Transit-time flow measurement parameters after protamine infusion in CABG surgeries.

OBJECTIVE: The objective of this study is to evaluate protamine sulfate effects on graft's blood flow by comparing transit-time flow measurement (TTFM) values before and after protamine administration. METHODS: This is an observational study with data collected between years 2018 and 2020. Immediate graft patency was evaluated using TTFM. Only patients with TTFM parameters registered before and after protamine infusion were included. The main three parameters studied were:  mean graft flow  (MGF),  pulsatility index (PI), and  diastolic flow (DF). In the first analysis, all conduits were evaluated regardless of the surgical technique used. In a second analysis, on-pump and off-pump groups were compared. Evaluated grafts were left internal thoracic artery, saphenous vein graft (SVG), radial artery, and right internal thoracic artery. Since SVG was numerically the most used graft, an exclusive analysis was created. RESULTS: Our study included 575 patients, resulting in a total of 1686 grafts, mean 2.93 grafts/patient. Off-pump surgery was performed in 158 patients. Before protamine infusion, inadequate TTFM parameters were observed in 3.8% of grafts. Overall, after protamine administration, MGF decreased in all grafts, but its reduction was not statistically significant. PI values increased in the SVG and DF values reduced in LIMA grafts. SVG group analysis showed that after protamine PI values were higher in OM1 and RCA. DF values increased in RCA. The comparison between off and on-pump surgeries, showed that in off-pump cases TTFM measures did not present statistically significant differences. CONCLUSION: Significant variations were observed in TTFM values before and after protamine administration. Although different, those values remained within the normal reference ranges. We recommend that flow measurement should be performed before protamine infusion.

The use of internal mammary vein in coronary artery surgery.

Arterial revascularization, and in particular, left internal mammary artery (LIMA), has shown to improve survival of patients with coronary artery disease. Complete revascularization often requires the use of other grafts and saphenous vein graft is still the most common conduit used. Several other types of grafts have been utilized during revascularization, including the radial artery and gastroepiploic artery. It is recognized that its venous structure can change when submitted to long-term blood pressure regimen. We, herein, report left internal mammary vein (LIMV) utilized as a novel conduit for coronary artery revascularization, that was patent after 6 years. LIMV is an easy graft to harvest if the LIMA is dissected as a pedicle. The long-term patency of LIMV is unknown, but its usage could be suggested for elderly patients with peripheral vascular disease, when long graft patency is not required.

Bentall-de Bono procedure for acute aortic dissection.

We present a patient with an acute type A aortic dissection that involves the aortic root. The high mortality of patients with this condition is often associated with operations performed by surgeons with minimal experience dealing with aortic diseases. Therefore, less-experienced surgeons often opt for less complicated techniques like supracoronary ascending aortic replacement. However, according to the latest guidelines for the management of aortic diseases, the aortic root should be replaced when it is compromised by the dissection. The Bentall-de Bono technique treats the aortic root and demands less experience than valve-sparing aortic surgery.

Geometric reconstruction of a left ventricular aneurysm with coronary artery bypass graft.

Left ventricular aneurysm is a late mechanical complication of untreated acute myocardial infarction. It has become relatively rare since the development of percutaneous cardiac intervention.  Most aneurysms are located at the anterior ventricular wall, and are caused by total occlusion of the left anterior descending artery. Usually, the anterior and apical walls initially become akinetic; this can sometimes evolve into dyskinesia. Thrombus formation is a common finding, since the apical contractility is impaired. This tutorial illustrates the challenging technical aspects of a large thrombus removal, along with the geometric reconstruction of the left ventricular aneurysm and coronary bypass surgery.

Single-lung ventilation with contralateral lung deflation: a simplified method for multivessel off-pump coronary artery bypass grafting.

There are many new alternative methods of minimally invasive myocardial revascularization that can be applied in selected patients who have multivessel coronary artery disease. However, these techniques often require new and expensive equipment. Most multivessel myocardial revascularization is performed via median sternotomy and involves the use of a conventional endotracheal tube. Both lungs are ventilated, and frequently the left pleural cavity is opened. In contrast, single-lung deflation naturally moves the mediastinum within the thorax toward the collapsed lung, without the need to open the pleural cavities. Herein, we describe a simple alternative procedure that facilitates off-pump multivessel coronary artery bypass grafting via complete median sternotomy: single-lung ventilation with contralateral lung deflation. This technique better exposes the more distal right and circumflex coronary artery branches with or without the opening of the pleural cavities.

Myocardial Inactivation of Thyroid Hormones in Patients with Aortic Stenosis.

OBJECTIVE: The human heart expresses the type 2 deiodinase (D2) that activates thyroxine (T4) to triiodothyronine (T3). At the same time, the inactivating type 3 deiodinase (D3) has been found in a rat model of right ventricular hypertrophy. It is not known whether the human myocardium metabolizes thyroid hormone. This study examined myocardial thyroid hormone metabolism in patients with aortic valve stenosis (AS) undergoing aortic valve replacement and in patients with coronary artery disease (CAD) undergoing coronary artery bypass grafting surgery. METHODS: Myocardial thyroid hormone metabolism was assessed by analyzing the difference in serum thyroid hormone levels between the aortic root (incoming blood) and the coronary sinus (outgoing blood) of patients undergoing cardiac surgery. A total of 23 patients with AS and 35 patients with CAD were included. Patients received a pre-surgical echocardiogram, and pre-, during and post-surgical thyroid hormone serum levels were collected in the myocardial and peripheral circulations. RESULTS: Patients with AS exhibited the expected left ventricle (LV) hypertrophy (i.e., 20-30% increase in LV posterior wall and interventricular septum thickness and ∼10% increase in AS in LV diastolic diameter). Immediately before cardiopulmonary bypass, blood flowing through the AS myocardium exhibited a 4.6% reduction in T3 and 6.9% increase in rT3 levels, decreasing the serum T3/rT3 ratio by 9.6%. T4 and thyrotropin serum levels remained similar between the aortic root and coronary sinus. In contrast, no myocardial thyroid hormone metabolism was observed in CAD patients. Notably, the AS myocardium lost the ability to inactivate thyroid hormone after cardiopulmonary bypass, possibly due to myocardial stunning. CONCLUSIONS: There is accelerated thyroid hormone inactivation in the AS myocardium, which is likely the result of D3 expression. No evidence to suggest thyroid hormone activation in the myocardium was obtained in the present study.

Minimally invasive single-vessel coronary artery bypass with the internal thoracic artery and early postoperative angiography: midterm results of a prospective study in 120 consecutive patients.

BACKGROUND: This prospective study was undertaken to determine the role of the minimally invasive direct coronary artery bypass with early postoperative angiography and midterm follow-up in 120 consecutive patients with single-vessel coronary artery disease. METHODS: Minimal access (6 to 10 cm), without complete sternotomy and no cardiopulmonary bypass, was used. The lesions were located at the proximal left anterior descending coronary artery in 95% of the patients. Routine coronary angiography was performed before discharge. RESULTS: Postoperative angiography was performed in 104 (90.4%) of those 115 patients who had coronary revascularization concluded by the mini-access method. The internal thoracic artery patency rate was 98.1% (95.2% grade A). Two (1.7%) patients presented with perioperative myocardial infarction, which led to the single in-hospital death (0.8%). Of the remaining 119 patients, 113 (95.0%) were asymptomatic. The event-free probability was 94.9% and the actuarial survival was 98.3% with 42 months of follow-up. CONCLUSIONS: For selected patients with single-vessel coronary artery disease and no major myocardial dysfunction, minimally invasive direct coronary artery bypass is a safe operation and a less invasive alternative to conventional coronary artery bypass grafting.

Extraanatomic aortic bypass for repair of aortic arch coarctation via sternotomy: midterm clinical and magnetic resonance imaging results.

BACKGROUND: We analyzed our 22 years of experience with extraanatomic bypass grafting for repair of aortic arch coarctation in adults. Results from early and midterm follow-up with clinical evaluation and magnetic resonance angiography are reported. METHODS: Between November 1979 and December 2001, 18 consecutive patients aged 18 to 61 years (mean, 31.8 +/- 13.3 years) underwent extraanatomic bypass grafting to repair coarctation of the aortic arch. Six patients (33.3%) had recoarctation after previous repair through a left thoracotomy, and 3 (16.7%) had associated cardiac diseases. The operative technique used in all patients was ascending aorta-to-descending thoracic aorta bypass with a polyethylene terephthalate fiber (Dacron) graft through a median sternotomy and posterior pericardial approach. RESULTS: Follow-up was completed in all patients, with a mean duration of 5.6 +/- 5.7 years (range, 12 months to 22 years). The follow-up interval exceeded 10 years in 5 patients. No neurologic complications, early or late mortality, late reoperations, or graft complications occurred. Six patients (33.3%) had mild hypertension. All patients were asymptomatic with patent Dacron grafts confirmed by echocardiography. Magnetic resonance angiography, performed in 15 (83.3%) patients, revealed that the Dacron grafts were still patent at a mean interval of 4.0 +/- 6.2 years (range, 5 days to 22 years) after repair. CONCLUSIONS: Extraanatomic ascending aorta-to-descending thoracic aorta bypass grafting for repair of aortic arch coarctation in adults is safe, with low morbidity and no mortality. The favorable midterm results indicate this technique is a safe and less invasive means of repairing aortic arch coarctation or recoarctation in adults.

Limited Left Thoracotomy for Reoperative Coronary Artery Bypass Grafting without Cardiopulmonary Bypass for Circumflex Grafting in Patients with Patent Internal Thoracic Artery Graft.

Abstract Background: We describe our experience with the limited left thoracotomy strategy for reoperative coronary artery bypass graft (CABG)to the circumflex coronary artery system, emphasizing the indications, our particular operative technique, and early clinical follow-up. Methods: From January 2001 to January 2002, 8 consecutive patients underwent redo revascularization via limited left thoracotomy and without cardiopulmonary bypass. This operation was indicated for patients with recurrent myocardial ischemia confined to the lateral wall of the left ventricle, especially if a patent left internal thoracic artery (LITA)-to-left anterior descending coronary artery (LAD)graft was present. Results: All 8 patients underwent successful redo revascularization via limited left thoracotomy. Eight patients received 14 saphenous vein grafts (mean 1.7 grafts/patient). No instances of postoperative myocardial infarction or death occurred. During a follow-up period ranging from 1 to 12 months (mean, 5. 2 months), all patients were asymptomatic and without evidence of ischemia or infarction. Conclusions: For select patients who have patent LITA grafted into the LAD and who need redo CABG to the coronary artery circumflex system, the limited left thoracotomy approach without cardiopulmonary bypass is a safe operation and a less invasive alternative to repeat sternotomy and conventional CABG.

[Initial results on the use of mechanical devices for proximal saphenous vein graft anastomoses: a clinical and angiographic evaluation].

OBJECTIVE: To report on our initial clinical experience of the utilization of a mechanical anastomotic device (MAD) to perform saphenous vein graft to aorta anastomosis. METHOD: Between June 2002 and May 2003, 17 patients, including 13 male, with a mean age of 64.4 +/- 9.4 years, were selected for coronary artery bypass grafting using MAD. A total of 49 anastomoses, 19 arterial and 30 vein grafts, were performed with a mean of 2.9 +/-0.5 anastomoses per patient. Eleven (36.7%) vein-graft anastomoses were performed with conventional sutures and 19 (63.3%) using MAD. The clinical evolution, enzymatic and electrocardiographic alterations as well as an angiographic study were analyzed in the postoperative period. RESULTS: Of the 17 patients, the mechanical device was used on 16 (94.1%). Six (37.5%) patients were operated on under cardiopulmonary bypass with a mean time of 102.9 +/-16.9 minutes. The postoperative evolution was satisfactory in all patients. No patient presented with enzymatic, myocardial infarction or other ischemic electrocardiographic alterations in the immediate postoperative period. Early postoperative angiography was performed in 9 (52.9%) patients. The anastomoses of the left internal thoracic artery to left anterior descending artery were patent in all cases. Of the 15 saphenous vein grafts studied, 11 (73.3%) were performed using MAD, 9 (81.8%) of which were patent. All the 4 conventionally sutured vein anastomoses were patent. No hospital deaths occurred. In the late follow-up, 88.2% of the patients were free of cardiac-related events. CONCLUSIONS: MAD for vein graft-to-aorta anastomoses proved to be feasible, but a wider analysis of the benefits of its utilization regarding operative time, aggression to the patient, patency of the grafts and final cost are necessary.

Synergism between keratinocyte growth factor and carboxymethyl chitosan reduces pericardial adhesions.

BACKGROUND: Mesothelial injury is the pivot in the development of adhesions. An increase in the proliferation of mesothelial cells was verified by in vitro studies with the use of keratinocyte growth factor (KGF). This study investigated the influence of KGF associated with thermo-sterilized carboxymethyl chitosan (NOCCts) in the reduction of pericardial adhesions. METHODS: An induction model of pericardial adhesion was carried out in 24 pigs. Animals were randomly allocated to receive topical application of KGF, KGF + NOCCts, NOCCts, or saline (control). At 8 weeks, intrapericardial adhesions were evaluated and a severity score was established. The time spent to dissect the adhesions and the amount of sharp dissection used, were recorded. Histologic sections were stained with sirius red for a morphometric evaluation using a computer-assisted image analysis system. Cytokeratin AE1/AE3 immunostaining were employed to identify mesothelial cells. RESULTS: The severity score expressed in median (minimum to maximum), in relation to the control group (17 [15 to 18]), was lower in the KGF + NOCCts group (7 [6 to 9], p < 0.01) followed by the KGF group (11.5 [9 to 12], 0.01 < p < 0.05) and the NOCCts group (12 [9 to 14], p > 0.05). The dissection time was significantly lower in the KGF + NOCCts group (7.1 + or - 0.6 vs 33.9 + or - 9.2 minutes, p < 0.001). A significantly less sharp dissection was also required in the KGF + NOCCts group. In the adhesion segment, a decreased collagen proportion was found in the KGF + NOCCts group (p < 0.05). Mesothelial cells were present more extensively in groups in which KGF was delivered (p = 0.01). CONCLUSIONS: The use of KGF associated with NOCCts resulted in a synergic action that decreases postoperative pericardial adhesions in a highly significant way.

[Evolution of cardiovascular surgery at the Instituto do Coração: analysis of 71,305 surgeries].

BACKGROUND: Cardiovascular surgery has been undergoing transformations due to the advancement of percutaneous techniques, clinical treatment and primary prevention. OBJECTIVE: Evaluation of incidence and mortality of heart surgeries performed at the Instituto do Coração (InCor-HCFMUSP). METHODS: Using database from the Instituto do Coração, analysis was carried out on cardiovascular surgeries performed between 1984 and 2007, taking into consideration trends of main procedures and of mortality rates. RESULTS: In 24 years, 71,305 heart surgeries were performed, with an annual average of 2971 procedures. The number of coronary artery bypass graft surgeries, which in the 1980s had an average of 856/year, is currently around 1.106/year. Heart valve procedures increased from 400 to 597 surgeries per year, growing 36.7%, when compared to the 1990s. Repair of congenital heart disease also had a significant increase of 50.8% in relation to the last decade. Global mortality average rate, which at baseline was 7.5%, is currently at 7.0% and 4.9% among elective procedures. In coronary artery bypass graft surgery, current average mortality rate is 4.8% and 8.5% in valve surgery. Repair of congenital heart disease accounts for 5.3%. CONCLUSION: Cardiovascular surgery continues increasing. The coronary artery bypass graft is still the most commonly performed surgery. However, profile of procedures has been undergoing changes with the largest increase of approach to cardiac valves and congenital heart disease. Mortality rates are higher when compared to international rates, reflecting the high complexity presented in tertiary service of national reference.

Transmyocardial laser revascularization plus cell therapy for refractory angina.

We report that the use of transmyocardial laser revascularization combined with intramyocardial injection is a therapeutic option for patients with severe ischemic heart disease (IHD) not amenable to conventional myocardial revascularization. Recently, cell therapy with autologous bone marrow cells (BMC) has been tested in clinical trials for severe IHD. We tested the hypothesis that TMLR combined with intramyocardial injection of BMC is safe, and may help increase the functional capacity and myocardial perfusion in patients with refractory angina. We enrolled 8 patients (7 men), 64+/-4 years old, with refractory angina, non-candidates for another procedure. TMLR (8+/-2 laser drills) was performed via a limited thoracotomy. BMC were obtained prior to surgery, and the lymphomonocytic fraction was separated by density gradient centrifugation. During surgery, 5 mL containing approximately 1.6+/-0.2 x 10(8) BMC (CD34+=1.7+/-0.4%) was delivered by multiple injections in the ischemic myocardium. We observed a reduction in the ischemic score as assessed by MRI from 1.56+/-0.09 (B) to 0.93+/-0.10 (6M) (P=0.01), as well as a reduction in functional class of angina from 3.6+/-0.2 (B) to 1.4+/-0.2 (6M) (P<0.0001). We concluded that, in this early experience, the combined strategy of TMLR plus cell therapy appeared to be safe, and may have synergistically acted to reduce myocardial ischemia, with clinically relevant improvement in functional capacity.