TransUrethral Needle Ablation of the Prostate (TUNA): Clinical Results and Ultrasound, Endoscopic, and Histologic Findings in Pilot Study of Patients in Urinary Retention

Abstract

Transurethral Needle Ablation of the prostate (TUNA) is a new thermal ablation treatment for benign prostatic hyperplasia (BPH) utilizing radiofrequency electric current delivered by needles into the depth of the prostate to produce an area of coagulative necrosis. A pilot study of 10 patients in urinary retention was undertaken to assess the procedure. After treatment, nine patients voided at a median time of 3 days, although a further two required transurethral resection because of chronic infection in one and chronic urinary retention in the other. At 3 months' follow-up, the mean Qmax was 13.0 mL/sec, the mean AUA Symptom Score was 9.1, and the mean quality of life score was 1.6. The mean Pdet fell from 73.3 to 39.0 cm H2O. On transrectal ultrasound at 3 months, cystic lesions were seen in two patients, with a third having large cavities. A 10.2% reduction in mean prostatic volume, from 48.8 cc to 43.8 cc, was noted but considered to be not significant. On endoscopy at 3 months, mucosal retraction was seen in seven patients, with cavities in two patients. Histologic study in patients undergoing transurethral resection 4 to 6 months after TUNA showed necrosis and fibrosis. It is considered that an area of coagulative necrosis is produced by TUNA that resolves either by scar formation with retraction or by liquefaction with cyst formation. If the lesion communicates with the urethra, a cavity may form, which is undesirable. Our early experience is encouraging. The TUNA treatment is effective, can be given without anesthesia, and should be either a day case or an office procedure. It should prove to have a significant place in the treatment of BPH.

Treatment of Benign Prostatic Hyperplasia through Transurethral Needle Ablation (TUNA^TM)

“…This observation is supported by the investigations of Harewood et al [27] who have treated 10 men in retention with TUNA. After 6 months, 8 out of 10 patients could void satisfactorily.…”

“…After 6 months, 8 out of 10 patients could void satisfactorily. Two patients had to undergo TURP: one due to an acute prostatitis, the other due to persisting subvesical obstruction [27].…”

Transurethral Needle Ablation (TUNA^TM)

“…Decrease or absence of staining for PSA, smooth muscle actin, stroma, neural tissue, alpha adrenergic and nitrinergic receptors are evident in the ablation lesion [23, 24]. The nitric oxide synthase (NOS) receptors are most vulnerable to thermal damage following the TUNA treatment as evident by the complete lack of their immunohistochemical staining within the initial hours [23].…”

Transurethral needle ablation of the prostate

“…Significant subjective improvement was found in early studies: the International Prostate Symptom Score halved after 6 months and flow rate increased by an average of 50%; positive results were then confirmed in other clinical trials [2][3][4][5]. TUNA was also tested in the management of patients with an indwelling catheter for acute or chronic urinary retention with favourable results [6,7]. Urodynamic investigation of TUNA treatment failed to show a clinically relevant improvement of voiding dynamics [8].…”