Impact of duration of chest tube drainage on pain after cardiac surgery.

OBJECTIVE: This study was designed to analyze the duration of chest tube drainage on pain intensity and distribution after cardiac surgery. METHODS: Two groups of 80 cardiac surgery adult patients, operated on in two different hospitals, by the same group of cardiac surgeons, and with similar postoperative strategies, were compared. However, in one hospital (long drainage group), a conservative policy was adopted with the removal the chest tubes by postoperative day (POD) 2 or 3, while in the second hospital (short drainage group), all the drains were usually removed on POD 1. RESULTS: There was a trend toward less pain in the short drainage group, with a statistically significant difference on POD 2 (P=0.047). There were less patients without pain on POD 3 in the long drainage group (P=0. 01). The areas corresponding to the tract of the pleural tube, namely the epigastric area, the left basis of the thorax, and the left shoulder were more often involved in the long drainage group. There were three pneumonias in each group and no patient required repeated drainage. CONCLUSIONS: A policy of early chest drain ablation limits pain sensation and simplifies nursing care, without increasing the need for repeated pleural puncture. Therefore, a policy of short drainage after cardiac surgery should be recommended

Myocardial angiogenesis induction with bone protein derived growth factors (animal experiment).

Myocardial angiogenesis induction with vascular growth factors constitutes a potential strategy for patients whose coronary artery disease is refractory to conventional treatment. The importance of angiogenesis in bone formation has led to the development of growth factors derived from bovine bone protein. Twelve pigs (mean weight, 73 +/- 3 kg) were chosen for the study. In the first group (n = 6, growth factor group) five 100 micrograms boluses of growth factors derived from bovine bone protein, diluted in Povidone 5%, were injected in the lateral wall of the left ventricle. In the second group (n = 6, control group), the same operation was performed but only the diluting agent was injected. All the animals were sacrificed after 28 days and the vascular density of the left lateral wall (expressed as the number of vascular structures per mm2) as well as the area of blood vessel profiles per myocardial area analysed were determined histologically with a computerised system. The growth factor group had a capillary density which was significantly higher than that of the control group: 12.6 +/- 0.9/mm2 vs 4.8 +/- 0.5/mm2 (p < 0.01). The same holds true for the arteriolar density: 1 +/- 0.2/mm2 vs 0.3 +/- 0.1/mm2 (p < 0.01). The surface ratios of blood vessel profiles per myocardial area were 4900 +/- 800 micron 2/mm2 and 1550 +/- 400 micron 2/mm2 (p < 0.01) respectively. In this experimental model, bovine bone protein derived growth factors induce a significant neovascularisation in healthy myocardium, and appear therefore as promising candidates for therapeutic angiogenesis

Minimally invasive harvest of the saphenous vein for coronary artery bypass grafting.

BACKGROUND: Preparation of the great saphenous vein for coronary artery bypass grafts is traditionally performed through one or many long cutaneous incisions. We describe the dissection of the great saphenous vein through small cutaneous incisions using the Mini Harvest System. METHODS: The device is composed of a retractor coupled to a light source. Introduced under the skin, above the anterior plane of the vein, it allows an easy preparation of the vein under direct vision. The entire vein can be dissected from the ankle to the groin through sequential cutaneous incisions along the leg. A prospective, randomized trial was performed to compare the minimally invasive vein harvest technique (group 1, n = 15) versus the standard method (group 2, n = 15). RESULTS: In addition to an internal mammary artery graft, 28 venous coronary bypass grafts were performed in group 1 (mean, 1.9 +/- 1.0) and 32 in group 2 (mean, 2.1 +/- 1.0). The mean cutaneous incision length divided by the mean length of the harvested vein was 10.8 cm/32.3 cm = 33% for group 1 and 37.6 cm/33.2 cm = 113% in group 2 (p < 0.001). Wounds were examined daily and a final assessment was performed on day 7. Better cicatrization, less hematoma and edema, and less pain were observed in group 1. CONCLUSIONS: Minimally invasive harvest of the great saphenous vein offers many advantages over the traditional harvest method. Besides the aesthetic aspect, healing is better and postoperative discomfort is reduced

Prélèvement minimal invasif de la veine saphène interne pour pontages aorto-coronariens [Minimally invasive internal saphenous vein harvesting for coronary artery bypass]

Harvesting of the great saphenous vein for coronary artery bypass grafting is usually performed through long cutaneous incisions. We report our experience of minimally invasive harvest of the saphenous vein using the "Mini Harvest System". This device is composed of a blade coupled to a light source. Through a small cutaneous incision, the blade is placed under the skin and allows progressive dissection of the vein under direct vision. We compare this technique ("minimal invasive" group, n = 48) to the conventional method in which extensive incisions are performed along the saphenous vein course ("standard", n = 54). Both groups are comparable in term of age, sex, diabetes, peripheral arterial disease or obesity. The number of bypass performed is also comparable in the two groups. The ratio of the mean length of the cutaneous incision and the mean length of the vein was 35.4 +/- 5.9% for the "minimal invasive" group and 104.5 +/- 23.3% for the "standard" group (p < 0.001). The local complication rate is significantly reduced with a reduction in local post-operative pain (2% vs. 17%, p = 0.01), a better healing (100% vs. 79%, p = 0.01), a reduction in hematoma (31% vs. 52%, p = 0.03) and in oedema (37% vs. 59%, p = 0.03). We conclude that besides the evident aesthetic benefit, minimally invasive harvest of the saphenous vein allows for a better cicatrization and reduces the post-operative discomfort without compromising the aorto-coronary bypass procedure

Intra-aortic balloon: evaluation of heparin-coating under various experimental conditions.

In a calf model, heparin coated intra-aortic balloon (IAB) was compared with standard balloon. In group 1, 9 of each IAB type were set to the automatic mode for 15 min, 45 min and 6 hours respectively, while in group 2, 3 of each IAB type were left deflated during 20 minutes to simulate balloon dysfunction. At the end of the procedures, 3 samples of each IAB were analyzed with scanning electron microscopy (SEM) for surface deposits. Macroscopically, the 12/12 heparin coated IAB of both groups and the 9/9 standard IAB of group 1 were free of deposits, whereas the 3/3 standard IAB of group 2 exhibited clot deposits. SEM revealed deposit-free surfaces in the 36/36 heparin coated samples of both groups, while 14/27 standard samples of group 1 (p<0.01 when compared with heparin coated samples) and 8/9 standard samples of group 2 (p = 0.02, same comparison) disclosed blood cells and fibrin deposits. Morphometrically, the proportion of standard sample surfaces covered with deposits, estimated according to a score system (0% = 0; 0.1-25% = 1; 25.1-50% = 2; 50.1-75% = 3; 75. 1-100% = 4), was 0.69+/-0.82 in group 1 (p<0.01 when compared with heparin coated samples) and 1.22+/-0.83 in group 2 (p<0.01, same comparison). Thus heparin coated IAB presents no deposits either after 6 hours of intravascular ballooning or after 20 minutes of stagnation. It seems to be a promising strategy for patients with absolute or relative contraindications to systemic heparinization

Air filtering capacity of an integrated cardiopulmonary bypass unit.

To limit the morbidity of cardiopulmonary bypass (CPB), a new concept of integrating pumping, oxygenation, and air removal into a single unit has been developed (CardioVention Inc., Santa Clara, CA). The air filtration capacity of this system was tested. Three calves (73.2 +/- 2 kg) were connected to the integrated system by jugular and carotid cannulation. The integrated unit was challenged with injections of boluses of air of 5, 10, and 20 ml, three times each, and for a blood flow of 3 L/min and 5 L/min, respectively. The bubble count and size were recorded downstream of the unit with a Doppler ultrasound. At 3 L/min, bubbles were detected after injections of 20 ml only (n = 7 for the nine boluses). At 5 L/min, 1 bubble was detected with the nine injections of 5 ml, 14 bubbles were detected with nine injections of 10 ml, and 25 bubbles were detected with nine injections of 20 ml. No bubble exceeded 40 microm in diameter as determined by the Doppler ultrasound. The air filtering capacity of the CardioVention system is excellent both in terms of bubble count and of size after injection of large boluses of air. Its integrated concept offers a simplification of the circuit with fewer devices and connections, which further reduces the risk of accidental air introduction

A simplified method of stabilization and hemostasis for minimally invasive coronary artery bypass.

We describe a simple method to achieve both hemostasis and stabilization of the left anterior descending coronary artery during minimally invasive coronary artery bypass grafting. This technique allows the surgeon to perform a precise anastomosis of the left internal mammary artery to the target vessel on a beating heart

Acute effects of transmyocardial laser revascularization on left-ventricular function: an haemodynamic and echocardiographic study.

While the lesions produced by transmyocardial laser revascularisation (TMLR) induce scar formation, it is important to determine whether this procedure can be deleterious for the left-ventricular function, which is already impaired by the underlying ischaemic process in some patients. Ten channels were drilled in the left lateral wall of the hearts of ten pigs (mean weight, 61 +/- 8.2kg) with a Holmium:YAG laser. Haemodynamic measurements and echocardiographic assessment of left-ventricular function were performed before the TMLR procedure, 5 and 30 min after, and lastly after 5 min of pacing at a rate increased by 30% of the baseline value. Echocardiographic assessment was in the short axis at the level of the laser channels, and included left-ventricular ejection fraction and segmental wall motility of the lasered area (scale 0-3:0 = normal 1 = hypokinesia, 2 = akinesia, 3 = dyskinesia). Values at 5 and 30 min were compared with baseline values; the difference was considered significant if p < 0.05. Haemodynamical values were stable throughout all the procedures. The ejection fraction showed a slight but significant decrease 5 min after the creation of the channels (60.4 +/- 6.8% vs 54 +/- 7.6%, p=0.02) and recovered at 30min. The segmental motility score of the involved areas increased to 1 after 5 min in five animals, and came back to 0 at 30 min except in one animal. Even with pacing no segmental dysfunction occurred. The reversibility of the segmental hypokinesia induced by TMLR, as well as the absence of pace-induced dysfunction 30 min after the procedure strongly suggest the inocuity of TMLR in this experimental set-up