Review for 10.1186/1471-230X-12-114 (2012)

Reviewer's report
Title:Obesity and diabetes mellitus and/or hyperlipidaemia are independent risk
factors for pre-transplant portal venous thrombosis in liver recipients
Version: 3Date:30 April 2012
Reviewer: massimo primignani
Reviewer's report:
In this retrospective study the Authors evaluate the pre-transplant thrombotic
events in a cohort of liver transplant recipients and try to identify the risk factors
for these complications. They conclude that metabolic disorders such as obesity
and diabetes mellitus and/or hyperlipidaemia are independent risk factors for
pre-transplant thrombosis.
Major compulsory revisions
1 - As for the main result of the study, the clinical risk factors for thrombosis in
the pre-transplant period, I wonder why diabetes and hyperlipidaemia are taken
together. Perhaps the number of patients with one only of these co-morbidity was
too low to attain enough statistical power for the analysis. However it is arbitrary
to put together diabetes and hyperlipidaemia. Moreover, the number of patients
with hyperlipidaemia or diabetes alone is not detailed. At last, obesity and
hyperlipidaemia are not defined at all.
2- As far as HAT is concerned, it is hard to consider it as a pre-transplant event,
because it is mainly a pre- re-transplant event.
3 – It is incorrect to consider together primary, secondary and tertiary transplants.
Likely the cause of thrombosis are different
4 – It is incorrect to consider together arterial and venous thrombosis. It is likely
that the causes for arterial and venous thrombosis are different
5 – In the text there is some confusion regarding which type of thrombotic event
in the pre-transplant period is concerned, i.e PVT only versus all thrombotic
events (either abdominal or not) among which PVT is the most frequent.
6 - Discussion: it is too long and not linear
In summary I suggest a thorough revision of this retrospective study focusing
only on pre-transplant PVT and on primary OLT.
Minor Essential Revisions
Abstract: diabetes and hyperlipidaemia are not listed among the considered risk
factors for thrombosis
Background: Page 3, line 15: The phrase is incomplete “Because of …?….. PVT
has been seen as an obstacle to OLT”
Materials and methods: numbers are continuously changing : 441 OLT in 437
recipients (line 1)
….. “ but 74 recipients had died before initiating the study”…… It is unclear.
Since the study is retrospective I don’t understand if these 74 patients are
included in the study (which refers to the pre-transplant period) or not.
…. “further 74 had no follow-up at the study center”. Again it is unclear if these
patient are included in the study , at least for the pre-transplant period, or not.
The information is not important for the assessment of PVT in the pre-transplant
period, whereas it is obviously important for the long-term outcome which is
unknown inthese patients. . Indeed, it is not clear how many patients are included
in the survival analysis of figure 1
As for recipients: is the number of recipients 437 (293 males + 144 females) or
341 (the sum of 286 primary, + 46 secondary + 9 tertiary? At last the sum of the
etiologies is 283
Results: 89 had thrombotic events (21.4%) from this percentage I can derive the
number of recipients.. . 416 However only 61 had a pre-transplant PVT, while 5
had DVT, 1 peripheral artery disease and 22 HAT (HAT , as stated above,
cannot be considered a pre-transplant thrombosis)
In the following section the number of PVT is increased (65/441)
Several References are incomplete: 11,12,17,19
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