Volatile Organic Compounds in the Early Diagnosis of Non-healing Surgical Wounds: A Systematic Review.

BACKGROUND: The normal healing of surgical wounds can be disrupted by infection and/or dehiscence, leading to development of chronic, non-healing wounds (NHW). Diagnosis of NHWs is via clinical acumen and analysis of microbiology wound swabs. Volatile organic compounds (VOCs) are emitted generally by human subjects and specifically as products of bacterial metabolism and are detected in the wound area. This systematic review will assess the potential use of VOCs released by surgical wounds as a non-invasive method for identifying bacterial species and the progression to NHW. METHOD: A systematic search of studies, via PRISMA guidelines, was conducted. Of 220 papers screened, seven studies were included. Outcome data were extracted on methods for VOC analysis and wound/bacterial VOC profiles. RESULTS: The studies have shown that VOC profiles are identified by two methods: gas chromatography-mass spectrometry and electronic nose. There are VOC profiles associated with causative bacterial species, with early indications that they could be anatomically specific or could monitor treatment effects. CONCLUSION: VOC profiling of bacterial species within wounds is possible and could become a point of care test. More research is needed on specific VOC profiles to wound location and whether these profiles may predict progression to NHW.

Continuous drain irrigation as a risk mitigation strategy for postoperative pancreatic fistula: a meta-analysis.

BACKGROUND: Postoperative pancreatic fistula serves as the principle cause for the morbidity and mortality observed after pancreatectomy. Continuous drain irrigation as a treatment strategy for infected pancreatic necrosis has previously been described; however, its role adter pancreatectomy has yet to be determined. The aim of this study was to determine whether continuous drain irrigation reduces postoperative pancreatic fistula. METHODS: A meta-analysis of the pre-existing literature was performed. The primary end point was whether continuous drain irrigation reduced postoperative pancreatic fistula after pancreatectomy. The secondary end point evaluated its impact on postoperative morbidity, mortality, and length of stay. RESULTS: Nine articles involving 782 patients were included. Continuous drain irrigation use was associated with a statistically significant reduction in postoperative pancreatic fistula rates (odds ratio [95% confidence interval] 0.40 [0.19-0.82], P = .01). Upon subgroup analysis, a significant reduction in clinically relevant postoperative pancreatic fistula was also noted (odds ratio 0.37 [0.20-0.66], P = .0008). A reduction in postoperative complications was also observed-delayed gastric emptying (0.45 [0.24-0.84], P = .01) and the need for re-operation (0.33 [0.11-0.96], P = .04). This reduction in postoperative complications translated into a reduced length of stay (mean difference -2.62 [-4.97 to -0.26], P = .03). CONCLUSION: Continuous drain irrigation after pancreatectomy is a novel treatment strategy with a limited body of published evidence. After acknowledging the limitations of the data, initial analysis would suggest that it may serve as an effective risk mitigation strategy against postoperative pancreatic fistula. Further research in a prospective context utilizing patient risk stratification for fistula development is, however, required to define its role within clinical practice.

Dynamic Physiological Culture of Ex Vivo Human Tissue: A Systematic Review.

Conventional static culture fails to replicate the physiological conditions that exist in vivo. Recent advances in biomedical engineering have resulted in the creation of novel dynamic culturing systems that permit the recapitulation of normal physiological processes ex vivo. Whilst the physiological benefit for its use in the culture of two-dimensional cellular monolayer has been validated, its role in the context of primary human tissue culture has yet to be determined. This systematic review identified 22 articles that combined dynamic physiological culture techniques with primary human tissue culture. The most frequent method described (55%) utilised dynamic perfusion culture. A diverse range of primary human tissue was successfully cultured. The median duration of successful ex vivo culture of primary human tissue for all articles was eight days; however, a wide range was noted (5 h-60 days). Six articles (27%) reported successful culture of primary human tissue for greater than 20 days. This review illustrates the physiological benefit of combining dynamic culture with primary human tissue culture in both long-term culture success rates and preservation of native functionality of the tissue ex vivo. Further research efforts should focus on developing precise biochemical sensors that would allow for real-time monitoring and automated self-regulation of the culture system in order to maintain homeostasis. Combining these techniques allows the creation of an accurate system that can be used to gain a greater understanding of human physiology.