Water jet dissection in neurosurgery: experimental results in the porcine cadaveric brain

Water jet dissection is currently under investigation as a new tool for use in neurosurgical procedures. The safety of this instrument has already been demonstrated. However, precise data demonstrating highly accurate tissue dissection in the brain in combination with vessel preservation are still missing.

In this study, 50 porcine cadaveric brains were dissected with the use of several nozzle types (80-150 in microm diameter, coherent straight or helically turned jet) and several levels of water jet pressure (1-40 bars). The dissection characteristics in various brain regions and the basilar artery were evaluated morphologically.

The best results regarding reliable function, dissection accuracy, and the correlation of water jet pressure with dissection depth were obtained with the 120-microm Helix Hydro-Jet nozzle. An almost linear relationship of pressure increase with dissection depth was demonstrated. The dissection depth varied significantly up to threefold, depending on the area investigated (greatest resistance was in the brainstem, followed by hemispheres and then the cerebellum). Vessels including the basilar artery resisted pressure up to 15 bars in most cases, whereas the basilar artery was dissected significantly more often with higher pressure.

The results indicate that 1) use of the water jet enables very precise and reliable brain parenchyma dissection with vessel preservation under conditions corresponding to the clinical situation, and 2) the nozzle type and water jet pressure must be selected carefully according to the brain area and tissue targeted. This study provides the morphological basis for further research with the use of the water jet technique in the brain. The water jet's characteristics may make this device a useful addition to the neurosurgical armamentarium.