Graft Patency (graft + patency)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Does Mediastinitis Affect the Graft Patency?

JOURNAL OF CARDIAC SURGERY, Issue 3 2005
Denyan Mansuro, lu M.D.
There are many studies that have focused on the graft patency. But, till now, no study has been done to detect the effects of mediastinitis to graft patency. So, we aimed to detect the effect of mediastinitis on the graft patency in patients who have undergone coronary artery bypass surgery. Sixteen of 45 patients who have been operated upon for coronary artery bypass surgery and developed mediastinitis, which was treated with open drainage and mediastinal irrigation with late wound closure, were included in the study. The mean age of the patients was 55 ± 11 (range 35,69) and nine of the patients were male. The graft patency was evaluated with control coronary angiographies after a mean period of 30.42 ± 43.17 months (range 1,132). The left internal thoracic artery was patent in all patients (100%). Right internal thoracic artery patency rate was 50% (1/2). One individual bypassed radial artery was patent, whereas the sequential bypassed graft was occluded. The patency ratio of radial artery anastomosis was 33% (1/3). Twelve of the 17 saphenous vein grafts were patent (70.58%). The total number of patent distal anastomosis was 30/38 (78.94%). When compared with the graft patency of patients without infection, it was found that mediastinitis does not affect the graft patency rates adversely. [source]


Contribution of Nitric Oxide Synthase to Improved Early Graft Patency in Human Saphenous Vein Graft Harvested by a Novel ,No-Touch' Technique

JOURNAL OF CARDIAC SURGERY, Issue 6 2002
JCS Tsui
Aim: Saphenous vein (SV) is the most commonly used conduit in bypass procedures but has a one-year occlusion rate of 15-30%. A new ,no-touch' technique where the SV is harvested with a cushion of surrounding tissue with no distension has led to improved early patency rates of 5% at 18-months. Nitric oxide (NO), synthesised by nitric oxide synthase (NOS) has properties beneficial to graft patency. Our aim was to study the distribution of NOS in SV harvested by this technique and the effect of distension and removal of perivascular tissue on NOS content of SV. Methods: Following ethical committee approval and patients' informed consent, SVs were harvested from ten patients undergoing coronary artery bypass grafting. A segment of vein was harvested by the conventional technique (surrounding tissue stripped and vein distended with saline); another part was stripped but not distended (,control') and the remaining parts harvested by the ,no-touch' technique. Samples of each segment were taken and transverse sections prepared for NOS identification using 3[H]L-NG nitroarginine (NO Arg) autoradiography and NADPH-diaphorase histochemistry. NOS isoforms were studied using standard immunohistochemistry. Endothelial cells and nerves were also identified using immunohistochemistry with CD31 and NF200 respecitvely, to confirm sources of NOS. Morphometric analysis of NADPH-diaphorase staining was carried out to study tissue NOS content. Results: NO Arg binding representing NOS was preserved on the lumen of ,no-touch' vessels whilst that on conventional and control vessels was reduced. NOS was also localised to the medial smooth muscle cells of all vein segments and to the intact adventitia of ,no-touch' segments. This was confirmed by NADPH-diaphorase staining, which revealed a mean reduction of NOS by 19.5% (p < 0.05, ANOVA) in control segments due to stripping of surrounding tissue alone and a reduction of 35.5% (p < 0.01, AVNOVA) in conventional segments due to stripping and distension, compared to ,no-touch' segments. Adventitial NOS sources in ,no-touch' vessels corresponded to vasa vasorum and paravascular nerves. All three NOS isoforms contributed to the preserved NOS in ,no-touch' vessels. Conclusions: Apart from preserved lumenal NOS, NOS sources are also located in the media and adventitia of SV grafts. These are reduced by both adventitial damage and vein distension during conventional vein harvesting. The ,no-touch' technique avoids these procedures, preserving NOS sources. This may result in improved NO availability in SV harvested by this technique, contributing to the improved patency rates reported. [source]


Outcome following bypass, and proximal and distal ligation of popliteal aneurysms

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 2 2007
B. Box
Background: The aim of this study was to describe early and late results of proximal and distal ligation for popliteal aneurysm (PA), combined with bypass, with particular reference to the fate of the excluded aneurysm. Methods: Of a cohort of 116 patients with PAs, 66 were treated with bypass and ligation. Graft patency was determined by duplex surveillance. In addition, 17 patients with bypassed PAs underwent a total of 33 duplex scans to determine flow within the aneurysm and change in size. Results: For initially patent PAs, 3-, 5- and 8-year primary bypass graft patency was 78, 78 and 51 per cent respectively. These rates were not statistically significantly different from those following bypass for thrombosed PA, 3- and 5-year primary patency being 72 and 65 per cent respectively. No PA produced further symptoms after bypass and ligation. No flow was seen in any aneurysm at follow-up. Only one showed an increase in size. Conclusion: Proximal and distal ligation with bypass produced satisfactory long-term patency with good exclusion of the PA. Copyright © 2006 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]


Temporary Epicardial Ventricular Stimulation in Patients with Atrial Fibrillation: Acute Effects of Ventricular Pacing Site on Bypass Graft Flows

JOURNAL OF CARDIAC SURGERY, Issue 4 2009
Navid Madershahian M.D.
This study aimed to evaluate the optimal epicardial ventricular pacing site in patients with AF following coronary artery bypass surgery (CABG). Methods: In 23 consecutive patients (mean age = 69.2 ± 1.9 years, gender = 62% male, ejection fraction [EF]= 50.4 ± 2.1%) monoventricular stimulations (VVI) were tested with a constant pacing rate of 100 bpm. The impact of ventricular pacing on bypass graft flow (transit-time flow probe) and pulsatility index (PI) were measured after lead placement on the mid paraseptal region of the right (RVPS) and the left (LVPS) ventricle, on the right inferior wall (RVIW), and on the right ventricular outflow tract (RVOT). In addition, hemodynamic parameters were measured. Patients served as their own control. Results: Comparison of all tested pacing locations revealed that RVOT stimulation provided the highest bypass grafts flows (59.9 ± 6.1 mL/min) and PI (2.2 ± 0.1) when compared with RVPS (51.3 ± 4.7 mL/min, PI = 2.6 ± 0.2), RVIW (54.0 ± 5.1 mL/m; PI = 2.4 ± 0.2), and LVPS (53.1 ± 4.5 mL/min; PI = 2.3 ± 0.1), respectively (p < 0.05). When analyzing patients according to their preoperative LV function (group I = EF > 50%; group II = EF < 50%), higher bypass graft flows were observed with RVOT pacing in patients with lower EF (p = n.s.). Conclusions: Temporary RVOT pacing facilitates optimal bypass graft flows when compared with other ventricular pacing sites and should be the preferred method of temporary pacing in cardiac surgery patients with AF. Especially in patients with low EF following CABG, RVOT pacing may improve myocardial oxygen conditions for the ischemic myocardium and enhance graft patency in the early postoperative period. [source]


Does Mediastinitis Affect the Graft Patency?

JOURNAL OF CARDIAC SURGERY, Issue 3 2005
Denyan Mansuro, lu M.D.
There are many studies that have focused on the graft patency. But, till now, no study has been done to detect the effects of mediastinitis to graft patency. So, we aimed to detect the effect of mediastinitis on the graft patency in patients who have undergone coronary artery bypass surgery. Sixteen of 45 patients who have been operated upon for coronary artery bypass surgery and developed mediastinitis, which was treated with open drainage and mediastinal irrigation with late wound closure, were included in the study. The mean age of the patients was 55 ± 11 (range 35,69) and nine of the patients were male. The graft patency was evaluated with control coronary angiographies after a mean period of 30.42 ± 43.17 months (range 1,132). The left internal thoracic artery was patent in all patients (100%). Right internal thoracic artery patency rate was 50% (1/2). One individual bypassed radial artery was patent, whereas the sequential bypassed graft was occluded. The patency ratio of radial artery anastomosis was 33% (1/3). Twelve of the 17 saphenous vein grafts were patent (70.58%). The total number of patent distal anastomosis was 30/38 (78.94%). When compared with the graft patency of patients without infection, it was found that mediastinitis does not affect the graft patency rates adversely. [source]


Fluoropolymer coated Dacron or polytetrafluoroethylene for femoropopliteal bypass grafting: a multicentre trial

ANZ JOURNAL OF SURGERY, Issue 3 2003
Brett I. Robinson
Background: This trial was designed to compare graft patency between expanded polytetrafluoroethylene (PTFE) and fluoro­polymer coated Dacron for femoropopliteal bypass in patients in whom saphenous vein was unavailable. Methods: A multicentre prospective trial randomized 129 patients (74 men, 55 women) who underwent femoropopliteal bypass using either a PTFE or fluoropolymer coated Dacron graft. The indication for operation was disabling claudication in 68 (52.7%) and critical limb ischaemia in 61 (47.3%) patients. Distal anastomosis was above the knee in 76 (58.9%) and below the knee in 53 (41.1%) patients. Results: Primary patency at 6, 12 and 24 months was 71%, 56% and 47% for PTFE and 50%, 36% and 36% for fluoropolymer coated Dacron (P = 0.002), respectively. Secondary patency at 6, 12 and 24 months was 77%, 60% and 48% for PTFE and 66%, 49% and 46% for fluoropolymer coated Dacron (P = 0.13), respectively. The superior primary patency of PTFE over fluoropolymer coated Dacron was most evident in patients with poor prognostic indicators for graft survival: critical limb ischaemia (P = 0.001); below-knee anastomosis (P = 0.01); and smaller (6 mm) diameter grafts (P = 0.002). Graft thrombosis developed in the first month in 22 of 61 (36%) patients receiving fluoropolymer coated grafts compared to six of 68 (8.8%) patients receiving PTFE, which accounts for the difference in primary patency. Successful thrombectomy in 10 of the 22 fluoropolymer coated grafts resulted in similar secondary patency. Conclusion: Polytetrafluoroethylene has superior primary patency and similar secondary patency to fluoropolymer coated Dacron. These results support the preferential use of PTFE in patients with critical limb ischaemia, especially when a below-knee distal anastomosis and smaller diameter graft is required. [source]


Outcome following bypass, and proximal and distal ligation of popliteal aneurysms

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 2 2007
B. Box
Background: The aim of this study was to describe early and late results of proximal and distal ligation for popliteal aneurysm (PA), combined with bypass, with particular reference to the fate of the excluded aneurysm. Methods: Of a cohort of 116 patients with PAs, 66 were treated with bypass and ligation. Graft patency was determined by duplex surveillance. In addition, 17 patients with bypassed PAs underwent a total of 33 duplex scans to determine flow within the aneurysm and change in size. Results: For initially patent PAs, 3-, 5- and 8-year primary bypass graft patency was 78, 78 and 51 per cent respectively. These rates were not statistically significantly different from those following bypass for thrombosed PA, 3- and 5-year primary patency being 72 and 65 per cent respectively. No PA produced further symptoms after bypass and ligation. No flow was seen in any aneurysm at follow-up. Only one showed an increase in size. Conclusion: Proximal and distal ligation with bypass produced satisfactory long-term patency with good exclusion of the PA. Copyright © 2006 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]


Early ostial saphenous vein graft stenosis associated with the use of Symmetry sutureless aortic proximal anastomosis device: Successful percutaneous revascularization

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 2 2004
Sharon L. Cline MD
Abstract A recent advance in technology permits the creation of sutureless proximal aortic anastomosis during coronary artery bypass graft surgery. This new tool has significant potential benefit by minimizing aortic manipulation with subsequent reduction in neuroembolization. Implantation of a nitinol-based proximal aortic connector (Symmetry) has a potential to elicit intimal hyperplastic reaction analogous to restenosis after coronary stent placement. We report cases of early vein graft stenosis in association with the use of the Symmetry device. Three patients suffered from severe ostial stenosis within 6 months of bypass surgery with symptomatic presentation. Of these three patients, two underwent successful percutaneous revascularization. Fluoroscopic star-shaped appearance of the metallic Symmetry allows device recognition during angiography. We review current data regarding graft patency with the use of Symmetry device and discuss technical issues to address specific problems during percutaneous revascularization. Catheter Cardiovasc Interv 2004;62:203,208. © 2004 Wiley-Liss, Inc. [source]


Double saphenous vein graft patency 23 years following coronary artery bypass surgery

CLINICAL CARDIOLOGY, Issue 2 2002
Edward A. Geiser M.D.
No abstract is available for this article. [source]