Is revision sphenoid ethmoidectomy with tissue removal bilaterally and partial septectomy medically indicated for a patient with chronic sinusitis and rhinocerebral mucormycosis, with imaging concerning for ongoing devitalized tissue?

Revision Sphenoid Ethmoidectomy is Medically Indicated and Urgent for This Patient

Revision sphenoid ethmoidectomy with tissue removal bilaterally and partial septectomy is absolutely medically indicated for this patient with rhinocerebral mucormycosis and imaging showing ongoing devitalized tissue in the posterior resection bed. This is a life-threatening invasive fungal infection requiring aggressive surgical debridement as the definitive treatment, particularly given the patient's high-risk status with diabetes and multiple prior surgeries. 1, 2

Critical Nature of Rhinocerebral Mucormycosis

• Acute invasive fungal sinusitis (AFIFS), including rhinocerebral mucormycosis, is rapidly progressive with a time course of less than 4 weeks and carries a mortality rate of 50% to 80%, making aggressive surgical intervention essential. 1

• This infection is particularly lethal in immunocompromised patients and those with poorly controlled diabetes, requiring a high index of suspicion and immediate intervention when these patients present with fever and sinonasal inflammation. 1

• In aggressive cases, intracranial and intraorbital extension can occur with cavernous sinus thrombosis, carotid invasion with pseudo-aneurysm formation, infarcts, and hemorrhage. 1

Surgical Debridement as Definitive Treatment

The primary treatment for rhinocerebral mucormycosis is aggressive surgical debridement of all devitalized tissue, making revision surgery with complete tissue removal the standard of care. 2

• Spheno-ethmoidectomy with or without maxillectomy is considered the definitive method to eradicate rhinocerebral mucormycosis, as the infection spreads from the nasal mucosa through the paranasal sinuses into the orbit and potentially to the brain. 2

• The pterygopalatine fossa serves as the main reservoir for rhinocerebral mucormycosis, and debridement of this area along with the sphenoid and ethmoid sinuses is the definitive management approach. 2

• After proliferation in the nasal cavity, the fungus reaches the pterygopalatine fossa, inferior orbital fissure, and retroglobal space, making complete surgical clearance of these areas essential. 2

Indication for Revision Surgery

The presence of ongoing devitalized tissue on imaging in the posterior resection bed is a clear indication for revision surgery, as residual necrotic tissue serves as a nidus for continued fungal proliferation and spread. 1, 2

• Many surgeons now remove only minimal amounts of middle turbinate tissue if necessary to achieve adequate visualization or to remove devitalized tissue, making targeted removal of necrotic tissue appropriate. 1

• Persistence of disease in the sphenoid and ethmoid sinuses after surgery may be caused by incomplete resection, and residual disease in the posterior ethmoid sinuses is particularly concerning as surgery in this area is technically challenging. 1

• Revision sphenoidethmoidectomy has demonstrated long-term success rates exceeding 90% when more thorough posterior ethmoidectomy and sphenoid clearance is performed. 3

Surgical Approach Justification

• Complete ethmoidectomy is necessary to remove diseased tissue and prevent recurrence from residual disease, particularly in the setting of invasive fungal infection. 4

• The Kerrison rongeur and microdebrider technique allows for reliably safe and efficient sphenoethmoidectomy by skeletonizing the skull base and lamina papyracea, which is appropriate for this complex revision case. 5

• Partial septectomy may be necessary to provide adequate surgical access for complete debridement of posterior disease, particularly given the patient's multiple prior surgeries and altered anatomy. 1, 6

Imaging and Preoperative Planning

• CT with contrast may be used to help define orbital and intracranial complications and should be aligned with image-guided procedure requirements to eliminate redundant imaging for surgical guidance. 1

• MRI of the face or sinuses without and with contrast provides more accurate evaluation of complex sinus secretions and extension of disease into adjacent soft tissues, which is critical for surgical planning in mucormycosis. 1

• Contrast-enhanced MRI with coverage through the cavernous sinuses is the test of choice for suspected cavernous sinus thrombosis and orbital complications, which are potential complications of rhinocerebral mucormycosis. 1

Critical Distinction from Routine Chronic Sinusitis

This case differs fundamentally from routine chronic sinusitis requiring failed medical management before surgery—rhinocerebral mucormycosis is a surgical emergency requiring immediate aggressive debridement regardless of medical therapy trials. 1, 2

• While routine chronic rhinosinusitis requires documented failure of at least 4 weeks of medical management including intranasal corticosteroids and saline irrigations before surgical intervention, invasive fungal sinusitis requires immediate surgical debridement. 1, 7

• The high morbidity and mortality (50-80%) associated with AFIFS in immunosuppressed or diabetic patients necessitates urgent surgical intervention rather than prolonged medical management trials. 1

Postoperative Considerations

• Continued medical management with systemic antifungal therapy (typically amphotericin B) must accompany surgical debridement, as the patient has already received retrobulbar amphotericin injection. 1

• Close postoperative surveillance with repeat imaging and endoscopy is essential to identify any residual or recurrent disease requiring additional debridement. 1

• The patient's underlying diabetes must be aggressively controlled, as poor glycemic control is a major risk factor for treatment failure and mortality in rhinocerebral mucormycosis. 1, 2