A radiofrequency method of thermal tissue ablation for benign prostatic hyperplasia

Bhanot, Shiv; Grigor, Ken; Hargreave, T. B.; Chisholm, Geo. G.

doi:10.1016/s0090-4295(99)80011-9

Cited by 12 publications

(3 citation statements)

References 14 publications

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“…The power density source term qv in the above heat-transfer equation is comprised of contributions from any externally applied power source qa and the internal power generation term qm secondary to metabolic effects within the tissue: <7v = qa + qm (2) The metabolic power generation term qm in the above equation is normally on the order of 1000 W m~3 (1 W kg1) for the resting physiological state. This is about two orders of magnitude smaller than the external power deposition qa obtained through external sources in most clinical applications and thus can be neglected by comparison for most practical purposes.…”

Section: Discussionmentioning

confidence: 99%

Transurethral Prostate Ablation Using Saline-Liquid Electrode Introduced via Flexible Cystoscope

Hoey

Dixon²,

Paul³

1998

Journal of Endourology

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An interstitial saline-electrode has been developed to couple radiofrequency (RF) energy to prostate tissue in order to produce large lesions quickly and controllably. In this study, we attempted to produce similar results using a flexible catheter introduced transurethrally via a flexible cystoscope. An insulated 4F catheter with an extendable needle electrode (26-gauge, 5-mm exposed metal tip) was introduced through a port of a flexible cystoscope into the urethra of 10 dogs via a small perineal incision (required for the canine U-shaped urethra). Under visual endoscopic guidance, the electrode was placed in the center of the prostate and the needle electrode extended at an angle into the prostate, one lobe at a time. Hypertonic saline (14.6% NaCl) was infused at 2 mL/min through the needle electrode into the tissue for 30 seconds before and during RF application. The energy (50 W, 475 kHz) was delivered for 30, 45, 60, or 90 seconds (RFT System; U.S. Surgical Corporation). Prostate and urethral temperatures were monitored using thermocouples mounted on the catheter. There was an automatic high-temperature shut-off if the urethra reached >42 degrees C or if impedance reached >300 omega during RF energy application. Prostate sizes ranged from 1.4 x 2.0 x 1.4 cm to 5.0 x 4.5 x 4.2 cm. In this group, there were no automatic shut-offs at any of the energy durations, and the lesions produced ranged from 1.3 x 1.3 x 1.1 cm (0.99 cm3) to 1.6 x 2.7 x 2.2 cm (5.03 cm3). The average ablation volumes produced were 1.76 cm3 at 30 seconds' RF application, 2.42 cm3 at 45 seconds, 3.96 cm3 at 60 seconds, and 5.03 cm3 at 90 seconds. Histologic examination revealed typical coagulation necrosis in the treatment zone without tissue desiccation. Introduction of the saline-electrode through a flexible cystoscope provides a minimally invasive procedure that quickly and controllably produces large lesions that may provide effective treatment for benign prostatic hyperplasia with less patient discomfort.

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Section: Discussionmentioning

confidence: 99%

Transurethral Prostate Ablation Using Saline-Liquid Electrode Introduced via Flexible Cystoscope

Hoey

Dixon²,

Paul³

1998

Journal of Endourology

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“…Most new treatments are still in the process of investigation. Yet despite only short-term results, uncertain patient selection criteria, and often unknown mechanisms of action, men throughout the world are being treated by drugs, microwaves, transurethral radiofrequency therapy (TURF), transurethral needle ablation (TUNA), high-intensity focused ultrasound, endoscopic laser therapy, or prostatic vaporisation [Berges et al, 1995;Bhanot et al, 1995;Gillenwater et al, 1995;Kabalin et al, 1995;Schulman and Zlotta, 1995;Schulze et al, 1995]. As a result, the so-called gold standard, transurethral resection of the prostate (TURP), is used less often than hitherto [Lu Yao et al, 1994].…”

Section: Introductionmentioning

confidence: 99%

“…The only way to define the role of each therapy is to quantify the effect of treatment on symptoms, prostatic morphology, and urodynamically defined obstruction. The assessment of each technique, on the basis of symptomatic improvement alone, has proved to be unsatisfactory because nearly all established and new treatment modalities show similar improvement in symptoms [Berges et al, 1995;Bhanot et al, 1995;Cowles et al, 1995;Dahlstrand et al, 1993;Gillenwater et al, 1995;Kabalin et al, 1995;Schulman and Zlotta, 1995;Schulze et al, 1995]. Symptoms associated with enlargement of the prostate do not correlate with either BOO or prostatic size at baseline and therefore cannot be used as a surrogate for the objective measurement of voiding dysfunction [Bosch, 1995;Bosch et al, 1995;Ko et al, 1995;Nitti et al, 1994;Rosier and de la Rosette, 1995;Van Venrooij et al, 1995;Yalla et al, 1995].…”

Section: Introductionmentioning

confidence: 99%