Detection of perfusion disturbances in digit replantation using near-infrared spectroscopy and serial quantitative fluoroscopy.

PURPOSE: The postoperative monitoring of digit replants continues to be a challenge. Current objective methods of digit monitoring have not been adopted widely because of their complexity or lack of sensitivity. Because tissue oxygen tension correlates directly with vascular inflow, a device that tracks changes in tissue oxygenation may be useful to monitor the perfusion and viability of digits after revascularization. A clinical study was undertaken to evaluate noninvasive monitoring of tissue oxygenation using near-infrared spectroscopy in postoperative digit replantation.

METHODS: Forty-eight patients were enrolled and 64 digits were monitored at 1 institute. There were 43 male and 5 female patients with an average age of 41 years (range, 13-79 y). Digits were monitored by clinical examination, fluorescein, and a tissue oximeter at 1- to 2-hour intervals for 24 to 48 hours.

RESULTS: Sixty-one digits survived and 3 digits failed. In the surviving digits the fluorescein and tissue oxygen saturation (StO2) readings were similar to the control digit readings. There were no significant differences between fluorescein and StO2 or between StO2 readings for control and surviving digits. In the digits that failed to survive both fluorescein and StO2 readings were significantly lower in the failed compared with control digits. The StO2 values for failed digits were 30% to 70% lower and showed greater variation than the StO2 values for the control digits. There were no complications associated with fluorescein or tissue oxygenation measurements.

CONCLUSIONS: Near-infrared spectroscopy measurement of tissue oxygenation correlates with fluorescein monitoring and digit perfusion. This noninvasive monitoring is easy, reliable, safe, and useful in postoperative monitoring of digit replantation.

TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic, Level I.