Pulmonary thromboembolism and unexpected death in infancy

Deep venous thrombosis, pulmonary embolism and long-distance flights

Deep vein thrombosis resulting in lethal pulmonary thromboembolism is not-infrequently encountered in forensic cases. Predisposing factors include immobility, recent surgery, previous deep venous thromboses/pulmonary thromboembolism, indwelling central venous lines, major trauma, the oral contraceptive pill, pregnancy, congenital cardiac disease, sepsis, malignancy, systemic lupus erythematosus, renal failure and certain inherited thrombophilias. Venous thrombosis associated with air travel was reported in the early 1950's and called the "economy class syndrome", although it is now recognized that reduced movement on long distance flights is more significant than seating class. Long-distance flights of eight hours or more are associated with a two to fourfold increase in the risk of deep venous thrombosis, but only in those individuals who have underlying risk factors. With increasing numbers of flights of more than 16 h duration forensic pathologists are well placed to monitor the potential impact of extended flying on the incidence of lethal pulmonary thromboembolism.

Pulmonary embolism and in situ pulmonary artery thrombosis in paediatrics

Data on paediatric pulmonary embolism (PE) are scarce. We sought to systematically review the current literature on childhood PE and conducted a search on paediatric PE via PubMed (1946–2013) and Embase (1980–2013). There was significant heterogeneity in reported data. Two patterns were noted: classic thromboembolic PE (TE-PE) and in situ pulmonary artery thrombosis (ISPAT). Mean age of presentation for TE-PE was 14.86 years, and 51% of cases were males. The commonest method for diagnosis of TE-PE was contrast CT with angiography (74% of patients). The diagnosis of TE-PE was often delayed. Although 85% of children with TE-PE had an elevated D-dimer at presentation, it was non-discriminatory for the diagnosis. In paediatric TE-PE, the prevalence of central venous catheters was 23%, immobilisation 38%, systemic infection 31% and obesity 13%, elevated Factor VIII or von Willebrand factor levels 27%, Protein C deficiency 17%, Factor V Leiden 14% and Protein S deficiency 7%. In patients with TE-PE, pharmacologic thrombolysis was used in 29%; unfractionated heparin was the most common initial anticoagulant treatment in 64% and low-molecular-weight heparins the most common follow-up treatment in 83%. Duration of anticoagulant therapy was variable and death was reported in 26% of TE-PE patients. In contrast to TE-PE, patients with ISPAT were not investigated systematically for presence of thrombophilia, had more surgical interventions as the initial management and were often treated with anti-platelet medications. This review summarises important data and identifies gaps in the knowledge of paediatric PE, which may help to design future studies.

Occult Adrenocortical Carcinoma and Unexpected Early Childhood Death

A four-year-old previously well boy collapsed unexpectedly and was taken immediately to hospital, where he developed seizures and cardiogenic shock with lethal, rapidly progressing multi-organ failure. At autopsy, the height was >90th percentile and there were indications of early virilization. Internally, a friable tumor of the left adrenal gland was identified that had invaded the left renal vein and inferior vena cava. Histology revealed typical features of an adrenocortical carcinoma with aggregated trabeculae of cells containing abundant eosinophilic cytoplasm and large pleomorphic nuclei. There was strong positive cytoplasmic staining for inhibin; mitochondria were shown on electron microscopy to contain prominent electron-dense granules. Death was due to massive pulmonary tumor embolism. Although adrenocortical carcinomas are very rare and are more commonly found in adults, the current case demonstrates that they may also occur in childhood and be responsible for unexpected death by the very unusual mechanism of tumor embolism.

Neonatal and infant pulmonary thromboembolism: a literature review

Pulmonary thromboembolism (PTE) is rare in neonates and infants; however evidence suggests it is underdiagnosed. The primary objective is to conduct a scientific review to determine if the presentation, diagnosis, treatment and outcomes of neonates and infants with PTE are consistent across studies. Secondly, to develop an algorithm to establish the diagnosis and management of the condition based on current information. Two authors searched the literature independently using existing databases and verified that identical articles were assembled. Infants aged less than 1 year with PTE were included and further categorized into neonates 28 days or less and infants 29 days to 1 year or less. Forty-five articles with 157 cases (121 neonates; 36 infants) were identified with PTE. All of the reports were descriptive and neither randomized controlled trials nor prospective or case-control studies were identified. The reports are sub-classified into cases of pulmonary air embolism (PAE) with a higher mortality rate and patients with PTE. Diagnostic and treatment strategies varied widely and were individually case-based, dependent on clinical findings, which influenced patient outcomes. Scientific data to guide an evidence-based, diagnostic and treatment approach to PTE is limited because of the absence of rigorous clinical trials. Large scale, multicenter collaborative studies are required to firmly establish the management of PTE in this population.

Molecular diagnosis of generalized arterial calcification of infancy (GACI)

Generalized arterial calcification of infancy (GACI) is a life-threatening disorder in young infants. Cardiovascular symptoms are usually apparent within the first month of life. The symptoms are caused by calcification of large and medium-sized arteries, including the aorta, coronary arteries, and renal arteries. Most of the patients die by 6 months of age because of heart failure. Recently, homozygous or compound heterozygous mutations for the ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) gene were reported as causative for the disorder. ENPP1 regulates extracellular inorganic pyrophosphate (PP_i), a major inhibitor of extracellular matrix calcification. A newborn was diagnosed with GACI. The infant died at the age of 7 weeks of cardiac failure and the parents were referred to Molecular Biology and Cytogenetic lab for further workup. Cytogenetics analysis was performed on the parents, which showed normal karyotypes and mutational analysis for the ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) gene was also performed. The mutational analysis showed that both father and mother of the deceased infant were heterozygous carriers of the mutation c.749C>T (p.P250L) in exon 7 of ENPP1 and it was likely, that the deceased child carried the same mutation homozygous on both alleles and died of GACI resulting from this ENPP1 mutation. The couple was counseled and monitored for the second pregnancy. Amniocentesis was performed at 15 weeks of gestation for mutational analysis of the same gene in the second pregnancy. The analysis was negative for the parental mutations. One month after the birth of a healthy infant, peripheral blood was collected from the baby and sent for reconfirmation. The results again were negative for the mutation and the baby was on 6 months follow up and no major symptoms were seen. The parents of the child benefited enormously by learning about the disease much in advance and also its risk of recurrence. The main aim of this study is to emphasize on two aspects: (i) the importance of modern molecular techniques in diagnosis such a syndrome and (2) the difficulties faced by the physician to provide appropriate diagnosis and the adequate genetic counseling to the family without molecular facilities.

Lower extremity deep venous thrombosis with fatal pulmonary thromboembolism caused by benign pelvic space-occupying lesions--an overview

Venous stasis predisposes to thrombosis. One hundred and sixty cases of fatal pulmonary thromboembolism were reviewed to determine how many cases had deep venous thromboses associated with venous blood flow reduction caused by external pressure from benign pelvic masses. Three cases were identified, representing 2% of cases overall (3/160): a 44-year-old woman with a large uterine leiomyoma (1048 g); a 74-year-old man with prostatomegaly and bladder distension (containing 1 L of urine); and a 70-year-old man with prostatomegaly and bladder distension (containing 3 L of urine). Although a rare cause of fatal deep venous thrombosis and pulmonary thromboembolism, space-occupying pelvic lesions can lead to extrinsic pressure on adjacent veins reducing blood flow and causing stasis and thrombosis. Individuals with large pelvic masses may, therefore, be at increased risk of pulmonary thromboembolism from deep venous thrombosis, particularly in the presence of concurrent risk factors such as immobility, thrombophilias, malignancy, and significant cardiopulmonary disease.

Fatal pulmonary embolism in a premature neonate after twin-to-twin transfusion syndrome

Thrombotic events are being increasingly recognized during the neonatal period. An infant girl was born at 29 weeks' gestation after a pregnancy complicated by twin-to-twin transfusion syndrome. After an initial uncomplicated clinical course, her oxygen requirement increased, which was interpreted as an early sign of bronchopulmonary dysplasia. At 3 weeks of age, she suddenly collapsed and died of severe pulmonary hypertension. At autopsy, multiple pulmonary artery emboli and several older renal vein thromboses were found. Results of genetic analyses of the infant and her family were negative for thrombophilia. Although embolism represents a frequent emergency in adults, fatal pulmonary embolism has never, to our knowledge, been described for premature infants. This case suggests that thrombotic events are underdiagnosed and that additional studies are needed to define infants at risk and optimal treatment strategies.

Massive pulmonary embolism in children

We present 3 children with massive pulmonary embolism and review 17 recent pediatric reports. Malignancies were a frequent cause (40%), and sudden death was common (60%). Compared with adults, diagnosis was more likely to be made at autopsy (P < .0001), more children were treated with embolectomy/thrombectomy (P = .0006), and mortality was greater (P = .03).

Successful surgical management of a neonate with a saddle pulmonary embolus

A female neonate presented with evidence of a massive ventilation-perfusion mismatch. She was subsequently found to have a saddle pulmonary embolus. The infant successfully underwent surgical pulmonary embolectomy.

Idiopathic arterial calcification and unexpected infant death

Two infants who died unexpectedly and who were found at autopsy to have idiopathic arterial calcification are presented. The first infant died within hours of the sudden onset of shortness of breath. The second infant died suddenly and unexpectedly in hospital where he was being treated for presumed sepsis and cardiac failure. Neither infant had significant past or family histories. Autopsy examination in both infants demonstrated widespread fibrointimal proliferation of elastic and muscular arteries with characteristic calcification of the internal elastic laminae. Kidneys and parathyroid glands were normal. Death in case 1 was attributed to extensive myocardial ischemic damage with right coronary artery ostial stenosis due to idiopathic arterial calcification. Death in case 2 was attributed to saddle pulmonary thromboembolism arising from a right atrial thrombus associated with cardiac failure secondary to idiopathic arterial calcification. These cases demonstrate the variable presentations, causes of death, and autopsy findings that may occur in this uncommon condition.

Mechanisms of sudden death and autopsy findings in patients with Arnold-Chiari malformation and ventriculoatrial catheters

Neurological and vascular complications of Arnold-Chiari malformation treated with ventriculoatrial shunting may result in sudden or unexpected death. Two patients with Arnold-Chiari malformation and ventriculoatrial shunting had variable clinical manifestations and diagnostic difficulties. A 3-year-old girl with a 1-day history of right-sided heart failure died unexpectedly soon after cardiac catheterization. At autopsy examination an adherent thrombus around the ventriculoatrial catheter tip, pulmonary infarction, and embolic pulmonary arterial hypertensive changes were found. In the second case, a 21-year-old man died suddenly after a brief episode of dyspnea. He had a 1-year history of "asthma" before death. Autopsy examination confirmed pulmonary infarction and embolic pulmonary arterial hypertensive changes. There was no histological evidence of asthma. Deaths in both cases were due to pulmonary infarction stemming from thromboemboli derived from ventriculoatrial catheterization. Both patients had evidence of long-standing clinically unsuspected vascular disease, which may have contributed to death. Cardiac catheterization may also have precipitated death in the first patient. Other possible problems leading or contributing to sudden death in such patients include pulmonary hypertension with chronic cor pulmonale, airway obstruction from recurrent laryngeal nerve paralysis, and shunt blockage with acute hydrocephalus. Lethal brainstem compression may also accompany relatively minor trauma associated with chronic cerebellar tonsillar herniation in these patients.