Post-traumatic subdural hygromas: observations concerning a surgical enigma

Analysis of Risk Factor for the Development of Chronic Subdural Hematoma in Patients with Traumatic Subdural Hygroma

OBJECTIVE

Although a high incidence of chronic subdural hematoma (CSDH) following traumatic subdural hygroma (SDG) has been reported, no study has evaluated risk factors for the development of CSDH. Therefore, we analyzed the risk factors contributing to formation of CSDH in patients with traumatic SDG.

METHODS

We retrospectively reviewed patients admitted to Hallym University Hospital with traumatic head injury from January 2004 through December 2013. A total of 45 patients with these injuries in which traumatic SDG developed during the follow-up period were analyzed. All patients were divided into two groups based on the development of CSDH, and the associations between the development of CSDH and independent variables were investigated.

RESULTS

Thirty-one patients suffered from bilateral SDG, whereas 14 had unilateral SDG. Follow-up computed tomography scans revealed regression of SDG in 25 of 45 patients (55.6%), but the remaining 20 patients (44.4%) suffered from transition to CSDH. Eight patients developed bilateral CSDH, and 12 patients developed unilateral CSDH. Hemorrhage-free survival rates were significantly lower in the male and bilateral SDG group (log-rank test; p=0.043 and p=0.013, respectively). Binary logistic regression analysis revealed male (OR, 7.68; 95% CI 1.18-49.78; p=0.033) and bilateral SDG (OR, 8.04; 95% CI 1.41-45.7; p=0.019) were significant risk factors for development of CSDH.

CONCLUSION

The potential to evolve into CSDH should be considered in patients with traumatic SDG, particularly male patients with bilateral SDG.

A single center's experience with the bedside subdural evacuating port system: a useful alternative to traditional methods for chronic subdural hematoma evacuation

Object

The traditional methods for managing symptomatic chronic subdural hematoma (SDH) include evacuation via a bur hole or craniotomy, both with or without drain placement. Because chronic SDH frequently occurs in elderly patients with multiple comorbidities, the bedside approach afforded by the subdural evacuating port system (SEPS) is an attractive alternative method that is performed under local anesthesia and conscious sedation. The goal of this study was to evaluate the radiographic and clinical outcomes of SEPS as compared with traditional methods.

Methods

A prospectively maintained database of 23 chronic SDHs treated by bur hole or craniotomy and of 23 chronic SDHs treated by SEPS drainage at Tufts Medical Center was compiled, and a retrospective chart review was performed. Information regarding demographics, comorbidities, presenting symptoms, and outcome was collected. The volume of SDH before and after treatment was semiautomatically measured using imaging software.

Results

There was no significant difference in initial SDH volume (94.5 cm3 vs 112.6 cm3, respectively; p = 0.25) or final SDH volume (31.9 cm3 vs 28.2 cm3, respectively; p = 0.65) between SEPS drainage and traditional methods. In addition, there was no difference in mortality (4.3% vs 9.1%, respectively; p = 0.61), length of stay (11 days vs 9.1 days, respectively; p = 0.48), or stability of subdural evacuation (94.1% vs 83.3%, respectively; p = 0.60) for the SEPS and traditional groups at an average follow-up of 12 and 15 weeks, respectively. Only 2 of 23 SDHs treated by SEPS required further treatment by bur hole or craniotomy due to inadequate evacuation of subdural blood.

Conclusions

The SEPS is a safe and effective alternative to traditional methods of evacuation of chronic SDHs and should be considered in patients presenting with a symptomatic chronic SDH.

Dynamics of subdural hygroma following decompressive craniectomy: a comparative study

Object

This retrospective comparative cohort study was aimed at discovering the risk factors associated with subdural hygroma (SDG) following decompressive craniectomy (DC) to relieve intracranial hypertension in severe head injury.

Methods

Sixty-eight of 104 patients who had undergone DC during a 48-month period and survived > 30 days were eligible for this study. To assess the dynamics of subdural fluid collections, the authors compared CT scanning data from and the characteristics of 39 patients who had SDGs with the data in 29 patients who did not have hygromas. Variables significant in the appearance, evolution, and resolution of this complication were analyzed in a 36-week longitudinal study.

Results

The earliest imaging evidence of SDG was seen during the 1st week after DC. The SDG volume peaked between Weeks 3 and 4 post-DC and was gradually resolved by the 17th week. Among the mechanisms of injury, motor vehicle accidents were most often linked to the development of an SDG after DC (p < 0.0007), and falls were least often associated (p < 0.005). Moreover, patients with diffuse brain injury were more prone to this complication (p < 0.0299) than those with an evacuated mass (p < 0.0001). There were no statistically significant differences between patients with and without hygromas in terms of age, sex, Glasgow Coma Scale score, intraventricular and subarachnoid hemorrhage, levels of intracranial pressure and cerebral perfusion pressure, timing of decompression, and the need for CSF diversion. More than 90% of the SDGs were ipsilateral to the side of the craniectomy, and 3 (8%) of 39 SDGs showed evidence of internal bleeding at ~ 8 weeks postinjury. Surgical evacuation was needed in 4 patients with SDGs.

Conclusions

High dynamic accidents and patients with diffuse injury were more prone to SDGs. Close to 8% of SDGs converted themselves into subdural hematomas at ~ 2 months postinjury. Although SDGs developed in 39 (~ 60%) of 68 post-DC patients, surgical evacuation was needed in only 4.

Traumatic subdural hygroma: five cases with changed density and spontaneous resolution

Thirty-four consecutive adult patients with subdural traumatic hygroma were analysed for clinical evolution, serial computed tomography scan (CT), and magnetic resonance imaging (MRI) over a period of several months. Five of the patients presented CT scan and MRI evolution data showing increasing density over a period of 11 days to 6 months post trauma. In these five patients, final clinical and CT scan data were benign, with complete spontaneous resolution. Descriptions in literature of evolving traumatic subdural hygroma have presented CT scan density modifications changing into chronic subdural hematoma. Our patients show another possibility, density transformation, which sometimes show as subdural hematoma in CT scan and MRI, but with final evolution where clinical condition and CT scan return to normal.

Origin of chronic subdural haematoma and relation to traumatic subdural lesions

The origin of chronic subdural haematoma (CSDH) and the pathogenesis of subdural hygroma (SDG) are still controversial issues. These issues and relationships between these traumatic subdural lesions are discussed. The origin of CSDH is usually a SDG, although a few cases are caused by acute subdural haematomas (ASDH). Subdural hygroma is produced by separation of the dura-arachnoid interface, when there is sufficient subdural space. When the brain remains shrunken, the SDG remains unresolved. Any pathologic condition inducing cleavage of tissue within the dural border layer at the dura-arachnoid interface can induce proliferation of dural border cells with production of neomembrane. In-growth of new vessels will follow, especially along the outer membrane, then bleeding from these vessels occurs. These unresolved SDGs become CSDHs by repeated microhaemorrhage from the neomembrane. Although most victims with ASDH underwent surgery or died, some patients could be managed conservatively. Since the ASDH is usually absorbed within a few weeks, only a very few ASDHs become CSDHs, when there is a sufficient potential subdural space. Chronic subdural haematoma can arise from ASDH, but more commonly from SDG. Such transformation, or development of a new subdural lesion, is a function of the premorbid status and the dynamics of absorption and expansion.

The pathogenesis and clinical significance of traumatic subdural hygroma

Subdural hygroma (SDG) is a common post-traumatic lesion. Despite its common occurrence, the pathogenesis and clinical significance are uncertain. The author reviewed the literature to clarify the present knowledge on the pathogenic, diagnostic and therapeutic aspects of this controversial lesion. A trivial trauma can cause a separation of the dura-arachnoid interface, which is the basic requirement for the development of a SDG. If the brain shrinks due to brain atrophy, excessive dehydration or decreased intracranial pressure, fluid collection may develop by a passive effusion. Most SDGs resolve when the brain is well expanded. However, a few SDGs become chronic subdural haematomas, when the necessary conditions persist over several weeks. Since the majority of patients with a SDG do not show a mass effect, surgery is rarely required. Outcome is closely related to the primary head injury not to the SDG itself. The complexity of SDG depends on various factors including the dynamics of absorption and expansion, duration of observation, and indication and rate of surgery, besides variety of the primary head injury in types and severity. SDG is a common epiphenomenon of head injury.

[Subdural effusions in children. Pathophysiology and treatment]

Nine children harboring subdural effusions were treated by subduro peritoneal shunt. These patients were followed-up by CT scans. The area of the subdural effusions was measured by quantitative morphology with a planimeter. With the surgical treatment, the subdural effusion disappeared completely or near completely in 8 patients. The patient's functional state were excellent in 4, good in 3 and bad in 2 in the postoperative follow-up. We aldo reviewed the literature as far as the pathophysiology and the treatment of the subdural effusions are concerned.

Subdural effusions: determination of contrast medium influx from CSF to the fluid accumulation by computed tomography as an aid to the indications for management

In 46 patients with subdural effusions CSF dynamics and especially the influx of contrast medium from CSF to the subdural fluid accumulation was investigated by serial computed tomography (CT). In 16 cases the subdural effusion was of traumatic and in 30 cases of non-traumatic origin. The results allowed a subdivision of the patients into three groups. Group 1: patients without contrast medium influx into the subdural fluid accumulation; group 2: patients with delayed influx; group 3: patients with immediate influx. In group 1 patients the subdural effusion acted as a space-occupying process with absolute indication for surgical treatment. Also in group 2 patients the further course showed that a surgical indication was given, because the fluid accumulation did not resolve under conservative management but increased in size, and/or the neurological deficit worsened. In all group 3 patients the subdural effusions decreased and finally disappeared conservatively. Group 1 patients with effusions on traumatic origin generally had more severe injuries than the patients of the other groups. The investigations caused no serious complications. This diagnostic method proved to be a reliable means for early differentiation between the possibility of conservative management or the indication for operative treatment in cases with subdural effusions of different origin.

Current reporting of responsiveness in acute cerebral disorders. A survey of the neurosurgical literature

One hundred sixty-six papers published in seven neurosurgical journals from 1983 through 1985 have been surveyed to determine the methods used for assessment of overall patient responsiveness in acute cerebral disorders (coma grading). Fifty-one different coma scales or modifications were found. The Glasgow Coma Scale (GCS) sum score (that is, the sum of the scores of the individual eye, verbal, and motor scales) dominated (54%), and was used in 73 (76%) of 96 of the head-injury studies; in 56 (77%) of these 73 studies it was the single method of grading neurological status. The GCS sum score was used in 16 (23%) of 70 studies in patients with other etiologies. The Hunt and Hess scale was used in 26 (57%) of 46 reports of patients with subarachnoid hemorrhage. In 31 (55%) of the 56 studies of head injuries using the GCS alone, it was not obvious if the 12- or 13-grade scale was used. In 13 studies (23%) no reference to methodological investigations was made. In 44 papers (79%) the handling of untestable features, such as intubation or swollen eyes, was not reported. In the 56 studies using the GCS alone, coma was defined in many different ways and in 22 studies the definition of coma was not specified. In 63% of reports, the GCS sum score scale was combined in one to five groups of scores and this was done in 32 different ways. No information was available to describe the procedure of data aggregation or the reliability of the 13-grade GCS sum score. The lack of standardization makes it unnecessarily difficult to perform valid comparisons between different series of patients. Since the GCS sum score is the most widely used scale, it is suggested that the reporting of the GCS sum score should be standardized regarding pseudoscoring, coma definition, and use of combined scores. Further studies on the reliability of the GCS sum score are needed.