TY - CHAP
T1 - Endovascular ultraviolet laser-facilitated reversal of vasospasm induced by subarachnoid hemorrhage in canines
AU - Watson, Brant D.
AU - Sadasivan, Chander
AU - Hurst, Robert W.
N1 - Publisher Copyright:
© Springer Nature Switzerland AG 2020.
PY - 2020
Y1 - 2020
N2 - Background: Because treatments for cerebral arterial spasm—a delayed consequence of subarachnoid hemorrhage (SAH)—are clinically inconsistent, we describe here a new method for reversal of arterial spasm, possibly extensible to nitric oxide (NO)-sensitive microvasculature. Methods: We subjected dogs to the intracisternal double-hemorrhage model of SAH (autologous blood injection on days 1 and 3) and began endovascular treatment of the spasmed basilar artery (BA) on Day 4. A conical-tip fused silica optical fiber was introduced via a microcatheter (inserted femorally) into the proximal vicinity of the spasmed BA. After local saline flushing of blood, an ultraviolet (UV) pulsed laser beam (355 nm Nd:YAG) was focused into the optical fiber and converted into a concentric ring beam, which facilitated endovascular irradiation for 30 s at intensities of 12–20 W/cm2. BA diameters were measured angiographically using a semiautomated routine over the entire BA length as well as the proximal, medial, and distal segments. Results: On Day 4 the BAs had constricted by 21 ± 11%. After UV laser irradiation on Day 4, the constricted BAs dilated to 93 ± 15% of their normal diameters within minutes, and the dilation (91 ± 12%) persisted on Day 5. Most BA segments recovered to their respective baselines after UV irradiation, even when the UV beam was located considerably proximal to the BA origin. At days 4 and 5, the percent BA dilation normalized to Day 4 pre-treatment decreased linearly (by scatter plot, p < 0.02) over a range of about 60 mm from the UV irradiation site. Conclusions: We conjecture that the vasodilator nitric oxide, produced at high local concentration from its vascular storage forms (chiefly nitrites) by UV laser-induced photoscission, stimulates a wave of arterial dilation, possibly by longitudinal propagation of transnitrosation reactions in the arterial wall, which reverses cerebral vasospasm semi-locally and thus avoids the deleterious effects of systemic treatment.
AB - Background: Because treatments for cerebral arterial spasm—a delayed consequence of subarachnoid hemorrhage (SAH)—are clinically inconsistent, we describe here a new method for reversal of arterial spasm, possibly extensible to nitric oxide (NO)-sensitive microvasculature. Methods: We subjected dogs to the intracisternal double-hemorrhage model of SAH (autologous blood injection on days 1 and 3) and began endovascular treatment of the spasmed basilar artery (BA) on Day 4. A conical-tip fused silica optical fiber was introduced via a microcatheter (inserted femorally) into the proximal vicinity of the spasmed BA. After local saline flushing of blood, an ultraviolet (UV) pulsed laser beam (355 nm Nd:YAG) was focused into the optical fiber and converted into a concentric ring beam, which facilitated endovascular irradiation for 30 s at intensities of 12–20 W/cm2. BA diameters were measured angiographically using a semiautomated routine over the entire BA length as well as the proximal, medial, and distal segments. Results: On Day 4 the BAs had constricted by 21 ± 11%. After UV laser irradiation on Day 4, the constricted BAs dilated to 93 ± 15% of their normal diameters within minutes, and the dilation (91 ± 12%) persisted on Day 5. Most BA segments recovered to their respective baselines after UV irradiation, even when the UV beam was located considerably proximal to the BA origin. At days 4 and 5, the percent BA dilation normalized to Day 4 pre-treatment decreased linearly (by scatter plot, p < 0.02) over a range of about 60 mm from the UV irradiation site. Conclusions: We conjecture that the vasodilator nitric oxide, produced at high local concentration from its vascular storage forms (chiefly nitrites) by UV laser-induced photoscission, stimulates a wave of arterial dilation, possibly by longitudinal propagation of transnitrosation reactions in the arterial wall, which reverses cerebral vasospasm semi-locally and thus avoids the deleterious effects of systemic treatment.
KW - Angiography
KW - Nitric oxide
KW - Rapid vasodilation
KW - Subarachnoid hemorrhage
KW - Ultraviolet laser irradiation
KW - Vasospasm
UR - https://www.scopus.com/pages/publications/85071280119
U2 - 10.1007/978-3-030-04615-6_19
DO - 10.1007/978-3-030-04615-6_19
M3 - Chapter
C2 - 31407073
AN - SCOPUS:85071280119
T3 - Acta Neurochirurgica, Supplementum
SP - 127
EP - 138
BT - Acta Neurochirurgica, Supplementum
PB - Springer-Verlag Wien
ER -