Abnormal origin of posterior circumflex humeral artery and subscapular artery: case report and review of the literature

The Arterial System of the Fasciocutaneous Deltoid Flap Pedicle on 320-Detector Row Computed Tomography and Clinical Application in the Foot and Hand

BACKGROUND

 Fasciocutaneous free deltoid flaps are used to reconstruct hand, foot, and maxillofacial defects. Although anatomical studies of this flap pedicle have been performed on cadavers, there are no reports on the use of 320-detector row computed tomography angiography (CTA-320) to investigate the deltoid flap pedicle in living humans. This study aimed to investigate the arterial characteristics of the deltoid flap pedicle using the CTA-320 system in living humans.

METHODS

 Twenty-seven adult Vietnamese patients with 54 healthy deltoid regions underwent CTA-320 to investigate arterial blood supply before clinical free-flap transfer. Two- and three-dimensional reconstruction images of the arterial pedicle were visualized, and clinical reconstruction results were evaluated.

RESULTS

 The cutaneous vessel branches of the deltoid flap were separated from the posterior circumflex humeral artery (PCHA) and originated from the axillary (77.78%), subscapular (12.96%), and brachial (9.26%) arteries. The PCHA penetrated the quadrangular space in 90.74% of patients. The cutaneous arterial branch was present in the deltoid-triceps groove in 100% of patients. The average diameter and length of the PCHA were 3.38 ± 0.58 and 43.08 ± 6.60 mm, respectively. The average diameter and length of the flap cutaneous branch were 1.49 ± 0.28 and 44.57 ± 4.83 mm, respectively. The findings of CTA-320 were aligned with the intraoperative clinical findings well. All deltoid flaps were successfully free-transferred with good outcomes.

CONCLUSION

 The CTA-320 is a practical and effective method for investigating deltoid flap pedicles. It enables accurate flap design and harvesting of flaps, thereby enhancing the clinical success of free-flap transfer.

Entrapment of subscapular artery by the splitting of radial nerve- putative clinical implications

The third part of the axillary artery has an intimate relationship with the cords of the brachial plexus. The subscapular artery, the largest branch of the axillary artery, arises from its third part. The radial nerve is a branch of the posterior cord of the brachial plexus and its supplies the extensors of the arm, forearm and dorsum of the hand. During routine undergraduate dissection of the axilla of a formalin-fixed cadaver of about 70 years, the subscapular artery was found sandwiched between two divisions of the radial nerve. These anterior and posterior divisions of the radial nerve arose immediately after the formation of the radial nerve and encircled the subscapular artery and fused to form a single nerve subsequently. This variant anatomy can lead to conditions like subscapular entrapment causing ischemia of the scapular region and radial nerve compression causing weakness of the extensors of the upper limb. Injury to the nerve and vessel can occur while performing diagnostic and therapeutic procedures in the area. Knowledge of these variations provides a precautious approach by surgeons and other interventionists while working on this area.