Assessment of drainage techniques for evacuation of chronic subdural hematoma: a consecutive population-based comparative cohort study

Reducing morbidity associated with subdural drain placement after burr-hole drainage of unilateral chronic subdural hematomas: a retrospective series comparing conventional and modified Nelaton catheter techniques

PURPOSE

Placement of a subdural drain after burr-hole drainage of chronic subdural hematoma (cSDH) significantly reduces risk of its recurrence and lowers mortality at 6 months. Nonetheless, measures to reduce morbidity related to drain placement are rarely addressed in the literature. Toward reducing drain-related morbidity, we compare outcomes achieved by conventional insertion and our proposed modification.

METHODS

In this retrospective series from two institutions, 362 patients underwent burr-hole drainage of unilateral cSDH with subsequent subdural drain insertion by conventional technique or modified Nelaton catheter (NC) technique. Primary endpoints were iatrogenic brain contusion or new neurological deficit. Secondary endpoints were drain misplacement, indication for computed tomography (CT) scan, re-operation for hematoma recurrence, and favorable Glasgow Outcome Scale (GOS) score (≥ 4) at final follow-up.

RESULTS

The 362 patients (63.8% male) in our final analysis included drains inserted in 56 patients by NC and 306 patients by conventional technique. Brain contusions or new neurological deficits occurred significantly less often in the NC (1.8%) than conventional group (10.5%) (P = .041). Compared with the conventional group, the NC group had no drain misplacement (3.6% versus 0%; P = .23) and significantly fewer non-routine CT imaging related to symptoms (36.5% versus 5.4%; P < .001). Re-operation rates and favorable GOS scores were comparable between groups.

CONCLUSION

We propose the NC technique as an easy-to-use measure for accurate drain positioning within the subdural space that may yield meaningful benefits for patients undergoing treatment for cSDH and vulnerable to complication risks.

Use of Novel Automated Active Irrigation With Drainage Versus Passive Drainage Alone for Chronic Subdural Hematoma-A Propensity Score-Matched Comparative Study With Volumetric Analysis

BACKGROUND

Passive drainage post-surgical evacuation of symptomatic chronic subdural hematoma (cSDH) is currently standard of care. High rates of infection, drain occlusion, and recurrence are associated complications.

OBJECTIVE

To explore the use of a novel double-lumen active automated irrigation and aspiration system, IRRAflow (IRRAS), for patients with cSDH and compared procedural and clinical outcomes against passive drainage alone with propensity score matching (PSM) and volumetric analysis.

METHODS

A prospectively maintained database was retrospectively searched for consecutive patients presenting with cSDH. One-to-one PSM of covariates (including baseline comorbidities and presentation hematoma volume) in active and passive irrigation groups was performed to adjust for treatment selection bias. Rates of hematoma clearance, catheter-related occlusion, and infection; number of revisions; and length of hospital stay were recorded.

RESULTS

This study included 55 patients: active continuous irrigation-drainage-21 (21 post-PSM) and passive drainage-34 (21 post-PSM). For PSM groups, a significantly higher rate of hematoma clearance was obtained in the active irrigation-drainage group (0.5 ± 0.4 vs 0.4 ± 0.5 mL/day) and in the passive drainage group; odds ratio (OR) = 1.291 (CI: 1.062-1.570, P = .002) and a significantly lower rate of catheter-related infections (OR = 0.051; CI: 0.004-0.697, P = .039). A nonsignificantly lower hematoma expansion rate at discharge was noted in the active irrigation-drainage group (4.8% vs 23.8%; OR = 0.127; P = .186). No statistical difference in all-cause in-hospital mortality or discharge Glasgow Coma Scale score was observed between groups.

CONCLUSION

Active and automated continuous irrigation plus drainage after cSDH surgical evacuation resulted in faster hematoma clearance and led to favorable clinical outcomes and low complication and revision rates compared with passive irrigation.

Effect of Irrigation Fluid Temperature on Recurrence in the Evacuation of Chronic Subdural Hematoma: A Randomized Clinical Trial

Importance

The effect of a physical property of irrigation fluid (at body vs room temperature) on recurrence rate in the evacuation of chronic subdural hematoma (cSDH) needs further study.

Objective

To explore whether irrigation fluid temperature has an influence on cSDH recurrence.

Design, Setting, and Participants

This was a multicenter randomized clinical trial performed between March 16, 2016, and May 30, 2020. The follow-up period was 6 months. The study was conducted at 3 neurosurgical departments in Sweden. All patients older than 18 years undergoing cSDH evacuation during the study period were screened for eligibility in the study.

Interventions

The study participants were randomly assigned by 1:1 block randomization to the cSDH evacuation procedure with irrigation fluid at room temperature (RT group) or at body temperature (BT group).

Main Outcomes and Measures

The primary end point was recurrence requiring reoperation within 6 months. Secondary end points were mortality, health-related quality of life, and complication frequency.

Results

At 6 months after surgery, 541 patients (mean [SD] age, 75.8 [9.8] years; 395 men [73%]) had a complete follow-up according to protocol. There were 39 of 277 recurrences (14%) requiring reoperation in the RT group, compared with 16 of 264 recurrences (6%) in the BT group (odds ratio, 2.56; 95% CI, 1.38-4.66; P < .001). There were no significant differences in mortality, health-related quality of life, or complication frequency.

Conclusions and Relevance

In this study, irrigation at body temperature was superior to irrigation at room temperature in terms of fewer recurrences. This is a simple, safe, and readily available technique to optimize outcome in patients with cSDH. When irrigation is used in cSDH surgery, irrigation fluid at body temperature should be considered standard of care.

Trial Registration

ClincalTrials.gov Identifier: NCT02757235.

The Role of Active or Passive Drainage after Evacuation of Chronic Subdural Hematoma: An Analysis of Two Randomized Controlled Trials (cSDH-Drain-Trial and TOSCAN Trial)

The evacuation of a chronic subdural hematoma (cSDH) is one of the most common procedures in neurosurgery. The aim of this study was to assess the influence of drainage suction in the surgical treatment of cSDH on the recurrence rate. Post hoc analysis was conducted on two randomized controlled trials (cSDH-Drain-Trial and TOSCAN trial) stratifying a total of 581 patients into active or passive drain type. Of the 581 patients, 359 (61.8%) and 220 (37.9%) were stratified into the active and passive drainage groups, respectively. The reoperation rate following postoperative recurrence was 23.1% and 14.1% in the active and passive drainage groups, respectively (p < 0.011). After propensity score matching, the differences in recurrence rate remained significant (26.6% versus 15.6%, p = 0.012). However, the functional outcome (mRS) at 6−12 months did not differ significantly (median [IQR]) between the 2 groups (passive drainage group 0.00 [0.00, 2.00], active drainage group 1.00 [0.00, 2.00], p = 0.431). Mortality was comparable between the groups (passive drainage group 12 (5.5%), active drainage group 20 (5.6%), p = 0.968). In the univariate analysis, active drainage, short (<48 h) duration of drainage, and early (<48 h) postoperative mobilization were significantly associated with a higher recurrence rate. However, the multivariate logistic regression model could not confirm that any of these parameters were significantly associated with recurrence. Our post hoc analysis proposes that using a passive instead of an active drain might be associated with a reduced recurrence rate after evacuation of a cSDH. We suggest gathering further evidence by means of a randomized controlled trial.

Burr hole craniostomy versus minicraniotomy in chronic subdural hematoma: a comparative cohort study

Background

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical diseases. In surgical management of CSDH, there is a lack of standardized guidelines concerning surgical techniques and a lack of consensus on which technique(s) are optimal. Neurosurgical centers have shown a wide variation in surgical techniques. The purpose of this study was to compare two different surgical techniques, one burr hole craniostomy with an active subgaleal drain (BHC) and minicraniotomy with a passive subdural drain (MC).

Methods

We conducted a multicenter retrospective cohort study at two neurosurgical centers in Sweden which included patients with unilateral CSDHs that received surgical treatment with either BHC or MC. The primary outcomes in comparison of the techniques were 30-day mortality, recurrence rate, and complications according to the Landriel Ibañez grading system for complications.

Results

A total of 1003 patients were included in this study. The BHC subgroup included 560 patients, and the MC subgroup included 443 patients. A 30-day mortality when comparing BHC (2.3%) and MC (2.7%) was similar (p = 0.701). Comparing recurrence rate for BHC (8.9%) and MC (10.8%) showed no significant difference (p = 0.336). We found that medical complications were significantly more common in the MC group (p = 0.001). Surgical complications (type IIb) was also associated with the MC group (n = 10, p = 0.003). Out of the 10 patients with type IIb complications in the MC group, 8 had postoperative acute subdural hematomas.

Conclusions

BHC was comparable to MC concerning 30-day mortality rate and recurrence rates. We did, however, find that MC was significantly associated with medical complications and serious surgical postoperative complications.

Use of Automated Irrigating Drainage System in Six Patients With Chronic Subdural Hematoma: A Single-Center Experience

Background

Chronic subdural hematoma (cSDH) is predicted to become the most common intracranial neurosurgical condition by 2030. Recurrence is estimated between 5-15%, and the use of a surgical drain is associated with lower recurrence rates. The authors present their experience with six patients undergoing cSDH evacuation with an irrigating drainage system, comprising the largest single-institution group in the United States (US).

Methods

IRB-approved, retrospective chart review was performed for six patients who underwent irrigating surgical drain placement during cSDH evacuation. Outcome measures included device settings and duration of the irrigating drain, postoperative length of stay, neurological status at follow-up, and hematoma recurrence.

Results

There were no recurrences noted within this group at last follow-up, with an average follow-up length over three months. The average postoperative length of stay was 2.67 ± 0.51 days. Patients were drained on average for 1.41 ± 0.49 days at 0cm water, irrigating at 55.25 ± 46.44cc/hr. On postoperative day one, average hematoma size and midline shift (MLS) reduction were respectively 13.43 ± 3.31mm and 5.71 ± 1.33mm. No device-related complications were noted.

Conclusion

The authors' early experience with this irrigating drainage device demonstrates that it is safe and effective for this population. Although this is a preliminary study on a small sample size, the excellent results warrant further investigation and establishment of a standard protocol to compare against current treatment regimens.

Incidence of surgery for chronic subdural hematoma in Finland during 1997-2014: a nationwide study

OBJECTIVE

The number of surgeries performed for chronic subdural hematoma (CSDH) has increased. However, these changes have been poorly reported. The authors aimed to assess the national incidence of surgeries for CSDH in Finland during an 18-year time period from 1997 to 2014. They hypothesized that the incidence of CSDH surgeries has continued to increase, particularly among the elderly.

METHODS

A nationwide register-based follow-up study was performed using the Finnish Care Register for Health Care. All adult patients undergoing primary CSDH surgeries during 1997-2014 were included. The study population was followed up from the time of CSDH surgery until death or the end of follow-up on December 31, 2017. The incidences of CSDH surgery per 100,000 person-years were calculated separately in each age group and sex. Age standardization was performed for those 20 years of age and older with weights from the 2013 European Standard Population. Negative binomial regression models were used to assess changes in incidence rate ratios (IRRs) during the study period.

RESULTS

In total, 9280 patients were identified. The age-standardized incidence of CSDH surgery increased from 12.2 to 16.5 per 100,000 person-years during 1997-2014. The age- and sex-adjusted incidence of CSDH surgery increased by 30% (IRR 1.30, 95% CI 1.20-1.41). The age- and sex-adjusted incidence increased more in the older age groups, with an IRR of 1.24 for those aged 60-69 years, 1.32 for those 70-79 years, 1.46 for those 80-89 years, and 1.85 for those aged 90 years or older. The adjusted incidence did not increase for those aged 18-59 years. The sex difference (2:1 men/women) was consistent throughout the study period, with a higher incidence among men. One year after the primary surgery, 19% of the population had a resurgery, and the 1-year case fatality rate was 15%. The median age of patients increased from 73 to 76 years.

CONCLUSIONS

During the past 2 decades, the age- and sex-adjusted incidence of CSDH surgery has increased in Finland, with major increases for those aged 60 years or older. This increase is likely to continue in parallel with the aging population and increased life expectancies.

Awake surgery in sitting position for chronic subdural hematoma

BACKGROUND

Chronic subdural hematoma (CSDH) is a common pathology in neurosurgery, especially in the elderly patients, and its incidence is likely to double in the next decade. Considering various features of CSDH and the procedure itself, a sitting position may retain the best characteristics of classic positioning, while offering additional comfort for both the patient and the surgeon. The aim of this study was to describe the technical aspects of this procedure in the sitting position, to evaluate safety and discuss the benefits and shortcomings of this modification.

METHOD

This study included a series of 55 patients surgically treated for CSDH in a sitting position at our department between December 2017 and September 2019, representing all the patients operated on during the study period by a single surgeon. Bilateral hematomas were present in 19 patients. Outcomes, during the 6-month follow-up period, were defined as good (CSDH and symptoms resolved) or poor (lethal outcome or reoccurrence). All complications were noted, with emphasis on pneumocephalus, and complications related to the sitting position: tension pneumocephalus, venous air embolism, and compression nerve injury.

RESULTS

Complications previously associated with the sitting position were not noted. The Glasgow Coma Scale and Markwalder Grading Scale scores improved significantly after the surgery (p < 0.001 and p = 0.018). Complications were noted in 17 patients (30.9%), and included 5 cerebrospinal fluid drainages, 3 hematoma reoccurrences, 2 wound infections, and 9 more single-occurring complications. The in-hospital mortality was 5.4% (3 out of 55 patients), while the overall mortality was 16.4% within the 6-month follow-up period.

CONCLUSIONS

In our series, even the severely ill patients tolerated the position well. No complications associated with the sitting position were noted. Future studies should confirm the safety of this position and evaluate the potential advantages for both the patient and the surgeon.

Risk factors for need of reoperation in bilateral chronic subdural haematomas

Background

Chronic subdural haematoma (CSDH) is one of the most common neurosurgical diseases. A subtype of CSDH is bilateral chronic subdural haematoma (bCSDH) which represents 20–25% of patients with CSDH and has a higher recurrence rate. There is no clear consensus on how bCSDH should be treated regarding upfront unilateral- or bilateral evacuation of both haematomas. The purpose of this study was to identify risk factors associated with reoperation of bCSDH.

Methods

A total of 326 patients with radiological evidence of bCSDH were included in this retrospective cohort study where 133 (40.8%) patients underwent primary bilateral evacuation and 193 (59.2%) primary unilateral evacuation. The two centres operated using different surgical approaches. Analyses were performed to identify risk factors associated with reoperation of bCSDH. Reoperation rate was defined as reoperation of CSDH on either side of the hemisphere within 3 months after primary evacuation.

Results

The cohort had a total reoperation rate of 26.4%. Patients which underwent unilateral evacuation had a reoperation rate of 32.1%, and the bilateral group had a reoperation rate of 18.0% (p=0.005). Multivariable logistic regression identified unilateral evacuation (OR 1.91, p=0.022) and complications according to Ibanez (OR 2.20, p=0.032) to be associated with the need of reoperation of bCSDH. One-burr hole craniostomy with active subgaleal drain was primarily performed in bilateral approach (69.4%) whereas patients operated with minicraniotomy with passive subdural drain were primarily operated by unilateral evacuation of the larger symptomatic side (92.8%).

Conclusions

Unilateral evacuation of bCSDH was associated with a higher risk for reoperation than upfront bilateral evacuations in this study. There is a need to further discuss the criteria for uni- or bilateral evacuation since patients are treated differently at different centres.

Net Drainage as a Novel Metric for Irrigating Drainage Systems in Chronic Subdural Hematoma Management: A Case Report

BACKGROUND AND IMPORTANCE

Chronic subdural hematoma (cSDH) is a common neurosurgical pathology with a projected increase in prevalence as the elderly population grows. Traditional treatment for cSDH involves burr hole drainage or craniotomy with or without a subdural drain. This case describes a novel irrigation and drainage protocol using IRRAflow dual-lumen catheter system that utilizes early irrigation and measurement of the net fluid output to improve postoperative outcomes.

CLINICAL PRESENTATION

A 75-yr-old male presented to the emergency department with 2 wk of progressive dizziness, headache, confusion, and left-sided weakness over the past week. Computed tomography (CT) of the head showed 25-mm-thick, right-sided cSDH with 7 mm of right-to-left midline shift. The patient was taken to the operating room for right-sided craniotomy for subdural hematoma evacuation with placement of IRRAflow irrigating drain in the subdural space. The IRRAflow drain irrigated at 100 cc/h for 23 h with net output consistently greater than irrigation rate. Head CT the following day showed a progressive decrease in subdural collection. The patient was discharged on postoperative day 2 and had complete resolution of his neurological symptoms by postoperative day 11.

CONCLUSION

As cSDHs become more prevalent in the aging population, development of improved management strategies is imperative. This report describes the use of an IRRAflow dual-lumen catheter with a novel protocol consisting of a high rate of irrigation but net fluid output, which led to rapid recovery and resolution of neurological deficits in a patient with a cSDH.

Subdural drainage techniques for single burr-hole evacuation of chronic subdural hematoma: two drains frontal-occipital position versus one drain frontal position

OBJECTIVE

Burr-hole craniostomy with a closed drainage system is the most commonly used technique for chronic subdural hematoma(CSDH), but the reoperation rate for hematoma recurrence is still high. This retrospective study aimed to compare the complications and recurrence of two subdural drains placement with tips frontal-occipital position (TFOP) versus one subdural drain placement with tip frontal position(OFP) following single burr-hole evacuation for the treatment of chronic subdural hematoma(CSDH).

METHODS

The authors analyzed data of all CSDH patients who underwent single burr-hole surgery with placement of subdural closed-drainage system(TFOP or OFP techniques) between January 2013 and December 2017. Data analysis included general patient data, complications, recurrence and clinical outcome.

RESULTS

A total of 331 patients were included(85 TFOP and 246 OFP). The TFOP group and OFP group were statistically comparable with respect to baseline characteristics except for preoperative Markwalder score (p = 0.019). Midline shift and subdural fluid thickness on first postoperative day were greater in OFP group than the TFOP group (p = 0.028; and p = 0.007, respectively). In addition, patients with OFP had a lower percent of hematoma change after surgery and much more residual subdural air than those with TFOP (p = 0.001; and p < 0.001, respectively). Postoperative complications and clinical outcome between the two groups showed no significant differences. During the 3-month follow-up, the rate of hematoma recurrence was significantly lower among patients treated with TFOP than those treated with OFP (p = 0.039).

CONCLUSIONS

The postoperative complications rate did not differ between TFOP group and OFP group for patients with CSDH. Considering the lower rate of recurrence, TFOP following single burr-hole evacuation might be a safe and promising option for CSDH treatment.

Preoperative antibiotic prophylaxis regimen in brain tumour surgery in Sweden: a quasi-experimental study

Background

There has been varied clinical practice concerning antibiotic prophylaxis in patients undergoing craniotomy. In Sweden, both Cloxacillin and Cefuroxime have frequently been used. We aimed to study the clinical effectiveness of these two regimens.

Methods

A quasi-experimental design was used. The sample consisted of 580 adult (> 18 years) patients operated 2012–2015, of which 375 received Cloxacillin (pre-intervention group) and 205 received Cefuroxime (intervention group). Primary endpoint was the incidence of surgical site infection (SSI) 12 months after surgery, while secondary endpoints were the need for reoperation due to SSI, the amount antibiotics used and the number of visits in the outpatient clinic related to SSI. A control group from another institution was reviewed to rule out clinical trial effects.

Results

When analysed by intention to treat, the pre-intervention group had a significant higher incidence of SSI, 13.3% (50/375) vs 5.4% (11/205) in the intervention group (p < 0.01). A treatment per protocol analysis confirmed the result. The number of reoperations due to SSI were significantly reduced in the intervention group, 3.4% (7/205) vs 8.3% (31/375) (p = 0.02), as was the total antibiotic use (p = 0.03) and the number of visits in the outpatient clinic (p < 0.01). In the control group, the reoperation rate as result of SSI was lower (p = 0.02) prior to the opposite change from Cefuroxime to Cloxacillin, 1.8% (27/1529) vs 3.1% (43/1378).

Conclusion

In Sweden, Cefuroxime as prophylaxis in brain tumour surgery by craniotomy seems to be superior to Cloxacillin.

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.

Type of Drain in Chronic Subdural Hematoma-A Systematic Review and Meta-Analysis

Background: Chronic subdural hematoma (cSDH) is one of the most common neurosurgical diseases, while burr-hole drainage is the most frequently used surgical treatment. Strong evidence exists that subdural drain (SDD) placement reduces recurrence rates. However, the insertion of a subperiosteal drain (SPD) was shown to lead to similar recurrence rates and less complications than SDD. The aim of this study is to provide a systematic review of the literature and conduct a meta-analysis of studies comparing SPD with SDD after burr-hole drainage of cSDH.

Methods: Pubmed and Embase databases were searched using a systematic search strategy to identify studies on drain location up to December 2019. Two independent researchers assessed the studies for inclusion and quality. Primary outcome measure was recurrence, while secondary outcome measures were drain misplacement, morbidity, mortality, and clinical outcome. Besides randomized controlled trials (RCT), we included non-randomized prospective cohort studies, as well as retrospective cohort studies. A fixed effects model was used if low heterogeneity (I² < 50%) was present, otherwise a random effects model was used.

Results: Following removal of duplicates, we screened 1109 articles of which 10 articles were included in our qualitative and quantitative analyses. One study was an RCT, three were non-randomized prospective cohort studies, and the remaining articles were retrospective cohort studies or subgroup analysis. In these 10 articles, 1,553 patients were treated with SPD and 1782 patients with SDD. Comparing the recurrence rate of cSDH a significant difference was found between SPD and SDD insertion (11.9 and 12.3%; RR 0.8, 95% CI 0.67–0.97, I² = 0%, z = −2.27, p = 0.02). SPD had significantly lower rates of drain misplacement and parenchymal injuries (1.2 and 7.8%; RR 0.17, 95% CI 0.07–0.42, I² = 0%, z = −3.4, p = 0.0001), as well as morbidity (6.4 and 8.2%; RR 0.65, 95% CI 0.5–0.84, I² = 44.5%, z = −3.32, p =0.0009). Mortality rates (5.0 and 4.6%; RR 0.83, 95% CI 0.6–1.14, I² = 0%, z = −1.2, p = 0.25) and favorable clinical outcome (89.6 and 88.9%; RR 1.1, 95% CI 0.89–1.24, I² = 54.2%, t = 0.98, p = 0.40) were comparable in both groups.

Conclusion: The insertion of SPD after burr-hole drainage of cSDH showed lower rates of recurrence, drain misplacements and parenchymal injuries, as well as overall morbidity, while clinical outcome and mortality were comparable to SDD. Therefore, the insertion of SPD after surgical drainage of cSDH should be encouraged.

The influence of irrigation fluid temperature on recurrence in the evacuation of chronic subdural hematoma

Background

Chronic subdural hematomas (cSDH) are one of the most common conditions requiring neurosurgical treatment. The reported recurrence after surgery is 3–21.5% with closed system drainage. In clinical practice, irrigation fluids at body temperature (37 °C) and at room temperature (22 °C) are routinely used in the evacuation of cSDH. Our hypothesis was that irrigation at body temperature might have more beneficial effects on coagulation and solubility of the chronic subdural hematoma than irrigation at room temperature. The aim of this study was to compare the effects of different intraoperative irrigation fluid temperatures on recurrence rates.

Methods

This was a retrospective study where we included all consecutive patients from a defined geographical area of western Sweden between September 2013 and November 2014. In the course of 6 months, we performed intraoperative irrigation at body temperature (37 °C, BT-group) during burr hole evacuation of chronic subdural hematoma. This was then compared with the previous 6-month period, when irrigation fluid at room temperature (22 °C, RT-group) was used. The primary endpoint was same-sided recurrence in need of reoperation within 6 months.

Results

Recurrence occurred in 11 of 84 (13.1%) patients in the RT-group compared with 4 of 88 (4.5%) in the BT-group (p = 0.013). There were no significant between-group differences regarding age, sex, duration of surgery, frequency of bilateral hematomas, hematoma density, and use of anticoagulant/antithrombotic therapy.

Conclusion

Our study demonstrates that intraoperative irrigation fluid at body temperature is associated with lower recurrence rates compared with irrigation fluid at room temperature. To investigate this further, a prospective randomized controlled trial has been initiated (clinicaltrials.gov, NCT0275235).

Trial registration

ClinicalTrials.gov Identifier: NCT0275235

Subperiosteal versus subdural drainage after burr hole evacuation of chronic subdural hematoma: systematic review and meta-analysis

BACKGROUND

The evidence for subperiosteal drainage (SPD) versus subdural drainage (SDD) in chronic subdural hematoma (CSDH) remains controversial, and most surgeons prefer to use SDD over SPD. We aim to assess the latest evidence on the use of SPD compared to SDD in patients with CSDH undergoing burr hole evacuation.

METHODS

We performed a systematic literature search on topics that assesses the use of SPD compared to SDD in patients with CSDH up until November 2019 from PubMed, EuropePMC, Cochrane Central Database, ScienceDirect, ProQuest, and ClinicalTrials.gov. The primary outcome was recurrent CSDH, and the secondary outcomes were mortality, surgical morbidities, and modified Rankin Score (mRS).

RESULTS

There were a total of 3241 subjects from 10 studies. SPD was shown to reduce recurrent CSDH (OR 0.66 [0.52, 0.84], p < 0.001; I²: 17%, p = 0.30) compared to SDD. Recurrent CSDH was lower in SPD group in subgroup analysis at 3-months (OR 0.63 [0.49, 0.81]; I²: 68%, p = 0.04) and 6-months (OR 0.66 [0.51, 0.85], p = 0.001; I²: 77%, p = 0.01) follow-up. However, there was no difference in CSDH recurrence upon subgroup analysis of RCTs. Similar mortality was demonstrated between SPD and SDD group (p = 0.13). The occurrence of parenchymal injury/new neurological deficit was significantly lower in SPD group (OR 0.26 [0.14, 0.51], p < 0.001; I²: 49%, p = 0.08). The rate of seizure, (p = 0.57), postoperative bleeding (p = 0.29), and infection (p = 0.25) were shown to be similar in both SPD and SDD group. Overall, the rate of surgical morbidity was significantly lower in SPD group (OR 0.61 [0.44, 0.85], p = 0.003; I²: 16%, p = 0.25). mRS at the end of follow-up was similar in SPD and SDD group (p = 0.12).

CONCLUSION

SPD was associated with less CSDH recurrence, but similar rate of mortality, seizures, postoperative bleeding, and infections compared to SDD. The rate of parenchymal injury/new neurological deficit was lower in the SPD group.

Hawthorne effect on surgical studies

BACKGROUND

The Hawthorne effect or 'observer effect' describes a change in normal behaviour when individuals are aware they are being observed. This may have an impact on effect estimates in clinical trials. The purpose of this study was to determine if the Hawthorne effect had been recorded as a risk of bias in surgical studies.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses compliant literature search was conducted till March 2019. Eligible studies included those reporting or not reporting the Hawthorne effect in surgical studies from the following databases: MEDLINE, Embase, CINAHL, AMED, BNI, HMIC, PsycINFO, Web of Science, Cochrane Library, Google Scholar and OpenGrey. Two reviewers independently reviewed the papers, extracted data and appraised study methods using the Newcastle Ottawa Scale or the Cochrane risk of bias tool. Data were analysed descriptively.

RESULTS

A total of 842 papers were identified, of which 16 were eligible. Six (37%) observational studies were identified with the aim of measuring the Hawthorne effect on their outcome with five reporting that the Hawthorne effect was responsible for the improvements in outcomes and one reporting no change in outcome due to the Hawthorne effect. Ten (63%) studies were identified, of which eight used the Hawthorne effect as an explanation to improvements seen in the control group or their secondary outcomes and two to compare their results with other studies.

CONCLUSION

There is considerable between-study heterogeneity on how the Hawthorne effect relates to surgical outcomes. Further consideration on reporting and considering the importance of the Hawthorne effect in the design of surgical trials is warranted.

Clinical and radiological factors predicting recurrence of chronic subdural hematoma: A retrospective cohort study

BACKGROUND

Chronic subdural hematoma (CSDH) is commonly encountered in the elderly patients and the recurrence rate is still high, therefore, identifying risk factors for CSDH recurrence is essential. The present study aimed to identify clinical and radiological factors predicting the recurrence of CSDH.

METHODS

We retrospectively identified 461 patients with CSDH who underwent surgical evacuation in our department. Univariable analyses were performed at first, variables with a P-value of <0.05 were entered into multivariable logistic regression model. Kendall's tau-b test was used to evaluate the relationship between brain atrophy and postoperative pneumocephalus.

RESULTS

Univariable analyses revealed that patients with the following characteristics have a higher recurrence rate, including age ≥80 years, antiplatelet and/or anticoagulant use, GOS = 3, the volume of drainage ≥100 ml, midline shift ≥10 mm, severe brain atrophy, severe postoperative pneumocephalus. Multivariable logistic regression demonstrated that midline shift ≥10 mm, severe brain atrophy, severe postoperative pneumocephalus, and volume of drainage ≥100 ml were independent risk factors for CSDH recurrence. Kendall's tau-b test revealed that there was no correlation between brain atrophy and postoperative pneumocephalus.

CONCLUSIONS

Midline shift ≥10 mm, severe brain atrophy, severe postoperative pneumocephalus, and volume of drainage ≥100 ml were independent risk factors for CSDH recurrence, CSDH patients with these characteristics should be taken precautions of recurrence and a closely follow-up should be carried out.

Standardized assessment of outcome and complications in chronic subdural hematoma: results from a large case series

INTRODUCTION

Chronic subdural hematomas (cSDH) are commonly deemed to have a benign prognosis. However, detailed and standardized data describing outcome and complications in a large prospective patient cohort is lacking.

METHODS

Retrospective analysis of prospectively collected data in our institutional patient registry on consecutive patients undergoing surgery for cSDH from 2013 to 2017. Complications were assessed according to the Clavien-Dindo grading system (CDG). The outcome was measured with respect to two endpoints: occurrence of a complication with CDG 3-5 and lack of improvement in Karnofsky Performance Status (KPS) at the last follow-up.

RESULTS

Out of 435 operations, 166 (38.3%) presented a complication until 3 months postoperative (CDG 1, 23 (5.3%); CDG 2, 62 (14.3%); CDG 3a, 7 (1.6%); CDG 3b, 64 (14.7%); CDG 4a, 2 (0.5%); and CDG 5, 8 (1.8%)). Higher CDG correlated with a lower KPS (r_s = - 0.27, p < 0.001). A lack of improvement in KPS was associated with a Charlson Comorbidity Index (CCI) > 1 and the iso- or hypodense appearance of the cSDH.

CONCLUSIONS

This study provides a reliable estimate of the rate of medical and surgical complications in cSDH surgery. Complications that required a surgical intervention turned out to be rare. Recording complications in a standardized and prospective fashion can therefore serve as a basis for assessing patient outcome and quality control within the department.

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.

Subperiosteal vs Subdural Drain After Burr-Hole Drainage of Chronic Subdural Hematoma: A Randomized Clinical Trial (cSDH-Drain-Trial)

BACKGROUND

The use of a subdural drain (SDD) after burr-hole drainage of chronic subdural hematoma (cSDH) reduces recurrence at 6 mo. Subperiosteal drains (SPDs) are considered safer, since they are not positioned in direct contact to cortical structures, bridging veins, or hematoma membranes.

OBJECTIVE

To investigate whether the recurrence rate after insertion of a SPD is noninferior to the insertion of a more commonly used SDD.

METHODS

Multicenter, prospective, randomized, controlled, noninferiority trial analyzing patients undergoing burr-hole drainage for cSDH aged 18 yr and older. After hematoma evacuation, patients were randomly assigned to receive either a SDD (SDD-group) or a SPD (SPD-group). The primary endpoint was recurrence indicating a reoperation within 12 mo, with a noninferiority margin of 3.5%. Secondary outcomes included clinical and radiological outcome, morbidity and mortality rates, and length of stay.

RESULTS

Of 220 randomized patients, all were included in the final analysis (120 SPD and 100 SDD). Recurrence rate was lower in the SPD group (8.33%, 95% confidence interval [CI] 4.28-14.72) than in the SDD group (12.00%, 95% CI 6.66-19.73), with the treatment difference (3.67%, 95% CI -12.6-5.3) not meeting predefined noninferiority criteria. The SPD group showed significantly lower rates of surgical infections (P = .0406) and iatrogenic morbidity through drain placement (P = .0184). Length of stay and mortality rates were comparable in both groups.

CONCLUSION

Although the noninferiority criteria were not met, SPD insertion led to lower recurrence rates, fewer surgical infections, and lower drain misplacement rates. These findings suggest that SPD may be warranted in routine clinical practice

Clinical Course in Chronic Subdural Hematoma Patients Aged 18-49 Compared to Patients 50 Years and Above: A Multicenter Study and Meta-Analysis

Objective: Chronic Subdural Hematoma (cSDH) is primarily a disease of elderly, and is rare in patients <50 years, and this may in part be related to the increased brain atrophy from 50 years of age. This fact may also influence clinical presentation and outcome. The aim of this study was to study the clinical course with emphasis on clinical presentation of cSDH patients in the young (<50 years).

Methods: A retrospective review of a population-based cohort of 1,252 patients operated for cSDH from three Scandinavian neurosurgical centers was conducted. The primary end-point was difference in clinical presentation between the patients <50 y/o and the remaining patients (≥50 y/o group). The secondary end-points were differences in perioperative morbidity, recurrence and mortality between the two groups. In addition, a meta-analysis was performed comparing clinical patterns of cSDH in the two age groups.

Results: Fifty-two patients (4.2%) were younger than 50 years. Younger patients were more likely to present with headache (86.5% vs. 37.9%, p < 0.001) and vomiting (25% vs. 5.2%, p < 0.001) than the patients ≥50 y/o, while the ≥50 y/o group more often presented with limb weakness (17.3% vs. 44.8%, p < 0.001), speech impairment (5.8% vs. 26.2%, p = 0.001) and gait disturbance or falls (23.1% vs. 50.7%, p < 0.001). There was no difference between the two groups in recurrence, overall complication rate and mortality within 90 days. Our meta-analysis confirmed that younger patients are more likely to present with headache (p = 0.015) while the hemispheric symptoms are more likely in patients ≥50 y/o (p < 0.001).

Conclusion: Younger patients with cSDH present more often with signs of increased intracranial pressure, while those ≥50 y/o more often present with hemispheric symptoms. No difference exists between the two groups in terms of recurrence, morbidity, and short-term mortality. Knowledge of variations in clinical presentation is important for correct and timely diagnosis in younger cSDH patients.

Rates of Repeated Operation for Isolated Subdural Hematoma Among Older Adults

IMPORTANCE

Elderly patients who undergo surgery for an isolated nontraumatic subdural hematoma (SDH) are at major risk for SDH reaccumulation, which can cause further injury and disability. Few population-based studies have examined how often nontraumatic SDH reaccumulates and necessitates repeated operation.

OBJECTIVE

To determine the rate of repeated operation after evacuation of nontraumatic SDH.

DESIGN, SETTING, AND PARTICIPANTS

In a cohort study, 2 parallel analyses were performed using data from the National Surgical Quality Improvement Project (NSQIP) from January 1, 2012, through December 31, 2015, and inpatient and outpatient claims data from a 5% nationally representative sample of Medicare beneficiaries from January 1, 2009, to September 30, 2015. In both samples, our cohort comprised patients 65 years or older who underwent surgical evacuation of nontraumatic SDH. Data were analyzed from March 28 to April 13, 2018.

MAIN OUTCOMES AND MEASURES

The outcome variable was repeated operation for SDH after the index operation. Survival analysis and Kaplan-Meier statistics were used to calculate cumulative rates.

RESULTS

Among 2 831 274 cases submitted to the NSQIP registry, 515 patients 65 years or older (mean [SD] age, 76.9 [7.4] years; 177 [34.4%] women; 367 [71.3%] white) who underwent craniotomy or craniectomy for nontraumatic SDH were identified. Within 30 days after the index surgery, 37 patients underwent a repeated operation for SDH. The cumulative 30-day mortality rate was 13.8% (95% CI, 11.0%-17.1%), and the repeated operation rate was 7.8% (95% CI, 5.7%-10.7%). Among a cohort of 1 952 305 Medicare beneficiaries, 1534 patients (mean [SD] age, 77.7 [7.0] years; 498 [32.5%] women; 1244 [81.1%] white) who underwent evacuation of nontraumatic SDH were identified. A total of 103 patients underwent a repeated operation within 90 days. The cumulative 30-day mortality rate was 11.6% (95% CI, 10.1%-13.3%), and the repeated operation rate was 4.9% (95% CI, 3.9%-6.2%); the cumulative 90-day mortality rate was 17.6% (95% CI, 15.7%-19.6%), and the repeated operation rate was 7.5% (95% CI, 6.2%-9.0%). The study found no evidence of a significant difference in cumulative repeated operation rates at 90 days between patients whose index surgery was a burr-hole procedure for chronic SDH (11.7%; 95% CI, 6.3%-21.3%) vs a craniotomy or craniectomy (7.2%; 95% CI, 6.0%-8.8%) (P = .14 by the log-rank test).

CONCLUSIONS AND RELEVANCE

In 2 large cohorts of US patients, approximately 5% to 10% of patients who underwent surgery for nontraumatic SDH were required to undergo repeated operation within 30 to 90 days. These results may inform the design of future prospective studies and trials and help practitioners calibrate their index of suspicion to ensure that patients are referred for timely surgical care.

Subdural Tension on the Brain in Patients with Chronic Subdural Hematoma Is Related to Hemiparesis but Not to Headache or Recurrence

BACKGROUND

Hemiparesis is a major symptom of chronic subdural hematoma (CSDH). Its severity does not always correlate with hematoma size. The authors analyzed hematoma thickness, pressure, and tension to clarify the mechanism of hemiparesis in CSDH patients.

METHODS

A burr-hole surgery was performed on 124 CSDHs in 102 patients. Hematoma thickness and midline shift were measured by computed tomography, and hematoma pressure was measured in surgery. According to Laplace law, tension was calculated as follows: (half the hematoma thickness × hematoma pressure)/2. Student t test and Pearson correlation coefficient (r) were applied in statistical analysis of findings.

RESULTS

Motor weakness was identified in 76.5% of our cases. Tension was strongly related to hemiparesis (r = -0.747, P < 0.01), whereas hematoma thickness (r = -0.458, P < 0.01) and pressure (r = -0.596, P < 0.01) were moderately correlated. Mean age of 14 patients (13.7%) with headache was much younger than those without headache (P < 0.01). Stronger midline shift (P < 0.01) and greater ratio of midline shift to hematoma thickness (P < 0.01) were statistically correlated with headache. Recurrence was recognized in 8 patients (7.8%), and stronger midline shift (P < 0.05) and greater ratio of midline shift to hematoma thickness (P < 0.05) were statistically associated with recurrence.

CONCLUSIONS

Tension is the most influencing factor to hemiparesis in CSDH patients. This study also elucidates the mechanism for quick recovery from hemiparesis after surgery in that tension on the motor cortex is decreased immediately by drainage.

Role of antithrombotic therapy in the risk of hematoma recurrence and thromboembolism after chronic subdural hematoma evacuation: a population-based consecutive cohort study

Objective

To establish the risk of recurrence in patients with chronic subdural hematoma (cSDH) on antithrombotic treatment (AT, i.e., antiplatelets and anticoagulants). Secondary end points were perioperative morbidity and mortality between groups (AT vs. no-AT group) and exploration if timing of resumption of AT treatment (i.e., prophylactic early vs. late resumption) influenced the occurrence of thromboembolism and hematoma recurrence.

Materials

In a population-based consecutive cohort, we conducted a retrospective review of 763 patients undergoing primary burr hole procedures for cSDH between January 1, 2005, and December 31, 2010, at the Karolinska University Hospital, Stockholm, Sweden. Early AT resumption was ≤30 days and late >30 days after the procedure.

Results

A total of 308/763 (40.4%) cSDH patients were on AT treatment at the time of diagnosis. There was no difference in cSDH recurrence within 3 months (11.0% vs. 12.0%, p = 0.69) nor was there any difference in perioperative mortality (4.0% vs. 2.0%, p = 0.16) between those using AT compared to those who were not. However, perioperative morbidity was more common in the AT group compared to no-AT group (10.7% vs. 5.1%, p = 0.003). Comparing early vs. late AT resumption, there was no difference with respect to recurrence (7.0% vs. 13.9%, p = 0.08), but more thromboembolism in the late AT resumption group (2.0% vs. 7.0%, p < 0.01).

Conclusion

In clinical practice, cSDH patients on AT therapy at the time of diagnosis have similar recurrence rates and mortality compared to those without AT therapy, but with higher morbidity. Early resumption was not associated with more recurrence, but with lower thromboembolic frequency. Early AT resumption seems favorable, and a prospective RCT is needed.

Predictors of Recurrence and Complications After Chronic Subdural Hematoma Surgery: A Population-Based Study

OBJECTIVE

To investigate predictors of recurrence and moderate to severe complications after burr-hole surgery for chronic subdural hematoma (cSDH).

METHODS

A retrospective review was conducted in a Scandinavian single-center population-based cohort of 759 adult patients with cSDH operated with burr-hole surgery between January 1, 2005 and December 31, 2010. Possible predictors of recurrence and complications, assessed using a standardized reporting system of adverse events, were identified and analyzed in univariable analyses. Variables with a P value < 0.10 were included in a multivariable regression model.

RESULTS

Recurrence was observed in 85 patients (11.2%), whereas moderate to severe complications were observed in 35 patients (4.6%). Bilateral hematoma (odds ratio [OR], 2.05; 95% confidence interval [CI], 1.25-3.35; P < 0.01) and largest hematoma diameter in millimeters (OR, 1.05; 95% CI, 1.01-1.09; P < 0.01) were independent predictors of recurrence in the multivariable model analysis. Glasgow Coma Scale (GCS) score of <13 (OR, 6.06; 95% CI, 2.72-13.51; P < 0.01) and Charlson Comorbidity Index (CCI) >1 (OR, 2.28; 95% CI, 1.10-4.75; P = 0.03) were independent predictors of moderate to severe complications.

CONCLUSIONS

Recurrence after cSDH surgery is more often encountered in patients with radiologically more extensive disease reflected by bilateral hematoma and large hematoma diameter. On the other hand, moderate to severe complications are more often seen in patients in a worse clinical condition, reflected by decreased level of consciousness and more comorbidities.