Establishment and Evaluation of Patient-Specific Virtual Ureteroscopy in Assisting Flexible Ureteroscopy for Urolithiasis.

OBJECTIVES: To establish virtual ureteroscopy (VU) through computed tomography urography (CTU) data from patients with upper urinary tract (UUT) stones indicated for flexible ureteroscopy (fURS) and to validate its effectiveness. METHODS: Patient-specific VU generation was accomplished through incorporating CTU data into specialized software (Crusher) developed on the open access Visualization Tools Kit (VTK). These were then presented to fURS experts and novice urologists for evaluation and comparison using modified Likert-type questionnaire of 10-point rating scales (1 = not at all useful/not at all realistic/poor, 10 = very useful/very realistic/ excellent). RESULTS: Face and content validation of VU from 5 fURS experts in 3 different centers: overall usefulness 7.4 ± 0.5, graphics 7.4 ± 0.5, intrarenal anatomy 8.4 ± 0.5, stone details 7.8 ± 0.4, usefulness in surgical planning and training 7.6 ± 0.9. Significant increase of detection in the number of calyces and stones was found from using CTU only to CTU-VU combined in the novice group ( P = .000). Before VU observation, novices found much fewer calyces and stones than experts ( P = .004 and .000, respectively). However, this gap disappeared after VU observation ( P = .327 and .292, respectively). VU feedback from the novices was superb. CONCLUSIONS: Establishing patient-specific VU through CTU data from renal stone patients is feasible. The present VU can significantly improve novice urologists' comprehension of intrarenal anatomy and stone information before fURS procedures. Face and content validity is also proved. This novel modality may serve as an important tool for fURS surgical planning, navigation, and training.

Evaluation of three-dimensional printing for laparoscopic partial nephrectomy of renal tumors: a preliminary report.

OBJECTIVES: To investigate the impact of three-dimensional (3D) printing on the surgical planning, potential of training and patients' comprehension of minimally invasive surgery for renal tumors. METHODS: Patients of a T1N0M0 single renal tumor and indicated for laparoscopic partial nephrectomy were selected. CT data were sent for post-processing and output to the 3D printer to create kidney models with tumor. By presenting to experienced laparoscopic urologists and patients, respectively, the models' realism, effectiveness for surgical planning and training, and patients' comprehension of disease and procedure were evaluated with plotted questionnaires (10-point rating scales, 1-not at all useful/not at all realistic/poor, 10-very useful/very realistic/excellent). The size of resected tumors was compared with that on the models. RESULTS: Ten kidney models of such patients were fabricated successfully. The overall effectiveness in surgical planning and training (7.8 ± 0.7-8.0 ± 1.1), and realism (6.0 ± 0.6-7.8 ± 1.0) were reached by four invited urologists. Intraoperative correlation was advocated by the two performing urologists. Patients were fascinated with the demonstration of a tactile "diseased organ" (average ≥ 9.0). The size deviation was 3.4 ± 1.3 mm. CONCLUSIONS: Generating kidney models of T1N0M0 tumors with 3D printing are feasible with refinements to be performed. Face and content validity was obtained when those models were presented to experienced urologists for making practical planning and training. Understandings of the disease and procedure from patients were well appreciated with this novel technology.

Validation of a novel non-biological bench model for the training of percutaneous renal access.

PURPOSE: The percutaneous renal access (PRA) is the most critical step of percutaneous renal surgery (PRS). For the training of PRA in the lab, a novel non-biological bench model was developed and set for validation test. MATERIALS AND METHODS: Experts in PRS (> 60 cases) and novices were included to perform fluoroscopy guided PRA on the model. Overall time, X-ray exposure time and puncture attempts were recorded to establish construct validity. After accomplishment, the experts rated the model using a standardized questionnaire for face and content validity based on a 5-point Likert scale, with 1 denoting very bad and 5 as excellent. Baseline and post-training data of novices were analyzed for skill acquisition. RESULTS: 9 experts and 30 novices were finally included. The overall appraisal was 4 by the experts, and consensus of all experts was reached for the model as an excellent training tool. Significant difference between experts and novices was detected with the experts using less total time 183.11 ± 29.40 vs. 278.00 ± 50.30 seconds (P < 0.001), shorter X-ray exposure time 109.22 ± 19.93 vs. 183.13 ± 38.83 seconds (P < 0.001), and fewer attempts 1.28 ± 0.44 vs. 2.35 ± 0.65 (P < 0.001). After training, the novices demonstrated significant skill improvement in total and fluoroscopy time, and number of attempts (P < 0.001). CONCLUSIONS: Our non-biological model provides a new method for PRA training. The face, content and construct validity were demonstrated. This model allows contact with PRA skills and could be applied to the first step in the learning curve.

A prospective comparative study between minimally invasive percutaneous nephrolithotomy in supine position and flexible ureteroscopy in the management of single large stone in the proximal ureter.

OBJECTIVE: To investigate the difference and relative advantages between minimally invasive percutaneous nephrolithotomy (MPCNL) in supine position and flexible ureteroscopy (FURS) in the management of surgically indicated single large stone in the proximal ureter. METHODS: Patients with single large stone in the proximal ureter with slight to moderate hydronephrosis were prospectively selected and assigned into groups of MPCNL and FURS on the basis of the patient's choice. Demographic data, operative duration, postoperative hospital stay, complication rate, and stone-free rate were recorded and compared. RESULTS: From October 2010 to May 2012, 76 such patients were consecutively included into the study. No significant difference was found in preoperative demographics, including age, sex, and severity of hydronephrosis. Stone size was 15.6 ± 2.5 and 14.9 ± 2.3 mm (P = .349), operative duration 49.3 ± 11.7 and 67.2 ± 17.3 minutes (P <.001), postoperative hospital stay 4.2 ± 1.1 and 1.8 ± 0.8 days (P <.001), stone-free rate (residual ≤ 3 mm) 93.7% and 84.1% (P = .198), and complication rate over grade II (modified Clavien system) 12.5% and 6.8% (P = .398) in MPCNL and FURS groups respectively. CONCLUSION: Both MPCNL in supine position and FURS are effective and safe surgical options for patients with single large stone in the proximal ureter, when indicated. FURS is associated with faster recovery and less invasiveness than MPCNL in supine position.

Validation of a novel non-biological bench model for the training of percutaneous renal access

Purpose: The percutaneous renal access (PRA) is the most critical step of percutaneous renal surgery (PRS). For the training of PRA in the lab, a novel non-biological bench model was developed and set for validation test. Materials and Methods: Experts in PRS (> 60 cases) and novices were included to perform fluoroscopy guided PRA on the model. Overall time, X-ray exposure time and puncture attempts were recorded to establish construct validity. After accomplishment, the experts rated the model using a standardized questionnaire for face and content validity based on a 5-point Likert scale, with 1 denoting very bad and 5 as excellent. Baseline and post-training data of novices were analyzed for skill acquisition. Results: 9 experts and 30 novices were finally included. The overall appraisal was 4 by the experts, and consensus of all experts was reached for the model as an excellent training tool. Significant difference between experts and novices was detected with the experts using less total time 183.11 ± 29.40 vs. 278.00 ± 50.30 seconds (P < 0.001), shorter X-ray exposure time 109.22 ± 19.93 vs. 183.13 ± 38.83 seconds (P < 0.001), and fewer attempts 1.28 ± 0.44 vs. 2.35 ± 0.65 (P < 0.001). After training, the novices demonstrated significant skill improvement in total and fluoroscopy time, and number of attempts (P < 0.001). Conclusions: Our non-biological model provides a new method for PRA training. The face, content and construct validity were demonstrated. This model allows contact with PRA skills and could be applied to the first step in the learning curve. .

Effectiveness of the UroMentor virtual reality simulator in the skill acquisition of flexible cystoscopy.

BACKGROUND: Virtual reality (VR) has been recognized as a useful modality in the training of surgical skills. With respect to basic endoscopic skill training of urology, we sought to investigate the effectiveness of the UroMentor(TM) virtual reality simulator (VRS) in the skill acquisition of flexible cystoscopy. METHODS: Urologists familiar with rigid cystoscopy procedures were selected to take part in a virtual training course of flexible cystoscopy. Changes in total operating time, frequency of injury, number of digital markers inside the bladder, and the global rating scale (GRS) scores were assessed following eight repeated training sessions on the UroMentor(TM). RESULTS: Eighteen urologists voluntarily took part in the study. Total operating time was significantly lower after eight sessions of training by comparison ((111 ± 10) seconds and (511 ± 67) seconds, respectively; P < 0.001). Additionally, the frequency of injury decreased with training from (12 ± 2) times to (5 ± 1) times (P < 0.001), while the number of digital markers observed increased from 9 ± 0 to 10 ± 1 (P = 0.005). Finally, training with the UroMentor(TM) resulted in a GRS increase from (1.3 ± 0.2) points to (3.9 ± 0.2) points (P < 0.001). CONCLUSION: the VRS UroMentor(TM) can improve urologists' ability to perform flexible cystoscopy and could be used as an effective training tool for trainees.

Training for percutaneous renal access on a virtual reality simulator.

BACKGROUND: The need to develop new methods of surgical training combined with advances in computing has led to the development of virtual reality surgical simulators. The PERC Mentor(TM) is designed to train the user in percutaneous renal collecting system access puncture. This study aimed to validate the use of this kind of simulator, in percutaneous renal access training. METHODS: Twenty-one urologists were enrolled as trainees to learn a fluoroscopy-guided percutaneous renal accessing technique. An assigned percutaneous renal access procedure was immediately performed on the PERC Mentor(TM) after watching instruction video and an analog operation. Objective parameters were recorded by the simulator and subjective global rating scale (GRS) score were determined. Simulation training followed and consisted of 2 hours daily training sessions for 2 consecutive days. Twenty-four hours after the training session, trainees were evaluated performing the same procedure. The post-training evaluation was compared to the evaluation of the initial attempt. RESULTS: During the initial attempt, none of the trainees could complete the appointed procedure due to the lack of experience in fluoroscopy-guided percutaneous renal access. After the short-term training, all trainees were able to independently complete the procedure. Of the 21 trainees, 10 had primitive experience in ultrasound-guided percutaneous nephrolithotomy. Trainees were thus categorized into the group of primitive experience and inexperience. The total operating time and amount of contrast material used were significantly lower in the group of primitive experience versus the inexperience group (P = 0.03 and 0.02, respectively). CONCLUSIONS: The training on the virtual reality simulator, PERC Mentor(TM), can help trainees with no previous experience of fluoroscopy-guided percutaneous renal access to complete the virtual manipulation of the procedure independently. This virtual reality simulator may become an important training and evaluation tool in teaching fluoroscopy-guided percutaneous renal access.

Virtual reality simulator for training urologists on transurethral prostatectomy.

BACKGROUND: A virtual reality simulator provides a novel training model for improving surgical skills in a variety of fields. They can simulate a variety of surgical scenarios to improve the overall skills required for endoscopic operations, and also record the operative process of trainees in real-time and allow for objective evaluation. At present, some simulators for transurethral resection of the prostate (TURP) are available. The utility of virtual reality simulators in training of transurethral prostatectomy was investigated. METHODS: Thirty-eight urologists were randomly selected to take part in a simulation based training of TURP using the TURPSim(TM) system. Pre and post-training global rate scale (GRS) scores and objective parameters recorded by the simulator were assessed. Then, questionnaires were filled out. RESULTS: Compared with baseline levels, the GRS scores of trainees increased (18.0 ± 4.0 vs. 12.4 ± 4.2, P < 0.001), while the rate of capsule resection (26.3% ± 0.6% vs. 21.2% ± 0.4%, P < 0.001), amount of blood loss ((125.8 ± 86.3) ml vs. (83.7 ± 41.6) ml, P < 0.001), external sphincter injury (3.6 ± 2.9 vs. 2.0 ± 2.0, P < 0.001) decreased significantly after training. Most trainees were satisfied with the simulator based training and believed that the simulator accurately mimicked actual surgical procedures and could help improve their surgical skills. CONCLUSIONS: As a new method of training on transurethral prostatectomy skills, training of TURP using a virtual simulator can help urologists improve their surgical skills and safety. Therefore, the application of the TURPSim(TM) system in education and training of urologic surgery is warranted.

[Face and content validation of the virtual reality transurethral prostatic resection simulator].

OBJECTIVE: To evaluate the face and content validation of the virtual reality transurethral resection of the prostate simulator (TURPSim(TM)). METHODS: The 60 urology doctor aged 26 - 50 years old all over the country were enrolled for virtual reality training of TURP from September 2010 to June 2011. Participants classified as experts (more than 50 procedures performed) and novices (50 or fewer procedures performed) performed TURPs on TURPSim(TM) involving resection of 25 - 80 g prostate. They completed questionnaires regarding utility for residency training, realism and overall score of the TURPSim(TM). Performances of two groups were evaluated after 2-day training. RESULTS: were recorded and analyzed. RESULTS: Mean utility for residency training, realism and overall score were (8.8 ± 1.1) and (8.5 ± 1.4), (8.0 ± 1.2) and (8.4 ± 1.1), (8.7 ± 0.9) and (8.6 ± 0.8) in experts and novices respectively. There was no significant difference between two groups (P > 0.05). Spearman's correlation coefficients analysis showed an significant positive correlation between utility for residency training and realism (r = 0.625, P = 0.000), utility for residency training and overall score (r = 0.691, P = 0.000) in experts, utility for residency training and realism (r = 0.702, P = 0.000), utility for residency training and overall score (r = 0.664, P = 0.001) in novices. Prostate resection rate (87.3% ± 7.7%), bleeding control rate (94.4% ± 6.6%) and safety (95.2% ± 5.5%) in novices increased after training (t = -3.689, -2.274, -2.507, all P < 0.05). CONCLUSIONS: The face and content validation of transurethral resection of the prostate simulator is good, virtual reality training of TURP may improve the skills necessary to perform TURP. Transurethral resection of the prostate simulator can be used to train urology residents.

[Establishment nephrolithiasis rat model induced by nanobacteria and analysis of stone formation].

OBJECTIVE: To establish nephrolithiasis rat model induced by nanobacteria and to determine the relationship of nanobacteria with nephrolithiasis. METHODS: Thirty adult male SD rats were randomized into 3 groups (n=10 each): group A, given an intravenous injection of nanobacteria; group B, given an intravenous injection of nanobacteria and taken tetracycline; group C, as normal control. Eight weeks later, all rats were sacrificed and the kidneys were examined for pathology and the 24-h urine N-acetyl-beta-D-aminoglycoside enzyme (NAG) and lactate dehydrogenase (LDH) were detected. RESULTS: Histopathological studies revealed nanobacteria induced renal tubular crystallization, which was significantly different among the 3 groups (P=0.033). The crystallization was higher in group A than that in group B. The urinary NAG and LDH excretion were significantly different among the 3 groups (P<0.001). CONCLUSION: Nanobacteria may be involved in the pathogenesis of nephrolithiasis. Tetracycline may inhibit stone formation.

[Effect of nanobacteria on cell damage and crystal retention in renal tubular epithelial cells].

OBJECTIVE: To study the damage of nanobacteria on HK-2 cells, the possible principles, the effect of crystals (COM) adhering to HK-2 cells after the damage. METHODS: Four groups were chosen for the study: control group, NB group, nHAP group and COM group. Morphological changes of the HK-2 cells were observed after HE stain and with TEM after 12 hours and 24 hours. Meanwhile, the levels of H2O2, LDH, MDA and ATPases were surveyed after 6 hours,12 hours and 24 hours, respectively. And 6, 12, and 24 hours later, COM crystals were mixed into the culture fluids of each group. Then phalloidin-FITC was used to finish fluorescent staining of the cells. At last, the adhering effects of each group with the laser scanning confocal fluorescence microscope were observed and contrasted. RESULTS: After HE stain and with TEM: in NB and nHAP group, the shape of the cells changed, brush borders were arranged in disorder, vacuoles formed in the kytoplasms, the mitochondria became swelled up, the karyotheca dissolved and the nucleolus disappeared in some cells. After 24 hours, in NB group, the number of the cells in which the karyotheca dissolved was more than that in nHAP group. After 12 and 24 hours, the level of H2O2 in NB group was higher than that in control group and nHAP group; After 6 and 24 hours, the level of MDA in NB group was higher than that in control group and nHAP group; At each time point, there was no significant difference in the level of LDH between control group, nHAP group and NB group; After 12 hours, the activities of Na+/K+ ATPases in NB group and nHAP group were lower than those in control group. And after 24 hours, the activity of Na+/K+ ATPases in NB group was lower than that in control group; After 12 and 24 hours, the activities of Ca2+/Mg2+ ATPases in NB group was lower than those in control group. After 12 hours, the activity of Ca2+/Mg2+ ATPases in nHAP group was lower than that in control group. The observation with the laser scanning confocal fluorescence microscope: after 12 hours, showed that the number of the crystals adhering to the cells in NB group and COM group increased, and in COM group, some crystals had entered the cells; after 24 hours, the adhering effects of the crystals in NB and COM group were similar to those after 12 hours, but the number of adhered crystals was more than that after 12 hours; At each time point, there was no significant change in control and nHAP groups. CONCLUSION: Nanobacteria has a damage effect on HK-2 cells, the damage increases with the acting time expanding. The damage is more severe than that of nHAP. In the damage process of nanobacteria, the lipid peroxidation may play an important role. After the damage of nanobacteria, the adhering effect of the COM crystals to the cells increases observably, and the number of crystals adhering to the cells becomes more and more with the acting time expanding. Although nHAP also has a damage effect on HK-2 cells, it does not effect the adhering process.

[Analysis of serum electrolytes in urolithiasis patients].

OBJECTIVE: To define the difference of serum calcium (Ca), phosphorus (P), potassium (K), sodium (Na), chlorine (Cl), carbon dioxide combining power (CO2CP), hydrogen ion concentration (pH) of urine and urine specific gravity (SG) between those patients suffering from urolithiasis and non-urolithiasis at the same time period. METHODS: Data from 1 164 patients admitted to the Department of Urology, Peking University People's Hospital from January, 2005 to July, 2007 were retrospectively reviewed. Seven hundred fourteen patients suffered from urolithiasis, and 450 patients were diagnosed as non-urolithiasis. Blood and urine were taken from the patient the next morning after admission. Serum levels of Ca, P, K, Na, Cl, CO2CP and urine pH and SG were checked by automatic biochemistry analyzer. The data were analyzed by software SPSS 13.0. RESULTS: Patients' ages in urolithiasis group varied from 5 to 87 years and the male to female ratio was 1.8:1. The patients in non-urolithiasis group aged from 12 to 94 years and the male to female ratio was 3.8:1. There was difference in the levels of serum Na, K, Cl, CO2CP, Ca and P between urolithiasis and non-urolithiasis groups (P<0.05). In male patients, serum Na, Ca and P levels in urolithiasis group were higher than those in non-urolithiasis group(P<0.05), serum K and urine pH levels were lower in urolithiasis group than those in non-urolithasis group (P<0.05). In female patients, serum Na level was higher in urolithiasis group than that in non-urolithiasis group (P=0.080). Logistic regression analysis showed that beta value of serum Na level in male and female group was 0.10 (P<0.01) and 0.09 (P=0.054) respectively. CONCLUSION: There was difference in serum electrolyte levels between urolithiasis group and non-urolithiasis group. The chang of serum Na level may play role in pathogenesis of urolithiasis.

[Effects of urotensin II on isolated rat hearts under normal perfusion and ischemia reperfusion].

To shed light on cardiac effects of the potent vasoconstrictive peptide urotensin II (U II), Langendorff-perfused isolated rat hearts were consecutively perfused with 0.1, 1 and 10 nmol/L U II, for 5 min at each dose, followed by 5-min washout. Moreover, isolated hearts subjected to 20-min global no-flow ischemia were reperfused with U II (1 or 10 nmol/L) for 20 min. Heart function parameters including heart rate, left ventricular pressure and dP/dt were monitored; content of protein and myoglobin, and activity of lactate dehydrogenase (LDH) in coronary effluent were determined; malondialdehyde (MDA) in myocardium and [(125)I]-U II binding sites in plasma membrane were measured after the completion of perfusion. The results showed that: (1) In normal rat hearts, the coronary flow was decreased and the heart function was suppressed by U II dose-dependently, and these changes were not abolished by washout. The leakage of cardiac protein, myoglobin and LDH increased with the increment of U II, but it diminished rapidly after washout. In contrast, MDA content in U II -treated myocardium was not statistically different from that in normal myocardium. (2) Ischemia-reperfusion caused significant decreases in coronary flow, suppression of heart function, and leakage of protein and LDH. In U II -reperfused hearts, all these disorders were significantly aggravated and myocardial MDA content significantly increased (P<0.01), to a greater extent in the presence of higher dose of U II. (3) The maximal binding capacity (B(max)) of U II receptors in plasma membrane from ischemia-reperfusion myocardium increased significantly as compared with that of normal myocardium (20.53+/-1.98 vs 14.65+/-1.78 fmol/mg pr, P<0.01), while Kd remained unchanged. These results indicate that U II caused injury to the isolated rat hearts under normal perfusion, and worsened the injury of the hearts under ischemia-reperfusion, in which U II receptors were up-regulated.