13 nov 2017 intra operative thrombolysis in acute limb ischemia
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Intraoperative thrombolysis can be used to dissolve residual thrombus after embolectomy. It has the benefits of restoring patency and reducing the need for extensive surgery. The technique involves catheter placement within the thrombus to directly infuse thrombolytic agents. Studies show this approach is generally safe and can improve outcomes when used as an adjunct to surgery for acute limb ischemia. Long term patency depends on identifying and treating the underlying cause of occlusion.
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13 nov 2017 intra operative thrombolysis in acute limb ischemia
- 1. Parach Sirisriro 13th Nov 2017
- 7. Reference Cronenwett, J. L. and K. W. Johnston (2014). Rutherford's Vascular Surgery E-Book, Elsevier Health Sciences. Moore, W. S. (2012). Vascular and Endovascular Surgery E-Book: A Comprehensive Review, Elsevier Health Sciences.
- 8. Reference • Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier. • Creager, M. A., et al. (2012). "Acute limb ischemia." New England Journal of Medicine 366(23): 2198-2206. • Robinson, W. P. and M. Belkin (2009). Acute limb ischemia due to popliteal artery aneurysm: a continuing surgical challenge. Seminars in vascular surgery, Elsevier. • Weaver, F. A., et al. (1996). "Surgical revascularization versus thrombolysis for nonembolic lower extremity native artery occlusions: results of a prospective randomized trial." Journal of vascular surgery 24(4): 513-523.
- 9. Outline • Basic principle of Intra operative thrombolysis • Indication and rational use • Technique • Outcome • Summary
- 10. Cronenwett, J. L. and K. W. Johnston (2014). Rutherford's Vascular Surgery E-Book, Elsevier Health Sciences.
- 11. The basic principle • Intravenous infusion for acute arterial occlusion : is minimally effective and usually not recommended • The potential for effective thrombus dissolution in this setting is minimal. • Intrathrombus infusion protects the plasminogen activator and plasmin from circulating inhibitors.
- 13. Objectives • The primary objectives : dissolve the occluding thrombus, restore perfusion, and allow evaluation of the underlying cause of the arterial or graft thrombosis.
- 14. • Additional advantages of thrombolytic therapy include the following: 1. Gain patency of an occluded nondiseased inflow source 2. Lyse thrombi in the distal vasculature 3. Convert a major vascular reconstruction into a limited, less extensive procedure Objectives
- 15. 4. Prevent arterial intimal injury from balloon catheter thrombectomy 5. Restore the patency of branch vessels 6. Reduce the extent of amputation Objectives
- 16. Application of Intra-arterial Thrombolytics Thrombosis after PTA Native Vessel Occlusion Acute Graft Occlusion Lower Extremity Ischemia Hemodialysis Access Acute Stroke Moore, W. S. (2012). Vascular and Endovascular Surgery E-Book: A Comprehensive Review, Elsevier Health Sciences.
- 17. Patient Selection of Intra-arterial Thrombolytics Ensure viability of ischemic tissue Shouldn’t do in patients with neurologic demise Indications High surgical risk of morbidity/mortality Poor surgical outcome Multiple previous surgeries Adjunct to surgery Moore, W. S. (2012). Vascular and Endovascular Surgery E-Book: A Comprehensive Review, Elsevier Health Sciences.
- 18. Patient Selection of Intra-arterial Thrombolytics <14 d of acute ischemia 71% successful lysis Adjuntive procedures required in 72% Decreased response in diabetics Predictors of success Passage through occlusion Placement of catheter within thrombus Moore, W. S. (2012). Vascular and Endovascular Surgery E-Book: A Comprehensive Review, Elsevier Health Sciences.
- 19. Contraindication Cronenwett, J. L. and K. W. Johnston (2014). Rutherford's Vascular Surgery E-Book, Elsevier Health Sciences.
- 20. Indications for Intra-arterial Thrombolytics Thrombosis after PTA Infrequent Onset typically <24 hrs following PTA 80% Success rate Moore, W. S. (2012). Vascular and Endovascular Surgery E-Book: A Comprehensive Review, Elsevier Health Sciences.
- 21. Indications for Intra-arterial Thrombolytics Native Vessel Occlusion Determine the Mechanism of Occlusion More effective in peripheral embolization (80%) than thrombotic occlusions (50-60%) Embolization from Atrial Fibrillation Well-organized component Poor response to lytic therapy Surgical embolectomy for proximal (iliac, femoral) Moore, W. S. (2012). Vascular and Endovascular Surgery E-Book: A Comprehensive Review, Elsevier Health Sciences.
- 22. • Native Vessel Occlusion • Thrombolysis for emboli from recent MI Thrombotic Arterial Occlusions Success (>50%) Adjunctive procedures to maintain patency Indications for Intra-arterial Thrombolytics
- 23. Popliteal Artery Occlusion with Distal Clot Propagation or Emboli • Poor surgical result Amputation risk – 40% Moderate ischemia ( Rutherford I , IIa) with angiogram no visible runoff Trial lytic therapy Severe ischemia (Rutherford IIb) Surgical exploration with intraoperative intraarterial lysis Indications for Intra-arterial Thrombolytics Robinson, W. P. and M. Belkin (2009). Acute limb ischemia due to popliteal artery aneurysm: a continuing surgical challenge. Seminars in vascular surgery, Elsevier.
- 24. Indications for Intra-arterial Thrombolytics • Acute Graft Occlusion Prosthetic Grafts Adjunct to convert urgent surgical therapy to elective revision Thrombectomy treatment of choice Autogenous Vein Grafts 75% success if thrombosis <14 days old Poor Response Long grafts Low flow grafts Early graft failure (<1 year old) Moore, W. S. (2012). Vascular and Endovascular Surgery E-Book: A Comprehensive Review, Elsevier Health Sciences.
- 25. Indications for Intra-arterial Thrombolytics • Lower Extremity Ischemia STILE (Surgery vs. Thrombolytics for Ischemia of LE) - 393 pts with native arterial or graft occlusion - tPA 0.05 mg/kg/hr for 12 hours or urokinase (250K bolus, then 4000 u/min for 4 hour, then 2000 u/min for up to 36 hrs) Thrombolysis Group - Failure to pass catheter in 28% of patients (Treatment Failure) - Acute Ischemia (<14 days) - Lower amputation and shorter hospital stays - 55% had a reduction in surgical procedure Surgery Group - Chronic Ischemia (>14 days) - Less recurrent ischemia, lower amputation rates Weaver, F. A., et al. (1996). "Surgical revascularization versus thrombolysis for nonembolic lower extremity native artery occlusions: results of a prospective randomized trial." Journal of vascular surgery 24(4): 513-523.
- 26. Indications for Intra-arterial Thrombolytics • Lower Extremity Ischemia STILE Conclusions Surgery was safer and more effective in patients with symptoms < 6 months duration, >14 days Lytics showed improved amputation free survival in patients with <14 days of ischemia No difference in outcome for thrombolytic agent Weaver, F. A., et al. (1996). "Surgical revascularization versus thrombolysis for nonembolic lower extremity native artery occlusions: results of a prospective randomized trial." Journal of vascular surgery 24(4): 513-523.
- 27. Indications for Intraoperative Thrombolytics 30% of embolectomies are incomplete Residual intravascular defects seen on completion angiography Further mechanical manipulation increases thrombogenicity Moore, W. S. (2012). Vascular and Endovascular Surgery E-Book: A Comprehensive Review, Elsevier Health Sciences.
- 28. Rational use • The rationale of intraoperative thrombolysis is post thromboembolectomy that residual thrombus in the originally occluded artery as well as thrombus in runoff and branch vessels inaccessible to the balloon catheter can be lysed. Moore, W. S. (2012). Vascular and Endovascular Surgery E-Book: A Comprehensive Review, Elsevier Health Sciences.
- 29. Safety of Intraoperative Intraarterial Thrombolysis • Ref : Regional and systemic effects of intraoperative intraarterial urokinase infusion during lower extremity revascularization in a multicenter, randomized, blinded, and placebo-controlled trial by Comerota et al8 studied • 134 patients were randomized to receive either placebo (saline) or one of three different doses of urokinase • Blood samples were drawn from the ipsilateral femoral and arm veins to compare the regional and systemic effects of the fibrinolytic. Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 30. • Endpoints were designed to evaluate the degree of plasminogen activation regional and systemic breakdown of fibrinogen and fibrin (from intraluminal thrombus) the degree to which a dose-response relationship the safety of intraoperative intraarterially infused urokinase. Safety of Intraoperative Intraarterial Thrombolysis Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 31. Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 32. • no significant decline in plasma fibrinogen, • no bleeding complications were observed. • This study confirms the safety of intraoperative thrombolysis. • Patients receiving intraoperative intraarterial urokinase had significantly better survival compared to placebo-treated patients. Safety of Intraoperative Intraarterial Thrombolysis Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 34. Techniques of Intraoperative Intraarterial Thrombolysis Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 35. Bolus Intraarterial Thrombolysis • 2 to 8 mg rt-PA is infused directly into the artery in a volume of saline generally 15 to 50 cc, depending upon the level of infusion. • After a wait period of 15 to 30 minutes, a repeat arteriogram is then performed . The arteriotomy is then closed and perfusion restored. Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 36. Continuous Intraarterial Infusion • Indication : persistent thrombus, the arteriotomy is closed and perfusion restored. • A small infusion catheter is placed and advanced distally for the intraarterial infusion of the lytic agent. • This is performed for 20 to 30 minutes Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 37. Manual High-Dose Isolated Limb Perfusion • Multi-vessel acute occlusion in the runoff bed • single or even double bolus dose of thrombolytic agent is likely to be inadequate. • A therapeutic continuous infusion were used Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 38. • Delivers maximal doses of a plasminogen activator into the runoff bed. • The patient is fully anticoagulated • The proximal tourniquet is inflated to suprasystolic pressure. • Catheters are properly positioned through an appropriate arteriotomy to deliver high doses of the plasminogen activator into the distal arterial bed. • Thrombolytic agent is infused directly into the arterial tree with a slow hand infusion for 60 minutes. A high dose of rt-PA, up to 100 mg in 500 to 1,000 mL saline, can be used safely. Manual High-Dose Isolated Limb Perfusion Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 39. Manual High-Dose Isolated Limb Perfusion Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 40. The following must be checked: • Limb viability – perfusion, pulses, Doppler signal, movement and sensation • Urine output – the patient must be kept adequately hydrated. If necessary, IV fluids should be given and the patient catheterized • Pulse, BP and temperature – 4-hourly • Daily full blood count (FBC), coagulation screen and fibrinogen, urea and electrolytes, glucose • Analgesia should be reviewed regularly. Intramuscular injections must not be given. Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 41. Endpoints • Thrombolysis is continued until the clot has cleared and flow has been restored. • Deterioration in the clinical status of the limb mandates urgent review and discussion • If bleeding occurs, stop the infusion and review the patient immediately. Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 42. Complication • CVA: most serious - intracerebral hemorrhage (0.5- 0.7%) major risk factors : age > 75 years ,hypertension ,female gender , prior use of anticoagulants • Significant bleeding: consult a haematologist for advice if bleeding persists after the infusion is stopped. Check the clotting and try to stop early before the patient becomes unstable. Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 43. • Acute clinical deterioration with increased pain: reassess, this is often due to distal embolization of thrombus which occurs in up to 5% of patients. • Reperfusion syndrome: this is caused when there has been prolonged and severe ischaemia. Complication Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 44. Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 45. Long term result Depend mainly on - correctable lesion is identified - the location of the occlusion. Larger vessel occlusions resolved better, an expected patency of 60% at 2 years lesion at level of popliteal occlusions have a lower long-term patency of about 30% at 2 years. - If a correctable lesion is identified and appropriately treated, long-term results are significantly improved Comerota, A. J. and R. Sidhu (2009). Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia? Seminars in vascular surgery, Elsevier.
- 46. Summary • In summary, an intraoperative fibrinolytic infusion indication in acute limb ischemia when residual thrombus inaccessible to the balloon catheter or persistent ischemia after restoration of flow. • Although the best method of delivery and most appropriate dosage have not been fully determined, • Reported clinical experience has allowed guidelines that permit the clinician to obtain the benefits of fibrinolytic infusion in these difficult cases with both safety and efficacy.
Editor's Notes
- And this is the example case of Today ALI Indication and rational use of intra op thrombolysis in this patient
- thrombolytic therapy is the activation of fibrin-bound plasminogen.’ The fibrin bond of the plasminogen contained within the thrombus makes the plasminogen molecule activation by the delivered plasminogen activator. . Once the plasminogen activator contacts and binds to fibrin-bound plasminogen, plasmin is produced locally,stimulating lysis OF THE THROMBUS
- intravenous infusion for acute arterial occlusion : is minimally effective and usually not recommended because the plasminogen activator delivered intravenously would have minimal surface contact with the occluding thrombus. The potential for effective thrombus dissolution in this setting is minimal. Intrathrombus infusion protects the plasminogen activator and plasmin from circulating inhibitors.
- The most commonly used plasminogen activators are streptokinase (SK),urokinase (UK),recombinant tissue plasminogen activator (rt-PA), prourokinase (proUK) (single-chainUK plasminogen activator),and acylated SK.
- of the infusion of the fibrinolytic agent are to dissolve the occluding thrombus, restore perfusion, and allow evaluation of the underlying cause of the arterial or graft thrombosis.
- 4. Prevent arterial intimal injury from balloon catheter thrombectomy 5. Restore the patency of branch vessels inaccessible to mechanical thrombectomy 6. Reduce the extent of amputation
- the viability of the ischemic tissues should be ensured. Candidates for intraarterial lytic therapy must be able to tolerate ischemia for the duration of the infusion. . Indications High surgical risk of morbidity/mortality Poor surgical outcome Multiple previous surgeries Adjunct to surgery
- In a prospective study of 80 consecutive patients receiving intraarterial urokinase for acute (<14 days) ischemia, successful lysis was accomplished in 71% (57 patients). Most of these patients required additional adjunctive procedures to maintain patency; only 28% of patients avoided the need for additional interventions. Diabetics fared signifcantly worse compared with nondiabetics. Most important, placement of the catheter within the substance of the thrombus was the best predictors of success.
- Thrombosis after balloon angioplasty is relatively infrequent, but when it occurs, local thrombolytic therapy is highly effective in restoring patency. The onset of occlusion is usually within 24 hours of dilatation; thus, the thrombotic material is fresh and highly sensitive to fibrinolysis.
- Determine the Mechanism of Occlusion More effective in peripheral embolization (80%) than thrombotic occlusions (50-60%) that emboli secondary to atrial fbrillation may have well-organized components and thus be resistant to fbrinolysis. For these reasons, surgical embolectomy is preferred for proximal (iliac, femoral) emboli secondary to atrial fbrillation
- . If the embolus is secondary to a recent myocardial infarction (i.e., the surgical risk is increased and the embolus is usually fresh clot), intraarterial fbrinolytic therapy should be considered.
- Acute Graft Occlusion Prosthetic Grafts Adjunct to convert urgent surgical therapy to elective revision Thrombectomy treatment of choice Autogenous Vein Grafts a trial of lytic therapy is an attractive alternative if the event is recent. 75% success if thrombosis <14 days old However, long saphenous vein grafts to tibial vessels in the lower third of the leg or ankle are less responsive to lytic therapy; casued these area is very low-flow grafts limited supplies of plasminogen
- Lower Extremity Ischemia STILE (Surgery vs. Thrombolytics for Ischemia of LE) - 393 pts with native arterial or graft occlusion - tPA 0.05 mg/kg/hr for 12 hours or urokinase (250K bolus, then 4000 u/min for 4 hour, then 2000 u/min for up to 36 hrs) Thrombolysis Group - Failure to pass catheter in 28% of patients (Treatment Failure) - Acute Ischemia (<14 days) - Lower amputation and shorter hospital stays - 55% had a reduction in surgical procedure Surgery Group - Chronic Ischemia (>14 days) - Less recurrent ischemia, lower amputation rates
- Lower Extremity Ischemia STILE Conclusions Surgery was safer and more effective in patients with symptoms < 6 months duration, >14 days Lytics showed improved amputation free survival in patients with <14 days of ischemia No difference in outcome for tPA vs. urokinase
- Comerota et al8 studied regional and systemic effects of intraoperative intraarterial urokinase infusion during lower extremity revascularization in a multicenter, randomized, blinded, and placebo-controlled trial by. In this study, 134 patients were randomized to receive either placebo (saline) or one of three different doses of urokinase Blood samples were drawn from the ipsilateral femoral and arm veins to compare the regional and systemic effects of the fibrinolytic.
- no significant decline in plasma fibrinogen, further substantiating the absence of a systemic fibrinolytic state. Importantly, no bleeding complications were observed. This study confirms the safety of intraoperative thrombolysis. An interesting observation regarding operative mortality was made. Patients receiving intraoperative intraarterial urokinase had significantly better survival compared to placebo-treated patients.
- management strategy for treating patients with intraoperative thrombolysis.
- Following Routine Thromboembolectomy 2 to 8 mg rt-PA is infused directly into the artery in a volume of saline sufficient to fill the vascular bed being infused, generally 15 to 50 cc, depending upon the level of infusion. After a wait period of 15 to 30 minutes, a repeat arteriogram is then performed and a second infusion can be administered if needed. The arteriotomy is then closed and perfusion restored
- Indication : persistent thrombus, the arteriotomy is closed and perfusion restored. A small infusion catheter is placed and advanced distally for the intraarterial infusion of the lytic agent. This is performed for 20 to 30 minutes
- Indication Multi-vessel acute occlusion in the runoff bed single or even double bolus dose of thrombolytic agent is likely to be inadequate. a therapeutic continuous infusion were used
- This high-dose isolated limb perfusion technique delivers maximal doses of a plasminogen activator into the runoff bed. The patient is fully anticoagulated The proximal tourniquet is inflated to suprasystolic pressure. Catheters are properly positioned through an appropriate arteriotomy to deliver high doses of the plasminogen activator into the distal arterial bed. Thrombolytic agent is infused directly into the arterial tree with a slow hand infusion for 60 minutes. A high dose of rt-PA, up to 100 mg in 500 to 1,000 mL saline, can be used safely. Repeat arteriography is performed to assess results
- The intraoperative arteriogram after balloon catheter thrombectomy of the popliteal and tibial vessels shows no perfusion into the foot. After arteriotomy closure, the patient’s foot remained pale and cool with no Doppler signals at the ankle. Additional thrombus could not be mechanically removed. (B) The patients’ limb was elevated A sterile blood pressure cuff was placed on the distal thigh and inflated to 250 mmHg. The popliteal vein was cannulated with a red rubber catheter and drained into a basin. Catheters were placed into the anterior tibial and posterior tibial arteries. One million IU of urokinase was infused into the lower leg in a volume of 1 L saline (500,000 IU/500 mL in each tibial artery) over 20 minutes. After completion of urokinase infusion, the limb was flushed with a heparin and saline solution. The red rubber catheter was removed and the venotomy was closed primarily. The arterial catheters were removed and the arteriotomy was closed with a patch. (C) A postinfusion arteriogram showed significant improvement of perfusion to the foot. The patient had a palpable dorsalis pedis pulse and a pink foot after wound closure
- Thrombolysis is continued until the clot has cleared and flow has been restored. Lytic stagnation is when there is no clearing of thrombus in between check angiograms and is an indication to stop the procedure. Deterioration in the clinical status of the limb mandates urgent review and discussion and, depending on the cause, may necessitate urgent surgical revascularization. If bleeding occurs, stop the infusion and review the patient immediately.
- Complications increase with the age of the patient, the duration of treatment and the dose of the lytic agent. Stop the infusion and the heparin if a complication develops. CVA: most serious - intracerebral hemorrhage (0.5-0.7%) major risk factors : age > 75 years ,hypertension ,female gender , prior use of anticoagulants perform an urgent CT scan if there are signs suggestive of CVA. If there is thrombotic CVA, seek expert neurological opinion and discuss whether to continue with thrombolysis; haemorrhage means game over. • Significant bleeding: consult a haematologist for advice if bleeding persists after the infusion is stopped. Check the clotting and try to stop early before the patient becomes unstable. Resuscitate the patient with blood and fresh frozen plasma (FFP) as necessary.
- Acute clinical deterioration with increased pain: reassess, this is often due to distal embolization of thrombus which occurs in up to 5% of patients. Macroemboli may lyse spontaneously or can be aspirated. Microemboli are much more serious and may cause trash foot. • Reperfusion syndrome: this is caused when there has been prolonged and severe ischaemia. Adult respiratory distress syndrome and renal failure are common sequelae and there is a high mortality.
- Intraoperative intraarterial use of thrombolytics can potentially dissolve residual thrombus, leading to improved revascularization. Parent et al4 reported the successful intraoperative use : 17 patients with angiographic evidence of residual thrombus in infrapopliteal arteries following operative thromboembolectomy. With a dwell time of 30 minutes, they achieved successful lysis in 88% of patients. Norem et al5 treated 19 patients having balloon catheter thromboembolectomy with intraoperative intraarterial streptokinase infusion. Following infusion, additional thrombus was retrieved with a subsequent balloon catheter thromboembolectomy, accompanied by angiographic improvement in all patients.