Review for 10.1186/s12876-018-0782-2 (2018)

Reviewer ’s report  
 
Title: Endo scopic Ultrasound -guided Transmural Drainage fo r Subphrenic Abscess: Report of 
Two Cases and a Literature Review  
 
Version: 1 Date: 04 Mar 2018  
 
Reviewer: Martin Kliment  
 
Reviewer's report:  
 
General comments:  
 
The au thors describe two cases of patients with a subphrenic abscess treated with an EUS -guided 
transgastric drainage and a review of the literature.  
 
 
 
The issue of a less invasive therapy of these patients is important and all the new information on 
this topic i s welcomed. Nearly all conclusions of the authors are supported by two described 
cases and the cases described in the literature.  
 
 
 
However, I can´t agree with a general statement and recommendaton, that the drainage catheters 
should be placed both internall y and externally in all patients. The necessity to insert an 
additional external drainage depends highly probably on the number and diameter of inserted 
internal DP stents. As shown in the table 1, there were 6 Patients successfully therated only wth 
an in ternal drainage. Importantly, five of these six patients were treated with insertion of two 
10French DP -Stents. The larger diameter of internal stent predispose to more efficient drainage 
and a longer patency of stents. Moreover, by multiple stening (two o r three paralel stents), the 
outflow of the fluid/pus is not only through the lumen of stents but also through the space 
between the stents. It can be anticipated, that therefore, the internal drainage is more efficient and 
the external drainage (naso -abscess drain) may not be necessary. Moreover, in a majority of 
patients treated with both external and internal dranage, the internal drainage consisted of only 
one 6 French internal DP stent with a significantly narrower lumen. This issue sholud also be 
discussed in the article.  
 
 
 
The terms naso -abscess drainage and external drainage are reffered to the same meaning in the 
article, but since in both case reports, there is mentioned only naso -abscess drainage and in the 
discussion and table 1 only an external dr ainage, it may result in the confussion and 
missinterpretation of external drainage as a percutaneous drainage.    
 
 
Specific comments:  
 
Case 1, page 5, third line: ...at seventeen days after surgery, preposition "at" should be omitted  
 
 
Case 1 page 6: in the methodology and technical aspects of EUS guided drainage, it would be 
useful to mention, to wich diamater was dilated the tunnel with a balloon (for practical reasons)  
Discussion page 11: As already mentioned in general comments, it should also be discusse d the 
number and diameter of used internal stent and their potential realtion to the simultaneously use 
of external drainge.  
 
 
Discussion, page 11: The comparison of complications of EUS -TD of abdominal abscesses with 
complications of EUS -guided biliary drai nage (EUS -BD) is not appropriate and should be 
omitted. Both are completely different clinical situations, resulting in different types and rates of 
complications. In comparison to EUS -BD, there is no risk of biliary leak with resulting biliary 
peritonitis  in EUS -TD of abdominal abscesses. Moreover, the inflammatory reaction of 
surrounding tissue in cases of abdominal abscess  that are adjacent to the stomach wall 
predispose to the better adherence of the stomach wall to abscess wall with the resulting lowe r 
risk of perforation and pneumoperitoneum in EUS -TD of abdominal abscesses.  
 
 
More similar to drainage of abdominal abscesses (including a subphrenic abscess) is a transmural 
drainage of pancreas fluid collections (pseudocyst, abscess, walled -off necrosis).  Therefore, 
when necessary, the comparison of complications should be done with these procedures.  
 
 
Discussion, page 12, line 16: ...after the word "fluid" should be inserted a word "collections" 
..."pancreatic fluid collections"  
 
 
Discussion, page 12, line 1 7: instead of the word " aperture" is more appropriate the word " 
lumen"  
 
 
Discussion, page 13: Concerning the lumen apposing stents, there are nowadyas concerns about 
the risk of bleeding, related to stent erosion into a vesel as the cavity of fluid colect ion collapses. 
Published are several cases of heavy bleeding after draining the walled -off necrosis with LAMS, 
that had to be radiologically coiled. This could be also mentioned in the discussion. Siddiqui A, 
Kowalski T, Loren D, et al. Fuly covered self -expanding metal stents versus limen -apposing 
fully covered self -expanfding metal stents versus plastic stents for endoscopic drainage of 
pancreatic walled -off necrosis: clinical outcomes and success. Gastrointest Endosc 2017; 
85(4):758 -765.            
 
 
Table  1: Column 10, first line: " Time to external drainage" it doesn´t describe exactly, what the 
parameter is, more appropriate titel: "Time to removal of external drainage" or "Duration of 
external drainage"  
 
 
Page 17 F: the formulation is not correct: better formulation: the drained abscess cavity became 
smaller/or shrank  
 
 
            Figure 2: Changes in body temperature, "body" should be inserted  
 
 
            Figure 3: A: CT shows a fluid collection "a" shlould be inserted  
 
 
            Figure 3: B: ...guidewire s coiling into the abscess cavity...corect: guidewire coiling in the 
abscess cavity  
 
 
Page 18, line 1: instead of naso -drainage catheter should be used "naso -abscess catheter  
 
 
Figure 4: Changes in body temperature "body" shloud be inserted  
 
 
References: Reference 36, page 25 -26, after Cilincal gastroenterology and hepatology: "the 
official clinical journal of the American Gasroenterological association" should be omitted.     
 
 
 
 
Are the methods appropriate and well described?  
If not, please specify what is required in your co mments 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.  
 
Not relevant to this manuscript  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
 
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years r eceived reimbursements, f ees, funding, or salary from an 
organisation that may in any way gain or lose financial ly from the publication of this 
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2. Do you hold any stocks or shares in an organisation that may in any way gain or lose 
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents  relating to the content of the 
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4. Have you received reimbursements, fees, funding, o r 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 you have any non -financial competing interests in relation to this paper?  
 
 
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below. If your reply is yes to any, please give details below.  
 
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