PHIL and Squid Embolization of Cerebral Arteriovenous Malformation: A Retrospective Case Series of 23 Patients.

Precipitating hydrophobic injectable liquid (PHIL; MicroVention, Aliso Viejo, CA, USA) and Squid (Balt, Irvine, CA, USA) are 2 newer liquid embolic agents used in endovascular embolization of cerebral arteriovenous malformation (AVM). This study aims to investigate and compare the effectiveness and safety profile of the 2 newer liquid embolic agents in the embolization of cerebral AVM. This is a retrospective study on all patients diagnosed with cerebral AVM undergoing endovascular embolization with liquid embolic agents PHIL and Squid admitted to the Division of Neurosurgery, Department of Surgery in Prince of Wales Hospital from January 2014 to June 2021. Twenty-three patients with cerebral AVM were treated with 34 sessions of endovascular embolization with either PHIL or Squid (17 sessions each) liquid embolic agents with a male to female ratio of 2.3:1 (male 16; female 7) and mean age of 44.6 (range, 12 to 67). The mean total nidus obliteration rate per session was 57% (range, 5% to 100%). Twenty-one patients (91.3%) received further embolization, stereotactic radiosurgery, or surgical excision after initial endovascular embolization. There were 2 morbidities (1 neurological and 1 non-neurological, 6%) and no mortalities (0%). All patients had static or improvement in modified Rankin Scale at 3 to 6 months at discharge. PHIL and Squid are effective and safe liquid embolic agents for endovascular embolization of cerebral AVM, achieving satisfactory nidal obliteration rates and patient functional outcomes.

Urokinase Is Safe and Effective in Reducing Recurrence in Chronic Subdural Hematoma After Burr-Hole Drainage.

OBJECTIVE: This study aimed to evaluate the safety and efficacy of subdural urokinase in reducing the recurrence of chronic subdural hematoma (cSDH). METHODS: Consecutive adults with cSDH and burr-hole drainage from 1 January 2013 to 31 December 2017 were retrospectively analyzed. Clinical records, radiologic images, laboratory data, and medication records were reviewed. The primary outcome was the recurrence rate of cSDH in patients with or without urokinase instillation. Secondary outcomes included complication rates such as infection and acute intracranial hemorrhage. Univariate and multivariate analyses were conducted to identify independent factors associated with cSDH recurrence. RESULTS: A total of 297 consecutive patients were identified for analysis. The average dosage of urokinase instillation via the subdural drain into the subdural space was 15,800 units (5000-60,000 units) over a mean duration of 2 days (1-6 days). The symptomatic recurrence rate of cSDH was significantly lower with urokinase at 3.0% versus 11.7% with no urokinase (odds ratio: 0.234; P = 0.022). Univariate analysis and multivariate analysis showed that bilateral cSDH and the presence of underlying liver disease were significantly associated with higher recurrence, while the instillation of urokinase was significantly and independently associated with lower recurrence (odds ratio = 0.311; P = 0.005). Complication rates including infection and hemorrhage were comparable with patients with or without urokinase and had no significant difference. CONCLUSIONS: Instillation of urokinase was safe for patients with cSDH. The recurrence rate of cSDH was significantly lower with urokinase.

ABC/2 formula for "bedside" postoperative pneumocephalus volume measurement.

BACKGROUND: Postoperative pneumocephalus is associated with a higher risk of recurrence of chronic subdural hematoma (cSDH). However, there is no verified simple way to measure the pneumocephalus volume at the bedside for daily clinical use. The ABC/2 method was shown to be a simple and reliable technique to estimate volumes of intracranial lesions, such as intracranial hematomas. This study aims to evaluate the accuracy of the ABC/2 formula in estimating volumes of pneumocephalus, as compared to the gold standard with computer-assisted volumetric analysis. METHODS: A total of 141 postoperative computed tomographic (CT) brain scans of cSDH patients with burr-hole drainage were analysed. Pneumocephalus volume was measured independently by both the ABC/2 formula and the computer-assisted volumetric measurement. For the computer-assisted measurement, the volume of the air was semiautomatically segmented and calculated by computer software. Linear regression was used to determine the correlation between the ABC/2 method and computer-assisted measurement. RESULTS: The postoperative pneumocephalus volume after bilateral burr-hole drainage was significantly larger than that of unilateral burr-hole drainage (29.34 ml versus 12.21 ml, p < 0.001). The estimated volumes by the formula ABC/2 significantly correlated to the volumes as measured by the computer-assisted volumetric technique, with r = 0.992 (p < 0.001). The Pearson correlation coefficient is very close to 1, which signifies a very strong positive correlation, and it is statistically significant. CONCLUSIONS: An excellent correlation is observed between the ABC/2 method and the computer-assisted measurement. This study verified that the ABC/2 method is an accurate and simple "bedside" technique to estimate pneumocephalus volume.