Table 1.
Summary of the characteristics of the included studies
| Reference | Study | Country | Study design | Total no | Inclusion criteria | Exclusion criteria | Study arms | Main findings | Age (mean ± SD, or range) | Male (%) | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Arm 1 (drain) | Arm 2 (no drain) | Arm 1 (drain) | Arm 2 (no drain) | Arm 1 (drain) | Arm 2 (no drain) | ||||||||
| [13] | Guilfoyle (2017) | England | RCT | 215 | - | - | 108 | 107 |
- At 5 years following surgery, the drain group continued to have significantly better survival than the no drain patients (P = 0.027) - Survival of patients in the drain group did not differ significantly from that of the general population whereas patients who did not receive a drain had significantly lower survival than expected (P = 0.0006) |
Both age of 78 years (range 35–95) | 74 | 26 | |
| [17] | Ayyappan Kutty (2013) | Turkey | RCT | 140 | All patients with radiologically proven chronic subdural hematoma, who had undergone burr hole evacuation for the same, between May 2005 and April 2011 |
1. Age less than 18 years 2. Oral anticoagulant use (warfarin) 3. Patients with bleeding diathesis |
70 | 70 |
- 11 out of 70 in no drain group had recurrence - Only 2 in no drain group had recurrence |
Both mean age 64.86 years and a median of 66 years | 79 | 83 | |
| [15] | Suryanarayanan (2014) | India | RCT | 200 | Patients with cSDH |
1. Patients with ipsilateral hematomas who had undergone CSF diversion within 6 months of presentation 2. Patients in whom surgery other than burr-hole evacuation was indicated 3. Patients not needing surgical treatment because of size of cSDH or clinical status of patients 4. Patients in whom brain completely surfaced after burr-hole drainage of CSDH |
100 | 100 |
- The recurrence between the two groups was statistically significant (P = 0.002) decrease in draining group - The difference for mortality in the two groups was statistically not significant (P = 0.744) |
- | - | - | |
| [14] | Santarius (2009) | United Kingdom | RCT | 215 | Patients with cSDH |
1. Patients with ipsilateral hematoma who had been treated within 6 months of presentation with a shunt for cerebrospinal fluid diversion in situ 2. Those in whom surgery other than burr-hole evacuation was indicated 3.Those in whom the operating surgeon judged drain insertion unsafe were also excluded |
108 | 107 |
- The rate of recurrence was significantly lower in the drain than in the no-drain group - Time-to-recurrence was longer in the drain - Mortality did not differ between groups - A discharge GCS of 15 was recorded in more participants with a drain than in those without |
- | 77 | 72 | |
| [21] | Laumer (1989) | Germany | RCT | 144 | Patients with cSDH | - | 97 | 47 |
- The rate of recurrence was significantly lower in the drain than in the no-drain group - High incidence of infection after operation in external drainage - No difference in incidence of seizure after operation between two groups |
- | - | - | |
| [22] | Tsutsumi (1997) | Japan | RCT | 90 |
cSDH was defined as including: 1. The presence of a typical neomembrane 2. Typical liquified blood within the hematoma cavity 3. If following acute SDH, at least 3 weeks had passed |
1. Hygromas 2. Infantile cSDHs, calcified or ossified cSDHs 3. Asymptomatic cSDHs |
53 | 37 |
- The rate of recurrence was significantly lower in the drain than in the no-drain group - The operative methods were correlated with magnetic resonance findings. In the high-intensity group, 1.1% of cSDHs recurred in patients in whom closed system drainage was used and 11.1% in patients without drainage - In the nonhigh-intensity group, 8.1% of cSDHs recurred in patients in whom closed system drainage was used and 23.1% in patients without drainage |
- | - | - | |
| [18] | Erol (2005) | Turkey | RCT | 70 | - | - | 35 | 35 | The most common etiological factor was trauma, complete resolution in the early period was higher in group B (burr-hole craniostomy-closed system drainage) compared to group A (burr-hole craniostomy-irrigation) (60% vs. 40%). Recurrence rates were 17% in group A and 14% in group B | 0–20, 1; 40–60, 12; > 60, 22 | 20–40, 3; 40–60, 13; > 60, 19 | 77% total men in the study | |
| [16] | Carlsen (2011) | Denmark | Cohort study | 344 | Difference protocols were used, patients unavailable for follow-up, re-operated because of acute subdural hematoma and primarily operated by craniotomy | 206 | 138 | There were no differences in the complication rates. Postoperative drainage reduces recurrence of chronic subdural hematoma without increasing the complication rate | - | - | |||
| [19] | Gurelik (2007) | Turkey | Randomized trial | 80 | - | - | 42 | 38 |
- No significant difference between recurrence rates of the two groups - No correlation between recurrence rate and age, sex, hematoma localization, or etiology |
58.4 | 59.2 | 67 | 58 |
| [20] | Javadi (2011) | Iran | RCT | 40 | - |
1. Child (18 years) 2. Midline shift 5 mm 3. Postshunt hematoma 4. Organized hematoma 5. Metastatic hematoma 6. Calcified hematoma |
20 | 20 |
- Loss of consciousness, and headache were the most common presentations - Recurrence occurred in one patient (5%) in burr-hole irrigation without drainage |
68 ± 17 | 65 ± 19 | 65 | 75 |
Abbreviations: cSDH chronic subdural hematoma, CSF cerebrospinal fluid, RCT randomized controlled trial, SD standard deviation