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The Annals of thoracic surgery 01/2013; 95(1):383. · 3.74 Impact Factor
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ABSTRACT: Introduction: Robotic-assisted coronary artery bypass grafting (r-CABG) requires the placement of ports bluntly through the chest wall. When removed, these ports create bleeding sites that can be difficult to detect and treat. This study evaluated whether a topical hemostatic agent placed locally within these sites helps to reduce bleeding and blood product requirements.Methods: We retrospectively analyzed outcomes for r-CABG cases where 5 mL of a flowable hemostatic agent was injected locally within all port sites (hemostat group, n = 62) compared with patients whose port sites were untreated (controls, n = 131). Outcomes included chest tube output, red blood cell (RBC) transfusions, length of hospital stay, and the risk of reoperation for bleeding. Analyses were adjusted for risk factors known to influence bleeding and Society of Thoracic Surgeons (STS) risk score as a weighted composite of variables, which controls for patient and clinical variables.Results: The 2 study groups had similar baseline characteristics and underwent the same r-CABG procedure. The hemostat group had significant reductions in RBC transfusion (24.2% versus 40.8% receiving blood; P = .026; 0.44 versus 1.39 U transfused postoperatively, P = .024). After adjustment for bleeding risks (using STS risk score), differences in transfusions remained significant. Reoperation rates for bleeding, length of stay, chest tube drainage, and intraoperative transfusions were not significantly different in the 2 groups.Conclusions: There was significantly reduced postoperative bleeding and less exposure to blood products in the hemostat group. These findings suggest that undetected bleeding from sites used for port access serves as an underappreciated source of morbidity after r-CABG.
Heart Surgery Forum 10/2012; 15(5):E272-6. · 0.63 Impact Factor
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ABSTRACT: Several centers have established that off-pump, multivessel coronary artery bypass grafting performed via a small thoracotomy (MVST) is feasible. However, this procedure can be challenging when posterolateral coronary targets need to be grafted. We hypothesized that use of cardiopulmonary bypass via peripheral access (MVST-PA) would improve outcomes compared with a completely off-pump approach (OP-MVST).
This was a prospective observational study of patients undergoing OP-MVST (n = 46) versus MVST-PA (n = 45) using bilateral internal mammary artery grafts onto the left anterior descending coronary artery and circumflex/right coronary artery distribution. Hemostasis was quantified by measuring platelet function (aggregometry), chest tube output, thrombolysis in myocardial infarction bleeding score (%hematocrit change at 24 hours), and transfusion requirements. The rate of mortality and major morbidity at 30 days was defined according to The Society of Thoracic Surgeons criteria. Estimated glomerular filtration rate (normalized to baseline levels) was determined daily until discharge.
The OP-MVST versus MVST-PA groups had similar risk factors at baseline and risks of composite morbidity/mortality at 30 days. However, renal failure was significantly increased after OP-MVST (10.87 vs 0%, P = 0.05), and MVST-PA affected hemostasis as evidenced by inhibition of platelet function (latency to response on aggregometry, 29.9 vs 17.9 seconds; P = 0.04) and higher transfusion requirement (2.31 vs 0.85 units of red blood cells/patient, P = 0.04; 55.6% vs 34.8% transfused; P = 0.059). However, 24-hour chest tube output was similar (645 vs 750 mL; P = 0.53).
In comparison with a completely off-pump strategy, use of cardiopulmonary bypass to assist MVST reduced the risk of renal dysfunction with only modest tradeoffs in other morbidities, for example, altered coagulation and higher transfusion requirements. These data justify further study of the effect of MVST-PA on renal complications.
Innovations Technology and Techniques in Cardiothoracic and Vascular Surgery 05/2012; 7(3):180-6.
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ABSTRACT: Endoscopic vein harvesting (EVH) is the standard of care for coronary artery bypass grafting (CABG) in the United States, but recent comparisons with open harvesting suggest that conduit quality and outcomes may be compromised in EVH. To test the hypothesis that problems with EVH may relate to its learning curve and conduit quality, we analyzed the quality and early function of conduits procured by technicians with varying experience in EVH.
Experienced (more than 900 cases, n=55 patients) and novice (less than 100 cases, n=30 patients) technicians performed EVH during CABG. Subsequently, optical coherence tomography (OCT) was used to examine the conduits for vascular injury, with segments identified as injured being further examined for gene expression with an array of genes related to tissue injury. Conduit diameter was measured intra- and postoperatively (day 5 and 6 months, respectively) with OCT and computed tomographic angiography.
Endoscopic vein harvesting by novice harvesters resulted in a greater number of discrete graft injuries and greater expression of tissue-injury genes than EVH done by experienced harvesters. Regression analysis revealed an association between shear stress and early dilation of engrafted vessels (positive remodeling) (R2=0.48, p<0.01). Injured veins showed blunted positive remodeling at 5 days after harvesting and a greater degree of late lumen loss at 6 months.
Under normal conditions, intraluminal shear stress leads to positive remodeling of vein grafts during the first postoperative week. Injury to conduits, a frequent sequela of the learning curve for EVH, was a predictor of early graft failure and of blunted positive remodeling and greater negative remodeling of endoscopically harvested vein grafts. Given the current annual volume of cases in which EVH is used, rigorous monitoring of the learning curve for this procedure represents an important and unrecognized issue in public health.
The Annals of thoracic surgery 01/2012; 93(1):11-7; discussion 17-8. · 3.74 Impact Factor
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Expert Review of Medical Devices 03/2010; 7(2):165-8. · 2.63 Impact Factor
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ABSTRACT: Off-pump coronary artery bypass (OPCAB) surgery is associated with a hypercoagulable state in which the platelet thrombin receptor, protease-activated receptor-1 (PAR-1), helps propagate a thrombin burst within saphenous vein grafts. Aprotinin, used in cardiothoracic surgery mainly for its antifibrinolytic properties, also spares platelet PAR-1 activation due to thrombin. We hypothesized that this PAR-1 antagonistic property provides an antithrombotic benefit during OPCAB surgery.
Patients were randomly assigned to receive saline (n = 38) or a modified full-dose regimen of aprotinin (n = 37) IV during OPCAB surgery. Blood sampled perioperatively from the coronary sinus, skin wounds, and systemic circulation was analyzed to test coagulation and platelet function. Major adverse cardiovascular events were monitored by obtaining troponin I at 24 h (myocardial infarction), predischarge computed tomography angiography (vein graft thrombosis), and by clinical examination for stroke.
Coronary sinus blood obtained immediately after OPCAB surgery showed significantly less activation in the aprotinin group, as judged by reduced formation of platelet-leukocyte conjugates (P < 0.02) and platelet-derived microparticles (P < 0.05). The aprotinin group showed inhibition of platelet aggregation induced by thrombin (P = 0.007) but not adenosine diphosphate. Thrombin generation, defined by F1.2 levels, was significantly reduced by aprotinin in the coronary sinus but not in skin wound incisions. Major adverse cardiovascular events were significantly reduced in aprotinin-treated patients (5.4% vs 29.7%, P < 0.05). Aprotinin also demonstrated antifibrinolytic properties through diminished red blood cell transfusion (P < 0.04) and reduced blood loss postoperatively (603 +/- 330 vs 810 +/- 415 mL, P < 0.004).
This study demonstrates that aprotinin protects patients undergoing OPCAB surgery from a hypercoagulable state by diminishing thrombin-induced platelet activation and thrombin generation within saphenous vein grafts, while maintaining systemic hemostatic and antifibrinolytic benefits. These results support further investigation of aprotinin and other PAR-1 antagonists in OPCAB surgery.
Anesthesia and analgesia 11/2009; 109(5):1387-94. · 3.08 Impact Factor
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ABSTRACT: Long-term success in ventricular assist device (VAD) recipients is limited by thromboembolic events, the prediction of which remains elusive. We evaluated the predictive value of aspirin hyporesponsiveness and markers of coagulation and fibrinolysis.
We prospectively enrolled patients scheduled to undergo VAD implantation between June 2004 and March 2006. Once before surgery, daily during hospitalization, and weekly after discharge we assessed platelet function, measured prothrombin activation fragment 1.2 (F1.2) and plasminogen activator inhibitor-1 (PAI-1) concentrations, and evaluated aspirin hyporesponsiveness by whole-blood aggregometry and thromboelastography. All patients received 325 mg oral aspirin daily from at least 7 days before VAD implantation. Follow-up continued until heart transplantation, death or closure of the database.
We included 26 patients (median follow-up 315 days, range 9-833 days). In eight (31%) patients, 14 thromboembolic events occurred at a median of 42 (interquartile range 26-131) days. Only six (43%) events based on whole-blood aggregometry and one (7%) based on thromboelastography coincided with aspirin hyporesponsiveness. Within-patient variability was high for both tests (59% and 567%, respectively). Compared with levels before surgery, PAI-1 concentrations were raised for up to 45 days (P <0.0001) and those of F1.2 for up to 3 days (P = 0.0001) after VAD implantation. PAI-1 and F1.2 levels did not rise significantly further before thromboembolic events.
Aspirin hyporesponsiveness was not associated with raised risk of future clinical thromboembolic events after VAD implantation. Impaired fibrinolysis, demonstrated by raised PAI-1 concentrations, might, however, indicate a predisposition to such events early after surgery.
Nature Clinical Practice Cardiovascular Medicine 03/2009; 6(2):147-57. · 7.04 Impact Factor
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ABSTRACT: Vasospasm is the primary obstacle to widespread adoption of the radial artery as a conduit in coronary artery bypass grafting. We used optical coherence tomography, a catheter-based intravascular imaging modality, to measure the degree of radial artery spasm induced by means of harvest with electrocautery or a harmonic scalpel in patients undergoing coronary artery bypass grafting.
Radial arteries were harvested from 44 consecutive patients with a harmonic scalpel (n = 15) or electrocautery (n = 29). Vessels were imaged before harvesting and after removal from the arm, with saphenous vein tracts serving as internal controls. Optical coherence tomographic findings for the degree of harvesting-induced injury were validated against histologic measures.
Optical coherence tomographic measures of endovascular dimensions and injury correlated strongly with histologic findings. Mean luminal volume, a measure of vasospasm, decreased significantly less after harvesting with a harmonic scalpel (9% +/- 7%) than with electrocautery (35% +/- 6%, P = .015). Completely intact intima was present in 11 (73%) of 15 radial arteries harvested with a harmonic scalpel (73%) compared with 9 of 29 arteries harvested by means of electrocautery (31%, P = .011). Intraoperative flow measurements and patency rates at 5 days postoperatively were not significantly different among groups.
Optical coherence tomography provides a level of speed and accuracy for quantifying endothelial injury and vasospasm that has not been described for any other modality, suggesting potential as an intraoperative quality assurance tool. Our optical coherence tomographic findings suggest that the harmonic scalpel induces less spasm and intimal injury compared with electrocautery.
The Journal of thoracic and cardiovascular surgery 12/2008; 136(5):1302-8. · 3.41 Impact Factor
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Emile N Brown,
Nicholas S Burris,
Zachary N Kon,
Michael C Grant,
Philip S Brazio,
Chenyang Xu,
Patrick Laird,
Junyen Gu,
Seeta Kallam,
Pranjal Desai, Robert S Poston
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ABSTRACT: The radial artery's (RA) tendency to spasm when used as a bypass graft may relate to features of the RA itself. We imaged RA conduits before and after CABG in order to characterize intimal abnormalities that might relate to the risk of spasm.
RA conduits from thirty-two CABG patients were imaged intraoperatively using catheter-based optical coherence tomography (OCT) and again on day 5 using 64-channel MDCT angiography. The change in luminal diameter between timepoints was measured in the proximal, mid and distal RA. "Spasm" was defined as focal or diffuse luminal narrowing to a diameter less than the target coronary. Lipid content in the RA was quantified by the degree of light attenuation on the OCT image.
Postoperative spasm was diagnosed in 18 of 32 (56%) RA grafts with the distal RA showing the most severe change versus the mid and proximal portions (-24.1+/-43.2% vs. -15.3+/-40.7%, -9.0+/-42.5% change in diameter respectively, p<0.01). The degree of attenuation of the OCT signal produced by the RA was strongly correlated with % diameter change (R=0.64, p=0.0005) and was significantly more pronounced in grafts with spasm versus no spasm (-1.97+/-0.61mm(-1) vs. -0.81+/-0.57mm(-1), p<0.0001). Histology confirmed lipid deposits in areas of RA with strong attenuation.
RA conduits otherwise considered acceptable for bypass grafting were often found by OCT imaging to have a substantial amount of lipid, which in turn strongly relates to the risk of postoperative spasm. Screening conduits based on characteristics of intimal quality may improve results following RA grafting.
Atherosclerosis 12/2008; 205(2):466-71. · 3.79 Impact Factor
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ABSTRACT: Minimally invasive coronary artery bypass grafting (miniCABG) decreases in-hospital morbidity versus traditional sternotomy CABG. We performed a prospective cohort study (NCT00481806) to assess the impact of miniCABG on costs and metrics that influence quality of life after hospital discharge.
One hundred consecutive miniCABG cases performed using internal mammary artery (IMA) grafting +/- coronary stenting were compared with a matched group of 100 sternotomy CABG patients using IMA and saphenous veins, both treating equivalent number of target coronaries (2.7 vs. 2.9), off-pump. We compared perioperative costs, time to return to work/normal activity, and risk of major adverse cardiac/cerebrovascular events (MACCE) at 1 year: myocardial infarction (elevated troponin or EKG changes), target vessel occlusion (CT angiography at 1 year), stroke, or death.
For miniCABG, robotic instruments and stents increased intraoperative costs; postoperative costs were decreased from significantly less intubation time (4.80 +/- 6.35 vs. 12.24 +/- 6.24 hours), hospital stay (3.77 +/- 1.51 vs. 6.38 +/- 2.23 days), and transfusion (0.16 +/- 0.37 vs. 1.37 +/- 1.35 U) leading to no significant differences in total costs. Undergoing miniCABG independently predicted earlier return to work after adjusting for confounders (t = -2.15; P = 0.04), whereas sternotomy CABG increased MACCE (HR, 3.9; 95% CI, 1.4-7.6), largely from lower target-vessel patency.
MiniCABG shortens patient recovery time, minimizes MACCE risk at 1 year, and showed superior quality and outcome metrics versus standard-of-care CABG. These findings occurred without increasing costs and with superior target vessel graft patency.
Annals of surgery 11/2008; 248(4):638-46. · 7.90 Impact Factor
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ABSTRACT: Multiple randomized trials have established a favorable safety profile for aprotinin use during cardiac surgery, but recent database analyses suggest an increased risk of adverse thrombotic events. Our group previously demonstrated that off-pump coronary artery bypass (OPCAB) is linked to a postoperative hypercoagulable state. In this study, we tested whether aprotinin influences thrombotic events after OPCAB.
Patients randomly received saline (n = 61) or aprotinin (2 x 10(6) kallikrein inhibiting units (KIU) loading dose, 0.5 x 10(6) KIU/hour [n = 59]) during OPCAB. Aprotinin levels (KIU/mL) were analyzed before, and 30 minutes (peak) and 4 hours after the loading dose. Estimated glomerular filtration rate (eGFR) was calculated daily based on Cockcroft equation with acute kidney injury (AKI) defined as eGFR less than 75% of baseline. Major adverse cardiac and cerebrovascular events (MACCE) were monitored during the first year, including acute graft failure by predischarge computed tomographic angiography.
Compared with placebo, the aprotinin group developed a significantly lower eGFR on day 3 (p < 0.006), but this difference resolved by day 5. Peak aprotinin level correlated with the degree of eGFR decline noted on day 3 (r = 0.56, p < 0.03) and independently predicted postoperative AKI (odds ratio 8.8, p < 0.008). The receiver operating characteristic analysis demonstrated that peak aprotinin level strongly predicts AKI (area under the curve = 0.86, 95% confidence interval 0.69 to 1.00). The percentage of patients reaching the composite MACCE endpoint was significantly reduced in the aprotinin versus placebo group (12 vs 34%, p = 0.01).
Compared with placebo, aprotinin use was associated with less MACCE but more AKI after OPCAB. The strong relationship between the peak aprotinin level and subsequent AKI suggests weight-based protocols for dosing aprotinin may reduce this risk.
The Annals of thoracic surgery 10/2008; 86(3):815-22; discussion 815-22. · 3.74 Impact Factor
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ABSTRACT: Cardiac transplantation remains the first choice for the surgical treatment of end stage heart failure. An inadequate supply of donor grafts that meet existing criteria has limited the application of this therapy to suitable candidates and increased interest in extended criteria donors. Although cold storage (CS) is a time-tested method for the preservation of hearts during the ex vivo transport interval, its disadvantages are highlighted in hearts from the extended criteria donor. In contrast, transport of high-risk hearts using hypothermic machine perfusion (MP) provides continuous support of aerobic metabolism and ongoing washout of metabolic byproducts. Perhaps more importantly, monitoring the organ's response to this intervention provides insight into the viability of a heart initially deemed as extended criteria. Obviously, ex vivo MP introduces challenges, such as ensuring homogeneous tissue perfusion and avoiding myocardial edema. Though numerous groups have experimented with this technology, the best perfusate and perfusion parameters needed to achieve optimal results remain unclear. In the present review, we outline the benefits of ex vivo MP with particular attention to how the challenges can be addressed in order to achieve the most consistent results in a large animal model of the ideal heart donor. We provide evidence that MP can be used to resuscitate and evaluate hearts from animal and human extended criteria donors, including the non-heart beating donor, which we feel is the most compelling argument for why this technology is likely to impact the donor pool.
European Journal of Cardio-Thoracic Surgery 09/2008; 34(2):318-25. · 2.55 Impact Factor
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Circulation 06/2008; 117(22):e473; author reply e476. · 14.74 Impact Factor
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ABSTRACT: Thoracic aortic injury remains a leading cause of death after blunt trauma. Thoracic aortic stents have the potential to treat aortic tears using a less invasive approach. We have accumulated the largest series of patients treated with blunt thoracic aortic injury over a 2-year period.
From July 2005 to present, 26 patients presenting with blunt aortic injury were treated with thoracic aortic endografting; these patients were retrospectively compared with the prior 26 patients presenting with similar aortic injury who were treated by open surgical repair. A Severity Characterization of Trauma score calculated for each patient predicts mortality based on severity of injury and degree of physiologic derangement on presentation.
Patients treated with endografting had a significantly shorter length of stay, less intraoperative blood loss, decreased 24-hour blood transfusion, and lower incidence of postoperative tracheostomy compared with patients undergoing open repair. Survival in both groups was similar despite a trend toward higher injury severity among patients treated with endografting.
This early experience suggests that aortic endografting may provide a safe and efficient treatment of aortic tears that cardiac surgeons can be successful in employing.
The Annals of thoracic surgery 06/2008; 85(5):1625-9; discussion 1629-30. · 3.74 Impact Factor
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ABSTRACT: Surgical and percutaneous coronary artery intervention revascularization are traditionally considered isolated options. A simultaneous hybrid approach may allow an opportunity to match the best strategy for a particular anatomic lesion. Concerns regarding safety and feasibility of such an approach exist. We examined the safety, feasibility, and early outcomes of a simultaneous hybrid revascularization strategy (minimally invasive direct coronary bypass grafting of the left anterior descending [LAD] artery and drug-eluting stent [DES] to non-LAD lesions) in 13 patients with multivessel coronary artery disease that underwent left internal mammary artery to LAD minimally invasive direct coronary bypass performed through a lateral thoracotomy, followed by stenting of non-LAD lesions, in a fluoroscopy-equipped operating room. Assessment of coagulation parameters was also undertaken. Inhospital and postdischarge outcomes of these patients were compared to a group of 26 propensity score matched parallel controls that underwent standard off-pump coronary artery bypass. Baseline characteristics were similar in both groups. All hybrid patients were successfully treated with DES and no inhospital mortality occurred in either group. Hybrid patients had a shorter length of stay (3.6 +/- 1.5 vs 6.3 +/- 2.3 days, P < .0001) and intubation times (0.5 +/- 1.3 vs 11.7 +/- 9.6 hours, P < .02). Despite aggressive anticoagulation and confirmed platelet inhibition, hybrid patients had less blood loss (581 +/- 402 vs 1242 +/- 941 mL, P < .05) and decreased transfusions (0.33 +/- 0.49 vs 1.47 +/- 1.53 U, P < .01). Six-month angiographic vessel patency and major adverse cardiac events were similar in the hybrid and off-pump coronary artery bypass groups. A simultaneous hybrid approach consisting of minimally invasive coronary artery bypass grafting with left internal mammary artery to LAD combined with revascularization of the remaining coronary targets using percutaneous coronary artery intervention with DES is a feasible option accomplished with acceptable clinical outcomes without increased bleeding risk.
American heart journal 04/2008; 155(4):661-7. · 4.65 Impact Factor
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Nicholas S Burris,
Emile N Brown,
Michael Grant,
Zachary N Kon,
Marc Gibber,
Junyen Gu,
Kimberly Schwartz,
Seeta Kallam,
Ashish Joshi,
Richard Vitali, Robert S Poston
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ABSTRACT: Concerns about intimal disruption and spasm have limited enthusiasm for endoscopic radial artery harvest (ERAH), although the risk of these problems after this procedure remains uncertain. Radial artery conduits were screened intraoperatively before and after ERAH vs open harvest using catheter-based high-resolution optical coherence tomography (OCT) imaging.
Twenty-four cadavers and 60 coronary artery bypass graft (CABG) patients scheduled to receive a RA graft underwent OCT imaging before (in situ) and after (ex vivo) open harvest or ERAH. Spasm was quantified by the percentage change in luminal volume between images. Intimal disruption was classified as minor or severe depending on whether the defect was confined to branch ostia or involved the luminal surface. Histology was used to confirm OCT findings.
Luminal volume significantly declined after harvest in all RAs from CABG patients, but there was no difference between groups: -43% +/- 29% vs -35% +/- 38% change after ERAH (n = 21) vs open harvest (n = 39; p = 0.342). Significantly more intimal injury was noted after ERAH vs open harvest (34/41 vs 9/43, intimal tears/total evaluated RAs, p < 0.0001). Most intimal injury was minor: only 2 tears involved the luminal surface of the RA (both after ERAH). Serial imaging in cadavers revealed that 86% of ostial tears occur in ERAH during the initial blunt dissection step using the endoscope.
Although branch injury is a pitfall of ERAH, OCT imaging documented that the quality of RA procured is acceptable and comparable with open harvest. Catheter-based OCT provides an important quality assurance tool for RA harvest.
The Annals of thoracic surgery 04/2008; 85(4):1271-7. · 3.74 Impact Factor
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ABSTRACT: Aspirin is the only drug proven to reduce saphenous vein graft (SVG) failure, but aspirin resistance (ASA-R) frequently occurs after off-pump coronary artery bypass grafting (OPCAB). The factors, mechanism, and best means for preventing and/or treating ASA-R have not been established. This study hypothesizes that thrombin production during OPCAB stimulates this acquired ASA-R.
A nonrandomized prospective cohort of 255 patients (n=465 SVG) who underwent OPCAB with varied use of aprotinin (21%) and different SVG preparation techniques (standard, 56% vs. low-pressure, 44%) was analyzed. A surplus SVG segment was obtained to assess endothelial integrity. ASA-R was determined at baseline, after surgery, and on Days 1 and 3 by three assays. The effects of aprotinin on thrombin responsiveness were analyzed by means of whole-blood aggregometry, SVG tissue factor (TF) activity, and transcardiac thrombin production (i.e., F1.2 levels in aorta versus coronary sinus). SVG patency was assessed on Day 5 with multichannel CT angiography.
ASA-R developed in 42 percent of patients after OPCAB. Multivariate analysis showed that ASA-R, endothelial integrity, and target size independently predicted early SVG failure. Aprotinin use was associated with: 1) reduced postoperative ASA-R (15%); 2) decreased platelet (PLT) response to thrombin; 3) reduced TF activity within SVG segments; 4) decreased transcardiac thrombin gradient; and 5) improved SVG patency.
ASA-R is a common post-OPCAB event whose frequency may be reduced by intraoperative use of aprotinin, possibly via TF and thrombin suppression. Improved perioperative PLT function after OPCAB may also inadvertently enhance the clinical relevance of these potential antithrombotic effects.
Transfusion 04/2008; 48(1 Suppl):39S-46S. · 3.22 Impact Factor
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Zachary N Kon,
Emile N Brown,
Richard Tran,
Ashish Joshi,
Barry Reicher,
Michael C Grant,
Seeta Kallam,
Nicholas Burris,
Ingrid Connerney,
David Zimrin, Robert S Poston
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ABSTRACT: Less-invasive options are available for surgical treatment of multivessel coronary artery disease. We hypothesized that stenting combined with grafting of the left anterior descending artery with the left internal thoracic artery through a minithoracotomy (hybrid procedure) would provide the best outcome.
Patients with equivalent numbers of coronary lesions (2.8 +/- 0.4) underwent either hybrid (n = 15) or off-pump coronary artery bypass through a sternotomy (n = 30). Early and 1-year outcomes were compared. Blood drawn from the aorta and coronary sinus immediately postoperatively was analyzed for activation of coagulation (prothrombin fragment 1.2 and activated Factor XII), myocardial injury (myoglobin), and inflammation (interleukin 8) by using an enzyme-linked immunosorbent assay. Target-vessel patency was determined by means of computed tomographic angiographic analysis.
The hybrid procedure was associated with significantly shorter lengths of intubation and stays in the intensive care unit and hospital and perioperative morbidity (P < .05). Intraoperative costs were increased but postoperative costs were reduced for the hybrid procedure compared with off-pump coronary artery bypass through a sternotomy. As a result, overall total costs were not significantly different between the groups. After adjusting for potential confounders, assignment to the hybrid group was an independent predictor of shortened time to return to work (t = -2.12, P = .04). Patient satisfaction after the hybrid procedure, as judged on a 6-point scale, was greater versus that after off-pump coronary artery bypass through a sternotomy. Finally, the hybrid procedure showed significantly reduced transcardiac gradients of markers of coagulation, myocardial injury, and inflammation and a trend toward significant improvement in target-vessel patency.
Perhaps because of reduced myocardial injury, inflammation, and activation of coagulation, patients undergoing the hybrid procedure had better perioperative outcomes and satisfaction, with excellent patency at 1 year's follow-up. These promising preliminary findings warrant further investigation of this procedure.
The Journal of thoracic and cardiovascular surgery 03/2008; 135(2):367-75. · 3.41 Impact Factor
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ABSTRACT: Accumulating evidence suggests that a hypercoagulable state influences early graft failure after off-pump coronary artery bypass (OPCAB). We hypothesized that regional myocardial ischemia caused by obligatory periods of coronary occlusion during OPCAB is an important trigger for this prothrombotic state.
Using a series of biomarkers, 60 consecutive patients undergoing OPCAB were monitored for myocardial injury (myoglobin), inflammation (TNF-alpha, IL-8) and thrombosis (thrombin generation-F1.2, contact activation pathway-FXII-a, platelet derived microparticles-via flow cytometry). The transcardiac gradients of these markers were determined by assaying both arterial and coronary sinus blood just after protamine administration. Intramyocardial pH was monitored continuously during coronary occlusion in a subset (N=30 grafts, 11 patients). The influence of management strategies affecting hemostasis (e.g. antiplatelet therapy, anti-fibrinolytics, peak activated clotting time (ACT) during heparinization) was analyzed.
Ischemic injury, depicted by the transcardiac myoglobin gradient, significantly correlated with intramyocardial acidosis during coronary occlusion (R=0.96, p<0.0001) and predicted the transcardiac gradients of TNF-alpha (R=0.83, p<0.001) and F1.2 (R=0.72, p<0.0001). Transcardiac F1.2 strongly correlated with TNF-alpha (R=0.73, p=0.01) and IL-8 (R=0.51, p=0.02). Patients receiving aprotinin (N=20) showed significantly lower transcardiac gradients for myoglobin (4.1+/-7.5% vs 72.9+/-108.8% change, p=0.002), F1.2 (31+/-37% vs 89+/-149%, p=0.03), FXII-a (2.6+/-4.1% vs 19.2+/-34%, p=0.04) and microparticles (7+/-3.9% vs 12.9+/-8%, p=0.01).
Strong correlations between myocardial ischemia and the transcardiac gradients of markers for inflammation and thrombosis suggest that even brief episodes of coronary occlusion in the beating heart may have pathophysiologic consequences. Aprotinin, but not other factors that influence the coagulation system, appears to mitigate this process during OPCAB.
European Journal of Cardio-Thoracic Surgery 03/2008; 33(2):215-21. · 2.55 Impact Factor
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Emile N Brown,
Zachary N Kon,
Richard Tran,
Nicholas S Burris,
Junyen Gu,
Patrick Laird,
Philip S Brazio,
Seeta Kallam,
Kimberly Schwartz,
Lisa Bechtel,
Ashish Joshi,
Shaosong Zhang, Robert S Poston
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ABSTRACT: Residual clot strands within the excised saphenous vein are an increasingly recognized sequela of endoscopic vein harvest. We hypothesized that endoscopic visualization facilitated by sealed carbon dioxide insufflation causes stagnation of blood within the saphenous vein. In the absence of prior heparin administration, this stasis provokes clot formation.
Forty consecutive patients having coronary artery bypass grafting underwent endoscopic vein harvest using sealed (Guidant VasoView, n = 30; Guidant Corp, Minneapolis, Minn) or open (Datascope ClearGlide, n = 10; Datascope Corp, Montvale, NJ) carbon dioxide insufflation followed by ex vivo assessment of intraluminal saphenous vein clot via optical coherence tomography. In the sealed carbon dioxide insufflation groups, clot formation was compared with (preheparinized, n = 20) and without (control, n = 10) heparin administration before endoscopic vein harvest, either at a fixed dose or titrated to an activated clotting time greater than 300 seconds. Risk factors for clot formation were assessed.
Residual saphenous vein clot was a universal finding in control veins (sealed carbon dioxide insufflation endoscopic vein harvest without preheparinization). At either dose used, heparin given before endoscopic vein harvest significantly decreased saphenous vein clot burden. A similar reduction in clot was observed when using open carbon dioxide insufflation endoscopic vein harvest without preheparinization. Intraoperative blood loss and blood product requirements were similar in all groups. Patient age and preoperative maximum amplitude of the thrombelastography tracing showed a linear correlation with saphenous vein clot volume.
By enabling the quantification of this issue as never before possible, optical coherence tomography screening revealed that intraluminal saphenous vein clot is frequently found after endoscopic vein harvest. Systemic heparinization before harvest or an open carbon dioxide endoscopic vein harvest system are benign changes in practice that can significantly lessen this complication.
The Journal of thoracic and cardiovascular surgery 12/2007; 134(5):1259-65. · 3.41 Impact Factor
