Techniques of Renal Arteriography Subhash Banerjee, MD UT 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 n ARAS > 30% (%) ARAS > 50% (%) Bilateral (%) Vetrovec et al, 1989 116 29% 23% Harding et al, 1992 1302 15% 28% Jean et al, 1994 196 33% 18% - Rihal et al, 2002 297 34% 19% Weber-Mzell et al, 2002 177 25% 11% 26% Routine screening for RAS during coronary angiography NOT indicated White et al. Circulation.2006; 114: 1892-1895

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 Renal artery duplex RAS + RAS - Angiography & intervention Technically good study Stop Poor study Angiography MRA or CTA RAS + RAS - Technically good study Stop Poor study Angiography Angiography & intervention Captopril scintigraphy + - Strong clinical suspicion Stop 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

upper poles oriented medially/posteriorly 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