Urethral wall stents were introduced as a minimally invasive intervention for benign prostatic hyperplasia (BPH) in the 1990s. Despite reports of longer-term efficacy in select patients,1,2 challenges with recurrent occlusion and stent migration3-5 prevented widespread adoption of this technology.
Over the past 10 years, however, novel designs and new materials have sparked renewed interest in developing the next generation of urethral stents.6 These investigators reported updated data on a single-arm study of 81 patients with symptomatic bladder outlet obstruction who received a temporary implantable nitinol device.7 The device—composed of three nitinol struts and an anti-migration anchoring leaflet—remained in place for 5 to 7 days, expanding and exerting radial force on the tissue to cause ischemic incisions at the 12, 5, and 7 o’clock positions. Implantation occurred under direct vision through a rigid 19F-22F cystoscope using light intravenous sedation, and removal through an open-ended 22F Foley catheter with topical anesthesia.
Indwelling catheterization was not used after device implantation or removal.
Functional results for the 50 (62%) evaluable patients were favorable at 3-years of follow-up. Efficacy was robust and remained stable throughout follow-up. Mean (SD) International Prostate Symptom Score (I-PSS), I-PSS Quality of Life, Qmax, and post-void residual were 8.55 (6.38), 1.76 (1.32), 15.2 (6.59) ml/s, and 9.38 (17.4) ml, respectively—all significantly improved from baseline (p < 0.01). No late postoperative complications occurred. There were no reports of sexual or ejaculatory dysfunction. After two years, no patients underwent alternative treatments. Additional information about the patients not included in the final analyses, and data describing patient perceptions of the device during the 5 to 7 days of indwelling time, would have been informative.
This study exemplifies a new class of urethral stents currently in development for symptomatic BPH. While multiple, similar devices are currently in clinical trials, it remains to be seen whether urethral stents will occupy a niche in minimally-invasive treatments for symptomatic BPH.
Written by: J. Kellogg Parsons, MD, MHS, Urologist, Professor of Urology, UC San Diego, Moores Cancer Center, La Jolla, California
References:
1. VanderBrink, Brian A., Ardeshir R. Rastinehad, and Gopal H. Badlani. "Prostatic stents for the treatment of benign prostatic hyperplasia." Current opinion in urology 17, no. 1 (2007): 1-6.
2. Masood, Shikohe, Hooman Djaladat, Chryssanthos Kouriefs, Margaret Keen, and John H. Palmer. "The 12‐year outcome analysis of an endourethral wallstent for treating benign prostatic hyperplasia." BJU international 94, no. 9 (2004): 1271-1274.
3. Hussain, Mahreen, Tamsin J. Greenwell, Julian Shah, and Anthony Mundy. "Long‐term results of a self‐expanding wallstent in the treatment of urethral stricture." BJU international 94, no. 7 (2004): 1037-1039.
4. Parsons, J. Kellogg, and E. James Wright. "Extraction of UroLume endoprostheses with one-stage urethral reconstruction." Urology 64, no. 3 (2004): 582-584.
5. Buckley, Jill C., and Leonard N. Zinman. "Removal of endoprosthesis with urethral preservation and simultaneous urethral reconstruction." The Journal of urology 188, no. 3 (2012): 856-860.
6. Amparore, Daniele, Sabrina De Cillis, Gabriele Volpi, Enrico Checcucci, Matteo Manfredi, Ivano Morra, Michele Di Dio, Cristian Fiori, Francesco Porpiglia, and ESUT Group. "First-and second-generation temporary Implantable nitinol devices as minimally invasive treatments for BPH-related LUTS: systematic review of the literature." Current Urology Reports 20, no. 8 (2019): 47.
Read the Full-Text Article: 3-Year Results Following Treatment with the Second Generation of the Temporary Implantable Nitinol Device in Men with LUTS Secondary to Benign Prostatic Obstruction - Full-Text Article