Anatomical conditions for the formation of a stable anastomosis in dacryocystorinostomy

Relevance Dacryocystorhinostomy (DCR) is the main method of surgical treatment of lacrimal duct obstruction, providing lacrimal fluid outflow into the nasal cavity through an artificial anastomosis [1, 2]. The relevance of this study is due to the need to clarify the anatomical and topographic criteria for successful anastomosis formation, which will improve the effectiveness of surgical treatment and reduce the risk of relapse of lacrimal obstruction. Objective To determine the anatomical factors affecting the success of dacryocystorhinostomy (DCR). Material and methods Analysis of 73 patients after DCR: 37 with relapse of obstruction, 36 with a successful outcome. The biometric parameters of the formed opening were measured: horizontal and vertical dimensions of the bone and soft tissue window, the height of the remaining bone fragment above and below the level of the common canal, as well as the depth of the pocket under the lower edge of the osteotomy [3]. Statistical analysis was performed using parametric and nonparametric methods at a significance level of p ≤ 0.05 [1–3]. Results Significant differences were found between the groups in the maximum horizontal size of the bone window (p = 0.015), horizontal size of the soft tissue window (p < 0.001), vertical size of the soft tissue window (p < 0.001), and the height of the bone fragment below the level of the common canal (p = 0.004). Formation of the bone window is a critical stage of DCR, affecting the success of the operation. Not only the location, but also the geometry of the structures are important (table). Comparison with the literature showed that previous studies underestimated the role of the bone window, focusing on the soft tissue part of the osteotomy. Conclusion Retrospective analysis of CT-DCR showed that the success of DCR is directly related to the size of the bone window, especially the horizontal one, the height of the bone fragment below the common canaliculus and the spatial relationship of the osteotomy and the lacrimal sac. These parameters must be taken into account when planning and performing DCR to reduce the risk of recurrence [4]. Keywords: dacryocystorhinostomy; computed tomography; reoperations; recurrences