To evaluate and compare two types of microdrills that are used in endonasal dacryocystorhinostomy.

We retrospectively analyzed medical records and video recordings of 51 patients with 65 affected eyes who underwent endonasal dacryocystorhinostomy for treatment of chronic dacryocystitis or primary acquired nasolacrimal duct obstruction at our hospital between 2005 and 2007. All procedures were performed by the same surgeon. The patients were randomly divided into two groups. For patients in group 1 the surgeon used the Diego powered dissector (Gyrus®), while patients in group 2 were treated using the Ossepro (Bein Air®) microdrill.

The operation success rate of group 1 was 96.6% and of group 2 was 94.2%. This difference was not statistically significant ( p >0.05). The mean operation time was longer in group 1 (45.6 min) than in group 2 (65.8 min). These values, along with the mean drill usage times for each group, were significantly different ( p =0.03). The mean revolution per minute(RPMs)or the two groups were also significantly different ( p =0.05).

Our results suggest that microdrills used in endonasal dacryocystorhinostomy should have protective shields to minimize mucosal damage, and employ rapid RPMs to efficiently produce bony openings in the thick anterior processes of the maxilla. The tips of microdrills should also be exposed, to better visualize and acquire good operating fields.