Grace Huang, M.D., Amanda Rhee, M.D. · Fontan pathway thrombi removal with AngioVac® aspiration...
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Fontan pathway thrombi removal with AngioVac® aspiration system Grace Huang, M.D., Amanda Rhee, M.D. Icahn School of Medicine at Mount Sinai, New York, NY 10029-6574 DISCUSSION CASE DESCRIPTION A 19 year old male with severe tricuspid stenosis and ventricular septal defect (VSD) status post bi-directional Glenn procedure at 6 months of age and extracardiac Fontan at age 5 presents to an outside hospital with shortness of breath, dizziness and SpO2 of 54%. He was found to have a bacterial pneumonia in addition to rhinovirus, which led to sepsis despite treatment. Patient’s respiratory and cardiovascular status continued to worsen and was started on milrinone, dopamine and norepinephrine. Cardiac catheterization to evaluate Fontan patency and hemodynamics showed a large left pulmonary artery (LPA) thrombus (Figure 1a) and Fontan pathway obstruction secondary to stenosis and thrombus at the anastomotic site to branch pulmonary arteries (Figure 1b). He was placed on a TPA infusion for 24 hours and reevaluated via repeat catheterization, which showed little improvement. IVC pressure = 20mmHg and SVC pressure = 14mmHg. Given the patient’s failure to improve, tenuous state and prior cardiac surgical history, the decision was made to endovascularly retrieve the clot using the AngioVac® aspiration system. The Angiovac ® has been marketed for en bloc removal of undesirable intravascular material while maintaining flow with extracorporeal circulation. Our patient came to the cardiac catheterization lab requiring milrinone and dopamine to maintain mean arterial pressures (MAP) >65. General anesthesia was induced with ketamine 2mg/ kg, fentanyl 2mg/kg, and 0.1 mg/kg vecuronium followed by endotracheal intubation. Maintenance anesthetic included a ketamine infusion along with midazolam, vecuronium, and fentanyl boluses. He was connected to the veno-venous bypass circuit using a 26Fr Gore Dry Seal sheath in his left femoral vein and a 16Fr reinfusion extracorporeal membrane oxygenation (ECMO) cannula to his right internal jugular vein. In our case, an additional venous reservoir was spliced into the sterile tubing so that we could add volume into an otherwise closed circuit. Under fluoroscopic guidance, the Angiovac® catheter was unable to pass distal through the patient’s calcified Fontan stenosis into the LPA to reach the LPA thrombus. The Fontan pathway was first dilated with a 14mm x 4cm Atlas balloon. The Angiovac® catheter was then advanced successfully to the LPA and 20mL of thrombi were removed from proximal LPA. The distal Fontan was then stented with a Palmaz 4010 stent mounted on an 18mm x 4cm balloon catheter. IVC injection at this point showed patent Fontan pathway with very mild stent narrowing at the anastomotic site of the Fontan (Figure 1d) and branch pulmonary artery junction (Figure 1c). Post intervention, SVC pressure=IVC pressure=LPA pressure=18mmHg. Aortic saturation improved from 81% to 95% Four units of packed red blood cells and one liter of crystalloid were given throughout the case. Dopamine was titrated off and the patient was kept intubated and transferred to the pediatric intensive care unit. Several complications can arise in a patient with complex congenital cardiac history. In this case, our patient’s thrombus in the Fontan pathway at the LPA along with the thrombus in his IVC left him with a filling defect to his left lung and markedly reduced preload to the heart. The Angiovac® catheter has been marketed for en bloc removal of undesirable intravascular material such as thrombi, myxoma, and vegetations while maintaining flow during extracorporeal circulation. After thrombi removal with the Angiovac® aspiration system, our patient was noted to have increased flow in Fontan pathway from IVC to bilateral branch pulmonary arteries. To our knowledge, there has been no report of the Angiovac® system being used in a clotted Fontan. The Angiovac® system has been used to remove right atrial thrombotic masses, refractory endocarditis vegetations, pulmonary arterial thrombi,. Alternative therapies include thrombolytic therapy and surgical intervention. In our case, thrombolytic therapy was not effective and surgical intervention carried a high risk given the patient’s previous two sternotomies for cardiac surgery and septic state. Fontan patients are predisposed to thrombotic events. Thromboembolism is likely the leading cause of death among Fontan patients and between 3% and 33% of patients with a Fontan will experience a thromboembolic event. Reports have shown a sharp increase in risk for mortality from thromboemboli 15 years after Fontan surgery. The pathogenesis behind this occurrence is not certain; however there are a few possible explanations. 1) The suboptimal hemodynamics in a Fontan pathway can predispose patients to hemostasis and hypercoagulable states including decreased levels of protein C, protein S, antithrombin III, factors II and X and increased platelet reactivity. Patients with Fontan circulation tend to have lower cardiac outputs because the single ventricular heart develops poor compliance and diastolic dysfunction. Suboptimal hemodynamics can cause hepatic impairment further affecting clotting factors. 2) Thrombi commonly originate in the actual Fontan circuit between the SVC, IVC and the pulmonary arteries leading to limitations in cardiac output. 3) Protein losing enteropathy (PLE) also plays a significant role in the formation of thromboemboli. PLE occurs at an incidence of 1.5%-11%. Onset ranges from one month to 20 years after Fontan operation. The pathogenesis of PLE involves chronically elevated right atrial and IVC pressures thus translating to increased portal vein pressures leading to intestinal congestion, lymphatic obstruction, mesenteric ischemia, and ultimately, enteric protein loss. Figure 1 (a-d): Cardiac catheter fluoroscopy images a) partially occluded left pulmonary artery with red arrow depicting clot b) red arrow shows thrombus partially obstructing stenotic Fontan pathway c) patent left pulmonary artery d) stented and patent Fontan pathway Figure 2 (a-c): a) red arrow showing thrombi collected in Angiovac® filter 2) a schematic of Angiovac® system circuit c) our circuit with a reservoir spliced into otherwise closed venovenous bypass circuit LITERATURE CITED 1: Trojnarska, O, Cieplucha, A. Challenges of management and therapy in patients with a functionally single ventricle after Fontan operation. Cardiology Journal, 2011; 18: 119-127. 2: Mondesert, B, Marcotte, F, et. al. Fontan Circulation: Success or Failure? Canadian Journal of Cardiology, 2013; 29: 811-820. 3: Todoran, T, Sobieszczyk, P. Catheter-Based Therapies for Massive Pulmonary Embolism. Progress in Cardiovascular Diseases, 2010; 52: 429-437. a b c d c b a
Transcript of Grace Huang, M.D., Amanda Rhee, M.D. · Fontan pathway thrombi removal with AngioVac® aspiration...
Fontan pathway thrombi removal with AngioVac® aspiration system Grace Huang, M.D., Amanda Rhee, M.D.
Icahn School of Medicine at Mount Sinai, New York, NY 10029-6574
DISCUSSION CASE DESCRIPTION
A 19 year old male with severe tricuspid stenosis and ventricular septal defect (VSD) status post bi-directional Glenn procedure at 6 months of age and extracardiac Fontan at age 5 presents to an outside hospital with shortness of breath, dizziness and SpO2 of 54%. He was found to have a bacterial pneumonia in addition to rhinovirus, which led to sepsis despite treatment. Patient’s respiratory and cardiovascular status continued to worsen and was started on milrinone, dopamine and norepinephrine.
Cardiac catheterization to evaluate Fontan patency and hemodynamics showed a large left pulmonary artery (LPA) thrombus (Figure 1a) and Fontan pathway obstruction secondary to stenosis and thrombus at the anastomotic site to branch pulmonary arteries (Figure 1b). He was placed on a TPA infusion for 24 hours and reevaluated via repeat catheterization, which showed little improvement. IVC pressure = 20mmHg and SVC pressure = 14mmHg.
Given the patient’s failure to improve, tenuous state and prior cardiac surgical history, the decision was made to endovascularly retrieve the clot using the AngioVac® aspiration system. The Angiovac ® has been marketed for en bloc removal of undesirable intravascular material while maintaining flow with extracorporeal circulation. Our patient came to the cardiac catheterization lab requiring milrinone and dopamine to maintain mean arterial pressures (MAP) >65. General anesthesia was induced with ketamine 2mg/kg, fentanyl 2mg/kg, and 0.1 mg/kg vecuronium followed by endotracheal intubation. Maintenance anesthetic included a ketamine infusion along with midazolam, vecuronium, and fentanyl boluses.
He was connected to the veno-venous bypass circuit using a 26Fr Gore Dry Seal sheath in his left femoral vein and a 16Fr reinfusion extracorporeal membrane oxygenation (ECMO) cannula to his right internal jugular vein. In our case, an additional venous reservoir was spliced into the sterile tubing so that we could add volume into an otherwise closed circuit.
Under fluoroscopic guidance, the Angiovac® catheter was unable to pass distal through the patient’s calcified Fontan stenosis into the LPA to reach the LPA thrombus. The Fontan pathway was first dilated with a 14mm x 4cm Atlas balloon. The Angiovac® catheter was then advanced successfully to the LPA and 20mL of thrombi were removed from proximal LPA. The distal Fontan was then stented with a Palmaz 4010 stent mounted on an 18mm x 4cm balloon catheter. IVC injection at this point showed patent Fontan pathway with very mild stent narrowing at the anastomotic site of the Fontan (Figure 1d) and branch pulmonary artery junction (Figure 1c). Post intervention, SVC pressure=IVC pressure=LPA pressure=18mmHg. Aortic saturation improved from 81% to 95% Four units of packed red blood cells and one liter of crystalloid were given throughout the case. Dopamine was titrated off and the patient was kept intubated and transferred to the pediatric intensive care unit.
Several complications can arise in a patient with complex congenital cardiac history. In this case, our patient’s thrombus in the Fontan pathway at the LPA along with the thrombus in his IVC left him with a filling defect to his left lung and markedly reduced preload to the heart. The Angiovac® catheter has been marketed for en bloc removal of undesirable intravascular material such as thrombi, myxoma, and vegetations while maintaining flow during extracorporeal circulation. After thrombi removal with the Angiovac® aspiration system, our patient was noted to have increased flow in Fontan pathway from IVC to bilateral branch pulmonary arteries. To our knowledge, there has been no report of the Angiovac® system being used in a clotted Fontan. The Angiovac® system has been used to remove right atrial thrombotic masses, refractory endocarditis vegetations, pulmonary arterial thrombi,. Alternative therapies include thrombolytic therapy and surgical intervention. In our case, thrombolytic therapy was not effective and surgical intervention carried a high risk given the patient’s previous two sternotomies for cardiac surgery and septic state.
Fontan patients are predisposed to thrombotic events. Thromboembolism is likely the leading cause of death among Fontan patients and between 3% and 33% of patients with a Fontan will experience a thromboembolic event. Reports have shown a sharp increase in risk for mortality from thromboemboli 15 years after Fontan surgery. The pathogenesis behind this occurrence is not certain; however there are a few possible explanations. 1) The suboptimal hemodynamics in a Fontan pathway can predispose patients to hemostasis and hypercoagulable states including decreased levels of protein C, protein S, antithrombin III, factors II and X and increased platelet reactivity. Patients with Fontan circulation tend to have lower cardiac outputs because the single ventricular heart develops poor compliance and diastolic dysfunction. Suboptimal hemodynamics can cause hepatic impairment further affecting clotting factors. 2) Thrombi commonly originate in the actual Fontan circuit between the SVC, IVC and the pulmonary arteries leading to limitations in cardiac output. 3) Protein losing enteropathy (PLE) also plays a significant role in the formation of thromboemboli. PLE occurs at an incidence of 1.5%-11%. Onset ranges from one month to 20 years after Fontan operation. The pathogenesis of PLE involves chronically elevated right atrial and IVC pressures thus translating to increased portal vein pressures leading to intestinal congestion, lymphatic obstruction, mesenteric ischemia, and ultimately, enteric protein loss.
Figure 1 (a-d): Cardiac catheter fluoroscopy images a) partially occluded left pulmonary artery with red arrow depicting clot b) red arrow shows thrombus partially obstructing stenotic Fontan pathway c) patent left pulmonary artery d) stented and patent Fontan pathway
Figure 2 (a-c): a) red arrow showing thrombi collected in Angiovac® filter 2) a schematic of Angiovac® system circuit c) our circuit with a reservoir spliced into otherwise closed venovenous bypass circuit
LITERATURE CITED
1: Trojnarska, O, Cieplucha, A. Challenges of management and therapy in patients with a functionally single ventricle after Fontan operation. Cardiology Journal, 2011; 18: 119-127. 2: Mondesert, B, Marcotte, F, et. al. Fontan Circulation: Success or Failure? Canadian Journal of Cardiology, 2013; 29: 811-820. 3: Todoran, T, Sobieszczyk, P. Catheter-Based Therapies for Massive Pulmonary Embolism. Progress in Cardiovascular Diseases, 2010; 52: 429-437.
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