Significance of functional and nutritive pulmonary circulation for vital reactions in the form of embolisms

The functional and nutritive circulation in the lungs is connected by anastomoses between the pulmonary and bronchial arteries. The anastomoses have the structure of blocked arteries from which arteriovenous anastomoses proceed to the peribronchial plexus. The pulmonary artery is provided with a flow impulse by the anastomoses, and oxygen-containing blood is admixed with the venous blood, thus forming an "aortalization" in the lungs. By diverting the bloodstream, venous blood can reach the bronchial artery. The peculiarities of the lung circulation are important for vital reactions in the form of macro- and microembolisms. Macroembolisms prove the functionality of the system if branches of the pulmonary artery are closed before the arteries are blocked. A hemorrhagic infarction either arises or does not arise, and the hemorrhagic infarction cannot exceed a certain limit. A microembolism is over and above the anastomoses. If the microembolism is greater, pressure in the arteria pulmonaris can cause blood from the pulmonary artery to overflow into the bronchial artery. Because arteriovenous anastomoses arise from the blocked arteries, microemboli can now reach the systemic circulation. Thus, the system described can explain the passage of microemboli into the systemic circulation, avoiding the capillaries of the lungs; on the other hand, larger microembolisms can prove the functionality of the system.     

An application of a quantitative analytical system for the grading of pulmonary fat embolisms

The severity of pulmonary fat embolism in 5 autopsied cases has been measured using a quantitative image analytical system. With reference to the mean size of the fat emboli, the cases were divided into 2 groupings regardless of the number of the emboli. The mean sizes of the emboli in 3 cases of the first group were significantly larger (about 490-600 microns 2) than those found in the 2 cases of the other group (about 220 and 235 microns 2). An investigation into the localization of fat emboli revealed that more were lodging in the small arteries and arterioles in the first group than in the second. Our results have indicated that a reliable grading of pulmonary fat embolism can not be established without a quantitative image analysis of the size and localization of the fat emboli, and that this quantitative analytical method is useful in achieving this reliable grading.     

Fat embolism in the spleen

A fat embolism is seldom seen in the spleen. In some cases, fat globules lie in the central arteries and capillaries of the Malpighian bodies only and in other cases in the red pulp in capillaries or sinus. Part of the fat droplets has been phagocytosed by mononuclear cells, especially when patients die some days after injury and the beginning of fat embolism in the systemic circulation. The distribution of fat emboli described can been explained by the peculiarities of vascular structures in form of sheathed capillaries, which arise from pencil arterioles and probably do not permit fat globules to pass the capillary wall in this part of the vasculature.     

Deaths associated with liposuction: case reports and review of the literature

Tumescent liposuction is a common cosmetic procedure that is performed as an outpatient service in physician's offices and is largely believed to be safe. The protuberant areas of the body containing the undesirable fat deposits are injected with normal saline containing lidocaine and epinephrine for pain control and hemostasis, and the waterlogged cells are suctioned out via cannula through a small incision. We recently encountered three cases in which deaths were attributed to this procedure. Two showed fat embolization in the lung and one died from fluid overload. The osmium tetroxide post-fixed lung sections showed fat emboli in the interstitial capillaries and arterioles. We reviewed the recent literature and found that pulmonary thromboemboli, fat embolization, fluid overload, and lidocaine and epinephrine intoxication are found at autopsy in many cases. Forensic pathologists responsible for determining the cause and manner of death should become familiar with the postmortem findings and risks of liposuction therapy and communicate them to their clinical colleagues and communities.     

Histologic detection of fat emboli

We describe a procedure for detection of fat emboli in formalin fixed tissue using osmium tetroxide postfixation. Intravascular fat in tissue postfixed in osmium tetroxide, embedded in epoxy or paraffin, and stained with toluidine blue, hematoxylin, or Oil Red O is more easily visualized than in frozen tissue that is stained with Oil Red O. With these methods, fat emboli may be detected years after the initial autopsy.     

Cerebral tissue pulmonary embolization due to head trauma: a case report with immunohistochemical confirmation

Pulmonary embolization of cerebral tissue as the result of severe head trauma is an uncommon, if not rare, phenomenon, and few cases have been reported in the literature. The authors discuss the case of a 51-year-old male who died six days after suffering extensive head trauma in a motor vehicle collision. At autopsy, white-gray emboli were found in several subsegmental pulmonary arteries. The results of histologic examination with the hematoxylineosin stain gave the impression that the emboli were necrotic cerebral tissue; however, routine special stains for neural tissue produced inconclusive results. Immunohistochemical staining of the emboli with monoclonal mouse anti-human neurofilament protein (Dako Corp., Carpinteria, California) confirmed the cerebral nature of the emboli. To the authors' knowledge, this is the first reported case of pulmonary embolization of cerebral tissue confirmed by immunohistochemistry.     

Sickle cell lung disease and sudden death: a retrospective/prospective study of 21 autopsy cases and literature review

Sudden death in the setting of sickle cell lung disease (SCLD), is periodically seen in the practice of medical examiners. The goal of the present study was to identify the most common pathologic findings of SCLD associated with sudden or unexpected death. A retrospective/prospective review of 21 autopsy cases from sickle cell patients between 1990 and 2004 was performed. Review of medical records, autopsy reports, and H&E-stained slides of lung tissue was performed. Oil-Red-O and elastic staining of lung tissue were evaluated. All cases were screened for both acute and chronic forms of SCLD. Patients admitted for sickle cell pain crisis ranged in age from 8 months to 65 years. Fifteen out of 21 cases (71.4%) showed significant pulmonary pathology. The most frequent lung findings included pulmonary edema (47.6%), pulmonary thromboembolism (38.1%), fat emboli (33.3%), pulmonary hypertension, grades I-IV (33.3%), and microvascular occlusive thrombi (28.5%). Our study demonstrates higher-than-expected percentages of acute and chronic sickle cell-related lung injury such as fat embolism (33.3%) and pulmonary hypertension (33.3%), with right ventricular hypertrophy (33.3%). Therefore, we propose a simple and high-yield autopsy algorithm of ancillary procedures that should be applied on all known and suspected autopsy cases of sickle cell disease.     

脂肪栓塞中苏丹Ⅲ染色的定量分析

目的探讨苏丹Ⅲ染色如何定量应用于脂肪栓塞的法医学鉴定。方法应用苏丹Ⅲ对11例肺脂肪栓塞猝死的案例和11例其他原因致死的案例进行染色,并结合统计学方法对脂肪栓塞的阳性面积百分率及脂肪栓子数进行定量分析。结果脂肪栓塞致死者肺内苏丹Ⅲ染色阳性面积百分率为（5±1．7）％、脂肪栓子数为（9±2．4）％,均远大于其他原因致死的案例（P〈0．01）。结论苏丹Ⅲ染色法定量分析在脂肪栓塞中的法医学鉴定上结果可靠。     

Sudden death from massive pulmonary tumor embolism due to hepatocellular carcinoma

Massive pulmonary embolism in cancer patients can be due to detached thrombi or tumor. Pulmonary tumor embolism is often undiagnosed antemortem. We report a 52-year-old Chinese man admitted for management of hepatocellular carcinoma (HCC). Computerized tomography showed tumor involvement of hepatic vein and inferior vena cava. He died suddenly on the day of admission. At autopsy the main pulmonary arteries of both lungs were blocked by large tumor emboli, the immediate cause of death. Although rapid death in patients with HCC is usually caused by intraperitoneal hemorrhage from spontaneous rupture of tumor, massive pulmonary tumor embolism should also be considered in these patients, especially when antemortem evidence of hepatic vein and/or inferior vena cava invasion is present.     

Maternal death due to non-traumatic fat embolism

The aim of this report is to document a case of non-traumatic fat embolism (NTFE) and to address the need for considerition of fat embolism in suspicious deaths resulting from respiratory distress in the postpartum period. A 28-years-old woman autopsied at the Morgue Department of the Council of Forensic Medicine is included to the study. This female became unconscious and developed respiratory distress 4 h after delivery, and this was followed by respiratory arrest. External examination revealed resuscitation marks and normal postmortem changes. Light microscopy revealed massive fat embolization involving most of the alveolar capillaries on several sections. Only in one particular area was a bone marrow embolus. Pathological diagnosis of the lung was diffuse pulmonary fat embolism. There was no evidence of other organ involvement with emboli. Other visceral organs showed no striking findings other than mild congestion. The cause of death was considered to be respiratory insufficiency resulting from severe fat embolism of the lungs.     

大鼠实验性肺脂肪栓塞的病理学研究

取大鼠皮下脂肪乳化后作自身静脉注射,观察自身脂肪栓子对肺血管的光镜和电镜变化。结果表明,注射后1天肺小动脉及毛细血管内充满大量脂滴。4天时达高峰并伴有肺水肿、灶性出血以及单核细胞吞噬脂滴,中性、嗜酸性白细胞的浸润。7天后脂滴逐渐消失、未见其他脏器栓塞。     

Death due to superficial soft tissue injuries.

A series of deaths due to multiple superficial injuries is reported. These cases represented 5% of a consecutive homicide series in the Northern Territory of Australia. All cases were characterized by extensive superficial injuries, particularly involving soft tissue, which were present over much of the body including the face, head, arms, legs, and trunk. Upper-limb fractures were present in some cases, as were fractured ribs. The internal organs and tissues were pale, but there was either little or no organ damage. No significant volume of free blood was found in any of the body cavities. In one case, fat emboli were identified in moderate numbers in the lung and kidney. Death due to multiple superficial soft tissue injuries has not previously been characterized in the literature.     

A Case of Sudden Infant Death Due to Incomplete Kawasaki Disease

Although Kawasaki disease (KD) is a self‐limiting disease, it may cause sudden cardiac death. Diagnosis of KD is principally based on clinical signs; however, some infant cases do not meet the criteria. Such cases are identified as incomplete KD. The sudden death risk in incomplete KD cases is similar to conventional KD. In our 5‐month‐old case, he had been admitted to a hospital for a fever and suppuration at the site of Bacille de Calmette et Guerin (BCG) vaccination. However, after discharge from the hospital, his C‐reactive protein (CRP) levels declined, he got indisposed and died suddenly. A medico‐legal autopsy revealed myocarditis, coronaritis, platelet‐aggregated emboli in coronary arteries, and myocardial degeneration, suggesting that the fatal myocardial infarction was due to thrombus emboli in the coronary arteries. Forensic pathologists therefore should pay attention to the cardiac pathology originated from incomplete KD as a potential cause in cases of sudden infant death.     

Nonfracture-associated fatal fat embolism in a case of child abuse

Fatal fat embolism is usually thought of as a sequel to long-bone fracture, although cases secondary to soft tissue injury and atraumatic conditions have been infrequently reported. In this case of a two-year-old child-abuse victim who sustained multiple blunt traumatic injuries without skeletal fractures, pulmonary and systemic (brain and kidney) fat emboli were identified. At autopsy, all thoracic and abdominal viscera were intact; cranial contents exhibited only diffuse symmetrical petechial hemorrhages of the white matter. Because of the severe and widespread nature of soft tissue hemorrhage, and the absence of a grossly discernible cause of death, fat embolism was suspected. Using a combination of frozen section with oil red O staining and formalin-fixed osmium stained tissues, the immediate cause of death was determined to be diffuse fat embolism. Review of the literature reveals a pathophysiologic basis for fat embolism in the absence of fracture, both as a consequence of an acute increase in local pressure at the site of trauma and an alteration of the emulsification of blood lipids during shock. In light of these findings, we present this case to remind the forensic science community to consider fat embolism as the cause of death in cases of blunt-force injury without fracture.     

Multivascular atheromatous coronary microembolism

We report an unusual case of coronary-multivascular, small coronary artery embolism by atheromatous elements originating in a plaque in the main right coronary artery of a 52-year-old man who died of acute thrombotic occlusion of the severely stenotic left anterior descending vessel. The embolized arteries showed the characteristic multiphasic inflammatory changes of different ages previously described in arteries occluded by this material. The myocardium supplied by the involved channels showed ischemic damage of varying ages. Both these observations indicate that the multiple emboli had been discharged at different times, rather than as a single shower. Finally, we make a plea for the use of the correct term "erosion" rather than "ulcer" for the lesion that is the source of the invasive obstructions.     

Cerebral ischemia or post traumatic thrombosis of the A. carotis occuring to a car driver (author's transl)]

A short while after leaving a public-house a 71 year old man as the driver of his car was involved in a head-on collision with another car. On admission to a hospital he was unconscious with a distinct debility for the left side of his body and showed a changing anisocoria. Angiography of the right carotid artery revealed an occlusion. It was suspected that this was the terminal state of a generalized arteriosclerotic occlusion which was considered being the reason for the accident. The autopsy-findings showed, however, a posttraumatic thrombosis (whiplash-trauma of the cervical vertebral column) of the right arteria carotis and of the right arteria vertebralis with thromboembolia in a small pontine artery with an infarct-like ischemic softening. The differentiation from an apoplexia is of importance for the differential diagnosis.     

Fat Transfer and Fatal Macroembolization

Fat embolism is usually associated with long bone fractures or other trauma. The diagnosis is usually clinical, and in most cases, emboli are not fatal and not usually seen on gross examination. At the Los Angeles County Coroner's Office, we autopsied the victim of fatal macroscopic fat embolization to the lungs. The patient died during buttock enhancement surgery when fat from liposuction was injected into her buttocks. Fat embolism from liposuction and fat injection is reportedly rare, and macroscopic embolization is rarer still. Varicose veins can occur in the area of the sciatic notch and are known to cause painful sciatica symptoms. We suggest them as a potential conduit for macroscopic fat to reach the lungs. Simple pre‐operative questioning for sciatica symptoms and possible radiologic study to rule out sciatic varices seem prudent before undertaking buttock‐enhancing surgery. Careful fat injection with pre‐aspiration is always advised.     

Fatal Case of Hydrophilic Polymer Emboli

Hydrophilic polymers are used to coat catheters and other intravascular devices. In general, these polymers have many salutary properties; however, in some instances, fragmentation of hydrophilic polymers coating intravascular devices can occur with fatal consequences. This report details the histopathologic changes in the lung seen following polymer fragmentation and embolization from a central venous catheter. Polymer emboli detected microscopically are intravascular and consist of basophilic, lamellated, and nonrefractile elements. Typically, an inflammatory response is present to a variable degree. Embolization can result in severe tissue injury with ischemia and infarction.     

Post-mortem finding of a non-fatal left heart ventricle perforation by a pleural drain. A case report

A 76-year-old male with a previous history of heart arrhythmia and decompensation was treated for a complicated thoraco-abdominal trauma. Accidentally, a pleural drain was inserted in his heart through the ventricular septum, perforating the left ventricle, the drain tip being buried in its posterior wall. This injury was not recognized until autopsy. The patient died 7 days after insertion of the drain of lung emboli, which were related to his primary trauma and not to the heart perforation.     

家兔肺脂肪栓塞后超微病理学观察

目的 研究脂肪栓塞后肺组织的超微结构变化.方法 通过向实验组家兔血管内注射脂肪诱导肺脂肪栓塞制作肺栓塞动物模型,分别于栓塞即刻(0 h)和栓塞后3、8 h及1、2、7、14d处死动物;对照组家兔注射同等剂量的生理盐水,其余处理方法与实验组相同.经HE和苏丹Ⅲ染色证实造模成功后,用透射电镜观察肺组织的超微结构变化.结果 ...