Use of an automated knot fastener shortens operative times in minimally invasive mitral valve repair.

INTRODUCTION: Longer durations of cardiopulmonary bypass and aortic cross clamp are associated with increased morbidity and mortality. Little is known about the effect of automated knot fasteners (Cor-Knot®) in minimally invasive mitral valve repair on operative times and outcomes. The aim of this study was to evaluate whether these devices shortened cardiopulmonary bypass and aortic cross clamp times and whether this impacted on postoperative outcomes. MATERIALS AND METHODS: All patients undergoing isolated minimally invasive mitral valve repair by a single surgeon between March 2011 and March 2016 were included (n = 108). Two cohorts were created based on the use (n = 52) or non-use (n = 56) of an automated knot fastener. Data concerning intraoperative variables and postoperative outcomes were collected and compared. RESULTS: Preoperative demographics were well matched between groups with no significant difference in logistic Euroscore (manual vs automated: median 3.1, interquartile range, IQR, 2.1-5.5, vs 5.4, IQR 2.2-8.3; P = 0.07, respectively). Comparing manually tied knots to an automated fastener, cardiopulmonary bypass and aortic cross clamp times were significantly shorter in the automated group (cardiopulmonary bypass: median 200 minutes, IQR 180-227, vs 165 minutes (IQR 145-189 minutes), P < 0.001; aortic cross clamp 134 minutes (IQR 121-150 minutes) vs 111 minutes (IQR 91-137 minutes), P < 0.001, respectively). There was no mortality and no strokes, nor were there any differences in postoperative outcomes including reoperation for bleeding, renal failure, intensive care or hospital stay. CONCLUSIONS: The use of an automated knot fastener significantly reduces cardiopulmonary bypass and aortic cross clamp times in minimally invasive mitral valve repair but this does not translate into an improved clinical outcome.

Propensity score-matched outcomes after thoracic epidural or paravertebral analgesia for thoracotomy.

It is not known which regional analgesic technique is most effective or safest after open lung resection. We retrospectively examined outcomes in 828 patients who received thoracic epidural analgesia and 791 patients who received paravertebral block after lung resection between 2008 and 2012. We analysed outcomes for 648 patients, 324 who had each analgesic technique, matched by propensity scores generated with peri-operative data. There were 22 out of 324 (7%) postoperative respiratory complications after thoracic epidural and 23 out of 324 (7%) after paravertebral block, p = 0.88. For any postoperative complication, there were 80 out of 324 (25%) and 78 out of 324 (24%) complications, respectively, p = 0.85. There were 17 out of 324 (5%) re-admissions to intensive care after thoracic epidural and 17 out of 324 (5%) after paravertebral block, p > 0.99, and the number of deaths before discharge were 6 out of 324 (2%) and 4 out of 324 (1%), respectively, p = 0.53. There was no significant difference in median (IQR [range]) hospital stay after thoracic epidural or paravertebral block, 6 (5-9 [2-94]) days vs. 6 (5-9 [2-122]), respectively, p = 0.83. Our study suggests that rates of complications as well as length of hospital stay after thoracic epidural analgesia and paravertebral blockade are similar. We were unable to compare analgesic efficacy due to incomplete data.

Pressure and oxygen debt on bypass - potential quality markers of perfusion?

No markers of quality of perfusion pressure and oxygen delivery during cardiopulmonary bypass (CPB), to complement rewarming rate, maximum temperature on rewarming, lowest haematocrit, and blood glucose, exist. Using the electronic acquisition of blood pressure on bypass (JOCAP system), the percentage of time perfusion pressure was below 30, 40, 50, 60 and 70 mmHg, average deviance, confidence interval, median, mode, standard deviation, variance, and average, maximum and cumulative oxygen debt were calculated. Numerous different readouts of achievement of maintenance of constant pressure on bypass and oxygen debt are now easily achievable with perfusion electronic data management systems. Mean, median, and mode offer poor discrimination of pressure control during CPB. Percentage of time perfusion pressure was below 30, 40, 50, 60 and 70 mmHg, average deviance, confidence interval, and standard deviation all have discriminatory power, but need clinical correlation for their significance. A composite score involving non-pressure readouts (e.g. oxygen delivery, arterial and venous saturations, and flow rates) may need to be integrated into any perfusion quality marker. Assessment of adequacy of constant perfusion pressure and oxygen delivery may allow the scientific evaluation of pressure and oxygen delivery on bypass for patients to be compared accurately. Currently, in studies involving CPB, blood pressure targets are stated with no quantitative assessment of adequacy of achievement of these targets. Electronic data monitoring during cardiopulmonary bypass, when correlated with clinical outcome, may help to provide a marker of quality of perfusion pressure during CPB and may, indeed, allow patient-specific perfusion pressure strategies to be developed.