The role of cinematic rendering in pre-operative planning of a thoracodorsal artery perforator flap (TDAP) phalloplasty: a case study

The thoracodorsal artery perforator (TDAP) flap is a muscle-sparing skin and fat flap that requires precise intramuscular dissection of the thoracodorsal artery perforators in the axillary region. Pre-operative image-based treatment planning is a crucial part of flap design. In this article, we discuss the first-ever reported use of the cinematic volume rendering technique (CVRT) to evaluate the thoracodorsal artery for a TDAP flap phalloplasty in a 49-year-old transgender patient. Cinematic volume rendering technique uses light maps to generate photo-realistic three-dimensional images of the thoracodorsal artery and its perforators. These images aid the surgeon in evaluating optimal perforators and latissimus dorsi muscle involvement for more efficient flap design.

A new approach of three-dimensional guidance in paediatric cath lab: segmented and tessellated heart models for cardiovascular interventions in CHD

BackgroundOptimal imaging is essential for catheter-based interventions in CHD. The three-dimensional models in volume-rendering technique currently in use are not standardised. This paper investigates the feasibility and impact of novel three-dimensional guidance with segmented and tessellated three-dimensional heart models in catheterisation of CHD. In addition, a nearly radiation-free two- to three-dimensional registration and a biplane overlay were used.Methods and resultsWe analysed 60 consecutive cases in which segmented tessellated three-dimensional heart models were merged with live fluoroscopy images and aligned using the tracheal bifurcation as a fiducial mark. The models were generated from previous MRI or CT by dedicated medical software. We chose the stereo-lithography format, as this promises advantage over volume-rendering-technique models regarding visualisation. Prospects, potential benefits, and accuracy of the two- to three-dimensional registration were rated separately by two paediatric interventionalists on a five-point Likert scale. Fluoroscopy time, radiation dose, and contrast dye consumption were evaluated. Over a 10-month study period, two- to three-dimensional image fusion was applied to 60 out of 354 cases. Of the 60 catheterisations, 73.3% were performed in the context of interventions. The accuracy of two- to three-dimensional registration was sufficient in all cases. Three-dimensional guidance was rated superior to conventional biplane imaging in all 60 cases. We registered significantly smaller amounts of used contrast dye (p<0.01), lower levels of radiation dose (p<0.02), and less fluoroscopy time (p<0.01) during interventions concerning the aortic arch compared with a control group.ConclusionsTwo- to three-dimensional image fusion can be applied successfully in most catheter-based interventions of CHD. Meshes in stereo-lithography format are accurate and base for standardised and reproducible three-dimensional models.