What are the key considerations for a maxillofacial surgeon performing Dacryocystorhinostomy (DCR)

Dacryocystorhinostomy (DCR) for the Maxillofacial Surgeon: Expanding Functional Horizons

Understanding DCR in the Maxillofacial Context

Maxillofacial surgeons should recognize DCR as a critical procedure within their scope when managing nasolacrimal duct obstruction (NLDO) secondary to facial trauma or orthognathic surgery, with fractures involving Le Fort II/III patterns and orbitonasal complex injuries carrying the highest risk of lacrimal system damage. 1

Epidemiology and Etiology in Maxillofacial Practice

• Fracture-related NLDO accounts for 81.93% of cases requiring DCR in maxillofacial settings, with Le Fort II and III fracture patterns contributing to 59% of these cases 1
• Male patients represent 67.47% of cases, with mean age of 32.24 years (range 18-59 years) 1
• Patients typically suffer epiphora for an average of 9.3 months before seeking definitive treatment 1
• Orthognathic surgery represents a significant iatrogenic cause, accounting for 18% of NLDO cases in maxillofacial populations 1

Preoperative Assessment and Planning

Clinical Evaluation

The maxillofacial surgeon must obtain a comprehensive lacrimal system assessment including clinical symptoms (sac swelling, purulent secretions, epiphora) and radiographic confirmation of outflow obstruction. 2

• Purulent secretions with epiphora are significantly correlated with post-operative success (p<0.001), and when present, X-ray examination may be redundant 2
• When epiphora is an isolated symptom without purulent discharge, dacryocystography (conventional or subtraction macrodacryocystography) must be performed to localize obstruction and assess lacrimal sac morphology 2
• Evaluate the phase of treatment: primary intervention versus retreatment cases, as this significantly impacts surgical planning 1

Imaging Requirements

Obtain cone beam CT or conventional CT extended to the orbit to visualize the osteomeatal complex, identify sinus septa, and assess anatomical variations that will impact surgical approach. 3

• CT imaging is mandatory for surgical planning, particularly in post-traumatic cases where anatomical distortion is expected 4
• Three-dimensional images (axial, coronal, sagittal) delineate the extent of disease and anatomic variants 4
• Fine-cut protocols provide higher resolution than thicker cuts and should be specifically requested 4

Sinus Assessment

Request otorhinolaryngology consultation if the patient has any history of sinusitis, nasal obstruction, chronic respiratory disease, or radiologic evidence of mucosal thickening >3mm with osteomeatal complex closure. 3, 4

• Acute rhinosinusitis represents a temporary contraindication; if symptoms persist beyond 10 days, mandatory ENT consultation is required before proceeding 4
• After infection treatment, a 30-day waiting period is advisable to obtain adequate mucosal trophism and osteomeatal complex patency 4
• Mucosal thickening up to 3mm without acute symptoms and with patent osteomeatal complex does not require further investigation 4

Surgical Approaches and Techniques

External DCR Approach

The external transcutaneous approach remains highly effective with success rates of 87-89%, avoiding disruption of medial canthal structures while providing excellent visualization. 2, 5

• Success rates are comparable between external and endoscopic approaches (88.6% vs. 82.4%, p=0.348) 5
• The external approach is particularly advantageous in revision cases and when significant anatomical distortion exists from prior trauma 1
• This approach allows direct visualization and manipulation of the lacrimal sac and surrounding bony structures 6

Endoscopic Endonasal DCR (EEDCR)

Endoscopic endonasal DCR presents as a minimally invasive alternative that is far less traumatic yet as efficacious as the conventional external approach, avoiding skin incision and medial canthal disruption. 2

• EEDCR is particularly valuable in patients with altered anatomy from previous surgery or trauma 7
• Transillumination-guided EEDCR using canalicular light probes significantly improves localization in challenging anatomy and revision cases 7
• The endoscopic approach allows simultaneous correction of intranasal pathology that may contribute to DCR failure 6
• Success rates of 82-87% are achievable with proper patient selection and technique 2, 5

Technical Considerations for Maxillofacial Surgeons

The surgery establishes a connection between the lacrimal sac and nasal cavity to bypass distal lacrimal apparatus obstruction, requiring meticulous attention to creating adequate bony ostium and preserving mucosa. 6, 7

• The procedure requires patent canaliculi and functional lacrimal pump for success 6
• In post-traumatic cases, assess for concurrent canalicular damage that may require additional repair 1
• Anatomical variations including sinus septa (present in ~30% of patients) must be identified preoperatively to modify surgical planning 3

Anesthesia Considerations

Most DCR surgeries can be performed under local anesthesia without sedation, though general anesthesia may be preferable for complex bilateral cases, reoperations, and younger patients. 5, 4

• Intraoperative success rate (ability to complete operation under local anesthesia) is 99.3%, with conversion to general anesthesia needed in only 0.7% of cases 5
• Success rates are higher under general anesthesia (96.7%) compared to local anesthesia (84.9%, p=0.019), though this may reflect age differences between groups 5
• Mean age of patients operated under general anesthesia is significantly younger (43.6 vs. 65.7 years, p<0.005) 5
• Retrobulbar or peribulbar anesthesia with monitored sedation is an option for unilateral procedures, though pure topical anesthesia may be sufficient in selected cases 4

Outcomes and Success Rates

Expected Results

Overall success rates (defined as complete or significant improvement in tearing with patent ostium) range from 82-87%, with post-operative success significantly correlated with presence of pre-operative purulent secretions. 2, 5

• 23 of 28 procedures (82%) achieved complete symptom resolution in one series 2
• Two patients (7%) experienced occasional epiphora, and three (11%) were unsuccessful 2
• Average follow-up of 31 months demonstrates durability of results 1
• The presence of purulent secretions pre-operatively is significantly correlated with lacrimal sac patency post-operatively (p<0.001) 2

Factors Affecting Success

• Primary procedures have higher success rates than revision cases 1
• Fracture patterns involving Le Fort II/III have predictable anatomy once properly assessed 1
• Duration of symptoms before treatment (average 9.3 months) does not appear to significantly impact outcomes within the studied range 1

Complications and Management

Intraoperative Complications

Strabismus can occur following DCR due to surgical manipulation of orbital tissue, though this is rare when proper technique is maintained. 4

• Adhesions and entrapment may extend into deeper orbit, requiring careful dissection 4
• Iatrogenic injury to extraocular muscles, particularly inferior oblique at its origin, may occur during implant placement along nasal wall 4
• Major complications of extensive sinus surgery are rare (0.36-1.5% of cases) and include hemorrhage, skull base injury, CSF leak, meningitis, and orbital injury 8

Postoperative Complications

• Temporary neurosensitive deficit (hypoesthesia) may occur but typically does not affect quality of life 4
• Local infection and scarring are potential complications requiring antibiotic coverage 4
• Continue broad-spectrum antibiotics for 7-10 days postoperatively 3

Integration with Maxillofacial Trauma Management

Timing Considerations

In the context of facial trauma, DCR should be considered as a staged procedure after initial fracture stabilization, typically performed once acute inflammation has resolved and anatomical relationships are restored. 1

• Patients suffer an average of 9.3 months with epiphora before seeking DCR, suggesting delayed recognition of lacrimal injury 1
• Early identification of NLDO in trauma patients allows for appropriate counseling and treatment planning 1
• Fractures involving nasal bones carry an innate risk of damaging the nasolacrimal duct system, requiring heightened awareness during initial trauma assessment 1

Surgical Planning in Post-Traumatic Cases

En bloc resection principles apply when addressing concurrent pathology, with surgical planning based on extent of injury as ascertained by clinical examination and radiographic imaging. 4

• Assess for concurrent maxillary sinus pathology that may require simultaneous treatment 4
• Evaluate for bony wall dehiscence; soft-tissue closure in context of healthy sinus is not a contraindication to DCR 4
• Missing sinus wall with hard-tissue erosion requires specialist evaluation to exclude neoplastic conditions 4

Postoperative Management

Immediate Care

Prescribe NSAIDs (ibuprofen 600mg TID) or acetaminophen 500mg TID for pain control, combined with nasal saline irrigations to improve mucociliary clearance. 3, 8

• Nasal corticosteroids reduce mucosal inflammation and improve outcomes 9
• Decongestants improve sinus drainage in the early postoperative period 9
• Monitor for signs of infection or obstruction requiring intervention 3

Long-Term Follow-Up

Average follow-up of 31 months is necessary to assess durability of results and identify late complications. 1

• Reassess patency and symptom resolution at regular intervals 5
• Endoscopic examination confirms ostium patency and identifies early stenosis 6
• Patient satisfaction correlates with complete resolution of epiphora and absence of recurrent dacryocystitis 2

Special Considerations for Maxillofacial Surgeons

Multidisciplinary Collaboration

Working under a multidisciplinary framework with ophthalmology and otorhinolaryngology enhances outcomes, particularly in complex post-traumatic cases. 4

• Consultation with comprehensive ophthalmology for lacrimal system assessment is essential 4
• ENT collaboration addresses concurrent sinonasal pathology 4, 8
• Orthoptists can assist in examination and diagnosis when strabismus complications arise 4

Expanding Functional Horizons

Maxillofacial surgeons are uniquely positioned to manage DCR given their expertise in facial trauma, orthognathic surgery, and complex three-dimensional anatomy of the midface. 1

• The pattern of NLDO in maxillofacial practice differs from primary ophthalmologic populations, with trauma and iatrogenic injury predominating 1
• Understanding anatomical variations and proper surgical planning are critical for success 1
• Integration of DCR into maxillofacial practice expands the scope of comprehensive facial reconstruction 1, 6

Common Pitfalls and How to Avoid Them

• Failing to obtain adequate preoperative imaging: Always obtain CT extended to orbit to assess osteomeatal complex and identify anatomical variants 3
• Proceeding with surgery in presence of active sinusitis: Delay surgery until infection is treated and 30-day waiting period has elapsed 4
• Inadequate assessment of canalicular patency: Ensure canaliculi are patent and lacrimal pump is functional before proceeding 6
• Ignoring concurrent sinonasal pathology: Address mucosal disease and osteomeatal complex obstruction to optimize outcomes 4, 8
• Insufficient bony ostium creation: Create adequate opening to prevent stenosis and ensure long-term patency 6
• Neglecting to assess for purulent secretions: Presence of purulent discharge is highly predictive of success and may obviate need for additional imaging 2