Purpose We evaluated the face, content and construct validity of the novel da Vinci® Skills Simulator™ using the da Vinci Si™ Surgeon Console as the surgeon interface. Materials and Methods We ...evaluated a novel robotic surgical simulator for robotic surgery using the da Vinci Si Surgeon Console and Mimic™ virtual reality. Subjects were categorized as novice—no surgical training, intermediate—surgical training with fewer than 100 robotic cases or expert—100 or more primary surgeon robotic cases. Each participant completed 10 virtual reality exercises with 3 repetitions and a questionnaire with a 1 to 10 visual analog scale to assess simulator realism (face validity) and training usefulness (content validity). The simulator recorded performance based on specific metrics. The performance of experts, intermediates and novices was compared (construct validity) using the Kruskal-Wallis test. Results We studied 16 novices, 32 intermediates with a median surgical experience of 6 years (range 1 to 37) and a median of 0 robotic cases (range 0 to 50), and 15 experts with a median of 315 robotic cases (range 100 to 800). Participants rated the virtual reality and console experience as very realistic (median visual analog scale score 8/10) while expert surgeons rated the simulator as a very useful training tool for residents (10/10) and fellows (9/10). Experts outperformed intermediates and novices in almost all metrics (median overall score 88.3% vs 75.6% and 62.1%, respectively, between group p <0.001). Conclusions We confirmed the face, content and construct validity of a novel robotic skill simulator that uses the da Vinci Si Surgeon Console. Although it is currently limited to basic skill training, this device is likely to influence robotic surgical training across specialties.
In recent years, the advancement of technology brought the laser powder bed fusion process to its industrialisation step. Despite all the advancements in process repeatability and general quality ...control, many challenges remain unsolved due to the intrinsic difficulties of the process, notably the residual stresses issue. This work aimed to assess the usability of Barkhausen noise analysis (BNA) for the residual stress in situ monitoring of laser powder bed fusion on Maraging steel 300 (18Ni-300/1.2709). After measuring the evolution of grain size distribution over process parameter changes, two series of experiments were designed. First, a setup with an external force allows to validate the working principle of BNA on the chosen material processed using LPBF. The second experiment uses on-plates samples with different residual stress states. The results show a good stability in microstructure, a prerequisite for BNA. In addition, the external load setup acknowledges that signal variation correlates with the induced stress state. Finally, the on-plate measurement shows a similar signal variation to what has been observed in the literature for residual stress variation. It is shown that BNA is a suitable method for qualitative residual stresses variation monitoring developed during the LPBF process and underlines that BNA is a promising candidate as an in situ measurement method.
Purpose
Predictive models in spine surgery are of use in shared decision-making. This study sought to develop multivariable models to predict the probability of general and surgical perioperative ...complications of spinal surgery for lumbar degenerative diseases.
Methods
Data came from EUROSPINE's Spine Tango Registry (1.2012–12.2017). Separate prediction models were built for surgical and general complications. Potential predictors included age, gender, previous spine surgery, additional pathology, BMI, smoking status, morbidity, prophylaxis, technology used, and the modified Mirza invasiveness index score. Complete case multiple logistic regression was used. Discrimination was assessed using area under the receiver operating characteristic curve (AUC) with 95% confidence intervals (CI). Plots were used to assess the calibration of the models.
Results
Overall, 23′714/68′111 patients (54.6%) were available for complete case analysis: 763 (3.2%) had a general complication, with ASA score being strongly predictive (ASA-2 OR 1.6, 95% CI 1.20–2.12; ASA-3 OR 2.98, 95% CI 2.19–4.07; ASA-4 OR 5.62, 95% CI 3.04–10.41), while 2534 (10.7%) had a surgical complication, with previous surgery at the same level being an important predictor (OR 1.9, 95%CI 1.71–2.12). Respectively, model AUCs were 0.74 (95% CI, 0.72–0.76) and 0.64 (95% CI, 0.62–0.65), and calibration was good up to predicted probabilities of 0.30 and 0.25, respectively.
Conclusion
We developed two models to predict complications associated with spinal surgery. Surgical complications were predicted with less discriminative ability than general complications. Reoperation at the same level was strongly predictive of surgical complications and a higher ASA score, of general complications. A web-based prediction tool was developed at
https://sst.webauthor.com/go/fx/run.cfm?fx=SSTCalculator
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Abstract Background Pathoanatomic studies have failed to map accurately the primary lymphatic landing sites of the urinary bladder. Objective To use single-photon emission computed tomography (SPECT) ...combined with computed tomography (CT) plus intraoperative gamma probe verification to map the primary lymphatic landing sites of the bladder. Design, setting, and participants Clinical trial of 60 consecutive cystectomy patients at a single centre. Intervention Flexible cystoscopy-guided injection of technetium nanocolloid into one of six non-tumour-bearing sites of the bladder for preoperative detection of radioactive lymph nodes (LNs) with SPECT/CT followed by intraoperative verification with a gamma probe. Backup extended pelvic LN dissection (PLND) for ex vivo detection of missed LNs. Measurements Three-dimensional projection of each LN site. Results and limitations A median of 4 (range: 1–14) radioactive LNs were detected per site and patient. Ninety-two percent of all LNs were found distal and caudal to where the ureter crosses the common iliac arteries. Eight percent were found proximal to the uretero-iliac crossing, none without simultaneous detection of additional radioactive LNs within the endopelvic region. Extended PLND resected 92% of all primary lymphatic landing sites; limited PLND resected only 52%. A few LNs may have been missed despite preoperative SPECT/CT, intraoperative gamma probe verification, and extended backup PLND. Conclusions Multimodality SPECT/CT plus intraoperative gamma probe show the template of the bladder’s primary lymphatic landing sites to be larger than is often thought. PLND limited to the ventral portion of the external iliac vessels and obturator fossa removes only about 50% of all primary lymphatic landing sites, whereas extended PLND along the major pelvic vessels, including the internal iliac, external iliac, obturator, and common iliac region up to the uretero-iliac crossing, removes about 90%. Trial registration ClinicalTrials.gov, ISRCTN39379749.
Postoperative readmission rates following radical cystectomy remain significant. Early identification of emerging complications could potentially allow for immediate institution of therapy.
To ...intensify postoperative patient-physician communication via a cellphone-based health care application (CHA) and to evaluate its potential for early detection of complications.
This was a pilot study involving 18 radical cystectomy patients. During the first 30 d, patients received a push cellphone notification twice a week requesting data input into the CHA. This was reduced to once a week from day 31 to day 90. De-identified recorded data were reviewed by the surgeon involved. If deemed necessary, patients were contacted by the surgeon via telephone to obtain more detailed clinical information.
Descriptive statistics were used.
Of the 18 patients enrolled, all completed the 90-d reporting period. On two occasions, interventions were necessary on the basis of data recorded on the CHA. One neobladder patient was given antibiotic therapy for pyelonephritis. Another patient reported weight loss and nausea with clinical suspicion of metabolic acidosis, and his sodium bicarbonate and fluid intake were increased. Limitations include the small number of cases from a single low-volume center.
CHA-based monitoring of clinical parameters within the crucial 90-d postoperative period following radical cystectomy provides meaningful information. In this pilot study, two potential readmissions were possibly avoided on the basis of recorded basic vital signs and early intervention.
Besides regular clinic follow-up visits after radical cystectomy, additional aids such as a cellphone-based health care application can provide treating physicians with relevant clinical information and may help to identify imminent deviations from normal postoperative recovery at an early stage.
Besides regular clinical follow-up after radical cystectomy, an additional aid such as a health care app can provide relevant clinical information and may help in identifying imminent deviations from the normal postoperative course at an early stage.
We compared brain activity of men with filled and emptied seminal vesicles by functional magnetic resonance imaging. We found that men with filled seminal vesicles had higher activation of brain ...areas involved in arousal and sexual desire.
Whether seminal vesicles play a role in sexual activity in men is unknown. No study so far has compared the neural processing of visual sexual stimuli in men depending on the filling state of the seminal vesicles.
To evaluate potential specific cortical activation by visual sexual stimuli with distended and empty seminal vesicles.
A prospective case-control trial was conducted. Six male individuals underwent two visits on 2 consecutive days for hormone analyses; Derogatis Interview for Sexual Functioning (DISF) questionnaire; functional magnetic resonance imaging (fMRI) with passively viewing sexual, neutral, positive, and negative emotional pictures; and structural pelvic MRI. After the first visit, the participants had to empty seminal vesicles by masturbation. During fMRI, every participant viewed alternating blocks of sexual, neutral, positive, and negative emotional pictures.
Comparisons between days 1 and 2 were evaluated using paired t tests.
No significant differences were observed regarding hormone analyses, DISF questionnaire score, and arousal scoring between days 1 and 2. Seminal vesicle volume was significantly lower on day 2 (p = 0.003). Significantly higher activation was observed in the right precentral gyrus, middle frontal gyrus, and right superior temporal sulcus when contrasted for sexual over neutral (p < 0.05).
In response to pictures with sexual emotional content, significantly higher activation was detected in brain areas involved in motor preparation (arousal) and coding of desirability of visual sexual stimuli in men with distended seminal vesicles than in the same men with emptied seminal vesicles. This suggests that the filling state of the seminal vesicles may influence sexual desire in men.
We compared brain activity of men with filled and emptied seminal vesicles by functional magnetic resonance imaging. We found that men with filled seminal vesicles had higher activation of brain areas involved in arousal and sexual desire.
Pelvic lymph node dissection (PLND) at the time of cystectomy remains the most accurate method of staging and can have a positive impact on cancer control, and there is general agreement as to its ...necessity at the time of surgery. There is, however, a lack of consensus regarding the terminology of PLND and controversy concerning the optimal extent of lymph node dissection, especially because recent investigations have suggested a survival benefit with extended PLND.
Purpose There is evidence from retrospective studies that radical cystectomy with extended pelvic lymph node dissection provides better staging and outcomes than limited lymph node dissection. ...However, the optimal limits of extended lymph node dissection remain unclear. We compared oncological outcomes at 2 cystectomy centers where 2 different extended lymph node dissection templates are practiced to determine whether removing lymphatic tissue up to the inferior mesenteric artery confers an additional survival advantage. Materials and Methods Patients undergoing radical cystectomy and extended lymph node dissection with curative intent from 1985 to 2005 were included in analysis if they met certain criteria, including clinically organ confined urothelial bladder carcinoma (cN0M0), pathological stage pT2-pT3, negative surgical margins and no neoadjuvant therapy. Survival and recurrence data were analyzed. Results Demographic data and pathological subgroup distribution (pT2 and pT3) were similar in the 554 University of Southern California and 405 University of Bern patients. University of Southern California patients had higher median number of lymph nodes removed than University of Bern patients (38 vs 22, p <0.0001) and a higher incidence of lymph node metastasis (35% vs 28%, p = 0.02). However, the University of Southern California and University of Bern groups had similar 5-year recurrence-free survival for pT2pN0-2 (57% vs 67%) and pT3pN0-2 (32% vs 34%) disease (p = 0.55 and 0.44, respectively). The overall recurrence rate was equal at the 2 institutions (38%). Conclusions Meticulous extended lymph node dissection up to the mid-upper third of the common iliac vessels appears to provide survival and recurrence outcomes similar to those of a super extended template up to the inferior mesenteric artery. Complete skeletonization in the extended lymph node dissection template is more important than nodal yield. This does not exclude the possibility that certain patient subgroups with suspicious nodes or after neoadjuvant chemotherapy may benefit from more extensive lymph node dissection.
There is substantial variability in the extent of the node dissection performed during radical cystectomy for bladder cancer. Here, we review the diagnostic assessment of lymph node metastasis and ...the prognostic and therapeutic benefit for pelvic node dissection for bladder cancer. A review of the applicable urologic literature regarding the topics of lymphadenectomy for bladder cancer was conducted. Nodal metastasis above a limited or standard template is not uncommon, with up to 16% of all nodal metastasis detected proximal to the aortic bifurcation. However, skip metastasis is extremely rare. Proteins associated purely with epithelial tissue such as cytokeratin (CK)-19, CK-20, and uroplakin II have been observed in reportedly negative nodal specimens, which indicates that routine microscopic analysis of nodal tissue may miss small foci of metastatic cancer. In addition to the surgical technique, the total number of lymph nodes removed is influenced by patient anatomy and pathologic processing and therefore may be unsuitable as a procedural quality statement. Consecutively, meticulous removal of tissue within a defined and uniformly applied template may be more relevant than absolute nodal count. Observational cohort series indicate an improved oncologic outcome for patients undergoing extensive nodal dissection. The results of two randomized controlled trials addressing the extent of nodal dissection for bladder cancer are forthcoming.
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