The Cephalic Vein: Anatomical Study and Evaluation of the Coracoid Process as a Topographical Bony Landmark

INTRODUCTION. Clinicians require accurate anatomical information when gaining central venous access. Despite the cephalic vein cut down (CVCD) procedure being described as a superior choice to other methods, the cephalic vein's (CV) anatomical variations can make it challenging to locate. We asked if the coracoid process (CP) could be utilized as an accurate topographical landmark to locate the CV. The present study set out to prove the CV will be located within 1 cm of the CP with statistical significance. METHODS. We conducted bilateral shoulder dissections on 41 cadavers to determine the location of the CV in relation to the CP. Distances were measured horizontally, vertically and directly from the CP to the CV utilizing digital calipers. We also measured diameter via extracted veins where the inner luminal circumference was measured and divided by π to obtain diameter. SUMMARY. Resulting means were: Straight line distance: 9.48 ± 4.45 mm, horizontal distance: 13.50 ± 6.45 mm, vertical distance: 11.03 ± 5.17 mm, and diameter: 1.59 ± 0.67 mm. A one sample student t-test on the straight-line distance, with the expected population mean set to 10 mm so that the H0 indicates the data would be ≥ 10 mm and the Ha indicates the data was [less than] 10 mm. The α was set to 0.05, had a resulting p=0.333906 and the test statistics was -1.860547. From the results, the H0 was rejected. Since clinicians will likely have more than just 10 mm of open incision space while gaining access to the CV, the t-test was repeated with an expected population mean of 15 mm. The resulting p-value was 3.66613e-16 and the H0 was rejected. When α was set to 0.0001. The results remained significant. CONCLUSION. We showed that the CV can be located within 1 cm of the CP with statistical significance. The average incision for the CVCD procedure is 3-6 cm. It can safely be assumed that the incision will be spread to a width of 1.5 cm. If the clinician does not quickly locate the CV, they can assume it is likely deeper than the muscle belly, a variation or absent. This will aid clinicians in avoiding unnecessary time searching for the vein and instead rapidly transition to an alternative approach, transitioning the original CVCD incision to the reservoir incision. With this new information, we hope to persuade more clinicians to make the CVCD their first and primary attempt for central venous access over the subclavian puncture.