Venous bullet embolism. A case report

Venous missile embolism to the pulmonary artery is a rare occurrence and controversy persists about the need to remove such a foreign body. This report describes a case of bullet embolism from the right common iliac vein to the left pulmonary artery. In this case the bullet was not removed.

Sudden death due to tricuspid valve myxoma with massive pulmonary embolism in a 15-month old male

Myxomas of the tricuspid valve are extremely rare, with only 13 cases reported in the world literature. We report the case of a 15-month old male with tricuspid valve myxoma and massive myxomatous pulmonary emboli discovered at autopsy.

Prevalence of acute pulmonary embolism in central and subsegmental pulmonary arteries and relation to probability interpretation of ventilation/perfusion lung scans

PURPOSE

The purpose of this investigation is to determine the prevalence of acute pulmonary embolism (PE) limited to subsegmental pulmonary arteries.

BACKGROUND

Contrast-enhanced helical (spiral) and electron-beam CT, in the hands of experienced radiologists who are skillful with this modality, are sensitive for the detection of acute PE in central pulmonary arteries, but have a low sensitivity for the detection of PE limited to subsegmental pulmonary arteries. The potential for CT to diagnose PE, therefore, is partially dependent on the prevalence of PE limited to subsegmental pulmonary arteries.

METHODS

Data are from the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED). The largest pulmonary arteries that showed PE, as interpreted by the PIOPED angiographic readers, were identified in 375 patients in PIOPED with angiographically diagnosed PE.

RESULTS

Among all patients with PE, 6% (95% confidence interval [CI], 4 to 9%) had PE limited to subsegmental branches of the pulmonary artery. Patients with high-probability ventilation/ perfusion (V/Q) scans had PE limited to subsegmental branches in only 1% (95% CI, 0 to 4%). Among patients with low-probability V/Q lung scans, 17% (95% CI, 8 to 29%) had PE limited to the subsegmental branches. Patients with low-probability V/Q scans and no prior cardiopulmonary disease had PE limited to the subsegmental pulmonary arteries in 30% (95% CI, 13 to 53%), whereas patients with low-probability V/Q scans who had prior cardiopulmonary disease had PE limited to subsegmental pulmonary arteries in 8% (95% CI, 2 to 22%) (p < 0.05).

CONCLUSION

Based on data from all patients with PE in PIOPED, the prevalence of PE limited to subsegmental pulmonary arteries is low, 6%. PE limited to subsegmental pulmonary arteries was most prevalent among patients with low-probability V/Q scans, particularly if they had no prior cardiopulmonary disease.

Deep venous thrombosis. The dilemma of diagnosis

Despite advanced medical technology, deep venous thrombosis continues to be a seriously underdiagnosed common postsurgical complication of the patient, particularly of lower extremity procedures, often requiring postoperative bed rest as in any routine podiatric surgery. Deep venous thrombosis and its complication, pulmonary embolism, are elusive clinical conditions since patients often tend to exhibit neither specific nor reliable signs or symptoms. However, the suspicion of the surgeon, generally based on subtle clinical manifestations, is the most important step in the diagnosis. Diagnosis will never be made unless he or she entertains the possibility. Since prevention of the potentially fatal outcome of pulmonary emboli secondary to deep venous thrombosis and possibly the serious morbidity caused by long-term sequelae in the lower extremity is now possible, the importance of an early, adequate diagnosis is indisputable. Diagnosis on clinical grounds alone is notoriously unreliable and objective tests are necessary to avoid overtreatment or undertreatment.

Is this the natural history of the retention wire? A case report

We report on a 71-year-old man who had a dual chamber pacemaker implanted in 1991. A Class IV fracture of the Telectronics Accufix 330-801 atrial lead was observed on a chest X ray in December 1993. Serial chest X ray and fluoroscopy documented stable position of the migrated fractured J wire. The patient remained asymptomatic and a decision for conservative monitoring was made. A subsequent finding of a right atrial mass on echocardiography and evidence of pulmonary embolism on lung scan prompted a change of strategy. The patient underwent atriotomy, and a right atrial thrombus was discovered associated with the fractured J retention wire, both of which were extracted uneventfully. This case is illustrative that despite apparent stability of a Class IV fracture, it may result in endothelial injury with a thrombogenic nidus and resultant complications.

Ovarian vein thrombosis during cesarean section. A report of two cases

BACKGROUND

Puerperal ovarian vein thrombosis occurs in 0.2-0.5% of deliveries. It is usually thought to result from infection, but it has been hypothesized that thrombosis may occur as a primary event, and radiologic studies raise the possibility that ovarian vein thrombosis may occur quite frequently.

CASES

Case 1 had right ovarian vein thrombosis diagnosed at the time of nonemergency cesarean section for placenta previa. This was treated with ligation of the infundibulopelvic ligament above the level of the clot. Subsequent magnetic resonance imaging showed contralateral ovarian vein thrombosis, and therefore anticoagulant therapy was begun. The patient was asymptomatic. Case 2 had right ovarian vein thrombosis extending to the inferior vena cava diagnosed at elective repeat cesarean section. She was heparinized in the recovery room; subsequent ventilation/perfusion scan showed a probable pulmonary embolism. Both patients recovered uneventfully.

CONCLUSION

These two cases demonstrate that ovarian vein thrombosis may occur as a primary event, in the absence of infection, and result in pulmonary embolism. Individualized management based on operative findings is recommended.

Cardiopulmonary responses to intravenous infusion of soluble and relatively insoluble gases

BACKGROUND

Carbon dioxide is the current gas of choice for pneumoperitoneum, but hemodynamic and acid-base effects secondary to its systemic absorption have been reported. Various studies have suggested inert gases as alternatives.

METHODS

We studied the cardiopulmonary responses to intravenous infusion of carbon dioxide, nitrous oxide, argon, helium, and nitrogen in anesthetized swine. The gas was infused into the femoral vein at a rate of 0.1 ml . kg-1 . min-1 for 30 min. The changes in end-tidal CO2, mean arterial pressure, hemodynamics, and arterial blood gases were compared to baseline values.

RESULTS

No animals died during infusion of the soluble gases (CO2 and N2O). Three of the five pigs infused with nitrogen died suddenly at 20 and 30 min of infusion. The animals in the insoluble gas groups (Ar, He, N2) experienced clinical pulmonary gas embolism and severe acidemia, hypercapnea and tachycardia.

CONCLUSIONS

Venous gas embolism is poorly tolerated when the gas is relatively insoluble. Insoluble gases should not be used for pneumoperitoneum when there is any risk of venous gas embolism.

Pulmonary embolism associated with acute stroke

OBJECTIVE

To describe the circumstances surrounding pulmonary embolism associated with stroke, the prophylactic measures, and the outcome in affected patients.

MATERIAL AND METHODS

We studied pulmonary embolism in patients with acute stroke at Mayo Clinic Rochester during a 2-decade period. Medical records of 30 patients with pulmonary embolus after stroke were reviewed. Pulmonary embolus was diagnosed on the basis of pulmonary angiograms, high-or intermediate-probability ventilation-perfusion scans, or autopsy findings.

RESULTS

Sudden death occurred in 15 of 30 patients (50%) with pulmonary embolism. In the other 15 patients, pleuritic pain or dyspnea was a major initial symptom. Pulmonary embolism occurred from day 3 to day 120 (median time, day 20) after the ictus. Prophylaxis against deep venous thrombosis was noted in only 4 of 30 patients. Pulmonary embolism was associated with deep venous thrombosis diagnosed clinically or at autopsy in 11 patients, invariably in the paralyzed leg.

CONCLUSION

Pulmonary embolism after ischemic or hemorrhagic stroke may defy antemortem diagnosis in half of the affected patients. Pulmonary embolism in patients with acute stroke can be a cause of early mortality (during the first month after the ictus).

Hormone replacement therapy and risk of venous thromboembolism: population based case-control study

OBJECTIVE

To evaluate the association between use of hormone replacement therapy and the risk of idiopathic venous thromboembolism.

DESIGN

Population based case-control study.

SETTING

Population enrolled in the General Practice Research Database, United Kingdom.

SUBJECTS

A cohort of 347,253 women aged 50 to 79 without major risk factors for venous thromboembolism was identified. Cases were 292 women admitted to hospital for a first episode of pulmonary embolism or deep venous thrombosis; 10,000 controls were randomly selected from the source cohort.

MAIN OUTCOME MEASURES

Adjusted relative risks estimated from unconditional logistic regression.

RESULTS

The adjusted odds ratio of venous thromboembolism for current use of hormone replacement therapy compared with non-users was 2.1 (95% confidence interval 1.4 to 3.2). This increased risk was restricted to first year users, with odds ratios of 4.6 (2.5 to 8.4) during the first six months and 3.0 (1.4 to 6.5) 6-12 months after starting treatment. No major risk differences were observed between users of low and high doses of oestrogens, unopposed and opposed treatment, and oral and transdermal preparations. The risk of idiopathic venous thromboembolism among non-users of replacement therapy was estimated to be 1.3 per 10,000 women per year. Among current users, idiopathic venous thromboembolism occurs at two to three times the rate in non-users, resulting in one to two additional cases per 10,000 women per year.

CONCLUSIONS

Current use of hormone replacement therapy was associated with a higher risk of venous thromboembolism, although the risk seemed to be restricted to the first year of use.

Prevention of thromboembolism with use of recombinant hirudin. Results of a double-blind, multicenter trial comparing the efficacy of desirudin (Revasc) with that of unfractionated heparin in patients having a total hip replacement

Specific inhibition of thrombin is a new method for the prevention of postoperative deep-vein thrombosis. The objective of this multicenter, randomized, double-blind study was to compare the efficacy and safety of desirudin (Revasc, CGP 39393; fifteen milligrams two times a day) with that of unfractionated heparin (5000 international units three times a day) in patients having a primary elective total hip replacement. The medications were administered subcutaneously, starting preoperatively and continuing for eight to eleven days. The primary end point was a confirmed thromboembolic event during the treatment period. The presence of deep-vein thrombosis was evaluated with bilateral venograms, which were centrally assessed by two independent radiologists. A total of 445 eligible patients were randomized: 220, to management with heparin, and 225, to management with desirudin. A per-protocol analysis of efficacy was performed for the 351 patients (79 per cent) for whom an adequate bilateral venogram had been made within eight to eleven days after the operation or who had had a proved thromboembolic event. The prevalence of confirmed deep-vein thrombosis was thirteen (7 per cent) of 174 patients who had received desirudin and forty-one (23 per cent) of 177 patients who had received heparin, a significant difference (p < 0.0001). The prevalence of proximal deep-vein thrombosis was also significantly reduced (p < 0.0001), by 79 per cent, in the group that had received desirudin (six [3 per cent] of 174 patients) compared with in the group that had received heparin (twenty-nine [16 per cent] of 177). There were no confirmed pulmonary embolisms or deaths during the period of prophylaxis. During a six-week follow-up period, pulmonary embolism was confirmed in four patients, all of whom had received heparin. There was no significant difference between the treatment groups with respect to bleeding variables or bleeding complications. These data demonstrate that a fixed dose of fifteen milligrams of desirudin, started preoperatively and administered subcutaneously twice daily for at least eight days, provided effective, safe prevention of thromboembolic complications, with no specific requirements for laboratory monitoring, in patients who had a total hip replacement.

Cost-effective prevention of pulmonary embolus in high-risk trauma patients

OBJECTIVE

To define the cost-effectiveness of screening ultrasound (US) and prophylactic inferior vena cava filters (VCF), approaches aimed at reducing the incidence of pulmonary embolus (PE) in high-risk trauma patients.

DESIGN

Cost-effective analysis.

MATERIALS AND METHODS

We constructed a decision tree with three approaches for PE prevention: no intervention, US, and VCF. Probabilities in each subtree were taken from published data. Sensitivity analyses evaluated all assumptions, probabilities, and outcomes for effects on baseline conclusions.

RESULTS

US is more cost-effective than VCF, with a cost/PE prevented of $46,300 compared with $93,700. The strategies become equally cost-effective only when VCF are placed in the radiology suite and length of stay is > or = 2 weeks.

CONCLUSIONS

US is the most cost-effective approach for PE prevention in high-risk trauma patients. VCF should be reserved for patients with an anticipated length of stay > or = 2 weeks who can safely have a filter placed in the radiology suite.

Diffuse microvascular pulmonary thrombosis associated with primary antiphospholipid antibody syndrome

Thromboembolism is a well-known complication of the hypercoagulable state associated with antiphospholipid (aPL) antibodies. Acute respiratory failure (ARF) with diffuse pulmonary infiltrates has been reported in only a few patients with aPL antibodies. We describe a 49 year old patient with spiking fever, livedo reticularis, mild haemoptysis and ARF. Chest radiography revealed diffuse bilateral pulmonary infiltrates, and high resolution computed tomography (CT) revealed patchy distribution of areas of ground-glass attenuations. Pulmonary emboli were excluded with angiography. Lung biopsy revealed diffuse microvascular thrombosis, without capillaritis. High serum levels of anticardiolipin (aCL) antibodies were found. The patient's condition improved dramatically after intravenous infection of 1 g methylprednisolone on three consecutive days, followed by 50 mg prednisone orally. The rapid improvement following the administration of glucocorticosteroids suggests that anticardiolipin associated microvascular thrombosis, without inflammatory lesions, may depend on an interference with beta2-glycoprotein I (beta2=GPI) by anticardiolipin.