Median artery arising from the radial artery: its significance during harvest of a radial forearm free flap

Radial forearm free flap in a patient with an unusual radial artery variation: a case report

Head and neck reconstruction poses unique challenges in rehabilitating surgical defects in terms of integrity, function, and form. The radial forearm free flap (RFFF) has been widely used for defect coverage, especially in the head and neck area, but its versatility allows it to be used for soft-tissue reconstruction in various parts of the body. The vascular features of the flap are quite constant and reliable. Nevertheless, abnormalities of the forearm vascular tree have been described over the decades. We report a case of intraoral reconstruction after verrucous carcinoma recurrence in a 74-year-old woman with an unusual forearm flap, which we called the median forearm free flap, based on a median branch of the radial artery that was preoperatively detected using handheld Doppler ultrasonography. The distally located skin paddle was predominantly supplied by the aberrant median vessel with its perforators. The flap was thus safely harvested with this atypical pedicle. Successful reconstruction of the intraoral defect was achieved, with an uneventful postoperative course.

The importance of a lifeboat-median artery forearm flap in Goldenhar Syndrome

We present a case of a 32-year-old male with left-sided Goldenhar Syndrome and delta phalanx of the thumb, who was offered free tissue transfer from the forearm to address an intra-oral soft tissue deficiency. Despite the presence of appropriately developed right radial artery, used in previous facial reconstruction, the left radial artery occurred to be hypoplastic. He ultimately underwent free flap transfer based on the anomalous persistent left median artery. We suggest that in face of an unusual hand anatomy, flexible flap creation techniques that allow a lifeboat strategy of adjusting flap design should be considered preoperatively. Level of evidence: Level V, therapeutic study.

Anatomical variations and evolution: re-evaluating their importance for surgeons

For several decades, anatomists and biological anthropologists have made an intensive study in anatomical variations in ancestral and living humans. While many anatomical variants do not require clinical attention, some may present diagnostic problems or augur adverse symptoms. It is only in the last few decades that a plausible argument has been made that anatomical changes in human individuals and lineages demonstrate ongoing microevolution. Since the mid-19th century, there has been a reduction in differential mortality. Increased variation of heritable traits is a consequential outcome of relaxation of natural selection. Consequently, this has contributed to various anatomical variations in musculo-skeletal anatomy, vascular anatomy as well as congenital disorders such as spina bifida occulta. The authors argue that surgeons and anatomists should improve their knowledge of evolution and its continuing influence on human morphology. Simply repeating the old mantra that anatomical variations are important because knowledge of them minimizes surgical complications, albeit important, is inadequate.

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

Background Harvest of the radial forearm flap (RFF) for reconstructive surgery is proceeded by the Allen test to assess for adequate contralateral perfusion of the hand, yet the Allen test may fail to detect anatomical variations in the radial artery such as aberrant branching. Therefore, the goal of this study was to systematically review the literature regarding anatomical abnormalities of the radial artery that can affect flap harvest and to perform a meta-analysis to estimate the prevalence of such abnormalities.

Methods A systematic review of the literature was conducted using five online databases to identify all instances of radial artery anatomical variations. Abstracts were reviewed and categorized into either (1) large cohort studies of anatomical variations identified by angiogram or (2) case reports specifically mentioning anomalous or accessory branches of the radial artery. Data from the large cohort studies were included in a random effect meta-analysis to estimate the prevalence of such variations.

Results Eighteen angiogram cohort studies containing a total of 18,115 patients were included in the meta-analysis. Accessory branches were the least common anatomical variant reported, with an estimated average prevalence of 0.5%. Prevalence estimates for more common anatomical variants, including radial artery loops (0.9%), stenosis (1.3%), hypoplasia (1.9%), tortuosity (4.3%), and abnormal origin (5.6%), were also calculated. Thirteen case reports detailing anomalous branches of the radial artery were identified, seven of which involved accessory branches encountered during RFF harvest with no incidence of flap loss.

Conclusion Radial artery accessory branches are exceedingly rare, but the prevalence of other anatomical variations that can affect harvest of the RFF warrants consideration. We recommend surgeons consider comprehensive screening prior to RFF harvest to avoid intraoperative discovery of anatomical variants and suggest a low threshold for repeat perfusion testing intraoperatively if radial artery accessory branches are encountered.

Erfolgreiche freie mikrovaskuläre A. radialis-Lappenplastik zur Phalluskonstruktion bei persistierender A. mediana (PMA)

Hintergrund Anomalien des Gefäßsystems des Unterarmes können bei der mikrochirurgischen Hebung einer A. radialis-Lappenplastik von großer Bedeutung sein. Insbesondere bei der Verwendung der fasziokutanen Radialislappenplastik zur Bildung eines Penoids ist auf Grund der erforderlichen Größenausmaße der Lappenplastik eine suffiziente arterielle Versorgung von grundlegender Bedeutung. Beim Auftreten einer persistierenden A. mediana können dabei die Perfusionsverhältnisse im Versorgungsgebiet der A. radialis und der A. ulnaris verändert oder diese sogar vollständig rückgebildet worden sein.

Patienten und Methoden Es erfolgte eine retrospektive Auswertung aller in unserer Klinik durchgeführten Phalloplastiken mit Radialispenoid von Januar 2016 bis Dezember 2018. Bei allen Patienten wurde die Technik nach Gottlieb und Levine oder nach Chang angewandt.

Ergebnisse In der retrospektiv untersuchten Kohorte von 48 Patienten wurde bei zwei Patienten intraoperativ eine persistierende A. mediana gefunden, was einer Inzidenz von 4,2 % entspricht. Bei beiden Patienten gelang die hinsichtlich der Perfusion komplikationslose Bildung eines Radialispenoids ohne Einschränkungen der Lappenperfusion oder der Perfusion der Hand. Eine Literaturübersicht liefert einen Überblick über die Inzidenz auftretender Aberrationen der Vaskularisierung des Unterarmes und die daraus ableitbaren Konsequenzen für die Planung einer A. radialis-Lappenplastik.

Schlussfolgerung Auch im Falle einer verlässlichen mikrochirurgischen Lappenplastik wie der A. radialis-Lappenplastik sollten dem mikrochirurgisch tätigen Chirurgen die Möglichkeiten der anatomischen Varianten der arteriellen Versorgung des Unterarmes, wie das Vorhandensein einer persistierenden A. mediana, bekannt sein. Der standardmäßig durchzuführende Allen-Test liefert in vielen Fällen keine eindeutige Rückschlussmöglichkeit und bedingt somit häufig erst intraoperative Zufallsbefunde. Eine sorgfältige präoperative Planung und Evaluation der Perfusion sowie die Erörterung von Alternativtechniken sind hierbei notwendig.

Dealing with vascular anomalies during radial forearm free flap harvest: report of two cases and review of the literature

Radial forearm free flap reconstruction for head and neck cancer is very common, and it is widely considered a workhorse flap. Although this flap has a relatively reliable anatomy, surgeons need to be aware of possible anatomical variations and how to deal with them. This paper presents the cases of two patients who underwent oral reconstruction, in whom anomalies of the radial artery were identified while raising a radial forearm free flap. Case 1 demonstrates the dominant branch of the radial artery joining the common interosseous artery approximately 9 cm from the first wrist crease. Case 2 demonstrates abnormal distal branching of the radial artery approximately 4 cm from the first wrist crease. Reconstruction with the flap was successful in both cases. A literature review of reported anomalies of the radial artery is presented, and how to deal with such vascular anomalies is discussed.

A rare variant of the ulnar artery with important clinical implications: a case report

BACKGROUND

Variations in the major arteries of the upper limb are estimated to be present in up to one fifth of people, and may have significant clinical implications.

CASE PRESENTATION

During routine cadaveric dissection of a 69-year-old fresh female cadaver, a superficial brachioulnar artery with an aberrant path was found bilaterally. The superficial brachioulnar artery originated at midarm level from the brachial artery, pierced the brachial fascia immediately proximal to the elbow, crossed superficial to the muscles that originated from the medial epicondyle, and ran over the pronator teres muscle in a doubling of the antebrachial fascia. It then dipped into the forearm fascia, in the gap between the flexor carpi radialis and the palmaris longus. Subsequently, it ran deep to the palmaris longus muscle belly, and superficially to the flexor digitorum superficialis muscle, reaching the gap between the latter and the flexor carpi ulnaris muscle, where it assumed is usual position lateral to the ulnar nerve.

CONCLUSION

As far as the authors could determine, this variant of the superficial brachioulnar artery has only been described twice before in the literature. The existence of such a variant is of particular clinical significance, as these arteries are more susceptible to trauma, and can be easily confused with superficial veins during medical and surgical procedures, potentially leading to iatrogenic distal limb ischemia.

Palmar type of median artery as a source of superficial palmar arch: a cadaveric study with its clinical significance

The superficial palmar arch (SPA) and its contributing arteries are highly variable. The palmar type of median artery (PMA) can be involved in the formation of the SPA by replacing the superficial palmar branch of the radial artery (RA) or the ulnar artery (UA). The present study was undertaken to investigate the presence of the PMA and its contribution in the formation of SPA in 42 cadavers (84 upper limbs) of Indian origin. When there was a PMA, its outer diameter was measured in the carpal tunnel. The PMA was found in 13 upper limbs (15.4%), and of these ten incidences (11.9%), the PMA took part in the formation of SPA, and in three instances (3.5%), the PMA did not make up part of the SPA. Out of the ten cases in which the PMA contributed to the formation of SPA, in six cases (7.1%), the PMA anastomosed with the UA; in three cases (3.5%), the PMA anastomosed with both the UA and the RA, and in one incidence (1.1%), the PMA joined the arteria radialis indicis (deep branch of the RA) to complete the SPA. The outer diameters of the median arteries varied between 0.8 and 2.6 mm with the mean value of 1.7 mm. The present study concludes that the median-ulnar type of SPA was the most common type of SPA when the PMA was encountered as a source of superficial arterial arcade of the hand, followed by the radial-median-ulnar type. The vascular patterns found in this study are important to hand surgeons. The present study of PMA origin, course, and its contribution to the SPA will add to the existing knowledge of the vascular anatomy of forearm and hand.