A simplified procedure for intra-arterial thrombolysis with tissue-type plasminogen activator in peripheral arterial occlusive disease: primary and long-term results

One-hundred and fifty patients with thrombotic and 60 patients with embolic occlusions of the superficial femoral and/or popliteal artery underwent a simplified IAT (intra-arterial thrombolysis) procedure. Ten mg rt-PA combined with 3000 IU Heparin were infused over 6 h, thereafter the extent of thrombolysis was checked fluoroscopically and the above mentioned treatment course repeated up to four times if necessary. The IAT regimen employed did not involve mechanical recanalization attempts; if complete thrombolysis revealed an underlying stenosis, a PTA (percutaneous transluminal angioplasty) was subsequently performed. IAT resulted in complete recanalization of 88 thrombotic occlusions (59%; 95% confidence interval: 50.8%-66.8%) and of 53 embolic occlusions (88%; 95% confidence interval: 77.1%-94.8% P < 0.001). In a further 33 (22%) thrombotic and four (7%) embolic occlusions IAT reduced the length of the occluded segment. At discharge, 102 (67%) patients with thrombotic and 55 (92%) patients with embolic occlusions were clinically improved. Overall, untoward effects occurred in 60 patients (29%): 47 (22%) were minor. Four patients (2%) suffered a systemic haemorrhage (three gastrointestinal, one macrohaematuria). The cumulative potency rate was significantly higher in patients with embolic occlusions throughout follow-up (82% vs 49% for thrombotic occlusions at 2 years, P < 0.001). Although all amputations were carried out in patients with thrombotic occlusions, follow-up mortality did not differ significantly between patients with embolic and thrombotic occlusions.

Superior mesenteric artery embolism: treatment with intraarterial urokinase

Four patients with a superior mesenteric artery (SMA) embolism were successfully treated with intraarterial urokinase. Angiography showed partial SMA occlusion by intraluminal thrombus in two cases and almost total occlusion in two cases. Laparotomy was performed in the latter two cases, one of which required resection of infarcted bowel. Several additional reports of partially occluding SMA emboli treated successfully with streptokinase were found in the literature. The use of intraarterial thrombolytic drugs is an important addition to the treatment of mesenteric embolism that, in some cases, can eliminate or simplify surgical management.

Cholesterol microembolization and stable renal function with continued anticoagulation

Cholesterol microembolization as a sequela of oral anticoagulant therapy has been reported to cause infarction of virtually any organ, often resulting in death. Until recently, discontinuance of anticoagulant therapy has been recommended, as this cessation has been shown to slow or halt further tissue infarction. I have described a patient with a prosthetic heart valve in whom the purple toes syndrome developed. Stable renal function followed the initiation of high-dose subcutaneous heparin therapy.

Effects of treatment with ticlopidine in heartworm-negative, heartworm-infected, and embolized heartworm-infected dogs

Ticlopidine hydrochloride was evaluated for its effectiveness in inhibiting platelet aggregation and serotonin release in 5 laboratory Beagles before and after heartworm implantation with 7 adult Dirofilaria immitis, and after embolization with 7 dead heartworms to mimic what happens after heartworm adulticide treatment. Five other laboratory Beagles, similarly implanted and embolized with heartworms, were used as nonmedicated controls. During the heartworm-negative stage, the dosage of ticlopidine that inhibited adenosine diphosphate (ADP)-induced platelet aggregation in 5 dogs by at least 50% after 5 days of treatment was 62 mg/kg of body weight once a day. In the same dogs implanted with 7 adult heartworms 21 days previously, mean (+/- SD) ticlopidine dosage required to obtain similar results was 71 (+/- 13) mg/kg given once daily. During the 21 days after dead heartworms were implanted in heartworm-infected dogs, mean ticlopidine dosage was 108 (+/- 35) mg/kg (range, 62 to 150 mg/kg). Ticlopidine treatment was associated with increased platelet numbers in all 5 dogs during the heartworm-negative stage and in 4 of 5 dogs during the heartworm implantation and heartworm embolization stages. Mean platelet volume tended to decrease as platelet numbers increased. At necropsy, gross and histologic pulmonary lesions were less severe in ticlopidine-treated dogs than in nonmedicated control dogs.

[Renal embolism. Revascularization using conservative treatment]

We report a case of embolism of the intrarenal arterial branches of a cardiac origin. The results of the urographic, ultrasound, ascending pyelography and laboratory work up prompted us to suspect the vascular nature of the condition. Its unilateral feature, involvement of the intrarenal arterial branches, and the coexisting mitral valve disease with atrial flutter advised conservative management with systemic anticoagulation.

Effects of treatment with aspirin or aspirin/dipyridamole combination in heartworm-negative, heartworm-infected, and embolized heartworm-infected dogs

To determine the drug dose required to inhibit platelet reactivity by at least 50%, 2 drug regimens were evaluated in heartworm-negative, heartworm-infected, and heartworm-infected dogs embolized with dead heartworms. Aspirin, or a combination of aspirin and dipyridamole, were administered to 2 groups of Beagles (n = 5 each) for 5 to 9 days; a third group of 5 Beagles served as nontreated controls. For heartworm-negative dogs, mean (+/- SD) aspirin dosage that inhibited collagen-induced platelet reactivity by at least 50% was 6 (+/- 2) mg/kg of body weight given once daily. The aspirin/diphridamole combination dosage was 1 mg of each drug/kg given every 12 hours. All dogs (n = 15) were implanted with 7 adult heartworms each and remedicated (or not treated) beginning at 21 days after heartworm implantation. In heartworm-infected dogs, mean aspirin dosage required to inhibit collagen-induced platelet reactivity greater than or equal to 50% was 10 (+/- 6) mg/kg. Mean dosage of aspirin/dipyridamole combination was 1.6 +/- (0.5) mg of each drug/kg given every 12 hours. When platelet reactivity in response to collagen was determined to be inhibited by at least 50% in all medicated dogs, each dog (n = 15) was embolized with 7 dead adult heartworms to mimic heartworm adulticidal treatment. Platelet reactivity was monitored for 21 days after treatment, and drug dose was adjusted to maintain platelet inhibition by at least 50%. In embolized dogs, mean aspirin dosage was 17 (+/- 14) mg/kg given once daily. Mean dosage of the aspirin/dipyridamole combination was 2.8 (+/- 1.3) mg of each drug/kg given every 12 hours. All dogs (n = 15) were euthanatized 21 days after heartworm embolization. Each lung lobe was evaluated for severity of lesions and presence of organized or fibrinous thrombi. Lesion severity in the aspirin- and aspirin/dipyridamole-treated dogs was not significantly different from that in control dogs.

Primary antiphospholipid syndrome (PAPS). Two case reports and therapeutic implications

Antiphospholipid antibodies (aPL) interfere with the coagulation system and can cause thrombosis and other clotting disorders. The combination of recurrent venous thrombosis, arterial embolism and recurrent fetal loss is nowadays considered to be primary antiphospholipid syndrome (PAPS), provided an underlying systemic lupus erythematosus (SLE) has been excluded and aPL have been detected. We report on two patients with PAPs, and show the course of their IgG- and IgM-anticardiolipin antibody (aCL) titers during immunosuppressive therapy with prednisone and azathioprine or cyclophosphamide. Over a period of 18 months this therapy was effective in preventing relapses of thrombo-embolism and other complications. Therapy with cyclophosphamide resulted in normalization of the aCL titers in one of the two reported cases. Azathioprine treatment reduced the aCL titer in the other patient, without fully normalizing it. Based on our observation, we propose to treat PAPS-associated severe and recurrent thrombo-embolic complications by aggressive immunosuppression, including azathioprine and cyclophosphamide.

Septic embolism complicating infective endocarditis

Embolic phenomena in patients with infective endocarditis may complicate the placement of a cardiac valvular prosthesis. To evaluate the vascular consequences of these emboli, a 15-year review of 102 patients undergoing valve replacement for proven infective endocarditis was undertaken. Thirty-one patients with 36 episodes of septic embolization were identified. Ten of these were separate extremity occlusive events. All patients with extremity emboli were admitted with pain; four had limb-threatening emboli. All patients grew gram-positive bacteria from their blood except a single Candida albicans isolate. Appropriate antimicrobial therapy was used in all patients. Angiography confirmed the diagnosis in 11 of 12 patients. Embolic targets included the lower extremities in all except a single instance. Four patients had multiple emboli. All but one of the vascular procedures were carried out subsequent to or simultaneously with cardiac valve replacement. Initial operative management included embolectomy (4) and primary amputation (2). Two delayed procedures were required. One patient died. Four patients had limited ischemia that resolved with antibiotics and anticoagulation. This report suggests that infective endocarditis requiring valvular replacement is associated with embolization in one third of patients. The presentation of peripheral vascular emboli is that of acute extremity ischemia. The diagnosis should be confirmed by angiography to rule out the possibility of multiple emboli. When possible, valve replacement should precede peripheral vascular management, which may include operative or medical components as dictated by the extent of limb ischemia.

Diffuse embolization following percutaneous transluminal coronary angioplasty of occluded vein grafts: the blush phenomenon

Percutaneous transluminal coronary angioplasty (PTCA) was performed on 146 saphenous vein grafts in 116 patients. In 29 patients, 31 grafts were totally occluded. Myocardial staining lasting over 5 minutes--"the blush phenomenon"--followed the opening of the occluded grafts in 9 of these patients. In 5 of these 9, enzyme release suggested infarction. A sixth patient died within a few hours of PTCA, with suspected infarction. Autopsy demonstrated diffuse and extensive distal coronary arterial embolization of grumous material, including cholesterol crystals, platelets, and fibrin. The blush phenomenon was not seen following PTCA in the remaining 20 patients with total occlusions, nor in any of the 87 patients with stenosed grafts. We have not observed the blush phenomenon following PTCA of more than 3300 coronary arteries. Of the 9 patients demonstrating the blush phenomenon, 6 had a recent history of myocardial infarction or unstable angina pectoris, compared with 4 of the remaining 20 patients with occluded grafts. We now approach occluded grafts with injection of intragraft thrombolytic agents or with atherectomy prior to PTCA. Future approaches may include atherectomy or laser angioplasty.

[Fibrinolytic therapy in non-coronary diseases]

Utilization of fibrinolytic drugs in non-coronary diseases has been described since 1949, but despite of that, works about that subject are very rare in the literature. In this paper we discuss the cases of three patients that were treated with such compounds for pulmonary embolism, peripheral arterial embolism, and thrombosis in mechanical aortic prosthesis. All patients had excellent in-hospital outcome, and were totally asymptomatic at the discharge time. It is emphasized the clinical symptoms, sometimes unexpected, and the importance of the complementary tests not only in the disease's diagnosis, but also in some decisions that must be taken during the patient's evolution, where they can help us to decide, for example, about the correct moment to stop the thrombolytic infusion. In conclusion, fibrinolytic drugs can be utilized in the management of many affections that otherwise would be treated by emergency surgery.

In utero arterial embolism from renal vein thrombosis with successful postnatal thrombolytic therapy

Thromboembolic events in the pediatric age group occur most commonly in neonates, and newborns of diabetic mothers are particularly at risk. We report a newborn with right renal vein and inferior vena cava thrombosis who apparently embolized across the foramen ovale antenatally with resultant right brachial artery occlusion. The baby was delivered by cesarean section from an insulin-dependent diabetic mother. At the time of birth, there was severe right arm ischemia with absent brachial and radial pulses. There was clinical evidence of distal embolization with a "trash" lesion of the distal right middle finger as well as a midforearm area of full-thickness skin loss. Ultrasound demonstrated a right renal vein thrombosis and a 95% occlusion of the inferior vena cava. Regional urokinase therapy was instituted through a lower extremity vein with a 5,000 U/kg bolus and then 5,000 U/kg/h continuous infusion. Twelve hours of infusion of urokinase led to clinical resolution of the right arm ischemia, with return of pulses. Follow-up ultrasound showed the right renal vein thrombosis and inferior vena cava clot to be completely resolved. The right middle finger and forearm lesions subsequently have healed primarily. We report this as a case of in utero arterial embolization with successful postnatal therapy using regional urokinase infusion.

[Intra-arterial fibrinolysis of superior mesenteric artery embolism]

Intra arterial fibrinolysis for acute mesenteric embolism. Acute mesenteric ischemia has a poor prognosis because the diagnosis is often too late (greater than 12 h), leading to a difficult surgery in old patients. The lesions of the bowel don't always allow a single operative embolectomy but often need a resection when there is a long time interval between onset of symptoms and therapy. We report a case of acute embolism in the superior mesenteric artery with the clot located in its terminal part. A rapid diagnosis was made by arteriography and intra-arterial fibrinolysis was attempted with success permitting the complete cure of the affection, without sequellae. This treatment is only likely to be successful if it is carried out within 10-12 hours of the onset of clinical signs and symptoms.

Effects of routine heparin therapy on plasma aldosterone concentration

Changes in plasma aldosterone, plasma renin activity, plasma cortisol, serum sodium and potassium concentrations were studied in 9 patients with thromboembolic diseases treated with heparin. Heparin was administered at doses of 700-1000 units/h for 7-10 days. Plasma aldosterone decreased from 239 +/- 33 to 114 +/- 25 pmol/l during heparin therapy and returned to basal levels after discontinuation of the therapy. In addition, responses to a low sodium intake (3 g/day) and ACTH were examined in 5 patients during and 2 weeks after heparin therapy. The increase in plasma aldosterone caused by low sodium intake was significantly attenuated during heparin therapy (124 +/- 5% increase from baseline) as compared with that 2 weeks after heparin therapy (148 +/- 7%, p less than 0.05). On the other hand, ACTH stimulated plasma aldosterone similarly during and at 2 weeks after heparin therapy (increase from baseline: 190 +/- 20% vs 193 +/- 9%). These results suggest that heparin decreased plasma aldosterone owing to attenuation of the angiotensin II-induced aldosterone production.

[Medical treatment of cholesterol crystal embolism]

Cholesterol crystal embolization is an often fatal disorder in the elderly. Clinical manifestations consist of skin lesions arterial hypertension and renal failure. In some cases the clinical picture is suggestive of vasculitis. The most frequent predisposing factors are operative and radiological vascular procedures and the use of anticoagulants. The diagnosis can be confirmed by skin, muscle or kidney biopsy. Data concerning management are scarce and contradictory. A review of the literature has revealed some controversy as to how and when cholesterol crystal embolization should be treated, and controlled studies are lacking. We discuss the use of various drugs such as anticoagulants, antiplatelet agents and corticosteroids. In practice, the usual treatment is symptomatic and includes therapy of the peripheral vascular disease, adequate control of blood pressure and appropriate management of renal insufficiency. The most effective measure is prevention.

Renal artery embolism: thrombolysis with recombinant tissue-type plasminogen activator

The case of a patient with acute occlusion of the right renal artery due to an embolus is described. Using transoesophageal echocardiography, the left atrial appendage could be identified as the source of embolism. Twenty hours after the onset of symptoms, the embolus could be successfully dissolved with an intra-arterial low-dose infusion of recombinant tissue-type plasminogen activator (10 mg loading dose, 20 mg continuous infusion within 12 h).

[Intra-arterial infusion with urokinase for embolism of the superior mesenteric artery]

We report the case of a 65 year old male patient in whom an early diagnosis of embolism of the superior mesenteric artery was made and successfully treated by an intraarterial infusion of urokinase.

Intra-arterial low-dose streptokinase infusion for superior mesenteric artery embolus

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Aneurysm formation after dynamic catheter assisted balloon angioplasty

A male patient underwent recanalisation of a symptomatic popliteal artery occlusion using a dynamic angioplasty catheter, followed by balloon dilatation. A small subintimal dissection lead to an acute reocclusion. Repeat balloon angioplasty reopened the occlusion but was complicated by a distal embolus which was successfully treated by thrombolytic therapy followed by oral anticoagulation. Angiography 9 months later, demonstrated an aneurysm at the site of initial dissection. The artery remained patent and the patient free of claudication. A causal relationship between dynamic angioplasty and subsequent aneurysm formation is suggested and the possible predisposing factors discussed.

Percutaneous management of emboli associated with hot tip laser-assisted angioplasty

We describe the percutaneous management of emboli that occurred in 3 patients during hot tip laser-assisted angioplasty procedures. One embolus was lysed with direct, local infusion of urokinase using an open-ended guidewire. Another embolus was removed using the transcatheter aspiration technique. The third embolus was partially lysed and then, using a steerable guidewire, displaced placed into a distal side branch. In all 3 cases of embolization, distal blood flow was reestablished using percutaneous techniques, obviating the need for surgical intervention.

[Pampiniform livedo--an acute cardinal symptom of a cutaneous cholesterol embolism]

Acute, painful, persisting, pampiniform and asymmetrical skin discolorations over the legs occurred after retrograde femoral artery catheterization in three patients suspected of having renal artery stenosis. The cause was found histologically to be embolization of cholesterol crystals to the arterioles of the corium-subcutis. Under treatment with acetylsalicylic acid the painful cutaneous changes gradually regressed. The possibility of cholesterol crystal emboli from atheromatous plaques in the aorta should be considered if the described skin changes occur, especially in the legs and with normal arterial pulsations. Proof lies in the histological picture of slit-like spaces in the arteriolar vessels at the corium-subcutis juncture, previously occupied by cholesterol crystals dissolved during fixation, and surrounding inflammatory changes with vessel wall thickening.

Future role of thrombolytic therapy in emergency medicine

Thrombolytic therapy offers the promise of major therapeutic intervention in many areas as well as in the treatment of patients with acute myocardial infarction who present to the emergency department. Infusion of tissue-type plasminogen activator (tPA) during field transport has been proven safe, but optimal methods for reliably diagnosing acute myocardial infarction in the prehospital setting have yet to be delineated. A major advance would be achieved if thrombolysis were proven effective in preventing the progression of unstable angina to actual infarction. However, early studies have yielded contradictory results. The use of tPA in dissolving peripheral arterial clots appears very promising, but long-term limb survival has yet to be demonstrated. Unlike heparin, thrombolytic agents can also lyse clot in peripheral deep veins and possibly lessen the tendency toward postphlebitic syndrome. The proper dosage regimen to minimize hemorrhage has not been determined. Pulmonary emboli can be lysed by tPA. IV infusion is as effective as intrapulmonary. Significant complications can be minimized, particularly if major vessel catheterization can be avoided for diagnosis. Even after catheterization for pulmonary angiography, however, thrombolytic therapy appears quite promising. The use of thrombolytic agents for embolic-thrombotic stroke is less promising: therefore, the risk of hemorrhagic complication may not outweigh the potential benefit. Thrombolytic therapy thus offers the potential for significant impact on the practice of emergency medicine.