[Water jet dissection in fatty tissue]

The first report about the use of water-jet dissection in surgery dates 1982. The advantage compared to conventional cutting is the preservation of vessels and nerves, thus facilitating the precise coagulation thereafter. Devices of the new generation with coherent jet are used in liver surgery in order to reduce blood loss. The use of water-jet dissectors in other fields of surgery is currently under investigation. The preparation of vessels in fatty tissue is of special interest for plastic surgeons. The technical parameters of the hydro- or water-jet device have to be optimised.

Abdominal fat tissue of fresh cadavers was cut under standardised conditions with different parameters of the dissector. The depth of the cuts and the morphology of the blood vessels were analysed.

Between 20 and 60 Bar cutting pressure of the water-jet and one single pass the cuts are 8 mm deep. Deeper cuts can be achieved by repeated application on the same cut. When using 40 Bar and 5 passes the cutting depth is 1.7 cm. Higher pressure as 50 or 60 Bar do not lead to deeper cuts. The water-jet dissection leads to a water uptake of the cut tissue. Morphologically all the vessels, lying in the cut are undamaged if the pressure doesn't exceed 40 Bar pressure range.

The optimal pressure for water-jet dissection of fatty tissue lies between 30 and 40 Bar. Higher pressure does not lead to deeper cuts, but increases the risk of vessel damage. The vessels in the remain morphologically intact if he cutting pressure lies below 50 Bar. The effect of the mechanical irritation of the vessels has to be investigated in vivo, before using the water-jet dissector for preparation of blood vessels in humans e.g. for flap dissection.