Clinical Analysis of Risk Factors for Recurrence in Patients with Chronic Subdural Hematoma Undergoing Burr Hole Trephination

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.

Factors associated with success of conservative therapy in chronic subdural hematoma: a single-center retrospective analysis

INTRODUCTION

Conservative therapy is a viable option for patients with chronic subdural hematoma (cSDH) who express no, or only mild symptoms. It is not clear which factors are associated with success of conservative therapy. This study aims to determine conservative therapy's success rate and to identify features possibly associated with success.

METHODS

A monocenter retrospective cohort study, including cSDH patients treated conservatively (wait-and-watch) from 2012 to 2022, was performed. The primary outcome was success of conservative therapy, defined as 'no crossover to surgery' during the follow-up period. Secondary outcomes were (1) factors associated with success, analyzed with univariate and multivariable logistic regression analyses, (2) 30-day mortality (3) time to crossover and (4) reasons for crossover.

RESULTS

We included 159 patients. Conservative therapy was successful in 96 (60%) patients. Hematoma volume (OR 0.79, 95% CI 0.69-0.92) and hypodense hematoma type (OR 3.57, 95% 1.38-9.23) were associated with success. Thirty-day mortality rate was 5% and the median duration between diagnosis and surgery was 19 days (IQR 8-39). Clinical deterioration was the most frequent reason for crossover (in 61/63 patients, 97%) and was accompanied by radiological hematoma progression in 42 patients (67%).

CONCLUSION

In this selected group of patients, conservative therapy was successful in 60%. Smaller hematoma volume and hypodense hematoma type were associated with success. As time until crossover was approximately three weeks, deploying conservative therapy as primary treatment seems safe and could be rewarding as surgical complications can be avoided. Improvement in patient selection in future cohorts remains warranted.

Correlation between Blood Type 0 and Risk of Chronic Subdural Hematoma Recurrence: A Single Center Retrospective Cohort Study

Chronic subdural hematoma (cSDH) is a common disease in the neurological and neurosurgical world. The recommended treatment for cSDH patients with moderate or severe neurological symptoms is surgical evacuation, but cSDH frequently recurs. The patient’s ABO blood type may influence the outcome. This study aims to evaluate the correlation between cSDH recurrence and blood type O. We performed a retrospective analysis of the data of patients with cSDH who were surgically treated. Recurrence was defined as the need for re-operation within the first 12 weeks after the initial surgery. We analyzed standard demographic data, duration and type of surgery, ABO blood types, and the re-operation rate. Univariate and multivariate analyses were conducted. A total of 229 patients were included. The recurrence of hematoma was identified in 20.5% of patients. Blood type O was found to be significantly associated with cSDH recurrence leading to re-operation within 12 weeks (p = 0.02, OR 1.9, 95% CI 1.1–3.5). Thrombocyte aggregation inhibition and oral anticoagulants were not predictors of cSDH recurrence. Patients with blood type O in our cohort were identified to be at higher risk of cSDH recurrence and may, therefore, be a more vulnerable patient group. This finding needs further evaluation in larger cohorts.

Comparison of Two Drainage Systems on Chronic Subdural Hematoma Recurrence

BACKGROUND

 Chronic subdural hematoma (CSDH) is a common type of intracranial hemorrhage, especially among the elderly, with a recurrence rate as high as 33%. Little is known about the best type of drainage system and its relationship with recurrence. In this study, we compare the use of two drainage systems on the recurrence rate of CSDH.

METHODS

 We retrospectively analyzed the charts of 172 CSDH patients treated with bedside twist drill craniostomy (TDC) and subdural drain insertion. Patients were divided into two groups: group A (n = 123) received a pediatric size nasogastric tube [NGT]), whereas group B (n = 49) had a drain commonly used for external ventricular drainage (EVD). Various demographic and radiologic data were collected. Our main outcome was recurrence, defined as symptomatic re-accumulation of hematoma on the previously operated side within 3 months.

RESULTS

 In all, 212 cases of CSDH were treated in 172 patients. The majority of patients were male (78%) and had a history of previous head trauma (73%). Seventeen cases had recurrence, 11 in group A and 6 in group B. The use of antiplatelet and anticoagulation agents was associated with recurrence (p = 0.038 and 0.05, respectively). There was no difference between both groups in terms of recurrence (odds ratio [OR] = 1.42; 95% confidence interval [CI]: 0.49-4.08; p = 0.573).

CONCLUSION

 CSDH is a common disease with a high rate of recurrence. Although using a drain postoperatively has shown to reduce the incidence of recurrence, little is known about the best type of drain to use. Our analysis showed no difference in the recurrence rate between using the pediatric size NGT and the EVD catheter post-TDC.

Middle meningeal artery embolisation: The review of a new treatment for chronic subdural hematomas

Background

This is a literature review aiming to provide an update about the recent findings related to the efficacy of middle meningeal artery embolization (MMAE) in the treatment of chronic subdural hematomas (cSDHs), comparison with conventional therapy and deduction of the current recommendations and indications.

Methods

The literature is reviewed using a search through the PubMed index using keywords. Studies are then screened, skimmed, and thoroughly read. 32 studies fulfilled the inclusion criteria and are included in the study.

Results

Five indications for the application of MMA embolization (MMAE) are deducted from the literature. The usage as a preventive measure after surgical treatment of symptomatic cSDHs in patients with a high risk of recurrence and the usage as a standalone procedure has been the most common reasons for indication of this procedure. Rates of failures for the aforementioned indications have been 6.8% and 3.8%, respectively.

Conclusion

The safety of MMAE as a procedure is regarded as a general theme in the literature and can be considered for future applications. Usage of this procedure in clinical trials with more patient segregation and timeframe assessment relative to surgical intervention are recommendations of this literature review.

Angiogenetic Factors in Chronic Subdural Hematoma Development

The levels of angiogenic factors were analyzed in eight patients who underwent the embolization of chronic subdural hematoma (CSDH) with non-adhesive liquid embolic agents. Four of these patients had previously undergone surgical treatment for hematoma removal and had recurrences of a similar volume, and four had an increase in hematoma volume due to rebleeding. The levels of vascular endothelial growth factor (VEGF), matrix metallopeptidase 9 (MMP 9), angiopoietin-2 (Ang2), transforming growth factor beta 1 (TGF-β1) and platelet-derived growth factor BB (PDGF-BB) in the arterial and venous blood were analyzed. The most significant results were obtained from the peripheral venous blood samples. The levels of VEGF in the samples of all the patients were close to normal or slightly decreased. There was an increase in the MMP9 levels (the factor that contributes to the disintegration of the vessel wall components) in all the patients. The Ang2 and especially the PDGF TGF-β1 (the factor that plays an important role in the growth of the vessel wall from the already existing blood vessel tissue) levels were distinctly low in most of the cases and slightly elevated only in a number of patients who had previously been operated on. The results obtained show that there is an imbalance in the angiogenesis factors in patients with rebleeding CSDH. At the same time, the factors determining the formation of the vessel wall were reduced, and the levels of factors contributing to the degradation of extracellular matrix components were significantly increased. Such factors could help us to anticipate the increased risk of hemorrhages. Highlights: The levels of VEGF, MMP 9, Ang2, TGF-β1 and PDGF-BB in the arterial and venous blood were analyzed. The most significant results were obtained from the peripheral venous blood samples. The results obtained show that there is an imbalance in the angiogenesis factors in patients with rebleeding CSDH. Such a profile of factors could help us to anticipate the increased risk of hemorrhages.

Brain re-expansion predict the recurrence of unilateral CSDH: A clinical grading system

Objective

Assessing the risk of postoperative recurrence of chronic subdural hematoma (CSDH) is a clinical focus. To screen the main factors associated with the perioperative hematoma recurrence. The brain re-expansion is the core factor of recurrence. A clinical prognostic scoring system was also proposed.

Methods

We included 295 patients with unilateral CSDH as the training group for modeling. Factors predicting postoperative recurrence requiring reoperation (RrR) were determined using univariate and multivariate regression analyses, and bivariate Pearson correlation coefficient analysis was used to exclude related factors. Receiver operating characteristic curve analysis evaluates the ability of main factors to predict RrR and determines the cut-off value of brain re-expansion rate. We developed a prognostic scoring system and conducted preliminary verification. A verification group including 119 patients with unilateral CSDH was used to verify the grading systems.

Results

The key factors for predicting unilateral CSDH recurrence were cerebral re-expansion rate (≤ 40%) at postoperative days 7–9 (OR 25.91, p < 0.001) and the preoperative CT density classification (isodense or hyperdense, or separated or laminar types) (OR 8.19, p = 0.007). Cerebral atrophy played a key role in brain re-expansion (OR 2.36, p = 0.002). The CSDH prognostic grading system ranged from 0 to 3. An increased score was associated with a more accurate progressive increase in the RrR rate (AUC = 0.856).

Conclusions

Our prognostic grading system could screen clinically high-risk RrR patients with unilateral CSDH. However, increased attention should be paid to brain re-expansion rate after surgery in patients with CSDH.

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.

Factors correlated with the postoperative recurrence of chronic subdural hematoma: An umbrella study of systematic reviews and meta-analyses

BACKGROUND

Chronic subdural hematoma (CSDH) is a common neurological disease, and the surgical evacuation of subdural collection remains the primary treatment approach for symptomatic patients. Postoperative recurrence is a serious complication, and several factors are correlated with postoperative recurrence.

METHODS

We searched Embase, Web of Science, PubMed, and Cochrane Library from their establishment to September 2020. Reports on randomized, prospective, retrospective, and overall observational studies on the management of surgical patients with CSDH were searched, and an independent reviewer performed research quality assessment. Factors that affect the postoperative recurrence of CSDH were extracted: social demographics, drugs (as the main or auxiliary treatment), surgical management, imaging, and other risk factors. We evaluated the recurrence rate of each risk factor. A random effect model was used to perform a meta-analysis, and each risk factor affecting the postoperative recurrence of CSDH was then evaluated and graded.

FINDINGS

In total, 402 studies were included in this analysis and 32 potential risk factors were evaluated. Among these, 21 were significantly associated with the postoperative recurrence of CSDH. Three risk factors (male, bilateral hematoma, and no drainage) had convincing evidence. The classification of evidence can help clinicians identify significant risk factors for the postoperative recurrence of CSDH.

INTERPRETATION

Only few associations were supported by high-quality evidence. Factors with high-quality evidence may be important for treating and preventing CSDH recurrence. Our results can be used as a basis for improving clinical treatment strategies and designing preventive methods.

FUNDING

No funding was received.

Use of the Subdural Hematoma in the Elderly (SHE) Score to Predict 30-Day Mortality After Chronic Subdural Hematoma Evacuation

BACKGROUND

The Subdural Hematoma in the Elderly (SHE) score has been recently developed to assess the 30-day mortality in acute and chronic subdural hematomas in patients >65 years and has shown good reliability. We aimed to validate the SHE score's accuracy to predict 30-day mortality on a homogeneous cohort of patients undergoing surgical chronic subdural hematoma evacuation at our Institution. We also investigated whether the SHE score could reliably predict the occurrence of 30-day chronic subdural hematoma recurrence needing surgery.

METHODS

We included patients from our prospectively collected database from January 2018 to January 2021. Patients with the availability of the following information were enrolled: age, Glasgow Coma Scale score on admission, hematoma volume, medical history, and outcome at 30 days. The SHE score was calculated for each patient, and the association between greater scores and 30-day mortality was investigated and its ability to predict 30-day and disease recurrence. Statistical significance was assessed for P < 0.05.

RESULTS

Three hundred twenty-one patients were included. Of them, 40 (12.5%) displayed mortality within 30-day: specifically, 0% of the group of patients with SHE score = 0, 4.3% of SHE score = 1, 14.5% of SHE score = 2, 39.3% of SHE score = 3, and 37.5% of SHE score = 4, with a statistically significant linear trend between greater SHE scores and 30-day mortality rates (P < 0.001, area under the curve 0.75 [0.67-0.82]). No significant association of the SHE score with the risk of recurrence needing surgery was detected (P = 0.4).

CONCLUSIONS

The SHE score proved helpful in predicting 30-day mortality in patients with chronic subdural hematomas, but no utility was observed to predict disease recurrence.

Modified Computed Tomography Classification for Chronic Subdural Hematoma Features Good Interrater Agreement: A Single-Center Retrospective Cohort Study

OBJECTIVE

The present study aimed to establish whether our modified Nakaguchi computed tomography (CT) classification improves the interrater agreement of chronic subdural hematoma (CSDH) classification and prediction of CSDH recurrence relative to 2 other CT classifications.

METHODS

This retrospective study considered 277 consecutive patients with CSDH and 307 hematomas treated with burr-hole surgery between January 2009 and December 2018. Two neurosurgeons blinded to patients' clinical data classified the CT scans of patients with CSDH into 4 or 5 types according to the Nomura classification (high, iso, low, mixed, and layering), Nakaguchi classification (homogenous, laminar, separated, and trabecular), and our modified Nakaguchi classification (homogenous, gradation, laminar, separated, and trabecular). The κ statistic was used to evaluate the interrater agreement of the 3 CT classifications. Univariable and multivariable logistic regression analyses were used to calculate odds ratios for CSDH recurrence.

RESULTS

κ values of the modified, Nakaguchi, and Nomura classification were 0.78, 0.63, and 0.70, respectively. During the 3 months follow-up, the recurrence rate for CSDH was 11.4% (35/307 hematomas). Of the types defined by the modified classification, the gradation type was associated with the highest recurrence (mean recurrence rate, 15.9% ± 0.3%). Multivariable logistic regression analyses showed that a gradation-type hematoma, as defined with the modified classification, was an independent risk factor associated with recurrence (odds ratio, 2.36; 95% confidence interval, 1.11-4.98; P = 0.025).

CONCLUSIONS

The modified classification was useful for preoperative CT classification of CSDH and the prediction of recurrence, with high agreement between raters.

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.

Neuroendoscopy-Assisted Evacuation of Chronic Subdural Hematoma with Mixed CT Density Through A Novel Small Bone Flap

OBJECTIVE

 Chronic subdural hematoma (CSDH) is a common neurosurgical condition with an increasing incidence and favorable prognosis. Surgery is the standard treatment for CSDH, and bur hole evacuation is the most widely employed technique. However, if mixed computed tomography (CT) density is found, burr hole hematoma evacuation is prone to recurrence. Endoscopic examination of the hematoma cavity provides a novel strategy. Here, we present a modification of burr hole evacuation by using neuroendoscopy through a novel small trapezoid bone flap and assess the advantages and risks of the procedure.

METHODS

 Twenty-five patients diagnosed with CSDH of mixed CT density were included in this study. Radiographic, epidemiologic, and clinical data were collected and analyzed. In all procedures the burr hole was replaced by a small trapezoidal cross-sectional bone flap, ∼2 cm in diameter. Neuroendoscopy was employed after the subdural cavity was cleaned and drained. The CSDH cavity was inspected thoroughly. If a blood clot, septa, stretching of cortical vessels, or intraluminal trabecular structures with active bleeding were found, the surgeon aspirated the region with a syringe pipe and/or used bipolar electrocoagulation.

RESULTS

 All 25 patients who received 26 neuroendoscopy-assisted operations achieved favorable clinical outcomes. The recurrence rate was 4%. The average operation time was slightly increased compared with the traditional burr hole evacuation due to the use of the neuroendoscope and eventual subsequent treatment.

CONCLUSION

 Neuroendoscopy provides excellent illumination and vision when a small bone flap is employed. The main advantages of this technique include the precise treatment of structures which are related with progression and recurrence of CSDH, and the minimally invasive nature of the procedure.

Does Drain Position and Duration Influence Outcomes in Patients Undergoing Burr-Hole Evacuation of Chronic Subdural Hematoma? Lessons from a UK Multicenter Prospective Cohort Study

Background

Drain insertion following chronic subdural hematoma (CSDH) evacuation improves patient outcomes.

Objective

To examine whether this is influenced by variation in drain location, positioning or duration of placement.

Methods

We performed a subgroup analysis of a previously reported multicenter, prospective cohort study of CSDH patients performed between May 2013 and January 2014. Data were analyzed relating drain location (subdural or subgaleal), position (through a frontal or parietal burr hole), and duration of insertion, to outcomes in patients aged >16 yr undergoing burr-hole drainage of primary CSDH. Primary outcomes comprised modified Rankin scale (mRS) at discharge and symptomatic recurrence requiring redrainage within 60 d.

Results

A total of 577 patients were analyzed. The recurrence rate of 6.7% (12/160) in the frontal subdural drain group was comparable to 8.8% (30/343) in the parietal subdural drain group. Only 44/577 (7.6%) patients underwent subgaleal drain insertion. Recurrence rates were comparable between subdural (7.7%; 41/533) and subgaleal (9.1%; 4/44) groups (P = .95). We found no significant differences in discharge mRS between these groups. Recurrence rates were comparable between patients with postoperative drainage for 1 or 2 d, 6.4% and 8.4%, respectively (P = .44). There was no significant difference in mRS scores between these 2 groups (P = .56).

CONCLUSION

Drain insertion after CSDH drainage is important, but position (subgaleal or subdural) and duration did not appear to influence recurrence rate or clinical outcomes. Similarly, drain location did not influence recurrence rate nor outcomes where both parietal and frontal burr holes were made. Further prospective cohort studies or randomized controlled trials could provide further clarification.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Prediction of postoperative recurrence of chronic subdural hematoma using quantitative volumetric analysis in conjunction with computed tomography texture analysis

Chronic subdural hematoma (CSDH) is a common disease in older individuals with a substantial rate of recurrence. The mechanism of CSDH recurrence remains unclear. This study aimed to detect imaging parameters that could indicate the risk for CSDH recurrence by using quantitative volumetric analysis and computed tomography (CT) texture analysis (CTTA). Clinical and imaging parameters were retrospectively investigated in 147 newly diagnosed CSDH lesions in 114 patients surgically treated at the Keio University Hospital during a 6-year period. For CT images, quantitative volumetric and texture analyses were performed. Hematoma volume, postoperative air volume, hematoma density, and texture parameters including kurtosis, skewness, and entropy were evaluated and compared with CSDH recurrence rate. Data were statistically evaluated, and a difference of p < 0.05 was considered significant. Reoperation for CSDH recurrence was required in 27 sides (18.4%) of 26 patients. Multivariate analysis showed that postoperative hematoma volume and postoperative hematoma density were independent risk factors for symptomatic CSDH recurrence that required reoperation. Postoperative hematoma volume, postoperative significant residual air, and postoperative hematoma density were also identified as independent risk factors for potential CSDH recurrence. Preoperative hematoma entropy was prone to be associated with both symptomatic and potential CSDH recurrence in univariate analysis, but not in multivariate analysis because of confounding factors. Quantitative volumetric analysis and CTTA could aid in distinguishing individuals at risk for CSDH recurrence.

Postoperative pneumocephalus increases the recurrence rate of chronic subdural hematoma

OBJECTIVES

Pneumocephalus is a common operative complication of chronic subdural hematoma. This study is to analyze the relationship between postoperative pneumocephalus and the recurrence and surgical outcomes.

PATIENTS AND METHODS

This is a retrospective case-cohort study, including a pneumocephalus group (n = 46) and a control group (n = 181). Their recurrence rates, CT attenuation values, hospital stay, healing time and the neurological status were recorded and analyzed.

RESULTS

The pneumocephalus group had a recurrence rate of 32.6%, significantly higher than the control (17.7%). In addition, the pneumocephalus group had a higher rate of postoperative epilepsy (21.7% vs 3.3%), longer hospital stay (11.5 ± 2.8 vs 7.8 ± 1.2 days), longer healing time (10.8 ± 5.4 vs 6.5 ± 2.3 months), and worse neurological scores than the control.

CONCLUSION

Pneumocephalus increases the recurrence rate of chronic subdural hematoma, and it not only prolongs the hospital stay and healing time, but also leads to deterioration of the neurological status.

Factors predicting reoperation of chronic subdural hematoma following primary surgical evacuation

OBJECTIVEChronic subdural hematoma (CSDH) is commonly encountered in neurosurgical practice. However, surgical evacuation remains complicated by a high rate of reoperation. The optimal surgical approach to reduce the reoperation rate has not been determined. In the current study, the authors evaluated the prognostic value of clinical and radiographic factors to predict reoperation in the context of CSDH.METHODSA retrospective review of 325 CSDH patients admitted to an academic medical center in the United States, between 2006 and 2016, was performed. Clinical and radiographic factors predictive of the need for CSDH reoperation were identified on univariable and multivariable analyses.RESULTSUnivariable analysis showed that warfarin use, clopidogrel use, mixed hypo- and isointensity on T1-weighted MRI, greater preoperative midline shift, larger hematoma/fluid residual on first postoperative day CT, lesser decrease in hematoma size after surgery, use of monitored anesthesia care (MAC), and lack of intraoperative irrigation correlated with a significantly higher rate of reoperation. Multivariable analysis, however, showed that only the presence of loculation, clopidogrel or warfarin use, and percent of hematoma change after surgery significantly predicted the need for reoperation. Our results showed that 0% (no reduction), 50%, and 100% hematoma maximum thickness change (complete resolution of hematoma after surgery) were associated with a 41%, 6%, and < 1% rate of reoperation, respectively. The use of drains, either large diameter or small caliber, did not have any effect on the likelihood of reoperation.CONCLUSIONSAmong many factors, clopidogrel or warfarin use, hematoma loculation on preoperative CT, and the amount of hematoma evacuation on the first postoperative CT were the strongest predictors of reoperation.

Prevalence of and risk factors for recurrence of chronic subdural hematoma

BACKGROUND

Chronic subdural hematoma (CSDH) is a common disease in neurosurgical practice with substantial recurrence rate. We aimed to estimate recurrence rate of CSDH and to identify risk factors for CSDH recurrence.

METHODS

We retrospectively studied consecutive cases with CSDH and performed surgical therapy in our hospital. Univariate and multivariate logistic regression analyses were performed to identify factors associated with recurrence of CSDH.

RESULTS

A total of 226 patients with CSDH were included; 34 patients recurred after surgery with a recurrence rate of 15.0%. Univariate analysis showed that the recurrence group had more patients with homogenous hyper-dense hematoma (20.6 vs 6.3%, p = 0.035) and shorter duration of subdural drainage post-surgery (1.2 ± 1.4 vs 1.5 ± 0.9, p = 0.022) than the non-recurrence group. Logistic regression analysis revealed that duration of subdural drainage (OR = 0.66, p = 0.05) and hyper-dense of hematoma (OR = 4.94, p = 0.012) were independent predictors for CSDH recurrence.

CONCLUSIONS

Homogenous hyper-dense of hematoma and duration of subdural drainage post-surgery were independent predictors for CSDH recurrence; longer duration of postoperative subdural drainage was associated with lower risk of recurrence.

Radiolological predictors of recurrence of chronic subdural hematoma

Objective:

Chronic subdural hematoma is one of the most common clinical entities encountered in daily neurosurgical practice. Considerable recurrence rates have been reported for chronic subdural hematoma following surgical evacuation. Many studies have suggested various radiological factors that may be associated with the recurrence of CSDH. However, the results are inconsistent. This study focuses on determining the radiological factors predictive of chronic subdural hematoma recurrence.

Methods:

A retrospective analysis of 113 patients diagnosed with chronic subdural hematoma who were surgically treated between August 2013 and December 2014 was performed. The radiological features were analyzed to clarify the correlation between these radiological factors and postoperative recurrence of chronic subdural hematoma.

Results:

Twenty patients (17.7%) experienced recurrence. Chronic subdural hematoma recurrence was found to be significantly associated (p<0.05) with preoperative hematoma thickness ≥ 20 mm. Midline shift, hematoma density and bilaterality were not significantly associated with recurrence. Post operative drainage also significantly (p<0.05) reduced chronic subdural hematoma recurrence.

Conclusion:

Preoperative hematoma thickness ≥ 20 mm is an independent predictor of recurrence of chronic subdural hematoma. Postoperative drainage also significantly reduces chronic subdural hematoma recurrence.

Risk Factors of Delayed Surgical Intervention after Conservatively Treated Acute Traumatic Subdural Hematoma

Objective

Acute subdural hematoma (ASDH) is generally considered a condition that should be managed surgically. However, some patients initially receive conservative treatment, a subset of whom require surgical intervention later. This study aimed to evaluate the predictors of delayed surgical intervention in ASDH patients who are initially managed conservatively.

Methods

From January 2007 to December 2015, 842 patients diagnosed with ASDH were treated at our institution. Among them, 158 patients with convexity ASDH were initially treated conservatively. Patients were divided into a delayed surgery group and a conservative group. Demographic characteristics, past medication and medical histories, and radiological and laboratory data were collected by retrospective chart review. Independent risk factors were identified with univariate and multivariate analyses.

Results

Twenty-eight patients (17.7%) underwent delayed surgical intervention. Their mean age was 69.0 years, and 82.1% were male. Hypertension, diabetes mellitus, and heart disease prevalence and use of anti-platelet agents did not significantly differ from the conservative group. However, age (p=0.024), previous cerebral infarction history (p=0.026), increased maximal hematoma thickness (p<0.001), midline shifting (p=0.001) and accompanying subarachnoid hemorrhage (p=0.022) on initial brain computed tomography (CT) scan, low hemoglobin level (p<0.001), high leukocyte count (p=0.004), and low glucose level (p=0.002) were significantly associated with delayed surgical intervention. In multivariate analysis, increased maximal hematoma thickness (odds ratio [OR]=1.279, 95% confidence interval [CI] 1.075–1.521; p=0.006), low hemoglobin level (OR=0.673, 95% CI 0.467–0.970; p=0.034), and high leukocyte count (OR=1.142, 95% CI 1.024–1.272; p=0.017) were independent risk factors for delayed surgical intervention.

Conclusion

Due to the high likelihood of delayed surgical intervention among minimal ASDH patients with a thicker hematoma on initial brain CT, lower hemoglobin level, and higher leukocyte count, these patients should receive more careful observation.

Effects of Oral Streptokinase-Streptodornase on Remnant Chronic Subdural Hematomas

OBJECTIVE

In most cases, the postoperative course of a chronic subdural hematoma (CSDH) is good, but CSDHs sometimes remain after the inserted catheter is removed, and the outcomes of such remnant hematomas are unclear. As oral streptokinase-streptodornase (OSS) has anti-inflammatory and hematologic effects, we assessed the effects of OSS on remnant CSDHs through a retrospective analysis of clinical data.

METHODS

This study included 101 patients with traumatic CSDH who had remnant CSDH after burr-hole trephination with the closed drainage system between October 2009 and December 2012. We assessed the clinical outcomes, remnant CSDH volume, and recurrence rate from computed tomography scans in order to evaluate the effects of OSS.

RESULTS

No significant differences were found in the changes in remnant hematoma volume between the OSS-treated and non-treated groups (p=0.531). The reoperation rate because of was 5.4% (2 patients) in the OSS-treated group and 6.3% (4 patients) in the non-treated group. The number of patients requiring reoperation did not differ between the groups (p=0.658).

CONCLUSION

OSS treatment was not associated with a significant reduction in the remnant CSDH volume or recurrence rate after burr-hole drainage. Thus, there seems to be no basis for using OSS in CSDH patients.

Clinical Features According to the Histological Types of the Outer Membrane of Chronic Subdural Hematoma

Objective

The aim of our study was to classify the outer membrane of chronic subdural hematoma (CSDH) histologically and to determine the clinical and radiological meaning of the classified membranes.

Methods

The outer membrane specimen of 31 patients who underwent surgery for CSDH were acquired in this study. The specimen was classified into four types and each were analyzed of the symptoms on the admission day and during the period from trauma to surgery. The radiological features such as subdural fluid density, Hounsfield number, thickness of the hematoma, and midline shift were analyzed.

Results

There were 6% of type I, 29% of type II, 39% of type III, and 26% of type IV neomembranes. The cases of CSDH accompanied by neurologic deficit were highest from type IV of 63%, followed by type II with 56%. On the radiological findings such as Hounsfield unit, hematoma thickness and midline shift, only hematoma thickness between type II and III were statistically significant (p=0.021). The hematoma thickness and midline shift were greatest in type II. On computed tomography scans, the isodense, hyperdense and laminar type that shows the high recurrence rate formed 75% of type II and 67% of type IV while type III had the low possibility of recurrence rate (33%).

Conclusion

We have identified that the outer membrane have the tendency to develop from type I to IV in time while type II and type IV may have more risk of neurologic deficit and the high possibility of recurrence.

Comparison of the Outcomes and Recurrence with Three Surgical Techniques for Chronic Subdural Hematoma: Single, Double Burr Hole, and Double Burr Hole Drainage with Irrigation

Objective

Chronic subdural hematoma (CSDH), a disease commonly encountered by neurosurgeons, is treated by burr hole drainage (BHD). However, the optimal surgical technique among the three types of BHD has not been determined.

Methods

We conducted a retrospective study on BHD performed on 93 patients who were diagnosed with CSDH. The subjects were divided into three groups based on the surgical technique performed: single BHD without irrigation (Group A, n=31), double BHD without irrigation (Group B, n=32), and double BHD with irrigation (Group C, n=30). The clinical factors, radiological factors and recurrences were compared between the three groups. Moreover, independent factors affecting the recurrence were analyzed.

Results

The change in hematoma thickness was 29.77±7.94%, 49.73±12.87%, and 75.29±4.32% for Group A, B, and C, respectively, while the change in midline shift was 40.81±15.47%, 51.78±10.94%, and 56.16±16.16%, respectively. Thus, Group C showed the most effective for resolution of hematoma and midline shift (p<0.05). Group A, B, and C had 12 cases (38.7%), 8 cases (25.0%), and 3 cases (10.0%) of recurrences, respectively. Group C had a statistically significantly fewer recurrence rate than Group A (p<0.05). Double burr hole, irrigation, and coagulopathy were each identified as independent factors that reduce recurrence (p<0.05).

Conclusion

Among the three techniques, the double BHD with saline irrigation resulted in the fewest recurrences. It is probably the most effective technique for preventing the recurrence of CSDH.