It is really too bad it got dragged out. A lymphocele is one of the known risks after RARP, if samples of lymph nodes are taken. You would think that would be the first thing to come to mind for a urologist, or even another MD after knowing you had RARP surgery.

"A lymphocele is a collection of lymphatic fluid in a body cavity, typically occurring after surgery or trauma that disrupts the lymphatic system. A lymphocele forms when lymphatic vessels are damaged or disrupted, causing lymph fluid to accumulate in a space within the body that is not lined by epithelium, unlike a true cyst or tumor (Wikipedia). It is most commonly seen after surgical procedures such as pelvic lymph node removal..."

My surgeon explained that when they remove lymph nodes during a RARP, they do not cauterize them or sew them shut. I envision a garden hose waiving around spewing lymph fluid. Normally the lymph fluid keeps draining and does not form a pocket. Some surgeons install a drain after surgery, mine does not. So, in my case lymph fluid built up in a pocket in my abdomen, started crushing my bladder (and some nerves) and got infected. By your description it sounds like the same happened to you.