Burr-hole drainage with or without irrigation for chronic subdural haematoma (FINISH): a Finnish, nationwide, parallel-group, multicentre, randomised, controlled, non-inferiority trial.

BACKGROUND: Chronic subdural haematoma is a common surgically treated intracranial emergency. Burr-hole drainage surgery, to evacuate chronic subdural haematoma, involves three elements: creation of a burr hole for access, irrigation of the subdural space, and insertion of a subdural drain. Although the subdural drain has been established as beneficial, the therapeutic effect of subdural irrigation has not been addressed. METHODS: The FINISH trial was an investigator-initiated, pragmatic, multicentre, nationwide, randomised, controlled, parallel-group, non-inferiority trial in five neurosurgical units in Finland that enrolled adults aged 18 years or older with a chronic subdural haematoma requiring burr-hole drainage. Patients were randomly assigned (1:1) by computer-generated block randomisation with block sizes of four, six, or eight, stratified by site, to burr-hole drainage either with or without subdural irrigation. All patients and staff were masked to treatment assignment apart from the neurosurgeon and operating room staff. A burr hole was drilled at the site of maximum haematoma thickness in both groups, and the subdural space was either irrigated or not irrigated before inserting a subdural drain, which remained in place for 48 h. Reoperations, functional outcome, mortality, and adverse events were recorded for 6 months after surgery. The primary outcome was the reoperation rate within 6 months. The non-inferiority margin was set at 7·5%. Key secondary outcomes that were also required to conclude non-inferiority were the proportion of participants with unfavourable functional outcomes (ie, modified Rankin Scale score of 4-6, where 0 indicates no symptoms and 6 indicates death) and mortality rate at 6 months. The primary and key secondary analyses were done in both the intention-to-treat and per-protocol populations. The trial was registered with ClinicalTrials.gov (NCT04203550) and is completed. FINDINGS: From Jan 1, 2020, to Aug 17, 2022, we assessed 1644 patients for eligibility and 589 (36%) patients were randomly assigned to a treatment group and treated (294 assigned to drainage with irrigation and 295 assigned to drainage without irrigation; 165 [28%] women and 424 [72%] men). The 6-month follow-up period extended until Feb 14, 2023. In the intention-to-treat analysis, 54 (18·3%) of 295 participants required reoperation in the group assigned to receive no irrigation versus 37 (12·6%) of 294 in the group assigned to receive irrigation (difference of 6·0 percentage points, 95% CI 0·2-11·7; p=0·30; adjusted for study site). There were no significant between-group differences in the proportion of people with modified Rankin Scale score of 4-6 (37 [13·1%] of 283 in the no-irrigation group vs 36 [12·6%] of 285 in the irrigation group; p=0·89) or mortality rate (18 [6·1%] of 295 in the no-irrigation group vs 21 [7·1%] of 294 in the irrigation group; p=0·58). The findings of the primary intention-to-treat analysis were not materially altered in the per-protocol analysis. There were no significant between-group differences in the number of adverse events, and the most frequent severe adverse events were systemic infections (26 [8·8%] of 295 participants who did not receive irrigation vs 22 [7·5%] of 294 participants who received irrigation), intracranial haemorrhage (13 [4·4%] vs seven [2·4%]), and epileptic seizures (five [1·7%] vs nine [3·1%]). INTERPRETATION: We could not conclude non-inferiority of burr-hole drainage without irrigation. The reoperation rate was 6·0 percentage points higher after burr-hole drainage without subdural irrigation than with subdural irrigation. Considering that there were no differences in functional outcome or mortality between the groups, the trial favours the use of subdural irrigation. FUNDING: State Fund for University Level Health Research (Helsinki University Hospital), Finska Läkaresällskapet, Medicinska Understödsföreningen Liv och Hälsa, and Svenska Kulturfonden.

Mortality of older patients with dementia after surgery for chronic subdural hematoma: a nationwide study.

BACKGROUND: dementia is associated with an excess risk of death but mortality after chronic subdural hematoma (CSDH) evacuation in older people with dementia is unknown. We assessed the association between dementia and 1-year case-fatality in older persons undergoing CSDH evacuation. METHODS: we conducted a nationwide Finnish cohort study including all older persons (≥60 years) undergoing CSDH evacuation during 1997-2014 (referred to as cases). We identified controls, without a diagnosis of CSDH, that were matched for age, sex and year of first hospitalisation with a new dementia diagnosis. We identified cases and controls with a pre-existing diagnosis of dementia. Outcome was 12-month mortality. Mortality was compared in case-only and case-control analyses. RESULTS: of 7,621 included cases, 885 (12%) had a pre-existing diagnosis of dementia. The proportion of cases increased from 9.7% in 1997-2002 to 12.2% in 2012-2014 (P = 0.038 for trend). In the case-analysis, dementia independently associated with 1-year case-fatality (dementia vs. no dementia odds ratio [OR] 1.50, 95% confidence interval [CI] 1.26-1.78). Sensitivity analysis suggested the association to be strongest for those 60-69 years old (OR 3.21, 95% CI 1.59-6.47). In the case-control matched analysis, 1-year mortality was 26% in the dementia CSDH surgery group compared to 16% in the dementia non-CSDH controls (P < 0.001). CONCLUSION: dementia is a significant risk factor for 1-year mortality after CSDH surgery in older people. The proportion of older CSDH patients having a pre-existing diagnosis of dementia is increasing. Thus, there is a need for improved evidence regarding the indications and benefits of CSDH evacuation among older persons.

Incidence of surgery for chronic subdural hematoma in Finland during 1997-2014: a nationwide study.

OBJECTIVE: The number of surgeries performed for chronic subdural hematoma (CSDH) has increased. However, these changes have been poorly reported. The authors aimed to assess the national incidence of surgeries for CSDH in Finland during an 18-year time period from 1997 to 2014. They hypothesized that the incidence of CSDH surgeries has continued to increase, particularly among the elderly. METHODS: A nationwide register-based follow-up study was performed using the Finnish Care Register for Health Care. All adult patients undergoing primary CSDH surgeries during 1997-2014 were included. The study population was followed up from the time of CSDH surgery until death or the end of follow-up on December 31, 2017. The incidences of CSDH surgery per 100,000 person-years were calculated separately in each age group and sex. Age standardization was performed for those 20 years of age and older with weights from the 2013 European Standard Population. Negative binomial regression models were used to assess changes in incidence rate ratios (IRRs) during the study period. RESULTS: In total, 9280 patients were identified. The age-standardized incidence of CSDH surgery increased from 12.2 to 16.5 per 100,000 person-years during 1997-2014. The age- and sex-adjusted incidence of CSDH surgery increased by 30% (IRR 1.30, 95% CI 1.20-1.41). The age- and sex-adjusted incidence increased more in the older age groups, with an IRR of 1.24 for those aged 60-69 years, 1.32 for those 70-79 years, 1.46 for those 80-89 years, and 1.85 for those aged 90 years or older. The adjusted incidence did not increase for those aged 18-59 years. The sex difference (2:1 men/women) was consistent throughout the study period, with a higher incidence among men. One year after the primary surgery, 19% of the population had a resurgery, and the 1-year case fatality rate was 15%. The median age of patients increased from 73 to 76 years. CONCLUSIONS: During the past 2 decades, the age- and sex-adjusted incidence of CSDH surgery has increased in Finland, with major increases for those aged 60 years or older. This increase is likely to continue in parallel with the aging population and increased life expectancies.

Finnish study of intraoperative irrigation versus drain alone after evacuation of chronic subdural haematoma (FINISH): a study protocol for a multicentre randomised controlled trial.

INTRODUCTION: Chronic subdural haematomas (CSDHs) are one of the most common neurosurgical conditions. The goal of surgery is to alleviate symptoms and minimise the risk of symptomatic recurrences. In the past, reoperation rates as high as 20%-30% were described for CSDH recurrences. However, following the introduction of subdural drainage, reoperation rates dropped to approximately 10%. The standard surgical technique includes burr-hole craniostomy, followed by intraoperative irrigation and placement of subdural drainage. Yet, the role of intraoperative irrigation has not been established. If there is no difference in recurrence rates between intraoperative irrigation and no irrigation, CSDH surgery could be carried out faster and more safely by omitting the step of irrigation. The aim of this multicentre randomised controlled trial is to study whether no intraoperative irrigation and subdural drainage results in non-inferior outcome compared with intraoperative irrigation and subdural drainage following burr-hole craniostomy of CSDH. METHODS AND ANALYSIS: This is a prospective, randomised, controlled, parallel group, non-inferiority multicentre trial comparing single burr-hole evacuation of CSDH with intraoperative irrigation and evacuation of CSDH without irrigation. In both groups, a passive subdural drain is used for 48 hours as a standard of treatment. The primary outcome is symptomatic CSDH recurrence requiring reoperation within 6 months. The predefined non-inferiority margin for the primary outcome is 7.5%. To achieve a 2.5% level of significance and 80% power, we will randomise 270 patients per group. Secondary outcomes include modified Rankin Scale, rate of mortality, duration of operation, length of hospital stay, adverse events and change in volume of CSDH. ETHICS AND DISSEMINATION: The study was approved by the institutional review board of the Helsinki and Uusimaa Hospital District (HUS/3035/2019 §238) and duly registered at ClinicalTrials.gov. We will disseminate the findings of this study through peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT04203550.

Transition of a Clinical Practice to Use of Subdural Drains after Burr Hole Evacuation of Chronic Subdural Hematoma: The Helsinki Experience.

BACKGROUND: A number of randomized controlled trials have shown the benefit of drain placement in the operative treatment of chronic subdural hematoma (CSDH); however, few reports have described real-life results after adoption of drain placement into clinical practice. We report the results following a change in practice at Helsinki University Hospital from no drain to subdural drain (SD) placement after burr hole craniostomy for CSDH. METHODS: We conducted a retrospective observational study of consecutive patients undergoing burr hole craniostomy for CSDH. We compared outcomes between a 6-month period when SD placement was arbitrary (July-December 2015) and a period when SD placement for 48 hours was routine (July-December 2017). Our primary outcome of interest was recurrence of CSDH necessitating reoperation within 6 months. Patient outcomes, infections, and other complications were assessed as well. RESULTS: A total of 161 patients were included, comprising 71 (44%) in the drain group and 90 (56%) in the non-drain group. There were no significant differences in age, comorbidities, history of trauma, or use of antithrombotic agents between the 2 groups (P > 0.05 for all). Recurrence within 6 months occurred in 18% of patients in the non-drain group, compared with 6% in the drain group (odds ratio, 0.28; 95% confidence interval, 0.09-0.87; P = 0.028). There were no differences in neurologic outcomes (P = 0.72), mortality (P = 0.55), infection rate (P = 0.96), or other complications (P = 0.20). CONCLUSIONS: The change in practice from no drain to use of an SD after burr hole craniostomy for CSDH effectively reduced the 6-month recurrence rate with no effect on patient outcomes, infections, or other complications.