TO THE EDITOR
Peroral pancreatoscopy (POPS) is an endoscopic, challenging procedure to directly visualize the main pancreatic duct, permitting tissue acquisition, and can be also used for therapeutic purposes, such as intracanalar lithotripsy. Although in the last decade technology has been continuing to improve with the recent development of single-operator digital cholangio-pancreatoscopy, pancreatic experience is limited.
In chronic pancreatitis, the goal of treatment is reducing pain by eliminating obstructing pancreatic stones. While the use of cholangioscopy for difficult biliary stones’ management is well documented, most pancreatic stones (< 5 mm) can be removed successfully by endoscopic retrograde cholangio-pancreatography (commonly known as ERCP). Patients with large stones require advanced therapeutic approaches, such as extracorporeal shock wave lithotripsy (ESWL) (alone or followed by ERCP), currently the mainstay of treatment. Unfortunately, in about 10% of cases, ESWL can fail or not be suitable; moreover, it is not available in many institutions. In this subgroup of patients, POPS guided-lithotripsy (POPS-gl) can play a role and have benefits.
“Extrema ratio” surgery offers the best long-term results for chronic pancreatitis. being associated with a lower rate of relapse; although, the biggest criticism of any study is that neither ESWL nor POPS-gl was included in the endoscopic arm. We must keep in mind that not all endoscopists performing cholangioscopy routinely have dexterity in direct intraluminal lithotripsy for difficult biliary stones’ treatment. This further restricts the field of endoscopist experts. Nowadays, if you look at the available literature, you realize the low volume of patients treated and that data must be interpreted with caution.
The most consistent study concerns a retrospective analysis involving 17 centers in the United States and Europe, where just over 100 cases (about 6 patients per center!) treated with POPS-gl were enrolled during 3 years. In others published reports, describing a systematic review and a retrospective multicenter cohort, the authors collected a total of 87 and 28 patients, respectively. From all these data, the scant volume of skilled endoscopists and the epidemiological scenario, we believe POPS must be developed in very few high-volume referral centers with standardized pathways and capable of performing multi-modality treatment.
In addition, we could reasonably assume that POPS-gl should be used as rescue therapy in special situations and will be associated fewer interventions, more wide de-obstructions and lower risk of infection. Thus, it seems wise to implement a new level of evidence in order to identify the ideal candidate who can achieve the maximum clinical result, while carefully balancing risk/benefits ratio.