Anastomosis: an important clinical term with multiple non-standardized definitions and no formal classification

Field: Medicine (Health Sciences)

Introduction Anastomosis is a frequently used and important clinical term with multiple meanings and no obvious standardized definition or classification. Anastomosis differs in meaning depending on whether the context is anatomical, physiological or surgical, which leads to confusion. Few textbooks offer a complete or working definition of ‘anastomosis’ even though the term is used ubiquitously. This review investigated the definition of ‘anastomosis’. Materials and methods A literature search was conducted on the most commonly used texts: anatomical, physiological and surgical along with common web-based resources to examine the use of ‘anastomosis’ and to determine the completeness of the definition. Results The literature search revealed that the most common definition, when presented, was ‘a communication of one vessel to another’. Collectively, three separate definitions were identified. Surprisingly, many textbooks did not offer a definition of anastomosis; those that did provided a single and limited definition. Conclusion Our suggested definition is: ‘The communication of a luminal vessel with another region of itself or branch of itself with another luminal vessel from a separate origin, or when capillary beds from separate origins interact to maintain tissue viability’. Due to its clinical importance, the results of our review suggest the term anastomosis could be defined comprehensively and classified. Introduction Anastomosis is a term that has existed since classical antiquity. The term can be traced back in recorded history to Erasistratus (Figure 1) and Galen (Figure 2), who both believed that the arteries are linked to the veins at their extremities by extremely fine, imperceptibly small, connecting channels1. This single definition has evolved into several distinct variations. At least three groups (anatomists, physiologists and clinicians) have variations on the term anastomosis and all are different. Some anatomists on the topic of the Circle of Willis may state that the Circle of Willis is an anastomosis amongst cerebral arterial vessels. They may further clarify that the Circle of Willis fails to provide adequate blood to an obstructed area, thus leading to a cerebrovascular accident ( Figure 3). Therefore, this type of definition is a structural, rather than a functional arterial anastomosis. Some physiologists may describe an anastomosis as the sharing of two sets of capillary beds and may note the importance of including an anastomosis to ensure tissue viability. This would represent a functional tissue viability anastomosis ( Figure 4). A surgeon might give an example of an anastomosis using a procedure referred to as an end-toend bowel anastomosis (Figure 5); * Corresponding author Email: bbenninger@westernu.edu Departments of Medical Anatomical Sciences1, Neuromuscular Medicine2, Family Practice3, Western University of Health Sciences, COMP– Northwest, Lebanon, OR, USA. Faculty, College of Dental Medicine4, Pomona CA. Departments of Orthopaedics5 and General Surgery6, Samaritan Health Services, Corvallis, OR, USA. Departments of Oral Maxillofacial Surgery7, Surgery8, Orthopaedics & Rehabilitation9, Oregon Health & Science University, Portland, OR, USA. Figure 1: Erasistratus, the father of physiology.