Paper #II-1

ENDOSCOPIC LASER SPECKLE PERFUSION IMAGING IN THE HUMAN KNEE

Jeremy Reed, MD

Calgary, AB

Co-Authors

R. Bray MD, FRCSC

K. Forrester PhD,

C. Leonard MSc

C. Stewart BSc

Objective

To assess the endoscopic Laser Speckle Perfusion Imaging system's (eLSPI, a novel device capable of real-time, optical, non-invasive measurement of tissue perfusion) ability to detect changes in tissue perfusion in the human knee secondary to:

1. 2 consecutive episodes of tourniquet induced occlusion of blood flow.

2. Re-perfusion hyperemia following tourniquet release.

3. Epinephrine induced vasoconstriction at concentrations of 0.5x10^-6M, 1x10^-6M, and 2x10^-6M.

Design

Case series of 5 patients.

Subjects

5 patients between the age of 18 and 42 requiring arthroscopic knee surgery.

Outcome

Assessment of the eLSPI's ability to detect changes in perfusion resultant from

Measures: like interventions.

Results

In each patient, two sequential tourniquet inflations produced consistent decreases in perfusion index measurements (numerical values linearly related to blood flow). All patients demonstrated varying degrees of post-tourniquet hyperemia. The eLSPI was able to detect a dose dependent response to the administration of intra-articular epinephrine. These decreases in perfusion were not consistent across patients.

Conclusions

The eLSPI system consistently detects changes in perfusion resultant from tourniquet inflation. The eLSPI is able to detect decreases in perfusion resultant from the administration of increasing concentrations of epinephrine. There is not a significant correlation in the degree of epinephrine response across patients.