- Email: [email protected]
Intraarterial thrombolysis for perioperative stroke in patients undergoing cardiac operations
Ann Thorac Surg 2002;74:2226 –9
aorta through a median sternotomy [1]. The results are encouraging compared with staged operation, especially considering the difficulties encountered in calling back patients for the second procedure on the descending aorta after a successful first step. However, we would like to focus on some aspects of the technique. Since September 2000, we have applied a similar philosophy to patients with indications for operation on intrapericardial structures and descending thoracic aorta in three instances: annuloaortic ectasia associated with chronic type B dissection in 1 patient, and coronary artery disease associated with descending aortic aneurysm in 2 (mean age, 72 ⫾ 6 years). We have not performed the distal anastomosis of the graft, but simply fashioned the prosthesis as a long “elephant trunk” through the open aortic arch, as described for acute type B dissections [2]. The difference from previous reports is that a much longer prothesis (18 to 20 cm) was implanted in the descending aorta. The diameter of the Dacron graft was 24 mm in two cases and 26 mm in one. No patient died or developed paraplegia/stroke. Duration of circulatory arrest was 39 ⫾ 11 minutes. Retrograde superior caval perfusion was used during circulatory arrest. Intensive care unit and hospital stays were 4.7 ⫾ 0.6 and 13.3 ⫾ 2.1 days, respectively. Mean follow-up is 8.7 ⫾ 4.7 months. The idea of pulling down the tubular prosthesis by securing it to a guidewire is brilliant, but our feeling is that completion of the distal anastomosis is potentially useless and certainly timeconsuming. In the series described by Beaver and Martin, circulatory arrest time averaged 72 minutes (with a minimum of 56 minutes) while the distal anastomosis was made and supraaortic trunks were reimplanted. Probably because retrograde cerebral perfusion was used, a surprisingly low incidence of cerebral complications occurred (7%). However, longer circulatory arrest and bypass times may have contributed significantly to mortality (14%) and morbidity rates (paraplegia, 14%; tracheostomy, 36%; renal failure, 28%; hospital stay, 32 ⫾ 22 days). Also, total exclusion of the periprosthetic space may contribute to spinal malperfusion. We agree with Beaver and Martin that a single-stage operation is advisable for extensive aneurysmal disease. We also feel that in case of diffuse arterial disease and, often, associated advanced age and impaired multiorgan function, extensive thoracotomy is less well tolerated than a median sternotomy despite the need for circulatory arrest. We have, therefore, applied a similar concept for combined cardiac and descending aortic disease. We are, however, concerned with problems related to prolonged hypothermic circulatory arrest (especially in this patient population) as recently reviewed in The Annals [3]. A long “elephant trunk” is our first-choice in these patients. Marco Pocar, MD, PhD Francesco Donatelli, MD Divisione e Cattedra di Cardiochirurgia IRCCS Ospedale Maggiore di Milano Universita` degli Studi di Milano Via Francesco Sforza, 35 20122 Milano, Italy e-mail: [email protected]
References 1. Beaver TM, Martin TD. Single-stage transmediastinal replacement of the ascending, arch, and descending thoracic aorta. Ann Thorac Surg 2001;72:1232–8. 2. Palma JH, Almeida DR, Carvalho AC, Andrade JC, Buffolo E. Surgical treatment of acute type B aortic dissection using an © 2002 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
CORRESPONDENCE
2227
endoprosthesis (elephant trunk). Ann Thorac Surg 1997;63:1081–4. 3. Hagl C, Tatton NA, Khaladj N, Zhang N, et al. Involvement of apoptosis in neurological injury after hypothermic circulatory arrest: a new target for therapeutic intervention? Ann Thorac Surg 2001;72:1457–64.
Reply To the Editor: We appreciate Drs Pocar and Donatelli’s comments. Admittedly, hypothermic circulatory arrest times are longer with our technique; however, we prefer to suture the distal end of the graft to prevent late rupture from endoleaks. Thomas M. Beaver MD Tomas D. Martin, MD Department of Thoracic and Cardiovascular Surgery University of Florida PO Box 100286 1600 SW Archer Rd Gainesville, FL 32610
Intraarterial Thrombolysis for Perioperative Stroke in Patients Undergoing Cardiac Operations To the Editor: We read with great interest the recent article by Dr Moazami and colleagues [1]. They reported successful outcome of intraarterial thrombolysis for an acute intracranial arterial occlusion after cardiac operation. Thrombolysis is an effective but potentially deleterious therapy and therefore, should be limited to patients with acute intracerebral vessel occlusion and salvageable tissue. The essential challenge of this approach for postcardiotomy stroke is adverse effects due to thrombolysis. Generally, major operation within the previous 14 to 30 days is considered a contraindication to fibrinolytic therapy because of incremental risk for surgical site bleeding. Hemorrhagic transformation of the infarction is another concern. We used the same strategies for postoperative stroke after cardiac operation for 3 patients with a recanalization rate of 100% [2]. In our experience, 2 of 3 patients improved significantly and 1 patient improved moderately. Our patients had delayed thromboembolism closely related to atrial fibrillation or mechanical valve, but radiologic and clinical improvement was striking. One patient had a small hemorrhagic cerebral infarction at the core of the ischemic area, yet bleeding complications due to use of fibrinolytic agents were minimal. Although early recanalization within 3 hours after stroke onset is universally safe, some patients show complete recovery treated several hours after the onset of stroke. Recently diffusion- and perfusion-weighed magnetic resonance imaging became available for early assessment of acute ischemic stroke [3]. Using this method, the differential diagnosis between complete cerebral infarct and reversible ischemia is possible. Selection of patients for reperfusion therapy will become clearer in the near future. However, organization of a stroke care team and immediate assessment of cerebral ischemia is necessary because the therapeutic window for cerebral reperfusion is still narrow. Compared to intravenous administration of tissue plasminogen activator, which is easy to perform, there are several benefits 0003-4975/02/$22.00
2228
CORRESPONDENCE
from intraarterial administration of fibrinolytic agents. First, because the local concentration of fibrinolytic agent may be higher by intraarterial administration, the required dose of the fibrinolytic agent can be minimized by real-time monitoring of cerebral perfusion with angiography. In the Prolyse in Acute Cerebral Thromboembolism (PROACT) study, partial recanalization was significantly greater after local administration in a pro-urokinase group than in the placebo group, whereas the incidence of intracranial hemorrhagic deterioration was the same [4]. Several large case series of treatment by intraarterial thrombolysis with urokinase or tissue plasminogen activator report complete or partial recanalization in 74% of the patients, which is higher than that achieved by intravenous administration, and the incidence of symptomatic intracranial hematoma is lower than that reported for intravenous thrombolysis [5, 6]. Second, additional intervention is possible for residual stenosis or thrombosis of an intracerebral artery. As for surgical site bleeding, none of the patients who received lytic therapy experienced bleeding in their operative sites in our series. Local intraarterial administration of fibrinolytic agents seems to be more effective than systemic administration of fibrinolytic agents. These results suggest potential benefits and acceptable safety of local thrombolysis. Although use of a thrombolytic agent after cardiac operation is controversial, we support Dr Moazami’s aggressive approach for ischemic stroke after cardiac operation. Ikuo Fukuda, MD Department of Surgery 1 Hirosaki University School of Medicine 5 Zaifu-cho, Hirosaki, Aomori 036-8562, Japan e-mail: [email protected] Mitsuyoshi Wada, MD Department of Radiology Tsukuba Medical Center Hospital 1-3-1 Amakubo, Tsukuba, Ibaraki 305-8558, Japan
References 1. Moazami N, Smedira NG, McCarthy PM, et al. Safety and efficacy of intraarterial thrombolysis for perioperative stroke after cardiac operation. Ann Thorac Surg 2001;72:1933–9. 2. Fukuda I, Gomi S, Meguro K, Wada M. Impact of immediate cerebral angiography for in-hospital cerebral thromboembolism after cardiovascular surgery. Jpn J Thorac Cardiovas Surg 2001;49:282–6. 3. Rohl L, Ostergaard L, Simonsen CZ, et al. Viability thresholds of ischemic penumbra of hyperacute stroke defined by perfusion-weighted MRI and apparent diffusion coefficient. Stroke 2001;32:1140 –6. 4. del Zoppo GJ, Higashida RT, Furlan AJ, Pessin MS, Rowley HA, Gent M. PROACT: a phase II randomized trial of recombinant pro-urokinase by direct arterial delivery in acute middle cerebral artery stroke. PROACT Investigators. Prolyse in Acute Cerebral Thromboembolism. Stroke 1998;29:4 –11. 5. Hacke W, Kaste M, Fieschi C, et al. Intravenous thrombolysis with recombinant tissue plasminogen activator for acute hemispheric stroke. JAMA 1995;274:1017–25. 6. Brott TG, Hacke W. Thrombolytic and defibrinogenating agents for ischemic and hemorrhagic stroke. In: Barnett HJM, Mohr JP, Stein BM, Yatsu FM, eds. Stroke, third ed. New York: Churchill Livingstone, 1998:1155–76. © 2002 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
Ann Thorac Surg 2002;74:2226 –9
Fontan Operation in a Patient With Separate Hepatic Venous Drainage: Is There a Problem? To the Editor: I read with great interest the recent report of Dr Lee and colleagues [1]. They described a patient in whom the inferior vena cava and the hepatic veins drained separately into the common atrium. They diverted the hepatic venous flow into the extracardiac Fontan conduit by means of an 8-mm intraatrial Gore-Tex (W.L. Gore and Associates, Flagstaff, AZ) tube graft. The operation was performed on a 22-month-old patient. A few questions and comments seem to be appropriate. Will hepatic veins provide sufficient flow to keep this conduit open? Will this shunt become a source of thromboembolism in future? Will the shunt permit an unobstructed hepatic venous flow as the child grows? Unfortunately, these questions cannot be answered at the present time. The future will show. I hope sincerely that none of these complications will happen to the patient described and look forward to a long-term follow-up. Separate hepatic venous drainage represents a difficult problem in patients undergoing Fontan or Kawashima operation. It is thought that diversion of the hepatic venous drainage to the pulmonary circulation is necessary to prevent pulmonary arteriovenous malformations, at least, in younger children. Thus, the conversion of the hepatic venous blood into the pulmonary circulation is desirable. The concern is, however, that because of low blood flow from hepatic veins, the risk of conduit thrombosis may be significantly increased. My colleagues and I observed thrombosis of both intracardiac and extracardiac conduits when used for diversion of the separate hepatic venous drainage into Fontan circuit [2]. In our article, we reviewed a number of alternative techniques that have been proposed to direct the hepatic venous blood flow to the pulmonary circulation without prosthetic conduits. Those included anastomosis of the hepatic veins to the azygous vein in case of azygous continuation of the inferior vena cava and a circumferential atrial tunnel from the origin of the hepatic veins to the superior vena cava by means of a flap of the right atrial wall. The benefits of these techniques remain unproven. I congratulate Dr Lee and colleagues on describing and successful implementation of yet one more promising technique for the conversion of the separate hepatic venous drainage into pulmonary circulation. As the survival of this challenging group of patients improves with advances of pediatric cardiac surgery, the separate hepatic venous drainage becomes an important issue. Igor E. Konstantinov, MD Division of Cardiovascular Surgery Hospital for Sick Children Toronto, ON M5G 1X8, Canada e-mail: [email protected]
References 1. Lee JR, Lee C, Chang JM, Bae EJ, Noh CI. Modified extracardiac Fontan in a patient with separate hepatic venous drainage. Ann Thorac Surg 2002;73:992–3. 2. Konstantinov IE, Puga FJ, Alexi-Meskishvili VV. Thrombosis of intracardiac or extracardiac conduits after modified Fontan operation in patients with azygous continuation of the inferior vena cava. Ann Thorac Surg 2001;72:1641–4. 0003-4975/02/$22.00
aorta through a median sternotomy [1]. The results are encouraging compared with staged operation, especially considering the difficulties encountered in calling back patients for the second procedure on the descending aorta after a successful first step. However, we would like to focus on some aspects of the technique. Since September 2000, we have applied a similar philosophy to patients with indications for operation on intrapericardial structures and descending thoracic aorta in three instances: annuloaortic ectasia associated with chronic type B dissection in 1 patient, and coronary artery disease associated with descending aortic aneurysm in 2 (mean age, 72 ⫾ 6 years). We have not performed the distal anastomosis of the graft, but simply fashioned the prosthesis as a long “elephant trunk” through the open aortic arch, as described for acute type B dissections [2]. The difference from previous reports is that a much longer prothesis (18 to 20 cm) was implanted in the descending aorta. The diameter of the Dacron graft was 24 mm in two cases and 26 mm in one. No patient died or developed paraplegia/stroke. Duration of circulatory arrest was 39 ⫾ 11 minutes. Retrograde superior caval perfusion was used during circulatory arrest. Intensive care unit and hospital stays were 4.7 ⫾ 0.6 and 13.3 ⫾ 2.1 days, respectively. Mean follow-up is 8.7 ⫾ 4.7 months. The idea of pulling down the tubular prosthesis by securing it to a guidewire is brilliant, but our feeling is that completion of the distal anastomosis is potentially useless and certainly timeconsuming. In the series described by Beaver and Martin, circulatory arrest time averaged 72 minutes (with a minimum of 56 minutes) while the distal anastomosis was made and supraaortic trunks were reimplanted. Probably because retrograde cerebral perfusion was used, a surprisingly low incidence of cerebral complications occurred (7%). However, longer circulatory arrest and bypass times may have contributed significantly to mortality (14%) and morbidity rates (paraplegia, 14%; tracheostomy, 36%; renal failure, 28%; hospital stay, 32 ⫾ 22 days). Also, total exclusion of the periprosthetic space may contribute to spinal malperfusion. We agree with Beaver and Martin that a single-stage operation is advisable for extensive aneurysmal disease. We also feel that in case of diffuse arterial disease and, often, associated advanced age and impaired multiorgan function, extensive thoracotomy is less well tolerated than a median sternotomy despite the need for circulatory arrest. We have, therefore, applied a similar concept for combined cardiac and descending aortic disease. We are, however, concerned with problems related to prolonged hypothermic circulatory arrest (especially in this patient population) as recently reviewed in The Annals [3]. A long “elephant trunk” is our first-choice in these patients. Marco Pocar, MD, PhD Francesco Donatelli, MD Divisione e Cattedra di Cardiochirurgia IRCCS Ospedale Maggiore di Milano Universita` degli Studi di Milano Via Francesco Sforza, 35 20122 Milano, Italy e-mail: [email protected]
References 1. Beaver TM, Martin TD. Single-stage transmediastinal replacement of the ascending, arch, and descending thoracic aorta. Ann Thorac Surg 2001;72:1232–8. 2. Palma JH, Almeida DR, Carvalho AC, Andrade JC, Buffolo E. Surgical treatment of acute type B aortic dissection using an © 2002 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
CORRESPONDENCE
2227
endoprosthesis (elephant trunk). Ann Thorac Surg 1997;63:1081–4. 3. Hagl C, Tatton NA, Khaladj N, Zhang N, et al. Involvement of apoptosis in neurological injury after hypothermic circulatory arrest: a new target for therapeutic intervention? Ann Thorac Surg 2001;72:1457–64.
Reply To the Editor: We appreciate Drs Pocar and Donatelli’s comments. Admittedly, hypothermic circulatory arrest times are longer with our technique; however, we prefer to suture the distal end of the graft to prevent late rupture from endoleaks. Thomas M. Beaver MD Tomas D. Martin, MD Department of Thoracic and Cardiovascular Surgery University of Florida PO Box 100286 1600 SW Archer Rd Gainesville, FL 32610
Intraarterial Thrombolysis for Perioperative Stroke in Patients Undergoing Cardiac Operations To the Editor: We read with great interest the recent article by Dr Moazami and colleagues [1]. They reported successful outcome of intraarterial thrombolysis for an acute intracranial arterial occlusion after cardiac operation. Thrombolysis is an effective but potentially deleterious therapy and therefore, should be limited to patients with acute intracerebral vessel occlusion and salvageable tissue. The essential challenge of this approach for postcardiotomy stroke is adverse effects due to thrombolysis. Generally, major operation within the previous 14 to 30 days is considered a contraindication to fibrinolytic therapy because of incremental risk for surgical site bleeding. Hemorrhagic transformation of the infarction is another concern. We used the same strategies for postoperative stroke after cardiac operation for 3 patients with a recanalization rate of 100% [2]. In our experience, 2 of 3 patients improved significantly and 1 patient improved moderately. Our patients had delayed thromboembolism closely related to atrial fibrillation or mechanical valve, but radiologic and clinical improvement was striking. One patient had a small hemorrhagic cerebral infarction at the core of the ischemic area, yet bleeding complications due to use of fibrinolytic agents were minimal. Although early recanalization within 3 hours after stroke onset is universally safe, some patients show complete recovery treated several hours after the onset of stroke. Recently diffusion- and perfusion-weighed magnetic resonance imaging became available for early assessment of acute ischemic stroke [3]. Using this method, the differential diagnosis between complete cerebral infarct and reversible ischemia is possible. Selection of patients for reperfusion therapy will become clearer in the near future. However, organization of a stroke care team and immediate assessment of cerebral ischemia is necessary because the therapeutic window for cerebral reperfusion is still narrow. Compared to intravenous administration of tissue plasminogen activator, which is easy to perform, there are several benefits 0003-4975/02/$22.00
2228
CORRESPONDENCE
from intraarterial administration of fibrinolytic agents. First, because the local concentration of fibrinolytic agent may be higher by intraarterial administration, the required dose of the fibrinolytic agent can be minimized by real-time monitoring of cerebral perfusion with angiography. In the Prolyse in Acute Cerebral Thromboembolism (PROACT) study, partial recanalization was significantly greater after local administration in a pro-urokinase group than in the placebo group, whereas the incidence of intracranial hemorrhagic deterioration was the same [4]. Several large case series of treatment by intraarterial thrombolysis with urokinase or tissue plasminogen activator report complete or partial recanalization in 74% of the patients, which is higher than that achieved by intravenous administration, and the incidence of symptomatic intracranial hematoma is lower than that reported for intravenous thrombolysis [5, 6]. Second, additional intervention is possible for residual stenosis or thrombosis of an intracerebral artery. As for surgical site bleeding, none of the patients who received lytic therapy experienced bleeding in their operative sites in our series. Local intraarterial administration of fibrinolytic agents seems to be more effective than systemic administration of fibrinolytic agents. These results suggest potential benefits and acceptable safety of local thrombolysis. Although use of a thrombolytic agent after cardiac operation is controversial, we support Dr Moazami’s aggressive approach for ischemic stroke after cardiac operation. Ikuo Fukuda, MD Department of Surgery 1 Hirosaki University School of Medicine 5 Zaifu-cho, Hirosaki, Aomori 036-8562, Japan e-mail: [email protected] Mitsuyoshi Wada, MD Department of Radiology Tsukuba Medical Center Hospital 1-3-1 Amakubo, Tsukuba, Ibaraki 305-8558, Japan
References 1. Moazami N, Smedira NG, McCarthy PM, et al. Safety and efficacy of intraarterial thrombolysis for perioperative stroke after cardiac operation. Ann Thorac Surg 2001;72:1933–9. 2. Fukuda I, Gomi S, Meguro K, Wada M. Impact of immediate cerebral angiography for in-hospital cerebral thromboembolism after cardiovascular surgery. Jpn J Thorac Cardiovas Surg 2001;49:282–6. 3. Rohl L, Ostergaard L, Simonsen CZ, et al. Viability thresholds of ischemic penumbra of hyperacute stroke defined by perfusion-weighted MRI and apparent diffusion coefficient. Stroke 2001;32:1140 –6. 4. del Zoppo GJ, Higashida RT, Furlan AJ, Pessin MS, Rowley HA, Gent M. PROACT: a phase II randomized trial of recombinant pro-urokinase by direct arterial delivery in acute middle cerebral artery stroke. PROACT Investigators. Prolyse in Acute Cerebral Thromboembolism. Stroke 1998;29:4 –11. 5. Hacke W, Kaste M, Fieschi C, et al. Intravenous thrombolysis with recombinant tissue plasminogen activator for acute hemispheric stroke. JAMA 1995;274:1017–25. 6. Brott TG, Hacke W. Thrombolytic and defibrinogenating agents for ischemic and hemorrhagic stroke. In: Barnett HJM, Mohr JP, Stein BM, Yatsu FM, eds. Stroke, third ed. New York: Churchill Livingstone, 1998:1155–76. © 2002 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
Ann Thorac Surg 2002;74:2226 –9
Fontan Operation in a Patient With Separate Hepatic Venous Drainage: Is There a Problem? To the Editor: I read with great interest the recent report of Dr Lee and colleagues [1]. They described a patient in whom the inferior vena cava and the hepatic veins drained separately into the common atrium. They diverted the hepatic venous flow into the extracardiac Fontan conduit by means of an 8-mm intraatrial Gore-Tex (W.L. Gore and Associates, Flagstaff, AZ) tube graft. The operation was performed on a 22-month-old patient. A few questions and comments seem to be appropriate. Will hepatic veins provide sufficient flow to keep this conduit open? Will this shunt become a source of thromboembolism in future? Will the shunt permit an unobstructed hepatic venous flow as the child grows? Unfortunately, these questions cannot be answered at the present time. The future will show. I hope sincerely that none of these complications will happen to the patient described and look forward to a long-term follow-up. Separate hepatic venous drainage represents a difficult problem in patients undergoing Fontan or Kawashima operation. It is thought that diversion of the hepatic venous drainage to the pulmonary circulation is necessary to prevent pulmonary arteriovenous malformations, at least, in younger children. Thus, the conversion of the hepatic venous blood into the pulmonary circulation is desirable. The concern is, however, that because of low blood flow from hepatic veins, the risk of conduit thrombosis may be significantly increased. My colleagues and I observed thrombosis of both intracardiac and extracardiac conduits when used for diversion of the separate hepatic venous drainage into Fontan circuit [2]. In our article, we reviewed a number of alternative techniques that have been proposed to direct the hepatic venous blood flow to the pulmonary circulation without prosthetic conduits. Those included anastomosis of the hepatic veins to the azygous vein in case of azygous continuation of the inferior vena cava and a circumferential atrial tunnel from the origin of the hepatic veins to the superior vena cava by means of a flap of the right atrial wall. The benefits of these techniques remain unproven. I congratulate Dr Lee and colleagues on describing and successful implementation of yet one more promising technique for the conversion of the separate hepatic venous drainage into pulmonary circulation. As the survival of this challenging group of patients improves with advances of pediatric cardiac surgery, the separate hepatic venous drainage becomes an important issue. Igor E. Konstantinov, MD Division of Cardiovascular Surgery Hospital for Sick Children Toronto, ON M5G 1X8, Canada e-mail: [email protected]
References 1. Lee JR, Lee C, Chang JM, Bae EJ, Noh CI. Modified extracardiac Fontan in a patient with separate hepatic venous drainage. Ann Thorac Surg 2002;73:992–3. 2. Konstantinov IE, Puga FJ, Alexi-Meskishvili VV. Thrombosis of intracardiac or extracardiac conduits after modified Fontan operation in patients with azygous continuation of the inferior vena cava. Ann Thorac Surg 2001;72:1641–4. 0003-4975/02/$22.00