The Use of Radial Artery for CABG: An Update

Rationale and design of a single-center randomized trial to compare the graft patency between the radial artery and the no-touch saphenous vein in coronary artery bypass grafting surgery (GRAFT-CAB Study)

BACKGROUND

Previous studies suggested only the radial artery and the No-touch (NT) technique were effective in reducing graft occlusion after coronary artery bypass grafting (CABG) surgery. However, there is no randomized trial comparing these 2 graft conduits. The optimum second conduit for CABG remains undetermined.

MATERIALS AND METHODS

This study is a prospective, single-center randomized clinical trial, aiming to compare the graft patency between the radial artery and the NT vein graft. All patients undergoing isolated CABG with left internal mammary artery (LIMA) plus at least 2 additional grafts will be considered eligible. About 774 cases (516 in the radial artery group and 258 in the NT vein group) will be enrolled in over 1 to 2 years. Participants will be randomized and allocated to two bypass strategies: the LIMA plus 1 radial artery and 1 conventional vein graft, or the LIMA plus 2 NT vein grafts. The primary outcome is graft occlusion at 1 year after CABG evaluated by CT angiography. The secondary outcomes include graft occlusion at 3 and 5 years and major adverse cardiac or cerebrovascular events at 1, 3, and 5 years follow-ups.

DISCUSSION

This study will define whether or not the NT vein has a lower graft occlusion rate than the radial artery in short and mid-term follow-ups, and provide new evidence for the second conduit choice in CABG surgery.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06014047. Registered on October 15th, 2023.

Duplicate Radial Artery Variation: A Comprehensive Analysis With Case Report, Literature Review, Embryological Insights and Clinical Significance

Thorough knowledge of the anatomical variations of the arterial pattern of the upper limb is of high clinical importance in many medical fields, from surgery to nursery and anesthesiologic practice. During a routine dissection at the Anatomy Department of the Medical University of Plovdiv, a rare variation of the vascular system in the upper limb of a study cadaver was observed. The exhibited variation was the occurrence of a brachioradial artery (BRA) that ran along the main axis of the arm, superficially to the median nerve. After dissection of the cubital fossa, an unusually underdeveloped radial artery was also spotted. Per our knowledge, such a type of duplicate radial artery, the coexistence of a BRA and an underdeveloped radial artery has not been reported in the relevant literature on the topic. The underdeveloped radial artery gave a major branch, the recurrent radial artery, a branch usually given by the brachial artery or the BRA in case of a BRA variation. Variations in the arterial pattern could potentially give insight into the features of the embryological development of the vascular system.

A Superficial Anatomical Variation in the Radial Artery Renders It Unsuitable as a Graft in Coronary Revascularization

In our experience, employing a radial artery in combination with an internal thoracic artery under specific conditions represents a superior option compared to using a vein graft in coronary artery surgery. Additionally, this combination is a remarkable alternative to utilizing bilateral thoracic arteries. We had planned the left radial artery as the second target graft in two patients undergoing coronary artery bypass surgery; the left internal thoracic artery to the left anterior descending branch would be the main graft in both patients. Anatomic variation of the radial artery, which presented as a superficial radial artery in both patients, led us to forego the use of the radial artery graft. This decision aimed to ensure sufficient blood supply to the palmar arch and prevent any potential inadequacy in the length of the coronary graft. The occurrence of this variation is exceptionally rare, accounting for approximately 0.02% based on our experience with radial artery harvesting. Furthermore, globally, the documentation of photographs depicting a superficial radial artery is even more infrequent.

Prevalence of The Arterial Hand Dominance Using the Modified Allen Test and Pulse Oximetry among Plastic Surgery Patients

Background

The ulnar and radial arteries are the major source of blood supply in the hand, as they form the superficial and deep palmar arches. Arterial hand circulation is one of the most complicated arterial trees and connections in the body, with tremendous variations in its structure. This study aimed to evaluate whether the ulnar artery or radial artery is the dominant artery in hand circulation among plastic surgery patients at King Khalid University Hospital and to correlate the arterial hand dominance with handedness and gender.

Methods

This is an analytical cross-sectional study conducted at King Khalid University Hospital in Riyadh, Saudi Arabia, on plastic surgery patients. The sampling method is purposive sampling. The calculated sample size is 28; however, 100 participants have been enlisted in the study. The data have been collected using the modified Allen test with a pulse oximeter.

Results

The collective prevalence of dual arterial dominance in our study was 69% compared with 56% and 30% for Little et al (P = 0.013) and Fuhrman et al (P < 0.001), respectively. With regard to gender, women were more likely to have a dual arterial blood supply than men, with the frequency values of 85% and 58.3% for women and men, respectively (P = 0.017).

Conclusions

Our study found that dual arterial supply is predominant among our participants, with 69% of our participants possessing a dual arterial supply, while 18% and 13% constitute the prevalence of radial and ulnar dominance, respectively. This contrasts with what has been reported previously in the literature.

Radial artery graft in coronary artery bypass surgery 1 week to 1 year postoperation

Background

The actual patency rate of the radial artery (RA) grafts 1 week and 1 year after coronary artery bypass grafting (CABG) has not been extensively reported on. We used coronary computed tomography angiography (CCTA) to evaluate the patency rate of RA grafts and compared it with that of saphenous vein (SV) grafts.

Methods

In this observational cohort study, 80 patients who underwent urgent or elective CABG with RA and SV grafts at Ruijin Hospital from August 2019 to June 2021 were included. Follow-up CCTA scans were completed about 1 year postoperation in the out-patient clinic. We graded the grafts into four classes: A, excellent; B, graft diameter <50% of target coronary artery; O, occluded; and S, string sign. Both S and O were defined as graft failure.

Results

The patients' mean age was 58.48±8.06 years, and 87.5% (70/80) of the patients were male. The 1-week patency rate of the left internal mammary artery (LIMA), RA, and SV grafts were 98.7% (75/76), 76.3% (61/80), and 93.8% (75/80), respectively. At 1 year, the patency rate of the LIMA, RA, and SV grafts were 97.4% (74/76), 80.0% (64/80), and 81.3% (65/80), respectively. The RA graft patency rate was lower than was the SV graft patency rate perioperatively [relative risk (RR): 0.918; 95% confidence interval (CI): 0.852-0.990; P=0.007]. Moreover, 63.6% (7/11) of RA grafts graded S and 25.0% (2/8) of RA grafts graded O were defined as patent (graded A or B) at 1 year postoperation. Compared with SV grafts, more RA grafts improved (RA: 12/80, 15.0%; SV: 0%) and fewer RA grafts deteriorated (RV: 10/80, 12.5%; SV: 19/80, 23.8%) from 1 week to 1 year (P=0.001). The patency rate of the 2 types of grafts became similar at 1 year postoperation (RR: 0.560; 95% CI: 0.113-2.781; P>0.99).

Conclusions

RA grafts had a lower patency rate than did SV grafts 1 week after operation. However, because of the "revival" phenomena and lower attrition rate, the patency rate of the two kinds of grafts did not show any significant difference at 1 year.

Late Clinical Outcomes of Total Arterial Revascularization or Multiple Arterial Grafting Compared to Conventional Single Arterial with Saphenous Vein Grafting for Coronary Surgery

Coronary surgery provides better long-term outcomes than percutaneous coronary intervention. Conventional practice is to use a single arterial conduit supplemented by saphenous vein grafts. The use of multiple arterial revascularization (MAG), or exclusive arterial revascularization (TAR), however, is reported as having improved late survival. Survival is a surrogate for graft failure that may lead to premature death, and improved survival reflects fewer graft failures in the non-conventional strategy groups. The reasons for not using MAG or TAR may be due to perceived technical difficulties, a lack of definitive large-scale randomized evidence, a lack of confidence in arterial conduits, or resources or time constraints. Most people consider radial artery (RA) grafting to be new, with use representing approximately 2-5% worldwide, despite select centers reporting routine use in most patients for decades with improved results. In conclusion, the current body of evidence supports more extensive use of total and multiple arterial revascularization procedures in the absence of contraindications.

Left Internal Mammary Artery as an Endocrine Organ: Insights Into Graft Biology and Long-term Impact Following Coronary Artery Bypass Grafting

The left internal mammary artery (LIMA) is considered the criterion standard vessel for use in coronary artery bypass grafting. In recent decades, countless studies have documented its superiority over other arterial and venous coronary artery bypass grafting conduits, although the full mechanisms for this superiority remain unknown. A growing body of literature has unveiled the importance of extracellular vesicles known as exosomes in cardiovascular signaling and various pathologic states. In this review, we briefly compare the clinical longevity of the LIMA relative to other conduits, explore the effects of varying grafting techniques on clinical and angiographic outcomes, and provide physiologic insights into graft function on a cellular and molecular level. Finally, we explore exosome signaling as it pertains to atherosclerosis in support of the LIMA as an "endocrine organ."

Distal Radial Artery Access for Recanalization of Radial Artery Occlusion and Repeat Intervention: A Single Center Experience

Background: Once occluded, the radial artery becomes unsuitable for repeat interventions and obligates the need for alternative vascular access, such as the femoral approach, which is not encouraged by current guidelines. With the dissemination of distal radial access (DRA), which allows the cannulation of the artery in its distal segment and which remains patent even in the case of radial artery occlusion (RAO), the option to perform angioplasty at this level becomes feasible. Methods: Thirty patients with RAO were enrolled in this pilot study. Recanalization was performed through DRA using hydrophilic guidewires. The feasibility endpoint was procedural success, namely the successful RAO recanalization, the efficacy endpoint was patency of the artery at 30 days, and the safety endpoint was the absence of periprocedural vascular major complications or major adverse cardiac and cerebrovascular events. Results: The mean age of the patients was 63 ± 11 years, and 15 patients (50%) were men. Most patients had asymptomatic RAO (n = 28, 93.3%), and only two (6.6%) reported numbness in their hands. The most common indication for the procedure was PCI (19, 63.2%). Total procedural time was 41 ± 22 min, while the amount of contrast used was 140 ± 28 mL. Procedural success was 100% (n = 30). Moreover, there were no major vascular complications (0%); only two small hematomas were described (10%) and one had an angiographically visible perforation (3%). One case of periprocedural stroke was reported (3%), with onset immediately after the procedure and recovering 24 h later. Twenty-seven radial arteries (90%) remained patent at the one-month follow-up. Conclusions: RAO recanalization is feasible and safe, and by using dedicated hydrophilic guidewires, the success rate is high without significantly increasing procedural time or the amount of used contrast.