Seung-June Oh

Purpose: This study aimed to evaluate the correlation between bladder outlet obstruction (BOO) and bladder trabeculation in patients with benign prostatic hyperplasia (BPH).Methods: We analyzed data from consecutive BPH patients from July 2014 to June 2024, who underwent urodynamic study (UDS) and cystourethroscopy. The results of free uroflowmetry, filling cystometry, and pressure-flow study were analyzed to evaluate functional parameters. For anatomical parameters, bladder trabeculation grade, lateral lobe protrusion of prostate, and bladder neck elevation (BNE) measured in cystourethroscopy were used. BOO was defined as the BOO index of 40 or higher in UDS. Bladder trabeculation was graded using our previous studies.Results: Among total of 1,452 BPH patients, 1,028 patients had trabeculation on cystoscopy. Age, serum prostate-specific antigen, postvoid residual, total prostate volume, transition zone volume, terminal type detrusor overactivity, detrusor pressure at the maximal flow rate, bladder contractility index (BCI), and BOO index increased according to increase in bladder trabeculation. Multivariable logistic analysis showed that bladder trabeculation was significantly associated with age (odds ratio [OR], 1.05; P<0.001), kissing sign (OR, 1.55; P=0.007), BNE (OR, 1.76; P<0.001), detrusor overactivity (OR, 1.88; P=0.002), BCI (OR, 1.01; P=0.037), BOO (OR, 2.27; P<0.001). BOO had the greatest correlation with bladder trabeculation. In addition, BOO index showed a positive correlation (r=0.39, P<0.001) with bladder trabeculation. BOO index well distinguished between moderate trabeculation of grade 2 or higher in receiver operating characteristic analysis (area under curve=0.72, P<0.001).Conclusions: Our results showed that the severity of BOO is positively associated with the severity of bladder trabeculation.

Purpose: To compare the accuracy of portable ultrasound bladder scanner (PUBS) for measuring bladder volume (BV) using manual fanning scan (MFS) and traditional motorized scan (TMS) methods.Methods: Patients with lower urinary tract symptoms who underwent a urodynamic study at the urology outpatient clinic from October to December 2024 were prospectively enrolled. BV was measured using TMS-type (TMS-BV) and MFS-type (MFS-BV) PUBS prior to free uroflowmetry. True BV (T-BV) was defined as the sum of the voided volume and the postvoid residual volume drained through the urethral catheter after voiding. TMS-BV and MFS-BV were compared and analyzed against T-BV.Results: Data from 39 patients (30 males and 9 females; mean age, 65.3±14.8 years) were analyzed. TMS-BV (230.9±157.9 mL) and MFS-BV (222.6±154.2 mL) did not differ significantly from T-BV (230.6±156.6 mL) (P>0.05). Comparison of the percentage of difference in volume between TMS-BV and MFS-BV across 100-mL BV ranges revealed no significant difference (P>0.05). The mean difference between TMS-BV and T-BV (0.2±50.2) did not differ significantly from the mean difference between MFS-BV and T-BV (-8.0±69.1) (P>0.05). The correlation between TMS-BV and T-BV (R2=0.90) was stronger than that between MFS-BV and T-BV (R2=0.81).Conclusions: The correlation between MFS-type PUBS and T-BV was lower than that between TMS-type PUBS and T-BV. However, the measurement accuracy of BV was similar using both methods.

Background: Most studies have analyzed the urodynamic characteristics of patients with Parkinson's disease (PD) and multiple system atrophy (MSA) using conventional urodynamic studies. Objectives: This study investigated the urodynamic characteristics of both diseases using video urodynamic study (VUDS). Methods: VUDS results from November 2004 to September 2020 were retrospectively analyzed at Seoul National University Hospital. The VUDS findings in patients with PD and those with MSA were compared. Movement disorder specialists diagnosed patients with PD and MSA. Results: A total of 709 patients, comprising 364 PD (260 men, 104 women) and 345 MSA (215 men, 130 women) cases, were identified. Patients with MSA had a significantly younger age at onset, lower maximum flow rate (Qmax), larger postvoid residual volume, higher rate of poor bladder compliance, higher prevalence of urinary incontinence, and lower detrusor pressure at Qmax than those with PD. Among the fluoroscopic findings of VUDS, patients with MSA had a higher rate of incompetent bladder neck (18.8% vs. 4.7%, P < 0.001), bladder trabeculation (33.0% vs. 17.0%, P < 0.001), and vesicoureteral reflux (2.9% vs. 0.5%, P = 0.019) than those with PD. In VUDS performed in patients without urinary incontinence in conventional urodynamic study, an incompetent bladder neck was found in 14.6% of patients with MSA and 3.3% of patients with PD ( P < 0.001). Conclusions: Our results demonstrate that VUDS can provide additional information on bladder urethral dysfunction, particularly regarding the risk of upper urinary tract damage and bladder neck status in patients with PD and MSA.

Objective: We aimed to prospectively investigate whether bladder volume measured using deep learning artificial intelligence (AI) algorithms (AI‐BV) is more accurate than that measured using conventional methods (C‐BV) if using a portable ultrasound bladder scanner (PUBS).Patients and Methods: Patients who underwent filling cystometry because of lower urinary tract symptoms between January 2021 and July 2022 were enrolled. Every time the bladder was filled serially with normal saline from 0 mL to maximum cystometric capacity in 50 mL increments, C‐BV was measured using PUBS. Ultrasound images obtained during this process were manually annotated to define the bladder contour, which was used to build a deep learning AI model. The true bladder volume (T‐BV) for each bladder volume range was compared with C‐BV and AI‐BV for analysis.Results: We enrolled 250 patients (213 men and 37 women), and a deep learning AI model was established using 1912 bladder images. There was a significant difference between C‐BV (205.5 ± 170.8 mL) and T‐BV (190.5 ± 165.7 mL) (p = 0.001), but no significant difference between AI‐BV (197.0 ± 161.1 mL) and T‐BV (190.5 ± 165.7 mL) (p = 0.081). In bladder volume ranges of 101–150, 151–200, and 201–300 mL, there were significant differences in the percentage of volume differences between [C‐BV and T‐BV] and [AI‐BV and T‐BV] (p < 0.05), but no significant difference if converted to absolute values (p > 0.05). C‐BV (R² = 0.91, p < 0.001) and AI‐BV (R² = 0.90, p < 0.001) were highly correlated with T‐BV. The mean difference between AI‐BV and T‐BV (6.5 ± 50.4) was significantly smaller than that between C‐BV and T‐BV (15.0 ± 50.9) (p = 0.001).Conclusion: Following image pre‐processing, deep learning AI‐BV more accurately estimated true BV than conventional methods in this selected cohort on internal validation. Determination of the clinical relevance of these findings and performance in external cohorts requires further study.Trial Registration: The clinical trial was conducted using an approved product for its approved indication, so approval from the Ministry of Food and Drug Safety (MFDS) was not required. Therefore, there is no clinical trial registration number.

Objective: This study aimed to analyze the outcomes of clinical management of patients with interstitial cystitis (IC).Patients and Methods: We retrospectively analyzed the electronic medical records of patients with IC who visited outpatient clinics with pelvic pain between October 2005 and December 2019. Pain was managed with cystoscopic surgery based on transurethral fulguration (TUF) for bladder ulcers. Cystectomy was performed for intractable pelvic pain. Patients were regularly followed and clinical outcomes were analyzed.Results: Of the 275 patients, 240 patients (57 men, 23.7% and 183 women, 76.3%) underwent initial cystoscopic surgery. Overall median follow‐up duration was 21.0 months and mean number of TUF was 1.0 (±0.8). Of these 240 patients, 71 (29.6%) did not require further surgical treatment, whereas 64 (26.7%) required a second TUF for recurrent pelvic pain. The median recurrence interval was 12.0 (interquartile range: 6.0–25.0) months. Of the 64 patients who received a second TUF, 15 (23.4%) underwent a third TUF after a median of 12.0 (interquartile range: 12.0–32.0) months. Of the 15 patients who received a third TUF, five patients required a fourth TUF because of recurrence of pain. One patient received until a seventh TUF. Overall, 168 of 240 patients (70.0%) achieved pain control with TUF. Eighteen patients (7.5%) underwent cystectomy (six patients with urinary diversion and 12 patients with cystectomy with bladder replacement).Conclusion: TUF‐based cystoscopic surgery is an effective basic treatment for pelvic pain management in patients with IC.

Purpose: This study investigated urinary incontinence (UI) following holmium laser enucleation of the prostate (HoLEP), based on the postoperative period, type of UI, and severity according to prostate volume.Methods: We analyzed prospectively collected data from patients who underwent HoLEP for benign prostatic hyperplasia at Seoul National University Hospital between January 2010 and June 2022. Patients were followed-up at 2 weeks, 3 months, and 6 months postoperatively. The patients were divided into 3 prostate volume groups: A (30–80 mL), B (81–120 mL), and C (>120 mL). We compared clinical outcomes and UI rates between the groups.Results: In total, 1,675 patients were included. The preoperative urgency UI (UUI) rate was 16.1%, with no significant difference between the groups (P=0.81). Two weeks postoperatively, the UUI rate was 6.0% (including a de novo UUI rate of 4.2%), with no significant differences between the groups. The stress UI (SUI) rate at 2 weeks postoperatively was 6.3%, and increased with larger prostate volume (P=0.04). The UUI and SUI rates decreased to 0.9% and 1.2%, respectively, 6 months postoperatively. Six months postoperatively, the SUI rate was significantly lower in group A (P=0.02), whereas the UUI rate did not differ between the groups (P=0.69).Conclusions: Our results demonstrated that the preoperative UUI rate was high at baseline. Both the UUI and SUI rates continuously decreased up to 6 months postoperatively. Although the SUI rates significantly differed according to prostate volume, there was no significant difference in the UUI rate.

Background: The purpose of this study is to evaluate the efficacy and safety of holmium laser prostatectomy in patients diagnosed with primary bladder neck obstruction (PBNO), compared with patients with benign prostatic hyperplasia (BPH). Methods: We analyzed the databases of patients who underwent a holmium laser prostatectomy or enucleation of the prostate for PBNO and BPH between January 2018 and August 2022. PBNO was diagnosed primarily based on cystourethroscopic findings. Patients were followed up according to a regular protocol at 2 weeks, 3 mo, and 6 mo postoperatively. Results: In total, 28 and 447 patients with PBNO and BPH, respectively, were identified. Preoperative urodynamic studies showed that detrusor underactivity was significantly more prevalent in the PBNO group (78.6%) than in the BPH group (57.5%) (p < 0.01). Both PBNO and BPH groups showed significant improvements in the total International Prostate Symptom Score, Overactive Bladder Symptom Score, and maximum flow rate at 6 mo postoperatively compared with the preoperative values (p < 0.01). Subjective satisfaction 6 mo after operation was not significantly different between the PBNO and BPH groups (p > 0.05). Complications in the PBNO group included recatheterization (n = 1, 3.5%), with no patients requiring blood transfusion or transurethral coagulation. Conclusions: Holmium laser prostatectomy was effective and safe for patients with PBNO, with elevated subjective patient satisfaction.

Purpose: Little is known about the soft tissue destruction by holmium laser clinically used for holmium laser enucleation of the prostate (HoLEP), subject to the distance between the laser fiber tip and the tissue surface. We aimed to investigate the impact of the distance between the laser fiber tip and the phantom surface (DLP) on a soft tissue phantom (STP) in relation to the surgical modes of HoLEP.Methods: STP responses to the laser pulses produced by a commercial holmium:yttrium aluminum garnet (Holmium:YAG) laser at an output setting 2 J were observed at different values of the DLP (0, 1, 2, 3, and 4 mm) to look at (1) the single laser pulse-induced cavitation bubble and its penetration into the STP, (2) the STP destruction by a single pulse, (3) the STP destruction by 60 pulses repeated at 12 Hz, and (4) the thermal effect by the multiple pulses visualized on a thermosensitive bovine serum albumin (BSA) STP.Results: We observed that the laser pulse produced a heated gas bubble in water centered at the laser fiber tip. The bubble shape depended on the DLP. The bubble completely penetrated into the STP at the DLP of 0 mm and the penetration decreased with the DLP. The size of the destruction of the STP by the laser pulses was shown to decrease as the DLP increased. Test with the BSA STP showed that, at the DLP of 3 mm, the destruction became insignificant while the thermal effects were still effective.Conclusions: We illustrated that soft tissue destruction by the Holmium:YAG laser is associated with cavitation effects. We provide for the first time experimental evidence for various surgical modes in HoLEP such as incision and hemostasis in relation to the DLP.

Objective: To analyze the results of excluding confusable diseases in patients with a presumptive diagnosis of interstitial cystitis (IC).Methods: We retrospectively reviewed the electronic medical records of consecutive patients with IC between October 2005 and December 2019.Results: Patients with pelvic pain underwent an initial workup. Of these, 646 patients (164 men, 25.4%; 482 women, 74.6%) underwent observational cystoscopy under the suspicion of IC. Fourteen patients had genitourinary tract malignancies (2.2%) (bladder cancer, n = 13; prostate cancer, n = 1). Of the 13 patients with bladder cancer, three were diagnosed during initial observation cystoscopy. The remaining 10 patients were diagnosed during subsequent follow‐up cystoscopic surgery. Urinary tuberculosis was identified in seven (1.1%) of 646 patients during the examination. Five (0.8%) of the six patients with suspected urinary tuberculosis at baseline imaging were positive for tuberculosis in the acid‐fast bacillus test. One patient developed tuberculous granulomas in the bladder tissue after a cystectomy for intractable pelvic pain.Conclusion: Our results show that continuous efforts to rule out bladder tumors or tuberculosis are still essential in the follow up of patients with suspected IC, even if these diseases are not excluded at the initial examination. Imaging studies are necessary to rule out tuberculosis.

Purpose: We aimed to evaluate the effect of self-training using a virtual reality head-mounted display simulator on the acquisition of surgical skills for holmium laser enucleation surgery.Methods: Thirteen medical students without surgical skills for holmium laser enucleation of the prostate were trained using multimedia to learn the technique via simulator manipulation. Thereafter, participants performed the technique on a virtual benign prostatic hyperplasia model A (test A). After a 1-week wash-out period, they underwent self-training using a simulator and performed the technique on model B (test B). Subsequently, participants were asked to respond to Training Satisfaction Questions. Video footage of hand movements and endoscope view were recorded during tests A and B for later review by 2 expert surgeons. A 20-step Assessment Checklist, 6-domain Global Rating Scale, and a Pass Rating were used to compare performance on tests A and B.Results: Thirteen participants completed both tests A and B. The 20-step Assessment Checklist and 6-domain Global Rating Scale evaluation results showed significantly improved scores in test B than in test A (P<0.05). No evaluator rated participants as passed after test A, but 11 participants (84.6%) passed after test B. Ten participants (76.9%) indicated that the simulator was helpful in acquiring surgical skills for holmium laser enucleation of the prostate.Conclusions: The virtual reality head-mounted display holmium laser enucleation of the prostate simulator was effective for surgical skill training. This simulator may help to shorten the learning curve of this technique in real clinical practice in the future.