RESUMO
The purpose of this study was to examine the prevalence and characteristics (victims' profiles, circumstances surrounding the incidents, and methods employed) of complex and complicated suicides over a 12-year period in the broader area of Athens, Greece. A retrospective analysis of 5,568 autopsy cases performed at the Department of Forensic Medicine and Toxicology of the National and Kapodistrian University of Athens from January 1, 2011, to December 31, 2022, was carried out. Out of a total sample of 5,568 autopsies, 360 suicide cases were identified, among which 14 (3.9%) were classified as complex suicides, and one case (0.3%) was identified as complicated suicide. Among the victims, 78.6% were males. The age range of the victims varied between 25 and 82 years old. The most prevalent method of complex suicide was the use of sharp objects followed by jumping from a height (42.8%). The next most common combination of methods was poisoning (21.4%) along with hanging. Prior suicidal attempts and suicide note were mentioned in 16.7% and 8.3% of the cases respectively. Overall, a total of 9 different methods were used in the above 14 cases. Only half (50.0%) of the victims had an established psychiatric diagnosis. In determining the cause of death in cases of a complex or complicated suicides, it is of utmost importance for the forensic pathologist to gather and analyze all available information provided by the police, the victim's relatives along with a thorough investigation of the scene, a detailed autopsy and a toxicological analysis.
RESUMO
Falls are the second cause of accidental deaths worldwide. Falls from height are also a common method of suicide. The aim of this study is to compare the characteristics of the victims, the circumstances of the fall and the severity and distribution of the injuries reported in an autopsy case series of falls from height. This study is a retrospective analysis of consecutive autopsy cases of suicidal and accidental falls from height which were investigated in the Department of Forensic Medicine and Toxicology of the National and Kapodistrian University of Athens during the period 2011-2019. The recorded variables included demographic data of the victim, height of fall, length of hospital stay, toxicological results, the existence and location of injuries and Injury Severity Score (ISS). Victims of suicidal falls were younger (55.53 vs. 62.98, p = 0.001), they fell from higher heights (12.35 vs. 5.18 m, p < 0.001), and they sustained more severe injuries compared with victims of accidental falls (ISS 51.01 vs. 40.88, p < 0.001). Injuries in the thorax, abdomen, pelvis, upper and lower extremities were more frequently observed after a suicidal fall (93.6% vs. 67.3%, 72.1% vs. 21.4%, 72.1% vs. 27.6%, 42.9% vs. 15.3%, 45.7% vs. 13.3%, respectively-p < 0.001), probably due to the higher height of fall. Our study outlines the differences in the profile of the victims and in the severity of injuries caused by falls from height depending on the intention of the victim to fall. However, a distinctive injury pattern in victims of suicidal falls was not demonstrated.
Assuntos
Ideação Suicida , Ferimentos e Lesões , Humanos , Autopsia , Estudos Retrospectivos , Escala de Gravidade do FerimentoRESUMO
This study described the regional distribution of layer-specific residual deformations in fifteen human aortas collected during autopsy. Circumferentially and axially cut strips of standardized dimensions from the anterior quadrant of nine consecutive aortic levels were photographed to obtain the zero-stress state for the intact wall. The strips were then dissected into layers that were also photographed to obtain their zero-stress state. Changes in layer-specific opening angle, residual stretches, and thickness at each aortic level and direction were determined via image analysis. The circumferential and axial opening angles of the intima were â¼240 deg and â¼30 deg, respectively, throughout the aorta; those of the adventitia were â¼150 deg and -20 deg to 70 deg. The opening angles of the intact wall and media were similar in either direction. The circumferential residual stretches of the intima and the axial residual stretches of the media showed high values in the aortic arch, decreasing in the descending thoracic aorta and increasing toward the iliac artery bifurcation, while the axial residual stretches of the adventitia increased distally. The remaining residual stretches did not vary significantly with aortic level, suggesting an intimal role in determining circumferential, as well as medial and adventitial roles in determining axial residual stretches. We conclude that the tensile residual stretches released in the intima and media upon separation, and the compressive residual stretches released in the adventitia may moderate the inverse transmural stress gradients under physiologic loads, resulting from the >180 deg circumferential opening angle of the intact wall.
Assuntos
Aorta , HumanosRESUMO
Our understanding of aortic biomechanics is customarily limited by lack of information on the axial residual stretches of the vessel in both humans and experimental animals that would facilitate the identification of its actual zero-stress state. The aim of this study was thus to acquire hitherto unreported quantitative knowledge of axial opening angle and residual stretches in different segments and quadrants of the human aorta according to age and gender. Twenty-three aortas were harvested during autopsy from the aortic root to the iliac bifurcation and were divided into ≥12 segments and 4 quadrants. Morphometric measurements were taken in the excised/curled configuration of rectangular strips considered to be under zero-stress using image-analysis software to study the axial/circumferential variation of axial opening angle, internal/external residual stretch, and thickness of the aortic wall. The measured data demonstrated: (1) an axial opening angle peak at the arch branches, decreasing toward the ascending and to a near-constant value in the descending thoracic aorta, and increasing in the abdominal aorta; (2) the variation of residual stretches resembled that of opening angle, but axial differences in external residual stretch were more prominent; (3) wall thickness showed a progressive diminution along the vessel; (4) the highest opening angle/residual stretches were found in the inner quadrant and the lowest in the outer quadrant; (5) the anterior was the thinnest quadrant throughout the aorta; (6) age caused thickening but greatly reduced axial opening angle/residual stretches, without differences between males and females.
Assuntos
Aorta Abdominal , Estresse Mecânico , Fenômenos Biomecânicos , Feminino , Humanos , MasculinoRESUMO
Sudden cardiac death is, by definition, an unexpected, untimely death caused by a cardiac condition in a person with known or unknown heart disease. This major international public health problem accounts for approximately 15-20% of all deaths. Typically more common in older adults with acquired heart disease, SCD also can occur in the young where the cause is more likely to be a genetically transmitted process. As these inherited disease processes can affect multiple family members, it is critical that these deaths are appropriately and thoroughly investigated. Across the United States, SCD cases in those less than 40 years of age will often fall under medical examiner/coroner jurisdiction resulting in scene investigation, review of available medical records and a complete autopsy including toxicological and histological studies. To date, there have not been consistent or uniform guidelines for cardiac examination in these cases. In addition, many medical examiner/coroner offices are understaffed and/or underfunded, both of which may hamper specialized examinations or studies (e.g., molecular testing). Use of such guidelines by pathologists in cases of SCD in decedents aged 1-39 years of age could result in life-saving medical intervention for other family members. These recommendations also may provide support for underfunded offices to argue for the significance of this specialized testing. As cardiac examinations in the setting of SCD in the young fall under ME/C jurisdiction, this consensus paper has been developed with members of the Society of Cardiovascular Pathology working with cardiovascular pathology-trained, practicing forensic pathologists.
Assuntos
Cardiopatias , Patologistas , Humanos , Idoso , Adulto , Lactente , Pré-Escolar , Criança , Adolescente , Adulto Jovem , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/patologia , Cardiopatias/complicações , Autopsia/métodos , CoraçãoRESUMO
Aortic dissection is a life-threatening event, during which a primary tear propagates along the aorta causing catastrophic delamination of the inner (intima with most of the media) from the outer layers (leftover media with adventitia). Our understanding of mode-I fracture resistance at different aortic regions is incomplete, although the anatomical localization of the dissection channel may be assigned to this factor. To determine whether the susceptibility to dissection propagation varied with aortic region, the average and standard deviation of peel tension (indices of adhesive strength between layers when pulled apart and its fluctuation) were measured in 24 cadaveric subjects. Measurements were made in the inner and outer quadrants of 9 consecutive regions. Strong regional heterogeneity was established that was age-related based on the following evidence: (1) the average and standard deviation of peel tension peaked in the ascending aorta, decreasing to almost constant values in the descending thoracic aorta, but increasing across the abdominal aorta; (2) axial differences were more pronounced in the inner quadrant, with differences among quadrants reaching significance proximally; (3) the average peel tension was greatly impaired from <40 to 40-60 but much less to >60-year-old subjects at most regions/quadrants, leading to non-uniform axial variations in all age groups; (4) gender affected little the data. This comprehensive series of delamination tests explains the clinical observation of most dissections initiating in the ascending aorta to extend distally and of few dissections initiating in the descending thoracic aorta to extend proximally, while supporting the increased vulnerability in aged subjects.
Assuntos
Aneurisma da Aorta Torácica , Dissecção Aórtica , Túnica Adventícia , Idoso , Aorta Abdominal , Aorta Torácica , Humanos , Pessoa de Meia-IdadeRESUMO
Blunt head injury is a major public health and socioeconomic problem causing death and disability particularly among the young population throughout the world. The purpose of the present study was to evaluate if the impact site is correlated with the subdural and epidural hematoma occurrence. A retrospective analysis of consecutive autopsy cases submitted to our Department during a 5-year period was performed. The basic criterion for inclusion in the study was death due to blunt head injury. The recorded variables included the circumstances of death, the existence, and location of head injuries, the primary impact site, age, gender, and toxicological results. A total number of 683 fatal head injury cases was recorded, with most of them being male (74.1%). In 424 cases (62.1%) fatal head injuries were due to road traffic accidents. Fall (from height or on the ground) was the cause of death in 220 (32.2%) cases followed by inflicted impact-assault in 26 (3.8%) cases. A subdural hematoma was found more frequently (26.9%) than epidural (5.0%). Epidural hematomas were found only under the primary impact site, whereas subdural hematomas were coup, contrecoup, or bilateral. An epidural hematoma was found to be almost 5 times more frequent in cases in which a subdural hematoma was present. A higher proportion of subdural, as well as epidural hematoma, was found when the site of impact was the temporal region, followed by the parietal one. Sex did not exert any influence on the probability of subdural and epidural hematoma, whereas for age, a 10% increase in the probability of subdural hematoma occurrence was observed with 10-year age increase.
Assuntos
Traumatismos Cranianos Fechados , Hematoma Epidural Craniano , Autopsia , Hematoma Epidural Craniano/epidemiologia , Humanos , Masculino , Estudos Retrospectivos , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Smoking has long been considered part of prison culture and studies have shown a high prevalence of smoking within correctional facilities. METHODS: A self-administered, anonymous questionnaire was administered to 173 male prisoners in the Chalkida prison, Greece. To assess current smoking habits, a hierarchical approach was adopted. The underlying conceptual framework included: (i) demographic parameters, (ii) adverse childhood history (physical abuse, parental neglect, parental divorce, alcoholism in the family, sexual abuse and psychiatric condition in the family), (iii) education, personality traits, such as impulsivity (Barrat Impulsivity Scale-11), aggression (Buss-Perry Aggression Questionnaire and Lifetime History of Aggression), and personal history of mental disease, (iv) prison-related features (duration of sentence, sentence already served and change in smoking habits during imprisonment). RESULTS: Eighty percentage of the study sample reported current smoking; 43.4% disclosed deterioration in their smoking habits during imprisonment. The hierarchical approach pointed to: (i) adverse childhood events, i.e. alcoholism in the family [adjusted odds ratio (OR) = 6.29, 95% confidence interval (CI): 2.44-16.25], psychiatric condition in the family (adjusted OR = 4.10, 95% CI: 1.31-12.84), physical abuse (adjusted OR = 2.90, 95% CI: 1.30-6.46), parental neglect (adjusted OR = 2.66, 95% CI: 1.19-5.95), parental divorce (adjusted OR = 2.14, 95% CI: 1.00-4.56), and (ii) impulsivity (adjusted OR = 2.26, 95% CI: 1.12-4.58) as independent risk factors. In addition, deterioration of smoking habits during imprisonment exerted an effect of borderline significance (adjusted OR = 2.02, 95% CI: 0.97-4.24). CONCLUSIONS: Heavy smoking in prison principally integrates two components: unfavourable childhood and current personality traits (impulsivity).
Assuntos
Acontecimentos que Mudam a Vida , Prisioneiros/psicologia , Fumar/psicologia , Adulto , Criança , Abuso Sexual na Infância/psicologia , Estudos Transversais , Relações Familiares , Grécia , Comportamentos Relacionados com a Saúde , Humanos , Modelos Logísticos , Masculino , Razão de Chances , Determinação da Personalidade , Prisioneiros/estatística & dados numéricos , Fatores de Risco , Assunção de Riscos , Fumar/epidemiologia , Abandono do Hábito de Fumar/estatística & dados numéricos , Meio Social , Inquéritos e QuestionáriosRESUMO
Self-immolation is a rare suicide method in the developed countries of the western world (0.06-1%); however, it has relatively higher prevalence rates in the developing countries of Asia and Africa (6-57%). The present study aims to examine self-immolation suicides within the Greek mainland (Attiki, Thrace, and Peloponnese) over a period of 9 years (2011-2019) in order to investigate the phenomenon in the Greek population forensically, identify the characteristics and motivations of suicide victims, explore its associations to socio-cultural or psychiatric factors, and describe a fatal case of suicide by self-immolation that was partially recorded on camera. The medical files (autopsy reports) of cases performed at the Departments of Forensic Medicine of the National and Kapodistrian University of Athens, Democritus University of Thrace, and the Forensic Service of Messinia-Peloponnese were retrospectively examined yielding 19 cases of suicides by self-immolation. A 3.7% prevalence of suicide by self-immolation among suicide fatalities within the Greek population was estimated. A distinctive feature of the Greek population regarding self-immolation was disclosed that it is being practiced predominantly by the elderly (mean age 2-3.5 decades higher than other countries). The phenomenon correlated strongly with poorly controlled mental disorders (mostly affective and adjustment disorders). Unlike other countries, there was no significant association with domestic or sexual violence, social or political protest, or religious issues. Therefore, the suicide victims preferred secluded or private outdoor locations (not public). Findings deriving from the examined variables localize Greek population culturally between the Western European and Asian African countries, but with its own idiosyncrasies.
Assuntos
Incêndios , Suicídio Consumado , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Carboxihemoglobina/análise , Feminino , Psiquiatria Legal , Grécia/epidemiologia , Humanos , Masculino , Transtornos Mentais/epidemiologia , Pessoa de Meia-Idade , Motivação , Estudos Retrospectivos , Distribuição por Sexo , Suicídio Consumado/psicologia , Suicídio Consumado/estatística & dados numéricos , Adulto JovemRESUMO
Symptoms from the genitourinary system are unusual in Kawasaki disease (KD). Renal involvement is even rarer and it is confirmed by biopsy when the person is alive. We describe the case of an 11-year-old boy admitted to the hospital complaining about prolonged fever (5 days) and hematuria. His urinalysis showed also pyuria, proteinuria and urinary renal tubular epithelial cells concentrations. During the next days, the patient presented limb edema. After almost 2 weeks of hospitalization the patient was transferred to the intensive care unit because of melena and intense abdominal pain. Upon admission, the patient collapsed and died. The diagnosis of KD was established during autopsy. The macroscopical and histopathological examination of the heart showed increased dimensions and weight and multiple thrombi in the coronary arteries with intramural dense polymorphonuclear inflammatory infiltration and necrosis. Histological examination of the kidneys revealed normal glomerulus, mild expansion of mesangial matrix, interstitial infiltration with lymphocytes, plasmatocytes and eosinophiles, normal vessels and normal immunofluorescence.
Assuntos
Febre de Causa Desconhecida/diagnóstico , Síndrome de Linfonodos Mucocutâneos/patologia , Sistema Urogenital/patologia , Criança , Hematúria , Humanos , MasculinoRESUMO
Sexual abuse includes any activity with a child, before the age of legal consent, that is for the sexual gratification of an adult or a significantly older child. Sexual mistreatment of children by family members (incest) and nonrelatives known to the child is the most common type of sexual abuse. Intrafamiliar sexual abuse is difficult to document and manage, because the child must be protected from additional abuse and coercion not to reveal or to deny the abuse, while attempts are made to preserve the family unit. The role of a comprehensive forensic medical examination is of major importance in the full investigation of such cases and the building of an effective prosecution in the court. The protection of the sexually abused child from any additional emotional trauma during the physical examination is of great importance. A brief assessment of the developmental, behavioral, mental and emotional status should also be obtained. The physical examination includes inspection of the whole body with special attention to the mouth, breasts, genitals, perineal region, buttocks and anus. The next concern for the doctor is the collection of biologic evidence, provided that the alleged sexual abuse has occurred within the last 72 hours. Cultures and serologic tests for sexually transmitted diseases are decided by the doctor according to the special circumstances of each case. Pregnancy test should also be performed in each case of a girl in reproductive age.
Assuntos
Abuso Sexual na Infância/diagnóstico , Criança , Feminino , Medicina Legal , Humanos , Masculino , Anamnese , Exame FísicoRESUMO
Driving under the influence of alcohol and/or psychoactive substances increases the risk of severe, even fatal motor vehicle accidents. The aim of this descriptive study was to present the impact of alcohol and/or psychoactive substances on fatal road traffic accidents (RTAs) during the period 2011-2017. For this purpose, the toxicological investigation reports from the Department of Forensic Medicine and Toxicology of the University of Athens were used. In total, 1,841 (32.2%) of the autopsies conducted by the Department of Forensic Medicine and Toxicology of the National and Kapodistrian University of Athens over a 7-year period (2011-2017) were victims of fatal RTAs. Blood and urine samples were collected and analyzed for the presence of alcohol and psychoactive substances. The results were classified according to sex, age, victim (car driver, motorcyclist, pedestrian, or passenger) and the date the accident occurred (day, month and year). In total, 40.7% of the RTA-related fatalities were associated with alcohol consumption, among which 20.3% were car drivers. Of these, 87.3% were male victims. A higher frequency of RTA-related fatalities associated with a blood alcohol concentration (BAC) >110 mg/dl was encountered in younger compared with older age groups. Psychoactive substances were detected in 348 (18.9%) of the victims (cannabis in 46.6% of these, benzodiazepines in 25.9%, opiates in 16.4% and cocaine in 11.1% of these). The percentage of the RTA-related victims that had consumed alcohol in combination with other psychoactive substances was 4.5%. On the whole, the findings of this study suggest that alcohol and psychoactive substances are probably risk factors for RTA-related fatalities.
RESUMO
PURPOSE: To investigate the particular features of students who express the desire to follow a forensic career. METHODS AND MATERIALS: Three hundred and four 6th-year students attending the compulsory practice in forensic medicine in the academic year 2005-2006 were asked to fill in a self-administered questionnaire at the end of the course. RESULTS: The predominant motivation for following forensics was the scientific interest (39.7%). Gender, marital status, religion, place of residence, number of siblings, father/mother being a health professional, being a religious individual were not associated with forensics. Higher grades were a negative predictor for the forensic specialty. A trend linking rejection of an afterlife and orientation towards forensic medicine was found. The fear of death was more intense in students rejecting forensics. Feelings of fear, aversion and grief during the last day of autopsy seemed to be important negative predictors. Stereotypes about forensic doctors (such as "forensic doctors have a peculiar character") significantly modified the decision of students, but the beliefs about the role of the autopsy practice (cause of anxiety for death, stimulus to live every moment in life) did not. CONCLUSION: Medical students who want to follow forensics present only small differences concerning their inherent features, beliefs, reactions, emotions and attitudes, compared with the rest of their fellow students.
Assuntos
Atitude do Pessoal de Saúde , Autopsia , Escolha da Profissão , Medicina Legal , Medicina , Motivação , Especialização , Distribuição de Qui-Quadrado , Feminino , Humanos , Masculino , Estatísticas não Paramétricas , Inquéritos e QuestionáriosRESUMO
Respect for confidentiality is firmly established in codes of ethics and law. Medical care and the patients' trust depend on the ability of the doctors to maintain confidentiality. Without a guarantee of confidentiality, many patients would want to avoid seeking medical assistance The principle of confidentiality, however, is not absolute and may be overridden by public interests. On some occasions (birth, death, infectious disease) there is a legal obligation on the part of the doctor to disclose but only to the appropriate authorities. Permissible disclosure can be granted by the patients' consent, for example, for the purpose of insurance they may wish to take out. Moreover, there are some ambivalent situations (such as criminal acts, or notification of sexual partner in case of a patient with AIDS) for which Greek law does not include relevant provisions, and the Codes of Medical Ethics do not offer clear guidelines. Therefore, the Greek doctor is called to estimate the situation and assume full responsibility for his decision. Finally, new considerations have arisen in the context of the recent advances in the field of telemedicine and electronic archiving. The paper discusses the current situation and legislation in Greece.
Assuntos
Confidencialidade/ética , Confidencialidade/legislação & jurisprudência , Notificação de Abuso , Papel do Médico , Temas Bioéticos , Ética Médica , Grécia , Humanos , Direitos do PacienteRESUMO
The ureters are retroperitoneal structures controlling urine transport from the kidneys to the bladder. Because of the relative scarcity of data on the biomechanical properties of human ureter and the established importance of knowing these properties for understanding its physiology, we initiated biomechanical studies in cadaveric tissue. Herein, we report definite zero-stress/no-load geometrical characterization at 15 regions along the ureter of human cadavers aged 23-82 years, estimating the opening angle, circumferential residual strains, axial curvature, and dimensional parameters. Opening angle decreased along the proximal 25% of ureter, increased and reached a maximum near the mid-ureter, and then gradually decreased toward the vesicoureteral junction (young: p < 0.05; middle-aged: p < 0.05; old: p > 0.05; males: p < 0.05; females: p < 0.05). Similar were the regional distributions of residual strain at the interface between epithelium-lamina propria and muscle and of internal but not external residual strain. Wall thickness increased steadily with aging ( p < 0.05 at few regions), while ureteral circumference did not ( p > 0.05 at most regions) and opening angle decreased ( p < 0.05 at several regions). Consistent with Fung's stress-growth law, the muscle layer thickened with age unlike the epithelium-lamina propria that thinned ( p < 0.05 at most regions for both thicknesses). Moderate-to-strong direct correlations of residual strain difference (= external - internal) with opening angle, wall thickness, and curvature were found in most ureters. The presented data will provide insight into the biomechanical response of ureter under zero/low-stress conditions and the relationship between ureteral remodeling and aging. Importantly, they may also be used to inform finite element models and computational studies simulating the ureter.
Assuntos
Envelhecimento/fisiologia , Estresse Mecânico , Ureter/anatomia & histologia , Ureter/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Urina , Adulto JovemRESUMO
BACKGROUND: Previous studies have not examined the participation of intimal, medial, and adventitial layers in providing mechanical strength to the ascending thoracic aortic aneurysm (ATAA) wall compared with the nonaneurysmal aorta. In this study we compared the mechanical properties of intact wall and its layers among ATAAs and nonaneurysmal aortas, with explicit consideration of the effects of valve morphology; that is, bicuspid aortic valve (BAV) versus tricuspid aortic valve (TAV), and aortic quadrant. METHODS: Whole ATAAs were taken from patients undergoing elective repair and nonaneurysmal aortas from age-matched autopsy subjects. These were cut into 2 circumferential and longitudinal tissue strips for the intact wall and its layers per quadrant, permitting examination of the aortic wall as a multilayered structure. Tissue underwent tensile testing for determination of failure properties. RESULTS: Intact wall and layer-specific failure stretches (ie, extensibilities) were significantly greater in nonaneurysmal and BAV-ATAA than in TAV-ATAA, unaccounted for by elastin/collagen content changes. Intact wall failure stress (ie, strength) was significantly greater in BAV-ATAA than in TAV-ATAA, in analogy with medial failure stress. Failure stress and stretch associated negatively with age in most subject groups, layers, and intact wall, but failure stretch correlated positively with residual stretch (ie, structural bonds between layers). CONCLUSIONS: No mechanical vulnerability of BAV-ATAA was found, corroborating current conservative guidelines regarding the management of bicuspid aortopathy. Weakening and added vulnerability was found in patients with valvular deficiency, aortic root aneurysm, hypertension, and hyperlipidemia. Aging led to increased susceptibility to dissection initiation or full rupture, or both, in both patient classes.
Assuntos
Aorta/fisiopatologia , Aneurisma da Aorta Torácica/fisiopatologia , Valva Aórtica/anormalidades , Doenças das Valvas Cardíacas/fisiopatologia , Valva Tricúspide/fisiopatologia , Valva Aórtica/fisiopatologia , Doença da Válvula Aórtica Bicúspide , Fenômenos Biomecânicos , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The ureter has been largely overlooked heretofore in the study of the biomechanics of soft biological tissues, although there has been significant motivation to use its biomechanical properties as inputs to mathematical models of ureteral function. Herein, we used histological analysis for quantification of collagen contents and thickness/area of ureteral layers, with concomitant geometrical analysis of zero-stress and no-load states, and inflation/extension testing to biomechanically characterize with the Fung-type model the ureters from cadavers. The effects of age and gender on the regional distribution of those properties were examined. Tissue properties did not differ (p>0.05) between the left and right ureter. Regional heterogeneity was established that was profoundly age-related but seldom gender-related, based on the following evidence: 1) In younger subjects, the axial stress-circumferential strain curves of upper ureter were shifted to smaller stresses and model parameter a2 representing axial stiffness was smallest (p<0.05), i.e. upper ureter was the least stiff region axially; 2) upper ureter underwent axial stiffening with advanced age, evidenced by the increasing (p<0.05) parameter a2, and the stress-strain curves were uniformly exhibited along the ureter, evidenced by the non-varying (p>0.05) parameters C,a1,a2,anda4; 3) aging raised (p<0.05) the collagen content of upper ureter to favor a near-uniform regional distribution; 4) wall thickness increased with age, unlike the opening angle and residual strains, reflecting the thickening of outer (muscular) vs. inner (mucosal) layers in aged subjects, with significant differences (p<0.05) in some regions; and 5) gender affected little (p>0.05) the opening angle and morphometry of no-load and zero-stress states.
Assuntos
Envelhecimento/fisiologia , Ureter/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Fenômenos Biomecânicos , Colágeno/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Estresse Mecânico , Ureter/anatomia & histologia , Ureter/metabolismoRESUMO
The biomechanical response of the human aorta varies with axial location, but little is known about the respective variation of residual strains. Such data are available for common lab animals, but in the traditional opening angle measurement the aorta is considered as an ideal cylinder and average residual strains are measured, so that the spatial variations of local residual strains are not determined. The present study provides opening angle and residual strain data throughout the course and around the circumference of the aorta harvested during autopsy. Opening angle showed notable topographical variation; the highest value was at the top of aortic arch, declining abruptly toward the ascending aorta and to a near-constant value in the descending aorta, and rising in the abdominal aorta. The variation of curvature and of external but not internal residual stretch resembled that of opening angle. Extensive residual stress and wall thickness differences were evidenced among quadrants, with the more pre-stressed being also the thicker quadrants. Gender had overall minor effects, but aging led to increased parameters, occurring earlier in the distal aorta but at later stages becoming predominant proximally. Differences in caliber were pronounced in older subjects, unlike those in opening angle, residual stretches, and thickness that were striking in middle-aged subjects. By contrast, curvature decreased with aging in relation to the smaller percentwise opening angle differences. Detailed knowledge of the zero-stress/no-load geometry of the human aortic wall is critical for an in-depth understanding of aortic physiology, while providing the basis for comparison with disease.
Assuntos
Fatores Etários , Aorta/fisiologia , Fatores Sexuais , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Aorta Abdominal , Aorta Torácica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Mecânico , Adulto JovemRESUMO
BACKGROUND: Aortic root aneurysms are relatively uncommon but their rupture is a detrimental event with acute hemodynamic compromise and high mortality, and there are few available data on their mechanical properties, although aneurysm rupture occurs when hemodynamic stresses exceed wall strength. This study aimed to fill this gap by examining the effect of aneurysm on the mechanical and structural properties of aortic sinuses. METHODS: Sinus tissue was procured from 16 aneurysmal patients during surgical repair and from 18 age-matched nonaneurysmal autopsy subjects, and grouped by age (young versus old), region (left versus right versus noncoronary), and direction (circumferential versus longitudinal). The tissue was submitted to histologic evaluation of elastin/collagen contents and to mechanical testing beyond rupture for the determination of failure properties and material characterization by the Fung-type model. RESULTS: Contrasting the direction-dependent (anisotropic) material constants and failure properties, and the primarily circumferential reinforcement of elastin/collagen fibers in healthy sinuses, near-similar (isotropic) properties and arbitrarily aligned fibers were found in the aneurysmal right and left coronary sinuses, together with less anisotropic properties in the aneurysmal noncoronary sinus. Variations between aneurysmal and healthy sinuses were comparable in young and old subjects. The former displayed significantly higher failure stress, failure stretch, and peak elastic modulus, justified by their increased elastin/collagen contents. CONCLUSIONS: We submit evidence of more isotropic histomechanical properties in the aneurysmal sinuses that seem consistent with the more axisymmetric stresses exerted on them owing to their more spherical shape, compared with the nondilated healthy sinuses that presented marked anisotropic properties.
Assuntos
Aneurisma da Aorta Torácica/fisiopatologia , Seio Aórtico/patologia , Seio Aórtico/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Aneurisma da Aorta Torácica/patologia , Aneurisma da Aorta Torácica/cirurgia , Fenômenos Biomecânicos , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Mecânico , Adulto JovemRESUMO
The surgeon may face in every day practice issues that may render him liable. The legal liability usually emerges due to the negligence exhibited during the preoperative, the operative and the postoperative stage. The surgeon, as any doctor, isn't liable for the result, but he is responsible for the correct diagnosis and therapeutic treatment, always according to the principles of the Medical science and to the possibilities available to him in every specific case (facilities and time). The continuous education about the issues of his speciality, the adaptation of scientifically approved techniques, the correct monitoring of the patient, both preoperatively and postoperatively, and finally the good communication with the patient are necessary for the proper practice of Medicine; but also constitute the "shield" of the surgeon against any possible legal conflict.