Graft Patency In Patients Research Articles

Failed Depiction of Patent Bypass Graft Due to Presence of Large Lateral Costal Artery

We report a rare case of failed depiction of a patent right internal thoracic artery (RITA) to left anterior descending artery (LAD) bypass on 64-slice multidetector row computed tomographic (MDCT) angiography due to the presence of a large lateral costal artery. A 66-year-old male with acute coronary syndrome due to triple vessel disease underwent urgent coronary artery bypass grafting, in which bilateral ITA and saphenous vein grafts were used. Postoperative MDCT angiography showed an occluded RITA-LAD bypass, which was eventually shown to be patent by angiography. Angiography also revealed a large lateral costal artery that was considered to affect the flow to the LAD. Thus, coil embolization of the branch was attempted. However, it was abandoned because the patient suffered from severe back and intercostal pain during balloon occlusion of the lateral costal artery. Postoperative MDCT angiography is not always accurate for the assessment of graft patency in patients with large ITA side branches. In addition, embolization is not always possible because occlusion of this large branch may cause severe pain when its size becomes quite large.

Completion duplex ultrasound predicts early graft thrombosis after crural bypass in patients with critical limb ischemia

To determine if intraoperative distal graft end-diastolic velocity (EDV) using completion duplex ultrasound (CDU) predicts patency of crural bypass in patients with critical limb ischemia (CLI). Records of 116 non-consecutive patients who underwent crural revascularization with vein conduit and CDU between 1998 and 2008 were reviewed. Bypass grafts were performed for rest pain (34%) or tissue loss (66%), while 56% of the reported cases were categorized as "disadvantaged" because of compromised vein quality or diseased arterial outflow. A 10-MHz low-profile transducer was used to image the entire bypass at case completion. Technical adequacy of the grafts was verified by absence of retained valves, arteriovenous fistulas, or localized velocity increases and presence of bypass-dependent distal pulses. Modified Rutherford scores were calculated as surrogate markers of runoff resistance and compared to distal graft EDV. The primary study end point was graft patency during a 1-year posttreatment period. Patency rates were determined using Kaplan-Meier life table methodology and compared using the log-rank test. Predictors of graft patency were determined by Cox proportional hazards. Primary, primary-assisted, and secondary patency for all crural bypasses were 62%, 66%, and 70% at 1 year, respectively. When stratified by tertiles of distal graft EDV (0 - <5 cm/s, 5-15 cm/s, >15 cm/s), 1-year primary patency rates were 32%, 64%, and 84% (P = .001). Low (0 - < 5 cm/s) distal graft EDV (hazard ratio [HR], 3.3 confidence interval [CI], 1.74-6.41; P < .001), poor-quality conduit (HR, 2.5; CI, 1.19-5.21; P = .016), age <70 (HR, 2.08; CI, 1.06-4.00; P = .031), and lack of statin use (HR, 2.04; CI, 1.04-4.00; P = .038) were independent predictors of graft failure. While the modified Rutherford score correlated with distal graft EDV (P = .05), it was not an independent predictor of patency (P = .58). Predictors of low EDV (<5 cm/s) included single-vessel runoff (odds ratio [OR], 3.33; CI, 1.14-9.71; P = .027), poor conduit (OR, 2.94; CI, 1.16-7.41; P = 0.024), and diabetes (OR, 2.86; CI, 1.14-7.21; P = .025). Distal graft EDV predicts crural vein graft patency in patients with CLI. Grafts with EDV <5 cm/s remain at high risk for early failure. The impacts on patency of statins, age, and poor-quality conduit are, again, confirmed. These results highlight the value of EDV using intraoperative CDU for anticipating and, possibly, improving results of open crural revascularization.

Early graft patency after off-pump and on-pump coronary bypass surgery: a prospective randomized study

Uncertainty persists regarding the impact of the off-pump technique on coronary bypass graft patency. The primary objective of this study was to assess coronary artery bypass graft patency in patients randomized to off-pump and on-pump multivessel coronary artery bypass grafting (CABG). Secondary objectives were clinical outcomes and neuropsychological functioning. One hundred and fifty patients were randomized to off-pump (n = 75) or on-pump CABG (n = 75). Graft patency was assessed by multidetector computed tomography 5 weeks after surgery. The two groups were similar regarding patients' characteristics and logistic Euroscore (3.6 vs. 3.7%). Mean number of grafts performed was 3.5 ± 0.6 and 3.5 ± 0.6 in off-pump and on-pump, respectively (P = 0.7). Raw graft patency rate was 89.9% in off-pump and 95.0% in on-pump (OR 2.2, 95% CI 1.07-4.44; P = 0.03). Nineteen (27%) off-pump and 9 (13%) on-pump patients had at least one occluded graft (P = 0.04) and the proportion of patent grafts per patient was 0.91 ± 0.2 in off-pump vs. 0.96 ± 0.1 in on-pump (P = 0.06). However, after adjusting by heparin dose, graft patency was not statistically different between groups (OR 0.87, 95% CI 0.25-2.98, P = 0.83). At 30 days, there was no statistically significant difference in major adverse events and neuropsychological functioning between off-pump and on-pump groups. One-year follow-up showed similar functional class and positive treadmill exercise tests. Under the conditions this trial was conducted, CABG performed off-pump had lower overall graft patency rate than on-pump, which was not statistically different after controlling for total heparin dose. Thirty-day complications, neuropsychological functioning, and one-year clinical and functional outcomes were not statistically different between the two techniques.

Failure to achieve clinical improvement despite graft patency in patients undergoing infrainguinal lower extremity bypass for critical limb ischemia

Studies of infrainguinal lower extremity bypass for critical limb ischemia (CLI) have traditionally emphasized outcomes of patency, limb salvage, and death. Because functional outcomes are equally important, our objectives were to describe the proportion of CLI patients who did not achieve symptomatic improvement 1 year after bypass, despite having patent grafts, and identify preoperative factors associated with this outcome. The prospectively collected Vascular Study Group of Northern New England database was used to identify all patients with elective infrainguinal lower extremity bypass for CLI (2003 to 2007) for whom long-term follow-up data were available. The primary composite study end point was clinical failure at 1 year after bypass, defined as amputation or persistent or worsened ischemic symptoms (rest pain or tissue loss), despite a patent graft. Variables identified on univariate screening (inclusion threshold, P < .20) were included in a multivariable logistic regression model to identify independent predictors. Long-term follow-up data were available for 1012 patients who underwent infrainguinal bypasses for CLI, of which 788 (78%) remained patent at 1 year. Of these, 79 (10%) met criteria for the composite end point of clinical failure: 21 (2.7%) for major amputations and 58 (7.4%) for persistent rest pain or tissue loss. In multivariable analysis, significant predictors of clinical failure included dialysis dependence (odds ratio [OR], 3.74; 95% confidence interval [CI], 1.84-7.62; P < .001) and preoperative inability to ambulate independently (OR, 2.17; 95% CI, 1.26-3.73; P = .005). A history of coronary artery bypass graft or percutaneous coronary intervention was protective (OR, 0.52; 95% CI, 0.29-0.93; P = .03). After infrainguinal lower extremity bypass for CLI, 10% of patients with a patent graft did not achieve clinical improvement at 1 year. Preoperative identification of this specific patient subgroup remains challenging. To improve surgical decision making and the overall care of CLI patients, further emphasis needs to be placed on functional outcomes in addition to traditional surgical end points.

Comparison of graft patency for off-pump and conventional coronary arterial bypass grafting using 64-slice multidetector spiral computed tomography angiography

Off-pump coronary artery bypass graft surgery (OPCAB) has been performed for many years and its use is increasing frequently, but it remains an open question whether OPCAB provides similar patency to conventional coronary artery bypass graft (CCABG) surgery with cardiopulmonary bypass. The present study assessed the graft patency in patients that had coronary arterial bypass grafting (CABG) performed on-pump and off-pump. A total of 237 patients with CABG performed by a single surgeon were retrospectively studied, in which 100 patients underwent CCABG and 137 patients underwent OPCAB; the two groups were well matched according to relative factors and no significant differences were found in both groups. Postoperatively, systematic assessment on the graft patency of all the patients was conducted with 64-slice multidetector spiral computed tomography angiography (MSCTA) at one month, 1 year, 2 years, 3 years and 4 years, respectively, to provide 641 grafts for analysis. Patency of left internal mammary artery (LIMA) was higher than that of saphenous vein (SVG) in both groups; no significant difference was seen in LIMA patency and SVG patency in both groups. Results of 64-slice MSCTA indicate that OPCAB provides similar patency to CCABG surgery with CPB.

The Role of Clopidogrel and Acetylsalicylic Acid in the Prevention of Early-Phase Graft Occlusion Due to Reactive Thrombocytosis after Coronary Artery Bypass Operation

Reactive thrombocytosis has been reported in 20% of patients after coronary artery bypass grafting (CABG), a frequency that might be related to the high incidence of thrombotic complications. The present study was planned to investigate the effect of combined treatment with clopidogrel and acetylsalicylic acid (ASA) on post-CABG reactive thrombocytosis. Included in this prospective, randomized study were 60 patients who underwent CABG operation with a 6-month follow-up. Three study groups were defined: group 1 (n = 20), a control group of patients who have not developed reactive thrombocytosis after CABG surgery; group 2 (n = 20), patients who have developed reactive thrombocytosis and continue taking ASA (300 mg/day); and group 3 (n = 20), patients who have developed reactive thrombocytosis and continue taking ASA (300 mg/day) with the addition of clopidogrel (75 mg/day). The mean ages and sex distributions of the patient groups were similar. There were no significant differences between the groups regarding cardiovascular risk factors, baseline laboratory findings, or intraoperative characteristics. Thrombocytosis disappeared within the first month after the operation in both treatment groups. An evaluation of graft patency in the sixth postoperative month revealed that group 2 had significantly more patients with a "positive" result in the exercise test than group 3 and that group 3 had a lower incidence of graft occlusion than group 2 (P < .01). Combination antiplatelet therapy with ASA and clopidogrel seems to be more effective than ASA alone for maintaining graft patency in patients with reactive thrombocytosis.

Refinement of survival prediction in patients undergoing lower extremity bypass surgery: Stratification by chronic kidney disease classification

End-stage renal disease (ESRD) imparts a significant survival disadvantage to individuals undergoing lower extremity revascularization; however, the influence of lesser degrees of renal impairment remains unclear. This study examined the prognostic significance of the chronic kidney disease (CKD) classification on survival, limb salvage, and graft patency in patients undergoing lower extremity arterial reconstruction. A prospective registry was evaluated for consecutive patients between January 31, 1995, and December 21, 2004, undergoing first-time, lower extremity vein bypass surgery. Glomerular filtration rate (GFR) was estimated with the Modification of Diet in Renal Disease equation using each patient's preoperative creatinine concentration. CKD categories were taken from current National Kidney Foundation Kidney Disease Outcomes Quality Initiative staging criteria. The cohort included 456 subjects, with a mean (+/- SD) age of 68.1 +/- 10.8 years. There were 274 men (60%) and 378 Caucasians (82.5%). Comorbidities included diabetes mellitus in 270 (59.0%), hypertension in 333 (72.7%), coronary artery disease in 242 (52.8%), and dyslipidemia in 203 (44.5%). The surgical indication was critical limb ischemia in 384 (83.8%). Among the variables examined, diabetes and critical ischemia as the indication for bypass were significantly skewed toward higher CKD classifications (P < .001). The 5-year survival rates by CKD class were, CKD 1 and 2, 57%; CKD 3, 46%; CKD 4, 23%; and CKD 5, 9.5%. On univariate analysis, age, coronary artery disease, diabetes mellitus, hypertension, critical ischemia, and CKD were significant predictors of mortality. After adjustment, however, only age (hazard ratio [HR], 1.05, 95% confidence interval [CI], 1.03 to 1.06) and CKD stages 4 (HR, 4.23; 95% CI, 2.04 to 8.75) and 5 (HR, 3.27; 95% CI, 1.96 to 5.45) retained significance. Subjects within the CKD 5 classification were more likely to have a major amputation (P = .018) compared with all other CKD classes. Notably, no relationship was detected between CKD category and graft patency. CKD staging adequately differentiates survival curves and risk for major amputation among patients with renal impairment who are undergoing lower extremity bypass surgery. This may help in clinical decision analysis as well as in the refinement of stratification in future clinical trial design where survival is an end point.

Pre‐emptive stellate ganglion block increases the patency of radial artery grafts in coronary artery bypass surgery

We evaluated the role of pre-emptive stellate ganglion block (SGB) in preventing radial artery spasm and increasing radial artery graft patency in patients undergoing off-pump coronary artery bypass surgery. In this prospective randomized study, 100 patients were divided into two equal groups (n= 50). In group A, SGB was achieved using 10 ml of ropivacaine and, in group B, SGB was not performed. Radial artery blood flow was measured pre- and intra-operatively. Post-operative clinical determinants (S-T segment elevation, use of inotropic agents, incidence of atrial fibrillation) were recorded. Early coronary angiography was performed. According to blood flowmeter measurements, the radial artery blood flow was significantly increased in patients with SGB. The incidence of atrial fibrillation, the need for inotropic agents and S-T segment elevation were all decreased in the SGB group. Angiographic intervention revealed that the incidence of graft spasm was also lower in the SGB group. Pre-emptive SGB is an effective method for increasing radial artery blood flow and preventing radial artery spasm. Complications related to radial artery spasm may be decreased and patients may have a more comfortable post-operative period with this method.

Does Periadventitial Fat-Derived Nitric Oxide Play a Role in Improved Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Surgery?

Background/Aims: The saphenous vein is commonly used for coronary artery bypass surgery but its patency is poor. Vascular damage occurs during conventional surgery. However, patency improves when the graft is harvested with minimal surgical trauma, partly due to preservation of vascular endothelial nitric oxide synthase (eNOS) and tissue sources of nitric oxide (NO), a factor possessing both dilatory and anti-proliferative properties. Apart from these grafts exhibiting an intact luminal endothelium they are harvested complete with a surrounding cushion of tissue, much of which is fat. Methods: Immunostaining for eNOS was performed on vein graft sections and reverse-transcriptase polymerase chain reaction and Western blotting were used to identify eNOS mRNA and protein. NO synthase activity was measured using the citrulline assay. Results: Immunohistochemistry identified eNOS staining of vein graft segments, including dense staining of the cushion of perivascular fat and associated structures surrounding the vein. eNOS protein was confirmed in both the vein and surrounding fat by Western blot analysis. Using the citrulline assay, the perivascular fat and underlying vein possessed comparable NO synthase activity. Conclusions: Our observations suggest that perivascular fat-derived NO plays a beneficial role in saphenous veins harvested atraumatically and used as grafts in patients undergoing coronary artery bypass surgery.

Comparison of SMART Stent Placement for Arteriovenous Graft Salvage versus Successful Graft PTA

To compare the SMART (shape memory alloy recoverable technology) stent with percutaneous transluminal angioplasty (PTA) alone in hemodialysis access venous stenoses. A prospective, nonrandomized study was undertaken in 60 patients with dysfunctional polytetrafluoroethylene dialysis grafts. Indications for stent placement were acute PTA failure, rapid restenosis, and vessel perforation. The primary endpoint was improved graft patency in patients treated with stents compared with that in patients whose disease responded to PTA alone. The secondary endpoints were lower postprocedural midgraft pressures and similar complication rates compared with PTA alone. The key venous stenosis was at the graft-to-vein anastomosis in all but two patients. Thirty-five patients showed a response to PTA alone. Sixteen patients received stents for stenoses greater than 30% after angioplasty, six for rapidly recurrent stenosis, and three for venous rupture. Nine patients received stents across the level of the elbow joint. Stenosis after intervention was significantly less frequent in the stent group (7% vs 16%; P = .001), but the midgraft systolic pressure ratios did not significantly differ. The clinical success rates were 100% after stent implantation and 97% after PTA alone. Except for venous rupture, there were no procedure-related complications, and, excluding early graft thrombosis, there were no complications at 30 days. A single stent fracture was found on follow-up. The mean primary graft patency times were 5.6 months after PTA and 8.2 months after stent treatment (P = .050). When stents were placed across the level of the elbow joint, the mean primary graft patency time was 8.9 months. Implantation of the SMART stent is safe and effective for the treatment of residual or rapidly recurrent dialysis access venous stenoses and is associated with better patency than PTA alone.

A comparison of transit-time flowmetry and intraoperative fluorescence imaging for assessing coronary artery bypass graft patency

Intraoperative graft patency assessment during coronary artery bypass grafting enables detection and immediate correction of graft failure. Currently transit-time flowmetry is used to assess graft patency on the basis of mean graft flow and derived values, such as the pulsatility index. Intraoperative fluorescence imaging, based on the fluorescence of indocyanine green dye, provides direct visual images to confirm graft patency. We performed a prospective observational study to assess intraoperative graft patency in patients undergoing coronary artery bypass grafting, by using an intraoperative fluorescence imaging system (SPY) and transit-time flowmetry (BF 2004). Poor flow with the intraoperative fluorescence imaging system was defined if there was an absence of fluorescence or if it did not appear within 15 seconds in the graft. A persistent mean graft flow value less than 5 mL/min and a pulsatility index greater than 5 with transit-time flowmetry were considered unacceptable and prompted graft revision. We assessed the intraoperative patency of 266 grafts in 100 coronary artery bypass grafting patients. Intraoperative fluorescence imaging and transit-time flowmetry confirmed adequate flow in 241 (91%) grafts in 75 patients (75%). Transient poor flow was detected with both intraoperative fluorescence imaging and transit-time flowmetry in 7 (2.6%) grafts in 7 (7%) patients. This subsequently proved to be adequate on repeat testing and hence did not necessitate graft revision. Both intraoperative fluorescence imaging and transit-time flowmetry confirmed persistent poor flow in 8 (3%) grafts in 8 (8%) patients that necessitated graft revision. However, in a further 10 (3.8%) grafts in 10 (10%) patients, transit-time flowmetry indicated persistently poor flows on the basis of mean graft flow and pulsatility index values, whereas the intraoperative fluorescence imaging system demonstrated satisfactory flow. These grafts were not revised. In most patients, both intraoperative fluorescence imaging and transit-time flowmetry are useful to confirm intraoperative graft patency. However, in a small proportion of patients (10%), graft patency assessment with transit-time flowmetry alone might prompt unnecessary graft revision.

MR-Angiographie und Flussreservenbestimmung nach minimalinvasiver direkter Koronararterien-Bypass(MIDCAB)-Operation der linken Arteria mammaria interna im Vergleich zur Mehrzeilen-CT

To evaluate graft patency, flow and flow reserve in patients with minimal invasive direct coronary artery bypass (MIDCAB) of internal mammary artery (IMA) grafts using a combined MR protocol with phase-contrast technique and MR angiography. At a 1.5T Magnetom Sonata (SIEMENS), 19 symptomatic (angina CCS I-III, intermittent thoracic discomfort, scar disorders) patients (59.9 +/- 7.9 years old) with 19 left internal mammary artery (LIMA) grafts implanted in minimal invasive technique were examined 6.9 +/- 1.5 years post surgery. Contrast enhanced MR angiography (TR 2.5 ms, TE 1 ms, flip angle 20 (o), spatial resolution 1.4 x 0.9 x 1.0 mm(3), breath hold technique, no ECG-triggering, 25 ml Gd-DTPA) was performed to assess bypass patency. Phase-contrast flow measurements with retrospective gating (TR 41 msec, TE 3.2 msec, flip angle 30 degrees , spatial resolution 1.1 x 1.1 x 5 mm(3), temporal resolution 42 msec, venc 90 cm/sec) were applied in the IMA grafts at rest and after stress induction with dipyridamole (0.56 mg/kg/BW). For comparison, graft patency was evaluated by multidetector-row computed tomography (16-row CT). In 9 patients a selective catheter angiography was performed. MIDCAB grafts were occluded in 4/19 patients. In 4 patients the anastomosis to LAD was highly stenotic (> 70 %) at MDCT (2 experienced investigators in consensus reading). In MRA 9 grafts could be delineated completely including the distal anastomosis to LAD (47 %). In 9 patients the distal part could not be evaluated. In patients with patent grafts (MDCT), a significant improvement of graft flow (at rest 75.4 +/- 33.3 ml/min; after stress 202.7 +/- 49.6; P < 0.002) and flow reserve (patent grafts 3.0 +/- 1.1; stenotic grafts 1.5 +/- 0.2, P < 0.02; occluded grafts 0.9 +/- 0.2, P < 0.01) after stress induction was detected. Diastolic-to-systolic peak velocity ratios (D/S-PVR) at baseline were not significant between patent and stenotic grafts. Mean flow at baseline and after stress induction and flow reserve show a high sensitivity (91/92 /83 %) and specificity (86 /100/83 %) for detection of graft stenosis. MR angiography combined with flow reserve measurements could distinguish between occluded/stenotic and patent grafts in all MIDCAB grafts. MR imaging allows combined assessment of bypass patency and flow with flow reserve in patients after MIDCAB. The protocol of this study is applicable for the evaluation of graft patency in patients after revascularization.

Does Mediastinitis Affect the Graft Patency?

As inflammation began to be recognized as a major contributor to the pathogenesis of atherosclerosis, we evaluated the patients that developed mediastinitis, a long-standing inflammatory process, after coronary artery bypass grafting. 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.

Does off-pump total arterial grafting increase the incidence of intraoperative graft failure?

Background Early graft failure is a common cause of cardiac mortality and morbidity after coronary artery bypass grafting, but there is little information on its natural incidence. Furthermore, there is particular concern about graft patency in off-pump coronary artery bypass grafting and total arterial grafting. Methods We performed a prospective observational study to assess intraoperative graft patency in patients undergoing off-pump and on-pump coronary artery bypass grafting, who also underwent total arterial grafting. We used an intraoperative imaging system, SPY (Novadaq Technologies Inc), based on the fluorescent properties of indocyanine green dye. Results We assessed the intraoperative graft patency of 533 conduits in 200 patients. The mean number of grafts was 2.7 per patient. Of these patients, 155 (78%) had off-pump coronary artery bypass grafting, and 45 (22%) had on-pump coronary artery bypass grafting. Overall, 161 (80%) had total arterial grafting, with composite arterial grafting performed in 120 (60%) patients. Fluorescence, confirming graft patency, was observed in all but 8 (1.5%) conduits in 8 (4%) patients, necessitating graft revision. Six (3.9%) and 2 (4.4%) of these patients, respectively, had off-pump coronary artery bypass grafting and on-pump coronary artery bypass grafting. Conclusion Intraoperative fluorescence imaging demonstrated a low (1.5%) but well-defined incidence of intraoperative graft failure, which affects around 4% of patients. This emphasizes the need for routine assessment of graft patency. Intraoperative fluorescence imaging permits detection and revision of failed grafts in the operating room. We found no difference in the incidence of failed grafts when comparing on-pump and off-pump total arterial grafting.

Late patency of the left internal thoracic artery graft in patients with and without previous successful percutaneous transluminal coronary angioplasty

The aim of this study was to compare early and late graft patency in patients with and without previous successful PTCA. Of the 70 patients who received both early and late follow-up angiography, 13 patients who had received successful PTCA at the left anterior descending coronary artery (LAD) before CABG (group I) and 31 patients who had not received preoperative PTCA in any vessel (group II) were retrospectively reviewed. There were no significant differences in patient characteristics including major coronary risk factors. The mean duration between the operation and control angiography was 35+/-23 months in group I and 36+/-19 months in group II (P=0.90). Occlusions of the LITA graft were observed in four patients of group I and in four patients of group II. Cumulative patencies of the LITA graft were 54% in group I and 83% in group II (P=0.12). The late patency rate of the LITA graft bypassed to the LAD in patients that received previous successful PTCA in the coronary artery tended to be lower than in patients without previous PTCA. This result should be confirmed by further prospective studies.

Evaluation of a novel sutureless anastomotic connector: From endothelial function to mid-term clinical and angiographic follow-up

Objectives We evaluated the effect of the St Jude Medical sutureless anastomotic connector on endothelium-dependent and -independent saphenous vein graft relaxation, as well as on clinical outcomes and graft patency in patients. Methods Human saphenous vein grafts were assigned to control or connector groups (loaded for 1 or 5 minutes; n = 18). Isometric dose-response curves to endothelium-dependent and -independent (sodium nitroprusside) vasodilators were constructed in saphenous vein grafts precontracted with phenylephrine. Thrombin-mediated vasorelaxation, an early determinant of saphenous vein graft failure, was also evaluated. Percent maximum relaxation was compared between groups. Patients in whom the St Jude Medical connector was employed underwent clinical follow-up, stress tests, and angiography 6 to 12 months postoperatively. Results A23187-induced endothelium-mediated relaxation, sodium nitroprusside-induced endothelium-independent relaxation, and thrombin-mediated vasorelaxation did not differ between control and connector saphenous vein grafts at either time point studied. Twenty-seven patients received St Jude Medical connectors. There was no hospital mortality; patients were followed for 679 ± 241 days. There was 1 late death; the connector saphenous vein graft was patent at postmortem. All connector saphenous vein grafts were patent at follow-up angiography. Four grafts had stenoses (30%-60%), without symptoms or requirement for intervention. All hand-sewn saphenous vein grafts were also patent. Conclusions The St Jude Medical connector does not impair endothelium-dependent vasorelaxation. In patients, patency of the connector saphenous vein grafts 6 to 12 months postoperatively was 100% but 22% of grafts had non–flow-limiting stenoses at or near the connector. Further long-term studies are required to confirm the safety of the St Jude Medical connector with regards to endothelial function and restenosis.

Drug-eluting stents: cost versus clinical benefit.

The publication in January 2001 of the first-in-man results showing zero restenosis after sirolimus-eluting stent implantation produced enormous excitement in the cardiological community.1 The long-awaited tool—a safe, restenosis-proof, easy-to-use stent—had been found. It was not too long thereafter that paclitaxel-eluting stents also demonstrated their capability to decrease restenosis. Today, both sirolimus- and paclitaxel-eluting stents have been shown in randomized trials to reduce restenosis as compared with conventional metallic stents (Figure 1).2–6 Most of these studies have been recently released in the form of abstracts during medical meetings and are still unpublished.3,5,6 In addition to sirolimus and paclitaxel, other agents have shown promising early results in recent studies, enlarging the body of evidence demonstrating the potential benefits of what are known as drug-eluting stents.7 Regulatory agencies have been very active in evaluating some of these devices in the United States, Europe, South America, and Asia. The sirolimus-eluting stent has been available for routine use in Europe, South America, and Asia since the first half of 2002 and received approval from the US Food and Drug Administration to be marketed in April 2003. Paclitaxel-eluting stents have also received CE (Conformite Europeenne) marking for commercialization in Europe and are now beginning to be commercialized. Figure 1. Randomized trials showing reduction of binary restenosis with drug-eluting stents.2–6 The case seemed to be closed. Restenosis, the Achilles’ heel of percutaneous revascularization, appeared defeated. However, since the sirolimus-eluting stents became available, very little has changed in the everyday life of almost all interventional laboratories in Europe. Why? Has the new treatment presented any undesirable effect? Was the desire to defeat restenosis not as great as supposed? The answer is none of the above. The limitation currently impeding more widespread use of the new technology is nontechnical, nonmedical, and nonbiological. The …

Long-term results justify autogenous infrainguinal bypass grafting in patients with end-stage renal failure

Introduction: Infrainguinal bypass grafting for limb-threatening ischemia in patients with end-stage renal disease is generally thought to be associated with increased operative risk and poor long-term outcome. This retrospective study was undertaken to examine the modern-era, long-term results of infrainguinal bypass grafting in dialysis-dependent patients. Methods: Over the past 5 years in a single institution, 425 lower extremities (368 consecutive patients) were revascularized for the indication of limb salvage. Sixty-four patients (82 limbs) were dialysis-dependent at the time of revascularization, and this group was analyzed separately. They exhibited statistically significant higher incidences of diabetes (83% vs 56%; P <.001), hypertension (91% vs 74%; P <.001), and more distal vascular disease, which required a greater proportion of proximal anastomoses at the popliteal level (24% vs 11%; P <.01) and distal anastomoses at the infrapopliteal level (75% vs 65%; P <.05). Results: Despite the higher prevalence of comorbid conditions and distal disease in patients with renal failure, their perioperative 30-day mortality rate remained low (4.9%) and was not significantly different from that in patients with functioning kidneys (2.9%; P = not significant). After a median follow-up of 11 months (range, 0-60 months), the 3-year autogenous conduit secondary graft patency in patients with renal failure was no different than in patients with functioning kidneys (67% ± 9% vs 64% ± 5%; P = not significant). Nonautogenous conduits in dialysis-dependent patients exhibited a significantly poorer outcome with only 27% ± 12% remaining secondarily patent at 2 years. As expected, both limb salvage and patient survival were significantly less in patients with renal faiture, although both exceeded 50% at 3 years (limb salvage 59% ± 8% vs 68% ± 5%; P <.05; patient survival 60% ± 8% vs 86% ± 4%; P <.001). The often-quoted phenomenon of limb loss, despite a patent bypass graft, occurred infrequently in this study (n = 3 of 82 limbs). Conclusion: Infrainguinal revascularization can be performed in dialysis-dependent patients with acceptable perioperative and long-term results, especially in patients in whom adequate autologous conduit is available. (J Vasc Surg 2001;34:27-33.)

Early outcome and graft patency in mammary artery grafting of left anterior descending artery with sternotomy or anterior minithoracotomy

Background. The main objective of this study was to retrospectively compare early outcome and graft patency in patients who underwent coronary artery bypass grafting with the internal thoracic artery to the left anterior descending artery via an anterior minithoracotomy or median sternotomy and without the use of extracorporeal circulation. Methods. One hundred thirty consecutive patients were studied. Median sternotomy was performed in 77 patients and anterior minithoracotomy in 53 patients. Results. There were no differences in early clinical data or persistent postoperative pain between the groups. Early graft patency was 88% in the thoracotomy group and 96% in the sternotomy group ( p = 0.3). Five of 7 patients who presented with a significant stenosis at the first coronary angiography had a normal angiogram at the reangiography. None of the patients with nonsignificant stenosis at the early coronary angiography had any clinical signs of ischemia or chest pain. Conclusions. In our experience, anterior minithoracotomy and median sternotomy are different and distinguishable regarding early outcome and early graft patency. Most of the stenoses visualized at the early coronary angiography had vanished at a later coronary angiography, which makes the interpretation of the angiogram hazardous as a tool for the decision for redo procedure in the early postoperative period.

Noninvasive evaluation of coronary artery bypass graft patency using three-dimensional angiography obtained with contrast-enhanced electron beam CT.

The purpose of this study was to determine the accuracy of three-dimensional coronary angiography obtained with electron beam CT in the assessment of the patency of coronary artery bypass grafts. Twenty-five patients who had undergone coronary artery bypass graft surgery were included. All patients underwent electron beam CT and conventional coronary angiography for the evaluation of the status of their bypass grafts. Three-dimensional reconstructions of the heart and bypass grafts were compared with selective angiographic images of the bypass grafts. Fifty-seven saphenous vein grafts and 22 left internal mammary artery grafts were evaluated for occlusion or patency. Sensitivity and specificity of electron beam CT in revealing left internal mammary artery patency were 80% and 82.4%, respectively. Sensitivity and specificity of electron beam CT in revealing saphenous vein graft patency were 91.7% and 91.1%, respectively. Sensitivity and specificity of electron beam CT for evaluating saphenous vein grafts according to coronary area were as follows: saphenous vein grafts to left anterior descending artery, 100% and 100%, respectively; to diagonal branch, 100% and 100%; to left circumflex artery, 100% and 88.9%; and to right coronary artery, 75% and 85.7%. Three-dimensional coronary angiography obtained with electron beam CT is a promising, useful, and relatively accurate diagnostic imaging technique for the evaluation of graft patency in patients who have undergone coronary artery bypass graft surgery.