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