Caudal vena cava kinking in dogs with ascites.

A 9-year-old dog with spontaneous ascites was found to have hepatic vein distension and a tortuous vena cava on abdominal ultrasound. In right lateral recumbency, the caudal vena cava crossed the diaphragm and became kinked before entering into the right atrium. Following this observation, we performed an experimental study in a normal dog to determine whether kinking of the caudal vena cava could be the result and not the cause of ascites. Ascites was induced using warm saline injected through a needle inserted into the abdominal cavity. Venograms were collected from different body positions, under four conditions: before and after a total of one, two and 3 liters of saline had been injected. Caudal vena cava kinking was observed in the experimental dog after 2 liters of fluid had been injected. Vena cava obstruction may cause ascites, but we found that sometimes caudal vena cava kinking can be the result and not the cause of the peritoneal effusion.

Distensible superficial venous orbital malformations involving the lower eyelid in two horses.

CASE DESCRIPTION: 2 horses were examined because of vascular masses involving the lower eyelid. CLINICAL FINDINGS: Both horses had a unilateral, fluctuant mass involving the lower eyelid. For horse 1, the mass had been present since birth and had slowly increased in size over time. The mass also changed in size in response to various environmental stimuli, alterations in the position of the horse's head, and digital obstruction of superficial vessels adjacent to the mass. Horse 2 was brought to the hospital for euthanasia, and no historical or antemor-tem data were available. A combination of contrast angiography, Doppler ultrasonography, surgical exploration, and blood gas analysis (horse 1) and postmortem and histologic examination (horse 2) were used to determine that the masses consisted of non-neoplastic distended venous channels with anastomoses to the inferior lateral palpebral and angularis oculi veins (both horses) as well as the facial vein (horse 2). Histologic examination (horse 2) revealed large, endothelial cell-lined, blood-filled spaces within the deep dermis consistent with a distensible superficial venous orbital malformation. TREATMENT AND OUTCOME: Horse 1 underwent surgical exploration and ligation of the vascular malformation. Six months after surgery, the mass was markedly reduced in size, and size of the mass was static regardless of head position or environmental stimuli. CLINICAL RELEVANCE: Thorough preoperative planning with Doppler ultrasonography, contrast angiography, and blood gas analysis is recommended when attempting surgical correction of these malformations in horses. Surgical ligation can result in a successful cosmetic and functional outcome.

Angiografia in vivo para avaliação da vascularização do casco de eqüinos / In vivo angiography for evaluation of equine foot vasculature

A proposta deste trabalho foi estabelecer a angiografia digital palmar como método de avaliação qualitativa in vivo da vascularização distal laminar em eqüinos em posição quadrupedal. Foram realizadas 15 angiografias de eqüinos mestiços, sendo seis machos castrados e nove fêmeas, com idade variando entre seis e oito anos. As angiografias foram realizadas, após bloqueio anestésico perineural do nervo digital palmar lateral ou medial, por meio da aplicação de 20mL de contraste na veia digital palmar lateral ou medial garroteada por atadura elástica e torniquete. Imediatamente depois, foi realizada a primeira exposição radiológica em incidência dorso-palmar. Após a dispersão do contraste, o mesmo procedimento foi realizado com o casco submetido ao tratamento térmico com água aquecida e com água resfriada. Em quatro animais, obteve-se imagem radiopaca, com bordas maldefinidas, de aspecto sombreado, ao redor de cada lâmina dérmica, que foi creditada à vasodilatação ocasionada pelo calor. Quando da vasoconstrição ocasionada pelo tratamento com frio, observou-se redução da imagem radiopaca laminar. Esse aspecto pôde ser comprovado em quatro radiografias, porém não se repetiu em todas as angiografias realizadas. Em sete radiografias, houve falha de preenchimento de contraste, o que inviabilizou a comparação entre tratamentos térmicos, sendo que as radiografias realizadas sem nenhum tratamento térmico possuíam preenchimento de contraste adequado. A angiografia digital em eqüinos mostrou-se um método sensível para evidenciar vasoconstrição e vasodilatação in vivo dentro do estojo córneo, porém inúmeros fatores podem contribuir para o aparecimento de artefatos de técnica, o que inviabiliza a comparação de alterações da perfusão laminar do casco por esse método.

This study was aimed at establishing the palmar digital angiography as an in vivo qualitative method of evaluation the laminar digital vasculature on horses in standing position. Six gelding and nine mares were used in this study, with age going from 6 to 8 years old. After the perineural anesthesia of lateral or medial palmar digital nerve and the surgical preparation an intravenous catheter was fixed to the palmar digital vein, lateral or medial. After performing a simple radiography an elastic bandage and tourniquet was applied to the area. The animal and the RX equipment were adequately positioned and 20mL of contrast were injected, followed by a first radiological exposition in dorsum palmar incidence. In sequence the tourniquet and the elastic bandage were removed for the dissipation of the contrast, keeping the venous access with infusion of isotonic saline solution. The same procedure was performed with the hoof submitted to the thermal treatment with warmed water and cold water. In four animals a radiopaque image, around each dermic lamina with vasodilatation induced by the heat was obtained, with poorly defined edges and blurred aspect. On the other hand, it was observed reduction of the radiopaque laminar image because of the vasoconstriction caused by the treatment with cold water. This fact can be seen only in four radiographies, but it has not being repeated in all angiographies performed. In seven radiographies incomplete contrast filling was observed. For this reason, it was not possible to compare the radiographs performed with no thermal treatment, that have had the appropriate filling of the contrast. The digital angiography in horses was showed to be a sensible method to evidence in vivo vasoconstriction and vasodilatation inside the hoof, however this method cannot be use to analyze alteration in the laminar perfusion because some techniques artefactual.

The use of thrombolytic agents.

Thrombi and thromboemboli are organized fibrin clots that may result in partial or total occlusion of arterial or venous blood flow. Consequences of occlusion of blood flow vary with the organ affected.Thrombolytic agents have been used for the dissolution of pathologic thrombi since the 1980s. While similar in their mechanisms of action and side effects, these agents differ in their specificity for fibrin and duration of activity. Newer thrombolytic agents have been developed to improve clot dissolution and minimize side effects. Their use in veterinary medicine has been reported, but guidelines for such use have not been published.

[Gene transfers of kallikrein, bradykinin receptor B2 and a mutated B2 receptor stimulate neoangiogenesis in peripheral ischemia]. / La surexpression de la kallicréine tissulaire, du récepteur B2 de la bradykinine et d'une forme mutée du récepteur B2, stimule la néoangiogenèse dans un modèle d'ischémie périphérique.

In this work, we evaluated the angiogenic effect of the gene transfer of human tissue kallikrein (TK), bradykinin B2 receptor (B2R) and a mutated form (RB2m) in a rabbit peripheral model of ischaemia. We studied the effects of the transfection of each of these factors and the effects of their co-transfection. In New Zealand anesthetised rabbits we first induced an ischaemia of the left posterior leg by ligation-excision of the superficial femoral artery and its collaterals. Seven days later, we performed i.m. injections in the ischemic tight with transfection solutions containing either the control (pcDNA3 empty backbone) or the pcDNA3-TK, the pcDNA3-TK and the pcDNA3-B2R, the pcDNA3-TK and the pcDNA3-B2Rm. Twenty eight days later, the therapeutic effect was evaluated using ultrasonographic debitmetry of the common iliac artery, perfusion index (PI) = ischemic leg blood flow /non ischemic leg blood flow (%) and capillaries measurements i.e. capillary density: number of vessels/mm2 and the ratio of vessels/muscular fiber, in the adductors and gastrocnemian muscles. The PI was increased in each treated group vs control (32.61 +/- 5.2%), pcDNA3-TK: 59.72 +/- 2.33%; p = 0.001; pcDNA3-RB2: 55.25 +/- 2.29%; p = 0.008; pcDNA3-TK + pcDNA3-RB2: 84.77 +/- 3.15%; p < 0.001; pcDNA3-TK + pcDNA3-RB2m: 103.25 +/- 4.9%; p < 0.001. The capillary density and the vessel/muscular fiber ratio increased in a parallel with the hemodynamic in the ischemic adductors (pcDNA3-TK + pcDNA3-B2Rm > pcDNA3-TK + pcDNA3-RB2 > pcDNA3-TK = pcDNA3-B2R; p < 0.001). There was no angiogenic effect measurable neither in the non ischemic adductors (right) nor in the gastrocnemian muscles. In rabbit peripheral ischaemia, the cotransfection of TK and B2R increases the arterial flow in the treated leg and potentiates the neoangiogenesis. Cotransfection of the B2Rm cDNA enhanced the synergic effect of this therapeutic strategy.

Incidence and morphology of endometrial angiopathies in mares in relationship to age and parity.

The morphology of endometrial blood vessels in uterine biopsy specimens from mares of varying age and reproductive status was examined by light (n = 117) and electron microscopy (n = 13), and additionally after elastase digestion (n = 86). Inflammatory vascular alterations were observed in 20.5% of the specimens. Smaller and larger arterial and venous vessels demonstrated mild to severe degenerative lesions. Unaltered vessels were detected only in maiden mares. Vessels in older maiden mares were frequently affected by angiosclerotic changes, characterized by mild to moderate perivascular and intimal sclerosis. The incidence and severity of angiosis increased with the number of previous pregnancies and with advancing age. Changes in multiparous mares resembled the so-called "pregnancy-sclerosis" of other species, with fraying and disruption of the membrana elastica interna, medial atrophy intimal, medial and adventitial elastosis and fibrosis, and calcification processes within the media. Ultrastructural studies revealed characteristic arterial changes in post-parturient mares, namely, disruption of the membrana elastica interna, as well as activated smooth muscle cells and immature elastic fibres within the intima and inner media, suggesting a pregnancy-induced pathogenesis. Haemodynamic and hormonal alterations during pregnancy and the puerperium possibly induce active vascular remodelling. Cycles of vascular growth during pregnancy and subsequent involution post partum are thought to result in progressive degenerative vascular changes, as seen in multiparous mares. Ageing processes, chronic inflammation and short foaling intervals have to be considered as additional pathogenetic factors. Furthermore, severe angiosis was frequently combined with phlebectasia and lymphangiectasia. This may indicate a reduced ability of the vessels to adapt to the varying demands of uterine circulation, with a decrease of uterine perfusion and lymph drainage. Angiosis in older, multiparous mares might therefore be intimately related to infertility.

B-mode and Doppler ultrasound imaging of the spleen with canine splenic torsion: a retrospective evaluation.

The ultrasonographic appearance of splenic torsion has been described; the splenic parenchyma can be normal, hypoechoic or anechoic with interspersed linear echoes (coarse/"lacy" appearance). The ultrasonographic parenchymal appearance of 15 dogs in this report with splenic torsion varied: mottled hypoechoic regions (n=2), diffusely hypoechoic (n=11) and normal (n=2). Because splenic torsion causes vascular congestion due to splenic vein compression and eventual thrombosis, visible splenic vein intraluminal echogenicities compatible with thrombi were seen in 13 dogs using B-mode. Using spectral Doppler and color Doppler imaging of the splenic veins, no measurable flow velocities were detected in any of the 15 dogs. The varied B-mode ultrasonographic appearance of the splenic parenchyma with splenic torsion necessitates B-mode evaluation of the splenic veins for intraluminal echoes and spectral or color Doppler evaluation for absent velocity flow.