By combining conventional medical imaging with some of the same 3-D modeling techniques used in Hollywood blockbusters,
McGowan Institute for Regenerative Medicine
affiliated faculty member Vijay Gorantla, M.D., Ph.D., associate professor of surgery in the Department of Surgery, Division of Plastic Surgery at the University of Pittsburgh, and administrative medical director of the Reconstructive Transplant Program at UPMC, and colleagues at UPMC are reinventing how plastic surgeons prepare for complicated face transplant surgeries. Researchers with the Reconstructive Transplant Program have developed a new fused 3-D model that can be manipulated by surgeons to prepare for surgery.
“This surgery is for patients with devastating injuries to the face, who have lost their ability to smell, eat, and engage socially and have no other conventional treatment options," said Dr. Gorantla.
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.
By combining information from multiple imaging exams and creating a sophisticated 3-D 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 3-D CT, CT angiography, MRI, and high-definition tractography, UPMC researchers developed a protocol for a 3-D model that shows a patient’s head and neck anatomy. This same type of modeling technology often is used in movies to animate computer-generated characters with detailed three-dimensional 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 Darren Smith, M.D., resident, UPMC Division of Plastic and Reconstructive Surgery.
“We are integrating data from multiple imaging sources into a single 3-D representation that allows for real-time user interaction and modification,” added Dr. 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 3-D modeling will help us customize 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 computerized patient model with a polygon mesh of a generic human face and customized it to the recipient’s facial anatomy. Dr. Smith said the ability to manipulate this 3-D facial envelope allows the entire surgical team to participate in planning exactly where bone, blood vessel, and nerves will be cut and connected, as well as to evaluate the outcomes of reconstructive transplantation, including nerve regeneration within the transplanted tissues.
"The goal of face transplantation is not just structural," Dr. Gorantla said. "It is about restoring function, so that patients are once again able to chew their food, smile, and regain the most important aspect of a normal face — to look human."
Illustration: YouTube, UPMC.
RSNA Press Release (11/26/11)
UPMC Media Relations (11/28/11)
YouTube: Video of UPMC’s Dr. Darren Smith discussing new 3-D imaging model for face transplant surgery preparation. (11/28/11)
Science Daily (11/28/11)
Bio: Dr. Vijay Gorantla
Abstract (Radiological Society of North America (RSNA), Chicago, IL, 11/27/11. Paper SSA15-01.)