Bilateral chronic subdural hematoma: unilateral or bilateral drainage?

Optimal drainage time after evacuation of chronic subdural haematoma (DRAIN TIME 2): a multicentre, randomised, multiarm and multistage non-inferiority trial in Denmark

BACKGROUND

Postoperative drainage after surgical evacuation of chronic subdural haematoma reduces the risk of recurrence, but the optimum drainage time is uncertain. We aimed to investigate the shortest possible drainage time without increasing the haematoma recurrence rate.

METHODS

We conducted a randomised, multi-arm and multistage non-inferiority trial at four neurosurgical centres in Denmark. We enrolled adult patients (aged ≥18 years) with symptomatic chronic subdural haematoma. All patients were treated according to the national standard practice with a burr hole above the maximum width of the haematoma. Patients were randomly assigned in a 1:1:1 ratio via a centralised web server to receive 6 h, 12 h, or 24 h of postoperative passive subdural drainage. Randomisation was done by an independent on-call neurosurgeon and was masked until 6 h after surgery. The primary outcome was symptomatic haematoma recurrence at 3 months after surgery; the rate of recurrence was assessed in a regression model for non-inferiority testing, with no missing data. Personnel assessing the primary outcome were masked to group allocation. Non-inferiority was assessed with a prespecified margin of 7%, in a modified intention-to-treat population-defined as patients with randomly assigned treatment excluding those withdrawing from study participation after randomisation, or experiencing acute rebleedings or accidental drain removal. This trial is registered with ISRCTN (number 15186366); the trial was stopped after the first interim analysis on the advice of an independent safety advisory committee.

FINDINGS

Between March 1, 2021, and June 30, 2022, 347 patients were enrolled and 331 were followed up to 3 months, 105 were assigned to 6 h of drainage, 111 to 12 h of drainage, and 115 to 24 h of drainage. At admission, 83 (25%) participants were women and 248 (75%) were men, mean age was 75·7 years (SD 10·5), median modified Rankin Scale score was 4 (IQR 3-5), and median Glasgow Coma Scale score was 15 (IQR 14-15). At 3 months after surgery, haematoma recurrence was reported in 28 (27%) of 105 patients who were assigned to 6 h drainage (predicted haematoma recurrence rate 27·0%, 95% CI 18·5 to 35·4), 22 (20%) of 111 assigned to 12 h drainage (19·5%, 12·0 to 27·0), and 12 (10%) of 115 assigned to 24 h drainage (10·4%, 4·8 to 16·0). The risk of haematoma recurrence was increased by 16·5 percentage points (95% CI 6·5 to 26·6) in patients drained for 6 h compared with 24 h, and by 9·1 percentage points (-0·4 to 18·5) in patients drained for 12 h compared with 24 h. Therefore, non-inferiority of 6 h and 12 h of drainage to 24 h of drainage was not established. 20 patients had died by 3 months, seven in the 6 h group, eight in the 12 h group, and five in the 24 h group. The most frequent known causes of death were haematoma recurrence (three in 12 h group), comorbidity (three in 12 h group), and pneumonia (one each in 6 h and 12 h groups, two in 24 h group). The most frequent complication was postoperative infection, reported in 20 (20%) patients in the 6 h group, 25 (23%) in the 12 h group, and 19 (17%) in the 24 h group. The most common infection source was the urinary tract.

INTERPRETATION

Patients surgically treated for symptomatic chronic subdural haematoma and postoperatively drained for 6 h or 12 h had higher rates of haematoma recurrence than did patients drained for 24 h. The findings from this non-inferiority trial provide evidence to support 24 h of postoperative drainage as the standard drain time when a fixed drain time approach is used. To provide solid evidence of generalisability of the results to countries other than Denmark, a multinational randomised controlled trial will be needed.

FUNDING

None.

Urokinase Plasminogen Activator Receptor: An Important Focal Player in Chronic Subdural Hematoma?

Chronic subdural hematoma (CSDH) development involves inflammatory, angiogenetic, and fibrinolytic mechanisms, several components of which are now unraveled through intensive research. The urokinase plasminogen activator receptor (uPAR) is part of the plasminogen activator system and possesses inflammatory, angiogenetic, and fibrinolytic capabilities. As a first, this study aims to identify uPAR in the hematoma fluid, hematoma membrane, dura mater, and systemic blood from patients with CSDH and, if present, to investigate if the uPAR level at the time of surgery may be a predictor for later developing recurrent CSDH. uPAR expression in the hematoma membrane and dura mater was analyzed using immunohistochemistry and presented as the H-score of the positive immunostaining. The uPAR levels in the hematoma fluid and systemic blood were determined using a multiplex antibody bead kit (Luminex). Samples were collected at the time of the first CSDH surgery, and in the case of recurrent CSDH within 90 days, the samples were again collected at reoperation. A comparison of uPAR expression between the hematoma membrane and dura mater, as well as uPAR levels in systemic blood and hematoma fluid, was performed using the Wilcoxon rank sum test. We included 112 patients, 26 of whom had recurrent CSDH. The median hematoma uPAR level was 22,125 (14,845-33,237) and significantly higher than the median systemic blood level of 789 pg/L (465-2,088) (p < 0.001). Similarly, the uPAR level of the hematoma membrane was 14.3 (7.54-44.8) and significantly higher than the dural uPAR level of 0.81 (0.3-1.98) (p < 0.001). For the first time, we identified uPAR in the subdural fluid, hematoma membrane, dura mater, and systemic blood from patients with CSDH. The high expression of uPAR in the subdural fluid and hematoma membrane indicates that the mechanisms of CSDH are predominantly in the subdural fluid collection and surrounding hematoma membrane.

The cellular composition of chronic subdural hematoma

INTRODUCTION

The pathophysiology of chronic subdural hematoma (CSDH) remains to be fully understood. Basic knowledge of the composition and features of cells in the CSDH fluid may contribute to the understanding of the seemingly complex processes involved in CSDH formation and recurrence. This study is the first to examine the composition of cells and of cellular features in both systemic blood and subdural fluid from CSDH patients. We hypothesized that the cellular composition and features in the hematoma fluid may be; 1) different from that in the systemic blood; 2) different between patients with and without recurrence; 3) and different between the first and second operation in patients with recurrent CSDH.

METHODS

Systemic blood and subdural hematoma fluid were collected from CSDH patients with and without recurrent CSDH at the time of primary and secondary surgery. Analyses of cells and cellular features included total number of white blood cells, erythroblasts, reticulocytes, platelets, neutrophilocytes, lymphocytes, monocytes, eosinophils, basophils, reticulocytes, immature granulocytes, mean corpuscular cell volume (MCV), mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, hemoglobin and hematocrit.

RESULTS

Of the 85 included patients, 20 patients were operated for a recurrent CSDH within 90 days follow-up. All cells found in the systemic blood were present in the CSDH fluid, but the composition was different (p < 0.0001). MCV was higher in the hematoma fluid from the primary operation of patients later developing a recurrent CSDH compared to patients not developing recurrence (p = 0.009). Also, the percentage distribution of inflammatory cells in hematoma fluid from patients with recurrent CSDH was different between the first and second operation (p = 0.0017).

CONCLUSION

This study is the first to investigate the cellular composition of CSDH fluid. Compared to systemic blood and to a reference distribution, an increased number of immune cells were present in the hematoma fluid, supporting an inflammatory component of the CSDH pathophysiology. MCV was higher in the subdural fluid at time of the first operation of CSDH patients later developing recurrence.

CLINICAL TRIAL REGISTRATION

The study was approved by the Scientific Ethical Committee of the Capital Region of Denmark (Journal no. H-20051073.

Subdural Levels of Interleukin 1-receptor Antagonist are Elevated in Patients with Recurrent Chronic Subdural Hematomas

Anti-inflammatory treatment reduces the risk of recurrent chronic subdural hematoma (CSDH), but clinical implementation is improper due to side effects. Exact knowledge of subdural molecules involved in recurrent CSDH may lead to targeted medical treatment and possibly improve the prospect of a personalized approach by eliminating the broad use of anti-inflammatory drugs on the entire CSDH population. With this study, we aim to (1) describe the associations between cytokine levels at the primary surgery and the risk of subsequent recurrence and (2) describe the association between cytokines in patients with recurrent CSDH between the first and second operations. Systemic and subdural levels of pro- and anti-inflammatory cytokines were measured and compared between patients with the first-time CSDH and recurrent CSDH. Cytokine levels were analyzed using a multiplex antibody bead kit. In case of recurrent CSDH within 90 days of follow-up, the samples were re-collected and analyzed. We included 101 adult CSDH patients of which 20 had a recurrence. The levels of cytokines in the CSDH fluid from patients who were operated on for the first-time CSDH were not associated with the risk of later developing a recurrence. We found interleukin-1 receptor antagonist (IL-1ra) to be elevated in subdural fluid in patients with recurrent CSDH at the time of their second operation (p = 0.0005). This study provides knowledge on cytokine composition in the subdural fluid in patients with CSDH with and without recurrence. IL-1ra is elevated in subdural fluid in patients with recurrent CSDH at the time of the second operation, identifying a possible medical target.

Modified Valsalva maneuver after burr-hole drainage of chronic subdural hematomas: A single-center cohort study

Background

Previous studies on the management of chronic subdural hematoma (cSDH) mainly focused on the risk of postoperative recurrence and measures to prevent it. In this study, we propose the use of a non-invasive postoperative treatment method, the modified Valsalva maneuver (MVM), as a means of reducing the recurrence of cSDH. This study aims to clarify the effects of MVM on functional outcomes and recurrence rates.

Methods

A prospective study was conducted at the Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from November 2016 to December 2020. The study included 285 adult patients who underwent burr-hole drainage for the treatment of cSDH and received subdural drains. These patients were divided into two groups: the MVM group (n = 117) and the control group (n = 98). In the MVM group, patients received treatment with a customized MVM device for at least 10 times per hour, 12 h per day. The study's primary endpoint was the recurrence rate of SDH, while functional outcomes and morbidity 3 months after surgery were the secondary outcomes.

Results

In the current study, 9 out of 117 patients (7.7%) in the MVM group experienced a recurrence of SDH, while 19 out of 98 patients (19.4%, p < 0.05) in the HC group experienced a recurrence of SDH. Additionally, the infection rate of diseases such as pneumonia (1.7%) was significantly lower in the MVM group compared to the HC group (9.2%, p < 0.001, odds ratio (OR = 0.1). After 3 months of the surgery, 109 out of 117 patients (93.2%) in the MVM group achieved a favorable prognosis, compared to 80 out of 98 patients (81.6%) in the HC group (p = 0.008, with an OR of 2.9). Additionally, infection rate (with an OR of 0.2) and age (with an OR of 0.9) are independent predictors of a favorable prognosis at the follow-up stage.

Conclusions

The use of MVM in the postoperative management of cSDHs has been shown to be safe and effective, resulting in reduced rates of cSDH recurrence and infection following burr-hole drainage. These findings suggest that MVM treatment may lead to a more favorable prognosis at the follow-up stage.

Surgical treatment and outcome of chronic subdural hematoma: a comparative study between Ethiopia and Norway

BACKGROUND

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical conditions. Here, we studied differences in demographics, treatment, and outcome for CSDH patients in low-income (Ethiopia) and high-income (Norway) countries and assessed potential outcome determinants.

METHODS

We included patients from Addis Ababa University Hospitals (AAUH) and Haukeland University Hospital (HUH) who had surgery for CSDH (2013-2017). Patients were included prospectively in Ethiopia and retrospectively in Norway.

RESULTS

We enrolled 314 patients from AAUH and 284 patients from HUH, with a median age of 60 and 75 years, respectively. Trauma history was more common in AAUH (72%) than in HUH patients (64.1%). More patients at HUH (45.1%) used anticoagulants/antiplatelets than at AAUH (3.2%). Comorbidities were more frequent in HUH (77.5%) than in AAUH patients (30.3%). Burr hole craniostomy under local anesthesia and postoperative drainage was the standard treatment in both countries. Postoperative CT scanning was more common at HUH (99.3%) than at AAUH (5.2%). Reoperations were more frequent at HUH (10.9%) than at AAUH (6.1%), and in both countries, mostly due to hematoma recurrence. Medical complications were more common at HUH (6.7%) than at AAUH (1.3%). The 1-year mortality rate at HUH was 7% and at AAUH 3.5%. At the end of follow-up (> 3 years), the Glasgow Outcome Scale Extended (GOSE) score was 8 in 82.9% of AAUH and 46.8% of HUH patients.

CONCLUSION

The surgical treatment was similar at AAUH and HUH. The poorer outcome in Norway could largely be explained by age, comorbidity, medication, and complication rates.

Middle meningeal artery embolization for chronic subdural hematomas. A systematic review of the literature focused on indications, technical aspects, and future possible perspectives

Background:

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical diseases that affect elderly and fragile patients and as a consequence, management can be challenging. Surgery represents the standard treatment; however, alternative options are under investigation. Middle meningeal artery (MMA) embolization is considered a minimally invasive treatment although with poor evidence. In this review, we tried to summarize the findings about MMA embolization as a treatment for a CSDH to provide a useful guidance for clinical practice and for future speculative aspects.

Methods:

Literature review on PubMed until March 2021 was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement. We conducted a research on PubMed with a various combinations of the keywords “CSDH” and “middle meningeal artery” and “embolization,” “refractory subdural hematoma,” and then we reviewed the references of the relevant studies as additional source of eligible articles.

Results:

Among the 35 studies eligible for this review, 22 were case series, 11 were case reports, one was a technical note, and 1 was a randomized trial. A total of 746 patients were found in the literature. Failure rate of MMA embolization was between 3.9 and 8.9% of the cases according the indication to treat CSDH (upfront vs. after surgery).

Conclusion:

The global impression deriving from the data available and the literature is that MMA embolization is a safe procedure with very low complications and with a low failure rate, both when associated with surgery or in case of a standalone treatment.

The effect of antithrombotic therapy on the recurrence and outcome of chronic subdural hematoma after burr-hole craniostomy in a population-based cohort

PURPOSE

To study the effect of antithrombotic therapy (ATT) on the outcome of operatively treated chronic subdural hematomas (CSDH).

METHODS

A retrospective population-based cohort study from Eastern Finland including all adult patients who underwent a burr-hole craniostomy (BHC) for CSDH during 2016 and 2017. The follow-up time for recurrence was 6 months and for mortality 3 years.

RESULTS

A total of 301 CSDH patients were included in the study. ATT (antithrombotic therapy; antiplatelet or anticoagulant medication) was used by 164 patients (54.5%) at the time of diagnosis. The hematoma was bilateral in 102 patients (33.9%). Forty-seven patients (15.8%) encountered hematoma recurrence. Bilateral CSDHs required reoperations more often than unilateral hematomas (12.6% vs. 22.0%; p = 0.036) regardless of the primary operation (uni- or bilateral). A bivariate logistic regression analysis showed that bilateral hematoma (OR 1.918; 95% CI 1.013-3.630; p = 0.045) and male gender (OR 2.363; 95% CI 1.089-5.128; p = 0.030) independently predicted hematoma recurrence. The overall three-year mortality was 27.9%. The use of ATT was not associated with CSDH recurrence, and the length of the temporary postoperative ATT discontinuation did not correlate with the rate of thromboembolic events.

CONCLUSIONS

ATT did not affect CSDH recurrence in our study population, and the duration of the temporary postoperative ATT discontinuation was not associated with the rate of thromboembolic complications. Male gender and bilateral hematomas were more frequently associated with recurrences.

Middle Meningeal Artery Embolization for the Treatment of Bilateral Chronic Subdural Hematoma

Background: Bilateral chronic subdural hematoma (bCSDH) is a frequent condition commonly linked to the need for retreatment; however, the reason for this high retreatment rate remains unclear. The middle meningeal artery (MMA) was found to have a relationship with the occurrence and development of chronic subdural hematomas. This study examines a possible method to reduce bCSDH recurrence using bilateral MMA embolization combined with bilateral burr-hole drainage.

Materials and Methods: Ten patients with bCSDH who underwent bilateral MMA embolization combined with bilateral burr-hole drainage at our hospital between June 2018 and May 2020, were retrospectively analyzed. Patients' clinical information, prognoses, imaging results, as well as surgical results were documented and analyzed.

Results: Ten patients were diagnosed with bCSDH with no comorbid brain diseases. They underwent bilateral MMA embolization combined with bilateral burr-hole drainage. We embolized the MMA immediately before burr hole drainage successfully and employed angiography to validate these results. All the patients attained relief of symptoms without adverse events, and no re-expansion or relapse was reported in the follow-up computed tomography.

Conclusion: Bilateral MMA embolization combined with bilateral burr-hole drainage is an available treatment for patients with bCSDH and may have the potential for preventing recurrence.

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.

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.

A novel rat model of chronic subdural hematoma: Induction of inflammation and angiogenesis in the subdural space mimicking human-like features of progressively expanding hematoma

Pathophysiological mechanisms of chronic subdural hematoma (CSDH) involve localized inflammation, angiogenesis, and dysregulated coagulation and fibrinolysis. The scarcity of reproducible and clinically relevant animal models of CSDH hinders further understanding the underlying pathophysiology and improving new treatment strategies. Here, we developed a novel rat model of CSDH using extracellular matrices (Matrigel) and brain microvascular endothelial cell line (bEnd.3 cells). One hundred-microliter of Matrigel-bEnd.3 cell (10⁶ cells per milliliter) mixtures were injected into the virtual subdural space of elderly male Sprague-Dawley rats. This approach for the first time led to a spontaneous and expanding subdural hematoma, encapsulated by internal and external neomembranes, formed as early as 3 d, reached its peak at 7 d, and lasted for more than 14 d, mimicking the progressive hemorrhage observed in patients with CSDH. The external neomembrane and hematoma fluid involved numerous inflammatory cells, fibroblasts, and highly fragile neovessels. Furthermore, a localized pathophysiological process was validated as evidenced by the increased expressions of inflammatory and angiogenic mediators in external neomembrane and hematoma fluid rather than in peripheral blood. Notably, the specific expression profiles of these mediators were closely associated with the dynamic changes in hematoma volume and neurological outcome. In summary, the CSDH model described here replicated the characteristics of human CSDH, and might serve as an ideal translational platform for preclinical studies. Meanwhile, the crucial roles of angiogenesis and inflammation in CSDH formation were reaffirmed.

Surgical occlusion of middle meningeal artery in treatment of chronic subdural haematoma: anatomical and technical considerations

BACKGROUND

The primary aim of chronic subdural haematoma (CSDH) treatment is to relieve pressure to improve neurological symptoms. The secondary aim is to avoid recurrence. The blood supply from the middle meningeal artery (MMA) to the haematoma membranes has recently become a research target, to enhance our understanding of the processes leading to growth and re-growth of a CSDH. Several studies indicate that endovascular embolization of the MMA (eMMA) reduces recurrence rates, but this effect must be confirmed in a randomized controlled setting. Endovascular embolization is an advanced and costly procedure carrying a significant risk of embolism in the elderly. The aim of this study was to assess anatomical and technical aspects of surgical occlusion of the MMA (soMMA) via a single same-procedure burr hole, as an alternative to eMMA.

METHOD

Technical aspects of soMMA were assessed using cadaver head dissection. MMA anatomy was examined by mapping the branching pattern and distribution of MMA in dry skulls, and CSDH position was investigated by analysis of computed tomography (CT) of CSDHs. Finally, we evaluated the possibility of CT-guided navigation to mark the branching point of the anterior MMA division on the skin.

RESULTS

We established anatomical landmarks to locate the MMA and found that particularly the anterior MMA branch can be occluded through a single burr hole at the pterion during the same procedure as haematoma decompression. CT of 1454 CSDHs in 1162 patients showed that the CSDH was anteriorly located in 57.5% compared with posteriorly in only 3%. This correlated with the anterior branch of the MMA being dominant in 58% of dry skull samples examined. We further confirmed that the MMA can be localized by neuronavigation as an alternative to using anatomical landmarks and average measurements.

CONCLUSION

A CSDH is mainly anteriorly located and supposedly primarily supplied by the anterior MMA branch. In a simulated setting, soMMA can be performed during the same procedure as haematoma decompression. A few reservations notwithstanding, we find that soMMA may be a viable alternative to eMMA in most CSDH cases and that soMMA should be further evaluated in a clinical setting.

Supervised Valsalva Maneuver after Burr Hole Evacuation of Chronic Subdural Hematomas: A Prospective Cohort Study

Research on chronic subdural hematoma (cSDH) management has primarily focused on potential recurrence after surgical evacuation. Herein, we present a novel postoperative/non-invasive treatment that includes a supervised Valsalva maneuver (SVM), which may serve to reduce SDH recurrence. Accordingly, the aims of the study were to investigate the effects of SVM on SDH recurrence rates and functional outcomes. A prospective study was conducted from December 2016 until December 2019 at the Goethe University Hospital Frankfurt. Of the 204 adult patients with surgically treated cSDH who had subdural drains placed, 94 patients were assigned to the SVM group and 82 patients were assigned to the control group. The SVM was performed by having patients blow into a self-made SVM device at least two times/h for 12 h/day. The primary end-point was SDH recurrence rate, while secondary outcomes were morbidity and functional outcomes at 3 months of follow-up. SDH recurrence was observed in 16 of 94 patients (17%) in the SVM group, which was a significant reduction as compared with the control group, which had 24 of 82 patients (29.3%; p = 0.05) develop recurrent SDHs. Further, the infection rate (e.g., pneumonia) was significantly lower in the SVM group (1.1%) than in the control group (13.4%; p < 0.001; odds ratio [OR] 0.1). At the 3-month follow-up, 85 of 94 patients (90.4%) achieved favorable outcomes in the SVM group compared with 62 of 82 patients (75.6%) in the control group (p = 0.008; OR 3.0). Independent predictors for favorable outcome at follow-up were age (OR 0.9) and infection (OR 0.2). SVM appears to be safe and effective in the post-operative management of cSDHs, reducing both recurrence rates and infections after surgical evacuation, thereby resulting in favorable outcomes at follow-up.

The Danish Chronic Subdural Hematoma Study-comparison of hematoma age to the radiological appearance at time of diagnosis

INTRODUCTION

Chronic subdural hematomas (CSDH) show different radiological characteristics on CT scans at the time of diagnosis. The reason for this is largely unknown. We hypothesize that the imaging characteristics reflect a time-linked pathophysiological evolution. We therefore conducted a retrospective study to examine a possible relation between the hematoma age and the radiological subtype of a CSDH.

METHODS

Demographic data on patients with CSDH were retrieved from a Danish national cohort from 2010 to 2012. CT scans obtained on admission to a neurosurgical department were categorized as homogenous, separated, mixed, or membranous hematoma subtypes. The time from a known date of head injury to time of diagnostic CT was defined as hematoma age. The hematoma age was correlated to radiological hematoma subtype at the time of diagnosis by analysis of variance testing.

RESULTS

In total, 543 patients were analyzed for hematoma age and classified in the following hematoma subtypes: 231 homogenous, 44 separated, 119 mixed, and 149 membranous. Patients with homogenous, separated, mixed, and membranous hematoma subtypes had a median interval of 37, 36, 40, and 60 days from head injury to diagnostic CT. We found that membranous hematoma is significantly older than other subtypes. Comparison between the other radiological subtypes showed no statistical hematoma age difference. The distribution of radiological subtypes in 590 patients without a known head injury was similar to that of patients with a known head injury. Additionally, we found that hematoma age was significantly younger for patients on antiplatelet medication.

CONCLUSION

In this large national cohort, patients with membranous CSDH had a significantly longer interval between head injury and diagnosis compared to other radiological subtypes. This indicates that the radiological appearance of CSDH evolves over time, causing an alteration from different early radiological subtypes to a radiological subtype with membranes.

CLINICAL TRIAL REGISTRATION NUMBER

The study was approved by the Danish Data Protection Agency (journal no.30-1145).

Application of Absolute Alcohol in the Treatment of Traumatic Intracranial Hemorrhage via Interventional Embolization of Middle Meningeal Artery

Background: Traumatic brain injury is a common condition in neurosurgery. Traditional methods of treatment include conservative treatment and surgical evacuation using burr-holes or craniotomy; however, studies have reported problems such as high re-expansion rates after conservative treatment of epidural hematoma and high postoperative recurrence rates of subdural hematoma. Solutions to these problems are lacking, and research into new treatment methods is ongoing. Among the potential new treatments, middle meningeal arterial embolization is an option. This study involved patients with acute epidural hematoma and chronic subdural hematoma. The purpose was to evaluate the use and effects of absolute alcohol to embolize the middle meningeal artery to treat intracranial hematoma. Material and Methods: A retrospective description study was 12 cases of intracranial hematoma who treated with absolute alcohol interventional therapy from our hospital between June 2018 and October 2019. Five patients with acute epidural hematoma and seven patients with chronic subdural hematoma were treated using absolute alcohol to embolize the middle meningeal artery. Patients' clinical data, imaging results, surgical results, and prognosis were recorded and analyzed. Results: All patients underwent absolute alcohol embolization of the middle meningeal artery, in combination with burr-hole drainage. All imaging data were confirmed preoperatively. We successfully used absolute alcohol to embolize the middle meningeal artery intraoperatively and confirmed these results by postoperative angiography. All patients achieved symptomatic relief without complications, and no recurrence or re-expansion was seen with follow-up computed tomography. Our study has been registered in the Chinese Clinical Trial Registry (http://www.chictr.org.cn, ChiCTR1800018714). Conclusion: The use of absolute alcohol to embolize the middle meningeal artery could be used as an attempt to treat acute epidural hematoma and chronic subdural hematoma.

Neurosurgical and Perioperative Management of Chronic Subdural Hematoma

Objective: Surgery and specifically burr hole craniostomy is the most common first choice treatment of patients with Chronic Subdural Hematoma (CSDH). However, several aspects of neurosurgical and peri-operative management are still a subject of research, such as how to treat bilateral CSDH and the anesthetic approach. We aim to investigate the effect of the surgical approach to bilateral CSDH and the effect of anesthesia modality on outcome of CSDH patients. Methods: We retrospectively included surgically treated CSDH patients between 2005 and 2019 in three hospitals in the Netherlands. The effect of the surgical approach to bilateral CSDH (unilateral vs. bilateral decompression) and anesthesia modality (general vs. local anesthesia) on outcome (complications, recurrence, and length of hospital stay over 4 days) was studied with logistic regression adjusting for potentially confounding radiological and clinical characteristics. Results: Data of 1,029 consecutive patients were analyzed, mean age was 73.5 years (±11) and 75% of patients were male. Bilateral CSDH is independently associated with an increased risk of recurrence within 3 months in logistic regression analysis (aOR 1.7, 95% CI: 1.1-2.5) but recurrence rate did not differ between primary bilateral or unilateral decompression of bilateral CSDH. (15 vs. 17%, p = 0.775). Logistic regression analysis showed that general anesthesia was independently associated with an increased risk of complications (aOR 1.8, 95% CI: 1.0-3.3) and with a length of hospital admission of over 4 days (aOR 8.4, 95% CI: 5.6-12.4). Conclusions: Bilateral CSDH is independently associated with higher recurrence rates. As recurrence rates in bilateral CSDH are similar for different surgical approaches, the optimal choice for primary bilateral decompression of bilateral CSDH could vary per patient. General anesthesia for surgical treatment of CSDH is associated with higher complication rates and longer hospital admission.

Predictors of acute intracranial hemorrhage and recurrence of chronic subdural hematoma following burr hole drainage

Background

To investigate predictors of postoperative acute intracranial hemorrhage (AIH) and recurrence of chronic subdural hematoma (CSDH) after burr hole drainage.

Methods

A multicenter retrospective study of patients who underwent burr hole drainage for CSDH between January 2013 and March 2019.

Results

A total of 448 CSDH patients were enrolled in the study. CSDH recurrence occurred in 60 patients, with a recurrence rate of 13.4%. The mean time interval between initial burr hole drainage and recurrence was 40.8 ± 28.3 days. Postoperative AIH developed in 23 patients, with an incidence of 5.1%. The mean time interval between initial burr hole drainage and postoperative AIH was 4.7 ± 2.9 days. Bilateral hematoma, hyperdense hematoma and anticoagulant drug use were independent predictors of recurrence in the multiple logistic regression analyses. Preoperative headache was an independent risk factor of postoperative AIH in the multiple logistic regression analyses, however, intraoperative irrigation reduced the incidence of postoperative AIH.

Conclusions

This study found that bilateral hematoma, hyperdense hematoma and anticoagulant drug use were independently associated with CSDH recurrence. Clinical presentation of headache was the strongest predictor of postoperative AIH, and intraoperative irrigation decreased the incidence of postoperative AIH.

Risk factors for the development of chronic subdural hematoma in patients with subdural hygroma

OBJECTIVE

Patients with subdural hygroma (SDG) are at increased risk of developing chronic subdural hematoma (CSDH). However, the factors that increase the risk of conversion are not fully understood. This study was to assess the risk factors of SDG conversion to CSDH.

METHODS

We reviewed the literature and retrospectively studied a series of cases in which CSDH was preceded by SDG to understand the natural history. We reviewed 45 cases of SDG from our hospital between 2015 and 2018. The cases were divided into two groups according to whether SDG converted into CSDH. Data were collected clinical presentation, imaging findings et al. Univariate and multivariate logistic regression analyses were performed to identify factors associated with SDG conversion.

RESULTS

Univariate analysis showed that the SDG thickness (p = .009), SDG location (p = .026), and bilateral SDG (p = .042) were significantly associated with CSDH development. Multivariate analysis revealed that SDG thickness (odds ratio, 1.6; 95% confidence interval, 1.111-2.324; p = .012) and bilateral SDG (odds ratio, 27.6; 95% confidence interval 2.889-263.548; p = .004) were independent risk factors for SDG development. Receiver operating characteristic curve analysis revealed that SDG thickness was a significant variable for predicting SDG development. A thickness >11.37 mm was an appropriate cutoff value, and the possibility of SDG conversion had a sensitivity 50.0% and specificity of 87.0%.

CONCLUSIONS

Bilateral SDG and SDG thickness were independent risk factors for SDG progression into CSDH. An SDG thickness >11.37 mm had a high risk of SDG conversion.

Contralateral progression after unilateral evacuation of bilateral chronic subdural hematomas: the volume relation ratio as prognostic factor?

OBJECTIVE

Unilateral evacuation of bilateral chronic subdural hematomas (bcSDHs) is associated with higher retreatment rates than an initial bilateral intervention. One reason for that is a possible progression in the size of the contralateral side after unilateral treatment. Thus, the authors focused their study on finding predictors of the need for contralateral retreatment.

METHODS

All patients who had undergone unilateral or bilateral evacuation of bcSDHs in the Department of Neurosurgery at the University Hospital of St. Poelten during a 5-year period (7/2012 to 6/2017) were retrospectively identified. The preoperative hematoma volume was calculated using the XYZ/2 method.

RESULTS

Of a total of 103 patients with bcSDHs, 61 patients underwent bilateral evacuation and 42 patients underwent unilateral evacuation. The retreatment rate after bilateral evacuation was significantly lower than that after unilateral evacuation (14.8% vs 31%, respectively; p = 0.049). Contralateral retreatment after unilateral evacuation was necessary in 9 patients (21.4%). The preoperative contralateral hematoma volume was significantly higher in those patients who needed contralateral retreatment after initial unilateral evacuation (68.4 cm3 vs 27.4 cm3, respectively; p < 0.001). Furthermore, the so-called volume relation ratio created by dividing the smaller by the larger hematoma volume was significantly higher when contralateral retreatment became necessary (0.56 vs 0.21, respectively; p < 0.001).

CONCLUSIONS

Patients needing evacuation of bcSDHs should be considered for primary bilateral evacuation if the hematoma volume on the smaller side is greater than 40 cm3 and the subsequent volume relation ratio is greater than 0.4.

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.

Outcomes of chronic subdural hematoma in patients with liver cirrhosis

OBJECTIVE: Burr hole craniostomy is an effective and simple procedure for treating chronic subdural hematoma (CSDH). However, the surgical outcomes and recurrence of CSDH in patients with liver cirrhosis (LC) remain unknown. METHODS: A nationwide population-based cohort study was retrospectively conducted using data from the Taiwan National Health Insurance Research Database. The study included 29,163 patients who underwent first-time craniostomy for CSDH removal between January 1, 2001, and December 31, 2013. In total, 1223 patients with LC and 2446 matched non-LC control patients were eligible for analysis. All-cause mortality, surgical complications, repeat craniostomy, extended craniotomy, and long-term medical costs were analyzed. RESULTS: The in-hospital mortality rate (8.7% vs 3.1% for patients with LC and non-LC patients, respectively), frequency of hospital admission, length of ICU stay, number of blood transfusions, and medical expenditures of patients with LC who underwent craniostomy for CSDH were considerably higher than those of non-LC control patients. Patients with LC tended to require an extended craniotomy to remove subdural hematomas in the hospital or during long-term follow-up. The surgical outcome worsened with an increase in the severity of LC. CONCLUSIONS: Even for simple procedures following minor head trauma, LC remains a serious comorbidity with a poor prognosis.

Factors Predicting the Need for Surgery of the Opposite Side After Unilateral Evacuation of Bilateral Chronic Subdural Hematomas

BACKGROUND

Patients with bilateral chronic subdural hematoma (bCSDH) undergo unilateral evacuation for the large or symptomatic side because the contralateral hematoma is either small or asymptomatic. However, the contralateral hematoma may subsequently grow and require evacuation.

OBJECTIVE

To characterize factors that predict contralateral hematoma growth and need for evacuation.

METHODS

A retrospective study on 128 surgically treated bCSDHs.

RESULTS

Fifty-one and 77 were bilaterally and unilaterally evacuated, respectively. Glasgow Coma Scale was lower and midline shift was higher in those evacuated unilaterally compared to those evacuated bilaterally. Hematoma size was a significant determinant of decision for unilateral vs bilateral evacuation. The contralateral side needed evacuation at a later stage in 7 cases (9.1%). There was no significant difference in terms of reoperation rate between those evacuated unilaterally and bilaterally. Greater contralateral hematoma thickness on the first postoperative day computed tomography (CT) and more postoperative midline shift reversal had higher rates of operation in the opposite side. There was no difference between the daily pace of hematoma decrease in the operated and nonoperated sides (0.7% decrease per day vs 0.9% for the operated and nonoperated sides, respectively).

CONCLUSION

Results of this study show that most bCSDHs evacuated unilaterally do not experience growth in the nonoperated side and unilateral evacuation results in hematoma resolution for both sides in most cases. Hematoma thickness on the opposite side on the first postoperative day CT and amount of midline shift reversal after surgery are the most important factors predicting the need for surgery on the opposite side.

Management of Subdural Hematomas: Part II. Surgical Management of Subdural Hematomas

PURPOSE OF REVIEW

Management of patients with subdural hematomas starts with Emergency Neurological Life Support guidelines. Patients with acute or chronic subdural hematomas (SDHs) associated with rapidly deteriorating neurologic exam, unilaterally or bilaterally dilated nonreactive pupils, and extensor posturing are considered imminently surgical; likewise, SDHs more than 10 mm in size or those associated with more than 5-mm midline shift are deemed operative.

RECENT FINDINGS

While twist drill craniostomy and placement of subdural evacuating vport system (SEPS) are quick, bedside procedures completed under local anesthesia and appropriate for patients with chronic SDH or patients that cannot tolerate anesthesia, these techniques are not optimal for patients with acute SDH or chronic SDH with septations. Burr hole SDH evacuation under conscious sedation or general anesthesia is an analogous technique; however, it requires basic surgical equipment and operating room staff, with a focus on a closed system with burr hole followed by rapid drain placement to avoid introduction of air into the subdural space, or multiple burr holes with extensive irrigation to reduce pneumocephalus and continue SDH evacuation via drain for several days. Acute SDH associated with significant mass effect and cerebral edema requires aggressive decompression via craniotomy with clot evacuation and frequently a craniectomy. Chronic SDHs that fail conservative management and progress clinically or radiographically are addressed with craniotomy with or without membranectomy. Surgical SDH management is variable depending on its characteristics and etiology, patient's functional status, comorbidities, goals of care, institutional preferences, and availability of specialized surgical equipment and adjunct therapies. Rapid access to surgical suites and trained staff to address surgical hemorrhages in a timely manner, with appropriate post-operative care by a specialized team including neurosurgeons and neurointensivists, is of paramount importance for successful patient outcomes. Here, we review various aspects of surgical SDH management.

The number of burr holes and use of a drain do not interfere with surgical results of chronic subdural hematomas

Burr hole evacuation has been the most frequently-used procedure for the treatment of chronic subdural hematomas (CSDH).

OBJECTIVE

To evaluate whether the use of a drain and/or the number of burr holes for treatment of CSDH modifies the rates of recurrence and complications.

METHODS

A retrospective review of 142 patients operated on because of CSDH, between 2006 and 2015, analyzing recurrence and complications of the use of one or two burr holes with or without the use of a drain.

RESULTS

Thirty-seven patients had bilateral CSDH (26%) and 105 (73.9%) patients had unilateral CSDH. Twenty-two (59.4%) patients were given a drain and 15 (40.6%) were not. A total number of recurrences occurred in 22 (15.5%) patients and the total number of complications was in six (4.2%) patients. Mean follow-up time was 7.67 months.

CONCLUSIONS

The number of burr holes and the use of the drain did not alter the rates of recurrence and complications in the treatment of CSDH.

Proposal of Treatment Strategies for Bilateral Chronic Subdural Hematoma Based on Laterality of Treated Hematoma

Background:

Chronic subdural hematoma (CSDH) is a disorder that is commonly seen in routine neurosurgery. Although risk factors for recurrence have been studied, the findings are inconsistent. Furthermore, bilateral CSDHs are operated unilaterally or bilaterally depending on symptoms or hematoma volume. Although there are cases in which hematomas on nonoperated side in unilaterally operated bilateral CSDHs requiring for additional operation, little have been studied on the effect of the surgical selection. The purpose of this study is to identify risk factors for recurrence in operated hematomas and additional operation in nonoperated hematomas and improve surgical strategy.

Materials and Methods:

We retrospectively reviewed patients who underwent surgery in our facility for bilateral CSDHs between January 2011 and December 2016. Univariate and multivariate analyses were performed to examine the relationship between recurrence or requirement for additional operation and clinical and radiological variables.

Results:

Recurrence was observed significantly more frequent for operated hematomas when hematoma type was separated type as reported previously. In unilaterally operated bilateral CSDHs, there were 22 hematomas on nonoperated side, and five hematomas required an additional operation after the first hospitalization. Increased volume of hematoma on the nonoperated side was the risk factors for additional operation (P = 0.022). Receiver operating characteristic (ROC) curve revealed that requirement for additional operation significantly increased when hematoma volume enlarged to approximately 44 cm³ or greater 1 day after operation.

Conclusions:

In unilaterally operated bilateral CSDHs, when hematoma volume on nonoperated side increased 1 day after the last operation, additional operation in the early stage is considerable to prevent re-hospitalization and deterioration of activities of daily living.

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.