Recurrence Of Chronic Subdural Hematoma Research Articles

Impact of antithrombotic therapy on surgical treatment in patients with chronic subdural hematoma

ObjectiveThe effects of antithrombotic therapy on chronic subdural hematoma (CSDH) are controversial. Herein, we investigated the association of antithrombotic therapy with surgical complications and outcomes in patients with CSDH. MethodsWe retrospectively analyzed 323 consecutive patients with CSDH who underwent single burr-hole craniostomy. ResultsOne hundred and eight patients (33%) underwent preoperative antithrombotic therapy. Hemorrhagic and thromboembolic complications were detected in 6 and 8 patients, respectively, which peaked at 3 and 4.5 days after CSDH surgery, respectively. CSDH recurrence was detected in 62 cases, and reoperation was required in 16 cases. Discontinuance of antiplatelet therapy for >2 weeks was significantly associated with thromboembolic complications (43%; p = 0.005). Postoperative use of multiple antithrombotic agents was significantly associated with CSDH recurrence (40%; p = 0.03). Further, earlier recurrence within 2 weeks was significantly associated with the following reoperation (62%; p = 0.006). ConclusionsTo reduce morbidity and minimize the risk of CSDH reoperation, the optimal timing for resumption of antithrombotic agents is approximately 3 days after CSDH surgery. Postoperative use of multiple antithrombotic agents can increase CSDH recurrence, while earlier recurrence may be a predictor for the following reoperation.

Predicting Chronic Subdural Hematoma Recurrence and Stroke Outcomes While Withholding Antiplatelet and Anticoagulant Agents.

Introduction: The aging of the western population and the increased use of oral anticoagulation (OAC) and antiplatelet drugs (APD) will result in a clinical dilemma on how to balance the recurrence risk of chronic subdural hematoma (cSDH) with the risk of withholding blood thinners.Objective: To identify features that predicts recurrence, thromboembolism (TEE), hospital stay and mortality. To identify the optimal window for resuming APD or OAC.Methods: We performed a retrospective multivariate analysis of a prospectively collected database. We then build machine learning models for outcomes prediction.Results: We identified 596 patients. The rate of recurrence was 22.17%, that of thromboembolism was 0.9% and that of mortality was 14.78%. Smoking, platelet dysfunction, CKD, and alcohol use were independent predictors of higher recurrence, while resolution of the SDH was protective. OAC use had higher odds of developing TEEs. CKD, developing a new neurological deficit or a TEEs were independent predictors of higher mortality. We find the optimal time of resuming OAC to be after 2 days but before 21 days as these patients had the lowest recurrence of bleeding associated with a low risk of stroke. The ML model achieved an accuracy of 93, precision of 0.84 and recall of 0.80 for recurrence prediction. ML models for hospital stay performed poorly (R2 = 0.33). ML model for stroke was overfitted given the low number of events.Conclusion: ML modeling is feasible. However, large well-designed prospective multicenter studies are needed for accurate ML so that clinicians can balance the risks of recurrence with the risk of TEEs, especially for high-risk anticoagulated patients.

Predictors of Chronic Subdural Hematoma Recurrence Following Surgical Intervention: A Review of the Recent Literature?

Chronic subdural hematoma (CSDH) is an increasingly common neurosurgical condition worldwide. Surgical evacuation is the mainstay of treatment, but re-operation is necessary in 10-20% of patients due to hematoma recurrence. Though risk factors for CSDH formation are welldescribed, there is less consensus regarding CSDH recurrence, due in part to variations in operative procedure and follow-up protocols.

A Prospective Randomized Study on the Preventive Effect of Japanese Herbal Kampo Medicine Goreisan for Recurrence of Chronic Subdural Hematoma.

Although the recurrence of chronic subdural hematoma (CSDH) after surgical treatment significantly affects the patients’ quality of life, the recurrence rate has not improved in decades. Goreisan, a Japanese herbal Kampo medicine, promotes the hydragogue effect and has been empirically used in the treatment of CSDH in Japan. We conducted a prospective randomized study to investigate whether Goreisan treatment decreases the recurrence rate of CSDH. Between March 2013 and December 2018, a total of 224 patients who underwent initial burr hole surgery for CSDH were randomly assigned to receive Goreisan for 3 months (Group G) or no medication (Group N). The primary endpoint was symptomatic recurrence within 3 months postoperatively, and the secondary endpoint was complications, including the adverse effects of Goreisan. Of 224 randomized patients, 208 were included in the final analysis (104 in Group G and 104 in Group N). The overall recurrence rate was 9.1% (19/208). The recurrence rate of Group G was lower than that of Group N (5.8% vs 12.5%, P = 0.09), but the difference was not statistically significant. However, a significant preventive effect of Goreisan was found in 145 patients with high-risk computed tomography (CT) features, namely, homogeneous and separated types (5.6% vs 17.6%, P = 0.04). Although the present study did not prove the beneficial effect of Goreisan treatment, it suggested the importance of selecting patients with an increased risk of recurrence. A subset of patients whose hematoma showed homogeneous and separated patterns on CT image might benefit from Goreisan treatment.

Endoscopically Observed Outer Membrane Color of Chronic Subdural Hematoma and Histopathological Staging: White as a Risk Factor for Recurrence.

Endoscopic treatment for chronic subdural hematoma (CSDH) has been reported, but endoscopic findings of CSDH have not been thoroughly investigated. This study aimed to elucidate the relationship between endoscopic findings and CSDH recurrence. Furthermore, it examined the association between Nagahori’s histopathological staging of CSDH and outer membrane color. Here, we retrospectively analyzed the operative videos of 70 patients with CSDH. The endoscopic findings were investigated, and their correlations with CSDH recurrence, the reduction ratio of the midline shift, and hematoma thickness on day 30 after the operation were analyzed. The outer membrane was white in 21 cases, yellow in 25 cases, and red in 24 cases. CSDH recurred in three (4.2%) patients, all of whom had a white outer membrane (adjusted odds ratio, 18; 95% confidence interval, 1.6–20.6; P = 0.007). The other endoscopic findings were not significantly related to CSDH recurrence, extent of the reduction ratio of the midline shift, or hematoma thickness. The outer membrane colors of white, red, yellow, and white almost corresponded to the histopathological staging from type I to IV in order. Our findings suggest that a white outer membrane is a risk factor for recurrence; these colors may represent the extent of inflammation related to the evolution of CSDH estimated from the histopathological findings.

Development and Validation of Nomogram-Based Prediction of Chronic Subdural Hematoma Recurrence after Initial Burr-Hole Surgery.

To establish, and validate a practical nomogram to predict recurrence of chronic subdural hematoma (CSDH) in patients after initial burr-hole surgery. The prediction model was developed from a training set of 272 patients with CSDH who had undergone standard burr hole with irrigation surgery. A separate external validation cohort comprising 112 patients who underwent the same operation was also included. Least absolute shrinkage and selection operator (LASSO) regression was adopted to minimize the high dimension of data and predictor selection. Binary logistic regression was used to develop the present model. Subsequently, a nomogram was established as the ultimate representation of the prediction model. Area under the curve (AUC) was used to identify the discrimination of the designed predictive nomogram. The calibration plot was used to verify the goodness-of-fit of the nomogram. Finally, Decision curve analysis (DCA) was employed to appraise the clinical applicability of the present nomogram. A total of 3 independent variables were filtered by LASSO analysis from the 22 candidate factors. The AUC of the training and validation sets were 0.833 (95%CI: 0.774-0.894) and 0.817 (95%CI: 0.711-0.922), respectively, which indicated a good discrimination ability. The calibration charts showed that the prediction probability and the actual probability fitted well. The DCA of the prediction model indicated an excellent clinical efficacy. The proposed nomogram can quantitatively and conveniently predict the recurrence rate of CSDH after burr hole with irrigation surgery. Besides it can facilitate customized treatment adjustment and follow-up of patients who are at a high-risk of recurrence.

Cerebral infarction caused by postoperative recurrence of chronic subdural hematoma in non-valvular atrial fibrillation with anticoagulation therapy

Cerebral infarction caused by postoperative recurrence of chronic subdural hematoma in non-valvular atrial fibrillation with anticoagulation therapy

The Crucial Role of Eosinophils in the Life Cycle, Radiographic Architecture, and Risk of Recurrence of Chronic Subdural Hematomas

The Crucial Role of Eosinophils in the Life Cycle, Radiographic Architecture, and Risk of Recurrence of Chronic Subdural Hematomas

Neuroendoscopic Technique for Recurrent Chronic Subdural Hematoma with Small Craniotomy.

To present a case series describing an endoscopic technique with a small craniotomy for recurrent chronic subdural hematoma (rCSDH) treatment. A total of 17 patients with rCSDH underwent neuroendoscopic hematoma removal with a small craniotomy under local or general anesthesia. The skin incision of the initial surgery on the convexity of the skull was extended, and a burr hole was created for a small craniotomy. After the removal of the outer membrane and hematoma through a small craniotomy, the hematoma was evacuated with a suction tube using the rigid endoscope. The entire hematoma cavity circumference was irrigated, while septations and trabeculae in the hematoma were cut. After hematoma evacuation, the inner membrane was incised and removed to allow brain expansion. Postoperative follow-up was performed for at least 6 months. The regrowth rate of rCSDH after the neuroendoscopy was 5.9%. One patient with recurrent chronic subdural hematoma regrowth required neuroendoscopy again, but no re-recurrence was observed for the next 6 months. All cases were successfully managed using this technique and the postoperative seizure rate was 23.5%. This neuroendoscopic technique with a small craniotomy could be useful for recurrent chronic subdural hematoma because the hematoma and septations can be visualized and evacuated along the entire circumference of the hematoma cavity, and the inner membrane can be torn to allow brain expansion.

Prediction of postoperative recurrence of chronic subdural hematoma using quantitative volumetric analysis in conjunction with computed tomography texture analysis

Chronic subdural hematoma (CSDH) is a common disease in older individuals with a substantial rate of recurrence. The mechanism of CSDH recurrence remains unclear. This study aimed to detect imaging parameters that could indicate the risk for CSDH recurrence by using quantitative volumetric analysis and computed tomography (CT) texture analysis (CTTA).Clinical and imaging parameters were retrospectively investigated in 147 newly diagnosed CSDH lesions in 114 patients surgically treated at the Keio University Hospital during a 6-year period. For CT images, quantitative volumetric and texture analyses were performed. Hematoma volume, postoperative air volume, hematoma density, and texture parameters including kurtosis, skewness, and entropy were evaluated and compared with CSDH recurrence rate. Data were statistically evaluated, and a difference of p < 0.05 was considered significant.Reoperation for CSDH recurrence was required in 27 sides (18.4%) of 26 patients. Multivariate analysis showed that postoperative hematoma volume and postoperative hematoma density were independent risk factors for symptomatic CSDH recurrence that required reoperation. Postoperative hematoma volume, postoperative significant residual air, and postoperative hematoma density were also identified as independent risk factors for potential CSDH recurrence. Preoperative hematoma entropy was prone to be associated with both symptomatic and potential CSDH recurrence in univariate analysis, but not in multivariate analysis because of confounding factors.Quantitative volumetric analysis and CTTA could aid in distinguishing individuals at risk for CSDH recurrence.

Multiple contralateral recurrence of bilateral chronic subdural hematoma: case report and literature review

We report a case of bilateral chronic subdural hematoma (CSDH) operated with a single burr-hole on the more symptomatic side (left) followed by a symptomatic expansion of the contralateral (right) hematoma 7 days after the surgery treated again with a burr-hole on the other side. A week later the patient presented again a bilateral CSDH that was re-operated on both side with a good outcome at 6 months follow-up. Relevant literature was reviewed, and we believe that the multiple recurrence of these hematomas in the opposite hemisphere resulted from the rapid drainage of the hematoma, which caused the rupture of weak bridging veins during drainage. Slow decompression is recommended to avoid rapid intracranial changes during drainage of a subdural hematoma.

Double-crescent sign as a predictor of chronic subdural hematoma recurrence following burr-hole surgery.

Subdural hygroma has been reported as a causative factor in the development of a chronic subdural hematoma (CSDH) following a head trauma and/or neurosurgical procedure. In some CSDH cases, the presence of a 2-layered space delineated by the same or similar density of CSF surrounded by a superficial, residual hematoma is seen on CT imaging after evacuation of the hematoma. The aims of the present study were to test the hypothesis that the double-crescent sign (DCS), a unique imaging finding described here, is associated with the postoperative recurrence of CSDH, and to investigate other factors that are related to CSDH recurrence. The authors retrospectively analyzed data from 278 consecutive patients who underwent single burr-hole surgery for CSDH between April 2012 and March 2017. The DCS was defined as a postoperative CT finding, characterized by the following 2 layers: a superficial layer demonstrating residual hematoma after evacuation of the CSDH, and a deep layer between the brain's surface and the residual hematoma, depicted as a low-density space. Correlation of the recurrence of CSDH with the DCS was evaluated by multivariate logistic regression modeling. The authors also investigated other classic predictive factors including age, sex, past history of head injury, hematoma laterality, anticoagulant and antiplatelet therapy administration, preoperative hematoma volume, postoperative residual hematoma volume, and postoperative brain reexpansion rate. A total of 277 patients (320 hemispheres) were reviewed. Fifty (18.1%) of the 277 patients experienced recurrence of CSDH within 3 months of surgery. CSDH recurred within 3 months of surgery in 32 of the 104 hemispheres with a positive DCS. Multivariate logistic analyses revealed that the presence of the DCS (OR 3.36, 95% CI 1.72-6.57, p < 0.001), large postoperative residual hematoma volume (OR 2.88, 95% CI 1.24-6.71, p = 0.014), anticoagulant therapy (OR 3.03, 95% CI 1.02-9.01, p = 0.046), and bilateral hematoma (OR 3.57, 95% CI 1.79-7.13, p < 0.001) were significant, independent predictors of CSDH recurrence. In this study, the authors report that detection of the DCS within 7 days of surgery is an independent predictive factor for CSDH recurrence. They therefore advocate that clinicians should carefully monitor patients for postoperative DCS and subsequent CSDH recurrence.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: A Series of 60 Cases

Chronic subdural hematoma (SDH) is a particularly challenging pathology due to high recurrence rates (2%-37%) and complex medical comorbidities that tend to afflict the patient population. Recently, there have been several case series published describing the use of middle meningeal artery (MMA) embolization as an alternative to surgery for treatment of new or recurrent chronic SDH. To describe our first 60 cases of MMA embolization for chronic SDH. MMA embolization was performed using angiography, selective microcatheterization of the MMA, and infusion of polyvinyl alcohol particles. Outcomes were assessed clinically and with interval imaging studies at 1 d, 2 wk, and 6 wk postprocedure, and additional intervals as indicated. MMA embolization was performed successfully on 60 total SDHs in 49 patients. This includes upfront treatment for new (not previously treated) SDH in 42, for recurrence in 8, and prophylaxis (soon after surgical evacuation) in 10. There were 3 mortalities (unrelated to the procedure), and no procedural complications. Of the 50 nonprophylactic cases, there were 4 (8.9%) cases of recurrence requiring surgical evacuation, and 31 (68.9%) that had resolution or reduction in size >50% of SDH at longest follow-up. Overall, 41 (91.1%) were stable or decreased in size and able to avoid surgery. MMA embolization may represent a minimally-invasive alternative to surgery for new or recurrent chronic SDH, or as prophylaxis to reduce the risk of recurrence after surgery. Given our encouraging results with a 91% long-term success rate, a large scale clinical trial is warranted.

A Grading System For The Prediction Of Unilateral Chronic Subdural Hematoma Recurrence After Initial Single Burr Hole Evacuation.

Background and purposePrevious studies have identified many risk factors related to the recurrence of chronic subdural hematomas (CSDHs). Among these factors, there may be deviations in measuring the midline shift, preoperative hematoma volume (PreHV), postoperative hematoma residual volume, and postoperative pneumocephalus in bilateral CSDHs. The aims of this study were to eliminate the impact of complicated situations on parameter measurement and to identify actual predictors for CSDH recurrence, and finally, to develop a grading system to predict unilateral CSDH (uCSDH) recurrence.Patients and methodsA total of 342 patients with uCSDH were identified. Predictors of uCSDH recurrence were obtained from univariable and multivariable logistic regression models. A prognostic grading system was developed based on the results of multivariable logistic regression and receiver operating characteristic (ROC) analyses. All patients were scored according to the grading system, and differences in the recurrence rate were reanalyzed according to the scores.ResultsAge, antiplatelet or anticoagulant use, midline shift, severe brain atrophy, drainage volume, and the ratio of the postoperative pneumocephalus volume (PostPV) to the postoperative hematoma cavity volume (PostHCV) were identified as independent risk factors for predicting the recurrence of uCSDH. The cut-off values of age, drainage volume, midline shift, and the ratio of the PostPV to the PostHCV were 67 years, 101 mL, 11.2 mm, and 31.61%, respectively. The recurrence rates were 1.7%, 12.4%, 19.4%, 53.3%, and 58.3% for scores of 0–1, 2, 3, 4, and 5–6, respectively, which significantly increased as the score increased (P<0. 001).ConclusionThe prognostic grading system for uCSDH on the basis of multivariable logistic regression and ROC analyses is applicable and reliable.

Dexamethasone Therapy in Symptomatic Chronic Subdural Hematoma (DECSA-R): A Retrospective Evaluation of Initial Corticosteroid Therapy versus Primary Surgery.

Worldwide, different strategies are being applied for symptomatic chronic subdural hematoma (CSDH). The aim of this study was to evaluate the efficacy of two treatment strategies for symptomatic CSDH: initial dexamethasone (DXM) therapy versus primary surgery by burr hole craniostomy (BHC). We retrospectively collected data for 120 symptomatic CSDH patients in two neurotrauma centers between 2014 and 2016, each with their own treatment protocol. Sixty patients received primary BHC (center A), and another 60 initial DXM therapy (center B). Primary outcome was evaluated by dichotomized modified Rankin Scale (mRS) score (0-3 and 4-6) and Markwalder Grading Scale (MGS) score at 3 months. Secondary outcomes were additional interventions, CSDH recurrence, mortality, complications, and duration of hospital stay. Baseline characteristics were similar in both groups. At 3 months, a favorable mRS score (0-3) was observed in 70% and 76% of patients in cohort A and B, respectively (odds ratio [OR] 0.77, 95% CI 0.30-1.98; p = 0.59). A favorable MGS score (0-1) was observed in 96% of patients in both groups (OR 0.98, 95% CI 0.45-2.15; p = 0.95). CSDH recurrence was 12% in cohort A and 22% in cohort B (p = 0.15). Mortality was 10% in both cohorts. In cohort B, additional surgery was performed in 83% at a median of 6 days, and significantly more patients had complications (55% vs. 35%, p = 0.02), a prolonged hospitalization (10 vs. 5 days; p = 0.02), and one or more follow-up cranial CT's (85% vs. 48%; p < 0.001). To achieve a favorable clinical outcome, initial DXM therapy was associated with a high rate of crossover to surgery, significantly longer overall hospital stay, and more complications compared with primary surgery.

Bedside Percutaneous Twist Drill Craniostomy of Chronic Subdural Hematoma-A Single-Center Study.

Background Chronic subdural hematoma (CSDH) is predominantly a disease of the elderly. Objectives This article studies the clinical and radiological outcomes in patients with CSDH who had undergone bedside percutaneous twist drill craniostomy (TDC). Patients and Methods A retrospective study was conducted in 80 patients who had undergone percutaneous TDC for CSDH between January 2017 and December 2018. Patients between 18 and 90 years of age were selected. CSDH showing computed tomography (CT) scan findings of homogeneous hypodensity, homogeneous isodensity, mixed density, and CSDH with hyperdense gravity-dependent fluid level were selected. CT evidence of multiple septations, recurrent CSDH, bilateral CSDH, and acute on CSDH were excluded. The presence of midline shift (MLS) was measured as any deviation of the septum pellucidum from the midline. The mass effect was determined by the effacement of the sulci, Sylvian fissure obscuration, or compression of lateral ventricles. Postoperative decrease in the signs and symptoms were considered as the postoperative clinical improvement. Improvement in the postoperative CT scan was determined by the decrease in the thickness of CSDH and absence of MLS with decrease in the mass effect. The presence of the CSDH with mass effect and MLS was considered as the significant residue in the postoperative CT scan. Statistical Analysis Statistical analysis is done using Epi Info software. Results The mean age range was 67.78 years ± 12.03 standard deviation (SD). There were 49 (61.25%) males and 31 (38.75%) females. Thirty-eight (47.5%) CSDHs were on the right side and 42 (52.5%) on the left side. The locations were in the frontotemporoparietal region in 91.25% patients and in the frontoparietal region in 8.75% patients. The mean duration of symptoms was 4.62 days ± 5.20 SD. History of trauma was present in 58.75% patients. The mean duration of trauma was 45.78 days ± 28.32 SD. The most common symptoms were weakness of the limbs (68.75%), altered sensorium or decreased memory (52.5%), and headache (32.5%). The preoperative Glasgow Coma Scale (GCS) score ranged from 4 to 15 (mean 12.86 ± 2.98 SD). Limb motor weakness was noted in 75% patients. The maximum thickness of the CSDH (in millimeter) in axial CT scan was 8 to 32 (mean 23.22 ± 4.87 SD). All of the 80 patients had MLS. Postoperative GCS ranged from 3 to 15 (mean 14.1 ± 2.78 SD). Postoperative power was improved in 95% of affected limbs. Postoperative power was deteriorated (including patients of complications and death) in 5% patients. Clinical improvement was noted in 93.75% patients. Postoperative CT scan improvement was noted in 95% patients. Two patients (2.5%) had significant residue which required reoperation. Two patients (2.5%) developed extradural hematoma which was operated. Five (6.25%) patients developed complications, among which 4 (5%) patients died. The mean duration of stay in the hospital was 6.82 days ± 4.16 SD. Conclusions CSDH is a disease of elderly population. CSDH is more common in male population. The most common symptom is weakness of the limbs. High clinical and radiological improvement can be achieved with TDC. TDC should be considered as a safe and effective alternative to burr hole craniostomy.

In Reply: A Reliable Grading System for Prediction of Chronic Subdural Hematoma Recurrence Requiring Reoperation After Initial Burr-Hole Surgery.

In Reply: A Reliable Grading System for Prediction of Chronic Subdural Hematoma Recurrence Requiring Reoperation After Initial Burr-Hole Surgery.

Letter: A Reliable Grading System for Prediction of Chronic Subdural Hematoma Recurrence Requiring Reoperation After Initial Burr-Hole Surgery.

Letter: A Reliable Grading System for Prediction of Chronic Subdural Hematoma Recurrence Requiring Reoperation After Initial Burr-Hole Surgery.

Recurrent Subacute Subdural Hematoma in a 67-Year-Old Female with Late Alzheimer’s Disease: A Case Report

Background: Chronic Subdural Hematoma (CSDH) is becoming an urgent public health issue due to an increase of incidence in aging populations like Taiwan. Though trauma still stands as the primary mechanism of CSDH, it is often overlooked in the elderly, especially those with mid-to-late stage Alzheimer’s Disease (AD). Coincidentally, the clinical presentation of mid-to-late stage AD shares significant overlap with CSDH. AD creates an immense challenge for physicians and family members to identify early signs of CSDH.&#x0D; The Case: We report a peculiar case of a 67-year-old female with a history of AD who presents to the Emergency room in Belmopan City, Belize, with recurrent CSDH. On admission her consciousness was disturbed and late stage dementia presented an enormous challenge for logical and meaningful history taking. Axial non-contrast computed tomography showed a crescent-shaped isodense subdural hematoma in the left hemisphere of the parietal lobe. She was stabilized and treated conservatively with corticosteroids, beta blockers, angiotensin-converting enzyme (ACE) inhibitors and diuretics.&#x0D; Conclusion: It is important for physicians to recognize and develop protocols to identify early signs of CSDH in patients with late stage AD. Early management is a key factor in minimizing more serious complications like recurrence, seizures, and tension pneumocephalus.

Risk Factors for Recurrence of Chronic Subdural Hematoma: A Single Center Experience

Chronic subdural hematoma (CSDH) is a common form of intracranial hemorrhage with a substantial recurrence rate. We aimed to investigate the predictive factors for the postsurgical recurrence of CSDH. We retrospectively reviewed the medical records of patients with CSDH who underwent surgery in West China Hospital between January 2012 and June 2018. Univariate and multivariate analyses were performed to identify the relationships between recurrence of CSDH and factors such as age, sex, history of injury, Markwalder grading, computed tomography findings, surgical methods, and outcomes. A total of 328 patients (281 men and 47 women) aged 22-93 years (mean age, 65.14 ± 13.76 years) were included. Computed tomography findings at admission showed mixed density hematoma in 136 patients, isodensity hematoma in 140, high-density hematoma in 34, and low-density hematoma in 18. The mortality and recurrence rate were 0.30% (1 of 328) and 2.44% (8 of 328), respectively. Six months postoperatively, 327 patients had Markwalder grade 0. Hematoma recurred in 8 patients of which 7 were mixed density hematoma and 1 was isodensity hematoma. Six patients who underwent craniotomy had thickened inner neomembrane that was resected. Univariate and multivariate analyses found mixed density hematoma to be an independent risk factor for the recurrence of CSDH. Burr hole craniostomy with irrigation and closed-system drainage is effective for the surgical treatment of CSDH. Mixed density hematoma is an independent predictor for the recurrence of CSDH. Presence of thick inner neomembrane might be the primary cause of CSDH recurrence.