When Dr Moosa Kunhi received a call while at his friend’s house to celebrate Eid this year, he didn’t know that he would be presented with one of the most challenging surgical cases of his career so far.
The cardiac surgeon who works at the VPS Lakeshore Hospital in Kochi was being called in by his oncologist colleague for help to remove a tumor from two-year-old Aadhi Thoppil Fabeer’s heart. The boy who had just arrived at the hospital from Dubai was breathless, unable to sit or lie down comfortably and seemed unlikely to survive until the next day. He had a yolk sac germ cell tumor, a rare condition and only the fifth reported case in the world. Furthermore, it was the only known case known to Kunhi where the tumor was present both inside and outside the heart.
“[The tumor] was fully occupying the right side of the heart, choking on of the valves and also growing outside the heart and pushing the heart to the extreme end,’ said Kunhi who recollects dropping all this plans for the rest of that evening and rushing to the hospital to organise his surgical team within an hour.
Kunhi was faced with the challenge of having to operate a tumor growing inside a vital organ that is normally filled with blood. Among the unknowns were the extent that the tumor had spread, the exact procedure a surgeon would have to follow to remove it and how long such a surgery would take.
Going into the heart blind – that is operating in a surgical field full of blood – would mean possibly missing some parts of the tumor that needed to be removed. It also posed the significant risk of damaging the hearts walls or valves or partitions or electrical conduction systems. Kunhi assessed that the only way to remove the tumor was to stop the boy’s blood circulation to perform the tumor resection.
Shutting down or suspending blood circulation in the human body cuts off oxygen supply via blood to the organs, sending them into distress, sometimes to the extent that they cannot recover. The most vulnerable part of the body is, of course, the brain. So to keep as much of brain and body function intact while operating in a bloodless field inside the heart, the VPS Lakeshore team undertook to perform a rather novel procedure called deep hypothermic circulatory arrest in which the body is cooled down to much below body temperature. The procedure, also called suspended animation or induced clinical death, lowers the body’s metabolism drastically to a level where cells draw in very little oxygen and can survive for hours with very little damage.
Evolution of hypothermia in medicine
A recent article in the online magazine Motherboard traces the use of hypothermia in medicine all the way back to the ancient Egyptians and Hippocrates who would cover the badly injured with snow and ice to slow the flow of blood and give the body time to heal. As we humans acquired knowledge of how the body and diseases work, they continued to experiment with hypothermia as a means of slowing down metabolism in people with traumatic injuries.
But a series of unfortunate accidents with surprisingly good outcomes sparked the interest in deep hypothermia in therapeutic use. Several cases have been reported since the late 90s of people being severely injured in skiing or other accidents in icy and snowy conditions, whose bodies cooled down to far below the normal human temperature of 37 degree Celsius, and who made full recoveries with remarkably little damage to their systems.
These cases, once seen as some kinds of medical miracles, have sown the seeds of investigation of how the human body functions in deep hypothermia. Researchers have even been trying to compare animal hibernation with induced hypothermia. The big difference between the two is that hibernation is well-regulated by the animal body while the human body constantly tries to fight off the hypothermic condition.
Essentially, cells in the body are sensitive to oxygen and a lack of oxygen causes them to die very quickly. But when cooled, cells like neurons in the brain, can run longer on less oxygen. This allows doctors more time to fix injured parts before the brain gets damaged.
The critical 40 minutes
In Fabeer’s case, the doctor’s at VPS Lakeshore assessed that they needed to keep the boy in a deep hypothermic state for 40 minutes to remove the tumor inside the heart. They could not risk keeping him in suspended animation for longer than that, not knowing what impact extended hypothermia may have on the brain.
“We had done hypothermia procedure before but not to this extent,” said Kunhi. “We had cooled down patients to 26 degrees or so and not for so long.”
The decision being made, a team of eight doctors began what would be a nine-hour surgery at 9.30 pm that evening. They opened the patient’s chest and attached tubes called cannulae to the two major blood vessels of the heart – the aorta and the superior vena cava – to redirect blood into a heart-lung machine.
A heart-lung machine carries an oxygenator and as the blood flowed through the coils of the oxygenator, water cooled to four degrees Celsius was circulated outside the coils. This brought the temperature of the patient’s blood and the body down to 15 degree Celsius. At that moment the brain and hart function monitors all register “zero” and the patient is clinically dead.
This tense moment was already three hours into surgery time. “Now each and every millisecond is important,” said Kunhi. “Our aim is now to go ahead and remove as much of the tumor as possible and reach a safe stage before restoring blood circulation to the brain. One has to be very clear that we have to finish the required amount of tumor removal within this 40 minutes.”
Relying on the full attention, precision and machine-like coordination of all the doctors and nurses inside the operating theatre Kunhi instructed that all cell phones be switched off. “I told my people that for the next 40 minutes we don’t have any connection to the outside world,” he recalled.
In the next 40 minutes, the doctors managed to remove 80 percent of Fabeer’s tumor – the whole of the growth inside the boy’s heart. Immediately, they warmed him back to 37 degrees, disconnected him from the heart-lung machine, closed the surgery and installed the boy in the hospital’s intensive care unit by seven o’clock in the morning.
“We were all very anxious and we didn’t know whether the child would wake up or not,” said Kunhi. “By eight o’clock we were very happy to see that the child was awake and started moving his limbs.”
After his successful surgery, Fabeer underwent chemotherapy and was discharged from the hospital a few weeks later.
While doctors continue to probe the use of deep hypothermia to save lives, space agencies are trying to find a true hibernation-like hypothermic state in humans that will help astronauts travel seemingly interminable distances in space. Till either the doctors or astronauts make a breakthrough, a safe cryosleep remains in the realm of science fiction.
This article was first published on Pulse on Scroll.in.
