Postoperative monitoring of microvascular replants continues to be a challenge. Many types of monitoring systems have been described with variable results reported. The ideal monitoring system would provide simple, continuous, accurate information regarding replant status in a noninvasive manner. Current techniques suffer from the lack of one or more of these attributes. The purpose of this study was to evaluate the potential use of a new technology,optical diffusion imaging spectroscopy (ODIS), for post-operative replantation monitoring.

Methods: Patients referred to our microsurgical service for digital replantation were evaluated in the emergency room for admission to the study protocol. Patients that were expected to undergo replantation were enrolled after informed consent was obtained. Data was obtained prospectively. Digits were evaluated post-operatively in a critical care setting for 12 to 48 hours. Routine fluorescein monitoring was performed. In addition, a measurement of oxygen saturation (StO2) and hemoglobing concentrationn ([Hgb]) was done with an ODIS pencil probe (ViOptix, Inc., Fremont, CA) at one to two hour intervals on the replanted digit(s) and a control digit. Qualitative color, turgor and capillary refill measurements were recorded. Arterial or venous insufficiency was noted and recorded as were any pharmacologic intervention, application of leeches, or secondary surgery.

Results: A total of 14 digits in 11 patients were enrolled. One patient did not undergo replantation and was withdrawn from the study. The ODIS probe was able to identify arterial insufficiency (n=1) and venous insufficiency (n=1) accurately as confirmed by clinical examination. Arterial insufficiency was treated with local papaverine and reversed. The venous insufficiency was treated with systemic heparin and resulted in replant survival. All digits survived.

Conclusion: The ODIS probe allows for safe and potentially continuous monitoring of digital perfusion to permit the rapid detection of clinically significant vascular changes. Prompt diagnosis may aid the early treatment of vascular compromise and may potentially lead to improved digit salvage rates. We continue to enroll patients in this study and will update our complete data at the time of presentation. We will also present preliminary data collected using the ODIS probe to monitor microvascular transplants post-operatively.