The Circle of Willes in Cryonics Perfusion

Blood flows into the brain primarily via the carotid arteries and the vertebral arteries. The Circle of Willis is a circular arterial structure in the brain that connects blood flowing in from the carotid arteries with blood flowing in from the basilar artery (which is fed by the vertebral arteries).
Blood flows from the Circle of Willis into brain tissue via the anterior, middle, and posterior cerebral arteries. Many studies have shown that the Circle of Willis is incomplete in most people. A 1998 study of 150 healthy adult volunteers showed a complete Circle of Willis in only 42% of cases — more often complete in younger persons and females [RADIOLOGY; Krabbe-Hartkamp,MJ; 207(1):103-111 (1998)]. A slightly more encouraging 2002 study of 118 healthy volunteers in the 65-68 age group, showed 47% had a complete Circle of Willis [THE JOURNAL OF CARDIOVASCULAR SURGERY; Macchi,C; 43(6):887-890 (2002)]

For cryonics purposes, it has been believed that perfusion into the carotid arteries, but not into the vertebral arteries will result in incomplete perfusion of the brain if the Circle of Willis is not complete. In particular, if both posterior communicating arteries are missing, then perfusing only through the carotid arteries will result in no blood getting to parts of the brain supplied by the posterior cerebral arteries. Both posterior communicating arteries were missing in 11% of those in the 1998 study and in 14% of those in the 2002 study cited above.

Nonetheless, a 2008 study showing Circle of Willis complete in only 40% of 99 patients found no case of insufficient perfusion in functional tests of patients given unilateral cerebral perfusion. The authors concluded that “extracranial collateral circulation” provides an alternative pathway to the Circle of Willis for cerebral crossperfusion [EUROPEAN JOURNAL OF CARDIOTHORACIC SURGERY; Urbanski,PP; 33(3):402-408 (2008)]. Although persons with missing posterior communicating arteries could easily have pathways to opposite sides of the brain, other variants of Circle of Willis incompleteness would be expected to prevent perfusion across hemispheres.

When the cryonics organization Alcor does a cephalic isolation (“neuro”) perfusion, the carotid arteries are initially cannulated and the vertebrals are not cannulated. Only if when the patient is being perfused into the carotid arteries no flow is seen coming from the vertebral arteries are the
vertebral arteries to be cannulated and the patient is to be perfused through both the carotids and the vertebrals. If, on the other hand, flow is seen coming from one of the vertebral arteries after perfusion of the carotids has begun, it is assumed that the Circle of Willis is complete and the vertebral arteries are clamped for the rest of the perfusion. Flow only needs to be seen in one of the vertebrals to confirm that the Circle of Willis is complete, because the vertebrals unite in the basilar artery before connecting to the Circle of Willis.

One Alcor employee has informed me that of 15-20 neuro patients perfused by this cephalic isolation method, not once has there been an absence of flow from the vertebrals and not once has Alcor perfused a cephalic isolation patient through the vertebral arteries. This would be slightly improbable, based on a 10-15% expected rate of incomplete communicating posterior arteries on both sides. But another Alcor employee remembers one or two cases where vertebral artery perfusion was done (which would match expectations).

When both posterior communicating arteries are not missing, there is another potential problem with perfusing only into the carotids and not the vertebrals — namely, loss of perfusion pressure. Perfusate entering the Circle of Willis could exit through the basilar artery (the vertebrals) instead
of through the cerebral arteries. Vascular resistance in the body is reportedly only one quarter what it is in the brain. Clamping the vertebral arteries (as is done during Alcor neuro perfusions) could prevent this problem. Blood flowing into the basilar artery need not be pushing all of the blood in the body, however, because arteries — and especially veins — have a large reserve capacity (a balloon-like ability to expand).

Possibly the reserve capacity of the brain would allow blood to flow into the brain as readily as into the body. Blood has about three times the viscosity of water, and vitrification solution has about twice the viscosity of blood. Viscosity will increase vascular resistance in all blood vessels, but the effect would be greater in the brain. The “no reflow” phenomenon would also create resistance in the blood vessels, which again might be greater in the brain than in the body.

Prior to the use of vitrification solution, the Cryonics Institute only perfused cryonics patients through the carotid arteries — there was no attempt to perfuse into the vertebral arteries. Nonetheless, dehydration was seen in the patients, and adequate effluent flow was seen from the jugular veins. Perfusion pressures were reportedly not excessive.

Currently, CI’s funeral director has been opening the chest (median sternotomy), and attempting to clamp the subclavian arteries, as well as the descending aorta, to perfuse into the ascending aorta. In several cases the ascending aorta has been perforated, forcing higher cannulations or the subclavians have been difficult to cannulate after having opened the chest. Our funeral director refused to open the chest at all for a known case of Methacillin- Resistant Staphylococcus Aureas (MRSA).

It would be preferable if a case could be made for perfusing all CI patients only through the carotids. Carotid-only has been recommended for vitrification perfusions overseas, as well as for glycerol perfusions in post-mortem sign-ups. Whether vitrification solution perfusion into the carotids can achieve adequate perfusion pressure in the brain — and whether adequate perfusion pressure can be verified by the observation of effluent from the jugular veins remains unresolved.

It should not be too difficult to clamp the vertebral arteries by cutting near the clavicle, as CI’s funeral director did when CI began the attempt to perfuse the vertebrals as well as the carotid arteries. Nonetheless, this would result in failure to perfuse portions of the brain supplied by the posterior cerebral arteries in the 10-15% of patients who are missing both posterior communicating arteries.

First published in The Immortalist, February, 2011 is the world’s largest independent website about cryonics and medical human biostasis.

In 2007 Aschwin de Wolf launched the cryonics blog Depressed Metabolism, the first professional blog to exclusively cover the science and practice of cryonics. Out of this platform emerged The Institute for Evidence-Based Cryonics (2008-2018), a non-profit aimed at educating the general public about cryonics. The Institute organized a number of groundbreaking symposiums on cryonics and dementia and cryonics revival scenarios. The Evidence-Based Cryonics Institute website also became the official host of the Scientist’s Open Letter on Cryonics and engaged in several campaigns to draw attention to recent breakthroughs in brain cryopreservation.

Biostasis continues the journey that started with Depressed Metabolism and the Institute for Evidence-Based Cryonics. Its goal remains to educate the general public about cryonics and human biostasis in all its aspects. We will keep publishing new content and historical documents relating to cryonics and remain the official host of the Scientist’s Open Letter on Cryonics. This year we will also announce the publication of the first detailed medical human biostasis protocol that will allow hospitals to educate themselves about offering cryonics as an elective medical procedure. In 2019 we will also announce a series of initiatives to study the theoretical aspects of conducting cell repairs at low-temperatures, or medical cryobotics.

All entries from the depressed metabolism and evidence-based cryonics website remain available on the biostasis website. Please update your links and spread the word about

Good Cryonics is Local

The enemies of a good cryonics case are time and temperature. Deployment of a standby team that can start rapid cooling upon circulatory arrest should take care of the temperature challenge. The time element is more challenging. Even if a patient is stabilized rapidly after pronouncement of legal death, logistical and legal challenges can interfere with timely transport to Alcor for subsequent procedures. For example, if a patient is rapidly cooled down in North Dakota but logistical challenges and flight schedules prevent arrival of the patient at Alcor until several days later, the patient will still be subjected to progressive deterioration of the fine structure of the brain, breakdown of the blood brain barrier, swelling, and a number of processes that prevent smooth cryoprotection of the brain, or even necessitate a “straight freeze” (cryopreservation without a cryoprotectant). How should Alcor deal with the challenge of having only one physical location in Arizona but being responsible for members all over the world?

The most obvious solution is for a terminal member to move to Alcor. In almost all cases this is the preferred solution because this prevents several potential logistical, legal, and technical challenges. The advantages of moving to Alcor are so great for both the cryonics organization and the patient that Alcor offers up to $10,000 in relocation assistance. To further incentivize such a choice, Alcor could consider further increasing the amount of relocation assistance and/or actively assist older and sick members to consider relocating.

Another solution is to bring all major Alcor procedures to the location of the patient. This is easier said than done. Whereas a patient relocation does not require major expenditures and logistical decisions on the part of Alcor, bringing cryoprotection to the patient is a non-trivial task because it entails performing Alcor’s operating room procedures at a remote location. In practice, this can be done, and Alcor has cautiously authorized “field cryoprotection” for overseas and selected US cases. In principle field cryoprotection is possible for both neuro-patients and whole body patients but true whole body field cryoprotection would require the creation of an adequately equipped vehicle or satellite facility, not to speak of medical expertise. Recognition of the fact that many Alcor members do not relocate when terminally ill, and potential cost savings, have prompted some Alcor officials to advocate expanding field cryoprotection to more members.

Since it is obviously easier to bring a patient to a hospital than a hospital to a patient, more effort will need to be spent in educating members of the advantages of timely relocation to the Scottsdale area.

There might be one route to bringing the hospital to the patient and that is to encourage the creation of several of “cryonics hubs” in areas with large numbers of Alcor members. Support and recognition from Alcor for such initiatives is necessary but a decentralized approach could be effective here. Local members can start with creating a cryonics infrastructure to assist professional standby teams. Such efforts can include maintaining a list of pertinent local regulations, cooperating funeral homes, local volunteers and medical professionals, and flight schedules. A more ambitious step would be to equip certain areas with a local rescue vehicle, as was done in the past in Southern California. A more ambitious step would be to equip such a vehicle for field cryoprotection or even set up such facilities in a cooperating funeral home or building. This is a formidable task that would require many hours of work and considerable expenses but it would produce a more robust response infrastructure for Alcor to utilize. It could also make some areas less vulnerable to episodes of deteriorating response capabilities at Alcor. Last but not least, bringing people together to engage in such a project will also tighten the social fabric and local visibility of cryonics.

Originally published as a column in Cryonics magazine, November – December, 2018

Hybrid Standby Infrastructure

Cryonics has limited appeal but cryonics organizations have assumed global responsibility to cryopreserve their members timely and competently. A hybrid model in which local members and volunteers work together with medical staff members and contractors to deliver the best possible cryonics care is the best answer to this situation. Taking Alcor as an example, what does this model entail in terms of infrastructure and staffing?

The most important response mandate of a cryonics organization is to ensure competent local response capabilities through full-time employment of medical professionals and cryonics experts at the facility. Unlike remote response capabilities, Alcor’s response to local cases should not be dependent on erratic, case-by-case, contracting with local medical professionals. While such professionals can supplement Alcor’s own capabilities, Alcor should never find itself in a situation where it cannot deploy an effective standby due to a shortage of available staff members. This mandate requires that Alcor’s staffing policy cannot be allowed to outcrowd its local response capabilities. In practice, this means having at least three staff members available for local case work with at least two of them being proficient (and preferably certified) in conducting medical procedures that are elemental to cryonics stabilization (placing IV lines, placing an endotracheal tube etc.).

A strong mandate to primarily deliver state-of-the-art care in the Scottsdale area may look rather meager in light of its global responsibilities, but considering the fact most Alcor members do not die suddenly, and are eligible for an attractive Alcor relocation-reimbursement, out-of-state cases may increasingly be seen as reflecting choices made by Alcor members, as opposed to inevitable events happening to them. The significantly higher costs, and potential logistical and legal complications, of out-of-state cases are a strong argument to further increase Alcor’s relocation reimbursement amount.

The next layer is to coordinate a network of professional cryonics response providers (such as Suspended Animation and ICE) and local groups to respond effectively to out-of-state cases. Such companies can provide a valuable element to deliver rapid response provided that access to such services does not lead to allowing the atrophy of local groups and response capabilities. Professional standby companies usually deploy out of a single state (or two at most), which means that relying on local capabilities created by members remains an essential component for responding timely to time-sensitive cases. To ensure consistent and competent non-local response coverage, the coordination and monitoring of non-local response capabilities should be an important job responsibility of a full-time Alcor staff member.

To augment the services of cryonics standby organizations and the resources available to local members, regions with substantial numbers of Alcor members should be encouraged and supported in creating robust physical cryonics responsibilities. In such areas, maintenance of a full set of standby kits, a response vehicle, and even on-site field cryoprotection capabilities should be pursued. These non-Scottsdale cryonics “hubs” should be allowed some degree of autonomy, provided their efforts conform with Alcor’s protocols and standards. Further enhancement of these cryonics hubs can be reaped if such efforts are supported by other cryonics-supporting activities such as research and public outreach. Examples of areas where such hubs would be feasible and desirable include New York City, Los Angeles, and San Francisco. The mandate for these areas should be to close the gap between Scottsdale-based cases and local cases.

International cases are a formidable challenge for Alcor and the cryonics hub idea will need to be extended to countries (or even a set of neighboring countries). Collaboration between members of different cryonics organizations is often a necessity in international cases. Transport times to the US necessitate the use of procedures such as field cryoprotection and shipping on dry ice

Originally published as a column in Cryonics magazine, September – October, 2018

Why Don’t You Start With Standby First?

In the 15 years I have been involved in cryonics I have observed a predictable pattern. An enthusiastic group of people want to create a new cryonics organization. Reasons can range from wanting to have a cryonics organization in their own continent or country (Europe, Australia) to having a distinctly different vision how cryonics should be practiced. Some of these attempts have succeeded and others have failed. The common denominator I have seen in the failed attempts is to do “something else” first before offering long-term maintenance. If this “something else” would simply comprise exercising due diligence in having a sensible financial and legal framework in place before accepting patients that is understandable. But here “something else” concerns achieving something even harder as a precondition for building a storage facility: creating state-of-the-art response capabilities.

One argument for this approach is that without adequate standby and stabilization having a cryonics storage facility is pointless. I do not think this is true and if this argument is followed to its logical conclusion there will never be a good moment to start offering storage as long as cryonics is as unpopular as it is right now. Sure, it is indisputable that a cryonics patient who receives a prompt response and good stabilization procedures will sustain less damage and better cryoprotection. This does not mean, however, that anything that falls short of this is doomed. The ultrastructure of the post-mortem brain is more robust than even most cryonicists assume and ice formation does not necessarily render the original structure of the brain un-inferable.

The other argument is often a variant on the idea that the most challenging element of a cryonics endeavour (i.e. storage) should be done last. But the hardest part of cryonics is not storage but standby. Creating cost-effective, dependable, responsible capabilities for a region larger than a city or small country is a non-trivial challenge. Let’s consider Europe for example. Providing standby coverage for all countries would require a massive initial investment with numerous medical professionals on retainers being available for a case at the right time at the right place…a case which may not happen for many years. Will such an organization be able to keep its supporters motivated and financially committed? In reality this mandate often creates a situation where the organization cannot live up to its standby claims, storage is (indefinitely) postponed, and interest wanes until the next attempt is made to do the same thing. It is no surprise, in my opinion, that some of the newer cryonics organizations (KrioRus, Oregon Cryonics) accepted patients for long term care from the get-go.

Standby is important and I do not pretend that it will take care of itself when there is storage. But whereas storage needs to be centralized (having a storage facility in each of the European countries at this point would be ludicrous) having sound and dependable standby capabilities is a decentralized process which can be pursued by different groups in different states or countries based on their different needs and (financial resources). As we speak, the UK and the Netherlands have made impressive efforts to create such capabilities and these efforts will further grow and spread when there is a facility with patients to care for. One needs to start somewhere and the most realistic path is to first create a sensible storage solution followed by de-centralized efforts to transport patients to the facility in the best possible condition.

Originally published as a column in Cryonics magazine, July – August, 2018

Cryonics Revival Scenarios

Ralph Merkle’s new article “Revival of Alcor Patients” constitutes an important contribution to the growing cryonics survival literature. What sets Merkle’s latest piece apart from (his) prior efforts is its extensive treatment of the validation of revival attempts (“did we do it right?”) and the ethical principles of revival.

The most important distinction between revival methodologies concerns those that involve in-situ repair and revival and those that aim for repair and revival on a different substrate (i.e. “mind uploading”) after conducting a (molecular) scan. Merkle also presents a revival scenario that involves a destructive scan of the cryopreserved individual, followed by in-silico repair, and biological revival. Some cryonicists (including the “godfather” of cryonics, Robert Ettinger) have expressed concerns that some of these proposals will not produce meaningful individual survival. In particular, it is argued that “running” a complete simulation of the brain on a computer won’t give rise to consciousness, let alone produce individual survival.

Since it may be quite some time before technology is at a state to favor one position over the other, we need sound principles to make prudent decisions now. In his article “Brain Preservation and Personal Survival: The Importance of Promoting Cryonics-Specific Research” (Cryonics magazine, November-December, 2017), Alexandre Erler introduces a new kind of “wager” to make such decisions when faced with philosophical uncertainty concerning the nature of identity and consciousness.

The use of Pascal-style “wagers” is nothing new in cryonics. The most famous wager was proposed by Ralph Merkle himself to compare the potential outcomes for an individual who faces a choice between signing up for cryonics or not. “Merkle’s Wager” consists of a matrix of four choices: Sign up and it works; sign up and it doesn’t work; don’t sign up and it works; don’t sign up and it doesn’t work. Merkle concludes that signing up for cryonics is the favored rational option. Michael O’Neil and Aschwin de Wolf extended this wager to making a choice between neuropreservation and whole body cryopreservation in their “The Case for Whole Body Cryopreservation” article (Cryonics magazine, expanded version, June 2014). Most readers may not be too concerned about the loss of identity-critical information in either cryopreservation option but being wrong on the nature of consciousness could be fatal. If consciousness is substrate-dependent and/or destroying the original brain (during a scan) excludes personal survival, choosing a wrong revival method can produce certain death, despite having received an excellent cryopreservation.

Erler simply asks the question what would be the prudent choice to make given that we cannot know with certainty (right now) which philosophical position is right. The short answer is that in-situ repair and revival of the preserved brain (or whole organism) will give rise to individual survival regardless of which philosophical view is correct.

One thing that is important to emphasize here, which is also discussed in Ralph’s repair article, is that non-destructive (molecular) scans of some kind and in-silico repair may still be a necessary step for in-situ biological repair and revival. The conservative position on revival is limited to the claim that it would not be prudent to instruct the cryonics organization to discard the original brain and seek revival by “running” that model on a computer.

Alcor allows for members to express their revival preferences. One complex question is whether it is currently possible to give informed consent for a revival scenario other than in-situ biological repair. A related question is to what degree cryonics organizations should honor requests for enhancements during the revival process, especially if these requests are (then) known to produce substantial identity-altering effects. There has been little in-depth discussion of these topics to date.

Originally published as a column in Cryonics magazine, May – June, 2018

What is Cryonics First Aid?

First aid in medicine is defined as “the assistance given to any person suffering a sudden illness or injury, with care provided to preserve life, prevent the condition from worsening, or to promote recovery.” Its aims can be summed up as the three P’s: preserve life, prevent further harm, and promote recovery. With the exception of the aim of “promoting recovery” this framework is applicable to cryonics, too.

The rationale for allowing laypersons to provide basic medical procedures rests on the recognition that the health condition of a person can rapidly change and/or professional responders may be unable get to the patient in a timely fashion. A major difference between mainstream medicine and cryonics, however, is that in cryonics there often is no local professional response team that can deploy quickly to stabilize the patient. As a consequence, one would expect to see more situations in which the initial, or even all, aspects of a cryonics case will need to be done by local volunteers—and that is exactly what has been observed. This does not necessarily indicate a deficiency on the part of professional cryonics standby organizations. Cryonics is simply not big enough to have professional response teams in every state and major city.

The objective of professional cryonics standby teams and cryonics first aid are the same: stabilize the condition of the patient. What sets cryonics first aid apart from the comprehensive protocols of professional standby organizations is the degree to which this objective can be accomplished and the equipment used.

Cryonics first response entails three procedures: cooling, circulation, and medications administration. One clear advantage that cryonics first aid responders have is that our most effective procedure, cooling, is also the easiest to implement. What usually sets good cryonics first aid apart from suboptimal cryonics first aid is the efficiency of cooling achieved and whether induction of hypothermia is augmented by chest compressions and medications administration. When cryonics first aid is done competently response time is fast, cooling rates are fast, circulation is restored, and a basic medications protocol to prevent clotting, brain injury, and swelling is administered.

The topic of cryonics first aid has not received as much attention as other topics in cryonics. In the early days of cryonics it did not make sense to draw a distinction between cryonics first aid and advanced procedures because all procedures were done by (trained) volunteers. And later, when professional cryonics standby organizations were formed, the topic also received little attention because it was not sufficiently recognized that there would still be a large role to play for local cryonics groups in the provision of cryonics procedures. It is only now when we have come to appreciate the advantages of a “hybrid” standby model in which local team members provide first aid, or interact with professional standby organizations, that there is a need to clearly define the objectives, scope, and physical infrastructure associated with cryonics first aid.

Some of the current questions about cryonics first aid that Alcor seeks to address include: What is the exact cryonics first aid protocol? Which items should be in a cryonics first aid kit? Should cryonics first aid kits be available to groups or also to individual members? What makes a local group eligible for a full set of standby kits instead of a first aid kit? What will cryonics first aid training comprise? What is the difference between Alcor’s first aid protocol and Alcor’s abbreviated protocol designed for professional standby teams in case of a delayed response? How do professional standby teams such as ICE and SA interact with local cryonics first aid responders? Should first aid capabilities be enhanced in areas with many members and an active local community?

Originally published as a column in Cryonics magazine, March – April, 2018

A hybrid model for standby?

In 2003 Charles Platt organized a week-long standby training in Arizona to teach a gathering of long-time and new Alcor members basic and advanced standby procedures. This well-attended meeting was one of the most ambitious gatherings to educate U.S. and international Alcor members in the knowledge and skills to participate in a case, from communicating with hospital staff to remote blood washout. Retrospectively, the timing of this event was problematic. For right then there were two ongoing developments that would largely render this model of doing cryonics procedures obsolete: the creation of Suspended Animation in Florida and the hiring of medical professionals at Alcor.

The rationale behind this transition is eminently understandable. If resources permit, why not run cryonics cases with medical professionals instead of motivated members and volunteers? If cryonics is a medical procedure, should it not also be conducted by medical professionals? As we look back on the rise of medical contracting in cryonics, however, I think some caveats and sobering observations should be made.

As Charles Platt astutely observes in his article “The Most Challenging Procedure” in this issue of the magazine, consistently deploying successful standbys in cryonics is a monumental challenge. Unless an organization has the resources to employ multiple medical professionals (paramedic, perfusionist, etc.) full-time, a typical case becomes a complex juggling act to ensure
enough medical professionals (who often are meaningfully employed elsewhere) can be at the bedside at the right time. In addition, medical professionals may have the skillsets to perform a subset of cryonics procedures but not all elements of a cryonics case are routinely taught in medicine. Case reports sometimes reveal a lack of understanding about the rationale of cryonics procedures and how to prioritize them in specific circumstances. Engaging medical contractors in extensive education about cryonics procedures and its subtleties is necessary but time-consuming and costly.

One unfortunate consequence of the medical professional contractor model of cryonics is that it can lead to the decline of member engagement in casework, neglected readiness resources and people at the main cryonics organization, and the atrophy of local cryonics groups. Cryonics organizations are especially vulnerable to this outcome when they agree to exclusively contract with an organization for their standbys. This is quite troubling from a community perspective but it also threatens the basic local standby infrastructure that that even professional standby organizations often need to draw upon to be effective.

In mainstream medicine there is a need for non-professionals to perform “first aid” before professionals arrive. In cryonics there is an even stronger need for such “first aid” because the professionals often are deployed out-of-state and may arrive too late. In such cases, local cryonics first aid responders will be forced to conduct the most important stabilization procedures such as rapid cooling and circulation. If professional standby organizations are not willing to take “post-mortem” cases, a compromised local cryonics infrastructure can be (literally) deadly.

What I want to propose here is to move toward a “hybrid” model of cryonics standby. The first layer of such a standby is the employment of several medical professionals at the cryonics organization who remain available for local and remote casework. The next layer is the establishment (or rejuvenation) of vibrant local member groups that can do basic cryonics first aid procedures and aid the cryonics organization or contract standby organizations. The third layer is to have in place a number of non-exclusive contracts with professional standby organizations to conduct casework or assist in Alcor-run cases. When this hybrid model is pursued with accountability and sound quality control, the benefits of both models of cryonics can be reaped.

Originally published as a column in Cryonics magazine, January -February, 2018

Groundbreaking Scientific Results Support that the Proposition of Human Medical Biostasis has Potential and Needs to be Brought into Mainstream Scientific and Medical Focus

March 13, 2018: A team from 21st Century Medicine has developed a technology that has been published in peer-review and then independently verified to enable near-perfect, long-term structural preservation of a whole, intact, large mammalian brain. This is a truly groundbreaking result and puts the proposition of human medical biostasis as a way to save humans, who otherwise would die, squarely within the realm of what may be possible in the foreseeable future.

This follows recent scientific evidence that long-term memory is not modified by the process of whole organism cryopreservation and revival in simple animal models.

The new breakthrough comes eight years after the Brain Preservation Foundation (BPF) launched the Brain Preservation Prize and today won that very prize.

Left Picture:  Vitrified pig brain at -135° Celsius (-211° Fahrenheit) – a temperature at which chemical and biological actively virtually has stopped and storage without any change or degradation is possible for centuries if not millennia.

Right Picture: Previously vitrified brain after rewarming later subjected to extensive electron microscopic examination, showing that near perfect ultrastructure was preserved.  Source: 21st Century Medicine / can also be accesses at BPF here.

As the two leading think-tanks and scientific networks in cryonics we have put together this brief, with  more information and our perspectives on what this important breakthrough means and does not mean for cryonics. ​

The Case for Field Cryoprotection

The last major technological innovation at Alcor was vitrification (cryopreservation without ice formation). Viability assays of brain slices and electron micrographs of brains cryopreserved with vitrification solutions show substantial improvements over the older cryopreservation protocols. But this was almost 20 years ago and it is time for another technological innovation that will improve patient care. I want to suggest that the strongest candidate for such an innovation is to introduce field cryoprotection for all Alcor members.

Field cryoprotection aims to close the gap in outcome between patients that are pronounced legally dead in the Scottsdale area (where Alcor is located) and patients that are pronounced legally dead in other US states by conducting the cryoprotective portion of Alcor’s procedure prior to transport to Alcor.

Currently the procedure would be to deploy a standby team to the patient’s bedside, start rapid cooling and cardiopulmonary support, replace the blood with an organ preservation solution, and then ship the patient to Alcor for cryoprotection and long term care. Those organ preservation solutions have been designed to counter the adverse effects of cold ischemia but are from for perfect. After about 6 hours of cold ischemia, the brain is rendered non-viable (no EEG can be recovered). Electron micrographs of mammalian brains show that the fine ultrastructure of the brain degrades in a time-dependent manner and blood vessels start to leak. As a general rule, when a patient is shipped to Alcor by air transport the blood brain barrier of the patient has been compromised, which can lead to swelling of the brain during cryoprotection. In whole body patients, substantial abdominal swelling during cryoprotective perfusion occurs, despite remote blood washout.

The good news is that preventing these outcomes does not require novel scientific breakthroughs but a simple commitment to eliminate shipment of patients on water ice in favor of doing field cryoprotection and subzero cooling in the field instead. This procedure is named “field cryoprotection.”

The reason why we call it “field cryoprotection” instead of “field cryopreservation” (or “field vitrification”) is because the patient is not cooled all the way down to liquid nitrogen temperature. While this is theoretically possible (and desirable), the logistics of this procedure are too demanding at this point. So instead of cooling the patient to liquid nitrogen temperature (-196° Celsius) the patient is shipped to Alcor on dry ice (-78.5° Celsius) where further cooldown begins. Research supports this is a safe temperature for shipping patients, provided stabilization and cryoprotection procedures are done timely and competently. From the patient’s perspective the advantages include minimization of cold ischemia, preservation of integrity of the vessels and blood brain barrier, and, under good conditions, cryoprotection can start when the brain is still in a viable state.

One of the most remarkable aspects of making field cryoprotection the default option for all eligible patients is that it does not just improve patient care but reduces cost as well. Right now, for non-local cases Alcor needs to deploy a team consisting of surgeons and technicians twice. Once at the patient’s bebside and later again at Alcor for cryoprotective perfusion. Field cryoprotection would eliminate this double employment in favor of one single deployment at the patient’s location. As a consequence, remote stabilization costs will go up but Alcor HQ costs will be basically eliminated except for a small cooling expense. This should allow for a non-trivial
decrease in costs per case, which can be passed on to the member in the form of lower cryopreservation costs or can be used to eliminate or decrease future increases.

During the last couple of years Steve Graber and Hugh Hixon have collaborated to improve neuro field cryoprotection technologies and the gap between conducting cryoprotection in Scottsdale or “on the road” has increasingly been closed.

Field cryoprotection procedures are currently only available to neuro members (or for whole body members who agree to neuro-cryoprotection only) but various approaches are currently being discussed to extend this technology to whole body members, too.

Field cryoprotection constitutes the next big step in cryonics. Currently only overseas members can benefit from this procedure but the time has come to cautiously extend this procedure to more members.  Eliminating water ice shipment in favor of field cryoprotection will be need to be incremental and closely evaluated but the patient care and cost advantages are evident.

Originally published as a column in Cryonics magazine, November -December, 2017