Acute subdural haematoma: Better results with neurosurgeons than general surgeons

Injury 14.489-492

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Acute subdural haematoma: Better results with neurosurgeons than general surgeons C. P. Yue, K. S. Mann and G. B. Ong Department of Surgery, University of Hong Kong, Queen Mary Hospital, Hong Kong

Summary

During an eleven year period, 123 patients with acute subdural haematoma were treated in our unit. The first 63 patients were managed by general surgeons with a mortality rate of 80.9 per cent. Good recovery among survivors was 4.7 per cent. The subsequent 60 patients were managed by neurosurgeons. The mortality rate then dropped to 60 per cent and the rate of good recovery rose to 2 1.6per cent. This improvement in outcome is statistically significant (PcO.02 and

P < 0.05 respectively). Early operation plus thorough evacuation of haematoma by craniectomy or craniotomy were the main factors found responsible for the improvement. INTRODUCTION ACUTE subdural haematoma

(ASDH) continues to have a distressingly high mortality and a severe disability rate among survivors (Becker, 1977; Gennarelli, 1982). Neurosurgeons in many centres have assumed increasing responsibility for the management of these patients. However, reports on the influence of neurological surgery on the outcome of ASDH as opposed to management by general surgeons are scarce in the literature. We reviewed the records of 123 patients with ASDH treated in our unit. The first 63 were operated upon by general surgeons, while the subsequent 60 patients were operated on by the neurosurgical team. In this retrospective analysis, we have assessed outcome in the two groups and we discuss what factors may be responsible for the improvement in those operated on by neurosurgeons. PATIENTS

From

AND

METHODS

197 1 to 198 I, a total of 14 140 patients

with head injuries were admitted to the Queen Mary Hospital, Hong Kong, which serves roughly one million people on the Hong Kong Island. All acute subdural haematomata operated upon within two days of injury and measuring more than 50 ml were included in this analysis. During the eleven-year period, a total of 123 cases were operated upon, which constituted 0.9 per cent of the admissions for head injury. Road accidents were responsible for ASDH in 71 patients, falls in 41, assaults in 6, and in 5 patients the exact mode of injury could not be determined. The male to female ratio was I .6 to I. Age ranged from 1 I months to 95 years with a mean age of 55. The eleven-year period was sub-divided into two periods. Period I covers the years from 1971 to 1976, period II, the years 1977 to 198 1. From 1977 onwards a neurosurgeon joined the Department and supervised the management of and operations on all patients with head injury. Diagnosis in both periods relied mainly upon clinical examination and exploratory burr-holes. Indications for exploration were similar in both periods: (I) deterioration of level of consciousness (2) presence of localizing signs (3) failure to tomography was not improve. Computerized available. Cerebral angiography was performed in only nine cases. The following factors were selected to show whether patients treated in the two periods were comparable: age, number of patients admitted in coma, number of patients with bilateral subdural haematomata and number of patients with noteworthy extracranial injury such as fractures of limbs, major injuries of chest and abdomen (Tub/e r). All

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Table /. Patient variables and period

No. of patients Mean age No. admitted in coma No. with bilateral SDH No. with significant extracranial injury

Tab/e //. Correlation of outcome to two periods

Outcome

Dead Vegetative Severely disabled Moderately disabled Good recovery Total

Period I No. (%)

Period II No. (96)

Period I

Period II

63 55 48 20 13

60 58 45 21 10

Table III. Types of operation and inadequately treated haematomas in relation to two periods

Total No. (%)

51 (80.9) 36 (60) 87 (70.7) 0 (0) 0 (0) 0 (0) 2 4 6 7 7 14 3 (4.7) 13(21.6)16(13.0) 63 60 123

who died as a direct consequence of the injury, or the complications thereof, were examined post mortem. Survivors were followed-up for at least 6 months before their final state was assessed. Statistical analysis was performed by the X2 test with Yate’s correction. A P value of 0.05 was regarded as statistically significant. those patients

RESULTS Outcome

The outcome of 123 patients was categorized according to the method of Jennett and Bond (1975) comparing periods I and II (Table II) for mortality and rate of good recovery. The differences in outcome in both periods were significant at a P value of less than 0.02 (X2 = 5.54) and 0.05 (X2 = 4.75) respectively. Delay before operation

Forty-eight patients in period I were admitted in coma and 47 died (98 per cent). In period II, 32 out of 45 similar patients died (7 I per cent). The difference was highly significant (PC 0.01, X2= 10.0). The time interval from admission to skin incision in these comatose patients in both periods was compared. In period I, the mean time between injury and operation was 14.2 hours as compared to 6.1 hours in period II.

No. of burr-holes alone No. of craniectomies No. of craniotomy flaps No. of missed haematomas No. of recurred haematomas

Period I

Period II

36 10 17

6 32 22

11

13

17

4

Inadequate operation

We defined a missed haematoma as a subdural collection of more than 50 ml discovered post mortem, and not found during exploration. ‘Recurrent haematoma’ refers to the post mortem finding of more than 50 ml of blood in the subdural space at the site of the operation. The number of simple burr-holes, craniectomies and osteoplastic craniotomy bone flaps in relation to the number of missed and recurrent haematomata were compared in both periods (Tab/e III). No difference was found in the number of missed haematomata (P> 0.05); however, the number of recurrent haematomata in period II was significantly lower (X2= 17.4, P
With the development of neurosurgery as a separate specialty, the management of severe head injury, including ASDH, has moved from the domain of general surgical units to specialized centres in many parts of the world. However, reports on the changes made by the introduction of specialized neurosurgery on the outcome of ASDH are few in the literature. We have not attempted to compare our results with those in other reported series because of differences in the mode of injury and in patient selection. Comparison was, however, made between results

Yue, Mann and Ong: Acute subdural

haematoma

from one centre with a similar organization throughout, using the criteria for selection and patient variables (Table I). The only significant change in the period studied was the introduction of specialized neurosurgery in our department from 1977 onwards. The mortality rate in the first period was 80.9 per cent which dropped to 60 per cent during the subsequent five-year period. The rate of good recovery was 4.7 per cent in period I which rose to 21.6 per cent in the following period. This is statistically significant at a P value of CO.02 and 0.05 respectively. Two factors, namely delay from admission to operation, and the number of inadequately treated haematomata, were thought to be important in this context. Prompt operation in comatose patients with ASDH has been stressed very often, yet very few authors have measured the delay in relation to increase in mortality. Recently Seelig et al. (198 I ) were able to show a major reduction in the mortality of patients operated on within 4 hours. In the Hong Kong Island, because ofthe relatively small area served by our unit (19.2 square miles), delay in ambulance transport to the hospital has never been long. The mean time from injury to admission of our patients was estimated to be less than 50 minutes. Delay was mainly after admission. The time interval from admission to operation was compared in the two groups of patients in periods I and II, and was reduced from a mean of 14.2 hours to one of 6.1 hours. Timely operation can be achieved by increased awareness, more careful observation and more efficient theatre organization. The most important factor identified was shortening the time to prepare the theatre, once the decision to operate was made. We measured this time by recording the time when the operation was booked and the time when the skin incision actually began (from the anaesthetic record). This was reduced from a mean of 1.6 hours in period I to 35 minutes in period II. Hooper (I 959) commented on the marked improvement of results in his cases of extradural haematomata being related to substantial reduction of the time to set up the theatre. Perhaps the same might hold true for ASDH. Simple burr-hole drainage has proved very effective in chronic subdural haematomata (Ohaegbulam, 1981; Tabbador, 1977). It is ineffective in ASDH where there may be clotted blood. laceration of the brain with bleeding points, none of which can be adequately dealt with through a small dural incision (Becker, 1977; Fell, 1975). In period I, simple burr-hole

491

exploration was the definitive treatment in 36 patients. Seventeen (26.9 per cent) recurrent haematomata were detected post mortem. In period II, burr-hole exploration was employed as an investigation. Once the diagnosis was established, it was immediately followed by craniectomy or craniotomy. The number of recurrent haematomata during this period dropped to only four (6.6 per cent). The difference is highly significant (PO.OS). Besides the two factors mentioned above, variables, especially non-operative other measures could possibly have effects on the outcome. Aggressive treatment of concommitant raised intracranial pressure due to cerebral oedema (Marshall, 1979), and the employment of intensive care units for the prolonged unconscious patients (Becker, 1977: Bricolo, 1980; Miller, 1981) are doubtless important in the management of patients with ASDH. However, without quantitative measurement of these variable factors and controlled studies, the extent to which these measures contribute to the outcome remains speculative (Jennett and Teasdale (1981). Thus in the present analysis, we were able to show that the introduction of specialized neurosurgery had brought about more prompt operative intervention and better surgical exposure to achieve thorough evacuation of haematomata. All these were accomplished within less than ideal conditions that were more suited to general surgery. Modem facilities like the CT scanner, measuring intracranial pressure. evoked potentials, etc, were not available. Nevertheless, it could be shown that a significant reduction in mortality and improvement in quality of life of survivors were possible.

REFERENCES

Becker D. P. and Miller I. D. (1977) The outcome from severe head injury with early diagnosis and intensive management. J. Neurosurg 47,49 I. Bricolo A. et al. (1980) Prolonged postraumatic unconsciousness: Therapeutic assets and liability. J. Neurosurg

52. 625.

Fell D. A. (1975) Acute subdural haematomas: Review of 144 cases. J. Neurosurg. 42, 37. Gennarelli T. A. et al. (I 982) Influence of the type of intracranial lesion on outcome from severe head injury. J. Neurosurg. 56, 26. Hooper R. (I 959) Observations on extradural haematoma. Br. J. Surg 47, 147.

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B. and Bond M. (1975) Assessment ofoutcome after severe brain damage: A practical scale. Lancet 1: 480. Jennett B. and Teasdale G. (198 1) eds Management of Head Injuries pp. 244-246. Philadelphia. F. A. Davis Company. Marshall L. F. et al. (1979) The outcome with aggressive treatment in severe head injuries. Part I: The significance of intracranial pressure monitoring. J. Jennett

Neurosurg.

50,20.

Miller J. D. et al. (198 I) Further experiences in management of severe head injury. J. Neurosurg. 54, 289.

Surgery Vol. 1 ~/NO. 6

Ohaegbulam S. C. (I 98 I) Surgically treated traumatic subacute and chronic subdural haematomas: A review of I32 cases. Injury 13, 23. Seelig J. M. et al. (1981) Traumatic acute subdural haematome: Major mortality reduction in comatose patients treated within 4 hours. NW En,q. J. Med. 304,151 I. Tabbador K. et al. (1977) Definitive treatment of chronic subdural haematoma by twist-drill craniostomy and closed system drainage. J. Neurosurg. 46, 220. Paper accepted 3 November 1982.

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