Hemodynamic and functional consequences of radial artery removal for coronary artery bypass grafting

A Prospective Randomized Study of Endoscopic Versus Conventional Harvesting of the Radial Artery

OBJECTIVE

The aims of the study were to determine whether endoscopic harvesting of the radial artery (RA) reduces morbidity due to pain, infection, and disability with improvement in satisfaction and cosmesis compared to the conventional technique and (2) to compare the 6-month angiographic patency of the RA harvested conventionally and endoscopically.

METHODS

In a prospective randomized study, 119 patients undergoing coronary artery bypass grafting using the RA were randomized to have RA harvested either conventionally (n = 59) or endoscopically (n = 60).

RESULTS

Radial artery harvest time (open wound time) was significantly reduced in the endoscopic group (36.5 ± 9.4 vs 57.7 ± 9.4 minutes, P < 0.001). Only one patient developed wound infection (1.6%) in the endoscopic group compared with six patients (10.2%), P = 0.061, in the conventional group. Although this was not statistically significant, clinically this was relevant in terms of reduction in postoperative morbidity. Postoperative pain in the arm incision was significantly lower in the endoscopic group at postoperative day 2 (P < 0.001) and at discharge (P < 0.001) and similar to the conventional open group at 6 weeks' follow-up (P = 0.103). Overall patient satisfaction and cosmesis were significantly better in the endoscopic group at postoperative day 2 (P < 0.001), at discharge (P < 0.001), and at 6 weeks' follow-up (P < 0.001). There was no difference in the arm disability postoperatively (P = 0.505) between the two groups. Six-month angiographic assessment of 23 patients (12 endoscopic and 11 open) revealed no difference in the patency rate (10/12 in endoscopic and 9/11 in open group).

CONCLUSIONS

Endoscopic RA harvesting reduced the incidence of postoperative wound infection and wound pain and improved patient satisfaction and cosmesis compared with conventional harvesting technique. There was no difference in the 6-month angiographic patency of the RA harvested conventionally and endoscopically.

Evaluation of the Forearm Dominancy Artery for Invasive Vascular Procedure with 3D-CT Angiography

The aim of this study was to evaluate the vascular dominance in the forearm as a factor in determining the choice of invasive vascular procedures in arteries of the forearm, using 3D-computerized tomography (3D-CT) angiographies of 92 forearms. The diameters of the ulnar and radial arteries were measured just distal to the bifurcation of the brachial artery, at the midpoint between the bifurcation and the wrist, and at the wrist crease. In 79 cases, the ulnar artery was larger than the radial artery after the bifurcation of the brachial artery. However, no statistically significant difference was observed at either the mid-forearm or the wrist crease. In the remaining 13 cases, the diameter of the radial artery was larger or the same as that of the ulnar artery after the bifurcation, but at the more distal sites no regular pattern could be detected. The findings suggest that 3D-CT angiography offers valuable preoperative details of the forearm vessels for cases requiring invasive vascular procedures on the forearm.

The effect of transradial coronary catheterization on upper limb function

OBJECTIVES

The aim of this study was to analyze the change of upper limb function when percutaneous coronary procedures were performed through the radial artery.

BACKGROUND

It is currently unknown if upper limb function is affected by transradial (TR) catheterization.

METHODS

Between January 2013 and February 2014, upper limb function was assessed in a total of 338 patients undergoing coronary catheterization in an ambulatory setting (85% radial approach, 15% femoral approach). Upper limb function was assessed with the self-reported shortened version of the Disabilities of Arm, Shoulder, and Hand questionnaire. The presence and severity of upper extremity cold intolerance was assessed with the self-reported Cold Intolerance Symptom Severity questionnaire. Both questionnaires were completed before the catheterization and at 30-day follow-up. Higher scores represent worse upper limb functionality or symptoms. The nonparametric Wilcoxon signed-rank test was used to assess the change of upper limb function and symptoms over time.

RESULTS

Upper limb function did not change significantly over time when catheterization was performed through the radial artery (p=0.06). The number of procedure-related extremity complaints that persisted during 30-day follow-up were not different between both access groups (TR access 10.5%, transfemoral access 11.5%; p=0.82). The upper extremity was not affected by cold intolerance after TR access at 30-day follow-up (p=0.91).

CONCLUSIONS

Upper limb function was not affected when coronary catheterizations and interventions were performed through the radial artery.

Palmar arch anatomy: Ajmer Working Group classification

Introduction

Forearm arteries are frequently used as workhorse site for cardiac catheterization, bypass grafting and haemodialysis access. There is paucity of data on palmar circulation in live human being and only cadaveric data are available till date. We, therefore, made an attempt to look at the various patterns of sufficient or insufficient palmar arch circulation and various anomalies of forearm arteries, to discuss their clinical implications.

Methods and results

We obtained the forearm and hand arteriograms of patients (n = 302) through radial (n = 200) and ulnar routes (n = 102). Modified Allen’s test was normal in all of our patients. On the basis of predetermined parameters angiograms were analysed and findings were divided into three groups. These three groups were further classified as type A, type B, type C superficial palmar arch.

Conclusion

We concluded that type A superficial palmar arch is most suitable for providing adequate collateral circulation in case of harvesting of forearm vessel, whereas type C superficial palmar arch appears to be highly susceptible for digital ischemia in case of radial or ulnar artery occlusion. Modified Allen’s test alone is not justifiable for documenting good collateral circulation and it should be supplemented by other tests to document good collateral circulation before proceeding to any radical procedure.

Radial artery compression in incomplete palmar arch for radial artery harvesting

BACKGROUND

incomplete palmar arch causing inadequate collateral flow is considered a contraindication for harvesting radial artery as a conduit for coronary artery bypass grafting. The objective of this pilot study was to assess whether iatrogenic radial artery compression could improve collateral circulation in the nondominant hand in such patients.

METHODS

5 patients scheduled for coronary artery bypass, with incomplete palmar arch suspected by an abnormal modified Allen's test and confirmed by dynamic color Doppler sonography, were included in the study. The flow in branches of the radial artery (superficial palmar branch and dorsal digital artery of the thumb) was measured by dynamic color Doppler sonography. Intermittent radial artery compression was applied to the nondominant hand, using a radial compression device for 15 days, and the tests were repeated to assess changes in radial artery branch flow.

RESULTS

flow in the superficial palmar branch was increased in 3 patients, with a significant increase in 2 of them. The 3 patients in whom the dorsal digital artery of the thumb could be seen on precompression Doppler, all had substantially increased flow. The increase in flow assessed by the modified Allen's test was statistically significant, but the flow change measured by Doppler sonography did not reach statistical significance.

CONCLUSIONS

collaterals developed during 15 days of intermittent radial artery compression. The collateral development led to increased flow in the radial artery branches. A larger sample is required to confirm the results.

A reassessment of the role of the radial forearm flap in upper extremity reconstruction

Our understanding of the hemodynamic consequences of radial artery harvest to the upper extremity has changed our considerations when approaching soft tissue defects of the hand. A critical assessment of the donor site morbidity of radial forearm (and radial artery) harvest is necessary to discern the role this flap should have in our current and future reconstructive armamentarium. A review of the available data and discussion of its implications is provided.

Radial artery cannulation: a comprehensive review of recent anatomic and physiologic investigations

Consistent anatomic accessibility, ease of cannulation, and a low rate of complications have made the radial artery the preferred site for arterial cannulation. Radial artery catheterization is a relatively safe procedure with an incidence of permanent ischemic complications of 0.09%. Although its anatomy in the forearm and the hand is variable, adequate collateral flow in the event of radial artery thrombosis is present in most patients. Harvesting of the radial artery as a conduit for coronary artery bypass grafting, advances in plastic and reconstructive surgery of the hand, and its use as an entry site for cardiac catheterization has provided new insight into the collateral blood flow to the hand and the impact of radial arterial instrumentation. The Modified Allen's Test has been the most frequently used method to clinically assess adequacy of ulnar artery collateral flow despite the lack of evidence that it can predict ischemic complications in the setting of radial artery occlusion. Doppler ultrasound can be used to evaluate collateral hand perfusion in an effort to stratify risk of potential ischemic injury from cannulation. Limited research has demonstrated a beneficial effect of heparinized flush solutions on arterial catheter patency but only in patients with prolonged monitoring (>24 h). Conservative management may be equally as effective as surgical intervention in treating ischemic complications resulting from radial artery cannulation. Limited clinical experience with the ultrasound-guided arterial cannulation method suggests that this technique is associated with increased success of cannulation with fewer attempts. Whether use of the latter technique is associated with a decrease in complications has not yet been verified in prospective studies. Research is needed to assess the safety of using the ulnar artery as an alternative to radial artery cannulation because the proximity and attachments of the ulnar artery to the ulnar nerve may potentially expose it to a higher risk of injury.

Reconstruction of the first web space in symbrachydactyly using the reverse radial forearm flap

PURPOSE

To present a new approach for the reconstruction of severe first web contractures using a distally based reverse radial forearm flap in symbrachydactyly patients.

METHODS

This study included 6 hands in 5 patients. Subjective evaluation included appearance, parent satisfaction (and patient satisfaction when appropriate), and ability to perform daily activities such as thumb-index grasp and pinch at follow-up evaluations. We measured the angle between the first and second rays using a goniometer at maximum radial abduction, and pinch and grasp strengths were evaluated as an objective assessment.

RESULTS

The average follow-up period was 2 years. All parents and patients were happy with the aesthetic appearance. They were completely satisfied in their daily living activities. The average first web angle measurement was 56 degrees . An average of 39 degrees of improvement of web measurement was achieved. For the unilateral 4 patients, the average pinch strength measurement was 80% of the normal contralateral hand and the grip strength was 75% of the normal contralateral hand.

CONCLUSIONS

The reverse radial forearm flap was found to be a safe and simple method in the reconstruction of severe first web contractures in symbrachydactyly patients. This method provided good coverage of appropriate thickness and skin quality, and supple soft tissue that filled the first web space.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Can the modified Allen's test always detect sufficient collateral flow in the hand? A computational study

Blood flow in the largest arteries of the arm up to the digital arteries is numerically modelled using the one-dimensional equations of pressure and flow wave propagation in compliant vessels. The model can be applied to different anatomies of arterial networks and can simulate compression of arteries, these allowing us to simulate the modified Allen's test (MAT) and to assess its suitability for the detection of sufficient collateral flow in the hand if radial blood supply is interrupted. The test measures blood flow in the superficial palmar arch before and during compression of the radial artery. The absence of reversal flow in the palmar arch with the compression indicates insufficient collateral flow and is referred to as a positive MAT. This study shows that small calibres of the superficial palmar arch and insufficient compression of the radial artery can lead to false-positive results. Measurement of the drop in digital systolic pressures with compression of the radial artery has proved to be a more sensitive test to predict the presence of sufficient ulnar collateral flow in networks with small calibres of the superficial palmar arch. However, this study also shows that digital pressure measurements can fail in detecting enough collateral flow if the radial artery is insufficiently compressed.

Superficial ulnar artery: Curse or blessing in harvesting fasciocutaneous forearm flaps

BACKGROUND

Superficial ulnar artery is a well-known vascular anomaly that may cause special risks because of possible impairment of the vessel by mistake during harvesting fasciocutaneous forearm flaps.

METHODS

The charts of patients who had undergone forearm flap transfer were reviewed for vascular anomalies. When a superficial ulnar artery was present, a superficial ulnar artery flap was raised and arteriography was performed postoperatively to figure out the vascular pattern in the contralateral arm.

RESULTS

Four superficial ulnar arteries were found during dissection of ulnar forearm flaps (n = 107). We were unable to identify any superficial ulnar artery when preparing the radial pendant (n = 27), and we did not notice any impairment of such an artery. The four superficial ulnar artery flaps healed uneventfully. Postoperative arteriography revealed a bilateral vascular anomaly in one of the four cases.

CONCLUSION

The superficial ulnar artery is a calculable anatomic variation as long as its possible presence is considered during flap harvesting. In these cases, the use of the superficial ulnar artery flap was found to be an easy and safe alternative.

Radial artery grafting

After its recent reintroduction in coronary surgery the radial artery is gaining wide acceptance as complementary arterial conduits for surgical myocardial revascularization. The main technical aspects of radial artery harvesting, the biological and vasoactive characteristics of radial artery grafts as well as the mid- to long-term angiographic results and the role of the antispatic therapy are reviewed.

Radial Artery Graft for Coronary Artery Bypass Surgery: Biological Characteristics and Clinical Outcome

The radial artery (RA) is gaining popularity as a bypass conduit for coronary artery bypass grafting, and its impact on clinical practice has been extensively explored. In the present article, we provide a review of postoperative hand circulation, vascular biological characteristics of the RA graft, the efficacy of vasodilator therapies, and mid-term clinical results of use of the RA graft. Fundamental studies revealed excellent vascular biological characteristics of the RA graft as a living arterial conduit, making it almost equivalent to the internal thoracic artery (ITA) graft. Clinical studies have yielded encouraging mid-term results. Most studies reported in favor of the RA graft over the saphenous vein graft with regard to patency rate, freedom from cardiac events, and survival. However, superiority of either the RA or right ITA graft has not been conclusively determined. The long-term results of RA grafts remain unknown, but at present, supplementary use of an RA graft with a left ITA graft appears feasible for CABG.

Implantation in coronary circulation induces morphofunctional transformation of radial grafts from muscular to elastomuscular

BACKGROUND

The purpose of this research was to investigate the in vivo morphofunctional changes induced in the radial artery (RA) by its use as coronary artery bypass conduit by comparing the morphological features and vasoreactivity of the native RA versus the coronary RA graft in the same patient.

METHODS AND RESULTS

Ten years after surgery, 10 patients were submitted to intravascular ultrasound examination of the RA graft of the controlateral (in situ) RA and of the internal thoracic artery (ITA) graft and to vasoactive challenges with acetylcholine and serotonin. Quantitative angiographic assessment showed that the mean diameter of the RA coronary grafts was significantly larger than that of the in situ RA and of the ITA (2.89+/-0.40 mm RA grafts, 2.14+/-0.52 mm in situ RA, 2.25+/-0.53 mm ITA grafts; P<0.001). The in situ RA demonstrated a typical muscular architecture, whereas RA coronary grafts showed a clear reduction of the thickness of the medial layer and had a less well-defined muscular component of the media with interposition of elastic tissue. Serotonin endovascular infusion elicited a strong spastic reaction in in situ RAs; the same challenge induced only moderate constriction in RA and ITA coronary grafts.

CONCLUSIONS

Implantation in the coronary circulation leads to major anatomic and vasoreactive modifications of the RAs that tend to lose the morphofunctional features of a muscular conduit and assume those of an elastomuscular artery, such as the ITA.

Chronic compensatory increase in ulnar flow and accelerated atherosclerosis after radial artery removal for coronary artery bypass

BACKGROUND

Only scant information is available on the chronic consequences of radial artery removal for coronary artery bypass surgery on forearm circulation.

METHODS

Twenty-five patients submitted to radial artery removal for coronary artery bypass were submitted to serial Doppler echocardiographic evaluation of the flow and morphology of the forearm arteries.

RESULTS

The peak systolic velocity of the ulnar artery of the operated side was significantly higher than that of the control site. The intimal-medial thickness of the ulnar artery was always significantly higher on the operated side, and this difference reached statistical significance at 10 years' follow-up. There was a significantly higher prevalence of atherosclerotic plaques in the ulnar artery of the operated versus control arm (7/25 vs 0/25, P = .03).

CONCLUSION

Radial artery removal for coronary artery bypass surgery leads to a chronic increase in ulnar flow accompanied by increased intimal-medial thickness and accelerated atherosclerotic disease. These findings might have potentially important implications for surgical indications and patient management.

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

BACKGROUND

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.

PATIENTS AND RESULTS

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.

CONCLUSION

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.

Harvest of the radial artery for coronary artery surgery preserves maximal blood flow of the forearm

BACKGROUND

Use of the radial artery as a conduit for coronary artery surgery has increased dramatically. It has been assumed that blood flow to the forearm will not be compromised by its removal.

METHODS

Sixteen patients who had the left radial artery harvested for coronary surgery at least 3 months earlier were studied. The right radial artery was not harvested. The radial, ulnar, and brachial artery diameters and flows were measured using pulsed wave Doppler with a 15-MHz linear array transducer. Measurements were performed at rest, with the right radial artery compressed, and after ischemia with forearm exercise.

RESULTS

At rest, the (mean +/- SE) diameter of the left ulnar artery was consistently greater than the right (2.4 +/- 0.09 versus 2.1 +/- 0.09 mm, p = 0.001) as was flow (74 +/- 9.9 versus 48 +/- 8.5 mL/min, p = 0.005). There was no difference between diameters or flows in the brachial arteries. After compression of the radial artery, flow increased in the right ulnar artery from 39 +/- 8.0 to 72 +/- 17.6 mL/min (p = 0.019) without an increase in ulnar artery size and was not different from the left ulnar artery flow at rest (p = 0.440). After ischemic forearm exercise, flow increased in the two brachial arteries almost equally (left, 348 +/- 50; right, 371 +/- 63 mL/min).

CONCLUSIONS

Blood flow to the forearm and hand is not compromised by harvest of the radial artery.

Outcome assessment of hand function after radial artery harvesting for coronary artery bypass

The radial artery has gained widespread acceptance as a conduit for coronary artery bypass. Advantages include minimal donor site discomfort, ease of handling, excellent early patency rates, and the possibility of freedom from late conduit atherosclerosis. Although most series describe minimal morbidity, a significant incidence of radial sensory neuropathy and isolated instances of hand claudication and ischemia have been reported. We performed an outcome study utilizing the Short Form-36, the Upper Limb-Disabilities of Arm, Shoulder and Hand, and a modified self-administered hand diagram to compare 288 patients undergoing coronary artery bypass utilizing the radial artery with a control group of 174 patients undergoing coronary artery bypass without the radial artery. The data were analyzed by the t test for continuous variables and the chi-square test for categorical variables, and subsequently a multivariate regression model was constructed. No patients developed hand claudication or ischemia. Although there was an incidence of radial sensory neuropathy of 9.9% associated with radial artery harvest, it was not significantly higher than the incidence in the control group (5.2%, p =.16). Intrinsic patient factors such as obesity, age, diabetes, and peripheral vascular disease were the principal determinants of overall health and quality of life issues.

Oxygen pressure measurement during grip exercise reveals exercise intolerance after radial harvest

BACKGROUND

Exercise intolerance of the hand after harvest of the radial artery is not well understood, although mild reductions of blood flow to the hand are reported. To ascertain its prevalence, patient symptoms implying potential exercise intolerance were evaluated by measuring transcutaneous oxygen pressure of the hand during grip exercise. For ascertaining predictive values, we verified ulnar flow reserve measured by Doppler ultrasonography before the harvest of radial artery.

METHODS

Forty patients whose radial artery was harvested for coronary bypass graft, were interviewed and tested 1 year after operation, and their preoperative ultrasonographic data compared.

RESULTS

Five patients (12.5%) had mild symptoms implying exercise intolerance. Exercise tests revealed severe decreases in tissue oxygenation in 7 patients (17.5%), but in accordance with symptoms (p = 0.0018). Tissue oxygenation in the operated hand was lower than in the nonoperated even in asymptomatic patients (p = 0.0011). Preoperative Doppler echography revealed that ulnar arteries of symptomatic patients were smaller (p = 0.0019) and carried lower blood flows during manual compression of the radial artery (p = 0.0004) compared with those of asymptomatic patients. Smaller ulnar arteries (less than 1.4 mm/m(2)) with poor flow reserves (less than 60 mL x min(-1) x m(-2) during radial compression) appear to indicate risks for exercise intolerance (p = 0.0004).

CONCLUSIONS

More than 10% of patients after harvest of radial arteries had mild symptoms implying exercise-intolerance, which accorded with abnormal tissue oxygenation during grip exercise. Work habits of patients should be considered in radial harvest decisions, especially if preoperative Doppler echography indicates lower flow reserves for the ulnar artery.

Long-term Arm Morbidity after Radial Artery Harvesting for Coronary Bypass Operation

BACKGROUND

The use of the radial artery (RA) in coronary bypass operations has become increasingly popular in recent years, but there is almost no documentation regarding the midterm and long-term arm complications.

METHODS

Between January 1 and December 31, 1998, 109 patients underwent operations for myocardial revascularization employing a pedicled RA as 1 of the coronary grafts. The patients were surveyed for subjective arm morbidities at 2 times during their follow-up: short term (mean, 7 months postoperatively; range, 0.3-14 months) and long term (mean, 49 months postoperatively; range, 46-57 months).

RESULTS

At the short-term follow-up, 33 (33.3%) of the patients had some complaints regarding the arm that was operated on, with 4 (4%) of the patients reporting arm disability with complaints that focused on pain (11, 11%), numbness (15, 15%), and parasthesias (12, 12%). At the longterm follow-up, only 9 patients (10.5%) still experienced some sort of inconvenience with the arm that was operated on, with 1 case of functional disability, 4 complaints (4.6%) of residual parasthesias, and 1 report (2.3%) each of pain or numbness. All but 2 of the patients with complaints at the short-term follow-up reported amelioration of symptoms at the long-term follow-up.

CONCLUSION

It appears that severe arm disability early after RA harvesting is likely to dissolve with time. Our favorable late follow-up results support the continuation of the employment of the RA as a conduit for coronary artery bypass grafting operations.

Long-term results of the radial artery used for myocardial revascularization

BACKGROUND

No information is available on the long-term results of radial artery (RA) grafts used as coronary artery bypass conduits.

METHODS AND RESULTS

In this report, we describe the long-term (105+/-9 months) angiographic results of a series of 90 consecutive patients in whom the RA was used as a coronary artery bypass conduit directly anastomosed to the ascending aorta. The long-term patency and perfect patency rates of the RA were 91.6% and 88%, respectively, versus 97.5% and 96.3% for internal thoracic artery grafts. The severity of stenosis of the target vessel clearly influenced long-term RA patency, whereas location of the target vessel and long-term use of calcium channel blockers did not influence angiographic results. Preserved endothelial function and absence of flow-limiting, fibrous, intimal hyperplasia were also documented.

CONCLUSIONS

Ten years after surgery, RA grafts have excellent patency and perfect patency rates. Appropriate surgical technique and correct indication are the key factors for long-term RA patency.

Recognition of potential morbidity after use of the radial artery as a conduit for coronary artery revascularization

The use of the radial artery as an alternative vascular conduit for coronary bypass surgery has become increasingly popular. The plastic surgery experience with radial forearm flaps has shown that sacrifice of the radial artery is not always a benign maneuver. The potential morbidity after using this conduit donor site in terms of hand dysfunction or wound healing problems can be significant, and frequently must ultimately be addressed as part of the role of the reconstructive surgeon. Case examples of skin necrosis, subsequent forearm wound infection and hypertrophic scarring after radial artery harvest are presented to introduce this as a real concern and to allow a review of the entire spectrum of potential problems in this regard. Any selection process where the radial artery may be chosen as the coronary revascularization conduit must anticipate these known donor site complications.

The snuffbox technique: a reliable color Doppler method to assess hand circulation

OBJECTIVE

Although the Allen test is crude and subjective, an objective color Doppler method has yet to be established in the assessment of hand circulation before radial artery harvesting. Doppler studies so far have neglected the Doppler principle that the insonation angles should be less than 30 degrees and have not been compared with any standard except the crude Allen test. We therefore introduced the snuffbox technique, measuring the radial artery at the anatomic snuffbox, which is the most distal area after harvesting. Color Doppler methods were compared with the stump pressure as a criterion standard.

METHODS

Maximal flow velocity and Doppler angles of the snuffbox, palmar artery, and ulnar artery were measured in 20 hands before and after radial artery harvesting. Stump pressure was measured during surgery.

RESULTS

Maximal flow velocity in the snuffbox decreased with radial artery compression and after radial artery harvesting. All the flow patterns in the snuffbox technique showed simultaneous reversal. Maximal flow velocity in the ulnar artery increased with radial artery compression and after radial artery harvesting. Maximal flow velocity in the palmar artery did not change significantly with radial artery compression or after radial artery harvesting. Doppler angles were 20.9 degrees +/- 6.0 degrees in the radial artery of the snuffbox, 82.5 degrees +/- 6.1 degrees at the palmar artery, and 81.0 degrees +/- 7.6 degrees at the ulnar artery. The changes in the snuffbox technique were highly correlated with the stump pressure ratio (P <.001).

CONCLUSIONS

Among various color Doppler methods, the snuffbox technique was precise and reliable.

Effects of radial artery harvesting on forearm function and blood flow

BACKGROUND

There is little information on the effects of radial artery harvesting on postoperative forearm function and blood flow. We evaluated the early changes in forearm neural sensation, circumference, grip power, cyclical exercise fatigue, and blood flow after radial artery harvesting for coronary artery bypass graft (CABG) surgery.

METHODS

Twenty-three patients with negative Allen's test of the nondominant forearm were recruited preoperatively and underwent assessment of bilateral forearm function (soft touch and pin-prick neural sensation, circumference, handgrip power, cyclical exercise fatigue) and blood flow measurements (forearm plethysmography). All vasoactive drugs were stopped 24 hours before assessments. Identical follow-up assessments were conducted (mean +/- SEM) 3.4 +/- 0.4 months postoperatively.

RESULTS

At the time of postoperative assessment all harvested forearm wounds were healed. There was no reduction of postoperative soft touch sensation but in 3 patients objective pinprick sensation was reduced in the distribution of the lateral antebrachial cutaneous nerve of the harvested forearms. Postoperative forearm circumference (p < 0.05) and grip power (p < 0.05) were significantly reduced in both forearms, however cyclical exercise fatigue was improved in both forearms. Preoperative and postoperative forearm blood flow at rest and in exercise-induced ischemic reperfusion were not significantly different in both forearms.

CONCLUSIONS

In patients with a negative Allen's test, harvesting of the radial artery does not adversely affect subsequent forearm function or blood flow to a clinically significant degree.

The radial artery is larger than the ulnar

BACKGROUND

The radial artery is presently widely used as a bypass graft for coronary artery reconstruction. However, the traditional opinion that the ulnar artery is the larger forearm artery has been questioned.

METHODS

The internal diameters of the radial and ulnar arteries were measured at the wrist in postmortem angiograms of 24 cadavers. Differences in mean values of variables between ulnar and radial arteries were analyzed using the Wilcoxon test.

RESULTS

The mean diameter of the radial artery was 28% larger than that of the ulnar artery in the right arm (p < 0.001) and 26% larger in the left arm (p < 0.001). In the right arm the radial artery was dominant in 20 of 24 cadavers (83%), the ulnar artery in 3 of 24 (13%), and the arteries were equal in 1 of 24 (4%). In the left arm the figures were 17 of 24 cadavers (71%), 3 of 24 (13%), and 4 of 24 (17%), respectively.

CONCLUSIONS

In view of the present investigation the radial artery should be considered the larger forearm artery of the hand in most patients.

Morbidity after procurement of radial arteries in diabetic patients and the elderly undergoing coronary revascularization

BACKGROUND

The use of radial arteries for coronary revascularization is increasing. There remain concerns regarding alteration of upper extremity function after radial artery procurement. This study evaluates the functional morbidity in higher risk patients.

METHODS

Between April 1997 and September 1999, 374 patients underwent unilateral or bilateral radial artery procurement. A questionnaire was used to evaluate symptoms related to motor and sensory function and changes in appearance after radial artery harvest.

RESULTS

Two hundred eighty-nine patients were successfully interviewed. The average age was 63 years. Median follow-up was 9.5 months (range, 2 to 23 months). No patient suffered limb loss. Altered gross and fine motor function, residual pain, paresthesias, numbness, pallor, swelling, and altered temperature sensation were compared among diabetic patients, patients older than 70 years, and patients without these characteristics.

CONCLUSIONS

Radial artery procurement for elective coronary revascularization can be done with minimal serious morbidity in higher risk patients. The most common symptoms were numbness and paresthesia. Despite the finding of greater residual pain in diabetic patients, we do not believe the use of radial artery conduits is contraindicated in these patients.

Radial artery harvesting for coronary bypass operations: neurologic complications and their potential mechanisms

OBJECTIVES

We sought to determine the incidence of self-reported neurologic hand complications after radial artery harvest for coronary artery bypass grafting.

METHODS

Between February 20, 1996, and December 31, 1999, 615 patients underwent coronary bypass operations with radial arteries. A scripted telephone interview was performed, collecting data on perceived thumb weakness and sensation abnormalities in the distribution of the radial nerve in 560 patients. The average time to follow-up interview was 14.5 +/- 9 months.

RESULTS

Neurologic complications were reported in 30.1%, decreased thumb strength in 5.5%, and any sensation abnormality in 18.1% of patients. There was a high rate of symptom improvement over an average of 8.7 +/- 7.5 months, such that only 12.1% of patients reported symptoms without any improvement. Associations between thumb weakness and sensory abnormalities imply median nerve damage in some patients. There were statistically significant associations between neurologic complications and diabetes, peripheral vascular disease, elevated creatinine levels, smoking, and number and site of radial artery harvest.

CONCLUSIONS

The overall rate of self-reported neurologic complications after radial artery harvest was higher than previously reported. These symptoms may be attributable to radial and median nerve injury caused by trauma and devascularization. These data have important implications not only in attempting to improve harvesting techniques but also in guiding informed consent before coronary artery bypass grafting.

Midterm endothelial function and remodeling of radial artery grafts anastomosed to the aorta

BACKGROUND

The purpose of this study was to elucidate the midterm endothelium-dependent vasodilatory capacity of radial artery grafts anastomosed to the aorta, as well as their morphometric evolution with the time.

METHODS

Five years after surgery we evaluated the response of aorta-anastomosed radial artery grafts to the endovascular infusion of acetylcholine in 11 of the first 61 patients operated on at our institution, and we compared it to the response with that of internal thoracic artery grafts. Moreover, the first 20 patients who had a perfect radial artery graft on angiography at 1 year were restudied at 5 years and subjected to a comparative analysis of the diameters of the radial artery graft and the grafted coronary arteries.

RESULTS

At midterm angiography, dilation of the 2 types of grafts was similar in response to acetylcholine administration (radial artery, from 2.61 +/- 0.39 to 2. 90 +/- 0.34 mm; internal thoracic artery, from 2.68 +/- 0.21 to 2.93 +/- 0.27 mm; P =.01 for both). The diameters of aorta-anastomosed radial artery grafts and grafted coronary arteries increased between both 1 and 5 years according to angiographic studies (radial artery grafts, from 2.08 +/- 0.45 to 2.54 +/- 0.53 mm; grafted coronary arteries, from 1.92 +/- 0.47 to 2.18 +/- 0.41 mm; P <.001 for both), but the increase was greater for the radial artery grafts (P <.001).

CONCLUSIONS

Aorta-anastomosed radial artery grafts maintain an appreciable capacity for endothelium-dependent vasodilatation 5 years after implantation and undergo a progressive increase in luminal diameter with time. These observations contradict the presumed tendency for progressive fibrous intimal hyperplasia to develop in radial artery grafts.

Clinical experience with autologous endothelial cell-seeded polytetrafluoroethylene coronary artery bypass grafts

OBJECTIVE

Autologous endothelial cell seeding was used to improve the patency of 4-mm polytetrafluoroethylene vascular prostheses.

METHODS

Since 1995, 14 patients with coronary artery disease received 21 autologous endothelial cell-seeded polytetrafluoroethylene vascular bypass grafts for coronary artery revascularization. The polytetrafluoroethylene grafts were seeded with the endothelial cells in a multiple step procedure, including cell culture techniques before coronary bypass operation. With the use of extracorporal circulation and cardioplegic arrest, a bypass operation was performed by means of conventional surgical techniques.

RESULTS

After a mean postoperative follow-up of 27.7 months (range, 7.5-48 months), the graft patency rate is 90.5%. Follow-up angiograms of the aorta-coronary polytetrafluoroethylene bypass grafts showed patent bypasses in all cases except two. Angiograms of all 19 patent endothelial cell-seeded polytetrafluoroethylene bypass grafts showed a smooth luminal borderline without stenotic regions. The percutaneous transluminal angioscopic evaluation showed a glossy white and smooth endoluminal graft surface without any fibrin, platelet, or erythrocyte deposits. Intravascular ultrasonographic examinations confirmed the results.

CONCLUSION

Patency of autologous endothelial cell-seeded 4-mm polytetrafluoroethylene vascular prostheses as coronary artery bypass grafts was much better than that of unseeded polytetrafluoroethylene grafts. Further evaluations and a larger population of patients will prove whether the encouraging patency will last.