A Practical Protocol to Measure Common Carotid Artery Intima-media Thickness

OBJECTIVE: To describe and test a practical protocol to measure common carotid intima-media thickness that uses the combined values of two longitudinal examination angles to increase sensitivity. METHOD: Between February and September 2005, 206 patients underwent duplex scan examination of carotid vessels, and the intima-media thickness of 407 common carotids were measured in three angles: transversal, longitudinal posterolateral, and anterolateral, with three intima-media thickness measurements for each near and far wall. In addition to numbers obtained from the three angles of measurement, a fourth visual perspective was obtained by combining the intima-media thickness results of posterolateral and anterolateral longitudinal views and considering the thickest wall measurement. RESULTS: Two hundred seventy (66.3%) carotid arteries had an intima-media thickness thicker than 1mm. The mean intima-media thickness values achieved by the different incidences were 1.26±0.6mm (transversal), 1.17±0.54mm (longitudinal anterolateral), and 1.18±0.58mm (longitudinal posterolateral). A significant difference in intima-media thickness measurement values was observed when the three angles of examination plus the combined positive results of both longitudinal angles were compared by ANOVA (P=0.005). The LSD Post-Hoc test determined that the combined longitudinal view results were similar to the transversal views (P=0.28) and had greater intima-media thickness means than isolated anterolateral or posterolateral longitudinal views (P=0.02 and 0.05, respectively). CONCLUSIONS: The protocol presented is a practical method for obtaining common carotid artery intima-media thickness measurements. The combined longitudinal posterolateral and anterolateral longitudinal views provide a more sensitive evaluation of the inner layers of the carotid walls than isolated longitudinal views

Transfixing lethal injury of the juxtahepatic vena cava and treatment with a stent graft: a new experimental model

As lesões das veias justa-hepáticas apresentam mortalidade elevada apesar das diferentes técnicas cirúrgicas de tratamento. Os objetivos desse estudo são: a) construir um modelo experimental de lesão letal transfixante de veia cava inferior (VCI) justa-hepática por técnica endovascular, e avaliar as alterações hemodinâmicas decorrentes dessa lesão. b) tratar a lesão por meio de reposição volêmica inicial e controle do sangramento com a colocação de endoprótese revestida (ER), c) acompanhar clinicamente o pós-operatório com ultra-som Doppler (USD) e cavografia. d) avaliar as alterações anatomopatológicas da VCI com a ER. Vinte cães anestesiados e monitorados [freqüência cardíaca (FC), pressão arterial média (PAM), pressão na VCI, pressão vesical, pressão peritoneal] foram submetidos a lesão transfixante da VCI justa-hepática, por técnica endovascular. Após a reposição volêmica inicial foram divididos em dois grupos: controle (GI)) e experimento (GII). O GI ficou em observação e quando a PAM atingiu níveis entre 40 e 30 mm Hg foi submetido a laparotomia para avaliação do sangramento e da lesão. O GII foi tratado com ER e acompanhado clinicamente com USD e cavografia após 4 (GIIA) e 8 semanas (GIIB) quando foram sacrificados e a VCI com ER foi analisada. O GI apresentou aumento significativo das pressões peritoneal, vesical e da VCI, hipotensão arterial, bradicardia e óbito após 80 minutos. No GII a sobrevida foi de 100%, sem repercussões clínicas. O USD e a cavografia mostraram que todas as ERs encontravam-se pérvias. O Doppler revelou padrão de fluxo monofásico pulsátil nos segmentos estudados. Ao US, as medidas dos diâmetros da ER nas 2ª (7,89 ± 1,20 mm), 4ª (7,24 ± 1,72 mm) e 8ª (8,04 ±1,15 mm) semanas, não mostraram diferenças estatísticas significantes. Na cavografia as medidas dos diâmetros da VCI antes da colocação da ER, logo após a sua colocação e após 4 e 8 semanas, não mostraram diferenças estatisticamente significantes entre os GIIA e GIIB. Esses dados analisados para o GII como um todo, mostram diferenças estatisticamente significantes; VCI (11,74 ± 0,86 mm) T=1,00 p= 0,007, após a colocação da ER (12,86 ± 0,41 mm) T= 0,00 p= 0,008 e no período tardio (8,44 ± 2,00 mm) T= 0,00 p= 0,005. A média da taxa de redução do diâmetro da luz da ER foi de 27,43 ± 20,00%. As medidas, em cm de H2O, da pressão na VCI, cranial (0,55 ± 0,50), caudal (1,15 ± 1,76) e no interior da ER (0,75 ± 0,63), não mostraram diferenças estatisticamente significantes. No estudo da VCI com ER, observamos a formação de neoíntima mais espessa do que às camadas média e íntima. Na área da lesão, a camada média estava seccionada e cicatrizada por tecido fibroconjuntivo. Concluindo, a) criamos um modelo experimental de lesão letal transfixante de VCI justa-hepática por técnica endovascular com mortalidade de 100% dos casos após 80 minutos da lesão, provocando hemoperitônio volumoso com aumento significante da pressão peritoneal, b) tratamos essa lesão com ER com sobrevida de 100%, c) verificamos através do USD e cavografia a perviedade da ER após 2, 4 e 8 semanas do tratamento, d) observamos espessamento significante da neoíntima com redução de 27% do diâmetro da luz, sem repercussão clínica ou aumento de gradiente pressóricoJuxtahepatic vein injuries present a high mortality rate despite the different surgical techniques for their treatment. The objectives of this study are: a) to develop an experimental model of transfixing lethal injury of the juxtahepatic inferior vena cava (IVC) through endovascular technique and to evaluate the hemodynamic alterations caused by this injury, b) to treat the lesion with initial volume replacement and hemorrhage control with the insertion of a stent graft (SG), c) to clinically follow the posttreatment period with Doppler ultrasound (DUS) and cavography, d) to evaluate the anatomopathological alterations of the IVC with the SG. Twenty anesthetized and monitored dogs [heart rate (HR), mean arterial pressure (MAP), vesical and, peritoneal pressure] were submitted to transfixing injury of the juxtahepatic IVC, by endovascular technique. After the initial volume replacement they were divided into two groups: control (GI) and experimental (GII). GI was maintained under observation and when MAP reached levels between 40 and 30 mm Hg the animals were submitted to laparotomy to evaluate bleeding and the lesion. GII was treated with SG and clinically followed by DUS and cavography after 4 (GIIA) and 8 weeks (GIIB), when they were sacrificed and IVC and SG were analyzed. GI presented a significant increase in peritoneal, vesical and IVC pressures, arterial hypotension, bradycardia, and death after 80 minutes. GII had a 100% survival rate, without clinical repercussions. DUS and cavography showed that all SG were patent. Doppler ultrasound showed a pattern of a monophasic pulsatile flux in all studied segments. On US, the measures of SG diameters in the 2nd (7.89 ± 1.20mm), 4th (7.24 ± 1.72mm) and 8th (8.04 ± 1.15mm) weeks did not show statistically significant differences. On cavography the measures of IVC diameters before the insertion of SG, immediately after its insertion and after 4 and 8 weeks did not show statistically significant differences between GIIA and GIIB. These data analyzed for the GII as a whole, showed statistically significant differences; IVC (11.74 ± 0.86mm) T=1.00 p=0.007, after the insertion of SG (12.86 ± 0.41mm) T=0.00 p=0.008 and in the late period (8.44 ± 2.00mm) T=0.00 p=0.005. The average rate of reduction in lumen diameter of SG was 27.43 ± 20,00%. The measures, in H2O cm of the IVC pressure, cranial (0.55 ± 0.50), caudal (1.15 ± 1.76) and in the interior of the SG (0.75 ± 0.63) did not show statistically significant differences. In the IVC study with SG, we observed the formation of a thicker neointima as compared to the media and intima layers. In the area of the lesion, the media layer was injured and cicatrized with fibroconjuctive tissue. In conclusion, a) we created an experimental model of transfixing lethal injury of the juxtahepatic IVC by endovascular technique with a mortality rate of 100% after 80 minutes of the injury, causing an important hemoperitonium with significant increase in peritoneal pressure, b) we treated this lesion with SG, with a survival rate of 100%, c) we verified through DUS and cavography the patency of the SG after 2, 4 and 8 weeks of treatment, and d) we observed significant thickening of the neointima with a reduction of 27% in the diameter of the lumen, without clinical repercussion or pressure gradient increas

Transfixing lethal injury of the juxtahepatic vena cava and treatment with a stent graft: a new experimental model

As lesões das veias justa-hepáticas apresentam mortalidade elevada apesar das diferentes técnicas cirúrgicas de tratamento. Os objetivos desse estudo são: a) construir um modelo experimental de lesão letal transfixante de veia cava inferior (VCI) justa-hepática por técnica endovascular, e avaliar as alterações hemodinâmicas decorrentes dessa lesão. b) tratar a lesão por meio de reposição volêmica inicial e controle do sangramento com a colocação de endoprótese revestida (ER), c) acompanhar clinicamente o pós-operatório com ultra-som Doppler (USD) e cavografia. d) avaliar as alterações anatomopatológicas da VCI com a ER. Vinte cães anestesiados e monitorados [freqüência cardíaca (FC), pressão arterial média (PAM), pressão na VCI, pressão vesical, pressão peritoneal] foram submetidos a lesão transfixante da VCI justa-hepática, por técnica endovascular. Após a reposição volêmica inicial foram divididos em dois grupos: controle (GI)) e experimento (GII). O GI ficou em observação e quando a PAM atingiu níveis entre 40 e 30 mm Hg foi submetido a laparotomia para avaliação do sangramento e da lesão. O GII foi tratado com ER e acompanhado clinicamente com USD e cavografia após 4 (GIIA) e 8 semanas (GIIB) quando foram sacrificados e a VCI com ER foi analisada. O GI apresentou aumento significativo das pressões peritoneal, vesical e da VCI, hipotensão arterial, bradicardia e óbito após 80 minutos. No GII a sobrevida foi de 100%, sem repercussões clínicas. O USD e a cavografia mostraram que todas as ERs encontravam-se pérvias. O Doppler revelou padrão de fluxo monofásico pulsátil nos segmentos estudados. Ao US, as medidas dos diâmetros da ER nas 2ª (7,89 ± 1,20 mm), 4ª (7,24 ± 1,72 mm) e 8ª (8,04 ±1,15 mm) semanas, não mostraram diferenças estatísticas significantes. Na cavografia as medidas dos diâmetros da VCI antes da colocação da ER, logo após a sua colocação e após 4 e 8 semanas, não mostraram diferenças estatisticamente significantes entre os GIIA e GIIB. Esses dados analisados para o GII como um todo, mostram diferenças estatisticamente significantes; VCI (11,74 ± 0,86 mm) T=1,00 p= 0,007, após a colocação da ER (12,86 ± 0,41 mm) T= 0,00 p= 0,008 e no período tardio (8,44 ± 2,00 mm) T= 0,00 p= 0,005. A média da taxa de redução do diâmetro da luz da ER foi de 27,43 ± 20,00%. As medidas, em cm de H2O, da pressão na VCI, cranial (0,55 ± 0,50), caudal (1,15 ± 1,76) e no interior da ER (0,75 ± 0,63), não mostraram diferenças estatisticamente significantes. No estudo da VCI com ER, observamos a formação de neoíntima mais espessa do que às camadas média e íntima. Na área da lesão, a camada média estava seccionada e cicatrizada por tecido fibroconjuntivo. Concluindo, a) criamos um modelo experimental de lesão letal transfixante de VCI justa-hepática por técnica endovascular com mortalidade de 100% dos casos após 80 minutos da lesão, provocando hemoperitônio volumoso com aumento significante da pressão peritoneal, b) tratamos essa lesão com ER com sobrevida de 100%, c) verificamos através do USD e cavografia a perviedade da ER após 2, 4 e 8 semanas do tratamento, d) observamos espessamento significante da neoíntima com redução de 27% do diâmetro da luz, sem repercussão clínica ou aumento de gradiente pressóricoJuxtahepatic vein injuries present a high mortality rate despite the different surgical techniques for their treatment. The objectives of this study are: a) to develop an experimental model of transfixing lethal injury of the juxtahepatic inferior vena cava (IVC) through endovascular technique and to evaluate the hemodynamic alterations caused by this injury, b) to treat the lesion with initial volume replacement and hemorrhage control with the insertion of a stent graft (SG), c) to clinically follow the posttreatment period with Doppler ultrasound (DUS) and cavography, d) to evaluate the anatomopathological alterations of the IVC with the SG. Twenty anesthetized and monitored dogs [heart rate (HR), mean arterial pressure (MAP), vesical and, peritoneal pressure] were submitted to transfixing injury of the juxtahepatic IVC, by endovascular technique. After the initial volume replacement they were divided into two groups: control (GI) and experimental (GII). GI was maintained under observation and when MAP reached levels between 40 and 30 mm Hg the animals were submitted to laparotomy to evaluate bleeding and the lesion. GII was treated with SG and clinically followed by DUS and cavography after 4 (GIIA) and 8 weeks (GIIB), when they were sacrificed and IVC and SG were analyzed. GI presented a significant increase in peritoneal, vesical and IVC pressures, arterial hypotension, bradycardia, and death after 80 minutes. GII had a 100% survival rate, without clinical repercussions. DUS and cavography showed that all SG were patent. Doppler ultrasound showed a pattern of a monophasic pulsatile flux in all studied segments. On US, the measures of SG diameters in the 2nd (7.89 ± 1.20mm), 4th (7.24 ± 1.72mm) and 8th (8.04 ± 1.15mm) weeks did not show statistically significant differences. On cavography the measures of IVC diameters before the insertion of SG, immediately after its insertion and after 4 and 8 weeks did not show statistically significant differences between GIIA and GIIB. These data analyzed for the GII as a whole, showed statistically significant differences; IVC (11.74 ± 0.86mm) T=1.00 p=0.007, after the insertion of SG (12.86 ± 0.41mm) T=0.00 p=0.008 and in the late period (8.44 ± 2.00mm) T=0.00 p=0.005. The average rate of reduction in lumen diameter of SG was 27.43 ± 20,00%. The measures, in H2O cm of the IVC pressure, cranial (0.55 ± 0.50), caudal (1.15 ± 1.76) and in the interior of the SG (0.75 ± 0.63) did not show statistically significant differences. In the IVC study with SG, we observed the formation of a thicker neointima as compared to the media and intima layers. In the area of the lesion, the media layer was injured and cicatrized with fibroconjuctive tissue. In conclusion, a) we created an experimental model of transfixing lethal injury of the juxtahepatic IVC by endovascular technique with a mortality rate of 100% after 80 minutes of the injury, causing an important hemoperitonium with significant increase in peritoneal pressure, b) we treated this lesion with SG, with a survival rate of 100%, c) we verified through DUS and cavography the patency of the SG after 2, 4 and 8 weeks of treatment, and d) we observed significant thickening of the neointima with a reduction of 27% in the diameter of the lumen, without clinical repercussion or pressure gradient increas

Parâmetros dopplervelocimétricos na avaliação da perviedade da anastomose portossistêmica intra-hepática transjugular (TIPS) Dopplerflowmetric patterns for evaluation of transjugular intrahepatic portosystemic shunt patency

A anastomose portossistêmica intra-hepática transjugular (TIPS) é um procedimento intervencionista minimamente invasivo realizado pela introdução de prótese metálica auto-expansível no parênquima hepático, via transjugular. Tem por objetivo tratar as complicações da hipertensão portal, principalmente a hemorragia digestiva alta e a ascite refratária. A estenose é complicação freqüente, embora o procedimento seja eficaz e com baixo índice de insucesso. O diagnóstico precoce da estenose é de fundamental importância, pois interfere no tipo de tratamento a ser realizado e o reaparecimento dos sintomas pode ser grave. O ultra-som Doppler é então utilizado para o seguimento dos pacientes portadores do TIPS, e vários parâmetros são descritos na literatura para o diagnóstico de estenose, como: as velocidades mínima e máxima no interior da prótese, a velocidade na veia porta, o gradiente de velocidade entre dois pontos da prótese, e outros. Infelizmente não há consenso sobre qual parâmetro ou conjunto de parâmetros é mais eficaz no diagnóstico, porque os protocolos de avaliação variam de instituição para instituição. Os autores realizaram uma revisão dos parâmetros de estenose descritos na literatura e de outros aspectos de fundamental importância na compreensão do procedimento, como as indicações, as contra-indicações e a fisiopatologia da estenose.<br>Transjugular intrahepatic portosystemic shunt (TIPS) is a minimally invasive interventional procedure that consists of placement of an auto expandable metallic stent in the hepatic parenchyma via transjugular. It is used to treat the complications of portal hypertension, particularly digestive bleeding of gullet varices and refractory ascites. Although TIPS is an efficient procedure with low rate of failure some complications such as stenosis are frequent. Early diagnosis of stenosis is mandatory since it interferes with the type of treatment and the reappearing symptoms can be serious. Doppler sonography is used in the follow-up of this patients and many parameters indicating TIPS stenosis are described in the literature such as the minimum and maximum velocity flow inside the stent, the velocity flow in portal vein, the velocity gradient between different sites of the stent, among others. Unfortunately there is no consensus on which parameter or group of parameters is more efficient for diagnosis because the evaluation protocols varied among institutions. The authors reviewed the parameters of stenosis reported in literature and other important aspects for comprehension of this procedure including indications, contraindications and physiopathology of stenosis

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field