https://orcid.org/0000-0002-4428-4450
Figures
Abstract
Background
Chronic subdural hematoma (CSDH) is commonly treated via surgical removal of the hematoma, placement of a routine indwelling drainage tube, and continuous drainage to ensure that the blood does not re-aggregate following removal. However, the optimal location for placement of the drainage tube remains to be determined.
Objectives
To aid in establishing a reference for selecting the optimal method, we compared the effects of different drainage tube placements on CSDH prognosis via a systematic review and meta-analysis of previous clinical studies.
Study eligibility criteria
We searched for clinical studies comparing the outcomes of subperiosteal/subgaleal drainage (SPGD) and subdural drainage (SDD) for CSDH published in English prior to April 1, 2022.
Results
Our analysis of the pooled results revealed no significant differences in recurrence rate between the SDD and SPGD groups. We also observed no significant differences in mortality or rates of postoperative complications (infection, pneumocephalus, or epilepsy) between the SDD and SPGD groups.
Citation: Chen C, Xiong Y, Huang X, Guo X, Kang X, Zhou J, et al. (2023) Subperiosteal/subgaleal drainage vs. subdural drainage for chronic subdural hematoma: A meta-analysis of postoperative outcomes. PLoS ONE 18(8): e0288872. https://doi.org/10.1371/journal.pone.0288872
Editor: Alvan Ukachukwu, Duke University Medical Center: Duke University Hospital, UNITED STATES
Received: December 1, 2022; Accepted: July 5, 2023; Published: August 1, 2023
Copyright: © 2023 Chen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the manuscript and its Supporting Information files.
Funding: The author(s) received no specific funding for this work.
Competing interests: The authors have declared that no competing interests exist.
Introduction
Chronic subdural hematoma (CSDH), a type of intracranial hematoma that occurs mainly in older adults [1, 2], is pathogenically characterized by the slow accumulation of blood between the cerebral cortex and dura mater [3, 4]. Clinical manifestations of CSDH vary depending on the size of the hematoma and the extent to which it compresses different parts of the brain, although common features include headache, limb weakness, mental disorders, and epilepsy [5, 6]. Previous studies have reported a CSDH incidence as high as 20.6/100,000 cases per year, with vascular injury due to head trauma representing the main cause of bleeding in 75% of cases [7, 8].
At present, the most common treatment strategy for CSDH involves surgical removal of the hematoma, placement of a routine indwelling drainage tube, and continuous drainage to ensure that the blood does not re-aggregate in the space left following removal of the hematoma [9, 10]. Research has demonstrated that the use of a conventional drainage tube can significantly reduce the rate of CSDH recurrence when compared with treatments implemented without a drainage tube [11, 12]. Despite the recent utilization of subperiosteal or subgaleal drainage (SPGD), subdural drainage (SDD) remains the most common strategy [13], and the optimal drainage location remains to be determined [14, 15]. To aid in establishing a reference for selecting the optimal drainage method, the present study aimed to compare the effects of different drainage tube placements on prognosis in patients with CSDH via a systematic review and meta-analysis of previous clinical studies.
Materials and methods
Search strategy
We searched the PubMed, Embase, and Cochrane databases for articles reporting the results of clinical studies comparing the outcomes of SPGD and SDD for CSDH (A complete search strategy is attached to the online material). Initially, all relevant studies published in English prior to April 1, 2022 were included based on a search conducted using the appropriate keywords (“drain”, “drainage”, “chronic subdural hematoma”) and MeSH terms. The search was restricted to RCTs and observational cohort studies. The reference lists of the included studies were further reviewed to ensure inclusion of other relevant clinical studies.
Selection criteria
Articles were independently retrieved and screened by two researchers (C. C. and Y. X.), and any differences in eligibility assessments were resolved through discussion. After excluding articles unrelated to the study topic based on titles and abstracts, two researchers (C. C. and Y. X.) read the full text of the remaining articles, which were then screened based on the following inclusion criteria: (a) inclusion of patients diagnosed with CSDH, (b) treatment strategy consisting of surgery and postoperative drainage, (c) clear distinction between SDD and SPGD for postoperative drainage, (d) availability of the full text and sufficient data. Exclusion criteria were as follows: (a) population consisting of patients without CSDH, (b) treatment involving non-surgical removal of the hematoma or surgical removal without catheter drainage, (c) incomplete or unextractable data, (d) no clear distinction between SDD and SPGD for postoperative drainage, (e) non-relevant study type (e.g., case reports, letters, comments, summaries of meetings, editorials, programs, guidelines, and animal research articles).
Data extraction and quality assessment
Two independent investigators (C. C. and Y. X.) extracted the data and assessed the quality of the studies using standardized tables that included year, author, trial design, inclusion criteria, and outcome measures. Missing data were obtained from the original author whenever possible. All differences were resolved through team discussion and evaluation. The Cochrane Collaboration’s Risk of Bias tool [16] and the Newcastle–Ottawa Scale [17] were used to assess the quality of RCTs and cohort studies, respectively. The Cochrane Risk of Bias tool evaluates the quality of RCTs across seven domains (allocation concealment, random sequence generation, blinding of participants and personnel, blinding of outcome assessment, data integrity, selective reporting, and other sources of bias). The maximum total score given by the Newcastle–Ottawa Scale is 9 points across the three categories of selection, comparability, and outcome (maximum scores of 4, 2, and 3 points, respectively). Scores of 7 or higher, 4–6, and 0–3 points correspond to “high quality”, “moderate”, and “weak”, respectively. The scores of the six observational cohort studies ranged from 7 to 8, indicative of generally high methodological quality.
Outcome measures
The primary outcome measures were the postoperative recurrence rate and mortality. Secondary outcome measures included postoperative infection, postoperative epilepsy and intracranial hematoma. Because pneumocephalus may be associated with adverse outcomes [18] it was also included as a secondary outcome in the present study, defined as the presence of intracranial gas on radiological findings.
Statistical analysis
RevMan5.3 was used to perform this meta-analysis of studies comparing the effects of SPGD and SDD on recurrence rate, mortality, postoperative infection, postoperative epilepsy, pneumocephalus, and intracranial hematoma in patients with CSDH. Outcomes were compared in terms of odds ratios (ORs), 95% confidence intervals, and P values for dichotomous variables. In addition, a random-effects model was used to pool the results of the primary studies. Heterogeneity was assessed using the I2 test, and an I2 ≤ 50% was considered to indicate acceptable heterogeneity as specified in the Cochrane manual.
Results
In total, 775 studies were retrieved based on the initial search strategy. After removing duplicates, 654 articles remained. Among them, 636 were excluded based on a review of the titles and abstracts. After further review, an additional three articles were excluded due to insufficient data. Thus, 15 studies [9, 10, 14, 15, 19–29] encompassing 4,318 patients were included in the final analysis. There were 2,547 patients in the SDD group and 1,985 patients in the SPGD group. The average follow-up time was 6.58 months. Three of these studies were randomized controlled trials (RCTs), while the remaining 12 were cohort studies. The detailed search strategy and selection process are shown in Fig 1. The characteristics of the included studies are presented in Table 1 (the complete NOS chart has been uploaded as online material) and Fig 2A.
SDD: Subdural drainage; SPGD: Subperiosteal or subgaleal drainage.
(a). Risk of bias for randomized controlled trials in the present analysis. (b) Funnel plot of publication bias for recurrence rates. M-H: Mantel–Haenszel statistic. CI: Confidence interval.
Recurrence
Across the 15 included studies [9, 10, 14, 15, 19–29], recurrence was reported in 512 patients at the end of follow-up. The analysis revealed no significant difference in the recurrence rate between the SDD and SPGD groups (odds ratio [OR]: 1.08 [95% confidence interval: 0.83, 1.42], I2 = 30%, P = 0.56) (Fig 3A). As more than 10 studies were included in the current analysis, publication bias was further analyzed using a funnel plot, which revealed no significant bias (Fig 2B). The SPDG group was then divided into subperiosteal drainage (SPD) and subgaleal drainage (SGD) subgroups to examine the effect of drainage tube placement on recurrence rate. No significant differences in recurrence were observed between the SPD (OR: 1.01 [0.73, 1.40], I2 = 0%, P = 0.96) and SGD groups (OR: 1.12 [0.71, 1.76], I2 = 55%, P = 0.64) (Fig 4A).
(a): Recurrence. (b) Mortality rate. (c) Postoperative infection. (d) Postoperative epilepsy. (e) Intracranial hematoma. (f) Pneumocephalus. SDD: Subdural drainage. SPGD: Subperiosteal or subgaleal drainage. M-H: Mantel–Haenszel statistic. CI: Confidence interval.
(a): Recurrence. (b) Mortality rate. (c) Postoperative infection. (d) Postoperative epilepsy. (e) Intracranial hematoma. (f) Pneumocephalus. SDD: Subdural drainage. SPGD: Subperiosteal or subgaleal drainage. SPD: Subperiosteal drainage. SGD: Subgaleal drainage. M-H: Mantel–Haenszel statistic. CI: Confidence interval.
Mortality rate
Across ten studies providing relevant data [9, 14, 15, 21–24, 27–29], 410 patients were reported to have died. There was no significant difference in mortality between the SDD and SPGD groups (OR: 1.16 [0.92, 1.48], I2 = 0%, P = 0.21) (Fig 3B). Further subgroup analysis revealed no significant difference in mortality between the SPD (OR: 0.99 [0.60, 1.63], I2 = 0%, P = 0.97) and SGD groups (OR: 1.22 [0.93, 1.60], I2 = 0%, P = 0.15) (Fig 4B).
Postoperative infection
At the end of the follow-up period, nine studies reported postoperative infection in 58 patients [9, 10, 14, 15, 21, 23, 27–29]. An analysis of the pooled results revealed no significant difference in the rate of postoperative infection between the SDD and SPGD groups (OR: 1.08 [0.60, 1.95], I2 = 0%, P = 0.80) (Fig 3C). Subgroup analysis revealed no significant difference in infection rates between the SPD (OR: 1.21 [0.46, 3.18], I2 = 44%, P = 0.69) and SGD groups (OR: 0.98 [0.30, 3.24], I2 = 0%, P = 0.98) (Fig 4C).
Postoperative epilepsy
Across 10 studies providing relevant data [9, 10, 15, 19, 21, 23, 25, 27–29], 90 patients were reported to have developed postoperative epilepsy, although there were no significant differences in the rate of postoperative epilepsy between the SDD and SPGD groups (OR: 1.03 [0.63, 1.69]; I2 = 6%; P = 0.91) (Fig 3D). Subgroup analysis also revealed no significant difference in the postoperative epilepsy rate between the SPD (OR: 0.88 [0.49, 1.58], I2 = 0%, P = 0.67) and SGD groups (OR: 1.42 [0.42, 4.76], I2 = 53%, P = 0.57) (Fig 4D).
Intracerebral hematoma
The outcome of postoperative intracerebral hematoma was utilized to assess the resultant injury to brain parenchyma caused by the maneuvering of the drainage tube. Across six studies providing relevant data, intracerebral hematoma was reported in 24 patients [9, 15, 19, 21, 26, 29], and there was no significant difference between the SDD and SPGD groups (OR: 1.68 [0.69, 4.06], I2 = 0%, P = 0.25) (Fig 3E). Subgroup analysis also revealed no significant difference in the postoperative epilepsy rate between the SPD (OR: 1.37 [0.45, 4.16], I2 = 5%, P = 0.58) and SGD groups (OR: 2.69 [0.58, 12.54], I2 = 0%, P = 0.21) (Fig 4E).
Pneumocephalus
The incidence of postoperative pneumocephalus was recorded in five studies [10, 15, 19, 20, 23], and an analysis of the pooled results revealed no significant difference in the incidence of pneumocephalus between the SDD and SPGD groups (OR: 1.32 [0.73, 2.39], I2 = 0%, P = 0.36) (Fig 3F). Subgroup analysis also revealed no significant difference in the postoperative epilepsy rate between the SPD (OR: 1.38 [0.57, 3.37], I2 = 0%, P = 0.48) and SGD groups (OR: 1.20 [0.47, 3.04], I2 = 22%, P = 0.70) (Fig 4F).
Subgroup analysis based on RCTs
Subgroup analysis based on RCTs (Soleman et al., Pathoumthong et al., and Kariaperumal et al.) [9, 20, 25] showed that SPGD was associated with similar recurrence (OR: 0.89 [0.15, 5.39], I2 = 40%, P = 0.90), mortality (OR: 1.00 [0.41, 2.42], P = 1.00), seizure (OR: 0.69 [0.27, 1.79], I2 = 0%, P = 0.45), intracerebral hematoma (OR: 1.20 [0.17, 8.71], P = 0.85), pneumocephalus (OR: 1.00 [0.03, 29.81], P = 1.00), and postoperative infection (OR: 3.86 [1.01, 14.66], P = 0.05) compared to SDD (Fig 5).
(a) Recurrence. (b) Mortality rate. (c) Postoperative infection. (d) Postoperative epilepsy. (e) Intracranial hematoma. (f) Pneumocephalus. SDD: Subdural drainage. SPGD: Subperiosteal or subgaleal drainage. SPD: Subperiosteal drainage. SGD: Subgaleal drainage. M-H: Mantel–Haenszel statistic. CI: Confidence interval. RCT: Randomized controlled trial.
Discussion
In the current study, we analyzed the influence of different catheterization methods on the postoperative prognosis of patients with CSDH via a meta-analysis of 15 studies involving 4,318 patients. The advantages and disadvantages of different postoperative catheterization and drainage methods for CSDH were evaluated by integrating and analyzing several outcome indicators, including rates of recurrence, mortality, and postoperative complications (Fig 6). Given its significant impact on the prognosis of CSDH, the postoperative recurrence rate was selected as the primary outcome [30–33]. Our analysis of the pooled results revealed no significant differences in recurrence rate between the SDD and SPGD groups, suggesting that the choice of postoperative drainage method does not significantly impact the rate of CSDH recurrence. Our pooled analysis also revealed no significant differences in mortality or rates of postoperative complications (infection, pneumocephalus, or epilepsy) between the SDD and SPGD groups. These results further suggest that the drainage method does not influence postoperative outcomes.
SDD: Subdural drainage; SPGD: Subperiosteal or subgaleal drainage.
CSDH is one of the most common neurosurgical conditions [13, 33]. While surgical removal of the hematoma is standard, the precise method used for postoperative drainage remains controversial [22, 34]. Several meta-analyses have reported a significantly lower recurrence rate of CSDH in patients treated with SPGD (SPD/SGD) than in patients treated with SDD [35–38]. However, in the present analysis, we observed no significant difference in recurrence rates between the SPGD and SDD group. This may be because only two of the 15 included studies [9, 24] reported a significant difference in recurrence between SPGD and SDD. Additionally, five more studies were included in the present meta-analysis [19–23], and no significant effect on the recurrence rate was reported in these newly included studies. Compared to a recently published meta-analysis [39], we updated four studies (3 cohort studies [19, 21, 22] and 1 RCT [20]) with a total of 735 participants. Therefore, we performed an updated analysis with the four newly published studies. Besides, compared to the recent meta-analysis, further subgroup analysis based on different complications between the two drainage methods was conducted in the present study. The pooled data showed that there were no significant differences in mortality, which was consistent with previous studies [35–39]. Meanwhile, the present study proved that there was no significant difference in the incidence of postoperative infection, epilepsy and pneumocephalus between the two drainage methods. Additionally, in the present meta-analysis, a subgroup analysis of the SPGD group was performed, revealing no significant differences in recurrence rates between the SPD and SGD groups, although there was substantial heterogeneity among the studies (I2 = 55%). This may be because active aspiration was performed in both groups in the study by Sjåvik et al. [24] but not in other studies. Further analysis based on the three RCTs included in the present study (Soleman et al., Pathoumthong et al., and Kariaperumal et al.) [9, 20, 25] showed that there was no significant difference in recurrence rate, mortality and incidence of surgical complications between the SDD group and the SPGD group.
Our study had some limitations. First, the studies included in the present analysis were mostly retrospective or prospective. Therefore, any conclusions drawn are limited by their respective research designs, including memory and observation biases. In addition, the duration of follow-up varied among studies. Subacute and late complications may be more evident in studies with longer follow-up times, highlighting the need for additional long-term analyses. Besides, many of the outcomes in the present analysis were only reported by a few of the studies included. Future research may focus more on this issue.
Conclusion
The present results demonstrate that the choice of SDD vs. SPGD has no significant effect on the prognosis of patients with CSDH. Thus, SPGD may be an alternative treatment option for CSDH. Further studies with larger sample sizes are warranted to confirm this finding.
Supporting information
S3 Appendix. Newcastle-Ottawa quality assessment scale.
https://doi.org/10.1371/journal.pone.0288872.s003
(DOCX)
References
- 1. Wei Z, Jiang H, Wang Y, Wang C. Effect of Twist-Drill Craniostomy With Hollow Screws for Evacuation of Chronic Subdural Hematoma: A Meta-Analysis. Frontiers in neurology. 2021;12:811873. pmid:35153988
- 2. Adhiyaman V, Chattopadhyay I, Irshad F, Curran D, Abraham S. Increasing incidence of chronic subdural haematoma in the elderly. QJM. 2017;110(6):375–8. pmid:28069915
- 3. Tang G, Chen J, Li B, Fang S. The Efficacy of Adjuvant Corticosteroids in Surgical Management of Chronic Subdural Hematoma: A Systematic Review and Meta-Analysis. Frontiers in neurology. 2021;12:744266. pmid:35095713
- 4. Edlmann E, Giorgi-Coll S, Whitfield PC, Carpenter KLH, Hutchinson PJ. Pathophysiology of chronic subdural haematoma: inflammation, angiogenesis and implications for pharmacotherapy. J Neuroinflammation. 2017;14(1):108. pmid:28558815
- 5. Uno M, Toi H, Hirai S. Chronic Subdural Hematoma in Elderly Patients: Is This Disease Benign? Neurologia medico-chirurgica. 2017;57(8):402–9. pmid:28652561
- 6. Agawa Y, Mineharu Y, Tani S, Adachi H, Imamura H, Sakai N. Bilateral Chronic Subdural Hematoma is Associated with Rapid Progression and Poor Clinical Outcome. Neurologia medico-chirurgica. 2016;56(4):198–203. pmid:26923835
- 7. Peng D, Zhu Y. External drains versus no drains after burr-hole evacuation for the treatment of chronic subdural haematoma in adults. The Cochrane database of systematic reviews. 2016;2016(8):Cd011402. pmid:27578263
- 8. Yu W, Chen W, Jiang Y, Ma M, Zhang W, Zhang X, et al. Effectiveness Comparisons of Drug Therapy on Chronic Subdural Hematoma Recurrence: A Bayesian Network Meta-Analysis and Systematic Review. Frontiers in pharmacology. 2022;13:845386. pmid:35401183
- 9. Soleman J, Lutz K, Schaedelin S, Kamenova M, Guzman R, Mariani L, et al. Subperiosteal vs Subdural Drain After Burr-Hole Drainage of Chronic Subdural Hematoma: A Randomized Clinical Trial (cSDH-Drain-Trial). Neurosurgery. 2019;85(5):E825–e34. pmid:31194877
- 10. Oral S, Borklu RE, Kucuk A, Ulutabanca H, Selcuklu A. Comparison of subgaleal and subdural closed drainage system in the surgical treatment of chronic subdural hematoma. Northern clinics of Istanbul. 2015;2(2):115–21. pmid:28058351
- 11. Santarius T, Kirkpatrick PJ, Ganesan D, Chia HL, Jalloh I, Smielewski P, et al. Use of drains versus no drains after burr-hole evacuation of chronic subdural haematoma: a randomised controlled trial. Lancet (London, England). 2009;374(9695):1067–73. pmid:19782872
- 12. Amirjamshidi A, Abouzari M, Eftekhar B, Rashidi A, Rezaii J, Esfandiari K, et al. Outcomes and recurrence rates in chronic subdural haematoma. British journal of neurosurgery. 2007;21(3):272–5. pmid:17612917
- 13. Soleman J, Kamenova M, Lutz K, Guzman R, Fandino J, Mariani L. Drain Insertion in Chronic Subdural Hematoma: An International Survey of Practice. World neurosurgery. 2017;104:528–36. pmid:28461277
- 14. Zhang JJY, Wang S, Foo ASC, Yang M, Quah BL, Sun IS, et al. Outcomes of Subdural Versus Subperiosteal Drain After Burr-Hole Evacuation of Chronic Subdural Hematoma: A Multicenter Cohort Study. World neurosurgery. 2019;131:e392–e401. pmid:31369879
- 15. Chih AN, Hieng AW, Rahman NA, Abdullah JM. Subperiosteal Drainage versus Subdural Drainage in the management of Chronic Subdural Hematoma (A Comparative Study). The Malaysian journal of medical sciences: MJMS. 2017;24(1):21–30.
- 16. Cumpston M, Li T, Page MJ, Chandler J, Welch VA, Higgins JP, et al. Updated guidance for trusted systematic reviews: a new edition of the Cochrane Handbook for Systematic Reviews of Interventions. The Cochrane database of systematic reviews. 2019;10:ED000142. pmid:31643080
- 17. Stang A, Jonas S, Poole C. Case study in major quotation errors: a critical commentary on the Newcastle-Ottawa scale. Eur J Epidemiol. 2018;33(11):1025–31. pmid:30259221
- 18. Nakaguchi H, Tanishima T, Yoshimasu N. Factors in the natural history of chronic subdural hematomas that influence their postoperative recurrence. Journal of neurosurgery. 2001;95(2):256–62. pmid:11780895
- 19. Singh J, Sobti S, Chaudhary A, Chaudhary V, Garg T. Comparative Study of Subgaleal and Subdural Closed Drain in Surgically Treated Cases of Chronic Subdural Hematoma. Asian journal of neurosurgery. 2021;16(1):96–8. pmid:34211874
- 20. Pathoumthong K, Jetjumnong C. Comparative study of subdural drain (SDD) versus sub periosteal drain (SPD) in treating patient with chronic subdural hematoma (CSDH). Surgical neurology international. 2021;12:421. pmid:34513185
- 21. Kamenova M, Wanderer S, Lipps P, Marbacher S, Mariani L, Soleman J. When the Drain Hits the Brain. World neurosurgery. 2020;138:e426–e36. pmid:32147547
- 22. Hwang Y, Choi S, Kim YS, Park JS, Choi JH, Jeun SS, et al. Comparative analysis of safety and efficacy in subperiosteal versus subdural drainage after burr-hole trephination for chronic subdural hematoma. Clinical neurology and neurosurgery. 2022;212:107068. pmid:34847484
- 23. Gazzeri R, Laszlo A, Faiola A, Colangeli M, Comberiati A, Bolognini A, et al. Clinical investigation of chronic subdural hematoma: Relationship between surgical approach, drainage location, use of antithrombotic drugs and postoperative recurrence. Clinical neurology and neurosurgery. 2020;191:105705. pmid:32035359
- 24. Sjåvik K, Bartek J Jr, Sagberg LM, Henriksen ML, Gulati S, Ståhl FL, et al. Assessment of drainage techniques for evacuation of chronic subdural hematoma: a consecutive population-based comparative cohort study. Journal of neurosurgery. 2017:1–7. pmid:28644099
- 25. Kaliaperumal C, Khalil A, Fenton E, Okafo U, Kaar G, O’Sullivan M, et al. A prospective randomised study to compare the utility and outcomes of subdural and subperiosteal drains for the treatment of chronic subdural haematoma. Acta neurochirurgica. 2012;154(11):2083–8; discussion 8–9. pmid:22932864
- 26. Ishfaq A. Outcome in Chronic Subdural Hematoma After Subdural vs. Subgaleal Drain. Journal of the College of Physicians and Surgeons—Pakistan: JCPSP. 2017;27(7):419–22. pmid:28818164
- 27. Häni L, Vulcu S, Branca M, Fung C, Z’Graggen WJ, Murek M, et al. Subdural versus subgaleal drainage for chronic subdural hematomas: a post hoc analysis of the TOSCAN trial. Journal of neurosurgery. 2019:1–9. pmid:31470410
- 28. Glancz LJ, Poon MTC, Coulter IC, Hutchinson PJ, Kolias AG, Brennan PM. Does Drain Position and Duration Influence Outcomes in Patients Undergoing Burr-Hole Evacuation of Chronic Subdural Hematoma? Lessons from a UK Multicenter Prospective Cohort Study. Neurosurgery. 2019;85(4):486–93. pmid:30169738
- 29. Bellut D, Woernle CM, Burkhardt JK, Kockro RA, Bertalanffy H, Krayenbühl N. Subdural drainage versus subperiosteal drainage in burr-hole trepanation for symptomatic chronic subdural hematomas. World neurosurgery. 2012;77(1):111–8. pmid:22154148
- 30. Lutz K, Kamenova M, Schaedelin S, Guzman R, Mariani L, Fandino J, et al. Time to and Possible Risk Factors for Recurrence after Burr-hole Drainage of Chronic Subdural Hematoma: A Subanalysis of the cSDH-Drain Randomized Controlled Trial. World neurosurgery. 2019;132:e283–e9. pmid:31479790
- 31. Abdullah HM, Dakurah T, Akoto H, Abaidoo B, Dakubo JCB, Yawson AE, et al. Predictors of recurrence of chronic subdural haematoma in a cohort study of patients presenting in a sub-Saharan African teaching hospital. BMC neurology. 2022;22(1):346. pmid:36104782
- 32. Grønhøj MH, Jensen TSR, Sindby AK, Miscov R, Hundsholt T, Debrabant B, et al. 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. Trials. 2022;23(1):213.
- 33. Zhu F, Wang H, Li W, Han S, Yuan J, Zhang C, et al. Factors correlated with the postoperative recurrence of chronic subdural hematoma: An umbrella study of systematic reviews and meta-analyses. EClinicalMedicine. 2022;43:101234. pmid:34988412
- 34. Greuter L, Lutz K, Fandino J, Mariani L, Guzman R, Soleman J. Drain type after burr-hole drainage of chronic subdural hematoma in geriatric patients: a subanalysis of the cSDH-Drain randomized controlled trial. Neurosurgical focus. 2020;49(4):E6. pmid:33002868
- 35. Xie Y, Lu Q, Lenahan C, Yang S, Zhou D, Qi X. A Comparison of Subperiosteal or Subgaleal Drainage with Subdural Drainage on the Outcomes of Chronic Subdural Hematoma: A Meta-Analysis. World neurosurgery. 2020;135:e723–e30. pmid:31899385
- 36. Pranata R, Deka H, July J. Subperiosteal versus subdural drainage after burr hole evacuation of chronic subdural hematoma: systematic review and meta-analysis. Acta neurochirurgica. 2020;162(3):489–98. pmid:31940094
- 37. Greuter L, Hejrati N, Soleman J. Type of Drain in Chronic Subdural Hematoma-A Systematic Review and Meta-Analysis. Frontiers in neurology. 2020;11:312. pmid:32390932
- 38. Ding H, Liu S, Quan X, Liao S, Liu L. Subperiosteal versus Subdural Drain After Burr Hole Drainage for Chronic Subdural Hematomas: A Systematic Review and Meta-Analysis. World neurosurgery. 2020;136:90–100. pmid:31927124
- 39. Henry J, Amoo M, Kissner M, Deane T, Zilani G, Crockett MT, et al. Management of Chronic Subdural Hematoma: A Systematic Review and Component Network Meta-analysis of 455 Studies With 103 645 Cases. Neurosurgery. 2022;91(6):842–55.