Major Pulmonary Embolism: Review of a Pathophysiologic Approach to the Golden Hour of Hemodynamically Significant Pulmonary Embolism

BACKGROUNDThe Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) addressed the value of ventilation/perfusion scans in acute pulmonary embolism (PE). The present study evaluates the risks and diagnostic validity of pulmonary angiography in 1,111 patients who underwent angiography in PIOPED:METHODS AND RESULTSComplications were death in five (0.5%), major nonfatal complications in nine (1%), and less significant or minor in 60 (5%). More fatal or major nonfatal complications occurred in patients from the medical intensive care unit than elsewhere: five of 122 (4%) versus nine of 989 (1%) (p less than 0.02). Pulmonary artery pressure, volume of contrast material, and presence of PE did not significantly affect the frequency of complications. Renal dysfunction, either major (requiring dialysis) or less severe, occurred in 13 of 1,111 (1%). Patients who developed renal dysfunction after angiography were older than those who did not have renal dysfunction: 74 +/- 13 years versus 57 +/- 17 years...

Complications and validity of pulmonary angiography in acute pulmonary embolism.

Authors/Task Force Members: Adam Torbicki, Chairperson (Poland)*, Arnaud Perrier (Switzerland), Stavros Konstantinides (Germany), Giancarlo Agnelli (Italy), Nazzareno Galiè (Italy), Piotr Pruszczyk (Poland), Frank Bengel (USA), Adrian J.B. Brady (UK), Daniel Ferreira (Portugal), Uwe Janssens (Germany), Walter Klepetko (Austria), Eckhard Mayer (Germany), Martine Remy-Jardin (France), and Jean-Pierre Bassand (France)

Guidelines on diagnosis and management of acute pulmonary embolism

Complications of right heart catheterization procedures in patients with pulmonary hypertension in experienced centers.

T hroughout medical history, unusual patient groups have often provided vital clues to the pathogenesis of disease. For example, the discovery of a small group of patients with a1proteinase inhibitor deficiency provided critical insights into the pathogenesis of emphysema. The study of hemophiliacs opened exciting new avenues of research and clinical intervention that are still being fruitfully explored. And chronic major-vessel thromboembolic pulmonary hypertension (C T-E PH) promises to be an instance in which a relatively small, unusual group of patients may provide much information about both thromboembolism and pulmonary vascular disease. C T-E PH is the result of single or recurrent pulmonary emboli arising from sites of venous thrombosis. The natural history of most emboli is to undergo total resolution, or resolution leaving minimal residua, with restoration of normal pulmonary hemodynamics.1-5 For reasons still unclear, the emboli in C T-E PH patients do not resolve completely; rather, they follow an aberrant path of organization and recanalization, leaving endothelialized residua that obstruct or significantly narrow major (main, lobar, or segmental) pulmonary arteries. From the reports of others6-1"2141 and our own experience with more than 250 C T-E PH patients, it is clear that there is a wide spectrum of residual embolic obstruction and therefore the degree to which pulmonary vascular resistance is increased. Some patients with chronic obstruction of one or more segmental or lobar arteries are nearly asymptomatic. At the other extreme are those who have major obstructions in multiple central pulmonary arteries and develop severe pulmonary hypertension and progressive right ventricular failure. This disorder is quite distinct from so-called "primary" pulmonary hypertension in which the obstructing lesions appear in the small, distal pulmonary arteries. While in primary pulmonary hypertension there may be thrombotic lesions in these small arter-

Chronic major-vessel thromboembolic pulmonary hypertension.

Pulmonary angiography is sensitive and specific in the diagnosis of pulmonary thromboembolism, but it remains an invasive procedure. Experience with 1,350 pulmonary angiograms was reviewed to ascertain the incidence, etiologies, and avoidance of complications. There were three deaths, all of which were secondary to cor pulmonale in patients with pulmonary hypertension and right ventricular end diastolic pressure (RVEDP) equal to or greater than 20 mmHg. Other complications consisted of cardiac perforation in 14 patients and endocardial or myocardial injury in six without sequelae, 11 significant arrhythmias and five cardiac arrests successfully treated, minor contrast material reactions in 11 patients, and a few insignificant complications. Carefully performed pulmonary angiography is safe if one avoids injecting contrast material into a patient with an elevated RVEDP.

The incidence, etiologies, and avoidance of complications of pulmonary angiography in a large series.

The use of pulmonary angiography as related to ventilation-perfusion scintigraphy was studied at two teaching hospitals in 600 patients clinically suspected of having pulmonary embolism, using a combined prospective-retrospective approach. Sixty patients underwent angiography, 30 in each institution. A minority of patients in each scintigraphic diagnostic category underwent angiography, but the scintigraphic diagnosis had a major impact on the frequency of requests for angiography. Inconclusive scintigraphy was the principal reason for requesting angiography, although nearly half of patients in whom scintigraphic assessment was indecisive were managed without further diagnostic measures. Few patients in the low-probability and high-probability scintigraphic categories received angiography. This study also indicates that a substantial patient selection bias may exist in series that correlate scintigraphic and angiographic results.

Use of pulmonary angiography for suspected pulmonary embolism: influence of scintigraphic diagnosis

Percutaneous balloon dilation of benign biliary strictures was successful in 15 of 18 patients in whom the procedure was attempted. Successful dilation was achieved in nine of 11 patients who had biliary enteric strictures, with follow-up of 22-55 months (mean, 35.4 months) after catheter removal in seven patients. Five of six strictures in the biliary tree that developed after surgery were successfully dilated, with long-term follow-up available in two patients (58 and 42 months). A patient with an inflammatory common bile duct stricture that was successfully dilated was followed up for 18 months. Percutaneous dilation of biliary tract strictures is a promising technique with good long-term results and may be the initial treatment of choice in biliary stricture management.

Percutaneous dilation of benign biliary strictures.

Many nuclear medicine physicians use criteria put forth by McNeil or Biello et al. to interpret lung scintigrams, while others use an integration of these and other reported or personal criteria. Interobserver variation within these schemes has not been assessed, nor have the schemes been compared with each other using the same set of scans. Two experienced nuclear medicine physicians independently read 98 scans that were collected over a two year period and that had angiographic correlation. Perfusion, ventilation, and radiographic abnormalities were described objectively, and each case was assigned to a McNeil category, a Biello category, and an estimate of probability was made based on the reader's own synthesis of criteria (modified criteria). The two readers differed widely in describing the number, size, and location of abnormalities. Despite the large interobserver variation in objective descriptions, there were no statistically significant differences between the receiver operating characteristic ...

Lung scan interpretation: effect of different observers and different criteria

In some patients acute pulmonary emboli may fail to resolve normally, resulting in chronic pulmonary embolism. This may lead to pulmonary hypertension, respiratory insufficiency, cor pulmonale, and death. The angiographic evaluation in nine patients with chronic pulmonary embolism who underwent embolectomy is presented. Particular emphasis on the predictive value of selective bronchial arteriography in four of these patients is considered. In chronic pulmonary embolism, pulmonary arteries distal to obstructed areas may remain patent and be supplied by hypertrophied bronchial arteries. Since back-bleeding of arterial blood from the bronchial circulation at surgery may predict the success of embolectomy, preoperative bronchial arteriography may be useful for predicting potential surgical success.

S R Mills

Papers

The incidence, etiologies, and avoidance of complications of pulmonary angiography in a large series.

Use of pulmonary angiography for suspected pulmonary embolism: influence of scintigraphic diagnosis

Percutaneous dilation of benign biliary strictures.

Lung scan interpretation: effect of different observers and different criteria

Angiographic evaluation of chronic pulmonary embolism.