Our study suggested a correlation between translesional pressure gradient and maturation of LMCs in intracranial atherosclerotic disease. Further studies with more exquisite and dynamic monitoring of cerebral hemodynamics and LMC evolution are needed to verify the current findings.

The fractional pressure ratio is introduced to quantitatively assess the hemodynamic significance of severe intracranial stenosis. A computational fluid dynamics-based method is proposed to non-invasively compute the FPR and compared against fractional pressure ratio measured by an invasive technique. Eleven patients with severe intracranial stenosis considered for endovascular intervention were recruited and an invasive procedure was performed to measure the distal and the aortic pressure ( P and P). The fractional pressure ratio was calculated as [Formula: see text]. The computed tomography angiography was used to reconstruct three-dimensional (3D) arteries for each patient. Cerebral hemodynamics was then computed for the arteries using a mathematical model governed by Navier-Stokes equations and with the outflow conditions imposed by a model of distal resistance and compliance. The non-invasive [Formula: see text], [Formula: see text], and FPR were then obtained from the computational fluid dynamics calculation using a 16-core parallel computer. The invasive and non-invasive parameters were tested by statistical analysis. For this group of patients, the computational fluid dynamics method achieved comparable results with the invasive measurements. The fractional pressure ratio and FPR are very close and highly correlated, but not linearly proportional, with the percentage of stenosis. The proposed computational fluid dynamics method can potentially be useful in assessing the functional alteration of cerebral stenosis.

Laparoscopic resection of congenital choledochal cyst and choledochojejunostomy in children is feasible and safe. The long-term results are good. There was a considerable learning curve during the development of the technique as experienced by the team.

Human facial transplantation, a form of composite tissue allotransplantation, has now become a clinical reality. We carried out the world's second partial facial transplantation in April 2006. We reviewed some issues associated with facial transplantation, especially focusing on the individual who underwent the transplant in our department. We discussed surgical indications, techniques, risks versus benefits, informed consent and psychosocial, societal and financial issues of facial transplantation. In our opinion, with the progresses in composite tissue allotransplantation, partial or full facial transplantation is becoming a timely and effective remedy for the significantly disfigured patients. However, there are a lot of problems unsolved, and as we have performed the transplant on only three individuals, no long-term outcome data are available. Facial transplantation needs further research.

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