The morbidity and mortality of reoperation for coronary artery disease and analysis of late results with use of actuarial estimate of event-free interval

Repeat Coronary Bypass Surgery or Percutaneous Coronary Intervention After Previous Surgical Revascularization

OBJECTIVE

To assess long-term survival with repeat coronary artery bypass grafting (RCABG) or percutaneous coronary intervention (PCI) in patients with previous CABG.

METHODS

From January 1, 2000, through December 31, 2013, 1612 Mayo Clinic patients underwent RCABG (n=215) or PCI (n=1397) after previous CABG. The RCABG cohort was grouped by use of saphenous vein grafts only (n=75), or with additional arterial grafts (n=140); the PCI cohort by, bare metal stents (BMS; n=628), or drug-eluting stents (DES; n=769), and by the treated target into native coronary artery (n=943), bypass grafts only (n=338), or both (n=116). Multivariable regression and propensity score analysis (n=280 matched patients) were used.

RESULTS

In multivariable analysis, the 30-day mortality was increased in RCABG versus PCI patients (hazard ratio [HR], 5.32; 95%CI, 2.34-12.08; P<.001), but overall survival after 30 days improved with RCABG (HR, 0.72; 95% CI, 0.55-0.94; P=.01). Internal mammary arteries were used in 61% (129 of 215) of previous CABG patients and improved survival (HR, 0.82; 95% CI, 0.69-0.98; P=.03). Patients treated with drug-eluting stent had better 10-year survival (HR, 0.74; 95% CI, 0.59-0.91; P=.001) than those with bare metal stent alone. In matched patients, RCABG had improved late survival over PCI: 48% vs 33% (HR, 0.57; 95% CI, 0.35-0.91; P=.02). Compared with RCABG, patients with PCI involving bypass grafts (n=60) had increased late mortality (HR, 1.62; 95% CI, 1.10-2.37; P=.01), whereas those having PCI of native coronary arteries (n=80) did not (HR, 1.09; 95% CI, 0.75-1.59; P=.65).

CONCLUSION

RCABG is associated with improved long-term survival after previous CABG, especially compared with PCI involving bypass grafts.

Coronary bypass graft perforation during percutaneous intervention

INTRODUCTION

Coronary artery bypass grafts are prone to accelerated atherosclerosis and as such graft stenosis is frequently encountered in clinical practice. Complications specific to graft- PCI include no-reflow, distal embolization, stent restenosis and thrombosis. Graft perforation during PCI is a rare coomplication of the procedure. Published literature on the predictors of perforation and management strategy remains limited to anecdotal cases.

METHOD

In this review we collected data on all cases of graft perforations reported in PubMed/Medline from 1987 to 2015.

RESULT

37 cases of graft perforation were reported. High risk grafts for perforations included, old grafts (14±7.8years) with more than 80% luminal stenosis. Perforations were noted after use of different cardiac devices and included stent placement (30%, N=11), balloon angioplasty (36%, N=14), post-dilation with non complaint balloon (16%, N=6), guide wire perforation (1 case), post IVUS imaging (1 case) and one case after use of thrombus extraction device. Average stent diameter of 3.7±0.7 mm, average balloon pressure of 15.5±5 atm and 3 or more balloon inflations commonly resulted in graft perforation. 78% of cases reported class III perforation. Covered stent implantation was strongly associated with controlling acute bleed after graft perforation than prolonged balloon inflation (p=0.0001). Majority of cases reported using covered stents (81%). Average stent diameter of 3.9±0.7mm, average stent length of 18.5±6mm and the average deployment pressure of 14±2atm were reported to be effective in controlling the bleed. 95% of the patients did well post procedure and with prolonged hospitalization (8±4days). 24% of cases reported cardiac tamponade causing hemodynamic compromise including 2 peri-procedural deaths.

CONCLUSION

Graft perforation can be effectively treated with covered stent grafts with good immediate results, short term outcome and acceptable peri-procedural risks.

European clinical experience with REPEL-CV®

The objective of the feasibility study was to gain European clinical experiences with REPEL-CV for reducing postoperative adhesions in pediatric patients undergoing cardiovascular surgery. The pediatric patient population included patients requiring staged cardiovascular sternotomy procedures where it was anticipated that the second sternotomy procedure would be performed 2-8 months subsequent to the initial procedure. At the time of the second sternotomy procedure, 13 out of 15 (86.7%) patients had no Grade 3 ('severe') adhesions. The mean percentage of the investigational surgical site with severe adhesions was 11%. There were five serious adverse events. All were anticipated (identified in the protocol and the investigator's brochure) and were considered by the investigators to be 'definitely not related' to the study device. Based on the incidence and extent of 'severe' adhesions and the safety profile for REPEL-CV as demonstrated in this study, the effectiveness and safety of REPEL-CV have been further demonstrated.

Assessment of the Efficacy of the Bio-Absorbable Oxidized Regenerated Cellulose for Prevention of Post-Operative Pericardial Adhesion in the Rabbit Model

Pericardial adhesions complicate re-operative cardiac surgery and several attempts have been made to reduce adhesion formation. The efficacy of bio-absorbable oxidized regenerated cellulose in preventing post-operative pericardial adhesions was evaluated in the present study. Forty New Zealand white rabbits were divided into four groups of 10. In all rabbits an area of pericardium (2 × 2 cm) was excised. The wound was left open in groups 1 and 2 but replaced with bio-absorbable oxidized regenerated cellulose in groups 3 and 4. Rabbits in groups 1 and 3 were killed 3 weeks after surgery and those in groups 2 and 4 were killed at 6 weeks. Groups 1 and 2 showed more severe pericardial adhesions, more fibrous reaction and increased visibility of coronary vessels than groups 3 and 4, although there was no difference in inflammation. Light microscopy showed a mesothelium-like cell layer in groups 3 and 4. It is concluded that bio-absorbable oxidized regenerated cellulose may be suitable in patients receiving staged cardiac surgery and in those with a high probability of re-operation.

Postoperative Pericardial Adhesion Prevention Using Carbylan-SX in a Rabbit Model

INTRODUCTION

The presence of dense adhesions within the pericardial space complicates reoperative cardiac surgery. Prior attempts to reduce adhesion formation after primary cardiac surgery using medications or biomaterials have had variable success. Carbylan-SX (Carbylan Biosurgery Inc., Palo Alto, CA) is a hyaluronan-based biomaterial, which has been shown to be effective at reducing adhesions in a nonthoracic rat model. This study evaluates whether Carbylan-SX can effectively reduce postoperative adhesions within the pericardial cavity.

METHODS

Thirty-eight New Zealand white rabbits underwent a left lateral thoracotomy. A pericardiotomy was made and epicardial adhesions were induced on the anterior surface of the heart using a Dremel device (Racine, WI). The rabbits were divided into four groups: controls with abrasions only receiving no treatment (n=10), Carbylan-SX films (n=10), Carbylan-SX aerosolized hydrogel (n=10), and Seprafilm (n=8). The pericardial sac and chest were subsequently closed. Rabbits were sacrificed at a mean of 15 days. For histological analysis, each heart was divided into 12 separate 1 mm sections. Computer imaging software was used to measure the adhesion thickness and the mean of 12 random measurements for each animal was recorded and statistical analysis performed.

RESULTS

Histological analysis revealed all treatment groups to be significantly better than the control (2159 mum thickness, P<0.0001) at preventing adhesions. The Carbylan-SX film and Carbylan-SX aerosolized hydrogel both proved to be better at preventing adhesions than Seprafilm (Genzyme Corp., Cambridge, MA) with an average adhesion thickness of 454 and 577 microm, respectively, compared with 1319 microm for Seprafilm (P<0.0001 and P<0.0005, respectively). The Carbylan-SX film and Carbylan-SX aerosolized hydrogel were equally effective at preventing adhesion formation.

CONCLUSION

Carbylan-SX film and Carbylan-SX aerosolized crosslinkable hydrogel are equally effective methods of reducing postoperative pericardial adhesions within the pericardial cavity. Both the Carbylan-SX film and aerosolized hydrogel showed a significantly greater reduction in adhesions than Seprafilm. Clinical application of Carbylan-SX could have significant therapeutic implications in the future.

Prevention of Postoperative Pericardial Adhesions With a Novel Regenerative Collagen Sheet

BACKGROUND

Postoperative pericardial adhesions make a repeat sternotomy time-consuming and dangerous. The purpose of this study was to evaluate the efficacy of a new collagen pericardial substitute for preventing postoperative pericardial adhesions.

METHODS

Our absorbable substitute consists of three layers: a middle layer of aterocollagen between two layers of sodium hyaluronic acid and aterocollagen. In experiment 1 in this study, the patch, made of 9,000 filaments of aterocollagen fibers, (group 1; n = 5) was compared with a patch made of 6,000 filaments (group 2; n = 7), an expanded polytetrafluoroethylene sheet (group 3; n = 6), and a control group (group 4; n = 4). Subsequently, in experiment 2, the patch was examined at 4 weeks (n = 5), 12 weeks (n = 5), and 24 weeks (n = 4) after the operation by light microscopy and scanning electron microscopy.

RESULTS

The area of adhesion in group 1 was significantly less as compared with that in the other three groups, and the coronary vessels were clearly identifiable; on the other hand, all the animals in the control group showed moderate to severe adhesions, and the coronary vessels were completely obscured. In experiment 2, formation of a membranous tissue resembling the native pericardial membrane was observed in all animals, and the thickness of this membrane showed a marked increase by 24 weeks after the operation. Light microscopy and scanning electron microscopy also showed the formation of a mesothelium-like lining.

CONCLUSIONS

The new absorbable and regenerative collagen patch seemed to be biocompatible, and its use was associated with minimal adhesion formation and preserved coronary anatomy.

Myocardial Protection in Reoperative Coronary Artery Bypass Grafting:. Toward Decreasing Morbidity and Mortality

Redo coronary artery bypass grafting (CABG) is associated with higher morbidity and mortality when compared to first-time CABG. Myocardial infarction and dysfunction contribute significantly to the increased risk of redo CABG. Results of reoperative coronary surgery have gradually improved, largely because of improvements in myocardial protection techniques. In the present review we will highlight the principles of myocardial protection in redo CABG patients with an emphasis on retrograde cardioplegia.

Evaluation of a bioabsorable polylactide film in a large animal model for the reduction of retrosternal adhesions

OBJECTIVES

An adult pig model of retrosternal adhesion formation via an inferior hemisternotomy was used to evaluate the formation and development of pericardial and retrosternal adhesions, as well as adhesion reduction using two thicknesses of a bioabsorbable polylactide film.

MATERIALS AND METHODS

Twenty-five adult female pigs (70 kg) were allocated to either a control group or four different treatments using two thicknesses (0.02 or 0.05 mm) of a polylactide film. In each animal, the film was placed either inside the pericardium or inside and outside the pericardium.

RESULTS

All animals demonstrated adhesions between the posterior and lateral surfaces of the heart and pericardium. Thick fibrous retrosternal adhesions and pericardial adhesions were noted in the control animals with complete obliteration of the anatomical plane. The polylactide films preserved the anatomical planes and reduced the adhesion response.

CONCLUSIONS

A reproducible animal model was used to examine the formation and reduction of retrosternal and pericardial adhesions. A polylactide film placed inside the pericardium or between the heart and sternum was able to limit adhesion formation and maintain the anatomical planes, which would facilitate reentry.

Randomized study to compare balloon angioplasty and elective stent implantation in venous bypass grafts: the Venestent study

The aim of the study was to compare acute and long-term angiographic and clinical outcome of balloon angioplasty and elective stenting in de novo lesions in the body of a saphenous vein graft (SVG). A total of 150 patients, with de novo lesions in SVG, were randomly assigned to balloon angioplasty or elective Wiktor I stent implantation. The angiographic restenosis rate at 6-month follow-up was 32.8% in the balloon group and 19.1% in the stent group (P = 0.069). At 1-year follow-up, target vessel revascularization rate was 31.4% vs. 14.5% (P < 0.05), and event-free survival was 60.0% vs. 76.3% (P < 0.05) for the balloon and stent group, respectively. Elective stent implantation in de novo SVG lesions is associated with a significant lower target vessel revascularization rate and a significant higher event-free survival at 1-year follow-up as compared to balloon angioplasty.

Next-Generation HydroGel Films as Tissue Sealants and Adhesion Barriers

BACKGROUND

The development of conveniently sprayed, tissue-adherent, inert hydrogel films has made possible the creation of novel products that can serve a dual function, as a surgical sealant to achieve immediate hemostasis, and as a barrier to prevent adhesion formation over time.

METHODS

A sprayable, in situ formed absorbable hydrogel film was evaluated as a tissue sealant in a heparinized canine carotid artery graft model. PTFE grafts with leaking end-to-side anastomoses were treated with the synthetic sealant, and hemostasis was evaluated upon restoration of blood flow. Also, the hydrogel films were evaluated as an adhesion barrier in a rabbit pericardial abrasion model.

RESULTS

The sprayable, in situ forming hydrogel film was shown to immediately seal carotid-PTFE anastomoses in six of six applications. Hydrogel application in a rabbit pericardial abrasion model resulted in a statistically significant reduction in the number and tenacity of adhesions.

CONCLUSIONS

This novel in situ formed sprayable hydrogel film has demonstrated a dual function as an effective tissue sealant and as an adhesion barrier in cardiovascular preclinical models. These next generation synthetic biomaterials are currently undergoing clinical investigations.

Coronary reoperations: recurrence of angina and clinical outcome with and without cardiopulmonary bypass

BACKGROUND

We compared our experience of minimal tissue dissection and target vessel revascularization without cardiopulmonary bypass (CPB) with the standard procedure of total dissection of the heart and complete revascularization with CPB in patients who had elective reoperative coronary artery bypass grafting (redo-CABG).

METHODS

We analyzed recurrence of angina and clinical outcome in 118 patients who had elective redo-CABG between January 1995 and April 2002. Seventy-four patients had redo-CABG with CPB, and 44 patients had redo-CABG without CPB.

RESULTS

Perioperative outcome was comparable with regard to morbidity and mortality rates. At follow-up, the mean Canadian Cardiovascular Society score was 1.3 +/- 0.6 in patients who had redo-CABG with CPB and 1.7 +/- 0.8 in patients who had redo-CABG without CPB (p = 0.02). At follow-up, patients who had redo-CABG without CPB had a higher rate of recurrence of angina (log rank = 0.001) and higher use of nitrates (p = 0.015). Target vessel revascularization was an independent predictor of recurrence of angina in younger patients (< 75 years; p = 0.012) but not in the elderly (> or = 75 years; p = 0.142).

CONCLUSIONS

In elective redo-CABG patients, minimal tissue dissection and target vessel revascularization without cardiopulmonary bypass did not add significant benefit with regard to perioperative morbidity and mortality. The unsatisfactory relief of symptoms does not seem to justify target vessel revascularization by a less invasive approach. Therefore, this technique should be offered exclusively to patients at high risk with complete revascularization using CPB, such as the elderly.

Risk assessment of slow or no-reflow phenomenon in aortocoronary vein graft percutaneous intervention

Slow or no-reflow phenomenon (SNR) complicates 10%-15% of cases of percutaneous intervention (PCI) in aortocoronary saphenous vein grafts (SVG). At present, there are no uniform, effective strategies to predict or prevent this common and potentially serious complication. The purpose of our study was to characterize variables correlated with the risk of SNR in SVG PCI in the era of stenting and glycoprotein IIb/IIIa receptor inhibitors. We identified 2,898 consecutive patients who had PCI, of whom 163 underwent PCI of at least one SVG. The clinical and angiographic characteristics of patients who developed SNR (SNR group) were compared with those who did not (no-SNR group). A total of 23 patients experienced SNR and 140 did not. Using a stepwise multivariate logistic regression analysis, four independent predictors for SNR were detected: probable thrombus (OR 6.9; 95% CI, 2.1-23.9; P = 0.001), acute coronary syndromes (OR 6.4; 95% CI, 2.0-25.3; P = 0.003), degenerated vein graft (OR 5.2; 95% CI, 1.7-16.6; P = 0.003), and ulcer (OR 3.4; 95% CI, 0.99-11.6; P = 0.04). The risk of developing SNR could be estimated according to the number of predictors found: low-grade risk (1%-10%) if < or = one variable was present, moderate risk (20%-40%) if two variables were present, and high risk (60%-90%) if three or more variables were present. We identified and quantified current risk factors for SNR and concluded that the risk of developing SNR during PCI in SVG can be predicted by simple clinical and angiographic variables obtained before PCI. This information may be useful when the risk of PCI has to be balanced against alternative strategies such as medical therapy or redo-bypass surgery or in the selection of those patients that will most benefit from the use of protection devices during PCI.

Are we making progress with percutaneous saphenous vein graft treatment? A comparison of 1990 to 1994 and 1995 to 1998 results

OBJECTIVES

We sought to determine whether strategies to reduce procedural distal embolization and late repeat revascularization have resulted in more favorable outcomes after saphenous vein graft (SVG) angioplasty.

BACKGROUND

Angioplasty of SVG lesions has been associated with frequent procedural and late cardiac events. Therefore, evolving strategies have been attempted to improve outcomes after SVG angioplasty.

METHODS

We compared our earlier experience (1990 to 1994) of 1,055 patients with 1,412 SVG lesions with a recent group (1995 to 1998) of 964 patients with 1,315 lesions.

RESULTS

Baseline characteristics were similar between the groups. However, there were significantly more unfavorable lesion characteristics (older, longer and significantly more degenerated SVGs) in the recent series. Between the two periods, there was decreased use ofatheroablative devices, whereas stent use increased. The procedural success rates (96.6% vs. 96.1%) were similar. However, one-year outcome (event-free survival) was significantly improved in the more recent experience (70.7% vs. 59.1%, p < 0.0001), especially late mortality (6.1% vs. 11.3%, p < 0.0001). Multivariate analysis showed stent use to be the only protective variable for both periods.

CONCLUSIONS

This study shows that despite higher risk lesions, strategies to reduce distal embolization have maintained high procedural success. Late cardiac events, including mortality, have also been substantially reduced.

Short-term outcome of stent implantation in saphenous vein grafts: predictors of distal embolization and restenosis

The present study, which aimed to determine the predictors of distal embolization and restenosis after stenting for vein graft disease, retrospectively analyzed 51 consecutive patients who underwent stent implantation for diseased saphenous vein grafts. Follow-up angiography was performed 6 months after the procedure and the clinical and angiographic variables were analyzed by multivariate logistic regression to determine the predictors of distal embolization and restenosis. Initial clinical success was achieved in 49 patients, 44 of whom underwent follow-up angiography and were enrolled in the retrospective analysis. Distal embolization occurred in 6 grafts (13.6%). Multivariate analysis showed that the lesion length and the total cholesterol level were independent predictors of distal embolization. Angiographic restenosis occurred in 13 (26.5%) of 49 lesions. The minimum luminal diameter and the percent diameter stenosis after stenting were associated with the occurrence of restenosis. Multivariate analysis of lesions located in the graft body identified graft age as an independent predictor of restenosis. Distal embolization can occur after vein graft stenting, especially in patients with hypercholesterolemia and diffuse stenosis. The post-stenting minimum luminal diameter and the percent diameter stenosis are predictors of restenosis. In particular, graft age is associated with the restenosis of graft body lesions.

Procedural results and intermediate clinical outcomes after multiple saphenous vein graft stenting

OBJECTIVES

We evaluated the early and mid-term (18-month) clinical events in a consecutive series of patients undergoing a nonstaged multiple saphenous vein grafting (SVG) intervention with stents as compared with a single SVG stent procedure.

BACKGROUND

Saphenous vein graft angioplasty has been limited by high rates of distal embolization, myocardial infarction, restenosis and late mortality. It is unknown whether stenting of multiple, different SVGs at the same setting is associated with higher risk.

METHODS

We evaluated in-hospital and mid-term clinical outcomes (death, Q wave myocardial infarction [MI] and repeat revascularization rates up to 18 months) in 70 consecutive patients treated with coronary stents in 2 (93% of patients) or 3 SVGs, as compared with 649 patients undergoing stenting of a single SVG between January 1, 1994 and December 31, 1997.

RESULTS

Overall procedural success was obtained in 97% of patients with 2 or 3 SVGs and 97% of patients with a single SVG (p = 0.94). Procedural complications were also similar (2.8% for multiple SVGs vs. 2.7% for a single SVG, p = 0.94). There was a higher prevalence of periprocedural non-Q wave MI (28% vs. 16%, p = 0.009) in the multiple SVG group. During follow-up (18 months), target lesion revascularization was 11% in multiple SVG and 15% in single SVG interventions (p = 0.19), and repeat revascularization (calculated per treated patient) was also similar for both groups (19% vs. 18%, p = 0.94). There was no difference in death (5.6% vs. 5.3%, p = 0.92) and Q wave MI rate (4.3% vs. 2.9%, p = 0.55) after the multiple SVG intervention. Overall cardiac event-free survival was similar for both groups (62% vs. 60%, p = 0.75). The study was powered to detect a clinically meaningful difference of 10% in mortality; smaller differences could not be evaluated on the basis of this sample size.

CONCLUSIONS

Simultaneous stenting of multiple SVGs in carefully selected patients has similar in-hospital procedural success and major complications rates, as well as mid-term (18-month) clinical outcomes, as compared with single SVG stenting. Thus, multiple SVG interventions using stents may be a viable revascularization strategy for carefully selected patients and suitable lesions in multiple SVG disease.

Catastrophic hemorrhage on sternal reentry: still a dreaded complication?

BACKGROUND

To define the incidence of catastrophic hemorrhage (CH) during reoperations, the experience of the University of New Mexico was reviewed and compared with the practice of surgeons contacted by questionnaire.

METHODS

At the University of New Mexico, 610 reoperations were reviewed and 210 deemed high risk because of multiple reoperation, aneurysm, patent grafts, chamber's enlargement, conduit or previous mediastinitis. In the questionnaire, we asked about reentry technique, occurrence and outcome of CH, and precautions for high-risk patients.

RESULTS

At the University of New Mexico there were 4 CH with 1 death, and in the questionnaire there were 2,046 CH with 392 deaths. Our rate per surgeon was lower than that of the questionnaire. Rate of CH according to the saw was 2.09 for reciprocating, 2.0 for sagittal, and 1.74 for stryker in the questionnaire. Our rate was lower (0.65) with a micro sagittal saw. High-risk category predicted CH during sternotomy (p = 0.01) but only conduit (p = 0.005) was significant by univariate analysis.

CONCLUSIONS

The risk of CH could be as high as 1%. The sagittal micro oscillating saw is the safest reported to date. Presence of a conduit increases the risk by 2.5 fold.

Reduction of retrosternal and pericardial adhesions with rapidly resorbable polymer films

BACKGROUND

The formation of postoperative cardiac adhesions makes a repeat sternotomy time consuming and dangerous. Many attempts have been made to solve this problem by using either drugs to inhibit fibrinolytic activity or different types of pericardial substitutes. The results have not been satisfactory.

METHODS

The efficacy of bioresorbable film prototypes made of polyethylene glycol (EO) and polylactic acid (LA) (EO/LA = 1.5, 2.5, and 3.0) in the prevention of adhesions after cardiac operations in canine models was tested. After desiccation and abrasion of the epicardium, a transparent bioresorbable film was placed over the heart. The pericardium was closed to allow intrapericardial adhesions (n = 32) or left open and attached to the chest wall to induce retrosternal adhesions (n = 17). Postoperative recovery was similar among the groups. Retrosternal and pericardial adhesions were evaluated at necropsy 3 weeks later by assessing area, tenacity, and density of the adhesions.

RESULTS

In the control dogs, tenacious, dense adhesions were observed. In contrast, adhesion formation was reduced at all sites covered by the films. The bioresorbable films were efficacious in the reduction of adhesion formation between epicardium and pericardium or between epicardium and sternum after cardiac operation. The EO/LA 1.5 film most effectively prevented the early adhesions.

CONCLUSIONS

The bioresorbable films (EO/LA = 1.5, 2.5, and 3.0) significantly reduced adhesion formation, with EO/LA = 1.5 (Repel CV) being optimal. As the barrier was rapidly resorbed, the capsule formation induced by permanent barriers was avoided.

Risk of distal embolization and infarction with transluminal extraction atherectomy in saphenous vein grafts and native coronary arteries. NACI Investigators. New Approaches to Coronary Interventions

Lower success rates have been reported when treating high-risk lesions in saphenous vein grafts (SVGs) and native coronary arteries with balloon angioplasty. The transluminal extraction atherectomy catheter (TEC) has been proposed to reduce the incidence of distal embolization (DE) in subsets of high-risk lesions. To define the utility of TEC in reducing the incidence of DE, all patients who were enrolled in the New Approaches to Coronary Interventions (NACI) Registry and had TEC planned as the sole treatment were studied (329 patients with 381 lesions). Of the lesions treated, 75.9% were in SVGs; 37.5% were thrombotic; and 15% were total occlusions. Adjunctive percutaneous transluminal coronary angioplasty (PTCA) was performed in 87.4% of lesions. Multivariate predictors of DE were: noncardiac disease, stand alone TEC, thrombus, and larger vessel size. DE was associated with an 18.5% in-hospital mortality vs. 3.0% without DE (P < 0.01) and a 25.9% MI rate vs. 5.0% without DE (P < 0.01). In conclusion, in this high-risk subset of patients, TEC is associated with an 8.3% incidence of DE with thrombotic and SVGs lesions. DE associated with TEC appears to carry high morbidity and mortality. Additional techniques to control DE are needed to reduce the frequency of complications in these patients.

Long-term follow-up after coronary artery bypass grafting reoperation

BACKGROUND

Coronary artery bypass grafting (CABG) reoperation is being performed with increasing frequency.

OBJECTIVE

To determine the clinical outcome and the long-term results of a second CABG.

SETTING

An 1100-bed urban university-affiliated hospital.

DESIGN

Retrieval of data on selected parameters from medical records before surgery and prospective follow-up afterwards.

PATIENTS AND METHODS

We studied the outcomes of 498 consecutive patients who underwent CABG reoperation in our institution from January 1978 to December 1989 and who were followed postoperatively. Their perioperative mortality, morbidity, and long-term follow-up results were re-evaluated. The end points of the study were December 1997, 15 years of follow-up, or the patient's death.

RESULTS

The perioperative mortality rate was 3%. The cumulative survival rates were 90.1%, 74%, and 63.4% at the 5-year, 10-year, and 15-year follow-ups, respectively. The cardiac event-free survival rates were 91.5%, 83.4%, and 67.8% at the 5-year, 10-year, and 15-year follow-ups, respectively. The risk factors adversely affecting long-term survival were advanced age, hypertension, and a low left ventricular ejection fraction (LVEF).

CONCLUSIONS

The long-term results of cumulative survival and cardiac event-free survival in patients who underwent CABG reoperation are good. Although this reoperation is safe overall, advanced age, hypertension, and a decreased LVEF significantly increase the surgical risk.

Prevention of retrosternal adhesion formation in a rabbit model using bioresorbable films of polyethylene glycol and polylactic acid

The purpose of this study was to test the efficacy of three bioresorbable films of polyethylene glycol (EO) and polylactic acid (LA) (EO/LA = 1.5, 2.5, and 3.0) in the prevention of adhesion formation between the epicardium and the sternum (retrosternal adhesions) in a rabbit model. Retrosternal adhesions were generated by sternotomy, pericardiotomy, and abrasion of the anterior epicardium. The adhesion barrier was placed between the epicardium and the sternum and sutured to the edge of the pericardium. Epicardial adhesions were evaluated 14-20 days later by assessing the area of the epicardium covered by adhesions. In the control rabbits, tenacious adhesions were observed between sternum and the central portion of epicardium (portion exposed through the pericardiotomy) which were difficult to dissect. When a bioresorbable film was placed over the pericardium, adhesion formation at the central strip of the epicardium (area between the sternum and the epicardium exposed through the pericardium) could be reduced or prevented. At this site, the areas of adhesion formation were 0% (EO/LA = 1.5), 8.4 +/- 2.8% (EO/LA = 2.5), and 5.6 +/- 4.7% (EO/LA = 3.0) of the central strip, significantly less than that observed in the control group, 78.0 +/- 5.8% (P < 0.01). At the anterior left and right and posterior apex of the heart (sites where the film was not placed), there were no differences between control and treatment groups. The films were completely resorbed at the time of necropsy in group EO/LA = 2.5 and 3.0. Small pieces of film were observed in group EO/LA = 1.5. In conclusion, the bioresorbable films [EO/LA = 1.5 (REPEL-CV), 2.5, or 3.0] were efficacious in the reduction of retrosternal adhesions to the epicardium.

Early results using an ePTFE membrane for pericardial closure following coronary bypass grafting

A prospective randomized trial was conducted to evaluate the early efficacy and safety of the Gortex surgical membrane. Three hundred two patients (265 males, 37 females) undergoing isolated coronary bypass surgery were randomized to receive a Gortex membrane (GM = 138) or have the pericardium left open (complication [C] = 164). The groups did not differ in age, gender, urgency of procedure, length of procedure, or use of arterial grafts. Two deaths occurred in each group giving an overall mortality of 1.3%. Fifty-three (17%) patients experienced some complication (C = 34, 21%), GM = 19 (14%). Although the combined complication rate was higher in the control group, this was not statistically significant (chi2 = 2.51, p = 0.11). Postoperative ischemic events (C = 8, GM = 4) observed between the groups were not significant (chi2 = 0.05, p = 0.8), and no statistically significant difference was observed between the incidences of infections (C = 7, GM = 5) or mediastinal complications (C = 3, GM = 3). The Gortex surgical membrane can be used safely without increasing the risk of infection or mediastinal complications. The incidence of recurrent myocardial ischemia, a possible indicator of graft compression, was not higher following membrane implantation. Efficacy at injury prevention will need to be determined by a longitudinal follow-up study presently underway.

The coexistence of abdominal aortic aneurysm and advanced gastric cancer associated with recurrent angina after coronary artery bypass grafting

A 76-year-old man with abdominal aortic aneurysm (AAA) and concomitant gastric cancer, who had undergone coronary artery bypass grafting (CABG), presented with recurrent exertional angina. Both lesions, the AAA and advanced gastric cancer, exhibited an absolute indication for urgent surgery. Coronary revascularization with percutaneous transluminal coronary angioplasty (PTCA) was carried out successfully before abdominal surgery. A one-stage abdominal operation was performed safely. The need for coronary revascularization complicates the treatment strategy for these patients with associated coronary artery disease. PTCA is the best option, especially if the patient presents with recurrent angina after prior CABG.

Stent placement compared with balloon angioplasty for obstructed coronary bypass grafts. Saphenous Vein De Novo Trial Investigators

BACKGROUND

Treatment of stenosis in saphenous-vein grafts after coronary-artery bypass surgery is a difficult challenge. The purpose of this study was to compare the effects of stent placement with those of balloon angioplasty on clinical and angiographic outcomes in patients with obstructive disease of saphenous-vein grafts.

METHODS

A total of 220 patients with new lesions in aortocoronary-venous bypass grafts were randomly assigned to placement of Palmaz-Schatz stents or standard balloon angioplasty. Coronary angiography was performed during the index procedure and six months later.

RESULTS

As compared with the patients assigned to angioplasty, those assigned to stenting had a higher rate of procedural efficacy, defined as a reduction in stenosis to less than 50 percent of the vessel diameter without a major cardiac complication (92 percent vs. 69 percent, P<0.001), but they had more frequent hemorrhagic complications (17 percent vs. 5 percent, P<0.01). Patients in the stent group had a larger mean (+/-SD) increase in luminal diameter immediately after the procedure (1.92+/-0.30 mm, as compared with 1.21+/-0.37 mm in the angioplasty group; P<0.001) and a greater mean net gain in luminal diameter at six months (0.85+/-0.96 vs. 0.54+/-0.91 mm, P=0.002). Restenosis occurred in 37 percent of the patients in the stent group and in 46 percent of the patients in the angioplasty group (P=0.24). The outcome in terms of freedom from death, myocardial infarction, repeated bypass surgery, or revascularization of the target lesion was significantly better in the stent group (73 percent vs. 58 percent, P = 0.03).

CONCLUSIONS

As compared with balloon angioplasty, stenting of selected venous bypass-graft lesions resulted in superior procedural outcomes, a larger gain in luminal diameter, and a reduction in major cardiac events. However, there was no significant benefit in the rate of angiographic restenosis, which was the primary end point of the study.

Angioplasty followed by coronary stenting at the anastomotic site of saphenous vein bypass graft with the native vessel: a case that needs special procedural strategy

In this report we describe a case in which a saphenous vein graft stenosis at the site of anastomosis with the left anterior descending artery (LAD) was dilated with a special Controlled Angioplasty Technology (CAT) balloon, and then stented. Balloon angioplasty and stenting at the site of anastomosis represents a technical problem because of diameter discrepancy and needs special attention in order to avoid minor or major complications.

Short- and long-term outcome of narrowed saphenous vein bypass graft: a comparison of Palmaz-Schatz stent, directional coronary atherectomy, and balloon angioplasty

Percutaneous treatment of saphenous vein graft (SVG) stenosis has been established as an alternative to repeat coronary artery bypass grafting. Intracoronary Palmaz-Schatz stent (PSS) and directional coronary atherectomy (DCA) have been suggested to provide better short- and long-term results than balloon angioplasty. Records of 840 patients with 931 SVG lesions treated with PSS (121 patients, 132 lesions), DCA (103 patients, 107 lesions), and balloon angioplasty (616 patients, 692 lesions) were reviewed. Inhospital and long-term outcome were compared among treated groups. The groups had similar clinical and angiographic baseline characteristics except for higher previously dilated grafts in the stent group and graft location among devices. Stent placement was angiographically successful in 99%, DCA in 95%, and balloon angioplasty in 93% of the lesions (p = 0.03). Quantitative angiography revealed a larger lumen diameter after procedure after PSS (3.2 mm) and DCA (3.1 mm) compared with 2.4 mm after balloon angioplasty (p = 0.0001). Angiographic complications (abrupt closure, severe dissections, or distal embolization) were evident in eight (6.1%) lesions after PSS placement, in 17 (15.9%) after DCA, and in 61 (8.8%) after balloon angioplasty. Serious in-hospital clinical complications (death, emergency coronary artery bypass grafting, or Q-wave myocardial infarction) were similar among devices. Survival rates were similar among the groups (p = 0.15). Repeat revascularization at follow-up was reported in 58 (60.4%) of patients after PSS, in 48 (51.1%) after DCA, and in 280 (49.4%) after balloon angioplasty. Correlates of additional revascularization at follow-up were older grafts, calcific lesions, previously dilated grafts, longer lesions, and patients with lower ejection fractions (odds ratio 1.06, 1.34, 1.43, 1.04, and 1.01, respectively). Correlates of mortality rate at follow-up were older patients, patients with lower ejection fractions, and distal embolization (odds ratio 1.04, 1.04, and 1.92, respectively). These data suggest that in patents with SVG stenosis the initial success and morbidity rates are similar when comparing PSS and DCA with balloon angioplasty. Although a larger lumen is obtained with PSS and DCA, patients who underwent balloon angioplasty had similar rates of cardiac events and requirements for additional procedures at follow-up.

The impact of a short interval ( < or = 1 year) between primary and reoperative coronary artery bypass grafting procedures

Reoperative (redo) coronary artery bypass grafting is an efficient treatment for patients with progressive coronary artery disease and those with conduit failure. Previous studies have demonstrated that a short time interval between primary and redo coronary artery bypass grafting is associated with a significantly higher mortality rate. In the present report this particular group have been specifically evaluated. Between 1 January 1990 and 1 October 1994, 383 consecutive patients underwent redo coronary artery bypass grafting. Thirty-three patients (8.6%) were operated on at < or = 1 year (group 1) and 350 patients at > 1 year after the primary bypass (group II). The main indications for redo in group I were graft failure (58%), incomplete revascularization (39%) and progress of disease (3%); respective values in group II were 26% 15%, and 23%. In addition, 36% of patients in group II had combinations of complications. Patient characteristics did not differ between groups, except a higher incidence of insulin-dependent diabetes in group I (P < 0.05). There was a higher incidence of left main stem stenosis of > 70% in group I (P < 0.05). Group I patients had a longer aortic cross-clamping time and needed thromboendarterectomy and patching of coronary vessels more often than did those in group II (P < 0.05). The internal mammary artery had been more frequently used at the primary coronary artery bypass grafting in group I (P < 0.01). The overall mortality rate was 8.9%; that in group I was 18% and in group II, 8% (P < 0.05). There was a higher incidence of non-fatal myocardial infarction and a need for prolonged ventilatory support (> 24 h) in group I. Other postoperative complications did not differ. Significant risk factors for mortality in group I were preoperative Canadian Cardiovascular Society class > or = 3, unstable angina, need for urgent operation and left ventricular ejection fraction < 40%, and > or = 70% left main stem stenosis. In group II, the risk factors were: unstable angina, urgent operation, left ventricular ejection fraction < 40%, internal mammary artery not used at primary coronary artery bypass grafting and the need for coronary thromboendarterectomy. The 3-year survival and cardiac event-free survival did not differ between the groups. This study has confirmed that early redo coronary artery bypass grafting (< or = 1 year from primary bypass) is associated with an increased operative risk.

Coronary angioplasty versus repeat coronary artery bypass grafting for patients with previous bypass surgery

OBJECTIVES

We attempted to determine the relative risks and benefits of percutaneous transluminal coronary angioplasty (PTCA) and repeat coronary artery bypass grafting (re-CABG) in patients with previous coronary bypass surgery (CABG).

BACKGROUND

Due to an expanding population of patients with surgically treated coronary artery disease and the natural progression of atherosclerosis, an increasing number of patients with previous CABG require repeat revascularization procedures. Although there are randomized comparative data for CABG versus medical therapy and, more recently, versus PTCA, these studies have excluded patients with previous CABG.

METHODS

We retrospectively analyzed data from 632 patients with previous CABG who required either elective re-CABG (n = 164) or PTCA (n = 468) at a single center during 1987 through 1988. The PTCA and re-CABG groups were similar with respect to gender (83% vs. 85% male), age > 70 years (21% vs. 23%), mean left ventricular ejection fraction (46% vs. 48%), presence of class III or IV angina (70% vs. 63%) and three-vessel coronary artery disease (77% vs. 74%).

RESULTS

Complete revascularization was achieved in 38% of patients with PTCA and 92% of those with re-CABG (p < 0.0001). The in-hospital complication rates were significantly lower in the PTCA group: death (0.3% vs. 7.3%, p < 0.0001) and Q wave myocardial infarction (MI) (0.9% vs. 6.1%, p < 0.0001). Actuarial survival was equivalent at 1 year (PTCA 95% vs. re-CABG 91%) and 6 years (PTCA 74% vs. re-CABG 73%) of follow-up (p = 0.32). Both procedures resulted in equivalent event-free survival (freedom from dealth or Q wave MI) and relief of angina; however, the need for repeat percutaneous or surgical revascularization, or both, by 6 years was significantly higher in the PTCA group (PTCA 64% vs. re-CABG 8%, p < 0.0001). Multivariate analysis identified age > 70 years, left ventricular ejection fraction < 40%, unstable angina, number of diseased vessels and diabetes mellitus as independent correlates of mortality for the entire group.

CONCLUSIONS

In this nonrandomized series of patients with previous CABG requiring revascularization, an initial stategy of either PTCA or re-CABG resulted in equivalent overall survival, event-free survival and relief of angina. PTCA offers lower procedural morbidity and mortality risks, although it is associated with less complete revascularization and a greater need for subsequent revascularization procedures.

Long-term clinical outcome after stent implantation in saphenous vein grafts

OBJECTIVES

We sought to determine the role of stent implantation in vein grafts by evaluating the long-term clinical outcome and estimated event-free survival at 5 years in 62 patients and by comparing our data with those of other treatment modalities previously reported.

BACKGROUND

Patients with recurrent angina after coronary artery bypass graft surgery pose a problem. Stent implantation has been advocated in an effort to avoid repeat operation and to address the limitations of balloon angioplasty.

METHODS

Patients undergoing stenting of a vein graft were entered into a dedicated data base. They were screened for death, infarction, bypass surgery and repeat angioplasty. Procedure-related events were included in the follow-up analysis. Survival and event-free survival curves were constructed by the Kaplan Meier method.

RESULTS

A total of 93 stents (84 Wallstent and 9 Palmaz-Shatz) were implanted in 62 patients. During the in-hospital period seven patients (11%) sustained a major cardiac event: two deaths (3%), two myocardial infarctions (3%) and three urgent bypass surgeries (5%). The clinical success rate, therefore, was 89%. During the follow-up period (median 2.5 years, range 0 to 5.9), another five patients (8%) died, 14 (23%) sustained a myocardial infarction, 12 (20%) underwent bypass surgery, and 14 (23%) underwent angioplasty. The estimated 5-year survival and event-free survival rates (free from infarction, repeat surgery and repeat angioplasty) were (mean +/- SD) 83 +/- 5% (95% confidence interval [CI] 73% to 93%) and 30 +/- 7% (95% CI 16% to 44%), respectively.

CONCLUSIONS

The in-hospital outcome of patients who underwent stent implantation in a vein graft is acceptable, but the long-term clinical outcome is poor. It is unlikely that mechanical intervention alone will provide a satisfactory or definite answer for the patient with graft sclerosis over the long term.

Protection of the right internal mammary artery in the retrosternal position with stented grafts

One of the limiting factors for the use of the right internal mammary artery as a pedicle graft to the anterolateral vessels of the left coronary system is the necessary midline crossover and the close proximity to the sternum. In this setting, the right internal mammary artery pedicle is at increased risk of injury during sternal reentry and dissection. A technique is described where stented polytetrafluoroethylene grafts were used to shield right internal mammary artery pedicles. There were no operative deaths or polytetrafluoroethylene-related complications. The right internal mammary artery was patent with its target vessel well perfused in 6 restudied patients.

Clinical markers, management, and long-term follow-up of early ischemia after coronary artery bypass grafting

In summary, the occurrence of angina or myocardial infarction within 1 year after coronary bypass is associated with a high incidence of significant angiographic abnormalities. Early angiography is necessary to identify high-risk patients who could undergo revascularization. Patients with other markers of ischemia should have a noninvasive approach (stress imaging test) as initial evaluation, before coronary angiography is considered. When technically feasible, coronary angioplasty can be performed safely and with a high success rate. Repeat coronary bypass in this group of patients is associated with higher in-hospital complications. Patients with less compromised coronary anatomy can be treated medically with a good long-term outcome.

Determinants of operative mortality in reoperative coronary artery bypass grafting

Previously suggested risk factors for operative mortality in reoperative coronary artery bypass grafting are contradictory. Therefore, we analyzed our data of 622 patients who underwent reoperative bypass grafting from January 1986 through June 1993. Among these patients, 258 had saphenous vein grafts alone and 364 had internal mammary artery grafting, including unilateral (342 patients) and bilateral (22 patients) mammary artery grafting with or without additional saphenous vein grafting. Overall operative mortality was 11.4% for reoperation compared with only 3.6% for primary bypass grafting during the same time frame. To determine risk factors for mortality and the influence of internal mammary artery grafting on the outcome, we analyzed 82 variables (31 preoperative, 17 intraoperative, and 34 postoperative) by univariate analysis. Significant variables or the variables having a trend (p < 0.2) to be associated with the mortality were included in stepwise multiple logistic regression analyses. Two regression analyses were separately performed. Regression 1 only included preoperative and intraoperative variables whereas regression 2 included postoperative variables as well. The logistic regressions demonstrate that preoperative variables (low ejection fraction [p = 0.0002], old age [p = 0.003], female gender [p = 0.011], and history of arrhythmia [p = 0.023]), intraoperative variables (emergency operation [p = 0.0001] and long perfusion time [p = 0.0001]), and postoperative variables (complications) are independently associated with higher mortality. Unlike previously described results, aortic crossclamp time, route of cardioplegia, use of internal mammary artery, number of grafts, and year of operation are not associated with operative mortality. The identification of these risk factors may have important implications in further improvement of the results of reoperative coronary artery bypass grafting.

Immediate results and late outcomes after stent implantation in saphenous vein graft lesions: the multicenter U.S. Palmaz-Schatz stent experience. The Palmaz-Schatz Stent Study Group

OBJECTIVES

This study reports the multicenter registry experience evaluating the safety and efficacy of the Palmaz-Schatz stent in the treatment of saphenous vein graft disease.

BACKGROUND

Saphenous vein graft angioplasty is associated with frequent periprocedural complications and a high frequency of restenosis. Stent implantation has been shown to reduce restenosis, with improved long-term outcomes in the treatment of native coronary artery disease. Preliminary experience with stent placement in the treatment of saphenous vein graft lesions has been favorable.

METHODS

Twenty U.S. investigator sites enrolled a total of 589 symptomatic patients (624 lesions) for treatment of focal vein graft stenoses between January 1990 and April 1992. Follow-up angiography was performed at 6 months, and the clinical course of all study patients was prospectively collected at regular intervals for up to 12 months.

RESULTS

Stent delivery was successful in 98.8% of cases, and the procedural success rate was 97.1%. The lesion diameter stenosis decreased from 82 +/- 12% (mean +/- SD) before to 6.6 +/- 10.2% after treatment. Major in-hospital complications occurred in 17 patients (2.9%); stent thrombosis was found in 8 (1.4%); and major vascular or bleeding complications were noted in 83 (14.3%). Six-month angiographic follow-up revealed an overall restenosis rate (> or = 50% diameter stenosis) of 29.7%. Multivariate logistic regression analysis indicated that 1) restenotic lesions, 2) smaller reference vessel size, 3) history of diabetes mellitus, and 4) higher percent poststent diameter stenosis were independent predictors of restenosis. The 12-month actuarial event-free survival was 76.3%.

CONCLUSIONS

Stent implantation in patients with focal saphenous vein graft lesions can be achieved with a high rate of procedural success, acceptable major complications, reduced angiographic restenosis and favorable late clinical outcome compared with historical balloon angioplasty control series. The rigorous anticoagulation regimen after stent placement results in more frequent vascular and other bleeding complications. Future randomized studies comparing standard balloon angioplasty with stent implantation are warranted to properly assess the full impact of stent placement in the treatment of saphenous vein graft lesions.

Comparative results of transluminal extraction coronary atherectomy in saphenous vein graft lesions with and without thrombus

OBJECTIVES

The purpose of this retrospective study was to compare the results of transluminal extraction coronary atherectomy in saphenous vein graft lesions with and without angiographic thrombus.

BACKGROUND

Percutaneous interventions in lesions with thrombus are associated with reduced procedural success and increased risk of complications. Use of the transluminal extraction catheter, which cuts and aspirates atheroma and thrombus, has been advocated as a potential revascularization strategy for lesions with thrombus.

METHODS

Baseline patient characteristics, lesion morphology, immediate angiographic results, in-hospital complications and follow-up were prospectively entered into an interventional cardiology data base. The results of transluminal extraction coronary atherectomy in saphenous vein bypass grafts with angiographic thrombus were compared with results in similar grafts without angiographic thrombus.

RESULTS

Transluminal extraction coronary atherectomy was performed in 175 patients with 183 vein graft lesions, including 59 lesions (32%) with thrombus (Group 1) and 124 (68%) without thrombus (Group 2). Compared with lesions in Group 2, lesions in Group 1 were associated with a higher incidence of baseline total occlusion, diffuse disease and abnormal Thrombolysis in Myocardial Infarction (TIMI) grade flow (p < 0.05); more severe diameter stenosis at baseline, after atherectomy and after final angiography (p < 0.05); a lower rate of clinical success (69% vs. 88%, p < 0.01); and more angiographic and clinical complications, including no reflow (p < 0.05), vascular repair (p < 0.05) and Q wave myocardial infarction (p = 0.09).

CONCLUSIONS

In transluminal extraction coronary atherectomy of saphenous vein bypass grafts, the presence of thrombus is associated with more baseline lesion complexity, reduced clinical success and increased risk of no reflow, Q wave myocardial infarction and vascular repair.

Comparative analysis of saphenous vein bypass vs. native coronary artery balloon angioplasty: technical differences and angiographic response

To evaluate technical differences and angiographic response of saphenous vein bypass graft angioplasty in comparison to native coronary arteries, we retrospectively analyzed 54 patients undergoing this procedure at The Toronto Hospital between February 1988 and May 1993. These subjects were temporally matched to a cohort of successful native coronary angioplasties, with comparison of technical parameters, pre-existing qualitative/quantitative (Cardiac Measurement System) stenotic morphology, and angiographic response; including changes in minimum lumen diameter. Saphenous bypass graft angioplasty utilized larger balloons (CABG, 3.27 +/- 0.65 vs. native, 2.90 +/- 0.37 mm, P < .05), and higher inflation pressures (CABG, 10.1 +/- 3.7 vs. native, 8.8 +/- 2.5 atm, P < .05), although in a relative sense, balloon/artery ratios were similar (CABG, 1.09 +/- 0.20 vs. native, 1.03 +/- 0.15, pNS). Pre-procedural bypass graft lesions were more complex, with more frequent ACC/AHA type B1 lesions [CABG, 24/54 (44%) vs. native, 16/54 (30%), P < .05] and luminal thrombus [CABG, 17/54 (31%) vs. native, 6/54 (11%), P < .05]. Quantitative angiography revealed larger "reference" diameters within saphenous veins (CABG, 3.41 +/- 0.76 vs. native, 3.04 +/- 0.51 mm, P < .05), although minimum lumen diameter was less severe (CABG, 0.83 +/- 0.41 vs. native, 0.77 +/- 0.36, P < .05). In terms of balloon angioplasty response, greater improvement in luminal diameter was seen in bypass graft lesions (CABG, 1.55 +/- 0.53 vs. native, 1.32 +/- 0.44 mm, P < .05), with the largest changes within the "body" of the saphenous vein (ostial, 1.53 +/- 0.37; body, 1.68 +/- 0.50; anastomosis, 1.37 +/- 0.57 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

Transluminal extraction catheter for the treatment of diseased saphenous vein grafts: a multicenter experience

To evaluate the efficacy, safety, and long-term results of atherectomy using the Transluminal Extraction catheter (TEC), patients with diseased saphenous vein grafts were enrolled in a prospective nonrandomized trial. Patients were followed to hospital discharge for acute complications and underwent routine 6-mo reevaluation with repeat cardiac catheterization to assess restenosis. Atherectomy was performed on 650 graft lesions in 538 consecutive patients (male 81%; mean age 66 yr; range 37-81). Mean graft age was 8.3 yr; (range 0.3-20) with 85% of grafts > 3 yr of age. Complex lesion morphology included thrombus (28%), ulceration (13%), and eccentricity (50%). Lesion success was achieved in 606 lesions (93%) with clinical success in 479 patients (89%). Lesion success was achieved in 90% of thrombus containing lesions, 97% of ulcerated lesions, and 97% of grafts > 3 yr. Complications included nonfatal myocardial infarction in 4 (0.7%) of patients, emergency bypass surgery in 2 (0.41%), and in-hospital death in 17 patients (3.2%). Angiographic follow-up at 6 mo was obtained from 268 lesions in 227 patients. The overall lesion angiographic restenosis rate was 60%. TEC atherectomy can be performed in patients with diseased saphenous vein grafts with high primary success and low complication rates. It is suitable for use in aged grafts, particularly in the presence of thrombus and ulcerations, and may be superior to balloon angioplasty alone in this group of patients.

Clinical and angiographic outcome following implantation of the new Less Shortening Wallstent in aortocoronary vein grafts: introduction of a second generation stent in the clinical arena

One of the factors felt to have contributed to the high rate of stent occlusion in the European registry of the coronary Wallstent in the 1980s was the frequent deployment of more than one stent to cover the target lesion. This resulted from a high degree of shortening of the Wallstent upon expansion. To overcome this limitation the design of the Wallstent was modified to reduce the degree of shortening. We report the results of a study of the first patients to undergo implantation of the new Less Shortening Wallstent. Thirty-five Wallstents were electively deployed in aortocoronary vein grafts in 29 patients. Stent deployment was successful in 35 of 36 attempts in 30 lesions. In five of the 30 lesions, a second stent was required to cover the proximal portion of the lesion. Angiographic success (< 50% residual diameter stenosis as determined by off-line quantitative coronary angiography) was achieved in all 29 patients. During the in-hospital phase, no major adverse cardiac event occurred (reintervention, re-CABG, myocardial infarction, or death) and five patients had hemorrhagic complications. Following hospital discharge, one patient had a subacute stent occlusion associated with symptoms and elevated cardiac enzymes at 11 days, another patient had symptoms and elevated cardiac enzymes (CK 300 U/I) at 22 days with a patent stent, five patients required balloon angioplasty within the 6 month follow-up period (four for restenosis and one for stent occlusion), one patient underwent re-CABG for a native artery stenosis distal to the anastomosis of the patent stented vein graft.(ABSTRACT TRUNCATED AT 250 WORDS)

Reoperative coronary grafting: changing patient profiles, operative indications, techniques, and results

To assess the changing trends in patient profiles, operative indications and techniques, and their impact on the results of reoperative myocardial revascularization, we reviewed the records of 750 consecutive patients who had an isolated first reoperation for coronary artery disease at the Massachusetts General Hospital from 1977 to 1992. The patients were chronologically grouped into three equal cohorts of 250 patients. Our assessment over time revealed a significantly (p < 0.03) increased incidence of the following: older age, peripheral vascular disease, grafts at the first revascularization, longer operative interval, interval infarctions and angioplasties, and congestive heart failure and unstable angina requiring greater use of preoperative intraaortic balloon pumping. At catheterization significantly more left main coronary disease, lower ejection fractions, and more patent but diseased grafts were found. The reoperations were significantly done more urgently, with more grafts placed and a greater use of mammary artery grafting. Despite these increased risks over time, median postoperative hospital stay was significantly shortened (p < 0.001), though hospital mortality (5.3%) and perioperative myocardial infarction (6.3%) did not change significantly. Significant multivariate predictors of hospital death were nonelective operation, perioperative myocardial infarction, prior myocardial infarction, and mammary artery grafting at the initial operation.

Palmaz-Schatz stenting for treatment of focal vein graft stenosis: immediate results and long-term outcome

OBJECTIVES

This study aimed to evaluate the effectiveness of Palmaz-Schatz stenting for the treatment of saphenous vein graft stenoses.

BACKGROUND

Failure of saphenous vein grafts is a common cause of recurrent ischemia after coronary bypass surgery. A second bypass surgery carries more risk than the initial procedure, and balloon angioplasty of vein grafts has yielded disappointing results. It has been hoped that stenting might offer a better treatment option.

METHODS

We examined the results of stent placement in 200 saphenous bypass graft lesions consecutively treated with either coronary (n = 146) or biliary (n = 54) Palmaz-Schatz stents. Immediate outcome and clinical follow-up (median 15.5 months) were examined in all patients. To document angiographic outcome, a second angiography was performed at 3 to 6 months for the first 120 consecutively stented lesions and was successfully obtained for 94 (78%).

RESULTS

The mean graft age (+/- SD) was 8.7 +/- 4 years. Stent placement was successful in 197 (98.5%) of 200 lesions, reducing the mean diameter stenosis from 74 +/- 14% to 1 +/- 15%. In 164 procedures, there was one in-hospital death (0.6%), no emergency bypass operations and no Q wave myocardial infarctions. There was one acute stent thrombosis (0.6%) but no subacute thromboses. Vascular repair was required after 14 procedures (8.5%), with transfusion in 23 additional cases (14%). Angiographic restenosis (diameter stenosis > or = 50%) at 3- to 6-month follow-up was 17% (95% confidence interval 9% to 25%). By Kaplan-Meier estimates, however, the 2-year second revascularization rate was 49%, reflecting the predominant revascularization performed to treat progressive disease at other sites because failure at the stented site occurred in only 22% of lesions.

CONCLUSIONS

Stenting resulted in excellent immediate and long-term angiographic results in this group of focally diseased, older saphenous vein grafts. Despite the high immediate success and very low (17%) angiographic restenosis rate at 6 months, approximately one half of these patients required further revascularization in the following 2 years, mainly because of disease progression at other sites.

Percutaneous transluminal angioplasty of saphenous vein grafts for medically refractory unstable angina

OBJECTIVES

We attempted to answer the question, Is balloon angioplasty a reasonable alternative to repeat coronary artery bypass graft surgery in patients with previous coronary bypass graft surgery, medically refractory unstable angina and vein graft lesions?

BACKGROUND

Patients with medically refractory unstable angina need revascularization. Patients with previous coronary artery bypass graft surgery and medically refractory angina are at "high risk" for adverse outcomes with repeat coronary bypass graft surgery. Conversely, patients with angioplasty of old vein grafts are also at "high risk" for adverse outcomes.

METHODS

Balloon angioplasty of 89 lesions in saphenous vein grafts was performed in 75 consecutive patients with medically refractory unstable angina. Of these 75 patients, 24 (32%) had myocardial infarct within 30 days, 23 (31%) had left ventricular ejection fraction < 0.35, and 50 (67%) had major comorbidity. Patients underwent standard balloon angioplasty with aggressive use of intravenous and intracoronary heparin, urokinase, nitroglycerin, oral aspirin, calcium channel blocking agents and coumadin.

RESULTS

Angiographic success (reduction of stenosis < or = 50% without major complication) was seen in 84 of 89 lesions. Clinical success (angiographic success plus hospital discharge without major complication) was seen in 70 of 75 patients. During index hospitalization, two patients (3%) died, two (3%) had nonfatal infarcts, and one (1%) had emergency reoperation (coronary bypass graft surgery). In late follow up (3 to 66 months), 14 (20%) patients were lost to follow-up, 17 (23%) had repeat percutaneous transluminal coronary angioplasty, 2 (3%) had late bypass graft reoperation, 18 (25%) had late death, and 1 (< 1%) had a heart transplant. Of the 41 patients alive after one or more angioplasties, 25 have little or no angina, and 16 have occasional or more angina. We compared long-term survival rate in these 75 patients with a cohort of patients with high risk, unstable angina from the Veterans Affairs Surgical Registry (2,570 patients). The 30-day survival rate was better in patients with coronary angioplasty (97% vs. 92%, p < 0.05), but by 6 months there was no difference, and by 5 years a trend toward a higher survival rate with coronary artery bypass graft surgery was seen.

CONCLUSIONS

Balloon angioplasty of saphenous vein grafts with aggressive adjunctive pharmacotherapy is a reasonable alternative to repeat coronary bypass graft surgery in patients with medically refractory unstable angina, previous coronary bypass graft surgery and saphenous vein narrowing.

Stenting or balloon angioplasty of stenosed autologous saphenous vein grafts in pigs

In a model of early and aggressive vein graft stenosis in pigs, an intervention was performed with a single stent (n = 12 grafts), multiple stents (n = 6), or balloon angioplasty (n = 6), while grafts with mild stenoses were left untreated (n = 8). Four weeks after intervention, angiography showed that grafts with single stents, balloon angioplasty, or untreated grafts had patency rates of 92%, 83%, and 83%, respectively. Grafts receiving multiple stents, however, showed only a 17% patency rate (p < 0.05). Balloon dilatation or placement of a single stent improved the angiographic minimal diameter by 0.6 +/- 0.2 and 0.8 +/- 0.3 mm, respectively, over the short term, but this gain was lost during the follow-up period. Multiple stents showed a similar gain (0.5 +/- 0.2 mm) but more loss occurred during the follow-up period (2.4 +/- 0.2 mm). Histology revealed no significant differences between the treatment groups except for the prolonged presence of thrombus remnants in association with the stent wires. In conclusion, single stents and balloon angioplasty show good patency in early saphenous vein graft narrowing but multiple stents show a high occlusion rate.

Clinical and angiographic results of transluminal extraction coronary atherectomy in saphenous vein bypass grafts

BACKGROUND

Transluminal extraction coronary (TEC) atherectomy is a relatively new device that has recently been approved by the Food and Drug Administration. Because of its ability to aspirate clot and atheromatous material, TEC atherectomy may be useful in patients with stenoses in saphenous vein bypass grafts.

METHODS AND RESULTS

TEC atherectomy was performed on 158 saphenous vein graft lesions in 146 consecutive patients with a mean age of 65 +/- 8 years (78% men). Clinical indications for atherectomy included stable angina (37%), unstable angina (54%), and postinfarction angina after recent (< 1 month) myocardial infarction (8%). Patients with acute myocardial infarction and target vessels < 2 mm in diameter were excluded. The mean age of the bypass graft was 8.3 +/- 3.0 years, and 17% were diffusely diseased and degenerated. Complex lesion morphology included total occlusion (6%), eccentricity (64%), ulceration (18%), and thrombus (28%). The TEC atherectomy cutter was successfully advanced through 144 lesions (91%), but technical failures occurred in 14 lesions (9%), and these were subsequently managed by successful balloon angioplasty. Quantitative angiography revealed an increase in lumen diameter from 0.9 +/- 0.5 mm, to 1.5 +/- 0.7 mm after TEC atherectomy, to 2.3 +/- 0.8 mm after percutaneous transluminal coronary angioplasty (PTCA) (P < .001), which corresponded to decreases in diameter stenosis from 75 +/- 14%, to 58 +/- 20% after TEC atherectomy, to 36 +/- 22% after PTCA (P < .001). Device success was achieved in 39.2% (post-TEC atherectomy decrease in diameter stenosis > or = 20%), and procedural success was achieved in 84% (final diameter stenosis < 50% in the absence of a major complication). Angiographic complications were evident in 33 lesions (20.7%) immediately after TEC atherectomy and in 8 lesions (5%) after PTCA, including distal embolization (11.9%), no-reflow (8.8%), and abrupt closure (5.0%), but no perforations. Adjunctive PTCA (and other medical therapy) successfully managed 61% of angiographic complications. Serious clinical complications included in-hospital death in 3 patients (2.0%), emergency bypass surgery in 1 patient who died (0.7%), Q wave myocardial infarction in 3 patients (2.0%), non-Q wave myocardial infarction in 4 patients (2.7%), vascular injury requiring surgical repair and/or blood transfusion in 9 patients (6.1%), and hemorrhagic cerebral infarction in 4 patients (2.7%). Using a composite clinical end point defined as in-hospital death, emergency bypass surgery, or myocardial infarction, the strongest independent correlate (P < .001) of a severe clinical complication was the development of one or more serious angiographic complications (no-reflow, distal embolization, or abrupt closure) immediately after TEC atherectomy. Complete clinical follow-up was available in 118 (92%) of 128 eligible patients at an interval of 6.0 +/- 2.5 months after discharge. Late cardiac outcome included recurrent angina treated with medical therapy (18%), repeat percutaneous intervention on the original target lesion (26%), repeat coronary artery bypass surgery (5%), Q wave myocardial infarction (4%), and late cardiac death (7%). Angiographic follow-up in 105 (80%) of 132 eligible lesions revealed a restenosis rate of 69% (defined as a diameter stenosis > 50%), including 30 lesions (29%) with total occlusion of the original lesion.

CONCLUSIONS

In patients with stenoses in saphenous vein bypass grafts, TEC atherectomy is limited by the frequent need for adjunctive balloon angioplasty to achieve adequate lumen enlargement and to manage TEC atherectomy-induced complications. Although the incidence of serious clinical complications is similar to that of other percutaneous interventions in vein grafts, there is a high incidence of restenosis and late vessel occlusion. Prospective randomized studies are needed to determine the best revascularization strategy for high-risk patients with old degenerated vein

Risk analysis of primary versus reoperative coronary artery bypass grafting

Reoperative coronary artery bypass grafting is being performed with increasing frequency, in part as a function of the increasing pool of patients who have undergone initial coronary artery bypass grafting and in part because of the natural progression of atherosclerosis. The great majority of patients require reoperation because of graft atherosclerosis or because of a combination of graft and native-vessel disease. Significant risk factors for reoperation include the lack of an internal mammary artery graft or incomplete revascularization at the time of the primary operation, age, and New York State Heart Association classification. Despite an increasing experience with reoperations, operative mortality remains high, approximately three to five times that of initial bypass operation. Similarly, reoperations are associated with increased morbidity, including increased rates of bleeding and low output states. Specific problems encountered at reoperation include graft atherosclerosis, progression of native-vessel disease, and a significant increase in perioperative bleeding. Bypass ischemic times tend to be longer. The use of retrograde cardioplegia and blood conservation programs may prove to be effective solutions for these problems. If perioperative results can be improved, it would appear that the long-term outlook for these patients is reasonably good.