Radial artery duplication

Unusual point-of-care-ultrasonography finding during arterial cannulation

Abstract

The radial artery is the most common choice for arterial cannulation, coronary interventions, and various interventional radiological procedures. Here, we describe a case of unilateral duplication of the radial artery detected during radial artery cannulation using point-of-care ultrasonography (POCUS). The duplication of the radial artery in the forearm can hinder trans-radial access secondary to variations in the diameter. An actual duplication also carries a high risk of accidental injury to the arterial wall during routine invasive procedures and other forearm procedures such as free flap construction. POCUS is invaluable for detecting arterial anomalies before proceeding with any interventional procedures.

Introduction

The radial artery is the most common choice for arterial cannulation, coronary interventions, and various interventional radiological procedures. Anatomical variations of such clinically relevant artery may interfere during its use in various diagnostic, therapeutic, or surgical interventions.[¹] The point-of-care ultrasound (POCUS) enhanced the success rate and safety of arterial cannulation.[²] Here, we describe a case of unilateral duplication of the radial artery detected during radial artery cannulation using POCUS. A real duplication of the radial artery in the forearm was rarely reported in the literature and was typically seen in the cadaver during anatomical dissection.[³] Perhaps, this is the first instance of radial artery duplication detected in real time using POCUS.

Case Report

A 40-year-old male patient diagnosed with an L2 spine fracture was posted for laminectomy and decompression in the prone position. The right radial arterial cannulation was planned after induction of anesthesia. A modified Allen's test confirmed the adequacy of collateral circulation in the right hand was unremarkable. The linear transducer probe (HFL38x, 13––6 MHz 6 cm; The SonoSite EDGE II; SonoSite, Inc. Bothell, WA, USA) was kept 3 cm proximal to the wrist joint out of the plane before proceeding for arterial cannulation. The POCUS image shows two arterial pulsations at that point [Figure 1]. The brachial artery was traced from the cubital fossa to solve the dilemma. We found that the brachial artery divides into the radial and ulnar artery; the radial artery continues distally and is 7–8 cm distal to the cubital fossa. It again divides into two, which continue up to the wrist joint [https://links.lww.com/SJAN/A34]. The primary and duplicated radial arteries run along the normal course of radial arteries till the wrist joint without reunion and joints with the palmar arch to supply the volar and thecal side of the hand [https://links.lww.com/SJAN/A34]. To rule out brachial artery duplication, it was traced right from the mid-arm region over the cubital fossa till it bifurcates into the radial and ulnar arteries. The findings also rule out the possibility of a low brachial artery division. The presence of an ulnar artery over the ulnar side reaffirms this extra vessel as the duplication of the radial artery. POCUS of the contralateral forearm showed normal vessel anatomy. Later the arterial cannula was placed on the left radial artery, and the procedure was uneventful. Written informed consent was obtained from the patient.

Figure 1: Ultrasound image showing two radial arteries, median nerve, and radius bone at 3 cm proximal to the wrist joint

Discussion

The radial artery is the most common upper extremity vessel subjected to anatomical variations with regard to its origin and course.[⁴] Anatomical variations of this clinically important artery carry implications for the interventional procedures of anesthesiologists, radiologists, and plastic surgeons.[⁵⁶] Knowledge of the vascular anatomy of the upper limb is paramount before proceeding with any invasive procedures in the arm or forearm. Among the anatomical variations of the arm and forearm vessels, variations of radial and ulnar arteries are mostly reported.[⁷] A high origin, duplication and the absence of its branches, diameter variations, tortuosity, and abnormal course are the anomalies of the radial artery reported in the literature.[¹⁴⁶⁷] Among the abnormal branching of the upper extremity arteries, a high radial artery origin is most commonly reported, with a prevalence rate of 9.46% noted in a recent cadaveric study.[⁷] Rodríguez-Niedenführ et al.[⁴] reported the incidence rate of radial artery duplication to be <0.02% per their criteria for anatomical nomenclature variations. However, an actual duplication of the radial artery in the forearm is rarely reported. To date, only two reports of primary radial artery duplication exist in the scientific literature detected during routine cadaveric dissection.[³] Bumbaširević et al.[⁵] reported duplication of the radial artery in the left hand of a male patient while performing a radial forearm flap. Yokoyama et al.[⁶] evaluated variations of the radial artery through ultrasound among patients requiring trans-radial coronary interventions and documented variations such as tortuosity, stenosis, hypoplasia, and radioulnar loop among 9.6% of patients. But no case of radial artery duplication was noted in their series.[⁶] The literature documented a 1–5% incidence of access failures to the radial artery.[⁶] Anatomical variations account for a significant cause of access failure in radial artery interventional procedures. The duplication of the radial artery in the forearm can hinder trans-radial access secondary to variations in the diameter and its usual anatomical course.[⁶] An actual duplication also carries a high risk of accidental injury to the arterial wall during routine invasive procedures and other forearm procedures such as free flap construction.[⁵⁶] There was literature suggesting the absence of ulnar or radial artery, and blind attempts at cannulation in such anomaly can lead to complications.[⁸] A low level of duplication of such an artery can lead to arterial injury.[⁹] There can be accidental cannulation of these duplicated arteries while attempting peripheral venous cannulations of the cephalic vein.[¹⁰]

POCUS is invaluable for detecting arterial anomalies before proceeding with any interventional procedures. The routine use of POCUS will enhance the safety and success of any arterial interventional procedures.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.