slide for review transplant renal artery stenosis

1. Post Transplant Renal Artery Stenosis
Chaken Maniyan M.D.
Fellow Nephrology
Phramongkutklao Hospital

2. Causes of post-transplant HTN
• Calcineurin inhibitors (65 - 90%)
• Corticosteroids
• Largely depends on dosage
• Transplant RAS 2 – 10 %
• Post-biopsy AVF Rare cause
• Chronic graft rejection
• Native kidneys & pre-transplant HTN
Ponticelli C et al . Informa Healthcare, London, UK, 2007.

3. Vascular complications after
kidney transplantation
• Arteriovenous fistula
• Pseudoaneurysm
• Graft thrombosis
• Transplant renal artery stenosis (TRAS)
Seratnahaei A. et al , Angiology ; 62(3) 219-224 2011

4. Epidemiology
• Prevalence of TRAS range1-23% in different series
• US renal data system registry à 823 TRAS among
41,867 recipients (incidence rate =1.9%)
• Usually occurs within 6 month – 2 years after KT
Bruno S, et al. J Am Soc Nephrol 2004; 15:134.

5. Risk factor
• Technical error during harvest or transplantation
• Renal artery atherosclerosis
• Neointimal hyperplasia, accelerated atherosclerosis
caused by immunosuppression
• Cytomegalovirus infection
• Delayed allograft function
Natalia O. et al , Seminar Vasc Surg 26 (2013) 205-212

6. Multivariate analysis of factor
contributing TRAS
Audard V, Matig, et al. Am J Transplant 2006; 6:95.

7. Clinical manifestation
• Worsening or refractory hypertension
• Graft dysfunction in absence of
• rejection, ureteric obstruction, or infection
• Fluid retention edema, CHF/flash pulmonary edema
• Paradoxically normal or low BP
• rapid deterioration of renal function after
diuretic therapy or addition of ACEI/ARB
Bruno S, et al. J Am Soc Nephrol 2004; 15:134.

8. Presence of a bruit ?
• Not specific (physiologic vascular turbulence in the
iliac or femoral arteries to anastomosis)
• Bruits from proximal iliac vessel stenoses or
biopsy-induced parenchymal AVF can also confound
clinical picture
• Significant stenosis can occur in absence of an
audible bruit
Bruno S, et al. J Am Soc Nephrol 2004; 15:134.

9. Differential Diagnosis
• Effect of CNI
• esp early after transplantation (highest doses)
• Atherosclerotic Iliac stenosis of native vessels
• accelerated by steroids and CNI
• Immunologic endothelial damage (chronic rejection)
• Thrombosed arteries of graft
W.Chen et al , Clin Kidney J (2015) 8: 71–78

10. Classical kidney transplantation
surgery

12. Diagnostic procedures of TRAS
Bruno S et al. J Am Soc Nephrol 2004 ;15 : 134 – 141.

13. Comparison of imaging in TRAS
W.Chen et al , Clin Kidney J (2015) 8: 71–78

14. Renal duplex ultrasound
• Renal duplex ultrasound is valuable for making the
diagnosis of transplant renal artery stenosis.
• CRITRIA FOR DIAGNOSIS
• Peak systolic velocities >200 cm/s
• Velocity gradient >2:1
• Resistive index >0.8
• OR presence of pulsus parvus et tardus
waveform
• Acceleration time > to 0.08 sec
Dimitroulis D, et al. Transplantation 2009;41:1609–14.

15. ipsilateral iliac artery
tardus-parvus waveform

16. Pseudo-TRAS
• Iliac artery disease proximal to the anastomosis •
• Low flow to transplanted kidney
• Signs & symptoms resembling those of TRAS
• Claudication or other signs of limbs hypoperfusion
• Treated by angioplasty or surgical revascularization
Aslam S et al. Transplantation 2001 ; 71 : 814 – 817.

17. Managemnt
• Untreat significant lesion of TRAS leads to graft
failure and death
• 3 Modalities
• Medical therapy
• Percutaneous intervention
• Surgical intervention
W.Chen et al , Clin Kidney J (2015) 8: 71–78

18. Medical Therapy
• ACEI should be used to control blood pressure
• In case of stable renal function AND
• no evidence of hemodynamically significant
stenosis (PSV <180 cm/s and RI >0.50.
• Other agents that are considered helpful for TRAS
are statins and acetylsalicylic acid
W.Chen et al , Clin Kidney J (2015) 8: 71–78

19. Endovascular treatment
• Indication
• presence of a hemodynamically significant
stenosis (>50% on catheter angiography)
• presence of >10% peak systolic pressure
gradient
• Treatment options include
• percutaneous transluminal angioplasty (PTA)
• PTA with bare metal
• PTA with drug-eluting stents

20. Percutaneous Intervention
• Percutaneous transluminal angioplasty (PTA) with stenting
has become à treatment of choice for TRAS
• decreased incidence of restenosis compared with PTA
alone (restenosis rate 10%Vs 39%)
• less invasive than surgical approach
• Complications (0-10%)
• Renal artery dissection,
• Stent restenosis,
• Thromboembolism
• Hematoma
• Pseudoaneurysm at the puncture site
W.Chen et al , Clin Kidney J (2015) 8: 71–78

21. Hemodynamic change after PTA
Ruggenenti P. et al Kidney Int 2010; 60:309.

22. PTA benefit
Seratnahaei A. et al , Angiology, 62(3) 219-224 , 2011

23. PTA lack benefit
Seratnahaei A. et al , Angiology, 62(3) 219-224 , 2011

24. Recanati-Miller Transplantation Institute,
Icahn School of Medicine at Mount Sinai, New York, NY

25. BMS , DES , PTA alone what is the best
D. M. Biederman et al , American Journal of Transplantation 2015; 15: 1039–1049
• No significant difference in
allograft survival at 360 d
• Patency was significantly higher in with DES
and BMS compared to PTA
• In postanastomotic TRAS subtype,patency
rates in DES higher compared to BMS

26. Surgical revascularization
• Indicated in cases of failed PTA or severe kinking or
stenosis
• Techniques include resection and revision of the
anastomosis, saphenous vein bypass graft of stenotic
segment, localized endarterectomy and
excision/reimplantation of the renal artery
• Higher rates of morbidity
• graft loss and ureteral injury
• mortality in up to 5% of cases
W.Chen et al , Clin Kidney J (2015) 8: 71–78

27. Thank you for your attention