Evaluation: Post-Pancreatectomy Hemorrhage (PPH) - Endovascular vs. Surgical Management Meta-Analysis

1. Clinical Impact Assessment - STRONG

• Incidence: 3-16% after pancreatectomy (weighted mean ~5%)
• Overall mortality: ~21% in pooled data (van Oosten et al., 2019, PMID 30962134)
• Mortality gap is wide: 16% with primary endovascular vs. 37% with primary relaparotomy (van Oosten 2019)
• Grade C PPH (severe, life-threatening) carries mortality exceeding 50% in surgical series
• The ISGPS classification (early vs. late, intraluminal vs. extraluminal, Grade A/B/C) is now well-established, giving any new meta-analysis a standardized framework to work within

2. Existing Literature Landscape - IMPORTANT CONSTRAINT

van Oosten A et al. (2019). "Diagnosis and management of postpancreatectomy hemorrhage: a systematic review and meta-analysis." HPB (Oxford) 21(8):953-961. [PMID 30962134]

• Interventional angiography mortality: 16%
• Relaparotomy mortality: 37%
• Endoscopy mortality: data also reported

3. Feasibility Assessment

Evidence Pool

What Makes it Feasible

• PPH is well-defined by ISGPS criteria (since 2007) - gives inclusion/exclusion clarity
• Most series report technical success, rebleeding, mortality, and hospital stay - enough for pooled proportions
• A pooled proportion meta-analysis (as you've specified) is the methodologically correct choice here given the absence of RCTs - this is appropriate and matches what the literature can support
• The topic does NOT require direct head-to-head RCT data to be valid - proportion-based comparisons with sensitivity analyses are publishable

What Makes it Challenging

• Selection bias is irreducible: endovascular is generally selected for hemodynamically stable patients; sicker patients go to OR - this confounding is nearly impossible to adjust for in a pooled proportion design
• Study-level data only: most primary studies won't allow subgroup adjustment - you need to acknowledge this as a primary limitation
• Small sample sizes per study: PPH is uncommon; many series have < 30 patients; heterogeneity (I²) will likely be very high
• Pooled proportions are non-comparative by nature: you'll be comparing two separate pools (endovascular studies and surgical studies), not head-to-head matched data - reviewers will push back on causal language

4. Key Refinements to Strengthen the Proposal

• Focus on late PPH only (>24h, Grade B/C) - this is where the intervention decision is most clinically contested and where most published series focus
• Specify extraluminal bleeding separately from intraluminal - these are managed very differently

• Primary: 30-day/in-hospital mortality (pooled proportion per arm)
• Secondary: technical success rate, rebleeding rate, complication rate (hepatic ischemia, abscess after TAE), need for crossover to surgery, hospital LOS

• TAE (coil embolization) vs. covered stent placement - these have meaningfully different hepatic complication profiles and rebleeding rates; lumping them reduces clinical utility

• Use GRADE or the Newcastle-Ottawa scale for cohort data; this significantly increases publication acceptance at top-tier journals

• Grade C is where management choice matters most; Grade A is self-limiting and Grade B often resolves conservatively - a Grade C-focused subgroup analysis would be the highest-impact finding

5. Overall Recommendation

"Outcomes of endovascular and surgical management of post-pancreatectomy hemorrhage: a systematic review and meta-analysis of pooled proportions"

Evaluation: Diverticulectomy vs. Segmental Resection for Meckel's Diverticulum in Children - Meta-Analysis

1. PROSPERO Search Results

• On one hand, no competing group appears to have registered this exact protocol - the registration lane is open
• On the other hand, the absence of registrations from experienced systematic reviewers may reflect the community's recognition that the primary evidence base is not robust enough to support a meaningful meta-analysis

2. The Existing Systematic Review - A Direct Competitor

Redman EP, Mishra PR, Stringer MD (2020). "Laparoscopic diverticulectomy or laparoscopic-assisted resection of symptomatic Meckel diverticulum in children? A systematic review." Pediatr Surg Int 36(8):901-910. [PMID 32436063]

• Population: children with symptomatic Meckel's diverticulum
• Comparison: laparoscopic diverticulectomy vs. laparoscopic-assisted segmental resection
• Included 11 studies, 248 children (133 diverticulectomy, 115 segmental resection)
• Found no statistically significant difference in complications (3% vs. 6.1%, p=0.39)
• Concluded limitations due to small patient numbers and variable follow-up
• Already provides the guidance surgeons need

3. Primary Evidence Pool - Feasibility Analysis

• A few additional case series (mostly ectopic pancreas, SARS-CoV-2 outcomes - not relevant)
• No RCTs (none exist or are planned in this field)
• No large database studies specifically comparing techniques in children

4. Key Structural Obstacles

A. The Indication-Confounding Problem (Most Critical)

• Narrow-based, long diverticulum → diverticulectomy is standard
• Wide-based, short diverticulum, ischemic/inflamed base, or bleeding with ectopic tissue near base → segmental resection is standard
• Obstruction with volvulus → segmental resection is mandated

B. Heterogeneity of Presentations

• GI bleeding (most studied indication)
• Intestinal obstruction
• Diverticulitis/inflammation
• Incidental findings
• Perforation

C. Outcomes Are Overwhelmingly Low-Frequency

• It occurs in roughly 1-5% of cases
• Even pooling 500 patients gives you ~5-25 events
• This is underpowered for a meaningful risk difference calculation
• The Redman 2020 review had exactly ONE patient with recurrent bleeding post-diverticulectomy in 133 children

D. Open vs. Laparoscopic Confounding

5. Overall Scoring

6. What Could Make This Work (Conditional Recommendations)

Bottom Line

Revised Assessment: You're Right - and Here's the Corrected Verdict

Conceding the Corrections

What This Changes

What Still Stands as a Real Obstacle

Net Recommendation: Now Conditionally Recommended

1. Frame the gap explicitly: "No formal random-effects meta-analysis with quantitative synthesis has been performed; the only existing systematic review was restricted to laparoscopic approaches and used informal pooling without heterogeneity assessment"
2. Broaden the scope beyond laparoscopic-only: Include open and laparoscopic approaches; stratify by approach in subgroup analysis - this directly addresses the 2020 paper's main limitation
3. Pre-specify subgroups by presentation: Bleeding, obstruction, inflammation/diverticulitis - analyze these separately; this is where the clinical question differs most importantly
4. Primary outcome choice matters: Use overall postoperative complication rate as primary, with rebleeding, bowel obstruction, anastomotic leak, reoperation, and LOS as secondary outcomes - this gives you enough events for meaningful pooling
5. Register on PROSPERO first - the lane is clear, and registration at a journal like Pediatric Surgery International, Journal of Pediatric Surgery, or World Journal of Pediatric Surgery will be expected before submission
6. Acknowledge confounding upfront in your limitations - do not let this be a reviewer surprise; address it in your methods as an inherent limitation of all non-randomized comparative surgical data

Evaluation: Endoscopic vs. Surgical Management of Pediatric Pancreatic Pseudocyst - Meta-Analysis

Verdict: Not Recommended - Topic is Already Taken

Gercel G, Erdeve B, Pirim A, et al. "Comparison of Efficacy and Outcome of Different Management Strategies for Pancreatic Pseudocysts in Children: A Systematic Review and Meta-Analysis." J Pediatr Surg. 2025 Dec. [PMID 40967505] - PROSPERO registration: CRD42024608528

Dissecting the Scope Gap - Is There Anything Left?

• Conservative management (CM) vs. any interventional management (IM)
• IM is treated as a single category - it lumps percutaneous external drainage, endoscopic drainage, and surgical drainage together
• 8 studies, 196 patients, search window January 2004 - December 2024
• Primary outcomes: recurrence, infection, need for additional intervention

• It does not compare endoscopic vs. surgical drainage head-to-head within the interventional arm
• It does not distinguish EUS-guided cystogastrostomy from transpapillary drainage from open vs. laparoscopic surgical cystogastrostomy
• It does not stratify by etiology (traumatic vs. pancreatitis-related pseudocysts behave very differently in children)

The Broader Landscape That Makes This Harder

Overall Scoring

What You Should Do Instead

DOCUMENT 1: PRISMA-Style Eligibility Checklist

Diverticulectomy vs. Segmental Bowel Resection for Meckel's Diverticulum in Children: Eligibility Criteria

SECTION A - INCLUSION CRITERIA

SECTION B - EXCLUSION CRITERIA

SECTION C - SPECIAL POPULATIONS AND SUBGROUP FLAGS

SECTION D - SCREENING FORM (for title/abstract stage)

1. Does the study include pediatric patients (age ≤18) with Meckel's diverticulum?   [ ] YES  [ ] NO  [ ] UNCLEAR
2. Does the study describe surgical treatment (resection of any type)?                [ ] YES  [ ] NO  [ ] UNCLEAR
3. Does the study report any postoperative outcome?                                   [ ] YES  [ ] NO  [ ] UNCLEAR
4. Is this a primary study with original patient data (not a review or editorial)?   [ ] YES  [ ] NO  [ ] UNCLEAR

→ Include for full-text review if all UNCLEAR or YES.
→ Exclude only if definitively NO on criteria 1, 2, or 3.

SECTION E - FULL-TEXT ELIGIBILITY FORM

DOCUMENT 2: PROSPERO Protocol

Complete Registration Protocol

PROSPERO Field-by-Field Submission

1. REVIEW TITLE

2. REVIEW QUESTION

3. SEARCHES

• MEDLINE (via PubMed) - from January 2000 to search date
• EMBASE (via Ovid) - from January 2000 to search date
• Cochrane Central Register of Controlled Trials (CENTRAL)
• Web of Science Core Collection
• Scopus
• Google Scholar (first 200 results, for grey literature)
• ClinicalTrials.gov (for any registered but unpublished trials)
• WHO International Clinical Trials Registry Platform (ICTRP)

("Meckel diverticulum"[MeSH] OR "Meckel's diverticulum"[tiab] OR "Meckel diverticulum"[tiab] 
OR "vitelline duct remnant"[tiab] OR "omphalomesenteric duct"[tiab])
AND
("diverticulectomy"[tiab] OR "diverticulum excision"[tiab] OR "wedge resection"[tiab] 
OR "segmental resection"[tiab] OR "bowel resection"[tiab] OR "ileal resection"[tiab] 
OR "small bowel resection"[tiab] OR "enterectomy"[tiab])
AND
("child"[MeSH] OR "children"[tiab] OR "pediatric"[tiab] OR "paediatric"[tiab] 
OR "infant"[tiab] OR "adolescent"[MeSH] OR "juvenile"[tiab])

4. TYPE OF STUDY TO BE INCLUDED

• Randomized controlled trials
• Non-randomized comparative studies (prospective or retrospective cohort studies, case-control studies)
• Retrospective case series (n ≥ 5) reporting outcomes stratified by surgical technique
• National database analyses and registry studies
• Multi-institutional collaborative studies

5. CONDITION OR DOMAIN BEING STUDIED

6. PARTICIPANTS / POPULATION

7. INTERVENTION(S), EXPOSURE(S)

8. COMPARATOR(S) / CONTROL

9. CONTEXT

• Surgical approach (open, laparoscopic, laparoscopic-assisted/extracorporeal, robotic)
• Geographic setting or country
• Institutional volume or type (tertiary referral center, general hospital)
• Year of publication (from January 2000)
• Etiology of symptomatic presentation (bleeding, obstruction, diverticulitis, perforation, incidental)
• Urgency of surgery (emergency vs. elective)

10. PRIMARY OUTCOME(S)

• Definition: Any complication occurring within 30 days of surgery or during the index hospitalization (whichever is longer), including wound infection, anastomotic leak, postoperative bowel obstruction, intra-abdominal abscess, ileus, and reoperation for any cause
• Reported as: proportion (number with any complication / total in group)
• Timeframe: 30 days post-surgery or index hospitalization

• Definition: Any episode of GI bleeding requiring investigation, transfusion, or re-intervention after index diverticulectomy for a bleeding indication
• Reported as: proportion (number with recurrent bleeding / total in diverticulectomy-for-bleeding group)
• Timeframe: Any follow-up duration reported

11. SECONDARY OUTCOME(S)

12. DATA EXTRACTION (SELECTION AND CODING)

• Titles and abstracts will be screened independently by two reviewers (Reviewer 1 and Reviewer 2) using the eligibility checklist (Document 1 above).
• Full-text review will be performed independently by the same two reviewers for all studies not excluded at title/abstract screening.
• Disagreements at both stages will be resolved by discussion; a third reviewer will adjudicate if consensus is not reached after discussion.
• The PRISMA 2020 flow diagram will be used to document the screening process, with reasons for exclusion recorded for every full-text article excluded.

• A pre-piloted standardized data extraction form (developed in Microsoft Excel or Covidence) will be used.
• Data extraction will be performed independently by two reviewers; discrepancies will be reconciled by cross-checking source documents.

• First author, year, journal, country, study design, study period
• Institutional type and volume (if reported)
• Funding source and conflicts of interest

• Total sample size; number per surgical group
• Age (mean/median, range, SD)
• Sex distribution (% male)
• Presentation type (bleeding, obstruction, diverticulitis, perforation, incidental; % per group)
• Urgency (emergency vs. elective; % per group)

• Surgical approach (open, laparoscopic, laparoscopic-assisted)
• Diverticulectomy technique (stapler, hand-sewn, wedge)
• Anastomosis type for segmental resection (end-to-end, side-to-side)
• Concurrent procedures performed

• Length and diameter (mean/median)
• Height:base ratio
• Presence of ectopic mucosa (gastric, pancreatic, other)
• Histological type of ectopic tissue

• All primary and secondary outcomes as defined above, per surgical group
• Follow-up duration (mean/median)
• Method of follow-up (clinical, endoscopic, imaging)

13. RISK OF BIAS (QUALITY) ASSESSMENT

• Sensitivity analyses (restricting to studies at low risk of bias)
• Narrative discussion of the strength of evidence

14. STRATEGY FOR DATA SYNTHESIS

• Dichotomous outcomes (complication rates, recurrence, reoperation, mortality): Pooled using random-effects model (DerSimonian-Laird method); results expressed as odds ratios (OR) with 95% confidence intervals (CI)
• Continuous outcomes (operative time, LOS): Pooled using random-effects model; results expressed as mean difference (MD) or standardized mean difference (SMD) with 95% CI
• Statistical heterogeneity: Assessed using Cochran's Q test (significance threshold p < 0.10) and I² statistic. I² will be interpreted as: <25% low, 25-50% moderate, 50-75% substantial, >75% considerable heterogeneity

• For studies reporting only one surgical technique, pooled proportions for each outcome will be calculated using the Freeman-Tukey double arcsine transformation to stabilize variance, within a random-effects model
• Results will be reported as pooled proportions with 95% CI

15. ANALYSIS OF SUBGROUPS OR SUBSETS

16. TYPE AND METHOD OF REVIEW

• Type: Systematic review and meta-analysis
• Methods follow: PRISMA 2020 reporting guidelines; MOOSE checklist for observational studies; Cochrane Handbook for Systematic Reviews of Interventions (version 6.x)

17. LANGUAGE

18. COUNTRY

19. ANTICIPATED OR ACTUAL START DATE

20. ANTICIPATED COMPLETION DATE

21. STAGE OF REVIEW AT TIME OF REGISTRATION

22. NAMED CONTACT

23. REVIEW TEAM MEMBERS AND THEIR ORGANISATIONAL AFFILIATIONS

24. CONFLICT OF INTEREST

25. SOURCES OF SUPPORT / FUNDING

26. DISSEMINATION PLANS

27. KEYWORDS

28. DETAILS OF EXISTING REVIEW ON THE SAME TOPIC

29. ADDITIONAL INFORMATION / NOTES

1. Restricting to studies at low risk of bias (NOS ≥7) only
2. Excluding studies published before 2010 (pre-modern laparoscopic era)
3. Restricting to studies with ≥10 patients per surgical arm
4. Excluding single-institution case series and retaining only multi-center or national database studies
5. Excluding studies where surgical technique selection was entirely at surgeon discretion without documented criteria (to reduce indication confounding)

How to Use These Documents

• Section D (4-question rapid form) is what your two screeners use at title/abstract stage in Covidence or Rayyan
• Sections A + B (full inclusion/exclusion table) is applied at full-text review, with exclusion codes (E1-E8) recorded for every rejected article
• Section C (subgroup flags S1-S7) goes onto your data extraction form - these are not exclusion criteria but must be captured per-study