Predominant mutations induced by the Thermococcus litoralis, vent DNA polymerase during DNA amplification in vitro

Severe stenosis or occlusion of either the superior or the inferior vena cava requires surgical bypass grafting in a selected group of patients. When the obstruction extends into the major tributaries, a bifurcated graft becomes necessary. We present the cases of 2 surgically treated patients, each of whom received a stented polytetrafluoroethylene bifurcated graft constructed at the time of the operation. Symptoms disappeared post-operatively in 1 patient and abated in the other. Both grafts became occluded within 1 year; however, that was sufficient time for collateral venous circulation to develop, enabling both patients to respond well to conservative therapy. We conclude that stented polytetrafluoroethylene bifurcated grafts may be suitable for selected patients as a bridge until collateral veins can form. The development of more compliant venous grafts may provide even more favorable results.     

Comparison of flow capacities of arterial and venous grafts for coronary artery bypass grafting: evaluation with exercise thallium-201 single-photon emission tomography

Stress thallium-201 tomography was performed to compare the flow capacities of arterial and saphenous vein grafts in patients with coronary artery bypass grafting (CABG). One hundred and seven consecutive patients (95 male and 12 female; mean age 58+/-9.1 years) underwent exercise-redistribution 201Tl myocardial single-photon emission tomography 4-5 weeks after CABG. When a reversible perfusion defect was present in the area covered by a patent bypass graft, the flow capacity of the graft was defined as insufficient. Of all 285 grafts, 211 were considered as complete bypass. Reversible perfusion defects were present in 29 (27%) of 108 myocardial areas supplied by patent arterial grafts but in only 5 (5%) of 103 myocardial areas supplied by patent saphenous vein grafts (P<0.0001). In the LAD area reversible defects were observed in 22 of 82 areas covered by arterial grafts, in contrast to only 1 of 29 areas covered by venous grafts (P<0.01); in the RCA area reversible defects were observed in 7 of 17 and 4 of 41 areas respectively (P<0.01). There was no difference between the native coronary artery stenosis bypassed by patent arterial and venous grafts (88%+/-12% vs 86%+/-14% respectively, P=0.27). In conclusion, flow capacities during peak myocardial demand were more frequently insufficient in arterial bypass grafts than in saphenous vein grafts.     

Cardiac revascularization using both mammary arteries

Both internal mammary arteries in combination with veins were used for revascularization of the hearth in fifty Danish patients undergoing coronary artery bypass grafting (CABG) at Gentofte Hospital during the period 1994-1996. Patients with insulin-dependent diabetes mellitus, obesity, and age over 75 years were excluded. The patients were followed for at least one month after the operation. No patients died, and the complication rate was low and comparable to standard CABG using the left mammary artery and vein grafts. It is known from the literature that 10 years after CABG only 50% of vein grafts remain patent, and half of these have severe atherosclerosis. The mammary artery is far more resistant to atherosclerosis and 15 years after the procedure fewer patients have recurrent angina when both mammary arteries have been used. Bilateral mammary artery grafts can be used in half of CABG-procedures, and are especially indicated in younger patients.     

Gastroepiploic artery graft in 400 patients

The right gastroepoploic artery (GEA) has been used for coronary artery bypass grafting (CABG) in 400 patients of a total of 1359 undergoing the same procedure during an 8-year period. There were 327 males and 73 females with a mean age of 59 years. Single-, double- and triple-vessel and left main disease were noted in 4, 51, 283 and 62 patients, respectively. Previous myocardial infarction was noted in 208 patients and 40 patients had undergone previous CABG. Internal thoracic artery (ITA) and inferior epigastric artery grafts were concomitantly used in 388 (97%) and 30 (8%) patients, respectively. The mean number of grafts was 3.2 including vein grafts, and 2.3 coronary arteries were bypassed with arterial grafts. The sites of GEA grafting were 43 anterior descending, 6 diagonal, 71 circumflex, and 287 right coronary arteries with 376 in situ and 24 free grafts including 7 sequential grafts. There were eight (2%) early and five (1.3%) late deaths. New Q waves were noted in six (1.5%) patients. Warm body circulation is thought to be favorable with a lower incidence of the need for intra-aortic balloon pump (0.6% vs 6.0%). Postoperative angiography revealed 94% (253/268) early (2 months) and 94% (47/50) late (2-5 years) patency of GEA grafts. In conclusion. GEA is a safe and effective arterial conduit for CABG.     

Constitutive nitric oxide synthase is expressed and nitric oxide-mediated relaxation is preserved in retrieved human aortocoronary vein grafts

Although little is known about the endothelial cell function of human saphenous vein coronary artery bypass grafts, there is evidence to suggest that receptor-activated, endothelial-dependent relaxation mediated by nitric oxide is impaired. This study examines the expression and function of endothelial cell constitutive nitric oxide synthase (cNOS) of aortocoronary vein bypass grafts and human saphenous veins obtained from 10 patients undergoing repeat coronary artery bypass grafting for recurrent ischemic symptoms. Following precontraction with norepinephrine (10(-5) M), responses to acetylcholine (receptor-mediated, endothelium-dependent), calcium ionophore (A23187; receptor-independent, endothelium-dependent), and sodium nitroprusside (endothelium-independent) were assessed. Following total RNA extraction using phenol/guanidinium isothiocyanate from specimens of human saphenous vein and vein graft, a quantitative RNase Protection Assay (RPA) was performed using a cRNA riboprobe corresponding to a fragment of the human endothelial cell cNOS gene. Histologically, the vein grafts showed both intimal hyperplasia development and focal atherosclerosis formation compared to the saphenous veins. Scanning electron microscopy of the saphenous veins and the vein grafts showed an intact endothelium. Precontracted vein grafts did not relax in response to acetylcholine; in contrast, the saphenous vein relaxed in a dose-dependent manner to reach a maximal relaxation of 19 +/- 4% precontracted tension. Saphenous veins and vein grafts relaxed in response to A23187 with maximal relaxation of 92 +/- 5 and 73 +/- 13%, respectively. Both vessels relaxed in a dose dependent manner to sodium nitroprusside. RPA normalized to beta-actin showed similar levels of expression of endothelial cell cNOS equivalent to 1 pg of sense RNA in both the saphenous vein and vein graft.(ABSTRACT TRUNCATED AT 250 WORDS)     

The potential for lower extremity revascularization without contrast arteriography: experience with magnetic resonance angiography

PURPOSE: We report an initial experience with 24 patients studied between March 1990 and April 1992 with magnetic resonance angiography (MRA) for lower extremity occlusive disease. METHODS: All patients underwent vascular intervention with either balloon angioplasty or bypass grafting, and in six patients this intervention was based on MRA findings alone. Eighteen patients were studied with both MRA and contrast arteriography, and there was observed agreement between the two studies in 98% of all arterial segments examined. RESULTS: Agreement between MRA and contrast arteriography was uniform for arterial segments below the inguinal ligament. Intraoperative findings and favorable early results of seven bypass grafts performed in six patients after MRA alone suggested this was a valid approach for patients at prohibitive risk of complications from contrast arteriography. CONCLUSIONS: Magnetic resonance angiography is accurate in demonstrating relevant anatomy in peripheral arterial occlusive disease and in selected patients may eliminate the need for contrast arteriography before lower extremity revascularization.     

Age specific prostate specific antigen reference ranges: population specific

BACKGROUND: Anastomosis of the left internal thoracic artery to the left anterior descending artery without sternotomy and without cardiopulmonary bypass is a standard approach in minimally invasive coronary artery bypass grafting. To expand the indications for minimally invasive coronary artery bypass grafting from one-vessel disease to two-vessel disease, we began to perform anastomosis of the right gastroepiploic artery (RGEA) to the right coronary artery (RCA). METHODS: From February to November 1996, an RGEA graft was used in 25 of the 100 patients who underwent minimally invasive coronary artery bypass grafting at our clinic. Eleven of the patients had only RCA disease and 14 had both RCA and left anterior descending artery disease. One of the operations was a redo coronary artery bypass grafting. The RGEA was anastomosed to the RCA through a laparotomy incision and the left internal thoracic artery was anastomosed to the left anterior descending artery through a left anterior thoracotomy. In 5 patients, the RGEA was lengthened by venous grafting. RESULTS: All patients underwent angiography after operation; 82.6% of the RGEA grafts and all the left internal thoracic artery grafts were functioning well. In three of the four nonvisualized RGEA grafts, the percentage of proximal stenosis of the RCA seen on postoperative angiography was not critical (40%, 50%, and 50%, respectively), allowing significant competitive flow through the native bypassed RCA. The patency of all the RGEA grafts without competitive flow was 95%, with a 95% confidence interval of 75.1% to 99.9%. CONCLUSIONS: The indications for minimally invasive coronary artery bypass grafting could be extended to primary operations in patients with left anterior descending artery and RCA lesions by using both the left internal thoracic artery and the RGEA.     

Effect of different methods of internal thoracic artery harvest on pulmonary function

BACKGROUND: In several clinical studies, internal thoracic artery (ITA) grafting for myocardial revascularization has been identified as increasing the risk of postoperative pulmonary complications. This study was designed to determine whether the technique used to harvest the ITA has an effect on postoperative pulmonary function. METHODS: Seventy-nine consecutive patients undergoing coronary artery bypass grafting using the left ITA were compared with patients undergoing coronary artery bypass grafting using saphenous vein grafts only. Two methods of ITA harvesting were used: (1) incision of the endothoracic fascia dissected off the ITA as a skeletonized vessel (group 1, n = 33) and (2) mobilization of the ITA as a wide musculofascial pedicle (group 2, n = 46). Thirty-two patients underwent coronary artery bypass grafting using saphenous vein grafts only (group 3). Pulmonary function tests were performed between postoperative days 20 and 30. RESULTS: The postoperative values of forced vital capacity were reduced in patients in all groups (p < 0.0001). The ratios of postoperative to preoperative forced vital capacity were 84% in group 1, 77% in group 2, and 84% in group 3. The reduction in group 2 was significant compared with group 1 (p < 0.05) and group 3 (p < 0.05). CONCLUSIONS: Postoperative pulmonary dysfunction was significantly greater in patients who underwent wide musculofascial pedicle dissection of the ITA compared with skeletonization of the artery. Thus, of the two techniques, the latter may be the method of choice with regard to lowering the incidence of postoperative pulmonary dysfunction.     

Investigations on the pathogenesis of primary varicose veins

The data from the clinical course and epidemiology of primary varicose veins of lower limb suggest that sex hormones can directly influence the development of the disease through their intracellular receptor localised in cells of venous wall. The purpose of this study was to determine the stereometric differences in the structure of healthy and varicose veins of lower limb and to determine the presence and localisation of oestrogen and progesterone receptors in the cells of vein. The segments of greater saphenous vein obtained from the 8 women operated for varicose vein were used for the study. The segments of the greater saphenous vein obtained from 8 women that underwent femoro-popliteal venous bypass procedure were used as control group. The vein samples for stereometric analysis were preserved in Buin's solution, embedded in paraffin and then evaluated with automatic analyser MagiCal. To determine the presence of oestrogen and progesterone receptors the immunohistochemic analysis LAB with monoclonal antibodies produced by DAKO was used. The decreased smooth muscle fraction in venous wall, thickening of adventitia, the change of the smooth muscle cells to stroma cells ratio in the muscular layer of venous wall and change of muscular layer to adventitia ratio were observed in varicose veins in comparison with control group. The oestrogen receptors were found in the nuclei of the smooth muscle cells and endothelium. The progesterone receptors were localised in nuclei of smooth muscle cells and cells of subendothelial layer. It seems that quantitative analysis of sex hormones receptor in the venous wall could be useful in the determination of patients with increased risk of the development of primary varicose veins.     

Bilateral thoracoscopic minimally invasive direct coronary artery bypass grafting using internal thoracic arteries

BACKGROUND: Single-vessel coronary artery bypass grafting of the left internal mammary artery (ITA) to the left anterior descending coronary artery using a minithoracotomy has been shown to produce excellent results with a very low mortality. However, this procedure cannot be used in patients with double- or triple-vessel disease. Our goal was to develop a minimally invasive direct coronary artery bypass grafting procedure without cardiopulmonary bypass for patients with multivessel disease. METHODS: Both ITAs were thoracoscopically harvested using video imaging. Limited bilateral anterior thoracotomies were performed in the fourth intercostal spaces, thus exposing the right coronary artery and the left anterior descending coronary artery. The right ITA-right coronary artery and ITA-left anterior descending coronary artery anastomoses were performed without cardiopulmonary bypass using 8-0 polypropylene sutures. RESULTS: This procedure was successfully performed in 3 patients. The patients were extubated in the operating room. Postoperative angiographic studies showed patent left ITA and right ITA grafts. CONCLUSIONS: Bilateral thoracoscopic minimally invasive direct coronary artery bypass grafting can be used to treat patients with a proximally diseased left anterior descending coronary artery and right coronary artery. Bilateral thoracoscopic ITA harvesting is a less invasive surgical technique that may become an option for the management of multivessel coronary artery disease.     

Angiographic predictors of graft patency and disease progression after coronary artery bypass grafting with arterial and venous grafts

BACKGROUND: There are few data about angiographic determinants of functional graft patency and native artery disease progression after coronary artery bypass grafting operation with arterial grafts compared with venous grafts. METHODS: Baseline and follow-up coronary angiograms at a mean of 2 years after operation in 91 patients with 194 arterial and 204 venous graft anastomoses were analyzed. RESULTS: Ninety-two percent of the arterial and 87% of the venous graft anastomoses were patent at follow-up angiography (p = 0.05, odds ratio = 2.63). Unlike that of arterial grafts, the patency rate of venous graft anastomoses correlated negatively with decreasing severity of the bypassed lesion. In contrast to venous grafts, in which angiographic graft function was basically dichotomous (fully patent or occluded), compromised flow of the arterial graft anastomoses was registered in 12%. Progression of the disease was more common in segments bypassed with venous grafts than with arterial grafts (p = 0.001, odds ratio = 2.03). CONCLUSIONS: Angiographic determinants of functional graft patency and progression of occlusive changes in the bypassed artery segments are different for arterial and venous grafts.     

Does arterial revascularization decrease the risk of infarction after coronary artery bypass grafting?

BACKGROUND: This study sought to determine whether extensive arterial grafting reduces the prevalence and consequences of infarct after coronary artery bypass grafting. METHODS: Post-primary coronary artery bypass grafting infarcts and time-related events thereafter were identified by 99.9% complete follow-up of 9,600 patients (1971 to 1992). The contribution of arterial grafting to freedom from infarct was assessed by multivariable hazard function analysis to adjust for other risk factors. RESULTS: Unadjusted 1-month and 10-year freedom from infarction was 97% and 86%. By multivariable analysis, arterial grafting lowered the prevalence of periprocedural (p = 0.005), intermediate term (p = 0.007 and 0.006), and late infarction (arterial grafting to the left anterior descending coronary artery, p = 0.0006). Unadjusted survival after first infarct after coronary artery bypass grafting was 74% and 52% at 1 and 10 years; arterial grafting improved 10-year survival from 48% to 59% (p = 0.002). An additional benefit or cost of extending arterial grafting (n = 1,727) beyond a single one could not be identified (p > 0.1). CONCLUSIONS: Arterial conduits, particularly to the left anterior descending coronary artery, should be used for coronary artery bypass grafting to reduce early and late myocardial infarction and its consequences. However, use of more than a single arterial graft appears to confer no additional benefit.     

Comparison of angioscopy and angiography for monitoring infrainguinal bypass vein grafts: results of a prospective randomized trial

PURPOSE: This study was designed to determine whether, in primary infrainguinal bypass grafts in which only saphenous vein is used as the graft conduit, routine monitoring with intraoperative angioscopy can improve early graft patency as compared with standard monitoring with intraoperative completion angiography; and to delineate the advantages and disadvantages of these two modalities and their respective roles for the routine monitoring of the infrainguinal bypass graft. METHODS: A total of 293 patients undergoing primary saphenous vein infrainguinal bypass grafting were prospectively randomized and monitored with either completion angioscopy or completion angiography. Clinical parameters, indications for operation, graft anatomy, and configuration were evenly matched in both groups. Forty-three bypasses were excluded from the study after randomization, including 12 veins randomized to angiogram, deemed inferior, and prepared with angioscopy. RESULTS: In the 250 bypass grafts (angioscopy 128, angiography 122) there were 39 interventions (conduit, 29; anastomosis, 8; distal artery, 2), 32 with angioscopy and 7 with angiography (p < 0.0001). Twelve (4.8%) of the 250 grafts failed in less than 30 days, four (3.1%) of 128 in the angioscopy group and eight (6.6%) of 122 in the angiography group (p = 0.11 by one-sided hypothesis test). CONCLUSION: Although no statistical improvement in the proportions of failures in primary saphenous vein bypass grafts routinely monitored with completion angioscopy rather than the standard completion angiogram was demonstrated, the study delineates a trend that favors completion angioscopy for routine vein graft monitoring and demonstrates the advantages of angioscopy in preparing the optimal vein conduit.     

Small arterial reconstruction using modified cadaveric saphenous veins

Human saphenous veins removed from cadaver donors were subjected to proteolytic enzymatic digestion, cross bonding, and heparin bonding. They were tested as small arterial substitutes in dogs. Eight of eleven were successful, persisting without development of stenosis or aneurysm, the longest for eighteen months. In humans, similarly prepared veins were used as arterial bypasses to revascularize ischemic limbs in eleven patients and aneurysmal degeneration of an earlier unmodified allograft bypass in one patient. Distal arterial anastomoses were to the tibial and peroneal arteries. Nine patients who had not undergone previous reconstructive surgery involving the vessel used for distal anastomosis were treated successfully; all remain with healed limbs between three and twelve months after surgery, eight with functioning bypasses. In three patients who had undergone previous operations on the same artery used for distal anastomosis, long bypasses failed, although amputation was avoided in one patient by additional bypass with modified vein to the profunda femoris artery. We conclude that modified saphenous vein allografts are suitable small arterial substitutes. It remains to be seen whether veins will maintain patency for long periods without development of complications.     

Vein harvest ischemia: a peripheral vascular complication of coronary artery bypass grafting

Lower-extremity ischemia can lead to impaired healing of saphenous vein excision sites in patients with significant peripheral vascular disease (PVD). Five patients who required infrainguinal revascularization for wound necrosis of the harvest site after coronary artery bypass grafting are described. The male/female ratio was 2:3 with a mean age of 67 (range 45-87) years. The most commonly associated problems were insulin-dependent diabetes mellitus (80%) and congestive heart failure (60%). The saphenous vein was harvested from the thigh and leg in three patients and exclusively from the leg in the others. Manifestations of ischemia ranged from persistent ulceration to complete wound disruption threatening limb loss. Impaired healing was isolated to infragenicular wounds in all patients. Pedal pulses were not detected in any of the affected extremities. Determination of the ankle/brachial pressure indices (ABI) revealed values of < 0.5 in three affected limbs. Non-compressible vessels resulted in falsely raised ABI of > 1.0 in the remaining two limbs; however, Doppler waveform analysis in these patients demonstrated significant PVD. Aggressive wound care and antibiotic therapy were continued for mean of 9 weeks before operative intervention. Infrainguinal reconstruction included femoropopliteal (two), femorotibial (two) and popliteal-tibial bypass (one). Autologous arm and saphenous veins in addition to expanded polytetrafluoroethylene grafts were used effectively. Limb salvage and wound healing were achieved in 100% of the patients without untoward sequelae. It is concluded that unrecognized PVD in patients undergoing coronary artery bypass grafting can lead to significant morbidity. Patients at risk may be identified with a combination of history, physical examination and non-invasive testing.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bacteria-specific lymphocyte proliferation in peripheral blood in reactive arthritis and related diseases

The inferior epigastric artery has been proposed as a suitable conduit for myocardial revascularization but its mid-term patency rate has not been assessed. A prospective clinical and angiographic study on the use of the inferior epigastric artery as an additional arterial conduit together with bilateral internal thoracic artery grafting was conducted in 38 patients. No deaths or major postoperative complications occurred. Twenty-three patients underwent repeat angiography after an average of 21.2 months. The left and right internal thoracic artery grafts patency rate was 95.6% (44/46), while inferior epigastric artery patency rate was 52.2% (12/23). By relating patency to the grafted coronary branch, the following results were obtained: 100% for the left anterior descending (3/3), right coronary (1/1) and ramus medianus (1/1); 40% (4/10) and 37.5% (3/8) for diagonals and obtuse marginals respectively. The low patency rates observed when the inferior epigastric artery is used on diagonals and obtuse marginals indicate that this vessel cannot be considered a suitable conduit for extensive application of arterial revascularization. We suggest that the inferior epigastric artery should only be used in patients presenting with contraindications to bilateral internal thoracic artery or right gastroepiploic artery grafting, or exhibiting unsuitable saphenous veins.     

Enteral nutrition modifies gut-associated lymphoid tissue in rat regardless of the molecular form of nitrogen supply

OBJECTIVES: It is not known whether the results of randomized trials comparing coronary artery bypass grafting to percutaneous transluminal coronary angioplasty for initial revascularization apply to repeat revascularization in patients with prior bypass grafts. We studied the differences between the patients with prior bypass grafts referred for surgery or angioplasty to identify the clinical and angiographic characteristics that correlated best with either choice and to find clues that might aid in selecting one treatment over the other. METHODS: Between 1992 and 1994, 870 patients underwent first isolated reoperation and 793 patients underwent first balloon angioplasty after a previous operation. A jeopardy score (0 to 8 points) was derived for each patient on the basis of the relative size of the ischemic territory. Clinical and angiographic data were analyzed for association with the revascularization strategy. RESULTS: The following characteristics were more prevalent in the reoperation group: male sex, diabetes, hypertension, valvular disease, normocholesterolemia, and severe left ventricular systolic dysfunction; fewer functioning venous and arterial grafts; and a higher jeopardy score (p < 0.01 for all) than in the angioplasty group. A higher jeopardy score, diabetes, and a lower number of functioning arterial or venous grafts were strong, independent predictors of referral for reoperation (p < 0.01 for all). In hospital death and Q-wave infarction (p < 0.01 for both) were more frequent in the reoperation group. CONCLUSIONS: Reoperation was the revascularization procedure of choice when larger regions of myocardium were in jeopardy. Angioplasty was more frequently chosen in the presence of a patent arterial graft to the left anterior descending coronary artery or multiple functioning bypass grafts. Reoperation was associated with a higher risk of in-hospital complications than angioplasty.     

Can duplex scan arterial mapping replace contrast arteriography as the test of choice before infrainguinal revascularization?

PURPOSE: Arteriography is the diagnostic test of choice before lower extremity revascularization, because it is a means of pinpointing stenotic or occluded arteries and defining optimal sites for the origin and termination of bypass grafts. We evaluated whether a duplex ultrasound scan, used as an alternative to arteriography, could be used as a means of accurately predicting the proximal and distal anastomotic sites in patients requiring peripheral bypass grafts and, therefore, replace standard preoperative arteriography. METHODS: Forty-one patients who required infrainguinal bypass grafts underwent preoperative duplex arterial mapping (DAM). Based on these studies, an observer blinded to the operation performed predicted what operation the patient required and the best site for the proximal and distal anastomoses. These predictions were compared with the actual anastomotic sites chosen by the surgeon. RESULTS: Whether a femoropopliteal or an infrapopliteal bypass graft was required was predicted correctly by means of DAM in 37 patients (90%). In addition, both anastomotic sites in 18 of 20 patients (90%) who had femoropopliteal bypass grafts and 5 of 21 patients (24%) who had infrapopliteal procedures were correctly predicted by means of DAM. CONCLUSION: DAM is a reliable means of predicting whether patients will require femoropopliteal or infrapopliteal bypass grafts, and, when a patient requires a femoropopliteal bypass graft, the actual location of both anastomoses can also be accurately predicted. Therefore, DAM appears able to replace conventional preoperative arteriography in most patients found to require femoropopliteal reconstruction. Patients who are predicted by means of DAM to require crural or pedal bypass grafts should still undergo preoperative contrast studies to confirm these results and to more precisely locate the anastomotic sites.     

Expansion of CTG repeats from human disease genes is dependent upon replication mechanisms in Escherichia coli: the effect of long patch mismatch repair revisited

OBJECTIVE: New techniques for minimally invasive coronary artery bypass grafting have recently emerged. The purpose of this study was to determine the safety and efficacy of Port-Access (Heartport, Inc., Redwood City, Calif.) coronary revascularization and to evaluate with angiography the early graft patency rate with this new approach. METHODS: From October 1996 to May 1997, 31 patients underwent Port-Access coronary artery bypass grafting with an anterior minithoracotomy and endovascular-occlusion cardiopulmonary bypass. There were 26 men and 5 women with a mean age of 62 years (range 42 to 82 years). Fifteen patients underwent single bypass; 12 patients underwent double bypass, and 4 patients underwent triple bypass. Bypass conduits included the left internal thoracic artery (n = 30), right internal thoracic artery (n = 2), radial artery (n = 10), and saphenous vein (n = 6). Three sequential grafts were used. Angiographic studies of the bypass grafts were performed in 27 of 31 patients (87%). RESULTS: There were no deaths, neurologic deficits, myocardial infarctions, or aortic dissections. Conversion to sternotomy was not required in any case. There were two reoperations for bleeding, one reoperation for tamponade, and one reoperation for pulmonary embolus. Postoperative angiography revealed anastomotic patency of the left internal thoracic artery to left anterior descending artery in 26 of 26 grafts (100%) with overall anastomotic patency in 43 of 44 grafts (97.7%). CONCLUSION: These results demonstrate that Port-Access coronary artery bypass can be performed accurately and safely with acceptable morbidity. This approach allows for multivessel revascularization on an arrested, protected heart with excellent anastomotic precision and reproducible early graft patency.     

Validation of an LC-MS assay for the quantification of the enantiomers of Org 4428 in human plasma

OBJECTIVE: The aim of this study was to assess the long-term results of use of the radial artery as a conduit for coronary artery bypass grafting. METHODS: After revival of the technique in 1989, the radial artery was used as a conduit in 910 patients undergoing coronary artery bypass grafting. A complete follow-up was obtained for the first 102 consecutive patients from 4 to 7 years after the operation (mean 5.27 +/- 1.30 years). Fifty-nine percent of the patients were receiving calcium-channel inhibitors. An electrocardiographic stress test was obtained for 51 patients, with no contraindications found. Routine follow-up angiography was performed in 50 cases, including those of all patients with symptoms. Thus 64 radial artery and 48 left internal thoracic artery grafts were followed up from 4 to 7 years after the operation (mean 5.6 +/- 1.40 years). RESULTS: The actuarial survival was 91.6% at 5 years, and the actuarial rate of freedom from angina was 88.7% at 5 years. Four patients underwent percutaneous transluminal angioplasty during the period of follow-up, and there were no reoperations for revision of the bypass. The electrocardiographic stress test showed negative results in 73% of cases, electrocardiographic changes alone in 21%, and clinically positive results in 6%. Angiography showed that the patency rate of the radial artery grafts was 83%. The patency rate of the left internal thoracic artery grafts (n = 47) was 91%. The difference in patency could be related to the implantation sites of the grafts, mainly the circumflex artery (51%) for the radial artery grafts and almost exclusively the left anterior descending artery (94%) for the left internal thoracic artery. CONCLUSION: The use of the radial artery for coronary bypass grafting provides excellent clinical and angiographic results at 5 years. Routine use of the radial artery in combination with the left internal thoracic artery can be recommended.