3D modelling technique could help improve face transplants

Researchers with the Reconstructive Transplant Program are said to have developed a fused 3D model that can be manipulated by surgeons to prepare for surgery.

Because face-transplantation surgery is medically complex, imaging plays a major role in selecting patients, planning donor and recipient surgery, and assessing postoperative motor and sensory function.

It is claimed that, by combining information from multiple imaging exams and creating a sophisticated 3D computer model, surgeons will be better able to assess the facial structure and contours, the underlying bone, muscles, nerves and vessels, as well as the full extent of the damage of a face-transplant candidate.

Using integrated information from different imaging exams of sample patients, including 3D computer tomography (CT), CT angiography, MRI and high-definition tractography, UPMC researchers developed a protocol for a 3D model that shows a patient’s head and neck anatomy.

According to a statement, this same type of modelling technology is often used in films to animate computer-generated characters with detailed 3D human features and facial expressions.

‘While there have been some fusions of imaging techniques before, this is the first time anyone has combined so many imaging techniques in a user-friendly model that can be manipulated for detailed face-transplant planning,’ said Dr Darren Smith, UPMC Division of Plastic and Reconstructive Surgery.

‘We are integrating data from multiple imaging sources into a single 3D representation that allows for real-time user interaction and modification,’ added Smith. ‘In assessing eligibility for face-transplant surgery, it is critical to understand whether the patient has enough blood vessels and bone structure to support new facial tissue.

‘This 3D modelling will help us customise the procedure to the patient’s individual anatomy so that the donor tissue will fit like a puzzle piece onto the patient’s face.’

Using this approach, the team overlaid the computerised patient model with a polygon mesh of a generic human face and customised it to the recipient’s facial anatomy.

Smith said the ability to manipulate this 3D facial envelope allows the entire surgical team to participate in planning exactly where bone, blood vessels and nerves will be cut and connected, as well as to evaluate the outcomes of reconstructive transplantation, including nerve regeneration within the transplanted tissues.