gms | German Medical Science

Background: Fluorescence microscopy is an innovative tool for the intraoperative evaluation of perfusion in soft tissue structures. In secondary neurosurgical interventions wound closure is highly endangered by the disturbance of tissue perfusion in scar tissue. Revision surgery has included cranioplasty, removal of chronic inflammation and/or muscle plastic.

Materials and methods: Only patients with a long medical history of complex wound healing and at least two previous head operations were included. ICG fluorescence microscopy was applied before scar opening and at the end of the operation (0,3 mg /kg) in the range of 800nm (OPMI Pentero, Zeiss and OH6, Leica). For the infrared video angiography ICG was administered intravenously and the following dynamic tissue perfusion was investigated during the arterial, capillary and venous phase. All operations were performed by the same OMF surgeon and neurosurgeon.

Results: Between May 2012 and September 2015 n= 20 patients were included in the study. All patients presented potential problems of tissue perfusion. In 16 patients (80%) a cranioplasty with different materials was performed additionally. Three patients (15%) got an individual muscle plastic.

In all patients the ICG fluorescence microscopy was successful used. In 5 patients (25%) skin incision was changed based on the first ICG fluorescence microscopy. In three patients the ICG showed at the end of the operation a slower perfusion of some tissue near the wound margin. In one patient the problematic area was removed without any problems postoperatively. In the remaining two patients (both with individual muscle plastic) both have to be reoperated because of tissue problems (one showed a suboptimal vascular supply of the muscle and one patient presented a wound dehiscence because of thin skin < 2mm). Altogether only these two patients had to be reoperated (10%). Mean time for follow up was 7.5 months (1 – 37).

Conclusion: Fluorescence microscopy enables the intraoperative diagnosis of tissue perfusion. ICG can help to optimize the skin incision and the operative strategy in co-operation of OMF surgeon and neurosurgeon. In our study all patients with sufficient tissue perfusion at the end of the operation showed a normal follow up. This method seems to be helpful to avoid re-operation in complex neurosurgical revision surgery.