Surgical treatment of chronic subdural hematoma based on intrahematomal membrane structure on MRI

Advances in chronic subdural hematoma and membrane imaging

Chronic subdural hematoma (cSDH) is projected to become the most common cranial neurosurgical disease by 2030. Despite medical and surgical management, recurrence rates remain high. Recently, middle meningeal artery embolization (MMAE) has emerged as a promising treatment; however, determinants of disease recurrence are not well understood, and developing novel radiographic biomarkers to assess hematomas and cSDH membranes remains an active area of research. In this narrative review, we summarize the current state-of-the-art for subdural hematoma and membrane imaging and discuss the potential role of MR and dual-energy CT imaging in predicting cSDH recurrence, surgical planning, and selecting patients for embolization treatment.

Neuroendoscopic Technique for Septated Chronic Subdural Hematoma: A Retrospective Study

OBJECTIVES

To compare the efficacy of neuroendoscopic hematoma evacuation (NHE) and burr hole craniotomy (BHC) for treating septated chronic subdural hematoma (sCSDH) and analyze the technical advantages of NHE in sCSDH treatment by data analysis.

METHODS

This study recruited 77 patients with sCSDH According to the type of operation, the patients were divided into NHE (n = 45) or BHC (n = 32) groups. Clinical data were retrospectively analyzed to evaluate and compare the efficacy of NHE and BHC for treating sCSDH.

RESULTS

NHE demonstrated higher complete hematoma clearance and postoperative midline recovery rates and shorter subdural drainage and postoperative bed rest durations compared with BHC (P < 0.05). The average NHE time (72.27 ± 18.27 minutes) was longer than that of BHC (54.91 ± 16.04 minutes) (P < 0.05). The average follow-up period was 30.9 (range, 7-51) months. The results revealed that 1 and 12 cases recurred in the NHE (2.2%) and BHC (18.8%) groups, respectively (P < 0.05). Additionally, a statistically significant difference in the Modified Rankin Scale scores of the 2 groups was observed 6 months after the operation (P < 0.05). During the follow-up period, neither group demonstrated any obvious operative complications.

CONCLUSIONS

NHE is more effective than BHC for treating sCSDH and is worth popularizing on a large scale; however, ways to better deal with the outer membrane of hematoma warrant further consideration.

Predictors and Outcomes of Subdural Hematomas Managed via Subdural Evacuation Port System

Background

Subacute subdural hematoma (SDH) is a common pathology most frequently affecting older patients and may be treated operatively through burr holes versus craniotomy or minimally invasively with bedside twist drill craniostomy. Less invasive intervention is favored when possible given a frequently comorbid population. The subdural evacuation port system (SEPS) is a popular treatment option that warrants investigation and reporting of its use and outcomes.

Methods

A retrospective review of consecutive patients undergoing SEPS drain placement for chronic or mixed density SDH between 2010 and 2021 was conducted. Outcomes of SDH recurrence, need for operating room procedure after SEPS placement, discharge disposition other than home, and modified Rankin Scale score <3 at discharge were modeled with logistic regression using multiple demographic, clinical, and radiographic features.

Results

Ultimately, 86 patients (mean age 68) were included in the analysis with 66 (78%) presenting with mixed-density SDHs. Radiographic factors such as hematoma thickness and midline shift were not associated with the need for an operating room procedure after SEPS placement or discharge disposition. However, the presence of septations and mixed-density SDH versus chronic SDH was significantly associated with increased odds of requiring an operative intervention after SEPS placement.

Conclusions

Subacute SDHs are a frequent neurosurgical issue in patient populations where less invasive measures are favored. SEPS drainage continues to be an effective treatment option. However, the presence of septations and mixed-density SDHs has a significantly increased odds of requiring surgical intervention that must be considered in the decision to pursue SEPS drainage.

Clinical and Radiologic Outcomes of Single Burr Hole Drainage and Minicraniotomy in the Treatment of Inhomogeneous Chronic Subdural Hematoma: A Retrospective Study

OBJECTIVE

The optimal treatment for inhomogeneous chronic subdural hematoma (CSH) remains unclear. This study thus aimed to compare single burr hole drainage with minicraniotomy in the treatment of inhomogeneous CSH, including complication and recurrence rates.

METHODS

The clinical and radiologic data of 240 patients with inhomogeneous CSH who underwent surgery between January 2005 and January 2021 were retrieved. A total of 111 patients were included in this study. Clinical and radiological outcomes were compared between the groups undergoing different surgery types.

RESULTS

A total of 102 (91.8%) patients showed clinical improvement after surgery; 81 (93.1%) and 21 (87.5%) patients showed improvements in clinical symptoms in the single burr hole and minicraniotomy groups, respectively. A total of 102 (91.9%) patients showed favorable radiological findings after the surgery, including inhomogeneous CSH disappearance in 64 (73.6%) burr hole and 13 (54.2%) minicraniotomy patients, and inhomogeneous CSH improvement in 17 (19.5%) burr hole and 8 (33.3%) minicraniotomy patients. There were no significant differences in the patient characteristics or surgical outcomes between the groups.

CONCLUSION

Single burr hole drainage showed a slightly better improvement in clinical and radiologic findings and lower recurrence and complication rates than minicraniotomy. There were no statistically significant differences between the two groups.

MRI appearance of chronic subdural hematoma

Objective

We aimed to describe the magnetic resonance imaging (MRI) characteristics of chronic subdural hematoma (cSDH) and to ascribe MRI patterns.

Methods

A total of 20 patients having 27 subdural hematomas underwent contrast-enhanced (CE) MRI of the brain at our institution between April 2019 and May 2021. The images were independently evaluated by two experienced neuroradiologists with regard to imaging characteristics on T1w, T2w, T2*-GRE, FLAIR, diffusion-weighted magnetic resonance imaging (DWI), and CE images.

Results

The signal characteristics of cSDH on T1- and T2-weighted images were rather heterogeneous. The majority of hematomas (74%) had internal septations. Surprisingly, contrast enhancement along the outer membrane adjacent to the cranium was noticed in all hematomas. There was also contrast enhancement along the inner membrane adjacent to the brain in more than one-third of the hematomas (37%). In approximately two-thirds of the cSDH (62%), there was a mass-like enhancement of the hematoma. Most hematomas (89%) were partially hypointense on T2*-GRE and/or susceptibility-weighted imaging (SWI). Restricted diffusion was detected in approximately one-third of the hematomas (33%).

Conclusion

Consistent contrast enhancement along the outer membrane, triangular-shaped contrast enhancement at the borders of the cSDH, and infrequent enhancement of the inner membrane may help to distinguish cSDH from other entities such as empyema and tumors. Mass-like enhancement may refer to non-solid hematomas and could be an indicator for hematoma growth and a possible surrogate for successful endovascular embolization. Restricted diffusion in a subdural mass is not specific for empyema but may also be found in cSDH.

Enigmatic rapid organization of subdural hematoma in a patient with epilepsy: A case report

BACKGROUND

Determining a subdural hematoma (SDH) to be chronic by definition takes 3 wk, whereas organized chronic SDH (OCSDH) is an unusual condition that is believed to form over a much longer period of time, which generally demands large craniotomy. Therefore, it is a lengthy process from the initial head trauma, if any, to the formation of an OCSDH. Acute SDH (ASDH) with organization-like, membranaceous appearances has never been reported.

CASE SUMMARY

A 56-year-old woman presented to our hospital with a seizure, and computed tomography (CT) on admission was negative for signs of intracranial hemorrhage. She had clear consciousness and unimpaired motor functions on arrival and remained stable for the following week, during which she underwent necessary examinations. On the morning of day 10 of hospitalization, she accidentally hit her head hard against the wall in the bathroom and promptly lapsed into complete coma within 2 h. Therefore, we performed emergency CT and identified a left supratentorial SDH that was an absolute indication for surgery. However, the intraoperative findings were surprising, with no liquefaction observed. Instead, a solid hematoma covered with a thick membrane was noted that strongly resembled an organized hematoma. Evacuation was successful, but the family stopped treatment the next day due to financial problems, and the patient soon died.

CONCLUSION

Neurosurgeons should address SDHs, especially ASDHs, with discretion and individualization due to their highly diversified features.

A Radiological Assessment of Chronic Subdural Hematomas

Chronic subdural hematoma (CSDH), which generally occurs in elderly patients, is a frequently diagnosed condition in neurosurgical departments. Computed tomography (CT) and magnetic resonance imaging (MRI) are the most preferred diagnostic modalities for CSDH assessment. With early diagnosis and adequate management, CSDH may show favorable prognosis in majority of the patients; however, recurrence after surgery can occur in a significant number of patients. The recently increasing number of CSDH studies could reveal the prognostic factors affecting CSDH recurrence. Particularly, radiological characteristics regarding the internal architecture of CSDH are considered closely associated with recurrence in surgically treated CSDH patients. In this literature review, we evaluated the various diagnostic modalities of CSDH and its radiological characteristics on CT and MRI. Furthermore, we summarized the prognostic factors of recurrence for the hematoma type based on the radiological findings.

Efficacy of endoscopic treatment for chronic subdural hematoma surgery

Endoscopic treatment is a potential therapeutic addition to chronic subdural hematoma (CSDH) surgery. However, the effect of endoscopic treatment remains controversial. Herein, we examined the optimal indication for endoscopic treatment in CSDH surgery. We retrospectively analyzed 380 consecutive patients with CSDH who underwent single burr-hole craniostomy. We defined postoperative rebleeding as radiological re-accumulation or increased computed tomography value of the hematoma. Reoperation was performed following further hematoma accumulation and/or neurological deterioration. Complicated CSDH was radiologically defined as a hematoma with a clot and/or fibrous septum. There were no differences in baseline characteristics or postoperative mortality and morbidity between the endoscope (97 patients) and control (283 patients) groups. The incidence of postoperative rebleeding (9.3% vs 25.1%, respectively; P = 0.001) and reoperation (0% vs 9.2%, respectively; P = 0.004) were significantly lower in the endoscope group versus controls. Multivariate analysis showed that males (odds ratio 2.14, 95% confidence interval 1.19-3.81; P = 0.012) and endoscopy (odds ratio 0.29, 95% confidence interval 0.13-0.59; P = 0.001) were independently associated with postoperative rebleeding. When CSDHs were divided into two types based on hematoma component, 175 patients exhibited complicated CSDH. There was a significant reduction in postoperative rebleeding (6.5% vs 23.0%, respectively; P = 0.010) and reoperation (0% vs 9.7%, respectively; P = 0.027) in complicated CSDH patients. Endoscopic treatment in CSDH surgery does not increase the risk of surgical complications. Complicated CSDH with a clot and/or septum may be an optimal indication for endoscopic treatment in CSDH surgery to reduce postoperative recurrence.

Hematoma subdural crónico: Una patología común de manejo complejo

Antecedentes:

El hematoma subdural crónico (HSDC) es una patología ampliamente estudiada, muy frecuente, sobre todo en adultos mayores; su cuadro clínico tiene una apariencia benigna y suele ir acompañado de múltiples comorbilidades asociadas a la edad, lo que resulta en un aumento de las complicaciones e incluso la muerte. Con el incremento de la expectativa de vida a nivel mundial, el uso de medicamentos antitrombóticos es cada vez más frecuente. El papel de estos fármacos en la evolución de la enfermedad como en la recurrencia, sigue siendo motivo de discusión.

Métodos:

Los autores revisaron la fisiopatología y características clínicas del HSDC. El presente artículo discute acerca de las terapéuticas actuales y las nuevas opciones de tratamiento que podrían mejorar los resultados. Este manuscrito es susceptible de cambios en el tiempo, con el desarrollo científico y tecnológico.

Resultados:

El HSDC puede ser abordado por vía quirúrgica y farmacológica; no obstante, un manejo individualizado requiere la consideracion cuidadosa de diversos factores. A pesar de los avances en el campo de la neurocirugía, la clásica trepanación craneal sigue siendo el Gold estándar en el HSDC y sobre todo en pacientes con síntomas graves. Se debe resaltar que aún hay aspectos de este procedimiento (como la localización del dren, número de drenajes, el efecto de la irrigación, la temperatura de la solución con que se irriga, etc.) que siguen siendo materia de estudio.

Conclusiones:

Entender el mecanismo de la enfermedad ha permitido explicar su historia natural y a su vez proponer nuevas alternativas de tratamiento. El manejo médico (atorvastatina, corticoides) ha generado gran interés por sus alentadores resultados preliminares. Recientemente, se ha reportado la terapia endovascular como una alternativa segura y existe gran expectativa por confirmar su efecto en estudios más grandes.

Radiological prognostic factors of chronic subdural hematoma recurrence: a systematic review and meta-analysis

Purpose

Chronic subdural hematoma (CSDH) is associated with high recurrence rates. Radiographic prognostic factors may identify patients who are prone for recurrence and who might benefit further optimization of therapy. In this meta-analysis, we systematically evaluated pre-operative radiological prognostic factors of recurrence after surgery.

Methods

Electronic databases were searched until September 2020 for relevant publications. Studies reporting on CSDH recurrence in symptomatic CSDH patients with only surgical treatment were included. Random or fixed effects meta-analysis was used depending on statistical heterogeneity.

Results

Twenty-two studies were identified with a total of 5566 patients (mean age 69 years) with recurrence occurring in 801 patients (14.4%). Hyperdense components (hyperdense homogeneous and mixed density) were the strongest prognostic factor of recurrence (pooled RR 2.83, 95% CI 1.69–4.73). Laminar and separated architecture types also revealed higher recurrence rates (RR 1.37, 95% CI 1.04–1.80 and RR 1.76 95% CI 1.38–2.16, respectively). Hematoma thickness and midline shift above predefined cut-off values (10 mm and 20 mm) were associated with an increased recurrence rate (RR 1.79, 95% CI 1.45–2.21 and RR 1.38, 95% CI 1.11–1.73, respectively). Bilateral CSDH was also associated with an increased recurrence risk (RR 1.34, 95% CI 0.98–1.84).

Limitations

Limitations were no adjustments for confounders and variable data heterogeneity. Clinical factors could also be predictive of recurrence but are beyond the scope of this study.

Conclusions

Hyperdense hematoma components were the strongest prognostic factor of recurrence after surgery. Awareness of these findings allows for individual risk assessment and might prompt clinicians to tailor treatment measures.

Analysis of Endoscopic Findings in the Chronic Subdural Hematoma Cavity: Bleeding Factors in Chronic Subdural Hematoma Natural History and as Predictors of Recurrence

OBJECTIVE

Possible factors associated with bleeding from endoscopy-detected chronic subdural hematomas (CSDHs) have rarely been analyzed. We therefore evaluated intraoperative endoscopic findings to elucidate the clinical course and assess predictors of CSDH recurrence.

METHODS

Altogether, 540 CSDHs were reviewed in this retrospective study. Six possible signs of bleeding were detected in the cavity: spotty bleeding on the outer membrane, hematoma clots, cerebral parenchymal suspension, stretched cortical vessels, intraluminal trabecular structures, and septa separating the cavity. We evaluated the association of each with the radiologic findings, endoscopic features, and interval from trauma to surgery and then assessed the correlation between each endoscopic feature and CSDH recurrence.

RESULTS

Spotty bleeding, cerebral parenchymal suspension, and stretched cortical vessels occurred during every period. Hematoma clots exhibited a 2-peak pattern with significant resurgence during the chronic phase. Trabecular structures significantly increased 61 days after the trauma, reaching 71.2% of patients on day 91. Septa were found in the cavity in only 12.5% during the initial 30 days but subsequently increased significantly to 37.3%. At 2 months, an exacerbation stage was inferred. The multivariable analysis revealed that trabecular structures and residual septa were significant independent risk factors for recurrence. We opened most septa intraoperatively. Their recurrence rate was 7.5%, which is lower than has been previously reported.

CONCLUSIONS

Evaluation of the changes in the endoscopic findings and their association with recurrence was useful for clarifying the mechanism of CSDH enlargement, the risk of recurrence, and the potential for endoscopic surgery.

Description of a Modified Technique (mini craniotomy-basal membranotomy) for Chronic Subdural Hematoma Surgery and Evaluation of the Contribution of Basal Membranotomy Performed as Part of This Technique to Cerebral Expansion

OBJECTIVE

To determine the effectiveness of basal membranotomy performed to ensure cerebral expansion in patients operated for chronic subdural hematoma.

METHODS

Patients who were operated for unilateral chronic subdural hematoma and underwent basal membranotomy in addition to hematoma drainage were included in the first phase of the study. After the superficial membranous structures were excised, the maximum perpendicular distance between the internal tabula and the cerebral surface was measured after subdural hematoma evacuation. Subsequently, basal membranotomy was performed, the maximum perpendicular distance between the internal tabula and the cerebral surface was measured again, and the improvement in cerebral expansion was statistically calculated. The improvement of cerebral expansion in the patients who had undergone double burr hole drainage was statistically calculated in the second stage of the study.

RESULTS

The cerebral expansion after the basal membrane excision was 41.1% in those with a 1.5- to 2-cm hematoma, 43.1% in those with a 2.1- to 3-cm hematoma, 43.5% in those with a 3.1- to 4-cm hematoma, and 45.4% in those with a hematoma thicker than 4 cm on average. No recurrence was seen during the 6-month follow-up in any patient. Double burr hole drainage revealed similar values for cerebral expansion increase with a mean value of 10%. The burr hole drainage was repeated because of recurrence in 5 patients during the 2-month follow-up.

CONCLUSIONS

The mini craniotomy-basal membranotomy technique provided statistically significantly better cerebral expansion in patients with chronic subdural hematoma when compared with the double burr hole drainage technique.

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.

Management of Subdural Hematomas: Part I. Medical Management of Subdural Hematomas

PURPOSE OF REVIEW

Subdural hematomas (SDH) represent common neurosurgical problem associated with significant morbidity, mortality, and high recurrence rates. SDH incidence increases with age; numbers of patients affected by SDH continue to rise with our aging population and increasing number of people taking antiplatelet agents or anticoagulation. Medical and surgical SDH management remains a subject of investigation.

RECENT FINDINGS

Initial management of patients with concern for altered mental status with or without trauma starts with Emergency Neurological Life Support (ENLS) guidelines, with a focus on maintaining ICP < 22 mmHg, CPP > 60 mmHg, MAP 80-110 mmHg, and PaO₂ > 60 mmHg, followed by rapid sequence intubation if necessary, and expedited acquisition of imaging to identify a space-occupying lesion. Patients are administered anti-seizure medications, and their antiplatelet medications or anticoagulation may be reversed if neurosurgical interventions are anticipated, or until hemorrhage is stabilized on imaging. Medical SDH care focuses on (a) management of intracranial hypertension; (b) maintenance of adequate cerebral perfusion; (c) seizure prevention and treatment; (d) maintenance of normothermia, eucarbia, euglycemia, and euvolemia; and (e) early initiation of enteral feeding, mobilization, and physical therapy. Post-operatively, SDH patients require ICU level care and are co-managed by neurointensivists with expertise in treating increased intracranial pressure, seizures, and status epilepticus, as well as medical complications of critical illness. Here, we review various aspects of medical management with a brief overview of pertinent literature and clinical trials for patients diagnosed with SDH.

First-line management of chronic subdural hematoma with the subdural evacuating port system: Institutional experience and predictors of outcomes

Chronic subdural hematoma (cSDH) is a common condition that disproportionately affects older patients. Given the greater risks of general anesthesia in this population, interest has turned towards less invasive surgical approaches such as the subdural evacuating port system (SEPS; Medtronic, Inc., Minneapolis, MN). There is a relative dearth of information about the outcomes following this procedure. Here, we present our institution's experience with SEPS and analyze factors associated with the outcomes. Using a prospectively maintained institutional database, we retrospectively identified all patients who presented with cSDH and received first line therapy with SEPS. Pre- and post-operative clinical and radiographic data was obtained from the electronic health record. Outcomes included success or failure, Modified Rankin Scale (mRS) at discharge, length of stay (LOS), and discharge disposition. A total of 126 patients met the inclusion criteria (36 females and 90 males; mean age of 71.6 years). None of the pre-procedural clinical or radiographic variables were associated with the likelihood of a successful outcome. Increasing age was associated with non-routine hospital discharge (p = 0.003), and lower presenting GCS was associated with longer hospital stay (p = 0.005). Greater thickness of the cSDH was associated with a lower likelihood of having a favorable outcome (mRS ≥ 3; p = 0.003). SEPS is an effective first-line therapy for cSDH. Variables previously reported to limit the effectiveness of the technique (presence of septations, mixed density collections) were not associated with treatment failure.

Chronic Subdural Hematoma: A Historical and Clinical Perspective

BACKGROUND

This review aims to highlight the clinical complexity of chronic subdural hematoma (cSDH) while presenting a brief historical discussion of cSDH.

METHODS

A thorough literature search of published English-language papers was performed in PubMed, Ovid, and Cochrane databases.

RESULTS

cSDH affects 1-5.3 per 100,000 individuals annually, with the incidence expected to rise as the U.S. population ages. The symptoms of cSDH are often nonspecific, with headaches being the most common complaint. Other symptoms include weakness, balance and gait problems, and memory problems.

CONCLUSIONS

A variety of clinical factors must be taken into account in the treatment of cSDH, and the multifaceted treatment paradigms continue to evolve.

Mini-Craniotomy Under Local Anesthesia for Chronic Subdural Hematoma: An Effective Choice for Elderly Patients and for Patients in a Resource-Strained Environment

BACKGROUND

Mini-craniotomy for chronic subdural hematoma (CSDH) is associated with lower rates of recurrence. However, the procedure is performed mostly with the patient under general anesthesia (GA) and therefore frequently requires an intensive care unit (ICU) facility, especially in the elderly population. Because of the unavailability of ICU beds, and to avoid GA, we started to perform this procedure with the patient under local anesthesia (LA).

MATERIALS AND METHODS

This was a retrospective medical chart review conducted in the section of Neurosurgery at the Aga Khan Hospital in Karachi, Pakistan. The study duration was 1 year. We included patients aged 55 years or older undergoing surgery for CSDH. Clinical characteristics, hospital stay, and recurrence rates were compared between 2 groups, local versus general anesthesia.

RESULTS

Thirty-five patients underwent mini-craniotomy for CSDH in the study period. Sixteen patients underwent mini-craniotomy under LA versus 19 patients for GA. Median age for the LA group was 67 years compared with 70 years in the GA group. Four patients from the LA group experienced postoperative complications versus 7 from the GA group. Only one patient in the LA group required an ICU bed in the postoperative period. There was no recurrence in LA group. The overall recurrence was 2.86%.

CONCLUSIONS

Mini-craniotomy for CSDH under LA is an equally effective procedure compared with mini-craniotomy under GA. In addition, it minimizes the risks of GA in the elderly population and obviates the need of a postoperative ICU bed. It also reduces operative time and hospital stay as compared with GA.

Membranectomy in Chronic Subdural Hematoma: Meta-Analysis

OBJECTIVE

Initial management strategies of chronic subdural hematoma (cSDH) are controversial and range from bedside twist-drill or burr-hole drainage to craniotomy with membranectomy (CWM). We aim to 1) perform a meta-analysis of the available data on the outcomes of CWM for treatment of cSDH in published English-language literature and 2) evaluate collective outcomes of CWM with respect to morbidity, mortality, and recurrence rates.

METHODS

A search of English-language literature performed in PubMed, Ovid, and Cochrane databases using key words ("subdural hematoma" or "chronic subdural hematoma") and ("membrane" or "membranectomy") from inception to December 2016 was conducted. Studies reporting outcomes of CWM in cSDH were included. Mortality, morbidity, follow-up duration, and recurrence rate data were extracted and analyzed. Pooled estimates and confidence intervals (CIs) were calculated for all outcomes using a random-effects model.

RESULTS

Of 301 articles found, 17 articles containing 5369 patients met our eligibility criteria. Mean follow-up duration ranged from 1-30.8 months. Collective mean mortality and morbidity rates were 3.7% and 6.9%, respectively (95% CI 2-5.4% and 2.1-11.6%; P < 0.001 and P = 0.004). The collective mean recurrence rate was 7.6% (95% CI: 5%-10.2%; P < 0.001).

CONCLUSIONS

Clinical data on outcomes of CWM in cSDH are limited to single institutional analyses, with considerable variation in recurrence rates and follow-up time. The rates we reported are comparable with the 5% mortality and 3%-12% morbidity rates and lower than the 10%-21% recurrence rate in the literature for burr holes or craniotomy without membranectomy. This meta-analysis provides an in-depth analysis of available data and reviews reported outcomes.

Twist Drill Procedure for Chronic Subdural Hematoma Evacuation: An Analysis of Predictors for Treatment Success

BACKGROUND

Twist drill craniostomy (TDC) is a minimally invasive and cost-effective technique to treat chronic subdural hematomas (CSDHs). Predictors for treatment success such as imaging characteristics, hematoma volume, and drainage volume are not established; thus, they are purpose of this analysis.

MATERIAL AND METHODS

We retrospectively evaluated all data of patients with CSDH undergoing TDC in our institution between January 2010 and December 2013. We analyzed imaging characteristics (extension and composition), volumetrically calculated pre- and postoperative hematoma volumes, measured drainage volume, and clinical course. Primary treatment success was defined as sufficient if definitive treatment was achieved via a single TDC (TDC-1) and insufficient if more than one TDC was needed. The need for open surgical evacuation was defined as treatment failure.

RESULTS

Data of 233 patients undergoing 387 TDCs were available for our study. A total of 67% of TDCs treated CSDHs effectively, whereas the remainder required further open surgical evacuation. Via use of the median-split-method, we found that sufficient treatment was achieved more frequently in smaller hematomas (P < 0.05). Treatment effectiveness was neither correlated with hematoma image characteristics (presence of membranes: P = 0.11, extent of chronification: P = 0.55) nor with the respective drainage volume (P = 0.95). Residual hematoma volume was consistently greater than expected by drainage calculation (P < 0.05).

CONCLUSIONS

TDC is an effective treatment option for CSDH. Sufficient treatment with single TDC was more common in smaller hematomas with an associated smaller residual hematoma. Failure of brain re-expansion after TDC may increase the treatment failure rates. In these cases, an open surgical evacuation might accelerate treatment and clinical recovery.

The Neurocritical and Neurosurgical Care of Subdural Hematomas

Subdural hematomas (SDHs), though frequently grouped together, can result from a variety of different etiologies, and therefore many different subtypes exist. Moreover, the high incidence of these lesions in the neurocritical care settings behooves practitioners to have a firm grasp on their diagnosis and management. We present here a review of SDHs, with an emphasis on how different subtypes of SDHs differ from one another and with discussion of their medical and surgical management in the neurocritical care setting. In this paper, we discuss considerations for acute, subacute, and chronic SDHs and how presentation and management may change in both the elderly and pediatric populations. We discuss SDHs that arise in the setting of anticoagulation, those that arise in the setting of active cerebrospinal fluid diversion, and those that are recurrent and recalcitrant to initial surgical evacuation. Management steps reviewed include detailed discussion of initial assessment, anticoagulation reversal, seizure prophylaxis, blood pressure management, and indications for intracranial pressure monitoring. Direct surgical management options are reviewed, including open craniotomy, twist-drill, and burr-hole drainage and the usage of subdural drainage systems. SDHs are a common finding in the neurocritical care setting and have a diverse set of presentations. With a better understanding of the fundamental differences between subtypes of SDHs, critical care practitioners can better tailor their management of both the patient's intracranial and multi-systemic pathologies.

Organized Chronic Subdural Hematomas Treated by Large Craniotomy with Extended Membranectomy as the Initial Treatment

Objective:

The aim of this retrospective study is to evaluate the efficacy and incidence of complications of craniotomy and membranectomy in elderly patients for the treatment of organized chronic subdural hematoma (OCSH).

Materials and Methods:

We retrospectively reviewed a series of 28 consecutive patients suffering from OCSH, diagnosed by magnetic resonance imaging (MRI) or computer tomography (CT) to establish the degree of organization and determine the intrahematomal architecture including inner membrane ossification. The indication to perform a primary enlarged craniotomy as initial treatment for nonliquefied OCSH with multilayer loculations was based on the hematoma MRI appearance – mostly hyperintense in both T1- and T2-weighted images with a hypointense web- or net-like structure within the hematoma cavity or inner membrane calcification CT appearance - hyperdense. These cases have been treated by a large craniotomy with extended membranectomy as the initial treatment. However, the technique of a burr hole with closed system drainage for 24–72 h was chosen for cases of nonseptated and mostly liquefied Chronic Subdural Hematoma (CSDH).

Results:

Between 1998 and 2015, 148 consecutive patients were surgically treated for CSDH at our institution. Of these, 28 patients which have OSDH underwent a large craniotomy with extended membranectomy as the initial treatment. The average age of the patients was 69 (69.4 ± 12.1). Tension pneumocephalus (TP) has occurred in 22.8% of these patients (n = 28). Recurring subdural hemorrhage (RSH) in the operation area has occurred in 11.9% of these patients in the first 24 h. TP with RSH was seen in 4 of 8 TP patients (50%). Large epidural air was seen in one case. Postoperative seizures requiring medical therapy occurred in 25% of our patients. The average stay in the department of neurosurgery was 11 days, ranging from 7 to 28 days. Four patients died within 28 days after surgery; mortality rate was 14.28%.

Conclusion:

Large craniotomy and extended membrane excision for OSDH still carry a high rate of mortality and morbidity in elderly patients. TP, RSH, and postoperative seizures are frequently seen complications in elderly patients.

Atorvastatin May Attenuate Recurrence of Chronic Subdural Hematoma

OBJECTIVE

Chronic subdural hematoma (CSDH) is a common form of intracranial hemorrhage with a substantial recurrence rate. Atorvastatin may reduce CSDH via its anti-inflammatory and pro-angiogenesis effects, but its effectiveness for preventing recurrent CSDH has never been explored. We hypothesized that atorvastatin is effective in reducing recurrence of CSDH after surgery and identified determining factors predictive of hematoma recurrence.

METHODS

A prospective study was conducted in 168 surgical cases of CSDH.All patients were randomly assigned to the group treated with atorvastatin or control group. Clinically relevant data were compared between two groups, and subsequently between the recurrence and non-recurrence patients. Multiple logistic regression analysis of the relationship between atorvastatin treatment and the recurrence using brain atrophy, septated and bilateral hematoma was performed.

RESULTS

Atorvastatin group conferred an advantage by significantly decreasing the recurrence rate (P = 0.023), and patients managed with atorvastatin also had a longer time-to-recurrence (P = 0.038). Admission brain atrophy and bilateral hematoma differed significantly between the recurrence and non-recurrence patients (P = 0.047 and P = 0.045). The results of logistic regression analysis showed that atorvastatin significantly reduced the probability of recurrence; severe brain atrophy and bilateral hematoma were independent risk factors for recurrent CSDH.

CONCLUSIONS

Atorvastatin administration may decrease the risks of recurrence.Patients with severe brain atrophy and bilateral CSDH are prone to the recurrence.

Surgical Treatments for Chronic Subdural Hematomas: A Comprehensive Systematic Review

BACKGROUND

Chronic subdural hematomas (CSDHs) are common neurosurgical conditions among elderly patients.

OBJECTIVE

To perform a detailed critical appraisal of all randomized controlled trials (RCTs) of surgical treatments for chronic subdural hematomas and to quantify their intervention effects.

METHODS

We performed a broad search for all RCTs with no language or date restrictions, asked the authors for missing data, and applied the Cochrane methods.

RESULTS

A total of 24 RCTs involved 1900 patients and 15 comparisons. All outcomes of practical interest were analyzed. Postoperative drainage after burr-hole evacuation reduced the rate of recurrence (risk ratio 0.48, 95% confidence interval 0.34-0.66, P < 0.00001) with no other clear benefits or complications.

CONCLUSIONS

This comprehensive, best evidence-based, quantitative, systematic review indicates that the use of a closed system drainage after burr-hole evacuation reduces the rate of recurrences but has no other significant differences. The findings also suggest that: (1) treatment with twist drills is equivalent to that with burr holes; (2) the postoperative bed header in the elevated position might reduce the length of hospital stay; (3) irrigation of the subdural space with thrombin solution in patients with high risk of recurrence might reduce this risk; and (4) treatment with twist drill followed by a closed system drainage during 48 hours, instead of 96 hours, might reduce general complication rates. Most of the trials suffered from unclear or high risks of bias and many involved small samples, precluding strong and definitive conclusions.

Superficial subarachnoid cerebrospinal fluid space expansion after surgical drainage of chronic subdural hematoma

BACKGROUND

The present study examined the computed tomography (CT) findings after surgery and overnight drainage for chronic subdural hematoma (CSDH) to clear the significance of inner superficial subarachnoid CSF space and outer subdural hematoma cavity between the brain surface and the inner skull.

METHODS

A total of 73 sides in 60 patients were evaluated. Head CT was performed on the day after surgery and overnight drainage (1st CT), within 3 weeks of surgery (2nd CT), and more than 3 weeks after surgery (3rd CT). Subdural and subarachnoid spaces were identified to focus on density of fluid, shape of air collection, and location of silicone drainage tube, etc. Cases with subdural space larger than the subarachnoid CSF space were classified as Group SD between the brain and the skull. Cases with subarachnoid CSF space larger than the subdural space were classified as Group SA. Cases with extremely thin (<3 mm) spaces between the brain and the skull were classified as Group NS.

RESULTS

Group SA, SD, and NS accounted for 31.9, 55.6 and 12.5% of cases on the 1st CT. No statistical differences were found between Groups SA, SD, and NS in any clinical factors, including recurrence. Group SA were found significantly more on 1st CT than on 2nd and 3rd CT.

CONCLUSIONS

Subarachnoid CSF space sometimes expands between the brain and skull on CT after surgical overnight drainage. Expansion of the arachnoid space may be a passive phenomenon induced by overnight drainage and delayed re-expansion of the brain parenchyma.

Predicting Recurrence after Chronic Subdural Haematoma Drainage

Background: Recurrence of chronic subdural haematomas (CSDHs) after surgical drainage is a significant problem with rates up to 20%. This study focuses on determining factors predictive of haematoma recurrence and presents a scoring system stratifying recurrence risk for individual patients. Methods: Between the years 2005 and 2009, 331 consecutive patients with CSDHs treated with surgery were included in this study. Univariate and multivariate analyses were performed searching for risk factors of increased post-operative haematoma volume and haematoma recurrence requiring repeat drainage. Results: We found a 12% reoperation rate. CSDH septation (seen on computed tomogram scan) was found to be an independent risk factor for recurrence requiring reoperation (p=0.04). Larger post-operative subdural haematoma volume was also significantly associated with requiring a second drainage procedure (p<0.001). Independent risk factors of larger post-operative haematoma volume included septations within a CSDH (p<0.01), increased pre-operative haematoma volume (p<0.01), and a greater amount of parenchymal atrophy (p=0.04). A simple scoring system for quantifying recurrence risk was created and validated based on patient age (< or ≥80 years), haematoma volume (< or ≥160cc), and presence of septations within the subdural collection (yes or no). Conclusion: Septations within CSDHs are associated with larger post-operative residual haematoma collections requiring repeat drainage. When septations are clearly visible within a CSDH, craniotomy might be more suitable as a primary procedure as it allows greater access to a septated subdural collection. Our proposed scoring system combining haematoma volume, age, and presence of septations might be useful in identifying patients at higher risk for recurrence.

Mini-craniotomy as the primary surgical intervention for the treatment of chronic subdural hematoma--a retrospective analysis

BACKGROUND

The incidence of chronic subdural hematoma (CSDH) is increasing, but optimal treatment remains controversial. Recent meta-analyses suggest burr hole (BH) drainage is the best treatment because it provides optimal balance between recurrence and morbidity. Mini-craniotomy may offer supplementary technical advantages while maintaining equal or better outcomes. This study investigates the outcome of mini-craniotomy as the sole treatment in patients with CSDH.

METHOD

We analyzed all patients operated on for CSDH with mini-craniotomy in our neurosurgical center between 2005-2010. Baseline patient characteristics (age, sex, comorbidities, imaging characteristics, known risk factors for development of CSDH and neurological examination at presentation) and outcomes (mortality, complications, recurrence and neurological examination at discharge) were recorded.

RESULTS

One hundred twenty-six adult patients were included, mean age was 73.9 (range 18 to 95) years old, and the sex ratio (M:F) was 2:1. Eighty-four percent of the patients showed clinical improvement at discharge, as shown by a decrease in the Markwalder score postoperatively (with 57 % Markwalder 0 and 23 % Markwalder 1). Recurrence rate was 8.7 %. Overall complication rate was 34.1 % (27.8 % medical complications and 6.3 % surgical complications). In-hospital mortality was 13.5 % (8.7 % due to pulmonary infections and 1.6 % to surgical complications). Preoperative Markwalder grade correlated significantly with complication rate, as did the presence of a neurodegenerative disease (p = 0.018). Factors significantly related to mortality in univariate analysis were arterial hypertension (p = 0.038), heart failure (p = 0.02), renal failure (p = 0.017), neurodegenerative disease (p = 0.001), cerebrovascular accident (p = 0.008) and coagulopathy (p = 0.019). Multivariate analysis was not able to confirm any significant relationship.

CONCLUSION

This is the first published series of CSDH in which all consecutive patients were operated on by mini-craniotomy. The invasiveness and complication rate of mini-craniotomy are equal to those of burr hole treatment, but visualization is superior, resulting in lower recurrences. A randomized controlled trial is indicated to identify the best surgical strategy for the treatment of CSDH.

Multiple Episodes of Hemorrhage Identified in MRI of Chronic Subdural Hematomas

Objective

Septa within the hematoma cavity are common, especially in the mixed density chronic subdural hematomas (CSHs). Although CT remains the diagnosis of choice, MRI is superior to detect the membranes in CSHs. We could obtain MRIs in 64 patients with CSH. We examined the value of MRI to understand the history of CSH.

Methods

We retrospectively examined the medical records and MRIs of 64 consecutive patients. MRI was selected to find any organic causes of neurologic symptoms. We classified the CSHs into septated or non-septated group, since classification of the septa was frequently obscure.

Results

Septa were identified by MRI in 43 patients (67%). They were more common in the over 70-years-old group. Unknown causes were more common in the septated group, which implies they might suffer from multiple traumas. The signal intensity of the CSH was variable. The methods of treatment were different between two groups. Surgery was more common in the septated group (p=0.021). Surgery was performed in 57 patients (89%). Burr-hole drainage was successful in 55 patients, even in the septated group.

Conclusion

Septa within the hematoma cavity may be related to the multiple episodes of head trauma. Repeated trauma may cause acute bleedings over the CSHs, which is one of the pathogenic mechanisms of hematoma enlargement. MRI could show the history of CSH.

The efficacy of dexamethasone on reduction in the reoperation rate of chronic subdural hematoma--the DRESH study: straightforward study protocol for a randomized controlled trial

Background

Chronic subdural hematoma (cSDH) is a common neurosurgical disease. It is often considered to be a rather benign entity. In spite of well established surgical procedures cSDH is complicated by a recurrence rate up to 30%. Since glucocorticoids have been used for treatment of cSDH in 1962 their role is still discussed controversially in lack of evident data. On the basis of the ascertained inflammation cycle in cSDH dexamethasone will be an ideal substance for a short lasting, concomitant treatment protocol.

Objective: to test the efficacy of dexamethasone on reduction inthe reoperation rate of cSDH.

Methods/Design

The study is designed as a double-blind randomized placebo-controlled trial 820 patients who are operated for cSDH and from the age of 25 years are included after obtaining informed consent. They are randomized for administration of dexamethasone (16-16-12-12-8-4 mg/d) or placebo (maltodextrin) during the first 48 hours after surgery. The type I error is 5% and the type II error is 20%. The primary endpoint is the reoperation within 12 weeks postoperative.

Discussion

This study tests whether dexamethasone administered over 6 days is a safe and potent agent in relapse prevention for evacuated cSDH.

Trial registration

EudraCT 201100354442

Primary enlarged craniotomy in organized chronic subdural hematomas

The aim of the study is to evaluate the efficacy of craniotomy and membranectomy as initial treatment of organized chronic subdural hematoma (OCSH). We retrospectively reviewed a series of 34 consecutive patients suffering from OCSH, diagnosed by magnetic resonance imaging (MRI) or contrast computer tomography (CCT) in order to establish the degree of organization and determine the intrahematomal architecture. The indication to perform a primary enlarged craniotomy as initial treatment for non-liquefied chronic subdural hematoma (CSDH) with multilayer loculations was based on the hematoma MRI appearance—mostly hyperintense in both T₁- and T₂-weighted images with a hypointense web- or net-like structure within the hematoma cavity. The reason why some hematomas evolve towards a complex and organized architecture remains unclear; the most common aspect to come to light was the “long standing” of the CSDHs which, in our series, had an average interval of 10 weeks between head injury and initial scan. Recurrence was found to have occurred in 2 patients (6% of cases) in the form of acute subdural hematoma. One patient died as the result of an intraventricular and subarachnoid haemorrhage, while 2 patients (6%) suffered an haemorrhagic stroke ipsilateral to the OCSH. Eighty-nine percent of cases had a good recovery, while 11% remained unchanged or worsened. In select cases, based on the MRI appearance, primary enlarged craniotomy seems to be the treatment of choice for achieving a complete recovery and a reduced recurrence rate in OCSH.

Multiple Densities of the Chronic Subdural Hematoma in CT Scans

Objective

Density of the chronic subdural hematoma (cSDH) is variable. It often appears to be mixed density. Multiple densities of cSDH may result from multiple episodes of trauma. We investigated the frequency of mixed density and the causes of head injuries representing each density.

Methods

We could collect 242 cases of chronic SDH. The cSDHs were classified into four groups; hypodensity, homogeneous isodensity, layered type, and mixed type on the basis of CT scans.

Results

The density of cSDH was isodense in 115 patients, hypodense in 31 patients, mixed in 79 cases, and layered in 17 cases. The cSDH was on the left side in 115 patients, on the right side in 70 patients, and bilateral in 40 patients. The history of trauma was identifiable in 122 patients. The etiology could be identified in 67.7% of the hypodense hematomas, while it was obscure in 59.5% of the mixed hematomas.

Conclusion

Mixed density of cSDH results from multiple episodes of trauma, usually in the aged. It is hard to remember all the trivial traumas for the patients with the mixed density cSDHs. Although there were membranes within the mixed density hematomas, burr-holes were usually enough to drain the hematomas.

Double-layer appearance after evacuation of a chronic subdural hematoma

OBJECTIVE

To investigate the reason for and the course of the double-layer appearance in the postoperative computed tomographies (CTs) of chronic subdural hematoma (CSDHs).

METHODS

We reviewed CSDH cases that were operated on during the last 3 years, between January 2008 and December 2010. We checked the preoperative, early postoperative, and late postoperative CTs of these patients. We investigated the relationship between the formation of a double-layer appearance and the prognoses and demographic characteristics of the patients.

RESULTS

Our database included 119 cases. A double-layer appearance was found in the postoperative CTs of 34 cases. The mean age of double-layer cases was older (72.5 ± 12.1) than that of the remaining 85 cases (63.1 ± 17.8). We did not find any relationship between the double-layer appearance and the reoperation/recurrence/death rates.

CONCLUSIONS

The double-layer appearance after evacuation of a CSDH might be caused by enlargement of the subarachnoid space and is not related to the presence of any residual hematoma. This appearance is not considered as a reason for reoperation.

The surgical management of chronic subdural hematoma

Chronic subdural hematoma (cSDH) is an increasingly common neurological disease process. Despite the wide prevalence of cSDH, there remains a lack of consensus regarding numerous aspects of its clinical management. We provide an overview of the epidemiology and pathophysiology of cSDH and discuss several controversial management issues, including the timing of post-operative resumption of anticoagulant medications, the effectiveness of anti-epileptic prophylaxis, protocols for mobilization following evacuation of cSDH, as well as the comparative effectiveness of the various techniques of surgical evacuation. A PubMed search was carried out through October 19, 2010 using the following keywords: "subdural hematoma", "craniotomy", "burr-hole", "management", "anticoagulation", "seizure prophylaxis", "antiplatelet", "mobilization", and "surgical evacuation", alone and in combination. Relevant articles were identified and back-referenced to yield additional papers. A meta-analysis was then performed comparing the efficacy and complications associated with the various methods of cSDH evacuation. There is general agreement that significant coagulopathy should be reversed expeditiously in patients presenting with cSDH. Although protocols for gradual resumption of anti-coagulation for prophylaxis of venous thrombosis may be derived from guidelines for other neurosurgical procedures, further prospective study is necessary to determine the optimal time to restart full-dose anti-coagulation in the setting of recently drained cSDH. There is also conflicting evidence to support seizure prophylaxis in patients with cSDH, although the existing literature supports prophylaxis in patients who are at a higher risk for seizures. The published data regarding surgical technique for cSDH supports primary twist drill craniostomy (TDC) drainage at the bedside for patients who are high-risk surgical candidates with non-septated cSDH and craniotomy as a first-line evacuation technique for cSDH with significant membranes. Larger prospective studies addressing these aspects of cSDH management are necessary to establish definitive recommendations.

Chronic subdural hematoma treated by small or large craniotomy with membranectomy as the initial treatment

OBJECTIVE

There are few studies comparing small and large craniotomies for the initial treatment of chronic subdural hematoma (CSDH) which had non-liquefied hematoma, multilayer intrahematomal loculations, or organization/calcification on computed tomography and magnetic resonance imaging. These procedures were compared to determine which would produce superior postoperative results.

METHODS

Between 2001 and 2009, 317 consecutive patients were surgically treated for CSDH at our institution. Of these, 16 patients underwent a small craniotomy with partial membranectomy and 42 patients underwent a large craniotomy with extended membranectomy as the initial treatment. A retrospective review was performed to compare the postoperative outcomes of these two techniques, focusing on improvement of neurological status, complications, reoperation rate, and days of post-operative hospitalization.

RESULTS

The mean ages were 69.4±12.1 and 55.6±9.3 years in the small and large craniotomy groups, respectively. The recurrence of hematomas requiring reoperation occurred in 50% and 10% of the small and large craniotomy patients, respectively (p<0.001). There were no significant differences in postoperative neurological status, complications, or days of hospital stay between these two groups.

CONCLUSION

Among the cases of CSDH initially requiring craniotomy, the large craniotomy with extended membranectomy technique reduced the reoperation rate, compared to that of the small craniotomy with partial membranectomy technique.

A comparative study of treatments for chronic subdural hematoma: burr hole drainage versus burr hole drainage with irrigation

Although chronic subdural hematoma (CSDH) is one of the most common entities encountered in neurosurgical practice, optimal surgical treatment for CSDH remains controversial. This study retrospectively compared results for CSDH between burr hole drainage alone and burr hole drainage with irrigation. Ninety-two patients with CSDH underwent surgery at our institution from January 1998 through December 2009. Fifty-eight patients received burr hole drainage alone (Group A), while 34 patients were treated using burr hole drainage with irrigation (Group B). Outcomes, recurrence rates, and death rates for the two groups were analyzed. Age, sex ratio, consciousness level on admission, radiodensity of hematoma on computed tomography before surgery, and duration of hospitalization were nearly the same in both groups. No significant differences were seen in good outcomes or death rates between groups, but poor outcomes were significantly more frequent in Group A (p=0.009). The recurrence rate was higher in Group A compared to Group B (10.3% vs. 2.9%). The authors used logistic regression analysis to identify factors associated with the outcome of CSDH, and found that duration of hospital stay, anti-coagulant therapy, presence of dementia and burr hole drainage alone were significantly associated with poor outcome of CSDH. These results indicate that burr hole drainage with irrigation has a significantly stronger association with good outcomes compared to drainage alone, and could be a reliable and effective operative method for the treatment of CSDH with a lower recurrence rate.

Choosing the best operation for chronic subdural hematoma: a decision analysis

OBJECT

Chronic subdural hematoma (CSDH), a condition much more common in the elderly, presents an increasing challenge as the population ages. Treatment strategies for CSDH include bur-hole craniostomy (BHC), twist-drill craniostomy (TDC), and craniotomy. Decision analysis was used to organize existing data and develop recommendations for effective treatment.

METHODS

A Medline search was used to identify articles about treatment of CSDH. Direct assessment by health care professionals of the relative health impact of common complications and recurrences was used to generate utility values for treatment outcomes. Monte Carlo simulation and sensitivity analyses allowed comparisons across treatment strategies. A second simulation examined whether intraoperative irrigation or postoperative drainage affect the outcomes following BHC.

RESULTS

On a scale from 0 to 1, the utility of BHC was found to be 0.9608, compared with 0.9202 for TDC (p = 0.001) and 0.9169 for craniotomy (p = 0.006). Sensitivity analysis confirmed the robustness of these values. Craniotomy yielded fewer recurrences, but more frequent and more serious complications than did BHC. There were no significant differences for BHC with or without irrigation or postoperative drainage.

CONCLUSIONS

Bur-hole craniostomy is the most efficient choice for surgical drainage of uncomplicated CSDH. Bur-hole craniostomy balances a low recurrence rate with a low incidence of highly morbid complications. Decision analysis provides statistical and empirical guidance in the absence of well-controlled large trials and despite a confusing range of previously reported morbidity and recurrence.

Prolonged drainage reduces the recurrence of chronic subdural hematoma

Recurrence of chronic subdural hematoma (CSH) is a significant problem in neurosurgical practice. Various risk factors associated with patient's characteristics and the pathogenesis of CSH have been investigated in many studies, but controversial findings are not uncommon. Therefore we made a retrospectively investigation focusing mainly on the factors associated with surgical techniques. in order to find out the factors that may affect the recurrence rate of CSH. The medical records of 97 consecutive patients with 121 CSHs, who were treated with burr-hole craniostomy and continuous drainage, were retrospectively reviewed. The relationships between the recurrence rate and some factors associated with surgery, such as location of burr-hole, thickness of residual hematoma, location of drainage catheter, intracapsular air postsurgery, duration of drainage were investigated. The average recurrence rate was 6.6% in this whole series. For patients with less than three days of drainage, the recurrence rate was 16.3%, whereas for those with 3 and more days of drainage, the recurrence rate was only 1.3%. The duration of drainage significantly related to recurrence rate. In addition, a higher recurrence rate seemed to be associated with more intracapsular air postsurgery, but it did not reach statistically significant level in this study. Prolonged duration of drainage did not increase the frequency of infection in this series. We found in this study that the duration of drainage play an important role in the treatment of CSH and 3 full days of drainage seems to be necessary, especially for patients of 60 years and over. We presumed that it takes at least 3 days of drainage for outer membrane of CSH to get the restoration of a normal balance between coagulation and fibrinolysis after surgery, which is necessary for termination of the vicious cycle and resolution of the hematoma.

ReviewNatural history of chronic subdural haematoma

This review will clarify the natural history of chronic subdural haematoma (SDH). Chronic SDH has dual origins, one from subdural hygromas (SDG) and the other from acute SDHs. It occurs only in patients with a suitable pre-morbid condition, i.e. sufficient potential subdural space (PSS). In unresolved SDGs, proliferation of dural border cells produces the neomembrane. Unresolved SDGs become chronic SDHs by repeated micro-haemorrhages from fragile new vessels, which were grown into the neomembrane. When PSS is sufficient, acute SDHs may become chronic SDHs. Chronic SDHs enlarge when rebleeding exceeds absorption and they become symptomatic. When the neomembrane is matured, the neocapillary is no longer fragile. If absorption exceeds rebleeding, the haematoma will disappear. Maturation of the neomembrane and stabilization of the neovasculature eventually result in spontaneous resolution. The fate of chronic SDH depends on the pre-morbid status, the dynamics of absorption-expansion and maturation of the neomembrane.

Membranectomy in organized chronic subdural hematomas: indications and technical notes

BACKGROUND

The aim of the present study is to present our operative method of removing organized CSDHs and to structure the criteria for choosing this approach as first treatment.

METHODS

Between 1991 and 1999 at our Institution, 14 consecutive patients with organized CSDHs required 16 craniotomies with membranectomy. They represent 5.8% of all patients (243) treated for CSDHs in the same period. All the patients had preoperative contrast-enhanced CT, and 9 patients also had contrast MRI.

RESULTS

Initially, 9 patients underwent one burr hole or twist-drill hole. Of these 9 patients, 3 were treated at the same surgery with craniotomy and membranectomy as second treatment, 3 underwent a second burr hole and then membranectomy at the same surgery, and 3 patients underwent a second burr hole 3, 4, and 21 days after the first one and then membranectomy. Five patients underwent immediate craniotomy and membranectomy. There were no morbidity or mortality associated with this procedure. All patients had a full recovery without recurrence.

CONCLUSIONS

Contrast-enhanced MRI has greatly improved opportunities for discovering neomembrane before surgical intervention. We believe that MRI detection of thick and extensive membranes or solid clot with mass effect makes an immediate craniotomy to remove CSDH necessary.