Evaluation of learning curves for contact laser vaporization of the prostate using the 980 nm diode laser for benign prostatic hyperplasia.

OBJECTIVES: We investigated the background of patients who underwent contact laser vaporization of the prostate (CVP) surgery and the learning curve of the operators. METHODS: A total of 207 patients who underwent CVP surgery for benign prostatic hyperplasia between August 2018 and March 2023 were included in this study. Patient background, perioperative results, pre- and postoperative urinary flow tests, and complications were collected retrospectively. RESULTS: We enrolled 12 doctors who were divided into expert (five doctors) and novice (seven doctors) groups based on the number of TURP experiences before CVP. The median patient age was 73 years (51-92 years) and prostate volume was 56 cc (15-190 cc) with no difference between the expert and novice groups. Complications included urinary retention (eight cases), hematuria (four), urinary tract infection (four), intraoperative perforation (two), and postoperative stricture (one). Both cases of intraoperative perforation occurred in the novice group. The expert group had a significantly shorter operative time (38 vs. 66 min) and a higher operative efficacy of prostate volume divided by operative time (1.43 vs. 0.88 cc/min). Postoperatively, IPSS, quality of life scores, and postvoid residual urine volume decreased, and maximal flow rate increased; however, there was no significant difference between the groups. The expert group showed stable operative time and operative efficacy after about five to eight cases, while the novice group showed stable after about 15 cases. CONCLUSIONS: Our findings suggest that CVP was safely performed at our hospital, and operators with limited experience in TURP can achieve stable perioperative results.

A prospective study of surgeons' workloads and associated factors in real-world practice.

New technologies such as laparoscopic and robotic surgery are spreading, and there is a demand for physicians to keep up with novel methods. In contrast to the recent focus on healthcare professional burnout, the mental and physical costs during surgery are not well-understood. We aimed to quantify surgeons' workloads in daily urological surgical practice and clarify potential background factors associated with such workloads. Urologists in Hokkaido, Japan, were invited to this study. Between December 2020 and December 2021, participants repeatedly reported workloads, which were assessed using the National Aeronautics and Space Administration-Task Load Index (NASA-TLX), after each surgery in conjunction with participants' names, patients' backgrounds, their roles (independent operator, operator under supervision, instructor, and 1st or 2nd assistant), and surgical outcomes, via SurveyMonkey®. Because of the heterogeneity among individuals, a linear mixed-effects model was utilized to analyze factors associated with NASA-TLX, calculating the parameter estimates (PE) of regression coefficients for each factor and their 95% confidence interval (CI). Sixty-five urologists (5 women) joined the study, and 2169 data were collected within 7 days after surgeries. A linear mixed-effects model revealed that female surgeons (PE + 15.56, 95% CI 2.36-28.77), urgent/emergency surgery (PE + 6.65, 95% CI 4.59-8.70), intraoperative complications (PE + 9.26, 95% CI 6.76-11.76), and near-miss incidents (PE + 3.81, 95% CI 2.27-5.36) were associated with higher workloads. Regarding the surgeons' role, operator under supervision (PE + 12.46, 95% CI 9.86-15.06) showed the highest workloads. Surgeons' workloads decreased as the number of previous cases of the same procedure increased. Surgeons' workloads were associated with various factors. Given that the highest workloads were for operators under supervision, instructors should be aware of trainees' high workloads and devise appropriate instructional interventions.

Gap analysis between trainees' subjective competencies and the competencies expected by instructors in urology: A need assessment survey in Japan.

OBJECTIVE: According to the rapid progress in surgical techniques, a growing number of procedures should be learned during postgraduate training periods. This study aimed to clarify the current situation regarding urological surgical training and identify the perception gap between trainees' competency and the competency expected by instructors in Japan. METHODS: Regarding the 40 urological surgical procedures selected via the Delphi method, we collected data on previous caseloads, current subjective autonomy, and confidence for future skill acquisition from trainees (<15 post-graduate years [PGY]), and the competencies when trainees became attending doctors expected by instructors (>15 PGY), according to a 5-point Likert scale. In total, 174 urologists in Hokkaido Prefecture, Japan were enrolled in this study. RESULTS: The response rate was 96% (165/174). In a large proportion of the procedures, caseloads grew with accumulation of years of clinical practice. However, trainees had limited caseloads of robotic and reconstructive surgeries even after 15 PGY. Trainees showed low subjective competencies at present and low confidence for future skill acquisition in several procedures, such as open cystectomy, ureteroureterostomy, and ureterocystostomy, while instructors expected trainees to be able to perform these procedures independently when they became attending doctors. CONCLUSION: Trainees showed low subjective competencies and low confidence for future skill acquisition in several open and reconstructive procedures, while instructors considered that these procedures should be independently performable by attending doctors. We believe that knowledge of these perception gaps is helpful to develop a practical training program.

Impact of postoperative complications on long-term survival in bladder cancer patients.

OBJECTIVE: To determine the impact of postoperative complications on long-term survival outcomes in patients with bladder cancer undergoing radical cystectomy. METHODS: This retrospective multi-institutional study included 766 bladder cancer patients who underwent radical cystectomy between 2011 and 2017. Patient characteristics, perioperative outcomes, all complications within 90 days after surgery and survival outcomes were collected. Each complication was graded based on the Clavien-Dindo system, and grouped using a standardized grouping method. The Comprehensive Complication Index, which incorporates all complications into a single formula weighted by their severity, was utilized. Overall survival and recurrence-free survival (local, distant or urothelial recurrences) were stratified by Comprehensive Complication Index (high: ≥26.2; low: <26.2). A multivariate model was utilized to identify independent prognostic factors. RESULTS: The incidence of any and major complications (≥Clavien-Dindo grade III) was 70 and 24%, respectively. In terms of Comprehensive Complication Index, 34% (261/766) of the patients had ≥26.2. Patients with Comprehensive Complication Index ≥ 26.2 had shorter overall survival (4-year, 59.5 vs. 69.8%, respectively, log-rank test, P = 0.0037) and recurrence free survival (51.9 vs. 60.1%, respectively, P = 0.0234), than those with Comprehensive Complication Index < 26.2. The Cox multivariate model identified the age, performance status, pT-stage, pN-stage and higher CCI (overall survival: HR = 1.35, P = 0.0174, recurrence-free survival: HR = 1.26, P = 0.0443) as independent predictors of both overall survivial and recurrence-free survival. CONCLUSIONS: Postoperative complications assessed by Comprehensive Complication Index had adverse effects on long-term survival outcomes. Physicians should be aware that major postoperative complications can adversely affect long-term disease control.

Stroma biglycan expression can be a prognostic factor in prostate cancers.

OBJECTIVES: This study analyzes the relationship between biglycan expression in prostate cancer and clinicopathological parameters to clarify the potential link between biglycan and prognosis and progression to castration-resistant prostate cancer (CRPC). METHODS: We retrospectively analyzed 60 cases of prostate cancer patients who underwent robot-assisted laparoscopic radical prostatectomy in Hokkaido University Hospital. RESULTS: Biglycan was expressed in the tumor stroma but not in tumor cells. There was no significant relationship with biochemical recurrence (p = 0.5237), but the expression of biglycan was 36.1% in the group with progression to CRPC. This indicates a significant relationship with progression to CRPC (p = 0.0182). Furthermore, the expression of biglycan-positive blood vessels was significantly higher (15.9%) in the group with biochemical recurrence than in the group without biochemical recurrence (8.5%) (p = 0.0169). The biglycan-positive vessels were 28.6% in the group with progression to CRPC, which was significantly higher than that in the group without progression to CRPC (p < 0.0001). CONCLUSION: This is the first study to show that stroma biglycan is a useful prognostic factor for prostate cancer.

Validation of the Japanese version of the Body Image Scale for bladder cancer patients.

The Body Image Scale (BIS) is a 10-item tool that measures the body images of cancer patients. This study aims to validate the Japanese version of the BIS for bladder cancer patients. A multicenter cross-sectional survey was used to identify the participants, which included Japanese bladder cancer patients. The percentage of missing responses, internal consistency, and known-group validity were evaluated. The correlations between the BIS and two HRQOL instruments (the Bladder Cancer Index and the SF-12) were assessed to determine convergent validity. Among 397 patients, 221 patients were treated by transurethral resection of bladder tumor (TURBT) endoscopically, 49 patients underwent cystectomy with neobladder, and 127 patients underwent cystectomy involving stoma. The percentage of missing responses in the BIS ranged from 8.1 to 15.6%. Cronbach's α coefficient was 0.924. Higher BIS scores indicate negative body image, and the median BIS score for patients with native bladders after TURBT (0.5) was significantly lower than those of the patients with neobladder (4.0) and stoma formation (7.0), which indicated the discriminatory ability of the BIS. Each domain of the Bladder Cancer Index and the role summary score of the SF-12 correlated to the BIS scores, which confirmed the convergent validity. A range of BIS scores were identified among patients who reported similar physical summary scores and mental summary scores of the SF-12. This study confirmed the reliability and validity of the Japanese version of the BIS for bladder cancer patients.

Automatic assessment of laparoscopic surgical skill competence based on motion metrics.

The purpose of this study was to characterize the motion features of surgical devices associated with laparoscopic surgical competency and build an automatic skill-credential system in porcine cadaver organ simulation training. Participants performed tissue dissection around the aorta, dividing vascular pedicles after applying Hem-o-lok (tissue dissection task) and parenchymal closure of the kidney (suturing task). Movements of surgical devices were tracked by a motion capture (Mocap) system, and Mocap-metrics were compared according to the level of surgical experience (experts: ≥50 laparoscopic surgeries, intermediates: 10-49, novices: 0-9), using the Kruskal-Wallis test and principal component analysis (PCA). Three machine-learning algorithms: support vector machine (SVM), PCA-SVM, and gradient boosting decision tree (GBDT), were utilized for discrimination of the surgical experience level. The accuracy of each model was evaluated by nested and repeated k-fold cross-validation. A total of 32 experts, 18 intermediates, and 20 novices participated in the present study. PCA revealed that efficiency-related metrics (e.g., path length) significantly contributed to PC 1 in both tasks. Regarding PC 2, speed-related metrics (e.g., velocity, acceleration, jerk) of right-hand devices largely contributed to the tissue dissection task, while those of left-hand devices did in the suturing task. Regarding the three-group discrimination, in the tissue dissection task, the GBDT method was superior to the other methods (median accuracy: 68.6%). In the suturing task, SVM and PCA-SVM methods were superior to the GBDT method (57.4 and 58.4%, respectively). Regarding the two-group discrimination (experts vs. intermediates/novices), the GBDT method resulted in a median accuracy of 72.9% in the tissue dissection task, and, in the suturing task, the PCA-SVM method resulted in a median accuracy of 69.2%. Overall, the mocap-based credential system using machine-learning classifiers provides a correct judgment rate of around 70% (two-group discrimination). Together with motion analysis and wet-lab training, simulation training could be a practical method for objectively assessing the surgical competence of trainees.

Objective evaluation of laparoscopic surgical skills in wet lab training based on motion analysis and machine learning.

BACKGROUND: Our aim was to build a skill assessment system, providing objective feedback to trainees based on the motion metrics of laparoscopic surgical instruments. METHODS: Participants performed tissue dissection around the aorta (tissue dissection task) and renal parenchymal closure (parenchymal-suturing task), using swine organs in a box trainer under a motion capture (Mocap) system. Two experts assessed the recorded movies, according to the formula of global operative assessment of laparoscopic skills (GOALS: score range, 5-25), and the mean scores were utilized as objective variables in the regression analyses. The correlations between mean GOALS scores and Mocap metrics were evaluated, and potential Mocap metrics with a Spearman's rank correlation coefficient value exceeding 0.4 were selected for each GOALS item estimation. Four regression algorithms, support vector regression (SVR), principal component analysis (PCA)-SVR, ridge regression, and partial least squares regression, were utilized for automatic GOALS estimation. Model validation was conducted by nested and repeated k-fold cross validation, and the mean absolute error (MAE) was calculated to evaluate the accuracy of each regression model. RESULTS: Forty-five urologic, 9 gastroenterological, and 3 gynecologic surgeons, 4 junior residents, and 9 medical students participated in the training. In both tasks, a positive correlation was observed between the speed-related parameters (e.g., velocity, velocity range, acceleration, jerk) and mean GOALS scores, with a negative correlation between the efficiency-related parameters (e.g., task time, path length, number of opening/closing operations) and mean GOALS scores. Among the 4 algorithms, SVR showed the highest accuracy in the tissue dissection task ([Formula: see text]), and PCA-SVR in the parenchymal-suturing task ([Formula: see text]), based on 100 iterations of the validation process of automatic GOALS estimation. CONCLUSION: We developed a machine learning-based GOALS scoring system in wet lab training, with an error of approximately 1-2 points for the total score, and motion metrics that were explainable to trainees. Our future challenges are the further improvement of onsite GOALS feedback, exploring the educational benefit of our model and building an efficient training program.

Comparative study of postoperative complications after radical cystectomy during the past two decades in Japan: Radical cystectomy remains associated with significant postoperative morbidities.

OBJECTIVES: During the past 2 decades, in order to improve perioperative and oncological outcomes, a minimally invasive approach, neoadjuvant chemotherapy (NAC), and an enhanced postoperative recovery program after surgery have been introduced into routine clinical practice of radical cystectomy (RC). Our aim was to examine the differences in clinical practice and postoperative complications after RC by comparing our previous and current cohorts. MATERIALS AND METHODS: A retrospective multi-institutional study. We collected all complications within 90 days after surgery between 2011 and 2017 (current cohort), and categorized them according to a standardized methodology. Then, we compared the outcomes with those in our previous study (previous cohort, 1997-2010). A multivariate logistic regression model was utilized to determine predictors of complications in the current cohort. RESULTS: A total of 838 patients were newly collected (current cohort), and 919 from the previous cohort were included in the subsequent analyses. In the current cohort, the rate of performing NAC was significantly higher (13% vs. 4%, respectively, P < 0.0001), and 26% (222/838) underwent laparoscopic RC (LRC, without robotic assistance: n = 210, with robotic assistance: n = 12). There was no significant difference in the overall complication [69% (580/838) vs. 68% (629/919), respectively, P = 0.7284] or major complication (Grades 3-5) [25% (211/838) vs. 22% (201/919), respectively, P = 0.1022] rates between the 2 cohorts. In both cohorts, the most frequent categories were infectious, gastrointestinal, wound-related, and genitourinary. In the current cohort, the performance status (odds ratio, OR = 2.11, P = 0.0013) and operative time (OR = 1.003, P = 0.0016) remained significant predictors of major complications. NAC was not associated with any or major complications. CONCLUSIONS: Surgical complications related to RC still remain significant problems, despite the recent improvements in surgical techniques and perioperative care. NAC did not increase the complications.

Motion analysis for better understanding of psychomotor skills in laparoscopy: objective assessment-based simulation training using animal organs.

BACKGROUND: Our aim was to characterize the motions of multiple laparoscopic surgical instruments among participants with different levels of surgical experience in a series of wet-lab training drills, in which participants need to perform a range of surgical procedures including grasping tissue, tissue traction and dissection, applying a Hem-o-lok clip, and suturing/knotting, and digitize the level of surgical competency. METHODS: Participants performed tissue dissection around the aorta, dividing encountered vessels after applying a Hem-o-lok (Task 1), and renal parenchymal closure (Task 2: suturing, Task 3: suturing and knot-tying), using swine cadaveric organs placed in a box trainer under a motion capture (Mocap) system. Motion-related metrics were compared according to participants' level of surgical experience (experts: 50 ≤ laparoscopic surgeries, intermediates: 10-49, novices: 0-9), using the Kruskal-Wallis test, and significant metrics were subjected to principal component analysis (PCA). RESULTS: A total of 15 experts, 12 intermediates, and 18 novices participated in the training. In Task 1, a shorter path length and faster velocity/acceleration/jerk were observed using both scissors and a Hem-o-lok applier in the experts, and Hem-o-lok-related metrics markedly contributed to the 1st principal component on PCA analysis, followed by scissors-related metrics. Higher-level skills including a shorter path length and faster velocity were observed in both hands of the experts also in tasks 2 and 3. Sub-analysis showed that, in experts with 100 ≤ cases, scissors moved more frequently in the "close zone (0 ≤ to < 2.0 cm from aorta)" than those with 50-99 cases. CONCLUSION: Our novel Mocap system recognized significant differences in several metrics in multiple instruments according to the level of surgical experience. "Applying a Hem-o-lok clip on a pedicle" strongly reflected the level of surgical experience, and zone-metrics may be a promising tool to assess surgical expertise. Our next challenge is to give completely objective feedback to trainees on-site in the wet-lab.

Development and validation of a porcine organ model for training in essential laparoscopic surgical skills.

OBJECTIVES: To develop a wet laboratory training model for learning core laparoscopic surgical skills and evaluating learners' competency level outside the operating room. METHODS: Participants completed three tasks (task 1: tissue dissection around the aorta; task 2: tissue dissection and division of the renal artery; task 3: renal parenchymal closure). Each performance was video recorded and subsequently evaluated by two experts, according to the Global Operative Assessment of Laparoscopic Skills and task-specific metrics that we developed (Assessment Sheet of Laparoscopic Skills in Wet Lab score). Mean scores were used for analyses. The subjective mental workload was also assessed (NASA Task Load Index). RESULTS: The 54 participants included 32 urologists, eight young trainees and 14 medical students. A total of 13 participants were categorized as experts (≥50 laparoscopic surgeries), eight as intermediates (10-49) and 33 as novices (0-9). There were significant differences in the Global Operative Assessment of Laparoscopic Skills and Assessment Sheet of Laparoscopic Skills in Wet Lab scores among the three groups in all three tasks. Higher NASA Task Load Index scores were observed in novices, and there were significant differences in tasks 1 (Kruskal-Wallis test, P = 0.0004) and 2 (P = 0.0002), and marginal differences in task 3 (P = 0.0745) among the three groups. CONCLUSIONS: Our training model has good construct validity, and differences in the NASA Task Load Index score reflect previous laparoscopic surgical experiences. Our findings show the ability to assess both laparoscopic surgical skills and mental workloads, which could help educators comprehend trainees' level outside the operating room. Given the decreasing opportunity to carry out pure laparoscopic surgeries because of the dissemination of robotic surgery, especially in urology, our model can offer practical training opportunities.

Health-related quality of life in Japanese patients with bladder cancer measured by a newly developed Japanese version of the Bladder Cancer Index.

INTRODUCTION: We validated a Japanese version of the Bladder Cancer Index (BCI) as a tool for measuring health-related quality of life (HRQOL) in bladder cancer patients treated with various surgical procedures. METHODS: The reliability and validity of the Japanese BCI were examined in 397 Japanese patients with bladder cancer via cross-sectional analysis. The patients simultaneously completed the Short Form (SF)-12, EQ-5D, and the Functional Assessment of Cancer Therapy-General and Bladder (FACT-G and FACT-BL). The differences in BCI subscales among various treatment groups were analyzed. RESULTS: This study involved 397 patients (301 males and 96 females), with a mean age of 70 years and a median disease duration of 29 months (IQR: 12-66 months). Of these patients, 221 underwent transurethral resection of a bladder tumor, and 176 patients underwent radical cystectomy (ileal conduit: 101 patients, ileal neobladder: 49, and ureterostomy: 26). Cronbach's alpha coefficient was ≥ 0.78 for all subscales, except the bowel bother subscale. Despite moderate correlations being detected between the function and bother score in urinary and bowel domains, the sexual function score was inversely correlated with the sexual bother score (r = - 0.19). A missing value percentage of > 15% was associated with old age (p < 0.05). The mean domain scores differed significantly among distinct clinically relevant treatment groups. CONCLUSIONS: Although revisions are needed to make it easier for elderly patients to comprehend, we confirmed the reliability and validity of the Japanese BCI. The Japanese BCI could be used for cross-cultural assessments of HRQOL in bladder cancer patients.

Retroperitoneal extragonadal germ cell tumor without distant metastasis: a case report.

A 66-year-old man was referred to our hospital for an incidentally detected 40-mm mass located at the inter-aortocaval area around the renal hilum. Positron emission tomography CT revealed high accumulation (SUVmax 12.382) without distant metastasis. Bilateral testes were normal by ultrasonography and physical examination, but the serum AFP level was increased to 1161 ng/mL. The pathology based on trans-duodenal needle biopsy demonstrated a yolk sac tumor; therefore, we diagnosed him with retroperitoneal primary germ cell tumor. Due to old age, the potential toxicity of systemic chemotherapy, and no significant signs of invasion to adjacent organs, we performed surgical resection. Although the AFP level decreased to 13.2 ng/mL postoperatively, it increased to 553 ng/mL 2 months after surgery without clinical recurrence on imaging studies. Four cycles of a VIP regimen (VP-16, ifosfamide, and CDDP) were performed, and the AFP level normalized to 2.4 ng/mL. The patient is now disease-free 1 year and 6 months after surgery.

[Giant Prostate Carcinoma : A Case Report and Long-Term Outcomes in Japanese Patients].

A 79-year-old male was referred to the Department of Gastroenterology in our hospital due to a large palpable abdominal mass, with the suspicion of a gastrointestinal stromal tumor. An abdominal computed tomographic (CT) scan revealed a huge mass of 270×208×144 mm which occupied the entire pelvic cavity. Since the specimens obtained by an endoscopic ultrasound-guided fine-needle aspiration via lower intestinal tract revealed a Gleason score 4＋4 prostate adenocarcinoma, he was then referred to our department. Prostate specific antigen (PSA) was elevated to 3,087 ng/ml, and positron emission tomography-CT revealed right obturator lymph node metastasis and bone metastasis of the left 5th rib. Degarelix was administered as an androgen deprivation therapy, and the PSA level had decreased to 62.4 ng/ml one month later. At the last follow-up, the PSA level was 0.67 ng/ml and the tumorsize had decreased to 88×83×110 mm. Next, we conducted a follow-up survey by mail of 20 reported Japanese cases of a giant prostate carcinoma, and data on 17 cases were available for analysis. In the total of 18 cases, including the present case, with a median follow-up time of 26 months, the 2-year overall survival rate was 85.7% for patients without metastasis, and 65.6% forthose with metastasis.