Prostate Tissue Can Slough Into the Bladder After Embolization, Study Finds

A complication once considered a rare curiosity of prostate artery embolization may be far more common than the published literature suggests, according to a retrospective cohort study from a single Irish academic teaching hospital. Researchers reviewing 65 consecutive patients treated between January 2019 and June 2025 found that six of them, or 9.2 percent, developed central gland detachment, a phenomenon in which fragments of necrotic prostate tissue break away and displace into the bladder lumen. The finding, published in CVIR Endovascular, challenges the widely quoted figure of less than one percent drawn from the largest published PAE cohorts, and points to severe prostate enlargement as a possible driving factor.

Prostate artery embolization is an established minimally invasive treatment for benign prostatic hyperplasia, offering an alternative to transurethral resection of the prostate for men at increased perioperative risk or those hoping to avoid TURP-related complications, including sexual dysfunction. The procedure blocks the arteries supplying the prostate with tiny particles, deliberately starving the overgrown gland of blood flow so that it shrinks. But when necrosis extends into the central gland near the bladder neck, sloughed tissue can pass into the bladder, causing bladder outlet obstruction, urinary retention, pain and occasionally infection.

The six affected men in this cohort reported passing strand-like solid material per urethra or through an indwelling catheter, and five of the six presented with urinary retention, which was intermittent in three of them. One patient developed a urinary infection after presenting with an obstructed suprapubic catheter and required admission to a high dependency unit. Symptoms emerged between two and 22 weeks after the procedure. Diagnosis was confirmed by cystoscopy in four of the six cases and by MRI in five, based on a combination of a new prostatic defect and free-floating prostatic tissue within the bladder.

The study’s most striking signal concerned prostate size. Mean baseline prostate volume across the cohort was 150 millilitres, far above the 83 to 107 millilitres reported in many published PAE series. When the researchers split the cohort at 150 millilitres, a threshold previously used in the urology literature to define very large prostates, central gland detachment occurred in five of 26 men above that threshold, an incidence of 19.2 percent, compared with just one of 39 men below it, or 2.6 percent. That difference was statistically significant, with a p value of 0.03, although the authors stress that the categorisation was exploratory given the small number of cases and was not intended as a validated risk prediction threshold.

Particle size also showed a suggestive, if statistically inconclusive, pattern. Eleven patients were embolised with particles smaller than 300 micrometres, either alone or in combination with larger particles, and three of them developed central gland detachment, an incidence of 27.3 percent. Among the 54 patients treated exclusively with 300 to 500 micrometre particles, three cases occurred, an incidence of 5.6 percent. The difference fell just short of statistical significance at p equals 0.056. Notably, three of the six cases occurred despite the use of the larger, medium-sized particles, making this, according to the authors, the largest reported series of detachment occurring after embolisation with particles greater than 300 micrometres. Local practice had shifted toward larger particles during the study period precisely because of published evidence linking very small particles to adverse events.

Management of the complication varied in intensity. Four of the six patients required cystoscopic removal of the sloughed prostatic tissue, while the remaining two resolved their symptoms with conservative management alone. Importantly, no patient showed evidence of bladder ischaemia on MRI or cystoscopy, suggesting the sloughing process remained localised to the prostate. Among the four patients who were catheter-dependent at baseline, two remained catheter-dependent at follow-up. For the other four men affected by detachment, voiding outcomes after the acute episode resolved were remarkably good: their average International Prostate Symptom Score fell from 22 before intervention to 2.3 afterward, and their quality-of-life score due to urinary symptoms dropped from 5.3 to 0.5. All four were fully continent at follow-up.

Ejaculatory function told a less reassuring story. Among five of the six affected men from whom sexual function data could be obtained, three of the four who had preserved ejaculatory function at baseline developed new retrograde ejaculation after the procedure. Follow-up MRI in these patients revealed large prostatic defects at the bladder neck, a mechanism the authors compare to the tissue loss that occurs during transurethral resection, which impairs bladder neck closure and redirects semen backward into the bladder. The authors note that quoted rates of ejaculatory dysfunction after PAE more broadly include 12 percent in a retrospective cohort study, 24 percent among participants of the UK ROPE trial, and 56 percent in a Swiss randomised controlled trial, figures they argue should not be understated even though dysfunction after PAE is generally less common and less severe than after TURP.

The authors place their findings in context by acknowledging that their cohort was unusual. Mean prostate volume of 150 millilitres exceeds that of most published PAE populations, and 43 percent of patients were catheter-dependent, both factors that may have inflated the observed incidence. Many of the men with very large prostates had been considered unsuitable for TURP, which is typically recommended for prostates up to approximately 80 millilitres, or carried prohibitive operative risk for prostatectomy, leaving embolization as one of few options. The authors suggest that in selected patients, a staged pathway involving PAE followed by cystoscopic tissue removal may represent an acceptable outcome, provided patients are counselled in advance about the possibility of ejaculatory dysfunction. They also flag an intriguing single observation: the only patient in the cohort who had undergone prior Rezum water vapour therapy subsequently developed detachment, raising a theoretical question about whether prior minimally invasive therapies that induce central gland necrosis might increase susceptibility.

The study’s limitations are substantial and the authors are candid about them. All procedures were performed by a single operator at a single academic hospital, limiting generalisability, particularly since prostate volumes at other centres may be lower. Risk factor analysis rested on just six cases, meaning any observed associations may have arisen by chance. Because routine post-procedural MRI was not performed and imaging or cystoscopy was requested only when suspicious symptoms appeared, subclinical cases may have been missed, potentially underestimating the true incidence. Ejaculatory dysfunction was assessed only in men who experienced detachment, so the true rate in the broader cohort was not evaluated, and symptom scores were available for only 58 percent of patients, largely because catheter-dependent patients could not complete them meaningfully. All embolisations used a single particle type, so the risk with glue or other embolic agents remains unexamined.

Even with those caveats, the study adds meaningful nuance to a complication previously thought to be solely a consequence of aggressive embolisation with very small particles. It suggests that severe prostatomegaly, rather than embolic technique alone, may be a key determinant of whether the central gland detaches, and it demonstrates that cases can occur even with medium-sized particles and conventional embolisation endpoints. For interventional radiologists, the implication is not that prostate artery embolization should be avoided, but that embolisation strategy should be individualised: balancing the goal of durable symptom relief against the risk of detachment and its ejaculatory consequences, tailored to what each patient prioritises, and supported by close collaboration between interventional radiology and urology services when the complication does arise.

Subject of Research: Incidence, risk factors and clinical outcomes of central gland detachment after prostate artery embolization

Article Title: Central gland detachment following prostate artery embolization: incidence, risk factors and clinical outcomes

Article References: O’Herlihy, F., Collins, S., Laffey, M., O’Malley, K., Power, R. E., & Farrelly, C. (2026). Central gland detachment following prostate artery embolization: incidence, risk factors and clinical outcomes. CVIR Endovascular, 9(1), Article 122. https://doi.org/10.1186/s42155-026-00774-9

Image Credits: AI Generated

DOI: 10.1186/s42155-026-00774-9

Keywords: prostate artery embolization, central gland detachment, benign prostatic hyperplasia, retrograde ejaculation, necrotic prostate tissue, cystoscopy, IPSS, prostate volume, embolization particles, interventional radiology, urinary retention, retrospective cohort study