These authors contributed equally to this work as a first author.
Chronic subdural hematoma (CSDH) is a common disease in neurosurgical departments, but optimal perioperative management guidelines have not yet been established. We aimed to assess the current clinical management and outcomes for CSDH patients and identify prognostic factors for CSDH recurrence.
We enrolled a total of 293 consecutive patients with CSDH who underwent burr hole craniostomy at seven institutions in 2018. Clinical and surgery-related characteristics and surgical outcomes were analyzed. The cohort included 208 men and 85 women.
The median patient age was 75 years. Antithrombotic agents were prescribed to 105 patients. History of head trauma was identified in 59% of patients. Two hundred twenty-seven of 293 patients (77.5%) had unilateral hematoma and 46.1% had a homogenous hematoma type. About 70% of patients underwent surgery under general anesthesia, and 74.7% underwent a single burr hole craniostomy surgery. Recurrence requiring surgery was observed in 17 of 293 patients (5.8%), with a median of 32 days to recurrence. The postoperative complication rate was 4.1%. In multivariate analysis, factors associated with CSDH recurrence were separated hematoma type (odds ratio, 3.906;
This is the first retrospective multicenter generalized cohort pilot study in the Republic of Korea as a first step towards the development of Korean clinical practice guidelines for CSDH. The type of hematoma and anesthesia was associated with CSDH recurrence. Although the detailed surgical method differs depending on the institution, the surgical treatment of CSDH was effective. Further studies may establish appropriate management guidelines to minimize CSDH recurrence.
Chronic subdural hematoma (CSDH) is an encapsulated collection of blood and blood degradation products layered between the dura mater and the arachnoid membrane [
Symptoms in patients with CSDH include headache, cognitive impairment, gait disturbance, or motor weakness. Although spontaneous resolution can occur, surgical treatment is indicated for symptomatic patients with CSDH [
Well-established clinical practice guidelines can contribute to better management strategies for patients with CSDH. The Neurotrauma Clinical Practice Guidelines Committee of the Korean Neurotraumatology Society was organized to prepare treatment guidelines for the management of patients with traumatic brain injuries. Therefore, the present study aimed to present the current clinical, treatment, and outcome characteristics of CSDH patient in the Republic of Korea through the first multicenter study of a generalized CSDH cohort to provide appropriate CSDH treatment guidelines in near future.
This study was approved by the Institutional Review Boards of seven institutions (Soonchunhyang University Cheonan Hospital, IRB No. SCHCA 2020-06-020; Yeungnam University Hospital, IRB No. 2020-06-046; St. Vincent's Hospital, IRB No. VC20RADI0130; Chungnam National University Hospital, IRB No. CNUH 2020-07-066; Dongsan Medical Center, IRB No. 2020-06-062-003; Uijeongbu St. Mary's Hospital, IRB No. UC20RIDI0102; Korea University Guro Hospital, IRB No. 2020GR0319). We conducted this retrospective, multicenter pilot study to assess the CSDH situation in the Republic of Korea. We retrospectively reviewed medical records and radiological imaging studies of adult patients (>18 years) who were diagnosed with CSDH and surgically treated between January 1, 2018 and December 31, 2018 at one of the seven participating institutions. A total of 299 patients underwent surgical treatment for CSDH. The following patients were excluded : five patients with no postoperative imaging studies and one patient who was treated with craniotomy for CSDH. A total of 293 patients were enrolled in this study, and all of them underwent burr hole trephination and drainage. Surgical techniques and postoperative management were performed according to the local policy.
Data were collected from the electronic medical records at each medical center. The data were investigated by dividing them into basic medical information and surgical information.
Basic medical information included patients demographics, symptoms and signs, preoperative mobility level, preoperative Markwalder’s grade [
Findings of radiological diagnostic tools, including computed tomography (CT) and magnetic resonance imaging (MRI), were reviewed. Based on preoperative CT and/or MRI, radiological characteristics, such as location and maximum width of hematoma and type of CSDH were reviewed. Hematomas were classified into four types based on radiologic images, as previously described by Nakaguchi et al. [
Surgical information included the method of anesthesia (local or general), location of the burr hole, number of burr holes, saline irrigation, method of drainage, usage of urokinase or tissue plasminogen activator (tPA), angle of bed maintained during drainage (flat, 15 to 30 degrees, or free), and use of medication after surgery (tranexamic acid, statin, or steroid). The method of drainage was classified as “free drain” or ‘‘amount-regulation’’ (a method of re-drainage after checking the total amount of drainage and stopping for 2 hours) or ‘‘velocity-regulating’’ (a method of adjustment of the amount of drainage per hour). In addition, the drainage maintenance period, hospitalization period, and recurrence period after the first operation were investigated.
The postoperative outcome was assessed using the Glasgow outcome scale [
The results were analyzed using IBM SPSS Statistics software (version 25.0; IBM Corp., Armonk, NY, USA). Descriptive statistics, such as frequency (n), percentage, median, mean, and range were used to describe variables and subgroup characteristics. When evaluating the univariate association with CSDH recurrence, a Pearson’s chi-square test, Fisher’s exact test, and linear-by-linear association analysis were used for categorical variables, and a Student’s t-test was used for non-categorical variables. Logistic regression analysis was performed to analyze the independent associations between recurrence and contributing factors. Variables with
A total of 293 patients were enrolled in this study. There were 208 men (71%), and the median age was 75 years (range, 22–95). Of the 293 patients, 83 (28.3%) were aged 80 years or older. The median body mass index was 23.2 (range, 14.8–33.2), corresponding to the upper limit of the normal range [
Recurrence was observed in 17 (5.8%) of the 293 patients. Four of the 17 patients underwent reoperation within 2 weeks of the initial surgery due to an increase in residual hematoma, and mean interval from initial surgery to reoperation was 32.1 days (range, 4–104). On the other hand, in patients whose drainage catheter maintenance period was 1, 2, 3, 4, and 5 days, recurrence occurred in six, five, three, two, and one case, respectively. To identify risk factors for CSDH recurrence, the clinical and radiologic characteristics of the non-recurrence group and the recurrence group were compared and analyzed.
Clinical and radiologic characteristics are summarized and compared in
Two hundred and fifty-one (70%) of 293 patients underwent surgery under general anesthesia. Two hundred and sixty-four (90%) of the 293 patients underwent one burr hole trephination. The other parameters are summarized in
Although there were no significant differences, most of the surgeries were performed with a burr hole in the parietal area, the bed was kept flat, the free drainage method was used, and postoperative symptoms showed favorable outcomes. Postoperative complications, including infection, seizure, acute subdural hematoma, acute epidural hematoma, and/or intracerebral hematoma, occurred in 12 (4.1%) of 293 cases. Surgery-related characteristics in the non-recurrence and recurrence groups are summarized in
Results of the univariate and multivariate analyses of the associations between various possible factors and recurrence were shown in
CSDH is a common disease found in neurosurgical departments, and its incidence has increased during the last decades [
In this study, we analyzed the current clinical and radiological characteristics, surgical factors, and outcomes of CSDH in the Republic of Korea through a retrospective multicenter study. The cohort included a majority of elderly male patients. The median age was 75 years, and 71% of the patients were male. Reports show that brain atrophy progresses with age, and the incidence of spontaneous CSDH related to age is significant [
Surgical treatment, especially burr hole craniostomy or trephination, is considered an effective and favorable first-line treatment for symptomatic CSDH. In this study, all patients underwent burr hole trephination and drainage. The effectiveness and safety of burr hole craniostomy for CSDH have been described in many papers [
Although this study was conducted with a relatively small number of seven institutions, the preferred surgical method, such as the location of the burr hole, number of burr holes, use of irrigation, and postoperative management including drainage method and patient’s posture was different for each institution or attending physician. In order to develop appropriate clinical guidelines, it is essential to conduct studies on data and consensus from various regions and multi-institutions rather than single-institutional cohort studies, which are susceptible to bias and methodological pitfalls [
Some interesting differences in surgical management such as anesthesia method, number of burr holes, and saline irrigation were noted. Among these 293 patients most underwent single burr hole craniostomy. However, 70% of 293 patients underwent surgery under general anesthesia. Sixty-four percent of patients were postoperatively managed with a flat head position, and 71% were managed using the free drainage method. In terms of postoperative head position, Miele et al. [
As mentioned above, the recurrence rate of CSDH varies. Previous studies have reported that various factors are associated with the recurrence of CSDH. Hematoma density [
In the separated type of CSDH, fibrinolysis occurs in hematoma, and it is known to be related to CSDH recurrence [
Heavy drinking was a significant risk factor for recurrence of CSDH in the univariate analysis but not in the multivariate analysis. It is difficult to find published studies demonstrating a significant association between alcoholism and CSDH recurrence. Kostić et al. [
The limitations of this study include those inherent in retrospective analyses and the relatively small number of cases. In our cohort, the quality of medical records varied among the cases at each institute. The retrospective nature of this study might have created a bias. Moreover, this study was conducted as a pilot study to prepare treatment guidelines for CSDH. Seven out of 45 advanced general hospitals in the Republic of Korea were enrolled to analyze the status of clinical management of CSDH for 1 year. Therefore, further study through the participation of more institutions and expansion of the number of patients is mandatory. Moreover, additional studies are also needed to find other detailed risk factors, such as cranial anatomical differences related to CSDH recurrence. In terms of long-term outcomes, several studies have reported that poor emotional or psychological prognosis and cognitive impairment occur approximately 5 years after CSDH treatment [
This retrospective, the multicenter study reported on the current management and surgical outcomes of patients with CSDH and identified several prognostic factors related to CSDH recurrence. The population characteristics of CSDH are similar to those previously reported. Although there were some differences in the surgical technique and management plan at each institution, the effectiveness of surgical treatment for CSDH was confirmed. Therefore, treatment guidelines based on the various characteristics of cases are necessary. Even though this study has limitations as it was a pilot study, we hope that it will contribute to establishing treatment guidelines for CSDH by providing a scientific basis for further studies.
No potential conflict of interest relevant to this article was reported.
This type of study does not require informed consent.
Conceptualization : HJO, KC
Data curation : KC
Formal analysis : KC
Funding acquisition : HJO, YS
Methodology : HJO, YS, YIK, KHK, SMK, MHL, KC
Project administration : KC
Visualization : HJO, YS, YHC
Writing - original draft : YHC
Writing - review & editing : HJO, YS, KC
This work was supported by funding from the Soonchunhyang University Research Fund and the Yeungnam University Grant (219A580025).
The online-only data supplement is available with this article at
Clinical and laboratory characteristics in non-recurrence group and recurrence group in 293 patients
Computed tomography demonstrating four types of chronic subdural hematoma. A : Homogeneous type. B : Laminar type. The arrowheads indicate the high-density laminar structure running along the inner membrane. C : Separated type. The arrow indicates a thick component of the liquefied hematoma. D : Trabecular type. The arrow indicates multiple septations created by fibrosis.
A-D : Comparison of recurrence rate according to age group, history of traumatic brain injury (TBI), alcohol consumption and antithrombotics.
Comparison of the differences in surgery related methods in chronic subdural hematoma patients.
Baseline characteristics of all 293 patients with chronic subdural hematoma
Value | |
---|---|
Age at treatment time (years) | 75 (22–95) |
80 years or older | 83 (28.3) |
Sex, male/female | 208 (71.0)/85 (29.0) |
BMI (kg/m2) | 23.2 (14.8–33.2) |
Clinical presentation | |
Seizure | 3 (1.0) |
Headache | 94 (32.0) |
Gait disturbance | 18 (6.0) |
Hemiparesis | 113 (39.0) |
Dysarthria | 14 (5.0) |
Mental deterioration | 30 (10.0) |
Cognitive impairment | 10 (3.0) |
None | 6 (2.0) |
Others |
3 (1.0) |
ND | 2 (0.7) |
Preoperative mobility | |
Independent | 187 (64.0) |
Assistant walking | 41 (14.0) |
Wheelchair | 37 (13.0) |
Bed-bound | 22 (8.0) |
ND | 6 (2.0) |
Median preoperative Markwalder’s grade | 1 (0–3) |
Period between head trauma and admission | |
Unknown | 119 (41.0) |
<2 months | 133 (45.0) |
≥2 months | 41 (14.0) |
Diagnostic tools | |
CT | 169 (58.0) |
MRI | 14 (5.0) |
CT+MRI | 110 (38.0) |
Radiological follow-up period (days), mean | 126.2 (1–807) |
Values are presented as median (range) or number (%) unless otherwise indicated.
“Others” included 1 of nausea/vomiting, 1 of facial palsy, and 1 of urine incontinence.
BMI : body mass index, ND : not done, CT : computed tomography, MRI : magnetic resonance imaging
Clinical and radiologic characteristics in non-recurrence group and recurrence group in 293 patients
Total (n=293) | Non Rc. group (n=276) | Rc. group (n=17) | ||
---|---|---|---|---|
Age (years) | 75 (22–95) | 75 (22–95) | 76 (39–88) | 0.941 |
Sex, male/female | 208 (71.0)/85 (29.0) | 194 (70.0)/82 (30.0) | 14 (82.0)/3 (18.0) | 0.411 |
Preoperative GCS | 0.345 | |||
13–15, mild | 269 (92.0) | 255 (92.0) | 14 (82.0) | |
9–12, moderate | 14 (5.0) | 12 (4.0) | 2 (12.0) | |
3–8, severe | 10 (3.0) | 9 (3.0) | 1 (6.0) | |
History of TBI | 0.617 | |||
Unknown | 119 (41.0) | 111 (40.0) | 8 (47.0) | |
Yes | 174 (59.0) | 165 (60.0) | 9 (53.0) | |
Period from head trauma | 0.441 | |||
Unknown | 119 (41.0) | 111 (40.0) | 8 (47.0) | |
<2 months | 133 (45.0) | 127 (46.0) | 6 (35.0) | |
≥2 months | 41 (14.0) | 38 (14.0) | 3 (18.0) | |
Alcohol consumption |
||||
None | 200 (68.0) | 191 (69.0) | 9 (53.0) | 0.141 |
Moderate drinking group | 53 (18.0) | 50 (18.0) | 3 (18.0) | 1.000 |
Heavy drinking group | 37 (13.0) | 32 (12.0) | 5 (29.0) | 0.050 |
Smoking | 66 (23.0) | 63 (23.0) | 3 (18.0) | 0.771 |
Comorbidities | ||||
Diabetes mellitus | 92 (31.0) | 83 (30.0) | 9 (53.0) | 0.060 |
Hypertension | 154 (53.0) | 144 (52.0) | 10 (59.0) | 0.594 |
Dyslipidemia | 26 (9.0) | 25 (9.0) | 1 (6.0) | 0.726 |
Preoperative drug history | ||||
Warfarin | 9 (3.0) | 8 (3.0) | 1 (6.0) | 0.421 |
NOAC | 10 (3.0) | 9 (3.0) | 1 (6.0) | 0.455 |
Antiplatelet agents | 86 (29.0) | 80 (29.0) | 6 (35.0) | 0.589 |
Statin | 74 (25.0) | 69 (25.0) | 5 (29.0) | 0.774 |
None | 116 (40.0) | 111 (40.0) | 5 (29.0) | 0.377 |
Antithrombotic discontinuation period before surgery (days) | 3 (0–100) | 3 (0–100) | 0 (0–15) | 0.230 |
Location of hematoma | 0.230 | |||
Unilateral | 227 (77.0) | 216 (78.0) | 11 (65.0) | |
Right/left | 105 (36.0)/122 (42.0) | 100 (36.0)/116 (42.0) | 5 (29.0)/6 (35.0) | |
Bilateral | 66 (23.0) | 60 (22.0) | 6 (35.0) | |
Maximum width of hematoma (mm), mean (range) | 22.8 (5.0–42.0) | 22.7 (5.0–40.5) | 25.8 (15.0–42.0) | 0.075 |
Type of hematoma | 0.494 | |||
Homogenous | 135 (46.0) | 129 (47.0) | 6 (35.0) | |
Laminar | 43 (15.0) | 42 (15.0) | 1 (6.0) | |
Separated | 64 (22.0) | 55 (20.0) | 9 (53.0) | |
Trabecular | 51 (17.0) | 50 (18.0) | 1 (6.0) |
Values are presented as median (range) or number (%) unless otherwise indicated.
Three patients had no data.
Rc. : recurrence, GCS : Glasgow coma scale, TBI : traumatic brain injury, NOAC : novel oral anticoagulants
Surgery related characteristics in non-recurrence group and recurrence group in 293 patients
Total (n=293) | Non-Rc. group (n=276) | Rc. group (n=17) | ||
---|---|---|---|---|
Anesthesia | 0.007 | |||
Local anesthesia | 87 (30.0) | 77 (28.0) | 10 (59.0) | |
General anesthesia | 206 (70.0) | 199 (72.0) | 7 (41.0) | |
Location of burr hole | 0.292 | |||
Frontal area | 13 (4.0) | 12 (4.0) | 1 (6.0) | |
Parietal area | 251 (86.0) | 238 (86.0) | 13 (76.0) | |
Frontal and parietal area | 29 (10.0) | 26 (10.0) | 3 (18.0) | |
Number of burr hole | 0.230 | |||
1 burr hole | 264 (90.0) | 250 (91.0) | 14 (82.0) | |
2 burr holes | 29 (10.0) | 26 (9.0) | 3 (18.0) | |
Saline irrigation during surgery | 136 (46.0) | 131 (47.0) | 5 (29.0) | 0.147 |
Drainage method | 0.195 | |||
Free drainage | 208 (71.0) | 198 (72.0) | 10 (59.0) | |
Regulate amount of drainage | 72 (25.0) | 67 (24.0) | 5 (29.0) | |
Regulate velocity of drainage | 13 (4.0) | 11 (4.0) | 2 (12.0) | |
Period of drainage catheter maintenance (days), mean (range) | 2.52 (0–9) | 2.53 (0–9) | 2.24 (1–5) | 0.188 |
Urokinase or tPA | 28 (1.0) | 28 (10.0) | 0 (0.0) | 0.422 |
Head position | 0.521 | |||
Flat | 187 (64.0) | 175 (63.0) | 12 (71.0) | |
15 to 30 degrees | 56 (19.0) | 53 (19.0) | 3 (18.0) | |
Free | 49 (17.0) | 47 (17.0) | 2 (12.0) | |
Period of initiating ambulation after surgery (days) | 2 (1–120) | 2 (1–120) | 2 (1–4) | 0.632 |
Duration of hospitalization (days) | 9 (2–138) | 9 (2–138) | 8 (3–73) | 0.795 |
Medication after surgery | ||||
Tranexamic acid | 17 (6.0) | 17 (6.0) | 0 (0.0) | 0.609 |
Statin | 54 |
51 (18.0) | 3 (18.0) | 1.000 |
Steroid | 6 (2.0) | 5 (1.0) | 1 (6.0) | 0.304 |
Glasgow outcome scale | 0.015 | |||
5 | 226 (77.0) | 216 (78.0) | 10 (59.0) | |
4 | 43 (14.0) | 38 (14.0) | 5 (29.0) | |
3 | 21 (7.0) | 21 (7.0) | 0 (0.0) | |
2 | 2 (1.0) | 1 (1.0) | 1 (6.0) | |
1 | 1 (1.0) | 0 (0.0) | 1 (6.0) | |
Mean interval to recurrence (days) | N/A | N/A | 32.1 (4–104) | |
Complications related operation | ||||
Infection | 2 (0.7) | 2 (0.7) | 0 (0.0) | |
Seizure | 2 (0.7) | 2 (0.7) | 0 (0.0) | |
Acute subdural hematoma | 5 (2.0) | 5 (2.0) | 0 (0.0) | |
Acute epidural hematoma | 2 (0.7) | 2 (0.7) | 0 (0.0) | |
Intracerebral hematoma | 1 (0.3) | 1 (0.4) | 0 (0.0) |
Values are presented as median (range) or number (%) unless otherwise indicated.
Thirty-five of these 54 patients had a history of taking statin prior to surgery.
Rc. : recurrence, tPA : tissue plasminogen activator, N/A : not applicable
Statistical analysis for prognostic factors relating to recurrence
Operation for recurrence |
||||||
---|---|---|---|---|---|---|
Univariate |
Multivariate |
|||||
OR | 95% CI | OR | 95% CI | |||
Age | 0.055 | 0.960–1.045 | 0.066 | ND | ||
Old age, >65 years | 1.741 | 0.187–6.231 | 0.394 | ND | ||
Female gender | 1.973 | 0.552–7.048 | 0.296 | ND | ||
BMI (kg/m2) | 1.033 | 0.887–1.204 | 0.674 | ND | ||
History of TBI | 0.757 | 0.283–2.021 | 0.578 | ND | ||
Smoking | 0.724 | 0.202–2.601 | 0.621 | ND | ||
Alcohol consumption | ||||||
None | Ref | Ref. | ||||
Moderate drinking group | 1.273 | 0.332–4.879 | 0.724 | 1.656 | 0.407–6.744 | 0.481 |
Heavy drinking group | 3.316 | 1.044–10.531 | 0.042 | 3.179 | 0.933–10.833 | 0.064 |
Comorbidities | ND | |||||
DM | 2.616 | 0.975–7.016 | 0.056 | |||
HTN | 1.310 | 0.484–3.540 | 0.595 | |||
Dyslipidemia | 0.628 | 0.080–4.932 | 0.682 | |||
Antithrombotic agents | 1.292 | 0.477–3.501 | 0.615 | ND | ||
Statin before surgery | 1.250 | 0.425–3.674 | 0.685 | ND | ||
Statin after surgery | 0.945 | 0.262–3.412 | 0.932 | ND | ||
General anesthesia | 0.271 | 0.100–0.737 | 0.011 | 0.277 | 0.097–0.791 | 0.017 |
Bilateral hematoma | 1.964 | 0.698–5.528 | 0.201 | ND | ||
Two burr hole craniostomy | 2.060 | 0.556–7.642 | 0.280 | ND | ||
Maximum width of hematoma | 1.067 | 0.993–1.146 | 0.078 | |||
Hematoma type | ||||||
Homogenous | Ref. | |||||
Laminar | 0.512 | 0.060–4.375 | 0.541 | 0.680 | 0.077–5.997 | 0.728 |
Separated | 3.518 | 1.195–10.361 | 0.022 | 3.906 | 1.275–11.970 | 0.017 |
Trabecular | 0.430 | 0.050–3.662 | 0.440 | 0.503 | 0.058–4.377 | 0.534 |
Saline irrigation during surgery | 0.461 | 0.158–1.344 | 0.156 | ND | ||
Drainage method | ND | |||||
Free drain | Ref. | |||||
Regulate drained amount | 1.478 | 0.488–4.478 | 0.490 | |||
Regulate drained velocity | 3.600 | 0.702–18.468 | 0.125 | |||
Head position | ||||||
Flat | Ref. | ND | ||||
15 to 30 degrees | 0.825 | 0.225–3.035 | 0.773 | |||
Free | 0.621 | 0.134–2.869 | 0.541 | |||
Period of initiating ambulation after surgery | 0.761 | 0.483–1.200 | 0.240 | |||
Laboratory findings | ND | |||||
Hemoglobin | 0.788 | 0.607–1.024 | 0.074 | |||
Platelet | 0.996 | 0.989–1.003 | 0.302 | |||
INR | 0.865 | 0.295–2.534 | 0.791 | |||
aPTT | 0.961 | 0.866–1.068 | 0.461 | |||
BUN | 1.001 | 0.958–1.046 | 0.966 | |||
Creatinine | 1.270 | 0.977–1.651 | 0.074 | |||
AST | 1.012 | 1.000–1.025 | 0.053 | |||
ALT | 1.021 | 0.994–1.048 | 0.126 |
OR : odds ratio, CI : confidence interval, ND : note done, BMI : body mass index, TBI : traumatic brain injury, Ref. : reference, DM : diabetes mellitus, HTN : hypertension, INR : international ratio, aPTT : activated partial thromboplastin time, BUN : blood urea nitrogen, AST : aspartate transaminase, ALT : alanine transaminase