Can Electric Nose Breath Analysis Identify Abdominal Wall Hernia Recurrence and Aortic Aneurysms? A Proof-of-Concept Study.

Introduction. This pilot study evaluates if an electronic nose (eNose) can distinguish patients at risk for recurrent hernia formation and aortic aneurysm patients from healthy controls based on volatile organic compound analysis in exhaled air. Both hernia recurrence and aortic aneurysm are linked to impaired collagen metabolism. If patients at risk for hernia recurrence and aortic aneurysms can be identified in a reliable, low-cost, noninvasive manner, it would greatly enhance preventive options such as prophylactic mesh placement after abdominal surgery. Methods. From February to July 2017, a 3-armed proof-of-concept study was conducted at 3 hospitals including 3 groups of patients (recurrent ventral hernia, aortic aneurysm, and healthy controls). Patients were measured once at the outpatient clinic using an eNose with 3 metal-oxide sensors. A total of 64 patients (hernia, n = 29; aneurysm, n = 35) and 37 controls were included. Data were analyzed by an automated neural network, a type of self-learning software to distinguish patients from controls. Results. Receiver operating curves showed that the automated neural network was able to differentiate between recurrent hernia patients and controls (area under the curve 0.74, sensitivity 0.79, and specificity 0.65) as well as between aortic aneurysm patients and healthy controls (area under the curve 0.84, sensitivity 0.83, and specificity of 0.81). Conclusion. This pilot study shows that the eNose can distinguish patients at risk for recurrent hernia and aortic aneurysm formation from healthy controls.

Comparing Five New Polymer Barriers for the Prevention of Intra-abdominal Adhesions in a Rat Model.

BACKGROUND: Intra-abdominal adhesions affect up to 93% of the patients after abdominal surgery, causing small-bowel obstruction, infertility, chronic abdominal pain, and iatrogenic bowel injury at reoperation. The efficacy of five new polymer antiadhesive barriers to avoid adhesion formation is evaluated in an ischemic button model in rats. MATERIALS AND METHODS: Five new, biodegradable polyurethane and copolyester-based, antiadhesive barriers (A1, A2, A3, B1, and B2) were evaluated in separate experimental groups and compared with two control groups (hyaluronate carboxymethylcellulose barrier and no antiadhesive barrier) in an ischemic button model (n = 11 per group operated). After 14 d, the quantity and quality of the adhesions were scored macroscopically. The Kruskal-Wallis with Mann-Whitney U post hoc and the Fisher's exact tests were used for data analysis. The Bonferroni correction method was applied, and a P-value <0.007 was considered significant. RESULTS: Two animals died during surgery and follow-up. A significant reduction of adhesions to ischemic buttons was found in the A2 group (median, 3.5; interquartile range, 2.25) compared with no adhesive barrier (median, 8.0; interquartile range, 2.0) (P = 0.001). The remaining groups did not differ significantly regarding adhesion quantity or quality. Adverse events were observed in the A2, A3, and B2 groups. CONCLUSIONS: The A2 antiadhesive barrier reduced the adhesion formation significantly compared with no anti-adhesive barrier, but applicability is questionable because of extensive adverse events observed due to implantation of the anti-adhesive barrier. The Nair score appears not to be sensitive enough to detect differences in adhesion formation in this model. Future research should focus on anti-adhesive barriers that are self-adhering.

The general surgeon's perspective of rectus diastasis. A systematic review of treatment options.

BACKGROUND: Diastasis of the rectus abdominis muscles (DRAM) is characterised by thinning and widening of the linea alba, combined with laxity of the ventral abdominal musculature. This causes the midline to "bulge" when intra-abdominal pressure is increased. Plastic surgery treatment for DRAM has been thoroughly evaluated, though general surgical treatments and the efficacy of physiotherapy remain elusive. The aim of this systematic literature review is to evaluate both general surgical and physiotherapeutic treatment options for restoring DRAM in terms of postoperative complications, patient satisfaction, and recurrence rates. METHOD: MEDLINE®, Embase, PubMed, PubMed Central®, The cochrane central registry of controlled trials (CENTRAL), Google Scholar, and the Physiotherapy Evidence Database (PEDro) were searched using the following terms: 'rectus diastasis', 'diastasis recti', 'midline', and 'abdominal wall'. All clinical studies concerning general surgical or physiotherapeutic treatment of DRAM were eligible for inclusion. RESULT: Twenty articles describing 1.691 patients (1.591 surgery/100 physiotherapy) were included. Surgical interventions were classified as plication techniques (313 patients; 254 open/59 laparoscopic), modified hernia repair techniques (68 patients, all open), and combined hernia & DRAM techniques (1.210 patients; 1.149 open/40 hybrid). The overall methodological quality was low. Plication techniques with interrupted sutures and mesh reinforcement were applied most frequently for DRAM repair. Open repairs were performed in 85% of patients. There was no difference in postoperative complications or recurrence rate after laparoscopic or open procedures, or between plication and modified hernia repair techniques. Physiotherapy programmes were unable to reduce IRD in a relaxed state. Though reduction of IRD during muscle contraction was described. CONCLUSION: Both plication-based methods and hernia repair methods are used for DRAM repair. Based on the current literature, no clear distinction in recurrence rate, postoperative complications, or patient reported outcomes can be made. Complete resolution of DRAM, measured in a relaxed state, following a physiotherapy training programme is not described in current literature. Physiotherapy can achieve a limited reduction in IRD during muscle contraction, though the impact of this finding on patient satisfaction, cosmesis, or function outcome is unclear.

Impact of hernia volume on pulmonary complications following complex hernia repair.

BACKGROUND: Despite a multitude of evidence-based prediction models and risk factors for postoperative complications after ventral hernia repair, estimating a patient's risk of postoperative complications after ventral hernia repair remains challenging. In an attempt to improve the preoperative assessment of complex hernia patients, some studies have examined pulmonary changes after hernia repair hypothesizing that large hernias lead to pulmonary changes and increased pulmonary complication rates. Some studies have described a correlation between hernia volume and pulmonary changes, although none provided compelling evidence to identify hernia volume as a risk factor for pulmonary complications. This study evaluates the relationship between hernia volume and postoperative pulmonary complications using computed tomography (CT)-based volume measurements. MATERIALS AND METHODS: Analysis of a prospectively maintained database of consecutive complex hernia patients from 2011 to 2014 undergoing endoscopic (ECST) or open component separation technique (CST) for a hernia defect with a minimum width of 6 cm and visual protrusion of the hernia sac ventral of the rectus abdominis muscles in supine position was performed. Hernia volume was calculated using multiple plane reconstruction of a standard abdominal CT-scan. Noted endpoints were pulmonary complications. RESULTS: Thirty-five patients underwent ECST (n = 20) or CST (n = 15) with a median defect volume of 474 cm3 (range, 114-2086 cm3). Observed complications were pneumonia (n = 4), pulmonary infiltrate (n = 3), aspiration pneumonia (n = 2), and acute respiratory distress syndrome (n = 1). Univariate and multivariate analyses showed that pulmonary complications were associated with "hernia volume" (P = 0.045; 95% CI: 1.008-1.910). CONCLUSIONS: Hernia volume is a promising risk factor for postoperative pulmonary complications and can be calculated using a standard abdominal CT-scan.