Hi all
In a mechanical thrombectomy, we try to declog an artery through device passes. You do one pass. If it works, you had a successful procedure. If it doesn’t, you have the option to 1) stop, which is not desirable and not frequent in the beginning; 2) try again; or 3) use a rescue strategy that is very effective in declogging, but very aggressive, with a higher risk of complications and a huge long-term burden for the patient.
Our team wants to define the optimal time for using the rescue strategy - how many times should you try the conventional strategies before rescuing?
The outcome is the clinical state of the patient after three months. We have a huge observational database with granular procedural data, including the strategy and response per attempt.
I would probably approach this through a per-pass comparison (e.g., for the second attempt, compare patients who got rescue therapy versus who did not, with the appropriate covariate adjustments), but I wonder:
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Whether that helps me define the optimal timing (after how many attempts) for rescuing or if it would only show me that the benefit eventually decreases over time;
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If the fact that patients without success in a given attempt would be included in the further can be problematic somehow;
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If I should ignore whether the patient underwent rescue therapy after the 3rd, 4th, 5th… pass when in the control group (new pass with conventional strategy) for the second pass.
This per-pass approach seems sound to me, but I have a feeling that it’s not the best way to address this question. I am also thinking about estimating the outcome distributions given each moment, strategy and a fixed set of covariate values and compare these estimates, but the overlap mentioned in (2) makes me question whether this would be appropriate.
An approach that could handle data from multiple passes at once and provide a more straightforward answer like “Changing after X failed attempts is the way to go” instead of “The benefit of rescuing decreases this way over time” would add a lot to this project. Is there any method you would recommend to address this question? I’d also appreciate references or examples of articles with similar scenarios.
Thanks in advance