[Show abstract][Hide abstract] ABSTRACT: Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell cancer (RCC), followed by papillary RCC (pRCC). It is important to distinguish these two subtypes because of prognostic differences and possible changes in management, especially in cases undergoing active surveillance. The purpose of our study is to evaluate the use of voxel-based whole-lesion (WL) enhancement parameters on contrast enhanced computed tomography (CECT) to distinguish ccRCC from pRCC.
In this institutional review board-approved study, we retrospectively queried the surgical database for post nephrectomy patients who had pathology proven ccRCC or pRCC and who had preoperative multiphase CECT of the abdomen between June 2009 and June 2011. A total of 61 patients (46 with ccRCC and 15 with pRCC) who underwent robotic assisted partial nephrectomy for clinically localized disease were included in the study. Multiphase CT acquisitions were transferred to a dedicated three-dimensional workstation, and WL regions of interest were manually segmented. Voxel-based contrast enhancement values were collected from the lesion segmentation and displayed as a histogram. Mean and median enhancement and histogram distribution parameters skewness, kurtosis, standard deviation, and interquartile range were calculated for each lesion. Comparison between ccRCC and pRCC was made using each imaging parameter. For mean and median enhancement, which had a normal distribution, independent t-test was used. For histogram distribution parameters, which were not normally distributed, Wilcoxon rank sum test was used.
ccRCC had significantly higher mean and median whole WL enhancement (p < 0.01) compared to pRCC on arterial, nephrographic, and excretory phases. ccRCC had significantly higher interquartile range and standard deviation (p < 0.01) and significantly lower skewness (p < 0.01) compared to pRCC on arterial and nephrographic phases. ccRCC had significantly lower kurtosis compared to pRCC on only the arterial phase.
Our study suggests that voxel-based WL enhancement parameters can be used as a quantitative tool to differentiate ccRCC from pRCC. Differentiating between the two main types of RCC would provide the patient and the treating physicians more information to formulate the initial approach to managing the patient's renal cancer.
[Show abstract][Hide abstract] ABSTRACT: To develop a robotic technique for exclusively trans-abdominal control of the supra-hepatic, infra-diaphragmatic inferior vena cava (IVC) to enable level 3 IVC tumor thrombectomy.
Robotic technique was developed in 3 fresh, perfused-model cadavers. Pre-operatively, inflow (right jugular vein) and outflow (left femoral vein) cannulae were inserted and connected to a centrifugal pump to establish a 10 mmHg pressure in the IVC for the water-perfused cadaver model. Using a 5-port trans-peritoneal robotic approach, the falciform ligament was detached from the anterior abdominal wall towards its junction with the diaphragm, and tautly retracted caudally; this adequately retracted the liver caudally as well. Triangular and coronary ligaments were incised, allowing ready visualization of supra-hepatic/infra-diaphragmatic IVC and right/left main hepatic veins. Under direct robotic visualization, IVC was circumferentially mobilized, vessel-looped and controlled.
All 3 robotic procedures were successfully completed trans-abdominally. Average robotic time to control the supra-hepatic IVC was 37min; in each case, the supra-hepatic IVC was circumferentially controlled with a vessel-loop. There were no intraoperative complications. Length of the mobilized supra-hepatic IVC measured between 2-3cm. Right and left supra-hepatic veins were clearly visualized in each case. Necropsy revealed no intra-abdominal/intra-thoracic visceral or vascular injuries to the supra-hepatic IVC, bilateral hepatic veins, or tributaries.
We developed a novel robotic technique for trans-abdominal control of the supra-hepatic infra-diaphragmatic IVC in a perfused human cadaver model. This approach may extend the application of advanced robotic techniques for the performance of major vena caval, hepatic and level 3 IVC renal tumor thrombus surgery.
Journal of endourology / Endourological Society 06/2015; DOI:10.1089/end.2015.0081 · 1.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To describe our approach for port placement and robot docking for pelvic and kidney surgery (KS).
We utilize a four-arm robotic approach and a 5-6 port placement consisting of: 1- 12 mm camera port, 3- 8 mm robotic ports, and 1 to 2 assistant ports. For radical prostatectomy, the working robotic ports run parallel below the level of the umbilicus. Radical cystectomy ports are more cephalad and above the level of the umbilicus. For transperitoneal KS, two bariatric robotic ports are used, aiming for an equilateral triangle configuration. With retroperitoneal (RN) KS, a balloon dilator and balloon port create the RN space; bariatric ports comprise the most anterior and posterior ports.
This technique has been utilized since 2010 on over 2,370 robotic urologic cases. To date, no procedure has required patient or robot positioning while maintaining 4th arm functionality with minimal robotic arm clashing.
Our approach of port placement and robot docking is reproducible and feasible for pelvic and kidney surgery.
Journal of endourology / Endourological Society 04/2015; DOI:10.1089/end.2015.0077 · 1.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Introduction: We present an updated version of our previously validated robotic partial nephrectomy (RPN) training model,1,2 which includes the reconstructive part of the procedure in addition to the tumor excision component. Material and Methods: For this pilot series, participants were recruited as novice (zero console cases), intermediate (1, but <100 cases), and expert (≥100 console cases). After parenchymal resection with opening of the collecting system, a 5-cm Styrofoam ball mimicking a lower pole tumor was glued on an ex vivo porcine kidney. Each participant performed an RPN using the da Vinci SI Surgical System to excise the Styrofoam tumor. For reconstruction and hemostasis, two horizontal mattress sutures were applied. Renal artery and collecting system were perfused respecting physiologic conditions to test hemostasis and watertightness. Participants completed a poststudy questionnaire assessing training model realism and utility and were anonymously judged by expert reviewers using a validated laparoscopic assessment tool.3 Focusing on expenses per kidney: the preparation time is around 10 min and the costs for disposables (tissue, Styrofoam ball, glue, and fixation) is ∼5 to 10 USD (without training instruments). Results: The 13 participants included 7 novices, 2 intermediates, and 4 experts. Overall, surgeons rated the training model as “very realistic” (median visual analogue score [VAS] 8/10) (face validity). Expert surgeons rated it as an “extremely useful” training tool for residents and attendings (median VAS 9/10) (content validity).4 Experts outscored all others on overall performance (p<0.05) (construct validity). Additionally, the video displays in a head-to-head manner the way an expert surgeon outscores a novice on individual metrics. Thereby, model validation and training potential are demonstrated. Conclusions: Our perfused RPN training model has demonstrated face, content, and construct validity. Herewith tumors of any complexity and reconstruction can be simulated without patients at risk. In addition, the easy to build up, reproducible, and cheap model can be used, for example, within a residency training program. It allows to evaluate individual learning curves and to differentiate distinct surgical skills. No competing financial interests exist. Runtime of video: 7 mins 52 secs
[Show abstract][Hide abstract] ABSTRACT: We demonstrate the construct validity, reliability, and utility of Global Evaluative Assessment of Robotic Skills (GEARS), a clinical assessment tool designed to measure robotic technical skills, in an independent cohort using an in vivo animal training model.
Using a cross-sectional observational study design, 47 voluntary participants were categorized as experts (>30 robotic cases completed as primary surgeon) or trainees. The trainee group was further divided into intermediates (≥5 but ≤30 cases) or novices (<5 cases). All participants completed a standardized in vivo robotic task in a porcine model. Task performance was evaluated by two expert robotic surgeons and self-assessed by the participants using the GEARS assessment tool. Kruskal-Wallis test was used to compare the GEARS performance scores to determine construct validity; Spearman's rank correlation measured interobserver reliability; and Cronbach's alpha was used to assess internal consistency.
Performance evaluations were completed on nine experts and 38 trainees (14 intermediate, 24 novice). Experts demonstrated superior performance compared to intermediates and novices overall and in all individual domains (p < 0.0001). In comparing intermediates and novices, the overall performance difference trended toward significance (p = 0.0505), while the individual domains of efficiency and autonomy were significantly different between groups (p = 0.0280 and 0.0425, respectively). Interobserver reliability between expert ratings was confirmed with a strong correlation observed (r = 0.857, 95 % CI [0.691, 0.941]). Experts and participant scoring showed less agreement (r = 0.435, 95 % CI [0.121, 0.689] and r = 0.422, 95 % CI [0.081, 0.0672]). Internal consistency was excellent for experts and participants (α = 0.96, 0.98, 0.93).
In an independent cohort, GEARS was able to differentiate between different robotic skill levels, demonstrating excellent construct validity. As a standardized assessment tool, GEARS maintained consistency and reliability for an in vivo robotic surgical task and may be applied for skills evaluation in a broad range of robotic procedures.