Review for 10.1186/s12876-019-1129-3 (2019)

Reviewer ’s report  
 
Title: Treatment of Post -Cholecystectomy Biliary  Strictures wi th Fully -Covered Self -Expanding 
Metal Stents - Results after 5 years of Follow -up 
 
Version: 1 Date: 06 Nov 2019  
 
Reviewer: Kishore Gurumoorthy Subramanya Bharathy  
 
Reviewer's report:  
 
The authors have written a nice paper analyzing 5 year outcome in a cohort of 18 patients with 
post cholecysterctomy bilary strictures (PCBS) who underwent endoscopic placement of a fully 
covered self expanding metal stent (FCSEMS) during the study period of 18 months.  
 
 
Major points  
 
Since the paper looks at long term  stent free rates at 5 years, it has to be clear as to which 
patients will benefit the most from the procedure. Although selection criteria are mentioned in 
the methods section, the following three points relate to patient selection.  
 
(i) What was the denom inator? Were all patients in 12 centers with type I, II Bismuth 
strictures assessed for FCSEMS placement? How many patients were assessed and how 
many were found to be eligible for the procedure?  
 
(ii) Since 14 out of 18 patients (78%) already had plastic stents in place, why was it decided 
to switch to a FCSEMS? What were the reasons for this decision and for how long did 
patients have their plastic stents in place prior to this? Recent data* does suggest 
excellent results in the long term for multiple pla stic stents. Also as per the current 
manuscript, for failure of FCSEMS, multiple plastic stents seems to have been the rescue 
option.  
 
*Costamagna G1 et al. Endotherapy of postcholecystectomy biliary strictures with multiple 
plastic stents: long -term resu lts in a large cohort of patients. Gastrointest Endosc. 2019 Jun 5. pii: 
S0016 -5107(19)31933 -9. doi: 10.1016/j.gie.2019.05.042. [Epub ahead of print]  
 
(iii) How do authors counsel, consent their patients for multiple plastic stents vs. FCSEMS vs. 
surgery ( Roux en Y hepaticojejunostomy) in the subgroup of patients with type I, II 
Bismuth PCBS? Is a multidisciplinary team decision involved?  
 
Although the numbers are small for any detailed analysis, what according to the authors are 
possible reasons for failu re of FCSEMS in 7 out of 18 patients? This may help in refining 
selection and choosing other modalities of treatment for this subgroup of patients.  
 
A table providing the outcomes of patients in three groups (Planned removal  Unplanned removal  
Complete dis tal migration) would put things in better perspective for readers.  
 
Planned removal  
 
Unplanned removal  
 
Complete distal migration  
 
Number of patients (n)  
 
11 
 
4 
 
3 
 
Median time, range when stent was removed/found missing     
 
Stricture resolution at the time of stent removal (n)     
 
Stent free status at 5 years  (n)    
 
If it is correct that 11 out of the 18 patients (61%) remained stent free at 5 years, this may be 
mentioned in the abstract for the sake of clarity, in addition to saying 11 out of the 13 (84.6%) 
who had stricture resolution after stent removal/passage rem ained stent free at 5 years  
 
 
Minor points  
 
Did the follow up protocol involve periodic LFT, MRCP? Patients who had cholangitis/ 
recurrent stricture obviously have had an ERC; in the 11 patients without symptoms, was the 
LFT normal at 5 years follow up with  some documentation of stricture resolution on MRCP?  
 
How many patients had associated vascular injury at the time of cholecystectomy? What was the 
median time to intervention (stenting) from the time of injury?  
 
In the discussion it is mentioned that endo scopic planned removal was done in 14 patients --- 
should be 11.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Unable to assess  
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manus cript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please speci fy what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing in terests, considering the following questions:  
 
1.  Have you in the past five years received reimbursements, f ees, funding, or salary 
from an organisation that may in any way gain or lose financial ly from the 
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future?  
 
3.  Do you hold or are you currently applying for any patents relating to th e content 
of the manuscript?  
 
4.  Have you received reimbursements, fees, funding, or salary from an organization 
that holds or has applied for patents relating to the content of the manuscript?  
 
5.  Do you have any other financial competing interests?  
 
6.  Do y ou have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, write 'I declare that I have  no competing interests' 
below. If your reply is yes to any, please give details below.  
 
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