Review for 10.1186/s12876-015-0255-9 (2015)

Reviewer's report
Title:Extracorporeal shock wave lithotripsy treatment of pancreatic stones
complicated with advanced stage autoimmune pancreatitis
Version:3Date:17 November 2014
Reviewer: Puneet Dhar
Reviewer's report:
This is an interesting study by a group which has published previously on the
progression of autoimmune pancreatitis going on to chronicity.
However some issues are unclear and need to be addressed.
1. That this is a retrospective study must be clearly stated in Methods - rather
than clarified in discussion in the limitations.
2. It is unclear how the study patients were selected - was it only from amongst
the patients that underwent lithotripsy - or was it from a prospective follow up of
patients with AIP - since many of them do not appear to be symptomatic!
3. It is unclear - if both the AIP and ordinary CP patients are selected or
consecutive. Were there any exclusions - eg for doubt of malignancy etc. This
would help the reader to understand applicability to their own patients!
4. Why was a comparative study not done of the entire cohort of patients with
chronic pancreatitis after AIP - their other papers show that more than 8 patients
were revealed to be chronic! So we lose potentially useful data on WHY they
selected these particular 8 patients for lithotripsy. This is particularly important as
most of them seem to have the vague "improvement of pancreatic function" as
the indication.
5. Why were asymptomatic patients subjected to a lot of invasive investigation
(ERCP) and treatment (Lithotripsy) - did they consent? Were they informed that
the treatment may NOT actually "improve" their pancreatic function? Was it a
part of a protocol or research study? This is important as many of the
investigations (ERCP, nasopancreatic tube insertion, ESWL) HAVE a potential
for complications which may be justified only if there is a real or believed benefit!
6. Unclear what was the first study to detect the stones - eg plain CT or MR?
Also if it was radiolucent - what was the indication of ERCP "when radiolucent
stones were identified". Also how were the "radiolucent stones" which "needed"
ESWL identified in the first place. These must be clarified.
7. Likewise the treatment outcome mentions only outcomes of stones - which
may be of interest to the investigators and the reader, but for the patient it would
be equally if not more important to judge the outcome based on the indication. So
if the indication was to improve pancreatic function - then the results must tell us
what WAS the difference in pancreatic function before and after the relevant
therapy! Even if it was negative, it is still important to know and can contribute to
the scant literature on this rare but important disease. End point of stone success
rather than clinical relief is rather odd.
8. It would be useful to mention about suspicion of malignancy and possible
indication of surgery in this setting - since changes of chronicity in AIP may
possibly be mimicked by malignancy (especially strictures in an already diseased
gland). A small note on this may also be relevant to help others avoid using an
unindicated treatment in a patient who may have a missed malignancy and be
better served by alternative therapy - especially resection.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
No competing interests!