Association of Transanal Total Mesorectal Excision With Local Recurrence of Rectal Cancer.

Importance: Proponents of novel transanal total mesorectal excision (TME) suggest the procedure overcomes the technical and oncologic challenges of conventional approaches for treating rectal cancer. Recently, however, there has been controversy regarding the oncologic safety of the procedure. Objective: To assess the association of transanal TME with the incidence of local recurrence (LR) of cancer and the probability of remaining free of LR during follow-up. Design, Setting, and Participants: This multicenter cohort study used data from 8 high-volume rectal cancer academic institutions from across Canada on all consecutive patients with primary rectal cancer treated by transanal TME at the participating centers. The study was conducted between January 2014 and December 2018, and data were analyzed from April 1, 2020, to September 15, 2020. Exposure: Transanal TME. Main Outcomes and Measures: The incidence of LR was reported as a direct measure of quality of resection. The cumulative probability of LR- and systemic recurrence (SR)-free survival at 36 months was estimated. Local recurrence and SR were defined as radiologic or endoscopic evidence of 1 or more new lesions in or outside the pelvis, respectively, documented during surveillance after the removal of the primary tumor. Results: Of 608 total patients included in the analysis, 423 (69.6%) were male; the median age was 63 years (interquartile range [IQR], 54-70 years). Local recurrence was identified in 22 patients (3.6%) after a median follow-up of 27 months (IQR, 18-38 months). The median time to LR was 13 months (IQR, 9-19 months). Sixteen of the 22 patients with LR (72.7%) were male, 14 (63.6%) received neoadjuvant chemoradiation, and 12 (54.5%) had American Joint Committee on Cancer stage III disease. Of those with LR, 16 (72.7%) had a negative circumferential radial margin and 20 (90.9%) had a negative distal resection margin, 2 (9.1%) experienced conversion to open surgery, and 15 (68.2%) also developed SR. The probability of LR-free survival at 36 months was 96% (95% CI, 94%-98%). According to the Cox proportional hazards regression model, the hazard ratio of LR was estimated to be 4.2 (95% CI, 2.9-6.2) times higher among patients with a positive circumferential radial margin than among those with a negative circumferential radial margin. Conclusions and Relevance: In this cohort study, transanal TME performed by experienced surgeons was associated with an incidence of LR and SR that is in line with the published literature on open and laparoscopic TME, suggesting that transanal TME may be an acceptable approach for management of rectal cancer.

Improving the Prediction of Cardiac Surgery-Associated Acute Kidney Injury.

INTRODUCTION: Acute kidney injury (AKI) is a potentially fatal complication of cardiac surgery. The inability to predict cardiac surgery-associated AKI is a major barrier to prevention and early treatment. Current clinical risk models for the prediction of cardiac surgery-associated AKI are insufficient, particularly in patients with preexisting kidney dysfunction. METHODS: To identify intraoperative variables that might improve the performance of a validated clinical risk score (Cleveland Clinic Score, CCS) for the prediction of cardiac surgery-associated AKI, we conducted a prospective cohort study in 289 consecutive elective cardiac surgery patients at a tertiary care center. We compared the area under the receiver operator characteristic curve (AUC) of a base model including only the CCS with models containing additional selected intraoperative variables including mean arterial pressure, hematocrit, duration of procedure, blood transfusions, and fluid balance. AKI was defined by the Kidney Disease Improving Global Outcomes 2012 criteria. RESULTS: The CCS alone gave an AUC of 0.72 (95% confidence interval, 0.62-0.82) for postoperative AKI. Nadir intraoperative hematocrit was the only variable that improved AUC for postoperative AKI when added to the CCS (AUC = 0.78; 95% confidence interval, 0.70-0.87; P = 0.002). In the subcohort of patients without preexisting chronic kidney disease (n = 214), where the CCS underperformed (AUC, 0.60 [0.43-0.76]), the improvement with the addition of nadir hematocrit was more marked (AUC, 0.74 [0.62-0.86]). Other variables did not improve discrimination. DISCUSSION: Nadir intraoperative hematocrit is useful in improving discrimination of clinical risk scores for AKI, and may provide a target for intervention.