Material removed by a debulking catheter from a body lumen can be preserved. Materials can be collected from many different patients and/or from multiple procedures on individual patients. Data which describe the properties or qualities of the removed material and/or the patient and/or the patient's family or environment can be stored on computer readable media. The stored data can be used to draw correlations, to stratify groups of patients, to provide risk assessments, to provide diagnoses and/or prognoses. Further tests can be done on the stored materials at later times after the procedures have been completed.