Dave, if your doctor doesn't know Rituxan should be given at least 12 weeks to work before trying something as drastic as surgery, you may want to get some other opinions on the matter. It's not time yet. Just so you know.
I'm 69 now; was 58 at diagnosis. In the first few years, I had no less than 8 doctors - one a university-based platelet disorder specialist and others of various unrelated specialities - pushing me to have my spleen removed so that I'd "be cured". I'm a bonafide surgi-phobe, so didn't want to do it for that reason mostly. But I've also done my homework about the procedure and discovered it's by no means a slam dunk cure, nor have the odds of success changed from time immemorial. Splenectomy works about 66% of the time, but only 40% or less in people over 60. It works most often for people under 40. Some years ago, I found an informal poll taken on a social media site by people who'd had one. I made my own chart of how many it worked for, how many it didn't. It came down to just about the same odds as professionals give. It only worked temporarily for several. Interestingly, many people for whom it failed didn't really regret their choice, but they tended to be younger, active people who didn't have time to waste being sick. Since their odds of success were higher, it probably wasn't a bad idea to try. I may have done it myself if I'd been at child-bearing age. Woulda-coulda, you know?
For less than a 40% success rate, the surgery itself is too risky for my taste. Clots, bleeding, infection, anesthesia problems... name it... and the complication rate is much higher for older people.
If you read the site's page on the pros (few) and cons (considerable) of the procedure, it may help you make up your mind. It did for me.
Here's the link ~ pdsa.org/splenectomy.html
For what it's worth, I've been on NPlate for about 3 years. No problems. I recommend you consider it or Promacta before parting with a healthy organ your body still needs for doing good things.
Good luck with whatever decision you make.