Comparison of ultrasound-guided oblique-axis versus short-axis approaches for right internal jugular vein cannulation in the left decubitus position: a prospective, randomized, single-center trial

Background Central venous cannulation in the left decubitus position is more difficult than in the supine position and may be required when patients cannot safely return to supine. Whether the oblique-axis (OA) approach improves the success and safety of right internal jugular vein (RIJV) cannulation compared with the short-axis (SA) approach remains unknown. Methods Seventy-four patients (ASA I–III) scheduled for elective surgery in the left decubitus position under general anesthesia requiring RIJV cannulation were randomly assigned 1:1 to the OA or SA group ( n = 37 each). Under real-time ultrasound guidance and a 20° Trendelenburg tilt, cannulation was performed by one of three experienced attending anesthesiologists, each with more than 15 years of experience in ultrasound-guided central venous cannulation. Venipuncture attempts and total procedure time were recorded by a separate investigator; patients were blinded by general anesthesia. The primary outcome was first-time puncture success; secondary outcomes were overall cannulation success, procedure time, venipuncture attempts, and mechanical complications. Results All 74 randomized patients completed the trial and were analyzed. The first-time puncture success rate was higher in the OA group (27/37 [73.0%] vs. 18/37 [48.6%]; risk difference 24.3%, 95% CI 2.8% to 45.9%; P = 0.032, Pearson chi-square test; Fisher exact test P = 0.056). Venipuncture attempts were fewer in the OA group (median 1 vs. 2; IQR 1–2; P = 0.037). Total procedure time did not differ significantly between groups (median 2.79 [IQR 2.46–3.19] vs. 3.01 [2.72–3.45] min; P = 0.060). Mechanical complications occurred in 6 of 37 patients (16.2%) in the SA group (one arterial puncture and five posterior wall penetrations) and in none in the OA group ( P = 0.025); overall cannulation success was 100% in both groups. Conclusions For RIJV cannulation in the left decubitus position, the oblique-axis approach was associated with a higher first-time puncture success rate than the short-axis approach and with fewer mechanical complications detected during or immediately after the procedure; however, the primary-endpoint evidence was borderline and the complication estimates were imprecise. Trial registration Chinese Clinical Trial Registry (ChiCTR2400091385; registered 28 October 2024).