28.1 Goals

The purpose of dacryocystorhinostomy (DCR) is to alleviate epiphora or dacryocystitis and restore lacrimal outflow by anatomically bypassing a distal lacrimal obstruction via a fistula from the lacrimal sac to the middle meatus of the nose.

28.2 Advantages

External DCR was first described in 1904 by Toti and over the subsequent decades has become a mainstay of treatment for complete or significant partial nasolacrimal obstruction causing epiphora and/or infection of the lacrimal sac. Unlike endoscopic DCR, external DCR does not rely on expensive, highly technical instrumentation and electronic endoscopic video systems. External DCR can be performed with a basic instrument set, which is particularly useful in areas where there may be few resources.

28.3 Expectations

Although the procedure has a steep learning curve and requires a solid understanding of the anatomy of the nose, lacrimal outflow system, and medial canthus, once the basics are mastered, a high success rate is expected. It has become a routine procedure in the armamentarium of the ophthalmic plastic surgeon, and has the benefit of over 100 years of commonplace use, resulting in a vast body of knowledge and medical literature. The success rate of this surgery is reported to be over 90%, based on a variety of outcome measures including relief of epiphora, resolution of infection, and demonstration of lacrimal patency with dye disappearance testing or lacrimal irrigation. This is generally 10% higher than the reported rates for endoscopic DCR, although in highly experienced hands and with modern endonasal technology, the rates may be similar.

28.4 Key Principles

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  Preoperative planning with lacrimal irrigation, and in select cases CT scan, is important to arrive at an appropriate diagnosis.

  
  
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  Hemostasis is critical for intraoperative visualization, minimization of surgical duration, and anatomic success.

  
  
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  A larger osteotomy (and corresponding mucosal fistula) may contribute to a higher success rate.

  
  
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  Gentle handling of mucosal tissues is key to minimize undue iatrogenic inflammation of the flaps that may incite scarring and reduce fistula size.

  
  
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  Placement of silicone lacrimal stents is important for anatomic success, and these stents are left in place between 3 and 8 weeks on average.

28.5 Indications

DCR is indicated for nasolacrimal obstruction resulting in epiphora or dacryocystitis. It is important to note that the majority of patients with complaints of epiphora do not have nasolacrimal obstruction, but rather one of the myriad causes of epiphora including secondary hypersecretion or, less commonly, proximal lacrimal outflow obstruction. In cases of epiphora without obvious infection, lacrimal irrigation in the office setting is essential to confirm and localize anatomic obstruction (Fig. 28‑1). When dacryocystitis is suspected, the diagnosis is confirmed when there is pain, erythema, or palpable mass in the area of the lacrimal sac with purulent discharge expressed from the puncta with pressure on the lacrimal sac (Fig. 28‑2). It is best to allow a hyperacute infection to improve with systemic antibiotics prior to undertaking external DCR, as the inflamed, friable tissues may tear when they are handled, may not hold sutures well, or could scar together, resulting in a decreased chance of surgical success.

28.6 Contraindications

DCR success requires a functioning upper lacrimal system including puncta, canaliculi, and common canaliculus. Patients with upper system obstruction may be candidates for conjunctivodacryocystorhinostomy (CDCR) with Jones tube, as this creates a bypass of the entire lacrimal system from ocular surface to nose. A functioning lacrimal pump is also required to move tears into the lacrimal sac; hence, patients with epiphora secondary to facial paralysis should not expect to see improvement after DCR.

28.7 Preoperative Preparation

Careful planning with regard to many details is critical to ensure success in DCR surgery. Patients must be medically fit for a surgical procedure under anesthesia, typically general anesthesia. Maintaining hemostasis is important intra- and postoperatively; therefore, bleeding risks, including thrombocytopenia, clotting disorders, and use of anticoagulant or antiplatelet medications should be screened for prior to surgery. If DCR surgery is necessary, then steps should be taken to minimize these risks, including platelet transfusion, cessation of anticoagulant medications, and sometimes even consideration of type and crossing for possible transfusion. These should all be done with the permission and supervision of the primary medical doctor. Preoperative computed tomography (CT) scans are not universally necessary in cases of primary acquired nasolacrimal duct obstruction. However, in cases of known or suspected trauma, malignancy, chronic inflammation, visible/palpable mass, or in otherwise atypical presentations (e.g., unilateral tearing in a 20-year-old man), sinus or maxillofacial CT scan protocol is recommended (Fig. 28‑3).