Minor traumatic intracranial dural hematomas
(up to 50 cm3) of suptratentorial localization

Grin A.A., Ioffe Yu.S., Krylov V.V.

Sklifosovsky Research Institute of Emergency Care, Moscow, Russia

Hematomas account for 2.0-16.6% of craniocerebral trauma (CCT) [1, 12, 30]. Before CT introduction tactics of hematoma treatment was simple: when diagnosed, it was removed as early as possible [8, 18, 24]. CT and MRI allowed to estimate quantitative parameters of hematoma (size, volume), time of its formation, localization, type, as well as a degree of its impact on the brain. It became possible to exercise dynamic control of evolution of intracranial pathology in general and hematomas in particular [22, 23]. Several reports, confirming possibility of resolution of subdural and epidural hematomas [10, 12, 21, 27, 28], and articles on their assimptomatics course [3, 7, 11, 13, 15, 25]. Indications for conservative treatment of itracranial hematomas (ICH) were widened to a considerable extent [4, 14 17, 26, 29].

Minor traumatic intracranial dural hematomas account for 3.0-18.2% of ICH [2, 12, 19]. Different authors refer acute and subacute traumatic intracranial dural (epidural, subdural, epi-subdural) hematomas of 50 cm3, localized supratentorially, to minor hematomas (MH) [5, 12, 19, 20, 28, 29]. When MH is diagnosed and a patient is in a compensated state, a neurosurgeon faces a problem of determining indications for surgical treatment. Possibility of avoiding an operation and carrying out conservative treatment in some patients reduces not only rates of invalidism and probable postoperative complications, but also expenses on treatment.

The study goal

Is to determine tactics of treatment of minor intracranial traumatic subdural and epidural hematomas (up to 50 cm3), localized supratentorially.

Material and Methods

A retrospective analysis of complex study of 120 patients with minor intracranial traumatic acute and subacute epi- and subdural hematomas (up to 50 cm3) was made.

MH were present in 2.8% of cases with CCT; they accounted for 14.7% of all ICH. There were 98 males and 22 females, aged 15-86 (a mean value of 39.6±16.0). Patients were admitted to the hospital in 1 hour-13 days after trauma; 35%, 58% and 26% of them were delivered during the first three hours, the first day and more than 3 days later respectively. The causes of trauma were as follows: life trauma - 60%, road trauma - 18%, on-the-job accident - 5%, falling from big height - 5%, trauma of unknown origin - 14%.

Multimodality examination of all patients was carried out. It included neurologic examination, X-rays of the skull (two views), echoencephaloscopy, CT. Volumes of hematoma, accompanying contusion foci, hydroma and a zone of perifocal edema were calculated during CT-examination [5]. Total volume of a pathologic density focus, was determined by summing up volumes of contusion foci, hematoma and hydroma. As for a high-density area of contusion focus(more than 65 HU), it was measured separately. Total volume of hematoma, hydroma and a high-density area of contusion focus with a zone of perifocal edema was of great interest for us. In our opinion, it was that very focus, whose direct pressing effect on the brain was considerably higher, than that of hematoma proper. Dislocation of cerebral median structures was estimated. Ventriculocranial indices (VCI) were measured for determining a degree of dilation or compression of brain ventricles. A state of brain cisterns (their filling with blood, deformity) was assessed.

Patients, admitted to the neurosurgical department, were examined by a neuro-ophthalmologist and neurologist. A differentiated scale of outcomes was used for their estimation [9]. Catamnesis taking was based on questioning and examination of 82 (80%) out of 103 patients, discharged for further treatment in an outpatient clinic. Statistical processing of the material was carried out. Pirson and Student criteria were used for determining correlation dependence and confidence of group difference respectively.

Results and Discussion

All patients were divided into three groups with the purpose of more differentiated determination of a MH volume effect on treatment. They were as follows: group I - 30 patients with hematomas of 4-15 cm3, group II - 35 patients with hematomas of 16-30 cm3, group III - 55 patients with hematomas of 31-50 cm3.

We found out some peculiarities of a clinical picture of minor hematomas. A greater part of patients was in a satisfactory state (24%) or a state of moderate severity (48%) on admission (fig.1). Usually they were delivered on the third day after trauma, when there appeared complaints of persistent headache and nausea or moderate hemispheric neurologic disorders. There was augmenting brain edema. We failed to reveal any dependence of a state severity on hematoma volume, as a patient's state was affected by other factors, including brain contusion, edema, angiospasm, age, somatic pathology, alcohol intoxication, etc. There was reliable difference in a state severity in groups of operated and non-operated patients (p<0.01). It can be used as one of the criteria in determining indications for an operation.

One more peculiarity concerned consciousness disturbances. The majority of cases (84%) had either mild disorders or preserved consciousness (topor - 61% of patients, clear consciousness - 23% of patients). A mean score in consciousness estimation, based on Glasgow Coma Scale (GCS), was equal to 12.3. Patients with associated severe brain contusion were unconscious. A level of consciousness suppression correlated with hematoma volume. There was reliable difference in a degree of consciousness suppression in groups of operated and non-operated patients (table 1).

Table 1

Mean Values of a Consciousness Level in Groups of Operated and Non-operated Patients with MH (n=120; p<0.01)

Treatment type A number of patients Glasgow Coma Scale
Surgical n = 54 10.9±3.2
Conservative n = 66 13.3±1.7

Thus, a state of consciousness is one of the criteria of determining indications for an operation in patients with MH. When a level of consciousness is characterized by the score of 14-15, conservative treatment can be carried out; if it is equal to 11 and less, a patient must be operated. As for the score of 12-13, one should take into consideration other parameters and stick to wait-and-see tactics.

Neurologic disorders in patients with MH, who were admitted in a satisfactory state or a state of moderate severity, were secondary and manifested themselves in 2-3 days. Absence of focal hemispheric neurologic disorders (58%) or their feebly marked manifestation (35%) on admission in the majority of patients was one more peculiar feature of MH. Rather often it was conditioned by the following facts: small-sized hematoma did not compress the underlying brain to a degree, which would result in impairment of its fuctions; hematoma was localized in a "silent" area from a functional point of view; more marked stem and common cerebral symptoms overlapped focal hemispheric neurologic disorders (16 cases). We did not find out any reliable dependence of focal neurologic disorders on hematoma volume. Neurologic symptoms were more dependent on localization and volume of a pathologic focus as a whole.

MH was characterized by absence of stem symptoms in the majority of cases (67%) and rarity of dislocation syndrome (12%). We did not discover any reliable dependence between presence of stem symptoms and hematoma volume (their rate in patient of the second and third groups was equal). However, appearance of dislocation symptoms was dependent on hematoma volume (they were watched only in patients of the third group). There was dislocation of the brain stem in hematoma of more than 30 cm3 and in some other intracranial pathology (brain edema, brain contusion, hydroma on the same side). Absence of stem symptoms in the majority of patients with MH was explained by the following: small hematomas did not cause marked compression of the brain and there were no big foci of brain contusion and perifocal edema in a greater part of cases. Threat of dislocation syndrome arose only when hematoma of 30-50 cm3 was combined with a focus of brain contusion and its edema. Thus, appearance of brain stem dislocation is dependent on the whole pathologic focus, consisting of hematoma, a contusion focus, a zone of perifocal edema, hemispheric/total brain edema and hydroma.

The situation in the group of patients with MH and dislocation syndrome was as follows:

There was moderate correlation between presence of stem and dislocation symptoms and a number of operated cases (p<0.01). All patients with stem symptoms were operated. Thus, presence of stem and dislocation symptoms is one of the criteria for determining indications for an operation in patients with MH.

DMS of the brain, estimated with the help of CT, was the most informative index. A peculiar feature of MH was DMS absence in more than a half of cases (56%). DMS of the brain was insignificant (3-4 mm) in 13% of patients. This index was equal to 5 mm and more only in 30.8% of cases (fig.2).

There was highly significant correlation between hematoma volume and DMS (r=0.51, p<0.001). The latter was dependent on a pathologic focus volume. There was reliable difference in values of DMS of the brain in groups of operated and non-operated patients (5.1 mm and 1.6 mm respectively, p<0.001). That was why dislocation of median structures was one of the criteria in determining indications for an operation.

Subdural, epidural and epi-subdural hematomas were watched in 78, 32 and 10 out of 120 patients respectively. We did not find any statistically significant dependence of symptoms distribution and indications for an operation on a type of hematoma. However, patients with epidural hematomas were operated more frequently (the operation rate of 59.4% in comparison with 39.7% in subdural hematomas). All patients with epidural hematoma of more than 20 cm3, localized in the area of a temporal lobe base, were subject to operation, as this localization is considered to be the main factor of development of temporal-tentorial dislocation. Traumatic subarachnoid hemorrhage causes aggravation of brain edema, hampered liquor resorption and increase of intracranial pressure as well. Epidural hematoma of the middle cranial fossa base is indicative of the skull base fracture, being an indirect sign of trauma of neighboring stem tissues.

MH was accompanied by focal contusions of the brain in 71% of patients. Total volume of a pathologic focus in MH was 52±38 ρμ3. There was reliable difference in this index in operated and non-operated cases.

Operations were performed in patients with hematoma of 38 cm3 (a mean value), combined with brain contusion, whose volume was equal to 25 cm3 (volumes of a high-density part of brain contusion and a zone of perifocal edema were 10 cm3 and 15 cm3 respectively). Total volume of a pathologic focus and a high-density part of this zone were 63 cm3 and 48 cm3 respectively. As for non-operated patients, hematoma mean volume, total volume of a pathologic focus, a high-density part of brain contusion and a zone of perifocal edema were represented by the following figures: 21 cm3, 45 cm3, 4 cm3 and 20 cm3 respectively.

One can easily understand necessity of performing an operation in, for example, hematoma of up to 30 cm3 and its positive effect, watched even without removal of a small high-density part of brain contusion (1/4 of hematoma volume on the average). The causes of it are as follows:

  1. An operation allows to decrease a critical mass, compressing the brain (total volume of intracranial pathologic substrates, leading to neurologic disorders in a patient).
  2. A subdural space is "cleaned" during an operation and it reduces a toxic effect of dissolved blood on the brain.
  3. Some amount of "excessive" liquor is eliminated from limited reserve liquor spaces during an operation.

There were no patients with hematoma of up to 15 cm3 among operated cases. As for patients with hematoma of 16-30 cm3 , 37 % of them were operated. As a rule, they had accompanying brain contusion or epidural hematoma in the area of the middle cranial fossa (fig.3).

Operations in hematoma of 31-50 cm3 were made in 75% of cases; 14 non-operated patients (25%) of this group had hematoma of more than 38 cm3, but no clinical signs of neurologic disorders and brain dislocation; CT examination of these cases was indicative of absence of big foci of brain contusion or its edema. Subdural and epi-subdural hematomas were observed in 12 and 2 out of 14 patients respectively. All hematomas were localized convexitally in projection of the second-fourth lobes of the brain. This fact demonstrated, that determination of indications for an operation in cases with MH should be based on complex estimation of several criteria. Hematoma volume was used as one of the criteria for choosing tactics of treatment of this pathology as well as forming this group of patients. Mean volume of hematoma in operated and non-operated patients was 38±10 cm3 and 22±13 cm3 respectively. Borderline volume, separating operated and non-operated patients, was 30 cm3 (fig.4).

Hence, patients with hematoma of not more than 30 cm3 can be treated conservatively; cases with hematoma of more than 40 cm3 are to be operated; as for patients with hematoma of 30-40 cm3, wait-and-see tactics can be used, when other criteria are indicative of possible conservative treatment (a level of consciousness, absence of dislocation syndrome and gross neurologic disorders, etc.). Sometimes temporizing tactics and conservative treatment are justified, even if hematoma volume exceeds 38 cm3; it becomes possible, when other criteria allow to consider use of this type of treatment and patients have no brain contusion focus. One of the principal conditions of conservative treatment of MH is round-the-clock control of a patient by a neurosurgeon, as well as possibility of twenty-four-hour CT/MRI examination.

One more criterion for determining indications for an operation in MH is VCI2, VCI3 and VCI1. As a rule, patients need an operation, when VCI1, VCI2 and VCI3 are less than 16.6%, 10.6% and 1.4% respectively (mean values in the group of operated cases). If these indices are or tend to be normal, conservative treatment is possible. There is reliable dependence of VCI on hematoma volume, total volume of a pathologic zone and volume of its high-density part.

One of the important diagnostic criteria in intracranial hemorrhages is a state of basal cisterns of the brain. Blood in basal cisterns or their deformity is one of the signs of a dislocation process. It conditions surgical tactics to a considerable extent. Cisterns deformity or their filling with blood were watched in 46 patients (38%) with MH; 35 of them were operated. A number of cisterns, which were filled with blood or deformed, correlated with hematoma volume (r=0.24, p<0.01). In our opinion, the explanation of this phenomenon is as follow: hematoma volume reflected hemorrhage intensity and correlated with dislocation syndrome. However, a degree of correlation of brain edema and volume of the whole pathologic focus with pathologic changes of cisterns was more marked (r=-0.5, p<0.01 and r=-0.49, p<0.05 respectively). It confirmed lesser significance of hematoma in brain compression in comparison with volume of the whole pathologic focus and a zone of secondary changes of the brain (edema, ischemia). Besides, a state of cisterns correlated with such factors, as VCI1, brain edema, total volume of a pathologic focus, dislocation syndrome, a level of consciousness, stem symptoms, a patient's state, VCI2, VCI3 (the factors are given in the order of correlation decrease).

There is direct and indirect connection between these factors in CCT. We consider blood in basal cisterns to be a cause of arterial vasospasm, promoting development of cerebral ischemia. Ischemic changes led to brain edema and swelling and increase of a pathologic zone. In its turn, it resulted in decrease of reserve liquor-containing spaces and was reflected in such parameters, as VCI. Secondary vascular changes in the brain stem area manifested themselves in stem and dislocation symptoms and inhibition of an activating effect of the reticular formation on brain segments, lying above it. There appeared consciousness disturbances. Hematoma volume was connected with cistern pathology to a lesser degree, as it was blood in a cistern cavity, which affected its state, but not hematoma proper. However, there were some cases, when hematoma of more than 30 cm3, a contusion focus and a zone of perifocal edema caused brain compression against a background of subarachnoid hemorrhage. It manifested itself in deformity of cisterna ambiens on the side of hematoma and DMS of the brain. Taking the above-mentioned facts into consideration, we came to a conclusion, that a state of cisterns was one more criterion of determining indications for an operation. Thus, conservative treatment is possible in case of isolated deformity of only cisterna ambiens or absence of cistern pathology. Surgical treatment is indicated, when pathology in the area of basal cisterns is watched and especially when it is combined with changes of cisterna ambiens.

There was reliable difference in a number of cases with changed cisterns in the groups of operated and non-operated patients (p<0.01). Mortality in operated patients with and without cistern pathology was 40% and 5% respectively. It proved significance of this criteria from the point of view of determining indications for an operation and prognostication of an outcome.

Operations were performed in 54 (45%) out of 120 cases; 66 patients (55%) were treated conservatively. Mean time of performing operations in patients with MH was 4.4±4.0 days since the moment of trauma and 2.8±2.7 days since the moment of admission. Delay in surgical interventions was explained by peculiarities of a clinical course of MH: tardy manifestation of clinical symptoms, a more mild course and, as a result, prolongation of a period of turning for medical assistance, wait-and-see behavior of some patients and their belief in successful conservative treatment.

There was significant negative correlation between hematoma volume and operation time. Surgical interventions in patients with hematomas of 16-30 cm3 were performed two times later as compared with cases, having hematomas of 31-50 cm3 (6.5 and 3.7 days respectively).

Reliable difference in operation time, depending on a type of hematoma, was watched. Operations in subdural hematomas were made two times later than interventions in epidural hematomas (5.6 and 2.6 days respectively). Operations in epidural hematomas were performed earlier due to a more rapid clinical course, quick appearance of manifestations and a brighter clinical picture. Epidural hematoma, limited in its spread by places of dura mater fixing to cranial sutures, was thicker, but its area was smaller than that of subdural hematoma. It was characterized by greater local compression of the brain and, as a result, more marked neurologic symptoms (common cerebral, focal, hemispheric and stem symptoms). Epidural hematoma of more than 20 cm3, localized at a temporal lobe base, was a cause of dislocation syndrome in 67% of cases. When these hematomas were localized convexitally and in "silent" areas, all patients suffered from headache. Persistent headache and ineffective conservative treatment were a cause of surgical intervention in 10 out of 22 cases; all operated patients had hematomas of more than 30 cm3. A period of clear consciousness was characteristic just of this very type of hematomas. Mean volume of epidural and subdural hematomas was approximately the same in operated patients (39.9 and 37.8 cm3 respectively); there was reliable difference in non-operated patients (epidural hematomas - 14.0±9.0 cm3 and subdural hematomas - 23.0±13.8 cm3, p<0.05).

Surgical treatment of MH was carried out with the help of osteoplastic trephination of the skull (19 cases - 35%), decompression craniotomy (34 cases - 63%), hematoma drainage through a burr hole (1 case - 2%).

Decompression craniotomy was used in decompensated patients, when there were an avalanche-like and acute development of symptoms, presence of marked consciousness disturbances, stem and gross focal hemispheric symptoms and CT-findings indicative of dislocation syndrome, foci of brain contusion and crush and total volume of a pathologic zone of more than 70 cm3. Decompression was made in intraoperative prolapse of the brain into trephination defect.

Operation time differed to a considerable extent. Decompression trephination was performed in patients, whose state was more severe, and it was done during the first 3 days on the average. Osteoplastic trephination was performed in 6 days (a mean value). In other words, decompression and osteoplastic intervention were used in acute and subacute hematomas respectively.

Hematoma volume, determined on the basis of CT-findings, correlated with its volume, watched during an operation (or autopsy). However, hematoma volume, calculated according to CT-data, was not an absolute value. It was used as a reference criterion for identifying groups of patients, who demanded special attention.

Peculiarities of a clinical picture in MH, watched by us, allowed to determine criteria (table 2) and to accumulate auxiliary data (table 3) for choosing tactics of treatment of such patients.

Table 2

Treatment of Patients with MH: Choice Criteria

Criteria

Treatment

 

Conservative

Surgical

Temporizing tactics

A general state

Satisfactory

Extremely severe and severe

Moderate severity

Consciousness (Glasgow Coma Scale)

14-15

11 and less

12-13

Stem symptoms

no

yes

mild

Dislocation symptoms

no

yes

no

Hematoma volume

up to 30 cm3

40 cm3 and more

30-40 cm3

Total volume of a pathologic focus

45 cm3 and less

60 cm3 and more

46-59 cm3

A high-density zone of contusion + hematoma volume

30 cm3 and less

50 cm3 and more

31-49 cm3

DMS of the brain according to CT-findings

0-4 mm

5 mm and more

0-5 mm

A state of cisterns

No changes

Obliteration of basal cisterns with blood and/or deformity of cisterna ambiens

No changes of basal cisterns, insignificant deformity of cisterna ambiens

VCI2
VCI3
VCI1

17 and more
2 and more
22 and more

£10.6
£1.4
£16.6

11-17
1.5-2
17-22

A state of the eye fundus

Absence of engorged disks or engorgement regress

Engorged disks of optic nerves on both sides

Engorgement absence or engorgement on one side

The total mortality rate was 14% (17 out of 120 patients with MH died). Fatal outcomes were watched in 15 (28%) operated and 2 (3%) non-operated patients. Low mortality in the group of non-operated cases was indicative of correct selection of patients for conservative treatment; it was conditioned by extracranial pathology. Causes of fatal outcomes in patients with MH were as follows: brain edema and dislocation, pneumonia, meningitis. Both non-operated patients died of pneumonia; fatal outcomes in this group were conditioned by a decompensated state due to existing somatic pathology. The main cause of death in the group of operated patients was brain edema and dislocation (53.3%), pneumonia (33.3%). There was a temporal-tentorial type of herniation in postmortem examination of patients, who died of brain edema and dislocation.

Table 3

Auxiliary Data for Determining Tactics of MH Treatment

Data

Treatment

 

Conservative

Surgical

Moderate

Focal symptoms

Absent or feebly marked

Gross

Moderate

Common cerebral symptoms

Absent or feebly marked

Persistent severe headache resistant to therapy

Moderate, responding to therapy

Hematoma localization

-

A temporal lobe base

-

High postoperative mortality in MH was conditioned by the following fact: a fatal outcome was predetermined by brain injury severity, but not by hematoma volume. That is why, mortality in patients with coma, caused by severe brain contusion, is always irrespective of hematoma volume and high. As for our series, 7 patients with deep coma died.

The analysis allowed to find out factors, having a reliable effect on fatal outcomes (they are given in the order of their significance):

  1. A level of consciousness.
  2. A state severity.
  3. Presence of dislocation syndrome.
  4. Total volume of a pathologic focus (hematoma is only a constituent of this parameter).
  5. Infectious and non-infectious complications.
  6. A period of time, which passes between the moment of trauma and an operation in patients with brain dislocation.
  7. Volume of a high-density part of brain contusion.
  8. Brain edema and stem symptoms.

The mortality rate in patients with MH was smaller, than mean statistical indices, typical of patients with epi- and subdural hematomas of supratentorial localization.

A period of follow-up varied from 1.5 up to 4 years. Excellent and good results in a remote period were watched in 88% of patients. It was a high index for cases with severe CCT. There was no reliable difference in outcomes of operated and non-operated patients. Not a single patient complained of epileptic seizures.

The analysis of CT-changes, watched in dynamics, showed that resolution of epidural hematomas of up to 30 cm3 took place in 14-35 days (8 out of 9 patients with MH). Resolution of subsural hematomas of up to 50 cm3 was observed in 14 days-3 months (20 out of 22 cases).

Conclusion

Minor traumatic epidural and subdural hematomas (not more than 50 cm3) account for 15% of all cases with ICH. MH were combined with focal brain contusions in 70% of patients. It predetermined surgical treatment to a great extent. Peculiarities of a clinical picture of MH consisted in compensated and subcompensated states of the majority of patients. Probability of temporal-tentorial dislocation in MH was extremely great, when hematoma of more than 30 cm3 was combined with brain contusion or edema. A level of consciousness, development of dislocation syndrome, DMS and ventricular indices were reliably dependent on total volume of a pathologic focus, watched in patients with MH.

Criteria of conservative treatment of such patients include hematoma of up to 30 cm3, a patient's satisfactory state, a level of consciousness (Glasgow Coma Scale score of 14-15), absence of stem and dislocation symptoms, DMS of less than 5 mm, intact basal cisterns, total volume of a pathologic focus of not more than 45 cm3, volume of a high-density part of not more than 30 cm3, VCI2>12%, VCI3>2% and VCI1>22%. Round-the-clock supervision of a neurosurgeon and possibility of CT/MRI control are mandatory conditions of conservative treatment.

Criteria of surgical treatment are as follows: hematoma of not more than 40 cm3; a severe or extremely severe state of a patient; a level of consciousness, characterized by the score of 11 and less (GCS); presence of stem and dislocation symptoms, DMS of more than 5 mm; obliteration of basal cisterns with blood and/or marked deformity of cisterna ambiens; total volume of a pathologic focus of more than 60 cm3; volume of a high-density part of more than 50 cm3; VCI2 10.6%, VCI3 1.4% and VCI1 16.6%.

Temporizing tactics in treatment of patients with MH is possible in hematoma of 31-39 cm3; moderate severity of a patient's state; a level of consciousness, characterized by the score of 12-13 (GCS); presence of feebly marked stem symptoms and absence of dislocation symptoms; DMS of up to 5 mm; intact basal cisterns or insignificant deformity of cisterna ambiens; total volume of a pathologic focus of 46-59 cm3 and volume of a high-density part of 31-49 cm3; VCI2=11-17%, VCI3=1.5-2% and VCI1=17-22%.

The most significant factors with an effect on an outcome in patients with MH are a level of consciousness disturbances, a state severity, presence of dislocation syndrome, total volume of a pathologic focus and volume of its high-density part, complications of CCT, deformity and/or obliteration of basal cisterns with blood, volume of brain contusion. There is no reliable difference in remote results of conservative and surgical treatment of patients with MH. Thus, discovered peculiarities of a clinical picture and the most reliable factors, conditioning a choice of treatment tactics and an outcome, allow to improve results of treatment of patients with MH.

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