Clinical feasibility of diffuse speckle contrast analysis for real-time tissue perfusion monitoring.

BACKGROUND: Adequate tissue perfusion is an important prognostic and diagnostic factor during the management of lower limb peripheral arterial disease. Convenient and real-time tissue perfusion monitoring remains an elusive challenge. METHODS: Tissue perfusion on the dorsal and plantar surfaces of both feet of 20 participants was measured during and after cuff-induced ischemia using a novel 4-channel, laser-based perfusion monitoring device based on diffuse speckle contrast analysis technology (Pedra sensors). Participants were free of significant peripheral arterial disease. Transcutaneous partial pressure of oxygen (TcPO2) measurements were recorded concurrently for comparison. RESULTS: Pedra sensors detected perfusion changes significantly more quickly than TcPO2 sensors. One minute after induced ischemia, the mean percent changes from baseline values (before ischemia) were -22.7±32.0% and -3.1±8.8% (P<0.001) for Pedra and TcPO2 sensors, respectively. One minute into induced ischemia, Pedra sensors had reached 50.5% of the 5-minute ischemia reading whereas TcPO2 sensors had reached only 18.6% of the 5-minute reading (P=0.046). Pedra sensors reported hyperemia immediately after cuff release with a mean percent change from baseline of 143.8±122.3%/173.4±121.8% on the dorsal/plantar surfaces while TcPO2 measurements were still recording negative changes at that time (-26.7±19.4%/-18.6±24.4% dorsal/plantar). Pedra sensors exhibited markedly lower interobserver and intraobserver variability than TcPO2 sensors. CONCLUSIONS: A device based on diffuse speckle contrast analysis reported tissue perfusion in real time. Cuff-induced ischemia and hyperemia following cuff release were rapidly and consistently detected on both the dorsal and plantar surfaces of the foot. Diffuse speckle contrast analysis may have value for real-time perfusion monitoring during angiography procedures.

The Impact of Operating Surgeon Experience, Supervised Trainee vs. Trained Surgeon, in Vascular Surgery Procedures: A Systematic Review and Meta-Analysis.

OBJECTIVE: The operative caseload of a surgeon has a positive influence on post-operative outcomes. For surgical trainees to progress effectively, maximising operating room exposure is essential, vascular surgery being no exception. Our aim was to ascertain the impact of supervised trainee led vs. expert surgeon led procedures on post-operative outcomes, across three commonly performed vascular operations. METHODS: A literature search was undertaken using the MEDLINE, Web of Science, and Cochrane databases up to 1 January 2018. Studies reporting outcomes following major lower limb amputation, fistula formation, or carotid endarterectomy (CEA) that involved a direct comparison between supervised trainee and experts were included, with odds ratios (ORs) calculated. Primary outcomes varied depending on the specific procedure: amputations-rate of amputation revision within 30 days; fistula formation-primary patency; CEA-stroke rate at 30 days. Meta-analysis with the Mantel-Haenszel method was performed for each outcome. RESULTS: Sixteen studies were included in the final review. Overall, trainees accounted for a third of all procedures analysed (n = 2 421/7 017; 34.5%). Only one study was identified that described rates of amputation revision, precluding any further analysis. Four studies on fistula formation were included, showing no significant difference in outcomes between trainees and experts in primary patency (OR 1.68, 95% confidence interval [CI] 0.42-6.75). Nine studies were identified reporting post-CEA stroke rates, also demonstrating no difference between trainees and experts (OR 0.89, 95% CI 0.59-1.32). CONCLUSION: In select cases, with appropriate training and suitable experience, supervised trainees can perform surgical procedures without any detriment to patient care. To ensure high standards for patients of the future, supported training programmes are essential for today's surgical trainees.