Traumatic subdural hygroma after endoscopy

The complication rate of Neuroendoscopy is not negligible even in experienced hands. The majority are minor complications that do not affect the final outcome, but sporadically major events may occur, leading to significant problems in surgical management and, occasionally, to permanent disabilities. Careful selection of patients on preoperative imaging studies and intensive training of surgeons is mandatory to improve results ¹⁾.

Clear predisposing factors for the formation of traumatic subdural hygromas could not be identified, but the outer diameter of the endoscope may play a role ²⁾.

A total of 13 patients < 1 year of age with intracranial cysts were operated on between 2005 and 2013. Six presented with hydrocephalus, four presented with seizure, one with abnormal head movement, and two had large asymptomatic cysts. Four children had infratentorial arachnoid cysts; of these, three required a transaqueductal procedure. All the patients underwent endoscopic cystoventriculostomy and/or cystocisternostomy and third ventriculostomy in selected cases with a biopsy from the cyst wall.

Clinically and radiologically all children showed significant improvement with an average follow-up ranging from 8 months to 6 years. There were no intraoperative complications. Three children developed subdural hygroma that subsided with conservative treatment ³⁾

They occurred in 9 of 34 (26%) patients 3 to 28 days after ETV. They were on the operated side in four and bilateral in five cases. There was no relevant age difference between patients with hygromas (median 127 days) and those without hygromas (median 166 days). Etiology of obstructive hydrocephalus had no impact on the frequency of hygromas. Hygromas occurred somewhat less frequently when a paediatric endoscope with an outer diameter of 3 mm was used for ETV instead of an endoscope with a diameter of 6 mm. Hygromas were asymptomatic and conservatively managed in five cases; 4 of 34 (12%) patients underwent surgery because of clinical symptoms of increasing intracranial pressure or increasing hygroma diameter. Two patients were treated with a temporary external drainage only and another two patients with an external drainage first and eventually a subduroperitoneal shunt. There were no neurological long-term sequelae.

Clear predisposing factors for the formation of hygromas could not be identified, but the outer diameter of the endoscope may play a role ⁴⁾.

Subdural hygroma occurred in 11 cases, seven requiring subdural shunting. In one of these cases, infection of the subdural space occurred and required a craniotomy. Cerebrospinal fluid (CSF) infection occurred in 11 cases. In one case, a frontal abscess developed and was managed with craniotomy. Cerebrospinal fluid fistula occurred in nine cases, intraventricular haemorrhages in two, technical failures in seven, subcutaneous CSF collection (managed with lumbo-peritoneal shunt) in one, thalamic contusion and post-operative transient akinetic mutism in one. This patient suddenly died 6 months later, probably as a consequence of closure of the stoma. Two patients developed secondary compartmentalisation of the ventricles after complicated endoscopic third ventriculostomy. In nine cases, these complications were associated. Overall, no patient died after the procedure (operative mortality 0), one patient died 6 months after the procedure for unexplained events (sudden death rate 0.4%), and three patients presented permanent disability as a consequence of surgical complication (permanent morbidity 1.3%).

Complication rate of neuro-endoscopic procedures is not negligible even in experienced hands. The majority are minor complications which do not affect the final outcome, but sporadically major events may occur, leading to significant problems in surgical management and, occasionally, to permanent disabilities. Careful selection of patients on pre-operative imaging studies and intensive training of surgeons are mandatory to improve results ⁵⁾.

Two cases of subdural hygroma occurred in a series of 77 neuroendoscopic procedures. An 8-year-old boy underwent neuroendoscopic cysto-cisternostomy of a left temporal arachnoid cyst. Routine postoperative magnetic resonance imaging 7 days later showed a large left-sided subdural hygroma without clinical symptoms. During the following 3 months, the subdural hygroma did not resolve spontaneously, so it was drained through a burr hole. A 3-month-old boy with aqueductal stenosis developed bilateral subdural hygromas after third ventriculostomy. Several punctures through the open anterior fontanelle relieved the hygromas but increasing head circumference required ventriculoperitoneal shunting 12 months later. Complications of neuroendoscopic procedures are increasingly reported, including various kinds of bleeding, infections, or damage of neuronal tissue. Only three previous cases of subdural hygroma or hematoma after neuroendoscopic interventions have been reported. The possible etiologies and clinical consequences of this rare complication have to be considered before selecting neuroendoscopy treatment ⁶⁾.

A case of an intracranial subdural hygroma resulting from intraoperatively undetected dural tear after unilateral biportal endoscopic (UBE) spine surgery for lumbar spinal stenosis.

An 80-year-old woman presented with insidious onset, gradually progressing low back pain, and right leg pain of 1-year duration. The pain radiated to the right L4-L5 dermatomes. Neurogenic intermittent claudication was <300 m. Motor function was normal. Lumbar magnetic resonance imaging showed lateral recess stenosis at the L3-L4 and L4-L5 levels. These lesions were operated on by the UBE decompression technique.No major complications were encountered during the operation. But soon we found out that there was an undiscovered dura tear. We placed the patient under close observation for 2 weeks. After 30 days, we confirmed that subdural hygroma had changed to chronic subdural hematoma. Conservative treatment was continued. On postoperative day 90), the condition was stable and the symptoms improved completely.

Lin et al. concluded that a spinal Cerebrospinal fluid fistula can result in an intracranial subdural hygroma. Intracranial subdural hygromas and hematomas after lumbar spinal surgery should be cautiously assessed and treated ⁷⁾.