|Year : 2022 | Volume
| Issue : 2 | Page : 94-99
Managing diffusely diseased coronary arteries – place of endarterectomy in today's scenario
Ameya Gadkari, Darshak Patel, Mrinal Patel, Kartik Patel, Chirag Doshi
Department of Cardiovascular and Thoracic Surgery, U. N. Mehta Institute of Cardiology and Research Centre, Civil Hospital Campus, Ahmedabad, Gujarat, India
|Date of Submission||08-Mar-2022|
|Date of Decision||05-May-2022|
|Date of Acceptance||10-May-2022|
|Date of Web Publication||12-Aug-2022|
Dr. Mrinal Patel
Department of Cardiovascular and Thoracic Surgery, U. N. Mehta Institute of Cardiology and Research Centre, Civil Hospital Campus, Asarva, Ahmedabad - 380 016, Gujarat
Source of Support: None, Conflict of Interest: None
Introduction: Surgical management of diffuse coronary artery disease (CAD) requires aggressive techniques for complete revascularization. Coronary endarterectomy (CE) coupled with coronary artery bypass grafting (CABG) is a valuable technique for this subset. The aim is to evaluate the perioperative and early results following CE.
Materials and Methods: Three hundred and eighty patients of diffuse CAD undergoing off-pump CABG were included in the study. CE was performed in 204 patients. The mean age of the patients was 62 ± 16.32 years. The male-to-female ratio was 1.43, and the mean SYNTAX score was 33.12 ± 6.42. The mean stay in the intensive care unit was 4.94 ± 2.72 for patients undergoing CABG with CE. The perioperative mortality was 4.9%. The patients were followed up at 3 months, and graft patency was assessed with computed tomography coronary angiography. The average graft patency was 86.725% for the grafts with CE. Patients with left anterior descending (LAD) CE had higher perioperative mortality (5%), overall survival (89.79% at 3 months), and graft patency rates (87%) were favorable. The outcome following single vessel CE was better than multivessel CE.
Conclusion: In patients with diffuse CAD, CE is a safe technique with comparable mortality and lesser complication rate if performed adequately. Despite perioperative difficulties, early outcomes are favorable for CE to the LAD artery grafted with the left internal thoracic artery. Single vessel CE yielded a better result as compared to multivessel CE.
Keywords: Coronary endarterectomy, diffuse coronary disease, coronary artery bypass grafting
|How to cite this article:|
Gadkari A, Patel D, Patel M, Patel K, Doshi C. Managing diffusely diseased coronary arteries – place of endarterectomy in today's scenario. Heart India 2022;10:94-9
|How to cite this URL:|
Gadkari A, Patel D, Patel M, Patel K, Doshi C. Managing diffusely diseased coronary arteries – place of endarterectomy in today's scenario. Heart India [serial online] 2022 [cited 2022 Sep 29];10:94-9. Available from: https://www.heartindia.net/text.asp?2022/10/2/94/353731
| Introduction|| |
Coronary artery disease (CAD) is a significant cause of mortality and morbidity in India. Treatment of discrete lesions with percutaneous coronary interventions or surgery has a good outcome. However, patients with diffuse CAD suffer the most mainly due to the nature of the disease and because surgical strategy is not well-defined. The main risk factors for diffuse CAD are diabetes, smoking, dyslipidemia, hypertension, hyperuricemia, and immunosuppressive therapy.
Accurate characterization of CAD anatomy based on the diagnostic angiogram is essential to select the optimal revascularization strategy. The SYNTAX score is a helpful tool to risk stratify and discriminate outcomes of patients with complex CAD undergoing coronary artery bypass grafting (CABG). Diffuse CAD is defined as the length of significant stenoses ≥20 mm, multiple significant stenoses (≥70% narrowing) in the same artery separated by segments of the normal vessel, and significant narrowing involving the whole length of the coronary artery.
Patients with diffuse CAD are at high risk for early and late adverse events after coronary revascularization. Standard bypass techniques are usually insufficient in diffusely diseased coronary arteries. Aggressive bypass strategies are required for diffusely diseased coronary territory.
Coronary endarterectomy (CE) is the most aggressive method for CABG for diffusely diseased arteries. The basic principle of CE is to extract the plaque completely. Although the results of past studies are not encouraging, there is a definite place for CE in the management of patients with diffuse CAD in today's scenario. Our study compares the surgical outcomes for patients with diffuse CAD undergoing CE in terms of morbidity, mortality, and early results.
| Materials and methods|| |
This prospective study included patients with diffuse CAD undergoing off-pump CABG in our institute from January 2019 to December 2021. The ethical committee of our institute gave clearance for the study. Written and informed consent was taken from all the patients in the study. Patients included in our study underwent off-pump CABG only. Those who were grafted on cardiopulmonary bypass were excluded from the study. The preoperative clinical condition of the patient in terms of ejection fraction, SYNTAX score, comorbidities (hypertension, diabetes mellitus, dyslipidemia, and chronic kidney disease), and perioperative course was noted. Dyslipidemia and chronic renal disease were defined as per ACC and KDIGO criteria., The patients were followed up at a minimum of 3 months, and graft patency and the overall outcome were assessed by two-dimensional echocardiography and computed tomography (CT) coronary angiography. The patients who underwent CABG + CE were classified as group 1 (endarterectomy emailArticle.asp?issn=2321-449x;year=2022;volume=10;issue=2;spage=94;epage=99;aulast=Gadkari group), and those who underwent only CABG were classified as group 2 (non-EA [non-EA] group). The two groups were compared in terms of early mortality, morbidity (Intra-aortic balloon pump [IABP] use and intensive care unit [ICU] stay), and graft patency at 3 months. All patients were followed up for a minimum of 3 months. In our study, both groups were matched regarding their preoperative left ventricular ejection fraction (LVEF) and SYNTAX scores. Matching ensured that preoperative status had minimum influence in altering the parameters' results.
The patients in the non-EA group underwent routine off-pump CABG with the left internal thoracic artery (LIMA) graft to the left anterior descending (LAD) artery and reversed saphenous vein conduits to obtuse marginal (OM) and right coronary artery (RCA) or posterior descending artery (PDA). All distal anastomoses were performed using 7-0 polypropylene sutures, and proximal anastomoses were done using 6-0 polypropylene sutures.
Patients in the EA group underwent routine off-pump CABG and EA to the required vessel. The decision to perform EA was left to the surgeon. Our technique can also be called a semi-open or semi-closed technique. The coronary artery was incised in the middle portion of its lesion, and the incision was then extended proximally and distally with Potts Scissors. The atheromatous core was carefully pulled proximally and distally and then sharply divided. In case of extension of the lesion, the incision was extended distally but not beyond the artery size of 1 mm. Reconstruction of the incised part of the vessel was performed with the in situ LIMA for LAD. The LIMA was dissected and incised to match the length of the LAD. The LIMA was anastomosed to the LAD with a continuous 7-0 polypropylene suture. A similar protocol was followed in conducting the EA of RCA and OM targets. At these sites, grafting was done with reversed SVG conduits incised accordingly to match the targets.
Following CE, according to our institutional protocol for anticoagulation, heparin infusion was started 4 h after shifting to the ICU. It was overlapped with aspirin and warfarin the following day and stopped later. Aspirin and warfarin were continued for 3 months in the postoperative period. After 3 months, dual antiplatelets were continued.
IABP was inserted in patients with borderline hemodynamics. No IABP was inserted prophylactically. All the IABP were inserted through the femoral arterial route. The criteria for IABP removal was hemodynamic stability of the patient. The decision to insert IABP was made on a case-to-case basis depending on the clinical scenario, and no objective criteria were established for the same.
Continuous variables were summarized using mean and standard deviation, and categorical values were summarized using frequencies and percentages. A two-sided Student t-test estimated the changes in the average LVEF, SYNTAX score, and ICU stay. A Chi-square test was used to compare the use of IABP, mortality, and graft patency at 3 months, between the two groups. The results were interpreted at a 5% level of significance. Microsoft Excel 2019 was used for the statistical analysis.
| Results|| |
A total of 380 patients were studied, of which 224 were males. The mean age of the patients was 62 ± 16.32 years. The presence of diabetes mellitus was 69.47% (264/380), hypertension 41.05% (156/380), chronic renal disease 22.63% (86/380), and dyslipidemia 79.47% (302/380). A total of 188 patients (49.47%) had a history of previous percutaneous coronary intervention in the form of stenting or balloon angioplasty. The mean SYNTAX score of the coronary lesions in our patients was 33.12 ± 6.42. These characteristics of our patient population are mentioned in [Table 1].
The patients were divided into two groups based on whether CE was performed or not. Of the 380 patients, 204 (53.68%) patients underwent CE which included LAD artery 48%, (98) OM 12.25% (25), RCA or PDA 20.09% (41), LAD + OM 7.3% (15), LAD + RCA 8.82% (18), and RCA + OM 3.43% (07).
The EA and non-EA groups were compared in terms of their perioperative parameters [Table 2]. The mean LVEF and the SYNTAX score of the lesions in the two groups were similar. The use of IABP in the non-EA group (16.47%) was nearly double that in the EA group (7.35%).The in-hospital mortality was 4.9% for the EA group and 4.54% for the non-EA group and the average ICU stay in both groups was nearly similar, as shown in [Table 2].
Based on the artery, in which EA was performed, it was found that the mean LVEF was lowest in patients with both LAD and RCA EA (32.2%). IABP use was maximum for patients with LAD EA (7.14%), and so was the mortality (5%). The mean ICU stay was lowest for patients with RCA EA [Table 3]. The total number of patients who underwent double vessel CE was 40 and single vessel CE was 164. The mortality in double vessel CE was 10% (4/40) compared to 3.6% (6/164) for single vessel CE.
|Table 3: Comparison of perioperative parameters for different coronary artery involvement|
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Out of 186 patients, who survived following CABG + CE, 175 came for follow-up at 3 months (follow-up was 94% complete). All patients in the EA group were asymptomatic except 2. Of the two symptomatic patients, one had dyspnea on exertion and other presented with occasional chest pain. CT angiography was performed in 175 patients who came for follow-up. The average graft patency rate was 86.725%. The patency of the grafts following EA as evaluated by CT coronary angiography at 3-month follow-up was highest for OM (23/25–92%), followed by LAD (86/98–87%) and RCA (34/41–82.92%). The graft blockage rate was higher for dual vessel EA. The graft patency for LAD + OM – 60% (9/15), LAD + RCA – 61.11% (11/18) and RCA + OM – 57% (4/7) [Table 4]. Furthermore, the graft patency rate for LAD, RCA, and OM was comparable to non-endarterectomized grafts [Figure 1] and [Figure 2].
|Figure 1: CT coronary angiography following CABG with (a) LAD endarterectomy and LIMA to LAD anastomosis showing patent graft with contrast visualization distal to anastomosis in the sagittal section. (b) rSVG from aorta to OM showing patent graft with distal contrast filling in coronal section. (c) Endarterectomy to PDA showing patent rSVG graft from aorta to PDA with good distal contrast filling. CT: Computed tomography, CABG: Coronary artery bypass grafting, LAD: Left anterior descending artery, LIMA: Left internal mammary artery, rSVG: Reversed saphenous vein graft, OM: Obtuse marginal, PDA: Posterior descending artery, 3-D VRT: Three-dimensional volume-rendering technique|
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|Figure 2: CT coronary angiography of patients post CABG (a) 3-D VRT image showing blocked LIMA to LAD graft a few centimeters from the origin (b) 3-D VRT image showing patent LIMA-LAD graft and blocked rSVG graft to PDA just after origin. CT: Computed tomography, CABG: Coronary artery bypass grafting, LAD: Left anterior descending artery, LIMA: Left internal mammary artery, rSVG: Reversed saphenous vein graft, OM: Obtuse marginal, PDA: Posterior descending artery, 3-D VRT: Three-dimensional volume-rendering technique|
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| Discussion|| |
CABG for CAD is a well-defined procedure. However, in today's scenario, cases with diffusely diseased coronaries are rising. Surgical management of such cases often requires CE. Initially, CE was a feared procedure due to the high mortality and morbidity. However, CE can be performed more safely in today's conditions with better intraoperative monitoring, surgical techniques, surgeon experience, and postoperative care and should not be abandoned considering the frequent points of criticism. The main indication for CE is the presence of diffusely diseased coronary arteries that are not suited for distal grafting. Off-pump CE is considered by many surgeons as the technique of choice, especially in high-risk patients.
CE can be performed by either a closed or an open technique. Although the open technique is advocated for an adequate result, it often requires the procedure to be done on cardiopulmonary bypass to avoid hemodynamic instability. Nishi et al. compared the open technique with the closed technique and found the 30-day mortality and early graft patency to be significantly better for the open technique. Myers et al. reported open LAD CE with good results. Since our study included CABG performed without cardiopulmonary bypass, we used the closed technique. When plaque extraction was incomplete through a limited arteriotomy or when the plaque was fractured or severely calcified, we extended the arteriotomy.
We performed CE on all arteries. However, different anatomical planes of the branches of LAD and the hard and frangible nature of LAD plaque make LAD CE particularly hazardous., In our study, IABP use and mortality were highest with LAD EA. However, on early follow-up, the LIMA to LAD grafts following CE showed a graft patency rate of 87%. Thus, early outcomes are favorable for CE to the LAD grafted with the LIMA despite perioperative difficulties. According to Schwann et al., graft failure was worse for veins and unchanged for arterial grafts following CE. In our study, graft patency rates were maximum for CE to OM (92%), followed by LAD (87%)
The results of single vessel LAD EA are better than multiple vessel endarterectomies with respect to early mortality, and the combinations of vessels most strongly associated with mortality were LAD or diagonal along with RCA. Our study included patients undergoing double EA in different combinations – LAD + RCA, LAD + OM, and OM + RCA. The mortality for patients with double vessel CE was significantly higher (10%) than patients undergoing single vessel CE (3.6%).
CE injures the endothelium and triggers an inflammatory and procoagulant cascade. Hence, early antiplatelet and anticoagulant therapy is advised following CE. However, late occlusion of grafts following CE is attributed to ongoing atherosclerotic activity. Due to multiple mechanisms, intraoperative IABP support may reduce the risk of acute thrombosis after CE.
As per our results, patients in the non-EA group had higher use of IABP support. However, this did not translate to higher perioperative mortality. This implies that those undergoing CE have had lower rates of developing acute cardiogenic decompensation in the postoperative period.
Many studies have shown that CE decreases graft patency., However, the confounding factors in this are the multiple comorbid conditions associated with diffuse CAD. Other factors that affect graft patency are the nature of the graft, surgical technique, status of myocardium being grafted, and postoperative anticoagulation., Arterial grafts confer more significant benefits than vein grafts. In our study, graft patency at 3 months for single vessel CE (LAD, RCA, and OM) was comparable to the non-EA group.
| Conclusion|| |
With the advances of modern cardiac surgery, clinical outcomes and graft patency following CE are encouraging. Patients undergoing CABG with CE have comparable operative mortality and complication rate. It indicates that CE may be a viable option in patients where culprit lesions will be otherwise inoperable. Despite perioperative difficulties, early outcomes are favorable for CE to the LAD artery grafted with the LIMA. Single vessel CE yields maximum benefit to the patient compared to multivessel CE.
Institutional Ethics Committee approval was taken for this study.
Ameya Gadkari - Collectin of data, Performance of study Darshak Patel - Performance of study, Data analysis, manuscript writing Mrinal Patel- Data analysis, manuscript writing Kartik Patel - Execution of study, data analysis Chirag Doshi - Concept, performance of study, data analysis.
Consent for publication
Written informed consent was obtained from patients for publication of patient data.
Financial support and sponsorship
U.N. Mehta Institute of Cardiology and Research Centre.
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4]