Hydro Jet dissection of abdominal wall perforator arteries: a pilot study

The Hydro Jet is a new surgical dissection instrument. Applying water to tissues under variable pressure makes selective tissue dissection possible. Larger vessels are less sensitive to water pressure and can be easily coagulated to minimize blood loss. However, the impact of the water pressure on the small blood vessels/microvasculature is not well known. These microvascular changes may be important in the future when using the Hydro Jet as a surgical tool in perforator flap surgery. The abdominal perforator arteries near the umbilicus were dissected with the Hydro Jet in five women who underwent an abdominoplasty for skin/fat excess. The inferior epigastric artery was dissected in one patient who underwent a transverse rectus abdominal musculocutaneous flap procedure for breast reconstruction. Pressure of dissection varied between 30 and 60 bar. Blood vessel specimens were taken and examined using light and electron microscopy. Eighteen samples were taken from six patients. Thirteen samples were dissected with the Hydro Jet; five samples served as controls. No vascular damage was observed microscopically from 30 to 40 bar. Clear signs of vascular damage were observed after dissection with 45 bar with swelling of the (sub)endothelium. At 50 bar dissections the edema of the surrounding stroma increased with loosening of the endothelium. At 60 bar dissections there was obvious damage to all vessel layers. Control samples showed no damage. Dissection of small vessels with the Hydro Jet up to 40 bar does not damage the structural layers histologically. Above this pressure serious damage occurs.