Impact of Conventional Cardiovascular Risk Factors on Left Internal Mammary Artery Graft Disease

Background:The development of atherosclerosis was considered as the common cause of the stenosis of coronary artery grafts. Left internal mammary artery (LIMA) was the best artery graft for further effectiveness of coronary artery bypass grafting (CABG). We sought to assess the impact of known conventional cardiovascular risk factors (RFs) on LIMA graft stenosis.Methods:A retrospective study including 618 participants, who had recurrence of chest pain after CABG, aged ≥18 years, hospitalized for coronary angiography in Beijing Anzhen hospital between 2010 and 2017 was performed. All the participants were confirmed to have LIMA graft. Multivariate analysis was conducted to determine the relationship between conventional RFs and LIMA graft stenosis.Results:Of the study, 220 (35.6%) participants continued to smoke, 504 (81.6%) were overweight or obese, and 411 (66.5%) and 242 (39.2%) reported concomitant hypertension and diabetes, respectively. LIMA graft stenosis occurred in 161 participants (26.1%). Postoperative smoking, a CABG duration of ≥10 years and hyperglycemia without diabetes had an increased risk of LIMA graft stenosis, the odds ratio (OR) was 1.86 [95% confidence interval (CI): 1.26–2.78], 2.24 (95%CI:1.33–3.478), and 2.44(95% CI:1.39–4.32), respectively. Statin use (OR, 0.28; 95% CI: 0.25–0.5) and low-density lipoprotein cholesterol (LDL-C) < 1.8 mmol/L (OR, 0.27; 95% CI: 0.14–0.53) had a significantly decreased risk of LIMA graft stenosis. While, only 15.4% (95/618) achieved the target LDL-C level.Conclusions:Postoperative smoking and hyperglycemia without diabetes had an increased risk of LIMA graft stenosis. Statin use and LDL-C <1.8 mmol/L decreased the risk.

Left Internal Mammary Artery to Left Anterior Descending Artery. An Alternative for old, High-Risk, Multivessel, Coronary Artery Disease Patients and an Approach for Hybrid Revascularization

In 1997, the first ambulatory off-pump left internal mammary artery (LIMA) to left anterior descending artery (LAD) anastomosis was performed via xiphoid approach, an intervention known today as the MINI-OPCAB operation. This operation has been performed in more than 150 patients around the world for the management of single and multiple vessel coronary artery disease, and 70 of those cases underwent the procedure in our Foundation from 1997 to 2021, showing no operative mortality or reintervention rates, low conversion rates, early hospital discharge, and 100% graft patency at the follow-ups. The minimally invasive direct coronary artery bypass (MIDCAB) procedure was introduced in 1994 by Benetti from Argentina, and was developed based on our previous experience performing off-pump coronary surgery by manipulating the ascending aorta through a left-sided small thoracotomy. Although it represents one of the most common minimally invasive procedures done worldwide, the original technique is not easy to reproduce, and in most cases the pleura is opened, which increases patients pain, morbidity, hospital length of stay, and hinders the realization of immediate hybrid revascularization after the procedure. The latest minimally invasive approaches for CABG include robotic-assisted procedures, in which the IMAs are harvested using robotic technology or the whole procedure is done using robotic technology. This approach has shown adequate short-term clinical results, however, there are no studies available reporting the procedure’s long-term results. Conclusion: The MINI-OPCAB operation is a friendly approach to perform Minimally Invasive Coronary Bypass Surgery in old, high-risk, multivessel coronary artery disease patients, and it represents a good intervention alternative for the majority of cardiac surgeons and cardiac specialized centers. We also consider this approach as ideal for patients who further require Hybrid Revascularization; however, more experience is needed to validate this initials results.

“Pleurotomy during CABG on the Clinical Outcome Following Left Internal Mammary Artery (LIMA) Harvesting”

Background: The internal mammary artery (IMA) is the graft of choice for coronary artery bypass grafting (CABG) due to superior patency and enhanced patient survival. Pleurotomy during coronary artery bypass grafting (CABG) may cause post-operative events, mostly pulmonary complications. Objective: To assess the impact of intact pleura during left internal mammary artery harvesting on clinical outcome. Materials and Methods: This Cross sectional observational study was carried out in the Department of Cardiac Surgery, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from January 2019 to December 2019.101 patients who underwent Department of Cardiac Surgery, BSMMU were enrolled in this study and divided into two groups: group A (n = 48, 36 male and 12 female patients at a mean age of 56.5 ± 11.2 years) underwent routine CABG and pleurotomy and group B (n = 53, 45 male and 8 female patients at a mean age of 55.4 ± 10.3 years) had CABG with intact pleura. The patients were compared regarding their demographic data, surgical data, and postoperative events. Results: The Incidence Of Postoperative Pericardial Effusion Was Similar Between The Groups, But The Incidence Of Postoperative Pulmonary Complications Such As Pleural Effusion (Except For Mild Pleural Effusion) On The Second (No: 10.4%, mild: 41.7%, moderate: 45.8% and severe: 2.1% in group A versus no: 42.6%, mild: 44.4%, moderate: 13%, and severe: 0 in group B) and fifth postoperative days (no: 27.1%, mild: 33.3%, moderate: 35.4%, and severe: 4.2% in group A versus no: 42.6%, mild: 44.4%, moderate: 13%, and severe: 0 in group B) was significantly lower in group B (p value < 0.001 and p value = 0.007, respectively). Also, the incidence of atelectasis (except for mild atelectasis) on the second (no: 2.1%, mild: 22.9%, moderate: 72.9%, and severe: 2.1% in group A versus no: 9.2%, mild: 59.3%, moderate: 31.5%, and severe: 0 in group B) and fifth postoperative days (no: 22.9%, mild: 39.6%, moderate: 35.4%, and severe: 2.1% in group A versus no: 39.6%, mild: 49.1%, moderate: 11.3%, and severe: 0 in group B) was significantly higher in group A (p value < 0.001 and p value = 0.004, respectively). Postoperative partial oxygen pressure and O2 saturation were similar between the groups, but partial carbon dioxide pressure was significantly lower in group A (p value = 0.017). Amount of bleeding (p value = 0.008) and duration of hospitalization (p value = 0.002) were significantly higher in group A than those in group B. Conclusion: Our results indicate that keeping the pleura intact has beneficial effects on the respiratory function, without increasing the incidence of postoperative pericardial effusion.

Accelerated hypofractionated radiotherapy for chest wall and nodal irradiation using hybrid techniques

Aim: This study compares three different hybrid plans, for left-sided chest wall (CW) and nodal stations irradiation using a hypofractionated dose regimen. Materials and methods: Planning target volumes (PTVs) of 25 breast cancer patients that included CW, supraclavicular (SCL) and internal mammary node (IMN) were planned with 3 different hybrid techniques: 3DCRT+IMRT, 3DCRT+VMAT and IMRT+VMAT. All hybrid plans were generated with a hypofractionated dose prescription of 40·5 Gy in 15 fractions. Seventy per cent of the dose was planned with the base-dose component and remaining 30% of the dose was planned with the hybrid component. All plans were evaluated based on the PTVs and organs at risk (OARs) dosimetric parameters. Results: The results for PTVs parameters have shown that the 3DCRT+IMRT and 3DCRT+VMAT plans were superior in uniformity index to the IMRT+VMAT plan. The OARs dose parameters were comparable between hybrid plans. The IMRT+VMAT plan provided a larger low dose volume spread to the heart and ipsilateral lung (p < 0·001). The 3DCRT+VMAT plan required less monitor units and treatment time (p = 0·005) than other plans. Conclusion: The 3DCRT+VMAT hybrid plan showed superior results with efficient treatment delivery and provide clinical benefit by reducing both low and high dose levels.

Comparison between Bilateral Internal Mammary Artery Graft and LIMAG in Patients Undergoing CA Bypass Grafting

Background: Increasing evidence continues to demonstrate a survival advantage for bilateral internal mammary artery (BIMA) over Left internal mammary artery for coronary artery bypass grafting (CABG). However, there are still uncertainties about which surgical approach is the best one to use with BIMA grafting. Objective: To compare Bilateral Internal Mammary Artery (BIMA) Grafting with Left Internal Mammary Artery (LIMA) Grafting during Coronary Artery Bypass Grafting (CABG) in terms of early mortality and sternal wound infections. Materials & Methods Randomized: control trialtechnique enrolled. The study was conducted at the Cardiac Surgery Department, King Edward Medical University (KEMU), Mayo Hospital Lahore Results: Total 96patients undergoing CABG were included in this study. Patients were randomly divided into 2 groups; each group contains 48 patients. Group A included patients having Left IMA to LAD; second and third graft by Great Saphenous Vein and Group B included patients having Bilateral Internal Mammary Arteries with Left IMA to LAD or OM and Right IMA to RCA, LAD or Ramus Intermedius. The superficial and deep sternal wound infections was recorded along with the different risk factors including diabetes, obesity, hypertension, smoking and use of inotropes intra-operatively and post operatively. The incision site over the sternum was being evaluated on daily basis throughout the stay of the patients (from 5–8 days). Diagnosis of Sternal infections was based on the presence of positive cultures, dehiscence of the sternum incision, fever, redness pain, and infected (purulent) secretions. Sternal instability and discharge, ventilation time, length of ICU stay, chest drainage, re-exploration and length of hospital stay was also recorded. Results:Not any of the patients included in these two treatment groups suffered from mortality (LIMA: 0%, BIMA: 0%). Deep sternal wound infection [LIMA: 4.17% & BIMA: 6.25%, p-value=0.646] and superficial wound infection [LIMA: 4.17% & BIMA: 6.25%, p-value=0.646] did not show any statistically significant association towards both grafts type. Patients who underwent BIMA grafting suffered from higher in hospital stay as compared to patients who underwent LIMAgrafting. i.e. [LIMA: 7.02 & BIMA: 8.02, P value = 0.000] Conclusion: Results of the study showed no significant difference for deep sternal wound infection and superficial wound infection between the two grafts BIMA and LIMA. However, patients who underwent BIMA grafting had significantly higher hospital stay as compared to patients who underwent LIMA grafting. Keywords: Bilateral, Internal, Mammary Artery, Grafting, Left, Internal Mammary Artery, Coronary Artery, Bypass, Grafting, Mortality, Sternal wound infections.

324 Unilateral pulmonary artery agenesis with controlateral embolism: a double vascular trouble

Methods and results A 60-year-old male patient underwent coronary angiography (CA) for a non-ST segment elevation myocardial infarction (NSTEMI). CA revealed significant multivessel disease. Both internal mammary arteries (AMI) were patent, with right IMA markedly larger than the left IMA. The exam revealed also an abnormal branch arising from the proximal right coronary artery extending backwards, likely to the right lung. Pre-operative chest radiograph demonstrated asymmetry of the two hemithoraces with slight elevation of the right hemidiaphragm, small ipsilateral lung, and mediastinal shift towards the right. The patient underwent urgent CABG surgery. Myocardial revascularization was successfully performed using both AMI and one saphenous vein segment. The postoperative course was complicated by respiratory failure requiring prolonged mechanical ventilation. A chest computed tomography angiography was performed, revealing complete absence of the right pulmonary artery and a left lower lobe segmental pulmonary embolism. Furthermore, blood in the hypoplastic right lung was supplied by multiple collaterals arising from RCA and right IMA. Intravenous heparin was started with clinical improvement. Two weeks later, a lung scintigraphy was performed, ruling out perfusion defects. The patient was discharged home on oral anticoagulation with warfarin. Conclusions Unilateral pulmonary artery agenesis (UPAA) is an uncommon congenital anomaly of the great vessels. Despite the absence of the pulmonary artery, blood supply of ipsilateral lung is provided by systemic collaterals originating from bronchial, intercostal, internal mammary, and sub-diaphragmatic arteries. More rarely, these collaterals may arise from the coronary arteries with different implications, ranging from asymptomatic condition to myocardial ischaemia and infarction. In our case, the condition was previously asymptomatic. The occurrence of pulmonary embolism contributed to worsen the ventilation–perfusion mismatch, explaining the respiratory failure during the postoperative period.