Anatomical Analysis and Feasibility Study of Next-Generation Fenestrated or Branched Stent-Grafts for the Treatment of Arch Aneurysms.

Purpose: To analyze the anatomical characteristics of arch aneurysms and evaluate the anatomical feasibility of 4 next-generation stent-grafts with either branched or fenestrated configurations. Materials and Methods: A retrospective analysis was conducted of 213 patients (mean age 75.0±7.1 years; 179 men) with arch aneurysms treated using total arch replacement or zone 0 or 1 thoracic endovascular aortic repair (TEVAR) from 2007 to 2017 at 2 Japanese hospitals. Anatomical analyses were performed using the centerline of flow technique on a 3-dimensional workstation. The anatomical feasibility of the Zenith A-branch, TAG Thoracic Branch Endoprosthesis (TBE), Terumo Aortic Relay Plus Double Branched (DB), and fenestrated Najuta stent-grafts were evaluated based on the instructions for use (IFU). Results: The mean lengths from the sinotubular junction (STJ) to the innominate artery (IA) and from the IA to the left common carotid artery were 114.9±15.9 and 12.8±5.6 mm, respectively. The mean aortic diameters at the STJ and IA were 31.3±3.4 and 34.1±5.3 mm, respectively. In terms of feasibility, 5.2% of patients were within the Zenith A-branch IFU, 40.8% for the TAG TBE, 24.9% for the Relay Plus DB, and 13.6% for the Najuta. Significant (>50% circumference) thrombus/calcification at the sealing zone affected nearly half of the patients, but there is currently no standardized definition or evaluation method for "significant" thrombus/calcification. Conclusion: Only 5% to 41% of arch aneurysm patients are anatomically suitable for TEVAR using any one of the next-generation branched or fenestrated stent-grafts. Furthermore, a definitive method of evaluating the thrombus/calcification burden needs to be established in future IFU.

[Aortic Valve Replacement after Balloon Valvuloplasty for Aortic Valve Stenosis in a Dialysis Patient with Cardiogenic Shock;Report of a Case].

A 67-year-old man on chronic hemodialysis was admitted with worsening congestive heart failure due to critical aortic stenosis. Echocardiography showed severe aortic stenosis with a valve area of 0.67 cm2 and an ejection fraction of 0.31. Cardiac catheterization revealed severe pulmonary hypertension with pulmonary artery pressures of 62/32 mmHg. In the middle of cardiac catheterization, the systolic pressure declined to 60 mmHg due to cardiogenic shock. Dopamine hydrochloride and dobutamine hydrochloride infusions were necessary to maintain a systolic pressure greater than 80 mmHg. Balloon aortic valvuloplasty was urgently performed. The patient's symptoms rapidly resolved except for angina on exertion. One month later, elective aortic valve replacement was performed. The postoperative course was uneventful and the he was discharged on the 60th postoperative day. A follow-up echocardiogram 6 months postoperatively revealed normal prosthetic valve function and an ejection fraction of 0.6.

Hemolytic Anemia Occurring 14 Years after Ascending Aortic Replacement for Acute Type A Aortic Dissection Due to Aortic Pseudoaneurysm Derived from Anastomotic Leakage: A Case Report.

A 64-year-old male patient who presented with symptoms indicative of hemolytic anemia was referred to our hospital. After obtaining the patient's history, it was found that hemolysis occurred 14 years after he underwent ascending aortic replacement for acute type A aortic dissection. Enhanced computed tomography revealed an aortic pseudoaneurysm at the proximal anastomosis, which was thought to be the cause of hemolysis. Furthermore, aortic valve regurgitation and dilatation of the sinus of Valsalva were also found on a transthoracic echocardiogram. Therefore, the Bentall procedure was performed. During the surgery, aortic pseudoaneurysm formation and vascular graft stenosis were observed. The postoperative course was uneventful, and hemolysis diminished soon after the surgery.

Clinical outcome of intraoperative hemodialysis using a hemoconcentrator during cardiopulmonary bypass for dialysis-dependent patients.

OBJECTIVES: The basic materials and structure of a hemoconcentrator incorporated into cardiopulmonary bypass (CPB) circuits are similar to those of hemodialyzers. Gravity drainage hemodiafiltration (GHDF) is an easy-to-use intraoperative renal replacement therapy (RRT) that utilizes a hemoconcentrator. This study aimed to verify whether GHDF can correct electrolyte imbalance and remove uremic toxins in dialysis-dependent patients and to evaluate the clinical outcomes of GHDF by comparing it with a conventional method of dilutional ultrafiltration (DUF). METHODS: This study retrospectively compared perioperative clinical values of 41 dialysis-dependent patients (21 patients with GHDF and 20 patients with DUF) who underwent open-heart surgery. Changes in serum parameters before and after passing through the hemoconcentrator were also compared. RESULTS: Compared to DUF, GHDF significantly lowered potassium, blood urea nitrogen, and creatinine levels at the outflow of the hemoconcentrator. Less catecholamine was needed to wean CPB in GHDF than in DUF. The P/F ratio (arterial blood oxygen pressure/inhaled oxygen concentration) at the end of surgery was significantly higher in GHDF than in DUF (450.8 ± 149.7 vs. 279.3 ± 153.5; p < 0.001). Postoperative intubation time was shorter in GHDF than in DUF (8.3 ± 5.9 vs. 18.7 ± 16.1 h; p = 0.006). The major morbidity and mortality rates were comparable in both groups. CONCLUSIONS: GHDF removed both potassium and uremic toxins more efficiently than DUF in dialysis-dependent patients. Less catecholamine was needed to wean CPB using GHDF. It improved the immediate postoperative respiratory function and enabled earlier extubation. GHDF is a novel and effective option for intraoperative RRT in dialysis-dependent patients undergoing open-heart surgery.

Causes of diminished renal function in the affected kidney after partial nephrectomy.

OBJECTIVE: To determine the cause of diminished renal function in the affected kidney after partial nephrectomy (PN) for renal tumour, we analyzed the relationship between operative data and postoperative recovery with respect to renal function. PATIENTS AND METHODS: From May 2005 to December 2010, pre- and postoperative (1 week and 3 months after the procedure) renal function was evaluated by 99mTc- mercaptoacetyltriglycine clearance in 51 patients treated with open partial nephrectomy (OPN; n = 24) and laparoscopic partial nephrectomy (LPN; n = 27). LPN was performed via retroperitoneal (RPLPN; n = 14) or transperitoneal (TPLPN; n = 13) routes. Renal cooling was performed after renal hilar clamping in OPN and RPLPN, although not in TPLPN. RESULTS: There were 10 patients (two in OPN, six in TPLPN, two in RPLPN) who had diminished renal function in the affected kidney from 1 week to 3 months after PN. Warm ischaemia (versus cold ischaemia; P = 0.017) during renal hilar clamping resulted in diminished renal function. Using multivariate analysis, renal cooling influenced postoperative diminished renal function (P = 0.008). CONCLUSIONS: Successful preservation of renal function after PN depends on renal cooling during renal hilar clamping. Cold ischaemia for avoiding renal damage is recommended if renal hilar clamping is necessary for tumour extraction.

Partial aortic root remodelling for fistula between the non-coronary sinus and the right atrium.

This report describes a rare case of the fistula between the non-coronary sinus and the right atrium (RA) after ascending aortic replacement for chronic aortic dissection. A 67-year-old lady had been suddenly suffering from severe dyspnoea with general fatigue for a couple of days. Trans-thoracic echocardiogram in the emergency room demonstrated massive shunt flow from the non-coronary sinus to the RA with remarkable dilatation of the RA, right ventricle (RV) and inferior vena cava, similar to the rupture of sinus of Valsalva (Konno-type IV). The fistula was successfully treated by partial remodelling of the aortic root in an emergency basis because of her life-threatening illness. Some remaining diseased aortic root, which may be related to initial dissection or inappropriate use of gelatin-resorcin-formalin glue at the previous ascending aortic replacement, may cause this kind of serious events. Modified aortic root remodelling method with only diseased sinus resected was successfully applied to the localised aortic root disorder.

Configurations of the mitral valve during off-pump coronary artery bypass grafting: endoscopic and three-dimensional analysis.

BACKGROUND AND AIM OF THE STUDY: During off-pump coronary artery bypass grafting (CABG), mitral regurgitation (MR) has been experienced in relation to the procedures. The study aim was to evaluate the mitral valve configuration, with particular focus on annular behavior, during off-pump CABG, using cardiac endoscopy and digital 3-D ultrasound sonomicrometry. METHODS: Following implantation of six crystals of the digital 3-D ultrasound sonomicrometer around the mitral annulus, and two crystals on the epicardial base of the papillary muscles, off-pump CABG was simulated in seven beagle dogs. The heart was perfused with pellucid Krebs-Henseleit solution in situ, with controlled left ventricular end-diastolic pressure (LVEDP). The behaviors of the mitral annulus and leaflets were then observed endoscopically with only cardiac displacement, 15 min occlusion of the left anterior descending artery (LAD), or 15 min occlusion of the left circumflex artery (LCx) with cardiac displacement. Dimensions between the crystals were also recorded using digital 3-D ultrasound sonomicrometry. RESULTS: With only cardiac displacement, no MR was observed endoscopically, and no major changes occurred in annular configuration when coronary perfusion was maintained. In one dog, MR was observed only from the anterolateral site after LAD occlusion. MR from the posteromedial site was observed by occlusion of the LCx in all cases, with significant (p < 0.01) enlargement of the mitral annular dimensions. CONCLUSION: Cardiac displacement alone did not cause MR if coronary perfusion was maintained. Occlusion of the LAD rarely caused MR from the anterolateral site, whereas occlusion of the LCx normally caused MR from the posteromedial site; the posteromedial annulus was enlarged, even when the LVEDP was controlled.

The Adamkiewicz artery: demonstration by intra-arterial computed tomographic angiography.

OBJECTIVE: The purpose of this study was to evaluate the feasibility of using multidetector-row CT angiography (CTA) with intra-arterial contrast injection (IA-CTA) to depict the artery of Adamkiewicz (arteria radicularis magna, ARM). METHODS: We performed IA-CTA in 27 preoperative patients with aneurysm or dissection of the descending thoracic or thoracoabdominal aorta. ARM was examined on multiplanar and curved planar reformation images and on the paging method, and we investigated detectability and visualization of the ARM, the level of branching, and right/left frequency as well as continuity from the origin to the ARM. Furthermore, the bolus characteristic of contrast medium in IA-CTA was investigated and compared with CTA with intravenous contrast injection (IV-CTA). The bolus characteristic of the contrast medium was assessed by the determination of the CT value in the aorta in each of the 16 cases in which both IA-CTA before surgery and intravenous IV-CTA at the time of admission were performed. RESULTS: The ARMs were clearly visualized and at least one ARM to be reserved was determined in all patients (100%). The average number of ARM observed was 1.4+/-0.58 per patient (39/27). Innate origin was determined in 90% (35/39) of ARMs and it ranged between the 8th thoracic vertebra and the 3rd lumbar vertebra levels, and branching from the left accounted for 63.2% (24/38). It was possible to observe the exact continuity from the innate origin to the ARM as well as from the secondary origin to the ARM mediated by collateral vesseles in 61.5% of the total ARMs (24/39). The CT value in the aorta calculated on IA-CTA was significantly higher than that on IV-CTA (p<0.05). As a result, the high bolus characteristic of contrast medium in IA-CTA was confirmed. CONCLUSION: It was possible to detect the ARM in all patients and to obtain information about the origin by IA-CTA. This method is considered useful for preoperative assessment of a descending thoracic or a thoracoabdominal aorta for aortic aneurysm or dissection.

Direct imaging of bileaflet mechanical valve behavior in the tricuspid position.

OBJECTIVE: The optimal orientation of a bileaflet mechanical valve for tricuspid valve replacement (TVR) has not yet been determined. The aim of this study was to use fiberoptic cardioscopy to evaluate the effect of orientation of a mechanical valve implanted in the tricuspid position on bileaflet mechanical valve behavior. METHODS: Twelve pigs (50-59 kg) underwent TVR with a St. Jude Mechanical Heart Valve (25 mm standard cuff model) after cardioplegic arrest. The mechanical valve was implanted horizontally in six pigs (Group H), and vertically in another six pigs (Group V). The heart was perfused with pellucid Krebs-Henseleit solution in situ and the mechanical valve behavior was observed with a fiberoptic endoscope during different heart rates (HRs) induced by ventricular pacing (60, 90, 120, 150 min(-1)). All images were recorded on a high-speed video system every 4 ms. The closing time lag (CTL) between the valve leaflets was calculated and compared between the two groups. RESULTS: In Group H, the lower valve leaflet tended to open incompletely and close earlier than the upper leaflet. The calculated CTL was 303+/-60 ms, 65+/-48 ms, 40+/-9 ms, and 40+/-26 ms at pacing HRs of 60, 90, 120, and 150 min(-1), respectively. In contrast to Group H, there was little difference in CTL between the right and left leaflets in Group V. The calculated CTL was 9+/-12 ms, 11+/-10 ms, 1+/-3 ms, and 6+/-7 ms at pacing HRs of 60, 90, 120, and 150 min(-1), respectively. There were significant differences in CLT between the two groups at each ventricular pacing rate (P < 0.01). CONCLUSIONS: Orientation of an implanted bileaflet valve in the tricuspid position significantly influenced leaflet motion. In a horizontal orientation, the lower valve leaflet opened incompletely and closed earlier than the upper leaflet. These results suggest that the gravity might affect leaflet motion and that bileaflet mechanical valves should be implanted vertically in TVR to prevent abnormal leaflet motion and thrombus formation.

Azygos vein aneurysm resection concomitant with heart valve repair via right thoracotomy.

Azygos vein aneurysm is very rare and is usually found incidentally because of its clinical silence. We report a case of recurrent pleural effusion caused by an azygos vein aneurysm in a patient with moderate mitral valve regurgitation (MR) and tricuspid valve regurgitation (TR). Since valve disease is considered a significant precipitating factor for both dyspnoea and pleural effusion, we decided to study the aetiologies of these conditions concomitantly. Azygos vein aneurysm resection in combination with tricuspid and mitral valve repair using cardiopulmonary bypass was performed successfully through a right anterior thoracotomy. The postoperative course was uneventful, and the patient reported improved exercise capacity.

[Sudden death and cardiovascular complications in Marfan syndrome: impact of surgical intervention].

Marfan syndrome is an autosomal dominant disorder of connective tissue characterized by abnormalities involving the skeletal, ocular, and cardiovascular systems. The cardiovascular complications of the syndrome lead to a reduced life expectancy for affected individuals if left untreated. Major cause of death include acute aortic dissection, aortic rupture, and sudden death, which resulted from congenital vascular fragility. Such life-threatening complications in Marfan syndrome can be managed effectively, by routine aortic imaging, beta-adrenergic blockade, and prophylactic replacement of the aortic root before the diameter exceeds 5.0 to 5.5 mm. Valve preserving aortic root reconstruction yielded improved postoperative quality of life compared with Bentall operation, by reducing late complications related to anticoagulants. It should be carried out before onset of aortic regurgitation for long-term native valve durability.

Surgical results of hemiarch replacement for acute type A dissection.

BACKGROUND: The appropriate surgical strategy for patients with an arch tear in acute type A dissection remains controversial. We retrospectively compared surgical results after hemiarch as compared with transverse aortic arch replacement in patients with an arch tear in acute type A dissection. METHODS: The records of 88 patients who consecutively underwent graft replacement for acute type A dissection between 1989 and 2001 were reviewed. The patients were divided into three groups: patients with ascending aortic replacement (group AS, n = 41), those with hemiarch replacement (group HA, n = 23), and those with transverse arch replacement (group AR, n = 24). Operative mortality and morbidity and late outcome were compared among the three groups. RESULTS: The overall early (30 day) mortality was 11.3% (10/88), and in-hospital mortality was 14.7% (13/88). In-hospital mortality in groups AS, HA, and AR were 7.3%, 8.6%, and 33.3%, respectively (p = 0.011). Cardiopulmonary bypass, circulatory arrest, and operation times were significantly shorter in group HA than in group AR (p < 0.001). A smaller amount of intraoperative transfusion of red blood cells (p = 0.0006) and fresh-frozen plasma (p = 0.0003) was needed in group HA than in group AR, and postoperative bleeding during the first 24 hours postoperatively was significantly less in group HA than in group AR (p = 0.0028). The incidence of postoperative coma did not differ among the three groups (p = 0.89), nor did the incidence of postoperative patent false channel in the descending thoracic aorta (p = 0.57). Actuarial survival rates after 5 years were significantly better in group HA (91.3% +/- 5.9%) than in group AR (44.4% +/- 14.3%, p = 0.018). Freedom from reoperation on the distal aorta within 5 years did not differ among the groups (p = 0.46). CONCLUSIONS: Hemiarch replacement for acute type A dissection demonstrated favorable early and late outcome. The extent of graft replacement influenced surgical mortality and morbidity. Whenever the intimal tear is located in the lesser curvature of the transverse arch, hemiarch replacement is recommended to improve overall operative mortality and morbidity.

Evaluation of native valve-sparing aortic root reconstruction with direct imaging--reimplantation or remodeling?

BACKGROUND: Aortic root reimplantation and remodeling have been used to preserve the native aortic valve. However, direct observation of valve motions with these techniques has not been performed. METHODS: Mongrel dogs were studied. The beating heart model was created using modified Tyrode's solution. Normal aortic valves and aortic valves preserved with the remodeling or reimplantation procedure were observed with an endoscope, and behavior was recorded on a high-speed video (200 frames/s). The aortic valve orifice area was measured at 11 data points per beat. A predictable maximum valve orifice area was defined as an area encircled by the three commissures. A ratio of each aortic valve orifice area to the predictable maximum valve orifice area was calculated. The control group, the reimplantation group, and the remodeling group were compared. RESULTS: The preserved aortic valve with reimplantation showed bending and asymmetric motion. The ratio of aortic valve orifice area and predictable maximum valve orifice area in the reimplantation group was significantly smaller compared with the control and remodeling groups. CONCLUSIONS: The opening and closing behavior of the aortic valve preserved with the reimplantation procedure was impaired. It was speculated that the remodeling procedure may preserve more physiologic root function compared with the reimplantation procedure.

Distensibility of the pulmonary autograft under systemic pressure.

BACKGROUND AND AIMS OF THE STUDY: Although the Ross procedure has recently been recognized as one of the best replacements of the aortic valve, regurgitation has occasionally been observed with dilatation of the sinotubular junction (STJ) and/or basal ring (BR). This study was designed to evaluate the native distensibility of the free pulmonary root under systemic pressure. METHODS: Pulmonary arterial grafts (n = 7) were taken from pig hearts and pressurized (20-100 cmH2O) with crystal sensors attached around the STJ and BR. Dimensions of the STJ and BR were measured using a digital 3-D ultrasonic sonomicrometer at different pressures (20-100 cmH2O) with and without the STJ and/or BR plicated with felt-strip to prevent overdistension. Valve insufficiency was evaluated macroscopically and endoscopically. RESULTS: All grafts showed no obvious valve insufficiency at 20 cmH2O. Grafts pressurized at 100 cmH2O showed 125+/-6% and 113+/-5% enlargement of dimensions compared with baseline (20 cmH2O) data at the STJ and BR respectively, with recognizable insufficiency. When the STJ was plicated to prevent overdistension at 100 cmH2O with less dilated BR (106%), mild excentric insufficiency was observed. In case of the BR plicated at 100 cmH2O with a less dilated STJ (112%), central slight regurgitation was observed. Both the STJ and BR plications resulted in no recognizable regurgitation. CONCLUSION: Free pulmonary arterial grafts were remarkably enlarged under systemic pressure with recognizable valve insufficiency; this could be prevented by maintaining the original dimensions of the graft STJ and BR.

Heparinless cardiopulmonary bypass with argatroban in dogs.

OBJECTIVES: Systemic heparinization is usually required for cardiopulmonary bypass (CPB). However, problems such as heparin-induced thrombocytopenia, protamine shock, and antithrombin III deficiency exist related to CPB with heparinization. The aim of this study was to evaluate argatroban (ARG) as a substitute for heparin during CPB. METHODS: In the pilot study, blood samples were sequentially obtained from dogs with continuous infusion of ARG at a dose of 10 (n = 6), 20 (n = 6), or 30 (n = 6) microg/kg per min for 2 h without CPB. In the main study, dogs underwent CPB for 2 h with 10 (n = 6) or 30 (n = 6) microg/kg per min of ARG or with heparin with blood samples obtained sequentially. Thrombogenicity in each group was evaluated by observation of the blood-contacting surfaces of the CPB circuits with scanning electron microscopy (SEM). Evidence of thromboembolism in the dogs was also investigated in histological specimens of the kidney and spleen in addition to microscopic observation at autopsy. RESULTS: In the pilot study, the activated coagulation time (ACT) reached a maximum level dose-dependently after continuous infusion of ARG for 30 min. ACT returned to the baseline value within 60 min after the termination of continuous infusion. In the main study, CPB with 30 microg/kg per min of ARG achieved thrombin-antithrombin III complex (TAT) level similar to that achieved by CPB with heparin. Platelet count with 30 microg/kg per min of ARG tended to be higher than that with heparin or 10 microg/kg per min of ARG. The SEM appearance of blood-contacting surfaces of the CPB circuits after infusion with 30 microg/kg per min of ARG appeared to be similar to that after infusion with heparin. Depositions on the blood-contacting surfaces of the CPB circuits were also frequently observed with 10 microg/kg per min of ARG. CONCLUSIONS: Coagulability related to CPB was controlled by the appropriate ARG dosage without the use of heparin in dogs. ARG may be a substitute for heparin in CPB.

Successful management of acute pulmonary embolism after surgery for lung cancer.

OBJECTIVE: Although many case reports of acute pulmonary embolism (APE) have been published, the literature dealing with the management of APE after resection of lung cancer is limited. This report describes seven cases of successful management of APE after surgery for lung cancer and discusses how to manage this problematic complication. METHODS: The medical charts of seven patients with APE after lobectomy and complete mediastinal lymphnode dissection were retrospectively reviewed. RESULTS: Six patients collapsed during their first attempt at walking after surgery in conjunction with a dramatic respiratory change. All these patients promptly underwent enhanced spiral computed tomography (CT) scanning. Bilateral clots were detected in all patients and one patient with a deep venous thrombus (DVT) in the femoral vein had a temporary inferior vena cava filter implanted. Non-surgical therapy was used for six patients: thrombolysis (systemic urokinase) and anticoagulant (heparin or argatroban) for four patients and only anticoagulant therapy started on the day after the operation using argatroban for two. There were no bleeding problems with these thrombolysis and/or anticoagulant therapies except in one case of hemorrhage induced by heparin usage on the day after the operation. None of the cases required allotransfusion in connection with these therapies. Thromboembolectomy was performed for one patient who was hemodynamically unstable due to massive embolism and primary atrial fibrillation. All patients were discharged from our hospital without major complications. CONCLUSIONS: Patients with pulmonary embolism after surgery for lung cancer can be treated aggressively with anticoagulants with/without fibrinolitics or even with pulmonary embolectomy on cardiopulmonary bypass, without excessive risk of bleeding complications. Enhanced spiral CT scanning was very helpful for making a simultaneous diagnosis of APE and DVT. The use of argatroban in conjunction with activated clotting time monitoring should be effective without causing bleeding problems during the early stages after pulmonary resection for lung cancer.

Neurological evaluation by intraoperative wake-up during carotid endarterectomy under general anesthesia.

Although general anesthesia allows relief from stressors such as pain, discomfort, or anxiety for patients undergoing carotid endarterectomy, neurologic assessment is less reliable than under local anesthesia. We describe a unique anesthetic management strategy for carotid endarterectomy patients incorporating the advantages of both general and local anesthesia. The technique allows thorough assessment of neurologic function during carotid cross-clamping by intraoperative wake-up, and guarantees airway management by tracheal intubation.

Clinical Comparative Study of Cardiopulmonary Bypass with Nikkiso and BioMedicus Centrifugal Pumps.

The Nikkiso centrifugal pump was evaluated in elective adult open heard surgery in comparison with the BioMedicus pump. Ten patients using the Nikkiso pump (Group N), and 10 patients using the BioMedicus pump (Group B) were examined for (or to determine) hemato-biologic parameters and patient outcome data as well as pump controllability. During cardiopulmonary bypass (CPB), both pumps maintained systemic perfusion satisfactorily without any mechanical adverse event. Rotation speed of the Nikkiso centrifugal pump (3,580 ± 100 rpm) was significantly higher than that of the BioMedicus pump (3,170 ± 100 rpm; p < 0.05) whereas changes in free plasma hemoglobin, platelet count, blood urea nitrogen, and creatinine levels showed no significant differences between the two groups. Urine output in Group N for 30 min after the initiation of CPB (7.10 ± 1.50 ml/kg/h) was significantly higher than that in Group B (3.23 ± 0.46 ml/kg/h; p < 0.05). Patient outcome data were similar in both groups, such as duration of intensive care unit stay, hospital stay, postoperative intubation time, amount of postoperative bleeding, and amount of blood transfused. These equivalent results with the BioMedicus pump suggested that the Nikkiso pump can be used in open heart surgery as a reliable and atraumatic CPB pump.

Comparison of Centrifugal and Roller Pump Hemolysis Rates at Low Flow.

We compared in vitro rates of hemolysis for a recently developed centrifugal pump with a conventional roller pump (10-10-00; Stöckert, Munich, Germany). Flow rates of 0.3 L/min and 1 L/min and a pressure of 200 mm Hg were chosen to simulate conditions during neonatal extracorporeal membrane oxygenation (ECMO). There was no significant difference in hemolysis rates between centrifugal and roller pumps (p = 0.57) nor between high and low flow (p = 0.86). The centrifugal pump caused no more blood trauma than the roller pump at the low-flow/high-pressure conditions required for neonatal ECMO. The Nikkiso pump is superior to roller pumps in size and priming volume (25 ml) and may permit development of a smaller and simpler ECMO system.