Prevalence of Accessory Branches and Other Anatomical Variations in the Radial Artery Encountered during Radial Forearm Flap Harvest: A Systematic Review and Meta-analysis

Unusual anomaly of the radial artery encountered during the elevation of a radial forearm free flap: a case report

The radial forearm free flap (RFFF) has become popular for head and neck reconstructions. Owing to a constant anatomy the RFFF is relatively easy to dissect. Nevertheless, anatomical variations of the radial artery have been reported. Some variations could affect the survival of the flap. This paper reports an unusual anomaly of the radial artery where the radial artery was not located between the brachioradialis (BR) and flexor carpi radialis. The radial artery was observed above the BR and on the radial side of the BR. The survival of the elevated flap was deemed questionable because it had only few perforators. So we decided to discard the flap and to elevate another free flap for the head and neck defect. The donor area on the forearm was covered using the original skin of the first flap as a full-thickness skin graft. This case highlights a means to deal with anomalies of the radial artery encountered during the elevation of RFFF and the checking process for variations of the radial artery before RFFF.

[Imaging and radial approach]

Radial approach allows in a large majority of cases to perform endovascular imaging. If we can assess anatomical variations with angiography, echography approach begins a mandatory tool to do the puncture safely, but also allows to identify anatomical variations and complications.

Preventing radial arterial catheter failure in critical care - Factoring updated clinical strategies and techniques

Radial artery catheterization is a frequently performed procedure for critically ill patients. The correct function of arterial catheters is essential to provide accurate and continuous hemodynamic monitoring, facilitating intermittent blood sampling and helping to optimize the workload for critical care nurses and physicians. However, they are not without their own problems. This narrative practice review discusses several clinical aspects that are not frequently considered but may contribute to enhanced catheter functionality, less device-related failure and more acceptable dwell times. Ultrasound has demonstrated unequivocal efficacies and safety with the procedure, improving first attempt success rates with children, the obese or patients with unstable clinical vital signs and shock. Moreover, anatomic variations of the radial artery are not rare, and ultrasound-guided catheterization reduces the incidence of insertion-related complications such as hematoma, posterior wall puncture, intimal dissection, and radial nerve injury. Ultrasound guidance offers several immediate benefits by enhancing the most appropriate insertion techniques, allows for the correct catheter to vessel ratio measurements to be performed and reduces the angle of insertion, which may affect catheter failure due to inappropriate catheter length. A deeper and more proximal cannulation site at least 4 cm from wrist joint, avoiding the area of wrist flexion, reduces mechanical complications related to patient movements and may improve catheter functionality and dwell along with a better area for stabilization and securement.

Evaluation of hyperspectral imaging to quantify perfusion changes during the modified Allen test

OBJECTIVES

To evaluate the capability of hyperspectral imaging (HSI), a contact-less and noninvasive technology, to monitor perfusion changes of the hand during a modified Allen test (MAT) and cuff occlusion test. Furthermore, the study aimed at obtaining objective perfusion parameters of the hand.

METHODS

HSI of the hand was performed on 20 healthy volunteers with a commercially available HSI system during a MAT and a cuff occlusion test. Besides gathering red-green-blue (RGB) images, the perfusion parameters tissue hemoglobin index (THI), (superficial tissue) hemoglobin oxygenation (StO2), near-infrared perfusion (NIR), and tissue water index (TWI) were calculated for four different regions of interest on the hand. For the MAT, occlusion (OI; the ratio between the condition during occlusion and before occlusion) and reperfusion (RI; the ratio between the non-occlusion state and the prior occlusion state) indices were calculated for each perfusion parameter. All data were correlated to the clinical findings.

RESULTS

False-color images showed visible differences between the various perfusion conditions during the MAT and cuff occlusion test. THI, StO2, and NIR behaved as expected from physiology, while TWI did not in the context of this study. During rest, mean THI, StO2, and NIR of the hand were 34 ± 2, 72 ± 9, and 61 ± 6, respectively. The RI for THI showed a roundabout threefold increase after reperfusion of both radial and ulnar artery and was thus, distinctly pronounced when compared with StO2 and NIR (~1.25). The OI was lowest for THI when compared with StO2 and NIR.

CONCLUSIONS

HSI with its parameters THI, StO2, and NIR proved to be suitable to evaluate perfusion of the hand. By this, it could complement visual inspection during the MAT for evaluating the functionality of the superficial palmary arch before radial or ulnar artery harvest. The presented RI might deliver useful comparative values to detect pathological perfusion disorders at an early stage. As microcirculation monitoring is crucial for many medical issues, HSI shows potential to be used, besides further applications, in the monitoring of (free) flaps and transplants and microcirculation monitoring of critically ill patients.

Navigating radial artery loops in neurointerventions

BACKGROUND

Although studies continue to demonstrate lower complications in neurointerventions using transradial access (TRA) compared with transfemoral approaches, anatomic radial variants can be difficult to navigate and remain one of the frequent causes of access site conversion.

OBJECTIVE

To evaluate predictors of TRA failure in neuroendovascular patients with radial loops and suggest a protocol for managing these anomalies.

METHODS

A prospective collection of patients undergoing TRA at participating institutions from July 2018 to September 2020 was reviewed. Patients with a radial loop were identified. Patient demographics and procedural characteristics were evaluated to determine predictors of both TRA failure and successful reduction of the radial loop.

RESULTS

We identified 32 transradial neurointerventions in which patients had radial loops. Twenty-two (68.8%) were identified by diagnostic angiography, and the majority were performed for evaluation or treatment of an aneurysm (56.3%). TRA failure occurred in 13 (40.6%) of the cohort and happened more frequently in patients over 60 years of age (p=0.01) and those with recurrent radial artery diameters ≤2 mm (p=0.02). Of the 19 patients who had successful TRA, 12 (63.2%) procedures were performed through the recurrent radial artery.

CONCLUSION

Although radial loops are associated with high transradial failure rates, our results suggest that the presence of a loop is not an absolute contraindication to TRA. Therefore, we recommend attempting loop navigation using our protocol. Patient age, vascular tortuosity, and recurrent radial artery size should help dictate when to convert to an alternative access site.