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Post Transplant Renal Artery Stenosis
Chaken Maniyan M.D.Fellow NephrologyPhramongkutklao Hospital
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 Cetal.Informa Healthcare,London,UK,2007.
Vascular complications after kidney transplantation
• Arteriovenous fistula
• Pseudoaneurysm• Graft thrombosis• Transplant renal artery stenosis (TRAS)
Seratnahaei A.etal, Angiology;62(3)219-2242011
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
BrunoS,etal.JAmSoc Nephrol 2004;15:134.
Risk factor
• Technical error during harvest or transplantation
• Renal artery atherosclerosis• Neointimal hyperplasia, accelerated atherosclerosis
caused by immunosuppression• Cytomegalovirus infection
• Delayed allograft function
NataliaO.etal,SeminarVasc Surg 26(2013)205-212
Multivariate analysis of factor contributing TRAS
Audard V,Matig,etal.AmJTransplant2006;6:95.
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
BrunoS,etal.JAmSoc Nephrol 2004;15:134.
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
BrunoS,etal.JAmSoc Nephrol 2004;15:134.
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
Classical kidney transplantation surgery
Diagnostic procedures of TRAS
Bruno S et al. J Am Soc Nephrol 2004 ;15 : 134 – 141.
Comparison of imaging in TRAS
W.Chen et al , Clin Kidney J (2015) 8: 71–78
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,etal.Transplantation2009;41:1609–14.
ipsilateraliliacartery
tardus-parvus waveform
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
AslamSetal.Transplantation2001;71:814– 817.
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
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
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
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
Hemodynamic change after PTA
Ruggenenti P. et al Kidney Int 2010; 60:309.
PTA benefit
Seratnahaei A.etal, Angiology,62(3)219-224,2011
PTA lack benefit
Seratnahaei A.etal, Angiology,62(3)219-224,2011
Recanati-MillerTransplantationInstitute,IcahnSchoolofMedicineatMountSinai,NewYork,NY
BMS , DES , PTA alone what is the best
D.M.Biederman etal,AmericanJournalofTransplantation2015;15:1039–1049
• Nosignificantdifferenceinallograftsurvivalat360d
• Patency wassignificantlyhigherinwithDESandBMScomparedtoPTA
• Inpostanastomotic TRASsubtype,patencyratesinDEShighercomparedtoBMS
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
Thank you for your attention