AUA2023: REFLECTIONS Temporary Implantable Nitinol Prostate Stent for Benign Prostatic Hyperplasia
By: Alia Codelia-Anjum, BS, NY-Presbyterian Hospital, Weill Cornell Medical Center, New York, New York; Dean Elterman, MD, MSc, FRCSC, University Health Network, University of Toronto, Ontario, Canada; Kevin Zorn, MD, FACS, FRCSC, Centre Hospitalier de l’Université de Montréal, Quebec, Canada; Naeem Bhojani, MD, FRCSC, Centre Hospitalier de l’Université de Montréal, Quebec, Canada; Silvia Secco, MD, FEBU ASST, Ospedale Metropolitano Niguarda, Piazza Ospedale Maggiore, Milan, Italy; Bilal Chughtai, MD, NY-Presbyterian Hospital, Weill Cornell Medical Center, New York, New York | Posted on: 20 Jul 2023
The minimally invasive space for benign prostatic hyperplasia (BPH) has been a hot topic with a plethora of novel technologies being presented in multiple AUA sessions this year. In efforts of moving BPH procedures further along in terms of high efficacy and increasing the safety profile, the temporary implantable nitinol device (iTIND), has been one of the first players on the market offering an easily reproducible procedure, requiring no permanent foreign body or use of energy.
The iTIND was US Food and Drug Administration approved in 2020; it is designed to permanently remodel the prostatic urethra during a temporary implantation period of only 5 to 7 days (see Figure). It is a single-use device supplied on a dedicated delivery system consisting of 3 nitinol cutting struts at the 12, 5, and 7 o’clock positions, an anchoring leaflet at the 6 o’clock position to prevent device migration, and a retrieval suture anchored to the distal part of the device. The cutting struts result in deep, bloodless incisions created through ischemic pressure. The subsequent necrosis permanently remodels the prostatic urethra and bladder neck. At the end of the treatment period (5-7 days), the device is completely removed through a silastic open-ended catheter.
In a recent animal study, 3 canines underwent placement of the cTIND, a modified iTIND device meant for use in canine models, to further understand its mechanism of action and the changes it induces to the bladder neck and prostatic urethra.1 The histologic findings after device implantation showed targeted areas of necrosis with no edema, minimal inflammation, and minimal injury to the surrounding prostatic tissue.
The ideal candidate for iTIND is a patient with a prostate volume of 25-75 cc, no obstructive median lobe, a high bladder neck, and good bladder function.2 Insertion and removal of the iTIND can be performed either in the operating room setting using IV sedation or in an in-office setting using local anesthesia or sedation. The iTIND may be placed via rigid cystoscopy or flexible cystoscopy.
In a randomized, multicenter study of 175 men by Chughtai et al, 118 patients received iTIND after a washout period of 1 month for α blockers and 6 months for 5-alpha reductase inhibitors.3 This included men with prostate volumes between 25 and 75 cc with no obstructive median lobe, a high bladder neck, and good bladder function. At 3-month follow-up visit, iTIND patients showed a reduction of more than 3 points in International Prostate Symptom Score (IPSS) with a rate of 79% when compared to the sham group of 60%. At the 12-month follow-up, the iTIND group’s maximum flow rate improved by 41.8% and quality of life improved by 42.2% when compared to baseline scores. While adverse events (AEs) occurred in 38.1% of the iTIND group vs 17.5% in the control, most AEs were a Clavien-Dindo grade of I or II. Additionally, 68% of AEs occurred within 7 days of treatment, while the device was in the body, and the most common AEs were dysuria and hematuria. Furthermore, when compared to other minimally invasive treatments, iTIND showed comparable improvement in IPSS and peak flow rate with a similar re-intervention rate of 4.7% to other iTIND studies.
In the longest-term study with 3 years of follow-up, 81 men with symptomatic benign prostatic obstruction were treated with iTIND.4 At 3-year follow-up, data were available for 50 patients, which showed a decrease in IPSS by 58.2%, improvement of maximum flow rate by 114.7%, and postvoid residual improvement by 85.4%, showing significant difference when compared to baseline assessment. The most common complications were hematuria (12.3%), urgency (11.1%), pain (9.9%), and dysuria (7.4%). All complications were a Clavien-Dindo grade of I or II and resolved within 30 days, with no late postoperative AEs occurring after 12 months. Throughout the 3 years of follow-up, no sexual or ejaculatory dysfunction was reported.
With an interest for minimally invasive and effective treatment options for BPH, the iTIND has become an increasingly popular and comprehensive means to address these needs.
- Garman T, Cho A, Stoddard MD, et al. The mechanism of action of cTIND for minimally invasive ischemic incision of the prostate: in vivo study. Urology. 2021;157:217-221.
- Elterman D, Gao B, Zorn KC, Bhojani N, Chughtai B. How I do it: temporarily implanted nitinol device (iTind). Can J Urol. 2021;28(4):10788-10793.
- Chughtai B, Elterman D, Shore N, et al. The iTind temporarily implanted nitinol device for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia: a multicenter, randomized, controlled trial. Urology. 2021;153:270-276.
- Amparore D, Fiori C, Valerio M, et al. 3-Year results following treatment with the second generation of the temporary implantable nitinol device in men with LUTS secondary to benign prostatic obstruction. Prostate Cancer Prostatic Dis. 2021;24(2):349-357.