GLOW800 Augmented Reality Fluorescence in Aneurysm Treatment

Chaddad, Feres; Ibe, Robert

February 03, 2020

GLOW800 Augmented Reality Fluorescence in Aneurysm Treatment

How AR Fluorescence GLOW800 can help surgeons before and after clipping

This case study from Prof. Dr. Feres Chaddad talks about the treatment of unruptured MCA (middle cerebral artery) and PCOM (posterior communicating artery) aneurysms with microsurgical clipping. It illustrates how the Augmented Reality Fluorescence GLOW800 can help surgeons before and after clipping with one augmented, real-time view of the cerebral anatomy, augmented by real-time vascular flow.

With GLOW800, Dr. Chaddad could instantly check the flow distal to the clip without interrupting his surgical workflow. He describes how he uses GLOW800 before clipping to see the flow running through all the vessels and the aneurysms. Post clipping, he uses GLOW800 to show the patency of the PCOM and the anterior choroidal arteries, as well as the superior and interior trunks of MCA. Also, he confirms the clip positions using GLOW800.

1. Initial Patient Presentation and First Surgery

Patient:
A 58-year-old female, with a medical history of well controlled hypertension presented with confusion and complete left hemiparesis.

Diagnosis:

A ruptured right MCA M1 aneurysm
Unruptured left MCA and PCOM aneurysms
Her only medications were antihypertensives.

Treatment decision:
The decision was made to urgently treat the ruptured right MCA aneurysm with microsurgical clipping, in order to protect the patient from rebleeding from the unstable aneurysm.

The unruptured aneurysms were on the contralateral side and needed another craniotomy. Therefore we opted to wait for full recovery from the first surgery and subsequently treat the unruptured aneurysms with microsurgical clipping.

Outcome first surgery: Treatment of the ruptured right MCA with microsurgical clipping

The surgery on the ruptured right MCA aneurysm was successful and she was discharged 24 days post op. At the time of her discharge she had recovered the strength in her left leg and arm, but the left facial weakness remained. The cardiologist that evaluated her during hospitalization maintained her previous medications, with good control of her hypertension.

Fig. 1: CT after first surgery. Image courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at the Federal University of Sao Paulo (UNIFESP), Sao Paulo, Brazil

2. Pre-Operative Assessment Before Second Surgery

Three 3 months after the first surgery to treat the right-sided ruptured MCA, the patient returned for microsurgical clipping of the unruptured left MCA and PCOM aneurysms. Her physical examination at this time showed her to have a good general appearance, no cardiac abnormalities or signs of peripheral vascular compromise, or other signs of disease. Her neurological examination showed persisting left central facial weakness but no other neurological abnormalities, including of the cranial nerves.

Fig. 2: Pre-Operative DSA showing the unruptured aeurysms and the clips from the prior surgery. Image courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil

Fig. 3: Showing the posterior circulation. Since we had a PCOM aneurysm to treat, we needed to know if the posterior circulation was dependent on the ICA (a persistent fetal circulation). Image courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil

The following images show the injection of the left ICA. We can see both aneurysms in the 3D reconstruction. Since we had both a PCOM and an MCA aneurysm to treat, we decided on a Transsylvian approach, through a Pterional craniotomy.

Fig. 4: 3D reconstruction showing the MCA aneurysm. Image courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil.

Fig. 6: 3D reconstruction showing both the MCA and PCOM aneurysms. Image courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil.

3. Intra-Operative Course and Images

We performed a Pterional craniotomy with the withdrawal of the lesser sphenoid wing. With this craniotomy, we exposed the superior and part of the middle temporal gyrus, the Sylvian fissure, and the inferior and part of the middle frontal gyrus. For the approach, we opened Sylvian fissure, separating the frontal lobe from the temporal lobe, where we could find the MCA with its branches (and the aneurysm on the M1 segment). On the proximal M1 MCA, we entered the carotid cistern, where we could find the MCA and the PCOM aneurysms. Prof. Feres Chaddad opened the Sylvian fissure using sharp dissection, maintaining the dissection on the arachnoid space.

Pre-Clipping

Identification of MCA & PCOM aneurysms with GLOW800 Augmented Reality Fluorescence from Leica Microsystems
Before clipping, GLOW800 helped to see the flow running through all the vessels and the aneurysms. GLOW800 also helped to distinguish the areas that were thrombosed, on the MCA aneurysm.

Fig. 8: GLOW800: Pre-Clipping. Video courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil.

After the recognition of the main structures – ICA, ACA (A1), optic nerve, PCOM, choroidal arteries, and MCA (M1 and M2 branches) – the PCOM aneurysm was clipped. It is vital to be sure that both PCOM and the anterior choroidal arteries are preserved.

Fig. 9: PCOM clippping. Video courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil.

Fig. 10: Visual confirmation of PCOM clipping. Video courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil

We then performed the occlusion of the MCA aneurysm. When this aneurysm was clipped we had to be sure that the superior and inferior trunks of M1 did not have a kink or a torsion that could lower the flow in these vessels.

Fig. 11: MCA clipping. Video courtesy of Prof. Dr. Chaddad Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil.

Fig. 12: Visual confirmation of MCA clipping. Video courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil.

Post-Clipping Videos

Visual confirmation of clip position with GLOW800 Augmented Reality Fluorescence from Leica Microsystems
Post clipping, GLOW800 was fundamental to show the patency of the PCOM and the anterior choroidal arteries, as well as the superior and interior trunks of MCA. GLOW800 is an instant tool to check the flow distal to the clip, which allows one to continue to work during its acquisition, even positioning the clip.

Fig. 13: GLOW800: Post-clipping. Video courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil.

4. Post Surgery

Fig. 14: CT showing clip positions. Image courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil.

Fig. 15: CT Angiogram showing clip positions. Image courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil.

Fig. 16: No flow into the clipped aneurysms confirmed on the 3D reconstruction. Image courtesy of Prof. Dr. Chaddad, Head of Vascular Neurosurgery at UNIFESP, Sao Paulo, Brazil.

Post Surgery Examination and Discharge

GCS 15, pupils equal, round, and reactive to light
Left central facial weakness
Normal motor function with muscle strength 5/5 bilaterally
She was discharged 4 days post surgery

5. Impact of GLOW800 Augmented Reality Fluorescence in Aneurysm Treatment

One augmented view during vascular neurosurgery improves confidence in intra-operative diagnosis

One augmented, real-time view means no more need to recall and try to reconcile the black and white blood flow video with the natural anatomical view
Crisp delineation helps you limit potential compromise or obstruction of surrounding perforators and small vessels
Full depth perception and no dark peripheries supports clear spatial orientation to aid manipulation of vessels

Fig. 17: GLOW800 Augmented Reality Fluorescence in Aneurysm Treatment.

Improved confidence in treatment

Visualization with GLOW800 AR supports each step of vascular neurosurgery procedures and also supports with post-operative imaging. For example during aneurysm clipping, it helps:

Confidently apply an aneurysm clip
Assess clip placement and aneurysm occlusion
Check if all branches proximal and distal to the clipped aneurysm are perfused and whether there is orthograde filling of the blood vessels
Confirm the clip has not caused any compromise of surrounding blood vessels, such as kinking or partial obstruction

Fig. 18: Visualization with GLOW800 AR supports each step of vascular neurosurgery.

A fundamental tool for the future practice and training in neurosurgery

In the binocular image injection (CaptiView) better defining (lowering) the dose of Indocyanine Green (ICG) was enough to generate the flow effect without saturating the view of the whole operative field. Also the microscope’s monitor offers a perfect view, where the observer can easily understand the anatomy and the clipping strategy adopted. Image settings can be effortlessly changed, to optimize the view as needed.