Till Örebro universitet

This thesis was based on a prospective randomized trial which was started in 1993 to compare the no touch (NT) with the conventional (C) technique of saphenous vein harvesting for CABG.

In paper I, was demonstrated superior patency for the NT grafts at short-term (1.5 years; 95,6% vs 89%; p < 0,05) and long-term follow-up (8.5 years; 90% vs 76%; p = 0,01).

In paper II, at long-term follow-up there were significantly more patients free from recurrent angina and in NYHA-class I in the NT group (67,3% vs 43,2%; p = 0,02). In addition there was no cardiac death and a trend towards improvement of hard clinical endpoints in the NT group.

In paper III, we tested the hypothesis that the NT harvesting technique could provide a reduced progression of the atherosclerotic disease in the vein graft wall by using cineangiography and an intravascular ultrasound (IVUS) assessment. At short-term follow- up, the cineangiogram showed more normal grafts in the NT group (89% vs 75%; p = 0,006). The IVUS assessment 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 grafts containing considerable hyperplasia (>0.9 mm; 25% vs 100%; p = 0.007) for the NT vein grafts. At long-term follow-up the cineangiogram showed more normal grafts, 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. The IVUS assessment 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 vein grafts.

In paper IV, was demonstrated a preserved left ventricular ejection fraction in the NT group compared with the C group (57,9 + 9,5% vs 49,4 + 13,3%; p = 0.004) at 16 years follow-up. Also, a smaller left atrium size, a lower BNP value and fewer patients with atrial fibrillation in the NT group indicated a better left ventricular diastolic function. In conclusion: This thesis showed that the no-touch vein harvesting technique provided a superior long-term patency compared with the conventional technique due to a delayed atherosclerotic process in vein grafts. This was associated with a preserved left ventricular systolic function at 16 years follow-up period.

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. (C) 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Objective: Conventional harvesting of the saphenous vein in coronary artery bypass surgery produces vessel damage that contributes to graft failure. A novel "no touch" technique provides high short- and long-term patency rates.

Method: This randomized longitudinal trial compares graft patency of two patient groups undergoing coronary artery bypass surgery. Conventional: 52 patients had their veins stripped, distended, and stored in saline solution. No-touch: 52 patients had veins removed with surrounding tissue, not distended, and stored in heparinized blood. Angiographic assessment was performed at mean time 18 months after the operation in 46 patients in the conventional group and 45 patients in the no-touch group and repeated at mean time 8.5 years in 37 patients from both groups.

Results: The distribution of the grafts to the recipient coronary arteries regarding their size and quality was similar in both groups. The angiographic assessment at 18 months postoperatively showed 89% conventional versus 95% no-touch grafts were patent. Repeated angiography at 8.5 years showed a patency rate for the conventional group of 76% and 90% for the no- touch group ( P =.01). The multivariate analysis showed that the most important surgical factors for graft patency were the technique of harvesting ( odds ratio = 3.7, P =.007) for the no- touch versus the conventional technique and the vein quality before implantation ( odds ratio = 3.2, P =.007) for veins that were of good quality. By comparison the patency of the thoracic artery grafts was 90%.

Conclusion: Harvesting the saphenous vein with surrounding tissue provides high short- and long-term patency rates comparable to the left internal thoracic artery.

BACKGROUND AND PURPOSE: Brachytherapy is sometimes suggested as an adjuvant treatment after surgery of some tumours. When introducing this, it would be useful to have an estimate of the dose distribution to different body sites, both near and distant to target, comparing conventional external irradiation to brachytherapy. The aim of the present study was to determine radiation doses with both methods at different body sites, near and distant to target, in an experimental situation on an operated left sided breast cancer on a female Alderson phantom. METHODS: Five external beam treatments with isocentric tangential fields were given by a linear accelerator. A specified dose of 1.0 Gy was given to the whole left sided breast volume. Five interstitial brachytherapy treatments were given to the upper, lateral quadrant of the left breast by a two plane, 10 needles implant. A dose of 1.0 Gy specified according to the Paris system was administered by a pulsed dose rate afterloading machine. Absorbed dose in different fixed dose points were measured by thermoluminescence dosimeters. RESULTS: Both methods yielded an absorbed dose of the same size to the bone marrow and internal organs distant to target, 1.0-1.4% of the prescribed dose. There was a trend of lower doses to the lower half of the trunk and higher doses to the upper half of the trunk, respectively, by brachytherapy. A 90% reduction of absorbed dose with brachytherapy compared to external irradiation was found in the near-target region within 5 cm from target boundary where parts of the left lung and the heart are situated. If an adjuvant dose of 50 Gy is given with the external radiotherapy and brachytherapy, the absorbed dose in a part of the myocardium could be reduced from 31.8 to 2.1 Gy. CONCLUSIONS: Near target, brachytherapy yielded a considerably lower absorbed dose which is of special importance when considering radiation effects on the myocard and lungs. We could not demonstrate any difference of importance, in absorbed dose to dose points distant to target.