Volumetric analysis on computed tomography Angiography in the management of thoracic aortic dissection in case of seven years follow-up period
Purpose. To establish the methods for estimating the volume of the true and false aortic canals applying computed tomography angiography (CTA) to a clinical case with hybrid stent-graft thoracic aorta with distal stent-graftinduced new entry associated (d-SINE) in the long-term follow-up period in comparison with a widely used technique of measuring diameters of the aorta on different levels. Materials and methods. Sequential analysis of CTA in a 7-year follow-up was performed. Aorta was divided into 3 segments, in each segment total aortic volumes (AV), volume of the true canal (TC), and volume of functional lumen of the false canal (FLFC) were calculated. The following were mathematically calculated: volume of the false canal (FC) via difference in volume between AV and TC, volume of the thrombosed lumen of FC as the difference between FC and FLFC, the coefficient of FC thrombosis, the degree of stent-graft opening. Mathematical assessment of excess volume of the graft was performed. Results. Modelling of aortic cavity, evaluation of changes in the volumes of TC and FC during a long-term follow-up, analysis of the factors inducing the development of the d-SINE syndrome were performed. When comparing the volume of the graft and the volume of the implantation zone, an excess of 234% was found, while the opening of the graft was 80%. When using the reference method based on the diameter of the true lumen of the aorta, the excess was 22% during one-year follow-up period showing no changes subsequently. Conclusion. Potentially, the method of measuring volumes based on CTA results can be used to complement the generally accepted method based on measuring diameters, since it does not require additional financial resources and has the potential to estimate effectiveness of treatment and identify complications predictors in the postoperative period to determine indications for reoperation.