Pushing the boundary

This is medical post. I saw an exciting procedure done on a stroke patient today which yet again steered me into the reflective mood.

Mr G is a previously fit and well 50 year old father of two who was admitted with stroke last week. It affected his vision, speech, swallowing, right arm and leg. He took a turn for the worse yesterday. He had another big stroke affecting the brainstem and he completely lost his airway and slipped into a coma.

His brain CT and MRI were pretty horrific to watch too. First of all let me explain the relevant basic of neuroanatomy. The brainstem controls our consciousness, breathing, heart rate – absolutely fundamental for survival. When the brainstem is gone, that’s when you call a person ‘brain dead’. The make up of our bodies naturally makes sure that the brainstem is constantly well supplied with oxygen and nutrient by having two arteries on each sides of the brainstem. They are also interconnected to one another (communicating), so that if one is blocked for any reason, the other one can compensate for the supply.

On Mr G’s brain, one of the arteries is completely occluded beyond salvage. The other artery had a section of significant narrowing (stenosis) and was almost completely blocked. The supply of the whole of the brainstem and indeed the back of the brain were hanging on just by a thread size hole for that tiny amount of oxygenated blood to flow through. If this pinhole is blocked, Mr G would die.

So the idea was to put a stent into the nearly-blocked artery to open up the narrowing. Stenting is routinely done for vessels on the heart muscles (coronary arteries) but not so much for the brain arteries. I’m not sure why. Maybe because there is too much at stake. The intrusion to the diseased and perhaps fragile vessel could rupture the arterial wall resulting in a disastrous bleed into the brain. Debris (like fat/atheroma which sticks on the wall of the arteries that cause the narrowing in the first place) could dislodge and travel upwards to occlude the vessel further ahead. But on balance, if we don’t press ahead, more clots (emboli) are likely to just take its course to occlude the tight narrow vessel – the catch is that we cannot guarantee that it will happen.

Seeing the procedure itself just made me realize so many other factors to weigh up. My hospital is the tertiary referral centre for neurosciences services in Manchester. We have unrivalled expertise of the different neuro sub-specialties. Even so, since this procedure has never been performed before here, a radiologist from the neighbouring teaching hospital (MRI) had to bring in some stents they normally use for coronary vessels. The procedure is done under direct x-ray screening. In total Mr G must have been subjected to about an hour worth of radiation on two planes.

In order to put the stent in the best position, a guidewire needed to go over the area of stenosis. They tried once, the wire stays at the proximal bend and would not advance further. They looked for a stiffer wire, and the radiologist tried pushing it in, again it wouldn’t budge. By then, Mr G has already been subjected to two hours worth of anesthetic (don’t forget that this is a patient who has just suffered a very serious stroke). There isn’t a wire stiffer than this in stock. This is so frustrating! At this point, I wondered if they are going to just abandon the procedure. So the visiting radiologist from MRI suggested two wires: one as the main guidewire and another one as a buddy wire just to help stiffen the main one. And so the team of radiologists deliberated for a while. I heard the radiologist from MRI said ‘by the way this is an untouched territory, we have no idea what is going to happen’. So the team went ahead, and the guidewires finally passed through. Carefully they deployed the stent, opened it up and we finally saw what we went there for. There was much more blood flow running through that previously stenosed area, and we saw much more perfusion distally lighting up as dark stuff on the x-ray. So it was a success. I later learnt that this stent-in-the-brain procedure is only the second one to be done in this country. Well done to the radiologists!

However this is not the end of the story. Radiological success is one thing, the clinical picture is another. Will Mr G wake up? Will he start breathing on his own? Will he ever be strong enough to undergo physio and be a functional man again? Some area of the brainstem has obviously been deprived of oxygen and nutrient for some hours, and whether we have done this procedure in time for the fresh blood to replenish and revive these dying neurons, no one has the answer. I guess this is the time the doctors would be telling the relatives that we just have to wait and see. Still, I am hopeful. From what I have seen today and all my experience in medicine, I can tell you that when doctors say that 'we will do everything we can', they mean it.


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