A tarmac road on the hill from the CMC roundabout to the Wossen roundabout displays a giant blue and red neon sign. The Axon Stroke & Spine Center is bound by the American Medical and Samaritan Surgical Centers, sister companies providing inpatient and outpatient medical and surgical speciality services.

The two-storey chained premises give off a complete medical centre vibe. Outpatients and attendants were scattered in the waiting area while some stretched their legs with support. Doctors were busy responding to calls from patients that wanted to schedule appointments. Nurses on the first floor were changing guards, handing their patients to night duty.

The energetic appearance on the ground and the first floor does not do justice to what goes on in the second-floor operation room.

Around 5pm last week, a 52-year-old female patient arrived at the emergency unit. She suffered a sudden onset of left-sided body weakness. Doctors suspected it happened after the patient discontinued her blood thinner medication a few days before the incident. She could not speak or lift the left side of her arms or legs. The CT scan revealed a blood clot on the right side of the blood vessel in her brain.

The blood flow to the right brain was blocked at a certain point, causing weakness on the reverse side.

The human brain needs constant blood flow. A blood clot stops the flow of oxygen and glucose, causing brain tissue death. A stroke happens when the blood flow to the brain is blocked, otherwise known as ischemic stroke or when blood vessels in the brain burst and bleed, known as hemorrhagic stroke. Ischemic stroke is the most common type, accounting for nearly 85pc of strokes, said Wondwossen G. Amanuel (MD), the world-renowned neurologist and stroke sub-specialist (neuro interventionalist). He has been practising from his centre in Harlingen, Texas, after graduating from George Washington University in neurology in 2013.

Immediately, the patient was rushed to the operation room (Cath Lab) to remove the clot, a procedure known as mechanical thrombectomy.

Thrombolytic therapy is the immediate treatment choice after the onset of a stroke. Clearing the blood clot reduces the effects. Without treatment, a blood clot in the brain is more likely to lead to severe brain damage. To get this treatment, patients from Ethiopia used to go to countries such as Kenya or South Africa. Besides the ability to make financial arrangements in a time-constrained situation, getting exposed to decreased pressures on air had its own disadvantages.

The patient admitted last week to Axon Centre was lucky. Wondwossen is the only qualified medical professional in the country to remove a blood clot with this procedure. Taking advantage of her weak side, he placed a catheter into the blood vessel through the left groin while monitoring the procedure on a screen in front of him. The passage of blood was magnified on the screen as black in contrast with the blank blood-deprived areas, identifying the point of the blockade.

The catheter, made of a wire mesh, travelled up to the blocked area. This happened in arteries with less than a three-millimetre diameter, smaller than the size of calligraphy markers.

After a careful journey, it finally reached the blocked area in the brain. The wire closed around the clot and pulled it out of the blood vessel. As the clot disappeared from the screen, the blood flow was restored with a finger snap. The blank blood-deprived areas on the screen lit up as a Christmas tree would brighten after its switch was on.

This incredible procedure took close to two hours. It usually takes less time, depending on the difficulty of the case.

As the patient was referred from another hospital, it took nearly nine hours from the presentation until she arrived at the stroke centre. For the specialist at the Centre, timing is a crucial element in determining the outcome. Acute stroke cases should be treated within 24 hours. The longer patients take to get to treatment centres, the further the tissue damage in the brain.

"Patients getting treatment within six hours of an incident have a better chance of full recovery," Wondwossen told Fortune.

Two large blood vessels along both sides of the neck supply blood from the heart to the brain. These vessels get smaller to tiny bits supplying oxygen and nutrients to the deepest parts of the brain. The position of blood clots determines the signs and symptoms at the time of presentation, according to Wondwossen. Sudden paralysis or weakness on one side of the body is noticed when blood flow is affected from one side, as the 52-year-old patient suffered.

Some patients may not be fortunate. When a major blood supply without any tributaries is blocked, patients experience loss of consciousness.

It happened to a 47-year-old male patient on vacation from the Middle East. He has a known cardiac disease history but no medication adherence. He was with his wife and children when he suddenly lost consciousness; he was referred to the stroke centre in about six hours. Upon referral, he was hooked up to machines to help him breathe and was diagnosed with a blood clot at the back of the brain.

Wondwossen described it as one of the deadliest phenomena known as "basilar artery occlusion."

Three days after the procedure, the patient recovered with impressive command. He remembered his wife and knew his name. He even gave Wondwossen a thumbs-up as they finished their rounds.

"He would not have survived if Wondwossen was not here," said Akeza Teame (MD), a medical director of American Medical Center, with more than two decades of experience in internal medicine, sub-specialising in infectious disease.