the meta‐analysis (RRs and 95% CIs), and the Newcastle‐Ottawa Scale was used for quality assessments. Main Results Of 429 studies identified, a total of 35 trials involving the application of balloon occlusion for patients with PAS disorder during CS were included. A total of 19 studies involving 935 patients who underwent PBOIIA were included in the PBOIIA group, and 851 patients were included in control 1 group. Ten studies including 428 patients with PAS who underwent PBOAA were allocated to the PBOAA group, and 324 patients without PBOAA were included in control 2 group. Simultaneously, we compared the effect on PBOAA and PBOIIA including seven studies, which referred to 267 cases in the PBOAA group and 313 cases in the PBOIIA group. The results showed that the PBOIIA group had a reduced EBL volume (MD: 342.06 mL, 95% CI: −509.90 to −174.23 mL, I 2 = 77%, P < 0.0001) and PRBC volume (MD: –1.57 U, 95% CI: −2.49 to −0.66 U, I 2 = 91%, P = 0.0008) than that in control 1 group. With regard to the EBL volume (MD: −926.42 mL, 95% CI: −1437.07 to −415.77 mL, I 2 = 96%, P = 0.0004) and PRBC transfusion volume (MD: –2.42 U, 95% CI: −4.25 to −0.59 U, I 2 = 99%, P = 0.009) we found significant differences between the PBOAA group and control 2 group. Prophylactic balloon occlusion (PBOAA and PBOIIA) had a significant effect on reducing intraoperative blood loss and blood transfusion volume in patients with PAS. Moreover, PBOAA was more effective than PBOIIA in reducing intraoperative blood loss (MD: −406.63 mL, 95% CI: −754.12 to −59.13 mL, I 2 = 92%, P = 0.020), but no significant difference in controlling PRBCs (MD: –3.48 U, 95% CI: −8.90 to 1.95 U, I 2 = 99%, P = 0.210) between the PBOIIA group and the PBOAA group. Hierarchical analysis was conducted by differentiating gestational weeks and maternal age to reduce the high heterogeneity of meta‐analysis. Hierarchical analysis results demonstrated the heterogeneities of the study were reduced to some extent, and gestational weeks and maternal age might be the cause of increased heterogeneity. Conclusion Prophylactic balloon occlusion is a safe and effective method to control hemorrhage and reduce PRBC transfusion volume for patients with PAS, and PBOAA could reduce more intraoperative blood loss than PBOIIA. However, we found no statistical difference in lessening packed red blood cell transfusion volume for PAS patients. Hence, preoperative prophylactic balloon occlusion is the recommended application for PAS patients in obstetric CSs. Furthermore, PBOAA is preferred for controlling intraoperative bleeding in patients with corresponding medical conditions.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.011 | 0.029 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.018 | 0.030 |
| Bibliometrics | 0.005 | 0.006 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.005 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".