Learning from the Left Quicker for Radial Procedures

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The learning curve for performing transradial coronary procedures via left radial access is shorter than that for right radial access, allowing inexperienced practitioners to more quickly achieve fluoroscopy times similar to those of senior operators, according to a report published online May 2, 2011, ahead of print in the American Journal of Cardiology. The researchers note that based on the results, an initial left-handed approach may be best for transradial training programs.

For the TALENT (Transradial Approach [Left vs. Right] and Procedural Times During Percutaneous Coronary Procedures) study, researchers led by Alessandro Sciahbasi, MD, of Policlinico Casilino (Rome, Italy), randomized 1,467 patients undergoing transradial diagnostic coronary angiography at 2 Italian hospitals to receive the procedure from 1 of 6 fellow trainees (n = 532) or 1 of 10 senior operators (n = 935). The physicians in each group were subsequently randomized to either a left- or right-handed radial approach. The learning curve for the fellow operators was assessed by analyzing outcomes in 3 stages of procedure volume: 0 to 100, 101 to 200, and more than 200.

A 5-Fr or 6-Fr sheath was used in all cases, and radial procedures were performed using a hydrophilic guidewire and hydrophilic sheath (Radifocus and Introducer II, respectively; Terumo, Tokyo, Japan). Judkins curve catheters were used for catheterization of the right and left coronary arteries.

During the study, a progressive reduction in fluoroscopy time (primary endpoint) was observed over the 3 stages of the learning curve for fellows training with the left radial approach. There were also decreases in radiation dose (dose-area product), radial cannulation time, and contrast dose, though the last measure did not reach statistical significance (table 1).

Table 1. Learning Curve: Left Radial Approach


0 to 100 Procedures
(n = 100)

101 to 200 procedures
(n = 100)

> 200 Procedures
(n = 72)

P Value

Fluoroscopy Time, sec





Dose-Area Product, Gy/cm2




< 0.001

≤ 3-min Radial Cannulation Time





Contrast Dose, mL

85.6 ± 48

74.5 ± 31

74.4 ± 32


For fellows training with the right radial approach, only cannulation time showed a significant reduction over the learning curve (table 2).

Table 2. Learning Curve: Right Radial Approach


0 to 100 Procedures
(n = 100)

101 to 200 procedures
(n = 100)

> 200 Procedures
(n = 60)

P Value

Fluoroscopy Time, sec





Dose-Area Product, Gy/cm2





≤ 3-min Radial Cannulation Time




< 0.001

Contrast Dose, mL

89.2 ± 31

88.2 ± 50

90.8 ± 57


For senior operators, fluoroscopy time remained consistent over time with either right radial or left radial procedures. For fellows and senior operators practicing the left radial approach, fluoroscopy times were almost the same by the end of the learning curve. However, right radial fluoroscopy times for fellows continued to exceed those of senior operators over the course of the learning curve.

The rate of crossover to the femoral approach was low (n = 4; 0.8%), with only 2 cases each in the left and right radial groups. There were no major vascular complications with either approach.

“[W]e observed a shorter need for training time for the [left radial approach] compared to the [right radial approach],” the researchers conclude. “In the left approach, a progressive and rapid reduction in fluoroscopy time was observed in the fellow group.”

Tortuosity, Catheters Make Right More Difficult

The researchers offer 2 explanations for the results. First, there was a higher incidence of subclavian tortuosity with the right radial approach (38 cases vs. 20 cases for the left radial approach; P = 0.007), potentially prolonging the procedure due to the increased difficulty of catheter manipulation, which may be particularly troublesome for less-experienced operators. Second, Judkins preshaped, curved catheters were used for the procedures. These are expressly designed for the transfemoral approach and therefore are more easily adapted to the left radial approach because of the direct access to the left coronary ostia that route enables.

“As operator experience increases over time, these difficulties are overcome, and as previously shown, expert operators do not show significant differences in fluoroscopy time between the [right radial approach] and the [left radial approach],” Dr. Sciahbasi and colleagues write.

“The message is very clear here,” James Tift Mann III, MD, of Wake Heart and Vascular Associates (Raleigh, NC), told TCTMD in a telephone interview. “And I think it’s a good lesson, that it may well be easier when you’re starting to do radial procedures to go from the left radial.”

Left as Good as Right with Experience

He echoed the investigators’ explanations for the difference between the 2 approaches. “The subclavian vessels may be quite tortuous, making catheter manipulation more difficult from the right arm. That’s a real thing for new operators,” Dr. Mann said. “The other thing for new operators is that catheters just fit nicely into the coronaries from the leg. There’s very little skill required to cannulate the coronaries from the leg or from the left arm, but from the right, there are manipulations that have to be learned to make it easier. It’s just more difficult.”

Ian C. Gilchrist, MD, of Hershey Medical Center (Hershey, PA), drew a slightly different conclusion from the study. “I think one of the take-home messages is that both the right and the left radial approach offer excellent results and an excellent outcome,” he said in a telephone interview with TCTMD. “You can look at the experienced operators and see that there is essentially no difference between right and left.”

In addition, rather than focusing on left vs. right access, Dr. Gilchrist noted that there was much inter-operator variability in terms of the amount of radiation used for all the inexperienced operators. “There’s a lot of room to tighten it up [on both sides],” he said.

Implications for Training Programs

Based on the results, the study authors recommend that hospitals initiating a transradial program for percutaneous coronary procedures start operators out with a left radial approach. “Indeed, transradial access is technically more demanding and time-consuming during the early learning curve,” the researchers write. “[P]robably at the very beginning of the program, the use of the [left radial approach] may allow operators to acquire more quickly adequate skill and confidence with the transradial approach.”

Drs. Mann and Gilchrist both agreed with this rationale for new programs. “For the site that needs to get up on its own, they may be a little worried about using the right radial, so the concept that the left radial is maybe a step closer to the femoral artery, that it has less tortuosity and it’s easier to use standard femoral catheters, that might be a stepping stone that they need to get into radial procedures,” Dr. Gilchrist said. “There are a lot of people in the United States who haven’t adopted radial yet, and there’s always a hundred excuses why not to try it. Perhaps this provides them with a little reassurance that maybe if they try it from the left, it’ll be a little easier for them and they’ll get their feet wet and pick up their skills a little.”


Sciahbasi A, Romagnoli E, Trani C, et al. Evaluation of the “learning curve” for the left and right radial approach during percutaneous coronary procedures. Am J Cardiol. 2011;Epub ahead of print.



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  • Dr. Sciahbasi makes no statement regarding conflicts of interest.
  • Drs. Mann and Gilchrist report no relevant conflicts of interest.