Internal Mammary Artery Coronary Bypass Research Articles

The use of three-dimensional imaging for R0 resection of a left upper lobe adenocarcinoma after coronary artery bypass surgery.

The use of three-dimensional imaging for R0 resection of a left upper lobe adenocarcinoma after coronary artery bypass surgery.

Use of quantitative cardiovascular magnetic resonance myocardial perfusion mapping for characterization of ischemia in patients with left internal mammary coronary artery bypass grafts

BackgroundQuantitative myocardial perfusion mapping using cardiovascular magnetic resonance (CMR) is validated for myocardial blood flow (MBF) estimation in native vessel coronary artery disease (CAD). Following coronary artery bypass graft (CABG) surgery, perfusion defects are often detected in territories supplied by the left internal mammary artery (LIMA) graft, but their interpretation and subsequent clinical management is variable.MethodsWe assessed myocardial perfusion using quantitative CMR perfusion mapping in 38 patients with prior CABG surgery, all with angiographically-proven patent LIMA grafts to the left anterior descending coronary artery (LAD) and no prior infarction in the LAD territory. Factors potentially determining MBF in the LIMA–LAD myocardial territory, including the impact of delayed contrast arrival through the LIMA graft were evaluated.ResultsPerfusion defects were reported on blinded visual analysis in the LIMA–LAD territory in 27 (71%) cases, despite LIMA graft patency and no LAD infarction. Native LAD chronic total occlusion (CTO) was a strong independent predictor of stress MBF (B = − 0.41, p = 0.014) and myocardial perfusion reserve (MPR) (B = − 0.56, p = 0.005), and was associated with reduced stress MBF in the basal (1.47 vs 2.07 ml/g/min; p = 0.002) but not the apical myocardial segments (1.52 vs 1.87 ml/g/min; p = 0.057). Extending the maximum arterial time delay incorporated in the quantitative perfusion algorithm, resulted only in a small increase (3.4%) of estimated stress MBF.ConclusionsPerfusion defects are frequently detected in LIMA–LAD subtended territories post CABG despite LIMA patency. Although delayed contrast arrival through LIMA grafts causes a small underestimation of MBF, perfusion defects are likely to reflect true reductions in myocardial blood flow, largely due to proximal native LAD disease.

Surgical left subclavian artery revascularization for thoracic aortic stent grafting: a single-centre experience in 101 patients.

To evaluate the indications, perioperative strategy and postoperative outcome of surgical left subclavian artery (LSA) revascularization combined with thoracic endovascular aortic repair (TEVAR) covering the LSA. Between 2000 and 2017, a total of 101 consecutive patients underwent surgical revascularization of the LSA prior to, concomitant or following TEVAR. Revascularization was performed through a small supraclavicular incision and consisted of a transposition or bypass graft, using intraoperative transcranial Doppler monitoring. Data regarding indication, procedural details and postoperative results were retrospectively analysed. In total, 63 subclavian-carotid bypass grafts and 38 subclavian-carotid transpositions were performed in the context of TEVAR. The majority was performed prior to stent grafting to reduce the risk of stroke (n = 50), spinal cord ischaemia (n = 20), left arm malperfusion (n = 10) or to preserve a patent left internal mammary artery coronary bypass graft (n = 2). Secondary revascularization was performed in 14 patients, 2 times immediately due to acute left arm malperfusion and 12 times to treat invalidating left arm claudication. No in-hospital mortality and permanent spinal cord ischaemia occurred. Two (2%) ischaemic strokes were observed in patients with concomitant procedures, and none when separate, staged procedures were performed. Additional complications observed were permanent peripheral nerve palsies (9%), chyle leakage requiring diet (6%) and 1 bypass occlusion requiring a redo procedure. In patients predominantly selected upon the anticipated risk of (posterior) stroke, spinal cord ischaemia and left arm malperfusion, surgical revascularization of the LSA proved to be a safe treatment option to preserve antegrade LSA flow in the context of TEVAR.

Invited Commentary

Invited Commentary

Invited Commentary

The authors of this study [1Rubens F.D. Chen L. Bourke M. Assessment of the association of bilateral internal thoracic artery skeletonization and sternal wound infection after coronary artery bypass grafting.Ann Thorac Surg. 2016; 101: 1677-1683Abstract Full Text Full Text PDF Scopus (25) Google Scholar] have again verified the safety of bilateral internal thoracic arterial (BITA) grafting in patients requiring coronary revascularization. Their sizeable experience involving a large cohort of patients comparing skeletonized pedicle harvesting with traditional pedicle harvesting techniques demonstrated equivalent rates of sternal infections and other related complications. Over time, arterial conduit use has become the standard of care, relegated to hallowed evidence-based acceptance in appropriately selected patients. However, despite the universal acceptance of single arterial grafting, ElBardissi and colleagues [2ElBardissi A.W. Aranki S.F. Sheng S. O’Brien S.M. Greenberg C.C. Gammie J.S. Trends in isolated coronary artery bypass grafting: an analysis of the Society of Thoracic Surgeons adult cardiac surgery database.J Thorac Cardiovasc Surg. 2012; 143: 273-281Abstract Full Text Full Text PDF PubMed Scopus (345) Google Scholar] revealed that only 4% to 12% of surgical revascularization procedures use BITA; clearly, evidence-based practice is rarely translated into routine clinical practice outside of reporting centers. Previous guidelines supporting arterial grafting with BITA conduits were often dependent on the severity of the native vessel disease; these studies often discouraged the use of BITA when the stenosis was not critical (<90%) [3Hillis L.D. Smith P.K. Anderson J.L. et al.American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines2011 ACCF/AHA guideline for coronary artery bypass graft surgery: executive summary: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines.J Thorac Cardiovasc Surg. 2012; 143: 4-34Abstract Full Text Full Text PDF PubMed Scopus (186) Google Scholar]. In regards to sternal complications, Dorman and coworkers [4Dorman M.J. Kurlansky P.A. Traad E.A. Galbut D.L. Zucker M. Ebra G. Bilateral internal mammary artery grafting enhances survival in diabetic patients a 30-year follow-up of propensity score–matched cohorts.Circulation. 2012; 126: 2935-2942Crossref PubMed Scopus (123) Google Scholar] addressed the effects of diabetes in a high-volume center with extensive BITA use. An even earlier large-scale, multicenter randomized arterial revascularization trial (ART) compared revascularization using BITA for the two most important left-sided target arteries with single internal thoracic artery (ITA) coupled with a combination of radial arteries or venous conduits for the remaining graft sites. This study demonstrated equivalent low 30-day (1%) and 1-year (2.5%) mortality rates, as well as similar rates of stroke and myocardial infarction, and the need for repeat revascularization for BITA grafting compared with the more traditional single ITA grafting strategy. Of note in this study was the increased incidence of sternal wound healing complications requiring reconstruction (1.9% versus 0.6%) in BITA patients compared with single ITA use, especially in diabetic patients. Although this randomized trial used a variety of ITA harvesting techniques, the results suggested that skeletonization of the ITA during harvesting may yield fewer sternal complications [5Taggart D.P. Altman D.G. Gray A.M. et al.ART InvestigatorsRandomized trial to compare bilateral vs. single internal mammary coronary artery bypass grafting: 1-year results of the Arterial Revascularisation Trial (ART).Eur Heart J. 2010; 31: 2470-2481Crossref PubMed Scopus (303) Google Scholar]. It is clear that skeletonization affords the surgeon increased arterial conduit length, creating the potential for multiple grafts of the left coronary circulation with a longer left ITA, as well as improving the distal reach of the right coronary arterial target sites with a skeletonized right ITA. Importantly, the known risk factors for suspected increased sternal complications from BITA use (increased body mass index, diabetes, peripheral vascular disease, female sex, and preoperative anemia) are more related to full sternotomy itself, instead of ITA harvesting, and were not significantly different in this report. Bilateral ITA utilization strategies for complex coronary revascularization has clearly demonstrated safety, diminished future interventions, improved graft longevity, and increased patient survival rates. The current report provides further evidence that harvesting techniques matter; hopefully studies like these will prevail over the continued reluctance to commit to more arterial grafting among the cardiac surgery community. The authors are to be congratulated for their excellent results, as well as advancing our understanding of this important topic. Assessment of the Association of Bilateral Internal Thoracic Artery Skeletonization and Sternal Wound Infection After Coronary Artery Bypass GraftingThe Annals of Thoracic SurgeryVol. 101Issue 5PreviewSkeletonization is a technique of bilateral internal thoracic artery (BITA) harvest that preserves sternal blood flow. We sought to identify the relationship of skeletonization and sternal wound infection in a population undergoing BITA harvest. Full-Text PDF

Invited Commentary

Shah and colleagues [1Shah A.A. Worni M. Onaitis M.W. et al.Thoracoscopic left upper lobectomy in patients with internal mammary artery coronary bypass grafts.Ann Thorac Surg. 2014; 98: 1207-1213Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar] have written a provocative essay about managing the critically important, but vulnerable, internal mammary conduit during video-assisted thoracic surgery (VATS) lobectomy. This is an important issue as many patients survive revascularization of their smoking-related coronary atherosclerotic occlusive disease and now live long enough to develop lung cancer. Before addressing appropriateness, it is important to emphasize several themes. First, the authors used careful judgment and planning. They reviewed operative reports considering internal mammary artery (IMA) orientation, pleural opening, preparation (skeletonized or pedicle), sequencing, and conduit age. Catheterization or computed tomographic angiography showed relative branch coronary artery importance and its dependence on the IMA graft. Injury strategies were planned with collaborative cardiac teams. Intraoperative transesophageal echocardiography, cardiac anesthesiology, and detecting and managing perioperative cardiac events were important. During surgery, their high VATS reliability experience facilitated dealing with hostile pleural spaces. Initiating safe dissection planes between the lung hilum and pericardium remote from the graft and stapling lung to leave a remnant on the sternotomy or IMA were useful strategies. Both improved exposure and reduced parenchymal bleeding so tissue remnants could be observed or debrided appropriately. Supplemental thoracoscopic viewpoints may have helped. Finally, by VATS emulation of open vascular control methods they could perform safe conversions, if required. Currently, our specialty actively debates the merits of VATS for any lung cancer, not just these advanced cases. We generally trust master open thoracic surgeons to venture into more advanced frontiers by leveraging their aggregated skills and judgment. Perhaps it is time to extend the same provisional acceptance to our minimally invasive colleagues. On a personal note, I perform IMA cases such as these based on an advanced VATS practice that followed an earlier career emphasizing cardiac surgery. However, performing advanced cases like these without the aggregate experience or backup teams probably is unwise. Physically frail or advanced chronic obstructive pulmonary disease patients might be good cases to avoid thoracotomy; alternatively, those with good ventricular function tolerate thoracotomy if their grafts are protected. Importantly, not every successful VATS or robotic program exists within a cardiac center of excellence. Thus, a frank discussion of the above issues or contingency plans should be communicated with all parties. Should a frail patient chance an IMA injury at a high VATS reliability, noncardiac hospital, or go to a heart center for likely thoracotomy? Such questions remain imponderable until others have replicated these authors’ excellent but modest experience. Until then, we must disclose all reasonable options to patients including those of thoughtful surgeons who consider VATS approaches unproven or undesirable. Thoracoscopic Left Upper Lobectomy in Patients With Internal Mammary Artery Coronary Bypass GraftsThe Annals of Thoracic SurgeryVol. 98Issue 4PreviewThis study examined outcomes of a technique for performing thoracoscopic left upper lobectomy (LUL) in patients with a previous left internal mammary artery (LIMA) coronary artery bypass graft, where a small wedge of lung parenchyma adjacent to the graft is left to avoid injury. Full-Text PDF

Thoracoscopic Left Upper Lobectomy in Patients With Internal Mammary Artery Coronary Bypass Grafts

This study examined outcomes of a technique for performing thoracoscopic left upper lobectomy (LUL) in patients with a previous left internal mammary artery (LIMA) coronary artery bypass graft, where a small wedge of lung parenchyma adjacent to the graft is left to avoid injury. All patients undergoing thoracoscopic LUL from 1999 to 2010 at a single institution were reviewed. Perioperative morbidity, cancer recurrence, and long-term survival were compared between patients who had (LIMA group) or did not have (control group) a previous LIMA graft. During the study period, 290 patients underwent thoracoscopic LUL; 14 (5%) had previous LIMA grafts. There was no perioperative mortality in the LIMA group versus 4 (1%) in the control group (p= 0.65). One patient (7%) in the LIMA group required conversion to thoracotomy, which was similar to the control group (n=16, 6%; p= 0.83). Overall perioperative morbidity was also not different between the groups (LIMA 36% [5of 14] versus control 29% [81 of 276], p= 0.61). No patient in the LIMA group had perioperative cardiac ischemia. For patients with lung cancer, 5-year survival (LIMA 50%vs control 63%, p= 0.23) and cancer recurrence rates (LIMA 27% (3 of 11) versus control 15% (36 of 242), p=0.27) were not different between the groups. Only 1LIMA recurrence was local, and it was not related to theparenchyma left on the LIMA graft. Thoracoscopic LUL can be performed safely in patients with LIMA bypass grafts. Leaving lungparenchyma on the graft may prevent injury and does notcompromise oncologic outcomes in appropriately selected patients.

Bilateral versus single internal mammary coronary artery bypass grafting in Sweden from 1997-2008.

BackgroundPrior observational studies have suggested better outcomes in patients who receive bilateral internal mammary arteries (BIMA) during coronary artery bypass grafting (CABG) compared with patients who receive a single internal mammary artery (SIMA). The aim of this study was to analyze the association between BIMA use and long-term survival in patients who underwent primary isolated CABG.Methods and ResultsPatients who underwent primary isolated non-emergent CABG in Sweden between 1997 and 2008 were identified. The SWEDEHEART registry and other national Swedish registers were used to acquire information about patient characteristics and outcomes. Unadjusted and multivariable adjusted regression models were used to estimate the association between BIMA use and early mortality, long-term survival, and a composite of death from any cause or rehospitalization for myocardial infarction, heart failure, or stroke in the overall cohort and in a propensity score-matched cohort. The study population consisted of 49702 patients who underwent CABG with at least one internal mammary artery, and 559 (1%) of those had BIMA grafting. In the adjusted analyses, BIMA use was not associated with better survival compared with SIMA use in the overall cohort (hazard ratio (HR) for death: 1.16, 95% confidence interval (CI): 0.97 to 1.37) or in the matched cohort (HR: 1.04, 95% CI: 0.78 to 1.40). The results were similar for early mortality and the composite endpoint. Reoperation for sternal wound complications was more common among BIMA patients (odds ratio: 1.71, 95% CI: 1.01 to 2.88).ConclusionsBIMA grafting was performed infrequently and was not associated with better outcomes compared with SIMA grafting in patients undergoing non-emergent primary isolated CABG in Sweden during 1997–2008.

Randomized trial to compare bilateral vs. single internal mammary coronary artery bypass grafting: 1-year results of the Arterial Revascularisation Trial (ART)

Randomized trial to compare bilateral vs. single internal mammary coronary artery bypass grafting: 1-year results of the Arterial Revascularisation Trial (ART)

Bilateral mammary artery vs. single mammary artery grafting: promising early results: but will the match finish with enough players?

This editorial refers to ‘Randomized trial to compare bilateral vs. single internal mammary coronary artery bypass grafting: 1-year results of the Arterial Revascularisation Trial (ART)’, by D.P. Taggart et al. , doi:10.1093/eurheartj/ehq318 A single internal mammary artery (SIMA) rather than vein graft to the left anterior descending coronary artery is undoubtedly the standard therapy in coronary bypass surgery. Surprisingly, the usage of two mammary arteries has not been accepted as the standard of care and the benefits and disadvantages have been a matter of debate for years. Numerous compelling retrospective studies have documented a clear benefit for bilateral mammary artery (BIMA) grafting over SIMA grafting in reducing the long-term risk of death, cardiac death, and late cardiac events.1 Nevertheless, there is a wide discrepancy between these findings in the literature and clinical practice. In the USA, BIMA usage is only around 4%2 and in Europe 12%.3 The saphenous vein is still a widely used graft because of its accessibility, sufficient length, and ease of manipulation. Bilateral mammary artery grafting has been associated with an increased rate of sternal dehiscence a potential complication, particularly in diabetics.4 It seems however that using skeletonized BIMA grafts may lower the incidence of sternal complications.5 Another argument that is often used against BIMA usage is that composite grafting is susceptible to the effect of flow competition and may lead to a higher incidence of graft occlusion or string sign in up to 20% of the patients.6 Nonetheless, this compares favourably with an astonishing 45% …

Randomized trial to compare bilateral vs. single internal mammary coronary artery bypass grafting: 1-year results of the Arterial Revascularisation Trial (ART)

Observational data suggest that the use of bilateral internal mammary arteries (BIMA) during coronary artery bypass graft surgery provides superior revascularization to a single internal mammary artery (SIMA), but concerns about safety have prevented the widespread use of BIMA. The Arterial Revascularisation Trial (ART) is a randomized trial of BIMA vs. SIMA, with a primary outcome of survival at 10 years. This paper reports mortality, morbidity, and resource use data at 1 year. Coronary artery bypass graft patients were enrolled in 28 hospitals in seven countries. Three thousand one hundred and two patients were randomly assigned to SIMA (n = 1554) or BIMA (n = 1548). The mean number of grafts was 3 for both groups. Forty per cent of the SIMA procedures and 42% of the BIMA were performed off-pump. Mortality at 30 days was 18 of 1548 (1.2%) for SIMA and 19 of 1537 (1.2%) for BIMA, and at 1 year was 36 of 1540 (2.3%) and 38 of 1529 (2.5%), respectively. The rates of stroke, myocardial infarction, and repeat revascularization were all ≤2% at 1 year and similar between the two groups. Sternal wound reconstruction was required in 0.6 and 1.9% of the SIMA and BIMA groups, respectively. Data from ART demonstrate similar clinical outcomes for SIMA and BIMA at 1 year but BIMA grafts are associated with a small absolute increase (1.3%) in the need for sternal wound reconstruction. The results suggest that the use of BIMA grafts is feasible on a routine basis. The 10-year results of the ART will confirm whether BIMA grafting results in lower mortality and the need for repeat intervention. Controlled-trials.com (ISRCTN46552265).

Enfermedad coronaria aneurismática severa en un adolescente con angina de esfuerzo secundaria a enfermedad de Kawasaki no diagnosticada previamente

We report a 16 year old male with a history of angina on exertion. A treadmill exercise test was positive for ischemia in concordance with a Thallium-201 scintigraphy showing a septal and infero-posterior reversible myocardial perfusión defect. Coronary angiography disclosed severe aneurysmal coronary artery disease. Bilateral internal mammary coronary artery bypass grafting was successfully performed. Kawasaki disease is the most likely etiology, although not confirmed.

Endovascular Therapy of Left Subclavian Artery Stenosis in Patients with Left Internal Mammary-Coronary Artery Bypass Graft

Purpose: We wanted to evaluate the clinical usefulness of percutaneous transluminal angioplasty (PTA) and stenting of left subclavian artery (LSA) stenosis in the patients with a left internal mammary artery (LIMA)-coronary artery bypass graft. Materials and Methods: From September 1998 to November 2005, significant proximal LSA stenoses were treated with PTA and stenting in 22 patients (15 men and 7 women) who had a prior LIMA-coronary artery bypass graft or who were willing to undergo LIMA-coronary artery bypass grafting. The technical success rates, complications and restenosis during the follow-up period were retrospectively evaluated. Results: Six patients had a prior LIMA bypass graft and 16 patients were treated before their coronary artery bypass surgery. The etiology of the LSA stenosis was atherosclerosis in all patients. Four patients were treated with PTA only, and stents were placed in 18 patients. Technical success was achieved in all patients. An embolism in the proximal LIMA occurred after stenting in one patient, and the LIMA was recanalized with transcatheter thrombolysis. During a mean follow-up of 30 months, only one patient was found to have recurrent LSA stenosis 29 months after stenting and this patient was successfully managed with angioplasty. Conclusion: Endovascular therapy is useful and efficacious for the treatment of LSA stenosis in patients with a LIMA-coronary artery bypass graft.

Technology Diffusion, Hospital Variation, and Racial Disparities Among Elderly Medicare Beneficiaries

Low rates of technology utilization in hospitals with high proportions of black inpatients may be a remediable cause of healthcare disparities. Our objective was to determine how differences in technology utilization among hospitals contributed to racial disparity and if temporal reduction in hospital procedure rate variation resulted in decreased racial disparity for these technologies. We identified 2,348,952 elderly Medicare beneficiaries potentially eligible for 1 of 5 emerging medical technologies from 1989-2000 and determined if these patients had received the indicated procedure within 90 days of their qualifying hospital admission. Initial multivariate regression models adjusted for age, race, sex, admission year, clinical comorbidity, community levels of education and income, and academic/urban hospital admission. The inpatient racial composition of each patient's admitting hospital and time-race interactions were added as covariates to subsequent models. Blacks had significantly lower adjusted rates (P < 0.001) compared with whites for tissue replacement of the aortic valve, internal mammary artery coronary bypass grafting, dual-chambered pacemaker implantation, and lumbar spinal fusion. Hospitals with > 20% black inpatients were less likely to perform these procedures on both white and black patients than hospitals with < 9% black inpatients, and racial disparity was greater in hospitals with larger black populations. There were no temporal reductions in racial disparities. Blacks may be disadvantaged in access to new procedures by receiving care at hospitals that have both lower procedure rates and greater racial disparity. Policies designed to ameliorate racial disparities in health care must address hospital variation in the provision of care.

Coronary steal from a left internal mammary artery coronary bypass graft by a left upper extremity arteriovenous hemodialysis fistula

In patients with end-stage renal disease undergoing hemodialysis, the upper extremity arteriovenous (AV) fistula is the dialysis access recommended by the DOQI guidelines for patients with appropriate vasculature. Upper extremity AV fistulae have long periods of usefulness, high flow rates, and low associated complication rates. Placement of AV access may result in increased cardiac output and increased cardiac oxygen demand in these patients. In general, cardiovascular complications from AV access have been limited. We report a novel cardiovascular complication of AV access in an end-stage renal disease patient with a coronary artery bypass graft employing the left internal mammary artery who experienced angina while undergoing hemodialysis. The angina was mediated at least in part by cardiac catheterization laboratory-documented steal of blood flow from the internal mammary artery graft. This phenomenon suggests the need to consider the impact of upper extremity access placement on blood flow to the left internal mammary artery in patients who previously have undergone placement of a coronary artery bypass graft. © 2002 by the National Kidney Foundation, Inc.

Angina refractaria por robo subclavio-coronario tratada mediante angioplastia y stent

The coronary-subclavian steal syndrome is a rare cause of recurrent myocardial ischemia in patients who have undergone left internal mammary-coronary artery bypass grafting. A significant left subclavian artery stenosis proximal to its origin, can result in an impaired or reversed flow in this graft and myocardial ischemia. We describe the case of a woman aged 76 who had undergone myocardial revascularization seven months before, and presented refractory angina with severe electrocardiographic ischemia in the left anterior descending artery territory. Arteriography confirmed this syndrome and the patient was successfully treated with percutaneous transluminal angioplasty and placement of two stents in the left subclavian artery. We review the clinical management, diagnostic methods and therapeutic options used in the subclavian-coronary steal syndrome.

Enhanced Nitric Oxide–Mediated Vascular Relaxation in Radial Artery Compared With Internal Mammary Artery or Saphenous Vein

Background —The superior long-term patency of internal mammary artery coronary bypass grafts compared with venous grafts has been attributed in part to increased endothelium-derived nitric oxide (·NO) production. Interest in the radial artery as an alternative bypass conduit has recently been revived; however, its biological characteristics remain incompletely defined. The purpose of this study was to compare the ·NO-mediated vasomotor properties of the radial artery to those of the internal mammary artery and saphenous vein. Methods and Results —Matched segments of radial artery, internal mammary artery, and saphenous vein (n=24 patients) were examined by use of organ-chamber methodology. Endothelium-dependent and -independent vasomotor responses were assessed by dose-response curves to acetylcholine, N G -nitro- l -arginine methyl ester (L-NAME), 8-bromo-cyclic 3′,5′-guanosine monophosphate (8-bromo-cGMP), and nitroglycerin. Maximum ·NO-mediated radial artery relaxation in response to acetylcholine (86±10%) was significantly greater than internal mammary artery (56±9%) or saphenous vein (11±5%, both P &lt;0.0001). Similarly, acetylcholine-stimulated cGMP accumulation in radial artery (9.1±1.7 pmol/mg protein) was also greater than internal mammary artery (6.2±0.3 pmol/mg protein) or saphenous vein (1.4±0.2 pmol/mg protein, both P &lt;0.05). Estimated basal endothelial ·NO production, assayed as the percent maximum contraction in response to L-NAME, was greater in radial artery (39±5%) than internal mammary artery (23±6%) or saphenous vein (5±2%, both P &lt;0.05). Maximum relaxation of all vessels to nitroglycerin was similar, although the sensitivity of radial artery to nitroglycerin was greater (EC 50 =33±7 nmol/L) than the internal mammary artery (203±32 nmol/L) or saphenous vein (97±12 nmol/L, both P &lt;0.05). Vascular cGMP in response to 0.1 μmol/L nitroglycerin was significantly higher in the radial artery (8.3±1.4 pmol/mg protein) compared with the internal mammary artery (3.5±1.3 pmol/mg protein) or saphenous vein (1.4±0.3 pmol/mg protein, both P &lt;0.0001). Relaxation to 8-bromo-cGMP was identical for all 3 conduits. Conclusions —These data indicate that ·NO-dependent relaxation of radial artery is greater than that of internal mammary artery or saphenous vein. This difference is related to endothelial production of ·NO and/or vessel sensitivity to ·NO. Such favorable physiological characteristics of radial artery could conceivably contribute to improved long-term patency of this conduit compared with saphenous vein.

P10 Double internal mammary coronary artery bypass does not increase the risk for sternal wound complications: A review of 317 consecutive patients

P10 Double internal mammary coronary artery bypass does not increase the risk for sternal wound complications: A review of 317 consecutive patients

Primary stent deployment in occlusive subclavian artery disease.

Primary (without antecedent balloon dilation) Palmaz stent implantation was successfully performed in 27 consecutive patients entering with 31 obstructed subclavian arteries. Stents (n = 50) were successfully deployed, using the brachial (n = 7), femoral (n = 16), or combined (n = 8) approach, to revascularize 31 subclavian vessels [8 occluded (26%); 23 stenotic (74%)], using a 6 or 7.5 French delivery system. The indications for intervention were arm claudication in 8 patients (30%), subclavian steal syndrome in 11 patients (41%), angina pectoris secondary to impaired blood flow to the left internal mammary artery coronary bypass in 6 patients (22%), and recanalization of a left subclavian occlusion to permit central arterial access and performance of a second interventional procedure 2 patients (7%). The percent diameter stenosis improved from 85 +/- 12% to 6 +/- 7% (P < 0.001); and, the peak and mean translesion gradients decreased, respectively, from 56 +/- 35 mm Hg to 3 +/- 4 mm Hg (P < 0.01), and 29 +/- 18 mm Hg to 2 +/- 2 mm Hg (P < 0.01). Procedural complications encountered were one stent dislodgement with migration into and uneventful deployment within the right external iliac artery, and two brachial artery repairs. No acute vessel closures, deaths, myocardial infarctions, cerebrovascular accidents, transient ischemic attacks, or need for transfusions occurred. Therefore, primary subclavian artery stent deployment can be performed using low-profile sheath systems with excellent success (100%), resulting in immediate restoration of pulsatile flow, and few complications. The incidence of lesion recurrence remains for follow-up studies.

The Coronary Subclavian Steal Syndrome: An Uncommon Sequel to Internal Mammary-Coronary Artery Bypass Surgery

Coronary subclavian steal syndrome is a possible sequel in patients who have undergone myocardial revascularization with an internal mammary artery. We report a case of this syndrome in a 67-years-old man. In 1990 he underwent a quadruple bypass: aorta-obtuse margin, aorta-right coronary (two sequential), internal artery mammary-descending coronary artery. Three months later he started to have angina pectoris. In April 1992 an aortic arch angiography and a coronary angiography were performed. The examination showed an occlusion of the left subclavian artery at its origin. The artery was opacified countercurrently by the left vertebral artery but the left mammary artery was not opacified. Left coronary angiography showed a very severe disease of left anterior descending coronary artery and retrograde flow through the anastomosis in the left mammary artery. The patient underwent a left common carotid-subclavian artery bypass operation using a 6 mm vascutex graft. Eighteen months later the patient is doing well without angina pectoris and with very little alteration of the perfusion in the left frontal lobe observed by SPECT neuroimaging with a lipophilic tracer (99mTc-HMPAO). We think that the coronary-subclavian steal syndrome can be treated successfully with low risk by means of common carotid-subclavian artery bypass.