Laser speckle imaging to evaluate scalp flap blood flow during closure in neurosurgical procedures

Background: To measure the degree of relative ischemia caused by skin closure, we explored the potential utility of intraoperative surface blood flow measurement with laser speckle imaging (LSI). Methods: Prospective observational study of eight subjects that underwent intraoperative LSI during elective cranial neurosurgical procedures at the time of skin closure. Results: Seven 1st time incisions, with closure techniques including sutures (n = 3), staples (n = 3), and one after galeal sutures. When compared to the control region, there was a mean 63.7% reduction in flow across all seven subjects (range 18.7–95.32%). Comparing by closure type, a higher flow reduction in the three subjects with suture closure (80.7% reduction) compared to staples (61.9% reduction, P = 0.0379). One subject had a complex wound where tightening and loosening of sutures were performed to ensure adequate perfusion. Suturing resulted in significantly more local decreased flow compared to staples (P < 0.0001). Conclusion: These findings demonstrate the relative feasibility of using LSI for preoperative vascular flow assessment in planning complex incision closure. These data also provide preliminary support for the hypothesis that skin closure itself causes relative ischemia compared to deep approximation or cautery of the skin edge and that the relative ischemia from staples closure is generally less than from suture closure.

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Laser Speckle Imaging Allows Real-Time Intraoperative Blood Flow Assessment During Neurosurgical Procedures

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2013.42 ◽

2013 ◽

Vol 33 (7) ◽

pp. 1000-1007 ◽

Cited By ~ 36

Author(s):

Nils Hecht ◽

Johannes Woitzik ◽

Susanne König ◽

Peter Horn ◽

Peter Vajkoczy

Keyword(s):

Blood Flow ◽

Real Time ◽

Bypass Graft ◽

Laser Speckle ◽

Neurosurgical Procedures ◽

Laser Speckle Imaging ◽

Speckle Imaging ◽

Intracranial Surgery ◽

Hemodynamic Compromise ◽

Real Time Visualization

Currently, there is no adequate technique for intraoperative monitoring of cerebral blood flow (CBF). To evaluate laser speckle imaging (LSI) for assessment of relative CBF, LSI was performed in 30 patients who underwent direct surgical revascularization for treatment of arteriosclerotic cerebrovascular disease (ACVD), Moyamoya disease (MMD), or giant aneurysms, and in 8 control patients who underwent intracranial surgery for reasons other than hemodynamic compromise. The applicability and sensitivity of LSI was investigated through baseline perfusion and CO2 reactivity testing. The dynamics of LSI were assessed during bypass test occlusion and flow initiation procedures. Laser speckle imaging permitted robust (pseudo-) quantitative assessment of relative microcirculatory flow and standard bypass grafting resulted in significantly higher postoperative baseline perfusion values in ACVD and MMD. The applicability and sensitivity of LSI was shown by a significantly reduced CO2 reactivity in ACVD (9.6 ± 9%) and MMD (8.5 ± 8%) compared with control (31.2 ± 5%; P < 0.0001). In high- and intermediate-flow bypass patients, LSI was characterized by a dynamic real-time response to acute perfusion changes and ultimately confirmed a sufficient flow substitution through the bypass graft. Thus, LSI can be used for sensitive and continuous, non-invasive real-time visualization and measurement of relative cortical CBF in excellent spatial-temporal resolution.

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