The Manchester experience

The Manchester experience
Presenter: James Young

Hello everyone. Thank you to Saj Attaullah, David Verity and all of the SOA team for the very kind introduction and asking me to speak today about the Manchester experience of managing spheno-orbital meningiomas.

Spheno-orbital meningiomas (SOMs) are a distinct subset of intracranial meningiomas. You have been shown in the previous talks today that they develop both an intraosseous and soft tissue component, which often expands to affect the orbital apex giving visual dysfunction, cranial nerve palsy, and proptosis. Often it is quite benign being found incidentally on a scan, however some patients act in an extremely aggressive manner and they can lose vision very quickly. As described this morning, there is a long-standing Manchester orbital skull base MDT clinic that has run by monthly MDT clinics. These patients can be reviewed there by neurosurgeons, skull base surgeons, ENT and orbital surgeons to review their cases and plan their management.

I would like to present a case of a 39-year-old female who has passed through this MDT. She presented with a two to three-month history of headaches and visual disturbance on the right-hand side. Her visual acuity on the Snellen chart it’s actually quite good at six over seven point five, but she has evidence of an optic neuropathy with a relative afferent pupillary defect (RAPD), reduced colour vision, an inferior defect on visual field and a sixth nerve palsy. On fundoscopy she had gross swelling of the right optic disc Externally there were only mild signs with slight fullness in the right upper lid, which measured two millimetres of axial proptosis.

This is her MRI scan and it shows quite a large right side sphenoid wing meningioma, it is starting to push the orbital contents more medially and if we move more towards the apex, you’ve lost the signal around the optic nerve, as you can see on the other side. This fits with a clinical picture of a compressive optic neuropathy. Therefore, she went on to have a joint neurosurgical and orbital procedure. The meningioma was debulked as much as possible, the orbit and the optic canal were decompressed. By three months post-op she has done quite well: visual acuity maintained slightly better than pre-op, she’d had normalisation of her colour vision, her Humphrey visual field test showed a normal visual field, although she still has had a subtle right RAPD. As you can see from the fundus photos that optic disc oedema has now resolved.

Patients need long term follow-up both clinically and radiologically. Unfortunately for this lady two years later we start to see a new visual field defect in her left eye. Her MRI scan was expedited, and she was found to now have a left-sided meningioma causing a compressive neuropathy. This is one of three cases we’ve seen with sequential cases: meningioma on one side, then through follow-ups they’ve ended up on the other side that needed surgery.

I would like to go through some surgical photos to provide an idea of what these patients go through. The majority of these photos are actually from this case -when she had left-hand side- surgery. Initially the temporalis muscle is brought down, craniotomy is then performed in a frontotemporal approach and once this craniotomy is removed, you get access to that sphenoid bone. Here’s a photo of a different patient on the right-hand side of a spheno-orbital band, which is an important anatomical landmark that denotes the lateral end of the superior orbital fissure.

You can then start removing all the involved bone. This is the lateral wall on our patient on the left-hand side, and then moving across moving the roof of the orbit. Once you’ve removed as much involved bone as you can, you decompress the optic nerve, and this is done through an anterior clinoidectomy, which allows you access and decompress the optic canal. You can see in this slide down at the bottom, where the arrow is pointing to, that the optic nerve is visible after decompression. This is right-hand side of a different patient that shows it a bit better; you see the optic nerve there and then next to it, you’ve got all the soft tissue contents of the superior orbital fissure. The involved soft tissue needs to be addressed after you’ve addressed the bony component.

Once you’ve removed the involved bones and soft tissue, you can start seeing more recognisable tissues in the orbit. For instance, these slides show a extra ocular muscle and the lacrimal gland. Once you’ve removed everything you can, you can consider reconstruction of the orbit. This is our lady having a MEDPOR TITAN implant to reconstruct her orbit. On the other hand, this is the other patient we’ve showed you, who is having a titanium mesh, an alternative option for reconstruction. Subsequently, the bones are closed, the skin and muscles then brought back to its normal anatomical position.

This is a video of our lady immediately post-op showing a pulsatile orbit. This can be regularly seen after surgery. The pulsatility is due to air still being inside and around the tissues transmitting the arterial pulsation to the orbit. She’s now followed up and this is her most recent MRI scan (from May of this year) and she’s maintaining stable vision in both eyes with no significant recurrence.

I would like to present the Manchester experience of the surgical management of these meningiomas. This data has been recently published in ‘Orbit’. It’s a retrospective case series over 17 years (2000-2017) and we’ve got 24 primary cases. The patients are slightly younger (50 years +/- 11 years) and there is a higher female predominance (91%. N=20). This is shown in our results, the vast majority 88% had significant proptosis presentation. Most previous case series are mainly from a neurosurgical point of view and often will only use visual acuity or maybe visual acuity and visual field as a measure of visual function preoperatively, as ours patients have been through the MDT, they’ve been seen by a ophthalmologist and have had measurement of their pupillary reactions, their colour vision, their visual field, and the visual acuity.

These results show that 42% (N=10) of our patients had reduced acuity at presentation or preoperatively. Interestingly 29% (N=7) of the patients have a normal visual acuity on the Snellen chart, but had evidence of an optic neuropathy, either through abnormal pupil reactions with loss of colour vision or loss of visual field. The remaining 29% (N=7) were felt to be high risk due to their radiological or clinical presentation. All had a frontotemporal approach (N=24) very similar to the case I presented, all had a decompression (N=24) and the vast majority had an optic canal decompression (N=17).

Regarding a three month visual outcome assessment, the seven patients who had normal visual function pre-operatively maintain it, and twelve had actually improvement of their visual function. We managed to improve or stabilise people’s visual function in 79% (N=19). Five deteriorated; one of these was a very atypical case of an aggressive tumour recurrence by three months. The four remaining cases that deteriorated, all had advanced optic neuropathy at time of surgery, therefore despite the surgery, they continued to slowly deteriorate postoperatively.

We have about seven years of follow-up on average in these patients, the initial five that deteriorated by 3 months didn’t recover any further after seven years. The remaining 19 patients: 14 of these remain stable, four had significant tumour recurrence that caused the further compressive optic neuropathy and one deteriorated from an unrelated cause.

If we compare our long-term outcomes with different case series out there, it’s quite difficult to draw strong conclusions, because these are all small retrospective case series. We have different case mixes, different sets of patients, levels of visual deterioration at surgery, different measurements of visual function, and different definitions of visual deterioration. As we can see there’s a large spread across the literature. The conclusion you can freely draw, is that some patients will deteriorate to recurrence in the future, and this backs up what we feel, that you can’t fully excise the tumour at surgery due to the widespread nature of it. Therefore regarding recurrences, the longer the follow-up the more likely they are to occur.

In regards to clinically significant recurrence in our cases, eight were picked up: clinically (N=5) and radiologically (N=3), and these were managed either through surgery (N=1), surgery and radiotherapy (N=5), or radiotherapy alone (N=2). Regards to operative complications, one patient had a lateral rectus trauma due to a drill injury, one patient required a CSF leak repair, a couple of wound infections and three patients had persistent cranial nerve defects.

My key points really are these: sphenoid-orbital meningiomas are quite rare and can be aggressive tumours, often affecting young females. In the Manchester experience, we can stabilise vision in the majority, and we feel that the setup in Manchester benefits the patient from joint neurosurgical and ophthalmology care.
Q & As section

Question 1
What about OCT and following up the vision and preoperative assessment. What do you think its role is?

Answer
For those who aren’t familiar with OCT it stands for Optical Coherence Tomography. OCT is a non-invasive scan of the back of the eye to measure the thickness of the optic nerve. It is regularly used in glaucoma, to manage the glaucomatous optic neuropathy. We don’t use it routinely at the moment, however we’re thinking of introducing it to these patients, because there’s some early case series coming out, showing that if the optic nerve still has quite a reasonable thickness to it, i.e. it doesn’t show atrophy, often the patients get a lot better visual outcomes from surgery. It therefore could help to counsel patients preoperatively as to possible visual outcomes. If the nerve is quite atrophic, on OCT, this can be relayed to the patient that visual recovery is guarded. However, this clearly needs more research.

Question 2
Did you know they were all benign on histopathology?

Answer
They were all confirmed meningiomas, in the vast majority were meningiothelial grade I. I think there was only one or two grade 2’s

Question 3
Do you reconstruct the lateral orbital wall in all cases and what’s your effect on the proptosis in that case? Because we’ve found that we’ve been over reconstructing and then perhaps there’s still an element of proptosis afterwards, so we’ve stopped reconstructing the lateral wall.

Answer
That’s definitely something that’s changed in the practice in Manchester, our review spans 17 years. Over these 17 years practice has changed. We used to reconstruct a lot and we mainly worried about enophthalmos. There’s a lot more data out there that’s showing that reconstruction might not be so necessary, so we’ve moved and doing it if it’s truly necessary and reconstruct as little as possible now.

Question 4
These tumours can be phenotypically quite different in the sense that some are relatively anterior or midpoint with exophthalmos, but the visual functions are alright -that’s one group of indications for surgery-. Then there are others who are much more posterior and/or have canal compression. It’s important looking forward to say ‘Do eye and vision get better with surgery?’ To exclude those who have entered because of proptosis as a cause of surgery. Then to look at those who have established canal compression, to see how affected the canal is and how long after the disease it started, if you can tell. It’s a heterogeneous group of patients; so we’ve got patients who we decompress for exophthalmos (1cm) and the vision is alright. There are others where the exophthalmos isn’t bad but the vision is compromised since they’ve got canal involvement -very posterior-. We should divide them out and we need to find out whether canal decompression is useful in those who have established compression at the canal or not. Further, find out how long have they had it and how long can it be left for, rather than have them all as one group of patients.

Answer
That’s a very good point. In fact we had a certain number of patients who were very young and have very aggressive visual loss associated exactly the type you’re describing, with really large hyperostotic components, causing compressive optic neuropathy posteriorly. We looked at the patients who’d had optic canal decompression versus the ones who didn’t. Because traditionally, if we go back 15 years, we weren’t doing optic canal decompressions. We found that although that follow-up was a little bit shorter, there was a greater proportion who preserved vision or vision improved in the patients where we did clinoidectomy, it is not canal decompression. And that’s our routine now, whether or not someone has a compressive optic neuropathy.