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).

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.

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 and to clarify the impact of tethering on surgical outcomes.

METHODS

This retrospective observational study included patients with moderate or greater functional tricuspid regurgitation who underwent initial tricuspid valve repair between January 2008 and December 2021. The patients were divided into two 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 tricuspid regurgitation 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 tricuspid regurgitation 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 tricuspid regurgitation. 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 tricuspid regurgitation with satisfactory midterm clinical outcomes. However, in patients with tethering, these procedures resulted in residual tethering, which could be leading to recurrent tricuspid regurgitation.

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.

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.

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.

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.

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.

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.

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.

Arterial and Venous Thrombosis Complicated in COVID-19: A Retrospective Single Center Analysis in Japan

Background: Thrombosis is a characteristic complication in coronavirus disease 2019 (COVID-19). Since coagulopathy has been observed over the entire clinical course, thrombosis might be a clue to understanding the specific pathology in COVID-19. Currently, there is limited epidemiological data of COVID-19-associated thrombosis in the Japanese population and none regarding variant strains of SARS-CoV-2. Here, we elucidate the risk factors and the pattern of thrombosis in COVID-19 patients. Methods: The patients consecutively admitted to Tokyo Medical and Dental University Hospital with COVID-19 were retrospectively analyzed. SARS-CoV-2 variants of concern/interest (VOC/VOI) carrying the spike protein mutants E484K, N501Y, or L452R were identified by PCR-based analysis. All thrombotic events were diagnosed by clinical symptoms, ultrasonography, and/or radiological tests. Results: Among the 516 patients, 32 patients experienced 42 thromboembolic events. Advanced age, severe respiratory conditions, and several abnormal laboratory markers were associated with the development of thrombosis. While thrombotic events occurred in 13% of the patients with a severe respiratory condition, those events still occurred in 2.5% of the patients who did not require oxygen therapy. Elevated D-dimer and ferritin levels on admission were independent risk factors of thrombosis (adjusted odds ratio 9.39 and 3.11, 95% confidence interval 2.08-42.3, and 1.06-9.17, respectively). Of the thrombotic events, 22 were venous, whereas 20 were arterial. While patients with thrombosis received anticoagulation and antiinflammatory therapies with a higher proportion, the mortality rate, organ dysfunctions, and bleeding complications in these patients were higher than those without thrombosis. The incidence of thrombosis in COVID-19 became less frequent over time, such as during the replacement of the earlier strains of SARS-CoV-2 by VOC/VOI and during increased use of anticoagulatory therapeutics. Conclusion: This study elucidated that elevated D-dimer and ferritin levels are useful biomarkers of thrombosis in COVID-19 patients. The comparable incidence of arterial thrombosis with venous thrombosis and the development of thrombosis in less severe patients required further considerations for the management of Japanese patients with COVID-19. Further studies would be required to identify high-risk populations and establish appropriate interventions for thrombotic complications in COVID-19.

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.

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.

Colon perforation as a complication of COVID-19: a case report

Background

Coagulopathy induced by COVID-19 has received much attention. Arterial and venous thrombosis of multiple organs due to COVID-19-related coagulopathy is associated with a poor outcome.

Case presentation

A 67-year-female was transferred to our hospital in need of intensive care for severe COVID-19 pneumonia. On day 7 after admission, despite the treatments, her respiratory and hemodynamic status deteriorated. Computed tomography revealed massive ascites and free air as well as wall defects of the transverse colon. An emergency laparotomy was undertaken in the intensive-care unit, and 17 cm of the transverse colon was resected. Histopathological findings revealed two perforation sites of 25 and 7 mm in diameter, necrosis of the intestinal mucosa around the perforation sites, and the microcirculatory thrombosis in the mesentery vessels which was suspected of having been induced by COVID-19-related coagulopathy.

Conclusions

The case highlights the risk of intestinal ischemia and perforation induced by COVID-19 coagulopathy. Physicians treating COVID-19 should recognize the risk and evaluate patients carefully.

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.

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).

A successful case of extracorporeal membrane oxygenation treatment for intractable pneumothorax in a patient with COVID-19

Background

Some patients with coronavirus disease 2019 (COVID‐19) develop pneumothorax. Tube thoracotomy and bulla resection could generate aerosols and cause virus transmission; the optimal treatment strategy remains unclear.

Case Presentation

A 57‐year‐old male was transferred as a severe COVID‐19 pneumonia case. On the 16th day after admission, the patient’s respiratory condition deteriorated, and the chest X‐ray revealed the presence of severe right‐sided pneumothorax. A chest drain was immediately inserted; however, a significant air leak continued, and severe ventilator settings were required. Thus, veno‐venous extracorporeal membrane oxygenation (VV‐ECMO) treatment was initiated to allow the lungs to rest. After 10 days of lung‐protective ventilation, the patient was weaned from ECMO and the chest drain was removed on the following day with no major comorbidities.

Conclusion

The combination of ECMO with lung rest strategy could be a treatment option for intractable pneumothorax with COVID‐19 to avoid unnecessary surgical procedures and aerosol generation.

Severe COVID-19 Pneumonia in a 30-Year-Old Woman in the 36th Week of Pregnancy Treated with Postpartum Extracorporeal Membrane Oxygenation

Patient: Female, 30-year-old

Final Diagnosis: Severe COVID-19 pneumonia

Symptoms: Dyspena

Medication: —

Clinical Procedure: Extracorporeal membrane oxygenation

Specialty: Critical Care Medicine • Infectious Diseases

Development of a Novel Heart Positioner for Minimally Invasive Coronary Surgery

PURPOSE

We developed a heart positioner, the Tentacles NEO, specifically designed for minimally invasive coronary artery bypass grafting (MICS-CABG).

DESCRIPTION

The device has 3 flexible suction tubes, with a suction cup at the tip of each tube. The suction tubes can be detached from the device body, allowing them to be manipulated in any direction through a small incision around the small thoracotomy. When the device displaces the heart, the suction cup moves behind the chest wall and does not crowd the operative field.

EVALUATION

Although the sideways suction force of the new device was as strong as that of the original device, Tentacles, the longitudinal and perpendicular force exerted was approximately 80% of the original device. Nevertheless, the new device could safely and favorably displace the heart in a pig model and even during off-pump CABG via sternotomy. During MICS-CABG, the device was able to displace the heart without crowding the operative field.

CONCLUSIONS

The new heart positioner, Tentacles NEO, is a useful and practical heart positioner suitable for MICS-CABG.

Early Clinical Experiences of Robotic Assisted Aortic Valve Replacement for Aortic Valve Stenosis with Sutureless Aortic Valve

Robotic assisted aortic valve surgery is still challenging and debatable. We retrospectively reviewed our cases of robotic assisted aortic valve replacement utilizing sutureless aortic valve with following surgical technique: 3 ports, 1 for endoscope and 2 for the robotic arms were inserted in the right chest and da Vinci Si robotic system (Intuitive Surgical, Sunnyvale, CA, USA) was adapted to these ports. Cardiopulmonary bypass was initiated through peripheral cannulations. A vent cannula was placed through the right superior pulmonary vein and a cardioplegia cannula in the ascending aorta. After cardioplegic arrest following aortic cross-clamp, the aortic valve was exposed through a clam shell aortotomy. Valvectomy along with decalcification was performed. Next using 3 guiding sutures the Perceval S valve (LivaNova, London, UK) was parachuted down and deployed. After confirming valve position, the aortotomy was closed. There were no major complications during the procedures and no conversion to sternotomy. Exposure of aortic valve was of high quality. Valvectomy required assistance with long scissors by the bedside surgeon for excision of the severely calcified valve cusps and effective decalcification of annulus. Postoperative convalescence was uncomplicated except for postoperative atrial fibrillation in 1 patient. Robotic assistance in aortic valve procedure enabled excellent exposure of the aortic valve and improved manipulation and suturing of the aortic annulus and aorta. There needs to be improvement of instrumentation for valve debridement and removal of calcium from the annulus. In addition, the sutureless valve technology contributes to the feasibility and the efficacy of this procedure.

Rescue Balloon Aortic Valvuloplasty After Sutureless Aortic Valve Replacement for Severe Paravalvular Leak

Sutureless aortic valve replacement (AVR) is a wide-spreading new technology that provides short clamping time and excellent hemodynamic outcomes. However, among its possible complications is the risk of paravalvular leak. We present the case of a 63-year-old woman who underwent minimally invasive right mini-thoracotomy AVR) with Perceval S sutureless valve (LivaNova, London, UK). Intraoperative transesophageal echocardiography revealed severe paravalvular leak with stent distortion. Rescue balloon valvuloplasty was performed through the right femoral artery, and resulted in the resolution of the paravalvular leak. This case illustrates the utility and feasibility of balloon valvuloplasty in trouble-shooting sutureless aortic valve stent distortion, thus avoiding a repeat aortic cross-clamp and valve replacement.

Bilateral External Iliac Artery Dissection in a Middle-Aged Male Athlete

We present the case of a bilateral external iliac artery (EIA) dissection in a 44-year-old male athlete. The patient was referred to our department for right lower abdominal pain without claudication during single squatting. His athletic history included participation in approximately five athletic events per year. Contrast-enhanced computed tomography (CT) revealed bilateral EIA dissection and right renal infarction. Following medical treatment for his hypertension and considering his medical history, a bilateral EIA replacement with 8-mm Dacron straight grafts was performed on the 24th day after hospital admission. Postoperative contrast-enhanced CT revealed good bilateral graft patency and perfusion following surgery.

Hyperspectral imaging of vascular anastomosis associated with blood flow and hemoglobin concentration

The feasibility of optical non-invasive evaluation of the graft function of vascular anastomosis was investigated in vitro using hyperspectral imaging (HSI) in the wavelength range from 500 to 600 nm. A Y-shaped vessel was made using porcine carotid arteries having an inner diameter of 3.5 to 4 mm. The graft vessel was anastomosed at a 45° angle with 8-0 polypropylene suture. Fresh porcine blood at an oxygen saturation of 100% was circulated in the specially designed circuit loop and through the graft or main vessel. The vessels were then irradiated with light, and the reflected light was captured with an HSI camera. The attenuation (A) image at each wavelength (λ) was obtained and the spectral A(λ) image was created. The spectral A(λ) image showed graft patency and changes in the hemoglobin concentration. The A(λ) decreased as the flow rate increased due to the orientation of the red blood cells. The experimental results indicated that imaging of the hemoglobin concentration without distortion from blood flow is possible using two wavelengths: 625 and 770 nm. This method is able to distinguish between the blood flow and changes in hemoglobin concentration. The multispectral and hyperspectral imaging method is useful for the non-invasive evaluation of graft function.

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.

Prevention of atrial fibrillation with ultra-low dose landiolol after off-pump coronary artery bypass grafting

PURPOSE

Postoperative atrial fibrillation (AF) is a common complication of cardiac surgery that is associated with an increased incidence of other complications. The goal of this prospective randomized study was to evaluate the effect of ultra-low dose landiolol hydrochloride for prevention of AF after off-pump coronary artery bypass grafting (CABG).

METHODS

The subjects were 47 patients who underwent isolated CABG and were randomly divided into those who received landiolol from ICU admission until the beginning of oral drug intake (Group L) and those administered diltiazem hydrochloride over the same period (Group D). The incidence of AF within one week after surgery was examined as the primary endpoint. Heart rate, blood pressure, cardiac output, and other hemodynamic parameters were used as secondary endpoints. The rates of adverse events were also recorded.

RESULTS

The incidences of AF in the first postoperative week were 4.8% and 27% in Groups L and D, respectively (p = 0.046). There were no differences in hemodynamic parameters between the Groups. In multivariate analysis, no factor emerged as a significant risk factor for postoperative AF. Two patients had adverse events of asthma and hypotension, respectively, in Group L.

CONCLUSION

Ultra-low dose landiolol is effective for preventing AF after CABG without worsening hemodynamics.

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.

Effect of different labio-lingual spaces in tray designs on the displacement of and pressure against a mobile tooth

The present study aimed to examine the effect of custom tray designs on the displacement of mobile tooth and local impression pressures during the impression procedure, using partially edentulous simulation models with six anterior teeth containing a mobile tooth prepared in previous studies. The custom trays were designed by altering the thickness of the respective spaces on the labial and lingual sides of the remaining tooth arch. In previous studies, the mobile tooth was displaced in the labial direction and local impression pressures of the mobile tooth were greater against the lingual side than the labial side for all custom tray designs. Furthermore, the custom trays perforated with holes on the lingual side were effective to reduce mobile tooth displacement, labial and lingual impression pressures against the mobile tooth, and the differences between them. Therefore, the present study was performed focusing on the labial and lingual thickness of spaces in custom tray designs. It was found that mobile tooth displacement, labial and lingual impression pressures against the mobile teeth and their differences were less in trays with spaces>3.0 mm thick on both the labial and lingual sides, but markedly greater in trays with a 1.5 mm-thick space on the labial side. These results indicate that the thickness of spaces on the labial side in the tray should not be reduced to prevent mobile tooth displacement.

Influence of lip support on the soft-tissue profile of complete denture wearers

Complete dentures change the soft-tissue profile, although the exact relationship remains unclear. This study examined the relationship between the presence and degree of lip support provided by dentures and the lateral views of the facial appearance of edentulous patients. The subjects were five edentulous patients (three men and two women). Their facial appearances with experimental record blocks, with and without their complete dentures, were measured using a three-dimensional laser measuring system. The experimental record block for each subject had different conditions in the anteroposterior direction anteriorly but the same vertical dimensions posteriorly. The lateral digital facial images were displayed on a computer monitor, and the linear and angular measurements were analysed using image analysis software. The nasolabial angle was smaller and the labial points projected more with excessive lip support versus with deficient support. Moreover, the counter of the nose was affected by the labial flange of the record base, particularly in the facial appearance of one subject with highly atrophic residual ridges. The lip support affected the lower facial soft-tissue profile, including the lower part of the nose; the nasolabial angle and positional relationship between the lips and Ricketts's esthetic plane (E plane) are useful indexes for examining lip support.

Dynamic viscoelastic properties of commercial glass-fibre reinforced resin used for crowns and bridges

In order to investigate the thermal stability, the physical and mechanical, and dynamic viscoelastic properties of glass-fibre reinforced composite materials were measured. The G' of the seven materials examined was within 5;20 +/- 14; 55 and 4;50-14; 35 GPa for dry and wet specimens in air at 37 degrees C, respectively, and decreased with increasing temperature. The G' values of dry specimens decreased by 7;74-15;4% when heated to 60 degrees C. The value of tan delta ranged from 0;0102 to 0;0295 and from 0.0181 to 0.0406 for dry and wet specimens in air at 37 degrees C, respectively. The coefficient of linear thermal expansion between 30 and 60 degrees C ranged from 0;557 to 3; 95 x 10-5/ degrees C. Moreover, the filler content ranged from 56; 36 to 88; 87 wt%. These results showed that the magnitudes of G', tan delta, and the coefficient of linear thermal expansion and water absorption depend on the inorganic filler or glass-fibre content; i.e. the amount of resin matrix. Moreover, for all the materials examined, the G' values were thermostable in the temperature range encountered in the oral cavity.

Immunolocalization of osteoclast differentiation factor in rat periodontium

The aim here was to observe the immunohistochemical localization of osteoclast differentiation factor (ODF)/receptor activator of NF kappa B ligand (RANKL) in the rat periodontium. Rat mandibles were demineralized and embedded in paraffin, and horizontal and frontal sections were prepared for immunohistochemical analysis. In horizontal sections, immunolocalization of RANKL was marked in the distal area of the periodontium of molars in which osteoclasts appeared, due to physiological tooth drift. In frontal sections, RANKL immunoreactivity was localized on spindle-shaped mesenchymal cells around blood vessels near the bone surface in the periodontium. In addition, immunoreaction for RANKL was detected on structures that appeared to be elongated cell processes near blood vessels in frontal sections. Immunohistochemical examination for the general antigen of nerve-specific protein suggested a similarity between these structures and nerve fibres.

Effects of oestrogen deficiency on osteoclastogenesis in the rat periodontium

This study was designed to investigate quantitative changes in osteoclast generation in rat periodontium following ovariectomy. Wistar rats, aged 9 weeks, were subjected to either ovariectomy (OVX) or sham surgery. Osmotic pumps were implanted in 24 rats and either 17beta-oestradiol or vehicle solution were infused continuously. The rats were assigned to one of the following groups: (1) OVX+vehicle; (2) sham+vehicle; or (3) OVX+ 17beta-oestradiol. On the days 7 and 14 after surgery, four rats in each group were killed. Mandibles were demineralized and embedded in paraffin. Frontal sections of alveolar bone in the region of the first molar were cut for enzyme histochemistry and immunohistochemistry. On day 7, there was no significant difference in the number of tartrate-resistant acid phosphatase (TRAP)-positive cells located on bone surfaces in either group. However, the number of TRAP-positive mononuclear cells that were separated from the bone surface was significantly higher in group 1 than in groups 2 and 3. On the day 14, the number of TRAP-positive cells in group 1, which were attached to the bone surface, was significantly higher than had been apparent on day 7. There were also significant increases in the number of nuclei of TRAP-positive cells attached to the bone in group 1 compared with groups 2 and 3 on day 14. These findings demonstrate that oestrogen deficiency induces of osteoclastogenesis in the rat periodontium and that quantitative changes in osteoclastogenesis could be prevented by E2 infusion.

The effect of oestrogen deficiency on the alveolar bone resorption caused by traumatic occlusion

This study, using 132 female rats, was designed to investigate whether oestrogen loss facilitates alveolar bone alterations induced by traumatic occlusion. Rats were ovariectomized (OVX) or underwent sham-operation (Sham). Seven days after surgery, half of the rats in each group were subjected to experimental traumatic occlusion (trauma), and the other half were left untreated. Thus, there were four groups: OVX+trauma, Sham+trauma, OVX, and Sham. Rats in each group were killed 1, 3, 5, 7, or 10 days after the introduction of occlusal trauma. The resected mandibles were processed without decalcification, and histomorphometric measurements were performed in the alveolar bone adjacent to the periodontal ligament of the first molar. The statistical assessment of the time- and group-specific differences by analysis of variance revealed significant differences between the OVX+trauma and Sham+trauma groups in the resorption parameters, but not in the formation parameters. The results show that the alveolar bone dynamics induced by traumatic occlusion are enhanced by oestrogen deficiency.

Impression pressures against teeth in a partially edentulous model with a mobile tooth: influence of impression tray design

The purpose of the present study was to examine the effect of custom tray designs on local pressures against teeth during the impression procedure. In a previous study, a partially edentulous simulation model with a mobile tooth was used, and the effect of custom tray designs on the displacement of the mobile tooth was examined during the impression procedure. Based on that study's results, we have assumed that the differences in impression pressures between the labial and the lingual sides of a mobile tooth could either cause or affect displacement. The present study was undertaken to determine the local impression pressures against each side of three anterior teeth, including one mobile tooth, using the same simulation model and the same custom trays as in the previous study. It was found that the local pressures exerted against teeth during the impression procedure were affected by the custom tray designs and varied according to the coronal shape, axis inclination and location of the teeth.

Malposition of the epiglottis after tracheal intubation via the intubating laryngeal mask

The intubating laryngeal mask has been reported to be a successful method of tracheal intubation although advancement of the tracheal tube via the laryngeal inlet into the trachea cannot be seen. Damage to the larynx or other tissues may occur during blind passage of a tracheal tube. We report a case in which the tracheal tube, advanced blindly, tucked the epiglottis into the laryngeal inlet, resulting in oedema of the epiglottis. This case illustrates the potential for airway obstruction after extubation when using the intubating laryngeal mask as a blind intubation guide.