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.

In November 2019, the unit was commissioned as a highly specialised service for foetal myelomeningocoele repair. Myelomeningocele is a type of spina bifida, a condition that happens before birth where the spinal column and spinal cord are not properly formed. Traditionally this is treated by operating on the baby shortly after birth. Recent studies show that for some babies this can be repaired by operating on the baby whilst still in the womb (fetal surgery). A total of 21 of these operations have been carried out by GOSH with University College London Hospitals NHS Foundation Trust (UCLH).

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

Number of neurosurgical operations

Type
of operation
April 2018 to March 2019 April 2019 to March 2020 April 2020 to April 2021
Brain Tumour 109 115 105
Cerebrospinal Fluid (CSF) related 267 281 229
Epilepsy 138 116 103
Craniofacial 232 248 189
Cranio-Cervical Junction 45 30 37
Cranio - Other 76 79 52
Spinal Tumour 12 22 16
Dysraphism 77 61 68
Spinal - Other 48 50 26
Vascular related 37 49 44
Neural Drug Delivery - 4 6
Total 1,041 1,055 875

Clinical outcome measures

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, April 2013 to March 2016

Neurosurgery Fig 1.1 2017

© 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
April 2020 to March 2021 875 40 63 15 1 1.83%
April 2019 to March 2020 1,055 21 77 10 1 1.04%
April 2018 to March 2019 1,041 25 71 9 4 1.25%

*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*† (all years are April to March)

Neurosurgery Fig 2.2 2021

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

† Vascular related includes stereotactic radiosurgery

Table 2.2 Adverse events by sub-specialty* (all years are April to March)

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
2020/21 105 3 7 5 1 5.71%
2019/20 115 0 6 7 1 6.96%
2018/19 109 2 12 4 0 3.67%
Cerebrospinal
Fluid (CSF) related
2020/21 229 6 25 3 0 3.67%
2019/20 281 4 40 0 0 0.00%
2018/19 267 3 30 4 4 3.00%
Epilepsy Surgeries 2020/21 103 3 4 2 0 1.94%
2019/20 116 1 3 0 0 0.00%
2018/19 138 4 6 0 0 0.00%
Craniofacial Surgeries 2020/21 189 14 13 0 0 0.00%
2019/20 248 11 10 1 0 0.40%
2018/19 232 12 9 1 0 0.43%
Spinal Surgeries 2020/21 110 7 10 2 0 1.82%
2019/20 133 1 7 2 0 1.50%
2018/19 137 3 6 0 0 0.00%
Vascular related - including stereostatic radiosurgery 2020/21 44 2 2 3 0 6.82%
2019/20 49 0 6 0 0 0.00%
2018/19 37 0 3 0 0 0.00%
Neural Drug Delivery 2020/21 6 1 0 0 0 0.00%
2019/20 4 0 0 0 0 0.00%
2018/19 - - - - - -

*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
April 2020 to March 2021 166 3 1.81%
April 2019 to March 2020 227 4 1.76%
April 2018 to March 2019 196 5 2.55%

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
April 2020 to March 2021 81 8 9.88%
April 2019 to March 2020 117 11 9.40%
April 2018 to March 2019 116 4 3.45%

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
April 2020 to March 2021 166 15 9.04%
April 2019 to March 2020 227 30 13.22%
April 2018 to March 2019 199 20 10.05%

This information was published in September 2021.