External DCR

The Relationships Between the Nasolacrimal Duct and the Anterior Wall of the Maxillary Sinus

OBJECTIVES/HYPOTHESIS

To examine the anatomic relationships between the lower end opening into the inferior meatus of the bony nasolacrimal duct (NLD) and the anterior wall of the maxillary sinus.

STUDY DESIGN

Anatomical investigation.

METHODS

A total of 206 individuals were recruited for detailed anatomic investigation of the lower end of the bony NLD and their relation to the anterior wall of the maxillary sinus by high-resolution computed tomography (HRCT) imaging. The observed features were classified as either a fusion type or separation type, according to the HRCT images. Additionally, the angle between the anterior and medial wall of the maxillary sinus was classified as either an anterior mode or lateral mode.

RESULTS

The NLD anatomical fusion type was found in 40.05% and the separation type in 59.95% of the HRCT imaging scans available. The anterior mode of angle between the anterior and medial wall of the maxillary sinus was present in 64.1% of the images, and the lateral mode in 35.9% of the images. In 165 cases of anatomical fusion, the anterior mode of angle was present in 15.8% and the lateral mode in 84.2% of cases. In 247 cases of anatomical separation, the anterior mode was present in 97.2% and the lateral mode in 2.8% of cases.

CONCLUSIONS

The surgical anatomy of the lower end of the bony NLD and anterior wall of the maxillary sinus displays varied relationships. Preoperative use of HRCT and an awareness of the particular type of anatomical feature present are likely to aid in planning and performing successful endoscopic medial maxillectomy.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:1030-1034, 2019.

Prevention and management of lacrimal duct injury

Due to the proximity of the lacrimal duct and sac to the uncinate process, occult injury to the lacrimal drainage system is common during uncinectomy and maxillary antrostomy. Fortunately, these injuries do not often progress to develop clinical symptoms as most either heal on their own, or drain into the middle meatus. In the event that injury to the lacrimal drainage system does become clinical evident, symptoms will present within the first two weeks following surgery. These symptoms may resolve over the ensuing weeks as the intranasal inflammation resolves. In cases of persistent epiphora, determination of the level of obstruction is critical for proper intervention. This can be achieved with several office-based studies as well as radiographic studies. If the obstruction is in the lacrimal duct, dacryocystorhinostomy is a highly successful surgical procedure. However, complications do occur with inadvertent violation of the orbit and cranial vault the subject of substantial publications while lacrimal duct injury (LDI) following FESS has been relatively neglected.