Blood vessels reorganize after face transplants

Blood vessels in face transplant recipients reorganize themselves, according to study findings that could expand the medical community’s understanding of biologic changes that occur following such transplants.

Researchers at Brigham and Women’s Hospital, Boston, presented results of their study at the recent annual meeting of the Radiological Society of North America (RSNA), according to a news release.

The first full-face transplantation in the United States was performed at Brigham and Women’s in 2011, and three have been performed there since. As part of the procedure, surgeons connect the patient’s major arteries and veins to those from a facial allograft to ensure healthy circulation in the transplanted tissue. Because the technology is new, relatively little is known about the vascular changes that help blood perfuse into the transplanted tissue. The development of new blood vessel networks in transplanted tissue is critical to the success of face transplant surgery.

To learn more, Frank J. Rybicki, M.D., Ph.D., director of the hospital’s Applied Imaging Science Laboratory, and Kanako K. Kumamaru, M.D., Ph.D., a research fellow, used 320-detector row dynamic computed tomography angiography (CTA) to study the facial allografts of the three most recent patients one year after their transplantation. The CTA technology enabled the researchers to view collateralization, a process in which the body stimulates existing blood vessels to elongate, widen and form new connections. Collateralization often results from anastomoses, or branches formed between adjacent blood vessels.

“The key finding of this study is that, after full face transplantation, there is a consistent, extensive vascular reorganization that works in concert with the larger vessels that are connected at the time of surgery,” Dr. Kumamaru said in the news release.

Results showed that the new blood vessel networks course posteriorly, or toward the ears and even farther behind the head, in addition to the large arteries and veins that course anteriorly in the face.

“We have found that since the vessels more commonly associated with the back of the head are critical to maintain the perfusion via vascular reorganization, it is essential to visualize these vessels and determine that they are normal preoperatively,” Dr. Kumamaru said in the news release. “Patients under consideration for face transplantation have universally had some catastrophic defect or injury.”

The authors noted the findings could help improve surgical planning and assessment of potential complications in face transplant patients. But do the findings have implications for other types of dermatologic surgery? Dermatology Times asked Tucson, Ariz., dermatologist Ronald G. Wheeland, M.D., a specialist in dermapathology, for his thoughts.

“Some of their findings may have a minor application in current dermatologic procedures like large Juri flaps for hair replacement surgery, possibly scalp reduction surgery, and - least likely - extremely large and complex wound reconstruction following Mohs surgery,” Dr. Wheeland says.