Optimal drainage time after evacuation of chronic subdural haematoma (DRAIN TIME 2): a multicentre, randomised, multiarm and multistage non-inferiority trial in Denmark.

BACKGROUND: Postoperative drainage after surgical evacuation of chronic subdural haematoma reduces the risk of recurrence, but the optimum drainage time is uncertain. We aimed to investigate the shortest possible drainage time without increasing the haematoma recurrence rate. METHODS: We conducted a randomised, multi-arm and multistage non-inferiority trial at four neurosurgical centres in Denmark. We enrolled adult patients (aged ≥18 years) with symptomatic chronic subdural haematoma. All patients were treated according to the national standard practice with a burr hole above the maximum width of the haematoma. Patients were randomly assigned in a 1:1:1 ratio via a centralised web server to receive 6 h, 12 h, or 24 h of postoperative passive subdural drainage. Randomisation was done by an independent on-call neurosurgeon and was masked until 6 h after surgery. The primary outcome was symptomatic haematoma recurrence at 3 months after surgery; the rate of recurrence was assessed in a regression model for non-inferiority testing, with no missing data. Personnel assessing the primary outcome were masked to group allocation. Non-inferiority was assessed with a prespecified margin of 7%, in a modified intention-to-treat population-defined as patients with randomly assigned treatment excluding those withdrawing from study participation after randomisation, or experiencing acute rebleedings or accidental drain removal. This trial is registered with ISRCTN (number 15186366); the trial was stopped after the first interim analysis on the advice of an independent safety advisory committee. FINDINGS: Between March 1, 2021, and June 30, 2022, 347 patients were enrolled and 331 were followed up to 3 months, 105 were assigned to 6 h of drainage, 111 to 12 h of drainage, and 115 to 24 h of drainage. At admission, 83 (25%) participants were women and 248 (75%) were men, mean age was 75·7 years (SD 10·5), median modified Rankin Scale score was 4 (IQR 3-5), and median Glasgow Coma Scale score was 15 (IQR 14-15). At 3 months after surgery, haematoma recurrence was reported in 28 (27%) of 105 patients who were assigned to 6 h drainage (predicted haematoma recurrence rate 27·0%, 95% CI 18·5 to 35·4), 22 (20%) of 111 assigned to 12 h drainage (19·5%, 12·0 to 27·0), and 12 (10%) of 115 assigned to 24 h drainage (10·4%, 4·8 to 16·0). The risk of haematoma recurrence was increased by 16·5 percentage points (95% CI 6·5 to 26·6) in patients drained for 6 h compared with 24 h, and by 9·1 percentage points (-0·4 to 18·5) in patients drained for 12 h compared with 24 h. Therefore, non-inferiority of 6 h and 12 h of drainage to 24 h of drainage was not established. 20 patients had died by 3 months, seven in the 6 h group, eight in the 12 h group, and five in the 24 h group. The most frequent known causes of death were haematoma recurrence (three in 12 h group), comorbidity (three in 12 h group), and pneumonia (one each in 6 h and 12 h groups, two in 24 h group). The most frequent complication was postoperative infection, reported in 20 (20%) patients in the 6 h group, 25 (23%) in the 12 h group, and 19 (17%) in the 24 h group. The most common infection source was the urinary tract. INTERPRETATION: Patients surgically treated for symptomatic chronic subdural haematoma and postoperatively drained for 6 h or 12 h had higher rates of haematoma recurrence than did patients drained for 24 h. The findings from this non-inferiority trial provide evidence to support 24 h of postoperative drainage as the standard drain time when a fixed drain time approach is used. To provide solid evidence of generalisability of the results to countries other than Denmark, a multinational randomised controlled trial will be needed. FUNDING: None.

Lumbar percutaneous transforaminal endoscopic discectomy: a retrospective survey on the first 172 adult patients treated in Denmark.

PURPOSE: To evaluate patient demographics, surgery characteristics, and patient-reported clinical outcomes related to the implementation of lumbar PTED in Denmark by surgeons novice to the PTED technique. METHODS: All adult patients treated with a lumbar PTED from our first surgery in October 2020 to December 2021 were included. Data was generated by journal audit and telephone interview. RESULTS: A total of 172 adult patients underwent lumbar PTED. Surgery duration was a median of 45.0 (35.0-60.0) minutes and patients were discharged a median of 0 (0-1.0) days after. Per operatively one procedure was converted to open microdiscectomy due to profuse bleeding. Post operatively one patient complained of persistent headache (suggestive of a dural tear), two patients developed new L5 paresthesia, and three patients had a newly developed dorsal flexion paresis (suggestive of a root lesion). Sixteen patients did not complete follow-up and 24 (14.0%) underwent reoperation of which 54.2% were due to residual disk material. Among the remaining 132 patients, lower back and leg pain decreased from 7.0 (5.0-8.5) to 2.5 (1.0-4.5) and from 8.0 (6.0-9.1) to 2.0 (0-3.6) at follow-up, respectively (p < 0.001). Additionally, 93.4% returned to work and 78.8% used less analgesics. Post hoc analysis comparing the early half of cases with the latter half did not find any significant change in surgery time, complication and reoperation rates, nor in pain relief, return to work, or analgesia use. CONCLUSION: Clinical improvements after lumbar PTED performed by surgeons novel to the technique are satisfactory, although the reoperation rate is high, severe complications may occur, and the learning curve can be longer than expected.

Endoscopic removal of lumbar disc herniation.

The technical development has caused a reintroduction of endoscopic techniques directed towards degenerative spine disease. A summary of the endoscopic procedure is given in this review. The spinal canal is reached through an inter-laminar or transforaminal access. In comparison with open surgery the percutaneous transforaminal access seems especially advantageous for the removal of paramedian and/or foraminal herniated disc material. However, careful patient selection is required, as the restricted manoeuverability and working zone of the endoscope and patient specific pathoanatomy in some cases will disfavour endoscopy.

The Danish Chronic Subdural Hematoma Study-Risk Factors for Second Recurrence.

BACKGROUND: Treatment of multiple recurrent chronic subdural hematomas (CSDH) is challenging. Identification of specific risk factors for multiple recurrences may allow a higher degree of personalized treatment, including closer postoperative follow-up, detailed prognostication, and a more aggressive initial surgical strategy, such as craniotomy, adjuvant embolization of the middle meningeal artery, or adjuvant medical treatment, such as steroids. The aim of this study was to identify pretreatment risk factors for a second recurrence of CSDH (re-re-CSDH) and risk factors for developing re-re-CSDH once operated for the first recurrence. METHODS: Clinical and demographic data on all Danish patients admitted to a neurosurgical department with CSDH between 2010 and 2012 were retrospectively recorded. Data were retrieved before the evacuation of a primary CSDH, a first recurrent CSDH (re-CSDH), and a re-re-CSDH. We compared patients undergoing first, second, and third CSDH evacuation to identify risk factors for re-CSDH and re-re-CSDH. RESULTS: The cohort comprised 1052 patients, with 172 patients with re-CSDH and 29 patients with re-re-CSDH. Risk factors for re-re-CSDH included radiological subtype, midline shift, and hematoma volume, while postoperative drainage lowered the risk of re-re-CSDH. These risk factors were not specific for re-re-CSDH. CONCLUSIONS: We found similar independent risk factors for re-CSDH and re-re-CSDH, and for re-re-CSDH once treated for re-CSDH. Hence, it was not possible to identify specific risk factors for patients at risk of re-re-CSDH at the time of the primary diagnosis.

Postoperative drainage for 6, 12, or 24 h after burr-hole evacuation of chronic subdural hematoma in symptomatic patients (DRAIN-TIME 2): study protocol for a nationwide randomized controlled trial.

BACKGROUND: Chronic subdural hematoma (CSDH) is a common acute or subacute neurosurgical condition, typically treated by burr-hole evacuation and drainage. Recurrent CSDH occurs in 5-20% of cases and requires reoperation in symptomatic patients, sometimes repeatedly. Postoperative subdural drainage of maximal 48 h is effective in reducing recurrent hematomas. However, the shortest possible drainage time without increasing the recurrence rate is unknown. METHODS: DRAIN-TIME 2 is a Danish multi-center, randomized controlled trial of postoperative drainage time including all four neurosurgical departments in Denmark. Both incapacitated and mentally competent patients are enrolled. Patients older than 18 years, free of other intracranial pathologies or history of previous brain surgery, are recruited at the time of admission or no later than 6 h after surgery. Each patient is randomized to either 6, 12, or 24 h of passive subdural drainage following single burr-hole evacuation of a CSDH. Mentally competent patients are asked to complete the SF-36 questionnaire. The primary endpoint is CSDH recurrence rate at 90 days. Secondary outcome measures include SF-36 at 90 days, length of hospital stay, drain-related complications, and complications related to immobilization and mortality. DISCUSSION: This multi-center trial will provide evidence regarding the shortest possible drainage time without increasing the recurrence rate. The potential impact of this study is significant as we believe that a shorter drainage period may be associated with fewer drain-related complications, fewer complications related to immobilization, and shorter hospital stays-thus reducing the overall health service burden from this condition. The expected benefits for patients' lives and health costs will increase as the CSDH patient population grows. TRIAL REGISTRATION: ISRCTN Registry ISRCTN15186366 . Registered in December 2020 and updated in October 2021. This protocol was developed in accordance with the SPIRIT Checklist and by use of the structured study protocol template provided by BMC Trials.

National randomized clinical trial on subdural drainage time after chronic subdural hematoma evacuation.

OBJECTIVE: Placement of a subdural drain reduces recurrence and death after evacuation of chronic subdural hematoma (CSDH), but little is known about optimal drainage duration. In the present national trial, the authors investigated the effect of drainage duration on recurrence and death. METHODS: In a randomized controlled trial involving all neurosurgical departments in Denmark, patients treated with single burr hole evacuation of CSDH were randomly assigned to 24 hours or 48 hours of postoperative passive subdural drainage. Follow-up duration was 90 days, and the primary study outcome was recurrent hematoma requiring reoperation. Secondary outcome was death. In addition, complications and length of hospital stay were recorded and analyzed. RESULTS: Of the 420 included patients, 212 were assigned 24-hour drainage and 208 were assigned 48-hour drainage. The recurrence rate was 14% in the 24-hour group and 13% in the 48-hour group. Four patients died in the 24-hour group, and 8 patients died in the 48-hour group; this difference was not statistically significant. The ORs (95% CIs) for recurrence and mortality (48 hours vs 24 hours) were 0.94 (0.53-1.66) and 2.07 (0.64-7.85), respectively, in the intention-to-treat analysis. The ORs (95% CIs) for recurrence and mortality per 1-hour increase in drainage time were 1.0005 (0.9770-1.0244) and 1.0046 (0.9564-1.0554), respectively, in the as-treated sensitivity analysis that used the observed drainage times instead of the preassigned treatment groups. The rates of surgical and drain-related complications, postoperative infections, and thromboembolic events were not different between groups. The mean ± SD postoperative length of hospital stay was 7.4 ± 4.3 days for patients who received 24-hour drainage versus 8.4 ± 4.9 days for those who received 48-hour drainage (p = 0.14). The mean ± SD postoperative length of stay in the neurosurgical department was significantly shorter for the 24-hour group (2 ± 0.9 days vs 2.8 ± 1.6 days, p < 0.001). CONCLUSIONS: No significant differences in the rates of recurrent hematoma or death during 90-day follow-up were identified between the two groups that randomly received either 24- or 48-hour passive subdural drainage after burr hole evacuation of CSDH.

Drain type and technique for subdural insertion after burr hole evacuation of chronic subdural hematoma.

Strengths and limitations of subdural versus subperiosteal drain location after burr hole evacuation of chronic subdural hematoma (CSDH) are currently debated. The safety of subdural placement of a drain has been questioned in a recent study by Soleman et al. from 2019, showing a misplacement rate of 17%, and these results have been further highlighted by the same authors, with a slightly lower misplacement rate of 15.8%, in the recent paper "When the drain hits the brain." The safety of subdural drainage for CSDH depends to a high degree on type of drain and surgical technique. In this technical note, we describe drain type and technique for drain placement which is standardized in Denmark.

The Danish Chronic Subdural Hematoma Study-comparison of hematoma age to the radiological appearance at time of diagnosis.

INTRODUCTION: Chronic subdural hematomas (CSDH) show different radiological characteristics on CT scans at the time of diagnosis. The reason for this is largely unknown. We hypothesize that the imaging characteristics reflect a time-linked pathophysiological evolution. We therefore conducted a retrospective study to examine a possible relation between the hematoma age and the radiological subtype of a CSDH. METHODS: Demographic data on patients with CSDH were retrieved from a Danish national cohort from 2010 to 2012. CT scans obtained on admission to a neurosurgical department were categorized as homogenous, separated, mixed, or membranous hematoma subtypes. The time from a known date of head injury to time of diagnostic CT was defined as hematoma age. The hematoma age was correlated to radiological hematoma subtype at the time of diagnosis by analysis of variance testing. RESULTS: In total, 543 patients were analyzed for hematoma age and classified in the following hematoma subtypes: 231 homogenous, 44 separated, 119 mixed, and 149 membranous. Patients with homogenous, separated, mixed, and membranous hematoma subtypes had a median interval of 37, 36, 40, and 60 days from head injury to diagnostic CT. We found that membranous hematoma is significantly older than other subtypes. Comparison between the other radiological subtypes showed no statistical hematoma age difference. The distribution of radiological subtypes in 590 patients without a known head injury was similar to that of patients with a known head injury. Additionally, we found that hematoma age was significantly younger for patients on antiplatelet medication. CONCLUSION: In this large national cohort, patients with membranous CSDH had a significantly longer interval between head injury and diagnosis compared to other radiological subtypes. This indicates that the radiological appearance of CSDH evolves over time, causing an alteration from different early radiological subtypes to a radiological subtype with membranes. CLINICAL TRIAL REGISTRATION NUMBER: The study was approved by the Danish Data Protection Agency (journal no.30-1145).

The Danish chronic subdural hematoma study-predicting recurrence of chronic subdural hematoma.

BACKGROUND: An increasing incidence of chronic subdural hematoma (CSDH) and an unchanging high recurrence rate of 10-20% call for individualized treatment. The aim of this study was to establish individualized prediction models for the risk of recurrence treating death as a competing risk. METHODS: A retrospective national cohort of unilateral CSDH was included for analysis. Using competing risk survival analysis, we tested whether available covariates were associated with the risk of recurrence. We further established a pre- and a postoperative prediction model, where predictors were chosen using a LASSO approach. The models were visualized in nomograms. Predictive performance was evaluated by c index and calibrations plots. RESULTS: A total of 763 patients with surgically evacuated unilateral CSDH were included for analysis. The recurrence rate was 14% while 12% of patients died during follow-up (1 year). In our association model, hematoma size, drain type, drainage time, presence of complications, and Glasgow Coma Score were significantly associated to recurrence. Subdural drain was associated with a lower recurrence risk than subgaleal drain. The preoperative model included hematoma size, hematoma density, and history of hypertension. The postoperative model included further drain type, drainage time, and surgical complications. CONCLUSION: The nomograms allow easy assessment of the recurrence risk for the individual patient, providing a better possibility for individual adjustment of treatment and follow-up. The predictive performance indicates that significant unaccounted or unknown factors still remain. The association test found passive subdural drain superior to passive subgaleal drain in minimizing the risk of CSDH recurrence.

[National guidelines for treatment of chronic subdural haematoma].

Chronic subdural haematoma (CSDH) is a collection of liquefied blood between the dura mater and the arachnoid layer of the brain. The incidence of CSDH increases with age and with an ageing population, and a rise in CSDH prevalence is anticipated. The Danish Chronic Subdural Hematoma Study was created on behest of the four neurosurgical departments in order to standardise treatment, research and development as well as creating the first Danish national guidelines in CSDH management. These guidelines are presented in this review.

Bilateral chronic subdural hematoma: unilateral or bilateral drainage?

OBJECTIVE Bilateral chronic subdural hematoma (bCSDH) is a common neurosurgical condition frequently associated with the need for retreatment. The reason for the high rate of retreatment has not been thoroughly investigated. Thus, the authors focused on determining which independent predictors are associated with the retreatment of bCSDH with a focus on surgical laterality. METHODS In a national database of CSDHs (Danish Chronic Subdural Hematoma Study) the authors retrospectively identified all bCSDHs treated in the 4 Danish neurosurgical departments over the 3-year period from 2010 to 2012. Univariate and multivariate analyses were performed to determine the relationship between retreatment of bCSDH and clinical, radiological, and surgical variables. RESULTS Two hundred ninety-one patients with bCSDH were identified, and 264 of them underwent unilateral (136 patients) or bilateral (128 patients) surgery. The overall retreatment rate was 21.6% (57 of 264 patients). Cases treated with unilateral surgery had twice the risk of retreatment compared with cases undergoing bilateral surgery (28.7% vs 14.1%, respectively, p = 0.002). In accordance with previous studies, the data also showed that a separated hematoma density and the absence of postoperative drainage were independent predictors of retreatment. CONCLUSIONS In bCSDHs bilateral surgical intervention significantly lowers the risk of retreatment compared with unilateral intervention and should be considered when choosing a surgical procedure.