Robotic Low Anterior Resection for Rectal Cancer: A National Perspective on Short-term Oncologic Outcomes. 
This study examines short-term outcomes and pathologic surrogates of oncologic results among patients undergoing robotic versus laparoscopic low anterior resection for rectal cancer.  A total of 6403 patients met inclusion criteria.  Although the robotic approach required significantly fewer conversions to open, surrogates for proper oncologic surgery were nearly identical between the 2 approaches.  Although laparoscopic low anterior resection (LLAR) has gained popularity as an acceptable approach, the robotic low anterior resection (RLAR) remains largely unproven.  We compared short-term oncologic outcomes between rectal cancer patients undergoing either RLAR or LLAR.  All patients with rectal cancer in the National Cancer Data Base undergoing RLAR or LLAR from 2010 to 2011 were included.  Predictors of RLAR were modeled with multivariable logistic regression.  Groups were matched on propensity to undergo RLAR.  Primary endpoints included lymph node retrieval and margin status, whereas secondary 30-day outcomes were mortality, hospital length of stay (LOS), and unplanned readmission rates.  A total of 6403 patients met inclusion criteria, of which 956 (14.9%) underwent RLAR.  RLAR patients were more likely to be treated at academic centers, receive neoadjuvant therapy, and have higher T-stage and longer time to surgery (all P < 0.001).  Neoadjuvant therapy and treatment at an academic/research center remained the only significant predictors of robotic use after multivariable adjustment.  After propensity matching, RLAR was associated with lower conversion (9.5 vs 16.4%, P < 0.001).  There were no significant differences in lymph node retrieval, margin status, 30-day mortality, readmission, or hospital LOS.  In this largest series to date, we demonstrated equivalent perioperative safety and patient outcomes for robotic compared to LLAR in the setting of rectal cancer.  Although the robotic approach required significantly fewer conversions to open, surrogates for proper oncologic surgery were nearly identical between the 2 approaches, suggesting that a robotic approach may be a suitable alternative.  Further studies comparing long-term cancer recurrence and survival should be performed.