Hemolytic characteristics of three suctioning systems for use with a newly developed cardiopulmonary bypass system.

INTRODUCTION: We have been developing a closed-circuit cardiopulmonary bypass (CPB) system ("Dihead CPB") for application during coronary artery bypass grafting (CABG) and valve surgery. To strive for minimal hemolysis during Dihead CPB, we compared the hemolysis caused by three different suction systems and performed a clinical study with the newly applied suction system. MATERIALS & METHODS: We evaluated the hemolysis caused by roller-pump suction, the SmartSuction® Harmony® and wall suction systems with respect to suction speed and compared the systems by means of in vitro studies. A clinical study was also performed on 15 volunteers to assess hemolysis and the adequacy of the newly applied suction system with Dihead CPB. RESULTS: Pressure inside the suction cannula was -22.5 ± 0.1 mmHg at a maximum flow of 1.5 L/min for roller-pump suction and -43.4 ± 0.1 mmHg at -150 mmHg of the set vacuum pressure of wall suction. With the SmartSuction, the pressure inside the cannula varied from -76.3 ± 1.0 to -130.3 ± 1.5 mmHg, depending on suctioning conditions. Suction speed (to suction 50 ml of blood) was fastest with the SmartSuction (69.7 ± 3.58 s) whereas, with roller suction, it was 117.3 ± 8.47 s and with wall suction 96.9 ± 7.10 s. The SmartSuction had the highest hemolysis rate (2.00 ± 0.33%) vs. 0.61 ± 0.10% for roller suction and 0.41 ± 0.11% for wall suction (p<0.001). The clinical study with wall suction showed no significant increase in plasma free hemoglobin during or after CPB compared with before surgery. CONCLUSIONS: Wall suction had less hemolysis than roller suction or the SmartSuction in the in vitro study and the clinical study with wall suction showed efficient suction speed and acceptable hemolysis, suggesting that Dihead CPB with wall suction is feasible for CABG.

[Successful Treatment with Aortic Stent Graft and Transcatheter Embolization for Bronchial Artery Aneurysm].

We report a case of bronchial artery aneurysm (BAA) successfully treated with a combination of transcatheter embolization and stent graft. A 50-year-old woman was referred to our hospital for further examination of a hemispherical bulging lesion on the middle esophagus detected by gastroscopy. Computed tomography (CT) revealed BAA with a 15 mm-diameter arising from the descending aorta on the left side of the esophagus. We performed transcatheter embolization combined with a stent graft because of a short neck. Postoperative course was uneventful. Follow-up CT showed complete isolation of the blood flow into the BAA. BAA is rare and often found incidentally by diagnostic imaging as shown in our case. Prompt treatment with complete isolation of blood inflow is required because the rupture of BAA is life-threatening.

Biventricular support using a centrifugal pump in a 6 year old with fulminant myocarditis.

We experienced a case of ventricular assist with both a pulsatile-flow and a continuous-flow pump in a pediatric patient, and herein report the clinical course and characteristics of the pumps. A 6-year-old female was diagnosed with fulminant myocarditis and transferred to our hospital for mechanical support. After 12 days of extracorporeal membrane oxygenation, we implanted a left ventricular assist device (LVAD) and a right ventricular assist device (RVAD) using centrifugal Gyro pumps with a membrane oxygenator in a paracorporeal fashion. The membrane oxygenator was removed on postoperative day (POD) 4, and the patient was weaned from the respirator on POD 6. The LVAD was exchanged on POD 13 and 17, and the RVAD was exchanged on POD 14 because of thrombus formation inside the pumps. The RVAD was removed on POD 25. On POD 32, the patient experienced cerebral infarction and the centrifugal Gyro pump was switched to an extracorporeal pulsatile pump. No thromboembolic event occurred after pump conversion, although continuous administration of vasodilators was required to avoid hypertension. She underwent successfully heart transplantation in the USA after 8 months of ventricular support. A centrifugal pump is considered useful for pediatric patients, as pump flow and blood pressure can be relatively easily controlled in the postoperative acute phase compared with the pulsatile pump. However, special care should be taken to monitor for thrombus formation when support length becomes longer than 13 days, and a switch to a pulsatile pump should be considered once the hemodynamic status stabilizes.

Pseudoaneurysm fistulated into the right atrium after double valve replacement.

We discuss a rare case of an ascending aorta pseudoaneurysm fistulating into the right atrium following prior aortic and mitral valve replacement. Transthoracic echocardiography and computed tomography revealed a pseudoaneurysm of the ascending aorta attached to the right atrium with fistulous communication. The pseudoaneurysm arose from the center of the former aortotomy. Emergency remedian sternotomy was performed without aneurysmal injury and with exposure of the left femoral artery and femoral vein. Aneurysmal resection and ascending aorta repair were performed without complication. Exposing peripheral vessels, and initiating cardiopulmonary bypass only after reentry, might be effective in resternotomy to approach ascending aorta pseudoaneurysms.

[Graft Replacement for Adult Aortic Coarctation].

Case 1:a 47-year-old woman who complained of sweating, finger tremor, and chest pain was diagnosed with coarctation of the aorta and hyperthyroidism. She had been diagnosed with hypertension at 25 years of age but had not undergone further examination. Graft replacement was performed without cardiopulmonary or temporary bypass. Case 2:a 30-year-old woman was diagnosed with coarctation during infertility treatment. Although health screening had revealed hypertension 8 years previously, no further assessment took place. She underwent graft replacement with partial cardiopulmonary bypass. In both cases, we conducted a clamp test to decide whether cardiopulmonary or partial bypass was necessary for graft replacement. Blood pressure discrepancy between upper and lower extremities disappeared immediately after surgery, and no ischemic complications were observed. Hypertension in young adults should prompt further scrutiny for anatomical disorders such as coarctation. A clamp test is considered helpful regarding the surgical approach to graft replacement for coarctation.

Platelet function during cardiopulmonary bypass using multiple electrode aggregometry: comparison of centrifugal and roller pumps.

Blood trauma may be lower with centrifugal pumps (CPs) than with roller pumps (RPs) during cardiopulmonary bypass (CPB), because, unlike RPs, CPs do not compress the tubing, and shear stress is considered lower in CPs than in RPs. However, relative platelet function remains unclear. Using multiple electrode aggregometry (MEA), we compared platelet function with CP and RP. Ten swine underwent CPB for 3 h, with five weaned off using CP and five using RP. Platelet function was measured using MEA, as were hemoglobin concentration and platelet count, before sternotomy, after heparin infusion, 30 min and 3 h after starting CPB, after protamine infusion, and 60 min after stopping CPB. Platelet activation was initiated with adenosine diphosphate (ADP), arachidonic acid (AA), and thrombin receptor-activating protein 6 (TRAP). Fibrinogen, platelet factor 4 (PF4), and ß-thromboglobin (ß-TG) concentrations were measured before sternotomy and 60 min after stopping CPB. In the CP group and using ADP, aggregation was significantly reduced 30 min (P = 0.019) and 3 h (P = 0.027) after starting CPB, recovering to baseline 60 min after CPB was stopped. In the RP group, aggregation was significantly decreased 30 min (P = 0.007) and 3 h (P = 0.003) after starting CPB and after protamine administration (P = 0.028). With AA, aggregation significantly decreased 30 min after starting CPB in both the CP (P = 0.012) and RP (P = 0.016) groups, slightly increasing 3 h after starting CPB and after protamine infusion, and recovering to baseline 60 min after CPB cessation. With TRAP, aggregation in the CP and RP groups decreased 30 min after starting the pump, although changes were not significant; aggregation gradually recovered after 3 h and returned to baseline 60 min after the pumps were stopped. There were no significant differences at all sampling points of MEA. In both groups, fibrinogen, PF4, and ß-TG concentrations were similar 60 min after pump cessation and before sternotomy. Platelet function, evaluated with MEA, was lowest 30 min after CPB was started but did not decrease over time in either group. As assessed by MEA, platelet function using CP and RP did not differ significantly. Platelet dysfunction was caused mainly by initial contact with foreign materials and may not be dependent on type of pump.

Pericoronary pseudotumor caused by helicobacter cinaedi.

Cardiac tumors and tumor-like lesions are uncommon; most are true neoplasms. We here report a case of a pericoronary tumor-like lesion surrounding the right coronary artery in a 39-year-old man who presented with fever and chest pain. Although clarithromycin was administered for 1 week, his fever persisted. Helicobacter cinaedi (H. cinaedi) was isolated from blood cultures and found to be sensitive to ceftriaxone. A computed tomography scan showed a tumor-like lesion with no (18)F-fl uorodeoxyglucose uptake surrounding the right coronary artery. After administration of ceftriaxone, the tumor-like lesion diminished in size according to meticulous computed tomography examinations. We therefore concluded that it was caused by H. cinaedi infection. The patient has been followed up closely for 1 year and remains asymptomatic.

[Left atrium thrombus after mitral valve replacement presented with syncope; report of a case].

Left atrial free ball thrombus (LABT) after mitral valve replacement (MVR) is very rare, and sudden death may occur by thrombus impaction to the mitral valve orifice. A 81-year-old woman who underwent MVR and tricuspid annuloplasty ten years ago presented with syncope. She was admitted to a hospital, and echocardiography revealed a LABT. When she took sitting position, she fainted. The free ball thrombus possibly impacted mitral valve orifice. She was transferred to our hospital and an emergent operation was performed. There was a LABT of 4 cm in diameter, which was removed. Postoperative course was uneventful. There are 12case reports which described LABT after MVR, and anticoagulant therapy was insufficient in most of those cases. Strict anticoagulant therapy is important to prevent left atrial thrombus after MVR.

Clinical results and pump analysis of the Gyro pump for long-term extracorporeal life support.

Rescuing patients in severe cardiac failure with extracorporeal support remains challenging. The Gyro pump is a centrifugal blood pump and was now used for cardiopulmonary bypass, although it was originally developed for long-term cardiac assist. Little is known about clinical experiences using this pump. Here, we report on the clinical results of long-term extracorporeal life support for over 4 days using the Gyro pump with Excelung, a hollow fiber oxygenator coated with silicone and heparin. Seven patients underwent extracorporeal life support with 15 pump and oxygenator combinations. Gyro and Excelung were used for venoarterial extracorporeal support in six patients and for right ventricular support in one patient. Patient characteristics, pump driving conditions, and blood chemistry were obtained retrospectively. All pumps were subsequently disassembled and examined macroscopically, with 6 of 15 pumps also examined by scanning electron microscopy (SEM). The patient mortality rate was 57.1%. Mean duration of support was 10.5 ± 7.2 days per pump and oxygenator combination. Lactate dehydrogenase and aspartate aminotransferase were generally maintained below 1000 and 100 IU/L, respectively, after the first 4 days of pump driving. Thrombi were found in two pumps, one used without anticoagulation and the other driven at a very slow rotational speed. SEM revealed no wear in the male bearings and very low wear and deformation (0.02 ± 0.03 mm) in the female bearings. The combination of Gyro and Excelung may be applicable for long-term biventricular and right ventricular support, although proper anticoagulation should be administrated to avoid thrombus formation inside the pump.

[The number of cardiovascular surgeons is decreasing in Nagano].

Shortage of medical doctors has been conspicuous since the residency program has been changed in 2004. We investigated the changes in the number of cardiovascular surgeons, surgical cases and institutes of Nagano from 1996 to 2008. The number of cardiovascular surgeons decreased from 28 to 19. The number of newly joined cardiovascular surgeons were 2.7 +/- 1.4/year from 1996 to 2001 and 1.1 +/- 0.4/year from 2002 to 2008. The number of retirement were 0.7 +/- 0.8/year and 2.3 +/- 1.0/year from 1996 to 2001 and from 2002 to 2008, respectively. The number of surgery cases increased from 340 in 1996 to 771 in 2008. Kaplan-Mayer analysis showed the 50% of cardiovascular surgeons retired in 19 years of their career, and the only 20% of surgeons survived after 29 years. The number of newly joined general surgeons was the only 3 since 2004. We are consolidating the institutes of cardiovascular surgery in Nagano to perform more surgery by fewer surgeons. It is important that working condition of cardiovascular surgeon adapt to young doctor's favor, and new positions should be created for elder cardiovascular surgeons to prevent early retirement.

Mechanical Thrombectomy for Postoperative Stroke in a Patient with Acute Aortic Dissection Type A.

Mechanical thrombectomy has been proposed to expand the treatment time window and enhance revascularization. However, it is unclear whether its use can be extended to patients with occlusions in acute aortic dissection, especially the thoracic aorta. A 55-year-old man underwent graft replacement for acute aortic dissection type A. On postoperative day 2, he developed stroke and computed tomography showed occlusion of the right middle cerebral artery. Mechanical thrombectomy was performed by transbrachial approach. Although successful recanalization was achieved, he suffered hemorrhagic stroke. Since there is no other effective treatment and the neurologic outcome with conservative management is poor, we consider mechanical thrombectomy to be a viable therapeutic option for the treatment of postoperative stroke in patients with acute aortic dissection type A. However, further study is warranted regarding the safety of this technique.

Double D Technique: An Innovative Modified Bifurcated Stent Graft Deployment Strategy for an Isolated Common Iliac Artery Aneurysm With a Challenging Renal Artery Anatomy.

PURPOSE: Endovascular aneurysm repair (EVAR) for an isolated common iliac artery aneurysm (iCIAA) sometimes requires a bifurcated stent graft (SG). In EVAR, it is essential to preserve the renal artery (RA). However, this is challenging in cases of anatomical variation. The double D technique (DDT) can be used in anatomically inadequate cases with a commercially approved bifurcated SG. Here, we report the repair of iCIAA in the presence of a challenging RA anatomy, through EVAR using the DDT. CASE REPORT: An 84-year-old woman was diagnosed with a maximal 35-mm diameter left iCIAA and a nonaneurysmal aorta by computed tomography (CT), which also showed that the right RA arose 50-mm above the aortic bifurcation. The DDT was chosen because commercially approved bifurcated SGs typically require a distance of >70 mm from the proximal position to the aortic bifurcation. Postoperative CT showed excellent results with no endoleaks or SG kinking and occlusion, as well as preservation of robust blood flow to the right RA. CONCLUSION: Endovascular aneurysm repair using the DDT can be an alternative option for treatment of iCIAA with a challenging RA anatomy.

Mini open stent grafting with half sternotomy for aortic arch aneurysm.

BACKGROUND: Open stent grafting is an alternative of graft replacement and thoracic endovascular aortic repair for aortic arch aneurysm. We have performed open stent grafting with half sternotomy (mini-OSG) to reduce in-hospital stay and recovery time of patients and herein report seven cases of mini-OSG for aortic aneurysm and dissection. CASE PRESENTATION: The patients' mean age was 66 years. Cardiopulmonary bypass was performed conventionally, and an open stent graft was inserted via an aortotomy on the aortic arch during circulatory arrest. No mortality occurred. The mean operation time was 387 min, and the mean blood loss was 587 ml. The patients were weaned from the ventilator 7.1 h postoperatively. No pseudoaneurysm or endoleakage was observed during the 2- to 20-month follow-up. CONCLUSIONS: Mini-OSG might be less invasive, although further studies and intensive follow-up are needed.

Open stent graft repair with upper-half Sternotomy for blunt thoracic aortic injury: a case report.

BACKGROUND: Thoracic endovascular aortic repair is now widely applied to the treatment of blunt aortic injury. However, its long-term outcomes remain unclear. Endoleakage and migration might occur in the long term, especially when younger patients undergo endovascular aortic repair. In open stent grafting, the proximal end of the open stent graft is directly sutured to the native aorta, which may reduce the risk of endoleakage and migration. We applied open stent grafting to the treatment of blunt aortic injury in the subacute phase and herein report the patient's clinical course. CASE PRESENTATION: A 20-year-old man with a developmental disorder collided with a steel tower while skiing. He was transferred to our hospital by helicopter. X-ray examination and computed tomography revealed fractures of left humeral head and femoral neck and aortic isthmus dissection. We did not perform an acute-phase operation because of the presence of multiple trauma and instead performed open stent grafting with an upper-half sternotomy 42 days after the injury. He recovered uneventfully without psychological problems other than his preexisting developmental disorder. No endoleakage or aneurysm was observed during an 18-month follow-up period. CONCLUSIONS: Open stent grafting might be an alternative to open surgery and thoracic endovascular aortic repair for blunt chest trauma, although intensive follow-up is needed.

Pseudoaneurysm of graft-graft anastomosis of a hand-sewn branched graft: a case report.

BACKGROUND: Pseudoaneurysm of graft-graft anastomosis is an extremely rare but potentially fatal complication after thoracic aorta replacement with a prosthetic graft. We report a case of pseudoaneurysm at the graft-graft anastomosis of a hand-sewn branched graft. CASE PRESENTATION: A 65-year-old man underwent total arch replacement with a hand-sewn branched graft for Stanford type A acute aortic dissection 22 years ago. During follow-up, serial CT scans showed a pseudoaneurysm on the branched graft which warranted reintervention. Surgical repair involved direct suture of multiple bleeding points which were found at the sites of the hand-sewn branches anastomosis. The postoperative course was uneventful, and no signs of bleeding were observed by CT after the reoperation. CONCLUSIONS: Long-term follow-up is essential to detect late complications at the site of hand-sewn anastomosis.

Patch detachment after mitral valve repair with posterior leaflet augmentation: a case report.

Mitral valve (MV) repair is indicated for patients with severe MR. We report a case of acute MR caused by patch detachment after posterior leaflet augmentation in MV repair. A 65-year-old male underwent MV repair with posterior leaflet augmentation and coronary artery bypass graft 1 month prior to this study. An inverted T-shaped incision was made on the posterior mitral leaflet (PML), and a piece of autologous fresh pericardium was sewn in the PML defect. Seven days after hospital discharge, he started feeling chest pain and presented with pulseless electrical activity. Ultrasonic cardiography showed severe mitral regurgitation (MR), which was suggestive of acute MR. We performed emergency reoperation. The edge of the autologous pericardial patch was detached from the anterior papillary muscle, and MV replacement was performed. He was discharged from the hospital 55 days after the reoperation and returned to his normal daily life. We conclude that avoidance of tension focalization during MV repair may be important.

Characteristics of cardiac allograft vasculopathy induced by immunomodulation in the miniature Swine.

PURPOSE: We aimed to develop swine cardiac transplantation model for study of cardiac allograft vasculopathy (CAV) and to characterize the mechanisms of its formation. METHODS: Heterotropic cardiac transplantation was performed in swine leukocyte antigen mismatched miniature swine, and CAV was induced by immunomodulation by cyclosporine A (CyA). Histology and immunohistochemistry were performed to identify cellular components of CAV. Fluorescence in situ hybridization (FISH) was developed for detection of 1 and Y-chromosome for identification of cell origin in the female donor to the male recipient heart transplantation model. RESULTS: CAV was successfully developed by immunomodulation of CyA. Severity of CAV revealed more prominent in the distal epicardial coronary arteries than proximal coronary arteries. Phenotype of the SMCs proliferated in the intimal thickening of CAV were mostly embryonal/secretory type. Our new chromosome specific probes for FISH method were useful for discrimination of sex of each cell, and proliferated SMCs were revealed to be mainly donor origin. CONCLUSION: CAV mimicking human heart transplantation can be developed by appropriate immunomodulation in the swine. In swine CAV, proliferated SMCs seen in the intimal thickening were demonstrated to be from the donor origin.

Early and midterm results of transapical and right axillary artery cannulation for acute aortic dissection.

BACKGROUND: We combined transapical cannulation and right axillary artery cannulation in the repair of acute type A aortic dissection in order to reduce mortality and morbidity in the presence of risk of malperfusion. Early and midterm outcomes were evaluated. METHODS: Between October 2009 and March 2012, 23 aortic dissection patients (age, 54.3 ± 13.5 years) received graft replacement using a combination of transapical and right axillary artery cannulation. Preoperative malperfusion was present in 16 patients (69.6%). Cardiopulmonary bypass was initiated with axillary artery cannulation applied via the right axilla and right atrial drainage, then aotric cannulation applied via the left ventricular apex. We retrospectively investigated mortality and morbidity as well as cardiac function, which were evaluated echocardiographically during hospitalization and once a year postoperatively. RESULTS: All patients received total arch replacement. In-hospital mortality was 4.3%, and no patient developed intraoperative malperfusion. Intraoperative stroke occurred in one patient (4.3%), and three patients (13.0%) suffered from delayed stroke (10-24 days). These delayed strokes might have resulted from cardiogenic thrombus, although no intracardiac thrombus was found. Mean ejection fraction was 66.1 ± 10.9% in the early postoperative period and 73.1 ± 8.7% midterm. There was no left ventricular asynergy or intracardiac thrombus seen on either early or midterm echocardiography. CONCLUSION: Transapical cannulation with right axillary artery cannulation is a safe and effective procedure that can reduce operative risk associated with aortic dissection. Although transapical cannulation does not appear to impair cardiac function, it may confer a risk of delayed stroke.

A pressure controller of selective cerebral perfusion with single centrifugal pump.

We are developing an original nonroller extracorporeal circulation system (NRECC). However, this NRECC could not perform selective cerebral perfusion (SCP). Therefore, we added cerebral perfusion lines and an automatic pressure controller to the system. The purpose of this study was to evaluate the stability and response of the pressure controller for the SCP in simulated clinical circulation. The NRECC consists of a centrifugal pump, four isolated vacuum suction lines and a conventional module. The SCP line branches from the main perfusion tubing and divides into three lines. Cerebral perfusion is regulated by a pressure controller, which is composed of an actuator, a pressure transducer, and a personal computer. The mock circuit was primed with normal saline, and the actual SCP pressure and flow were measured when the target pressure settled at 60, 80, and 100 mm Hg. The main perfusion flow was maintained at 4 L/min and the main perfusion pressure was altered from 120 to 300 mm Hg. The pressure and flow data were recorded. The SCP pressure was maintained within +/-1.47 mm Hg when the set pressure was 80 mm Hg. Fluctuation of flow in the SCP line was within the range of +/-2.8%. The time needed to reach the steady state pressure was 8+/-1 seconds when the initial setting of the roller occluder was full-open, and it took only 3+/-1 seconds to reach the next initial set pressure. We have developed the NRECC-SCP system. The SCP pressure is stable and quickly reaches steady state via the pressure controller. This system is useful for extracorporeal circulation during aortic arch operation.

Left atrial appendage enlarged by coronary artery fistula after surgical closure of appendage.

Two years previously, a 73-year-old man with mitral regurgitation underwent mitral annuloplasty and left atrial appendage (LAA) exclusion by suturing the orifice from the endocardium. However, the mitral regurgitation became exacerbated, and the left atrium enlarged rapidly over a 6-month period. Computed tomography showed a heterogenic mass in the LAA, and coronary angiography revealed a coronary artery-LAA fistula. Reoperation revealed a thrombus filling the appendage and two small orifices of the coronary artery-LAA fistula located in the endocardium of the appendage. We excised the LAA and closed these fistula orifices concomitant with mitral valve replacement.