Results of a 5-year multicenter trial of a new generation cooled high energy transurethral microwave thermal therapy catheter for benign prostatic hyperplasia.

PURPOSE: We determined the safety, effectiveness and 5-year durability of the new generation, cooled, high energy microwave treatment Cooled ThermoCath® catheter with the Targis® cooled high energy transurethral microwave thermal therapy system by performing a prospective, multicenter trial in men with lower urinary tract symptoms and clinical benign prostatic hyperplasia. MATERIALS AND METHODS: At 5 American centers a total of 66 men were treated with the catheter at a 28.5-minute session. Patients were taught self-catheterization after treatment. They returned after 1 and 6 weeks, 3 and 6 months, and annually for 5 years to assess the American Urological Association symptom score, uroflowmetry, quality of life, Symptom Problem Index, Benign Prostatic Hyperplasia Impact Index, treatment satisfaction, adverse events and need for re-treatment. RESULTS: Average treatment duration was 29 minutes. Of the 66 men 33 (50%) required no posttreatment catheterization of any kind, 25 (38%) used intermittent self-catheterization and 8 (12%) required indwelling catheterization with or without self-catheterization. No acute retention events were reported after the initial catheterization through 5 years. No serious adverse events were associated with treatment. Traditional efficacy measures showed highly significant improvement from 6 weeks and thereafter (p <0.001). A total of 19 men (29%) underwent additional medical or surgical benign prostatic hyperplasia related treatment at some time during the 5-year followup. Six men (9%) underwent surgical benign prostatic hyperplasia related treatment. At 5 years 40 of 51 men (78%) reported satisfaction with benign prostatic hyperplasia treatment. CONCLUSIONS: Cooled, high energy transurethral microwave thermal therapy using a new generation treatment catheter produced safe, durable, clinically relevant results in men with lower urinary tract symptoms caused by benign prostatic hyperplasia for 5 years after treatment with acceptable medical and surgical re-treatment rates.

Control of breathing in in vitro brain stem preparation from goldfish (Carassius auratus; Linnaeus).

In vitro brain stem preparations from goldfish (Carassius auratus) were used to first determine whether this species possesses central chemoreceptors able to modulate respiratory activity. Preparations were superfused with an artificial cerebrospinal fluid (aCSF); fictive breathing was recorded extracellularly by placing a suction electrode on cranial nerve VII. Reducing the level of O2 in the gas mixture used to bubble the aCSF from a hyperoxic level (80% or 98.7% O2) to a relative hypoxic level (20% or 40% O2) increased the frequency of the fictive respiratory burst (P = 0.0002). Reducing the pH of the aCSF from 7.9 to 7.4 by increasing CO2 in the superfusate did not affect fictive breathing. Chloride-mediated neurotransmission (GABA/glycine) is a major modulator of respiratory activity; however, its effect on the neural circuits that regulate breathing in teleosts remains unknown. Bath application of GABA (0.5, 5.0 mM) decreased burst frequency but not amplitude; this effect was dose dependent (drug × concentration: P = 0.01). Superfusion of the preparations with aCSF containing 1.25 µM of bicuculline methochloride and 1.50 µM of strychnine hydrochloride (GABAA and glycine receptor antagonists, respectively) increased burst frequency (P = 0.002) and amplitude (P < 0.001). We conclude that respiratory activity produced by the goldfish brain stem is not responsive to the moderate CO2 levels used in this study; it may contain O2 chemoreceptors, but the relatively small response could also reflect nonspecific effects of hypoxia on the central nervous system. Cl(-)-mediated neurotransmission inhibits fictive breathing; this aspect of respiratory regulation is similar to other groups of vertebrates.