A Sharp Right Turn: A Case of Aortic to Right Atrial Fistula During Transcatheter Aortic Valve Replacement.

BACKGROUND Aorto-atrial fistulas (AAFs) are rare lesions typically associated with paravalvular abscesses or aortic aneurysms. Iatrogenic AAFs have been described after cardiac surgery. While these lesions are often asymptomatic, they can cause shunting and volume overload. Diagnosis of AAFs can be challenging. Transesophageal echocardiography plays a critical role in their diagnosis. CASE REPORT A 91-year-old man undergoing transcatheter aortic valve replacement (TAVR) for severe aortic stenosis had extreme tortuosity of the aorta and iliofemoral vessels. The patient developed a fistula from the non-sinus of Valsalva to the right atrium during the procedure. After the procedure, the patient developed stroke and retroperitoneal hematoma. CONCLUSIONS This case represents the first full report of an aorta to right atrial fistula after TAVR. The anatomy of the aortic root in relation to the right atrium and ventricle may make aorta to right ventricle fistulas more common than aorta to right atrial fistulas. This patient's vascular tortuosity may have played a role in the development of this lesion. Blood flow in an aorta to right atrial fistula occurs during both systole and diastole, making both right and left ventricle overload possible. Echocardiography is essential to the diagnosis of these lesions. Both vascular injury and landing zone rupture are possible during TAVR, although the observed timing and anatomy of this lesion suggest that it was caused during retrograde access of the left ventricular outflow tract via the ascending aorta.

Anesthetic Considerations for a Novel Method of Surgical Ventricular Remodeling Using the BioVentrix Revivent TC System.

Surgical ventricular remodeling (SVR) is an invasive method of treating patients with heart failure who also have ischemic cardiomyopathy and reduced ejection fraction (EF). Introduced in the mid-1980s, this technique was met with varying success and relatively high morbidity and mortality despite its theoretical benefits. The development of the BioVentrix Revivent TC System (BioVentrix, Inc., San Ramon, CA) as a less-invasive method of surgical ventricular remodeling has created a novel, multidisciplinary approach to heart failure management, which necessitates multiple subspecialties. Currently in the trial phase in the United States and widely used in Europe, the positive results to date appear promising for the rapid adoption of this procedure. For the cardiac anesthesiologist, a thorough understanding of the patient population, procedural goals, and intraoperative management is essential. This overview discusses the advancement in surgical ventricular remodeling, the pertinent surgical steps of the BioVentrix Revivent TC System placement, and specific anesthetic considerations for this novel procedure.

Standardization improves postoperative patient handoff experience for junior clinicians.

OBJECTIVES: Effective communication among health care providers is critically important for patient safety. Handoff of patient care from the operating room (OR) to the intensive care unit (ICU) is particularly prone to errors. The process is more complicated in an academic environment in which junior clinicians are being trained. Standardization of, and training in, transitions of care can be a crucial means to improve patient safety. STUDY DESIGN: Pre- and postintervention surveys of health care providers. METHODS: Based on a workflow analysis and qualitative needs assessments, we developed a 3-step protocol to standardize the handoff of care from the OR to the ICU for adult patients after cardiac surgery and to provide an effective learning environment. The process starts during surgery, continues when the patient leaves the OR, and concludes with the actual face-to-face transfer of care between providers, at the bedside, in the ICU. We conducted pre- and postimplementation surveys among physician trainees and nursing staff regarding their perception of the handoff process. RESULTS: We surveyed 42 clinicians before and 33 after implementation of the handoff process. Prior to implementation, most clinicians expressed a need to improve the current process; this perceived need was significantly greater in health care professionals with 4 or fewer years of experience. Post implementation, clinicians saw a significant improvement in information provided, efficiency, relevance to patient care, and psychological safety, a concept in which participants feel accepted and respected in a group setting without fear of negative consequences or judgement. CONCLUSIONS: Our workflow-oriented, standardized process for handoff of care from the OR to the ICU can improve perceived communication and psychological safety, especially for junior clinicians.

Peripheral Nerve Injury in Thoracic Surgery Detected by Automated Somatosensory Evoked Potential Monitoring.

Study Objective. Our objectives were to estimate the incidence of symptoms of peripheral nerve injury (sPNI) in thoracic surgical patients undergoing video-assisted thoracic surgery or open thoracotomy and to determine whether intraoperative somatosensory evoked potentials (SSEPs) waveform changes correlate with postoperative peripheral neuropathic symptoms. Methods. We conducted a prospective observational study in the operating room of a tertiary hospital. We measured SSEPs intraoperatively and assessed patients for sPNI postoperatively. Results. Forty-four patients consented. Six were excluded from analysis. We found that 42% (95% confidence interval [CI] = 26% to 57%) of patients undergoing thoracic surgery had significant changes in SSEP amplitude and latency. Furthermore, 16% (95% CI = 4% to 28%) of patients had new postoperative symptoms of sensory or motor deficits in an upper extremity. We calculated a sensitivity of 66.7% (95% CI = 29.0% to 100%) and a specificity of 50% (95% CI = 33% to 67.3%) for the identification of sPNI based on automated intraoperative SSEP changes. Conclusions. We identified the incidence of SSEP changes in thoracic surgery (42%) and the incidence of postoperative sPNI after thoracic surgery (16%). We identified a positive correlation between intraoperative SSEP changes and postoperative sPNI, which after multivariate analysis was not significant given the small sample size of the study. By the time sensory and/or motor changes are detected postoperatively, it may be too late to reverse the nerve damage. Future versions of the EPAD device could provide anesthesiologists a way to monitor for the development of sPNI, and make changes before a potential injury becomes permanent.

A Comparison of Transesophageal to Transthoracic Echocardiographic Measures of Right Ventricular Function.

OBJECTIVES: To assess the concordance between transesophageal echocardiographic (TEE) and transthoracic echocardiograpic (TTE) measures of right ventricular (RV) function using standard 2-dimensional and Doppler methods. The authors hypothesized that there would be significant disagreement in tricuspid annular plane systolic excursion (TAPSE), fractional area change, right-sided index of myocardial performance, and tricuspid annular systolic velocity (S'). DESIGN: Prospective observational. SETTING: Cardiac operating room at a single academic medical center. PARTICIPANTS: All adult patients undergoing elective cardiac surgery at a single tertiary care academic medical center over 6 months. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The fractional area change, S', TAPSE, right-sided index of myocardial performance, and tricuspid annular diameter were measured with TEE and TTE to assess for concordance using the concordance correlation coefficient and paired t tests, including 95% confidence limits. The study demonstrated that quantitative measures of RV function by TEE correlate poorly with TTE measurements in close temporal proximity under similar hemodynamic conditions. CONCLUSIONS: When performing an assessment of RV function, transesophageal echocardiographers should exercise caution when extrapolating data validated by TTE to TEE studies. Measures of RV function by TEE tend to have fair agreement to TTE measurements obtained in close temporal proximity under similar hemodynamic conditions. Most importantly, the present study showed that TAPSE and S' values obtained from the modified transgastric RV inflow view tend to have lower values than those measured with TTE. Given the propensity for underestimating measurements from the modified transgastric RV inflow view, the authors conclude that values equal to or greater than established norms for tricuspid annular motion may be used to establish normal-but not abnormal-RV function.

A Case of Myocardial Ischemia Detected by Global Longitudinal Strain Using Intraoperative Speckle-Tracking Echocardiography in a High-Risk Patient Undergoing Abdominal Aortic Aneurysm Repair.

BACKGROUND Global longitudinal strain (GLS) detected by echocardiography has been shown to have a prognostic role in the evaluation of myocardial ischemia in several clinical settings. A case is presented where GLS was used to detect intraoperative myocardial ischemia in a high-risk patient undergoing open abdominal aortic aneurysm repair. CASE REPORT A 75-year-old Caucasian man with non-insulin dependent diabetes mellitus and a 60 pack-year smoking history presented with a one-week history of exertional chest pain. Two-dimensional (2D) speckle-tracking echocardiography was used to calculate myocardial velocities and deformation parameters, including GLS. A reduced baseline GLS of -18.2% was found with dysfunction of the basal anterior, inferior, and mid anterolateral wall of the left ventricle. During aortic cross-clamping, his basal segments became mildly hypokinetic, although his ejection fraction (EF) remained unchanged at 50-55%. Despite normal left ventricular systolic function on visual assessment, his GLS decreased to -14.2% during aortic cross-clamping with similar segmental changes noted in the baseline GLS analysis. After the release of the aortic cross-clamp, his basal segments returned to normal and his left ventricular systolic function improved with an EF of 60-65% and the GLS recovered to -18.4% with improvement in the basal segmental function. CONCLUSIONS This case report showed that detection of GLS by echocardiography was a sensitive indicator of myocardial dysfunction that was superior to regional ventricular wall assessment. Detection of early changes in myocardial function by evaluating GLS may assist in guiding anesthetic management in high-risk patients with ischemic heart disease.

An Anti-Coagulation Conundrum: Implantation of Total Artificial Heart in a Patient with Heparin-Induced Thrombocytopenia Type II.

BACKGROUND Heparin-induced thrombocytopenia (HIT) is a rare but life-threatening complication of heparin administration. It can present a major clinical dilemma for physicians caring for patients requiring life-saving urgent or emergent cardiac surgery. Studies have been published examining the use of alternative anticoagulants for patients undergoing cardiopulmonary bypass (CPB), however, evidence does not clearly support any particular approach. Presently, there are no large-scale, prospective randomized studies examining the impact of alternative anticoagulants on clinical outcomes for HIT-positive patients requiring cardiac surgery. CASE REPORT We present the case of a patient who underwent SynCardia Total Artificial Heart (TAH) implantation following a recent left ventricular assist device (LVAD) placement. The patient was receiving argatroban for type II HIT with anuric renal failure, and developed a thrombus which occluded the inflow cannula of the LVAD. Based on a published study and after establishing consensus with the surgical, anesthesiology, perfusion, and hematology teams, we decided to use tirofiban as an antiplatelet agent to inhibit the platelet aggregation induced by heparin, and ultimately used heparin as the anticoagulant for cardiopulmonary bypass. CONCLUSIONS When selecting anticoagulation for a HIT-positive patient requiring CPB, so that benefits outweigh risks, it is of paramount importance that the decision be based on a multitude of factors. The team caring for the patient should have a shared mental model and be familiar with the pharmacology, devices used, and local practices. These three elements should be integrated with patient-specific comorbidities along with local monitoring capabilities to ensure safe, efficient patient care.

Do gastrotomies require repair after endoscopic transgastric peritoneoscopy? A controlled study.

BACKGROUND: The optimal method for closing gastrotomies after transgastric instrumentation has yet to be determined. OBJECTIVE: To compare gastrotomy closure with endoscopically delivered bioabsorbable plugs with no closure. DESIGN: Prospective, controlled study. SETTING: Animal laboratory. SUBJECTS: Twenty-three dogs undergoing endoscopic transgastric peritoneoscopy between July and August 2007. INTERVENTIONS: Endoscopic anterior wall gastrotomies were performed with balloon dilation to allow passage of the endoscope into the peritoneal cavity. The plug group (n = 12) underwent endoscopic placement of a 4 x 6-cm bioabsorbable mesh plug in the perforation, whereas the no-treatment group (n = 11) did not. Animals underwent necropsy 2 weeks after the procedure. MAIN OUTCOME MEASUREMENTS: Complications related to gastrotomy closure, gastric burst pressures, relationship of burst perforation to gastrotomy, and the degree of adhesions and inflammation at the gastrotomy site. RESULTS: After the gastrotomy, all dogs survived without any complications. At necropsy, burst pressures were 77 +/- 11 mm Hg and 76 +/- 15 mm Hg (P = .9) in the plug group and no-treatment group, respectively. Perforations occurred at the site of the gastrotomy in 2 of 12 animals in the plug group and in none of the 11 dogs in the no-treatment group (P = .5). Finally, there were minimal adhesions in all dogs (11/11) in the no-treatment group and minimal adhesions in 3 and moderate adhesions or inflammatory masses in 9 of the 12 animals in the plug group (P = .004). LIMITATIONS: Small number of subjects, animal model, no randomization. Gastrotomy trauma during short peritoneoscopy may not be applicable to longer procedures. CONCLUSIONS: After endoscopic gastrotomy, animals that were left untreated did not show any clinical ill effects and demonstrated adequate healing, with fewer adhesions and less inflammation compared with those treated with a bioabsorbable plug.

Gastrotomy closure using bioabsorbable plugs in a canine model.

The repair of gastric perforation commonly involves simple suture closure using an open or laparoscopic approach. An endolumenal approach using prosthetic materials may be beneficial. The role of bioprosthetics in this instance has not been thoroughly investigated, thus the authors evaluated the feasibility of gastric perforation repair using a bioabsorbable device and quantified gross and histological changes at the injury site. Twelve canines were anesthetized and underwent open gastrotomy. A 1-cm-diameter perforation was created in the anterior wall of the stomach and plugged with a bioabsorbable device. Intralumenal pH was recorded. Canines were sacrificed at one, four, six, eight, and 12 weeks. The stomach was explanted followed by gross and histological examination. The injury site was examined. The relative ability of the device to seal the perforation was recorded, as were postoperative changes. Tissue samples were analyzed for gross and microscopic tissue growth and compared to normal gastric tissue in the same animal as an internal control. A scoring system of -2 to +2 was used to measure injury site healing (-2= leak, -1= no leak and minimal ingrowth, 0= physiologic healing, +1= mild hypertrophic tissue, +2= severe hypertrophic tissue). In all canines, the bioprosthesis successfully sealed the perforation without leak under ex vivo insufflation. At one week, the device maintained its integrity but there was no tissue ingrowth. Histological healing score was -1. At 4-12 weeks, gross examination revealed a healed injury site in all animals. The lumenal portion of the plug was completely absorbed. The gross and histological healing score ranged from -1 to +1. The application of a bioabsorbable device results in durable closure of gastric perforation with physiologic healing of the injury site. This method of gastrotomy closure may aid in the evolution of advanced endoscopic approaches to perforation closure of hollow viscera.