Surg Radiol Anat DOI 10.1007/s00276-013-1234-x
Original Article
The lateral thoracic artery revisited Marios Loukas · Maira du Plessis · Deyzi Gueorguieva Owens · Christopher R. Kinsella Jr · C. Robert Litchfield · Alpen Nacar · Olivia Lu · R. Shane Tubbs
Received: 15 July 2013 / Accepted: 1 November 2013 © Springer-Verlag France 2013
Abstract Background Although the variations in the origin of the branches of the axillary and subclavian arteries have been well documented, little information regarding the highly variable lateral thoracic artery (LTA) is available. Descriptions of the LTA variations may prove useful during procedures of the lateral aspects of the thorax such as reconstructive plastic surgery and modified radical mastectomy. Purpose The aim of this study was to examine the anatomy of the LTA and offer an accurate account of its variability. Methods The entire course and distribution of the LTA was examined in 420 formalin-fixed adult human cadavers. Results The LTA was found in 96.7 % of the specimens, showing great morphological variability and classified into six types according to its origin. The most common type was where the LTA arose from the thoracoacromial artery (Type I 67.62 %). In decreasing order of incidence were origins from: the axillary artery (Type II 17.02 %), the thoracodorsal artery (Type III 5 %), and the subscapular artery (Type IV 3.93 %). Additionally, multiple LTAs were present (Type V 3.09 %) and complete absence of LTA (Type VI 3.33 %) was observed. M. Loukas (*) · M. du Plessis · D. G. Owens · C. R. Litchfield · A. Nacar · O. Lu · R. S. Tubbs Department of Anatomical Sciences, School of Medicine, St. George University, St. George, Grenada, West Indies e-mail: [email protected] C. R. Kinsella Jr Department of General Surgery, St. Louis University School of Medicine, St. Louis, USA R. S. Tubbs Division of Pediatric Neurosurgery, Children’s Hospital, Birmingham, AL, USA
Conclusion Despite variations in origin of the vessels, our dissections demonstrated that the ultimate tissue distribution of the LTA remained typical in the vast majority of the specimens and descended on the lateral border of the pectoralis minor. Our results illustrate the need for re-evaluation of the branches of the thoracoacromial artery with possible consideration that the LTA arises from it, instead of directly from the axillary artery. We hope that the information supplied by this study will provide useful information to anatomists and surgeons alike. Keywords Lateral thoracic artery · Pectoralis major myocutaneous flap · Blood supply to breast · Axillary artery branches
Introduction Regardless of intensive research spanning two centuries in the anatomical sciences, some arterial structures in the human body remain still controversial regarding their origin and distribution [17, 20]. One of these structures is the lateral thoracic artery (LTA). Standard anatomy textbooks describe the LTA as arising from the second [1, 2, 23, 24, 32–34] part of the axillary artery, traveling to the lateral border of the pectoralis minor and then passing along the deep surface of the pectoralis major, supplying the axillary lymph nodes, serratus anterior, pectoral muscles, and subscapularis muscle [1, 2, 23, 24, 32–34, 40]. In the female, it also serves as a major blood supply to the breast and often anastomoses with branches from the internal thoracic artery [12, 24, 32–34, 40, 41]. It has also been reported to branch off from the first [7, 11] and third part [24] of the axillary artery either on its own or as a common trunk with one or more of the other branches [5, 24]. The most commonly
13
mentioned variations regarding its origin are from either the thoracoacromial artery (or trunk as it is commonly referred to in surgical literature) [5, 8, 12, 13, 22, 28] or the subscapular artery [5, 8, 13, 29, 35]. Although the surgical anatomy of the axilla and the lateral portion of the external thoracic wall have been well described, recent scientific reports concerning the blood supply of the pectoralis major when used as a musculocutaneous flap [9], lateral thoracic (axillary) flap [21], pectoralis major myocutaneous flap [15, 22, 30, 39], as well as the arterial contributions of the breast and in particular the nipple–areolar complex related to reconstructive surgery and modified radical mastectomy procedures reemphasize the clinical importance of this artery [4, 25, 26, 36–38]. Through our experience from many axillary dissections, we have observed that great variations exist regarding the origins and distributions of this artery. The aim of our study, therefore, was to describe the origin and distribution of the LTA, and provide a comprehensive picture of its surgical anatomy across a large number of specimens.
Materials and methods The anatomy of the LTA was examined in 420 adult human cadavers during the period 2002–2013 at St George’s University, School of Medicine in Grenada. A total of 184 female and 236 male cadavers with a mean age of 70 years (range 48–86) were dissected bilaterally. The specimens were without any grossly evident axillary pathologies or surgical procedures. All the cadavers were routinely fixed with a formalin/phenol/alcohol solution using a standard embalming technique. The branches of the axillary artery were identified according to their position as proposed by Loukas et al. [16]. Following a preliminary examination, images from all dissected specimens were recorded with a Sony digital camera (model: Nikon D90) and studied using a computer-assisted image analysis system [Lucia software 5.0, made by Nikon (Laboratory Imaging Ltd.)]. The digital camera was connected to an image processor (Nvidia GeForce GT 650) and linked to a computer. Digitized images of the LTAs, together with their surrounding structures, were stored in the Lucia program (2,048 × 1,536 pixels) and converted to intensity gray levels from zero (darkest) to 32 bits (lightest). After setting the scale to 1 mm on all pictures, the program was able to use this information to calculate pixel differences between two selected points, such as origin and termination of a given artery, as previously described [19]. The purpose of the software was to allow easy and accurate translation of pixel differences into metric measurements. Results were analyzed using Student’s t test (SPSS software) and differences between means were considered statistically significant with p
Original Article
The lateral thoracic artery revisited Marios Loukas · Maira du Plessis · Deyzi Gueorguieva Owens · Christopher R. Kinsella Jr · C. Robert Litchfield · Alpen Nacar · Olivia Lu · R. Shane Tubbs
Received: 15 July 2013 / Accepted: 1 November 2013 © Springer-Verlag France 2013
Abstract Background Although the variations in the origin of the branches of the axillary and subclavian arteries have been well documented, little information regarding the highly variable lateral thoracic artery (LTA) is available. Descriptions of the LTA variations may prove useful during procedures of the lateral aspects of the thorax such as reconstructive plastic surgery and modified radical mastectomy. Purpose The aim of this study was to examine the anatomy of the LTA and offer an accurate account of its variability. Methods The entire course and distribution of the LTA was examined in 420 formalin-fixed adult human cadavers. Results The LTA was found in 96.7 % of the specimens, showing great morphological variability and classified into six types according to its origin. The most common type was where the LTA arose from the thoracoacromial artery (Type I 67.62 %). In decreasing order of incidence were origins from: the axillary artery (Type II 17.02 %), the thoracodorsal artery (Type III 5 %), and the subscapular artery (Type IV 3.93 %). Additionally, multiple LTAs were present (Type V 3.09 %) and complete absence of LTA (Type VI 3.33 %) was observed. M. Loukas (*) · M. du Plessis · D. G. Owens · C. R. Litchfield · A. Nacar · O. Lu · R. S. Tubbs Department of Anatomical Sciences, School of Medicine, St. George University, St. George, Grenada, West Indies e-mail: [email protected] C. R. Kinsella Jr Department of General Surgery, St. Louis University School of Medicine, St. Louis, USA R. S. Tubbs Division of Pediatric Neurosurgery, Children’s Hospital, Birmingham, AL, USA
Conclusion Despite variations in origin of the vessels, our dissections demonstrated that the ultimate tissue distribution of the LTA remained typical in the vast majority of the specimens and descended on the lateral border of the pectoralis minor. Our results illustrate the need for re-evaluation of the branches of the thoracoacromial artery with possible consideration that the LTA arises from it, instead of directly from the axillary artery. We hope that the information supplied by this study will provide useful information to anatomists and surgeons alike. Keywords Lateral thoracic artery · Pectoralis major myocutaneous flap · Blood supply to breast · Axillary artery branches
Introduction Regardless of intensive research spanning two centuries in the anatomical sciences, some arterial structures in the human body remain still controversial regarding their origin and distribution [17, 20]. One of these structures is the lateral thoracic artery (LTA). Standard anatomy textbooks describe the LTA as arising from the second [1, 2, 23, 24, 32–34] part of the axillary artery, traveling to the lateral border of the pectoralis minor and then passing along the deep surface of the pectoralis major, supplying the axillary lymph nodes, serratus anterior, pectoral muscles, and subscapularis muscle [1, 2, 23, 24, 32–34, 40]. In the female, it also serves as a major blood supply to the breast and often anastomoses with branches from the internal thoracic artery [12, 24, 32–34, 40, 41]. It has also been reported to branch off from the first [7, 11] and third part [24] of the axillary artery either on its own or as a common trunk with one or more of the other branches [5, 24]. The most commonly
13
mentioned variations regarding its origin are from either the thoracoacromial artery (or trunk as it is commonly referred to in surgical literature) [5, 8, 12, 13, 22, 28] or the subscapular artery [5, 8, 13, 29, 35]. Although the surgical anatomy of the axilla and the lateral portion of the external thoracic wall have been well described, recent scientific reports concerning the blood supply of the pectoralis major when used as a musculocutaneous flap [9], lateral thoracic (axillary) flap [21], pectoralis major myocutaneous flap [15, 22, 30, 39], as well as the arterial contributions of the breast and in particular the nipple–areolar complex related to reconstructive surgery and modified radical mastectomy procedures reemphasize the clinical importance of this artery [4, 25, 26, 36–38]. Through our experience from many axillary dissections, we have observed that great variations exist regarding the origins and distributions of this artery. The aim of our study, therefore, was to describe the origin and distribution of the LTA, and provide a comprehensive picture of its surgical anatomy across a large number of specimens.
Materials and methods The anatomy of the LTA was examined in 420 adult human cadavers during the period 2002–2013 at St George’s University, School of Medicine in Grenada. A total of 184 female and 236 male cadavers with a mean age of 70 years (range 48–86) were dissected bilaterally. The specimens were without any grossly evident axillary pathologies or surgical procedures. All the cadavers were routinely fixed with a formalin/phenol/alcohol solution using a standard embalming technique. The branches of the axillary artery were identified according to their position as proposed by Loukas et al. [16]. Following a preliminary examination, images from all dissected specimens were recorded with a Sony digital camera (model: Nikon D90) and studied using a computer-assisted image analysis system [Lucia software 5.0, made by Nikon (Laboratory Imaging Ltd.)]. The digital camera was connected to an image processor (Nvidia GeForce GT 650) and linked to a computer. Digitized images of the LTAs, together with their surrounding structures, were stored in the Lucia program (2,048 × 1,536 pixels) and converted to intensity gray levels from zero (darkest) to 32 bits (lightest). After setting the scale to 1 mm on all pictures, the program was able to use this information to calculate pixel differences between two selected points, such as origin and termination of a given artery, as previously described [19]. The purpose of the software was to allow easy and accurate translation of pixel differences into metric measurements. Results were analyzed using Student’s t test (SPSS software) and differences between means were considered statistically significant with p
