Periampullary diverticulum in endoscopic retrograde cholangiopancreatography: A paper tiger?

How to cite this article:
Arabi TZ, Almuhaidb A. Periampullary diverticulum in endoscopic retrograde cholangiopancreatography: A paper tiger?. Saudi J Gastroenterol 2023;29:1-2
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Arabi TZ, Almuhaidb A. Periampullary diverticulum in endoscopic retrograde cholangiopancreatography: A paper tiger?. Saudi J Gastroenterol [serial online] 2023 [cited 2023 Jan 26];29:1-2. Available from: https://www.saudijgastro.com/text.asp?2023/29/1/1/367748

See accompanying article on page 12

Periampullary diverticulum (PAD) is an anatomical anomaly characterized by an outpouching of the duodenal wall through a defect of the muscular wall near the ampulla.[1] PAD can be seen in up to 32.8% of patients undergoing endoscopic retrograde cholangiopancreatography (ERCP).[2] Although often asymptomatic, PAD is associated with an increased risk of a wide spectrum of biliary pathologies, including biliary stone formation and pancreatitis.[1] PAD may present a technical challenge for endoscopists performing ERCPs, leading to the utilization of alternative cannulation techniques. This anatomical variation could result in increased rates of difficult biliary cannulation and post-ERCP adverse events (AEs).

It has been previously hypothesized that PAD may significantly decrease successful biliary cannulation rates.[1] However, meta-analyses studying ERCP success rates in PAD patients have shown contradicting results. In their meta-analysis, Jayaraj et al. demonstrated that PAD patients have a 50% less chance of successful cannulation when compared to non-PAD patients.[3] On the other hand, Mu et al. found no difference between the patient groups in the post-2000 era.[4] In this issue of Saudi Journal of Gastroenterology, Xia et al. analyze the factors influencing ERCP outcomes in PAD patients and compare the technical success of ERCP between PAD and non-PAD patients.[5] Xia et al. concluded that PAD patients have significantly higher difficult cannulation rates than non-PAD patients (10.6% vs. 8%, P < 0.0001); however, PAD had no effect on ERCP clinical success.[5]

It is worth noting that Xia et al. only included data from ERCPs performed by expert endoscopists who individually perform over 150 procedures per year.[5] This limits the generalizability of the results, as expert endoscopists may not be widely available. Previous studies have highlighted increased successful cannulation rates with increased ERCP experience.[6]

Studies comparing the outcomes between various PAD subtypes are limited. Previously, Yue et al. found lower successful cannulation rates in type I and III PAD patients (Boix classification) compared to type II PAD patients.[7] However, no difference between the PAD types was noted in regard to difficult cannulation rates.[7] Xia et al. found that type I PAD is associated with more difficult biliary cannulation, lower clinical success rates, and increased AEs.[5] This is also consistent with a previous study by Tabak et al., which associated type I PAD with difficult cannulation.[8]

The effectiveness of different ERCP techniques in PAD patients has not been extensively studied in the previous literature. Endoscopic sphincterotomy (EST) is a safe and effective method in PAD patients.[8] In the current study, small EST with or without balloon dilation was associated with greater clinical success than large EST.[5] Further studies are needed to highlight the differences between small and large EST in patients with PAD.

Furthermore, the authors studied the effect of alternative cannulation methods (needle-knife fistulotomy, trans-pancreatic biliary sphincterotomy, and pre-cut techniques) on the outcomes of ERCP and their AEs.[5] Usage of secondary cannulation methods did not correlate significantly with AEs.[5] Notably, the current study did not compare the effectiveness between the three techniques. To our knowledge, this has not yet been studied in the literature. We recommend that future research shed light on this topic in order to identify the safest and most effective option in PAD patients.

Several prophylactic measures may be taken to prevent post-ERCP pancreatitis, including somatostatin injection, non-steroidal anti-inflammatory drugs, and pancreatic duct stenting.[9] Data surrounding their effects in PAD patients are limited. Using univariate analysis, Xia et al. demonstrated that somatostatin injection alone and rectal indomethacin with somatostatin are significantly associated with AEs.[5] Similarly, rectal indomethacin with somatostatin was significantly associated with AEs in multivariate analyses.[5] However, the authors were unable to confirm this effect in patients who received somatostatin only, due to the limited patient sample size.[5] These findings should be interpreted with caution, as the authors did not highlight the indications for the various prophylactic measures used in the study.[5] The association between somatostatin and AEs may simply be attributed to the risk category of the patient, rather than the injection itself.[5] Further studies are needed to confirm these findings and assess the effectiveness of different prophylactic methods in PAD patients.

Overall, the study by Xia et al. provides a comprehensive look into various aspects of ERCP in patients with PAD.[5] The study is one of very few which describe the differences in outcome between PAD types, as well as the effect of various ERCP techniques and prophylactic measures on PAD patients. Although there are limitations to the study, it provides novel information and a new outlook on the effects of PAD on ERCP outcomes. Emerging evidence is suggesting that PAD in ERCP may only be a paper tiger: intimidating, yet less inimical than originally thought.

References

1.Altonbary AY, Bahgat MH. Endoscopic retrograde cholangiopancreatography in periampullary diverticulum: The challenge of cannulation. World J Gastrointest Endosc 2016;8:6:282.

2.Boix J, Lorenzo-Zúñiga V, Añaños F, Domènech E, Morillas RM, Gassull MA. Impact of periampullary duodenal diverticula at endoscopic retrograde cholangiopancreatography: A proposed classification of periampullary duodenal diverticula. Surg Laparosc Endosc Percutan Tech 2006;16:4:208-11.

3.Jayaraj M, Mohan BP, Dhindsa BS, Mashiana HS, Radhakrishnan G, Dhir V, et al. Periampullary diverticula and ERCP outcomes: A systematic review and meta-analysis. Dig Dis Sci 2019;64:5:1364-76.

4.Mu P, Yue P, Li F, Lin Y, Liu Y, Meng W, et al. Does periampullary diverticulum affect ERCP cannulation and post-procedure complications? An up-to-date meta-analysis. Turk J Gastroenterol 2020;31:3:193-204.

5.Xia C, Sun L, Peng L, Cui F, Jin Z, Huang H. Factors and techniques associated with endoscopic retrograde cholangiopancreatography outcomes in patients with periampullary diverticulum: Results from a large tertiary center. Saudi J Gastroenterol 2022 2023;29:12-20.

6.Ekkelenkamp VE, Koch AD, Rauws EA, Borsboom GJ, de Man RA, Kuipers EJ. Competence development in ERCP: The learning curve of novice trainees. Endoscopy 2014;46:11:949-55.

7.Yue P, Zhu K-X, Wang H-P, Meng W-B, Liu J-K, Zhang L, et al. Clinical significance of different periampullary diverticulum classifications for endoscopic retrograde cholangiopancreatography cannulation. World J Gastroenterol 2020;26:2403-15.

8.Tabak F, Ji GZ, Miao L. Impact of periampullary diverticulum on biliary cannulation and ERCP outcomes: A single-center experience. Surg Endosc 2021;35:5953-61.