Approaches to achieving radical life extension involve many scientific unknowns. There is uncertainty around whether the different forms of aging damage can be repaired. There is an approach to immortality that replaces scientific unknowns with huge technical challenges.
The technically challenging approach is:
1. Rejuvenate the body by growing a body using an egg cell gene edited to not grow the brain
2. Transfer the rejuvenated brain to the rejuvenated body
3. Connect the brain and restore the spinal cord
4. Rejuvenate the human brain through 6-10 surgeries that each replace 10-16% of the old brain with new young grown brain tissue
The brain surgeries for rejuvenating the brain would be done over 20 years. The brainless body would be grown over about 15-18 years and would need to be on constant life support. The brain surgeries would be causing intentional and planned major strokes which would require recovery, restoration and therapy. Repairing the spinal cord and other problems associated with the brain transfer are discussed in detail in the following paper.
Critical to the success for achieving the end goal (a form of physical immortality) is full recovery from the intentional induced major stroke surgeries and maintaining the identity and personality and consciousness of the individual.
The brain rejuvenation surgeries and processes is discussed at this article and this article which both have videos.
Whole brain transplantation in man: Technically feasible (2022, Sergio Canavero, Surgery Neurological International)
This concept of a brain transplant is an advanced plan based on Dr. Canavero’s who has previous experience with acute spinal cord repair. Canavero and others have proven spinal cord repair in animals from rats to cats, dogs, and monkeys. That work was never believed possible until Dr. Canavero assembled a team of scientists worldwide to solve the many aspects of that achievement. The work was based on a fundamental misunderstanding of the mechanisms involved in spinal neuron regrowth. His revelation that the short neurons regrow to re-establish primitive motor pathways present in species from their origins is a breakthrough in science.
Now, Dr. Canavero is challenging science and humanity with the possibility of a brain transplant. Kidney, liver, lung, hand, heart, and face transplants have all been done in the late 20th century. Yet, the scientific success was delayed in these major advances by the emotional, ethical, and religious objections which were raised. This project of a brain transplant will not doubt undergo similar criticism. Yet, the scientific question remains as to whether such a transplant can be achieved.
BRAVE, the BRain Anastomosis Venture is part of a larger scope project – PERSEUS – that aims at moving an old brain into a young immunoconditioned body (or a nonsentient clone tout court when this becomes available) and kick off rejuvenation of the brain, as afforded by Progressive Brain Replacement (J Hebert, accompanying editorial).
Challenges of Brain Transfer:
1. Impossibility to extract the brain proper from the dura mater, given the intimate relationship between the brain’s venous and cerebrospinal fluid (CSF) outflow and the dural cranial sinuses
2. Impossibility to resuture the internal carotid and vertebral arteries (ICAs/VAs) and the internal jugular veins (IJV) once the brain is laid on the donor’s skull base
3. Lack of an efficient technology to functionally reconnect the 12 pairs of cranial nerves
4. Lack of a technology to reconnect the severed spinal cord
5. Undetermined neuroprotective measures to deploy between the moment of physical separation of the brain from R’s skull and re-establishment of circulation after positioning on D’s skull base
6. Possible immune rejection if BT is carried out on a heterologous body rather than R’s clone.
The last three points are covered elsewhere.
* the spinal cord – once sharply severed – can be functionally reconnected in primates (GEMINI protocol: Fully reviewed in Canavero and Ren)
* Brain protection through profound hypothermia has been demonstrated by Dr. White 50 years ago in primates and more recently confirmed in China. Other techniques can boost hypothermia’s effects. The brain is a partially immunoprivileged organ.
* Brain Transfer on a clone would not require immunosuppressants. Tolerogenic protocols are being developed that may be tapped for heterologous brain transfers.
The Brain is Transplanted Along With the Dural Sac
Sparing the dural venous sinuses along with all the veins and arachnoidal granulations is currently unachievable. Besides, the subdural circulation of CSF would be totally disrupted. The solution is transplanting the brain inside the dural sac.
Briefly, both individuals are trachetomized and ventilated and installed in the upright position. Heads are secured on both sides with a fixation apparatus adapted from the maxillofacial equivalent and centered on the mastoids. A standard fixation is of course to no avail given the wide dural exposition necessary for a BT and the associated ultraextensive craniectomy.
Predicated on the complete expendability of R’s body, the approach in R starts with a nasion-C7 spinous process linear incision followed by full thickness scalping of the head down to the orbital ridges. The skull cap is removed in standard fashion, with multiple burr holes on the two sides of the superior longitudinal sinus and other holes, including along the basal circumference. A standard wide craniectomy frees the cerebellum.
As R’s brain encased in its dura (hypophysis included) is being freed from the cranial vault and base, a robotic scoop with retractable tines is brought into the operating field. This envelops the brain and supports it as the dural detachment proceeds, and facilitates the final transfer onto D.
Vascular Reconnection
BRAVE requires a rapid restart of the circulation to R’s brain. However, anatomical (in particular, the highly constrained surgical space of the cranial fossae) and technical considerations[3] rule out standard manual sutured anastomosis of neurovascular structures. Instead, BT exploits sutureless vascular anastomosis (SVASTOM).
A pretransplant angiography in both R and D is mandatory to assess the entire vasculature, including anatomic variations.
Cranial Nerve Reconnection
Similarly to vascular reconnection, sutured anastomosis is ruled out for cranial nerve reconstruction. Besides the constrained operative space, microsuturing cannot reestablish cranial nerve function rapidly, being exclusively dependent on regeneration. In addition, microsuturing is traumatizing to the nerve (reviewed in De Medinaceli). It goes without saying that BT is acceptable exclusively under condition that rapid recovery of neural transmission ensues. The patient is expected to emerge from post transplant-induced coma with cranial nerve function already present or rapidly recovering. Neural fusion (NF) and sutureless nerve anastomosis (SNATOM) aim at solving this problem. NF would reestablish immediate transmission of electrical impulses, while SNATOM firms up the coaptation.
Importantly, R’s and D’s cranial nerves are severed beyond the actual point of final connection so that any Wallerian degeneration that usually starts within minutes of section is offset by severing the initially degenerating extra-length once the brain has been placed on D’s skull base and fusion initiated (see in Canavero and Ren).
Rodent studies show that, at least for healthy sciatic nerves, stretching up to 30% is not harmful: this is important for surgical maneuvering .
All cranial nerves have less than 100,000 axons each, with the optic nerve being the outlier (1,200,000 fibers).
Unless performed in a clone, variation of the diameter of cranial nerves must be assessed with high-resolution MRI before BT in D.
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
Known for identifying cutting edge technologies, he is currently a Co-Founder of a startup and fundraiser for high potential early-stage companies. He is the Head of Research for Allocations for deep technology investments and an Angel Investor at Space Angels.
A frequent speaker at corporations, he has been a TEDx speaker, a Singularity University speaker and guest at numerous interviews for radio and podcasts. He is open to public speaking and advising engagements.
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