Search

Background Total arch replacement (TAR) with a frozen elephant trunk (FET) is a common technique for acute aortic dissection, but there is no consensus on the optimal size of the FET. Methods Forty-four patients who underwent TAR with FET for acute aortic dissection at our hospital since 2014 were included. The aortic diameter obtained from FET was measured on postoperative computed tomography (CT) and the estimated oversizing ratio was calculated. We investigated the relationship between the estimated oversizing ratio and postoperative outcomes. We also measured the maximum true lumen diameter, circumference of the true lumen, and total aortic diameter at the same level as the FET end on preoperative CT and examined the correlation with the aortic diameter obtained from FET. Results The average estimated oversizing ratio was 109%. Early postoperative CT showed complete thrombosis of the false lumen in 41 (93.2%) patients. No distal stent graft-induced new entry occurred during follow-up. The correlation coefficients between the three measurements and aortic diameter obtained from FET were 0.64 (maximum true lumen diameter), 0.76 (true lumen diameter calculated from circumference), and 0.72 (total aortic diameter), respectively. Conclusions The aortic diameter obtained from FET on postoperative CT was strongly correlated with the true lumen diameter calculated from the circumference and total aortic diameter on preoperative CT. It is reasonable to select a size of approximately 130% of the true lumen diameter calculated from the circumference or 80% to 85% of the total aortic diameter.

To evaluate the outcomes of total arch replacement using the frozen elephant trunk technique with a FROZENIXBetween January 2015 and December 2020, we used the frozen elephant trunk technique in 47 patients with acute aortic dissection and 12 patients with chronic aortic dissection. The primary endpoints were 30-day mortality, late aorta-related death and late aortic events. The secondary endpoints included early surgical complications and any aortic events (e.g. stent graft-induced new entry, frozen elephant trunk angle change).In the acute group, there were no aorta-related deaths, although 13 patients (27.7%) experienced an aortic event; stent graft-induced new entry occurred in 6 patients (12.8%). In the chronic group, 1 patient (9.1%) experienced aorta-related death, and 9 (81.8%) experienced an aortic event; stent graft-induced new entry occurred in 4 patients (36.4%). During the late phase after surgery, there was a significant increase in the frozen elephant trunk angle in both groups. In the AAD group, both the FET angle and spring-back angle were significantly enlarged in the late phase. There were no significant differences between groups in the degree of angle change, the overall survival, or aortic event-free survival.Total arch replacement using the frozen elephant trunk technique affords good early-stage results for both acute and chronic aortic dissection. During follow-up, careful monitoring for aortic events and appropriate therapeutic interventions are required. If surgeons are to use this device, they must have a thorough understanding of its spring back force and other features.

To establish whether emergency surgery performed outside working hours (after hours) contributed to adverse outcomes for patients with acute type A aortic dissection (ATAAD).We reviewed the operation records of ATAAD repair in our institution from 2004 to 2019 (n = 187). Emergency surgery was performed by one of a few teams of experienced surgeons, regardless of the time of day. Patients were divided into two groups based on the surgery start time: during working hours (n = 65) and after hours (n = 122). A propensity score-matched analysis was performed for 58 pairs of patients.The overall in-hospital mortality was 6.9% for the working-hours group and 13.8% for the after-hours group. There were no significant differences between the groups in the relatively limited study population (n = 187). Surgeon experience and aortic interventions did not differ remarkably between the groups. After-hours repair was not associated with postoperative complications. There were no significant differences in the long-term survival or aortic event-free rates between the groups.After-hours surgery did not affect the short- or long-term outcomes of ATAAD repair under our backup system, which supports the recommendation of immediate surgical repair. Efforts to minimize the discrepancies between working hours and after hours could help to improve the surgical outcomes of patients undergoing ATAAD repair.

Coronary artery fistula (CAF) is one of the most common coronary artery anomalies. The most common fistulas originate from the right coronary artery and drain into the right heart structures. Due to the variety of coronary fistulas, the surgical treatment strategy is individualized for each case. We report two cases of giant aneurysmal CAF originating from the left circumflex artery. One case required coronary artery bypass grafting, while the other did not.

The frozen elephant trunk (FET) technique is useful in the single-stage treatment of aortic arch aneurysms. Since there is no established implantation method for evaluating the distal end of the FET during surgery, we propose the FET positioning method using the ostium of the coronary artery on transesophageal echocardiography (TEE) as an index. We performed 11 total arch replacement operations using an FET for aortic arch aneurysm. The planned position of the FET was determined by computed tomography (CT), and the distance to the ostium of the coronary artery was measured. Intraoperatively, using TEE as a guide, the FET was implanted using our method. Postoperative CT was evaluated the distance from the planned FET position, and the average and median difference was only 0.96 cm and 0.6 cm, respectively. TEE-guided FET deployment using the coronary artery ostium as an index is a simple and reproducible technique.

Daikenchuto (TJ-100) is a Japanese traditional herbal medicine that enhances postoperative enterokinesis and increases the intestinal blood flow. Daikenchuto has historically played a positive role in the perioperative management of gastrointestinal surgery. However, the effect of Daikenchuto on improving nutrition after cardiac operation has never been reported. This study evaluated the effect of Daikenchuto administration after cardiac operation. Eighty-four patients who underwent isolated first aortic valve replacement (AVR) at our department from May 2008 to December 2014 were enrolled in this study and retrospectively examined. We administered Daikenchuto when patients started their water intake. Blood tests were performed before and seven days after AVR. We prescribed Daikenchuto for 21 patients (group D). The reductions in the albumin level and prognostic nutritional index (p = 0.045, p = 0.008, respectively, multivariate analysis of variance) after the operation were significantly lower in group D (3.75 ± 0.3 to 3.33 ± 0.4 and 44.7 ± 4.8 to 41.3 ± 6.7 mg/dl, respectively) than in the group without Daikenchuto (group N, 63 patients) (3.74 ± 0.5 to 3.13 ± 0.4 and 44.6 ± 6.3 to 37.7 ± 5.3 mg/dl, respectively). There were no significant differences in the incidence rates of postoperative complications or hospitalization duration between the two groups. Postoperative Daikenchuto administration is considered to be safe and effective for improving the postoperative nutritional status after simple AVR as well as digestive surgery.

Introduction The efficacy of endovascular treatment for complicated Stanford type B acute aortic dissection is being established. However, aortic events sometimes occur, and some cases require surgical intervention. Report A 52 year old man underwent ascending aorta replacement for Stanford type A acute aortic dissection in August 2016. Post-operative computed tomography (CT) showed residual dissection from the aortic arch to the right common iliac artery and a large re-entry in the right common iliac artery (RCIA). Two months after the operation, CT revealed enlargement of the false lumen of the thoracic aorta and the thoracic aortic diameter. Aiming to reduce the false lumen and remodel the aorta, a three stage operation was performed, as described below. Four months after the dissection, total aortic arch replacement and a frozen elephant trunk insertion were performed as the first stage. Subsequently, as a second stage operation, thoracic endovascular repair (TEVAR) was performed using a Zenith® Dissection Endovascular System (Cook Japan Co., Ltd, Tokyo, Japan), with the aim of expanding the true aortic lumen. The implanted devices were a stent graft for the proximal part and two bare stents for the middle and distal part. As a third stage operation, abdominal aortic endovascular treatment was performed with the purpose of closing the re-entry from the RCIA. However, two years after the three stage operation, CT showed that the thoracic aorta was over 60 mm in diameter. Graft replacement of the thoraco-abdominal aorta was performed. The bare stents were expected to be easily removable from the aorta, but unexpectedly, they were strongly attached to the intima, which made it extremely difficult to perform surgical and aortic operations. Discussion Surgical operations for the aorta can become more difficult after bare stent placement in the aorta., Highlights • Surgical operations on the aorta can be hampered after intra-aortic bare stent placement. • The bare stents and the intima of the true lumen were integrated. • Operability seemed to be relatively smooth when the electric cautery was operated at a high output.

We herein report a case of leg malperfusion caused by dynamic obstruction after aortic dissection diagnosed by the exercise ankle brachial pressure index test that could not be diagnosed solely by examining the symptoms and investigations at rest. This case suggests that exercise can be a key factor in the diagnosis of this complication. Furthermore, blood pressure elevation can be an exacerbating factor in dynamic obstruction. We recommend conducting an aggressive evaluation of the symptoms and medical examinations not only at rest but also under stress.

The patient was an 81-year-old man. Transcatheter aortic valve implantation( TAVI) was performed for severe aortic stenosis using Evolut R. The patient moved to intensive care unit without an adverse event after the operation. But repeated acute heart failure occurred several times during hospital stay. Mitral regurgitation (MR) was worsened from mild at baseline to moderate or more by transthoracic echocardiography. Various factors that worsened MR after TAVI have been reported, and treatment strategy for severe aortic stenosis patients with MR should be carefully developed.

Isolated left ventricular noncompaction, where broad trabeculae and deep intertrabecular recesses are observed in the left ventricular myocardium resulting from an arrest in normal embryogenesis, is a rare cardiomyopathy. We present a report on isolated trabeculectomy and postoperative echocardiographic follow-up showing recovery of cardiac function for isolated left ventricular noncompaction.

OBJECTIVES The aim of this study was to evaluate the outcomes of the frozen elephant trunk (FET) technique, using the J Graft FROZENIX for Stanford type A acute aortic dissection, in comparison with the unfrozen elephant trunk technique. METHODS Between January 2010 and August 2018, we performed total arch replacement for Stanford type A acute aortic dissection in our hospital. Thirty patients were treated by the elephant trunk procedure (ET group), and 20 patients were treated by the FET procedure (FET group). To evaluate aortic remodelling, we measured the area of the aorta, the true lumen and the false lumen at 12 months of follow-up. RESULTS Preoperative characteristics and operation time were not significantly different between the 2 groups. The quantity of blood transfused was much greater in the ET group than in the FET group. Resection or closure of the most proximal entry tear was obtained in 73.3% (22 out of 30 patients) in the ET group and 100% (20 out of 20 patients) in the FET group (P = 0.015). There was no case that had recurrent nerve palsy or paraplegia in the FET group. Stent graft-induced new entry occurred in 3 cases (15.8%) in the FET group. There were no significant differences between the 2 groups in aortic area, true lumen area or false lumen area. CONCLUSIONS Total arch replacement with the FET technique in Stanford type A acute aortic dissection carries a risk of distinct complications; however, with thorough advance planning, it should be possible to safely institute this treatment. Further randomization, with a comparison of each technique, is required to provide clear conclusions whether the FET is useful for acute Stanford type A aortic dissection.

The patient was a 68-year-old man who underwent triple-vessel OPCAB uneventfully with aortic proximal anastomosis at one site using the saphenous vein with a mechanical device, not a side clamp, with mild traction of the ascending aorta by aortic taping. On postoperative day 7, computed tomography revealed extremely localized AAD with a tear on the posterior wall of the ascending aorta. Emergent ascending aortic replacement was successfully performed. Surprisingly, the tear extended laterally along the traction site of the tape. To our knowledge, this is the first report of AAD early after OPCAB originating at a location other than the sites of proximal anastomosis or side clamping. Proximal anastomosis with a mechanical device to the towed aorta may indirectly or directly injure the intima of the posterior wall, causing this complication. Manipulating the aorta under abnormal pressure should be avoided.

To assess the safety and anatomical suitability of using a Gore Iliac Branch Endoprosthesis (IBE) in aortoiliac and iliac aneurysm repair. Between 2017 and 2020, 20 patients underwent endovascular aneurysm repair (EVAR) with a Gore IBE device (bilateral IBE, n = 1) after expanding the instructions for use (IFU) criteria. We evaluated the early clinical outcomes and suitability of the IFU criteria, retrospectively. Six patients (30%) met all the IFU criteria. Anatomical suitability according to the IFU criteria for the collective total of 21 IBE limbs was confirmed for 10 (47.6%) proximal common iliac arteries, 21 (100%) external iliac arteries, 18 (85.7%) internal iliac arteries, and in the length from the lowest renal artery to the iliac bifurcation in 15 (71.8%) patients. Assisted primary technical success was achieved in all patients with various bail-out techniques. One patient (5%) required a bare-stent insertion 7 days after EVAR for severe stenosis in the ipsilateral limb caused by a small terminal aorta. There was no case of occlusion of an iliac branch component device. Gore IBEs were implanted safely and effectively with various bail-out techniques to repair aortoiliac and iliac aneurysms in our Japanese patients with a low rate of inclusion IFU criteria.

Optimal management of aortic root in type A aortic dissection (AAD) is controversial. To determine the most appropriate strategy, we studied the late outcomes after conservative repair of aortic root. 234 AAD patients (mean age 68 ± 12 years) underwent surgical repair using supracommissural replacement (SCR) for aortic root reconstruction from 1989 to 2014. Ascending aortic replacement or hemi-arch replacement was performed in 180 patients (non-arch group), whereas total arch replacement (TAR) was performed in 54 patients. In both groups, proper and firm reapproximation of proximal edge was performed exactly at the sinotubular junction (STJ). The long-term durability of preserved aortic root (mean follow-up 89 months) was evaluated. Hospital mortality occurred in 25 of 234 patients (10.6%). Aorta-related deaths occurred in five patients (four in non-arch; one in TAR), with over 90% 10-year actuarial survival rate in each group. Among 19 aorta-related events, there were only four proximal events (three in non-arch; one in TAR). The 10-year freedom rate from proximal aorta-related events exceeded 90%, with no significant difference in both groups. Freedom rate from moderate aortic regurgitation at 10 years was statistically similar between non-arch (86.3%) and TAR (85.7%) groups. The long-term durability of SCR with proximal aortic reapproximation exactly at the STJ was acceptable with low rates of proximal aortic events. This technique can be the standard technique for aortic root reconstruction in AAD patients, except those with aortic root pathology.

Supplemental Digital Content is available in the text, Before surgery and other invasive treatments, decisions must be made on whether to discontinue drugs and provide appropriate drug holidays especially for antithrombotic drugs, and this is made difficult by the large number of available drugs and associated guidelines. We have therefore developed an online application for perioperative drug discontinuation and resumption management, named Saga Application for Management of Drug Holidays in PeriOperative Periods (SAMPOP). Multidisciplinary medical staff at Saga University Hospital (SUH) worked together to build an evidence-based Perioperative Drug Discontinuation Management Database (PDDMD) and developed the user-friendly SAMPOP online application via preliminary verification at SUH. From September 2018 to February 2020, 420 medical staff at SUH, including physicians, nurses, and pharmacists, installed and tested SAMPOP. Rate per surgical procedure for forgetting to discontinue antithrombotic drugs preoperatively decreased from 0.18% to 0.09% as of August 2019, 12 months after the introduction of SAMPOP (P = .1359). In addition, six months later, it decreased further to 0.03% as of February 2020 (P = .0436). Forgetting to resume antithrombotic drugs postoperatively decreased from 0.20% to 0.02% as of August 2019, 12 months after the introduction of SAMPOP (P = .0008). There was no case of forgetting to resume the medication in the last 6 months. SAMPOP may be useful for management of drug holidays in the clinic and warrants further evaluation of its safety and efficacy.

Background The optimal management of a retrograde type A aortic dissection (RAAD) is controversial, and few reports have discussed the long-term outcomes of surgical strategies. To determine the most appropriate strategy, we studied the early and late outcomes of RAAD cases. Methods From 1998 to 2014, 44 patients with RAAD (mean age of 63 ± 11 years) underwent surgical repair. Ascending aortic replacement (AAR) was performed in 21 patients and ascending and total arch replacement (TAR) was performed in 23 patients. Eight of the patients who received TAR underwent complete resection of the primary tear in the distal arch or descending aorta (TAR-R[+]), whereas the remaining 15 patients received elephant trunk implantation as an alternative procedure for tear resection (TAR-R[–]). The early and late outcomes (mean follow-up, 86.5 months) were evaluated. Results Hospital mortality occurred in 4 of the 44 (9.1%) patients, with no mortalities among the patients undergoing TAR-R[–]. There was a tendency toward a higher incidence of late aorta-related events in the AAR group, with a significantly higher patency rate of the false lumen in the proximal site of the residual aorta compared with the TAR group ( p = 0.009). Furthermore, the 5-year rate of freedom from aortic growth greater than 50 mm was significantly lower after AAR than after TAR ( p = 0.04). A multivariate analysis indicated that the initial ascending aortic diameter (odds ratio [OR], 1.5; p = 0.02) and AAR (OR, 29.1; p = 0.01) were independent predictors of late aortic expansion. Conclusions The surgical outcomes were acceptable in both the AAR and TAR groups. The long-term outcomes potentially support the aggressive adoption of TAR in relatively younger patients with significant ascending aortic enlargement at presentation.

Background: In thoracoabdominal aneurysm (TAAA) repair, our technical modification of visceral reconstruction using longer cut pre-sewn side branches has provided good surgical outcomes. Here, we assessed the long-term durability and patency of revascularized branches using computed tomography (CT) to confirm the validity of our approach. Methods: Early and late CT evaluations were performed in 11 TAAA patients (males: 5; mean age: 60.6 years) using the Coselli graft to evaluate the position of main graft and the diverging pattern and patency of side branches. Seven of 11 were sutured in an extra-anatomical fashion using longer cut side branches. Results: In Anatomical (n = 4) and Extra-anatomical (n = 7) groups, the early patency of side branches was not significantly different. Although the late patency of right renal artery (RA) was 100% in both groups, the one of left RA was 60% in Extra-anatomical, while 100% in Anatomical. Furthermore, the main graft in Extra-anatomical was significantly posterior and leftward to the spine with left RA side branch diverging at an acute angle. Conclusions: When a pre-sewn branched graft designed for TAAA is used, the graft should be sutured in a fashion similar to normal patient anatomy to minimize the possibility of kinking of RA side branch for the patency.

Tracheo-innominate artery fistula is fatal unless treated surgically. We describe our surgical approach and results in seven patients. The average patient age was 15.7 years; all patients had prior severe neurological deficits. Three of seven patients were in hemorrhagic shock; control of preoperative bleeding was achieved with tracheostomy tube cuff overinflation. The innominate artery and the trachea were exposed through a collar incision and partial upper sternotomy. The innominate artery was divided at the aortic arch and at the bifurcation, with one exception. Cerebral blood flow was monitored by the blood pressure difference in the bilateral upper extremities and by near-infrared spectroscopy. The tracheal fistula was left adherent to the innominate artery in all but one patient. All patients were discharged without new neurologic deficits or severe morbidity. Overall survival was 84% at 37 months, without any vascular, tracheal, or neurological events.

If the aortic root dilates after native aortic valve-sparing root reconstruction with remodeling, aortic regurgitation may recur. However, it has not been demonstrated clearly that the aortic root dilates after remodeling.This study enrolled 15 patients who underwent an aortic valve-sparing operation with remodeling (2002-2014) but without any ventriculo-aortic junction (VAJ) fixation. Technically, special care was taken to pass the sutures through the fibrous annulus. The diameter of the aortic root (VAJ, neosinus of Valsalva, and sinotubular junction), degree of aortic regurgitation, and effective height of the aortic valve were measured in the patients. All patients had postoperative follow-up, and the median follow-up period was 7.3 (IQR: 3.1-8.3) years.The mean preoperative diameters of the VAJ, sinus of Valsalva, and sinotubular junction were 23.5 ± 2.3 (20-27) mm, 51.1 ± 7.2 (43-60) mm, and 42.4 ± 9.4 (29-58) mm, respectively. The postoperative diameters of the VAJ changed from 21.6 ± 2.6 (early) to 21.8 ± 2.9 mm (late) (p = 0.75). The diameters of the sinus of Valsalva and sinotubular junction changed from 26.5 ± 3.0 (early) to 28.5 ± 4.2 mm (late) (p = 0.0013), and 22.4 ± 3.0 (early) to 24.3 ± 3.3 mm (late) (p = 0.0003), respectively. The effective height of the aortic valve changed from 9.7 ± 1.3 (early) to 8.9 ± 2.0 mm (late) (p = 0.08). The degree of aortic regurgitation (grade: 0-4) changed from 0.3 ± 0.5 (early) to 1.2 ± 0.8 (late) (p = 01558).Significant VAJ dilation and changes in aortic valve configuration after our remodeling procedure were not observed. Therefore, fixation of the annulus with remodeling may not be needed for cases without preoperative dilation of the annulus.

The efficacy and safety of surgical intervention for atrial myxoma are established, but the operative approach to tumor resection and atrial reconstruction are controversial. A biatrial approach is generally used for excision of atrial myxoma and has many advantages. In contrast, there are a few reports about the method of double-patch reconstruction, and the right and left atrium are individually reconstructed with the two patches. We found it to be effective in the case reported here. We suggest that this method can be applied to atrial myxoma in which extensive resection is necessary.

We have treated three patients with blunt traumatic right atrial rupture, all of whom survived after an emergent cardiac repair without cardiopulmonary bypass. Cardiac tamponade was seen in two of the three cases on ultrasonographic cardiography (UCG). The site of rupture was the right atrial appendage in two cases and the superior vena cava-right atrial (SVC-RA) junction in one case. Hemostasis had been obtained at the time of pericardiotomy because of compression by hematoma. Some patients with a right atrial rupture respond to initial volume resuscitation. Suspecting some cardiac injuries in patients with traumatic pericardial effusion on UCG, a patient with a right atrial rupture can survive with a high probability, without the use of cardiopulmonary bypass.

BACKGROUND Heart rate variability (HRV) is an indicator of autonomic nervous system functionality and a recognized predictor of cardiac death; however, the changes in HRV occurring in progressive heart failure are not fully understood. The purpose of this study was to evaluate the progressive changes of autonomic system activity in progressive heart failure by rapid ventricular pacing in an animal model. METHODS Heart failure was induced in 13 mongrel dogs (27.8 +/- 3.7 kg) by rapid ventricular pacing (230 beats/min) for 4 weeks and maintenance of pacing at a reduced rate (190 beats/min) for 2 weeks. Time domain analysis and spectral analysis of HRV were performed with the MemCalc system after 30 minutes of pacing cessation every week. Hemodynamic and echocardiographic data were obtained before and after induction of heart failure. RESULTS Cardiac output decreased significantly (3.6 L/min versus 1.6 L/min, P < .001) after 6 weeks of ventricular pacing. Significantly increased were the heart rate (126 beats/min versus 138 beats/min, P < .05), left ventricular end-diastolic pressure (9.1 mm Hg versus 30.9 mm Hg, P < .001), and pulmonary capillary wedge pressure (8.0 mm Hg versus 18.7 mm Hg, P < .001). High-frequency components progressively decreased. Low-frequency components progressively decreased except at 5 weeks after the pacing. A ratio of low- to high-frequency components increased in moderate heart failure and decreased in severe heart failure. CONCLUSIONS Changes in the high-frequency component and low-frequency component are important for assessing heart failure in progressive heart failure. Serial follow-up measurements of HRV might be helpful for patients with such disease.

The purpose of this study was to evaluate the feasibility of our innovative, replaceable heart valves that can be easily detached from the sewing ring at the time of repeat replacement. The prototype devices consist of the base magnet ring assembly and the valve magnet ring assembly that utilize magnetic coupling force for the locking mechanism. Magnetic coupling strength was evaluated in vitro. Prototype bioprosthetic valves were implanted acutely in three sheep to confirm the feasibility of the replaceable mitral valve. The static separation force of prototype size #25 was 12.5 lb, meeting the design goal. In situ attachment and detachment of the valve magnet ring assembly from the base magnet ring assembly were very easily accomplished in all animals. The magnetic coupling did not decouple even under extremely high left ventricular pressures. We have demonstrated the feasibility of this innovative concept of a replaceable mitral valve.

To evaluate the effects of downsizing of the total artificial heart (TAH), we compared the anaerobic threshold (AT) values in calves with two different types of TAH (Cleveland Clinic–Nimbus TAH and the downsized MagScrew TAH). Exercise studies were performed using a treadmill in 12 calves. During the exercise, parameters to obtain the AT were measured. To evaluate the determinants of the AT, a linear regression analysis was performed between AT and potential variables. AT values from 29 studies revealed no significant differences between the two different TAHs, with no significant differences in hemodynamic or oxygen metabolic parameters. AT values correlated well with pump flow/body weight (Q) multiplied by the hemoglobin level, regardless of the TAH used. In conclusion, downsizing of the original TAH design did not reduce AT without any significant differences in hemodynamic or oxygen metabolic parameters during exercise in calves.

We are developing the PediPump, a magnetically suspended, mixed-flow pump, as an implantable pediatric ventricular assist device (VAD). Lamb cadaver fitting studies were performed to determine the optimal pump location and optimal design of the inflow and outflow conduits for chronic in vivo studies. A prototype of the PediPump right and left ventricular assist devices (RVAD and LVAD, respectively) were implanted via a sternotomy or left thoracotomy in four lamb cadavers (3.7-34.2 kg). Via a sternotomy, the RVAD and LVAD required long inflow cannulas when placed into the right or left thoracic cavities, respectively. Via a left thoracotomy, with both pumps implanted in the left thoracic cavity, the RVAD required a 70 degrees inflow cannula and a bent outflow graft while the LVAD required a 130 degrees inflow cannula and a straight outflow graft. In conclusion, left thoracotomy provided optimal fitting for both LVAD and RVAD for the small lamb model.

ObjectivesWe sought to investigate the short-term and midterm effects of left atrial appendage exclusion on left atrial function. Left atrial appendage exclusion is considered a possible therapeutic option for stroke prevention in patients with atrial fibrillation. Favorable outcomes have encouraged widespread use of left atrial appendage exclusion for cardiac surgical patients—even for patients in sinus rhythm who have stroke risk factors; however, the chronic effects on left atrial function of left atrial appendage exclusion are unclear.MethodsNineteen mongrel dogs (29.7 ± 5.2 kg) in sinus rhythm were studied. The Doppler signals from the pulmonary venous flow, transmitral flow, and tissue Doppler imaging of mitral annular motion were obtained before and after left atrial appendage exclusion. Dogs were evaluated in the same manner at 7 days (n = 2), 30 days (n = 7), or 90 days (n = 10) after left atrial appendage exclusion.ResultsExcept for a significant increase in early diastolic transmitral flow velocity after left atrial appendage exclusion (P = .01), no significant differences were found in any parameters related to the transmitral flow and tissue Doppler imaging measurements throughout follow-up. The systolic components of pulmonary venous flow at follow-up revealed a significant reduction relative to baseline (peak systolic velocity P < .0001, systolic velocity-time integral P < .0001), despite the lack of significant changes in left atrial pressure, left ventricular volume, and stroke volume.ConclusionLeft atrial appendage exclusion may affect left atrial reservoir function in the short-term and midterm periods. Further long-term studies with more clinically relevant models are needed.

Background Small caliber vascular prostheses are not clinically available because synthetic vascular prostheses lack endothelial cells which modulate platelet activation, leukocyte adhesion, thrombosis, and the regulation of vasomotor tone by the production of vasoactive substances. We developed a novel method to create scaffold-free tubular tissue from multicellular spheroids (MCS) using a “Bio-3D printer”-based system. This system enables the creation of pre-designed three-dimensional structures using a computer controlled robotics system. With this system, we created a tubular structure and studied its biological features. Methods and Results Using a “Bio-3D printer,” we made scaffold-free tubular tissues (inner diameter of 1.5 mm) from a total of 500 MCSs (2.5× 104 cells per one MCS) composed of human umbilical vein endothelial cells (40%), human aortic smooth muscle cells (10%), and normal human dermal fibroblasts (50%). The tubular tissues were cultured in a perfusion system and implanted into the abdominal aortas of F344 nude rats. We assessed the flow by ultrasonography and performed histological examinations on the second (n = 5) and fifth (n = 5) day after implantation. All grafts were patent and remodeling of the tubular tissues (enlargement of the lumen area and thinning of the wall) was observed. A layer of endothelial cells was confirmed five days after implantation. Conclusions The scaffold-free tubular tissues made of MCS using a Bio-3D printer underwent remodeling and endothelialization. Further studies are warranted to elucidate the underlying mechanism of endothelialization and its function, as well as the long-term results.

The DexAide right ventricular assist device (RVAD) is an implantable centrifugal pump modified from the CorAide left ventricular assist device. As previously published, in vitro performance testing of the DexAide RVAD has met design criteria, and the nominal operating condition of 4 l/min and 20 mm Hg pressure rise was achieved at 2,000 rpm, with a power consumption of 1.9 watts. In vivo studies in 14 calves have demonstrated acceptable hemodynamic characteristics. The calf inflow cannula design is still evolving to minimize depositions on the cannula observed in most experiments. Fitting studies were performed in 5 cadavers and 2 patients to reconfigure the cannulae for use in humans. The design and development of external electronics have been completed for the stand-alone RVAD system, and verification tests are under way in preparation for preclinical tests. Work on the external electronics design for the biventricular assist system is ongoing. In conclusion, the initial in vitro and in vivo studies have demonstrated acceptable hemodynamic characteristics of the DexAide RVAD. The design and development of the external electronic components for the stand-alone RVAD system have been completed. The calf inflow cannula is being redesigned, and chronic in vivo tests are under way.

BACKGROUND Cardiac electromechanical remodeling following left ventricular reconstruction (LVR) surgery is not fully understood. Further development of an animal model will facilitate investigations in this area. In the present study, we aimed to establish a novel LVR procedure without the use of cardiopulmonary bypass in a rabbit left ventricular (LV) aneurysm model. METHODS LV aneurysm was created in 6 rabbits by ligation of the distal left coronary artery. More than a month later, LVR aneurysm surgery was performed off-pump using a purse-string suture around the aneurysm. Cardiac dimensions and function were evaluated using echocardiographic techniques perioperatively and 4 weeks after LVR surgery. Six structurally normal hearts were used as controls. RESULTS LVR surgery was successfully performed in all 6 rabbits. Both LV end-diastolic volume (LVEDV, 4.6 +/- 0.9 to 3.3 +/- 0.6 mL; P < .01) and LV end-systolic volume (LVESV, 2.5 +/- 0.6 to 1.5 +/- 0.2 mL, P < .01) were decreased immediately postsurgery versus presurgery, and LV ejection fraction (LVEF) was increased (44.5 +/- 5.3 to 55.6 +/- 4.8%, P < .001). For comparison, in normal rabbits (n = 6), LVEDV, LVESV and LVEF were 3.1 +/- 0.7 mL, 1.2 +/- 0.5 mL, and 64.5 +/- 8.8%, respectively. During follow-up, one rabbit died 3 weeks after surgery from an unknown cause. In the remaining 5 animals, improvements of LVEDV (3.7+/- 0.4 mL, P < .05), LVESV (1.7 +/- 0. 3 mL, P < .01), and LVEF (53.1 +/- 2.8%, P < .01) were maintained versus presurgery values for more than 4 weeks after LVR. CONCLUSIONS Off-pump LVR of rabbit LV aneurysm is an effective and less invasive surgery that resulted in sustained improvement in cardiac function with no gross intraoperative or postoperative mortality. This may be a useful model for investigations of electromechanical remodeling following LVR.

Background The left atrial appendage is a frequent source of thromboemboli in patients with atrial fibrillation. Exclusion of the left atrial appendage may reduce the risk of stroke in patients with atrial fibrillation. The atrial exclusion device, previously developed to perform left atrial appendage exclusion on a beating heart, was modified to accommodate different anatomic patterns of the human left atrial appendage and to ensure uniform pressure and occlusion. The purpose of this study was to evaluate this second-generation atrial exclusion device during a midterm period in a canine model. Methods Ten mongrel dogs (mean weight 28.9 ± 4.6 kg) were used in this study. The atrial exclusion device, constructed from two parallel and rigid titanium tubes and two nitinol springs with a knit-braided polyester fabric, was implanted at the base of the left atrial appendage through a left thoracotomy on a beating heart using a specially designed delivery tool. Dogs were evaluated at 30 days (n = 4) and 90 days (n = 6) by epicardial echocardiography, left atrial and coronary angiography, gross pathology, and histologic inspection. Results Device implantation was performed without complications in all dogs. Complete left atrial appendage exclusion without device migration or hemodynamic instability was confirmed, and there was no damage to the left circumflex artery or pulmonary artery. Macroscopic and microscopic assessments revealed favorable biocompatibility during midterm follow-up. Conclusion The atrial exclusion device enabled rapid, reliable, and safe exclusion of the left atrial appendage. Clinical application may provide a new therapeutic option for reducing the risk of stroke in patients with atrial fibrillation.

We describe a patient with acute mitral regurgitation due to complete rupture of the papillary muscle immediately after successful late reperfusion for inferior myocardial infarction. An 81-year-old woman was admitted complaining of mild chest discomfort. Although the electrocardiograms, biochemical test results, and her clinical history showed that several days had passed since the onset of acute myocardial infarction, a late coronary stenting was performed. Immediately after successful stenting, she suddenly developed acute pulmonary edema, leading to cardiogenic shock. In addition to high pulmonary capillary wedge pressure (mean 35 mmHg), color Doppler imaging revealed massive mitral regurgitation caused by complete rupture of the posterior papillary muscle. Emergent mitral valve replacement with a prosthetic valve was performed, saving the patient. Hence, late reperfusion should be considered carefully when treating a patient with a high risk, such as an elderly patient or a patient with single-vessel disease or initial transmural myocardial infarction.

Background Although several investigators have analyzed coronary artery blood flow under various conditions, almost all these studies have measured only some branches of the left anterior descending (LAD), left circumflex (LCX), or right coronary (RCA) artery. Methods In a canine model of acute ischemia ( n =5), we simultaneously assessed (a) regional myocardial blood perfusion using microspheres and (b) phasic coronary blood flow patterns as measured by three epicardial flow probes placed around the LAD, LCX, and RCA. Results The results from this study indicated that the LAD supplies blood to the epicardial ( r =0.687, p r =0.556, p =0.0021), and endocardial layers ( r =0.666, p =0.0001) of the LAD area; the LCX supplies the midwall ( r =0.514, p =0.0051) and endocardial layer ( r =0.621, p =0.0004) of the LCX area, antero-lateral papillary muscle ( r =0.548, p =0.0025), and postero-medial papillary muscle ( r =0.641, p =0.0002), especially during the diastolic phase; and the RCA supplies the right ventricular apex ( r =0.559, p =0.0020), left atrium ( r =0.618, p =0.0005), right atrium ( r =0.471, p =0.0114), and postero-medial papillary muscle ( r =0.486, p =0.0088), especially during the systolic phase. Conclusions These results are potentially relevant to understanding the physiology of myocardial blood perfusion and to improving treatment of acute myocardial ischemia and infarction.

Objectives Noninvasive cardiac imaging techniques have had an increasing role in the diagnosis of coronary artery disease. However, these techniques are not widely available as a tool in the office setting. The purpose of this study was to provide an accurate assessment of coronary artery disease for screening purposes using Coronary Transit Index (CTI) assessment with small, high-resolution gamma cameras. Methods Total coronary blood flow was measured with ultrasonic flow probes placed around the left anterior descending coronary artery, left circumflex coronary artery, and right coronary artery in a total of 33 conditions in 5 healthy mongrel dogs. The coronary blood flow was reduced stepwise with vascular occluders placed around the coronary arteries. The procedure for obtaining CTI included 4 parts: 1) The animal was injected intravenously with a bolus of a radioactive tracer (2.5–5.0 mCi of 99mTc-DTPA); 2) Dedicated gamma sensors monitored the passage of the injected bolus; 3) Time–activity curves were measured at the left ventricle with and without its wall; 4) The ratio of the washout rates of the 2 curves determined the CTI. Results Coronary Transit Index was successfully obtained from the left ventricle. The coronary blood flows measured by flow probes were well correlated with the regional myocardial blood flow. The percentage of the baseline value of the total coronary blood flow had the highest correlation (R = 0.807, p Conclusions These data indicated that a new diagnostic system using CTI successfully identified reduced coronary blood flow.

Background The aim of our study was to develop a completely scaffold-free, viable, contractile cardiac tissue capable of being grafted into the damaged native heart. Methods Our technology is based on the fundamental characteristics of the self-assembling nature of cells. We created contractile cardiac spheroids by plating a mixture of rat neonatal ventricular cardiomyocytes, human dermal fibroblasts, and human coronary microartery endothelial cells in ultralow attachment plates. First, the optimal cell ratios for the 3 cell sources were determined. Next, approximately 1 × 10 4 optimal spheroids were fused into a patch-like construct, and the morphologic characteristics and mechanical functions of these patches were evaluated. Finally, the cardiac patches were grafted into the hearts of F344 nude rats, and histologic studies were performed after transplantation. Results Synchronous beating of the cardiac patch was confirmed electrophysiologically and mechanically. A micronetwork of endothelial cells was also demonstrated in the construct, and the histologic study performed 5 days after transplantation showed the grafts to be viable, with functioning microvascular structures inside the graft tissue. Conclusions We consider the application of our scaffold-free 3-dimensional tissue engineering technology to cardiac regeneration therapy is feasible and expect that this technology will become a promising tool for the treatment of end-stage heart failure.

Introduction: Small caliber synthetic vascular grafts are not clinically available. We developed a novel method to create scaffold-free tubular tissue from multicellular spheroids (MCS) using a “Bio-3D printer”-based system, which enables the creation of various three-dimensional structures pre-designed using a computer system. With this system, we created a tubular structure (Fig. 1), and studied its biological features. Methods: We made 1.5 mm in diameter scaffold-free tubular tissues from MCS (1.25 x 10[[Unable to Display Character: ⁷]] cells) composed of human umbilical vein endothelial cells (40%), human aortic smooth muscle cells (10%) and normal human dermal fibroblasts (50%) using a Bio-3D printer. The vessels were cultured in a perfusion system. We implanted grafts into the abdominal aortas of F344 nude rats, and assessed the flow by ultrasonography and performed histological examinations on the second (N=5) and fifth (N=5) days after implantation. Results: All grafts were patent. Remodeling of the vessel (enlargement of the lumen area and thinning of the wall) was observed (Fig. 2). A layer of endothelial cells was developed after implantation of the graft (Fig. 3). Conclusions: The scaffold-free vascular grafts made of MCS using a Bio-3D printer showed biological features comparable to native vessels. Further studies are warranted toward the clinical application of this novel technology.

Objective The left atrial appendage is a frequent source of thromboemboli in patients with atrial fibrillation. Exclusion or excision of the left atrial appendage may reduce the risk of stroke in patients with atrial fibrillation. We evaluated the ability of a novel device to exclude the left atrial appendage during early and intermediate follow-up periods in a canine model. Methods Eight mongrel dogs (mean weight 29.1 ± 4.0 kg) were used in this study. The occlusion device, constructed from 2 stainless steel strips covered with a knit braided polyester fabric, was implanted at the base of the left atrial appendage through a left thoracotomy on a beating heart. Dogs were evaluated at 7 days (n = 2), 30 days (n = 2), and 90 days (n = 4) by epicardial echocardiography, left atrial angiography, histologic inspection, and gross pathology. Results Device implantation was performed without complications in all animals. Complete exclusion of the left atrial appendage from the circulation was confirmed acutely and chronically by echocardiographic and angiographic evaluations. There was no device migration or damage to adjacent structures. Conclusion This novel device enables rapid, reliable, and safe exclusion of the left atrial appendage. The device provides a new therapeutic option for reducing the risk of stroke in patients with atrial fibrillation.

The Cleveland Clinic Foundation CPB/ECMO Initiative Forward Casualty Management System is an economical, compact, transportable, disposable system designed to permit a rapid expansion of trauma management services requiring cardiopulmonary bypass (CPB) or extracorporeal membrane oxygenation (ECMO) pulmonary support. The system, composed of a rotary blood pump, a pump motor driver, and an electronic control console as the blood pumping subsystem, also includes commonly used compatible commercial oxygenators, venous reservoirs, and cannulae. In vitro durability testing accumulated over 100 hours without failure. In vivo reliability was tested in 10 calves under general anesthesia during 6 hours of CPB and ECMO under full heparinization at nominal operating conditions of 4-5 l/min and 2-4 l/min blood flow respectively, and mean arterial pressures between 65 and 100 mm Hg. A mean time to failure of 57 hours was reached during the animal series. Results of these test series demonstrated that this system has the capability to reliably operate during a 6-hour conventional CPB or ECMO procedure, while providing flexibility and ease of use for the operator.