Cho Seoyoung, Chang Jupill, Kim Woosuk, Eom Kidong, Kim Jaehwan
Department of Veterinary Medical Imaging, College of Veterinary Medicine, Konkuk University, Seoul, Republic of Korea.
SD Animal Medical Center, Seoul, Republic of Korea.
Front Vet Sci. 2024 Oct 17;11:1464750. doi: 10.3389/fvets.2024.1464750. eCollection 2024.
The external jugular vein (EJV) is a superficial vein of the neck in dogs; its significance is evident in veterinary clinical practice, encompassing surgeries and interventional procedures. However, there have been no reports on EJV variations in canines, despite extensive studies on variations in the jugular veins in humans. This study aimed to use CT imaging to evaluate the prevalence of anatomic vascular variations of the EJVs in Shih Tzu dogs and to describe the clinical and CT characteristics of these vascular variants.
This is a retrospective, multi-center study. The medical imaging records of Shih Tzu dogs that underwent pre- and post-contrast CT examinations of the head, neck, and thorax at the Veterinary Medical Teaching Hospital, Konkuk University, and 10 referral hospitals between 2015 and 2023 were reviewed.
We defined five types of EJV vascular variants: normal (type I), unilateral hypoplasia (type II), unilateral aplasia (type III), bilateral hypoplasia (type IV), and bilateral aplasia (type V), based on the morphological and diameter differences observed in the transverse images of Shih Tzu dogs. CT images from 547 Shih Tzu dogs revealed 119 cases (21.7%) of EJV variants. Type I was observed in 428 dogs (78.2%), type II in 46 dogs (8.4%), type III in 41 dogs (7.5%), type IV in 14 dogs (2.6%), and type V in 18 dogs (3.3%). In types II-V, compensatory drainage through the internal jugular vein (IJV) was observed, often involving the medial passage of the maxillary or linguofacial veins. A moderate negative correlation ( = -0.5) was recorded between the hypoplastic EJV and the affected-side IJV ( < 0.01). Some cases exhibited other supplementary drainage routes, such as the hyoid venous arch or median thyroid vein. Additionally, 63 persistent left cranial vena cava (PLCVC) cases (11.9%) were identified among 529 Shih Tzu dogs, showing a significant association with EJV abnormalities ( < 0.05).
Overall, this study identified anatomical variants of the EJV in Shih Tzu dogs and introduced a new classification system. These findings revealed that EJV variants and compensatory tributary enlargement were more prevalent than previously recognized, emphasizing the need to consider these nuances in veterinary procedures and imaging.
颈外静脉（EJV）是犬颈部的一条浅表静脉；其在兽医临床实践中的重要性在外科手术和介入操作中显而易见。然而，尽管对人类颈静脉变异进行了广泛研究，但关于犬类EJV变异的报道却很少。本研究旨在利用CT成像评估西施犬EJV的解剖血管变异发生率，并描述这些血管变异的临床和CT特征。
这是一项回顾性多中心研究。回顾了2015年至2023年间在建国大学兽医学院教学医院和10家转诊医院接受头部、颈部和胸部对比增强CT检查的西施犬的医学影像记录。
根据西施犬横断图像中观察到的形态和直径差异，我们定义了五种EJV血管变异类型：正常（I型）、单侧发育不全（II型）、单侧缺如（III型）、双侧发育不全（IV型）和双侧缺如（V型）。547只西施犬的CT图像显示119例（21.7%）EJV变异。I型在428只犬（78.2%）中观察到，II型在46只犬（8.4%）中观察到，III型在41只犬（7.5%）中观察到，IV型在14只犬（2.6%）中观察到，V型在18只犬（3.3%）中观察到。在II - V型中，观察到通过颈内静脉（IJV）的代偿性引流，常涉及上颌静脉或舌面静脉的内侧通道。发育不全的EJV与患侧IJV之间存在中度负相关（r = -0.5）（P < 0.01）。一些病例表现出其他辅助引流途径，如舌骨静脉弓或甲状腺中静脉。此外，在529只西施犬中发现63例（11.9%）持续性左头臂静脉（PLCVC）病例，与EJV异常有显著相关性（P < 0.05）。
总体而言，本研究确定了西施犬EJV的解剖变异，并引入了一种新的分类系统。这些发现表明，EJV变异和代偿性支流增大多于先前的认识，强调在兽医手术和影像学中需要考虑这些细微差别。
