Kathryn Ann Schlosser, Sean R Maloney, Tanushree Prasad, Paul D Colavita, Vedra A Augenstein, Brant T Heniford. Carolinas Medical Center
Aims: Increased intra-abdominal pressure after AWR is hypothesized to contribute to postoperative RF. The impact of abdominal subcutaneous fat volume (SQFV), intra-abdominal volume (IAV), hernia volume (HV), and ratio of HV:IAV (loss of domain) is even less clearly elucidated. This study examines the impact of abdominal and hernia size on postoperative RF in AWR.
Methods: A prospective institutional database was queried for OVHR with preoperative CT scans (2007-2017). Respiratory failure (RF) was defined as new, persistent oxygen requirement prompting more than one day of high flow nasal canula, bipap, transfer to ICU, and/or reintubation. 3-D volumetric software was used to analyze hernia and abdominal tissue distribution. Demographics, operative characteristics, and outcomes were evaluated. Given the high degree of multicollinearity between markers of hernia dimensions and adiposity distribution, a principal component analysis was performed to create new component variables (PC1, PC2) for multivariate analysis. Variables PC1 and PC2 included BMI, defect area, HV, IAV, SQFV, and HV:IAV.
Results: A total of 1,103 patients (58.1% female) had pre-OVHR CTs. A total of 91 (8.3%) patients developed RF, 78 required transfer to the ICU, and 46 being reintubated. RF patients had significantly higher BMI (37.4±9.1vs.33.1±7.3kg/m2,p<0.0001), were older (62.9±10.5vs.58±12.5yr,p<0.0001), and had higher rates of asthma, CHF, and diabetes (p<0.01 all values). RF patients had longer OR time (245.5±106.5vs.198.1±85.0min, p<0.0001), had more panniculectomies (53.9%vs.32.3%,p<0.0001), contaminated cases (39.6%vs25.4%,p=0.003), larger defect size (238.1±160.1vs.138.2±127.1cm2,p<0.0001), HV (1919.3±1804.5vs.843.0±1186.5cm3), IAV (4324.8±6464.8vs.4187.0±211.6cm3, p=0.02), and a HV:IAV ratio (0.52±0.59vs.0.25±0.43,p<0.0001). There was no difference in number of previous abdominal operations or hernia repairs, SQFV, or performance of component separation. After principal component analysis controlling for multicollinearity, PC1 consisted mostly of hernia dimensions, with HV demonstrating a 56% correlation, HV:IAV 46.2%, and defect area 43.2%. PC2 consisted of primarily SQV (66.0%) and BMI (56.6% correlation). Multivariate analysis was performed to control for potentially confounding factors including PC1, PC2, age, number of previous surgeries, asthma, COPD, diabetes, panniculectomy, contamination, fascial defect closure, and component separation. PC1 was associated with postoperative RF (OR1.5,CI1.3-1.73), while PC2 was not (OR 1.16,CI0.97-1.38). Other factors associated with RF included diagnosis of asthma or COPD (OR3.55,CI1.54-8.18), age (OR1.05,CI1.02-1.07), and diabetes (OR1.78,CI1.07-2.97).
Conclusion: Hernia dimensions and distribution of abdominal adiposity significantly correlate with respiratory outcomes after OVHR. Hernia dimensions, including defect area, HV, and the ratio of HV:IAV, directly impact RF while BMI and SQFV do not predict RF after AWR.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 94960
Program Number: S155
Presentation Session: Plenary II
Presentation Type: Podium