Nationwide Trends in Utilization of Minimally Invasive Techniques for Blunt Abdominal Trauma.

BACKGROUND: Despite increasing use of minimally invasive surgical (MIS) techniques for trauma, limited large-scale studies have evaluated trends, outcomes, and resource utilization at centers that utilize MIS modalities for blunt abdominal trauma. METHODS: Operative adult admissions after blunt assault, falls, or vehicular collisions were tabulated from the 2016-2020 National Inpatient Sample. Patients who received diagnostic laparoscopy or other laparoscopic and robotic intervention were classified as MIS. Institutions with at least one MIS trauma operation in a year were defined as an MIS Performing Institution (MPI; rest: non-MPI). The primary endpoint was mortality, with secondary outcomes of reoperation, complication, postoperative length of stay (LOS), and hospitalization costs. Mixed regression models were used to determine the association of MPI status on the outcomes of interest. RESULTS: Throughout the study period, the proportion of MIS operations and MPI significantly increased from 22.6 to 29.8% and 45.9 to 58.8%, respectively. Of an estimated 77,480 patients, 66.7% underwent care at MPI. After adjustment, MPI status was not associated with increased odds of mortality (adjusted odds ratio [AOR] 1.09, 95% confidence interval [CI] [.96,1.24]), reoperation (AOR 1.02, CI [.87,1.19]), or any of the tabulated complications. There was additionally no difference in adjusted LOS (ß-.18, CI [-.85, +.49]) or costs (ß+$1600, CI [-1600, +4800]), between MPI and non-MPI. DISCUSSION: The use of MIS operations in blunt abdominal trauma has significantly increased, with performing centers experiencing no difference in mortality or resource utilization. Prospectively collected data on outcomes following MIS trauma surgery is necessary to elucidate appropriate applications.

Subsets of microsatellite-unstable colorectal cancers exhibit discordance between the CpG island methylator phenotype and MLH1 methylation status.

Although the presence of MLH1 methylation in microsatellite-unstable colorectal cancer generally indicates involvement of the CpG island methylator phenotype (CIMP) in the development of the tumor, these two conditions do not always correlate. A minority of microsatellite-unstable colorectal cancers exhibit discordance between CIMP and MLH1 methylation statuses. However, the clinicopathological features of such microsatellite-unstable colorectal cancers with discrepant MLH1 methylation and CIMP statuses remain poorly studied. Microsatellite-unstable colorectal cancers (n=220) were analyzed for CIMP and MLH1 methylation statuses using the MethyLight assay. Based on the combinatorial CIMP and MLH1 methylation statuses, the microsatellite-unstable colorectal cancers were grouped into four subtypes (CIMP-high (CIMP-H) MLH1 methylation-positive (MLH1m+), CIMP-H MLH1 methylation-negative, CIMP-low/0 (CIMP-L/0) MLH1m+, and CIMP-L/0 MLH1 methylation-negative), which were compared in terms of their associations with clinicopathological and molecular features. The CIMP-L/0 MLH1 methylation-negative and CIMP-H MLH1m+ subtypes were predominant, comprising 63.6 and 24.1% of total microsatellite-unstable colorectal cancers, respectively. The discordant subtypes, CIMP-H MLH1 methylation-negative and CIMP-L/0 MLH1m+, were found in 5 and 7% of microsatellite-unstable colorectal cancers, respectively. The CIMP-H MLH1 methylation-negative subtype exhibited elevated incidence rates in male patients and was associated with larger tumor size, more frequent loss of MSH2 expression, increased frequency of KRAS mutation, and advanced cancer stage. The CIMP-L/0 MLH1m+ subtype was associated with onset at an earlier age, a predominance of MLH1 loss, and earlier cancer stage. None of the CIMP-L/0 MLH1m+ subtype patients succumbed to death during the follow-up. Our findings suggest that the discordant subtypes of colorectal cancers exhibit distinct clinicopathological and molecular features, although the proportion of discordant subtypes is low. The microsatellite-unstable colorectal cancers of the same CIMP status tended to exhibit different clinicopathological features depending on MLH1 methylation status.