Transradial Access for Peripheral and Cerebrovascular Interventions
Renal artery stenting (RAS) has been associated with conflicting results in randomized trials. Nevertheless, the procedure may be effective in selected patients with renal artery stenosis and uncontrolled hypertension and/or renal failure. While RAS is usually performed using TFA and curved guiding catheters, TRA may offer several advantages in this context. For example, in patients with downsloping take-off of the renal arteries, TRA allows for an easier and more stable vessel engagement, thereby reducing the need for catheter manipulations in the aorta and the associated risk of distal embolization, as well as reduced contrast amount. In addition, the favorable support allows the use of standard 0.014″ guidewires, with a reduced risk of perforation of distal renal branches. Finally, direct stenting may be more frequently attempted from this approach, with a reduced risk of renal embolization.
As for other percutaneous interventions, TRA may minimize access-site complications during renal interventions. This observation may be of particular importance in this setting, because as shown in a randomized clinical trial, the favorable effects of RAS at the renal level may be counterbalanced by access-site complications.
How to do Renal Artery Stenting by Transradial Access.Table 2 and Figure 2 illustrate RAS by TRA. Renal arteries are easily cannulated with a standard 100 cm, 6 Fr multipurpose guiding catheter using a left TRA. This catheter usually allows an optimal alignment with the renal arteries in case of downsloping take-off of these vessels. For patients with a horizontal take-off of renal arteries, a 6 Fr Judkins right guiding catheter may be more suitable. Alternatively, a 110 cm-long, 5 Fr sheath with different curve tips may also be used (Flexor Ansel; Cook Medical, Inc). RAS is performed using balloon-expandable stents and most 0.014″-compatible devices fit into 6 Fr guiding catheters and 5 Fr sheaths. In tall patients (>180 cm or 5.9 feet), 6 Fr, 125 cm-long guiding catheters (eg, special catheters by Cordis Corporation) with a plain hemostatic valve (by Cook Medical, Inc or Terumo Corporation) may be required; in that case, stents with a minimum 135 cm shaft length (eg, Herculink Elite by Abbott Vascular) should be used.
(Enlarge Image)
Figure 2.
Bilateral renal artery stenting by transradial access. Renal arteries were cannulated via right transradial access with a 100 cm long, 6 Fr multipurpose guiding catheter (Medtronic). After balloon predilatation, renal artery stenting was successfully performed over a 0.014-inch stiff guidewire (Extra-Sport; Abbott Vascular) with two balloon-expandable stents (Hyppocampus, Medtronic).
Published Reports of Renal Artery Stenting by Transradial Approach. Scheinert et al first published a series of 18 patients with renovascular hypertension treated with RAS by TRA. They reported a 100% success rate without access-site complications. Trani et al, in 62 consecutive, non-randomized patients undergoing RAS, reported no difference in terms of procedural success rate (both 100%) between TRA and TFA, but they had shorter procedural and fluoroscopy times and a trend toward decreased contrast use in the TRA group.
When to Use Transradial Approach for Renal Artery Stenting. Left TRA may be used as a preferred alternative to transbrachial access to treat renal artery stenosis in patients with poor femoral access, but independently of the ease of TFA, the TRA may become the standard approach for RAS, especially in patients with downsloping renal artery take-off.
Percutaneous Interventions of Visceral Arteries. Chronic mesenteric ischemia due to stenosis in the visceral arteries can be a cause of malabsorption and postprandial abdominal pain that is encountered with increased frequency in an aging population. In this high-risk patient group, endovascular treatment is frequently preferred over surgery. The same anatomical arguments favoring TRA for RAS do also apply to visceral artery revascularization. In fact, also visceral vessels often have a downsloping take-off from the aorta and may be better cannulated from the arm than from the leg. Visceral artery can usually be accessed with standard equipment such as a 100 cm multipurpose 6 Fr guiding catheter or a 90 cm 6 Fr sheath (eg, Cook Shuttle) advanced over a 125 cm 5 Fr diagnostic catheter. Preliminary favorable results of angioplasty of visceral arteries using TRA have been reported.
Transradial Access for Percutaneous Interventions of Renal and Visceral Arteries
Renal Artery Stenting
Renal artery stenting (RAS) has been associated with conflicting results in randomized trials. Nevertheless, the procedure may be effective in selected patients with renal artery stenosis and uncontrolled hypertension and/or renal failure. While RAS is usually performed using TFA and curved guiding catheters, TRA may offer several advantages in this context. For example, in patients with downsloping take-off of the renal arteries, TRA allows for an easier and more stable vessel engagement, thereby reducing the need for catheter manipulations in the aorta and the associated risk of distal embolization, as well as reduced contrast amount. In addition, the favorable support allows the use of standard 0.014″ guidewires, with a reduced risk of perforation of distal renal branches. Finally, direct stenting may be more frequently attempted from this approach, with a reduced risk of renal embolization.
As for other percutaneous interventions, TRA may minimize access-site complications during renal interventions. This observation may be of particular importance in this setting, because as shown in a randomized clinical trial, the favorable effects of RAS at the renal level may be counterbalanced by access-site complications.
How to do Renal Artery Stenting by Transradial Access.Table 2 and Figure 2 illustrate RAS by TRA. Renal arteries are easily cannulated with a standard 100 cm, 6 Fr multipurpose guiding catheter using a left TRA. This catheter usually allows an optimal alignment with the renal arteries in case of downsloping take-off of these vessels. For patients with a horizontal take-off of renal arteries, a 6 Fr Judkins right guiding catheter may be more suitable. Alternatively, a 110 cm-long, 5 Fr sheath with different curve tips may also be used (Flexor Ansel; Cook Medical, Inc). RAS is performed using balloon-expandable stents and most 0.014″-compatible devices fit into 6 Fr guiding catheters and 5 Fr sheaths. In tall patients (>180 cm or 5.9 feet), 6 Fr, 125 cm-long guiding catheters (eg, special catheters by Cordis Corporation) with a plain hemostatic valve (by Cook Medical, Inc or Terumo Corporation) may be required; in that case, stents with a minimum 135 cm shaft length (eg, Herculink Elite by Abbott Vascular) should be used.
(Enlarge Image)
Figure 2.
Bilateral renal artery stenting by transradial access. Renal arteries were cannulated via right transradial access with a 100 cm long, 6 Fr multipurpose guiding catheter (Medtronic). After balloon predilatation, renal artery stenting was successfully performed over a 0.014-inch stiff guidewire (Extra-Sport; Abbott Vascular) with two balloon-expandable stents (Hyppocampus, Medtronic).
Published Reports of Renal Artery Stenting by Transradial Approach. Scheinert et al first published a series of 18 patients with renovascular hypertension treated with RAS by TRA. They reported a 100% success rate without access-site complications. Trani et al, in 62 consecutive, non-randomized patients undergoing RAS, reported no difference in terms of procedural success rate (both 100%) between TRA and TFA, but they had shorter procedural and fluoroscopy times and a trend toward decreased contrast use in the TRA group.
When to Use Transradial Approach for Renal Artery Stenting. Left TRA may be used as a preferred alternative to transbrachial access to treat renal artery stenosis in patients with poor femoral access, but independently of the ease of TFA, the TRA may become the standard approach for RAS, especially in patients with downsloping renal artery take-off.
Percutaneous Interventions of Visceral Arteries. Chronic mesenteric ischemia due to stenosis in the visceral arteries can be a cause of malabsorption and postprandial abdominal pain that is encountered with increased frequency in an aging population. In this high-risk patient group, endovascular treatment is frequently preferred over surgery. The same anatomical arguments favoring TRA for RAS do also apply to visceral artery revascularization. In fact, also visceral vessels often have a downsloping take-off from the aorta and may be better cannulated from the arm than from the leg. Visceral artery can usually be accessed with standard equipment such as a 100 cm multipurpose 6 Fr guiding catheter or a 90 cm 6 Fr sheath (eg, Cook Shuttle) advanced over a 125 cm 5 Fr diagnostic catheter. Preliminary favorable results of angioplasty of visceral arteries using TRA have been reported.