Neurosurgery clinical outcomes

Clinical outcomes are measurable changes in health, function or quality of life that result from our care. Constant review of our clinical outcomes establishes standards against which to continuously improve all aspects of our practice.

About the Neurosurgery Service

The neurosurgical unit of Great Ormond Street Hospital (GOSH) is the largest paediatric neurosurgery unit in the United Kingdom, and the only paediatric neurosurgery unit in the North Thames area. The unit performs around 1000 procedures each year, providing neurosurgical input to various highly specialised multidisciplinary teams for the management of conditions such as:

As GOSH is one of only four supra-regionally funded craniofacial centres and one of the UK's four specialised Children’s Epilepsy Surgery Service (CESS) centres, the neurosurgery unit is responsible for an increasing volume of craniofacial and, in particular, epilepsy cases.

The following table shows the number of neurosurgical operations at GOSH for the past three years.

Number of neurosurgical operations

Type of operation Number of operations
2016/17 2017/18 2018/19
Brain Tumour 146 117 109
Cerebrospinal Fluid (CSF) related 229 267 267
Epilepsy 124 155 138
Craniofacial 203 242 232
Cranio-Cervical Junction 54 45 45
Cranio - Other 79 94 76
Spinal Tumour 13 5 12
Dysraphism 69 73 77
Spinal - Other 39 49 48
Vascular related 78 63 37
Total 1,034 1,110 1,041

Clinical outcome measures

Summary:

1. Risk-adjusted mortality

2. Adverse events

3. Shunt infection rates

4. Early shunt re-operation rates

1. Risk-adjusted mortality rates

The Neurosurgical National Audit Programme (NNAP) was established by the Society of British Neurological Surgeons in 2013 as part of a major quality improvement initiative. The programme aims to support neurosurgical units in the UK and Ireland to improve patient care, outcomes, safety, and experience by providing high quality, robust audit data that is analysed and presented in a consistent and clinically relevant way. Results are available for both adult and paediatric centres.

Fig 1.1: Risk-adjusted 30-day mortality rate, 2013 to 2016

Risk-adjusted 30-day mortality rates Neurosurgery Fig 1.1 2013-2016

© 2014-2017 University Hospitals Birmingham NHS Foundation Trust, all rights reserved

This ‘funnel plot’ diagram displays the mortality ratio for elective procedures in paediatric neurosurgery centres for the three years April 2013 to March 2016. The results are ‘risk-adjusted’, which means that the mortality rate of hospitals where operations are performed on higher risk patients is adjusted to account for these factors. This enables calculation of a predicted mortality rate, against which centres are benchmarked. Expected mortality for each centre will vary from chart to chart depending on the number of procedures performed and the risk profile of the patients treated in that time period. The horizontal yellow line represents the expected ratio. The solid black lines are known as the ‘control limits’. Risk-adjusted rates appearing between the control limits are within the normal range. The results of all centres for this period are within normal range. 

2. Adverse events

The GOSH neurosurgical unit has a zero tolerance approach to adverse events including surgical complications. Every such event is reviewed in a weekly meeting attended by all members of the unit, and actions designed to prevent repetition are discussed. Adverse events are defined here as “Any untoward event related to a child’s admission to the neurosurgical unit that had the potential to increase their stay in hospital and/or produce a temporary or permanent worsening of their health.”

It is important to emphasise that while a number of reports use surgical complications as a measure of performance, within the neurosurgical department at GOSH we choose to use the adverse event rate (which may or may not be related to surgical complications) as we feel this better reflects the patient’s experience and provides a more transparent view of our performance. For example, if a child were to develop a chest infection following an operation, this is unlikely to be reported as a surgical complication but we still report it as an adverse event.

Adverse events are graded as follows:

  1. No increase in hospital stay* and no neurological injury (threatened or actual)
  2. Increase in hospital stay* but no neurological injury (threatened or actual)
  3. An event that either threatened or caused neurological injury
  4. Death

*Includes readmission and/or extra procedure(s) with general anaesthetic 

Table 2.1 Adverse events*

Year  Total Operations Grade 1 adverse events Grade 2 adverse events Grade 3 adverse events Grade 4 adverse events Percentage of adverse events Grades 3 and 4
2018/19 1,041 25 71 9 4 1.25%
2017/18 1,110 26 90 12 6 1.62%
2016/17 1,034 38 91 12 1 1.26%

*procedures undertaken in the department that are not neurosurgical, such as muscle biopsies, have not been included.

Figure 2.2 Adverse events by sub-specialty*

Figure 2.2 Adverse events by sub-specialty*

*non-primary neurosurgical procedures such as muscle biopsies etc have not been included

Table 2.2 Adverse events by sub-specialty*

Specialty Year Total procedures Grade 1 adverse events Grade 2 adverse events Grade 3 adverse events Grade 4 adverse events

Percentage of adverse events Grades 3 & 4

Brain Tumour Surgeries 2018/19 109 2 12 4 0 3.67%
2017/18 117 3 17 7 0 5.98%
2016/17 146 4 19 7 0 4.79%
Cerebrospinal Fluid (CSF) related 2018/19 267 3 30 4 4 3.00%
2017/18 267 9 36 0 1 0.37%
2016/17 229 4 33 0 1 0.44%
Epilepsy Surgeries 2018/19 138 4 6 0 0 0.00%
2017/18 155 1 4 3 0 1.94%
2016/17 124 6 6 1 0 0.81%
Craniofacial Surgeries 2018/19 232 12 9 1 0 0.43%
2017/18 242 9 7 0 0 0.00%
2016/17 203 14 14 1 0 0.49%
Spinal Surgeries 2018/19 137 3 6 0 0 0.00%
2017/18 127 0 10 0 0 0.00%
2016/17 136 5 10 1 0 0.74%
Vascular related 2018/19 37 0 3 0 0 0.00%
2017/18 63 2 1 1 1 3.17%
2016/17 78 2 5 1 0 1.28%

*non-primary neurosurgical procedures such as muscle biopsies etc have not been included

Shunt operations

A shunt is a device that diverts accumulated cerebrospinal fluid (CSF) around obstructed pathways and returns it to the bloodstream. It is inserted in a neurosurgical procedure so that the upper end is in a ventricle of the brain and the lower end leads either into the heart (ventriculo-atrial) or into the abdomen (ventriculo-peritoneal). Permanent shunts are intended to stay in place for life. However, sometimes additional operations are required as a result of mechanical failure of the shunt, infection of the CSF, shunt blockage, or other reasons.

We have included all shunt procedures, where the shunt was inserted, revised or internalised. We have included lumbar-peritoneal shunts, valveless shunts and subgaleal shunts, but excluded external ventricular drains (EVDs).

3. Shunt infection rates

Shunt infections occur when CSF microscopy or culture demonstrate an organism in the CSF, or when there is an abnormally high number of white blood cells in the CSF, in the presence of fever, shunt malfunction or neurological symptoms. Shunt infection requires removal of the shunt and subsequent antimicrobial treatment. The shunt is then re-inserted once the infection has been treated.

Table 3.1 Number and rate of shunt infections

Year Total number of shunt operations Number of shunt infections Percentage of shunt infections
2018/19 196 5 2.55%
2017/18 180 6 3.33%
2016/17 159 5 3.14%

4. Early shunt re-operation rates

The early shunt re-operation rate is defined as the proportion of patients who require a second shunt operation within 30 days of the first operation for any reason.

4.1 Early shunt re-operations - primary shunt procedures

Numerator: Number of primary (initial) shunt procedures requiring a second shunt procedure within 30 days of the initial procedure, for any reason

Denominator: Number of primary shunt procedure (first or initial procedures only)

Table 4.1 Number and rate of early primary shunt re-operations

Year Total patients for primary shunt procedures Patients requiring re-operation within 30 days Percentage of re-operation
2018/19 116 4 3.45%
2017/18 117 14 11.97%
2016/17 112 12 10.71%

4.2 Early shunt re-operations - all shunt procedures

Numerator: Number of shunt procedures requiring a second shunt procedure within 30 days of the first procedure, for any reason

Denominator: Total number of shunt procedures

Table 4.2 Number and rate of all early shunt re-operations

Year Total patients for all shunt procedures Patients requiring re-operation within 30 days Percentage of re-operation
2018/19 199 20 10.05%
2017/18 183 27 14.74%
2016/17 161 19 11.80%

This information was published in November 2019 and will be updated in November 2020.