European Journal of Cardiovascular Medicine

The axilla is a clinically important anatomical region containing major neurovascular and lymphatic structures, frequently approached in procedures such as sentinel lymph node biopsy, axillary dissection, breast reconstruction, and vascular surgeries. A precise understanding of axillary anatomy and its variations is essential to ensure safe surgical practice and to minimize intraoperative complications [1].

Among the known variations, the axillary arch (AA) or Langer’s arch is the most common muscular anomaly of the axilla. It is described as a fibromuscular slip arising from the latissimus dorsi, crossing the axillary neurovascular bundle, and inserting variably into structures such as the pectoralis major, coracobrachialis, or brachial fascia. Depending on its insertion, it may be classified as complete or incomplete [2,3].

The axillary arch is clinically significant due to its potential to compress neurovascular structures, mimic axillary masses, and interfere with surgical access during axillary procedures. It has also been associated with conditions such as thoracic outlet syndrome and shoulder instability. The reported prevalence ranges from 2% to 7%, with considerable variation in morphology and laterality [3,4].

First described by Ramsay and later detailed by Langer, the axillary arch continues to be of anatomical and surgical importance. Cadaveric studies play a crucial role in identifying such variations and enhancing surgical awareness, thereby improving clinical outcomes and reducing complications [2].

This descriptive observational study was conducted in the Department of Anatomy on 25 formalin-embalmed adult human cadavers utilized for routine undergraduate dissection in MIMS, Nellimarla, Vizianagaram. A total of 50 axillae were systematically dissected following standard anatomical protocols. The skin, superficial fascia, and deep fascia were carefully reflected to expose the axillary contents. Detailed dissection was carried out to identify the latissimus dorsi, pectoralis major, and the axillary neurovascular bundle. Special emphasis was placed on the identification of the axillary arch (Langer’s arch), when present. For each identified axillary arch, detailed observations were recorded, including its origin, insertion, morphology (muscular or fibromuscular), and its anatomical relationship to adjacent neurovascular structures. The variation was further classified as complete or incomplete based on its insertion pattern. Laterality (unilateral or bilateral occurrence) was also documented. Photographic documentation was obtained for representative findings. The study was conducted in accordance with institutional ethical standards for the use of cadaveric material in anatomical research.

A total of 50 axillae from 25 cadavers were examined. The axillary arch was identified in only one cadaver, yielding an overall incidence of 4% (1/25 cadavers) and 2% (1/50 axillae), which is lower than the commonly reported incidence of 2–7% in the literature [9,10]. The variation was bilateral in occurrence, a relatively less frequent presentation [8].

In both axillae of the affected cadaver, a well-defined axillary arch was observed, exhibiting a fibromuscular morphology, with proximal muscular fibers transitioning into a distal tendinous component, consistent with previously described variants [9,10]. The arch originated from the anterior border of the latissimus dorsi muscle, crossed the axillary neurovascular bundle, and inserted into the coracobrachialis muscle and coracoid process in addition to coracobrachialis muscle, representing a complete type. Such atypical insertions have been occasionally reported in anatomical studies [11].

The arch was found in close proximity to the axillary vessels and adjacent neural structures, in agreement with earlier reports highlighting its intimate relationship with the neurovascular bundle and potential clinical implications [9,12]. No unilateral or incomplete forms of the axillary arch were observed in the remaining specimens.

Fig:1 langers arch inserted to Coracobrachialis and coracoid process on left side

Table: Comparison of Present Study with Previous Studies on Axillary Arch

        
The axillary arch is a well-documented anatomical variation with a reported incidence of 2–7%, most commonly presenting unilaterally and inserting into the pectoralis major. In the present study, the incidence was within the reported range; however, the bilateral occurrence observed is relatively uncommon. The arch exhibited a fibromuscular morphology and a rare insertion into the coracobrachialis muscle, deviating from the classical description. Such variations may be attributed to the persistence of embryological muscle planes and demonstrate considerable diversity in morphology and attachment.

Clinically, the close relationship of the axillary arch with the neurovascular bundle is of significant importance, as it may lead to compression symptoms, mimic axillary masses, or complicate surgical procedures such as axillary dissection and sentinel lymph node biopsy. The present finding underscores the importance of awareness of such variations among surgeons and anatomists to prevent intraoperative complications and ensure optimal surgical outcomes.

Fig:2 langers arch inserted to Coracobrachialis on right side

The present study highlights a rare presentation of the axillary arch characterized by bilateral occurrence, fibromuscular morphology, and insertion into the coracobrachialis muscle. Such variations are clinically significant due to their proximity to neurovascular structures. Awareness of these anomalies is essential to prevent surgical complications and improve outcomes. KEY MESSAGE Awareness of rare axillary arch variations is essential to prevent neurovascular injury and ensure safe surgical outcomes during axillary procedures. CONFLICTS OF INTEREST There are no conflicts of interest

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