by Ben Best
The Cryonics Institute's 74th patient was a 79-year-old woman from Kingston, Ontario, Canada who was cryopreserved by her only son, with her consent. Of the 7 most recent patients, prior-to and including this one, 5 have been mothers cryopreserved by sons. She deanimated (was pronounced dead) on Mother's Day (Sunday, May 14, 2006).
This patient was a non-smoker in reasonably good health until she contracted breast cancer a year-and-a-half before her deanimation. The cancer was removed by mastectomy, but apparently not soon enough to prevent it from spreading to her lungs. In October 2005 she was told that she had one year left to live. Although she had little interest in cryonics when her son first mentioned the idea, when he suggested it again in February 2006 she was quite positive about being cryopreserved. Her son believes that the confrontation with her mortality may have been quite persuasive.
Nonetheless, the mother went into the hospital a week before her deanimation and it was only at that time that the son contracted us to begin making arrangements. Prior to going into the hospital the mother had been ambulatory and no one suspected that she did not still have many more months to live. Even in the hospital she deanimated sooner than was expected. Nonetheless, by the time of her deanimation her weight had dropped from 112 pounds to 75 pounds. She was placed in hospital refrigeration soon after deanimation and three hours later the funeral director packed her with ice. No heparin was given and there was some delay completing the Cryonics Institute paperwork, and in wiring money to our bank.
This was the second case of a cryonics patient deanimating in the Canadian Province of Ontario, the first being a Toronto CI patient in 2002. (See The First Cryonics Case in Toronto, Canada.) Because of concern that there might be delays at the Canada/USA border, the Toronto patient was perfused with glycerol and driven to Michigan in dry ice. Because the Toronto case did not experience border delays we felt more confident that there would be no delay this time. The patient was driven from Kingston, Ontario to Clinton Township, Michigan without border delay.
As always, the perfusion was performed at Faulmann & Walsh Funeral Home, but this time the surgery was performed by Sarah Walsh, daughter of Jim Walsh, who (like her father) is a licensed funeral director. Ice from the casket the patient had been shipped in were placed in bags that were packed under and around the patient's head.
The same surgical procedure was used on the 74th patient as was begun with CI's 69th patient, without having to cut any bones. The carotid and vertebral arteries were cannulated independently on the left side. The brachiocephalic trunk (which feeds both the right carotid and vertebral) was cannulated on the right. The subclavian artery was clamped distal to the cannulations on each side. Drainage was through the jugulars.
Her brain was perfused with 2.5 liters of m−RPS−2 washout/carrier solution, 2 liters of 10% VM−1 ( Vitrification Mixture), 3 liters of 30% VM−1 and 3 liters of 70% VM−1. Perfusion pressure was maintained in the physiological range of 80mm Hg to 120mm Hg, which means that the flow rate was slower for the more viscous 70% VM−1 solution than for the less concentrated (and less viscous) solutions.
Although some clots were seen, the clotting was not as bad as had been expected. The son thought that some anti-coagulant may have been administered to his mother in the hospital because of her bedridden condition, but he was unsure of this. Low molecular weight heparins are often given to prevent clotting in immobilized patients [AMERICAN FAMILY PHYSICIAN; Rydberg,EJ;59(6):1607-1612 (1999)].
Burr holes on each side of her skull were used to determine the refractive index of the brain fluid until there was complete saturation with 70% VM−1 solution. The left side reached full saturation, but the right side, while approaching full saturation, stopped short. There was no brain edema on either side, but the face became swollen on the right side. Possibly edema in the right neck was causing blockage and thereby reducing perfusion. Nonetheless, even 60% VM−1 should be adequate to vitrify, and 70% VM−1 is much more than adequate. The refractive index of the right burr hole solution was close to the refractive index of 70% VM−1. So the concentration of VM−1 on the right side was probably closer to 70% than to 60%. Total brain perfusion time had been one hour and ten minutes.
Upon completion of perfusion of the brain, a thermocouple was placed in one of the burr holes and the skin over the burr holes was stitched shut. A loop in the thermocouple was tied to the skin of the skull to secure the thermocouple. The head was then placed in a plastic box containing crushed dry ice to accelerate cooling of the VM−1 saturated brain during the time that the body was being perfused. The plastic box has a hole in the side for the neck and a slider to fit to the upper neck. The bottom of the neck rests on the edge of the plastic box.
The body was perfused with Ethylene Glycol (EG) cryoprotectant, which is highly penetrating, but not as vitrifying as VM−1. Perfusion was down the carotids with drainage still through the jugulars. 4.75 liters of washout solution was followed by 10% EG, 1.5 liters of 30% EG and 6 liters of 80% EG. Although the legs appeared to perfuse reasonably well, abdominal swelling caused the perfusion to end after 20 minutes. According to CI Facilities Manager Andy Zawacki, the bodies of cancer victims often perfuse poorly. On the other hand, ethylene glycol is more likely to cause edema than are less penetrating cryoprotectants. A thermocouple was placed in the patient's chest to be used to monitor body temperature during cooling.
We have no pretense that this body perfusion does any more than reduce freezing damage. It will be at least a decade before anyone can vitrify every organ, and monitoring vitrification of every organ would not be an easy task. With stem cells and artificial organ technologies on the horizon, the importance of vitrifying every organ is dubious.
The patient was transported from the funeral home to the CI Facility with her head still sticking into the plastic box filled with crushed dry ice. During transport the temperature reading of the thermocouple in the burr hole dropped from −3ºC to −12ºC. In the future we will add fluid to the crushed dry ice to accelerate the cooling capacity of the plastic box.
The plastic box was removed from the head just before the patient was placed into the computer-controlled cooling box. She was placed on a sleeping bag that was sitting on her wooden backboard. Another thermocouple was placed deep down her nose into the pharynx for a close proxy of temperature in the center of the brain. The sleeping bag was wrapped around her and she was strapped into place for transfer to the cooling box.
Once she was in the cooling box the sleeping bag was opened so
she could experience the full effect of cooling. Another thermocouple
was placed in a cardboard box to monitor ambient temperature without
direct exposure to liquid nitrogen. The top of the cooling box
was sealed with pink foam-board insulation.
|First 23 Hours||Full 170 Hours|
The thermocouple in the burr hole was used as the controlling thermocouple by our LabVIEW computer control system. Cooling of vitrified tissue should be as rapid as possible to glass transition temperature (Tg), but should not go much below that temperature.
The cooling strategy was to cool the surface of the brain as rapidly as possible to Tg and then wait until the temperature in the center of the brain approached Tg. Once the center of the brain was close to Tg the surface was warmed slightly in the hope that the entire brain could be of uniform temperature in a highly viscous "liquid" state just above Tg. This is not "annealing", because annealing involves warming a solid to just below melting temperature as a means to relieve thermal stress in a solid. By remaining just above Tg for the entire brain and cooling very slowly through Tg we believe we achieve the greatest temperature uniformity and the least thermal stress, while relying on the very high viscosity to prevent devitrification.
Twenty-three hours after the cooling box cooling had begun, the desired thermal uniformity had been achieved and we began a slow cooling to −192ºC that lasted about six days. We did not concern ourselves with body temperature. To have done so would have detracted from optimum cooling of the brain. Body temperature did not begin to approximate brain temperature until about 35 hours.
This patient was the second to be put into the
(HSSV−6−7 was filled before HSSV−6−6).
Each patient has a rope tied to their backboard which allows for movement, placement
and even removal, if a move should be necessary. These ropes are separated when
adding a new patient, and then tied together again to be fished-out when need
again (as when adding another new patient).
|Patient's Head sticks into Plastic Box||Patient Hoisted into Cooling Box||Closing the Door of the Cooling Box|
|Patient tied to Board and Identification Plate||Andy Sorts Ropes in a Cryostat|