Reliability of Sedillot’s triangle as a potential anatomical landmark for central venous catheter insertion: insights from cadaveric study

Sedillot's triangle (ST), formed between the sternal and clavicular heads of sternocleidomastoid (SCM) muscle, is often used as an anatomical landmark for internal jugular vein (IJV) cannulation, but its reliability has been questioned. This cadaveric study aimed to evaluate the effectiveness of ST in locating IJV. Dissections were performed on 23 adult cadavers (46 sides). ST was exposed, and a pin was inserted at its apex to assess its relationship with IJV. Dimensions of ST and distance between apex and IJV were measured (only in cases with unsuccessful puncture), along with IJV diameter at the apex. Showed that 92.00% of sides had a fully formed ST, while 8.00% (all left-sided) lacked a gap between the SCM heads. On right side, the needle corresponded directly with IJV in 19 (82.60%) cases, but missed laterally and medially in two (8.69%) cases each. On left side, successful IJV puncture occurred in 11 (61.11%) cases, with lateral and medial misses in five (27.77%) and two (11.11%) respectively. The mean height and width of ST was 64.30±7.86 mm and 20.08±6.26 mm on right side and 63.95±7.28 mm and 15.56±9.91 mm on left side. IJV diameter at the apex was significantly higher in male and on right side. Overall, right ST proved to be a reasonably reliable landmark for successful central venous catheter. However, anatomical variability, particularly on left side, suggests that caution should be exercised, and additional methods such as ultrasound guidance may improve the accuracy and safety of IJV cannulation using this approach.