The correlation of matrix metalloproteinase 9-to-albumin ratio in wound fluid with postsurgical complications after body contouring.

BACKGROUND: The authors' earlier retrospective report of surgical complications after abdominal contouring surgery provided evidence that post-bariatric surgery patients are at increased risk of developing wound complications compared with a normal population. This prospective pilot study was designed as a comparative analysis of both surgical and wound healing characteristics between massive weight loss and normal patients who present for abdominal contouring surgery. METHODS: Excisional wounds were created and polytetrafluoroethylene tubing was inserted during the preoperative period for later harvesting in patients undergoing abdominal contouring following Roux-en-Y gastric bypass for weight loss (n = 16) or abdominoplasty (n = 17). Wound fluids were sequentially collected from drains and subjected to matrix metalloproteinase (MMP) analysis. Standard postsurgical complications were documented. RESULTS: Surgical complications were more common in weight loss patients (47 percent) than in control patients (25 percent). MMP analyses showed that MMP-9 levels remained significantly elevated at postoperative day 4 in patients who subsequently experienced complications in either the weight loss group (p = 0.02) or the control group (p = 0.03). Other parameters showed no significant differences between massive weight loss patients and controls. CONCLUSIONS: Although many markers were examined, the ratio of MMP-9 to albumin was the only predictor of postsurgical complications in any group. This lends further support to growing evidence that MMP-9 may be a useful biomarker of postsurgical complications. This pilot work showed no causal factors that explain the higher rates of postsurgical complications in the post-bariatric surgery patient population. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

Experimental observations of channel reciprocity in single-mode free-space optical links.

This article describes observations made during a recent series of single-mode lasercom experiments in which high-rate data transmission was demonstrated between a small aircraft and a ground station separated by distances up to 80 km. A significant result of the subsequent data analysis was the discovery of near-unity correlations between the signal fluctuations observed by power monitors at the two ends of the link. This evidence of reciprocity is presented, along with the description of a preliminary concept for utilizing this channel state information to improve link performance.

The effect of weight loss surgery and body mass index on wound complications after abdominal contouring operations.

Abdominal contouring operations are in high demand after massive weight loss. Anecdotally, wound problems seemed to occur frequently in this patient population. Our study was designed to delineate risk factors for wound complications after body contouring. Our retrospective institutional analysis was assembled from 222 patients between 2001 and 2006 who underwent either abdominoplasty (N = 89) or panniculectomy (N = 133). Weight loss surgery (WLS) before body contouring occurred in 63% of our patients. Overall the wound complication rate in these patients was 34%: healing-disturbance 11%, wound infection 12%, hematoma 6%, and seroma 14%. WLS patients had an increase in wound complications overall (41% vs. 22%; P < 0.01) and in all categories of wound complications compared with non-WLS-patients by univariate methods of analysis. In a multivariate regression model, only American Society of Anesthesiologists Physical Status Classification was a significant independent risk factor for wound complications. In conclusion, WLS patients are at increased risk for wound complications and American Society of Anesthesiologists Physical Status Classification is the most predictive of risk.

Autologous breast reconstruction: the Vanderbilt experience (1998 to 2005) of independent predictors of displeasing outcomes.

BACKGROUND: Optimal surgical outcomes are dependent on an appreciation of comorbid conditions that may handicap results. The purpose of this retrospective analysis was to delineate risk factors for complications after autologous breast reconstruction. STUDY DESIGN: An institutional database was constructed of patients who underwent autologous breast reconstruction from 1998 to 2005. Variables captured included age, diabetes and smoking status, prereconstruction radiation therapy, concomitant breast resection, preoperative albumin, flap type, and body mass index (BMI; based on World Health Organization classifications: BMI>25, overweight; >30, obese). The primary outcome was noninfectious wound complications (NIWC), a novel classification based on the extent of tissue derangement and need for operative intervention. Secondary outcomes were wound infection, hematoma, hernia, and fat necrosis. Statistical analysis was performed using chi-square tests and multiple logistic regression. RESULTS: The analysis included 200 flaps (transverse rectus abdominis myocutaneous [TRAM]=171; latissimus dorsi=29) in 180 patients. There were 19 infections (9.5%), 3 total flap losses (1.5%), 14 hematomas (7%), and 11 donor-site hernias (6%). The incidences of fat necrosis and any NIWC were 18% and 36%, respectively. Mean followup was 13.1 months (range 1.1 to 51.7 months). Multiple logistic regression demonstrated that obesity (BMI>30) is a statistically significant independent risk factor for any NIWC (hazards ratio=6.58; 95% CI, 2.85 to 15.18; p < 0.01) and for NIWC requiring operative treatment (NIWC>or=3; hazard ratio=6.23; 95% CI 2.15 to 18.05; p < 0.01). Increased BMI predicts NIWC, NIWC requiring operative intervention, and wound infection (p < 0.01). CONCLUSIONS: These data suggest that obesity is a strong predictor of simple and complex NIWC and of wound infection after autologous breast reconstruction. Obese patients should be counseled about their significantly increased risk of experiencing these unwanted outcomes.

Are adrenal injuries predictive of adrenal insufficiency in patients sustaining blunt trauma?

Adrenal insufficiency (AI) is an uncommon life-threatening development in trauma patients. The aim of this study was to determine if adrenal injury sustained during blunt trauma is associated with an increased risk of AI. A single-institution retrospective cohort review was performed over a 3-year period on all patients with blunt trauma requiring intensive care admission and mechanical ventilation for longer than 24 hours. Adrenal injuries were identified on admission CT scan. All patients with AI were identified as noted by practice management guidelines. Patients were stratified by Injury Severity Score (ISS) as less than 16, 16 to 25, and greater than 25 and relative risks were calculated. Multiple logistic regression was performed using age, race, sex, Glasgow Coma Scale, ISS, length of hospitalization, and adrenal injury as covariates with AI as the outcome of interest. A secondary analysis was then performed with adrenal injury classified as bilateral versus unilateral or no adrenal injury and relative risks were calculated for ISS strata. A total of 2072 patients were identified with 71 developing AI. Adrenal injuries were noted in 113 patients with eight subsequently developing AI. Multiple logistic regression model (P < 0.01) showed that age (P < 0.01) and increasing ISS (P = 0.02) were predictive of AI. Adrenal injury was not an independent predictor of AI (P = 0.12). After controlling for age and ISS, adrenal injury was not an independent predictor of the development of AI. Adrenal insufficiency should be considered with increasing injury severity and age in the intensive care setting after blunt trauma.