Chronic subdural hematoma: concepts of physiopathogenesis. A review

Burr hole drainage and burr hole drainage with irrigation to treat chronic subdural hematoma: A systematic review and meta-analysis

OBJECTIVE

Numerous studies have investigated different operative procedures for treating chronic subdural hematoma (CSDH); however, the results are controversial. This meta-analysis was performed to evaluate the efficacy of burr hole drainage without irrigation (BHD) and burr hole drainage with irrigation (BHDI) for CSDH.

METHODS

We searched the following electronic databases to identify all studies from their inception to September 2017: Cochrane Library, Science Direct, MEDLINE, EMBASE, Scopus, Google Scholar, the China Biomedical Database (CBM), and the Chinese National Knowledge Infrastructure (CNKI). Randomized clinical trials (RCTs), prospective cohort studies, retrospective observational cohort studies, and case-control studies investigating BHD and BHDI for the treatment of CSDH were included. The Cochrane Collaboration's RevMan 5.3 software was used for meta-analysis.

RESULTS

In total, 7 retrospective cohort studies and 2 RCTs involving 993 participants were included. Comprehensive analysis results of 9 studies indicated that the recurrence of the BHDI was similar to that in BHD (odds ratio [OR] = 1.27, 95% confidence interval [CI] = .61-2.63, P = .53). Moreover, analysis for comparing recurrence in the 2 RCTs was not significantly different (OR = 1.14, 95% CI = .16-8.24, P = .95).In addition, meta-analysis of pneumocephalus (OR = 5.91, 95% CI = .61-56.86, P = .12) and mortality (OR = 0.94, 95% CI 0.14-6.16, P = .95) was not significantly different.

CONCLUSIONS

The results of this meta-analysis demonstrated that procedures with or without irrigation in the treatment of CSDH might have similar effect regarding recurrence and complications; therefore, irrigation might not be necessary. However, well-conducted RCTs and high-quality observational studies are still required to corroborate this issue.

Preoperative predictive factors for surgical and functional outcomes in chronic subdural hematoma

BACKGROUND

Chronic subdural hematoma (CSDH) is a frequently encountered neurosurgical condition, especially in the elderly. We investigated predictive factors for surgical and functional outcomes after burr-hole drainage (BHD) surgery.

METHODS

All patients with CSDH treated by BHD between January 2012 and December 2014 were included in this study. All patients were classified by symptom, clinical grade, time, location, hematoma density, midline shift, and other characteristics. Pre- and postoperative CT evaluation was performed at 0, 3, and 6 months. Clinical grades were classified as described in Markwalder et al. Surgical and clinical outcomes were evaluated with the brain expansion rate and modified Rankin Scale (mRS). Brain expansion rate was calculated as the ratio between post- and pre-operative hematoma thickness. Recurrence was defined as the occurrence of symptoms and hematoma on CT within 6 months.

RESULTS

This study included 130 patients over 2 years. Among the variable parameters, young age (<75), iso-density of hematoma on CT, and short duration from symptom to surgery were correlated with good brain expansion. Patients with good brain expansion had fewer recurrences. In terms of mRS, young age, iso-density, and good clinical grade were correlated with good functional outcomes.

CONCLUSIONS

Clinicians should be more aware of general conditions and medical problems, especially in elderly patients. Membranectomy should be considered in patients with a long duration of symptoms or hypo-dense hematomas to promote good brain expansion and good mRS scores.

The level of circulating endothelial progenitor cells may be associated with the occurrence and recurrence of chronic subdural hematoma

OBJECTIVES

The onset of chronic subdural hematoma may be associated with direct or indirect minor injuries to the head or a poorly repaired vascular injury. Endothelial progenitor cells happen to be one of the key factors involved in hemostasis and vascular repair. This study was designed to observe the levels of endothelial progenitor cells, white blood cells, platelets, and other indicators in the peripheral blood of patients diagnosed with chronic subdural hematoma to determine the possible relationship between the endothelial progenitor cells and the occurrence, development, and outcomes of chronic subdural hematoma.

METHOD

We enrolled 30 patients with diagnosed chronic subdural hematoma by computer tomography scanning and operating procedure at Tianjin Medical University General Hospital from July 2009 to July 2011. Meanwhile, we collected 30 cases of peripheral blood samples from healthy volunteers over the age of 50. Approximately 2 ml of blood was taken from veins of the elbow to test the peripheral blood routine and coagulation function. The content of endothelial progenitor cells in peripheral blood mononuclear cells was determined by flow cytometry.

RESULTS

The level of endothelial progenitor cells in peripheral blood was significantly lower in preoperational patients with chronic subdural hematomas than in controls. There were no significant differences between the two groups regarding the blood routine and coagulation function. However, the levels of circulating endothelial progenitor cells were significantly different between the recurrent group and the non-recurrent group.

CONCLUSIONS

The level of circulating endothelial progenitor cells in chronic subdural hematoma patients was significantly lower than the level in healthy controls. Meanwhile, the level of endothelial progenitor cells in recurrent patients was significantly lower than the level in patients without recurrence. Endothelial progenitor cells may be related to the occurrence and recurrence of chronic subdural hematoma.

Developing a model of chronic subdural hematoma

Chronic subdural hematoma (CSDH) is a common neurosurgical condition that has a high incidence in the increasing elderly population of many countries. Pathologically, it is defined as a persistent liquefied hematoma in the subdural space more than 3 weeks old that is generally encased by a membraneous capsule. CSDHs likely originate after minor head trauma, with a key factor in its development being the potential for a subdural cavity to permit its expansion within, which is usually due to craniocerebral disproportion. The pathogenesis of CSDH has been attributed to osmotic or oncotic pressure differences, although measurements of these factors in the CSDH fluid do not support this theory. Current belief is that CSDH arises from recurrent bleeding in the subdural space, caused by a cycle of local angiogenesis, inflammation, coagulation and ongoing fibrinolysis. However, because of a lack of detailed knowledge about the precise mechanisms, treatment is often limited to surgical interventions that are invasive and often prone to recurrence. Thus, it is possible that an easily reproducible and representative animal model of CSDH would facilitate research in the pathogenesis of CSDH and aid with development of treatment options.

Outcome of contemporary surgery for chronic subdural haematoma: evidence based review

OBJECTIVE

To evaluate the results of surgical treatment options for chronic subdural haematoma in contemporary neurosurgery according to evidence based criteria.

METHODS

A review based on a Medline search from 1981 to October 2001 using the phrases "subdural haematoma" and "subdural haematoma AND chronic". Articles selected for evaluation had at least 10 patients and less than 10% of patients were lost to follow up. The articles were classified by three classes of evidence according to criteria of the American Academy of Neurology. Strength of recommendation for different treatment options was derived from the resulting degrees of certainty.

RESULTS

48 publications were reviewed. There was no article that provided class I evidence. Six articles met criteria for class II evidence and the remainder provided class III evidence. Evaluation of the results showed that twist drill and burr hole craniostomy are safer than craniotomy; burr hole craniostomy and craniotomy are the most effective procedures; and burr hole craniostomy has the best cure to complication ratio (type C recommendation). Irrigation lowers the risk of recurrence in twist drill craniostomy and does not increase the risk of infection (type C recommendation). Drainage reduces the risk of recurrence in burr hole craniostomy, and a frontal position of the drain reduces the risk of recurrence (type B recommendation). Drainage reduces the risk of recurrence in twist drill craniostomy, and the use of a drain does not increase the risk of infection (type C recommendation). Burr hole craniostomy appears to be more effective in treating recurrent haematomas than twist drill craniostomy, and craniotomy should be considered the treatment of last choice for recurrences (type C recommendation).

CONCLUSIONS

The three principal techniques-twist drill craniostomy, burr hole craniostomy, and craniotomy-used in contemporary neurosurgery for chronic subdural haematoma have different profiles for morbidity, mortality, recurrence rate, and cure rate. Twist drill and burr hole craniostomy can be considered first tier treatment, while craniotomy may be used as second tier treatment. A cumulative summary of data shows that, overall, the postoperative outcome of chronic subdural haematoma has not improved substantially over the past 20 years.

Cisternographic pattern of spontaneous liquoral hypotension

We describe five cases of headache due to spontaneous liquoral hypotension, the syndrome comprising sudden, intense and oppressive orthostatic holocranial headache. The headache improved in the recumbent position and was accompanied by nausea and sometimes vomiting. There was no history of lumbar puncture or previous trauma. CSF tension was low or negative. The CSF showed a raised protein content and increased red and white cell counts. CT scan was normal or showed a slit ventricular system. Improvement was complete three to eight weeks from onset. The treatment consisted of bed rest and oral and parenteral fluid replacement. An isotope cisternography carried out in all patients while the headache was present showed a cisternographic pattern characterized by a combination of premature elimination and failure to detect the isotope at the cerebral convexity. Scan images did not show CSF leakage at any site. This stereotyped reaction pattern suggests that CSF hyperabsorption is the most likely pathophysiological mechanism of this entity.

Nonsurgical management of extradural hematomas in children

With the advent of computerized tomography (CT), an increasing number of patients with only minimal neurological symptoms and no signs of brain herniation are found to harbor subacute or chronic extradural hematomas (EH's). The authors present the cases of 11 symptomatic but neurologically normal children with medium to large EH's managed by close observation. These EH's were discovered 4 hours to 6 days after injury; three were in the posterior fossa, seven over the frontoparietal convexity, and one in the temporal fossa. These clots were followed by serial CT scans. Nine children recovered without surgery from 4 to 18 days after injury, and all had evidence on CT of spontaneous clot resorption. Of these nine EH's, five clots displayed volume expansion from 5 to 16 days after injury before final resorption occurred. Expansion correlated with persistence or increase in symptoms, whereas resorption correlated with improvement. Two patients showed gradual uncal herniation on Days 6 and 8, respectively, presumably during the "expansile phase" of their clots. Both had emergency craniotomy and recovered without morbidity. It is hypothesized that the resorption dynamics of the subacute or chronic EH are similar to that of the chronic subdural hematoma, with predictable volume changes, and the outcome of each lesion depends on the interplay between the patient's intracranial pressure buffering capacity and the rate of volume change. If subtle signs of brain dysfunction are adopted to signal the failure of conservative treatment and the need for craniotomy, these patients may be safely, and many successfully, managed without surgery. Factors that influence outcome of medical treatment include the size, location, configuration, and the rapidity of accumulation of the clot, the presence of associated intradural lesions, the extracranial decompression of blood through skull diastases, and the age of the patient. These factors, the criteria for patient selection, and the indications for immediate operative intervention are discussed.

CT scanning after drainage of subdural haematoma: An unusual case

A unique patient with bilateral subdural haematomas with localized subdural membranes on one side is reported. Serial CT scans suggested that the membranes resolved spontaneously after drainage of the haematoma. The pathophysiology of subdural haematoma and the value of CT scanning in postoperative follow-up are discussed, especially in regard to learning more about the optimal treatment in this still somewhat enigmatic problem.

Physiopathogenesis of subdural hematomas. Part 2: Inhibition of growth of experimental hematomas with dexamethasone

A previously described experimental hematoma model, achieved by the subcutaneous injection of 12 ml of autologous hemolyzed blood clotted in situ, was made in 33 rats. Sventeen animals served as controls; the other 16 received daily intra-muscular injections of dexamethasone. After an initial decrease in size, 47% of the lesions in the control animals enlarged to a mean weight of 12.1 +/- 2.5 gm, while the lesions in the 16 steroid-treated rats weighted 3.2 +/- 0.70 gm (p less than 0.01). Histologically, lesions from the steroid group showed absence of neomembrane formation. These data offer further support to the theory that the neomembrane development and subsequent enlargement of subdural hematomas is due to inflammatory reactions of tissues in contact with large blood clots.

Physiopathogenesis of subdural hematomas. Part 1: Histological and biochemical comparisons of subcutaneous hematoma in rats with subdural hematoma in man

The dorsal subcutaneous injection in rats of 12 ml or more of autologous hemolyzed whole blood clotted in situ induced the formation of sterile, hemispheric lesions, 47% of which showed an initial decrease in volume followed by a progressive enlargement. The behavior, histology, and biochemical characteristics of the liquid contents of these lesions were found to be remarkably similar to those of subdural hematomas in man. To evaluate the role of the various blood components that may have influenced the formation and growth of these lesions, more than 150 clots composed of human platelet-free plasma, autologous hemolyzed blood, or autologous whole blood were implanted subcutaneously in rats by either surgical or injection techniques. The in vitro behavior of the different clots used was also assessed. This systematic approach led to the following conclusions: 1) the composition and volumes of the clots are critical variables; 2) plasma-fibrin provides the matrix shape of the lesions; 3) the breakdown products derived from erythrocytes, hemoglobin, leukocytes, and other solid blood elements induce neomembrane formation and contribute to the lesion's subsequent growth; and 4) inflammation mechanisms appear to be essential, while cerebrospinal fluid plays no discernable role in this process.