Cumulative sum analysis of the learning curve for retrograde intrarenal stone surgery in newbie surgeons.

INTRODUCTION: This study investigated the learning curve of retrograde intrarenal surgery (RIRS) in patients with medium-sized stones using cumulative sum analysis (CUSUM) to evaluate the competence and proficiency of three new surgeons during their first RIRS procedures. MATERIALS AND METHODS: We conducted a retrospective review of 227 patients from 2019 to 2022 at a single institution. The patients were divided into four groups based on the operating surgeon: tutor surgeon (85 patients), newbie surgeon A (21 patients), newbie surgeon B (85 patients), and newbie surgeon C (36 patients). Patients had one or multiple stones with the largest stone diameter fell within the range of 10-30 mm. Fragmentation efficacy was calculated as "removed stone volume (mm3) divided by operative time (minutes)." CUSUM analysis monitored changes in fragmentation efficacy and validated surgical outcomes. RESULTS: No statistically significant differences were observed in the total stone volume, maximum stone size, or total operation time between the three newbie surgeons and the tutor surgeon. The mean fragmentation efficacy value was comparable among the newbie surgeons, but significantly different from that of the tutor surgeon. The minimum acceptable fragmentation efficacy level was set at 25.12 mL/min, based on the tutor's average value. The CUSUM curves for the three surgeons initially remained relatively flat until Cases 12-15, after which they increased and eventually plateaued. Stone-free rates and postoperative complications did not differ significantly among the surgeons. CONCLUSION: Learning curve analysis for the three newbie surgeons indicated that approximately 12-15 cases were required to reach a plateau.

WITHDRAWN:Current Status of Benign Prostatic Hyperplasia Prescription in Korea Based on the Clinician's Urology Specialty Using Nationwide Healthcare System Data.

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Can natural killer cell activity help screen patients requiring a biopsy for the diagnosis of prostate cancer?

ABSTRACT Purpose To evaluate the usefulness of natural killer cell activity (NKA) in diagnosing prostate cancer (PC). Materials and Methods The medical records of patients who underwent transrectal prostate biopsy (TRBx) at Korea University Ansan Hospital between May 2017 and December 2017 were retrospectively reviewed. NKA levels were measured using NK Vue® Tubes (ATgen, Sungnam, Korea). All blood samples were obtained at 8 AM on the day of biopsy. Patients with other malignancies, chronic inflammatory conditions, high prostate-specific antigen (PSA) level (>20ng/mL), or history of taking 5-alpha-reductase inhibitor or testosterone replacement therapy were excluded. Results A total of 102 patients who underwent TRBx for PC diagnosis were enrolled. Among them, 50 were diagnosed with PC. Significant differences in age and NKA level were observed between the PC and no-PC groups. Receiver operating characteristic (ROC) curve analysis showed that the optimal cut-off of NKA level for the prediction of PC was 500pg/dL, with a sensitivity of 68.0% and a specificity of 73.1%. In addition, NKA level (0.630) had the greatest area under the ROC curve compared to those for the ratio of total PSA to free PSA (0.597) and PSA density (0.578). Conclusions The results of this pilot study revealed that low NKA and high PSA levels were likely to be associated with a positive TRBx outcome. NKA detection was easy and improved the diagnostic accuracy of PC.

Can natural killer cell activity help screen patients requiring a biopsy for the diagnosis of prostate cancer?

PURPOSE: To evaluate the usefulness of natural killer cell activity (NKA) in diagnosing prostate cancer (PC). MATERIALS AND METHODS: The medical records of patients who underwent transrectal prostate biopsy (TRBx) at Korea University Ansan Hospital between May 2017 and December 2017 were retrospectively reviewed. NKA levels were measured using NK VueR Tubes (ATgen, Sungnam, Korea). All blood samples were obtained at 8 AM on the day of biopsy. Patients with other malignancies, chronic inflammatory conditions, high prostate-specifi c antigen (PSA) level (>20ng/mL), or history of taking 5-alphareductase inhibitor or testosterone replacement therapy were excluded. RESULTS: A total of 102 patients who underwent TRBx for PC diagnosis were enrolled. Among them, 50 were diagnosed with PC. Significant differences in age and NKA level were observed between the PC and no-PC groups. Receiver operating characteristic (ROC) curve analysis showed that the optimal cut-off of NKA level for the prediction of PC was 500pg/dL, with a sensitivity of 68.0% and a specifi city of 73.1%. In addition, NKA level (0.630) had the greatest area under the ROC curve compared to those for the ratio of total PSA to free PSA (0.597) and PSA density (0.578). CONCLUSIONS: The results of this pilot study revealed that low NKA and high PSA levels were likely to be associated with a positive TRBx outcome. NKA detection was easy and improved the diagnostic accuracy of PC.

Preoperative sterile pyuria as a prognostic biomarker for intravesical recurrence in upper urinary tract urothelial carcinoma.

Purpose: To evaluate if preoperative sterile pyuria can be a prognostic factor for intravesical recurrence (IVR) and overall survival (OS)in patients with upper tract urothelial carcinoma (UTUC) undergoing surgery. Materials and Methods: We retrospectively reviewed the medical records of patients who were diagnosed with UTUC from October 2003 to December 2016 at Korea University Medical Center. Sterile pyuria was defined as urine containing five or more white blood cells per high-power field in the absence of bacteria in urine culture. We used a stepwise multivariable Cox proportional hazards model to assess the independent effects of the prognostic factors for IVR and OS. Results: We investigated a total of 176 patients who were diagnosed with UTUC. Among them, 91 (51.7%) patients had preoperative sterile pyuria. There were no significant differences in the baseline characteristics between the pyuria and non-pyuria groups concerning tumor grade, T stage, tumor multiplicity, and recurrence history. However, there was a significant difference in the IVR between the two groups. In the multivariable analysis, preoperative sterile pyuria, diabetes mellitus, high-grade tumor, and lymphovascular invasion were revealed as independent risk factors for IVR, and only lymphovascular invasion was identified as an independent risk factor for OS. Conclusions: Preoperative sterile pyuria is significantly associated with IVR in patients with UTUC undergoing surgery, but it is not associated with OS. Furthermore, diabetes mellitus, high-grade tumor, and lymphovascular invasion are also independent prognostic factors for these patients.

Seasonal Variation of Overactive Bladder Symptoms in Female Patients.

PURPOSE: To evaluate seasonal variations of overactive bladder (OAB) symptoms in women who visited hospital clinics. METHODS: Medical records of female patients treated for OAB symptoms from January 2011 to December 2017 were retrospectively reviewed. Patients with pyuria at the first visit, those who did not complete the questionnaire, and those with <3 overactive bladder symptom scores (OABSS) were excluded. Uroflowmetric parameters, 3-day micturition diary, and OABSS were analyzed. RESULTS: A total of 582 patients with OAB symptoms who visited the hospital were enrolled in this study. Patients were grouped into 1 of the 3 season groups (cold, intermediate, and hot) depending on the average temperature of the month that the patient first visited the urologic department outpatient clinic. The total OABSS was significantly different between the 3 season groups (cold [7.25±3.20] vs. intermediate [6.24±3.40] vs. hot [5.51±3.20], P=0.001). The proportion of patients who had moderate OAB symptoms (6≤OABSS) was higher in the cold season group (56.2%) than in the other season groups (intermediate, 42.1%; hot, 31.8%; P=0.002). Differences in the number of micturitions (12.12±4.56 vs. 10.95±4.39, P=0.021) and number of urgent urinary incontinence episodes (2.06±0.94 vs. 2.48±0.87, P=0.001) between the cold and hot season groups were also significant. However, differences in the nocturia episode, total daytime voided volume, and mean voided volume between season groups were not significant. CONCLUSION: Different urinary symptoms and uroflowmetric parameters were correlated with seasonal variation. OAB symptoms might be worse in cold season than in other seasons.

Is androgen deprivation therapy associated with cerebral infarction in patients with prostate cancer? A Korean nationwide population-based propensity score matching study.

PURPOSE: Previous studies have suggested that androgen deprivation therapy (ADT) is associated with cerebral infarction. However, conflicting results have been reported by other researchers. The aim of this study was to evaluate the association between ADT and cerebral infarction in patients with prostate cancer (PC) using big data. MATERIALS AND METHODS: Using information from the National Health Insurance Service database representative of the entire Korean adult PC population (n = 206 735), data regarding ADT and cerebral infarction between 2009 and 2016 were analyzed. Adjusted hazard ratios for cerebral infarction associated with ADT were estimated using propensity score-matched Cox proportional hazards models and Kaplan-Meier survival analyses. RESULTS: The final cohort comprised 36 146 individuals with PC, including 24 069 men (66.6%) who underwent ADT. During the mean follow-up of 4.1 years, 2792 patients were newly diagnosed with cerebral infarction. In the unmatched cohort, there was a significant difference in the annual incidence of cerebral infarction between the ADT and non-ADT groups (22.8 vs 14.6 per 1000 person-years, respectively). However, there was no significant difference between the ADT and non-ADT groups in the matched cohort (14.9 vs 14.6 per 1000 person-years). The adjusted hazard ratio for cerebral infarction for PC patients who underwent ADT was 1.045 (95% CI 0.943-1.159; P = 0.401) compared with those who did not undergo ADT. In addition, the cumulative duration of ADT was also not associated with an increased risk for cerebral infarction. However, older age, hypertension, diabetes, myocardial infarction, congestive heart failure, peripheral vascular disease, renal disease, dementia, and atrial fibrillation were revealed to be factors contributing to cerebral infarction. CONCLUSION: This nationwide population-based study revealed that ADT was not associated with cerebral infarction after adjusting for potential confounders.

Analysis of Present Status for Surgery of Benign Prostatic Hyperplasia in Korea Using Nationwide Healthcare System Data.

PURPOSE: There are no established statistical data available for the comparison of different surgical methods adopted for the resection of benign prostatic hyperplasia (BPH). This study investigates the present status related to BPH surgery in Korea for the past 8 years. METHODS: National-level data from the National Health Insurance Service and National Statistical Office were analyzed in this study. From 2010 to 2017, the trends of surgeries for BPH were reviewed according to the procedure code including transurethral resection of the prostate (TURP), holmium laser enucleation of the prostate (HoLEP), or high-power potassium titanyl phosphate (KTP), and this trend also analyzed by age, geographic distribution, and hospital type. RESULTS: Over the past 8 years, there was not much change in the total number of BPH-related surgeries (range, 10,393- 11,072). Although there was not much alteration in the number of conventional TURP (from 6,801 in 2010 to 6,645 in 2017), the number of HoLEP has dramatically increased (from 278 in 2010 to 3,805 in 2017). The number of HoLEP surgeries after 2011 exceeded the number of surgeries using KTP, and the gap is anticipated to rise. The number of surgeries by age group was most common in the 70s and the total number of surgeries is decreasing in all age groups; for HoLEP, the trend is steadily increasing over the age of 60 years. Most of the BPH surgeries were performed in metropolitan areas, such as Seoul, Gyeonggido, and Busan, and in larger hospitals compared to smaller hospital settings. CONCLUSION: Through the data of the National Health Insurance Service, we could apprehend the present status of BPH-related surgery in Korea. Then, we could know about the trend according to several factors and we think these results will be valuable as academic references as well.

Selective clamping hand-assisted laparoscopic partial nephrectomy for localized renal tumors: A novel technique.

Purpose: In this study, we described our initial experience and analyze the learning curve of segmental renal artery branch clamping with hand-assisted laparoscopic partial nephrectomy (PN) using special instruments. Materials and Methods: We conducted a retrospective review of consecutive cases of hand-assisted laparoscopic PN (LPN) between May 2015 and April 2018. Patient demographics, tumor characteristics, perioperative details, postoperative complications, and warm ischemic time for segmental artery branch clamping were included in our analysis. We used the cumulative sum (CUSUM) method to generate learning curves. Results: Segmental renal artery branch clamping was successfully completed in 16 of 20 patients. The median tumor size was 2.9 cm (range, 1.7-7.0 cm), median operation time was 185 minutes (range, 140-245 minutes), median blood loss was 291 mL (range, 100-600 mL), and median hospital stay was 5 days (range, 4-7 days). The median selective ischemic time was 21 minutes (range, 16-35 minutes). No patient had postoperative complications, acute or delayed bleeding. The median pre- and postoperative serum creatinine levels (0.91 and 0.98 mg/dL, respectively), and the pre- and postoperative estimated glomerular filtration rate (89.7 and 79.6 mL/min per 1.73 m2, respectively) were similar. Upon visual assessment of the CUSUM plots, a downward inflection point for decreasing total operation time was observed in the 9th case and estimated blood loss in the 12th case. Conclusions: Our study shows that segmental renal artery branch clamping hand-assisted LPN for localized renal tumors is feasible, safe, and has a relatively short learning curve.

α-Blocker and Risk of Dementia in Patients with Benign Prostatic Hyperplasia: A Nationwide Population Based Study Using the National Health Insurance Service Database.

PURPOSE: A recent study demonstrated that tamsulosin increased the risk of dementia in patients with benign prostatic hyperplasia. However, this study had a number of limitations. We evaluated the association between α-blockers and dementia in patients with benign prostatic hyperplasia. MATERIALS AND METHODS: From the National Health Insurance Service database we collected and analyzed data on α-blockers and dementia in the entire Korean adult population with benign prostatic hyperplasia between January 2011 and December 2011. These patients were followed until September 2017. We tested the effect of α-blockers on the risk of dementia using propensity score matched Cox proportional hazard regression models and Kaplan-Meier survival analysis. RESULTS: During a mean ± SD followup of 1,580 ± 674.3 days all study inclusion and exclusion criteria were met by 59,263 patients with benign prostatic hyperplasia. In the unadjusted cohort the incidence of dementia in the tamsulosin, doxazosin, terazosin, alfuzosin and no medication cohorts were 17.97%, 18.55%, 20.64%, 17.62% and 22.60%, respectively. After propensity score matching the risk of dementia did not significantly differ in the tamsulosin cohort vs the doxazosin and alfuzosin cohorts (HR 1.038, 95% CI 0.960-1.121 and HR 1.008, 95% CI 0.925-1.098), respectively. Compared to the tamsulosin cohort the terazosin cohort had a higher risk of dementia (HR 1.112, 95% CI 1.052-1.196). However, the risk of dementia was significantly lower in the terazosin cohort than in the no medication cohort. CONCLUSIONS: The study findings indicate that benign prostatic hyperplasia medication is not associated with a risk of dementia by duration of use or by type.

Electric field control of nonvolatile four-state magnetization at room temperature.

We find the realization of large converse magnetoelectric (ME) effects at room temperature in a magnetoelectric hexaferrite Ba0.52Sr2.48Co2Fe24O41 single crystal, in which rapid change of electric polarization in low magnetic fields (about 5 mT) is coined to a large ME susceptibility of 3200 ps/m. The modulation of magnetization then reaches up to 0.62µ(B)/f.u. in an electric field of 1.14 MV/m. We find further that four ME states induced by different ME poling exhibit unique, nonvolatile magnetization versus electric field curves, which can be approximately described by an effective free energy with a distinct set of ME coefficients.