To the Editor
Prostatic artery embolization (PAE) is an established minimally invasive treatment for lower urinary tract symptoms (LUTS) attributed to benign prostatic hyperplasia [1]. Central gland detachment and spontaneous prostatic tissue elimination have been reported after particulate embolization, particularly in patients with marked intravesical median lobe protrusion [2, 3]. Recently, liquid embolic agents based on ethylene–vinyl alcohol copolymer (EVOH) have been explored for PAE because of their radiopacity, controlled delivery, and distal embolic penetration [4, 5]. We report intravesical sequestration of the adenomatous transition zone, containing polymerized EVOH, after PAE with Squid 12 (Balt, Montmorency, France).
A 68-year-old man, without diabetes, smoking, or anticoagulant use, was referred for severe LUTS refractory to alpha-blocker therapy and recurrent acute urinary retention. Prostate-specific antigen (PSA) was 22 ng/mL and multiparametric MRI showed no suspicious lesion (PI-RADS 2) but marked intravesical protrusion of an enlarged median lobe. Previous systematic biopsies had been negative. The prostate measured 56 cm3 and the International Prostate Symptom Score (IPSS) was 26/35.
Bilateral PAE was performed using Squid 12. A proximal EVOH plug was formed, and no angiographic evidence of non-target embolization was detected despite a distal pudendal anastomosis (Supplementary Fig. 1).
Acute urinary retention occurred on day 2, followed by an Enterococcus faecalis urinary tract infection. Over the following weeks, the patient developed persistent dysuria, recurrent urinary tract infections, exertional hematuria, and transient incontinence. These symptoms were initially managed as infectious and post-embolization complications, and no cross-sectional imaging was obtained during this interval. PSA decreased to 1.60 ng/mL at 6 weeks.
At 3 months, MRI showed regression of the median lobe with central cavitation resembling a resection cavity, and a large intravesical mass initially suspected to represent an intravesical blood clot (Fig. 1). CT urography demonstrated a hyperdense intravesical lesion composed of devitalized adenomatous tissue containing dense material consistent with polymerized EVOH (Fig. 2). Cystoscopy confirmed a freely mobile necrotic mass corresponding to en bloc detachment of the transition zone (Fig. 3; Video 1). Transurethral fragmentation and evacuation were performed. Histopathology confirmed extensive ischemic necrosis with embedded embolic material and no malignancy. Symptoms resolved. Six months after PAE, the patient was free of urinary retention, recurrent infection, and hematuria, with an IPSS score of 5/35.
Fig. 1.
Prostate MRI before and after prostatic artery embolization. Preprocedural sagittal (a) and axial T2-weighted images (b) showing benign prostatic enlargement with nodules in the transition zone and intravesical protrusion of the median lobe. c, d Three-month follow-up MRI. Prostate volume had decreased to 15 cm3, corresponding to a 73% reduction. c A large intravesical mass is visible (white arrow), initially interpreted as clot retention. d Central cavitation (red arrow) with regression of the median lobe, resembling a transurethral resection cavity
Fig. 2.
CT urography demonstrating intravesical sequestration of devitalized prostatic tissue. CT scan showing a hyperdense intravesical mass corresponding to a sequestrum arising from the adenomatous transition zone (arrowhead), containing dense polymerized embolic material (red arrow). Residual intraprostatic Squid cast is also visible (white arrow). a, b Axial images. c Coronal reconstruction. d Sagittal reconstruction
Fig. 3.
Cystoscopic view confirming a freely mobile necrotic intravesical mass before transurethral fragmentation and evacuation
Near-total volume reduction with transition-zone sloughing has been reported after PAE [6], including with particulate agents in patients with prominent median lobe protrusion. This anatomical risk factor was present in our patient. What has not, to our knowledge, been previously described is sequestration of an entire transition zone containing identifiable polymerized EVOH, raising the question of whether distal liquid embolic penetration may have contributed to the extent of ischemic necrosis or accelerated tissue detachment. This cannot be established from a single case, and a comparative assessment across embolic agents would be needed.
Persistent or worsening LUTS, recurrent infection, or hematuria after PAE, especially in patients with significant median lobe protrusion, should prompt early cross-sectional imaging rather than presumptive treatment for post-embolization syndrome, since delayed diagnosis of tissue sequestration may prolong avoidable morbidity.
Supplementary Information
Additional file 1: Supplementary Video 1. Cystoscopic visualization and transurethral evacuation of the intravesical sequestrum. The video shows a freely mobile necrotic mass within the bladder lumen, corresponding to en bloc detachment of the adenomatous transition zone after prostatic artery embolization. Transurethral fragmentation and evacuation were performed.
Additional file 2: Supplementary Figure 1. Selective angiography during bilateral prostatic artery embolization using Squid 12. (a) Superselective left prostatic angiogram obtained through a microcatheter (black arrow), demonstrating intraprostatic arterial supply and a distal anastomosis with the internal pudendal circulation (white arrow; star indicates the pudendal artery). (b) Post-embolization image showing dense intraprostatic Squid cast (black arrow). (c) Superselective right prostatic angiogram demonstrating the prostatic arterial trunk supplying the central gland (white arrow).
Acknowledgements
Artificial intelligence-assisted tools were used for language editing and improvement of readability. All scientific content was reviewed, edited, and approved by the authors, who take full responsibility for the final manuscript.
Abbreviations
- CT
Computed tomography
- EVOH
Ethylene-vinyl alcohol copolymer
- IPSS
International Prostate Symptom Score
- LUTS
Lower urinary tract symptoms
- MRI
Magnetic resonance imaging
- PAE
Prostatic artery embolization
- PSA
Prostate-specific antigen
Authors’ contributions
QS and DG conceptualized the case report. QS performed the embolization procedure, collected and interpreted the clinical and imaging data, and drafted the manuscript. DG contributed to clinical and urological management and manuscript revision. MB, LP, and LL contributed to imaging interpretation and manuscript revision. All authors read and approved the final manuscript.
Funding
No funding was received for this work.
Data availability
All data generated or analyzed during this study are included in this published article and its supplementary information files.
Declarations
Ethics approval and consent to participate
Ethics approval was not required for this single case report according to local/institutional requirements. Written informed consent was obtained from the patient.
Consent for publication
Written informed consent was obtained from the patient for publication of this case report and any accompanying images.
Competing interests
The authors declare that they have no competing interests.
Footnotes
Publisher's Note
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References
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Additional file 1: Supplementary Video 1. Cystoscopic visualization and transurethral evacuation of the intravesical sequestrum. The video shows a freely mobile necrotic mass within the bladder lumen, corresponding to en bloc detachment of the adenomatous transition zone after prostatic artery embolization. Transurethral fragmentation and evacuation were performed.
Additional file 2: Supplementary Figure 1. Selective angiography during bilateral prostatic artery embolization using Squid 12. (a) Superselective left prostatic angiogram obtained through a microcatheter (black arrow), demonstrating intraprostatic arterial supply and a distal anastomosis with the internal pudendal circulation (white arrow; star indicates the pudendal artery). (b) Post-embolization image showing dense intraprostatic Squid cast (black arrow). (c) Superselective right prostatic angiogram demonstrating the prostatic arterial trunk supplying the central gland (white arrow).
Data Availability Statement
All data generated or analyzed during this study are included in this published article and its supplementary information files.