Long-Term Follow-Up of Patients with Intraurethral Prostheses

Development of a rapidly computable descriptor of prostate tissue temperature during transurethral conductive heat therapy for benign prostate hyperplasia

Benign prostate hyperplasia (BPH) is a condition in older men in which the mass of tissue in the prostate gland gradually increases over the course of many years, ultimately leading to urinary outflow obstruction. Current treatment of this condition is to surgically remove the obstructing tissue. One novel alternative therapy being studied is transurethral thermocoagulation of excessive prostatic mass. In this approach, a heat-emitting catheter is placed in the prostatic urethra, and the intraprostatic segment of the catheter is heated to temperatures above 60 degrees C for one hour. Two-dimensional cylindrical-co-ordinate computer simulations of this treatment modality were run to model resultant temperature distributions within the prostate gland and surrounding tissues. The simulations revealed that resultant tissue temperature changes were related directly to the power delivered to the catheter and inversely to the rate of blood perfusion. Further analysis of the temperature profiles produced a rapidly computable predictor of tissue temperature in the radial dimension. Using the predictor, a 'kill radius' around the prostatic urethra can be easily computed on-line, during treatment, from clinically available data, catheter power and catheter temperature. The computed kill radius may serve as a useful predictor of the extent of thermal devitalization of unwanted obstructing tissue and the long-term success of the treatment in relieving urinary outflow obstruction without surgery.

Interventional radiology of the lower urinary tract and its relationship to surgical treatment

Interventional radiological techniques of the lower genitourinary (GU) tract are large and varied and continue to expand because of technological advances and also because budgetary restraints are being placed on our medical society. This has stimulated continuous search for alternative ways of treating disease in a more cost-effective fashion. As a result, there has been an overall decrease in morbidity and mortality, as well as postprocedural incapacity. We review the most important and newest modalities and provide some background of the processes affecting the lower GU tract.