CASA Avmed – In my opinion, a biased, intellectually dishonest regulator

[Nowluke]

To clarify, a specialist is a post graduate fellowship in a relevant discipline. Aerospace medicine specialists are denoted by the post nominals FACASM in Australia, the lesser post graduate qualification being a diploma in aerospace medicine, generally from the UK and generally held by (ex) military doctors; NZ also has a program and some Aus universities have started up equivalents to a lower post grad level. It also generally a secondary speciality after general practice, general surgery etc. There would be 10 or fewer surgeons in Aus with the qualification. It, like all specialties, takes several years and has an examination process. The other end of the scale has a number of 6-12 week courses to become a DAME, this is the minimum amount of training to provide some occupational context for clinical advice to be placed in alongside regular professional development. I don't know what mix of these differing skillsets CASA has.

It's obvious you feel strongly about your issues but you do yourself a disservice and practice the same alleged selective use of facts in how you're going about engaging on this. Repeatedly you choose very limited aspects that support your narrative to the cost of your credability here.

As previous, the absolute gold standard for your condition would a meta-analysis of a number of long term follow up studies in aircrew to determine your risks. The opinion of a "specialist" is the lowest evidentiary weight in clinical decision making. Brandishing your supporting narrative and and then claiming that it 'proves' you're cured and thus now at baseline risk is meaningless in the context of the decision being made. All it does is demonstrate, at a single time point that you remain at the baseline risk of your clinical cohort- not back to the standard. You may indeed be theoretically 'fit to fly' on that day and the next but nowhere has it been addressed, in what you put forward, in a comprehensive way, with clear clinical research based evidence.

It is churlish to suggest you have not undergone surgery in the broader sense, an endovascular procedure is of the same nature as keyhole surgery or imaging guided interventions. Generally, they have more positive results (quicker recovery, less infections etc), hence the trend towards them. However, just because no one has opened your skull and put a scalpel in does not mean you no longer fall under the post operative precautions and physiological changes that are universal to all physical interventions to anatomical structures. A change was made and hopefully you are now at lower risk of an event but it is not a stochastic on/off; yes/no change with an absolute outcome.

You again attempt to shape your narrative around “it wasn’t my/in my brain” therefore the rules don’t apply. It’s the circulation to the sac your brain sits in, both are dependant on blood from your neck and spine and the same endovascular access techniques are used. A poor outcome to your treatment will absolutely affect the function of your brain.

The high value you continue to place on your limited ‘specialist’ opinions on fitness to fly has not been situated anywhere up the clinical evidentiary scale. It remains the very lowest evidentiary (in the clinical, not legal) basis to assess your risk. There is large body of work on neurovascular, neuro-malignancy and head trauma that underlies the position for having a post incident/intervention 12 month assessment period. I devalue them even further when the absolute statements along the lines of “no risk of incapacity” and “100% success” are made by your treating doctors. They have misspoken grossly and not provided an accurate assessment of your risks; at best a statement of short term resolution can be drawn from them and some further extension into the medium term from your imaging. Again, it forms a foundation for long term success and risk reduction but it does not allow you to then infer this off into 1-2 years into the future.

Unfortunately, my position is somewhere approaching the objective one. If there is no higher research on your risks then it does become a case of trumps. Until you (or your supportive specialists) start dropping things like :

Link, M. J., Coffey, R. J., Nichols, D. A., & Gorman, D. A. (1996). The role of radiosurgery and particulate embolization in the treatment of dural arteriovenous fistulas. Journal of neurosurgery, 84(5), 804-809.

and quoting out the long term risks and rates, you’re not even on the playing field (note this is not applicable to you, just a very proximal cohort using a different process). That they have not done this is a big issue in any serious consideration of your concerns.

The position you’re in of apparently insurmountable standards is just that, insurmountable, you logically cannot provide proof of a negative prospectively. You no longer met the standard, the current gold standard relevant clinical research defines the guidelines and no amount of single point in time imaging will change the fundamental hazard that underlies the ‘waiting period’ - esp. when your question of fitness to fly is in it’s full context - i.e. the 1/2 year licence period.

To its extreme, it will end up the case that at day 364 you remain not fit and then the next day, through administrative magic, you then are. Unless you can create the body of knowledge to change the gold standard position i.e. a number of longitudinal clinical studies on endovascular repair of AVM of your type in aircrew using your technique and compound then you’re going nowhere fast, no amount of letters from a procedural specialist will change that. There is a vast difference in your apparent clinical ‘fix’ and returning, with evidence, to the standard.

As andrewr said it may even be the case you no longer meet basic class 2 as well. Vis Austroads the non-driving for intracranial procedures is advisory only; non-driving periods may be varied by the neurosurgeon - this may be applicable to the basic class 2 but I would say CASA may/may not align with this.

You've taken repeated umbrage and described it as dishonest when terms like significant and high etc are used. It is a shorthand for the rate of unacceptability at which the hazard is realised when an appreciation of the condition in the environment is made with respect to the standards acceptable within the safety management system. This rate is whatever is set by the regulator and it is the best that can be made with the scientific, not single expert, knowledge available and it will change over time. And people will disagree with it.

I don’t want to engage in some giant internet forum battle over this. I only responded initially as you were very vocal along a narrative that was fundamentally incorrect from a (my) clinical aeromedicine view. I don’t care about your CASA dealings or the administrative parts as the root cause has been the failures of communication with you by your treatment team and the lack of understanding of aeromedicine. My position may even be incorrect as in the future the evidence I spoke about will come into being, it could even exist now. Although you would not be in this position were that the case.