gms | German Medical Science

66th Annual Meeting of the German Society of Neurosurgery (DGNC)
Friendship Meeting with the Italian Society of Neurosurgery (SINch)

German Society of Neurosurgery (DGNC)

7 - 10 June 2015, Karlsruhe

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Does indocyanine green angiography alter local cerebral perfusion? Intraoperative use of a combined laser-Doppler spectrophotometry system during aneurysm surgery

Meeting Abstract

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  • Björn Sommer - Neurochirurgische Klinik
  • Kurt Wiendieck - Neurochirurgische Klinik
  • Barbara Bischoff - Neurochirurgische Klinik
  • Ilker Eyüpoglu - Neurochirurgische Klinik
  • Karl Rössler - Neurochirurgische Klinik
  • Hubert Schmitt - Anästhesiologische Klinik, Universitätsklinikum Erlangen
  • Michael Buchfelder - Neurochirurgische Klinik
  • Oliver Ganslandt - Neurochirurgische Klinik

Deutsche Gesellschaft für Neurochirurgie. 66. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC). Karlsruhe, 07.-10.06.2015. Düsseldorf: German Medical Science GMS Publishing House; 2015. DocDI.25.02

doi: 10.3205/15dgnc239, urn:nbn:de:0183-15dgnc2392

Published: June 2, 2015

© 2015 Sommer et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.

Outline

Text

Objective: Intraoperative indocyanine green (ICG) angiography is a routine procedure in aneurysm surgery to assess the patency of blood flow in parent, branching, and perforating arteries. We wanted to test if ICG has an impact local microvascular blood flow parameters using a novel non-invasive measurement device.

Method: We performed intraoperative real-time measurements with the laser-Doppler spectrophotometry system “Oxygen-to-see (O2C)” in 15 consecutive patients operated upon for incidental cerebral aneurysms. This measurement device allows real-time monitoring of capillary venous oxygenation (SO2), post-capillary venous filling pressures (rHb) and blood flow (flow) in 7 mm tissue depth using a fiber optic probe. Subdural measurement sites corresponded to the distal supply territory of the aneurysmatic blood vessel. For routine monitoring after microsurgical clipping, both micro-Doppler ultrasound and ICG angiography were used to assess changes in vessel integrity. Additionally, we performed monitoring of somatosensory evoked potentials (SEP) with median and posterior tibial nerve stimulation.

Results: All aneurysms (MCA: 6, ACA: 4, AcomAnt: 3, ACI: 2) were treated successfully by microsurgical clipping. The sampling rate was 2 Hz for the spectrophotometry system and 40 Hz for the laser-Doppler flowmeter. Recordings were acquired over a time span of 83 ± 22 seconds. Of 15 patients (9 female, 6 male; age 54.7 ± 13 yrs.), 14 patients showed an increase in flow of 18.4% ± 12.8% after injection of ICG. In one patient, flow decreased by 5.8%. Due to its fluorescence properties, the near-infrared spectrum of the spectrophotometry system showed typical changes of SO2 and rHb. SEP monitoring revealed no changes in latency or amplitude of N20 or P40. In all cases, no postoperative neurological deficit occurred. There were no surgical complications.

Conclusions: The observed changes in blood flow after application of ICG angiography cannot be explained solely by the measurement principle. If the increase in microperfusion has any impact on metabolic changes that alter cerebral perfusion and if the chemical properties of indocyanine green influence cerebral autoregulation remains to be determined by additional investigations.

This study was supported by the Johannes und Frieda Marohn-Stiftung (Erlangen, Germany).