Operative Neurosurgery

The recurrence rate of chronic subdural hematoma cSDH seems to be related to the excessive neoangiogenesis in the parietal membrane, which is mediated via vascular endothelial growth factor (VEGF). This is found to be elevated in the hematoma fluid and is dependent on eicosanoid/prostaglandin and thromboxane synthesis via cyclooxygenase-2 (COX-2).

Recurrence rates after chronic subdural hematoma (CSDH) evacuation with any of actual techniques twist drill craniostomy (TDC), burr hole craniostomy, craniotomy range from 5% to 30%. ¹⁾

Chon et al. shown that postoperative midline shifting (≥5 mm), diabetes mellitus, preoperative seizure, preoperative width of hematoma (≥20 mm), and anticoagulant therapy were independent predictors of the recurrence of chronic subdural hematoma. According to internal architecture of hematoma, the rate of recurrence was significantly lower in the homogeneous and the trabecular type than the laminar and separated type ²⁾.

Antiplatelet therapy significantly influences the recurrence of CSDH ³⁾.

Remaining pneumocephalus is seen as an approved factor of recurrence ^{4) 5)}.

Jack et al.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).

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. The proposed scoring system combining haematoma volume, age, and presence of septations might be useful in identifying patients at higher risk for recurrence ⁶⁾.

Opening the internal hematoma membrane does not alter the rate of patients requiring revision surgery and the number of patients showing a marked residual hematoma six weeks after evacuation of a CSDH ⁷⁾.

In the study of Lee et al, an extended surgical approach with partial membranectomy has no advantages regarding the rate of reoperation and the outcome. As initial treatment, burr-hole drainage with irrigation of the hematoma cavity and closed-system drainage is recommended. Extended craniotomy with membranectomy is now reserved for instances of acute rebleeding with solid hematoma ⁸⁾.

Surgeons should consider informing patients with diabetes mellitus that this comorbidity is associated with an increased likelihood of recurrence

^{9) 10) 11)}.

Balser et al. report 11% recurrence, which included individuals who recurred as late as 3 years after initial diagnosis ¹²⁾.

Close imaging follow-up is important for CSDH patients for recurrence prediction. Using quantitative CT volumetric analysis, strong evidence was provided that changes in the residual fluid volume during the 'self-resolution' period can be used as significantly radiological predictors of recurrence ¹³⁾.

A structural equation model showed a significant association between increased antiinflammatory activity in hematoma fluid samples and a lower risk of recurrence, but this relationship was not statistically significant in venous blood samples. Moreover, these findings indicate that anti-inflammatory activities in the hematoma may play a role in the risk of a recurrence of CSDH ¹⁴⁾.

Irrigation with artificial cerebrospinal fluid (ACF) decreased the rate of CSDH recurrence ¹⁵⁾.

Chronic subdural hematomas (cSDHs) have shown an increasing incidence in an ageing population over the last 20 years, while unacceptable recurrence rates of up to 30 % persist. The chronic subdural hematoma recurrence rate seems to be related to the excessive neoangiogenesis in the parietal membrane, which is mediated via vascular endothelial growth factor (VEGF). This is found to be elevated in the haematoma fluid and is dependent on eicosanoid/prostaglandin and thromboxane synthesis via cyclooxygenase-2 (COX 2). With this investigator-initiated trial (IIT) it was thought to diminish the recurrence rate of operated-on cSDHs by administering a selective COX-2 inhibitor (Celecoxib) over 4 weeks' time postoperatively in comparison to a control group.

The thesis of risk reduction of cSDH recurrence in COX-2-inhibited patients was to be determined in a prospective, randomised, two-armed, open phase-II/III study with inclusion of 180 patients over a 2-year time period in four German university hospitals. The treated- and untreated-patient data were to be analysed by Fisher's exact test (significance level of alpha, 0.05 [two-sided]).

After screening of 246 patients from January 2009 to April 2010, the study had to be terminated prematurely as only 23 patients (9.3 %) could be enrolled because of on-going non-steroid anti-rheumatic (NSAR) drug treatment or contraindication to Celecoxib medication. In the study population, 13 patients were treated in the control group (six women, seven men; average age 66.8 years; one adverse event (AE)/serious adverse event (SAE) needing one re-operation because of progressive cSDH (7.7 %); ten patients were treated in the treatment group (one woman, nine men; average age 64.7 years; five AEs/SAEs needing two re-operations because of one progressive cSDH and one wound infection [20 %]). Significance levels are obsolete because of insufficient patient numbers.

The theoretical advantage of COX-2 inhibition in the recurrent cSDH could not be transferred into the treatment of German cSDH patients as 66.6 % of the patients showed strict contraindications for Celecoxib. Furthermore, 55 % of the patients were already treated with some kind of COX-2 inhibition and, nevertheless, developed cSDH. Thus, although conceptually appealing, an anti-angiogenic therapy with COX-2 inhibitors for cSDH could not be realised in this patient population due to the high prevalence of comorbidities excluding the administration of COX2 inhibitors ¹⁶⁾.

Recurrence rates after chronic subdural hematoma (CSDH) evacuation with any of actual techniques twist drill craniostomy (TDC), burr hole craniostomy, craniotomy range from 5% to 30%. Use of drain has improved recurrence rates when used with burr-hole craniostomy. Now, we analyze predictors of recurrence of TDC with drain.

Three hundred twelve consecutive patients with CSDH have been studied in a retrospective study. Operative technique in all patients consisted in TDC with drain. Data recorded included any associated comorbidity. Radiologic measures of the CSDH before and after the procedure were studied. Clinical evaluation included Modified Rankin Scale, Glasgow Coma Scale (GCS), and neurological deficits. Two groups were compared: recurrence group and nonrecurrence group. Follow-up was for at least 1 year.

Twelve percent experienced recurrence. Preoperative CSDH width, preoperative midline shift, postoperative midline width, postoperative CSDH width, and residual CSDH 1 month later were significantly associated with CSDH recurrence. The logistic regression model for the multivariate analysis revealed that postoperative midline shift and postoperative neurological deficit were significantly associated with CSDH recurrence. The duration of treatment with dexamethasone was found not to be related with recurrence. Mortality before hospital discharge was 1%. Hospital stay was 2.5 days.

TDC with drain has similar results in recurrence rates, morbidity, mortality, and outcome as other techniques as burr-hole craniostomy with drain. Preoperative and postoperative hematoma width and midline shift are independent predictors of recurrence. Brain re-expansion and time of drain maintenance are important factors related with recurrence of CSDH. Future CSDH reservoirs must avoid negative pressure and sudden pressure changes inside the whole closed drain system ¹⁷⁾