Formal robotic training diminishes the learning curve for robotic pancreatoduodenectomy: Implications for new programs in complex robotic surgery.

INTRODUCTION: The learning curve associated with robotic pancreatoduodenectomy (RPD) is a hurdle for new programs to achieve optimal results. Since early analysis, robotic training has recently expanded, and the RPD approach has been refined. The purpose of this study is to examine RPD outcomes for surgeons who implemented a new program after receiving formal RPD training to determine if such training reduces the learning curve. METHODS: Outcomes for consecutive patients undergoing RPD at a single tertiary institution were compared to optimal RPD benchmarks from a previously reported learning curve analysis. Two surgical oncologists with formal RPD training performed all operations with one surgeon as bedside assistant and the other at the console. RESULTS: Forty consecutive RPD operations were evaluated. Mean operative time was 354 ± 54 min, and blood loss was 300 ml. Length of stay was 7 days. Three patients (7.5%) underwent conversion to open. Pancreatic fistula affected five patients (12.5%). Operative time was stable over the study and lower than the reported benchmark. These RPD operative outcomes were similar to reported surgeon outcomes after the learning curve. CONCLUSION: This study suggests formal robotic training facilitates safe and efficient adoption of RPD for new programs, reducing or eliminating the learning curve.

N-cadherin impedes proliferation of the multiple myeloma cancer stem cells.

Multiple myeloma (MM) is an incurable malignancy of the plasma cells localized to the bone marrow. A rare population of MM cancer stem cells (MM-CSCs) has been shown to be responsible for maintaining the pull of residual disease and to contribute to myeloma relapse. The stem cells are found in a bone marrow niche in contact with the stromal cells that are responsible for maintaining the proliferative quiescence of the MM-CSC and regulate its self-renewal and differentiation decisions. Here we show that both MM and bone marrow stromal cells express N-cadherin, a cell-cell adhesion molecule shown to maintain a pool of leukemic stem cells. Inhibition of N-cadherin using a neutralizing antibody led to an increase in the MM cell proliferation. A decrease in MM cell adhesion to the bone marrow stroma was observed in the first 24 hours of co-culture followed by a 2.3-30-fold expansion of the adherent cells. Moreover, inhibition of N-cadherin led to a 4.8-9.6-fold expansion of the MM-CSC population. Surprisingly, addition of the N-cadherin antagonist peptide resulted in massive death of the non-adherent MM cells, while the viability of the adherent cells and MM-CSCs remained unaffected. Interestingly, the proliferative effects of N-cadherin inhibition were not mediated by the nuclear translocation of ß-catenin. Taken together, our findings demonstrate the crucial role of N-cadherin in regulating MM cell proliferation and viability and open an interesting avenue of investigation to understand how structural modifications of N-cadherin can affect MM cell behavior. Our findings suggest that targeting N-cadherin may be a useful therapeutic strategy to treat MM in conjunction with an agent that has anti-MM-CSC activity.