Ultrastructural Features of the Aortic Wall in a Patient with Kommerell Diverticulum.

We report on the ultrastructural features of the aortic wall in a patient with Kommerell diverticulum. A 70-year-old woman with a right aortic arch, aberrant left subclavian artery, and Kommerell diverticulum underwent a successful total arch replacement plus the frozen elephant trunk procedure with anatomical left subclavian artery reconstruction. Small pieces of the ascending aorta, distal arch, right common carotid artery, and left subclavian artery were investigated ultrastructurally. In the ascending aortic wall, multiple cystic cavities were observed in the subintimal region of the media by scanning electron microscopy. Changes in organelles, including mild dilation of rough-surfaced endoplasmic reticulum and mitochondrial swelling and degrading, were also observed in all specimens by transmission electron microscopy. These ultrastructural features may indicate the fragility or stress of the aortic wall and are useful when considering the early surgical intervention of a patient with Kommerell diverticulum.

Long term follow-up of the endovascular trans-vessel wall technique for parenchymal access in rabbit with full clinical integration.

OBJECTIVE: Endovascular techniques are providing options to surgical/percutaneous cell transplantation methods. Some cells, e.g. insulin producing cells, are not suitable for intra-luminal transplantation and for such cells, other options must be found. We have constructed a "nanocatheter" with a penetrating tip for vessel perforation, thereby creating a working channel for parenchymal access by endovascular technique. To finish the procedure safely, the distal tip is detached to provide a securing plug in the vessel wall defect. MATERIALS AND METHODS: We have performed interventions with full clinical integration in the superior mesenteric artery (SMA), the subclavian artery and the external carotid artery in rabbits. No hemorrhagic- or thromboembolic events occurred during the procedure. Stenosis formation and distal embolisation were analyzed by angiography and macroscopic inspection during autopsy at five, 30 and 80 days. All animals and implanted devices were also evaluated by micro-dissections and histochemical analysis. RESULTS: In this study we show safety data on the trans-vessel wall technique by behavioral, angiographical and histological analysis. No stenosis formation was observed at any of the follow-up time points. No animals or organs have shown any signs of distress due to the intervention. Histological examination showed no signs of hemorrhage, excellent biocompatibility with no inflammation and a very limited fibrous capsule formation around the device, comparable to titanium implants. Further, no histological changes were detected in the endothelia of the vessels subject to intervention. CONCLUSIONS: The trans-vessel wall technique can be applied for e.g. cell transplantations, local substance administration and tissue sampling with low risk for complications during the procedure and low risk for hemorrhage, stenosis development or adverse tissue reactions with an 80 days follow-up time. The benefit should be greatest in organs that are difficult or risky to reach with surgical techniques, such as the pancreas, the CNS and the heart.

Espessamento médio-intimal na origem da artéria subclávia direita como marcador precoce de risco cardiovascular / Intima-media thickness in the origin of right subclavian artery as an early marker of cardiovascular risk

OBJETIVO: O espessamento médio-intimal (EMI) na artéria carótida comum é considerado fator de risco cardiovascular e marcador de doença arterial coronariana precoce. O objetivo deste trabalho foi investigar a existência de correlação entre o EMI nas artérias carótidas e na origem da artéria subclávia direita, e avaliar o EMI na artéria subclávia como um marcador mais precoce para avaliação de risco cardiovascular. MÉTODOS: Cento e seis pacientes consecutivos, 52 homens e 54 mulheres, com média de idade de 51 anos, foram submetidos à avaliação das artérias carótidas e subclávia direita pela ultra-sonografia vascular com Doppler colorido. Para avaliar a associação entre EMI das artérias carótidas e subclávia direita calcularam-se o coeficiente de correlação de Pearson e o intervalo de 95 por cento de confiança para esse coeficiente. A qualidade da medida do EMI da artéria subclávia direita para diagnóstico de espessamento precoce, considerando-se o espessamento da carótida como padrão de referência (> 0,8 mm), foi descrita por valores de sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo e acurácia. Pontos de corte para o EMI da artéria subclávia foram sugeridos pela Curva ROC. Valores de p < 0,05 foram considerados estatisticamente significantes. RESULTADOS: Na associação entre 41 artérias carótidas sem EMI, 30 (73 por cento) artérias subclávias direitas apresentavam EMI > 0,8 mm. O valor médio de EMI obtido na artéria carótida foi de 0,87 mm (DP = 0,23) e na artéria subclávia direita foi de 1,17 mm (DP = 0,46), com coeficiente de correlação de 0,31 (95 por cento IC: 0,12 ; 0,47). A avaliação pela curva ROC demonstrou um valor de corte de 0,7 mm para EMI da artéria subclávia direita, tendo como padrão de referência o valor de corte de EMI da artéria carótida de 0,8 mm (sensibilidade 91 por cento, especificidade 27 por cento, VPP 66 por cento, VPN 65 por cento e acurácia 66 por cento). CONCLUSÃO: Existe boa correlação entre o EMI...

OBJECTIVE: Common carotid artery intima-media thickness (IMT) is considered a factor of cardiovascular risk and an early marker of coronary artery disease. This study aimed to investigate the existence of a correlation between IMT in the carotid arteries and at the origin of the right subclavian artery, as well as to evaluate IMT in the subclavian artery as an earlier marker of cardiovascular risk. METHODS: One hundred and six consecutive patients, 52 males and 54 females, average age 51 years, underwent color Doppler ultrasonography to evaluate carotid and right subclavian arteries. The relationship between carotid IMT and right subclavian IMT was assessed using the Pearson's correlation coefficient analysis and a 95 percent confidence interval. Reliability of right subclavian artery IMT measurement for the diagnosis of early thickening (considering a > 0.8 mm carotid thickness as reference) was described as to sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Cut-off values for the right subclavian IMT were indicated by the ROC curve, and p values < 0.05 were considered statistically significant. RESULTS: Out of the 41 patients whose carotid arteries were IMT-free, 30 (73 percent) had right subclavian artery IMT values > 0.8 mm. The mean IMT value for the carotid artery was 0.87 mm (SD = 0.23) and for the subclavian artery, 1.17 mm (SD = 0.46), with a 0.31 correlation coefficient (95 percent CI: 0.12; 0.47). The ROC curve analysis indicated a cut-off value of 0.7 mm for the right subclavian artery IMT, using as reference a 0.8 mm cut-off value for the carotid artery (91 percent sensitivity, 27 percent specificity, 66 percent PPV, 65 percent NPV, and 66 percent accuracy). CONCLUSION: Our study showed that carotid artery IMT correlates well with right subclavian artery IMT. With a 0.7 mm cut-off value, it is possible to detect IMT in the right subclavian artery earlier than in the carotid arteries. The IMT at the...

Is the Watanabe heritable hyperlipidemic rabbit a suitable experimental model for percutaneous transluminal coronary angioplasty in humans? A light microscopic, immunohistochemical and ultrastructural study.

OBJECTIVES: This study was designed to assess an experimental model for the study of mechanisms that underlie restenosis after percutaneous transluminal coronary angioplasty. BACKGROUND: The Watanabe heritable hyperlipidemic (WHHL) rabbit lacks the receptor for low density lipoproteins, produces atherosclerotic lesions very similar to those in humans and, therefore, could serve as a suitable model. METHODS: Percutaneous transluminal angioplasty was performed on the left subclavian artery of 10 homozygous rabbits. The animals were killed at a few hours or 3, 7, 14 or 28 days after the procedure. The artery was fixed by perfusion, and the site of angioplasty was examined by both light and electron microscopy with the use of conventional and immunohistochemical staining techniques. RESULTS: Angioplasty had caused a flap-like or dissecting tear into the media. At day 3, cells within the preexisting media adjacent to the injury had the ultrastructural characteristics of synthetic smooth muscle cells. At day 7, spindle cells at the site of injury stained either negative or very weakly positive with a marker for actin; ultrastructurally, these cells had the synthetic phenotype. At day 14, the spindle cells showed a mix of contractile and synthetic phenotypes. The surface was partially covered by endothelial cells. At day 28, the dominant cell type was the contractile smooth muscle cell and the surface was completely covered by endothelial cells. CONCLUSIONS: Both the injury and the response to injury after percutaneous transluminal angioplasty were almost identical to that seen in humans after coronary angioplasty. Thus, the WHHL rabbit appears to be an appropriate experimental model for use in further studies.

Human neonatal and adult vascular smooth muscle cells in culture.

Neonatal vascular smooth muscle cells (SMC) in culture have been demonstrated to be quite different from adult SMC and to be similar to intimal SMC in animal models. To characterize human neonatal vascular SMC in culture, cultures of arterial SMC were prepared by an explant method from the subclavian arteries of autopsied patients (10 adults and 6 neonates). The morphology and growth characteristics of these cells were compared. All cells were positively immunostained with HHF 35, a monoclonal antibody specific for muscle actin. Electron microscopically, both adult and neonatal SMC were of synthetic phenotype. SMC from neonates had a short population doubling time (PDT, 28.6 +/- 7.5 hr) and high saturation density (SD, 37.5 +/- 11.9 x 10(4) cells/cm2). They did not show hill and valley growth patterns. Among the SMC cultured from adult media, two subtypes were distinguished, based on their growth characteristics. Classical adult SMC (7 of 10 cases) grew in hill and valley patterns with long PDT and low SD values (61.7 +/- 28.8 hr, 6.5 +/- 1.9 x 10(4) cells/cm2, respectively). The second subtype (3 of 10 cases), neonatal-type adult SMC, had PDT and SD values (22.9 +/- 4.0 hr, 31.3 +/- 14.7 x 10(4) cells/cm2, respectively) similar to those of neonatal SMC. Intimal SMC became senescent in early phases of subculture. To test for the possible participation of autocrine growth factors in the heterogeneity of the growth patterns, Northern blot analysis was conducted for PDGF-A, TGF-beta, c-myc, and c-fos mRNA in three types of SMC. There was no significant difference in these mRNA levels between the SMC. We demonstrated that human neonatal vascular SMC in culture are quite different in their growth characteristics from classical adult SMC in culture and that neonatal-type SMC can be isolated from adult media.