Due to their anatomical location, occipital condylar fractures (OCFs) are usually not observed during traditional autopsies and are therefore considered a rare injury. The aim of this study was to determine the true frequency of OCFs using post-mortem computed tomography (PMCT) in traumatic casualties. We retrospectively analyzed 438 PMCT studies of victims of traffic accidents, falls from height, violence, and low-energy head injuries (324 males and 114 females). OCFs were present in 22.6% of cases ( n = 99), mostly in victims of railway accidents (48.5%, n = 17), falls from height (26.6%, n = 29), cyclists (24%, n = 6), and pedestrians hit by cars (22.5%, n = 29). Isolated OCFs were found in 5.5% of cases ( n = 24), most often in cyclists (12%, n = 3) and pedestrians (9.3%, n = 12) hit by cars. There were no OCFs in the cases of fatalities caused by violence or accidental low-energy head injury. PMCT scans revealed that OCFs are common in high-energy injury fatalities and can be useful for determining the mechanism of trauma more precisely.

Background Intracranial arterial dissections might be attributed to the particular biomechanical properties of their specific layers. Also, knowledge of adventitia properties would be crucial in the context of intracranial balloon angioplasty. Aims The purpose of this work was to determine the rupture pressure of separated adventitia and compare it to intact cerebral arterial segments. Methods Brain specimens were harvested from 14 autopsy subjects (age range from 23 to 86 years). Pressure-inflation tests were conducted on proximal segments of middle cerebral arteries and separated adventitia layers from contralateral arteries to assess the rupture pressure values. Results The averaged rupture pressure of adventitia layers was 1.41 SD 0.25 atm (1072 SD 190 mmHg), whereas for intact arterial segments it was 2.32 SD 0.70 atm (1763 SD 532 mmHg) and diminished with age according to nonlinear regression trends. The difference beetween the aformentioned rupture pressures was positively correlated with rupture pressure of intact arterial segments ( R= 0.88; p < 0.001). Conclusions The obtained experimental results indicate a leading role of adventitia in building arterial strength under supraphysiological pressure conditions. The greater the rupture pressure of complete cerebral arteries, the smaller the contribution of adventitia in overall wall resistance.

Spontaneous intracranial haemorrhage is one of the most dramatic neurological disasters. The source of haemorrhage is linked to the pathology of the arterial wall or is unknown. Because the risk of haemorrhagic stroke increases with age, we tried to investigate the relationship between age and rupture pressure of cerebral arteries. In the presented study, 51 segments of large cerebral arteries (at the level of the circle of Willis and its incoming and outgoing branches) were obtained from 33 cadaver brains aged 12-86 years. The segments were pressurized up to the rupture. The rupture pressure was noted. The highest observed pressure was 4.3atm in specimen aged 24 years. The lowest pressure 1.19atm was observed in specimen aged 80 years. The mean value of rupture pressure of all investigated segments was 2.28atm. Statistical analysis showed a nonlinear exponential decrease of the rupture pressure of the large cerebral arteries with age. The main conclusion from our study is that drop of cerebral arteries strength is observed to the age of 40. Later this lowering is visible but not so evident.

VAMCS should be considered as the cause of neurological deficits when other pathological entities are ruled out. In symptomatic conflict of the VA with the medulla, microvascular decompression using a Gore-Tex implant can be an effective method of treatment. Nevertheless, a statistical analysis on all reported cases showed favorable results using the VA repositioning technique when compared with MVD (success rate 91% vs. 58%, p<0.05).

Aim of the study. To determine the morphological features distinguishing small unruptured saccular intracranial aneurysms (sIAs) with high and low wall strength (WS) in post mortem subjects.Clinical rationale for the study: Subarachnoid haemorrhage caused by sIA rupture is associated with increased mortality and morbidity. Analysis of the morphology and biomechanical properties of sIAs might facilitate the identification of clinically relevant risk factors for sIA rupture. Material and methods.Eight single unruptured sIAs were found among eight subjects during 184 post mortem examinations. After assessment of the dimensions, aspect ratio (AR), size ratio (SR), height/width ratio (HW), bottleneck factor (BNF), and shape, sIAs with adjacent cerebral arteries were subjected to quasi-static increasing pressure until the wall of the cerebral artery or sIA ruptured. Results.In three specimens, the sIA ruptured at a significantly lower average pressure than the other cases, in which the rupture occurred within the wall of the adjacent cerebral artery (769 vs. 1,259 mmHg; p = 0.035). The sIAs with low WS, i.e. sIAs that ruptured during experiments, were characterised by significantly increased dome dimensions compared to sIAs with high WS (p < 0.05). At the same time, no significant differences were observed between high and low WS categories regarding AR, SR, HW, and BNF, or the presence of an irregular dome shape.Conclusions and clinical implications. Dome dimension was the only feature that distinguished unruptured sIAs as having low or high WS, and this supports observations that sIAs with increased dome dimensions are characterised by an increased risk of rupture. Thus, dome dimension may be more useful than other morphometric parameters, such as AR, SR, HW and BNF, in assessing the rupture risk assessment of small unruptured sIAs.

Arterial walls are a multilayer structures with nonlinear material characteristics. Furthermore, residual stresses exist in unloaded state (zero-pressure condition) and they affect arterial behavior. To investigate these phenomena a number of theoretical and numerical studies were performed, however no experimental validation was proposed and realized yet. We cannot get rid of residual stresses without damaging the arterial segment. In this paper we propose a novel experiment to validate a numerical model of artery with residual stresses. The inspiration for our study originates from experiments made by Dobrin on dogs’ arteries (1999). We applied the idea of turning the artery inside out. After such an operation the sequence of layer is reversed and the residual stresses are re-ordered. We performed several pressure-inflation tests on human Common Carotid Arteries (CCA) in normal and inverted configurations. The nonlinear responses of arterial behavior were obtained and compared to the numerical model. Computer simulations were carried out using the commercial software which applied the finite element method (FEM). Then, these results were discussed.

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Introduction: Saccular intracranial aneurysm (sIA) rupture is a serious cerebrovascular event associated with inflammatory destructive processes leading to gradual weakening of the sIA wall. The aim of the present study was to identify the morphological and histological determinants for low wall strength in unruptured sIAs harvested from autopsy subjects. Material and methods: A total of eight single unruptured sIAs were identified and excised with adjacent cerebral arteries during 8 of 184 postmortem examinations. The dome morphology was assessed for each sIA at a constant pressure of 100 mmHg. Then, after 5 preconditioning cycles which assured muscle fibre relaxation, sIA specimens were subjected to gradually increasing intraluminal pressure at a rate of 20 mmHg/s until rupture of the sIA or cerebral artery was achieved. Micro-structural degenerative changes and inflammatory cell infiltration within the sIA wall were quantitatively analysed after pressurization of the sIA specimens. The microscopic analysis of the slides stained with histological methods (HE, Mallory trichrome, Masson trichrome, orcein) and immunohistochemical methods (LCA, CD3, CD68) was performed. Results: The wall of the sIA ruptured in three specimens, while in the other cases, rupture occurred at the arterial wall. The mean maximal dome size was significantly larger in sIAs with low wall strength, that is, in sIAs that ruptured during pressurization, than in sIAs with high wall strength (6.46 mm vs. 2.43 mm, p = 0.034). Moreover, a significantly higher average percentage of wall hyalinization in sIAs that ruptured than in sIAs that did not rupture was observed (30% vs. 0%, p = 0.006). In contrast, the degree of inflammatory cell infiltration did not differ between the wall strength categories. Conclusions: Our results support the observations that larger sIAs may be at a higher risk of rupture. Histological analysis revealed that hyalinization corresponds to the weakened regions of the wall of unruptured sIAs.