[Digital subtraction dacryocystography (DS-DCG) and evaluation of results of endonasal lacrimal duct surgery].

103 patients with obstructive epiphora, or illacrimation, underwent endonasal lacrimal surgery (dacryocystorhinostomy in the modification of Veis-Cdlaus and canaliculorhinostomy). Postoperative complications included local infections and were seen in 7 cases (6.8%). After finishing the treatment 90 patients (87.4%, Table 4) were free of symptoms and remained so for years of follow-up. Recurrent stenosis developed in 13 cases (12.6%). DS-DCG provides valuable information for confirming the indication for surgery and determining the surgical procedure in obstructive epiphora. In addition it may help to assess a successful outcome of the operation in the course of treatment (Fig. 7 and 8). By means of real time substraction the successive opacification is visualised on the monitor screen during injection thus controlling the examination. Incomplete contrast filling and overopacification are avoided. Digitalisation may direct the extent of homogenisation of the background of the radiographic image. Anatomical structures are preserved and weakly contrasted structures are depicted precisely and independent of the background. Stenoses before (Fig. 2 and 3), within (Fig. 4) and behind (Fig. 6) the lacrimal sac can be differentiated from complete, incomplete (Fig. 4) and functional stenoses.