Decrease in pulmonary function and oxygenation after lung resection.

Respiratory deficits are common following curative intent lung cancer surgery and may reduce the patient's ability to be physically active. We evaluated the influence of surgery on pulmonary function, respiratory muscle strength and physical performance after lung resection. Pulmonary function, respiratory muscle strength (maximal inspiratory/expiratory pressure) and 6-min walk test (6MWT) were assessed pre-operatively, 2 weeks post-operatively and 6 months post-operatively in 80 patients (age 68±9 years). Video-assisted thoracoscopic surgery was performed in 58% of cases. Two weeks post-operatively, we found a significant decline in pulmonary function (forced vital capacity -0.6±0.6 L and forced expiratory volume in 1 s -0.43±0.4 L; both p<0.0001), 6MWT (-37.6±74.8 m; p<0.0001) and oxygenation (-2.9±4.7 units; p<0.001), while maximal inspiratory and maximal expiratory pressure were unaffected. At 6 months post-operatively, pulmonary function and oxygenation remained significantly decreased (p<0.001), whereas 6MWT was recovered. We conclude that lung resection has a significant short- and long-term impact on pulmonary function and oxygenation, but not on respiratory muscle strength. Future research should focus on mechanisms negatively influencing post-operative pulmonary function other than impaired respiratory muscle strength.

Dacron Graft Intussusception Technique for Treatment of Type A Aortic Dissections: Technical Notes and Preliminary Results.

INTRODUCTION: Optimal surgical management for acute type A aortic dissection (AAAD) remains unclear. The in-hospital mortality rate is still high (15%), and the intraoperative bleeding is an independent risk factor for hospital mortality. OBJECTIVE: The aim of our study was describe a new method for aortic anastomosis in the repair of AAAD and report the hospital mortality and bleeding complications. METHODS: Between January 2008 and November 2014, 24 patients, 16 male, median age 62 years, underwent surgical treatment of AAAD. The surgical technique consisted of intussusception of a Dacron tube in the dissected aorta, which is anastomosed with a first line of 2-0 polyester everting mattress suture and a second line of 3-0 polypropylene running suture placed at the outermost side. Open distal anastomosis was performed with bilateral selective antegrade cerebral perfusion in 13 (54.1%) patients. RESULTS: Cardiopulmonary bypass and aortic clamping time ranged from 75 to 135 min (mean=85 min) and 60 to 100 min (mean=67 min), respectively. The systemic circulatory arrest ranged from 29 to 60 min (mean=44.5 min). One (4.1%) patient required reoperation for bleeding, due to the use of preoperative clopidogrel. The postoperative bleeding was 382-1270 ml (mean=654 ml). We used an average of 4.2 units of red blood cells/patient. There were two (8.3%) hospital deaths, one due to intraoperative bleeding and another due to mesenteric ischemia. The average length of stay in the intensive care unit and hospital was 44 hours and 6.7 days, respectively. CONCLUSION: This new method for surgical correction of AAAD was reproducible and resulted in satisfactory clinical outcomes.

Dacron graft intussusception technique for treatment of type a aortic dissections: technical notes and preliminary results

Abstract Introduction: Optimal surgical management for acute type A aortic dissection (AAAD) remains unclear. The in-hospital mortality rate is still high (15%), and the intraoperative bleeding is an independent risk factor for hospital mortality. Objective: The aim of our study was describe a new method for aortic anastomosis in the repair of AAAD and report the hospital mortality and bleeding complications. Methods: Between January 2008 and November 2014, 24 patients, 16 male, median age 62 years, underwent surgical treatment of AAAD. The surgical technique consisted of intussusception of a Dacron tube in the dissected aorta, which is anastomosed with a first line of 2-0 polyester everting mattress suture and a second line of 3-0 polypropylene running suture placed at the outermost side. Open distal anastomosis was performed with bilateral selective antegrade cerebral perfusion in 13 (54.1%) patients. Results: Cardiopulmonary bypass and aortic clamping time ranged from 75 to 135 min (mean=85 min) and 60 to 100 min (mean=67 min), respectively. The systemic circulatory arrest ranged from 29 to 60 min (mean=44.5 min). One (4.1%) patient required reoperation for bleeding, due to the use of preoperative clopidogrel. The postoperative bleeding was 382-1270 ml (mean=654 ml). We used an average of 4.2 units of red blood cells/patient. There were two (8.3%) hospital deaths, one due to intraoperative bleeding and another due to mesenteric ischemia. The average length of stay in the intensive care unit and hospital was 44 hours and 6.7 days, respectively. Conclusion: This new method for surgical correction of AAAD was reproducible and resulted in satisfactory clinical outcomes.

Pedicled no-touch saphenous vein graft harvest limits vascular smooth muscle cell activation: the PATENT saphenous vein graft study.

OBJECTIVE: Neointimal hyperplasia secondary to vascular smooth muscle cell (VSMC) activation limits the long-term patency of saphenous vein grafts (SVGs). We compared markers of vascular injury and VSMC activation in SVGs harvested using the pedicled 'no-touch' (NT) vs the conventional (CON) technique. METHODS: Patients undergoing coronary artery bypass surgery were enrolled in the PATENT SVG trial (clinicaltrials.gov NCT01488084). Patients were randomly allocated to have SVGs harvested with the NT technique from one leg and the CON method from the other. SVG segments underwent morphometry, histological and electron microscopy assessments and transcript measurements of VSMC activation and differentiation markers. Leg wound functional recovery and harvest site complications were assessed using a quality-of-life questionnaire. RESULTS: A total of 17 patients (65.3 ± 7.3 years) were enrolled. SVGs harvested using the NT vs CON technique exhibited preserved intimal, medial and adventitial architecture. CON harvest was associated with greater medial Kruppel-like factor 4 transcript levels (0.26 ± 0.05 vs 0.11 ± 0.02, P < 0.05). CON samples had significantly lower medial serum response factor (0.53 ± 0.11 vs 1.44 ± 0.50, P < 0.05) and myocardin (0.59 ± 0.08 vs 1.33 ± 0.33, P < 0.05) transcript levels. MicroRNA-145, an inhibitor of VSMC activation and differentiation, was higher in the NT vs CON samples (1.84 ± 1.03 vs 0.50 ± 0.19, P < 0.05). Leg assessment scores were worse in the NT legs at 3 months, but similar to CON scores at 12 months. CONCLUSIONS: SVGs harvested using the 'NT' technique exhibit an early molecular and morphological pattern consistent with decreased VSMC activation compared with CON harvesting. Functional leg recovery was similar in both groups at 12 months. Larger studies are required to corroborate these findings.

Perivascular fat-derived leptin: a potential role in improved vein graft performance in coronary artery bypass surgery.

Perivascular tissue (PVT) surrounding many blood vessels, including those used as bypass conduits, is the source of adipocyte-derived relaxing factors, one of which is leptin. Here, we assessed leptin levels and identified leptin localization in the cushion of fat surrounding 'no-touch-harvested' saphenous veins (SVs) used as grafts in 15 patients undergoing coronary artery bypass surgery (CABG). Leptin protein was identified in perivascular fat (PVF) extracts by Western blot analysis and leptin levels were 2.2 (0.5-4.2) ng/mg protein [mean (range), n=10] as assessed by ELISA. There was dense leptin immunostaining of fat and adipocyte membranes surrounding these no-touch SV grafts. PVT-derived factors are suggested to play an important role in the superior patency rate of the internal thoracic artery used as a bypass graft. Our findings suggest that, as a potent vasodilator, PVF-derived leptin may also play an important role both at harvesting and in the improved long-term performance of no-touch SVs in patients undergoing CABG.

The "no-touch" harvesting technique for vein grafts in coronary artery bypass surgery preserves an intact vasa vasorum.

OBJECTIVES: Our objective was to evaluate the impact of vein graft harvesting technique on structure and function of vasa vasorum. METHODS: Paired segments of great saphenous veins harvested either with conventional harvesting technique or no-touch technique were obtained from 9 consecutive patients undergoing coronary artery bypass grafting. Quantitative measurements, using immunohistochemistry and morphometry, were performed. Ultrastructural analyses of vasa vasorum were performed with electron microscopy. Video footage of superficial vasa vasorum in an implanted saphenous vein graft harvested with the no-touch technique was captured during a coronary bypass operation and is presented for online viewing. RESULTS: The total area of vasa vasorum in vein grafts harvested with the conventional technique was significantly reduced both in the media (P = .007) and in the adventitia (P = .014) compared with vein grafts harvested with the no-touch technique. Ultrastructural findings indicated that the no-touch technique preserved an intact vasa vasorum whereas the conventional technique did not. Video footage showed retrograde flow in the vasa vasorum in vein graft harvested with the no-touch technique. CONCLUSIONS: These findings show that the no-touch technique for saphenous vein graft harvesting for coronary bypass grafting preserves an intact vasa vasorum. This could represent one of the mechanisms underlying the improved patency of saphenous vein grafts harvested with this technique.

Slower progression of atherosclerosis in vein grafts harvested with 'no touch' technique compared with conventional harvesting technique in coronary artery bypass grafting: an angiographic and intravascular ultrasound study.

OBJECTIVES: In a long-term randomised coronary artery bypass grafting (CABG) study, the patency rate using a new 'no touch' (NT) vein-graft preparation technique was superior to the conventional (C) technique. This cineangiographic and intravascular ultrasound (IVUS) substudy examined possible mechanisms. METHODS: A total of 45 patients (118 grafts) in the NT group and 46 patients (112 grafts) in the C group had patent grafts at short-term follow-up after 18 months. Thirty-seven patients (91 grafts) in the NT group and 37 patients (77 grafts) in the C group had patent grafts at long-term follow-up after 8.5 years, and were evaluated on a scale from 0 (normal) to 2 (significant stenosis) by cineangiogram. IVUS was performed in 15 NT grafts and 14 C grafts in the short-term follow-up, and 27 NT grafts and 26 C grafts in the long-term follow-up, in grafts considered normal by the cineangiogram. The grafts were evaluated with respect to lumen volume, intimal thickness, incidence of plaque and plaque components. RESULTS: In the short-term follow-up, the cineangiogram showed more normal grafts (89.0% in the NT group compared with 75.0% in the C group), and the number of grafts with stenosis was 11.0% in the NT group compared with 25.0% in the C group (p=0.006). IVUS showed less mean intimal thickness (0.43 (0.07)mm vs 0.52 (0.08)mm; p=0.03), less grafts with considerable intimal hyperplasia (≥ 0.9 mm; 20% vs 78.6%; p=0.011) and fewer patients with considerable hyperplasia (≥ 0.9 mm; 25% vs 100%; p=0.007). In the long-term follow-up, the cineangiogram showed more normal grafts, with 91.2% in the NT group compared with 83.1% in the C group; there were fewer grafts with significant stenosis, with 7.7% in the NT group compared with 15.6% in the C group (p=0.14). IVUS showed fewer grafts containing multiple plaques (14.8% vs 50%; p=0.008), less advanced plaque with lipid (11.8% vs 63.9%; p=0.0004) and less maximal plaque thickness (1.04 (0.23)mm vs 1.32 (0.25)mm; p=0.02) in the NT group compared with the C group. CONCLUSION: The superior long-term patency rate using the NT vein-graft technique at CABG could be explained by a significantly slower progression of atherosclerosis.

Retaining perivascular tissue of human saphenous vein grafts protects against surgical and distension-induced damage and preserves endothelial nitric oxide synthase and nitric oxide synthase activity.

OBJECTIVE: Conventional harvesting of saphenous vein used for coronary artery bypass surgery induces a vasospasm that is overcome by high-pressure distension. Saphenous vein harvested with its cushion of perivascular tissue by a "no touch" technique does not undergo vasospasm and distension is not required, leading to an improved graft patency. The aim of this study is to investigate the effect of surgical damage and high-pressure distension on endothelial integrity and endothelial nitric oxide synthase expression and activity in saphenous vein harvested with and without perivascular tissue. METHODS: Saphenous veins from patients (n = 26) undergoing coronary artery bypass surgery were prepared with and without perivascular tissue. We analyzed the effect of 300 mm Hg distension on morphology and endothelial nitric oxide synthase/nitric oxide synthase activity using a combination of immunohistochemistry, Western blot analysis, reverse transcriptase polymerase chain reaction, and enzyme assay in distended (with and without perivascular tissue) compared with nondistended (with and without perivascular tissue) segments. RESULTS: Distension induced substantial damage to the luminal endothelium (assessed by CD31 staining) and vessel wall. Endothelial nitric oxide synthase expression and activity were significantly reduced by high-pressure distension and removal of, or damage to, perivascular tissue. The effect of distension was significantly less for those with perivascular tissue than for those without perivascular tissue in most cases. CONCLUSION: The success of the saphenous vein used as a bypass graft is affected by surgical trauma and distension. Veins removed with minimal damage exhibit increased patency rates. We show that retention of perivascular tissue on saphenous vein prepared for coronary artery bypass surgery by the "no touch" technique protects against distension-induced damage, preserves vessel morphology, and maintains endothelial nitric oxide synthase/nitric oxide synthase activity.

No touch vein harvesting technique for CABG improves the long-term clinical outcome.

OBJECTIVES: To investigate the long-term clinical outcome, averaging 8.5 years, of two saphenous vein harvesting techniques for CABG; no touch (NT) versus conventional (C). DESIGN: In a randomized study, 49/52 in group NT and 44/52 in group conventional were evaluated for reangina, myocardial infarction, new revascularization, functional class, risk factors and medical treatment. The vein grafts and the native coronary arteries were correlated to the occurrence of reangina. RESULTS: There were significantly more patients free from angina and in NYHA class I (67.3 versus 43.2%; p =0.02) in group NT compared to group C. No cardiac death was found in group NT versus three in group C. There were trends towards fewer patients with cardiac death or myocardial infarction (3.8 vs. 13.4%; p =0.16), more patients free from angina (75.5 vs. 63.6%; p =0.26) and fewer patients with graft occlusion (24.3 vs. 43.2% (p =0.14) in group NT. CONCLUSIONS: The results of the NT-technique are encouraging with no cardiac deaths, significantly more asymptomatic patients and a trend towards impact on hard clinical endpoints compared to the conventional technique.

The no-touch technique of harvesting the saphenous vein for coronary artery bypass grafting surgery.

A new 'no-touch' (NT) technique of saphenous vein (SV) preparation for coronary artery bypass grafting (CABG) surgery was developed where the vein is harvested with a pedicle of surrounding tissue, which protects the vein from spasm therefore obviating the need for distension. The adventitial layer and the structures contained within the cushion of surrounding tissue possess both mechanical and functional properties that protect the vein from spasm and ischemia. In addition, the surrounding tissue supports excessively long vein grafts and prevents kinking. A detailed description of the technique is presented and this is the first time we publish the technique as a videoclip.