Summary: Background: The advantage of water-jet dissection is the preservation of vessels and nerves. Especially in liver surgery, blood loss can be significantly decreased. 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 optimal technical parameters were investigated. Methods: Abdominal fat tissue of fresh cadavers was cut under standardized conditions with different parameters of the water-jet dissector. Results: One single pass at a cutting pressure between 20 and 60 Bar makes an incision of 8 mm. Deeper cuts can be achieved by repeated application on the same cut. Five passes at 40 Bar results in a depth of 1.7 cm without vessel damage. If the applied pressure is 50 or 60 Bar, up to 7% damaged vessels can be found. The water-jet dissection leads to a water uptake of the cut tissue. Conclusions: The optimal pressure for water-jet dissection of fatty tissue lies between 30 and 40 Bar. The effect of the mechanical irritation of the vessels has to be investigatedin vivo before using the water-jet dissector for preparation of blood vessels in humans, e.g. for flap dissectio
