Pulmonary embolism associated with surgically proved deep venous thrombosis

Pulmonary embolism associated with surgically proved deep venous thrombosis

Pulmonary Embolism Associated with Surgically Proved Deep Venous Thrombosis James W. Williams, MD, Tampa, Florida Louis G. Britt, MD, Memphis, Tenness...

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Pulmonary Embolism Associated with Surgically Proved Deep Venous Thrombosis James W. Williams, MD, Tampa, Florida Louis G. Britt, MD, Memphis, Tennessee Roger 1. Sherman, MD, Tampa, Florida

The frequency of pulmonary embolization in patients with deep venous thrombosis is unknown. Since pulmonary embolization frequently occurs in persons with asymptomatic venous thrombosis, this information has been difficult to obtain but is critical to epidemiologic definition of thromboembolic disease. To study these problems, a homogeneous

group of surgical

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Clinical Study Patient Population. From February 1972 through March 1973, eighty-one patients requiring major amputation of a lower extremity (above or below the knee) at the City of Memphis Hospitals were selected for study. Indications for amputation were those of end-stage arterial insufficiency not amenable or refractory to reconstructive arterial surgery. The mean age was seventytwo years, with a range of forty-two to one hundred two years. Forty-three subjects were female and thirty-eight were male; sixty-eight were Negro. and thirteen were Caucasian. Three patients were treated with tourniquets and cooling of the gangrenous leg prior to amputation. Tourniquets were applied below the knee to occlude both venous and arterial circulation in an effort to prevent toxic absorption from a septic gangrenous extremity. All amputations were performed by surgical resi-

From the Department of Surgery, Cii of Memphis Hospttak, Memphis, Tennessee. Reorint reauests should be addressed to James W. WIlllams. MD. Department of ‘Surgery. University of South Florida Callege of ‘kdklne, Tampa General Hospital, Administration Building, Room 229. Tampa, Florida 33606.


dents at the City of Memphis Hospitals under close staff supervision. Method of Study. The femoral or popliteal vein was inspected for the presence of thrombus at the time of surgery. One week postoperatively a perfusion lung scan was obtained using 1311 macroaggregated albumin and the Nuclear Chicago PhoGamma camera. The lung scan was considered positive for embolization if the area of decreased perfusion appeared normal on the chest x-ray film. Patients with positive lung scans were further studied, when possible, by pulmonary arteriography with selective injection of both main pulmonary arteries. The arteriographic criterion for embolization was abrupt intraluminal interruption of a lobar or segmental artery. Drugs that affect platelet activity, such as aspirin, [email protected], and Robitussine, were not given to patients under study.

Results Examination during surgery and routine eiramination by the pathologist revealed venous thrombosis in the amputated leg in nine of the eightyone patients, or 11 per cent. None of these nine patients had clinical evidence of venous thrombosis as characterized by swelling, edema, tenderness, or other physical findings in the extremities that could not be attributed to arterial insufficiency or gangrene. Lung scans performed one week postoperatively revealed embolization in all nine patients. Two patients had angiographic documentation of the emboli, and emboli were documented at autopsy in a third patient. (Table I.) Two of the nine patients died during the postoperative period, a mortality of 22 per cent. The causes of death in these pa-

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tients were multiple pulmonary emboli in one and cerebral infarction in the other. In the entire group there were eight deaths, a mortality of 10 per cent. Comments The frequency of pulmonary embolization in patients with symptomatic deep venous thrombosis has been reported but not clearly defined [I]. In patients dying from embolism with unilateral clinical thrombosis, the fatal embolus may arise from the unaffected leg as often as from the affected leg


The frequency with which asymptomatic thrombi in the venous system detach and embolize is very difficult to determine. Careful postmortem examination of the legs and lungs of unselected patients has permitted a necropsy estimate of the incidence of embolism from deep venous thrombosis and a thrombus detection index (TDI) has been calculated [2-41: TDI = Number

of patients


of patients

with embolism with venous

in the series thrombosis

x 100

Necropsy data indicate that this index varies from 20 to 65 per cent depending on the types of patients studied [2-41. Data of this nature have been essentially unavailable from clinical sources. The incidence of nonfatal asymptomatic embolization from asymptomatic thrombosis is unknown. The development of noninvasive methods for studying the deep venous system and pulmonary blood flow has enabled investigators to screen large numbers of asymptomatic patients and to collect this type of data. 1251-labelled fibrinogen has made detection of venous thrombosis in asymptomatic patients reliable, noninvasive, and apparently safe [5]. In a recently reported series of patients [6], asymptomatic thrombus extending into the thigh was associated with pulmonary embolization in 50 per cent, a thrombus detection index of 50 per cent. In the patients we have described requiring amputation, asymptomatic deep venous thrombosis was discovered at operation in nine of eighty-one, or 11 per cent. This was an unexpectedly high percentage, but this figure undoubtedly underestimates the incidence of deep venous thrombosis in the group since the venous system of only one leg can be examined at operation. The explanation for the high incidence of deep venous thrombosis in these patients is still conjectural. Nevertheless, the sluggish flow in the venous system due to arterial


129, May 1975




and Deep Venous

Clinical Data




No No Yes Yes No No





Positive Positive Positive Positive Positive Bilateral defects Bilateral defects Positive




Total Percentage


Lung Scan

Documentation Angiography Angiography


Dextran Yes Yes Yes No No Yes No

Autopsy, bilateral emboli Died, no autopsy









.. 56

insufficiency, immobilization of the extremity, and advanced age of the patients, the frequent association of pulmonary and cardiac disease, the occurrence of infarcted tissue or infection in the leg, and major surgery undoubtedly contribute to the observed high rate of thromboembolism. One week postoperatively, all nine patients with surgically discovered thrombus had scan evidence of pulmonary embolism, and in three of the patients embolism was documented by angiography or at autopsy. Because of the inaccuracy of the scan, we cannot justifiably assert that all nine patients had pulmonary embolism, which would produce a thrombus detection index of 100 per cent. Nevertheless, 33 per cent of these patients had unequivocal evidence of embolism. Mortality of the patients with venous thrombosis discovered at operation was 22 per cent whereas mortality for the entire group was 10 per cent, which suggests that the discovery of venous thrombosis at operation is a grave prognostic sign. For these reasons, the deep veins should be examined carefully for thrombosis at the time of amputation. If thrombus is present, systemic heparinization within twenty-four hours may prevent or diminish morbidity and mortality. Summary In a prospective study, thrombosis of the femoral or popliteal veins was discovered at operation in nine of eighty-one patients requiring amputation of a lower extremity for arterial insufficiency. One week postoperatively, all nine patients had evidence of pulmonary embolism on the lung scan. Embolization was documented by arteriography in



Britt, and Sherman

two patients and at autopsy in a third patient. In none of these patients was there clinical evidence of venous thrombosis prior to operation. Two of the subjects with proved thrombosis died during study, a mortality of 22 per cent, whereas the mortality for the entire group’ was 10 per cent. It is concluded that the deep venous system of patients requiring amputation for ischemia should be examined carefully at operation. These patients have a high incidence of deep venous thrombosis and the discovery of thrombus at the time of operation places them in a particularly high risk group.


References 1. Sevitt S, Gallagher NG: Venous thrombosis and pulmonary embolism: a clinical pathologic study in injured and burned patients. Br J Surg 48: 475. 1961. 2. Gibbs NM: Venous thrombosis of the lower limbs with particular reference to bed rest. Br J Surg 45: 15. 1957. 3. Hume M. Sevitt S. Thomas DP: Venous Thrombosis and Pulmonary Embolism. Cambridge, Harvard University Press, 1970, p 206. 4. Roberts GH: Venous thrombosis in hospital patients. A postmortem study. Scot Med J 8: 11, 1963. 5. Hicks BH, Hazel1 J: Safe use of liz5 fibrinogen. Lancet 2: 931. 1973. 6. Nicolaides AN, DuPont PA, Desai S, et al: Small doses of subcutaneous sodium heparin in preventing deep venous thrombosis after major surgery. Lancer 2: 690. 1972.

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