Off-pump long onlay bypass grafting using left internal mammary artery for diffusely diseased coronary artery

Off-pump onlay-patch grafting using the left internal mammary artery for a diffusely diseased left anterior descending artery: in-hospital and mid-term outcomes

BACKGROUND

The aims of this study were to evaluate the in-hospital and mid-term outcomes of the off-pump onlay-patch grafting procedure using the left internal mammary artery (LIMA) for a diffusely diseased left anterior descending artery (LAD) and to identify the risk factors for postoperative LIMA graft failure in a single-center retrospective study.

PATIENTS AND METHODS

A total of 63 patients (52 males, 65.7±9.0 years) undergoing LAD arteriotomy with or without concomitant endarterectomy, followed by reconstruction using LIMA onlay-patch at the time of off-pump coronary artery bypass grafting at our institute from January 2014 to December 2016 were reviewed. The operative mortality, major postoperative morbidity, follow-up all-cause mortality, major adverse cardiac events at follow-up, and postoperative LIMA graft patency were analyzed. The risk factors for postoperative LIMA graft failure on the basis of baseline and surgical characteristics were identified by multivariable logistic regression analysis.

RESULTS

Eighteen (28.6%) patients underwent concomitant open LAD endarterectomy. The operative mortality rate was 1.6%. Major postoperative morbidity included perioperative myocardial infarction (3.2%), low cardiac output (1.6%), and reoperation for bleeding (1.6%). During the follow-up period of 24.2±9.5 months, all-cause mortality was 1.7% and the incidence of major adverse cardiac events was 6.8%. No repeat revascularization was recorded. In total, 88.1% of LIMA grafts showed FitzGibbon grade A patency determined by noninvasive coronary computed tomography angiography during follow-up. In addition, concomitant LAD endarterectomy and intraoperative LIMA graft flow were found to be independent risk factors for mid-term LIMA graft failure by multivariable logistic regression analysis (odds ratio=2.681, 95% confidence interval: 1.314-9.856, P=0.007 and odds ratio=0.932, 95% confidence interval: 0.791-0.976, P=0.021, respectively).

CONCLUSION

Revascularization of a diffusely diseased LAD using the off-pump LIMA onlay-patch technique results in encouraging clinical outcomes with favorable angiographic results. Concomitant LAD endarterectomy and intraoperative LIMA graft flow are associated with the risk of postoperative LIMA graft failure.

Intimal regeneration after coronary endarterectomy and onlay grafting in coronary artery bypass grafting

OBJECTIVES

Coronary onlay grafting, with or without endarterectomy, has been widely used for the treatment of diffuse lesions. Recent studies have demonstrated excellent long-term patency and favorable remodeling of onlay anastomosis; however, the underlying mechanisms remain unknown. Here, we describe the mechanism of intimal regeneration based on postmortem pathological evaluation of a patient who had undergone onlay grafting with coronary endarterectomy.

METHODS

The onlay anastomosis was analyzed using a combination of immunohistological stainings, namely, H&E, vimentin, α-SMA, factor VIII, and Ki-67, to identify the source and mechanism of intimal regeneration after onlay grafting with endarterectomy.

RESULTS

Our results suggest that the regenerated endothelium derives from the smooth muscle cells of the endarterectomized media of the coronary artery and that it circumferentially covers the internal lumen of the arterial graft.

CONCLUSIONS

Intimal regeneration, derived from the smooth muscle cells of the endarterectomized coronary artery that proliferate toward the graft lumen, may be a key mechanism that underlies the observed favorable remodeling after onlay grafting during coronary endarterectomy.

Segmental clamp and distal perfusion technique for reducing myocardial ischemia during coronary onlay grafting on a beating heart

We present a segmental clamp with distal perfusion technique to reduce myocardial ischemia during onlay grafting, on a beating heart. After a proximal coronary arteriotomy for 2-3 cm, the distal artery is perfused through a cannula, with femoral arterial blood (distal perfusion with external shunt). During proximal and distal coronary snare clamping with distal perfusion, onlay anastomosis is performed, from the heel toward the point of cannula insertion. We then move the proximal clamp to the onlay area and open the graft, to get early proximal coronary reperfusion. The arteriotomy is extended, and this procedure is repeated to achieve complete beating heart onlay anastomosis. We safely performed this procedure on the beating heart off-pump or on-pump in 95 patients with no perioperative myocardial infarction, no intraoperative hemodynamic deterioration, no 30-day mortality. This technique reduces regional myocardial ischemic and secures the safety for onlay grafting on the beating heart.

Long Segmental Reconstruction of Diffusely Diseased Left Anterior Descending Coronary Artery Using Left Internal Thoracic Artery with Extensive Endarterectomy

In coronary artery bypass grafting, a diffusely diseased left anterior descending coronary artery (LAD) is an obstacle to achieving complete revascularization, consequently leading to the possibility of a poor prognosis. Long segmental reconstruction with or without endarterectomy is a revascularization method for treating diffusely diseased coronary arteries. Herein, we report a successful case of long segmental reconstruction of a diffusely diseased LAD using a left internal thoracic artery onlay patch after endarterectomy.

Histopathological heterogeneity of in-stent restenosis in four coronary endarterectomy specimens

Here, we histopathologically compare four patients undergoing coronary artery bypass with coronary endarterectomy and onlay patch grafting for in-stent restenosis (ISR) after the implantation of a bare-metal stent (BMS), sirolimus-eluting stent (SES), or paclitaxel-eluting stent (PES) in an everolimus-eluting stent (EES). Heterogeneity of ISR was noted histopathologically. In ISR for BMS, restenosis is likely caused by so-called neoatherosclerosis that occurred which altered the healing process of BMS implantation. Two ISR cases for SES showed a histopathological heterogeneity: one showed nodular calcified thrombus around stent strut protruding into the lumen, and the other showed concentric neointima composed of CD68-positive foam cell proliferation. In the ISR lesion for PES in EES, infiltrations with foam cells macrophages, particularly numerous eosinophilic cell infiltrations, suggest a peristent strut hypersensitivity reaction. We found a remarkable histopathological heterogeneity of ISR. The study using coronary endarterectomy specimens can give us pivotal information about the histopathological heterogeneity of ISR.

A surgical case report of off-pump onlay patch grafting for pseudoaneurysm with diffusely calcified coronary artery

Coronary pseudoaneurysm usually occurs after catheter-based intervention as a result of traumatic dissection or perforation of a coronary artery in 4%-5% of cases. Here, we report the successful case of pseudoaneurysm occurring after percutaneous coronary angioplasty (PTCA) against the severely calcified coronary artery treated with off-pump long onlay patch bypass technique using internal thoracic arteries. We report the case of a 59-year-old woman treated with off-pump onlay patch grafting for pseudoaneurysm after coronary angioplasty against the diffusely calcified coronary lesion. The portion of the endoarterectomized left anterior descending coronary artery proximal to the resected aneurysm extending 5cm distally was successfully reconstructed with long onlay patch using the internal thoracic arterial graft.

Mammary Artery Patch Reconstruction of Left Anterior Descending Coronary Artery

Most patients with diffuse coronary disease require endarterectomy for revascularization. In view of the high morbidity and mortality associated with coronary endarterectomy, patch angioplasty and reconstruction of the coronary artery was developed. We retrospectively evaluated 104 patients who underwent mammary artery patch angioplasty of the left anterior descending coronary artery. The procedure consisted of laying open the entire diseased segment of the coronary artery and patching it with an in-situ left internal mammary artery onlay patch, without endarterectomy, in an off-pump procedure. One (0.9%) patient died, 2 (1.8%) suffered perioperative myocardial infarction, and an intraaortic balloon pump was used in 2. The mean blood loss was 224 mL. Intensive care unit stay was 2.5 days, and hospital stay was 7.8 days. At 1-year follow-up, most patients were in New York Heart Association functional class I. Follow-up angiography was carried out in 16 patients and showed good patency of all anastomoses. Arterial patch reconstruction of the left anterior descending coronary artery can be performed safely and effectively in an off-pump procedure, with excellent early and intermediate results.

Angiographic Fate of Collateral Vessels After Surgical Revascularization of the Totally Occluded Left Anterior Descending Artery

BACKGROUND

Coronary artery bypass grafting (CABG) is best indicated for chronic total occlusion of the left anterior descending artery (LAD) with collaterals. We investigated angiographic changes in the collateral circulation after CABG.

METHODS

Preoperative and postoperative angiograms were reviewed in 42 patients who underwent grafting onto occluded LADs. We described the type, location, and size of collaterals, the Rentrop grading, and collateral frame count (CFC). Regional wall motion of the LAD area was also evaluated with the centerline method. Postoperatively, we measured the lengths of LAD proximal (Lp) and distal (Ld) to the graft anastomotic site.

RESULTS

Preoperative collaterals comprised 78 pathways (septal 42%, branch-branch 20%, atrial 19%, bridging 18%). After CABG, residual collaterals were identified, mainly through the septal pathways, in 6 patients (14%), most of whom were diabetic. The residual collaterals were a part of those which had been opacified in earlier phases of the preoperative angiograms (CFC: 17 +/- 3 vs 25 +/- 15, p = 0.01). Also, the Ld was shorter in these patients so that Lp/Ld was greater than in patients without residual collaterals (0.80 +/- 0.24 vs 0.53 +/- 0.28, p = 0.04). We found no association of residual collaterals with the improvement of LAD regional wall motion after CABG.

CONCLUSIONS

Even after successful CABG, some collaterals with earlier filling of the LAD remain, mainly through the septum. Although the clinical significance remains to be clarified, complex and diffuse atherosclerosis associated with more distal graft anastomoses may contribute to maintaining collaterals after CABG to the occluded LAD, especially in diabetic patients.

Early and Midterm Results of Off-Pump Coronary Artery Bypass Grafting

BACKGROUND

Early outcomes of off-pump coronary artery bypass grafting have been documented by numerous studies. However, there have been few reports concerning midterm outcomes after off-pump coronary artery bypass grafting.

METHODS

We retrospectively reviewed the records of 602 consecutive patients (24.8% female) who underwent isolated off-pump coronary artery bypass grafting between April 2001 and July 2004. Mean age was 66.7 +/- 9.3 years. Mean Canadian Cardiovascular Society score was 2.5 +/- 0.9. Early postoperative angiograms were evaluated during the same period of hospitalization. Midterm outcomes, including overall patient survival, freedom from cardiac death, and freedom from the combined endpoint of cardiac events, were evaluated.

RESULTS

The average number of distal anastomoses per patient was 3.6 +/- 1.4. The average operation time was 286.1 +/- 72.1 minutes. Long segmental reconstruction of the left anterior descending coronary artery was performed in 218 patients (36.2%). Total arterial grafting was performed in 466 patients (77.4%). Thirty-day mortality was 0.5%. Overall patency rate for all grafts and anastomoses was 97.5% and 97.6%, respectively. Mean follow-up time was 2.9 +/- 1.0 years. Cumulative patient survival at 5 years was 87.9% +/- 2.4%. Freedom from cardiac death was 97.7% +/- 0.6% at 5 years. Freedom from the combined endpoint of cardiac events was 83.8% +/- 2.3% at 5 years.

CONCLUSIONS

Early and midterm outcomes after off-pump coronary artery bypass grafting have acceptable mortality and cardiac events rates, with favorable early graft patency rates.

Long Segmental Reconstruction of Diffusely Diseased Left Anterior Descending Coronary Artery With Left Internal Thoracic Artery With or Without Endarterectomy

BACKGROUND

The diffusely diseased left anterior descending coronary artery (LAD) remains a challenge for both interventional cardiologists and cardiac surgeons. In this study we assessed the surgical outcomes obtained from coronary artery reconstruction, with or without endarterectomy, for a diffusely diseased LAD.

METHODS

Two hundred and fifty patients were treated with an extended LAD reconstruction, with or without endarterectomy, as part of coronary artery bypass grafting to achieve complete revascularization. The left internal thoracic artery (LITA) was used to reconstruct the LAD in all patients. There were 197 men and 53 women. The mean age was 65.1 +/- 9.0 years. Coronary artery reconstruction was performed without endarterectomy in 183 patients (73.2%) and with endarterectomy in 67 patients (26.8%). The off-pump technique was used in 204 patients (81.6%).

RESULTS

The operative mortality was 1.6%. Perioperative myocardial infarction was observed in 6.4% of the patients. The mean LAD incision length was 4.3 +/- 1.7 cm. The patency rate of the LITA to LAD was 98.6% by early angiographic examination (mean, 7.5 +/- 2.6 postoperative days). There were 3 late cardiac-related deaths at a mean follow-up of 21.2 +/- 10.7 months. The actuarial survival was 92.0% at 45 months. Freedom from death or cardiac events was 88.1% at 45 months.

CONCLUSIONS

Coronary artery reconstruction, with or without endarterectomy, using the left internal thoracic artery for a diffusely diseased LAD can be performed with acceptable early and midterm results.

Synergy of old and new technology results in successful revascularization of the anterior myocardium with relief of angina in the absence of suitable targets

BACKGROUND

Diffuse and distal left anterior descending (LAD) coronary disease that is refractory to conventional surgical and/or percutaneous revascularization represents a clinical and economic dilemma. Transmyocardial laser revascularization (TMLR) has improved angina without clear measurable improvement of myocardial perfusion. This study was undertaken to determine if combining a Vineberg implant with TMLR of the LAD distribution enhances myocardial perfusion and relieves symptoms.

METHODS

Twenty-one patients with an obliterated LAD and a viable anterior wall underwent off-pump coronary artery bypass grafting (OPCAB) (2.6 grafts/patient). Eight were studied with preoperative, postoperative-early (4-9 days), and postoperative-late (3-5 months) stress and rest nuclear imaging. In all but 3 cases, the Vineberg implant was modified such that the distal end of the conduit, as it emerged from the muscular tunnel, was anastomosed to any patent LAD segment. The anterior wall, to the left of the LAD, was also instrumented with a Holmium yttriumaluminum- garnet laser (8-16 sites).

RESULTS

There has been 100% follow-up with durations ranging from 6 to 36 months. There were no deaths. All patients had complete relief of their angina. Serial perfusion scans demonstrated a 2-phase improvement in perfusion. Three of the patients underwent angiography of the implant at 6 to 9 months; angiography in each case demonstrated a patent robust conduit. The 1 patient studied at 24 months demonstrated several sites of a myocardial "blush" consistent with neovascularization.

CONCLUSIONS

Although some of the benefits of TMLR/Vineberg may be a consequence of collateral blood flow from other revascularized regions, we believe there to be a synergistic effect on perfusion and angina relief by these combined procedures which may be related to angiogenesis.