Burr-hole drainage with or without irrigation for chronic subdural haematoma (FINISH): a Finnish, nationwide, parallel-group, multicentre, randomised, controlled, non-inferiority trial.

BACKGROUND: Chronic subdural haematoma is a common surgically treated intracranial emergency. Burr-hole drainage surgery, to evacuate chronic subdural haematoma, involves three elements: creation of a burr hole for access, irrigation of the subdural space, and insertion of a subdural drain. Although the subdural drain has been established as beneficial, the therapeutic effect of subdural irrigation has not been addressed. METHODS: The FINISH trial was an investigator-initiated, pragmatic, multicentre, nationwide, randomised, controlled, parallel-group, non-inferiority trial in five neurosurgical units in Finland that enrolled adults aged 18 years or older with a chronic subdural haematoma requiring burr-hole drainage. Patients were randomly assigned (1:1) by computer-generated block randomisation with block sizes of four, six, or eight, stratified by site, to burr-hole drainage either with or without subdural irrigation. All patients and staff were masked to treatment assignment apart from the neurosurgeon and operating room staff. A burr hole was drilled at the site of maximum haematoma thickness in both groups, and the subdural space was either irrigated or not irrigated before inserting a subdural drain, which remained in place for 48 h. Reoperations, functional outcome, mortality, and adverse events were recorded for 6 months after surgery. The primary outcome was the reoperation rate within 6 months. The non-inferiority margin was set at 7·5%. Key secondary outcomes that were also required to conclude non-inferiority were the proportion of participants with unfavourable functional outcomes (ie, modified Rankin Scale score of 4-6, where 0 indicates no symptoms and 6 indicates death) and mortality rate at 6 months. The primary and key secondary analyses were done in both the intention-to-treat and per-protocol populations. The trial was registered with ClinicalTrials.gov (NCT04203550) and is completed. FINDINGS: From Jan 1, 2020, to Aug 17, 2022, we assessed 1644 patients for eligibility and 589 (36%) patients were randomly assigned to a treatment group and treated (294 assigned to drainage with irrigation and 295 assigned to drainage without irrigation; 165 [28%] women and 424 [72%] men). The 6-month follow-up period extended until Feb 14, 2023. In the intention-to-treat analysis, 54 (18·3%) of 295 participants required reoperation in the group assigned to receive no irrigation versus 37 (12·6%) of 294 in the group assigned to receive irrigation (difference of 6·0 percentage points, 95% CI 0·2-11·7; p=0·30; adjusted for study site). There were no significant between-group differences in the proportion of people with modified Rankin Scale score of 4-6 (37 [13·1%] of 283 in the no-irrigation group vs 36 [12·6%] of 285 in the irrigation group; p=0·89) or mortality rate (18 [6·1%] of 295 in the no-irrigation group vs 21 [7·1%] of 294 in the irrigation group; p=0·58). The findings of the primary intention-to-treat analysis were not materially altered in the per-protocol analysis. There were no significant between-group differences in the number of adverse events, and the most frequent severe adverse events were systemic infections (26 [8·8%] of 295 participants who did not receive irrigation vs 22 [7·5%] of 294 participants who received irrigation), intracranial haemorrhage (13 [4·4%] vs seven [2·4%]), and epileptic seizures (five [1·7%] vs nine [3·1%]). INTERPRETATION: We could not conclude non-inferiority of burr-hole drainage without irrigation. The reoperation rate was 6·0 percentage points higher after burr-hole drainage without subdural irrigation than with subdural irrigation. Considering that there were no differences in functional outcome or mortality between the groups, the trial favours the use of subdural irrigation. FUNDING: State Fund for University Level Health Research (Helsinki University Hospital), Finska Läkaresällskapet, Medicinska Understödsföreningen Liv och Hälsa, and Svenska Kulturfonden.

Therapeutic efficacy of drilling drainage combined with intraoperative middle meningeal artery occlusion in the management of chronic subdural hematoma: a clinical study.

BACKGROUND: The bone holes in the skull during surgical drainage were accurately located at the site of the MMA. The MMA was severed, and the hematoma was removed intraoperatively; furthermore, surgical drainage removed the pathogenic factors of CSDH. This study aimed to describe and compare the results of the new treatment with those of traditional surgical drainage, and to investigate the relevance of this approach. METHODS: From December 2021 to June 2023, 72 patients were randomly assigned to the observation group and the control group. The control group was treated with traditional surgical drainage, while the observation group was treated with DSA imaging to accurately locate the bone holes drilled in the skull on the MMA trunk before traditional surgical drainage. The MMA trunk was severed during the surgical drainage of the hematoma. The recurrence rate, time of indwelling drainage tube, complications, mRS, and other indicators of the two groups were compared, and the changes of cytokine components and imaging characteristics of the patients were collected and analyzed. RESULTS: Overall, 27 patients with 29-side hematoma in the observation group and 45 patients with 48-side hematoma in the control group were included in the study. The recurrence rate was 0/29 in the observation group and 4/48 in the control group, indicating that the recurrence rate in the observation group was lower than in the control group (P = .048). The mean indwelling time of the drainage tube in the observation group was 2.04 ± 0.61 days, and that in the control group was 2.48 ± 0.61 days. The indwelling time of the drainage tube in the observation group was shorter than in the control group (P = .003). No surgical complications were observed in the observation group or the control group. The differences in mRS scores before and after operation between the observation group and the control group were statistically significant (P < .001). The concentrations of cytokine IL6/IL8/IL10/VEGF in the hematoma fluid of the observation and control groups were significantly higher than those in venous blood (P < .001). After intraoperative irrigation and drainage, the concentrations of cytokines (IL6/IL8/IL10/VEGF) in the subdural hematoma fluid were significantly lower than they were preoperatively. In the observation group, the number of MMA on the hematoma side (11/29) before STA development was higher than that on the non-hematoma side (1/25), and the difference was statistically significant (P = .003). CONCLUSION: In patients with CSDH, accurately locating the MMA during surgical trepanation and drainage, severing the MMA during drainage, and properly draining the hematoma, can reduce the recurrence rate and retention time of drainage tubes, thereby significantly improving the postoperative mRS Score without increasing surgical complications.

[Az arteria meningea media embolisatio szerepe a krónikus subduralis haematoma kezelési algoritmusában, legújabb evidenciák és saját tapasztalataink]. / Az arteria meningea media embolisatio szerepe a krónikus subduralis haematoma kezelési algoritmusában, legújabb evidenciák és saját tapasztalataink.

Chronic subdural hematoma is one of the most common diseases requiring a neurosurgical operation that affect elderly and fragile patients. In addition to standard neurosurgical operations (trepanation and craniotomy), embolization of the meningeal artery media is an alternative solution. Several review aerticles have confirmed the very high rate of success and safety of the endovascular treatment. We present the technical details and results of our 10 consecutive selective media meningeal artery embolization procedures for residual chronic subdural hematomas. Our interventions were performed without complications and all resulted in complete recovery. 

Comparative analysis of surgical techniques in the management of chronic subdural hematomas and risk factors for poor outcomes.

Chronic subdural hematomas (CSDH) are increasingly prevalent, especially among the elderly. Surgical intervention is essential in most cases. However, the choice of surgical technique, either craniotomy or burr-hole opening, remains a subject of debate. Additionally, the risk factors for poor long-term outcomes following surgical treatment remain poorly described. This article presents a 10-year retrospective cohort study conducted at a single center that aimed to compare the outcomes of two common surgical techniques for CSDH evacuation: burr hole opening and minicraniotomy. The study also identified risk factors associated with poor long-term outcome, which was defined as an mRS score ≥ 3 at 6 months. This study included 582 adult patients who were surgically treated for unilateral CSDH. Burr-hole opening was performed in 43% of the patients, while minicraniotomy was performed in 57%. Recurrence was observed in 10% of the cases and postoperative complications in 13%. The rates of recurrence, postoperative complications, death and poor long-term outcome did not differ significantly between the two surgical approaches. Multivariate analysis identified postoperative general complications, recurrence, and preoperative mRS score ≥ 3 as independent risk factors for poor outcomes at 6 months. Recurrence contribute to a poorer prognosis in CSDH. Nevertheless, use burr hole or minicraniotomy for the management of CSDH showed a similar recurrence rate and no significant differences in post-operative outcomes. This underlines the need for a thorough assessment of patients with CSHD and the importance of avoiding their occurrence, by promoting early mobilization of patients. Future research is necessary to mitigate the risk of recurrence, regardless of the surgical technique employed.

Organized Chronic Subdural Hematoma (OCSDH) Mimicking Meningioma.

Organized chronic subdural hematoma (OCSDH) is a relatively rare condition that forms over a longer period of time compared to chronic subdural hematoma and is sometimes difficult to diagnose with preoperative imaging. We resected an intracranial lesion in a 37-year-old Japanese man; the lesion had been increasing in size for >17 years. The preoperative diagnosis based on imaging findings was meningioma; however, pathological findings revealed OCSDH. Clinicians should be aware that OCSDH mimics other tumors and consider surgical strategies for this disease.

Aquaporin 2 in Cerebral Edema: Potential Prognostic Marker in Craniocerebral Injuries.

Despite continuous medical advancements, traumatic brain injury (TBI) remains a leading cause of death and disability worldwide. Consequently, there is a pursuit for biomarkers that allow non-invasive monitoring of patients after cranial trauma, potentially improving clinical management and reducing complications and mortality. Aquaporins (AQPs), which are crucial for transmembrane water transport, may be significant in this context. This study included 48 patients, with 27 having acute (aSDH) and 21 having chronic subdural hematoma (cSDH). Blood plasma samples were collected from the participants at three intervals: the first sample before surgery, the second at 15 h, and the third at 30 h post-surgery. Plasma concentrations of AQP1, AQP2, AQP4, and AQP9 were determined using the sandwich ELISA technique. CT scans were performed on all patients pre- and post-surgery. Correlations between variables were examined using Spearman's nonparametric rank correlation coefficient. A strong correlation was found between aquaporin 2 levels and the volume of chronic subdural hematoma and midline shift. However, no significant link was found between aquaporin levels (AQP1, AQP2, AQP4, and AQP9) before and after surgery for acute subdural hematoma, nor for AQP1, AQP4, and AQP9 after surgery for chronic subdural hematoma. In the chronic SDH group, AQP2 plasma concentration negatively correlated with the midline shift measured before surgery (Spearman's ρ -0.54; p = 0.017) and positively with hematoma volume change between baseline and 30 h post-surgery (Spearman's ρ 0.627; p = 0.007). No statistically significant correlation was found between aquaporin plasma levels and hematoma volume for AQP1, AQP2, AQP4, and AQP9 in patients with acute SDH. There is a correlation between chronic subdural hematoma volume, measured radiologically, and serum AQP2 concentration, highlighting aquaporins' potential as clinical biomarkers.

[Transient neurological deficits in a patient with chronic subdural hematoma].

A 62-year-old, right-handed man was diagnosed with asymptomatic bilateral chronic subdural hematomas and underwent hematoma removal on the left side only. At 1 month after surgery, he was admitted to our hospital because he began to have one or two attacks/day of apraxia of speech and dysesthesia of the right hand with a duration of approximately 5 |min. The left hematoma had not re-expanded, but fluid-attenuated inversion resonance imaging showed hyperintense lesions in the sulci adjacent to the hematoma. Moreover, single-photon emission computed tomography revealed low-uptake lesions in the left cerebrum adjacent to the hematoma. Electroencephalogram showed no abnormalities, and CT angiography showed a slight deviation of the left middle cerebral arteries due to the hematoma. The attacks disappeared within 10 days, although the volume of the hematoma was unchanged. It was suggested that his transient neurological deficits were caused by cerebral ischemia related to chronic subdural hematoma.

Assessment of Surgical Treatment and Outcome of Chronic Subdural Hematoma at University of Gondar Comprehensive Specialized Hospital, a one Year Prospective Study.

OBJECTIVE: Chronic subdural hematomas (CSDHs) are a relatively common condition defined as an abnormal collection of blood and its break down products in the subdural space, usually accompanied by a history of preceding mild head trauma. Surgical management remains the mainstay of treatment. The objective of this study was to assess the surgical treatment outcome of patients operated on for CSDH at University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia. This comprehensive novel study serves as a benchmark for assessing therapeutic outcomes among patients with CSDH in the context of Ethiopia. METHODS: Institution-based prospective observational study was conducted among patients operated on for symptomatic CSDH at University of Gondar Comprehensive Specialized Hospital from January 1, 2023, to December 31, 2023 G C. RESULT: A total of 107 patients (70 males (65.4%) and 37 females (34.6%) with a male to female ration of 1.9:1 and mean age of 62.4 and a standard deviation of 13.7 (range from 23 to 92) were studied. Fifyt-one (47.7%) of the patients had a history of antecedent trauma. In terms of clinical symptoms, 86 (80.4%) patients had weakness as the chief complaint, followed by headache in 81 (75.7%). Among complications, recurrence is the most common, which was seen in 16 (15%) patients, followed by altered mental status (confusion, delirium) in 18 (16.8%) patients. The mean duration of the hospital stay was 6 days, with a standard deviation of 4 days. The majority of the patients had a good recovery with the resumption of normal life: 92 (86%), 10 (9.3%) patients had moderate disability, were disabled but independent, 2 (1.8%) patients had severe disability, were dependent on daily support, and 3 (2.8%) patients died. CONCLUSION: CSDHs are a relatively common condition characterized by an abnormal collection of blood. Antecedent trauma is the usual risk factor. Complication can happen following surgical intervention; however, patients with CSDH generally have a good prognosis.

Occult middle meningeal artery to middle cerebral artery anastomosis associated with prior trauma.

The report describes a patient who presented with traumatic right temporoparietal calvarial fracture with chronic right subdural haematoma who underwent right middle meningeal artery embolisation with n-BCA during which direct filling of an anterior temporal branch of the middle cerebral artery was observed.

Initial experience using middle meningeal artery embolisation for patients with recurrent and high-recurrence-risk chronic subdural haematoma.

Recurrence rates following surgical management of chronic subdural haematoma (CSDH) range from 5 to 33 %. There is growing evidence which suggests middle meningeal artery embolisation (MMAe) may reduce recurrence rates when used as surgical adjunct or standalone treatment. In this study we described our experience of this new procedure in the our UK institution. Patients with recurrent CSDH or CSDH at high risk of recurrence were selected for MMAe on a case-by-case basis following MDT discussion. A departmental database was used to identify patients treated. 26 CSDH were embolised in 20 patients; 9 CSDH were de-novo and 17 were recurrent. 10/26 CSDH were treated with MMAe only. No procedural mortality, access site or thrombo-embolic complications occurred. One patient experienced symptomatic collection growth 12 h following MMAe and required surgical drainage. 15 (75 %) of patients were living at home at follow-up (mean 14 months). On imaging follow-up 15/18 showed CSDH volume reduction or resolution, 1/18 remained stable requiring no further treatment, 2/18 patients suffered recurrent CSDH requiring treatment. In both recurrent cases incomplete embolisation was noted on procedural imaging (posterior division of MMA not embolised). Persistent posterior MMA division filling was significantly associated with collection recurrence (p = 0.002). Our results suggest MMAe as a stand-alone or adjuvant therapy can be performed safely in a UK neuroscience setting and is associated with high rates of symptomatic CSDH size reduction or resolution in problematic CSDH that have either recurred or are prone to recurrence.

Comparative efficacy of dexamethasone versus surgery for chronic subdural hematoma: A systematic review and meta-analysis.

OBJECTIVE: To assess the comparative efficacy of dexamethasone (DXM) as monotherapy in comparison to surgery among the patients of chronic subdural hematoma (CSDH). METHODS: We searched MEDLINE, PUBMED, EMBASE, and Cochrane Central Register of Controlled Trials databases from inception till September 2023. Data was extracted, pooled and analyzed from all the studies that assessed the comparative efficacy of DXM as monotherapy in contrast with surgery as the primary treatment of CSDH. RESULTS: A total of 6 studies involving 704 patients were included in our meta-analysis. Comparison of surgery to DXM revealed there was no statistically significant difference between the two groups regarding mortality [RR=1.09; 95% CI; 0.52-2.28 P = 0.83]. However, a significantly higher incidence of secondary surgical intervention was observed in the DXM group [RR 4.24; 95% CI; 2.06-8.71 P < 0.0001]. No significant difference in performance was observed in terms of poor postoperative outcomes within hospital stay [RR 1.12, 95% CI, 0.40-3.19 P=0.83] and at 6 months [RR 0.92, 95%CI, 0.40-2.13 P=0.85]. CONCLUSION: DXM had a significantly higher incidence of secondary surgical intervention. However, there was no difference regarding mortality and other safety outcomes between surgery and DXM for the patients with CSDH. Observational studies showed that DXM was associated with a lower risk of poor postoperative outcomes within hospital stay and had shorter duration of hospital stay, but the recurrence rate was lower in the surgery group.

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.

Acute-to-chronic subdural hematoma: radiographic and clinical progression from acute subdural hematoma.

INTRODUCTION: The pathogenesis of chronic subdural hematoma (CSDH) has not been completely understood. However, different mechanisms can result in space-occupying subdural fluid collections, one pathway can be the transformation of an original trauma-induced acute subdural hematoma (ASDH) into a CSDH. MATERIALS AND METHODS: All patients with unilateral CSDH, requiring burr hole trephination between 2018 and 2023 were included. The population was distributed into an acute-to-chronic group (group A, n = 41) and into a conventional group (group B, n = 282). Clinical and radiographic parameters were analyzed. In analysis A, changes of parameters after trauma within group A are compared. In analysis B, parameters between the two groups before surgery were correlated. RESULTS: In group A, volume and midline shift increased significantly during the progression from acute-to-chronic (p < 0.001, resp.). Clinical performance (modified Rankin scale, Glasgow Coma Scale) dropped significantly (p = 0.035, p < 0.001, resp.). Median time between trauma with ASDH and surgery for CSDH was 12 days. Patients treated up to the 12th day presented with larger volume of ASDH (p = 0.012). Before burr hole trephination, patients in group A presented with disturbance of consciousness (DOC) more often (p = 0.002), however less commonly with a new motor deficit (p = 0.014). Despite similar midline shift between the groups (p = 0.8), the maximal hematoma width was greater in group B (p < 0.001). CONCLUSION: If ASDH transforms to CSDH, treatment may become mandatory early due to increase in volume and midline shift. Close monitoring of these patients is crucial since DOC and rapid deterioration is common in this type of SDH.

Advances in pathogenic mechanisms, diagnostic methods, surgical and non-surgical treatment, and potential recurrence factors of Chronic Subdural Hematoma: A review.

Chronic Subdural Hematoma (CSDH) is a common hemorrhagic disease in neurosurgery, and with the intensification of global aging, its incidence is gradually increasing. With the advancement of scientific technology, the etiological concepts and surgical treatments for CSDH have continually evolved over time. Currently, neuroscientists' understanding of CSDH is no longer confined to bridging vein rupture; exploration of various mechanisms such as angiogenesis, maturation of blood vessels, and inflammation is also underway. In-depth exploration and discovery of pathogenic mechanisms guide the updating of clinical treatment strategies and methods. For different types of CSDH, there is now a clear guidance for the targeted selection of treatment methods. However, the current treatment of CSDH cannot completely solve all problems, and the updating of treatment methods as well as the development and validation of new effective drugs remain challenges for the future. In addition, the recurrence of CSDH is a significant issue that needs to be addressed. Although we have reviewed potential recurrent factors that may be associated, the strength of this evidence is insufficient. Future research should gradually focus on validating these recurrent factors and exploring new ones, in order to optimize the existing understanding and treatment of CSDH.

Quantitative Assessment of Brain Expansion After Evacuation of Chronic Subdural Hematoma as a Predictor of Recurrence.

BACKGROUND: A lack of brain expansion is considered a risk factor for recurrence after evacuation of a chronic subdural hematoma (CSDH). To the best of our knowledge, no studies have reported on objective measurement of brain expansion after evacuation of a CSDH. METHODS: We performed a retrospective analysis of prospectively collected data of patients undergoing 2 burr hole evacuation of a CSDH. We measured the depth of the brain surface from the frontal burr hole dural opening after hematoma evacuation using a specially devised measuring tool. Other predictors analyzed for recurrence of hematoma were age, gender, a history of hypertension, the use of anticoagulant and/or antiplatelet agents, Glasgow coma scale score at presentation, unilateral or bilateral hematoma, computed tomography appearance, and hematoma thickness. RESULTS: Among 88 patients who underwent hematoma evacuation, 3 (3.4%) underwent surgery for recurrence. The significant factors associated with recurrence were the presence of bilateral hematoma (P = 0.001), hematoma width >2.3 cm (P = 0.04), gradation type of hematoma on the computed tomography scan (P = 0.03), and the depth of the brain after hematoma evacuation (P = 0.02). The brain expanded less in those with recurrence, with a mean depth of the brain of 18 ± 6 mm versus 7.27 ± 7.8 mm in those without recurrence. CONCLUSIONS: Evacuation of a CSDH through 2 burr holes, along with copious irrigation and bed rest for 3 days, resulted in a very low recurrence rate without the use of a drain. A lack of brain expansion might be a predictor of recurrence. To the best of our knowledge, this is the first study to quantitatively measure the depth of the brain at surgery in patients undergoing surgery for CSDH.

Challenges and patient outcomes in chronic subdural haematoma at the level of a regional care system A multi-centre, mixed-methods study from the East of England.

BACKGROUND: Chronic subdural haematoma (cSDH) is a common neurosurgical pathology affecting older patients with other health conditions. A significant proportion (up-to 90%) of referrals for surgery in neurosciences units (NSU) come from secondary care. However, the organisation of this care and the experience of patients repatriated to non-specialist centres are currently unclear. OBJECTIVES: This study aimed to clarify patient outcome in non-specialist centres following NSU discharge for cSDH surgery and to understand key system challenges. The study was set within a representative neurosurgical care system in the east of England. DESIGN AND METHODS: We performed a retrospective cohort analysis of patients referred for cSDH surgery. Alongside case record review, patient and staff experience were explored using surveys as well as an interactive c-design workshop. Challenges were identified from thematic analysis of survey responses and triangulated by focussed workshop discussions. RESULTS: Data on 381 patients referred for cSDH surgery from six centres was reviewed. One hundred and fifty-six (41%) patients were repatriated following surgery. Sixty-one (39%) of those repatriated suffered an inpatient complication (new infection, troponin rise or renal injury) following NSU discharge, with 58 requiring institutional discharge or new care. Surveys for staff (n = 42) and patients (n = 209) identified that resourcing, communication, and inter-hospital distance posed care challenges. This was corroborated through workshop discussions with stakeholders from two institutions. CONCLUSIONS: A significant amount of perioperative care for cSDH is delivered outside of specialist centres. Future improvement initiatives must recognise the system-wide nature of delivery and the challenges such an arrangement presents.

Middle meningeal artery patency after surgical evacuation for chronic subdural hematoma.

BACKGROUND: Chronic subdural hematoma (CSDH) often requires surgical evacuation, but recurrence rates remain high. Middle meningeal artery (MMA) embolization (MMAE) has been proposed as an alternative or adjunct treatment. There is concern that prior surgery might limit patency, access, penetration, and efficacy of MMAE, such that some recent trials excluded patients with prior craniotomy. However, the impact of prior open surgery on MMA patency has not been studied. METHODS: A retrospective analysis was conducted on patients who underwent MMAE for cSDH (2019-2022), after prior surgical evacuation or not. MMA patency was assessed using a six-point grading scale. RESULTS: Of the 109 MMAEs (84 patients, median age 72 years, 20.2% females), 58.7% were upfront MMAEs, while 41.3% were after prior surgery (20 craniotomies, 25 burr holes). Median hematoma thickness was 14 mm and midline shift 3 mm. Hematoma thickness reduction, surgical rescue, and functional outcome did not differ between MMAE subgroups and were not affected by MMA patency or total area of craniotomy or burr-holes. MMA patency was reduced in the craniotomy group only, specifically in the distal portion of the anterior division (p = 0.005), and correlated with craniotomy area (p < 0.001). CONCLUSION: MMA remains relatively patent after burr-hole evacuation of cSDH, while craniotomy typically only affects the frontal-distal division. However, MMA patency, evacuation method, and total area do not affect outcomes. These findings support the use of MMAE regardless of prior surgery and may influence future trial inclusion/exclusion criteria. Further studies are needed to optimize the timing and techniques for MMAE in cSDH management.