The right radial approach is an increasingly utilized first-line vascular access site for coronary catheterization. Variations of the left radial approach, however, have proven to be technically difficult. A newly developed vascular access technique involving cannulation of the distal radial artery located at the anatomic “snuffbox” of the left hand (sometimes referred to as the snuffbox approach) was reported, with data reflecting numerous advantages over the conventional left radial access approach.
We describe the case of a 65-year-old Filipino male admitted for chest pain and treated as a case of non-ST segment elevation myocardial infarction (NSTEMI). Past medical history revealed a prior coronary artery bypass graft (CABG) procedure in 2004. Coronary angiography and intervention were done with the left distal radial artery accessed via the anatomic snuffbox approach. Intraprocedural findings noted a patent left internal mammary artery (LIMA) graft, and a saphenous vein graft-right posterior descending artery (SVG-RPDA) with 60% disease and thrombus at the mid segment of the SVG. Successful intervention of the mid to distal SVG using two overlapping everolimus-eluting platinum chromium stents was done with no technical difficulties. The patient had an unremarkable post procedure course and was discharged with an improved status. We believe this case is one of the first documented cases of a successful SVG intervention via the left distal radial snuffbox approach, as well as the first of its kind to be documented in the Southeast Asian region.
The transradial approach to cardiac catheterization has been extensively utilized, developed, and championed since its introduction in 1993.1,2 The advantages of this approach are numerous, including reduced incidence of major hemorrhage, lower peri-procedural complication rates, rapid mobilization of the patient post procedure, and strong patient preference for this access site.3-5 In most circumstances, the right transradial approach serves as the first-line or “default” site of radial access, with the left transradial approach reserved for special clinical scenarios, such as in post-CABG patients, where visualization of grafts are necessary for coronary angiography and potential intervention. However, the left transradial approach may be ergonomically inconvenient for the operator and technically dangerous for the patient, with a higher incidence of vascular crossover, dye usage, and radiation exposure.6 Recently, a newly developed vascular access technique involving cannulation of the distal radial artery via the anatomic “snuffbox” of the left hand (snuffbox approach) was reported, offering numerous advantages compared to the conventional left radial access approach.5,6 We describe the case of a post-CABG patient that underwent coronary intervention of a saphenous vein graft utilizing a left distal radial approach.
A 65-year-old Filipino male was admitted at the emergency room for complaints of severe, crushing chest pain. He was hypertensive and diabetic, and had undergone a CABG procedure in 2004. The patient’s operative records revealed the following grafts: left internal mammary artery (LIMA) to left anterior descending artery (LAD), SVG to first diagonal artery (D1) sequential to the first obtuse marginal branch (OM1), SVG to RPDA and distal right coronary artery (RCA). Physical examination was unremarkable, with stable vital signs noted. A 12-lead electrocardiogram revealed sinus bradycardia with poor R wave progression and the presence of 0.5 mm T wave inversions on leads V5, V6, I, and aVL, suggestive of lateral and high lateral wall myocardial ischemia (Figure 1).
The patient was treated as a case of NSTEMI and loaded on a P2Y12 inhibitor (ticagrelor) with baseline biomarkers noted to be positive (troponin I: 0.16 ng/mL). An anti-anginal medication (isosorbide dinitrate [ISDN]) was started, and the patient was admitted to the hospital’s coronary care unit and scheduled for cardiac catheterization.
Preparations were made for coronary angiography and percutaneous intervention.
The patient’s left arm was pronated, positioned over his chest, and secured in place. The distal segment of the left radial artery was palpated in the radial fossa (“anatomic snuffbox”), and noted to be distinct and well developed. The puncture site was thoroughly cleansed and local anesthesia (lidocaine HCl 1.0%; 0.5 mL to 1.0 mL) was extensively infiltrated around the fossa. Arterial puncture with the modified Seldinger’s technique was done using a 21-gauge needle. A 6 French vessel dilator was gently introduced and secured (Figure 2). Backflow was verified with the coronary angiogram then carried out. Left heart catheterization was done to cannulate and visualize the left main coronary system, the right coronary system, and the LIMA and SVG grafts, respectively. Intraprocedural findings noted a patent LIMA-LAD graft and a 60% stenosis at the mid segment of the SVG-RPDA/distal RCA graft, with a thrombus visualized. Successful dilation and stenting of the mid-distal SVG was done using two overlapping 3.5 mm x 16 mm everolimus-eluting platinum chromium stents with no technical difficulties. A reduction of the stenosis was appreciated (from 60% to 0%) with TIMI-3 flow restored (Figure 3). The patient tolerated the intervention with no episodes of hypotension or arrhythmias. The left distal arterial access site remained stable, with no bleeding noted during or after the procedure. Hemostasis was achieved by manual pressure, with complete hemostasis documented within 2 hours post procedure. The patient was subsequently discharged with an improved status, and maintained on optimized medical therapy including dual antiplatelets, anti-ischemics, and statins.
Left distal radial artery access for catheterization was first described by Babunashvili in 2011 as a retrograde technique for cannulating occluded radial arteries.7 In 2017, Kiemeneij published the first detailed report of the anatomical snuffbox approach of the left distal radial artery, having performed a large series of successful coronary diagnostic and interventional procedures.8 His report described the technique to be not only procedurally feasible, but also to afford distinct advantages:
(a) Increased comfort for the operator, who can work from the patient’s right side with ease, especially with the patient’s hand maintained in a pronated rather than an awkward supinated position;
(b) Minimized operator radiation exposure, given the enhanced ergonomics and distance from the radiation source;
(c) Potentially minimized rates of radial artery occlusion, given that the puncture site in the snuffbox approach is distal, with no reported incidence of traumatic injury or larger vessel wall damage.8
Several other case reports soon followed Kiemeneij’s series. Davies et al described the case of a 55-year-old male with ischemic cardiomyopathy and extensive attachments, including an intra-aortic balloon pump, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) cannulation, and invasive hemodynamic monitors. Due to the lack of conventional vascular access sites, the snuffbox approach to the left distal radial artery was used.9 Another case was reported by Vilela et al, of an 82-year-old post percutaneous transluminal coronary angioplasty patient with an aortic-femoral bypass graft and a previous aortic stent. The snuffbox approach was used as a successful alternative after difficulty was encountered with the traditional right radial artery access site.10 Further refinements in technique have led to a growing use of the distal radial artery approach, with both left and right transradial sites utilized. A current literature search reveals several case series reporting increasing success across individual institutions.11,12 Within the Southeast Asian region, Aramsareewong documented successful performance of the left radial artery snuffbox approach in a post ST-segment elevation myocardial infarction (STEMI) patient undergoing percutaneous coronary intervention (PCI).13
Despite an extensive literature search, we were unable to find any additional report of an SVG intervention performed via the left distal radial snuffbox approach. Although one of the aforementioned case series employs this approach in post-CABG patients, no interventions were carried out on coronary graft vessels.12 We believe the case herein to be the first documented successful SVG intervention via the left distal radial approach. Despite the relatively small body habitus of the Filipino population, the successful treatment of an SVG graft via the left radial snuffbox approach contributes to a larger body of evidence supporting the use of this approach across a variety of clinical scenarios.
Disclosures: The authors report no conflicts of interest regarding the content herein.
The authors can be contacted via Keith Andrew L. Chan, MD, at email@example.com.
- Sandhu K, Butler R, Nolan J. Expert opinion: transradial coronary artery procedures: tips for success. Interv Cardiol. 2017 May; 12(1): 18-24.
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- Zahran M, Alreshq R, Kolkailah A, et al. Transradial versus transfemoral approach for diagnostic coronary angiography and percutaneous coronary intervention in patients with coronary artery disease. Cochrane Database Syst Rev. 2018 Apr 18; 4: CD012318.
- Archbold, R, Robinson N, Schilling R. Radial artery access for coronary angiography and percutaneous coronary intervention. BMJ. 2004 Aug 21; 329(7463): 443-446.
- Jolly SS, Yusuf S, Cairns J, et al; RIVAL trial group. Radial versus femoral access for coronary angiography and intervention in patients with acute coronary syndromes (RIVAL): a randomised, parallel group, multicentre trial. Lancet. 2011 Apr 23; 377(9775): 1409-1420.
- Michael TT, Alomar M, Papayannis A, et al. A randomized comparison of the transradial and transfemoral approaches for coronary artery bypass graft angiography and intervention: the RADIAL-CABG Trial (RADIAL Versus Femoral Access for Coronary Artery Bypass Graft Angiography and Intervention). JACC Cardiovasc Interv. 2013 Nov; 6(11): 1138-1144.
- Babunashvili A, Dundua, D. Recanalization and reuse of early occluded radial artery within 6 days after previous transradial diagnostic procedure. Catheter Cardiovasc Interv. 2011 Mar 1; 77(4): 530-536.
- Kiemeneij F. Left distal transradial access in the anatomical snuffbox for coronary angiography (ldTRA) and interventions (ldTRI). EuroIntervention. 2017 Sep 20; 13(7): 851-857.
- Davies R, Gilchrist I. Back hand approach to radial access: The snuff box approach. Cardiovasc Revasc Med. 2018 Apr - May; 19(3 Pt B): 324-326.
- Vilela FD, Boechat e Salles JA, Cortes LA, et al. Distal transradial access in the anatomical snuffbox for coronary angiography and aortography. J Anat Physiol Stud. 2017; 1(1): 1-3. Available online at http://sciaeon.org/articles/Distal-Transradial-Access-in-the-Anatomical-Snuffbox-for-Coronary-Angiography-and-Aortography.pdf. Accessed July 8, 2019.
- Gubolino L, Barros de Toledo J, Teixeirense P, et al. Diagnostic and interventional coronary procedures by the distal radial artery in the anatomical snuffbox: a real world analysis. J Cardiovasc Dis Diagn. 2018: 6(5): 337.
- Kim Y, Ahn Y, Kim I, et al. Feasibility of coronary angiography and percutaneous coronary intervention via left snuffbox approach. Korean Circ J. 2018 Dec; 48(12): 1120-1130.
- Aramsareewong T. TCTAP C-210 The first left distal transradial access in the anatomical snuff box angioplasty (IdTRA). 23rd Cardiovascular Summit TCTAP 2018. J Am Coll Cardiol. 2018 Apr; 71(16 Supplement): S280-S282. Available online at http://www.onlinejacc.org/content/71/16_Supplement/S280. Accessed July 9, 2019.