Obtaining the biomechanical behavior of ascending aortic aneurysm via the use of novel speckle tracking echocardiography.

INTRODUCTION: Ex vivo measurement of ascending aortic biomechanical properties may help understand the risk for rupture or dissection of dilated ascending aortas. A validated in vivo method that can predict aortic biomechanics does not exist. Speckle tracking transesophageal echocardiography (TEE) has been used to measure ventricular stiffness; we sought to determine whether speckle TEE could be adapted to estimate aortic stiffness in vivo and compare these findings with those obtained by ex vivo tissue measurements. METHODS: A total of 17 patients undergoing ascending aortic resection were recruited to with a mean aortic diameter was 56.16 ± 15 mm. Intraoperative speckle TEE tracking analysis was used to calculate aortic stiffness index using the following equation: ß2=ln(SBP/DBP)/AoS, where ß2 is the stiffness index; SBP is systolic blood pressure; DBP is diastolic blood pressure; and AoS is the circumferential strain. Ex vivo stiffness was obtained by mechanical tissue testing according to previously described methods. The aortic ring at the pulmonary trunk was divided into 4 equal quadrants. RESULTS: The in vivo stiffness index for the inner curvature, anterior wall, outer curvature, and posterior wall were 0.0544 ± 0.0490, 0.0295 ± 0.0199, 0.0411 ± 0.0328, and 0.0502 ± 0.0320, respectively. The mean ex vivo 25% apparent stiffness for inner curvature, anterior wall, outer curvature, and posterior wall were 0.0616 ± 0.0758 MPa, 0.0352 ± 0.00992 MPa, 0.0405 ± 0.0199 MPa, and 0.0327 ± 0.0106 MPa, respectively. The patient-matched ex vivo 25% apparent stiffness and in vivo stiffness index were not significantly different (P = .8617, 2-way analysis of variance with repeated measures). CONCLUSIONS: The use of speckle TEE appears to be a promising technique to estimate ex vivo mechanical properties of the ascending aortic tissue.

Management of a Rare Complication of Epidural Analgesia in an Obese Laterally Positioned Parturient: Catheter Entrapment Next to the Inferior Vena Cava.

Intravascular, subdural, intrathecal, and subcutaneous placement of epidural catheters are known complications and common causes of anesthesia and analgesia failure. Because the epidural space is located near the retroperitoneum and catheters are placed blindly, it is possible that misplacement could involve other structures, including the inferior vena cava, the aorta, and the lumbar plexus. We report a case of an obese laterally positioned parturient who presented with an epidural catheter lodged in the retroperitoneum. The catheter provided inadequate analgesia for labor, and postpartum computed tomography revealed it to be located in the retroperitoneal space just adjacent to the inferior vena cava. Conventional removal techniques were unsuccessful, and the catheter was finally removed after insertion of a guide wire under fluoroscopy. We conclude that obesity and lateral positioning are factors that increase the risk of epidural catheter misplacement, and a large distance from skin to loss of resistance is a potential sign of misplacement. We recommend ultrasound imaging to aid in the insertion of epidural catheters in high-risk patients.

Laparoscopic splenectomy in a patient with a Heartmate(®) II left ventricular assist device.

INTRODUCTION: Since the publication of the REMATCH trial results, it is estimated that almost 5 million Americans have been found to have heart failure. Limited availability of organs for transplantation, coupled with wider selection criteria for destination therapy, has resulted in a substantial increase in the number of patients with permanently assisted circulation. Given the high rate of complications related to circulatory assist devices, it is expected that these patients will be undergoing noncardiac surgical procedures more commonly. MATERIALS AND METHODS: We describe a laparoscopic splenectomy in a patient supported with a Heartmate II left ventricular assist device. Using this case as a model, we discuss hemodynamic changes associated with pneumoperitoneum and anesthesia induction. Additionally, an extensive literature search was performed to asses the frequency of laparoscopic procedures performed on patients with circulatory support. RESULTS: Laparoscopic splenectomy was performed without significant hemodynamic changes. To our knowledge, this is the first laparoscopic splenectomy performed in a patient with this mode of circulatory support. CONCLUSION: Laparoscopic procedures can safely be performed in patients with compensated heart failure, who are supported with ventricular assist devices.

The use of the Impella LP 2.5 percutaneous microaxial ventricular assist device as hemodynamic support during high-risk abdominal surgery.

Physiologic changes associated with anesthesia and technical aspects of noncardiac surgical procedure expose patients with severely depressed myocardial function to an enormous risk of perioperative complications and morbidity. In cases when these patients require mechanical circulatory support while undergoing emergent or elective operations, perioparative monitoring becomes of paramount importance.

Intra-atrial implantation of a mitral valve prosthesis in a heavily calcified mitral annulus.

Extensive annular calcification of the mitral valve can make anatomic implantation of a prosthesis extremely difficult and challenging. We herein describe a surgical technique of mitral valve replacement in a 78-year-old man with multiple medical co-morbidities suffering from severe mitral regurgitation with extensive circumferential calcification of the mitral annulus. The pertinent literature is reviewed and the technical steps and clinical presentation are discussed.