Dynamic alterations in cerebral, celiac and renal flows resulting from ascending aorta, subclavian artery and femoral artery cannulations of extracorporeal devices.

INTRODUCTION: The aim of this study was to assess the relationships among cardiac output, extracorporeal blood flow, cannulation site, right (RCa) and left carotid (LCa), celiac (Ca) and renal artery (Ra) flows during extracorporeal circulation. METHODS: A mock circulatory circuit was assembled, based on a compliant anatomical aortic model. The ascending aorta, right subclavian and femoral artery cannulations were created and flow was provided by a centrifugal pump (Cp); cardiac output was provided by a roller pump (Rp). Five volume flow rates were tested. The Rp was set at 4 L/min with no Cp flow (R4-C0) and the basic volume flow rates of the vessels were measured. The flow of the Cp was increased while the Rp flow was decreased for other measurements; R3-C1, R2-C2, R1-C3 and R0-C4. Measurements were repeated for all cannulation sites. RESULTS: The RCa flow rate at R4-C0 was higher compared to the R3-C1, R2-C2, R1-C3 and R0-C4 RCa flows with subclavian cannulation. The RCa flow decreased as the Cp flow increased (p<0.05). The RCa flow with ascending aortic and femoral cannulation was higher compared to subclavian cannulation. Higher flows were obtained with subclavian cannulation in the LCa compared to the others (p<0.05). R4-C0 Ca and Ra flows were higher compared to other Ca and Ra flows with femoral cannulation. Ca and Ra flows decreased as Cp flow increased. Flows of the Ca and Ra with ascending and subclavian cannulations were not lower compared to the R4-C0 flow (p<0.05). CONCLUSION: This study shows that prolonged extracorporeal circulation may develop flow decrease and ischemia in cerebral and abdominal organs with both subclavian and femoral cannulations.

Should we change the cannulation site for right subclavian artery cannulation? An experimental study with a newly designed cannula.

BACKGROUND:: In this experimental study, we primarily aimed to show the hemodynamic effects and superiority of this newly designed cannula for perfusion compared to standard subclavian cannulation. The new cannula (Figure 1) allows bidirectional axial flow and it directly fits in the brachiocephalic trunk (innominate artery). METHODS:: We used a cardiopulmonary bypass roller pump, reservoir, 3/8- 1/2- 1/4-inch Y-connectors and tubing set. Lines were set as seen in Figures 2, 3, 4 and 5. The anatomy of the aorta (ascending, arch, branches, descending) was mimicked, using tubing sets with different sizes and the connectors yielding similar angles and configurations. In this experimental vascular system, systemic vascular resistance was created with partial clamping of the common tubing set. The cannulation sites were created in the subclavian artery and the innominate artery. Perfusion was established with the same pump rate and the same occlusion pressures (systemic vascular resistance). The pressure readings were obtained in the right carotid artery, the left carotid artery and the left subclavian artery. RESULTS:: These experimental models of vasculature allowed us to measure pressures in the carotid system for different cannulation set-ups, using both our newly designed double-outflow cannula, which was introduced via the innominate artery, and the standard arterial cannula, which was introduced via the subclavian artery. Higher pressure recordings were obtained in the carotid system with the new cannula introduced through innominate artery. CONCLUSION:: Higher cerebral perfusion readings were obtained with our newly designed bidirectional cannula introduced via the innominate artery compared to standard cannulation through the right subclavian artery.

Measure the Vascular Flow Volume rather than Vascular Stenosis and Pressure Gradient.

We aimed to investigate the extent to which measurements of flow volume (FV) with colour flow duplex ultrasonography (CDU) could predict tissue perfusion. A 68 year-old male patient was admitted to our clinic complaining of intermittent claudication in the right leg. Digital subtraction angiography showed total occlusion of the right femoral artery. The right popliteal artery (PA) was filling by collaterals. CDU showed that the FV in the right PA was higher than in the left. Arterial-venous FV measurement with CDU should be performed rather than the detection of arterial stenosis to assess whether intervention is necessary.

Tips and pearls for "true" dextroposition of the aorta in tetralogy of Fallot.

Infundibular stenosis may develop secondary to ventricular septal defect, and transannular patch plasty can affect mortality and morbidity rates. Therefore, dextroposition of the aorta has been investigated in order to eliminate discrepancies in the literature. Figures and illustrations from the selected references have been investigated and "actual dextroposition of the aorta" has been evaluated as far as the aorta is visible. A careful examination of these figures revealed the following tips and pearls for accurate diagnosis of dextroposition of the aorta: Aorta and ventricular septal defect should be adjacent for a "true" dextroposition of the aorta; the plane where the aorta exits from the ventricle should penetrate the plane of the ventricular septal defect towards the right ventricle; if the aorta and ventricular septal defect intersect at one edge, the aorta may seem to be dextroposed; new diagnostic modalities are necessary to evaluate the actual dextroposition status of the aorta for the proper planning of treatment.

Assessment of protective effects of methylprednisolone and pheniramine maleate on reperfusion injury in kidney after distant organ ischemia: a rat model.

BACKGROUND: Ischemia/reperfusion (I/R) injury of tissues is a common problem that cardiovascular surgeons are faced with. Suppression of inflammation, which plays an important role in the pathogenesis of I/R injury, may reduce this damage. The aim of this study is to investigate the protective effects of methylprednisolone (MP)--a potent anti-inflammatory agent--and pheniramine maleate (FM)--an antihistamine that also has some anti-inflammatory effects--on reperfusion injury of kidneys developing after ischemia of the left lower extremity of rats. METHODS: Twenty-eight randomly selected male Sprague-Dawley rats weighing 320 to 370 g were divided into four groups, each consisting of seven rats. Group 1 was the control group. Group 2 was the sham group. Rats in group 3 were subjected to I/R and given FM, and rats in group 4 were subjected to I/R and given MP. A tourniquet was applied at the level of the left groin to subjects in group 2 after induction of anesthesia. One hour of ischemia was performed, and no drug was administered. In group 3, half of a total dose of 10 mg/kg FM was administered before ischemia, and the remaining half was given intraperitoneally before reperfusion. In group 4, subjects received a single dose of 50 mg/kg MP intraperitoneally in the 30th minute of ischemia. Kidneys of all subjects were removed after 24 hours. Extracted tissues were investigated regarding histological and biochemical parameters. RESULTS: Malondialdehyde--the end product of lipid peroxidation as an important indicator of I/R injury--levels were significantly lower in group 3 than in group 2 (P < 0.05). Malondialdehyde levels were also lower in group 4 than in group 2, but this difference was insignificant (P > 0.05). Superoxide dismutase and glutathione peroxidase enzyme activities were found to be significantly higher in group 3 than in group 2 (P < 0.05). However, there was no difference between group 4 and group 2 in terms of these activities. Histological examination demonstrated that both MP and FM had protective effects against I/R injury, but this effect was more potent for FM than for MP. CONCLUSIONS: FM has a protective effect against reperfusion injury in rat kidney after distant organ ischemia.

Crossover femoropopliteal bypass: single graft or double grafts.

BACKGROUND: Both single-graft crossover femoropopliteal (COFP) bypass and crossover femorofemoral plus femoropopliteal bypasses using double grafts may be performed for patients with a medical history of abdominal vascular operations or comorbidity, thereby ineligible for retroperitoneal or transperitoneal approaches. In this study, these two methods were compared. METHODS: A total of 15 patients who were operated on between February 2002 and March 2010 were included and studied retrospectively. Eight of them underwent crossover femorofemoral bypass plus femoropopliteal bypass with double grafts (group 1), whereas the rest seven underwent single-graft COFP bypass (group 2). All the patients were included either in class 3 or class 4 according to Fontaine classification. Preoperative arterial Doppler ultrasound and arteriography were obtained from every patient. Pre- and postoperative ankle-brachial indices were measured. Postoperative clinical parameters were obtained from medical records. RESULTS: Median primary and secondary patency rates were 40.5 (7-105) months and 58 (7-105) months in group 1, respectively. In group 2, these rates were 42 (2-84) months and 44 (11-84) months, respectively. Two patients in group 1 and one patient in group 2 were amputated. There were no significant differences between both groups in terms of duration of hospital stay, duration of intensive care unit stay, and units of packed red blood cells transfused (P > 0.05). In addition, postoperative ankle-brachial indices were significantly improved in both groups (P < 0.05). COFP bypass can be performed for limb salvage in cases with critical limb ischemia with a medical history of previous vascular surgery or comorbidity, thereby ineligible for aortic reconstruction. CONCLUSION: This procedure may also be performed as continuous COFP bypass using a single graft.

The renal effect of replacement fluids in controlled severe hemorrhagic shock: an experimental study.

BACKGROUND: This experimental study examined the effects of resuscitation with Ringer's lactate (RL), 6% hydroxyethyl starch (130/0.4-HES), and the combination of RL and HES on renal function in hemorrhagic shock (HS). METHODS: Twenty-four male New Zealand white rabbits weighing 2198-3435 g were divided at random into four groups. HS was constituted by maintaining the mean arterial blood pressure at 30 mmHg and blood lactate at >4 mM/L. Subsequently, Group 1 (control) was not resuscitated, while the study rabbits' resuscitation was initiated with RL (Group 2), HES (Group 3), or the combination of RL and HES (Group 4). RESULTS: In all groups, the serum creatinine and blood urea nitrogen (BUN) levels were observed to be within normal limits, while the lactate dehydrogenase and alpha-1 microglobulin levels statistically significantly increased when time points were compared with beginning values (p<0.05). Furthermore, cystatin-C levels were observed to be increased after the HS (p<0.05), but returned to the normal level after resuscitation in all the study groups. Interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha levels were increased in all the rabbits after HS (p<0.05), and there were no significant differences among the study groups after resuscitation (p>0.05). There were no differences in the histological imaging between the groups (p>0.05). CONCLUSION: The 6% HES (130/0.4) did not have any harmful effects on the kidney when it was used alone or in combination with crystalloid for resuscitation of HS in rabbits.

Right coronary artery fistula draining into the right atrium and associated with mitral valve stenosis: a case report.

Coronary artery fistula (CAF) is a rare congenital anomaly of the coronary arteries in which abnormal connections are present between the coronary artery branch and the cardiac chambers or a major vessel. The incidence of CAF is estimated at 1 in 50,000 live births, and it is detected in approximately 0.2% of the adult population during coronary angiography. Reports of the coincidence of mitral stenosis and CAF are rare in the literature. We report a case of CAF and mitral valve stenosis in a patient with dyspnea and fatigue before valve replacement and surgical radiofrequency ablation. Coronary angiography showed a connection between the right coronary artery and right atrium. A fistula opening into the right atrium is rare in patients with coronary artery anomalies and mitral valve disease. Coronary angiography of the patient 1 month after surgical repair showed that the coronary anatomy was normal and the fistula was occluded. CAF can be diagnosed more frequently if coronary angiography is performed simultaneously with cardiac catheterization to evaluate valve functions or nonatherosclerotic myocardial ischemia in each valvular heart disease case. Surgical repair of CAF is the first-choice treatment to prevent complications and improve quality of life.

Surgical treatment of prosthetic valve thrombosis: ten years' experience.

BACKGROUND AND AIM OF THE STUDY: Prosthetic valve thrombosis (PVT) is a rare, but serious, complication of heart valve replacement with a mechanical substitute. Herein is presented the authors' surgical experience of 18 patients with PVT. METHODS: A total of 1,584 heart valve operations was performed in 1,365 patients at the authors' institution between June 1995 and September 2005. Surgical reports of prosthetic valve reoperations over the same period were screened. Preoperative, operative and postoperative data were collected from the patient cohorts. RESULTS: Since July 1997, 18 patients (12 females, six males; mean age 35.9 +/- 11.3 years; range: 22-60 years) presented with PVT. The subtherapeutic anticoagulation level was the major etiologic factor involved in the pathogenesis of PVT. Thrombosis occurred in the mitral position in 14 patients (78%), and in the aortic position in four (22%). All mechanical valves implanted were bileaflet (1,097 St. Jude Medical, 324 CarboMedics, and 163 Sorin). The mean duration from valve replacement to PVT was 48.3 +/- 15.4 months. The majority of patients presented with poor functional status (56% in NYHA class IV) and poor anticoagulation (INR < or = 2 in 72% of cases). Valve re-replacement was performed for all patients. The 30-day mortality was 16.7%. CONCLUSION: PVT is a potentially fatal complication of heart valve replacement. These acceptable results suggest that early surgical intervention might be a safe and effective treatment of choice in patients with PVT. Patients with mechanical valve prostheses should be informed adequately about the need for, and the importance of, an effective anticoagulation regimen.