The posterior circumflex humeral artery with variant origin and course

Vinay Sharma; Padamjeet Panchal; Aruna Arya; CS Ramesh Babu

doi:10.4103/NJCA.NJCA_221_22

CASE REPORT

Year : 2023 | Volume : 12 | Issue : 1 | Page : 60-62

The posterior circumflex humeral artery with variant origin and course

Vinay Sharma¹, Padamjeet Panchal², Aruna Arya³, CS Ramesh Babu⁴
¹ Professor, Department of Anatomy, Muzaffarnagar Medical College, Muzaffarnagar, Uttar Pradesh, India
² Additional Professor, Department of Anatomy, AIIMS, Patna, Bihar, India
³ Assistant Professor, Department of Anatomy, Muzaffarnagar Medical College, Muzaffarnagar, Uttar Pradesh, India
⁴ Rtd. Associate Professor, Anatomy Deptt., Muzaffarnagar Medical College, Muzaffarnagar, Uttar Pradesh, India

Date of Submission	05-Nov-2022
Date of Decision	16-Dec-2022
Date of Acceptance	29-Dec-2022
Date of Web Publication	21-Feb-2023

Correspondence Address:
Vinay Sharma
Department of Anatomy, Muzaffarnagar Medical College, Muzaffarnagar, Uttar Pradesh
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/NJCA.NJCA_221_22

Abstract

The posterior circumflex humeral artery (PCHA) typically emanates from the axillary artery (AxA) that supplies the shoulder region and surrounding structure. During routine dissection, we noticed that a truncus profundocircumflexus arose as a branch of Brachial Artery distal to teres major (TM), which branches into profunda brachii, besides PCHA. This circumflex humeral artery, winding around the TM muscle, coursed superolaterally and reached the quadrangular space for its usual vascular territory. Adequate awareness of such rare variations observed in the present study is pertinent for physicians for quadrangular space syndrome, radiologists to avert misreading of angiographs, and orthopedics in case of trauma to the axilla, shoulder region, and upper arm or during invasive vascular procedures.

Keywords: Axilla, quadrangular space, variation

How to cite this article:
Sharma V, Panchal P, Arya A, Ramesh Babu C S. The posterior circumflex humeral artery with variant origin and course. Natl J Clin Anat 2023;12:60-2

How to cite this URL:
Sharma V, Panchal P, Arya A, Ramesh Babu C S. The posterior circumflex humeral artery with variant origin and course. Natl J Clin Anat [serial online] 2023 [cited 2023 Mar 20];12:60-2. Available from: http://www.njca.info/text.asp?2023/12/1/60/370137

Introduction

The posterior circumflex humeral artery (PCHA) typically emanates independently from the distal third segment of the axillary artery (AxA) below the subscapularis muscle (distal border) and supplies vast vascular territory. Epiphyseal branches distribute the blood of PCHA to the humeral head beside the shoulder joint and by muscular twigs to significant parts of the deltoid muscle, teres major (TM), teres minor, and triceps muscles.^[1],[2],[3] The PCHA is a giant branch among the two circumflex humeral branches that originate at the level of the subscapularis muscle (distal border). The PCHA was escorted by the axillary nerve that runs posteriorly, reaching up to the quadrangular space.^[2]

PCHA variations in origin, course, and relation are not uncommon, and prior knowledge of such rare variant patterns is imperative for surgeons in preventing vascular catastrophes in the case of proximal humeral trauma. An unusual course of PCHA can increase the chances of quadrangular space syndrome due to its compression while passing through a quadrangular space.^[2] The patient may come with a presentation of pain in the shoulder and adjacent region due to compression of PCHA and axillary nerve.

Case Report

A routine dissection of the left side axillary region of a female cadaver aged 65 was done. While dissecting the branches of the AxA, the origin of PCHA could not be located as a branch of AxA. Instead, we found a common trunk named truncus profundocircumflexus (TPC),^[4] originating from the brachial artery proximately to the distal border of the TM muscle. On tracing, TPC was found passing backward and traversing the lower triangular space. Later, the TPC bifurcated into PCHA and profunda brachii artery (PBA). The PCHA was later traced ascending on the posterior aspect of the humerus toward the quadrangular area and then escorted by the axillary nerve undercover of the deltoid muscle [Figure 1].

Figure 1: Origin of Posterior Circumflex Humeral Artery from truncus profundocircumflexus

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Discussion

Various authors report numerous AxA origin, course, and branch variations. The existence of a variant origin of the PCHA with the anomalous course is not uncommon.

Elajnaf and Alashkham^[4] did a cadaveric study on 10 dissected shoulders to explore any existing abnormalities of the circumflex humeral artery concerning its origin. They observed in dissected axilla, that the AxA gave anterior circumflex humeral artery (ACHA) (70% of cases) as a single trunk, and PCHA in 80% as a single trunk, whereas in 10% of cases, the PCHA originated from a subscapular artery (SsA).

Huelke^[5] observed the presence of variations of the AxA branches sprouting point in 89 adult cadavers (67 males and 22 females) and found the existence of a typical independent origin of PCHA in 78.7% of sides and from SsA (15.2%) or the PBA (2.8%) in sides of a cadaver, respectively. The origin of the PCHA was found to be proximal to that of the ACHA.

Hattori et al.^[6] observed a retrospective study of 82 Japanese adult patients admitted for upper extremity reconstruction. These patients were evaluated thoroughly for vascular status using multidetector-row computed tomography angiography for reconstruction surgery. The PCHA conventional origin and branching pattern were observed in only 33.9% of cases, and abnormal patterns of the PCHA origin from a lateral thoracic artery, circumflex scapular artery, or brachial artery have been reported. PCHA, dorsal thoracic artery, and circumflex scapular artery originated from a common trunk of a SsA in 12.9% of cases. Sometimes there is a high abnormal SsA origin along with truncus subscapulocircumflexus (common trunk of PCHA and circumflex scapular artery) is seen in 11.3% of cases^[4] or directly originating (9.7%) from AxA or common trunk (8.1%) trifurcation into SsA, PCHA, and PBA.

In the present study, the brachial artery gave Truncus Profundocircumflexus (TPC) distal to the inferior margin of TM and ramifies into PBA and PCHA. The PCHA then arched upward toward the subdeltoid muscle region but does not appear in quadrangular space.

The present case was similar to Iliev et al.^[7] who reported variation in the course and different branching patterns of PCHA in a 63-year-old male. It branched from the initial part of the brachial artery below TM without being escorted any nerve to the axilla. The terminal branches reach their usual destination to supply the deltoid muscle, shoulder joint, and nearby structures.

This case was almost similar to the case reported by Mohandas Rao et al.^[8] registering a rare case of PCHA where it originated from the AxA. The PCHA had a particularly long course, traversing downward in lower triangular space accompanied by the radial nerve to reach the scapular region after winding around the TM and passing in a quadrangular area, deep to the fibers of the deltoid muscle. They claimed to notify the term “PCHA forming a hairpin loop” for its unique course. The PCHA is subjected to more risk of injury during its looped path while traversing through quadrangular space. Its close relationship to the glenohumeral joint. They noted that PBA was absent, while there was TPC ramifying as PCHA and PBA branches as in our case. This typical hairpin loop of the PCHA is more prone to injury during a fractured neck of the humerus or an operative procedure on the upper part of the humerus.

According to Adachi^[9] who studied 398 Japanese cadavers and observed in about 4.3% of cases, PCHA sweeps either below the margin of the latissimus dorsi or TM and is designated as a Group F variant in his study.

The modes of origin and relation of PBA to the TM were the critical factors considered by Charles et al. to classify into seven types in an American male population. Our case belongs to Type V of this classification [Figure 2]. It arises with the PCHA sharing the common trunk in 4% of the population.^{[10],[11],[12]} According to Eichholz, PBA (Type V) was also seen in apes and considered an atavistic type of origin of PCHA as a common trunk.^[12]

Figure 2: Classification of the branching pattern of the profunda brachii artery. A: Axillary, B: Brachial, P.B: Profunda Brachial, S: Subscapular, P.H.C: Posterior Humeral Circumflex, A.H.C: Anterior Humeral Circumflex. T.M: Lower Border of Teres Major Muscle

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Such an abnormal origin and course of the PCHA may increase the probability of an uncommon quadrangular space syndrome due to the entrapment of neurovascular structures while traversing the quadrilateral space situated in the subdeltoid and posterior scapular regions. The patient arrives with a chief complaint of intermittent, vague anterior shoulder pain, paresthesia, and tenderness. In addition, glenohumeral joint movements such as abduction, forward flexion, and outward rotation may worsen the clinical symptoms.

Embryological basis

During the early developing phase of cranial limb buds, the dorsal aorta gives intersegmental arteries (7^th) that form an excellent meshwork capillary throughout the mesenchymal tissue. This primitive vascular pattern consists of a primordial axis artery and draining inputs into a peripheral marginal sinus. Angiogenesis causes vascular pattern changes during the due course of time. The smaller new vessels may unite to form larger vessels. In due course, in the developing arm region, the axially placed primitive artery became the main supplying vessel.^[13]

According to Arey, the genesis of abnormal blood vessels may be due to numerous factors, as observed in the present case. For example, aberrant course acquired by primitive vascular plexuses, perseverance of vascular channels that usually obliterate, regression of normal blood vessels that generally persist or arrest in further development or coalesce, and absorption of some segment of the typically discrete blood vessel.^[14],[15]

Conclusion

The clinical relevance of PCHA is significant due to its course close to the humerus bone, muscular relation near the shoulder joints, and its arterial supply to that region. The rare vascular abnormalities are unpredictably more frequent than anticipated. These variations have a crucial role in trauma to the upper part of an arm while considering surgical intervention. An abnormal and lengthy course may also lead to quadrangular space syndrome.

Acknowledgments

”The authors sincerely thank those who donated their bodies to science so that anatomical research could be performed. Results from such research can potentially increase humankind's overall knowledge, which can improve patient care. Therefore, these donors and their families deserve our highest gratitude.”^[16]

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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