Langer’s arch: A rare but important consideration for axillary surgery with implications for training

Abstract

Knowledge of anatomical variations in the axillary region is important, as these may be encountered during procedures for breast cancer as well as in reconstructive and vascular surgery. Langer's arch (LA) is an example of an anatomical aberration in the axilla with important surgical implications. 1 Carl Ritter von Edenberg von Langer provided an accurate account of its structure in 1846. 2 In general, it arises as a muscular bundle or tendinous band from latissimus dorsi and inserts into structures around the anterosuperior part of the humerus, crossing the axillary neurovascular bundle from dorsomedial to ventrolateral 3 (Figure 1). A recent meta-analysis estimates an overall prevalence of 5.3%, but the average surgical prevalence was 2.1%. 4 The discrepancy between anatomical and clinical incidence may be attributed to lack of recognition and/or under-reporting in the surgical setting. Inability to recognize this anomaly may cause disorientation during axillary dissection, resulting in inadequate clearance, with implications for regional disease recurrence and inaccurate staging. However, if identified, LA can be safely divided intra-operatively in order to clarify important anatomical landmarks and facilitate adequate dissection. We present a case to highlight the confusion it can cause during ALND. With indications for ALND decreasing, curtailing operative caseload, surgeons are less likely to encounter this anatomical anomaly during training. Improving knowledge and understanding of LA are important to ensure breast surgeons' preparedness for axillary surgery.

Variations of accessory thoracic muscles identified in the ethnically diverse whole-body donation population in Northern California

“…Because the accessory thoracic muscles discussed above are common in the general population and closely associated with clinically important structures such as the neurovascular bundles and lymph nodes in the axillary region, awareness of their implications to medical procedures such as surgery and potential chronic conditions is warranted [6,23]. For instance, potential interference of the axillary arch and the pectoralis quartus with sentinel lymph node biopsy and axillary lymphadenectomy have been discussed [10,17,21]. Also, compression on the neurovasculature in the axilla by the axillary arch may be involved in conditions such as a thoracic outlet syndrome [5] and can cause deep vein thrombosis [15].…”

“…Muscles demarcating the axilla are used as critical landmarks of the region. An understanding of accessory muscles located in this region allows more accurate decision making during surgical procedures involving lymph nodes in the breast [10,17,21]. One of the well-known accessory thoracic muscles of this class is the axillary arch.…”

Axillary arch (of Langer): A large‐scale dissection and simulation study based on unembalmed cadavers of body donors

“…Axillary anatomy in individuals featuring axillary arches differs from axillary anatomy described as norm situation. Although comprehensive traditional textbooks acknowledge this variation (Henle, 1871; Testut, 1884; Waldeyer, 2012), interventionalists and surgeons might become confused during clinical examination, harvesting of biopsies of axillary lymph nodes or trans‐axillary surgery (Endres, 1893; Hong et al., 2015; Markou et al., 2023; Scrimgeour et al., 2020). Thus, awareness of the possibility to meet axillary arches during interventions and profound knowledge of their connections, dimensions, appearance and tissue composition is critical for radiologists and surgeons.…”