Prospective Repeated-Measures Study of Popliteal Vein Diameter During the First 48 Hours After Commercial Air Travel to Bogota for a Plastic Surgery Intervention

Research Inc100 enrolled

Overview

This prospective repeated-measures study will evaluate how long popliteal vein dilation persists after international commercial air travel to Bogota. Adult medical travelers will undergo standardized bilateral popliteal vein ultrasound within 24 hours before departure, within 2 hours after arrival, and at 24 and 48 hours after arrival, all before surgery. The primary outcome is change in mean bilateral popliteal vein diameter over time.

Eligible international travelers will complete a standardized preflight ultrasound and three postarrival examinations before surgery or intravenous fluid therapy. Each scan will be performed after a fixed resting period using the same popliteal landmark, minimal transducer pressure, and triplicate bilateral measurements. Flight duration, class, seat characteristics, movement, fluid intake, compression stocking use, and venous risk factors will be recorded. Mixed-effects analysis will estimate the postflight diameter and cross-sectional-area trajectory and the proportion returning to within 10% of baseline by 48 hours.

Study Type

OBSERVATIONAL

Enrollment

100

Conditions

Physiologic Venous Dilation Air Travel

Interventions

Standardized Bilateral Popliteal Vein Duplex UltrasoundDIAGNOSTIC_TEST

After at least 10 minutes of supine rest, the popliteal vein will be imaged at a fixed landmark with minimal probe pressure. Anteroposterior and transverse diameters, cross-sectional area, compressibility, and flow will be recorded in both legs, with three repeated measurements averaged. Linked arm/group(s): Postflight Repeated-Measures Cohort.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 65 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age 18 to 65 years. * International commercial flight to Bogota with total airborne time of at least 4 hours. * Preflight baseline ultrasound obtained within 24 hours before departure using the standardized protocol. * Arrival ultrasound completed within 2 hours after reaching the study site and before surgery or intravenous fluid therapy. * Availability for 24-hour and 48-hour examinations. * Written informed consent. Exclusion Criteria: * Known current deep venous thrombosis or pulmonary embolism. * Therapeutic anticoagulation at enrollment. * Major lower-extremity venous surgery, active leg infection, or condition preventing popliteal ultrasound. * Surgery, prolonged immobilization, or substantial intravenous fluid administration before completion of the 48-hour measurement. * Pregnancy. * Nondiagnostic baseline examination or inability to reproduce the landmark.

Outcomes

Primary Outcomes

Change in Mean Bilateral Popliteal Vein Diameter

At each visit, the mean of three anteroposterior diameter measurements in each leg will be calculated, followed by the mean of both legs. Change from the participant's preflight value will be reported in millimeters and as percent change.

Time frame: Within 24 hours before departure; within 2 hours after arrival at the study site; 24 +/- 2 hours after arrival; and 48 +/- 2 hours after arrival. 1 week

Secondary Outcomes

Return of Popliteal Vein Diameter to Baseline

Proportion of participants whose mean bilateral diameter is within plus or minus 10% of their preflight value.

Time frame: 24 +/- 2 hours and 48 +/- 2 hours after arrival. 1 week

Incidental Venous Thrombosis or Abnormal Compressibility

Number and proportion of participants with a new noncompressible venous segment or other finding requiring diagnostic clinical evaluation. This research protocol is not designed as a definitive thrombosis screening examination unless the final duplex protocol is expanded.

Time frame: From preflight baseline through 48 hours after arrival. 1week