I hope (and very much doubt) that your recovery will not turn in to something like mine, but just a heads up, perhaps: I had a liver resection done in 4/10, and the incision went from one side of my rib cage to the other, then up my sternum, so maybe it was about 25-28" total. I had the same trouble initially that you are describing, but I don't think mine was ever more than about 3.5 cm deep (that's how far it was from my skin to my fascia). Stuff was draining out and eventually over the course of a couple of weeks they had to open the entire incision. Then I had a (nightmare) wound vac for quite a while (I can't remember how long now) and that thing drained about 600 cc of pus every day (but the infection, amazingly, was always localized...I was never given any antibiotics for it) There was tons of tunneling, and the tissue growth, despite the wound vac, was very slow. Eventually, about 2 months after the liver resection they took me back to the OR and re-opened the whole mess back to the fascia because there was so much tunneling going on just superior to the fascia. Once they did that, they acknowledged that it NEVER would have healed without doing so. At that point, I went to wet-to-dry dressings twice a day, every day, and the incision never fully healed until mid-October or early-November (ie 6-7 months). The scar is hideous (but who cares,I lived through it
All this is just to point out that 10 cm is a LONG way to heal. While the wound vac didn't work for me, it might work for you, it reportedly work spectacularly for many people and perhaps you'd want to ask your wound nurse about it.
Why what happened to me almost certainly won't happen to you:
1) I have had type 1 diabetes for 48 years, and that has a big impact on would healing
2) I was incredibly ill at the time of my liver resection, very malnourished from months of nausea, and had very low serum protein levels (further impeding would healing)
3) My home care nurse really had no idea how to work with the wound vac, and didn't know enough to ask for help, nor did I know enough to realize she needed help. She actually created much of the tunneling by poking around under the new tissue.
At any rate, I hope you will heal very quickly. Try to keep your protein intake crazily high, as your body needs tons of protein while you are recovering from surgery, you also need a lot of spare calories. This is just my personal opinion (and not medical advice) but it seems to me like getting this repacked every couple of days might not be enough. The act of removing the old packing debrides the wound (ie removes old tissue that MUST come out to promote the growth of new tissue) and I wonder if you might heal more quickly if the packing was exchanging/replaced more often? JMHO.
Best wishes as you continue to recover from your surgery.