RESUMO
Objective: The aim of this study was to investigate whether pre-operative comorbidity status measured by the Charlson comorbidity index (CCI) or cardiopulmonary exercise testing (CPET) is associated with postoperative complications and length of stay (LOS) in patients undergoing robot-assisted radical cystectomy and intracorporeal urinary diversion (RARC-ICUD). Patients and methods: We conducted a retrospective study of a prospectively maintained database of 428 consecutive patients who underwent RARC-ICUD at a tertiary referral centre between 2011 and 2019. CCI was correlated with peri-operative outcomes including postoperative LOS, Clavien-Dindo (CD) complications and survival. A planned subgroup analysis was performed to evaluate the relationship between pre-operative CPET, and the same outcomes utilising the threshold of anaerobic threshold (AT) ≥ 11/ <11 ml/kg/min were analysed. Results: Of the total cohort, 350 patients undergoing RARC-ICUD with complete data were included in the final analysis. A CCI score ≥5 was associated with a higher rate of CD III-V complications at 30-day incidence rate ratio (IRR) = 3.033, (p = 0.02) and at 90-day IRR 2.495, (p = 0.04) postsurgery. LOS was not associated with CCI; the strongest association with LOS was a CD complication of any grading. CCI did not predict readmission or mortality rates after surgery. Subanalyses of patients who underwent pre-operative CPET found that CPET <11 ml/kg/min did not predict for LOS, CD complications or death within 1 year of surgery. Conclusions: CCI score is a simple, reliable and cost-effective way of identifying patients at increased risk of complication after RARC-ICUD. Surgeons performing radical cystectomy should consider utilising CCI to augment pre-operative patient counselling prior to RARC-ICUD.
RESUMO
We present a new formula for the angular momentum J^{µν} carried away by gravitational radiation in classical scattering. This formula, combined with the known expression for the radiated linear momentum P^{µ}, completes the set of radiated Poincaré charges due to scattering. We parametrize P^{µ} and J^{µν} by nonperturbative form factors and derive exact relations using the Poincaré algebra. There is a contribution to J^{µν} due to static (zero-frequency) modes, which can be derived from Weinberg's soft theorem. Using tools from scattering amplitudes and effective field theory, we calculate the radiated J^{µν} due to the scattering of two spinless particles to third order in Newton's constant G, but to all orders in velocity. Our form-factor analysis elucidates a novel relation found by Bini, Damour, and Geralico between energy and angular momentum loss at O(G^{3}). Our new results have several nontrivial implications for binary scattering at O(G^{4}). We give a procedure to bootstrap an effective radiation reaction force from the loss of Poincaré charges due to scattering.
