Techniques of Renal Arteriography

Subhash Banerjee, MDUT Southwestern Med. Ctr &

VA North Texas Health care;

Dallas, TX

Indications For Renal Artery Angiography & Revascularization

• Persistent hematuria of unresolved cause

• Detection of renal tumor vacularity, venous invasion embolization

• Suspected renal artery stenosis (RAS)

• Suspected transection of the renal artery (penetrating injury)

• Detection of inflammatory conditions, aneurysm or AVM

• Evaluation of renal vascular anatomy of prospective donors

• Evaluation of postoperative renal transplantation

• Diagnosis of thrombosis revealed by renal venography

• Collection of a sample of blood from the renal vein

Prevalence of Atherosclerotic (A)RAS at Cardiac Catheterization

Study, Year nARAS > 30%

(%)ARAS > 50%

(%)Bilateral

(%)

Vetrovec et al, 1989

116 29% 23% 29%

Harding et al, 1992 1302 29% 15% 28%

Jean et al, 1994 196 33% 18% -

Rihal et al, 2002 297 34% 19% 19%

Weber-Mzell et al, 2002

177 25% 11% 26%

White et al. Circulation.2006; 114: 1892-1895

Routine screening for RAS during coronary angiography NOT indicated

Objectives of Renal Arteriography

• Identify main as well as accessory vesels• Localize site of stenosis or disease• Determine type of disease (atherosclerotic or FMD)• Provide hemodynamic significance• Determine likelihood of a favorable response to

revascularization• Identify associated pathology (aorta, renal mass etc)• Detect restenosis after percutaneous or surgical

revascularization

Proposed Algorithm for Diagnosis of RAS & Renal Artery Angiography

Clinical suspicion of RAS/Indication for Revascularization

Captopril scintigraphy

+ -

Strong clinicalsuspicion

Stop

MRA or CTA

RAS + RAS -

Technically good study

Stop

TechnicallyPoor study

Angiography

Angiography & intervention

Renal artery duplex

RAS + RAS -

Angiography & intervention

Technically good study

Stop

TechnicallyPoor study

Angiography

MRA: magnetic resonance angiography; CTA: Computed tomographic angiography

Adapted from Vascular Medicine by Creager et al

Renal Artery Angiography

• Catheter-based angiography remains the standard

• Digital subtraction angiography (imaging matrix 1024 x 1024; 16” image II)

• Oblique views of the aorta to visualize renal artery origins

• Pressure gradients should also be obtained, whenever feasible

• Imaging hardware and software:

– Bolus chase, rapid image acquisition

– Vessel diameter analysis, regional pixel shifting, image stacking

– 3D reconstruction, angioscopic representation of DSA

• Low osmolar iodinated contrast, gadolinium, CO2 angiography

Renal Anatomy

Between transverse processes of T12-L3, left kidney more superior than right,

upper poles oriented medially/posteriorly

Renal Artery Angiography: Technical Considerations

• Access:– Groin: ideally contra-lateral, long sheaths– Brachial: caudally angulated, aorto-iliac disease

• Flush aortography with multi-side hole catheter (L1-L2)• Prior to selective renal artery catheterization an aortogram must be

performed• Anterio-posterior & oblique views (visualization of renal artery origins)

– Right: RAO 10ο-20ο, LAO 10ο

– Left: LAO 0ο-15ο

• Selective angiography of renal arteries– Shaped sheaths– Guiding catheters (Soft tip Omni, Cobra 2, Simmons, RDC etc)– Support guide-wire within aorta

• Trans-lesional gradient (catheter, pressure wire)

Non-selective Renal Angiogram: Early Division of Right Renal Artery

Renal Angiography and Intervention: Transfemoral approach

Renal Artery Stenosis & Complex Aortoiliac Disease

Renal Artery Angiography: Brachial Approach

• Complications lower with femoral route• Left brachial approach:

– Acute caudal angulation – Inability to engage with reverse curve catheters– Aorto-iliac PAD– Infrarenal abdominal aneurysm– graft in the femoral region– rigid (non-elastic) arteries, tight calcified stenoses– dilated abdominal aorta

• Complications with brachial approach greater – In patients with a small or diseased brachial artery– When a 7 French or larger sheath is required

• Use of a multipurpose catheter from left brachial approach• Radial artery approach might be preferable over brachial because (lower complication &

higher patient satisfaction)– Long sheaths and guidewires– Problems with catheter pushability & guidewire torque control– Sheath size is usually limited to 6 French

Hessel et al. Radiology 1981; 138:273-281 Scheinert et al. Catheter Cardiovasc Interv 2001; 54:442-447

Renal Artery Angiography: Translesional Gradient

• RAS less than 50% in diameter are not significant • “Gray zone” (50-70% diameter stenosis)• Four French (1.35mm) catheter across 4 mm renal artery• Pressure guide wire system• Thermodilution technique to measure flow (Angioflow) • Change in SBP could be a source of uncertainty:

– When gradient is small– Simultaneous recording in the renal artery & aorta is preferable

• 20 mm or greater systolic gradient results from a significant stenosis

• 10% peak systolic gradient or >5% difference in MAP

B. De Bruyne et al. JACC, Volume 48, Issue 9, Pages 1851-1855

Renal Artery Angiography

• Anatomic variations in the renal vasculature occur in approximately 25-40% of patients

• Accessory, renal arteries are the most common arterial variation, with most of these branches supplying the lower pole of the kidney

• Kidney position in the retroperitoneum is subject to variation as well

Non-selective Renal Angiogram: Aberrant Renal Artery Below Right Renal Artery

Non-selective Renal Angiogram: Accessory Renal Artery Below Right Renal Artery

Non-selective & Selective Renal Angiography

Accessory renal artery Aberrant renal artery

Renal Arteriography• Conclusions:

– Careful patient selection – Careful pre-procedural preparation & planning– Start with flush aortography– Selective renal arteriography– Anticoagulation primarily with UFH– Brachial/radial arterial access for challenging

anatomy– Translesional gradient assessment of

intermediate stenoses (with pressure wire)

Clinical Clues to the Diagnosis of Renal Artery Stenosis (RAS)

• Onset of HTN <30y or severe hypertension at >55y (Class I; LOE B)

• Accelerated, resistant, or malignant hypertension (Class I: LOE C)

• Unexplained atrophic kidney/size discrep. >1.5 cm (Class I; LOE B)

• Sudden, unexplained pulmonary edema (Class I; LOE B)

• Unexplained renal dysfunction (Class IIa; LOE B)

• Development of new azotemia or worsening renal function after

administration of an ACE inhibitor or ARB agent (Class I; LOE B)

• Multivessel CAD or PAD (Class IIb; LOE B)

• Unexplained CHF or refractory angina (Class IIb; LOE C)

White et al. Circulation.2006; 114: 1892-1895