Anatomia

What is known today as the triangle of Koch (the triangular locus of the atrioventricular node, TLAVN) is bordered by the fibrous attachment of the septal cusp of tricuspid valve, the opening of the coronary sinus and tendon of valve of inferior vena cava (TIVCV). This is a concept developed cumulatively by several exceptional anatomists. The literature was reviewed with a focus on the discovery of the atrioventricular node by Sunao Tawara (January 1906), its previous announcement by Tawara’s mentor Ludwig Aschoff (1905), and the contributions of the authors who described the other components of the triangular locus. Francesco Todaro discovered the TIVCV (1865); Tawara described the atrioventricular node and its relationship with the fibrous attachment of the septal cusp of tricuspid valve and the opening of the coronary sinus. The first description of assembling all components was provided by Arthur Keith (March 1906). Keith was also the first to consider the triangular locus as a useful landmark for identifying the atrial structures of the conduction system discovered by Tawara and Wilhelm His Jr. (1893). Julius Tandler named the TLAVN as Koch’s triangle (1913). Keith’s contributions to this topic have been particularly overlooked. The “triangular locus of the atrioventricular node” or “triangle of the atrioventricular node” are more instructive and impartial names.

While performing a routine anatomical dissection on a male donor, undergraduate medical students observed an uncommon vascular anomaly: a persistent left superior vena cava (LSVC). Prior to the anatomical dissection, computed tomography (CT) images were obtained in an embalmed condition. Relevant anatomical structures were measured using the JiveX DICOM Viewer. The left brachiocephalic vein (LBV) was present as a communicating vessel with a markedly reduced diameter between the LSVC and the right superior vena cava (RSVC). The diameters of RSVC and LSVC averaged 19.4 mm and 15.2 mm, respectively. The LSVC drained into a dilated coronary sinus (CS), which measured 22.7 mm in diameter. In addition, the left accessory hemiazygos vein collected the 2nd to 5th left intercostal veins, forming a small-caliber venous arch (2.1 mm in diameter) at the T5 vertebral level, which crossed anterior to the thoracic aorta, before draining into the LSVC. In comparison, the azygos venous arch on the right side is connected to the RSVC at T4. Knowledge of such venous variations through preoperative imaging—such as CT, MRI, or echocardiography—can be essential for procedural planning and for minimizing inadvertent complications. This case also highlights a dual approach, combining anatomical dissection with detailed CT analysis of the same specimen, which can both enhance undergraduate anatomical education and contribute to high-quality morphological research.

Background/Objectives: Zenker’s diverticulum (ZD) is a rare but clinically relevant condition. It is a false, pulsion-type diverticulum due to the protrusion of mucosal and submucosal layers through the Killian’s Triangle. Its pathogenesis is multifactorial and entails cricopharyngeus muscle dysfunction and age-related tissue degeneration. This review addresses the current evidence regarding the anatomy, pathophysiology, clinical presentation, diagnostic approach, and therapeutic management of ZD. Methods: For this literature review, we searched the PubMed and Scopus databases using combinations of keywords relevant to Zenker’s diverticulum, including “Zenker’s diverticulum,” “esophageal diverticula,” “diagnosis,” “endoscopic treatment,” and “surgery”. We included articles published in recent decades, with a focus on most recent ones regarding clinical studies, systematic reviews, meta-analyses, and descriptions of new diagnostic and therapeutic techniques. Results: Characteristic symptoms comprise progressive dysphagia, regurgitation of undigested food, halitosis, and, in advanced cases, aspiration-related respiratory complications. Diagnosis of ZD is primarily based on barium swallow esophagography and endoscopic evaluation, complemented by other imaging techniques. Current therapeutic options include traditional open surgery and endoscopic procedures, including newer minimally invasive techniques. Conclusions: ZD is the most common type of esophageal diverticulum and can have a disabling impact on a patient’s quality of life. It is commonly underdiagnosed or misdiagnosed as another condition, and prevalence is expected to increase with the growing population ageing. Improved understanding of its pathophysiology is needed to refine diagnostic and therapeutic strategies and minimize recurrences and risks.