1. Kersten Morgan Bates and Arindam Chaudhuri
Deliberate stent-graft extension and endotacking straightens the hyperangulated aortic neck during endovascular aneurysm repair
Kersten Morgan Bates and Arindam Chaudhuri
Bedfordshire-Milton Keynes Vascular Centre, Bedford Hospital NHS Trust, Kempston Road, Bedford, UK

2. Clinical Summary
We present a case of deliberate stent graft extension and endotacking to straighten a hyperangulated neck of abdominal aortic aneurysm.

3. Clinical History
Independent 90-year-oldJehovah’s Witness referred with asymptomatic 5.5cm AAA found incidentally on CT
PMH:
Chronic Renal Impairment
Left pyeloplasty
Left renal artery stenosis (RAS)
Atrophic right kidney
Hypertension
Hypercholesterolemia
Myelodysplastic syndrome
Pre-operative erythropoietin therapy resulting in an increase of her hemoglobin levels from 9 to 13g/dl

4. Pre-Operative Imaging and Plan
Pre-operative CTA showing hyperangulated AAA neck:
A angle 64.4o
B angle 55.6o
Pre-operative considerations:
Type I endoleak anticipated due to loss of apposition of native artery and stent graft along outer curve of neck
It was therefore anticipated that endotacking along the 2 to 4 o’clock positions would be needed to prevent this loss of apposition
Deliberate extension with a cuff would cover eventuality of low deployment and also stiffen the system rather than use a pre-deployed balloon-expandable stent e.g. Palmaz

5. Procedure Epidural Anaesthesia Bilateral femoral cut-downs
Cook Zenith Low Profile Stent body (Cook Aortic Intervention, Bloomingdale, USA) deployed
noted to be lower than anticipated due to decreased visibility at the neck and neck hyperangulation.
Spiral Z limbs (Cook Aortic Intervention) deployed
APTUS HeliFX endostaples (n=2; Aptus Endosystems Inc., Sunnyvale, USA) deployed at 2 and 4 o’clock onto body
A RENU extension cuff (Cook Aortic Intervention) deployed and ballooned
Final run - no endoleak; decreased angulation <30 o

6. Post-Operative
Post -operatively her renal function deteriorated and she became anuric
The left ureter was stented but despite this, the kidney was ischaemic and she was discharged requiring long term dialysis
Likely aetiopathogenesis was micro-embolisation during neck ballooning, in a background of RAS.

7. Discussion
20% of AAA’s have been shown to have inadequate necks for standard stent grafts
Reasons for hostile neck anatomy include:
neck length <15 mm
neck diameter >28 mm
angulation >60 degrees (between the long axis of the aneurysm sac and the long axis of the juxta-renal aorta)
Hostile anatomy is associated with a four-fold increased risk of Type I endoleak

8. Discussion
The Cook endograft is only licensed for use for neck angulation <600
The only device licensed for hyperangulated necks up to 90o is the Aorfix (Lombard, Didcot, UK)
The cumulative stiffness of the Gianturco stents of the extension cuff and the nitinol stents of the LP body are not exactly known, but this combination resulted in neck straightening in this case
Apposition was improved by the use of endotacking to more closely align stent graft with native vessel
We would look forward to using this approach in other such patients
References
Malina M, Resch T, Sonesson B. EVAR and complex anatomy: An update on fenestrated and branched stent grafts. Scandinavian Journal of Surgery 2008; 97(2):
Dillavou ED, Muluk SC, Rhee RY, Tzeng E, Woody JD, Gupta N, Makaroun MS. Does hostile neck anatomy preclude successful endovascular aortic aneurysm repair? J Vasc Surg 2003; 38:
Chisci E, Kristmundsson T, de Donato G, Resch T, Setacci F, Sonesson B, Setacci C, Malina M. The AAA with a Challenging Neck: Outcome of Open Versus Endovascular Repair With Standard and Fenestrated Stent-Grafts. J Endovasc Ther 2009; 16: 137–146.
Antoniou GA, Georgiadis GS, Antoniou SA, Kuhan G, Murray D. A meta-analysis of outcomes of endovascular abdominal aortic aneurysm repair in patients. J Vasc Surg 2013; 57 (2) :