Transpapillary drainage has a major benefit on treatment outcomes in patients undergoing EUS-guided transmural drainage of pancreatic pseudocysts

LETTERS TO THE EDITOR Transmural drainage versus transpapillary stenting and transmural drainage: not an open and shut case.yet To the Editor: We read with interest the retrospective study comparing transmural drainage (n Z 95) of pseudocysts with combined transmural/transpapillary drainage technique (n Z 79).1 Although there was no difference in the clinicoradiologic resolution of pseudocysts, an attempt at transpapillary intervention negatively impacted long-term resolution. As the authors point out, of 79 patients, a pancreatogram was successful in 66, of whom only 6 had a normal duct. Of the remaining 60 patients, 47 had ductal leak/disruption and 28 had stones/strictures with/without a leak/disruption; 17 patients underwent bridging stent placement. If all patients with failed cannulation are considered to have a ductal defect and if the 6 patients with normal pancreatogram are excluded, a bridging stent was placed in just about 25% of patients. To our knowledge, there is no benefit to stent placement in disconnected ducts (complete disruption). Three studies have shown that only the placement of a stent bridging a partial disruption is predictive of treatment success.2-4 Of the 47 patients with a duct leak/disruption, it is unclear how many had a partial or complete disruption, and the outcome must be analyzed based on this discrimination. Although other interventions included sphincterotomy, sphincteroplasty, and nonbridging pancreatic stenting, their clinical benefits remain unproven. Because only 31 of 79 patients underwent single-session combined treatment, it is important to know what the index treatment was in the other 60% and the reasons for subsequent intervention (range, 0-34 days): Was it suboptimal short-term outcome or an elective intervention? Also, how did the clinical outcomes vary among centers that routinely practiced index combined, single-session approach versus a second intervention on an “as-needed” basis? The fact that 60% underwent an additional intervention, cannulation failed in 16%, and pancreatic duct was normal in just 9% suggests selection bias; it is likely that these patients had predefined ductal pathology that also mandated transpapillary intervention in the first place.

REFERENCES 1. Yang D, Amin S, Gonzalez S, et al. Transpapillary drainage has no added benefit on treatment outcomes in patients undergoing EUS-guided transmural drainage of pancreatic pseudocysts: a large multicenter study. Gastrointest Endosc 2016;83:720-9. 2. Varadarajulu S, Noone TC, Tutuian R, et al. Predictors of outcome in pancreatic duct disruption managed by endoscopic transpapillary stent placement. Gastrointest Endosc 2005;61:568-75. 3. Telford JJ, Farrell JJ, Saltzman JR, et al. Pancreatic stent placement for duct disruption. Gastrointest Endosc 2002;56:18-24. 4. Shrode CW, Macdonough P, Gaidhane M, et al. Multimodality endoscopic treatment of pancreatic duct disruption with stenting and pseudocyst drainage: how efficacious is it? Dig Liver Dis 2013;45:129-33. http://dx.doi.org/10.1016/j.gie.2015.12.012

Transpapillary drainage has a major benefit on treatment outcomes in patients undergoing EUS-guided transmural drainage of pancreatic pseudocysts To the Editor:

Ji Young Bang, MD, MPH Division of Gastroenterology and Hepatology Indiana University Indianapolis, Indiana, USA Shyam Varadarajulu, MD Center for Interventional Endoscopy Florida Hospital Orlando, Florida, USA

We read with interest the study by Yang et al1 evaluating the role of transpapillary (TP) drainage in the management of pancreatic pseudocysts. The article concludes that TP drainage provides no additional benefit to transmural (TM) drainage and consequently has no role in the management of pancreatic pseudocysts. However, the data provided do not justify this conclusion. The term “transpapillary drainage” has traditionally referred to placement of a TP stent into a pancreatic fluid collection (PFC) for drainage.2,3 In this article, TP drainage refers to endoscopic retrograde pancreatography (ERP) for stent placement across a pancreatic duct (PD) leak. This illdefined terminology confuses the results. Only a few patients underwent ERP. The therapeutic goal of ERP in patients with PFCs is placement of a PD stent across a PD leak or stricture, or completion of a pancreatic sphincterotomy if a PD leak cannot be traversed.4-6 The article states that 47 patients were found to have a PD leak, but a stent was able to traverse the leak in only 17 patients. Only in those 17 patients would a benefit of ERP be expected. The article contains no subgroup analysis of these patients as a predictor of success for PFC drainage. Without successful treatment of a PD pathologic condition, pseudocyst recurrence would be expected. However, this would be appreciated only after removal of the TM stent. The percentage of TM stents in place at the time of follow-up is not described. In summary, the conclusion of the article that ERP provides no additional benefit in the management of pancreatic pseudocysts is not justified. This highlights the need for consensus terminology and ongoing investigation to

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Letters to the Editor

define optimal management of drainage within subgroups of patients with and without PD leakage.

DISCLOSURE Dr Kahaleh is a consultant for Boston Scientific, Xlumina, and Maunakea, and receives research support from Gore, MI Tech, Pinnacle, and Maunakea. All other authors disclosed no financial relationships relevant to this publication. Amy Tyberg, MD Michel Kahaleh, MD Division of Gastroenterology and Hepatology Weil Cornell Medical College Cornell University New York, New York, USA REFERENCES 1. Yang D, Amin S, Gonzalez S, et al. Transpapillary drainage has no added benefit on treatment outcomes in patients undergoing EUS-guided transmural drainage of pancreatic pseudocysts: a large multicenter study. Gastrointest Endosc 2016;83:720-9. 2. Barthet M, Sahel J, Bodious-Bertei C, et al. Endoscopic transpapillary drainage of pancreatic pseudocysts. Gastrointest Endosc 1995;42: 208-13. 3. Binmoeller KF, Seifert H, Walter A, et al. Transpapillary and transmural drainage of pancreatic pseudocysts. Gastrointest Endosc 1995;42: 219-24. 4. Nealon WH, Bhutani M, Riall TS, et al. A unifying concept: pancreatic ductal anatomy both predicts and determines the major complications resulting from pancreatitis. J Am Coll Surg 2009;208:790-9; discussion 9-801. 5. Trevino JM, Tamhane A, Varadarajulu S. Successful stenting in ductal disruption favorably impacts treatment outcomes in patients undergoing transmural drainage of peripancreatic fluid collections. J Gastroenterol Hepatol 2010;25:526-31. 6. Makola D, Krenitsky RD, Parrish RD, et al. Efficacy of enteral nutrition for the treatment of pancreatitis using standard enteral formula. Am J Gastroenterol 2006;101:2347-55. http://dx.doi.org/10.1016/j.gie.2016.01.030

Response: We thank the authors for their interest in our article,1 and we appreciate their comments. In our study, pancreatic duct (PD) leak/disruption was identified on index cross-sectional imaging in 6 of 95 (6.3%) patients undergoing transmural drainage (TMD) alone, compared with 14 of 79 (17.7%, p Z .03) patients undergoing combined drainage (CD) with both transpapillary drainage (TPD) and TMD.1 However, despite this statistical difference, PD leak/disruption was not a predictor of treatment outcome on logistic regression analysis. The authors raise the point that we do not know what proportion of these disruptions were complete (ie, disconnected ducts) and hence the www.giejournal.org

patients were not candidates for TPD, versus those that were partial and thus patients may receive clinical benefit from TPD. It is our assertion, however, that this distinction may not matter because the successful performance of endoscopic retrograde pancreatography (ERP) and successful completion of the intended diagnostic/therapeutic intervention occurred in only 36 of 79 (46%) patients, with an overall CD technical success rate of 35 of 79 patients (44%). In other words, when the endoscopists chose to pursue ERP as part of a multimodal intervention to manage the pseudocyst, they were unsuccessful in carrying out this intervention in more than 50% of cases. Failure to assess for leak endoscopically, provide TPD, or both was more the norm than the exception. Furthermore, a subgroup analysis comparing patients who underwent TMD alone with those whose experience with CD was technically successful also failed to demonstrate any difference in symptomatic or radiologic resolution rates. Alone, TMD is an acceptable intervention for the management of pancreatic pseudocysts. Hookey et al2 reported that there was no significant difference in the technical and clinical success rates among different drainage techniques (TP alone, TMD alone, or CD) in their series of 116 patients who underwent endoscopic management of various types of pancreatic fluid collections. Furthermore, they demonstrated a strong trend toward a higher recurrence rate of pancreatic fluid collection in patients undergoing CD than in those receiving TMD alone. Antillon et al3 prospectively evaluated TMD alone in a cohort of 33 patients with pancreatic pseudocysts and demonstrated during a median 46-week follow-up that 94% of patients had resolution of symptoms, 82% had complete radiologic resolution, and only 1 patient had a recurrence. In addition, the results of a meta-analysis recently presented by our group also demonstrated that there was no advantage to PD stenting in the TMD of pancreatic fluid collections, and further support the findings of our multicenter study.4 Last, our results and conclusions are further strengthened by our rigorous definition of long-term treatment success in that all long-term outcomes were assessed only after all prostheses had been removed for a minimum of 2 weeks.1 There is currently no consensus on the optimal approach to the endoscopic management of pancreatic pseudocysts and fluid collections. The use of ERP and the addition of TPD, when technically feasible and when clinically appropriate, is acceptable. On the other hand, we have observed that in the vast majority of cases, TMD alone is sufficient management and is associated with low rates of clinical or radiologic recurrence on long-term follow-up. Hookey et al2 postulated that pure TMD may allow for the formation of a more mature cyst–enterostomy fistula and that a transpapillary PD stent may hinder this process, thus in actuality Volume 83, No. 5 : 2016 GASTROINTESTINAL ENDOSCOPY 1047