A vesical pressure measurement system is provided. One or more elements of the system are operably combinable with a previously deployed urinary drainage catheter. The system includes a urodynamic data system and a urinary drainage catheter balloon adaptor. The data system is characterized by a pressure sensor for vesical pressure measurement, and a processor/controller for receiving, processing and/or displaying select urodynamic patient parameters comprising sensed/monitored pressure data. The adaptor operably unites the pressure sensor of the data system to a balloon inflation valve of the catheter. The adaptor includes an adaptor valve for connection to the balloon inflation valve, and a housing, the housing including a balloon inflation valve portion and an adaptor valve portion, the portions urgingly uniteable in furtherance of establishing and maintaining a secure interface between the balloon inflation valve and the adaptor valve.