Second-gen implantable nitinol device delivers sustained relief of LUTS

In men with lower urinary tract symptoms (LUTS) due to benign prostatic obstruction (BPO), temporary implantation of the second-generation nitinol device (iTIND) produces marked and durable improvements in symptoms and quality of life, as shown in a study.

International Prostate Symptom Score (IPSS), quality of life (QoL), and maximum urinary flow rate (Qmax) changed from baseline by −46 percent, −44.5 percent, and 84 percent (p<0.0001 for all), respectively, over 3 years of follow-up. [Prostate Cancer Prostatic Dis 2021;24:349-357]

The investigators pointed out that the improvements occurred despite the inclusion of patients with obstructive median lobes, which was identified as a predictor of treatment failure in a previous report. When these patients were excluded, the corresponding changes in IPSS, QoL, and Qmax were −58 percent, −55 percent, and 114 percent (p<0.0001). [World J Urol 2020;38:3235-3244]

“No late postoperative complications, ejaculatory dysfunction, or additional treatment failures were observed between 24 and 36 months,” they added.

Prostatic urethra remodeling

The nitinol device, when implanted and left in place for 5–7 days, works to reshape the prostatic urethra and bladder neck through ischaemic pressure, which should relieve the obstruction to the bladder outlet without ablating or resecting tissue. On top of it, the device does not stay permanently in the body.

In comparison, transurethral resection of the prostate (TURP), the current gold standard surgical treatment for BPH, has been shown to provide a durable effect on symptoms and urinary flow but at the cost of higher morbidity rate (20 percent), including urinary incontinence, bleeding requiring blood transfusion, urethral stricture, TUR syndrome, erectile dysfunction, and retrograde ejaculation. [Cochrane Database Syst Rev 2019;12:CD009629; Minerva Urol Nefrol 2019;71:427; Eur Urol 2015;67:1099-1109]

Meanwhile, novel laser-based ablative techniques, which also prove effective at relieving benign prostate hyperplasia-related symptoms, still pose a risk of complications similar to those seen with TURP. [Eur Urol 2015;67:1099-1109; Eur Urol 2012;62:315-323; Minerva Urol Nefrol 2019;71:569-575]

The second-generation iTIND device improves on its predecessor by incorporating three struts instead of four. The struts are constructed from double intertwined nitinol wires configured in a tulip shape. The two devices also differ in its cranial portion, such that the second-gen device has the three intertwined wires linked together. This supports the action of the struts on the urethral mucosa when expanded, avoiding potential injuries of the bladder mucosa. Finally, the top of the device is not pointy as opposed to the first-gen device, which needs a soft plastic cover. [Curr Urol Rep 2019;20:47]

Minimal risk

In the current study, 81 men with symptomatic BPO were washed-out 1 month for alpha-blockers and 6 months for 5α-reductase inhibitors. They underwent implantation of the iTIND device under light sedation; removal was done 5–7 days later with topical anaesthesia.

Functional results at 36 months were available for 50 patients and demonstrated that iTIND efficacy remained stable through 3 years. The procedure seemed well tolerated, with low mean visual analogue scale pain scores of 4 and 2 (0–10) during implantation and removal, respectively.

“No intraoperative complications were reported, and all patients were discharged without a catheter on the same day of the procedure,” according to the investigators.

All devices were removed successfully after a mean of 5.9 days. Postoperative adverse events (AEs) were minimal, with all complications graded as I or II according to the Clavien–Dindo system and resolved within 30 days.

The rate of procedure-related AEs with iTIND was favourably low even when measured up against other minimally invasive procedures such as Urolift and Rezum (urinary tract infection: 6.2 percent vs 12.5 percent and 21.5 percent, respectively; haematuria: 12.3 percent vs 41 percent and 13.8 percent; pain: 9.9 percent vs 17.9 percent and 17 percent). [Eur Urol 2015;68:643-652; Urology 2012;79:5-11; Urology 2015;86:1042-1047; Can J Urol 2015;22:7772-7782]

“The very low rate of early postprocedural AEs, and the absence of any late or ongoing treatment-related complications or side effects may be attributed to the nonpermanent implantation of the device and is a significant benefit to patients,” the investigators noted

“Finally, none of the previously sexually active patients reported a deterioration in sexual or ejaculatory function at any of the follow-up visits… This finding demonstrates that the procedure appears to preserve sexual function,” they added.

Despite the presence of limitations, including the lack of a control arm (eg, sham procedure), the current study confirms the safety and efficacy of iTIND implantation over 36 months after surgery, according to the investigators.