Rapid interstitial digital subtraction lymphangiography may have enabled visualization of the peripheral lymphatic system and was technically successful in 97% of limbs, with no major adverse events, according to a porcine pilot study.
Researchers evaluated the feasibility, safety, and image quality of interstitial digital subtraction lymphangiography (DSLA) using intradermal iodinated contrast injection in 10 healthy pigs. A total of 30 hind limbs were examined across 15 sessions. Each limb received 6 mL of iodinated contrast media across three interdigital sites using a controlled injection system followed by dynamic imaging at 2 to 6 frames per second.
Technical success, defined as visualization of at least one lymphatic collector, was achieved in 97% (n= 29/30) of the limbs. Among successful examinations, image quality was rated good in 52% (n = 15), fair in 38% (n = 11), and poor in 10% (n = 3) of the limbs. Interreader agreement for image quality was high,.
The estimated mean time to superficial inguinal lymph node visualization was approximately 75 seconds, with no statistically significant difference between the left and right limbs. Contrast washout from distal lymphatic vessels occurred in a mean of just under 34 minutes. No venous opacification was observed during any procedure.
Anatomically, DSLA delineated medial and lateral lymphatic pathways originating from interdigital spaces, with drainage toward inguinal and popliteal lymph nodes. Popliteal lymph nodes were visualized in 60% of the limbs, and superficial inguinal lymph nodes in 83%. An anatomic variant lacking a distinct lateral pathway was observed in 13% of the limbs.
No major complications occurred during the procedures or within 3 days of follow-up. Minor injection site edema occurred in 27% of limbs and resolved spontaneously within 24 hours.
Several limitations were noted. The study was conducted in a small sample of healthy animals, and performance in disease states such as lymphedema remains unknown. Image quality depended on precise intradermal needle placement, and the customized injection system introduced variability in contrast distribution. Visualization of central lymphatic structures was limited, and findings may not directly translate to humans because of differences in skin structure and lymphatic anatomy.
Lead study author Fei Sun, MD, of the Centro de Cirugía de Mínima Invasión Jesús Usón in Spain, and colleagues concluded that interstitial DSLA “is a technically feasible, rapid, and safe method for visualizing the peripheral lymphatic anatomy and contrast agent transit at high resolution in a porcine model.”
The research in this study was funded by the Ministry of Science, Innovation, and University with support from the European Union–Next Generation EU through the Recovery, Transformation and Resilience Plan, as well as the European Regional Development Fund of Extremadura Operational Program 2021 to 2027 and Junta de Extremadura. Full disclosures can be found in the study.
Source: Radiology
