Effect of tandem lesions on hemodynamic parameters: an experimental study

Abstract

Background and aim: The morphology and extensity of the stenotic lesion is crucial as well as the obstruction ratio. It is well known that the complexity of lesion has direct impact on endovascular treatment (PTCA/stent), however; different arrangement of the lesions is underestimated and not well studied. We sought to evaluate the hemodynamic effects of different stenotic lesion models and arrangements in vitro Methods: Vascular circulation was simulated in vitro. Oxygenator, tubing set, polytetrahidroflouroethylene synthetic graft, pressure and flow rate sensors were used to build the simulation model. Measurements of isolated short, isolated long, identical stenotic tandem short, identical stenotic tandem long, sub-critical long and critical short lesion combination were performed and hemodynamic parameters were recorded. Results: Tandem lesions were more likely to result critical stenosis comparing single lesions with same obstruction ratio. This difference became more significant as the obstruction ratio was raised. Tandem long lesions were also resulted more critical stenosis than tandem short lesions. It can be claimed that tandem lesions can result more flow restriction with reference to single lesions with same stenotic ratio. Contrary to expectations, tandem short lesions were found more stenotic compared with the same degree long individual lesions. Conclusions: It is effortless to give decision for simple, discrete and individual lesions while ideal decision for long and complicated lesions may remain unclear. Even if these "gray zone" lesions considered non-critical while investigating them one by one, it must be kept in mind overall stenotic effect of these lesions may lead to a more hemodynamic impairment.