Milking dilatation: a pilot study

Under certain circumstances during microsurgical anastomosis, vasospasm may persist, despite the use of multiple topical vasodilators. Mechanical dilatation may be needed but is difficult to perform in vessels smaller than 1 mm in diameter. Milking dilatation, a simple maneuver similar to a milking patency test, is introduced and tested for vessels of such a size. The femoral arteries of 10 Sprague-Dawley rats were used. Milking dilation was performed on both sides, and a forceful milking dilation method was also used 10 times on one side subsequently. The dilated segments demonstrated a 67.3 percent (29 to 100 percent) increase in their original sizes. The vessels were all patent, with no gross signs of thrombosis or aneurysm formation, when exposed immediately, 1 week, and 4 weeks post procedure. Half of the dilated segments, even those forcefully dilated, returned to their normal size at 4 weeks; the remainder were still dilated. The results of this study demonstrated that milking dilatation is effective and safe for dilating arteries about I mm in diameter or less. However, further study is required before any long-term conclusions can be drawn.