Left Internal Mammary Artery Group Research Articles

Left internal mammary on-lay patch vs. saphenous vein patch in reconstructing diffusely diseased left anterior descending artery

Background: Several operative techniques were described to reconstruct the diffusely diseased left anterior descending coronary artery (LAD). The superiority of the left internal mammary artery (LIMA) vs. the saphenous vein patch is controversial in LAD reconstruction. Thus, this study compared LIMA on-lay patch vs. saphenous vein patch in reconstructing diffusely diseased LAD artery.
 Methods: This study was conducted between June 2020 and May 2022 including 60 patients with a diffusely diseased LAD. LIMA patch was used in 30 patients (Group I) and saphenous vein patch in 30 patients (Group II) without endarterectomy. Males presented 85%; the mean age was 56.68 ± 6.44 years. The mean patch length in the LIMA group was 4.48±0.87 cm and 4.60± 0.93 cm in the saphenous vein group.
 Results: The mean aortic cross-clamp and cardiopulmonary bypass times were 66.80± 19.93 and 108.00± 25.74 minutes in the LIMA group and 84.40± 30.65 and 132.53± 45.41 minutes in the venous Group (P= 0.011 and 0.013, respectively). The mean intensive care unit stay was 50.40 ± 38.65 hours in Group I and 92.00± 51.62 hours in Group II (P˂ 0.001). Four patients (13.3%) needed an intra-aortic balloon pump (IABP) in Group I, and 11 patients (36.7%) in Group II (P= 0.037). Postoperative low cardiac output occurred in 13.3% of Group I and 53.3% in Group II (P= 0.001). Postoperative atrial fibrillation occurred in 13.3% of Group I, while in Group II was 33.3% (P= 0.067). The renal complications were 3.3% in Group I and 16.7% in Group II (P= 0.085). Two patients (6.7%) were complicated with bleeding in Group I, and nine (30.0%) in Group II (P= 0.02). The postoperative ejection fraction was 58.17± 5.25% in Group I and 53.3± 5.23% in Group II (P= 0.001). On the first postoperative day, the creatine kinase-myoglobin binding level was 61.73± 30.19 IU/L in Group I and 92.63± 45.88 IU/L in Group II (P= 0.004). Hospital mortality occurred in one patient (3.3%) in Group I and two in Group II (6.7%) (P˃ 0.99).
 Conclusion: LAD reconstruction using the LIMA patch could have better early outcomes than the saphenous vein patch.

A Comparative Study of Pedicled Versus Skeletonized Left Internal Mammary Artery Harvesting Techniques Regarding Rate of Mediastinitis Post CABG in Diabetic Patients

Background: For grafting the left anterior descending (LAD) coronary artery, the left internal mammary artery (LIMA) has become the gold standard. Pedicled and skeletonized methods are the two most common harvesting procedures. Objective: In this study we compared between both techniques regarding incidence of postoperative mediastinitis in diabetic patients. Patients and methods: 80 diabetic patients with controlled diabetes i.e. HbA1c below 7 underwent on-pump coronary artery bypass grafting (CABG) surgery were included in this study. The patients were divided into two groups, according to the procedure applied to harvest the LIMA: Group 1: 40 patients underwent pedicled LIMA and Group 2: 40 patients underwent skeletonized LIMA. After CABG surgery, the cases had a 3-month follow-up time. Results: In the pedicled LIMA group, the frequency of excessive intraoperative usage of bone wax was significantly increased. A significant increase was found regarding the occurrence of sternal wound infections (SWI) in the pedicled LIMA group (22.5%) versus (12.5%) within the skeletonized one, (P-value = 0.003). The univariate analysis of the factors related to SWI in all of the studied CABG patients were obesity [OR (95% CI): 15.61 (5.78-42.12), P <0.001], pedicled ITA [OR (95% CI): 4.3(1.4-12.9), P 0.004], intraoperative excessive use of bone wax [OR (95% CI): 14.53(6.48-32.56), P <0.001], and intraoperative excessive use of diathermy [OR (95% CI): 17.31(7.55-39.4), P <0.001]. Conclusion: In comparison to pedicled LIMA, skeletonized LIMA in CABG was correlated to reduced occurrence of superficial as well as deep SWI among diabetic patients.

Left or bilateral internal mammary artery employment in coronary artery bypass grafting: midterm results.

The gold standard for coronary artery bypass grafting to the left anterior descending artery is use of the left internal mammary artery. Better long-term survival has been reported using bilateral internal mammary arteries compared to left internal mammary artery only, but many surgeons are reluctant to employ bilateral internal mammary arteries in coronary artery bypass grafting. This study aimed to evaluate the effectiveness and safety of bilateral internal mammary artery use. From 2014 to 2017, 1703 patients underwent coronary artery bypass grafting in our institute. Of these, 772 met the inclusion criteria and were randomly assigned to receive bilateral (n = 387) or left (n = 385) internal mammary artery grafts. The mean age was 67.1 ± 6.0 years (range 48-85 years) and 474 (61.4%) were male. The mean number of diseased vessels was 3.1 ± 0.9, and mean EuroSCORE II was 3.4% ± 1.1%. Hospital mortality was 1.2% in the left internal mammary artery group vs. 1.8% in the bilateral internal mammary artery group (p = 0.55). There was no difference in procedure-related complications between groups. Mean follow-up was 65.9 months. Survival in the bilateral internal mammary artery group at 1, 3, and 5 years was 98.7%, 98.7%, and 94.8% vs. 98.1%, 98.1%, and 90.9%, respectively, in the left internal mammary artery group (p = 0.63). Application of bilateral internal mammary arteries in coronary artery bypass grafting is safe and effective, with comparable midterm results to those with the left internal mammary artery only.

Left Internal Mammary Artery Skeletonization Reduces Bleeding—A Randomized Controlled Trial

The objective of this study was to compare the impact of skeletonized versus pedicled left internal mammary artery (LIMA) harvesting on bleeding after coronary artery bypass grafting (CABG). In a randomized, single-blinded trial with a parallel group design and equal allocation, we randomly assigned 62 patients undergoing primary elective CABG in a tertiary cardiac center to skeletonized or pedicled LIMA dissection. Before surgery, all aspects of coagulation were assessed. Patients were blinded to LIMA dissection technique and monitored for cumulative drainage at 12 hours (primary outcome) as well as myocardial necrosis markers. With recruitment complete, there were 31 patients in each group; all patients were analyzed. Median postoperative drainage was 395 mL at 12 hours in all patients; it was lower by 28% at 12 hours (P= .02) in patients with skeletonized LIMA (Cohen's d, 0.6; 95% confidence interval (CI), 0.09-1.11). Patients with a LIMA pedicle received more fresh-frozen plasma transfusions than did the skeletonized LIMA group (Median 3; interquartile range 3-5 versus median 3; interquartile range 3-3; P= .03). Study arms did not differ in blood coagulation. Left internal mammary artery skeletonization (odds ratio= 0.04; 95% CI, 0.003-0.44; P= .009) and higher body mass index (odds ratio= 0.63; 95% CI, 0.45-0.89; P= .008) decreased the odds of being in the top drainage quartile at 12 hours (≥550 mL). Creatine kinase was lower in skeletonized LIMA directly after surgery (median 218 U/L; interquartile range 175-310 U/L versus median 424 U/L; interquartile range 256-510 U/L; P < .001), at 6 hours (median 324 U/L; interquartile range 239-424 U/L versus median 529 U/L; interquartile range 374-707 U/L; P < .001), and 12 hours after surgery (median 351 U/L; interquartile range 277-552 U/L versus median 695 U/L; interquartile range 509-1067 U/L; P < .001). Left internal mammary artery skeletonization results in lower mediastinal drainage after CABG than pedicled LIMA harvesting.

Skeletonized versus pedicled left internal mammary artery harvesting and risk of sternal wound infection after coronary artery bypass surgery

Background: The left internal mammary artery (LIMA) is the gold standard conduit for coronary artery bypass grafting (CABG). There are two harvesting methods, either pedicled or skeletonized. The choice of any technique must consider its complication profile, especially sternal wound infections (SWI). This study aims to evaluate and compare the occurrence of SWI after pedicled and skeletonized LIMA harvesting techniques for CABG.&#x0D; Methods: This prospective observational study included 300 patients who had CABG between 2016 and 2019. We included patients who had pedicled LIMA (n=200) in group 1 and who had skeletonized LIMA (n=100) in group 2. All patients completed a follow-up period of 3 months after CABG. The evaluation during follow-up included: sternal instability, signs of wound infection, temperature, the microbiological study of wound discharge, and chest computed tomography scan.&#x0D; Results: There was no significant differences in age (p = 0.20), male to female ratio (p = 0.43), body mass index (p = 0.12), NYHA I/II (p = 0.50), diabetes mellitus (p = 0.28), ejection fraction (p= 0.14), and EuroSCORE II (p= 0.09) between groups. No significant difference in cardiopulmonary bypass time (p = 0.24), and cross-clamp time (p= 0.19) between groups. There was a significant increase in the total operating time in skeletonized LIMA group (212.77±75.25 min vs. 190.78±55 minutes, p= 0.004). Skeletonized LIMA was significantly associated lower incidence of SWI than that with pedicled LIMA (4% vs 15.5%, p= 0.003), and non-significantly lower incidence of deep SWI (1% vs 4.5%, p= 0.11). The risk factors for SWI in patients who had pedicled IMA were obesity (OR: 13.06, 95%CI: 3.98-42.89), diabetes mellitus (OR: 10.51, 95%CI: 2.35-46.84), and excessive diathermy (OR: 12.62, 95%CI: 3.93-40.54).&#x0D; Conclusion: Obesity, diabetes, and the use of excessive diathermy for hemostasis may increase the risk of sternal wound infection with pedicled LIMA harvest compared to skeletonized LIMA in patients undergoing CABG.

Mid-term graft patency of right versus left internal mammary artery as arterial conduit usage for left anterior descending artery revascularisation: Insights from a single-centre study of propensity-matched data

BackgroundPrevious studies reported the strategy of in situ skeletonised right internal mammary artery (RIMA) grafting to the left anterior descending artery (LAD). However, few reports have focused on assessing RIMA graft patency rate after grafting to the LAD. This study aimed to assess mid-term graft patency of in situ skeletonised RIMA grafting to the LAD versus in situ skeletonised left internal mammary artery (LIMA) grafting to the LAD in a single-centre propensity-matched study. Materials and methodsAfter propensity score matching, 185 pairs of patients who received first, scheduled, isolated off-pump coronary artery bypass grafting (OPCAB) surgery were assigned to either a RIMA group (patients who received retrosternal crossover in situ skeletonised RIMA-LAD grafting with additional conduits grafting) or a LIMA group (patients who received in situ skeletonised LIMA-LAD grafting with additional conduits grafting). The primary endpoint was mid-term internal mammary artery (IMA) graft failure after grafting to the LAD and was determined by coronary computed tomography angiography examination. The secondary endpoints were mid-term all-cause mortality and the composite mid-term clinical outcome. ResultsThe graft patency rate of in situ skeletonised RIMA-LAD graft was not inferior to in situ skeletonised LIMA-LAD graft during a follow-up period of 36.6 ± 12.1 months (97.2% vs. 96.6%, p = 0.752). Kaplan-Meier curves showed a similar cumulative IMA graft failure between the two groups (χ2 = 0.092, Log-rank p = 0.762). And Cox regression analysis revealed that grouping was not an independent factor for follow-up IMA graft failure after grafting to the LAD (HR = 0.93, 95% CI: 0.68–2.13). Additionally, Kaplan-Meier curves showed similar cumulative survival free from adverse events between the two groups (χ2 = 2.365, p = 0.124, respectively). ConclusionsRevascularisation of the LAD using a skeletonised RIMA resulted in excellent mid-term graft patency and clinical outcomes.

Thoracoscopic Left Upper Lobectomy in Patients With Internal Mammary Artery Coronary Bypass Grafts

This study examined outcomes of a technique for performing thoracoscopic left upper lobectomy (LUL) in patients with a previous left internal mammary artery (LIMA) coronary artery bypass graft, where a small wedge of lung parenchyma adjacent to the graft is left to avoid injury. All patients undergoing thoracoscopic LUL from 1999 to 2010 at a single institution were reviewed. Perioperative morbidity, cancer recurrence, and long-term survival were compared between patients who had (LIMA group) or did not have (control group) a previous LIMA graft. During the study period, 290 patients underwent thoracoscopic LUL; 14 (5%) had previous LIMA grafts. There was no perioperative mortality in the LIMA group versus 4 (1%) in the control group (p= 0.65). One patient (7%) in the LIMA group required conversion to thoracotomy, which was similar to the control group (n=16, 6%; p= 0.83). Overall perioperative morbidity was also not different between the groups (LIMA 36% [5of 14] versus control 29% [81 of 276], p= 0.61). No patient in the LIMA group had perioperative cardiac ischemia. For patients with lung cancer, 5-year survival (LIMA 50%vs control 63%, p= 0.23) and cancer recurrence rates (LIMA 27% (3 of 11) versus control 15% (36 of 242), p=0.27) were not different between the groups. Only 1LIMA recurrence was local, and it was not related to theparenchyma left on the LIMA graft. Thoracoscopic LUL can be performed safely in patients with LIMA bypass grafts. Leaving lungparenchyma on the graft may prevent injury and does notcompromise oncologic outcomes in appropriately selected patients.

A meta-analysis comparing bilateral internal mammary artery with left internal mammary artery for coronary artery bypass grafting.

Increasing evidence continues to demonstrate a survival advantage for bilateral internal mammary artery (BIMA) over left internal mammary artery (LIMA) for coronary artery bypass grafting (CABG). We performed an updated meta-analysis of published studies comparing BIMA versus LIMA in CABG operations and assessed differences in long-term survival. Electronic searches for studies comparing BIMA versus LIMA were performed using three databases from 1972 to December 2012. Studies with at least four years of follow-up and at least 100 patients in each group were included for review. We used a random-effect model and pooled hazard ratios from across all included studies. No randomized controlled trials and 27 observational studies totaling 79,063 patients (19,277 BIMA, 59,786 LIMA) were included for final analysis. The BIMA group demonstrated significantly better long-term survival than the LIMA group [hazard ratio, 0.78; confidence interval, 0.72-0.84; P<0.00001]. In an updated meta-analysis, we demonstrate an increase in long-term survival in patients receiving BIMA as a primary grafting strategy over those receiving a LIMA. Although no randomized controlled trials were included in this meta-analysis, the survival benefit seen with a BIMA cannot be overlooked when determining which operation to perform in CABG patients. Until the long-term results of the ART trial are published, we offer best available evidence in favor of BIMA over LIMA for CABG surgery.

Multiple Arterial Grafts Improve Late Survival of Patients Undergoing Coronary Artery Bypass Graft Surgery

Background— Use of the left internal mammary artery (LIMA) in multivessel coronary artery disease improves survival after coronary artery bypass graft surgery; however, the survival benefit of multiple arterial (MultArt) grafts is debated. Methods and Results— We reviewed 8622 Mayo Clinic patients who had isolated primary coronary artery bypass graft surgery for multivessel coronary artery disease from 1993 to 2009. Patients were stratified by number of arterial grafts into the LIMA plus saphenous veins (LIMA/SV) group (n=7435) or the MultArt group (n=1187). Propensity score analysis matched 1153 patients. Operative mortality was 0.8% (n=10) in the MultArt and 2.1% (n=154) in the LIMA/SV ( P =0.005) group, which was not statistically different ( P =0.996) in multivariate analysis or the propensity-matched analysis ( P =0.818). Late survival was greater for MultArt versus LIMA/SV (10- and 15-year survival rates were 84% and 71% versus 61% and 36%, respectively [ P &lt;0.001], in unmatched groups and 83% and 70% versus 80% and 60%, respectively [ P =0.0025], in matched groups). MultArt subgroups with bilateral internal mammary artery/SV (n=589) and bilateral internal mammary artery only (n=271) had improved 15-year survival (86% and 76%; 82% and 75% at 10 and 15 years [ P &lt;0.001]), and patients with bilateral internal mammary artery/radial artery (n=147) and LIMA/radial artery (n=169) had greater 10-year survival (84% and 78%; P &lt;0.001) versus LIMA/SV. In multivariate analysis, MultArt grafts remained a strong independent predictor of survival (hazard ratio, 0.79; 95% confidence interval, 0.66–0.94; P =0.007). Conclusions— In patients undergoing isolated coronary artery bypass graft surgery with LIMA to left anterior descending artery, arterial grafting of the non–left anterior descending vessels conferred a survival advantage at 15 years compared with SV grafting. It is still unproven whether these results apply to higher-risk subgroups of patients.

Is There an Association Between Radon Exposure and the Incidence of Thyroid Cancer?

Is There an Association Between Radon Exposure and the Incidence of Thyroid Cancer?

Anatomical and functional assessment of single left internal mammary artery versus arterial T-grafts 12 years after surgery

We determined whether ultrasonographic left internal mammary artery (LIMA) findings correspond with 64 multislice computed tomography (MSCT) in patients 12 years after coronary artery bypass grafting. We included 34 patients (63.2+/-9.2 years), 16 with conventional single LIMA (group I) and 18 arterial T-grafts (group II), in a cross-sectional study. Patients underwent transthoracic proximal LIMA ultrasonography at rest and during the Azoulay maneuver, transthoracic echocardiography of the left ventricle and 64-MSCT, 11.5+/-1.4 years postoperatively. MSCT scans showed three string sign LIMA grafts (19%) in group I and three distal string sign LIMA grafts (17%) and 16 occluded T-graft anastomoses (22%) in group II. LIMA diameters and areas are significantly larger in group II in the origin, 3.5+/-0.7 vs. 2.5+/-0.5 mm, P=0.00007 and 0.09+/-0.04 vs. 0.05+/-0.02 cm(2), P=0.00019 and in the third intercostal space, 3.4+/-0.7 vs. 2.5+/-0.5 mm, P=0.00009 and 0.09+/-0.03 vs. 0.05+/-0.02 cm(2), P=0.000047. Most ultrasonographic LIMA findings do not differ between the groups. Thus, proximal LIMA diameters and areas are significantly larger in T-grafts and ultrasonographic variables equalize between the groups at rest and during the Azoulay maneuver 12 years after surgery.

Does the use of bilateral internal mammary artery grafts impact survival of veterans undergoing coronary artery bypass surgery?

Background The impact of bilateral internal mammary artery (BIMA) versus single left internal mammary artery (LIMA) grafts on long-term survival in veterans after coronary artery bypass graft (CABG) surgery is unknown. Methods A review of prospectively collected data identified all patients (n = 784) who underwent primary isolated CABG surgery from December 1991 through December 1998. Grafting was performed with LIMA in 713 (90.9%) patients and with BIMA in 71 (9.1%) patients. We identified 66 propensity-matched patient pairs. Results The matched cohort was all male. The mean follow-up was 9.7 ± 3.8 years. Comparing matched patients showed no significant survival benefit for the BIMA group versus the LIMA group at 5 years (89% versus 86%) and 10 years (73% versus 69%) ( P = .99). Factors associated with decreased survival were advanced age, higher New York Heart Association heart failure class, and diabetes. Conclusions Using BIMA grafting instead of LIMA grafting had no significant survival benefit for male veterans who underwent CABG surgery. Further study is needed to fully evaluate the role of BIMA grafting in this unique patient population.

A Comparison of Bilateral with Single Internal Mammary Artery Grafts on Postoperative Mediastinal Drainage and Transfusion Requirement

The superiority of the left internal mammary artery (LIMA) graft over autogenous saphenous vein as a bypass conduit in coronary artery bypass surgery has been well established. Early and late patency rates of bilateral internal mammary artery (BIMA) grafts exceed those of vein grafts, and patients who receive BIMA have improved long-term survival rates and more freedom from reoperations and other cardiac events. But because of other concerns, particularly the question of increased risk of postoperative bleeding, controversy still surrounds the perioperative period. In the present study we sought to determine whether BIMA grafting was an independent risk factor of postoperative bleeding and of blood product use in patients undergoing primary elective coronary artery revascularization. For this purpose, 33 consecutive patients scheduled for BIMA grafting were matched with 66 patients operated on by single LIMA grafting. Patients in the LIMA group had significantly less postoperative mediastinal drainage than those in the BIMA group (median: 722 vs 920 mL, P = 0.0001). Fifty-six patients received blood products (56% vs 51% in LIMA and BIMA groups, respectively; P = 0.67). In multivariate analysis, BIMA and operative duration were independent predictors of increased postoperative drainage. Nevertheless, in logistic regression, BIMA was not significantly associated with blood product use, unlike precardiopulmonary bypass hematocrit and duration of surgery (OR and 95% CI: 0.89 [0.80-0.96] P = 0.01; 1.009 [1.001-1.019] P = 0.04, for an increase of 1% in hematocrit and 1 min in duration of surgery, respectively). In conclusion, these data support the idea that BIMA graft slightly increases postoperative drainage but not transfusion requirement.

Single Versus Bilateral Internal Mammary Artery for Isolated First Myocardial Revascularization in Multivessel Disease: Long-Term Clinical Results in Medically Treated Diabetic Patients

We evaluated our experience to investigate if the use of bilateral internal mammary artery (BIMA) grafting, with or without complementary saphenous vein grafts (SVG), increases the quality of the results of coronary bypass grafting in medically treated diabetic patients who undergo first myocardial revascularization, when compared with the use of a single left internal mammary artery (LIMA) and SVG. From October 1991 to December 2001, 558 diabetic patients with multivessel coronary disease had first isolated myocardial revascularization using LIMA and SVG (group LIMA) in 217 cases and BIMA +/- SVG (group BIMA) in 341. Propensity score analysis identified 400 patients, 200 for each group, with similar preoperative characteristics. Thirty-day outcome and 8-year freedom from death from any cause, cardiac death, acute myocardial infarction (AMI), AMI in a grafted area, redo/percutaneous transluminal coronary angioplasty (PTCA), redo/PTCA in a grafted area, target cardiac events, and any event were evaluated. Follow-up ranged from 2.0 to 12.2 years (mean 6.0 +/- 2.0). There was no difference between groups except the cardiac deaths, which were significantly higher in the LIMA group (7 versus 0, p = 0.015). The BIMA group showed better 8-year freedom from death any cause (86.7 +/- 3.2 versus 79.5 +/- 4.1, p = 0.0274), cardiac death (96.3 +/- 1.4 versus 88.4 +/- 4.0, p = 0.0406), acute myocardial infarction (99.5 +/- 0.5 versus 92.0 +/- 3.9, p = 0.0092), and acute myocardial infarction in a grafted area (99.5 +/- 0.5 versus 93.4 +/- 3.7, p = 0.0204). Cox analysis confirmed that the use of LIMA and SVG was an independent predictor for lower freedom from death (hazard ratio [HR] = 1.8, p = 0.0310), cardiac death (HR = 1.9, p = 0.0426), AMI (HR = 9.7, p = 0.0033) and AMI in a grafted area (HR = 8.2, p = 0.0410). In diabetic patients with multivessel disease who undergo first myocardial revascularization, BIMA +/- SVG provides higher freedom from death, any cause, and cardiac-related death, if compared with LIMA + SVG. It plays a protective role in reducing the incidence of late AMI.

Use of the internal mammary artery graft and in-hospital mortality and other adverse outcomes associated with coronary artery bypass surgery.

There is clear evidence that patients having coronary artery bypass graft surgeries with an internal mammary artery (IMA) have better long-term survival. Some studies have suggested a short-term protective effect as well but, because older and sicker patients are less likely to receive an IMA graft, there has been concern that the apparent protective effect of the IMA on short-term mortality has been confounded by other risk factors. This study was intended to examine the independent effect of IMA grafts on in-hospital mortality while adjusting for patient and disease factors. We studied the use of the left IMA (LIMA) in 21 873 consecutive, isolated, first-time coronary artery bypass graft procedures from 1992 through 1999. A total of 87% of the patients received a LIMA graft. LIMA graft use was associated with a significantly decreased risk of mortality. The crude odds ratio for death (LIMA versus no LIMA) was 0.26 (95% confidence intervals, 0.22, 0.31; P:<0.001). LIMA grafts were protective across all major patient and disease subgroups. The odds ratios by subgroup ranged from 0.13 to 0.48. After adjustment for all major risk factors, the odds ratio for death was 0.40 (95% confidence intervals, 0.33, 0.48; P:<0.001). Rates of cerebrovascular accident, return to cardiopulmonary bypass, return to the operating room for bleeding, and mediastinitis or sternal dehiscence requiring surgery were also less in the LIMA group, although not significantly so. These data suggest that in addition to its well-documented patency and long-term beneficial effect, LIMA grafting has a strong protective effect on perioperative mortality.