Review for 10.1186/s12876-015-0260-z (2015)

Reviewer's report
Title:Positive regulatory effects of perioperative probiotic treatment on
postoperative liver complications after colorectal liver metastases surgery: a
double-center and double-blind randomized clinical trial
Version:2Date:19 December 2014
Reviewer: Luca Gianotti
Reviewer's report:
Positive regulatory effects of perioperative probiotic treatment 1 on postoperative
liver
complications after colorectal liver metastases surgery: a double-center and
double-blind
randomized clinical trial, by Zhihua Liu et al.
This is a potentially interesting study. Although there are several potential flaws
and the paper needs to be reorganized deeply.
1. in the abstract, as well in the material section is not clear at all with type of
surgery the patients received. It appears intuitive to think that they underwent
synchronous colo-rectal and liver resection but there is no mentioning of the
extent and type of hepatectomy.
2. There are a multitude of endopoints. It is not clear which is the primary one
and the secondary one.
3. The introduction is too long and full of redundant information and sometimes
also real commonplaces (such as epidemiology and role of surgery)
4. statistical methods are unclear, especially the sample size calculation (12
pts/group) and 134 patinets were enrolled (great confusion !!)
5. It may be that most of the finding are related to pringle manoeuvre !. There is
not data on how may patients received pringle and the time of pringle.
6. A mean of three hours for a combined colorectal resection and hepatic
resection seems not believable at all.
7. The description of inclusion and exclusion criteria are repetitive
8. Which stain of probiotic bacteria were used ?? (BL-88, LA-11, LP ??). An
international coding for probiotic should be used otherwise no one may
reproduce the study design
9. Are these probiotics dried or alive ?
10. Which is the definition of septicaemia ?. Positive blood coltures ? or simple
SIRS ?
11. bowel preparation may affect deeply the survival of probiotic. Did the authors
test for viability
12. I am always quite doubtful when I see zero surgical complications in such a
extensive surgery. 134 simultaneous colorectal resection and liver resection with
no surgical-related morbidity is very uncommon to find in the international
literature. I have looked at the same group previous publications and it seems
that in none of their trials there is one anastomotic leak, fistula, or bleeding in
hundreds of cases.
13. It is unclear why only 117 /134 completed the study.
14. Are there patients receiving TPN or enteral feeding ?
15. the authors state that some infections such as central line and pneumonia
are not correlated with intestinal infection. Which is the rational for this statement
?
16. diarrhea is not an infectious complication unless pathogens are proven in the
stools.
17. there is overlapping period of patients enrollement with their previous
publications about RCTs. How is it possible ?
18. in the present study they could not reproduce the effect of probiotic on
intestinal permeability (as measured by L/M ratio) found their previous
publications. Why ?
19. In the discussion is too long and there are multiple repetitions of the results
and prosaic sentences (liver get a dual blood supply, etc)
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
no conflict