Endograft repair of infra-renal aortic aneurism with extension iliac grafts. Pre-op Ct revealed aneurism to be 1.8 cm below left renal artery. Post op CT revealed proximal renal artery stenosis of the left renal artery. . This appears to have been missed and not addressed by vascular surgery. One year later renal function as down significantly. The left kidney has hypertrophied significantly. Nephrology attributes decreased renal function to left renal artery stenosis and left kidney injury from graft placement.
Seems like a well know issue. Unclear to me if in 2021 this was preventable to just a risk of the procedure.. Also unclear is if there was anything to be done if the post op CT issue had been recognized.
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Do you believe there might have been medical error?
So I think there is something to clarify here. The question is is the renal artery covered by the endograft or is there native vessel stenosis. I think there is more of a case if the endograft is covering the orifice of the renal. Then yes that should be picked up in the intraoperative angiogram or post op ct and attempts should be made to salvage. However, if there was native vessel disease, that is usually not treated at time of EVAR for aortic aneurysm if no specific reason. Then likely this is progression of disease and not much of a case in my opinion. If it is from the endograft then there should be a CTA confirming that with radiographic evidence.
Do you believe there might have been causation (i.e. the medical error resulted in an injury)?
Again I think as mentioned above this is dependent on if there is radiographic evidence that the endograft is covering the renal orifice. I think if that is the case then there is more of a basis for failure to recognize. It is a known complication but then it is dependent on if it was identified or why it wasn't and why nothing was done for this.
What makes you a good expert for this case?
I believe I would be a good reviewer for this case for multiple reasons. My fellowship in vascular surgery was completed at Stanford University where I placed over 100 of aortic endografts and am well published with multiple aortic repair publications. I also completed a second advance aortic fellowship in China at the main aortic center in Beijing. Currently I conduct about 20-40 aortic aneurysm repairs a month which is categorized as high volume.
How often do you encounter cases similar to this one in your practice?
I have had cases where the endograft has encroached or covered a renal artery. We have been able to recannulate with a variety of different techniques and stent in various parallel configurations to ensure there is adequate flow into a renal artery.
Do you believe there might have been medical error?
If the left renal artery stenosis were significant, the kidney would have atrophied. Seldom do we intervene on renal artery narrowing without actively clinically significant hypertension. It also is not clear to what degree there is stenosis from the EVAR itself, nor is it clear what the change in creatinine has been. Lastly, if the other kidney is functioning well, then there should not be a significant overall change in renal function.
Do you believe there might have been causation (i.e. the medical error resulted in an injury)?
See above. See above See above
What makes you a good expert for this case?
I am a vascular surgeon that performs EVAR’s as well as renal artery interventions.
How often do you encounter cases similar to this one in your practice?
EVARs and AAA, ~30 per year, renal stenosis 1-2 cases per year. The combination is rare. Renal disease is a very common part of my practice, although rarely from stenosis and the narrowing of the artery or arteries generally over 80% to impact renal function.
Do you believe there might have been medical error?
Impossible to tell without review of images from preop CT, intraoperative angiograms, and postoperative CT. I have seen plenty of cases where there was pre-existing renal artery stenosis that was simply not commented upon by the diagnostic radiologist on a CT scan, resulting in the impression that the finding after surgery is "new". Regardless, the standard of care, based on the CORAL trial, for renal artery stenosis is medical management in the absence of both uncontrolled hypertension AND progressive renal insufficiency. The description of the above case is likewise flawed in that renal artery stenosis would lead to renal atrophy (shrinking), not renal hypertrophy (enlargement).
Do you believe there might have been causation (i.e. the medical error resulted in an injury)?
Renal artery stenosis would be nearly impossible to cause during EVAR absent covering the artery with the stent graft, or causing severe injury with a wire, both of which would be immediately noticeable. This should not be hard to determine with close review of imaging studies (NOT imaging reports).
What makes you a good expert for this case?
I am a very busy vascular surgeon (professor and division chief at a major academic center) and aortic, renal and mesenteric arterial surgery is the majority of my practice; I have a referral practice for just these types of problems and a large number of my operations are "rescue" operations for cases that have gone awry at other institutions. Review of this case would be relatively straightforward based on the description - would need images of preop CT angiogram, intraoperative angiography from EVAR, and postoperative CT angiogram.
How often do you encounter cases similar to this one in your practice?
Never in my own patients that I am aware of, but I treat renal artery disease and aortic disease routinely, and I have reviewed similar cases for both plaintiffs and defendants in the past. I do approximately 75 aortic operations/year including open and endovascular, plus a large number of renal and mesenteric artery interventions (both open and endovascular).
Do you believe there might have been medical error?
The IFU for most of these devices require a 15mm infrarenal neck length for seal. At 18mm, the anatomy here appears to be amenable to endovascular aneurysm repair (EVAR) BUT REQUIRES ACCURATE PLACEMENT OF THE GRAFT AT THE INFERIOR EDGE OF LOWEST RENAL ARTERY. Once the graft is deployed, a completion angiogram is ALWAYS done to assess seal, flow, and to ensure no compromise of the adjacent branch vessels (ie, renal arteries above, and internal iliac arteries below) by the graft. Occasionally, the lowest renal is partially compromised by the graft. In those cases, a stent or stent graft should be placed to preserve renal flow AT THE TIME OF EVAR.
Do you believe there might have been causation (i.e. the medical error resulted in an injury)?
Itb is important to review the images to ensure that the renals were seen clearly (imaging with adjustment for parallax must be done to avoid missing encroachment. Additionally, guidelines recommend followup CTA within 1 to 3 months of implant. That, too, should show demonstrate compromise. At that point, renal intervention should be immediately undertaken. This case sounds like a failure to rescue.
What makes you a good expert for this case?
I have 20+ years of EVAR casework, and have instructed others in proper placement and management of secondary complications.
How often do you encounter cases similar to this one in your practice?
At least 2 to 3 time a year I'll have a case with a marginal neck where aggressive placement at the renals are required. Surgical tenets demand that ALL infrarenal aorta should be covered by the endograt to exclude any potential aneurysm-bearing tissue. As such, ALL grafts should be placed immediately at the lowest renal. When renal artery compromise occurs, immediate stenting is performed. Ignoring or missing this compromise is not acceptable.
Do you believe there might have been medical error?
- Based on large database studies, there is a known renal artery complication rate between 1% to 4% in the setting of endovascular aortic aneurysm repair (Zettervall, 2017). - The later higher end of complications included supra-renal fixated grafts, thus part of the question here is the type of endograft that was utilized. - Additionally, imaging of the patient native anatomy before deployment of the endograft might indicate a possible renal artery stenosis. - The major driver of treatment of renal artery stenosis is based on clinical factors (that is predominately uncontrolled hypertension in the setting of several medication treatments) (Bensen, 2015). - The key to this case will be the examination of pre-operative imaging (more than likely a CT scan), intra-operative imaging (fluoroscopic imagines, possibly intra-vascular ultrasound) and post-operative imaging (CT scan, ultrasound, etc.). ---------------------------------------- Benson RA, Paraskevas KI, Patterson BO, Loftus IM. Symptomatic Renal Artery Stenosis and Infra-renal AAA. Eur J Vasc Endovasc Surg. 2015 May;49(5):606-9. doi: 10.1016/j.ejvs.2015.01.019. Epub 2015 Mar 27. PMID: 25817562. Zettervall SL, Deery SE, Soden PA, Shean K, Siracuse JJ, Alef M, Patel VI, Schermerhorn ML; Vascular Study Group of New England. Editor's Choice - Renal complications after EVAR with suprarenal versus infrarenal fixation among all users and routine users. Eur J Vasc Endovasc Surg. 2017 Sep;54(3):287-293. doi: 10.1016/j.ejvs.2017.05.012. Epub 2017 Aug 2. PMID: 28779856; PMCID: PMC5659342.
Do you believe there might have been causation (i.e. the medical error resulted in an injury)?
- Again, depending on the above points - The key aspect of this case was there an issue at the initial EVAR that led to the occurrence of renal artery stenosis
What makes you a good expert for this case?
- I undertake and/or oversee several of these types of procedures in my practice. I am called as the senior partner to aid my partners in handling these types of complications. My experience over 14 years has included managing patients who undergo these complications in an open and endovascular fashion.
How often do you encounter cases similar to this one in your practice?
- Our group has also published on EVAR outcomes in our center and more broadly in the larger health system in a variety of aspects (Otoya, 2023; Tse, 2020; Newton, 2018). - Our practice undertakes around 20 EVAR cases in a given year similar to the one described. - Our rate of procedure-based complications as it pertains to renal artery stenosis is less than 1% - I have personally undertaken these types of EVAR cases and have handled my own complications as well as from other surgeons inside and outside my own medical center. - I can speak not only based on my training but my experience the one described in the case and can speak to the diagnostic imaging, work-up, intra-operative decision making, and open/endovascular approaches to these types of patients. ---------------------------------------- Newton DH, Kim C, Lee N, Wolfe LG, Pfeifer J, Amendola M. Sarcopenia Predicts Poor Long-Term Survival in Patients Undergoing Endovascular Aortic Aneurysm Repair. Journal of Vascular Surgery. 2018. Feb;67(2):453-459. PMID: 28847662. Otoya D, Lele S, Boyd S, Lavingia K, Amendola MF. Diagnosis of mental illness does not affect postoperative outcomes in patients undergoing endovascular aortic aneurysm repair in the VA healthcare system. J Vasc Surg. 2023 Nov;78(5):1221-1227. doi: 10.1016/j.jvs.2023.06.023. Epub 2023 Jul 1. PMID: 37399970. Tse W, Newton D, Amendola M, George M, Pfeifer J. Frailty index predicts long-term mortality and postoperative complications in patients undergoing endovascular aortic aneurysm repair. J Vasc Surg. 2020. Nov;72(5):1674-1680. doi: 10.1016/j.jvs.2020.01.045. Epub 2020 Mar 10. PMID: 32169360.
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