Applying Runthrough Guidewire To Transseptal Puncture Without Iodinated Contrast Agent

Aims: Conventional transseptal puncture(TSP) relies on fluoroscopy and iodinated contrast agent to distinctly position the transseptal needle at the left atrium, however, there exists great challenges in clinic in patients with contrast hypersensitivity or allergy-like reactionsin the procedure. This study aimed to evaluate a novel approach to TSP assisted by Runthrough guidewire and fluoroscopy without use of iodinated contrast agent. Methods: Sixty patients with paroxysmal atrial fibrillation undergone radiofrequency catheter ablation were enrolled from February 2021 to October 2021, and randomised to routine TSP group and Runthrough guidewire assisted group. The two groups were compared regarding the total operative time, length of fluoroscopy exposure, difference of radiation dose in X-ray, and the safety was evaluated in the patients undergone TSP without iodinated contrast agent. Results: There were no differences in baseline demographics or clinical characteristics between the two groups. Although the total procedure time[(1.98±0.29) min vs.(2.11±0.14) min, P<0.04],length of fluoroscopic exposure [(1.83±0.30) vs.(1.98±0.14), P<0.19] and radiation dose in X-ray[(27.83±3.21) uGym2vs.(29.13±1.57) uGym2, P<0.30] were somewhat statistically different between groups, yet the difference was insignificant. No complications, including pericardial tamponade and aortic perforation, occurred in all patients. Conclusion: Iodine-free TSP under the guidance of Runthrough guidewire and fluoroscopy can be a simple, safe, economical and effective approach to TSP, and may be reproduced as a novel option for TSP in patients with contrast hypersensitivity or allergy-like reactions.

A novel CT contrast agent for intestinal-targeted imaging through rectal administration

In this study, a novel CT contrast agent used by rectal administration is developed for targeting intestinal imaging. Iopamidol, an iodinated contrast agent, is loaded in chitosan (CS) nanospheres modified by Anti-5-HT3R (AH) antibody. The obtained AH-CS-I nanospheres (AH-CS-I Ns) would combine to 5-HT3 receptors highly expressed on the gastrointestinal mucosal, enhancing the intestinal-targeting ability of the contrast agent. The AH-CS-I Ns were administered by the rectal route for intestinal CT imaging, and FITC-labeled AH-CS-I Ns were prepared for investigating the in vivo distribution of the contrast agent. As a result, obvious contrast enhancement could still be observed at 6 h post administration because of the poorly absorption of enteral AH-CS-I Ns. Unlike the intravascularly administered agents, AH-CS-I Ns would not accumulate in the kidney and induce adverse reactions. Therefore, this technology has potential applications in the examination of intestinal diseases and could reduce the side effect of commercial iopamidol.