Periprocedural transfusion in patients undergoing transfemoral transcatheter aortic valve implantation.

OBJECTIVES: The aim of this investigation was to identify patient's characteristics and periprocedural variables related to periprocedural transfusion in transfemoral Transcatheter Aortic Valve Implantation (tf-TAVI). BACKGROUND: Transfusion of allogenic red-blood cells (RBC) in tf-TAVI and the number of transfused units has been linked to an increased 30-day mortality. In line with the trend of minimization and cost-effectiveness, transfusion should be avoided, wherever possible. METHODS: Between 2007 and 2015, 1,734 procedures were analyzed from our prospective registry for RBC-transfusion. Multiple logistic regression analysis was used to identify the dependent variables. RESULTS: Transfusion was considered necessary in 14% (n = 243) of the patients. Female gender (OR [95% CI]) (1.680 [1.014-2.783]) and preprocedural moderate (7.594 [4.404-13.095]) and severe anemia (8.202 [0.900-74.752]) according to WHO were the most important preprocedural variables. Periprocedural, pericardial effusion (12.109 [3.753-39.063]), emergency extracorporeal circulation (54.5288 [6.178-481.259]) and major vascular injury (2.647 [1.412-4.962]) were related to transfusion. The same applies to moderate (4.255 [1.859-9.740]) and severe anemia (31.567 [8.560-116.416]) as well as periprocedural experience (0.072 [0.035-0.149] - 0.141[0.079-0.251], P < 0.001) CONCLUSION: Procedural experience, serious adverse events, low pre- and periprocedural Hb levels and female gender were the main variables relating to transfusion. Even in experienced high-volume centers, transfusion is still necessary in a considerable number of patients.

Dexmedetomidine versus propofol-opioid for sedation in transcatheter aortic valve implantation patients: a retrospective analysis of periprocedural gas exchange and hemodynamic support.

PURPOSE: Different sedation regimens have been described for use during transfemoral transcatheter aortic valve implantation (tf-TAVI) for treatment in patients with severe aortic stenosis. The purpose of this study was to compare dexmedetomidine (DEX) with a combination of propofol-opioid (PO) with respect to periprocedural gas exchange and hemodynamic support. METHODS: Data from a cohort of patients sedated with either DEX or PO for tf-TAVI were retrospectively analyzed from a prospectively maintained TAVI registry. Operative risk was determined from comorbidities and risk scores. Periprocedural partial pressure of carbon dioxide (PaCO2) was chosen as the primary endpoint. Other differences in gas exchange, need for catecholamine therapy, the frequency of conversion to general anesthesia, and need for sedative "rescue therapy" (in DEX patients) were secondary endpoints. Inverse probability of treatment weighting (IPTW) was used for analysis to minimize any selection bias. RESULTS: Of the 297 patients (140 PO, 157 DEX) included, the median [interquartile range] periprocedural PaCO2 values of DEX patients were significantly lower than in PO patients (40 [36-45] mmHg vs 44 [40-49] mmHg, respectively; median difference -4 mmHg; 95% confidence interval, -5 to -3 mmHg; P < 0.001). Hypercapnia (PaCO2 > 45 mmHg) was significantly less frequent in DEX patients compared with the PO group (25% vs 42%, respectively; P = 0.005). Vasopressor support was more frequent in the PO group compared with DEX (68% vs 25%, respectively; P < 0.001). Conversion to general anesthesia was not different between groups (9%, PO vs 3%, DEX; P = 0.051). Additional sedatives/opioids were required in 25 (16%) of the DEX patients. CONCLUSIONS: In sedated TAVI patients, DEX was associated with lower PaCO2 values and reduced requirements for vasopressor support, making it a promising alternative to PO for sedation during TAVI. TRIAL REGISTRATION: www.ClinicalTrials.gov (NCT01390675). Registered 11 July 2011.

Factor VIII inhibitor bypass activity and recombinant activated factor VII in cardiac surgery.

OBJECTIVE: Postcardiopulmonary bypass hemorrhage remains a serious complication of cardiac surgery. Given concerns regarding adverse effects of blood product transfusion and limited efficacy of current antifibrinolytics, procoagulant medications, including recombinant factor VIIa (rFVIIa) and factor eight inhibitor bypass activity (FEIBA), increasingly have been used in managing refractory bleeding. While effective, these medications are associated with thromboembolic complications. This study compared the efficacy and risk of adverse events of rFVIIa and FEIBA in cardiac surgical patients with refractory bleeding. DESIGN: This retrospective study evaluated 168 patients who underwent cardiac surgery and received either FEIBA or rFVIIa to manage postbypass hemorrhage. Demographic, clinical, and outcomes data were collected and statistical analysis performed to compare thromboembolic event rates, relative efficacy, and 30-day mortality following administration of these medications. SETTING: Single university hospital. PARTICIPANTS: Patients undergoing cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULT: Sixty-one patients received rFVIIa, and 107 received FEIBA. Demographics, surgical procedures, and preoperative anticoagulation were similar between the cohorts; however, the rFVIIa cohort had longer durations of cardiopulmonary bypass (305.1 v 243.8 min, p<0.01). There were no significant differences in the number of thromboembolic events, 30-day mortality, or rates of revision surgery. Neither group demonstrated a clear relationship between dosage and occurrence of thromboembolic events. The rFVIIa cohort received more platelets than the FEIBA cohort (3.13 v 1.67 units, p = 0.01), but transfusion rates of other blood products were similar. CONCLUSIONS: This study suggests that rFVIIa and FEIBA have similar efficacy and adverse event profiles in managing intractable postbypass hemorrhage in cardiac surgical patients. Further prospective studies are required.

Immediate postoperative percutaneous stenting of superior vena cava obstruction following heart transplantation in adult patients with pacemaker leads.

Vena cava superior syndrome is a serious complication after heart transplantation, leading to low cardiac output, cerebral edema, and multi-organ dysfunction. We report three adult patients who underwent heart and heart-lung transplantation and required immediate postoperative balloon angioplasty and stent placement by interventional radiology. The observed obstructions were located at sites of intraoperatively removed pacemaker or defibrillator wires. Percutaneous stent placement immediately improved the hemodynamic condition of the patients. Early recognition of the complication and availability of immediate intervention are essential to prevent further deterioration.

Late profound muscle weakness following heart transplantation due to Danon disease.

INTRODUCTION: Postoperative muscle weakness is a serious complication in surgical intensive care patients. It is mostly described as critical illness polyneuromyopathy. Risk factors include intensive care length of stay, sepsis, poor glycemic control, and combined use of corticosteroids and neuromuscular blocking agents, malnutrition, and electrolyte imbalance. METHODS: We report a case of late-progressive, profound weakness after heart transplantation for noncompaction cardiomyopathy which required prolonged mechanical ventilation. The patient's muscle strength recovered completely after prolonged rehabilitation. RESULTS: Electromyographic assessment showed myopathy. Muscle biopsy revealed Danon disease, a genetic disorder affecting the lysosomal-associated membrane protein 2 gene (LAMP2). CONCLUSIONS: The finding of this genetic disorder was unexpected, because the preoperative echocardiographic diagnosis of noncompaction cardiomyopathy has not been reported in Danon disease. This report underlines the need for early availability of pathology results from the explanted heart, which showed the same disorder.

Transesophageal echocardiography guidance for stent-graft repair of a thoracic aneurysm is facilitated by the ability of partial stent deployment.

Transesophageal echocardiography (TEE) is routinely used in our Institution for monitoring correct positioning of thoracic aortic stent grafts. We present a case of successful endovascular repair of three discrete thoracic aortic aneurysms with Zenith TX2 endovascular stent grafts in an 82-year-old female patient. Our focus is on the increased value of TEE guidance because of the ability of partial stent deployment and manipulation during insertion.

Lung transplant airway hypoxia: a diathesis to fibrosis?

RATIONALE: Chronic rejection, manifested pathologically as airway fibrosis, is the major problem limiting long-term survival in lung transplant recipients. Airway hypoxia and ischemia, resulting from a failure to restore the bronchial artery (BA) circulation at the time of transplantation, may predispose patients to chronic rejection. To address this possibility, clinical information is needed describing the status of lung perfusion and airway oxygenation after transplantation. OBJECTIVES: To determine the relative pulmonary arterial blood flow, airway tissue oxygenation and BA anatomy in the transplanted lung was compared with the contralateral native lung in lung allograft recipients. METHODS: Routine perfusion scans were evaluated at 3 and 12 months after transplantation in 15 single transplant recipients. Next, airway tissue oximetry was performed in 12 patients during surveillance bronchoscopies in the first year after transplant and in 4 control subjects. Finally, computed tomography (CT)-angiography studies on 11 recipients were reconstructed to evaluate the post-transplant anatomy of the BAs. MEASUREMENTS AND MAIN RESULTS: By 3 months after transplantation, deoxygenated pulmonary arterial blood is shunted away from the native lung to the transplanted lung. In the first year, healthy lung transplant recipients exhibit significant airway hypoxia distal to the graft anastomosis. CT-angiography studies demonstrate that BAs are abbreviated, generally stopping at or before the anastomosis, in transplant airways. CONCLUSIONS: Despite pulmonary artery blood being shunted to transplanted lungs after transplantation, grafts are hypoxic compared with both native (diseased) and control airways. Airway hypoxia may be due to the lack of radiologically demonstrable BAs after lung transplantation.

Early Outcome in Patients Requiring Conversion to General Anesthesia During Transfemoral Transcatheter Aortic Valve Implantation.

Transfemoral Transcatheter Aortic Valve Implantation (tf-TAVI) has become an established therapy-option for patients with symptomatic severe aortic stenosis. Conscious sedation (CS) has proven to be an alternative to general anesthesia . So far, the outcome of patients undergoing unplanned periprocedural conversion from CS to general anesthesia has not been investigated. All patients undergoing transfemoral transcatheter aortic valve implantation in CS between 2014 and 2019 were included. The primary end point was early safety at 30 days according to Valve Academic Research Consortium-2 criteria. The reasons for conversion and length of ICU-/ hospital stay were further analyzed. Of 1,058 included patients 35 (3.3%) required a conversion. The end point was documented in 13 (37%) of the converted and 110 (11%) of nonconverted patients (p < 0.001). The causes were: unrest in 11/35 patients, procedural complications in 10/35 patients, respiratory distress in 8/35, and cardiovascular decompensation in 6 patients (17.1%). Compared with the group without conversion (Median (interquartile range ), 4 [4-5] days), length of hospital stay was longest in the group with procedural complications (6 [1-11] days) followed by cardiovascular decompensation (5 [4-7] days). In conclusion, the conversion rate to general anesthesia was low in a large cohort of unselected transcatheter aortic valve implantation patients. Additionally, hospital stay was longer dependent on the reason for conversion.

Dexmedetomidine and the reduction of postoperative delirium after cardiac surgery.

BACKGROUND: Delirium is a neurobehavioral syndrome caused by the transient disruption of normal neuronal activity secondary to systemic disturbances. OBJECTIVE: The authors investigated the effects of postoperative sedation on the development of delirium in patients undergoing cardiac-valve procedures. METHODS: Patients underwent elective cardiac surgery with a standardized intraoperative anesthesia protocol, followed by random assignment to one of three postoperative sedation protocols: dexmedetomidine, propofol, or midazolam. RESULTS: The incidence of delirium for patients receiving dexmedetomidine was 3%, for those receiving propofol was 50%, and for patients receiving midazolam, 50%. Patients who developed postoperative delirium experienced significantly longer intensive-care stays and longer total hospitalization. CONCLUSION: The findings of this open-label, randomized clinical investigation suggest that postoperative sedation with dexmedetomidine was associated with significantly lower rates of postoperative delirium and lower care costs.

Acute cellular insulin resistance and hyperglycemia associated with hypophosphatemia after cardiac surgery.

Successful glycemic control reduces morbidity and mortality in cardiac surgery patients. Protocols that include insulin infusions are commonly followed to achieve target blood glucose levels. Insulin resistance has been reported and linked to low serum phosphate levels in animal models and studies in diabetic outpatients, but not in postoperative patients. The following case series is a retrospective observational review of 8 cardiac surgery patients who developed insulin resistance early after surgery; this resistance was reversed by correcting serum hypophosphatemia. We discuss the multiple underlying mechanisms causing hypophosphatemia.

Vancomycin plasma concentrations in cardiac surgery with the use of profound hypothermic circulatory arrest.

OBJECTIVE: This study was undertaken to compare the effect of deep hypothermic circulatory arrest, compared with moderate hypothermia, on the plasma concentrations and pharmacokinetic profile of vancomycin, administered as prophylaxis, in patients undergoing cardiac surgery with cardiopulmonary bypass. METHODS: Two groups of adult cardiac surgery patients were prospectively studied. One group consisted of 12 patients undergoing valvular surgery with moderate hypothermia, and another group was of 12 patients undergoing surgery with the use of profound hypothermic circulatory arrest. Vancomycin was administered before skin incision, and plasma levels were measured at regular intervals for 24h. RESULTS: The plasma concentrations of vancomycin showed a similar pattern in both groups. The pharmacokinetic profile showed a three-compartment model in both groups. CONCLUSION: The dosing of vancomycin, if used as antibiotic prophylaxis, does not need to be adjusted in cardiac surgery patients when undergoing profound hypothermic circulatory arrest, since the plasma concentrations and pharmacokinetic profile are similar to patients with moderate hypothermia. The pharmacokinetic profile, consisting of three compartments, was not changed by the differences in temperature.

Factors portending endoleak formation after thoracic aortic stent-graft repair of complicated aortic dissection.

BACKGROUND: Endoleaks after stent-graft repair of aortic dissections are poorly understood but seem substantially different from those seen after aneurysm repair. We studied anatomic and clinical factors associated with endoleaks in patients who underwent stent-graft repair of complicated type B aortic dissections. METHODS AND RESULTS: From 2000 to 2007, 37 patients underwent stent-graft repair of acute (< or =14 days; n=23), subacute (15 to 90 days; n=10) or chronic (>90 days; n=4) complicated type B aortic dissections using the Gore Thoracic Excluder (n=17) or TAG stent-grafts (n=20) under an investigator-sponsored protocol. Endoleaks were classified as imperfect proximal seal, flow through fenestrations or branches, or complex (both). Variables studied included coverage of the left subclavian artery, aortic curvature, completeness of proximal apposition, dissection chronicity, and device used. Endoleaks were found during follow-up (mean, 22 months) in 59% of patients, and they were associated with coverage of the left subclavian artery (complex, P<0.001), small radius of curvature (type 1 and complex, P=0.05), and greatest length of unapposed proximal stent graft (complex, P<0.0001). During follow-up, 10 endoleaks resolved spontaneously, 6 required reintervention for false lumen dilatation, and 2 were stable without clinical consequences. CONCLUSIONS: Endoleaks are common after stent-graft repair of aortic dissection and may lead to false lumen enlargement necessitating reintervention. Anatomic complexities such as acute aortic curvature and covered side branches were associated with endoleaks, illustrating the need for dissection-specific device development.

Stent-graft repair of an aortic rupture caused by invasive hemangiopericytoma.

We describe a patient with a history of hemangiopericytoma, who had hemoptysis develop due to a pseudoaneurysm of the thoracic aorta from an intrathoracic metastasis. Stent-graft repair successfully excluded the aneurysm from the aorta. Transesophageal echocardiography showed to be an important guide for correct placement of the device.

Intraoperative colon mucosal oxygen saturation during aortic surgery.

BACKGROUND: Colonic ischemia after aortic reconstruction is a devastating complication with high mortality rates. This study evaluates whether Colon Mucosal Oxygen Saturation (CMOS) correlates with colon ischemia during aortic surgery. MATERIALS AND METHODS: Aortic reconstruction was performed in 25 patients, using a spectrophotometer probe that was inserted in each patient's rectum before the surgical procedure. Continuous CMOS, buccal mucosal oxygen saturation, systemic mean arterial pressure, heart rate, pulse oximetry, and pivotal intra-operative events were collected. RESULTS: Endovascular aneurysm repair (EVAR) was performed in 20 and open repair in 5 patients with a mean age of 75 +/- 10 (+/-SE) years. CMOS reliably decreased in EVAR from a baseline of 56% +/- 8% to 26 +/- 17% (P < 0.0001) during infrarenal aortic balloon occlusion and femoral arterial sheath placement. CMOS similarly decreased during open repair from 56% +/- 9% to 15 +/- 19% (P < 0.0001) when the infrarenal aorta and iliac arteries were clamped. When aortic circulation was restored in both EVAR and open surgery, CMOS returned to baseline values 56.5 +/- 10% (P = 0.81). Mean recovery time in CMOS after an aortic intervention was 6.4 +/- 3.3 min. Simultaneous buccal mucosal oxygen saturation was stable (82% +/- 6%) during aortic manipulation but would fall significantly during active bleeding. There were no device related CMOS measurement complications. CONCLUSIONS: Intra-operative CMOS is a sensitive measure of colon ischemia where intraoperative events correlated well with changes in mucosal oxygen saturation. Transient changes demonstrate no problem. However, persistently low CMOS suggests colon ischemia, thus providing an opportunity to revascularize the inferior mesenteric artery or hypogastric arteries to prevent colon infarction.

Plasma cefazolin levels during cardiovascular surgery: effects of cardiopulmonary bypass and profound hypothermic circulatory arrest.

OBJECTIVES: We sought to assess the effects of cardiopulmonary bypass and profound hypothermic circulatory arrest on plasma cefazolin levels administered for antimicrobial prophylaxis in cardiovascular surgery. METHODS: Four groups (10 patients per group) were prospectively studied: vascular surgery without cardiopulmonary bypass (group A), cardiac surgery with a cardiopulmonary bypass time of less than 120 minutes (group B), cardiac surgery with a cardiopulmonary bypass time of greater than 120 minutes (group C), and cardiac surgery with cardiopulmonary bypass and profound hypothermic circulatory arrest (group D). Subjects received cefazolin at induction and a second dose before wound closure. Arterial blood samples were obtained preceding cefazolin administration, at skin incision, hourly during the operation, and before redosing. Cefazolin plasma concentrations were determined by using a radial diffusion assay, with Staphylococcus aureus as the indicator microorganism. Cefazolin plasma concentrations were considered noninhibitory at 8 microg/mL or less, intermediate at 16 mug/mL, and inhibitory at 32 microg/mL or greater. RESULTS: In group A cefazolin plasma concentrations remained greater than 16 microg/mL during the complete surgical procedure. In group B cefazolin plasma concentrations diminished to 16 microg/mL or less in 30% of the patients but remained greater than 8 microg/mL. In group C cefazolin plasma concentrations decreased to less than 16 microg/mL in 60% of patients and were less than 8 microg/mL in 50% of patients. In group D cefazolin plasma concentrations reached 16 microg/mL in 66% of the patients but decreased to 8 microg/mL in only 1 patient. CONCLUSIONS: For patients undergoing cardiac surgery with a cardiopulmonary bypass time of greater than 120 minutes, a single dose of cefazolin before skin incision with redosing at wound closure does not provide targeted antimicrobial cefazolin plasma levels during the entire surgical procedure. Patients undergoing profound hypothermic circulatory arrest are better protected, but the described protocol of prophylaxis is not optimal.