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.

A benchmark in the isolated tricuspid valve surgery is necessary.

Advances in surgical techniques, enabling correction of regurgitation, and preserving the tricuspid valve, are also factors that encourage early surgical indication and improve long-term outcomes.

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.

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.