Reoperation for myocardial revascularization

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.

Management and prevention of cardiovascular hemorrhage associated with mediastinitis

OBJECTIVE

To elucidate the causes of cardiovascular hemorrhage associated with mediastinitis and to review recommendations for prevention and treatment.

SUMMARY BACKGROUND DATA

Mediastinal debridement with immediate or early coverage using healthy, vascularized tissue has lead to greatly reduced morbidity and mortality for patients with mediastinitis. Myocardial hemorrhage has been anecdotally reported.

PATIENTS AND METHODS

Over a 36-month period, 7 patients developed massive cardiovascular bleeding after undergoing debridement for poststernotomy mediastinitis. Causes included puncture or erosion by a sternal edge in three and tearing at the myocardial-sternal interface in four.

RESULTS

Five patients survived and remain infection-free at an average of 24 months of follow-up. In these patients, ventricular defects were closed with pledgeted sutures and muscle transposition was used concomitantly to reinforce the repair. This involved a slide of the left pectoralis major muscle and turnover of the right pectoralis in three patients, bilateral sliding in one patient, and bilateral pectoralis and an omental flap in one patient who required additional coverage of the lower mediastinum.

CONCLUSIONS

When a patient who has undergone mediastinal debridement shows evidence of significant bleeding, we recommend application of pressure for control of hemorrhage, expeditious return to an operating room with available cardiopulmonary bypass, and immediate muscle coverage with healthy, well-vascularized tissue. Finally, early sternectomy might largely prevent this life-threatening complication.

Coronary angioplasty in symptomatic patients after bypass surgery

With the availability of percutaneous transluminal coronary angioplasty (PTCA), the management of patients who present with recurrent angina following coronary artery bypass surgery (CABG) has changed. From January 1987 to December 1988, 149 symptomatic post CABG patients underwent coronary angiography at our institution. Ninety were treated with medical antianginal therapy, 14 had repeat surgery, and 45 underwent PTCA. Complications of repeat CABG included one death, two perioperative myocardial infarctions, and four patients with postoperative supraventricular arrhythmia. PTCA was performed on 42 lesions in 37 native vessels (88% success rate), and on 24 lesions in 23 vein grafts (91.7% success rate). Complications included acute reocclusion (one patient), peripheral artery occlusion (one patient), hematoma formation (one patient), and periprocedure myocardial infarction (one patient). No deaths occurred. At a mean follow-up of 5.9 +/- 3.8 months, 10 patients had recurrent symptoms, six of whom were found to have restenosis. Repeat PTCA was successfully accomplished in four patients; the other two were treated medically. It is concluded that PTCA is a feasible alternative to repeat CABG in selected patients and can be achieved with a high success rate and minimal complications.

An approach to reoperative median sternotomy

Cardiac reoperations using a previous median sternotomy incision are becoming more common as the population of patients who have had cardiac surgery increases. Repeat median sternotomy can be complicated by major hemorrhage and secondary myocardial ischemia. A standard approach to reoperative median sternotomy has been developed over the past several years at Georgetown University. Details of the method are presented. From January 1, 1980 through April 30, 1988, 179 patients underwent repeat median sternotomy. The technical approach to the operation became standard as of July 1,1983. Two of 66 patients operated before this date sustained major hemorrhage requiring emergent institution of cardiopulmonary bypass. One mortality in the group was directly related to hemorrhage at the sternotomy. No episode of major hemorrhage and no mortality related to the sternotomy occurred in 113 patients who underwent repeat sternotomy after July 1, 1983. Reoperation for bleeding occurred in 8.4% of the patients. We believe the technical considerations presented increase the safety of reoperative cardiac surgery.

Percutaneous transluminal angioplasty of saphenous vein graft stenosis: long-term follow-up

Percutaneous transluminal angioplasty was used to treat 101 patients with saphenous vein bypass graft stenosis at a mean of 50.1 months (range 2 to 196) after coronary artery bypass surgery. The patients presented between March 1981 and April 1987. A total of 107 saphenous vein grafts were dilated at 117 sites. The primary success rate was 91.8%. The incidence of cardiac complications was 7.1%. There were no cardiac complications in 53 patients with grafts implanted less than 36 months before angioplasty (Group 1). The 48 patients with grafts implanted for greater than 36 months (Group 2) had a 12.5% incidence rate of myocardial infarction, a 4% incidence rate of emergent bypass surgery and a 4% incidence rate of death for an overall cardiac complication rate of 14.9% (p less than 0.01). Follow-up was obtained at a mean of 16.8 +/- 13.9 months (range 1 to 54) in 87 patients (97% of successful cases). Repeat coronary angiography was performed in 49 patients and revealed restenosis in 30 patients (61.2%), with no difference in recurrence rates for proximal, mid or distal graft sites. Clinical recurrence (defined as recurrence of symptoms, myocardial infarction, repeat angioplasty, surgery or death) was 33.1% for Group 1 patients and 64.1% for Group 2 patients (p less than 0.01). The complication and recurrence rates of saphenous vein graft angiography are significantly higher when performed for late (greater than 36 months) vein graft failure. All therapeutic options should be carefully examined before proceeding with angioplasty for saphenous vein graft stenosis in this type of patient.

Role of angioplasty in patients with previous coronary artery bypass surgery

Fifty-nine patients with previous coronary artery bypass surgery (CABG) underwent coronary artery or vein graft angioplasty following a recurrence of symptoms, 141 lesions were attempted in 70 procedures. The overall angiographic success rate was 77%. Some angiographic success was achieved in 83% of patients. Complications included myocardial infarction in three (4.3%), death in one (1.4%), and iliac artery thrombosis in one (1.4%). No patients were referred for urgent surgery. Twenty-eight patients have undergone repeat coronary arteriography after 7.5 +/- 2.6 months (mean +/- SD), and 31% of lesions have recurred. Fifty-eight percent of patients without recurrence at follow-up continue to have improved symptoms. Treadmill exercise time was significantly prolonged in patients in whom all attempted lesions had been successfully dilated and in those in whom only some lesions were dilated. Our experience suggests that approximately 29% of patients with recurrence of angina following CABG may be suitable for angioplasty.

Early and late results of re-operation for coronary artery disease: a 13-year experience

A second coronary artery bypass grafting procedure was performed for recurrent angina in 119 patients between 1970 and mid-1983. Angiographic findings were assessed and computerized using the Brandt myocardial scoring system. The myocardial score was similar prior to the first and second operations. Graft failure was the most common indication for re-operation, either alone (48%) or in combination with progression of coronary artery disease (29%) or incomplete revascularization (10%). Progression of coronary artery disease alone was an indication in 9% and previous incomplete revascularization alone in 4%. The completeness of revascularization at the end of operation was analysed using a new index, the myocardial score/graft coverage rate. This showed that revascularization was less complete at the second operation than at the first (P less than 0.0001). The hospital mortality at re-operation was 2.5% and the peri-operative myocardial infarction rate was 9.2%. The follow-up period was 54 months (range 10-160 months). Actuarial survival was 94% at 5 years and 74% at 10 years. The average onset of recurrent angina was earlier after the second operation than after the first (P = 0.001). Using a cumulative actuarial curve, survival at 8 years was 85%, a further 6% of patients had undergone a third or fourth operation, and a further 25% were in NYHA Classes III or IV. Therefore 54% achieved a good or excellent result. It was concluded that re-operation is a worthwhile procedure.

Percutaneous transluminal angioplasty in patients with prior myocardial revascularization surgery

Direct myocardial revascularization surgery using either the saphenous vein or internal mammary artery has become the definitive surgical treatment for coronary artery occlusive disease. Certain patients who have undergone these procedures, however, have recurrent myocardial ischemia due to progression of disease in unbypassed vessels, to obstruction in the arteries distal to the insertion of the bypass conduit, or to disease of the conduit itself. Balloon angioplasty may be used to relieve myocardial ischemia in these situations; however, initial studies suggested a low primary success rate coupled with excessive mortality and morbidity. Improvements in patient selection, equipment and technical expertise now allow angioplasty to be performed in this patient population with results comparable to that in the general coronary angioplasty population. Of the 3,016 angioplasty procedures performed between September 1980 and June 1987, 236 patients had previously undergone revascularization surgery. The primary success rate was 93% (390 of 419 stenoses successfully dilated). Overall, clinical restenosis was observed in 39%, including a 43% restenosis rate in patients undergoing only saphenous vein graft angioplasty. This did not differ appreciably from the restenosis rate in postbypass patients undergoing angioplasty of only native vessels (37%) or internal mammary arteries (42%). Emergency revascularization surgery was required in 7 of 236 patients (3%), each of whom had myocardial infarction. One of 236 patients (0.4%) died. Thus, angioplasty may be used to relieve recurrent myocardial ischemia in patients with prior direct myocardial revascularization procedures with a high initial success rate and acceptable risk. Early (less than 6 months) restenosis is not infrequent and remains the largest obstacle to a satisfactory clinical outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous transluminal angioplasty of stenotic coronary artery bypass grafts: 5 years' experience

In a 60 month period (January 1981 to December 1985), 82 patients (79% male with a mean age of 60 years) had 83 saphenous vein grafts and 5 internal mammary artery grafts with a total of 101 stenotic sites treated with percutaneous transluminal coronary angioplasty. The mean time between bypass surgery and angioplasty was 51.2 months. The procedure was technically successful in 85% of patients, 86% of grafts and 85% of the sites attempted. In these cases, the mean diameter stenosis was reduced from 77 +/- 14 to 27 +/- 20% (p less than 0.001), the mean pressure gradient from 49 +/- 16 to 7 +/- 6 mm Hg (p less than 0.001). Emergency coronary artery bypass graft surgery was necessary in one patient (1.2%) whereas myocardial infarction occurred in three patients (3.6%). There were no hospital deaths. Clinical follow-up was obtained in all 82 patients. Before angioplasty, 23% were in Canadian Cardiovascular Society functional class II, 60% in class III and 17% in class IV. With a mean clinical follow-up period of 21.4 +/- 2.3 months, 71% are in class I, 17% in class II and 12% in class III. There were two deaths, 3 months or more after angioplasty, one probably due to graft closure. So far, angiographic follow-up (at 7.9 +/- 2.1 months) has been available in 26 patients. Ten patients (with 10 grafts) exhibited graft restenosis; six of them have had second successful repeat angioplasty. Among the many variables analyzed, statistically significant predictors of success were a higher measured balloon/graft ratio (p less than 0.001), smaller diameter graft (p less than 0.001), and shorter lesion length (p less than 0.01). The only predictor of complication was diffuseness of disease in the graft (p less than 0.05). The statistically significant predictors of recurrence were the residual stenosis after the initial angioplasty (p less than 0.01) and the measured balloon/graft ratio (p less than 0.01). Angioplasty of coronary artery grafts appears to be a feasible and efficacious procedure with a low complication rate. The technique is a satisfactory alternative to repeat surgery in selected patients.

Percutaneous transluminal coronary angioplasty after previous coronary artery bypass surgery

To improve symptomatic status and avoid repeat coronary artery bypass graft surgery (CABG), 115 lesions were approached for transluminal coronary angioplasty (PTCA) in 94 patients (82 men, 12 women) with angina pectoris and prior CABG at a mean of 60 months (range 4 to 192) after CABG. Fifteen patients were in Canadian Cardiovascular Society functional class I, 32 were in class II, 31 were in class III, and 16 were in class IV. Patients were 37 to 76 years old (mean 57). PTCA was successful (at least a 40% reduction in stenosis diameter and improvement in symptomatic status) in 83 patients (88%) and 103 (90%) lesions. Mean stenosis was reduced from 80 +/- 14% to 20 +/- 16% (mean +/- standard deviation) and mean pressure gradient from 41 +/- 7 mm Hg to 14 +/- 6 mm Hg. Seven patients had lesions that could not be crossed for technical reasons and these patients underwent non-emergency CABG. Four patients required emergency CABG after PTCA; 1 patient subsequently died and 2 survived acute myocardial infarction. One patient had a femoral artery laceration, which required surgical repair. At a mean follow-up of 8 +/- 4 months, 63 patients (76%) with initially successful results were free of angina or in improved condition. Of the remaining 20 patients, 18 consented to repeat coronary angiography. Four patients did not have restenosis. Of the 14 patients with documented restenosis, 5 underwent successful repeat PTCA, 5 had repeat CABG, and 4 were treated medically. Thus, when coronary anatomy is suitable, PTCA is an effective alternative to reoperation in symptomatic patients with prior CABG.

Complex coronary angioplasty: multiple coronary dilatations

Selected patients underwent PTCA of multiple stenoses in different vessels or in the same vessel. Three hundred nine patients underwent 685 PTCA procedures in various combinations of arterial and vein graft stenoses. A multiple dilatation procedure was defined as successful when all lesions attempted were successfully dilated, or when the considered-critical-stenosis was successfully dilated and this resulted in a patient clinical improvement. Angiographic success was achieved in 599 of 685 lesions attempted (87.4%) and in 285 of 309 patients (92.2%). Complications included a mortality rate of 1.0%, an MI rate of 4.2% per patient and 1.9% per lesion attempted, and a 3.6% incidence of emergency CABG. Follow-up data show that 58 patients (20.4%) had clinical evidence of a lesion recurrence, and that 92.5% (37 of 40 patients) who underwent repeat angioplasty had a successful procedure. A sustained clinical improvement was obtained in 264 of 309 patients (85.4%). The data indicate that multiple dilatations are feasible with good success rates and acceptable complication rates. Further evaluation of this extended application of PTCA is needed to clearly establish its role in the therapy of CAD.