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RenovascularRenovascularhhypertensionypertension UpdateUpdate

Seminars in Hypertension Seminars in Hypertension ManagementManagement

Dr Jonathan C.U. YUNGDr Jonathan C.U. YUNG24/11/200624/11/2006

IImportant correctable cause of mportant correctable cause of secondary HTsecondary HT

�� <1% <1% in mild elevations of BPin mild elevations of BP•• RenalRenal--artery artery stenosisstenosis. . SafianSafian RD; RD; TextorTextor SC N SC N EnglEngl

J Med 2001 Feb 8;344(6):431J Med 2001 Feb 8;344(6):431--4242

�� 1010--45% acute, severe, refractory HT45% acute, severe, refractory HT•• Detection of Detection of renovascularrenovascular hypertension. State of the hypertension. State of the

art: 1992. Mann SJ; Pickering TG. Ann Intern Med art: 1992. Mann SJ; Pickering TG. Ann Intern Med 1992 Nov 15;117(10):8451992 Nov 15;117(10):845--53.53.

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Clinical:Clinical:�� Early Age of OnsetEarly Age of Onset <30 years of age<30 years of age

�� Late Onset Late Onset >55yrs with severe HT>55yrs with severe HT

�� Refractory/ Resistant HT despite medicationRefractory/ Resistant HT despite medication > 3 anti HT medications> 3 anti HT medications

�� Acute rise BP in previously stable Acute rise BP in previously stable hypertensiveshypertensives

�� Malignant HTMalignant HT

�� Acute elevation in Cr after ACEI/ARBAcute elevation in Cr after ACEI/ARB

�� Severe HT with recurrent Flash pulmonary Severe HT with recurrent Flash pulmonary oedemaoedema

�� Abdominal bruit Abdominal bruit localisedlocalised to one sideto one side

CausesCauses

��FibromuscularFibromuscular dysplasiadysplasia (FMD)(FMD)

��AtherosclerosisAtherosclerosis

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FibromuscularFibromuscular dysplasiadysplasia(FMD)(FMD)

��noninflammatorynoninflammatory, , nonatheroscleroticnonatheroscleroticdisorder leading to arterial disorder leading to arterial stenosisstenosis

��occurs in every arterial bedoccurs in every arterial bed��Renal 60Renal 60--75%75%

��Internal CarotidsInternal Carotids

Clinical:Clinical: (FMD)(FMD)

�� F>M= 10:1F>M= 10:1

�� Age <50yrAge <50yr

�� accounts for 105% of accounts for 105% of renovascularrenovascular HTHT

�� Bilateral disease in 50%Bilateral disease in 50%

�� HTHT

�� progressive worsening of renal function is progressive worsening of renal function is relatively rare.relatively rare.�� usually occurs in usually occurs in intimalintimal / / perimedialperimedial FMDFMD

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AtherosclerosisAtherosclerosis

��accounts for 5accounts for 5--22% of CRF in 22% of CRF in age>50yrsage>50yrs

��associated with systemic associated with systemic atherosclerosisatherosclerosis

��44--5x higher rates of coronary , 5x higher rates of coronary , cerebrovascularcerebrovascular, peripheral arterial , peripheral arterial and heart failure ratesand heart failure rates

How common is the How common is the problem?problem?

��4000 4000 patientspatients

��abdominal abdominal aortographyaortography immediately immediately after coronary angiographyafter coronary angiography

��Conlon PJ et al Conlon PJ et al Severity of renal vascular disease Severity of renal vascular disease predicts mortality in patients undergoing coronary predicts mortality in patients undergoing coronary angiography, KI 2001 Oct; 60(4):1490angiography, KI 2001 Oct; 60(4):1490--77

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Incidental RAS:Incidental RAS:

�� >=50%>=50% lesionlesion�� 9.1%9.1%

�� >=75%>=75% lesionlesion�� 4.8%4.8%

�� significantly associated with reduction in significantly associated with reduction in survival ( 57% survival ( 57% vsvs 89% ) 89% )

�� BilateralBilateral�� 0.8%0.8%

ProgressionProgression of of AtherosclerosisAtherosclerosis

How fast?How fast?

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Prospective study of Prospective study of atherosclerotic disease atherosclerotic disease progression in the reprogression in the rennal al

arteryartery

Caps MT et al Circulation 1998 Caps MT et al Circulation 1998 Dec 22Dec 22--29;98(25):286629;98(25):2866--7272

Follow up duplex US of Follow up duplex US of 295 kidneys over295 kidneys over 33 33

monthsmonths

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cumulative incidence of cumulative incidence of progression at 3 yrs:progression at 3 yrs:

�� < 60% < 60% stenosisstenosis�� 28%28%

�� > 60% > 60% stenosisstenosis�� 49%49%

�� complete occlusion occurred only in 3% complete occlusion occurred only in 3% casescases

TestsTests

��Renal Renal arteriographyarteriography

��Magnetic Resonance AngiographyMagnetic Resonance Angiography

��Computer Computer TomographicTomographicAngiographyAngiography

��Duplex Doppler Duplex Doppler UltrasonographyUltrasonography

��OthersOthers

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Renal Renal arteriographyarteriography

Gold StandardGold Standard

Magnetic Resonance Magnetic Resonance AngiographyAngiography

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MRA: MRA: Newer studies: Newer studies:

�� Sensitivity 100%Sensitivity 100%�� Specificity71Specificity71-- 96%96%�� Technical improvements continue:Technical improvements continue:

�� the use of breaththe use of breath--hold MR angiography with hold MR angiography with paramagnetic contrast material, paramagnetic contrast material, gadopentategadopentatedimegluminedimeglumine, substantially improves the ability to , substantially improves the ability to visualize some (but not all) accessory arteries visualize some (but not all) accessory arteries

•• Magnetic resonance angiography has a high reliability in Magnetic resonance angiography has a high reliability in the detection of renal artery the detection of renal artery stenosisstenosis. . PostmaPostma CT; CT; JoostenJoostenFB; FB; RosenbuschRosenbusch G; G; ThienThien TT.. Am J Am J HypertensHypertens 1997 1997 Sep;10(9 Pt 1):957Sep;10(9 Pt 1):957--63.63.

Computer Computer TomographicTomographicAngiographyAngiography

�� combines diagnostic accuracy of combines diagnostic accuracy of arteriographyarteriography with low risk of IV DSAwith low risk of IV DSA

�� Accuracy lowers when serum Cr > Accuracy lowers when serum Cr > 150umol/L 150umol/L �� due to reduced renal blood flowdue to reduced renal blood flow

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Duplex Doppler Duplex Doppler UltrasonographyUltrasonography

�� Provides Both anatomical and functional Provides Both anatomical and functional assessment of renal arteriesassessment of renal arteries

�� possible to detect bilateral disease or possible to detect bilateral disease or recurrent diseaserecurrent disease

�� Problems:Problems:�� time consumingtime consuming

�� very operator dependentvery operator dependent

Other tests:Other tests:

�� Plasma Plasma ReninRenin

�� elevated in 50elevated in 50--80% cases80% cases

�� CaptoprilCaptopril RenogramRenogram

�� ACEI induced decline in GFR in ACEI induced decline in GFR in stenoticstenotic kidneykidney

�� 2005 ACC/AHA guidelines: no longer used as 2005 ACC/AHA guidelines: no longer used as screening testscreening test

�� IVPIVP

�� decrease in renal sizedecrease in renal size

�� delayed delayed calicealcaliceal appearance timeappearance time

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TreatmentTreatment

��Unilateral Unilateral vsvs Bilateral RASBilateral RAS

��Atherosclerosis Atherosclerosis vsvs FMDFMD

Bilateral RASBilateral RAS

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Indication:Indication:

�� hemodynamicallyhemodynamically significant significant stenosisstenosis

�� Both vessels showing >75% Both vessels showing >75% stenosisstenosis

3 3 Modalities:Modalities:

�� AntiAnti--HT medicationsHT medications

�� PercutaneousPercutaneous angioplastyangioplasty

�� SurgerySurgery

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Anti HT medicationsAnti HT medications

ACEI/ARB +/ACEI/ARB +/-- HCTZHCTZ

�� bilateral renal bilateral renal ischaemiaischaemia induces activation of RASinduces activation of RAS

�� Na+ expansionNa+ expansion

�� Volume expansionVolume expansion

�� But: But: hemodynamicallyhemodynamically mediated decline in GFRmediated decline in GFR

�� Rise in CrRise in Cr

�� Can you have both BP control and stable renal function?Can you have both BP control and stable renal function?

�� Would Would normalisationnormalisation of BP lead to long term of BP lead to long term ischaemicischaemic atrophy?atrophy?

�� Atherosclerotic lesions do progress Atherosclerotic lesions do progress

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Ca channel BlockersCa channel Blockers

�� dilates dilates preafferentpreafferent arteriolearteriole

�� easier to maintain serum Creasier to maintain serum Cr

�� ??�� some animal studies suggest that calcium some animal studies suggest that calcium

channel blockade may not protect the channel blockade may not protect the stenoticstenotickidney and may worsen the hypertensive kidney and may worsen the hypertensive injury in the injury in the nonstenoticnonstenotic kidney when kidney when compared to ACE inhibitioncompared to ACE inhibition

Beta BlockersBeta Blockers

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Risk factor reductionRisk factor reduction

PercutaneousPercutaneous angioplasty+ angioplasty+ stentstent placementplacement

�� Predictive factors for benefit:Predictive factors for benefit:�� High systolic BPHigh systolic BP

�� Renal insufficiencyRenal insufficiency

•• Renal artery angioplasty and Renal artery angioplasty and stentstent placement: placement: predictors of a favorable outcome. predictors of a favorable outcome. BurketBurket MW; MW; Cooper CJ; Kennedy DJ; Brewster PS; Cooper CJ; Kennedy DJ; Brewster PS; AnselAnsel GM; GM; Moore JA; Moore JA; VenkatesanVenkatesan J; J; HenrichHenrich WLWL.. Am Heart J Am Heart J 2000 Jan;139(1 Pt 1):642000 Jan;139(1 Pt 1):64--71.71.

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SurgerySurgery

��RevascularisationRevascularisation

��NephrectomyNephrectomy for nonfunctioning, for nonfunctioning, atrophic kidneyatrophic kidney

2005 2005 ACC/AHA guidelines:ACC/AHA guidelines:

�� surgery in patients with atherosclerotic renal surgery in patients with atherosclerotic renal artery artery stenosisstenosis who have indications for who have indications for revascularization and have multiple small revascularization and have multiple small renal arteries or require aortic reconstruction renal arteries or require aortic reconstruction near the renal arteries for other indications near the renal arteries for other indications ((egeg, aneurysm repair or severe , aneurysm repair or severe aortoiliacaortoiliacocclusive disease)occlusive disease)

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Unilateral RASUnilateral RAS

Medical therapyMedical therapy

�� indicated in all patientsindicated in all patients�� ACEI/ARB +/ACEI/ARB +/-- HCTZHCTZ�� Ca channel BlockersCa channel Blockers�� Beta BlockersBeta Blockers

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Problems with Medical therapy:Problems with Medical therapy:

�� progressive progressive StenosisStenosis�� 3030--60% increase in 60% increase in stenosisstenosis within 4within 4--7 years7 years

�� Atherosclerosis> Atherosclerosis> fibromuscularfibromuscular dysplasiadysplasia

�� Long term Long term ischaemicischaemic loss of renal massloss of renal mass

PercutaneousPercutaneousAngioplastyAngioplasty

��success rate dependent on:success rate dependent on:

��site of lesionsite of lesion

��pathologypathology

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Site of lesion:Site of lesion:

�� Best: incomplete occlusion in the main renal Best: incomplete occlusion in the main renal arteryartery

�� Poor: total occlusions / Poor: total occlusions / ostialostial lesionslesions

pathology:pathology:

�� atherosclerosisatherosclerosis�� cure rates: 8cure rates: 8--20%20%

�� 2 year 2 year restenosisrestenosis: 8: 8--30%30%

�� fibromuscularfibromuscular dysplasiadysplasia�� cure rates : 50cure rates : 50--85%85%

�� 2 year 2 year restenosisrestenosis: <10%: <10%

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PercutaeousPercutaeous Angioplasty + Angioplasty + StentingStenting

�� recommended in recommended in ostialostial atherosclerotic atherosclerotic lesionslesions

�� long term benefits long term benefits awaitawait further trialsfurther trials

SurgerySurgery

�� Bypassing Bypassing stenoticstenotic segmentsegment

�� NephrectomyNephrectomy of small atrophic kidneyof small atrophic kidney

�� Predictor of clinical response Predictor of clinical response ( ( normalisationnormalisation of BP):of BP):�� <5 yr history of HT<5 yr history of HT

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�� Mr. CheungMr. Cheung

�� 51/M 51/M

�� HTHT

�� ESRF of unknown cause.ESRF of unknown cause.

�� USG: bilateral small kidney.USG: bilateral small kidney.

�� CAPD started on 11/2002.CAPD started on 11/2002.

�� CadavericCadaveric renal transplant on 26/12/2002.renal transplant on 26/12/2002.

�� Urine output right away according patientUrine output right away according patient

�� no HD/CAPD done after OTno HD/CAPD done after OT

�� Best Cr Best Cr 118118 umolumol/L/L

�� other details unknownother details unknown

�� discharge from hospital D20discharge from hospital D20

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�� no particular c/o no particular c/o

�� good urine outputgood urine output

�� BP150/95 mmHgBP150/95 mmHg

�� wound healing wellwound healing well

�� graft :graft :nontendernontender..

�� urine urine dipstixdipstix: Alb 1+/RBC : Alb 1+/RBC --veve

seen in transplant clinic on seen in transplant clinic on 29/1/200329/1/2003

�� Cyclosporine A 200mg BDCyclosporine A 200mg BD

�� PrednisolonePrednisolone 20mg daily20mg daily

�� MMF 500mg MMF 500mg bdbd

�� Acyclovir 200mg Acyclovir 200mg tdstds

�� BetalocBetaloc 25mg 25mg bdbd

Medications:Medications:

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05/02/200305/02/2003

�� SeptrinSeptrin 480mg daily was added480mg daily was added

�� BetalocBetaloc was changed to was changed to DiltiazemDiltiazem

2/20032/2003--5/20035/2003

�� Cr 135Cr 135�� 133133��122122�� 132 132 umoLumoL

�� BP 16/4/2003: 151/91 mmHgBP 16/4/2003: 151/91 mmHg�� 21/5/2003: 174/110 mmHg21/5/2003: 174/110 mmHg�� 26/5/2003: 178/86 mmHg26/5/2003: 178/86 mmHg

�� ↑↑dosage of dosage of aldometaldomet , , diltiazemdiltiazem and and betalocbetaloc

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�� Doppler USG of graft Kidney(17/6): normal Doppler USG of graft Kidney(17/6): normal echogenicityechogenicity with preserved with preserved corticocortico--medullarymedullarydifferentiation. Doppler findings are differentiation. Doppler findings are unremarkable with RI of unremarkable with RI of interlobarinterlobar arteriesarteriesranges from 0.58 to 0.61. Graft kidney was 10.5 ranges from 0.58 to 0.61. Graft kidney was 10.5 cm in length.cm in length.

�� Cr ~153 on 23/6/2005 (~120Cr ~153 on 23/6/2005 (~120--150)150)

�� C/O ankle edema C/O ankle edema

�� stopped stopped septrinseptrin /acyclovir//acyclovir/diltiazemdiltiazem

�� RamiprilRamipril ++BetalocBetaloc+ + AldometAldomet on 25/6/2003 on 25/6/2003

�� postpost--renal transplant 6mthrenal transplant 6mth�� C/O C/O GeneralisedGeneralised oedema, oedema,

�� decrease urine output.decrease urine output.

�� no other urinary symptomsno other urinary symptoms

�� not on herbs/NSAIDnot on herbs/NSAID

Clinical admission on 1/7/2003 for Clinical admission on 1/7/2003 for abnormal RFTabnormal RFT

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�� BP 154/80mmHgBP 154/80mmHg

�� euvolumiceuvolumic

�� afebrileafebrile

�� Urine Urine multistixmultistix: RBC 1+, albumin 1+: RBC 1+, albumin 1+

�� no graft tendernessno graft tenderness

�� Cr: 1031Cr: 1031�� WCC 5.1, WCC 5.1, HbHb 11.6, platelet 133.11.6, platelet 133.

�� MUS: no growthMUS: no growth

�� CMV pp65 CMV pp65 antigenaemiaantigenaemia: : --veve

USG AbdomenUSG Abdomen

�� USG of USG of abdabd: transplant kidney over right : transplant kidney over right iliac iliac fossafossa with normal size and outline , with normal size and outline , 10.3 cm in length. No definite 10.3 cm in length. No definite perinephricperinephricfluid collection is seen. fluid collection is seen. PelvicalycealPelvicalycealsystem is not dilated . No renal stone of system is not dilated . No renal stone of renal mass is noted. Main renal vein is renal mass is noted. Main renal vein is patent. Sampling of intrapatent. Sampling of intra--renal vascular renal vascular resistance within normal limit (RI 0.6resistance within normal limit (RI 0.6--0.7)0.7)

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�� Renal Renal BxBx

�� 1)consistent with borderline acute cellular 1)consistent with borderline acute cellular rejection.rejection.

�� 2)Features suggestive of mild ATN2)Features suggestive of mild ATN

�� 3)Presence of CMV virus inclusions within 3)Presence of CMV virus inclusions within renal tubules.renal tubules.

�� 3x pulse methyprednisolone was given3x pulse methyprednisolone was given

�� Increase Increase prednisoloneprednisolone to 40mg daily.to 40mg daily.

�� 2/52 Iv ganciclovir was started2/52 Iv ganciclovir was started

�� Put on IPDPut on IPD

�� Cr level:1031> 669Cr level:1031> 669-->400>400

�� Increase of urine output 1Increase of urine output 1--1.5 L per day 1.5 L per day plan:plan:�� 1)outpatient IV 1)outpatient IV ganciclovirganciclovir

�� 2)Captopril DTPA scan to R/O RAS after RFT 2)Captopril DTPA scan to R/O RAS after RFT stablizedstablized

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�� Urine output increased to 1Urine output increased to 1--1.5 L daily1.5 L daily�� Cr further improve 400Cr further improve 400-->277>277-->>185185

�� CaptoprilCaptopril RenogramRenogram: DTPA prompt : DTPA prompt perfusion of the graft kidney, perfusion of the graft kidney, renogramrenogramreach its peak within 3.5 minutes, tracer reach its peak within 3.5 minutes, tracer washout is satisfactorywashout is satisfactoryConclusion: Conclusion: no evidence of RASno evidence of RAS

77--8/2003:8/2003:

�� C/O Decreased of urine output again.C/O Decreased of urine output again.

�� Cr 169(14/8)Cr 169(14/8)-->465(21/8)>465(21/8)-->>648648(22/8)(22/8)

�� Doppler US 23/8/03: In anastomotic site, Doppler US 23/8/03: In anastomotic site, arterial flow shows high resistance flow (RI arterial flow shows high resistance flow (RI 1.2)with increase peak systolic velocity 1.2)with increase peak systolic velocity (~330m/s). However, main renal art and (~330m/s). However, main renal art and intraloberintralober renal art show lowrenal art show low--resistant flow resistant flow with RI<0.7 with RI<0.7

22/8/200322/8/2003

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�� 29/8: renal bx: Some tubules suggestive 29/8: renal bx: Some tubules suggestive degenerative and regenerative change. degenerative and regenerative change. The glomeruli , capillaries , mesangium The glomeruli , capillaries , mesangium and capsules are unremarkable. IF and capsules are unremarkable. IF microscopy show no deposits. Features microscopy show no deposits. Features are suspicious of ATN.are suspicious of ATN.

�� Cr Cr 10651065�� Put on APDPut on APD

�� MRI angiogram on 8/9/03: highly MRI angiogram on 8/9/03: highly suggestive of underlying renal artery suggestive of underlying renal artery stenosis at the site of renal artery stenosis at the site of renal artery anastomosisanastomosis..

�� Renal angiogram +angioplasty performed Renal angiogram +angioplasty performed on 15/9/03on 15/9/03

MRI AngiographyMRI Angiography

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�� Cr 896(12/9)Cr 896(12/9)-->336(15/9)>336(15/9)-->199(25/9)>199(25/9)-->>134134(9/10)(9/10)

�� AAnti HT medication reduced to nti HT medication reduced to DiltiazemDiltiazemSR 90mg dailySR 90mg daily

�� BP 135/85mmHgBP 135/85mmHg

ProgressProgress

Thank YouThank You

Dr Jonathan C. U. YUNGDr Jonathan C. U. YUNG

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Transplant Renal artery Transplant Renal artery stenosis(TRAS)stenosis(TRAS)

�� Relatively frequent cause of refractory HT and Relatively frequent cause of refractory HT and allograft dysfunction in renal transplant patientsallograft dysfunction in renal transplant patients

�� it is important because it is potentially curableit is important because it is potentially curable

�� incidence rates vary from 1%to 23%.incidence rates vary from 1%to 23%.�� Different techniques used in diagnosis Different techniques used in diagnosis

Most frequent presentation:Most frequent presentation:

�� Increasingly severe HT with/without allograft Increasingly severe HT with/without allograft dysfunction, between 3 months to 2 yrs after dysfunction, between 3 months to 2 yrs after TxTx, , (but can present at any time after transplantation)(but can present at any time after transplantation)

�� use of ACEI may produce dramatic presentationuse of ACEI may produce dramatic presentation�� rapid deterioration of RFT, or event acute renal rapid deterioration of RFT, or event acute renal

failure, severe hypotension failure, severe hypotension

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Causes Causes �� Technical causeTechnical cause

�� trauma (e.g clamping, trauma (e.g clamping, cannulationcannulation, traction ) , traction ) to donor or recipient art during procurement or to donor or recipient art during procurement or transplantationtransplantation

�� suture techniquesuture technique•• TRAS has been more commonly observed after TRAS has been more commonly observed after

endend--toto--end arterial end arterial anastomosisanastomosis espesp when when endarterectomyendarterectomy is required to render the is required to render the hypogastrichypogastric art suitable for use.art suitable for use.

•• TRAS is rare when a Carrel patch of the donor TRAS is rare when a Carrel patch of the donor aorta is used for endaorta is used for end--toto-- side side anastomosisanastomosis to the to the external iliac art. external iliac art.

�� Immunologic causeImmunologic cause�� rabbit arterial endothelium exposed to rabbit arterial endothelium exposed to xenoxeno

and and alloantibodiesalloantibodies developed developed intimalintimalproliferationproliferation

�� in humans, histological changes (extensive in humans, histological changes (extensive fibrous endarteritis and fibrous endarteritis and intimalintimal proliferation) in proliferation) in the the stenosedstenosed arteries strikingly similar to arteries strikingly similar to vascular lesions of renal allograft rejectionvascular lesions of renal allograft rejection

�� However, a similar incidence of TRAS in HLAHowever, a similar incidence of TRAS in HLA--identical livingidentical living--related donor grafts has also related donor grafts has also been found.been found.

�� Immunologic factors may not be the major Immunologic factors may not be the major etiologic determinant etiologic determinant

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�� CyclosporinCyclosporin AA�� cases report that TRAS completely resolved cases report that TRAS completely resolved

after the withdrawal of after the withdrawal of cyclosporincyclosporin

DiagnosisDiagnosis

�� Presence of renal bruitPresence of renal bruit

-- indicate increased vascular turbulence, indicate increased vascular turbulence, lack both sensitivity and specificity for lack both sensitivity and specificity for TRASTRAS

-- TRAS can be presence with no audible TRAS can be presence with no audible bruitbruit

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�� Plasma Plasma reninrenin activityactivity�� renal renal hypoperfusionhypoperfusion induced induced reninrenin production from production from

justaglomerularjustaglomerular cellscells�� result is hard to analysis due to influences from result is hard to analysis due to influences from

antihypertensive used and patients native kidneysantihypertensive used and patients native kidneys�� selective venous sampling (from the vena cava, the selective venous sampling (from the vena cava, the

infrainfra-- and supra renal iliac and renal veins) with with and supra renal iliac and renal veins) with with without without captoprilcaptopril augmentaitonaugmentaiton increases the specificityincreases the specificity

�� Disadvantages: expensive, invasive, requires meticulous Disadvantages: expensive, invasive, requires meticulous technique (technique (espesp in handling and labeling of samples), in handling and labeling of samples), results are not readily availableresults are not readily available

�� Radiological imagingRadiological imaging�� Duplex and colorDuplex and color--flow Doppler USGflow Doppler USG

•• highly sensitivehighly sensitive

•• noninvasive noninvasive

•• useful for screeninguseful for screening•• intrarenalintrarenal resistant index (RI): calculated from the signals of resistant index (RI): calculated from the signals of

the segmental renal arteries, can detect RAS with a the segmental renal arteries, can detect RAS with a sensitivity of 70% to 93% and a specificity of 90% to 96%sensitivity of 70% to 93% and a specificity of 90% to 96%

•• 1010--20% rate of failure20% rate of failure

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�� Spiral CT angiogramSpiral CT angiogram•• provide satisfactory 3provide satisfactory 3--dimensional reconstruction dimensional reconstruction

of vessels and requires less IV contrast then of vessels and requires less IV contrast then conventional angiographyconventional angiography

�� MRI angiogramMRI angiogram•• mainly the 1st 3cm of the renal art can be mainly the 1st 3cm of the renal art can be

visualized with accuracy and excessive motion visualized with accuracy and excessive motion artifact may encounter artifact may encounter

�� Isotopic Isotopic renographyrenography performed before and performed before and after a dose of after a dose of captoprilcaptopril�� reported sensitivity of 75% and specificity of reported sensitivity of 75% and specificity of

67%67%

�� however, it is highly predictive of however, it is highly predictive of physiologically significant renal art physiologically significant renal art stenosisstenosis

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Digital subtraction angiographyDigital subtraction angiography

�� Gold standard for diagnosis of TRASGold standard for diagnosis of TRAS

�� To evaluate the extent of intrarenal vascular To evaluate the extent of intrarenal vascular disease and the dimensions of the kidneys.disease and the dimensions of the kidneys.

�� Diagnostic in 93% of caseDiagnostic in 93% of case

�� Invasive, contrast nephropathy.Invasive, contrast nephropathy.

--Low or isoLow or iso--osmolar contrast for normal renal functionosmolar contrast for normal renal function

--CO2 angiography for renal insufficiency CO2 angiography for renal insufficiency

�� Reserved for patients with features that are Reserved for patients with features that are compatible with TRAScompatible with TRAS

TreatmentTreatment

1)1) Conservative treatmentConservative treatment

2)2) Percutaneous transluminal renal Percutaneous transluminal renal angioplastyangioplasty

3)3) Surgical correctionSurgical correction

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�� Conservative treatmentConservative treatment�� spontspont regression of TRAS has been described regression of TRAS has been described

�� most patients experience poorly controlled most patients experience poorly controlled hypertension and worsening allograft functionhypertension and worsening allograft function

�� HemodynicallyHemodynically significant significant stenosisstenosis (>70% (>70% stenosisstenosis, pressure gradient >15mmHg) are , pressure gradient >15mmHg) are likely to produce impaired function and have a likely to produce impaired function and have a tendency to progress with a substantial risk of tendency to progress with a substantial risk of graft lossgraft loss

PTRAPTRA

�� Technical success rate is over 80%.Technical success rate is over 80%.�� BP control improved over 75 %and renal BP control improved over 75 %and renal

function stabilized or improved in over 80%.function stabilized or improved in over 80%.

�� A 60 % failure rate reported in those patients A 60 % failure rate reported in those patients with arterial kinkingwith arterial kinking

�� Complication such as arterial Complication such as arterial rupture,dissection and thrombosis occurs rupture,dissection and thrombosis occurs at rate of 10% at rate of 10%

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�� RestenosisRestenosis rate range of 10% to 33%.rate range of 10% to 33%.

�� PTRA is repeatable and a repeat PTRA is repeatable and a repeat procedure can maintain longprocedure can maintain long--term term improvementimprovement

�� Metallic Metallic stentsstents have been used recently to have been used recently to treat recurrent TRAStreat recurrent TRAS

�� In general, PTRA is recommend as the In general, PTRA is recommend as the intervention of 1st choice for TRAS that intervention of 1st choice for TRAS that are short and linear are short and linear

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Surgical correctionSurgical correction

�� Resection and Resection and revisonrevison of of anastomosisanastomosis, , saphenoussaphenous vein bypass graft of the vein bypass graft of the stenoticstenotic segment, patch graft, localized segment, patch graft, localized endarterectomyendarterectomy

�� Difficult operation and technically Difficult operation and technically demandingdemanding

�� High success rate 65High success rate 65--95%, 95%,

�� Recurrent rate of approximately 12%.Recurrent rate of approximately 12%.

�� A significant risk of graft loss (15A significant risk of graft loss (15--20%), 20%), ureteralureteral injury(14%) , injury(14%) , reoperationreoperation (13%) (13%) and mortality (5%).and mortality (5%).

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SummarySummary

�� 1) TRAS should be considered in any 1) TRAS should be considered in any patients who has severe hypertension or patients who has severe hypertension or unexplained deterioration in renal function unexplained deterioration in renal function at any time after transplantation at any time after transplantation

�� 2) Several imaging techniques are 2) Several imaging techniques are available to confirm the diagnosis and their available to confirm the diagnosis and their use will depend , in part, on the center use will depend , in part, on the center experience experience

�� 3)PTRA is the 1st choice of intervention if 3)PTRA is the 1st choice of intervention if neededneeded