Review for 10.1186/1471-230X-12-173 (2012)

Reviewer's report
Title:Percutaneous ultrasonographically guided liver punctures: A study of 2007
patients over 10 years
Version: 1Date:17 May 2012
Reviewer: Holger Lutz
Reviewer's report:
Major Compulsory Revisions
1. The design of this study is claimed to be prospective in recording
complications and risk factors. Though, e.g. coagulation parameters (platelet
count, Quick’s test and PTT) were fully documented in only 34.2% percent (n =
780) of puncture procedures as well as diameter of target lesions was not
documented for all punctures. The authors need to clarify collection of data and
study design, as the objective of this study was to establish the clinical relevance
of these factors on a prospective collected basis.
2. The introduction is rather short – the authors should consider to give more
information on typical complications, data on the different techniques and risk
factors concerning liver biopsies, especially differentiating parenchymal biopsy
and focal lesion biopsy.
3. The authors explain the definition of “puncture procedure”, “puncture” and
“passes”, though in data analysis, only the number of puncture procedures is
used. Thus, the benefit of this classification in this study is unclear. The authors
need to clarify, if there was a significant difference in the risk of complications
based on numbers of passes or punctures, or if this classification is not needed
in this manuscript.
4. The description of patient monitoring is not clear: Was ultrasound control
performed in all patients after biopsy or only in patients with CB or ABM? If not,
why was this not included in the study design (prospective)? At which time point
was ultrasound control performed? Was the procedure predefined for in- and
outclinic patients, and was it different? How could this influence the detection of
(subclinical) complications? This consideration is important because of the low
overall incidence of complications documented in all patients.
5. The selection of patients includes 1346 patients, who did not undergo liver
biopsy. These procedures are only included for defining experienced or
unexperienced examiners. As the influence of experience on liver biopsy safety
is examined in this study, these procedures should be excluded from the
analysis. This is particularly important, as the results of this study show, that
there is a higher risk for complication in experienced examiners. The authors
speculate, that this is caused by the risk of the procedure, more likely to be
performed by an experienced investigator. Can this speculation be supported by
any data?
6. The characterization of lesions and liver disease are sparse. The authors do
not give information of underlying diseases in all patients included in this study;
this is especially important when the number of complications is only 27, and
further data on these patients would be helpful. In Table 1, only complications are
listed in detail. Furthermore, “small amount of free intra-abdominal fluid” needs to
be specified (bleeding?). The authors discuss the risk of bleeding in patients with
severe fibrosis: can data on severity of liver disease be provided and correlated
with risk of bleeding?
7. The authors claim to compare risk of bleeding in different needle sizes, though
they compare fine needle aspiration cytology (FNAC) and cutting biopsy (CB).
The authors state, that the impact of this is negligible. Is there any data available
concerning that matter? Were all biopsies using FNAC and CB performed with
needles the same size?
- Minor Essential Revisions
8. The term “puncture procedure” is not typically used for liver biopsies. The
authors should consider to use the standard term “liver biopsy”.
9. In the second line of the results part of the abstract, “significantly” needs to be
changed to “significant”.
Level of interest: An article of limited interest
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests