Factors Contributing to Successful Transvenous Retrograde Thoracic Duct Cannulation.

PURPOSE: To identify key factors for successful transvenous retrograde cannulation (TVRC) of the thoracic duct. MATERIALS AND METHODS: A total of 47 consecutive patients (62.1 ± 13.2 years; 32 men) who underwent attempted TVRC between July 2016 and July 2021 were included. Reasons for interventions were chylous leakage from the chest (n = 36), abdomen (n = 6), and other sites (n = 5). Patient age, sex, access vein (femoral vs brachial), anatomic classification (presence of dominant channel vs plexiform) of the terminal thoracic duct, and engagement of a diagnostic catheter into the jugulovenous junction were included in the analyses. Anatomic details were evaluated according to catheter-based high-pressure lymphangiography and conventional intranodal lymphangiography. The Firth bias-reduced penalized-likelihood logistic regression model was used to analyze prognostic factors. RESULTS: TVRC was successful in 33 of the 47 patients (70%). In univariate analysis, femoral access, diagnostic catheter engagement, and presence of dominant channel were significant positive prognostic factors (P <.05). In multivariate analysis, diagnostic catheter engagement and presence of dominant channel were significant prognostic factors (P <.05). Diagnostic catheter engagement showed the highest prognostic performance (accuracy = 0.872), followed by presence of a dominant channel. High-pressure catheter-based lymphangiographic findings showed better performance (accuracy, 0.844 vs 0.727) than intranodal lymphangiography to delineate the anatomy of the terminal thoracic duct. CONCLUSIONS: A secure selection of the jugulovenous junction and the presence of a dominant channel in the terminal portion of the thoracic duct were significant prognostic factors for successful TVRC.

Effectiveness of caudal block in patients with spinal stenosis accompanied by redundant nerve root syndrome.

OBJECTIVE: Redundant nerve root syndrome (RNRS) is characterized by tortuous, elongated, and enlarged nerve roots in patients with lumbar spinal stenosis. This study was performed to evaluate the effects of caudal block in patients with RNRS and assess factors associated with RNRS. METHODS: Patients with lumbar spinal stenosis who underwent caudal block were retrospectively analyzed. A comparative analysis of pain reduction was conducted between patients with RNRS (Group R) and those without RNRS (Group C). Generalized estimating equation analysis was used to identify factors related to the treatment response. RNRS-associated factors were analyzed using logistic regression analysis. RESULTS: In total, 54 patients were enrolled (Group R, n = 22; Group C, n = 32). Group R had older patients than Group C. The caudal block showed less pain reduction in Group R than in Group C, but the difference was not statistically significant. Generalized estimating equation analysis showed that RNRS was the factor significantly associated with the treatment response. The dural sac anteroposterior diameter and left ligamentum flavum thickness were associated with RNRS in the logistic regression analysis. CONCLUSIONS: Caudal block tended to be less effective in patients with than without RNRS, but the difference was not statistically significant.