Table 3 Final ranking of procedures with the change of ranking arising from analyses from round two and round three outlined

1

Patient positioning, pinning positions and flap design

 ↔ 

2

Intracranial pressure (ICP) probe insertion

 ↔ 

3

External ventricular drain (EVD) insertion

 ↔ 

4

Burr hole evacuation of chronic subdural / extradural haematoma

 ↔ 

5

Lumbar puncture and lumbar drain insertion

↑3

6

Cervical, thoracic and lumbar laminectomy / laminotomy

↓1

7

Trauma flap craniotomy (for subdural haematoma, extradural haematoma), decompressive craniectomy and decompressive bifrontal craniectomy

↑3, ↑10, ↑21

8

Burr hole brain biopsy including stereotactic

↓1

9

Lumbar microdiscectomy

↑2

10

Ventriculoperitoneal (VP) shunt insertion including abdominal dissection

↑2

11

Excision of convexity meningioma

↑10

12

Pterional approach—craniotomy

↓6

13

Endoscopic third ventriculostomy (ETV)

↓4

14

Transcortical approach to glioblastoma (GBM) resection / debulking

↓1

15

Sylvian fissure splitting and exposure of the middle cerebral artery (MCA) bifurcation

↓1

16

Anterior cervical discectomy and fusion (ACDF)

↓1, ↑6

17

Retrosigmoid approach—craniotomy

↓1

18

Midline suboccipital approach—posterior fossa decompression, foramen magnum decompression (bone only versus opening dura)

 ↔ , ↑3

19

Midline suboccipital approach—midline approach to tumour resection

↓2

20

Elevation of compound depressed skull fracture with dural repair

↑13

21

Transsphenoidal hypophysectomy and biopsy of sellar lesion

↓1

22

Microvascular decompression (facial nerve, trigeminal nerve etc.)

 ↔ 

23

Pedicle screw insertion: cervical, thoracic, lumbar

↑4

24

Cranioplasty using autologous, titanium or acrylic implants

↓1

25

Interhemispheric approach—craniotomy

↓2

26

Intra-axial haematoma evacuation (intraparenchymal haematoma) / supratentorial lobar

↓1

27

Dural repair / cerebrospinal fluid (CSF) leak repair

↓3

28

Resection of parasagittal and falcine meningiomas

 ↔ 

29

Infratentorial intracerebral hemorrhage (ICH) evacuation

↓3

30

Endoscopic biopsy of intra- and paraventricular brain tumours

↓1

31

Ventriculopleural shunt insertion including pleural dissection

 ↔ 

32

Endoscopic fenestration of cyst / arachnoid cyst

↓2

33

Clipping of aneurysm (saccular, complex etc.)

↓1

34

Lobectomy for haemorrhagic contusion

 ↔ 

35

Orbitozygomatic approach—craniotomy

↑2

36

Resection of midline ventricular lesion (eg colloid cyst)

 ↔ 

37

Middle fossa / extended middle fossa approach—craniotomy

↓2

38

Ventriculoatrial shunt insertion including neck dissection

↑4

39

Resection of 4th ventricular tumours

 ↔ 

40

Resection of sphenoid ridge meningioma

↓2

41

Complex extra-axial lesion resection (intrinsic cerebellar tumour, vestibular schwannoma etc.)

↓1

42

Resection of olfactory groove meningioma

↓1

43

Resection of petrous ridge meningioma

 ↔ 

44

Craniofacial repair of a CSF leak

 ↔ 

45

Craniocervical junction tumour resection

 ↔ 

46

Syringopleural shunt insertion

 ↔ 

47

Myelomeningocele repair

 ↔