ULTRASONOGRAPHY was performed in a 79-yr-old man to determine the spatial relationship between his common carotid artery (CCA) and internal jugular vein (IJV) to guide central venous catheter placement before surgery. This figure revealed IJV duplication (A), with two unusually small IJVs. One (5 mm wide) was on the lateral side of the neck along the CCA; the other (10 mm wide) was on the medial side along the CCA (B), midway between the clavicle head and mandible angle (C). The medial IJV had a curved course and crossed the CCA. The lateral IJV was straight and joined the medial branch approximately 45 mm from the clavicle, forming a single IJV measuring 13 mm wide, 6.6 mm thick, and 8.0 mm deep at a point 30 mm from the clavicle (D).
The embryologic development of the IJV is determined by genetics, hemodynamics, growth factors, neural factors, and mechanical constraints. Jugular venous duplication occurs when these factors combine to prevent vascular pruning (selective removal of vascular branches) from occurring when it normally would, resulting in medial and lateral IJVs1 ; its incidence is approximately 4 cases per 1,000 cervical dissections.2 The two IJVs may join to a form a single vessel, as in our case, or they may enter the subclavian vein separately.1 The duplication is usually discovered during surgery2 and occasionally on computed tomography scan but seldom during ultrasonography.3 Jugular venous duplication is a clinically significant finding that can increase the difficulty of puncture point selection for the successful central venous catheter placement, necessitating particular care.
The authors declare no competing interests.