Clinical Consequences of Incidental Durotomy during Full-Endoscopic Lumbar Decompression Surgery in Relation to Intraoperative Epidural Pressure Measurements

Abstract

Background: Seizures, neurological deficits, bradycardia, and, in the worst cases, cardiac arrest may occur following incidental durotomy during routine lumbar endoscopy. Therefore, we set out to measure the intraoperative epidural pressure during lumbar endoscopic decompression surgery. Methods: We conducted a retrospective observational cohort study to obtain intraoperative epidural measurements with an epidural catheter-pressure transducer assembly through the spinal endoscope on 15 patients who underwent lumbar endoscopic decompression of symptomatic lumbar herniated discs and spinal stenosis. The endoscopic interlaminar technique was employed. Results: There were six (40.0%) female and nine (60.0%) male patients aged 49.0667 ± 11.31034, ranging from 36 to 72 years, with an average follow-up of 35.15 ± 12.48 months. Three of the fifteen patients had seizures with durotomy and one of these three had intracranial air on their postoperative brain CT. Another patient developed spinal headaches and diplopia on postoperative day one when her deteriorating neurological function was investigated with a brain computed tomography (CT) scan, showing an intraventricular hemorrhage consistent with a Fisher Grade IV subarachnoid hemorrhage. A CT angiogram did not show any abnormalities. Pressure recordings in the epidural space in nine patients ranged from 20 to 29 mm Hg with a mean of 24.33 mm Hg. Conclusion: Most incidental durotomies encountered during lumbar interlaminar endoscopy can be managed without formal repair and supportive care measures. The intradural spread of irrigation fluid and intraoperatively used drugs and air entrapment through an unrecognized durotomy should be suspected if patients deteriorate in the recovery room. Ascending paralysis may cause nausea, vomiting, upper and lower motor neuron symptoms, cranial nerve palsies, hypotension, bradycardia, and respiratory and cardiac arrest. The recovery team should be prepared to manage these complications.

Treatment Concept and Technical Considerations of Biportal Endoscopic Spine Surgery for Lumbar Spinal Stenosis

“…Increasing the input water pressure to improve water output is not a good trick. If there was not good water output already, just putting water input in higher pressure will cause the cervical epidural pressure to increase, which may increase intracranial pressure [40][41][42]. Clinically sufficient water pressure can be achieved in a setting where two saline bags are placed 60-70 cm higher under natural gravity from the patient's back level in the prone position on the surgical table.…”

Overview and Prevention of Complications During Full-Endoscopic Cervical Spine Surgery

“…Although the exact mechanism of seizures during fully endoscopic spine surgery is still undetermined, factors such as infusion fluid containing cefazolin, infusion rate, prolonged operative time, dural tear, and sevoflurane anesthesia may increase the risk of seizures [46]. Symptoms and signs, such as headache, neck pain, seizures, elevated blood pressure, or bradycardia, should be carefully monitored in patients [49,50]. Lin et al [46] reported the cases of seizures during full-endoscopic lumbar surgery and found that a socalled red flag sign-characterized by uncontrollable hypertension combined with a decreasing pulse rate-occurred in all 3 patients who experienced a seizure.…”

“…Although not definitively established, this phenomenon bears similarity to the Cushing reflex, a cardiovascular response to compensate for increased intracranial pressure. This reflex sometimes occurs during endoscopic brain surgery, wherein the working space inside the brain is maintained with infused water pressure [49,50]. Previously, when a dural tear occurred during fully endoscopic spine surgery, 3 of 15 patients experienced seizures, and 1 of the 3 patients exhibited intracranial air on a postoperative CT scan [50].…”

“…This reflex sometimes occurs during endoscopic brain surgery, wherein the working space inside the brain is maintained with infused water pressure [49,50]. Previously, when a dural tear occurred during fully endoscopic spine surgery, 3 of 15 patients experienced seizures, and 1 of the 3 patients exhibited intracranial air on a postoperative CT scan [50]. Thus, strict control of epidural pressure is required when a dural tear occurs during surgery.…”