The operative field of endoscopic sinus surgery lies adjacent to the orbit and cranial base, involving complex anatomic structures in a confined space. Complications may arise in cases of complex pathology, unclear or variant anatomy, heavy intraoperative bleeding, or a lack of surgical expertise in endoscopic techniques. During the early development of endoscopic techniques, the incidence of surgical complications was relatively high. However, with the standardization of surgical procedures and advancements in surgical instruments, the rate of complications has significantly decreased. Nonetheless, the potential for complications demands continued vigilance.
Factors Contributing to Surgical Complications
Anatomic Factors
The complex anatomy of the nasal cavity and sinuses, as well as the presence of anatomic variants, can increase the risk of complications. Previous trauma or prior surgeries may disrupt or eliminate key anatomic landmarks, while space-occupying lesions that erode the cranial base or orbital bones may alter normal anatomic structures.
Bleeding in the Operative Field
A clear surgical field is critical for endoscopic sinus surgery. Severe disease, vascular injury, or anticoagulant use can result in significant bleeding, impairing visualization and increasing the risk of anatomic misjudgment and subsequent complications.
Surgeon Experience and Operative Technique
The surgeon's proficiency in endoscopic techniques and familiarity with endoscopic anatomy are important factors affecting surgical safety. For example, while powered cutting and suction instruments can improve surgical efficiency, improper use may inadvertently damage the lamina papyracea or cranial base, leading to complications.
Classification of Surgical Complications
Complications can be categorized based on severity or location:
Classification by Severity
Minor complications include mild bleeding and nasal adhesions, which have relatively low clinical impact.
Severe complications involve significant bleeding, diplopia, blindness, or intracranial injury, requiring prompt and active management.
Classification by Location
Complications may be classified as intranasal, orbital, intracranial, or systemic.
Intranasal Complications
Bleeding
Bleeding may occur intraoperatively or postoperatively.
Intraoperative bleeding is often limited to mucosal oozing or minor vessel injuries, which can be controlled with packing and compression, with minimal impact on the procedure. Severe bleeding, such as from injury to the anterior ethmoidal artery, sphenopalatine artery, or internal carotid artery, may cause profuse hemorrhage requiring a combination of packing, electrocautery, and interventional embolization for hemostasis.
Postoperative secondary bleeding may result from scab detachment, blood pressure fluctuations, or wound infection.
Surgical Cavity Adhesions
Adhesions commonly occur between the nasal septum and inferior turbinate or between the middle turbinate and lateral nasal wall. These are related to severe mucosal disease, extensive mucosal damage during surgery, and narrow nasal cavities, which impair nasal airflow and drainage.
Sinus Ostium Obstruction
Obstruction of the maxillary, frontal, or sphenoid sinuses after surgery can result from incomplete opening of the sinus ostium, extensive mucosal damage around the ostium, exposure of bone, or scar formation due to individual healing factors.
Orbital Complications
Lacrimal Duct Injury
Manifested as epiphora, this may occur when opening the maxillary sinus too far anteriorly, thereby damaging the nasolacrimal duct or sac, or when creating a window in the inferior meatus that injures the nasolacrimal duct opening.
Ocular Movement Impairment
Diplopia or strabismus may occur due to damage to the lamina papyracea, resulting in injury to extraocular muscles or hematoma formation causing compression.
Orbital Hematoma or Emphysema
Injury to the lamina papyracea may allow blood or air to enter the orbit, leading to orbital hematoma or emphysema. Clinical manifestations include proptosis, conjunctival hyperemia, restricted ocular movement, and subcutaneous emphysema around the eyelids. Severe cases may require removal of nasal packing and orbital decompression surgery.
Visual Impairment
Causes include direct or indirect injury to the optic canal, increased intraorbital pressure compromising blood supply, or retinal artery spasm. Visual impairment can occur intraoperatively or postoperatively, necessitating close monitoring of vision during the perioperative period. In the case of optic canal injury compressing the optic nerve, optic nerve decompression surgery may be considered.
Intracranial Complications
Injury to critical structures such as the cranial base or dura mater can result in complications like cerebrospinal fluid rhinorrhea, encephalocele, intracranial air, intracranial hemorrhage, meningitis, or intracranial infection. When cranial base injury is identified, steps should be taken to minimize further damage, and cranial base repair and reconstruction should be promptly performed. Postoperative care involves aggressive infection prevention and close monitoring of central nervous system signs and systemic symptoms.
Prevention and Management of Surgical Complications
Prevention Measures
Comprehensive knowledge of endoscopic anatomy of the nasal cavity and sinuses is essential, especially for high-risk areas like the orbital walls and cranial base. Preoperative high-resolution CT of the paranasal sinuses is critical for evaluating nasal and sinus anatomy, assessing the extent and nature of the disease, and identifying key anatomic landmarks, such as the anterior ethmoidal artery, cribriform plate, lamina papyracea, and optic canal, and their relationships with surrounding structures.
Precise surgical techniques should be employed to minimize mucosal damage. Hemostasis should be carefully maintained to avoid operating in a field with significant bleeding. In cases where critical structures are injured, further damage should be avoided, and repair should be conducted promptly to reduce the severity of complications.
Postoperative Monitoring and Management
Postoperative observation of the patient's condition is important to detect complications early and address them promptly. Regular follow-up and standardized medical treatment are helpful in reducing complication rates.