Asian Cardiovasc Thorac Ann 2008;16:439-443
© 2008 Asia Publishing EXchange Ltd
Current Incidence of Peripheral Arterial Embolism and Role of Echocardiography
Arash Mohammadi Tofigh, MD,
Mersedeh Karvandi, MD,
Raphaël Coscas, MD1
Shahid Beheshti University/MC, Tehran, Iran CHU Pitie-Salpetriere, Paris, France
For reprint information contact: Arash Mohammadi Tofigh, MD Tel: 98 21 2293 2846 Fax: 98 21 7755 7069 Email: arash_mtofigh{at}yahoo.com, Imam Hussein Hospital, Shahid Beheshti University/MC, Tehran, Iran.
 |
ABSTRACT
|
|---|
We reviewed the incidence and outcome of all cases of upper and lower limb embolism surgically treated in our vascular unit, from January 2001 to June 2006, to assess the role of transthoracic and transesophageal echocardiography in defining the source of the embolus. Transthoracic echocardiography was carried out postoperatively, and patients in whom the embolic source was not found underwent transesophageal echocardiography. There were 85 patients (mean age, 69 years) who underwent embolectomy: 58 for lower and 27 for upper limb ischemia. The source or potential source of thrombus was demonstrated in 17 (20%) patients after transthoracic echocardiography. Fifty-three patients had transesophageal echocardiography, the source of embolism was found in 85%, and the subsequent management was changed in 47% of them. Arterial limb emboli are still prevalent in developing countries. Transthoracic echocardiography is a good screening tool for detecting a potential cardiac source of peripheral embolism, with transesophageal echocardiography being reserved for specific indications.
|
INTRODUCTION
|
|---|
Surgical embolectomy is still the preferred method of treatment for limb-threatening ischemia, especially when associated with neuromuscular impairment, and it remains an important technique in vascular surgery despite other methods such as arterial thrombolysis.1 Patients presenting with acute embolic occlusion tend to be elderly with coexisting medical problems. These factors are reported to contribute to persistent risks of amputation and death after embolectomy.1–3 Our experience did not reflect these findings, so we carried out this review to determine the incidence and outcome of all cases of embolectomy treated in our unit over a 5-year period.
Transthoracic echocardiography (TTE) is performed to identify a potential cardiac embolic source. Echocardiography may demonstrate mitral stenosis, bacterial endocarditis, or atrial myxoma, all of which are amenable to treatment, as well as additional unsuspected structural diseases, even in the presence of atrial fibrillation (AF).4 Some previous studies concentrated on the role of echocardiography in patients with embolic stroke and showed that transesophageal echocardiography (TEE) is better than TTE in detecting a cardiac source of peripheral embolism; others have suggested that most abnormalities found on TEE can be predicted by TTE.5–9 However, there is little information on the roles of TEE and TTE in detecting the source of noncerebral peripheral emboli.9–11 Thus, an additional aim of this study was to reassess both types of echocardiography in the management of patients after peripheral embolectomy.
|
PATIENTS AND METHODS
|
|---|
The majority of our patients were primary referrals from a local population of approximately 1 million, with the remainder being tertiary referrals from east and south of Tehran (up to 4 million people) as we are the sole vascular unit in the area. A prospective database of patients who underwent embolectomy for acute limb ischemia was established in January 2001, and the data were analyzed retrospectively in June 2006. The anesthesia, surgical technique, and postoperative complications were reviewed. Embolectomy was performed with a 3F or 4F Fogarty balloon catheter through a femoral approach for lower limb emboli and a brachial approach for upper limb emboli. The operating surgeon and anesthetist decided whether the procedure should be carried out under local or general anesthesia. All embolectomies were undertaken with full anticoagulation, and the patient was started on warfarin postoperatively, unless this was contraindicated. Angiography was performed if revascularization was unsatisfactory. Our exclusion criteria were atherosclerotic thrombotic occlusions requiring bypass, and arterial occlusion after trauma, recent cardiac surgery, or previous arterial reconstruction. All patients underwent TTE primarily and if the source of emboli was not found, TEE was performed. A senior registrar in echocardiography performed the procedures following a set protocol 22, using a GE Vivid 3. For TEE, the patient was given either local anesthetic spray or intravenous benzodiazepam and placed in the left lateral position. Patients who did not have TEE because of a high risk of aspiration during the procedure and those who declined further investigations were excluded from the study. The study was approved by the Institutional Review Board of Shahid Beheshti University of Medical Sciences, and patient consent was obtained in all cases. Eighty-five patients with a median age of 69 ± 5 years (M/F 1:1.9) were included in the analysis. Their characteristics are listed in Table 1
.
|
RESULTS
|
|---|
Ten (17%) of the 58 lower limb and 5/27 (19%) upper limb embolectomies were carried out under general anesthesia; the rest were performed under local anesthesia with or without sedation. The 30-day mortality rate was 10.3% (6 patients) after lower limb and 0% after upper limb embolectomy. Three deaths were from acute myocardial infarction, 1 from respiratory failure secondary to pneumonia, 1 from acute renal failure, and the other was due to sepsis and multiple organ failure secondary to bacterial endocarditis. Four (4.7%) patients had recurrent embolism: 3 in a lower and 1 in an upper limb. In 3 patients, a concurrent cerebral embolic accident was noted. The pathological diagnoses of all surgical specimens were reported as thrombus, which did not always correlate with the echocardiographic findings. Eight (14%) patients had lower limb fasciotomies and 6 (10%) required below-knee amputations. There was no upper limb fasciotomy or amputation. The mean hospital stay was 10 days, and 76 (89%) patients were anticoagulated before discharge from hospital. Those who were not anticoagulated had recent history of gastrointestinal or cerebral hemorrhage, or terminal lung cancer.
TTE in the postoperative period to evaluate potential sources of emboli showed that 55 (65%) patients were in AF; 41 (75%) of them were receiving anticoagulants or antiplatelet agents. A direct cardiac source of the embolism was detected in 17 (20%) patients and 15 (18%) had a potential source (Table 2). No source of thrombus formation was identified in 53 (62%) patients, so TEE was performed. As a result, sources of emboli were determined in 45 (85%) of them, 4 had an upper limb embolism with a proximal aneurysm that was found later by angiography, no sources of the emboli could be confirmed in the other 4 (Table 3). The TEE study changed the subsequent management of 25 (47%) patients (Table 4).
|
DISCUSSION
|
|---|
It has been suggested that the incidence of peripheral arterial emboli is declining due to improved prescribing of anticoagulants for patients in AF and decreased incidence of rheumatic heart disease.12 Although we are the sole vascular unit in the area, we have a biased sample because of the referred patients. Our results suggest that despite the declining incidence, surgical embolectomy is still important in developing countries. The amputation and mortality rates after lower limb embolectomy are equivalent to the best reported results in other series.13 This improvement on earlier historical series may be the result of increasing use of local anesthesia and improvements in postoperative care. The incidence of AF in patients presenting with acute limb embolus is high compared to that in previous studies.14 Despite clear guidelines regarding anticoagulation for patients in AF, many are still not receiving warfarin prophylaxis.15
Current understanding of potential cardiac etiologies for systemic embolism is incomplete, and there is considerable controversy as to the indications for TTE and TEE in patients with peripheral embolic events. At one extreme, some clinicians advocate echocardiography in nearly all patients on the principle that even if a cardiac abnormality is unlikely, the risk of echocardiography is so low that evaluation still is warranted. At the other extreme, some clinicians argue that echocardiography is indicated only if there is definite evidence of cardiac disease in the history or physical examination. This study shows that TEE is more sensitive than TTE in detecting spontaneous echo contrast and thrombus in the left atrial appendage after peripheral arterial emboli, although these abnormalities can sometimes be predicted by the presence of left atrial dilatation or left ventricular/mitral valve abnormalities.6,8,9,15,16 These abnormalities are obvious on TTE, and some clinicians regard such findings as enough evidence for anticoagulation without requiring confirmation by TEE. Some structural abnormalities of the heart are also well shown on TTE, which is highly sensitive in demonstrating apical left ventricular thrombus, tricuspid valve disease, or anterior aortic root pathology. However, TEE is better at detecting vegetations, aortic dissection, aortic root atheroma, and small tumors.6,16,17 A patent foramen oval used to be detected more commonly by TEE, especially using second harmonic imaging and intravenous contrast.17,18 It is also important to note that TEE in our patients changed the subsequent management in 47% of them, so it seems that TEE played an important role in these patients. It may be indicated if endocarditis, atrial myxoma, thoracic aortic atheroma or dissection is suspected clinically, or if the TTE results are not diagnostic. TEE is usually performed in young patients (
45 years), even if they have no clinical evidence of heart disease with normal TTE. This is based on an extrapolation of stroke data showing that TEE may demonstrate unsuspected tumors, thrombi, and other abnormalities in approximately 1% of those presenting with an embolic stroke.19 This evidence has led to the widely accepted indications for TEE: normal TTE but clinical suspicion of a cardiac source; TTE unclear in young patients; or suspected atrial myxoma, endocarditis, or aortic pathology.
It was concluded that TTE is a good noninvasive screening tool after a peripheral embolic event. It can be used to decide which patients should have TEE, a more expensive, invasive, and unpleasant investigation, that often requires sedation.
|
REFERENCES
|
|---|
- Berridge DC, Kessel D, Robertson I. Surgery versus thrombolysis for acute limb ischaemia: initial management [Review]. Cochrane Database Syst Rev 2000;CD002784.
- Yeager RA, Moneta GL, Taylor LM Jr, Hamre DW, McConnell DB, Porter JM. Surgical management of severe acute lower extremity ischemia. J Vasc Surg 1992;15:385–91.[Medline]
- Hernandez-Richter T, Angele MK, Helmberger T, Jauch KW, Lauterjung L, Schildberg FW. Acute ischemia of the upper extremity: long-term results following thromboembolectomy with the Fogarty catheter. Langenbecks Arch Surg 2001;386:261–6.[Medline]
- Cheitlin MD, Alpert JS, Armstrong WF. ACC/AHA guidelines for the clinical application of echocardiography: executive summary. A report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on Clinical Application of Echocardiography). Developed in collaboration with the American Society of Echocardiography. J Am Coll Cardiol 1997;29:862–79.[Medline]
- Black IW, Hopkins A, Lee CL, Jacobson B, Walsh WF. The clinical role of transesophageal echocardiography. Aust NZ J Med 1990;20:759–64.[Medline]
- Pearson AC. Transthoracic echocardiography versus transesophageal echocardiography in detecting cardiac sources of embolism [Review]. Echocardiography 1993;10:397–403.[Medline]
- Hofmann T, Meinertz T. Transesophageal echocardiography in patients with systemic arterial embolism. Herz 1993;18:301–17.[Medline]
- Lee RJ, Bartzokis T, Yeoh TK, Grogin HR, Choi D, Schnittger I. Enhanced detection of intracardiac sources of cerebral emboli by transesophageal echocardiography. Stroke 1991;22:734–9.[Abstract/Free Full Text]
- Leung DY, Black IW, Cranney GB, Walsh WF, Grimm RA, Stewart WJ, et al. Selection of patients for transesophageal echocardiography after stroke and systemic embolic events. Role of transthoracic echocardiography. Stroke 1995;26:1820–4.[Abstract/Free Full Text]
- Chambers JB, de Belder MA, Moore D. Echocardiography in stroke and transient ischaemic attack. Heart 1997;78(Suppl 1):2–6.[Free Full Text]
- Homma S, Di Tullio MR, Sacco RL, Mihalatos D, Li Mandri G, Mohr JP. Characteristics of patent foramen oval associated with cryptogenic stroke. A biplane transesophageal echocardiographic study. Stroke 1994;25:582–6.[Abstract]
- Campbell WB, Ridler BM, Szymanska TH. Two-year follow-up after acute thromboembolic limb ischaemia: the importance of anticoagulation. Eur J Vasc Endovasc Surg 2000;19:169–73.[Medline]
- Varty K, St Johnston JA, Beets G, Campbell WB. Arterial embolectomy. A long-term perspective. J Cardiovasc Surg (Torino) 1992;33:79–84.[Medline]
- Kuukasjarvi P, Riekkinen H, Salenius JP, Vattulainen K, Lindholm S. Prevalence and predictive value of ECG findings in acute extremity ischemia. J Cardiovasc Surg (Torino) 1995;36:469–73.[Medline]
- Singer DE, Albers GW, Dalen JE, Go AS, Halperin JL, Manning WJ. Antithrombotic therapy in atrial fibrillation: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004;126:429S–56S.[Medline]
- Castello R, Pearson AC, Labovitz AJ. Prevalence and clinical implications of atrial spontaneous contrast in patients undergoing transesophageal echocardiography. Am J Cardiol 1990;65:1149–53.[Medline]
- Mas JL. Patent foramen ovale, atrial septal aneurysm and ischaemic stroke in young adults. Eur Heart J 1994;15:446–9.[Free Full Text]
- Kühl HP, Hoffmann R, Merx MW, Franke A, Klötzsch C, Lepper W, et al. Transthoracic echocardiography using second harmonic imaging: diagnostic alternative to transesophageal echocardiography for the detection of atrial right to left shunt in patients with cerebral embolic events. J Am Coll Cardiol 1999;34:1823–30.[Abstract/Free Full Text]
- Hart RG, Miller VT. Cerebral infarction in young adults: a practical approach [Review]. Stroke 1983;14:110–4.[Free Full Text]
TOP
ABSTRACT
INTRODUCTION
