Observational Ultrasound Study of Subclavian Vein Anatomy: Comparison of Safety Margins Between Supraclavicular and Infraclavicular Positions According to Arm Position
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Asan Medical Center
- Enrollment
- 55
- Locations
- 1
- Primary Endpoint
- Shortest Distance Between the Subclavian Vein (SCV) and Subclavian Artery (SCA)
Study Overview
Brief Summary
The purpose of this observational study is to evaluate and compare the anatomical safety margins of the subclavian vein using ultrasound. Medical professionals commonly use the subclavian vein to insert central venous catheters, but nearby vulnerable structures, such as the lung and artery, can be at risk during the procedure.
This study investigates two different ultrasound probe positions: supraclavicular (above the collarbone) and infraclavicular (below the collarbone). It also examines how changing the patient's arm position (from resting in a neutral position to being raised at a 90-degree angle) affects the distance between the vein and these vulnerable structures.
Participants are adult patients scheduled for surgery under general anesthesia who already require ultrasound-guided vascular access. Immediately after falling asleep from anesthesia, researchers will perform a brief 3 to 5-minute ultrasound scan of the collarbone area. This is a strictly non-invasive imaging study; no research-related needle punctures or catheter insertions will be performed. The findings aim to provide robust anatomical evidence to make future vascular procedures safer for patients.
Detailed Description
Central venous catheterization via the subclavian vein (SCV) is clinically favored due to its lower infection and thrombosis rates. However, traditional landmark-guided approaches carry the risk of mechanical complications, including pneumothorax and inadvertent arterial puncture. While real-time ultrasound guidance is strongly recommended to minimize these risks, there is an ongoing debate regarding the optimal probe position-specifically, the supraclavicular (SC) versus the infraclavicular (IC) view. Furthermore, clinical practitioners frequently utilize arm abduction to facilitate venous access, yet its dynamic effect on the anatomical safety margin (the distance between the SCV and adjacent vulnerable structures like the subclavian artery [SCA] and pleura) remains insufficiently quantified.
This prospective, non-invasive observational study aims to address this knowledge gap. The study will enroll 55 adult patients scheduled to undergo
Study Protocol:
Timing: Immediately following the induction of general anesthesia, during the standard pre-procedural preparation period, a brief (approximately 3 to 5 minutes) ultrasound assessment will be conducted.
Imaging: An investigator will obtain short-axis ultrasound views of the SCV from both the SC and IC positions.
Study Design
- Study Type
- Observational
- Observational Model
- Case Only
- Time Perspective
- Prospective
Eligibility Criteria
- Ages
- 20 Years to 79 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Patients requiring ultrasound-guided vascular procedures.
- •Age between 20 and 79 years.
- •Patients who have voluntarily provided written informed consent for this clinical study.
- •American Society of Anesthesiologists (ASA) physical status classification I, II, or III.
Exclusion Criteria
- •Anatomical variations of the clavicle (e.g., history of clavicle fracture).
- •Suspected thrombosis at the target site.
- •Known anatomical abnormalities of the subclavian vein or artery.
- •Inability to abduct the arm (e.g., due to shoulder joint abnormalities).
- •Patient refusal to participate.
Arms & Interventions
Observation Group
Adult patients undergoing general anesthesia who are scheduled for ultrasound-guided vascular catheterization.
Intervention: Non-invasive sonographic observation (Other)
Outcomes
Primary Outcomes
Shortest Distance Between the Subclavian Vein (SCV) and Subclavian Artery (SCA)
Time Frame: Immediately after the induction of general anesthesia (within 3 to 5 minutes)
The shortest anatomical distance between the SCV and SCA is measured in the neutral arm position to evaluate the safety margin. The difference between the supraclavicular (SC) and infraclavicular (IC) views will be analyzed using a paired t-test or Wilcoxon signed-rank test.
Secondary Outcomes
- Relative Position of the Subclavian Artery (SCA) to the Subclavian Vein (SCV)(Immediately after the induction of general anesthesia (within 3 to 5 minutes))
- Sonographic Continuous Variables of the SCV and Adjacent Structures(Immediately after the induction of general anesthesia (within 3 to 5 minutes))
- Sonographic Cross-Sectional Area (CSA) Variables of the SCV and Adjacent Structures(Immediately after the induction of general anesthesia (within 3 to 5 minutes))
- Sonographic Proportion and Index Variables of the SCV and Adjacent Structures(Immediately after the induction of general anesthesia (within 3 to 5 minutes))
Investigators
Jun-Young Park
Associate Professor
Asan Medical Center