Blood consumption in total arterial coronary artery bypass grafting.

BACKGROUND: Accumulating evidence consistently demonstrates that blood transfusion in cardiac surgery is related to decreased short- and long-term survival. We aimed to evaluate periprocedural blood loss and transfusion rates in elective, isolated total arterial coronary artery bypass grafting (CABG) using exclusively skeletonized bilateral internal mammary arteries (IMAs). METHODS: We identified 1011 consecutive patients with coronary artery disease who underwent CABG between 1/2007 and 12/2014. Of them, 595 patients who presented preoperative hemoglobin levels >9md/dl and underwent elective, isolated CABG for multi-vessel coronary artery disease were included in the study population. 419 patients (70.4%) received total arterial CABG using skeletonized bilateral IMAs, in 176 patients (29.6%) mixed CABG (single IMA & saphenous vein) was performed. Propensity score adjustment using 16 variables was applied to control for treatment effect. RESULTS: In patients undergoing total arterial CABG, heterologous blood transfusion could be avoided in 87.8% of all cases. Propensity score adjusted results showed a significantly lower incidence of erythrocyte concentrate transfusion in patients undergoing total arterial CABG compared to mixed CABG (odds ratio 2.74, 95% confidence interval 1.38-5.43, P = 0.004). There were no statistically significant differences in the rates of thrombocyte concentrate (P = 0.39) and fresh frozen plasma transfusions (P = 0.07). CONCLUSIONS: In this study, patients who underwent elective, isolated total arterial CABG using exclusively skeletonized bilateral IMAs showed reduced transfusion rates of erythrocyte concentrates compared to mixed CABG using a combination of single IMA and saphenous vein grafts. No evidence for a higher incidence of complications was found with a total arterial approach.

Successful management of a case of electrical storm due to invasive endocarditis.

We present a 44-year-old man with invasive aortic and tricuspid valve endocarditis complicated by electrical storm, which was immediately diagnosed and successfully treated due to the patient's telemetry electrocardiogram (ECG). This case highlights a rare but potentially fatal complication in patients with invasive endocarditis and the need for very careful clinical evaluation and monitoring of these patients.

Superior venous drainage in the "LifeBox": a portable extracorporeal oxygenator with a self-expanding venous cannula.

BACKGROUND: In an experimental setting, the performance of the LifeBox, a new portable extracorporeal membrane oxygenator (ECMO) system suitable for patient transport, is presented. Standard rectilinear percutaneous cannulae are normally employed for this purpose, but have limited flow and pressure delivery due to their rigid structure. Therefore, we aimed to determine the potential for flow increase by using self-expanding venous cannulae. METHODS: Veno-arterial bypass was established in three pigs (40.6+/-5.1 kg). The venous line of the cardiopulmonary bypass was established by cannulation of the external jugular vein. The arterial side of the circulation was secured by cannulation of the common carotid artery. Two different venous cannulae (SmartCanula 18/36F 430mm and Biomedicus 19F) were examined for their functional integrity when used in conjunction with the centrifugal pump (500-3000 RPM) of the LifeBox system. RESULTS: At 1500, 2000, 2500, and 3000 RPM, the blood flow increased steadily for each cannula, but remained higher in the self-expanding cannula. That is, the 19F rectilinear cannula achieved a blood flow of 0.93+/-0.14, 1.47+/-0.37, 1.9+/-0.68, and 1.5+/-0.9 l/min, respectively, and the 18/36F self-expanding cannula achieved 1.1+/-0.1, 1.9+/-0.33, 2.8+/-0.39 and 3.66+/-0.52 l/min. However, when tested for venous line pressure, the standard venous cannula achieved -29+/-10.7mmHg while the self-expanding cannula achieved -13.6 +/-4.3mmHg at 1500 RMP. As the RPM increased from 2500 to 3000, the venous line pressure accounted for -141.9+/-20 and -98+/-7.3mmHg for the 19F rectilinear cannula and -30.6+/-6.4 and -45+/-11.6mmHg for the self-expanding cannula. CONCLUSION: The self-expanding cannula exhibited superior venous drainage ability when compared to the performance of the standard rectilinear cannula with the use of the LifeBox. The flow rate achieved was approximately 40% greater than the standard drainage device, with a maximal pump flow recorded at 4.3l/min.

Does retrograde cerebral perfusion via superior vena cava cannulation protect the brain?

OBJECTIVE: The retrograde cerebral perfusion via cannulation of the superior vena cava is a widespread method for optimising protection of the brain during hypothermic circulatory arrest. METHODS: In 14 cadavers (8 females, 6 males) of the local department of pathology, an examination was performed to check the competence of the valves of the internal jugular veins. After a complete preparation of the superior vena cava, the innominate vein and both internal jugular veins, ligating all side branches, a retrograde perfusion on 7 cadavers was installed, documenting flow and pressure of each internal jugular vein (IJV) in vitro. Afterwards, the veins were opened and their valves inspected. RESULTS: In all 14 cadavers, anatomically and functionally competent valves on the right proximal IJV were found. Only 1/14 cadaver had no valve in the left proximal IJV. Additional rudimentary and incompetent valves could be identified in 1/14 cadaver on the distal right IJV, and in 2/14 cadavers on the left IJV. Retrograde flow measurement of 7/14 cadavers revealed 0 ml/min in 4/7 cadavers, 6 ml/min in 1/7, 340 ml/min in 1/7 and 2500 ml/min in 1/7 cadaver. CONCLUSIONS: As a rule, anatomically and functionally competent valves in the proximal IJV are present. In human beings, they obstruct the direct retrograde inlet to the intracranial venous system, which suggests an unbalanced and unreliable perfusion of the brain. Therefore, retrograde cerebral perfusion by cannulating the superior vena cava may help flushing out embolism and supporting 'the cold jacket' of the brain. However, its effect of retrograde backflow cannot be a sign of adequate cerebral perfusion.

Clinical anatomy of the atrioventricular node artery.

BACKGROUND AND AIM OF THE STUDY: The study aim was to describe the topographical relationship of the atrioventricular (AV) node artery and mitral valve annulus fibrosus with regard to AV node dysfunction following mitral valve replacement or ring annuloplasty. METHODS: The anatomy of the AV node artery was analyzed in 55 human hearts without previous pathological alterations. Selective coronary angiograms were performed to identify the AV node origin. Run-off of the AV node artery and its topographical relationship to the mitral valve attachment was analyzed in dry-dissected hearts. The position of the AV node was verified by histological sectioning. RESULTS: The AV node artery originated from the right coronary artery in 73% of examined cases, and from the left coronary artery in 27% of cases. The left AV node artery was closely related to the mitral valve attachment, especially at the area of the left proximal part of the posterior leaflet. CONCLUSION: These morphological data were compared to clinical reports emphasizing the postoperative incidence of AV block after mitral valve implantation and ring annuloplasty. The occurrence of early postoperative AV node block ranged from 20% to 37%. By comparing the present data with available literature, it can be stated that there is a high risk of intraoperative damage to the left AV node artery during manipulation of the mitral valve annulus fibrosus.

Aortopulmonary fistula occurring 4 years after replacement of the ascending aorta.

A 62-year-old man presenting with congestive heart failure due to a fistula between an aortic pseudoaneurysm and the right pulmonary artery is described. The shunt occurred 4 years after aortic valve and supracoronary graft replacement and was diagnosed by transesophageal contrast echocardiography. After redo surgery the patient made an uneventful recovery.

Absence of histamine-induced nitric oxide release in the human radial artery: implications for vasospasm of coronary artery bypass vessels.

Radial artery (RA) bypass grafts can develop severe vasospasm. As histamine is known to induce vasospasm, its effect on RA was assessed compared with the classic bypass vessels internal mammary artery (MA) and saphenous vein (SV). The vessels were examined in organ chambers for isometric tension recording. Histamine induced contractions on baseline; the sensitivity was higher in RA and SV than MA. After precontraction with norepinephrine, histamine did not evoke relaxations of RA but induced relaxations of MA and less of SV at lower concentrations; it induced contractions at higher concentrations, reaching similar levels in all three vessels. Indomethacin did not affect the response of MA and RA but potentiated relaxations and reduced contractions of SV. Endothelium removal, N(omega)-nitro-L-arginine methyl ester (L-NAME), or the H2-receptor blocker cimetidine did not affect the response of RA, but inhibited relaxations and enhanced contractions in MA and inhibited relaxations in SV; in the latter, only L-NAME enhanced contractions. Real-time PCR detected much lower expression of endothelial H2-receptor in RA than MA or SV. Western blots revealed similar endothelial nitric oxide (NO) synthase expression in all three vessels. Relaxations to acetylcholine were identical in RA and MA. Thus histamine releases NO by activating the endothelial H2-receptor, the expression of which is much lower in RA than MA or SV. H2-receptor activation also releases prostaglandins in SV, partially antagonizing NO. The lack of histamine-induced NO production represents a possible mechanism of RA vasospasm.

Advantages of subclavian artery perfusion for repair of acute type A dissection.

OBJECTIVE: Arterial perfusion through the right subclavian artery is proposed to avoid intraoperative malperfusion during repair of acute type A dissection. This study evaluated the clinical and neurological outcome of patients undergoing surgery of acute aortic type A dissection following subclavian arterial cannulation compared to femoral artery approach. METHODS: From 1/97 to 1/03, 122 consecutive patients underwent surgery for acute type A aortic dissection. Subclavian cannulation was performed in 62 versus femoral cannulation in 60 patients. Clinical characteristics in both groups were similar. Mean age was 61 years (SD+/-14 years, 72% male) and mean follow-up was 3 years (+/-2 years). Patient outcome was assessed as the prevalence of clinical complications, especially neurological deficits, mortality at 30 days, perioperative morbidity and time of body temperature cooling and analyzed by nominal logistic regression analysis for odds ratio calculation. RESULTS: Arterial subclavian cannulation was successfully performed without any occurrence of malperfusion in all cases. Patients undergoing subclavian cannulation showed an odds ratio of 1.98 (95% CI 1.15-3.51; P=0.0057) for an improved neurological outcome compared to patients undergoing femoral cannulation. Re-exploration rate for postoperative bleeding was significantly reduced in the subclavian group (P<0.0001), as well as occurrence of myocardial infarction (P<0.0001) and duration for body temperature cooling (P=0.004). The 30-day mortality of patients with femoral cannulation was significantly higher compared to patients with subclavian artery cannulation (24 versus 8%; P=0.0179). CONCLUSIONS: Arterial perfusion through the right subclavian artery provides an excellent approach for repair of acute type A dissection with optimized arterial perfusion body perfusion and allows for antegrade cerebral perfusion during circulatory arrest. The technique is safe and results in a significantly improved clinical and especially neurological outcome.

Early bypass occlusion after deployment of nitinol connector devices.

BACKGROUND: Reducing the negative side effects associated with extracorporeal circulation is the major advantage of off-pump revascularization. However, side clamping of a calcified aorta for proximal anastomoses can cause emboli, resulting in neurologic damage. This problem has been addressed by introducing a mechanical anastomosis device (Symmetry, St Jude Medical) that allows vein-to-aorta anastomosis without manipulating the aorta. This report describes our experience with this device. METHODS: Between June 2001 and April 2002, 77 connectors (1.3 per patient) were deployed in 61 patients (51 men and 10 women; mean age, 68 +/- 8.6 years) undergoing off-pump coronary artery bypass grafting or beating-heart revascularization. Intraoperative quality assessment included transit-time flow measurement (Medistim) and indocyanine green-based angiography (Spy, Novadaq). RESULTS: The surgeons were meticulously trained in loading of the device. No postoperative neurologic deficits were detected. Fifty-three patients had an uneventful course. However, 8 (13.1%) patients with 12 implanted connectors were symptomatic within 8 months (1 day to 8 months). Angiography revealed significant (95%) stenosis or even occlusion of the proximal vein-to-aorta anastomosis at the level of all connectors. Four patients underwent reoperation (2 dilated-stented and 2 treated with drugs). CONCLUSION: On the basis of these observations, the routine use of the connector was halted at our institution. At the moment, the use of this therapy is reserved for patients with severely calcified aortas with no technical alternative. Further investigations appear necessary to evaluate the clinical patterns of this otherwise promising technology.

Short-term results of endovascular AAA repair with the Excluder bifurcated stent-graft.

PURPOSE: To evaluate the safety and efficacy of endovascular abdominal aortic aneurysm (AAA) repair with a commercial modular stent-graft. METHODS: Between February 1998 and May 2000, 66 consecutive patients (56 men; mean age 70 years, range 51-87) were recruited for a single-center study to examine the safety and efficacy of the Excluder stent-graft for endovascular AAA repair. The patients were predominantly asymptomatic (2 symptomatic) and categorized as ASA III or IV (62, 94%), with aneurysms that ranged from 35 to 89 mm in diameter (mean 56). Surveillance included clinical examination and computed tomographic aortography at discharge, 6 weeks, and at 6, 12, and 24 months. RESULTS: All endoprostheses were implanted as intended, but 1 patient succumbed to an intraprocedural brainstem infarction (1.5% 30-day mortality rate). The major and minor morbidity rates were 21% and 4.5%, respectively. Primary technical success at discharge was 68% (45/66), largely as the result of a 30% (20/66) endoleak rate. The aneurysm exclusion rate at 30 days was 88%. During the mean 5.8-month follow-up, no device migration, limb kinking, aneurysm rupture, or limb thrombosis was observed. CONCLUSIONS: Endoluminal AAA repair with the bifurcated Excluder stent-graft is safe and efficacious in the short term. Longer surveillance will have to demonstrate if the excellent early results can be maintained over the years.