ASO Author Reflection: Learning Curves in Robotic Partial Nephrectomy-Not Only the Surgeon Counts

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Last Resort from Nursing Shortage? Comparative Cost Analysis of Open vs. Robot-Assisted Partial Nephrectomies with a Focus on the Costs of Nursing Care

Despite perioperative advantages, robot-assisted surgery is associated with high costs. However, the lower morbidity of robotic surgery could lead to a lower nursing workload and cost savings. In this comparative cost analysis of open retroperitoneal versus robot-assisted transperitoneal partial nephrectomies (PN), these possible cost savings, including other cost factors, were quantified. Therefore, patient, tumor characteristics, and surgical results of all PN within two years at a tertiary referral center were retrospectively analyzed. The nursing effort was quantified by the local nursing staff regulation and INPULS® intensive care and performance-recording system. Out of 259 procedures, 76.4% were performed robotically. After propensity score matching, the median total nursing time (2407.8 vs. 1126.8 min, p < 0.001) and daily nursing effort (245.7 vs. 222.6 min, p = 0.025) were significantly lower after robotic surgery. This resulted in mean savings of EUR 186.48 in nursing costs per robotic case, in addition to savings of EUR 61.76 due to less frequent administrations of erythrocyte concentrates. These savings did not amortize the higher material costs for the robotic system, causing additional expenses of EUR 1311.98 per case. To conclude, the nursing effort after a robotic partial nephrectomy was significantly lower compared to open surgery; however, this previously unnoticed savings mechanism alone could not amortize the overall increased costs

Characterization of CD147, CA9, and CD70 as Tumor-Specific Markers on Extracellular Vesicles in Clear Cell Renal Cell Carcinoma

Extracellular vesicles (EVs) are secreted by healthy and tumor cells and are involved in cell–cell communication. Tumor-released EVs could represent a new class of biomarkers from liquid biopsies. The aim of this study was to identify tumor-specific EV markers in clear cell renal carcinoma (ccRCC) using cell lines and patient-derived tissue samples. EVs from ccRCC cell lines (786-O, RCC53, Caki1, and Caki2) and patient tissues were isolated via ultracentrifugation. EVs were characterized using transmission electron microscopy, nanoparticle tracking analysis, and Western blotting using exosome and putative tumor markers (epithelial cell adhesion molecule (EpCAM), carbonic anhydrase 9 (CA9), CD70, CD147). The tumor markers were verified using immunohistochemistry. CA9 was expressed in Caki2 cells and EVs, and CD147 was found in the cells and EVs of all tested ccRCC cell lines. In tumor tissues, we found an increased expression of CA9, CD70, and CD147 were increased in cell lysates and EV fractions compared to normal tissues. In contrast, EpCAM was heterogeneously expressed in tumor samples and positive in normal tissue. To conclude, we developed an effective technique to isolate EVs directly from human tissue samples with high purity and high concentration. In contrast to EpCAM, CA9, CD70, and CD147 could represent promising markers to identify tumor-specific EVs in ccRCC

Organ-Specific Uptake of Extracellular Vesicles Secreted by Urological Cancer Cells

Extracellular vesicles (EVs) secreted by cancer cells have been shown to take a pivotal part in the process of local and systemic tumor progression by promoting the formation of a supportive local tumor microenvironment and preparing premetastatic niches in distant organ systems. In this study, we analyzed the organ-specific uptake of EVs secreted by urological cancer cells using an innovative in-vivo approach. EVs from benign and malignant prostate, kidney, and bladder cells were isolated using ultracentrifugation, fluorescence-labeled and injected intravenously in immunodeficient mice. After 12 or 24 h, the animals were sacrificed, their organs were harvested and analyzed for the presence of EVs by high-resolution fluorescence microscopy. Across all entities, EVs were taken up fast (12 h > 24 h), and EVs from malignant cells were taken up more efficiently than EVs from benign cells. Though not entirely organ-specific, EVs were incorporated in different amounts, depending on the entity (prostate: lung > liver > brain; kidney: brain > lung > liver; bladder: lung > liver > brain). EV uptake in other organs than lung, liver, brain, and spleen was not observed. Our results suggest a role of EVs in the formation of premetastatic niches and an organotropism in EV uptake, which have to be examined in more detail in further studies

Primary Tumor Resection Decelerates Disease Progression in an Orthotopic Mouse Model of Metastatic Prostate Cancer

Radical prostatectomy in oligometastatic prostate cancer is a matter of intense debate. Besides avoiding local complications, it is hypothesized that primary tumor resection may result in better oncological outcomes. The aim of our study was to analyze the effect of primary tumor resection on disease progression in an orthotopic prostate cancer mouse model. First, the optimal time point for primary tumor resection, when metastases have already occurred, but the primary tumor is still resectable, was determined as 8 weeks after inoculation of 5 × 105 LuCaP136 cells. In a second in vivo experiment, 64 mice with metastatic prostate cancer were randomized into two groups, primary tumor resection or sham operation, and disease progression was followed up for 10 weeks. The technique of orthotopic primary tumor resection was successfully established. Compared with the sham operation group, mice with primary tumor resection showed a significantly longer survival (p < 0.001), a significantly slower PSA increase (p < 0.01), and a lower number of lung metastases (p = 0.073). In conclusion, primary tumor resection resulted in slower disease progression and longer survival in an orthotopic mouse model of metastatic prostate cancer. In future studies, this model will be used to unravel the molecular mechanisms of primary tumor/metastasis interaction in prostate cancer

Three Different Learning Curves Have an Independent Impact on Perioperative Outcomes After Robotic Partial Nephrectomy: A Comparative Analysis

Background Robot-assisted partial nephrectomy (RAPN) has become widely accepted, but its different underlying types of learning curves have not been comparatively analyzed to date. This study aimed to determine and compare the impact that the learning curve of the department, the console surgeon, and the bedside assistant as well as patient-related factors has on the perioperative outcomes of RAPN. Methods The study retrospectively analyzed 500 consecutive transperitoneal RAPNs (2007–2018) performed in a tertiary referral center by 7 surgeons and 37 bedside assistants. Patient characteristics and surgical data were obtained. Experience (EXP) was defined as the current number of RAPNs performed by the department, the surgeon, and the assistant. As the primary outcome, the impact of EXP and patient-related factors on perioperative outcomes were analyzed and compared. As the secondary outcome, a cutoff between “experienced” and “inexperienced” was defined. Correlation and regression analysis, receiver operating characteristic curve analysis, Fisher’s exact test, and the Mann–Whitney U test were performed, with p values lower than 0.05 denoting significance. Results The EXP of the department, the surgeon, and the assistant each has a major influence on perioperative outcome in RAPN irrespective of patient-related factors. Perioperative outcomes improve significantly with EXP greater than 100 for the department, EXP greater than 35 for the surgeon, and EXP greater than 15 for the assistant. Conclusions The perioperative results of RAPN are influenced by three different types of learning curves including those for the surgical department, the console surgeon, and the assistant. The influence of the bedside assistant clearly has been underestimated to date because it has a significant impact on the perioperative outcomes of RAPN

Open versus robot-assisted partial nephrectomy: A longitudinal comparison of 880 patients over 10 years

Background Most comparisons between robot‐assisted partial nephrectomy (RAPN) and open partial nephrectomy (OPN) indicate the superiority of RAPN, but the learning curve is often not considered. Methods All consecutive partial nephrectomies from the very first RAPN at a single tertiary referral centre (n = 818, 500 RAPN vs. 313 OPN) were retrospectively analyzed. Complications, success rates and surgical outcomes were compared. Inequalities between cohorts and the inherent learning curve were controlled by subgroup comparisons, regression analyses, and propensity score matching. Results Overall, RAPN had fewer complications, less blood loss, and shorter length of stay. However, an inherent learning curve caused higher complications for the first 4 years. Thereafter, perioperative outcomes clearly favoured RAPN, even for more complex tumours. Conclusions In one of the largest monocentric cohorts over more than 10 years, RAPN was found to be superior to OPN. However, not all advantages of RAPN are immediate because a learning curve must be passed

Cancer-associated fibroblasts stimulate primary tumor growth and metastatic spread in an orthotopic prostate cancer xenograft model

The unique microenvironment of the prostate plays a crucial role in the development and progression of prostate cancer (PCa). We examined the effects of cancer-associated fibroblasts (CAFs) on PCa progression using patient-derived fibroblast primary cultures in a representative orthotopic xenograft model. Primary cultures of CAFs, non-cancer-associated fibroblasts (NCAFs) and benign prostate hyperplasia-associated fibroblasts (BPHFs) were generated from patient-derived tissue specimens. These fibroblasts were coinjected together with cancer cells (LuCaP136 spheroids or LNCaP cells) in orthotopic PCa xenografts to investigate their effects on local and systemic tumor progression. Primary tumor growth as well as metastatic spread to lymph nodes and lungs were significantly stimulated by CAF coinjection in LuCaP136 xenografts. When NCAFs or BPHFs were coinjected, tumor progression was similar to injection of tumor cells alone. In LNCaP xenografts, all three fibroblast types significantly stimulated primary tumor progression compared to injection of LNCaP cells alone. CAF coinjection further increased the frequency of lymph node and lung metastases. This is the first study using an orthotopic spheroid culture xenograft model to demonstrate a stimulatory effect of patient-derived CAFs on PCa progression. The established experimental setup will provide a valuable tool to further unravel the interacting mechanisms between PCa cells and their microenvironment

Robot-assisted versus open radical cystectomy: A cohort study on perioperative outcomes accounting for stage selection bias and surgical experience

Background Most comparisons of robot-assisted (RARC) versus open radical cystectomy (ORC) for urothelial carcinoma do not factor the inherent stage selection bias or surgical experience. Methods We compared the perioperative outcomes of 229 RARC and 335 ORC at a single tertiary referral centre with propensity score matching and multiple regression models, when controlling for tumour and patient characteristics, surgeon's experience and type of urinary diversion. Results RARC had less major complications (19.8% vs. 34.1%) and ICU admissions (6.6% vs. 19.8%), with lower blood loss (400 vs. 500 ml) and transfusion rates. The operating time was longer (336 vs. 286 min), but decreased with surgeon's experience. RARC had less positive surgical margins (3% vs. 8.4%) and a higher lymph node count (14 vs. 11). Conclusions In this large single centre series comparing RARC with ORC controlling for stage selection bias and surgical experience, RARC proved significantly better outcomes, especially with intracorporeal urinary diversion

Robot-Assisted versus Laparoscopic Donor Nephrectomy: A Comparison of 250 Cases

Living kidney donation is the best treatment for end-stage renal disease, however, the best surgical approach for minimally-invasive donor nephrectomy (DN) is still a matter of debate. This bi-centric study aimed to retrospectively compare perioperative outcomes and postoperative kidney function after 257 transperitoneal DNs including 52 robot-assisted (RDN) and 205 laparoscopic DNs (LDN). As primary outcomes, the intraoperative (operating time, warm ischemia time (WIT), major complications) and postoperative (length of stay, complications) results were compared. As secondary outcomes, postoperative kidney and graft function were analyzed including delayed graft function (DGF) rates, and the impact of the surgical approach was assessed. Overall, the type of minimally-invasive donor nephrectomy (RDN vs. LDN) did not affect primary outcomes, especially not operating time and WIT; and major complication and DGF rates were low in both groups. A history of smoking and preoperative kidney function, but not the surgical approach, were predictive for postoperative serum creatinine of the donor and recipient. To conclude, RDN and LDN have equivalent perioperative results in experienced centers. For this reason, not the surgical approach, but rather the graft- (preoperative kidney function) and patient-specific (history of smoking) aspects impacted postoperative kidney function