Is left endoscopic dacryocystorhinostomy, left lacrimal sac biopsy, and left probing with Crawford tube placement medically indicated for a patient with chronic left nasolacrimal duct obstruction, swelling, and tearing?

Medical Necessity of Left Endoscopic Dacryocystorhinostomy for Chronic Nasolacrimal Duct Obstruction

Left endoscopic dacryocystorhinostomy (DCR) with lacrimal sac biopsy and probing with Crawford tube placement is medically indicated for this patient with chronic left nasolacrimal duct obstruction presenting with years of symptoms, swelling, and tearing. 1

Primary Indication and Standard of Care

• Endoscopic DCR represents the standard surgical approach for symptomatic nasolacrimal duct obstruction (NLDO) after conservative management has failed or is inappropriate. 1

• The patient's chronic presentation with years of symptoms, confirmed swelling, and persistent tearing establishes clear functional impairment requiring surgical intervention. 2

• Endoscopic DCR is widely considered a valid alternative to external approaches for treating nasolacrimal duct obstruction, with established efficacy in both primary and revision cases. 2

Evidence Supporting the Proposed Surgical Approach

Success Rates and Outcomes

• Endoscopic DCR achieves anatomical success in 91.54% of primary cases and functional success (resolution of epiphora with free lacrimal flow) in 90.4% of primary procedures. 2

• The combination of endoscopic DCR with silicone stent placement (Crawford tube) is the established technique, with stents typically remaining in place for approximately 3 months. 2

• Even in revision cases, endoscopic DCR maintains anatomical success rates of 89.36% and functional success rates of 85.1%, demonstrating durability of the approach. 2

Technical Considerations for This Case

• The lacrimal sac biopsy component is appropriate as patients with chronic dacryocystitis and nasolacrimal duct obstruction may have concomitant pathology requiring histological evaluation. 1

• Modified endoscopic DCR techniques involving creation of a large posterior flap at the lacrimal sac wall have demonstrated superior success rates (89.1%) compared to conventional techniques (71.7%), a statistically significant difference. 3

• Terminal DCR approaches that achieve total separation of the lacrimal sac from the nasolacrimal duct show 88% success rates and may be particularly beneficial in cases of idiopathic or partial obstruction. 4

Addressing the CPB Criteria Concern

The question references that "combined endoscopic membranous nasolacrimal duct resection and retrograde lacrimal stent placement" is considered insufficient evidence per CPB criteria. However, this is a distinct procedure from what is proposed:

• The planned procedure is endoscopic DCR with probing and Crawford tube placement, NOT retrograde stent placement alone. 1, 2

• Endoscopic DCR involves creating a rhinostomy opening between the lacrimal sac and nasal cavity with removal of bone and mucosa, which is fundamentally different from simple retrograde stenting. 2, 4

• The addition of lacrimal sac biopsy and probing represents comprehensive surgical management rather than a minimally invasive stenting-only approach. 1

Quality of Life and Morbidity Considerations

• Chronic epiphora (tearing) significantly impacts quality of life, causing visual obstruction, skin maceration, and social embarrassment. 2

• Years of symptoms indicate failed conservative management and progression to chronic disease requiring definitive surgical correction. 2

• The presence of swelling suggests chronic dacryocystitis, which carries risk of acute infection and potential orbital complications if left untreated. 1

Common Pitfalls to Avoid

• Meticulous surgical technique and precise follow-up are key aspects in achieving both functional and anatomical success with endoscopic DCR. 2

• Failure to adequately expose the lacrimal sac or create a sufficiently large rhinostomy opening can lead to surgical failure requiring revision. 3

• The silicone stent must remain in place for the full recommended duration (approximately 3 months) to prevent premature closure of the rhinostomy site. 2

• Intraoperative complications to monitor include thermal injury to the canaliculus, though this is rare with proper technique. 5

CPT Code Alignment

The procedures align with the CPT codes mentioned:

• CPT 68815 corresponds to probing of nasolacrimal duct with or without irrigation, with insertion of tube or stent (Crawford tube placement). 2

• CPT 31239 corresponds to nasal/sinus endoscopy with dacryocystorhinostomy. 2

• These codes accurately reflect the comprehensive surgical approach planned for this patient's chronic nasolacrimal duct obstruction. 1, 2