A technique for safe deep facial tissue dissection: Indocyanine green–assisted intraoperative real-time visualization of the vasa nervorum of facial nerve with a near-infrared camera

Abstract

During deep tissue dissection in the face, it is sometimes difficult to distinguish the facial nerve from surrounding tissue, leading to a risk of facial nerve injury. To identify the facial nerve during such procedures, we used a fluorescence-assisted near-infrared camera. Indocyanine green (ICG)-assisted direct visualization was used intraoperatively in 13 cases. The procedures included excision of neurofibromas (n = 10) and lymphatic malformations (n = 3). Intravenously injected ICG was distributed systemically and filled the lumen of epineural vessels around the nerves (vasa nervorum) within 1 min. The nerve trajectories were directly visualized using a fluorescence-detecting near-infrared camera. The facial nerve was distinguishable from surrounding tissues such as retaining ligaments and, in all cases, was safely secured, preserving postoperative facial nerve function. Postoperative mean differences of left/right facial volume were significantly reduced compared with preoperative values. Patient satisfaction ranged from satisfied to very satisfied. Injuries to the facial nerve could be effectively avoided via direct intraoperative visualization of the vasa nervorum of nerve through intravenous ICG injection. A portable near-infrared camera enabled direct and real-time visualization of the vasa nervorum, facilitating injury prevention. This technique might help to reduce the risk of disastrous complication of facial palsy through a simple and efficient method.