Methods of treating the prostate include administering a thermal ablation therapy and inhibiting the obstruction or closure of the prostatic urethral opening by forming a biodegradable stent in situ in the subject such that the stent attaches to the walls of the prostatic urethra. A related method of treating BPH includes thermally treating or ablating localized tissue in the prostate with a treatment catheter and inserting flowable stent material via the treatment catheter into the prostate (either before, during, or after the thermal treatment), forming the flowable stent material so that it defines a stent that remains in position after removal of the treatment catheter to inhibit the closure of the urinary passage. Associated stents and catheters are included.