Endoscopic Dacryocystorhinostomy
Endoscopic dacryocystorhinostomy (EndoDCR) is a surgical procedure performed through an endonasal approach to the lacrimal sac with a camera-mounted endoscope. Like conventional DCR, it aims to form a permanent opening of the lacrimal sac and duct into the nose, bypassing the obstructed portion of the nasolacrimal duct. It is performed most commonly when a complete or partial nasolacrimal duct obstruction is present but can also be used to prevent recurrent dacryocystitis. It can also be performed when an acute dacryocystitis is present after systemic antibiotics have been initiated even in the presence of residual inflammation and swelling.
PREOPERATIVE EVALUATION AND PREPARATION
A detailed medical history should include previous surgeries involving the lacrimal system, the nose, and the paranasal sinuses. Proper imaging with a computed tomography scan is obtained if a history of trauma with possible naso-orbital fracture is disclosed. Bone deformities or hardware used to reduce the fracture may hamper access to the sac from an endoscopic approach. History of abnormal bleeding is investigated. Anticoagulants including aspirin should be stopped before surgery for a period long enough to reverse its effect and not be resumed for 5 days following surgery. If for medical reasons the discontinuation of anticoagulants cannot be done, an alternative approach should be considered.
A bone subtraction dacryocystography may be obtained when a partial obstruction is present, in cases of recurrent dacryocystitis and when a diverticulum is suspected. Careful examination of the nose is mandatory before surgery. Ideally, an endoscopic evaluation of the nasal cavity is performed in the clinic. It allows the surgeon to determine if sufficient space is present to perform the endoscopic surgery. When available space is limited, a general anesthesia may be proposed or an external approach may be preferred. Nasal endoscopy may also disclose the presence of nasal anomalies including tumor, polyps, septal deviations, and nasal mucosal inflammation or synechiae.
Probing of the canalicular system should be performed. Obstruction of the common canaliculus is a contraindication to endonasal surgery and an external canaliculodacryocystorhinostomy (CanaliculoDCR) should be considered. When diffuse canalicular scarring is present, placement of a Jones tube is the best solution and can be performed endoscopically.
Surgical setup and anesthesia
The surgery can be performed under local anesthesia with sedation in most patients. General anesthesia is preferred if the surgical access is restricted or if for various reasons the collaboration of the patient cannot be obtained. Proper monitoring including oxygen saturation measurement should be available. The patient is in supine position with a moderate inclination from head to toe of about 20° to 30°. A solution of lidocaine 4% with epinephrine 0.25% spray is applied to the nostril 5 minutes before injection to minimize pain at the time of local infiltration. A solution of cocaine 4% is also an alternative.
Surgery