Effects of bail-out endoscopic necrosectomy on clinical outcomes in infected walled-off pancreatic necrosis: Systematic review and meta-regression analysis

Aim. To perform a systematic review and meta-regression analysis of the effects of the number of endoscopic transluminal necrosectomies on clinical outcomes in patients with infected walled-off pancreatic necrosis, including clinical success and adverse event rates.

Materials and methods. The analysis included 9 studies (470 patients) of 2020–2025, selected by PRISMA criteria. The risk of bias was assessed using the ROBINS-I tool. Meta-regression was performed in Python 3.9 using a weighted least squares method. The weight of the studies was calculated as the inverse variance of the standard error (1/SE2) adjusted for sample size. The regression coefficient (β), 95% confidence intervals (95% CI), and heterogeneity (I2) were analyzed.

Results. The increase in the number of endoscopic transluminal necrosectomies to 3–5 procedures was significantly associated with increased clinical success (β = 1.904, p = 0.047) and resulted in the efficacy of 90–100%. However, meta-regression showed a trend towards an increase of 9.7% in adverse events (complications) with each additional necrosectomy (β = 0.97, p = 0.083), especially bleeding (n = 22) and stent migration (n = 12). The highest and lowest rate of adverse events was observed in 4 (40.3%) and 1.3 (1.5%) endoscopic procedures, respectively. The balance of efficacy and safety is achieved for 3–4 interventions.

Conclusion. A bail-out approach with 3–4 endoscopic transluminal necrosectomies shows the best ratio of efficacy (95–100% success) to acceptable risk of adverse events (12–14%). Prospective studies are needed to reduce heterogeneity and clarify the optimal number of minimally invasive surgery based on the volume (size) and severity of pancreatic necrosis.

1. Banks P.A., Bollen T.L., Dervenis C., Gooszen H.G., Johnson C.D., Sarr M.G., Tsiotos G.G., Vege S.S.; Acute Pancreatitis Classification Working Group. Classification of acute pancreatitis – 2012: revision of the Atlanta classification and definitions by international consensus. Gut. 2013; 62 (1): 102–111. https://doi.org/10.1136/gutjnl-2012-302779.

2. Cherdantsev D.V., Noskov I.G., Filistovich V.G., Solomennikov V.A. Minimally invasive treatment of a giant pancreatic pseudocyst. Pirogov Russian Journal of Surgery. 2023; 2: 120–126 (In Russ.). doi: 10.17116/hirurgia2023021120

3. Pervova O.V., Cherdantsev D.V., Kurbanov D.Sh., Stroev A.V., Djatlov V.Yu., Beljaev K.Yu. Clinical case of successful treatment of patient with severe infected pancreatic necrosis. Siberian Medical Review. 2016; 6: 91–99 (In Russ.).

4. Fedorov A.V., Ektov V.N., Khodorkovsky M.A., Skorynin O.S. Potential of minimally invasive drainage interventions for acute pancreatitis. Journal of Experimental and Clinical Surgery. 2022; 15 (2): 165–173 (In Russ.). https://doi.org/10.18499/2070-478X-2022-15-2-165-173.

5. Shabunin A.V., Korzheva I.Yu., Bedin V.V., Lukin A.Yu., Tavobilov M.M., Komissarov D.Yu., Kolotilshchikov A.A. Experience in endoscopic transluminal pancreatic necrosectomy performed in cases of infected necrotizing pancreatitis. Moscow Surgical Journal. 2018; 5: 16–21 (In Russ.). https://doi.org/10.17238/issn2072-3180.2018.5.16-21

6. Remizov S.I., Andreev A.V., Durleshter V.M., Gabriel S.A., Zasyadko O.V. Technological features of open and minimally invasive surgical treatment of local complications of purulent-necrotic pancreatitis. Pirogov Russian Journal of Surgery. 2023; 7: 72–79 (In Russ.). https://doi.org/10.17116/hirurgia202307172

7. Page M.J., McKenzie J.E., Bossuyt P.M., Boutron I., Hoffmann T.C., Mulrow C.D., Shamseer L., Tetzlaff J.M., Akl E.A., Brennan S.E., Chou R., Glanville J., Grimshaw J.M., Hróbjartsson A., Lalu M.M., Li T., Loder E.W., Mayo-Wilson E., McDonald S., McGuinness L.A., Stewart L.A., Thomas J., Tricco A.C., Welch V.A., Whiting P., Moher D. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021; 372: n71. https://doi.org/10.1136/bmj.n71

8. Masoumi S., Shahraz S. Meta-analysis using Python: a hands-on tutorial. BMC Med. Res. Methodol. 2022; 22 (1): 193. https://doi.org/10.1186/s12874-022-01673-y

9. Sterne J.A., Hernán M.A., Reeves B.C., Savović J., Berkman N.D., Viswanathan M., Henry D., Altman D.G., Ansari M.T., Boutron I., Carpenter J.R., Chan A.W., Churchill R., Deeks J.J., Hróbjartsson A., Kirkham J., Jüni P., Loke Y.K., Pigott T.D., Ramsay C.R., Regidor D., Rothstein H.R., Sandhu L., Santaguida P.L., Schünemann H.J., Shea B., Shrier I., Tugwell P., Turner L., Valentine J.C., Waddington H., Waters E., Wells G.A., Whiting P.F., Higgins J.P. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions. BMJ. 2016; 355: i4919. https://doi.org/10.1136/bmj.i4919

10. Hozo S.P., Djulbegovic B., Hozo I. Estimating the mean and variance from the median, range, and the size of a sample. BMC Med. Res. Methodol. 2005; 5: 13. https://doi.org/10.1186/1471-2288-5-13

11. Wan X., Wang W., Liu J., Tong T. Estimating the sample mean and standard deviation from the sample size, median, range and/or interquartile range. BMC Med. Res. Methodol. 2014; 14: 135. https://doi.org/10.1186/1471-2288-14-135

12. Bland M. An introduction to medical statistics. 3rd ed. Oxford: OUP Oxford; 2000. 405 p.

13. Bartholdy A., Werge M., Novovic S., Hadi A., Nøjgaard C., Borch A., Feldager E., Gluud L. L., Schmidt P. N. Endoscopic treatment with transmural drainage and necrosectomy for walled-off necrosis provides favourable long-term outcomes on pancreatic function. United European Gastroenterol. J. 2020; 8 (5): 552–558. https://doi.org/10.1177/2050640620916029

14. Pattarapuntakul T., Charoenrit T., Wong T., Netinatsunton N., Ovartlarnporn B., Yaowmaneerat T., Tubtawee T., Boonsri P., Sripongpun P. Clinical Outcomes of the Endoscopic Step-Up Approach with or without Radiology-Guided Percutaneous Drainage for Symptomatic Walled-Off Pancreatic Necrosis. Medicina (Kaunas). 2023; 59 (3): 569. https://doi.org/10.3390/medicina59030569

15. Dorrell R., Cecil A., Pawa S., Russell G., Pawa R. Standardized approach to removal of lumen apposing metal stents following endoscopic necrosectomy: one size does not fit all. Therap. Adv. Gastroenterol. 2025; 18: 17562848251320739. https://doi.org/10.1177/17562848251320739

16. Pawa R., Dorrell R., Clark C., Russell G., Gilliam J., Pawa S. Delayed endoscopic necrosectomy improves hospital length of stay and reduces endoscopic interventions in patients with symptomatic walled-off necrosis. DEN Open. 2022; 3 (1): e162. https://doi.org/10.1002/deo2.162

17. Olsen G. A., Schmidt P. N., Novovic S., Hansen E. F., Karstensen J. G. Novel powered 5.0-mm endoscopic debridement catheter for endoscopic transmural necrosectomy of pancreatic walled-off necrosis: a case series. Gastrointest. Endosc. 2024; 99 (2): 267–270. https://doi.org/10.1016/j.gie.2023.10.044

18. Seicean A., Pojoga C., Mostean O., Bolboaca S., Ilie M., Rimbas M., Gheorghiu M., Lucaciu L., Bartos A., Al Hajjar N., Sandru V., Constantinescu G., Seicean R. What is the Impact of the Proportion of Solid Necrotic Content on the Number of Necrosectomies during EUS-Guided Drainage using Lumen-Apposing Metallic Stents of Pancreatic Walled-off Necrosis? J. Gastrointestin. Liver Dis. 2020; 29 (4): 623–628. https://doi.org/10.15403/jgld-3128.

19. Kim Y.S., Cho J.H., Cho D.H., Park S.W., Moon S.H., Park J.S., Lee Y.N., Lee S.S. Long-term Outcomes of Direct Endoscopic Necrosectomy for Complicated or Symptomatic Walled-Off Necrosis: A Korean Multicenter Study. Gut Liver. 2021; 15 (6): 930–939. https://doi.org/10.5009/gnl20304

20. Dhillon A., Li S., Sandha S., D’Souza P., Sandha G. Performance Characteristics of a Lumen-Apposing Metal Stent for Pancreatic Fluid Collections: A Prospective Cohort Study. J. Can. Assoc. Gastroenterol. 2020; 4 (4): 158–164. https://doi.org/10.1093/jcag/gwaa023

21. Wu S., Dou X., Li N., Zhu H., Wang L., Liu M., Yu C. Postponed endoscopic necrosectomy results in a lower rate of additional intervention for infected walled-off necrosis. Sci. Rep. 2024; 14(1): 11610. https://doi.org/10.1038/s41598-024-61675-2