Acute kidney injury after open ventral hernia repair: an analysis of the 2005-2012 ACS-NSQIP datasets.

PURPOSE: Acute kidney injury (AKI) is a serious postoperative complication, negatively impacting mortality rates, extending length of stay, and raising hospital costs. The purpose of this study was to examine AKI following open ventral hernia repair (OVHR) using a large, heterogeneous database to determine the incidence and identify risk factors for this complication. METHODS: Using the 2005-2012 ACS-NSQIP database, patients undergoing open ventral hernia repair were identified by CPT codes. Patients with acute kidney injury within 30 days of surgery were compared to controls by multivariate logistic regression across preoperative and intraoperative characteristics. RESULTS: Of 48,629 open ventral hernia repair patients identified in the dataset, AKI developed in 1.4% (681 patients). Multivariate logistic regression determined a number of factors associated with AKI. These include WHO Class III obesity (OR = 2.57, p < 0.001), history of cardiovascular disease (OR = 1.81, p < 0.001), diabetes (OR = 1.29, p = 0.028), hypoalbuminemia (OR = 1.42, p = 0.004), and chronic kidney disease (for a baseline GFR of 60-89 mL/min/1.73 m2, OR = 1.62, p = 0.001; for 30-59 mL/min/1.73 m2, OR = 2.25, p < 0.001; for 15-29 mL/min/1.73 m2, OR = 4.96, p < 0.001). Intraoperative factors include prolonged operative time (for ≥1 SD above the mean, OR = 1.68, p = 0.002; for ≥2SD above the mean, OR = 2.76, p < 0.001) and intraoperative transfusion (OR = 2.44, p < 0.001). CONCLUSIONS: Patients with a history of obesity, chronic kidney disease, cardiovascular history, diabetes, and hypoalbuminemia are at increased risk for AKI when undergoing OVHR. Intraoperative variables such as prolonged operative times and blood transfusions may also suggest increased risk. Preoperative identification of patients with these characteristics and perioperative hemodynamic stabilization are important first steps to minimize this complication.

Wound risk assessment in ventral hernia repair: generation and internal validation of a risk stratification system using the ACS-NSQIP.

BACKGROUND: There is a need for validated risk models to better stratify surgical site occurrences (SSO) following open ventral hernia repair (OVHR). The addition of more generalizable and validated risk models will serve to improve perioperative care in OVHR patients. METHODS: We reviewed the 2005-2011 ACS-NSQIP databases identifying encounters for OVHR. The dependent outcome measure of interest was SSO, defined as superficial surgical site infection, deep infection, organ space infection, or wound dehiscence. Multivariate logistic regression of independently associated factors was performed and internally validated using a bootstrap technique. A composite risk score, the Hernia Wound Risk Assessment Tool (HW-RAT) was created using weighted beta coefficients. The HW-RAT was compared to existing models from the literature. RESULTS: A total of 60,187 patients who met inclusion criteria were identified in the 2005-2011 ACS-NSQIP databases. The incidence of SSO in the study was 6.2% (N = 3,732). SSO risk factors were broken down based on rounded risk scores into the following groups: mild, intermediate, moderate, and severe risk. Severe risk factors related to operative time and degree of wound contamination. Moderate risk factors included class III obesity, component separation, dependent functional status, and inpatient hernia surgery. Patient stratification was performed based on total risk score into HW-RAT risk groups 1 through 5 which demonstrated significant discrimination between and across each group (P < 0.01, C-statistic = 0.71) with an incidence of SSO that ranged from 3.3 to 26.5%. CONCLUSION: We present an internally validated risk model of SSO in OVHR (HW-RAT), which complements and builds upon current risk models. LEVEL OF EVIDENCE: Prognostic/risk category, level II.