Prostate-specific antigen density as the best predictor of low- to intermediate-risk prostate cancer: a cohort study.

Background: Evaluation of prostate cancer (PCa) when serum prostate-specific antigen (PSA) level is vaguely elevated is complicated. This is because serum PSA levels only reflect the number of prostate epithelial cells. We aimed to compare PSA and various prostate volume-related factors to determine which one can best predict PCa in patients with a PSA level of 2.5-20 ng/mL. Methods: Patients who underwent transrectal ultrasound (TRUS)-guided prostate biopsy at the Inje University Sanggye Paik Hospital between January 2018 and July 2021 and who had a PSA level of 2.5-20 ng/mL were retrospectively identified (n=275). Among them, based on biopsy results, patients were divided into cancer group and non-cancer groups, and age, PSA, total prostate volume (TPV), peripheral zone volume (PZV), peripheral zone PSA density (PZ-PSAD), transitional zone-PSAD (TZ-PSAD), and PSAD were compared and analyzed using receiver operating characteristic (ROC) and univariate analyses. Results: The areas under ROC curves (AUCs) for age, total PSA, TPV, PZV, PZ-PSAD, TZ-PSAD, and PSAD for predicting PCa in patients with a PSA level of 2.5-20.0 ng/mL were 0.678, 0.680, 0.671, 0.639, 0.731, 0.736, and 0.764, respectively. In univariate and multivariate analysis, all categorical variables were divided based on the cut-off value and used to predict PCa. Those with a PSAD of ≥0.218 ng/mL2 were found to be at an increased risk of PCa than those with a PSAD of <0.218 ng/mL2 [odds ratio (OR) =3.51; 95% confidence interval (CI): 1.306-9.415], which was the best result, followed by TZ-PSAD with a cut-off value of 0.353. At a PSAD level of 0.218 ng/mL2, 85.0% of the PCa group could avoid unnecessary biopsy and 61.4% of the non-PCa group could reduce missed diagnosis when the TRUS findings were inaccurate. Conclusions: PSAD may inform biopsy decisions as the best predictor of PCa when TRUS findings are ambiguous in patients with a PSA level of 2.5-20.0 ng/mL.

Feasibility, Safety, and Functional Outcomes of Pelvic Hypothermia Induced Using a Rectal Cooling Device During Robot-Assisted Radical Prostatectomy: A Phase I/II Trial.

Introduction: Radical prostatectomy (RP) is one of the standard treatments for localized prostate cancer. However, in terms of functional outcomes, there are aspects that still need improvements. We designed this prospective phase I/II clinical trial to assess the safety, clinical feasibility, and functional outcomes of hypothermic robot-assisted RP (RARP). Material and Methods: Twenty patients with preoperative total 5-item International Index of Erectile Function scores ≥12 points, scheduled for RARP, were enrolled in the study. Pelvic hypothermia was induced using an endorectal cooling device (BelloCool System). The primary outcome was the completion rate of the planned hypothermic RARP. Secondary outcomes included the drop in neurovascular bundle (NVB) temperature, adverse (including device-related) events, continence, and potency recoveries, and postoperative quality of life. Contemporaneous patients (propensity score-matched for baseline characteristics) who satisfied the inclusion criteria were included in the control group. Results: The completion rate of the planned hypothermic surgery was 100%. The nadir NVB temperature was 24.9 [22.4, 28.2]°C, which was 10.2 [7.0, 13.1]°C lower than the nadir core body temperature. There was no device-related adverse event, and bowel function was well preserved for the whole follow-up period. At 12 months postoperatively, potency and continence recovery rates were higher in the hypothermic group than in the control group (40% vs 15%, p = 0.027 and 95% vs 80%, p = 0.167, respectively). The Kaplan-Meier curve showed faster recovery rate of potency in the hypothermic group (hazard ratios = 3.46, log-rank p < 0.01). Conclusions: Hypothermic RARP using the BelloCool™ endorectal cooling system is safe and feasible. A large-population-based randomized controlled trial is needed to confirm the potential for a benefit in continence and potency recovery.

Effectiveness of a newly-developed training module using 3D printing for the navigation during retrograde intrarenal surgery.

PURPOSE: This study aimed to evaluate the feasibility of the newly-developed three-dimensional (3D) printed training module for navigation during retrograde intrarenal surgery. MATERIALS AND METHODS: Two specialists provided orientation to all trainees. The 3D printing model consisted of eight calyces in each kidney. One navigation time started from the moment when the endoscope entered the ureter. After navigation was completed, the navigation time was recorded. The goal was to perform ten navigation times for each side, starting from the right or the left side at random. After the experiment, all trainees were asked to fill out a questionnaire. RESULTS: The average training period of all 17 trainees was 3.05±1.80 years. Eleven trainees (64.7%) had the experience of assisting surgery for <100 cases, and six trainees (35.3%) had the experience of assisting surgery for 100 to 500 cases. Nine trainees (52.9%) began training from the right, and eight trainees (47.1%) started from the left. The average navigation time of 308 trials was 153.4±92.6 seconds. The maximum and minimum navigation times were 354.3±177.2 seconds and 80.1±25.6 seconds. The mean navigation time of the first and the last trials of all trainees significantly decreased from 251.4±108.0 seconds to 93.9±33.2 seconds. The average reduction in navigation time was 201.3±133.3 seconds. Almost all trainees were satisfied with the training. CONCLUSIONS: The newly-developed 3D printing navigation training module seems to be adequate to improve surgical skills of flexible ureteroscopy.

Geriatric assessment using the G8 to predict postoperative complications in patients undergoing major uro-oncologic surgery: Comparison with the Charlson Comorbidity Index.

OBJECTIVE: To evaluate the ability of the G8 assessment to predict postoperative complications in older adults undergoing major uro-oncologic surgery in comparison with the Charlson Comorbidity Index (CCI). MATERIALS AND METHODS: The study included patients ≥65 years old who underwent major uro-oncologic surgery between December 2017 and December 2019 and were enrolled in the Seoul National University Prospectively Enrolled Registry for Genitourinary Cancer (SUPER-GUC). Odds ratio (OR) smoothing was used to visualize risk according to G8 scores. Chi-square tests were used to compare postoperative complication rates according to G8 score or CCI category. RESULTS: A total of 657 patients undergoing radical prostatectomies (n = 372, 56.6%), partial/radical nephrectomies (n = 149, 22.7%), radical cystectomies (n = 76, 11.6%), and nephroureterectomies (n = 60, 9.1%) were included. Complication rates did not significantly differ between patients with CCI scores ≥1 and those with CCI scores of 0 (15.0% vs. 12.4%, p = 0.34). However, the complication rate was significantly higher in patients with G8 scores ≤14 than in those with G8 scores >14 (18.1% vs. 10.5%, p = 0.005). When the OR smoothing curve was used to divide patients into three groups based on G8 scores of <10, 10-14, and > 14, we observed significant differences in complication rates among the groups (37.5% vs. 16.9%. vs. 10.5%; p = 0.001). CONCLUSION: The G8 can aid in predicting postoperative complications in patients ≥65 years old. Comprehensive geriatric assessment is warranted in patients with G8 scores ≤14 prior to major uro-oncologic surgery. Older patients with G8 scores <10 should be counseled regarding the very high risk of surgery.

Laparoscopic Ablation System for Complete Circumferential Renal Sympathetic Denervation.

GOAL: The catheter-based renal denervation (RDN) showed promising results for patients in lowering BP, but there were also many non-responders. One of the possible reasons was the incomplete neural ablation due to the ablation of renal nerves at random sites resulting in asymmetric innervation patterns along the renal artery. METHODS: We developed a laparoscopic ablation system that is optimized for complete RDN regardless of renal arterial innervation and size. To demonstrate its effectiveness, we evaluated the system using computational simulation and 28-day survival model using pigs. RESULTS: The ablations were focused around the tunica externa, and the ablation patterns could be predicted numerically during RDN treatment. In the animal study, the mean reduction of systolic BP and diastolic BP in the bilateral main renal arteries was 22.8 mmHg and 14.4 mmHg (P<0.001), respectively. The respond to immunostaining targeting tyrosine hydroxylase was significantly reduced at treatment site (108.2 ± 7.5 (control) vs. 63.4 ± 8.7 (treatment), P<0.001), and an increased degree of sympathetic signals interruption to kidneys was associated with the efficacy of RDN. CONCLUSION: The laparoscopic ablation system achieved complete circumferential RDN at the treatment site and could numerically predict the ablation patterns. SIGNIFICANCE: These findings clearly suggest that the proposed system can significantly improve the RDN effectiveness by reducing the variation to the percentage of injured nerves and open up a new opportunity to treat uncontrolled hypertension.

How to reduce 'double-firing'-induced scope damage by investigating the relationship between laser fiber core degradation and fiber jacket burn?

PURPOSE: 'Double-firing effect' in which laser firing occurs in the fiber tip and its proximal part is caused by different breakdown rates between fiber jackets and cores. This study investigated a new safe distance concept to prevent scope damage by analyzing the breakdown of the laser fiber jacket and cores. METHODS: Laser fibers were fixed in a benchtop simulation model. The fiber tip was in contact with uniform phantom stones and submerged in saline. Four different energy settings (1.0 or 2.0J x 10Hz or 30Hz) and two different fiber sizes (200 µm and 365 µm) were tested. After three minutes of use at each energy setting, the length of fiber shortening and jacket burn were measured. The fibers were stripped to measure the length of core degradation. RESULTS: Mean degradation lengths were 4.2 to 7.8 mm. There was no statistical difference in the mean lengths of fiber core degradation and jacket burn. However, core degradation was longer than the jacket burn in half of the samples. The mean difference in lengths between core degradation and jacket burn was 0.49 ± 0.90 mm. Lengths of core degradation and the jacket burn were longer at the setting of high-power energy and 200 µm fiber - 2J with 30 Hz. CONCLUSION: To reduce 'double-firing'-induced damage, the authors recommend that laser fiber should be cut 1.0 mm longer than visible jacket burn at high-power settings after 3-min continuous fragmentation. After cutting the fiber, the laser should be checked whether 'double-firing' is no more seen.

Efficacy and Safety of X-incision with Inversed Morcellation in Holmium Laser Enucleation of the Prostate: Comparison to Conventional Morcellation.

BACKGROUND: Three-quarters of aged men experience lower urinary tract symptoms with benign prostate hypertrophy (BPH). Transurethral resection of the prostate (TURP) and holmium laser enucleation of the prostate (HoLEP) are standard endosurgical procedures in patients with BPH. Previous studies reported better results in patients undergoing HoLEP than in those undergoing TURP. METHODS: This study compared the efficiency and safety of conventional morcellation and morcellation performed after X-incision during enucleation, a newly added technique in HoLEP. Overall, 174 patients were selected as the final study population. The populations were stratified with respect to resected volumes. A t-test were used to compare the conventional morcellation and X-incision procedure groups. RESULTS: In morcellation times and rates, there were significant differences in stratified resected mass (g) between the groups. The results also showed a decreased incidence of bladder injury as a surgical complication. CONCLUSION: We believe morcellation performed after X-incision procedure during enucleation is efficient and safe for older adults with BPH.