(UroToday.com) Dr Rovner moderated a symposium on Bulkamid®, a periurethral injection which was approved by the FDA in 2020 for the treatment of stress urinary incontinence (SUI) due to intrinsic sphincter deficiency (ISD) or in women who have SUI or stress predominant mixed urinary incontinence (UI). It is now the leading bulking agent in Europe, Australia, and Canada and the #1 treatment procedure in the UK.
In the US, over 2000 patients have been treated with Bulkamid. Although just approved in the US one year ago, this agent has been around for several years and there are multiple publications on different patient populations (e.g. in the elderly, post-stress UI surgery, after radiation, etc). It has long-term data; 3-5 years’ data, has good safety and efficacy data. Bulkamid is different from the 3 other commercially available bulking agents; Coaptite, Macroplastique, and Durasphere. These other agents are particulate injectables, mixed in a carrier gel, which dissipates in the tissues. The actual bulking effect is due to the matter left behind, the micro-particles and inflammatory response and other changes that result in whatever durable effect these bulking agents have. Bulkamid differs as it is not a particulate bulking agent but a homogenous non-particulate hydrogel consisting of 2.5% cross-linked polyacrylamide and 97.5% water. Once injected, the bulking effect is initially from the water and the polyacrylamide, and then fibrous cells and vascular ingrowth results in a long-term cushioning effect resulting in a long durable effect. The injection process is very proprietary and materials used for injecting Bulkamid differ from other injectables. It comes in 2- 1 cc syringes with a disposable sheath (plastic) that has a 0-degree lens. The sheath rotates allowing precision when placing the material in the urethra. 
Dr Rovner reviewed the efficacy of Bulkamid noting that Sokol (2014) compared Bulkamid with Contigen and at 12 months, nearly 50% of patients reported no SUI episodes. Bulkamid has also been compared to TVT and no serious Bulkamid complications were seen. In a study of 256 pts looking at long-term efficacy at 5 yrs, durability was good. In a study of 388 pts, 7-year follow-up, 1/3 received a 2nd injection but in those who received only a single injection, at 7yrs, 67.1% reported cure or improvement and 80.99 % had not received further incontinence treatment. Bulkamid has a good safety profile as Dr Rovner reviewed 8 studies. Risk of acute urinary retention was 5.7% in one study, less than seen with previous peri-urethral injections (Contigen).
Dr Rovner’s panel consisted of Dr Una Lee, Seattle Washington, Dr Nicole Fleischmann, White Plains, NY, and Dr Elizabeth Bozeman, Fulton, New York. The panel had a lively discussion about bulking agents in general and Bulkamid specifically. Dr Lee's has experience with all agents as they urethral coaptation but she was not routinely using these agents (not a “bulker”) till Bulkamid was approved. She feels Bulkamid fills a need for women with SUI as it is an efficacious and low-risk procedure. Dr Fleischmann was an early adopter of Bulkamid. Dr Bozeman has been “bulking” for over 25 yrs and has been a strong advocate., has used all products. She had the best results with Macroplastique but has found Bulkamid to be totally different. Dr Fleischmann liked the science behind Bulkamid, as it is a non-particulate agent, and felt that a hydrogel would be better maintained in the body. She feels that the Bulkamid technique is easy. Dr Bozeman demonstrated the size of the scope and how you would handle the sheath, the syringe and needle with the agent. With Macroplastique, she finds the volume large and felt she was achieving continence by compressing the urethra whereas Bulkamid is different- as the injection is submucosal causing a coaptation of the bladder neck. Dr Lee notes that there is a learning curve as it differs from previous peri-urethral injection techniques and agents. She likes the safety profile, it is low risk, will not cause harm. Retention is a possibility, but if it occurs, it is very transient and short-term. Dr Lee noted that it is indicated for ISD but also for mixed UI and has found that it does not worsen urgency symptoms. Dr Lee encouraged clinicians who are interested in injecting Bulkamid, to train on a “pigs bladder” to become familiar with the technique. Dr Rovner feels that the Bulkamid procedure is not particularly complicated for the urologist who performs endoscopy.
Presented by: Eric Rovner, MD, Director of the section of voiding dysfunction, female urology, and urodynamics in the Department of Urology at MUSC, Charleston, South Carolina
Written by: Diane K. Newman, DNP, ANP-BC, FAAN, Adjunct Professor of Urology in Surgery, Perelman School of Medicine, University of Pennsylvania and Co-Director of the Penn Center for Continence and Pelvic Health during the 2021 Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction (SUFU) Winter Meeting
References:
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