A hypertensive response to irrigation: endoscopic repair of a ventral spinal CSF leak

Spontaneous intracranial hypotension (SIH) is most commonly caused by spinal CSF leaks, with ventral dural defects frequently requiring surgical repair when conservative measures fail. Endoscopic transforaminal approaches have emerged as minimally invasive alternatives to traditional open techniques, but the physiological consequences of continuous irrigation in the presence of a dural defect remain poorly understood. The authors report the case of a 36-year-old woman with recurrent SIH due to a persistent ventral T11-12 CSF leak despite prior laminectomy, revision repair, and multiple targeted interventions. She underwent transforaminal endoscopic discectomy and ventral dural repair. During the procedure, under continuous gravity-assisted irrigation, she developed sudden, severe, and reproducible hypertension with her systolic blood pressure reaching 275 mm Hg, refractory to anesthetic deepening and multiple antihypertensive agents. Irrigation cessation resulted in immediate hemodynamic normalization, while irrigation reintroduction led to recurrence of the hypertensive response. The procedure was completed after minimizing irrigation, and the patient stabilized postoperatively without further hemodynamic instability. The authors propose that this phenomenon reflects direct transmission of irrigation-induced epidural pressure into the intrathecal space through the persistent dural defect, resulting in acute intracranial pressure elevation and sympathetic activation. In contrast to standard endoscopic cases, chronic CSF leak states may create a compartmentalized and fibrotic epidural environment with reduced compliance and impaired outflow, predisposing the epidural space/operative field to rapid pressure accumulation even under low-pressure irrigation systems. This case highlights a previously underrecognized mechanism of intraoperative hemodynamic instability during endoscopic spine surgery and underscores the importance of considering altered pressure dynamics in patients with CSF leaks. Surgeons should maintain a high index of suspicion for irrigation-related complications in this population and consider strategies to minimize inflow pressure, optimize outflow, and promptly interrupt irrigation in the setting of unexplained physiological changes. These findings have important implications for surgical planning, intraoperative management, and the safe expansion of endoscopic techniques in CSF leak repair.