Author’s response to reviews

Title: Re-interventions after endovascular aortic repair for infrarenal abdominal aneurysms: A

retrospective cohort study

Authors:

Håkan Roos (hakan.roos@vgregion.se)

Henrik Djerf (henrik.djerf@vgregion.se)

Ludvig Brisby Jeppsson (ludvigbrisbyjeppsson@gmail.com)

Victoria Fröjd (victoria.frojd@vgregion.se)

Tomas Axelsson (tomasaxels@gmail.com)

Anders Jeppsson (anders.jeppsson@vgregion.se)

Mårten Falkenberg (marten.falkenberg@vgregion.se)

Version: 1 Date: 27 Apr 2016

Author’s response to reviews:

Reviewer 1

The reviewer wrote:: In my opinion, this article should be published in the journal. It's about a

current topic of great interest. It brings the experience of a single center and, nevertheless,

contains a range of patients and a follow-up series quite acceptable.

Answer: We thank the reviewer for this comment

The reviewer wrote: It might have been advisable to spare the elective from the emergent

patients. Although decreasing the sample since it would have resulted in a more homogeneous

sample. However, the comparison between the two groups is presented clearly and is also useful.

Answer: We agree with the reviewer that there are pros and cons with the inclusion of different

groups in the report but the aim of the study was to report results of an unselected series of

patients.

The reviewer wrote: The complication rate is high but similar to other published series. Access

related complications are more frequent in open cases, as in most published studies. As for the

non-access related complications, the presentation of the results is exhaustive but a little

complicated to understand, since the data are extensive and are somewhat complex to

understand.

Answer: We do acknowledge that the choice to report the entire cohort makes the data more

complex but hope that the added information from an unselected group gives a valuable

contribution to the manuscript.

The reviewer wrote: Of special interest is the statistically significant differences between patients

who come for reoperation due to symptoms compared to patients in which the leak was detected

during the follow up. I think it is very interesting and reinforces the need for check ups of these

patients.

Answer: We agree with the reviewer that EVAR follow-up is still essential.

The reviewer wrote: Finally, another factor that can complicate the interpretation of results are

the use of multiple prostheses and various techniques used in its implantation. A more

homogeneous but also smaller sample would be easier to interpretate.

Answer: We again agree with the reviewer but hope that the added information from the

unselected cohort is valuable.

Reviewer #2:

The reviewer wrote: 1) I would like to know if this hospital still intervene routinely patients with

these aneurysm with traditional surgery (not including reoperation) and what percentage in these

9 years of patients with infrarenal aorta aneurysms (symptomatic or non-symptomatic) have

operated conventionally in relation to total.

Answer: The percentage of endovascular treatment has increased during the study period,

numbers in percentage are added in the manuscript on page 5 line 86. EVAR was used in 28 %

of treated AAA in 2005 compared to 56 % in 2013. Both open-repair and EVAR were used for

treatment of ruptured AAA during the study period.

The reviewer wrote: 2) I would like you to clarify something the idea that the attitude of women

from surgeons can transcend the need for reoperation or not (line 327).

Answer: Women underwent significantly less re-interventions than men in the present study

which is in accordance to other studies (ref 16 and 20 in the manuscript). The reasons are

unclear, and we propose in the manuscript that anatomical factors with smaller ilical vessels may

be one factor that reduces the need for re-interventions. In addition, a restrictive attitude to re-

interventions among patients and physicians may also contribute. We admit that this is pure

speculation but it has been shown in cardiac disease that women are less likely to be diagnosed

and treated compared to men. We have now rewritten the sentence to make it clear that we

clearly speculate about the reasons.

The reviewer wrote: 3) Being type 2 endoleak the most common cause of reoperation, I would

like to know if this review of his work, has served to develop strategies to prevent these

endoleaks during the initial surgery (direct embolization of lumbar branches, mesenteric, indirect

embolization sack, etc.).

Answer: So far the present work has not changed our strategies. We do not use routine coiling of

inferior mesenteric or lumbar arteries at initial surgery.

The reviewer wrote: 4) I would like to reflect how long you waited for embolization of this

contralateral internal iliac artery (line 273).

Answer: The patient with staged coiling of one internal iliac artery had this procedure performed

25 days prior to EVAR treatment and contralateral coiling. The iliac branched device occluded

day 2 after surgery. This information is added on page 12 line 273.

The reviewer wrote: 5) Lines 199 - 201. As it has been found in the data, when the distal

anchoring area is located in the external iliac artery, the number of arterial thrombosis and acute

ischemia during follow-up increases (worsens the run-off). However, so I can infer from the text,

you had only one case of iliac-branch. Have influenced this finding in the handling of

revascularization versus embolization of the internal iliac artery in your daily practice?

Answer: There were 15 cases of iliac branched devices in the series and we have avoided to

embolize the internal iliac artery whenever possible. This information is added on page 6, line

123.

The reviewer wrote: 6) At line 288 mentions that survival does not depend on the type of stent,

but what about complications? I mean, for example, at 251-252 lines, which were more frequent

report the type I endoleaks with prostheses without anchor hooks.

Answer: The only difference between types of stents found was the reported increased incidence

of proximal extensions in stents without proximal anchoring hooks.

The reviewer wrote: 7) Problems with references:

Line 330: reference 15 has nothing to do with survival in women after EVAR.

Line 345: the diameter of the common iliac referred by Ohrlander et al., it refers to the reference

23 and not to 22.

Line 346-8: his group demonstrated the genesis of extraction forces in the reference 25 and not

24. (the 25th is not referenced in the text but it appears in the list).

Answer: Thank you, we do apologize for mistakes with the references, this is now corrected in

the manuscript.

8) Lapse: line 364: please correct the word coclusions

Answer: Thank you, this is now corrected in the manuscript.