Preoperative Computed Tomography of the Right Gastroepiploic Artery for Coronary Artery Bypass Grafting.

BACKGROUND: Grafting the right gastroepiploic artery (GEA) to the right coronary artery (RCA) is effective, but preoperative evaluation of arterial conduit availability has not been established. By comparing the midterm graft results, we aimed to assess the efficacy of preoperative evaluation of the GEA using computed tomography (CT).Methods and Results: We retrospectively examined patients who underwent isolated coronary artery bypass grafting surgery between April 2010 and December 2020, and those whose GEA was grafted to the RCA were selected: 55 patients were included in the study analysis. Postoperative evaluations were performed during the early phase, 1 year postoperatively, and at follow-up evaluations. The outer diameter of the proximal GEA was compared with the midterm graft patency grade on CT and patients were classified as Functional (Grade A) or Dysfunctional (Grades O or B). The proximal GEA outer diameters were significantly different between the Functional and Dysfunctional groups (P<0.001). Furthermore, multivariate Cox regression analysis revealed that this diameter was an independent predictor of graft functionality (P<0.001). Patients with outer proximal diameters larger than the cutoff value had superior graft results at 3 years postoperatively. The rate of freedom from a dysfunctional graft at 3 years postoperatively was 95.5% and 45.5% for the Larger and Smaller diameter subgroups, respectively (P<0.001). CONCLUSIONS: Preoperative evaluation of the outer diameter of the proximal GEA, excluding calcified GEA, using CT is a minimally invasive and useful method, and may improve midterm results of in-situ GEA grafting, even in severe stenotic lesions.

Surgical strategy for inflammatory thoracic aortic aneurysms in the endovascular surgery era.

OBJECTIVE: Inflammatory thoracic aortic aneurysms (TAAs) are very rare aortic conditions. Resection and replacement of the inflammatory aorta is the first-line treatment, and thoracic endovascular aortic repair (TEVAR) has recently been reported as a less invasive alternative even for this aortic cohort. In the present study, we reviewed our experience with inflammatory TAAs and assessed the preoperative management, surgical procedures, and outcomes. METHODS: From 2006 to 2019, 21 surgeries were performed for inflammatory TAAs in 17 of 2583 patients (0.7%) who had undergone cardiovascular surgery at our institution. The etiologies were Takayasu's arteritis in 13 patients, giant cell arteritis in 2, antineutrophil cytoplasmic antibody-associated vasculitis in 1, and unknown in 1. The mean follow-up period was 66.2 ± 50.2 months (range, 19-186 months). RESULTS: Three patients had undergone multiple surgeries. The aorta was replaced in 14 patients (ascending aorta in 9, aortic arch in 4, and thoracoabdominal aorta in 1). Three isolated TEVARs were performed in two patients and single-stage hybrid aortic repair (ascending aorta and partial arch replacement combined with zone 0 TEVAR) in four patients for extended arch and descending thoracic aortic aneurysms. Stent grafts were deployed on the native aorta in five of the seven TEVARs. The perioperative inflammation was well-controlled with prednisolone (mean dose, 7.4 ± 9.4 mg) in all patients except for one who had required two surgeries under inflammation-uncontrolled situations. No aorta-related complications, including anastomotic aneurysms and TEVAR-related aortic dissection, developed during the follow-up period, and the 5-year freedom from all-cause death was 92.9%. CONCLUSIONS: The mid-term outcomes of surgery for inflammatory TAAs were acceptable. Although replacement remains the standard procedure for inflammatory TAAs, TEVAR is a less invasive acceptable alternative when the inflammation is properly managed.

One-Stage Hybrid Total Aortic Arch and Descending Thoracic Aortic Repair is a Safe and Secure Procedure With Less Postoperative Complications for Extended Aortic Arch Aneurysms.

PURPOSE: Hybrid aortic arch repair (HAR) has been implemented for extended aortic arch and descending thoracic aortic disease since 2012 in our institution. This study aimed to estimate the early and mid-term efficacy and safety of HAR. MATERIALS AND METHODS: From 2007 to 2019, 56 patients underwent HAR for extended aortic arch disease, and 75 patients underwent total arch replacement (TAR) for arch-limited disease. HAR comprises 3 procedures: replacement of the aorta, reconstruction of all arch vessels, and thoracic endovascular aortic repair (TEVAR) from zone 0 to the descending aorta after cardiopulmonary bypass is off in 1 stage. The type II-1 HAR procedure, in which the ascending aorta and aortic arch distal to the brachiocephalic artery are replaced, was the most frequently selected procedure (40/56 patients). The outcomes of the type II-1 HAR procedure were compared with those of TAR using the Cox regression analysis. RESULTS: The median follow-up period was 36 months. In HAR, the operative mortality, in-hospital mortality, and postoperative permanent neurological deficits were not observed. The paraplegia rate was 1.8%. TEVAR-related complications occurred in 3 patients. Among the patients with non-ruptured atherosclerotic aortic arch aneurysm (31 type II-1 HAR patients and 36 TAR patients, the postoperative respiratory support time in those who underwent type II-1 HAR was quicker than in those who underwent TAR (p<0.01). The rate of 6 year freedom from all-cause death in type II-1 HAR (83.1%) was numerically higher than that in TAR (74.7%), and the rate of 6 year freedom from surgery-related complications in type II-1 HAR (90.3%) was numerically lower than that in TAR (96.9%) due to the occurrence of TEVAR-related complications, and the rate of 6 year freedom from reintervention to the descending thoracic aorta in type II-1 HAR (100%) seemed to be better than that in TAR (83.7%). However, Cox regression analysis did not reveal any statistical difference between the 2 procedures. CONCLUSIONS: HAR, especially the type II-1 procedure, can treat extended aortic arch disease with acceptable survival outcomes. The development of TEVAR technology will further improve the outcomes of HAR in the future.

Efficacy of multidisciplinary team approach with extracorporeal membrane oxygenation for COVID-19 in a low volume ECMO center.

Veno-venous extracorporeal membrane oxygenation (VV ECMO) is an effective and proven adjunct support for various severe respiratory failures requiring invasive mechanical ventilation and cardiovascular support. In response to the rapidly increasing number of COVID-19 patients in Japan, we launched an ECMO support team comprised of multidisciplinary experts including physicians, nurses, perfusionists, and bioethicists in preparation for the threat of a pandemic. From April 2 to July 15, 2020, Tokyo Medical and Dental University hospital treated 104 PCR confirmed COVID-19 patients. Among those, 34 patients were admitted to intensive care unit (ICU) and 5 patients required VV ECMO. All management related to ECMO was decided by the ECMO support team in addition to participation of the ECMO support team in daily multidisciplinary rounds in the ICU. Median age was 54 years old. Duration from onset to mechanical ventilation (MV) and MV to ECMO were 8 and 7 days, respectively. Four patients (80%) were successfully weaned off from ECMO. One patient died after 81 days of ECMO run. Four patients were discharged and recovered to their prehospital quality of life without major disability. We achieved a high survival rate using ECMO in our low volume ECMO institution during the COVID-19 pandemic. Multidisciplinary decision-making and a team approach for the unclear pathology with an emerging infectious disease was effective and contributed to the survival rate.

New generation extracorporeal membrane oxygenation with MedTech Mag-Lev, a single-use, magnetically levitated, centrifugal blood pump: preclinical evaluation in calves.

We have evaluated the feasibility of a newly developed single-use, magnetically levitated centrifugal blood pump, MedTech Mag-Lev, in a 3-week extracorporeal membrane oxygenation (ECMO) study in calves against a Medtronic Bio-Pump BPX-80. A heparin- and silicone-coated polypropylene membrane oxygenator MERA NHP Excelung NSH-R was employed as an oxygenator. Six healthy male Holstein calves with body weights of about 100 kg were divided into two groups, four in the MedTech group and two in the Bio-Pump group. Under general anesthesia, the blood pump and oxygenator were inserted extracorporeally between the main pulmonary artery and the descending aorta via a fifth left thoracotomy. Postoperatively, both the pump and oxygen flow rates were controlled at 3 L/min. Heparin was continuously infused to maintain the activated clotting time at 200-240 s. All the MedTech ECMO calves completed the study duration. However, the Bio-Pump ECMO calves were terminated on postoperative days 7 and 10 because of severe hemolysis and thrombus formation. At the start of the MedTech ECMO, the pressure drop across the oxygenator was about 25 mm Hg with the pump operated at 2800 rpm and delivering 3 L/min flow. The PO2 of the oxygenator outlet was higher than 400 mm Hg with the PCO2 below 45 mm Hg. Hemolysis and thrombus were not seen in the MedTech ECMO circuits (plasma-free hemoglobin [PFH] < 5 mg/dL), while severe hemolysis (PFH > 20 mg/dL) and large thrombus were observed in the Bio-Pump ECMO circuits. Plasma leakage from the oxygenator did not occur in any ECMO circuits. Three-week cardiopulmonary support was performed successfully with the MedTech ECMO without circuit exchanges. The MedTech Mag-Lev could help extend the durability of ECMO circuits by the improved biocompatible performances.

Evaluation of platelet aggregability during left ventricular bypass using a MedTech MagLev VAD in a series of chronic calf experiments.

The impact of continuous flow left ventricular assist device (LVAD) pumping on platelet aggregation was investigated in animal experiments utilizing six calves. A single-use MagLev centrifugal blood pump, MedTech MagLev, was used to bypass the calves' hearts from the left atrium to the descending aorta at a flow rate of 50 ml/kg/min. The LVAD's impact on blood coagulation activities was evaluated based on the platelet aggregability, which was measured with a turbidimetric assay method during the preoperative, operative, and postoperative periods. Heparin and warfarin were used for anticoagulation, while aspirin was used for the antiplatelet therapy. A decrease in platelet aggregation immediately after the pump started was observed in the cases of successful long-term pump operation, while the absence of such a decrease might have caused coagulation-related complications to terminate the experiments. Thus, the platelet aggregability was found to be significantly affected by the pump, and its initial trend may be related to the long-term outcome of the mechanical circulatory support.

Mechanical simulation study of reapproximated sternum rigidity comparing sternal fixation devices.

BACKGROUND: A reliable sternal fixation is one of the most basic parts of cardiac surgery requiring sternotomy for preventing wound complications and promoting early recovery. Although various products have been released to the markets, the characteristics of each device are still unclear. METHODS: A simulation study was conducted to compare the properties of two sternal fixation device: a commonly used monofilament stainless-steel wire and a newly designed cable comprised of several titanium alloys strands. Sternum models made of monomer casting nylon were tied with each material and displaced in longitudinal, antero-posterior, and horizontal directions. Resistance against each directional external force was measured and compared. RESULTS: The titanium cable showed a higher resistance to every directional displacement since slight deviations and a twofold higher maximum strength than the stainless wire. CONCLUSION: An in vitro simulation study revealed the titanium cable system provide stronger sternum fixation than stainless-steel wire.

Ring annuloplasty, optionally combined with edge-to-edge leaflet plications, should be amended with subvalvular repair techniques to efficaciously treat tricuspid regurgitation with severe tethering.

OBJECTIVES: This study aimed to evaluate the outcomes of tricuspid annuloplasty with/without additional edge-to-edge plications in patients with functional tricuspid regurgitation (TR) and to clarify the impact of tethering on surgical outcomes. METHODS: This retrospective observational study included patients with moderate or greater functional TR who underwent initial tricuspid valve repair between January 2008 and December 2021. The patients were divided into 2 groups based on whether they had tethering (preoperative tethering area ≥0.75 cm2). All patients underwent annuloplasty, and edge-to-edge plications were added at the regurgitant leakage site identified by saline tests. The surgical outcomes of each group and the effect of tethering on recurrent moderate or greater TR were evaluated. RESULTS: One hundred and thirty-three patients were included in this study. During the follow-up period of 55.3 (standard deviation: 44.9) months, the 5-year survival rates were 78.4% in patients without tethering and 76.1% in patients with tethering (P = 0.78). The 5-year cumulative incidence rates of readmission for heart failure and recurrent TR were 10.8% and 1.3% in patients without tethering and 23.0% and 29.5% in patients with tethering, respectively (P = 0.12 and <0.001). Multivariable analyses revealed that the preoperative and predischarge tethering areas predicted recurrent TR. A large tethering area remained postoperatively in patients with tethering. CONCLUSIONS: In patients without tethering, annuloplasty and additional edge-to-edge plications are effective in avoiding recurrent TR with satisfactory midterm clinical outcomes. However, in patients with tethering, these procedures resulted in residual tethering, which could be leading to recurrent TR.

Fulminant myocarditis with COVID-19 infection having normal C-reactive protein and serial magnetic resonance follow-up.

A 44-year-old woman who was quarantined for 5 days after the diagnosis of coronavirus disease of 2019 (COVID-19) was transferred to our hospital with the complaint of chest pain. The patient was unvaccinated. Electrocardiography revealed ST elevation in the lateral leads. Echocardiographic biventricular dysfunction with oedematous wall thickening was identified. Cardiac enzyme levels were elevated; however, C-reactive protein (CRP) levels, and the coronary angiogram were normal. The patient required mechanical circulatory support to stabilize haemodynamics and was treated with remdesivir, baricitinib, and intravenous methylprednisolone. She recovered after 13 days of mechanical support. Serial cardiac magnetic resonance imaging revealed acute myocardial oedema and subsequent fibrosis. An endomyocardial biopsy on admission showed mild interstitial inflammatory infiltrates with endomyocardial fibrous thickening and mild interstitial fibrosis of the myocardium. Normal CRP levels suggested minor involvement of interleukin (IL)-6, supporting the efficacy of baricitinib.

Surgical extraction of cardiac implantable electronic device leads based on a heart team approach.

BACKGROUND: As cardiac implantable electronic devices, such as pacemakers, cardioverter defibrillators, and cardiac resynchronization therapies, have become more popular, device extraction has become more frequent. At our institution, individual treatment strategies are discussed at a heart team meeting. Transvenous lead extraction (TVLE) is a first-line treatment; however, surgical lead extraction (SLE) is sometimes selected as a primary choice to provide optimal treatment and maintain the medical safety policy. This study aimed to investigate the validity of this heart team decision-making. METHODS: From 2013 to 2021, 384 consecutive patients underwent lead extraction at our institution. RESULTS: SLE was proposed as the primary intervention for 21 patients who had high risk of bleeding, difficult TVLE conditions, large vegetations, and other concomitant cardiac diseases. Of the 363 TVLE patients, 10 patients required surgical intervention; 5 had TVLE difficulty followed by SLE and 5 had excessive bleeding. SLE was performed in 26 patients, 19 of whom required valve surgery, and 8 required plication of the great veins. In 4 of the 17 hybrid procedures with SLE and TVLE, excessive bleeding occurred due to laceration of the superior vena cava and innominate vein. Operative mortality was not observed in SLE patients but was observed in 1 of the 4 TVLE patients who required emergent open-chest hemostasis. CONCLUSIONS: The heart team discussion was essential to provide optimal treatment and maintain medical safety policies for each patient. SLE should be selected for patients with high risk of TVLE or other cardiac complications such as tricuspid valve incompetence.

Left ventricular assist device mode: Co-pulse left ventricular unloading in a working mode of ex vivo heart perfusion.

BACKGROUND: For normothermic ex vivo heart perfusion (EVHP), a resting mode and working mode have been proposed. We newly developed a left ventricular assist device (LVAD) mode that supports heart contraction by co-pulse synchronized LVAD. METHODS: Following resting mode during time 0 to 1 hour, pig hearts (n = 18) were perfused in either resting, working, or LVAD mode during time 1 to 5 hour, and then myocardial function was evaluated in working mode at 6 hour. The preservation ratio was defined as the myocardial mechanical function at 330 minute divided by the function at 75 minute. In LVAD mode, LVAD unloaded the pressure and the volume in the left ventricle in the systolic phase. RESULTS: The LVAD group was significantly associated with higher preservation ratios in cardiac output (resting, 33 ± 3; working, 35 ± 5; LVAD, 76% ± 5%; p < 0.001), stroke work, dP/dt maximum, and dP/dt minimum compared with the other groups. Glucose consumption was significantly reduced in the resting group. The LVAD group was significantly associated with higher myocardial oxygen consumption (resting, 2.2 ± 0.3; working; 4.6 ± 0.5; LVAD, 6.1 ± 0.5 mL O2/min/100 g, p < 0.001) and higher adenosine triphosphate (ATP) levels (resting, 1.1 ± 0.1; working, 0.7 ± 0.1; LVAD, 1.6 ± 0.2 µmol/g, p = 0.001) compared with the others. CONCLUSION: These data suggest that myocardial mechanical function was better preserved in LVAD mode than in resting and working modes. Although our data suggested similar glycolysis activity in the LVAD and working groups, the higher final ATP in the LVAD group might be explained by reduced external work in LVAD.

A prospective randomized controlled study to assess the effectiveness of super FIXSORB WAVE® for sternal stabilization after sternotomy.

BACKGROUND: We developed a new sternal fixation device, Super FIXSORB WAVE®, a corrugated plate made of u-HA/PLLA, to improve sternal stability after sternotomy. This present study aimed to evaluate the new device clinically. METHODS: This prospective, single-blinded, multicenter trial randomized 69 patients to either wire cerclage only (group C, n = 30) or wire cerclage plus Super FIXSORB WAVE® (group W, n = 39). The primary endpoint was a degree of sternal displacement at six months. Displacement of the sternal halves in the anteroposterior and lateral directions was measured using computed tomography horizontal section images at the third costal and fourth intercostal levels. The secondary endpoints were sternal pain and quality-of-life over 6 months. RESULTS: Group W showed significantly reduced sternal anteroposterior displacement at both the third costal (0 [0-1.9] mm vs. 1.1 [0-2.1] mm; P = 0.014) and fourth intercostal (0 [0-1.0] mm) vs. 1.0 [0-1.8] mm; P = 0.015) levels than group C. In group W, lateral displacement was suppressed without a significant increase from 2 weeks to 6 months, while it increased in group C. There was no significant difference in postoperative sternal pain and quality-of-life between the two groups. No adverse events, such as infection, inflammation, or foreign body reaction, were observed with this device. CONCLUSIONS: Using Super FIXSORB WAVE®, sternal displacement was significantly suppressed in both the anteroposterior and lateral directions. The use of this device results in safe and easy sternal reinforcement without any adverse events, and sternal healing can be accelerated. CLINICAL TRIAL REGISTRY NUMBER: This study was registered in the Japan Registry of Clinical Trials (February 21, 2019; jRCTs032180146).

Bovine pericardial patch repair for abdominal aortic pseudoaneurysm to preserve lumbar arteries.

We describe a case of aortic repair using bovine pericardium for a pseudoaneurysm of a dissecting abdominal aorta. A 71-year-old man had undergone several aortic replacement surgeries for type B aortic dissection. He developed paraparesis after thoraco-abdominal aortic surgery and recovered. After 3 years, the scheduled computed tomography scan showed a pseudoaneurysm of the dissecting abdominal aorta. Because he was at high risk of spinal cord ischaemia, aortic repair using bovine pericardium was performed, and all lumbar arteries were preserved. During the 12-month follow-up, he was asymptomatic, and computed tomography scans showed no dilation of the aorta.

Efficacy of singular and composite annular repositioning and subvalvular surgical techniques to treat functional tricuspid regurgitation due to leaflet tethering: Early results of a feasibility study.

OBJECTIVES: The goal of this study was to evaluate the outcomes of patients with subvalvular procedures for functional tricuspid regurgitation (TR) with severe leaflet tethering. METHODS: Of 175 patients who had tricuspid valve surgery between June 2016 and June 2021, a total of 17 patients with functional TR with a preoperative tethering height ≥8 mm underwent subvalvular procedures (annular repositioning [An-Rep]) to reduce septal leaflet tethering, papillary muscle relocation to reduce anterior leaflet tethering, and/or papillary muscle bundling [PMB] to reduce anterior and posterior leaflet tethering along with ring annuloplasty at our institution. A single subvalvular procedure was performed in 9 patients (An-Rep in 5 patients, PMB in 4 patients; group S), and a combination of subvalvular procedures was performed in 8 patients (An-Rep and papillary muscle relocation in 5 patients, An-Rep and PMB in 3 patients; group C). RESULTS: Predischarge TR grades and tethering height were significantly improved (3.2 ± 1.3-1.0 ± 0.5, p = 0.001; 9.9 ± 2.5 mm-5.5 ± 2.8 mm, p < 0.001, respectively). An-Rep and PMB significantly reduced the postoperative closing angles of the septal and anterior leaflets, respectively. During the 20.4 ± 19.5-month follow-up period, the rates of freedom from death and moderate TR at 2 years were 41.7% in group S, and 71.4% in group C (p = 0.39), respectively. In group C, TR recurrence was not observed at 2 years postoperatively. CONCLUSIONS: Subvalvular procedures were effective in reducing the predischarge TR grades and tethering height. The combination of subvalvular procedures might be a durable strategy to prevent recurrent TR.

The rotational position of the aortic valve: implications for valve-sparing aortic root replacement.

OBJECTIVES: There are few reports on the rotational position of the aortic valve relative to the base of the left ventricle, and its influence on valve-sparing aortic root replacement (VSRR) has not been reported. Based on our experience with complications such as right atrial perforation and tricuspid valve injury, we investigated the cause of these complications in terms of morphological variations in the aortic root and its surrounding structures. METHODS: The aortic valve rotation relative to the base of the left ventricle was assessed in 30 patients with tri-leaflet aortic valves who underwent VSRR. The influence of such anatomical variations on surgical procedures was investigated. RESULTS: The aortic valve was positioned normally in 25 patients (83.3%), rotated counterclockwise in 4 (13.3%), and rotated clockwise in 1 patient (3.3%). In patients with a counterclockwise rotated aortic valve, the non-coronary sinus was the largest compared with other sinuses. This aortic valve rotation could be diagnosed by multidetector row computed tomography. In all patients who had difficulty in the external dissection of the right sinus of Valsalva, the aortic valve was counterclockwise rotated and forcible dissection had a risk of right atrial perforation and tricuspid valve injury. CONCLUSIONS: Aortic valve rotation is an element that complicates VSRR. The rotational position of the aortic valve can be diagnosed preoperatively using multidetector row computed tomography and understanding the anatomy of the aortic valve related to rotational position help decide proper surgical decision-making in performing aortic root reconstruction procedure.

Long-term outcomes of papillary muscle relocation anteriorly for functional mitral regurgitation.

OBJECTIVES: This study aimed to evaluate the outcomes of the patients who underwent restrictive annuloplasty (RA) plus papillary muscle relocation anteriorly (PMR-A) with the risk factors in mitral valve repair for functional mitral regurgitation (FMR). METHODS: Eighty-six patients underwent mitral valve repair with RA for FMR. Thirty-five of them received additional bilateral papillary muscle relocation for severe leaflet tethering. The papillary muscles were relocated posteriorly (PMR-P) early in the study. Then, in the later period, the technique was modified to PMR-A, in which the papillary muscles were relocated anteriorly for 24 cases. The survival of the patients undergoing RA + PMR-A was examined retrospectively, adjusting for differences in patient background. RESULTS: Twenty-three deaths were observed during the follow-up period out of the 86 cases. Independent preoperative risk factors for survival were left ventricular ejection fraction, patient age and B-type natriuretic peptide (BNP) level. Among the patients with BNP <1000 pg/ml, 5-year survival after RA plus PMR-A was 84.7%, while RA alone was 78.6% and RA + PMR-P 57.1%. Cox proportional hazards regression adjusted for the preoperative risk factors showed a significantly higher hazard ratio of RA + PMR-P to RA + PMR-A (12.77, P = 0.011), while the hazard ratio of RA alone to RA + PMR-A was not significantly different. Furthermore, reverse remodelling of the left ventricle was observed for 3 years only in RA + PMR-A. CONCLUSIONS: Long-term survival for patients who underwent RA plus bilateral PMR-A was promising. Patients with significantly higher BNP had lower survival after valve repair for FMR.

Mid-term results of mitral valve reconstruction with autologous pericardial patch for active infective endocarditis with extensive leaflet destruction.

OBJECTIVES: This study aimed to evaluate the outcomes of our repair technique using autologous pericardial patches for active infective endocarditis with extensive mitral valve destruction. METHODS: From 2009 through 2016, 12 patients with extensive mitral leaflet destruction due to infective endocarditis underwent mitral valve repair with an autologous pericardial patch. Mid-term clinical outcomes and echocardiographic findings of these patients were retrospectively assessed. RESULTS: The perioperative mortality rate was 8.3% (1/12). Postoperatively, the mitral regurgitation grade was ≤ 1 + in all patients. During 5.0 ± 3.2 years of follow-up, there was no recurrence of infective endocarditis or death. There were no cases of mitral regurgitation grade > + 1 and pressure gradient > 5 mmHg during follow-up among 6 patients who underwent posterior leaflet reconstruction, whereas elevation of the pressure gradient was observed in patients who underwent reconstruction of two areas of the anterior leaflet and survived up till the follow-up phase among 3 patients who underwent anterior leaflet repair. The mitral regurgitation grade worsened and pressure gradient was elevated during the follow-up phase in the 2 patients who underwent bi-leaflet repair, and reoperation was performed. CONCLUSION: Mitral valve reconstruction using autologous pericardial patch is a useful treatment option for extensive mitral valve destruction due to active infective endocarditis. Our clinical data revealed that good mid-term results were obtained for posterior leaflet lesions, while extensive anterior leaflet and bi-leaflet lesion repair did not yield satisfactory results. The indication for surgical repair should be carefully evaluated when an extensive anterior region is involved.

Alterations in red blood cell volume and hemoglobin concentration, viscoelastic properties, and mechanical fragility caused by continuous flow pumping in calves.

In this study, we have analyzed the changes in mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and the dynamic deformability and mechanical fragility of red blood cells (RBCs) in five male Holstein calves (body weight: 95.6 ± 10.8 kg) whose circulation was partially supported with a novel magnetically levitated extracorporeal centrifugal blood pump MedTech Dispo. One hour after the pumping has started, the MCV increased and the MCHC decreased by 1.064 ± 0.006 and 0.906 ± 0.050 times, respectively, as compared with those of the prepumped blood (P < 0.05). The deformability index L/W, where L and W are the long and short axes of the two-dimensional RBC images, respectively, sheared by a cyclically reversing shear flow increased indicating that the RBCs pumped for 1 h exhibited more elastic characteristics (P < 0.05). In addition, when the pumped blood cells were sheared for 30 min with a uniform shear stress of 25.38 Pa, the hemolysis level decreased dramatically as compared with the control blood, as more fragile RBCs were destroyed by pumping, leaving behind less fragile RBCs. All these characteristics of the RBCs exposed to continuous flow resemble those of young RBCs having larger MCV, lower MCHC, higher elasticity, and lower fragility. In conclusion, during continuous flow pumping, the RBCs having relatively lower threshold for hemolysis to mechanical shear stress generated by continuous flow blood pump (CFBP) are destroyed first and removed from circulation in the early stage of application of CFBP, thus leaving behind less fragile and stronger RBCs.

One-month biocompatibility evaluation of the pediatric TinyPump in goats.

The TinyPump is an extracorporeal, magnetically driven centrifugal blood pump with its impeller suspended magnetically and hydrodynamically to provide short-term mechanical circulatory support for children and infants. We have previously demonstrated that the in vivo experiments of the experimental TinyPump showed acceptable stable performance at pump flows averaging around 1.0 L/min with low hemolytic and thrombogenic properties for up to 2 weeks. We present here the 1-month in vivo evaluation of the TinyPump, whose design was modified further for more durable operation. The pump was implanted as a left ventricular assist device in five goats (12.5-26.7 kg), with inflow inserted into the left ventricular apex and outflow anastomosed to the descending aorta. Five animals were supported for 110 pump days, with mean pump flow of 1.19 ± 0.03 L/min at a pump speed of 2679 ± 97 rpm. Two animals reached the scheduled end point of 30 days without device failure, and mean plasma-free hemoglobin was 1.7 ± 0.8 mg/dL. Hematologic and biochemical data of these two animals showed no evidence of cardiovascular, renal, or hepatic dysfunction. Although further experiments are needed, the modified TinyPump offers promise as a short-term mechanical circulatory support device in pediatric population.

A laceration of a wired silastic tracheostomy tube: A case report and review of the literature.

Fractured tracheostomy tube is a rare, late complication. It typically occurs at the junction of metallic tube. We report an atypical case with laceration of the main trunk of a silastic tube after short period of use (10 days).