Hi again Kate,
With no given time for surgery dates, the charts can't really offer any info. regarding 'the moment'.
I am therefore looking at transits to the natal chart for the dates concerned (if they don't change yet again!!).
Although using Western astrology and the Placidus house system, I had similar thoughts to Shanti that surgery dates showed no negativity from my personal p.o.v. NO date(s) are ever going to give a perfect picture because of emotional and nervous strain at the time.
Tr. Moon is in the positive sign that deals with health. Although it squares the 8th house (surgery) natal planets, as well as tr. Mercury on 8th house cusp, this could be considered the natural state of worry and nerves that all will go well, that accompanies any major surgery. Mercury in Pisces could represent the loss of (mental)consciousness and comatise state through applied anaesthesia during surgery, also natural.
What I find encouraging is that transit Saturn (structured substance) makes no adverse aspects to the chart. Transit Uranus (vertebrae) has finally entered and settled in stable Taurus, which it no longer leaves through any retrograde motion. Tr. Uranus (change through re-formation) semi-squares natal Sun (spinal column) in Pisces in 8th, and positively aspects natal Saturn(physical structure, bones) in the 1st house, that is ruler of the 6th house chronic, long term issues). Both houses are concerned with the physical condition. Uranus could well 'break the mould' of fixity of so long. Perhaps the surgeon (Uranus rules 7th house) will introduce a new technique regarding your complaint?
Transit Neptune will conjoin natal Sun-Mars over a period of time, which will hopefully offer aid in reducing pain through one means or the other.
Transit Pluto shows no cooperation before retrograding. Yet its next aspect when going direct again and crossing 6th house cusp is the positive conjunction with natal Jupiter begin 2020. I would hope for you that this means a finalisation of what once was, and the transition and trans-formation of health issues creating a new way of life.
It must be said that so much depends upon your own mental and spirit of mind in the coming period. Keep the Faith and try to think positive.
Good luck to you.