gms | German Medical Science

60th Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Benelux countries and Bulgaria

German Society of Neurosurgery (DGNC)

24 - 27 May 2009, Münster

Experimental optimization of blood vessel laser coagulation for neurosurgical applications

Meeting Abstract

  • P. Reinacher - Abteilung für Neurochirurgie, Universitätsklinikum der RWTH Aachen
  • H. Wiederhold - Abteilung für Neurochirurgie, Universitätsklinikum der RWTH Aachen
  • J.M. Gilsbach - Abteilung für Neurochirurgie, Universitätsklinikum der RWTH Aachen
  • A. Lenenbach - Fraunhofer-Institut für Lasertechnik, Aachen

Deutsche Gesellschaft für Neurochirurgie. 60. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit den Benelux-Ländern und Bulgarien. Münster, 24.-27.05.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. DocMO.12-07

doi: 10.3205/09dgnc086, urn:nbn:de:0183-09dgnc0869

Published: May 20, 2009

© 2009 Reinacher et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: To investigate different parameters of laser coagulation for microsurgical and endoscopic neurosurgical operations.

Methods: Different laser systems were studied: A neodym-doped yttrium aluminium garnet (Nd:YAG) with max.28 Watt (W) at 1064nm, two different ytterbium YAG fiber laser systems with max.120W and 200W at 1070nm and a frequency doubled Nd:YAG system emitting 18W at 532nm. First experiments were carried out in an experimental vessel model using swine coronary arteries perfused with bovine serum albumin solution. 561 coagulations were performed in air and under saline solution. Further investigations were carried out in 20 male Sprague-Dawley rats (220-380g), coagulating 176 vessels in air and 161 under saline solution at 37°C. Laser performance was varied, vessel diameters were measured and success of coagulation was determined by cutting the coagulated vessels.

Results: Success of coagulation did not correlate with vessel diameters. In the vessel model the coagulation in air was optimal (99% success) using 6W and the Nd:Yag Laser system (1064nm). Under saline solution, necessary laser performance for successful (100%) coagulation was 75W (ytterbium YAG fiber laser, 1070nm). In the animal model the coagulation in air was successful using 12W (94%) and 14W (98%, ytterbium YAG fiber laser with max.120W, 1070nm). Coagulation through saline solution was not feasible using laser systems with 1064 or 1070nm. Increasing laser performance resulted in heating up and damaging the surrounding tissue, but not in coagulating the target vessel. Using the frequency doubled Nd:YAG system (532nm), at 6W all targeted vessels (n=50) were successfully coagulated.

Conclusions: This study using a vessel model and an animal model allowed a systematic investigation of optimal parameters for laser coagulation in different settings. For coagulation in air, the ytterbium YAG fiber laser (1070nm) using 12W was sufficient. This could be used in microsurgical operations. When using a laser through a saline solution, as in endoscopic neurosurgical procedures, the investigated systems with 1064nm or 1070nm were not able to obtain a satisfactory coagulation success even at high performances >100W, only heating up the surrounding tissue. Using the frequency doubled Nd:YAG system (532nm), 50/50 vessels could be successfully coagulated using only 6W. This system could be applied safely for vessel coagulation in endoscopic neurosurgical procedures.