Patency Of Radial Artery Grafts Research Articles

Skeletonized harvesting improves the early-term and mid-term perfect patency of a radial artery graft

A radial artery (RA) graft is frequently used for coronary artery bypass grafting (CABG), but little information exists regarding the early- and mid-term patency associated with the harvesting procedure. The objective of this study is to compare the early- and mid-term patency of the RA graft obtained using non-skeletonized and skeletonized harvesting. Altogether, 131 patients and 159 anastomoses were studied. In 85 patients the RA was harvested non-skeletonized (group A: procedures between September 2000 and November 2002), whereas in 46 patients the RA was harvested skeletonized (group B: procedures between November 2002 and April 2004). Angiography results were analyzed before discharge [A: postoperative day (POD) 14.7 +/- 2.9, 75 patients, 90 anastomoses; B: POD 13.7 +/- 1.9, 38 patients, 47 anastomoses], and after 1 year (A: POD 386.8 +/- 149.3, 44 patients, 51 anastomoses; B: POD 267.1 +/- 148.7, 11 patients, 13 anastomoses). There was no difference in patency between the two groups (group A vs group B, 96.7% vs 100%, P = not significant [NS], in the early-term, 96.2% vs 100%, P = NS, in the mid-term). However, the perfect patency rates for groups A and B were 86.7% and 98.1%, respectively, in the early-term (P = 0.034) and 77.5% and 100%, respectively, in the mid-term (P = 0.048). The location and severity of the target vessel did not influence the angiographic results. The early- and mid-term patency of RA grafts was excellent, and skeletonized harvesting improved the perfect patency rates at both time points.

Midterm Angiographic Patency and Vasoreactive Profile of Proximal Versus Distal Radial Artery Grafts

No data are available on the different angiographic results and the in vivo vasoreactivity of radial artery (RA) grafts obtained from different parts of the conduit, although it is known that the distal segment of the artery has a more pronounced muscular component. This study was conceived to evaluate the angiographic patency and tendency to spasm of proximal versus distal RA grafts. In 29 patients, at the time of surgical myocardial revascularization, the radial artery was divided into two separate conduits, so that these patients received a total of 58 radial grafts (29 from the proximal and 29 from the distal portion of the artery). All cases were submitted to midterm angiography and vasoactive challenges to verify angiographic patency and vasoreactive profile. Radial artery patency rate was 28 of 29 for both groups. Nine cases of string sign were reported, all in the distal series (p = 0.001). The perfect patency rate of distal grafts was markedly lower than that of proximal grafts (19 of 29 versus 27 of 29; p = 0.02). Vasoactive challenges testified to a higher vasospastic attitude of distal grafts. Radial artery grafts obtained from the distal portion of the artery have a higher vasospastic tendency, greater incidence of string sign, and lower midterm perfect patency rate than graft taken from the more proximal part of the artery. The proximal part of the RA should be preferred for use as a conduit for surgical myocardial revascularization.

Invited commentary

This is an interesting and important study looking at the patency, morphology and vasoactive responses of proximal versus distal radial artery grafts. The authors reviewed 29 patients who received two radial artery grafts each. The patency of the radial arteries were studied using angiography at a mean follow-up of 66 months. The radial grafts were divided into two groups, those originating from the proximal segment and those from the distal radial artery. This study was motivated by the fact that several authors had noted a predominantly muscular morphology in the distal radial artery and had argued that this might affect patency rates if the muscular segments were more prone to vasospasm.

Is postoperative calcium channel blocker therapy needed in patients with radial artery grafts?

Chronic calcium channel blocker therapy has traditionally been considered necessary in patients carrying a radial artery graft, even in the absence of objective data to support it. This report was conceived to evaluate the angiographic and clinical effects of calcium channel blocker therapy during the first postoperative year. A total of 100 consecutive patients who received a radial artery graft at our institution were randomly assigned to receive (n = 53) or not receive (n = 47) calcium channel blocker therapy with oral diltiazem 120 mg/daily started in the early postoperative period. At 1-year follow-up, all patients were reassessed clinically and by Tl 201 myocardial scintigraphy, and 83 of them underwent control angiography. In 12 cases we also evaluated the response of the radial artery to the endovascular infusion of serotonin. No difference in terms of clinical outcome, scintigraphic results, and patency rate was found between patients who received or did not receive calcium channel blocker therapy. Endovascular serotonin infusion evoked an evident spastic reaction of radial artery grafts, not attenuated by calcium channel blocker therapy. Calcium channel blocker therapy started immediately after surgery and continued for the first postoperative year does not affect radial artery graft patency and clinical and scintigraphic outcomes. On the basis of these data, the prophylactic use of calcium channel blocker therapy in patients with radial artery grafts seems unsubstantiated.

Letters Regarding Article by Khot et al, “Radial Artery Bypass Grafts Have an Increased Occurrence of Angiographically Severe Stenosis and Occlusion Compared With Left Internal Mammary Arteries and Saphenous Vein Grafts”

To the Editor: Since its first clinical use by Carpentier in 1971,1 the radial artery (RA) has become one of the grafts of choice in coronary surgery. The article by Khot et al2 claims that the patency of RA grafts is lower than that of internal mammary artery (IMA) as well as venous grafts. We believe that their methodology is flawed, primarily because the sample studied is composed almost exclusively of patients presenting with angina, ECG changes, or both. In most other published reports, only ≈20% of patients have recurrent angina at 5 years. Therefore, we believe that the denominator used to calculate the rates of patency is incorrect, and the results obtained by the authors may be misleading. Furthermore, it would appear that the RA was often used in high–occlusion-risk situations, which could account for the low observed patency rate in this highly selected population. For example, 22% of the patients underwent redo surgery, a substantially high proportion of patients in a daily practice, and a situation in which target vessels are often suboptimal. In one third of the cases, the RA was anastomosed to the right coronary artery, which is known to be at high risk for occlusion, whereas the number of right IMA grafts constructed in this area was so small that it did not allow a statistical comparison. Therefore, we believe that it is dangerous to extrapolate the patency data observed in this series to a homogeneous cohort of patients. These results are at variance with previously published series, which established that the patency of the RA graft was 92% and 83% at 1 and 5 years, respectively. These rates are comparable to those of the right IMA graft. Several studies have reported that use of the RA as opposed to vein grafts improved …

The radial artery as a coronary bypass conduit: dealing with hyperreactivity

The radial artery as a coronary bypass conduit: dealing with hyperreactivity

A Randomized Comparison of Radial-Artery and Saphenous-Vein Coronary Bypass Grafts

In the past decade, the radial artery has frequently been used for coronary bypass surgery despite concern regarding the possibility of graft spasm. Graft patency is a key predictor of long-term survival. We therefore sought to determine the relative patency rate of radial-artery and saphenous-vein grafts in a randomized trial in which we controlled for bias in the selection of patients and vessels. We enrolled 561 patients at 13 centers. The left internal thoracic artery was used to bypass the anterior circulation. The radial-artery graft was randomly assigned to bypass the major vessel in either the inferior (right coronary) territory or the lateral (circumflex) territory, with the saphenous-vein graft used for the opposing territory (control). The primary end point was graft occlusion, determined by angiography 8 to 12 months postoperatively. Angiography was performed at one year in 440 patients: 8.2 percent of radial-artery grafts and 13.6 percent of saphenous-vein grafts were completely occluded (P=0.009). Diffuse narrowing of the graft (the angiographic "string sign") was present in 7.0 percent of radial-artery grafts and only 0.9 percent of saphenous-vein grafts (P=0.001). The absence of severe native-vessel stenosis was associated with an increased risk of occlusion of the radial-artery graft and diffuse narrowing of the graft. Harvesting of the radial artery was well tolerated. Radial-artery grafts are associated with a lower rate of graft occlusion at one year than are saphenous-vein grafts. Because the patency of radial-artery grafts depends on the severity of native-vessel stenosis, such grafts should preferentially be used for target vessels with high-grade lesions.

Patency of the Radial Artery Graft: Angiographic Study in 209 Symptomatic Patients Operated between 1995 and 2002 and Review of the Current Literature

The purpose of this study is to define the long-term patency of the radial artery (RA) graft and review the current literature. Two hundred and eighty-six RA symptom-directed graft angiograms were studied in 209 patients. The preoperative patient characteristics and intraoperative variables were collected prospectively from patients who had primary coronary artery bypass grafting between 1995 and 2002. A total of 166 (79%) patients were male with a mean age of 65 years. The mean period from operation to re-angiogram was 35 months. Actuarial techniques are not valid in graft patency studies as the time when the graft occluded is not known. Therefore, RA patency was analyzed at four categorical time intervals. The RA was grafted to the left anterior descending artery (LAD) in six patients (2%), diagonal (DIAG) in 29 (10%), obtuse marginal (OM) in 166 (58%), right coronary artery (RCA) in 9 (3%) and posterior descending artery (PDA) in 76 (27%) cases. The graft failure was defined as >or=80% stenosis. A total of 259 (91%) grafts were patent and 26 (9%) had failed. Most grafts were widely patent or occluded. The LAD/DIAG patency was 30/35 (86%), OM patency 154/166 (93%) and RCA/PDA patency 79/84 (94%). The interval from surgery to angiogram did not affect the RA graft patency (86% at <1 year, 95% at 1-3 years, 89% at 4-5 years, 96% at >5 years). Even in a patient cohort with adverse symptoms, excellent RA patency was achieved that remained almost constant through all time intervals studied. Better selection, harvesting and preservation may further improve early patency.

Mid-term angiographic results of radial artery (RA) graft in CABG: Does the proximal site of anastomosis affect graft patency?

Use of arterial conduits in coronary artery bypass grafting (CABG) is based on the documented excellent patency rates of left internal thoracic (mammary) artery (LITA). Alternative arterial conduits such as radial artery and gastroepiploic artery also showed superior long-term patency rates compared to vein grafts. Free arterial grafts are being used increasingly to replace the long saphenous vein as a conduit. This study was undertaken to compare two methods of radial artery grafting as a free graft and a composite graft. Between January 1997 and October 2003 a total of 441 patients were operated for coronary artery bypass grafting using radial artery (RA) as one of the conduits. Among these patients, 125 patients received radial artery as a composite graft; In 68 patients RA was used with left internal thoracic artery as a composite y graft (n=68), and in 57 patients it was used with right internal thoracic artery (RITA) as an in situ composite pedicle graft (n=57). In the remaining 316 patients the radial artery was used as a free graft. Angiographic evaluation of radial artery graft was carried out in 63 patients who consented. Angiograms were carried out after an interval of 6–72 months (mean of 28.15±21.17 months). Of these 63 patients who underwent reangiography, the different surgical strategies used were RITA+RA composite in situ graft (n=34), LITA+RA composite y graft (n=17) and aorto coronary (free) RA graft (n=12). There were 3 hospital deaths in the series 441 patients. Among the 63 patients who underwent check angiography 60 patients were in NYHA C1 I and 3 patients were in C1 II. None of the patients had perioperative myocardial infarction. Angiographically overall radial artery graft patency rate was 94.1% (59 patients). In patients with RITA and RA in situ grafts patency rate was 94.1%, LITA+RA composite y graft patency was 94.1% and aorto coronary (free) radial artery grafts patency was 91.6%. In 63 selected asymptomatic patients studied, we found that radial artery graft when used as an aortocoronary (free) graft or as a composite y graft with left internal thoracic artery or in situ pedicle graft with right internal thoracic artery the patency rates were comparable in all three groups.

The impact of the preoperative severity of target-vessel stenosis on the short-term patency of radial artery grafts.

The fate of a grafted radial artery remains unknown. The purpose of this study was to determine whether the preoperative severity of stenosis of the target vessel influence short-term patency of radial artery (RA) grafts used as coronary artery bypass conduits. In 54 patients who had coronary artery bypass grafting (CABG) with RA grafts, RA patency was determined with multi-slice computed tomography (MSCT) 1 year after CABG. These patients were divided into three groups on the basis of the percentage of the target vessel stenosis: mild (< 60%, n=17), moderate (60% to 79%, n=19), and severe (>/= 80%, n=18). MSCT was also performed 1 week later to exclude early occlusion of RA grafts. In 3 patients, the MSCT failed to adequately discriminate the status of the RA graft due to poor image resolution. The overall incidence of RA occlusion was 23.5% (12 of 51) at 1 year in the entire population. The mild stenosis, moderate stenosis and severe stenosis group showed an occlusion rate of 50% (8 of 16), 23.5% (4 of 17) and 0% (0 of 18), respectively. The severe stenosis group had significantly lower rate of RA graft occlusion compared to the mild stenosis group (p < 0.001) and moderate stenosis group (p < 0.05). No difference in occlusion between grafts used for the different coronary artery branches could be demonstrated. Preoperative severity of the target coronary artery significantly affected the short-term RA grafts patency. Correct indication is the key factor for short-term RA patency.

Atherosclerotic involvement of the radial artery in patients with coronary artery disease and its relation with midterm radial artery graft patency and endothelial function

Background The radial artery has recently been proposed as an alternative arterial conduit for surgical myocardial revascularization. This study was conceived to evaluate the degree of atherosclerotic involvement of the radial artery in patients with coronary artery disease and the eventual influence of a subtle degree of preoperative atherosclerosis on the midterm results of radial artery grafts. Methods and results The intima-media thickness of the radial artery, common carotid artery, and internal thoracic artery was evaluated in 42 coronary artery disease patients and in 26 control patients. All radial arteries were then used for myocardial revascularization; 30 patients submitted to control angiography after 5 years. The mean intima-media thickness was 0.92 ± 0.22 mm for the common carotid artery, 0.54 ± 0.16 mm for the internal thoracic artery, 0.55 ± 0.11 mm for the radial artery in coronary artery disease patients versus 0.79 ± 0.14 mm, 0.52 ± 0.11 mm, and 0.56 ± 0.09 mm, respectively, in control patients ( P = .001 only for the common carotid artery). No correlation was found between the intima-media thickness of the carotid, internal thoracic, and radial artery. No correlation was found between the preoperative intima-media thickness of the radial artery and the midterm patency and endothelial-mediated vasodilating capacity of radial artery grafts. Conclusion In coronary artery disease patients, radial artery atherosclerotic involvement is more frequent than that of the gold standard internal thoracic artery but still by far less severe than that of the common carotid artery. The early atherosclerotic signs often observed in the radial artery do not seem to have the potential to influence radial artery graft patency and endothelial function.

Different cell death rates determine growth of vascular smooth muscle cells from human aortocoronary bypass vessels: Implications for patency of radial artery grafts

Different cell death rates determine growth of vascular smooth muscle cells from human aortocoronary bypass vessels: Implications for patency of radial artery grafts

Effect of target stenosis and location on radial artery graft patency.

The purpose of this study was to evaluate the effect of target vessel characteristics on radial artery patency when used as a composite T graft. Between October 1993 and March 2001, 1022 patients underwent coronary bypass with the internal thoracic artery-radial artery composite T graft. Of these, angiography has been performed on 109 patients at a mean 27.1 months (range, 2-70 months) postoperatively for symptoms of ischemia. By means of Cox proportional hazard models, the relationships between anastomotic patency and target vessel location, proximal stenosis, target diameter, and quality were assessed. A total of 231 radial artery anastomoses were evaluated. The mean stenosis for patent anastomoses was 82% compared with 71% for occluded anastomoses (P <.001). Anastomotic patency for targets with moderate stenosis (< or = 70%) was worse than that for vessels with critical stenosis (> or = 90%; relative risk, 1.7; 95% confidence interval, 1.3-2.2; P <.001). Patency for targets of the right coronary artery was statistically inferior to that for targets of the left anterior descending artery (relative risk, 1.8; 95% confidence interval, 1.2-2.9; P =.01) and bordered on significance versus that for the circumflex artery distribution (relative risk, 1.6; 95% confidence interval, 1.0-2.8; P =.06). When directed toward critically stenosed targets of the left anterior descending or circumflex arteries, radial artery patency was not statistically different that that of the internal thoracic artery (P =.19). Radial artery patency is sensitive to both target location and proximal target stenosis. Selective use of the radial artery to targets of the left anterior descending and circumflex distributions remains encouraging. Radial artery grafts to targets of the right coronary artery or those with moderate stenosis appear to be at particularly high risk of failure.

Predictors of radial artery patency for coronary bypass operations

Background. Few data exist regarding angiographic predictors of radial artery patency for coronary bypass grafting, and the benefit of calcium antagonists is not clear. Methods. One hundred fifteen patients were studied who had myocardial revascularization with the radial artery plus internal mammary and vein grafts with 3.5 ± 1.1 grafts per patient. Sixty-three patients received diltiazem and 52 patients did not. Base line and follow-up angiographies were analyzed 1 year postoperatively in 50 of these patients with a quantitative computerized method. Results. One hundred fourteen patients survived and were followed for 30.1 ± 12.6 months. Patency for mammary grafts was 100%, for radial grafts it was 80%, and for saphenous vein grafts it was 68%. Patent radial artery grafts had significantly greater degree of stenosis in the native vessels than occluded grafts (73% ± 14% vs 40% ± 24%), ( p = 0.0007; confidence interval = 95%). Radial artery patency increased to 92% when arteries with 70% or more stenosis were considered. No differences were observed for clinical and angiographic end points in the patients that received diltiazem compared with the rest who had not. Conclusions. The degree of stenosis in the native coronary artery significantly influences the patency rate of radial artery grafts, independent of diltiazem.

Clinical and Angiographic Effects of Chronic Calcium Channel Blocker Therapy Continued Beyond First Postoperative Year in Patients With Radial Artery Grafts

Background This study was conceived to elucidate the clinical and angiographic effects of chronic calcium channel blocker therapy (CCCBT) continued after the first postoperative year in patients in whom the radial artery (RA) was used for myocardial revascularization. Methods and Results Patients who received RA grafts at our institution and who at 1 year had no scintigraphic evidence of ischemia in the RA territory or angiographic evidence of RA malfunction (n=120) were randomly assigned to continue (n=63) or suspend (n=57) the CCCBT with diltiazem (120 mg/d). After 5 years, all patients were reassessed clinically and by stress myocardial scintigraphy, and 87 of them (45 from the continued group that continued CCCBT and 42 from the group that suspended CCCBT) were restudied angiographically. No differences regarding either the clinical and scintigraphic results or the RA angiographic status were demonstrated between the 2 groups. Conclusions After the first postoperative year, the continuation of CCCBT does not affect RA graft patency or clinical and scintigraphic results.

Phenoxybenzamine prevents spasm in radial artery conduits for coronary artery bypass grafting

Over the past decade, there has been a marked increase in the use of arterial conduits to perform coronary artery bypass grafting (CABG).1 The clinical and survival benefits of bilateral internal thoracic artery grafts have established them as conduits of first choice for CABG,2 whereas the radial artery has rapidly become the third most commonly used arterial conduit.3 The radial artery is a versatile conduit, which can be harvested easily and safely, has handling characteristics superior to those of other arterial grafts, and comfortably reaches any coronary target. Several studies3 have reported superior patency of radial artery grafts compared with vein grafts at up to 5 years after CABG. Enthusiasm for widespread use of the radiPHENOXYBENZAMINE PREVENTS SPASM IN RADIAL ARTERY CONDUITS FOR CORONARY ARTERY BYPASS GRAFTING

Radial artery in CABG: could the early results be comparable to internal mammary artery graft?

Background. The accidental detection of patency of radial artery grafts, by Acar, which had been labeled as blocked 18 years earlier, has led to its revival as a conduit in coronary artery bypass surgery. We used radial artery as one of the grafts in 287 patients from February 1996 to June 1998. Here we present our early clinical experience and the midterm angiographic follow up of the initial 62 patients. Methods. A no touch, atraumatic harvesting technique coupled with gentle hydrostatic and pharmacological dilatation of the radial artery graft was employed. Radial artery was used to revascularize coronary vessels with >80% proximal stenosis. Postoperatively, the patients were administered a low dose nifedipine that was continued for 6 months thereafter. The patients were followed up clinically after discharge from the hospital and angiographic evaluation of the grafted radial artery by selective injection was done at a mean interval of 16.2 ± 5.1 months (3–24 months) postoperatively. Results. There was no perioperative or late myocardial infarction or mortality. No significant complications related to the harvesting of radial artery were encountered. Angiographically, the radial artery grafts were found to be patent in 96.8% of patients (60/62). Mild distal anastomotic narrowing was seen in angiogram of one patient with good filling of the target vessel. Another patient showed diffuse spasm of radial artery graft. The patency of the pedicled left internal mammary grafts was also 98.2% (56/57). All the patients were asymptomatic. Conclusions. Radial artery seems to be an excellent alternate arterial conduit for myocardial revascularization with early and midterm patency rates equivalent to that of pedicled internal mammary artery, and it should be used more often for myocardial revascularization as an adjunct to pedicled internal mammary artery graft.

Radial artery graft for coronary revascularization: Technical considerations

Use of the radial artery for coronary artery bypass grafting is controversial. Between November 1992 and December 1994, the radial artery artery graft was used in 165 patients (mean age, 63.7 years) undergoing coronary revascularization. To prevent spasm, the radial artery was not skeletonized, and calcium-channel blockers were administered routinely. No ischemic or functional complications occurred in the hand after harvesting of the radial artery. Only 1 patient (0.6%) sustained a perioperative myocardial infarction in an area revascularized with a radial artery. The overall mortality was 3.0% (5 patients), but no deaths were caused by failure of the radial artery graft. During a mean follow-up of 14.0 months, angina recurred in 5 patients (3.0%), all of whom had widely patent radial artery grafts on angiography. Radionuclide exercise studies were performed 1 year after operation in 84 patients, 2 of whom (2.4%) had stress-induced defects in areas grafted with a radial artery. Perioperative myocardial infarction, mortality, and recurrent angina usually were not related to failure of the radial artery graft. Our results suggest that the radial artery is an excellent alternative conduit for myocardial revascularization and may be used safely, especially in patients with poor-quality or unavailable saphenous veins.

Revival of the radial artery for coronary artery bypass grafting

Eighteen years after its first introduction for coronary artery revascularization, the radial artery (RA) was reinvestigated because of unexpected good long-term results in the early series. Since July 1989, 104 patients underwent myocardial revascularization using 122 RA grafts (18 patients received two grafts). The left internal mammary artery (IMA) was concomitantly used as a pedicled graft in 100 cases and the right IMA in 19 cases; a free IMA graft was used in 29 cases and a saphenous vein graft in 24 cases. A mean of 2.8 grafts per patient were performed. Nine patients underwent associated procedures: carotid endarterectomy (3), aortic valve replacement (3), Bigelow procedure (1), and mitral valve repair (2). The target artery receiving the RA was the circumflex (n = 59), diagonal (n = 29), right coronary (n = 27), and left anterior descending (n = 7). One patient died (0.96%) and 2 had perioperative myocardial infarct. Sternal wound infection was noted in 3 cases of double IMA implantation. No ischemia of the hand was observed. All patients received diltiazem started intraoperatively and continued after discharge. In addition aspirin (100 mg/day) was given at discharge. Early angiographic controls (<2 weeks) were obtained in the first 50 consecutive patients and revealed 56 of 56 patent RA grafts, 48 of 48 patent left IMA grafts, 11 of 11 patent right IMA grafts, 14 of 18 patent free IMA grafts, and 8 of 9 patent vein grafts. Six patients had localized narrowing of the RA conduit unrelated to the anastomotic lines (spasm). Late angiographic control was obtained after a mean follow-up of 9.2 months in 27 patients; 29 RA grafts were patent (93.5%) and free of spasm and 2 were occluded. This study showed that the RA may be a reasonable alternative to other types of conduits to complement the left IMA.