RESUMEN
Background: High quality surgical care for colorectal cancer (CRC) includes obtaining a negative surgical margin. The Michigan Surgical Quality Collaborative (MSQC) is a statewide consortium of hospitals dedicated to quality improvement; a subset of MSQC hospitals abstract quality of care measures for CRC surgery, including positive margin rate. The purpose of this study was to determine whether positive margin rates vary significantly by hospital, and whether positive margin rates should be a target for quality improvement. Methods: We performed a retrospective cohort study of patients who underwent CRC resection from 2016 to 2020. The primary outcome was the presence of a positive margin. Univariate and multivariable analyses were performed to test the association of positive margins with patient, hospital, and tumor characteristics. Results: The cohort consisted of 4211 patients from 42 hospitals (85 % colon cancer and 15 % rectal cancer). The crude positive margin rate was 6.15 % (95 % CI 4.6-7.4 %); this ranged from 0 % to 22 % at individual hospitals. In multivariable analysis, factors independently associated with positive margins included male sex, underweight BMI, metastatic cancer, rectal cancer (vs. colon), T4 T-stage, N1c/N2 N-stage, and open surgical approach. After adjusting for these factors, there remained significant variation by hospital, with 8 hospitals being statistically-significant outliers. Conclusions: Positive margins rates for CRC vary by hospital in Michigan, even after rigorous adjustment for case-mix. Furthermore, several hospitals achieved near-zero positive margin rates, suggesting opportunities for quality improvement through the identification of best practices among CRC surgery centers.
RESUMEN
Fatty infiltration (FI) of rotator cuff (RC) muscles is common in patients with RC tears. Studies have demonstrated that fibro-adipogenic progenitors (FAPs), a population of resident muscle stem cells, are the main contributors of FI, which adversely affects muscle quality and RC repair success. Although FI is common in RC injuries, it is not frequently reported after other musculotendinous injuries. Additionally, studies have shown the development of different pathology patterns across muscle groups suggestive of intrinsic differences in cellular composition and behavior. This study evaluates FAP distribution and differentiation properties across anatomic locations in mice. Muscles from seven different anatomic locations were harvested from PDGFRα-eGFP FAP reporter mice. FAPs were quantified using histology and FACS sorting with BD Aria II with CD31- /CD45- /Integrinα7- /Sca-1+ and PDGFRα reporter signal (n = 3 per muscle). The cells were analyzed for adipogenesis using immunocytochemistry and for proliferation properties with Brdu-Ki67 staining. In a separate group of mice, RC and tibialis anterior muscles received glycerol injection and were harvested after 2 weeks for FI quantification (n = 4). One-way analysis of variance was used for statistical comparisons among groups, with significance at p < 0.05. FAPs from the RC, masseter, and paraspinal muscles were more numerous and demonstrated greater proliferative capacity and adipogenic potency than those from the tibialis anterior and gastrocnemius. The RC demonstrated significantly greater levels of FI than the tibialis anterior after glycerol-injection injury. Clinical Significance: This study suggests differences in FAP distribution and differentiation characteristics may account for the propensity to develop FI in RC tears as compared with other musculotendinous injuries. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1113-1121, 2020.
