A case of amniotic fluid embolism successfully treated by multidisciplinary treatment.

BACKGROUND: Amniotic fluid embolism (AFE) is a life-threatening obstetric emergency. Because the maternal mortality associated with AFE is very high, early recognition and prompt treatment are important for improving the prognosis. We report a case of amniotic fluid embolism successfully treated by multidisciplinary treatment. CASE PRESENTATION: A 39-year-old woman with fetal congenital heart anomaly and polyhydramnios was scheduled for induction of delivery at 37 weeks of gestation with labor epidural analgesia. Uncontrollable bleeding occurred 30 min after vaginal delivery. Based on the clinical diagnosis of AFE, massive blood transfusion, insertion of an aortic occlusion balloon catheter, and hysterectomy was performed. Total blood loss was 12,000 mL. The diagnosis of AFE was confirmed by pathological examination. She was discharged with no complications. CONCLUSION: We report a case of AFE who were rescued by prompt diagnosis and treatment.

A case of laparotomic cholecystectomy in a patient with biventricular assist devices.

We describe a patient with biventricular assist devices who had systemic inflammation because of cholecystitis that required open cholecystectomy, and we discuss the anesthetics and monitors that should be used in unstable patients with ventricular assist devices (VADs) who are undergoing major surgery. The patient was a 40-year-old man in the dilated phase of hypertrophic obstructive cardiomyopathy, who was implanted with an internal left VAD and external right VAD. We anesthetized the patient with a combination of a low dose of sevoflurane and ketamine to minimize vasodilation. We chose ketamine because we expected it to have a postoperative analgesic effect. An INVOS™ (Medtronic) monitor was beneficial, especially since the pulse oximeter did not work because of a pulse deficit. The FloTrach™ (Edwards Lifesciences) failed to measure the stroke volume and its variability. The left VAD, the Jarvik2000, did not show its flow rate. However, we were able to estimate that the flow was stabilized, because the flow rate of the right VAD was stable, and there was no significant change in both ventricles and septa, as shown on transesophageal echocardiography.

Successful pulmonary embolectomy for massive pulmonary embolism during pregnancy: a case report.

BACKGROUND: Pulmonary embolism (PE) resulting from venous thromboembolism is a leading cause of maternal mortality in pregnancy. In patients with massive PE and hemodynamic instability, the treatment options often considered are thrombolytics, inferior vena caval filters, or embolectomy. We report here the case of a patient with massive PE at 28 weeks' gestation, who underwent emergency pulmonary embolectomy via cardiopulmonary bypass. CASE PRESENTATION: A 35-year old primigravida with a history of massive PE at 25 weeks of gestation was referred to our hospital at 28 weeks of gestation, following treatment failure after insertion of an inferior vena cava filter and heparin administration. Emergency thrombectomy was performed, and intracardiac echography was used for intraoperative fetal heart rate monitoring. However, the patient developed hemodynamic collapse following anesthesia induction; hence, emergency cardiopulmonary bypass (CPB) was performed via median sternotomy. Thrombectomy and tricuspid valve plication were performed under cardiac arrest. After confirming postoperative hemostasis, heparin administration was resumed. At 40 weeks of gestation, labor was induced under epidural analgesia. Both mother and child were discharged with no complications. CONCLUSION: In conclusion, intracardiac echography is useful for fetal heart rate monitoring during emergency cardiac surgery in pregnancy. Careful CPB management is important to maintain uteroplacental blood flow. Although there is no consensus on the delivery methods in such cases, epidural analgesia during labor was useful in reducing cardiac load and wound traction.

Periarteritis in lung from a continuous-flow right ventricular assist device: role of the local Renin-Angiotensin system.

BACKGROUND: We previously reported renal arterial periarteritis after implantation of a continuous-flow left ventricular assist device in calves. The purpose of the present study was to investigate whether the same periarteritis changes occur in the intrapulmonary arteries after implantation of a continuous-flow right ventricular assist device (CFRVAD) in calves and to determine the mechanism of those histologic changes. METHODS: Ten calves were implanted with a CFRVAD for 29 ± 7 days, and we compared pulmonary artery samples and hemodynamic data before and after CFRVAD implantation prospectively. RESULTS: After implantation, the pulsatility index (pulmonary arterial pulse pressure/pulmonary arterial mean pressure) significantly decreased (0.88 ± 0.40 before vs 0.51 ± 0.22 after; p < 0.05), with severe periarteritis of the intrapulmonary arteries in all animals. Periarterial pathology included hyperplasia and inflammatory cell infiltration. The number of inflammatory cells positive for the angiotensin II type 1 receptor was significantly higher after implantation (7.8 ± 6.5 pre-CFRVAD vs 313.2 ± 145.2 at autopsy; p < 0.01). Serum angiotensin-converting enzyme activity significantly decreased after implantation from 100% to 49.7 ± 17.7% at week 1 (p = 0.01). Tissue levels of angiotensin-converting enzyme also demonstrated a significant reduction (0.381 ± 0.232 before implantation vs 0.123 ± 0.096 at autopsy; p = 0.043). CONCLUSIONS: Periarteritis occurred in the intrapulmonary arteries of calves after CFRVAD implantation. The local renin-angiotensin system (not the angiotensin-converting enzyme pathway) plays an important role in such changes.

Does general anesthesia increase the diagnostic yield of endoscopic ultrasound-guided fine needle aspiration of pancreatic masses?

BACKGROUND: : Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of the pancreas has become the preferred method for tissue diagnosis for pancreatic solid masses. The yield of EUS-FNA in this setting is influenced by multiple factors. We hypothesized that general anesthesia (GA) may improve EUS-FNA yield by improving patient cooperation and stillness during the procedure. Our objective was to assess the association between the sedation method employed and the diagnostic yield of EUS-FNA. METHODS: : A retrospective cohort study was conducted involving consecutive patients who received EUS-FNA for diagnosis of a solid pancreatic mass at the Cleveland Clinic (Cleveland, OH) gastrointestinal endoscopy units from 2007 to 2009. We compared the diagnostic yield of EUS-FNA between patients receiving GA provided by an anesthesiologist (GA group) and patients receiving conscious sedation (CS) provided by a qualified registered nurse (CS group). RESULTS: : Of 371 patients, a cytological diagnosis was obtained in 73/88 patients (83%) in the GA group and 206/283 patients (73%) in the CS group. Anesthesiologist-delivered GA was associated with an increased odds of having a successful diagnosis as compared with CS (adjusted odds ratio [95% CI]: 2.56 [1.27-5.17], P = 0.01). However, the incidence of complication during or after the procedure was not different between the groups (P > 0.99). CONCLUSIONS: : Anesthesiologist-delivered GA was associated with a significantly higher diagnostic yield of EUS-FNA. GA should be considered a preferred sedation method for EUS-FNA of a solid pancreatic mass.

Novel implantable device to detect cardiac allograft rejection.

BACKGROUND: Allograft rejection remains the nemesis of solid organ transplantation. Soul Mate is a novel implantable wireless data transmission system that analyzes 9 intramyocardial electrogram parameters recorded from 4 or 6 configurations of 2 or 3 epicardial leads to detect allograft rejection. This study determined the ability of the Soul Mate to detect early rejection of transplanted hearts. METHODS AND RESULTS: Five dogs underwent heterotopic cervical heart transplantation and simultaneous implantation of the Soul Mate's Cardiac Rejection Monitoring Device. Dogs were initially immunosuppressed, but subsequent drug discontinuation allowed allograft rejection to appear. Allograft biopsies were performed at regular intervals to determine rejection grade, which was compared to a calculated rejection score determined as percent change from baseline of values for each intramyocardial electrogram. There was significant correlation between the biopsy results and the evolution of 5 parameters. The strongest correlation (r=0.939; P<0.001) was obtained using the "general median" parameter from 4 configurations, assessed 1 day before the biopsy, with a sensitivity of 85.7% and a specificity of 100% compared to the myocardial biopsy results. CONCLUSIONS: The Soul Mate allograft rejection monitoring system accurately detected transplanted heart rejection in a canine model noninvasively with continuous sampling. This proof-of-concept study suggests that the Soul Mate could be used to more intensely and more frequently monitor cardiac allografts for rejection.

A novel device for left atrial appendage exclusion: the third-generation atrial exclusion device.

OBJECTIVE: Occlusion of the left atrial appendage is proposed to reduce the risk of stroke in patients with atrial fibrillation. The third-generation atrial exclusion device, modified to provide uniform distribution of pressure at appendage exclusion, was assessed for safety and effectiveness in a canine model and compared with a surgical stapler. METHODS: The atrial exclusion device consists of 2 parallel, straight, rigid titanium tubes and 2 nitinol springs with a knit-braided polyester fabric. Fourteen mongrel dogs were implanted with the device at the base of the left atrial appendage via a median sternotomy. In each dog, the right atrial appendage was stapled with a commercial apparatus for comparison. The animals were evaluated at 7 days (n = 3), 30 days (n = 5), and 90 days (n = 6) after implantation by epicardial echocardiography, left atrial and coronary angiography, gross pathology, and histology. RESULTS: Left atrial appendage exclusion was complete and achieved without hemodynamic instability, and coronary angiography revealed that the left circumflex artery was patent in all cases. A new endothelial tissue layer developed on the occluded orifice of the left atrium 90 days after implantation. This endothelial layer was not evident on the stapled right atrial appendage. CONCLUSION: In dogs, the third-generation atrial exclusion device achieved easy, reliable, and safe exclusion of the left atrial appendage with favorable histologic results. Clinical application could provide a new therapeutic option for reducing the risk of stroke in patients with atrial fibrillation.

Heart rate variability in a progressive heart failure model with rapid ventricular pacing.

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.

Reduced pulsatility induces periarteritis in kidney: role of the local renin-angiotensin system.

OBJECTIVE: The need for pulsatility in the circulation during long-term mechanical support has been a subject of debate. We compared histologic changes in calf renal arteries subjected to various degrees of pulsatile circulation in vivo. We addressed the hypothesis that the local renin-angiotensin system may be implicated in these histologic changes. METHODS AND RESULTS: Sixteen calves were implanted with devices giving differing degrees of pulsatile circulation: 6 had a continuous flow left ventricular assist device (LVAD); 6 had a continuous flow right ventricular assist device (RVAD); and 4 had a pulsatile total artificial heart (TAH). Six other calves were histologic and immunohistochemical controls. In the LVAD group, the pulsatility index was significantly lower (0.28 +/- 0.07 LVAD vs 0.56 +/- 0.08 RVAD, vs 0.53 +/- 0.10 TAH; P < 0.01), and we observed severe periarteritis in all cases in the LVAD group. The number of angiotensin II type 1 receptor-positive cells and angiotensin converting enzyme-positive cells in periarterial areas was significantly higher in the LVAD group (angiotensin II type 1 receptor: 350 +/- 139 LVAD vs 8 +/- 6 RVAD, vs 3 +/- 2 TAH, vs 3 +/- 2 control; P < .001; angiotensin-converting enzyme: 325 +/- 59 LVAD vs 6 +/- 4 RVAD, vs 6 +/- 5 TAH, vs 3 +/- 1 control; P < .001). CONCLUSIONS: The reduced pulsatility produced by a continuous flow LVAD implantation induced severe periarteritis in the kidneys. The local renin-angiotensin system was up-regulated in the inflammatory cells only in the continuous flow LVAD group.

Acute reduction of functional mitral regurgitation in canine model using an epicardial device.

PURPOSE: This study evaluated the short-term feasibility of a novel epicardial device that treats functional mitral regurgitation by simultaneously changing the mitral and the left ventricular geometry. DESCRIPTION: We implanted a prototype device that consists of 2 tissue anchors, a deflector, and a flexible tightening chord in 7 mongrel dogs with heart failure and functional mitral regurgitation induced by rapid ventricular pacing. Hemodynamic and echocardiographic data were obtained before and after device implantation. EVALUATION: The device acutely reduced the mitral regurgitation grade from 3.2 +/- 0.3 to 0.9 +/- 0.5 (p < 0.001). Left ventricular end-diastolic volume (79.6 +/- 23.6 to 61.2 +/- 16.9 mL; p = 0.004) and end-systolic volume (63.1 +/- 17.3 to 49.2 +/- 12.3 mL; p = 0.006) decreased substantially. End-systolic elastance significantly increased from 1.9 +/- 1.0 to 2.6 +/- 1.4 mm Hg/mL (p = 0.02). Device implantation did not alter coronary perfusion. CONCLUSIONS: The epicardial device acutely reduced functional mitral regurgitation and improved left ventricular geometry. Further studies are required to demonstrate the long-term safety and efficacy of this concept.

Beating heart cardioscopy: a platform for real-time, intracardiac imaging.

PURPOSE: The purpose of this study was to develop a method for real-time, fiberoptic, intracardiac imaging to serve as a platform for closed-chest, intracardiac surgery on the beating heart. DESCRIPTION: Fiberoptic cardioscopy of the left and right heart was conducted in a porcine model. A cardiopulmonary bypass circuit maintained systemic organ perfusion and a separate circuit replaced intracardiac blood with oxygenated, modified Krebs-Henseleit perfusate. EVALUATION: Video images of structures in the left and right sides of an in vivo beating heart were obtained, including the inner surface of the left and right atria and ventricles, the mitral and aortic valves, the Thebesian veins, and the coronary sinus. Effective isolation of the heart from systemic and intracardiac blood flow and control of perfusion rates were important factors for successful image acquisition. CONCLUSIONS: Fiberoptic cardioscopy is a novel approach that allows for visualization of the structures within a nonarrested heart on bypass. It lays the groundwork for a platform that could lead to more successful percutaneous valvular and intracardiac procedures in a stable hemodynamic environment.

Impact of left atrial appendage exclusion on left atrial function.

OBJECTIVES: We 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. METHODS: Nineteen 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. RESULTS: Except 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. CONCLUSION: Left 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.

Evaluation of a novel device for left atrial appendage exclusion: the second-generation atrial exclusion device.

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.

A novel technique for functional mitral regurgitation therapy: mitral annular remodeling.

BACKGROUND: Functional mitral regurgitation (AIR) plays a pivotal role in the pathophysiology of congestive heart failure, a major cause of cardiac morbidity and mortality. We have developed a mitral annular remodeling procedure through injection of a nonabsorbable substance into the peri-annular tissue of the posterior mitral annulus to reduce the mitral annular dimension in the septal-lateral axis. The purpose of this study is to describe a novel procedure for treatment of functional AIR and report its effects on the geometry of the mitral annulus and degree of AIR. METHODS: Seven preliminary studies were performed using an epicardial approach in a healthy dog model to establish the feasibility of this injection procedure. Unexpectedly, 2 of 7 healthy dogs had a functional AIR of grade 1 to 2+. In these 2 cases, the hemodynamic, angiographic, and echocardiographic assessments were conducted. RESULTS: A nonabsorbable substance injection was successfully performed on a beating heart without instability of hemodynamics or any evidence of myocardial ischemia in all 7 dogs. In the 2 dogs with a functional AIR, it was confirmed that the septal-lateral dimension decreased from 3.2 +/- 0.2 to 2.6 +/- 0.5 cm and the observed MR was reduced (AIR area from 1.2 +/-0.1 to 0 cm2) without any adverse effects on hemodynamics or coronary circulation (circumflex artery flow, 36.5 +/- 0.4 to 40.5 +/- 0.1 mL/min). CONCLUSION: Off-pump mitral annular remodeling through substance injection may be one procedural option for treatment of functional AIR.