In vitro validation of the luminal measurement of a novel catheter based moulding technique

Objective-To investigate a modified angioplasty balloon catheter, which use s a novel balloon polymer to produce luminal moulds. Design-The catheter was tested in polyurethane phantoms of diameter 1.5 to 4.0 mm. Inflations were to 1.4 atmospheres for 20 seconds at 37 degrees C. The moulds were viewed by reinflating the balloon to 0.34 atmospheres and q uantified using macrophotography and caliper measurement. Results-Evidence of systematic error was found with lumen diameters less th an or equal to 2.0 mm, accuracy being 0.32 to 0.80 mm and precision 0.23 to 0.24 mm. However, between 2.5 and 4.0 mm the accuracy of measuring luminal diameters was 0.01 mm, the precision 0.06 mm, and the absolute mean error 0.05 mm. The results for percentage diameter stenosis were -1.15%, 0.86%, a nd 1.21%, and for lesion length they were 0.20, 0.60, and 0.41 mm, respecti vely. Conclusions-The prototype catheter shows a high degree of accuracy and prec ision in phantoms of diameter 2.5 to 4.0 mm-the range within which most int erventional work is performed. Further work on this technique as a method o f direct three dimensional moulding of the coronary artery lumen is warrant ed.