Helen Seeley

Timing of surgery for supratentorial aneurysmal subarachnoid haemorrhage: report of a prospective study

Objectives: The debate on the timing of aneurysm surgery after subarachnoid haemorrhage (SAH) pivots on the balance of the temporal risk for fatal rebleeding versus the risk of surgical morbidity when operating early on an acutely injured brain. By following a strict management protocol for SAH, the hypothesis has been tested that in the modern arena of treatment for aneurysmal SAH the timing of surgery to secure supratentorial aneurysms does not affect surgical outcome. Methods: Over a 6 year period, patients admitted with a diagnosis of SAH to a regional neurosurgical unit have been prospectively studied. All have been on a management protocol in which early transfer and resuscitation has been followed regardless of age and clinical condition. Angiographic investigation and surgery have been pursued in those who have been able to at least flex to pain. A total of 1168 patients (60.7% female, mean age 54.3) with proved SAH were received on median day 1 (86.4% arrived within 3 days) of the ictus. Of these, 784 (67.1%) showed aneurysms on angiography and were prepared for surgery. Those who received surgery for a supratentorial aneurysm within 21 days of the ictus were included in the final analysis (n=550). Patients with an initial negative angiogram, with posterior circulation aneurysms, or aneurysms treated by endovascular means, with aneurysms requiring emergency surgery for space occupying haematomas, with aneurysms which re-bled before surgery, and those who received very late surgery (after 21 days from ictus) were excluded. Surgical outcomes at hospital discharge and after 6 months were assessed using the Glasgow outcome score (GOS). Discharge destination and duration of stay in a neurosurgical ward were also documented. The influence of the timing of surgery (early group day 1–3 postictus, intermediate group day 4–10, or late group day 11–21) was analysed prospectively. Results: 60.2% of cases fell into the early surgery group, 32.4% into the intermediate group, and 7.5% into the late operated group. Late surgery was due to delays in diagnosis, transfer, and logistic factors, but not clinical decision. The demographic characteristics, site of aneurysm, and clinical condition of the patients at the time of initial medical assessment were balanced in the three surgical timing groups. There was no significant difference in GOS between the surgical timing groups at 6 months (favourable GOS score 4 and 5: 83.2%, 80.5%, and 83.8% respectively; p=0.47, Kruskal-Wallis test). Outcome was favourable in 84% of patients under 65 years, and 70% in those over 65. The discharge destinations (home, referring hospital, nursing home, rehabilitation centre) showed no significant difference between surgical timing groups. There was no significant difference in mean time to discharge after admission to this hospital from the referring hospital (16.2, 16.2, and 14.6 days for early, intermediate, and late groups respectively; p=0.789, Analysis of variance (ANOVA)). As a result, there was reduction in the mean duration of total hospital inpatient stay in favour of the earliest operated patients (mean time 18.1, 22.0, and 28.3 days respectively; p=0.001. ANOVA showed that besides age, the only determinant of surgical outcome and duration of stay was presenting clinical grade (p<0.0005). Conclusion: The current management of patients presenting with SAH from anterior circulation aneurysms allows early surgery to be followed safely regardless of age. The only independent variables affecting outcome are age and clinical grade at presentation. The timing of surgery did not significantly affect surgical outcome, promoting a policy for early surgery that avoids the known risks of rebleeding and reduces inpatient stay.

Efficacy of antibiotic-impregnated shunt catheters in reducing shunt infection: data from the United Kingdom Shunt Registry

OBJECT In recent years CSF shunt catheters impregnated with rifampicin and clindamycin have been introduced to the United Kingdom (UK) market. These catheters have been shown to be effective in vitro against cultures of Staphylococcus epidermidis. The authors used data collected by the UK Shunt Registry to assess the efficacy of antibiotic-impregnated catheters (AICs) against shunt infection by using a matched-pair study design. METHODS The UK Shunt Registry contains data on nearly 33,000 CSF shunt-related procedures. The authors identified 1139 procedures in which impregnated catheters had been used, and accurate information was known about diagnosis, number of revisions, sex, and age in these cases. The database was ordered chronologically and searched forward and backward for cases with these same characteristics but involving conventional catheters. Matches were found for 994 procedures. RESULTS Among the 994 procedures in which AICs had been used, 30 shunts were subsequently revised because of shunt infection. Among the 994 controls, 47 were subsequently revised for infection (p = 0.048, chi-square test). CONCLUSIONS The UK Shunt Registry does not collect data on causative organisms, and the surgeon is relied on entirely for the diagnosis of infection. However, with the large number of matched pairs evaluated, the authors attempted to reduce bias to a minimum. Their data suggest that AICs have the potential to significantly reduce shunt infections.

Prospective study of clinical and radiological outcome after anterior cervical discectomy.

Most surgeons undertaking anterior cervical discectomy (ACD) introduce a bone graft or cage into the disc space when the decompression is complete to prevent segmental collapse and preserve cervical spine alignment. We have conducted a prospective observational cohort study to investigate the relationship between cervical spine alignment and clinical outcome in 55 patients undergoing ACD without interbody graft or cage. At 12 months, the overall alignment of the cervical spine and the presence of segmental kyphosis at the operated level were correlated with clinical outcome measured by SF 36, Neck Disability Index and visual analogue neck pain score. Loss of the overall cervical lordosis was present in 30 patients and segmental kyphosis was found in 18. Analysis of clinical outcome showed no statistical differences between patients with preserved and abnormal cervical and segmental alignment. Disturbance of cervical and segmental alignment is common in patients following cervical discectomy, but does not appear to compromise clinical outcome at 12 months.Most surgeons undertaking anterior cervical discectomy (ACD) introduce a bone graft or cage into the disc space when the decompression is complete to prevent segmental collapse and preserve cervical spine alignment. We have conducted a prospective observational cohort study to investigate the relationship between cervical spine alignment and clinical outcome in 55 patients undergoing ACD without interbody graft or cage. At 12 months, the overall alignment of the cervical spine and the presence of segmental kyphosis at the operated level were correlated with clinical outcome measured by SF 36, Neck Disability Index and visual analogue neck pain score. Loss of the overall cervical lordosis was present in 30 patients and segmental kyphosis was found in 18. Analysis of clinical outcome showed no statistical differences between patients with preserved and abnormal cervical and segmental alignment. Disturbance of cervical and segmental alignment is common in patients following cervical discectomy, but does not appear to compromise clinical outcome at 12 months.

Assessing quality of life after traumatic brain injury: examination of the short form 36 health survey.

Measuring health-related quality of life (HRQoL) has an important role in the comprehensive assessment of patient recovery following traumatic brain injury (TBI). We examined the validity of domain and summary scores derived from the Medical Outcomes Survey 36-Item Short Form Health Questionnaire (SF-36) as outcome measures for TBI in a prospective study of 514 patients with a range of functional impairment (Glasgow Outcome Scale-Extended [GOSE] scores 3-8). Item scaling criteria for the eight domain scores were tested and principal component analysis was used to examine if physical and mental component summary scores were valid. External validity was assessed by comparison with GOSE. Mean response, variance, and distribution of the items were largely equivalent, and item-own scale correlations corrected for overlap all exceeded the threshold for equivalent contribution to domain scores and convergent validity. All corrected item-own scale correlations were greater than the respective item-other correlations indicating no scaling failures, and reliability coefficients for the domain scores were high and substantially more than the inter-domain correlations. Overall, criteria for summing items into domain scores were satisfied, and there was a significant relationship of increasing score with more favorable GOSE class across all domains. However, there were floor and/or ceiling effects in four of the eight domains, and principal component analysis of the domain scores demonstrated only a unidimensional structure to the data. We conclude that individual SF-36 domain scores are valid measures of HRQoL in TBI patients, but that the physical and mental component summaries should be interpreted with caution.

Measurement of outcome in patients with cervical spondylotic myelopathy treated surgically.

The objective was to establish the role of the Short Form 36 (SF 36) as an objective measure of clinical outcome in cervical spondylotic myelopathy (CSM), and took the form of a prospective observational study. Seventy patients with symptomatic CSM were treated by surgical decompression. Health status was measured pre- and 3 months postoperation using objective, validated patient completed measures. These were the SF 36, neck disability index, myelopathy disability index and analogue scores for neck pain and arm symptoms. SF 36 scores were compared with age matched control data. Twelve-month postoperative data are available in a proportion of the cohort. CSM patients have lower preoperative SF 36 scores than age-matched population controls. Comparing pre- and postoperative SF36 scores for the physical functioning domain 64% of patients improve, 23% show no change and 14% of patients continue to deteriorate (Wilcoxon P< 0.0001). These changes are replicated in other domains of the SF36 and by the other measures of outcome. The SF36 is responsive, valid, and practical. Its use for determining outcome in the surgical treatment of CSM is recommended.

Mapping rehabilitation resources for head injury.

Several reports have pointed to the unevenness in the UK of services for rehabilitation after head injury. A study was conducted in the Eastern Region of England to define the key stages in recovery and rehabilitation, by an iterative process of questionnaire, interview and consensus conference. Findings were translated into a draft set of maps showing current availability of services which were revised after feedback. Working groups then developed a set of definitions and classification codes for each stage of rehabilitation which were likewise disseminated for feedback. The maps were then redrafted to correspond with the definitions together with a flowchart of potential head injury rehabilitation services. The definitions were piloted at a regional neurosurgery unit and a rehabilitation hospital. Core services for neurorehabilitation region-wide were found to be variable and uncoordinated with fragmented and inequitable allocation of resources. The definitions and mapping system that emerged from this study should facilitate the design of care pathways for patients and identify gaps in the services.

Factors implicated in deaths from subarachnoid haemorrhage: are they avoidable?

The major causes of death following subarachnoid haemorrhage are the effects of the initial bleed, aneurysmal rebleeding and delayed cerebral ischaemia. Although in many cases the causes are unavoidable, in others they are potentially preventable. By conducting a Regional Audit of patients who have died from subarachnoid haemorrhage, we have attempted to quantify these concerns. The medical records and CT scans of 200 patients who died from subarachnoid haemorrhage in hospitals in the East Anglian Region over a 5-year period were analysed, with particular regard to the identification of potentially avoidable factors, including radiologically confirmed rebleeding, marked hydrocephalus, and poor fluid and electrolyte resuscitation. Thirty-three patients presented with World Federation of Neurosurgical Societies (WFNS) Grade V with fixed pupils. These patients were deemed unsalvageable. Of the remainder, 106 were good grade (WFNS I-III) at initial presentation, 77 (73%) of whom died as a result of rebleeding (mean 10.4 days post-bleed) indicating delays in transfer and definitive treatment. Of the 61 poor grade patients (WFNS IV and V with reactive pupils) marked hydrocephalus occurred in 15 (25%) and poor resuscitation in 37 (61%). These were considered contributing factors to their poor clinical condition. Rebleeding was the main cause of death in the good grade patients, and correctable factors were identified which are known to contribute to a poor clinical condition in poor grade patients. The need for more rapid and active clinical intervention is indicated.

Inappropriate acute neurosurgical bed occupancy and short falls in rehabilitation: implications for the National Service Framework

Patients undergoing neurosurgical intervention may require different types of organized rehabilitation. A prospective study was performed of the care needs of neurosurgical inpatients between the ages of 16 and 70 years who were in acute wards for more than 2 weeks. Only 58% of bed occupancy days were devoted to essential acute neurosurgical ward management. This figure was even lower for patients admitted with subarachnoid haemorrhage (36%) or traumatic brain injury (38%). Overall, 21% of bed days would have more appropriately spent in ‘rapid access’/acute rehabilitation beds, 13% in ‘active participation’ rehabilitation beds and 5% in cognitive/behavioural rehabilitation units. Addressing this unmet need would increase the availability of acute neurosurgery beds, without needing to build and staff more neurosurgery wards.

Loss of inter-vertebral disc height after anterior cervical discectomy

Most surgeons undertaking anterior cervical discectomy (ACD) introduce a bone graft or cage into the disc space when the decompression is complete. This is done to prevent segmental collapse, preserve cervical spine alignment and to promote fusion. We have conducted a prospective observational cohort study to investigate the relationship between loss of disc height, cervical spine alignment and clinical outcome in 140 patients undergoing ACD without inter-body graft or cage. At a minimum of 12 months after operation changes in disc space height and cervical spine alignment were correlated with clinical outcome measured by SF36, Neck Disability Index, and visual analogue neck and arm pain scores. There was no relationship between loss of disc height and outcome. Loss of the overall cervical lordosis was present in 71 patients and segmental kyphosis was found in 69. Analysis of clinical outcome showed no significant differences between patients with preserved and abnormal cervical alignment. Neither loss of disc height nor disturbance of cervical alignment compromised clinical outcome in the first year following ACD.

Continuous Assessment of Cerebral Autoregulation — Clinical Verification of the Method in Head Injured Patients

Previously, using transcranial Doppler ultrasonography, we investigated whether the hemodynamic response to spontaneous variations in cerebral perfusion pressure (CPP) provides reliable information about cerebral autoregulatory reserve. In the present study we have verified this method in 166 patients after head trauma. Waveforms of intracranial pressure (ICP), arterial pressure and transcranial Doppler flow velocity (FV) were captured daily over 0.5-2.0 hour periods. Time-averaged mean flow velocity (FV) and CPP were resolved. The correlation coefficient indices between FV and CPP (Mx) were calculated over 3 minutes epochs, and averaged for each investigation. An index of CBF (flow velocity diastolic to mean ratio) was calculated independently for each investigation. Mx depended on CPP (p < 0.0001) increasing to positive values when CPP decreased below 60 mm Hg. This threshold coincided with an averaged breakpoint for autoregulation, expressed by the index of CBF. Mx depended on outcome following head injury stronger than the Glasgow Coma Score on admission (ANOVA, F values 18 and 15 respectively; N = 166). In patients who died, cerebral autoregulation was disturbed during the first two days following injury. These results indicate an important role for the continuous monitoring of autoregulation following head trauma.