Michael N. Terjimanian

Surgical Site Infection and Analytic Morphometric Assessment of Body Composition in Patients Undergoing Midline Laparotomy

BACKGROUND Obesity is a known risk factor for surgical site infection (SSI). Our hypothesis is that morphometric measures of midline subcutaneous fat will be associated with increased risk of SSI and will predict SSI better than conventional measures of obesity. STUDY DESIGN We identified 655 patients who underwent midline laparotomy (2006 to 2009) using the Michigan Surgical Quality Collaborative database. Using novel, semiautomated analytic morphometric techniques, the thickness of subcutaneous fat along the linea alba was measured between T12 and L4. To adjust for variations in patient size, subcutaneous fat was normalized to the distance between the vertebrae and anterior skin. Logistic regression analyses were used to identify factors independently associated with the incidence of SSI. RESULTS Overall, SSIs were observed in 12.5% (n = 82) of the population. Logistic regression revealed that patients with increased subcutaneous fat had significantly greater odds of developing a superficial incisional SSI (odds ratio [OR] = 1.76 per 10% increase, 95% CI 1.10 to 2.83, p = 0.019). Smoking, steroid use, American Society of Anesthesiologists (ASA) classification, and incision-to-close operative time were also significant independent risk factors for superficial incisional SSI. When comparing subcutaneous fat and body mass index (BMI) as the only model variables, subcutaneous fat significantly improved model predictions of superficial incisional SSI (area under the receiver operating characteristic curve [AUC] 0.60, p = 0.023); BMI did not (AUC 0.52, p = 0.73). CONCLUSIONS Abdominal subcutaneous fat is an independent predictor of superficial incisional SSI after midline laparotomy. Novel morphometric measures may improve risk stratification and help elucidate the pathophysiology of surgical complications.

Analytic morphometric assessment of patients undergoing colectomy for colon cancer

Analytic morphometrics provides objective data that may better stratify risk. We investigated morphometrics and outcome among colon cancer patients.

Cost of Major Surgery in the Sarcopenic Patient

BACKGROUND Sarcopenia is associated with poor outcomes after major surgery. There are currently no data regarding the financial implications of providing care for these high-risk patients. STUDY DESIGN We identified 1,593 patients within the Michigan Surgical Quality Collaborative (MSQC) who underwent elective major general or vascular surgery at a single institution between 2006 and 2011. Patient sarcopenia, determined by lean psoas area (LPA), was derived from preoperative CT scans using validated analytic morphomic methods. Financial data including hospital revenue and direct costs were acquired for each patient through the hospitals finance department. Financial data were adjusted for patient and procedural factors using multiple linear regression methods, and Mann-Whitney U test was used for significance testing. RESULTS After controlling for patient and procedural factors, decreasing LPA was independently associated with increasing payer costs (

Morphometric Age and Mortality After Liver Transplant

6,989.17 per 1,000 mm(2) LPA, p < 0.001). The influence of LPA on payer costs increased to

The importance of improving the quality of emergency surgery for a regional quality collaborative.

26,988.41 per 1,000 mm(2) decrease in LPA (p < 0.001) in patients who experienced a postoperative complication. Further, the covariate-adjusted hospital margin decreased by

Dorsal muscle group area and surgical outcomes in liver transplantation

2,620 per 1,000 mm(2) decrease in LPA (p < 0.001) such that average negative margins were observed in the third of patients with the smallest LPA. CONCLUSIONS Sarcopenia is associated with high payer costs and negative margins after major surgery. Although postoperative complications are universally expensive to payers and providers, sarcopenic patients represent a uniquely costly patient demographic. Given that sarcopenia may be remediable, efforts to attenuate costs associated with major surgery should focus on targeted preoperative interventions to optimize these high risk patients for surgery.

A statewide, community-based assessment of alvimopan's effect on surgical outcomes.

IMPORTANCE Morphometric assessment has emerged as a strong predictor of postoperative morbidity and mortality. However, a gap exists in translating this knowledge to bedside decision making. We introduced a novel measure of patient-centered surgical risk assessment: morphometric age. OBJECTIVE To investigate the relationship between morphometric age and posttransplant survival. DATA SOURCES Medical records of recipients of deceased-donor liver transplants (study population) and kidney donors/trauma patients (morphometric age control population). STUDY SELECTION A retrospective cohort study of 348 liver transplant patients and 3313 control patients. We assessed medical records for validated morphometric characteristics of aging (psoas area, psoas density, and abdominal aortic calcification). We created a model (stratified by sex) for a morphometric age equation, which we then calculated for the control population using multivariate linear regression modeling (covariates). These models were then applied to the study population to determine each patients morphometric age. DATA EXTRACTION AND SYNTHESIS All analytic steps related to measuring morphometric characteristics were obtained via custom algorithms programmed into commercially available software. An independent observer confirmed all algorithm outputs. Trained assistants performed medical record review to obtain patient characteristics. RESULTS Cox proportional hazards regression model showed that morphometric age was a significant independent predictor of overall mortality (hazard ratio, 1.03 per morphometric year [95% CI, 1.02-1.04; P < .001]) after liver transplant. Chronologic age was not a significant covariate for survival (hazard ratio, 1.02 per year [95% CI, 0.99-1.04; P = .21]). Morphometric age stratified patients at high and low risk for mortality. For example, patients in the middle chronologic age tertile who jumped to the oldest morphometric tertile have worse outcomes than those who jumped to the youngest morphometric tertile (74.4% vs 93.2% survival at 1 year [P = .03]; 45.2% vs 75.0% at 5 years [P = .03]). CONCLUSIONS AND RELEVANCE Morphometric age correlated with mortality after liver transplant with better discrimination than chronologic age. Assigning a morphometric age to potential liver transplant recipients could improve prediction of postoperative mortality risk.

Analytic morphomics corresponds to functional status in older patients

Introduction:Within a large, statewide collaborative, significant improvement in surgical quality has been appreciated (9.0% reduction in morbidity for elective general and vascular surgery). Our group has not noted such quality improvement in the care of patients who had emergency operations. With this work, we aim to describe the scope of emergency surgical care within the Michigan Surgical Quality Collaborative, variations in outcomes among hospitals, and variations in adherence to evidence-based process measures. Overall, these data will form a basis for a broad-based quality improvement initiative within Michigan. Methods:We report morbidity, mortality, and costs of emergency and elective general and vascular surgery cases (N = 190,826) within 34 hospitals participating in the Michigan Surgical Quality Collaborative from 2005 to 2010. Adjusted hospital-specific outcomes were calculated using a stepwise multivariable logistic regression model. Adjustment covariates included patient specific comorbidities and case complexity. Hospitals were also compared on the basis of their adherence to evidence-based process measures [measures at the patient level for each case—Surgical Care Improvement Project (SCIP)-1 and SCIP-2 compliance]. Results:Emergency procedures account for approximately 11% of total cases, yet they represented 47% of mortalities and 28% of surgical complications. The complication-specific cost to payers was

Abdominal aortic calcification and surgical outcomes in patients with no known cardiovascular risk factors.

126 million for emergency cases and

Sarcopenia and failure to rescue following liver transplantation.

329 million for elective cases. Adjusted patient outcomes varied widely within Michigan Surgical Quality Collaborative hospitals; morbidity and mortality rates ranged from 16.3% to 33.9% and 4.0% to 12.4%, respectively. The variation among hospitals was not correlated with volume of emergency cases and case complexity. Hospital performance in emergency surgery was found to not depend on its share of emergent cases but rather was found to directly correlate with its performance in elective surgery. For emergency colectomies, there was a wide variation in compliance with SCIP-1 and SCIP-2 measures and overall compliance (42.0%) was markedly lower than that for elective colon surgery (81.7%). Conclusions:Emergency surgical procedures are an important target for future quality improvement efforts within Michigan. Future work will identify best practices within high-performing hospitals and disseminate these practices within the collaborative.