Abordagem transcirúrgica e acompanhamento pós-operatório de um canino com um shunt esplênico-azigos / Transurgical approach and postoperative follow-up of a canine with a splenic-azygos shunt

Background: The most frequent hepatic circulatory abnormality in dogs is the portosystemic shunt, characterized by an atypical deviation of the hepatic blood flow, that causes the blood that should be drained by the liver through the portal vein to be diverted to another systemic vein, as a result of the presence of the anomalous vessel. This diversion leads to reduced hepatic blood flow and, consequently, organ dysfunction, along with the accumulation of many toxins in the circulation, for instance, ammonia and short-chain fatty acids. The main objective of this paper is to Report the clinical case of a canine female diagnosed with an extrahepatic portosystemic shunt and submitted to surgical treatment using an ameroid constrictor ring in the obstruction of the anomalous vessel. Case: A canine Shih-Tzu, at the age of 1 year and 8 months, was brought to the Veterinary Hospital presenting a history of emesis and smaller body structure than other animals from the same litter. The animal had been diagnosed with portosystemic shunt at age 1 month, by means of complementary biochemistry, ultrasonography and computed tomography examinations. The latter identified the anomalous vessel, which originated from the left gastric vein and was inserted into the azygos vein in the portohepatic region. During the surgical intervention, after median pre-retro-umbilical celiotomy, a calibrous vessel was identified, coming out of the junction of two splenic veins and a gastric vein that penetrated the diaphragm and connected to the azygos vein in the thorax before flowing into the vena cava

Cirrose hepática associada à ingestão de Cycas revoluta em canino / Hepatic cirrhosis associated with ingestion of Cycas revoluta in canine

Background: Cycas revoluta (“sago palm”) is a toxic ornamental plant which, when ingested, can cause hepatotoxic effects, gastrointestinal signs, and neurological alterations. Albeit rarely, C. revoluta ingestion can culminate with chronic severe hepatitis associated with hepatic fibrosis. The objective of this work is to report a case of hepatic cirrhosis consequent to ingestion of C. revoluta in a dog and describe the clinical and pathological aspects that accompany the development of chronic hepatopathy, as a way to provide information that may help diagnosis of this condition. Case: A 9-month-old male mongrel dog was presented for examination with a history of increased abdominal volume and anorexia 20 days after ingesting the seeds of Cycas revoluta. Laboratory exams revealed hypochromic microcytic anemia, neutrophilic leukocytosis, monocytosis, thrombocytopenia, decreased albumin, and elevation of the enzymes alanine aminotransferase and alkaline phosphatase. Ultrasound scanning showed presence of hepatomegaly, a heterogeneous hepatic parenchyma, and free fluid in the peritoneum. The animal was treated and was discharged from the hospital. Twenty days later, the patient returned to the hospital exhibiting prostration, vomiting, ascites, and pale mucous membranes. The alterations observed in the previous laboratory exams persisted except for thrombocytopenia, which was absent. A new treatment was administered, and the animal was discharged three days later. However, the patient returned once again exhibiting hyporexia, hemorrhagic diarrhea, and slight prostration that progressed to severe prostration, lateral decubitus and death approximately two months after ingesting the plant. Necropsy revealed a markedly poor body condition, slight icterus, limb edema, ascites and hydrothorax, and an atrophied liver with a yellowish color and an irregular, but firm, capsule surface. Additional alterations included...

Abordagem transcirúrgica e acompanhamento pós-operatório de um canino com um shunt esplênico-azigos / Transurgical approach and postoperative follow-up of a canine with a splenic-azygos shunt

Background: The most frequent hepatic circulatory abnormality in dogs is the portosystemic shunt, characterized by an atypical deviation of the hepatic blood flow, that causes the blood that should be drained by the liver through the portal vein to be diverted to another systemic vein, as a result of the presence of the anomalous vessel. This diversion leads to reduced hepatic blood flow and, consequently, organ dysfunction, along with the accumulation of many toxins in the circulation, for instance, ammonia and short-chain fatty acids. The main objective of this paper is to Report the clinical case of a canine female diagnosed with an extrahepatic portosystemic shunt and submitted to surgical treatment using an ameroid constrictor ring in the obstruction of the anomalous vessel. Case: A canine Shih-Tzu, at the age of 1 year and 8 months, was brought to the Veterinary Hospital presenting a history of emesis and smaller body structure than other animals from the same litter. The animal had been diagnosed with portosystemic shunt at age 1 month, by means of complementary biochemistry, ultrasonography and computed tomography examinations. The latter identified the anomalous vessel, which originated from the left gastric vein and was inserted into the azygos vein in the portohepatic region. During the surgical intervention, after median pre-retro-umbilical celiotomy, a calibrous vessel was identified, coming out of the junction of two splenic veins and a gastric vein that penetrated the diaphragm and connected to the azygos vein in the thorax before flowing into the vena cava…(AU)

Cirrose hepática associada à ingestão de Cycas revoluta em canino / Hepatic cirrhosis associated with ingestion of Cycas revoluta in canine

Background: Cycas revoluta (“sago palm”) is a toxic ornamental plant which, when ingested, can cause hepatotoxic effects, gastrointestinal signs, and neurological alterations. Albeit rarely, C. revoluta ingestion can culminate with chronic severe hepatitis associated with hepatic fibrosis. The objective of this work is to report a case of hepatic cirrhosis consequent to ingestion of C. revoluta in a dog and describe the clinical and pathological aspects that accompany the development of chronic hepatopathy, as a way to provide information that may help diagnosis of this condition. Case: A 9-month-old male mongrel dog was presented for examination with a history of increased abdominal volume and anorexia 20 days after ingesting the seeds of Cycas revoluta. Laboratory exams revealed hypochromic microcytic anemia, neutrophilic leukocytosis, monocytosis, thrombocytopenia, decreased albumin, and elevation of the enzymes alanine aminotransferase and alkaline phosphatase. Ultrasound scanning showed presence of hepatomegaly, a heterogeneous hepatic parenchyma, and free fluid in the peritoneum. The animal was treated and was discharged from the hospital. Twenty days later, the patient returned to the hospital exhibiting prostration, vomiting, ascites, and pale mucous membranes. The alterations observed in the previous laboratory exams persisted except for thrombocytopenia, which was absent. A new treatment was administered, and the animal was discharged three days later. However, the patient returned once again exhibiting hyporexia, hemorrhagic diarrhea, and slight prostration that progressed to severe prostration, lateral decubitus and death approximately two months after ingesting the plant. Necropsy revealed a markedly poor body condition, slight icterus, limb edema, ascites and hydrothorax, and an atrophied liver with a yellowish color and an irregular, but firm, capsule surface. Additional alterations included...(AU)

Hepatic microcirculatory failure / Falência microcirculatória hepática

Liver ischemia has been considered a frequent problem in medical practice, and can be associated to a number of surgical and clinical situations, such as massive hepatic resections, sepsis, liver trauma, circulatory shock and liver transplantation. After restoring blood flow, the liver is further subjected to an additional injury more severe than that induced by ischemia. On account of the complexity of mechanisms related to pathophysiology of ischemia and reperfusion (I/R) injury, this review deals with I/R effects on sinusoidal microcirculation, especially when steatosis is present. Alterations in hepatic microcirculation are pointed as a main factor to explain lower tolerance of fatty liver to ischemia-reperfusion insult. The employment of therapeutic strategies that interfere directly with vasoactive mediators (nitric oxide and endothelins) acting on the sinusoidal perfusion seem to be determinant for the protection of the liver parenchyma against I/R. These approaches could be very suitable to take advantage of marginal specimens as fatty livers, in which the microcirculatory disarrangements hamper its employment in liver transplantation.(AU)

A isquemia hepática é um problema relativamente freqüente na prática clínica, sobrevindo em situações diversas como ressecções hepáticas maciças, sepse, trauma hepático extenso, choque circulatório e transplante hepático. Durante a restauração do fluxo sanguíneo, o fígado é submetido a uma agressão adicional ainda mais intensa que aquela imposta pela isquemia. Devido à complexidade dos diversos mecanismos envolvidos na fisiopatologia da lesão por isquemia e reperfusão (I/R) hepática, esta revisão se limitará a discorrer sobre os efeitos da I/R na microcirculação sinusoidal, com ênfase para as alterações microvasculares que tomam lugar no fígado esteatótico pós-isquêmico. O desarranjo microcirculatório é apontado como um importante fator para explicar a reduzida tolerância do fígado esteatótico ao insulto isquêmico. O desenvolvimento de estratégias terapêuticas capazes de interferir diretamente com os mediadores vasoativos (óxido nítrico e endotelinas) relacionados ao déficit perfusional será determinante para a proteção do parênquima hepático frente às alterações induzidas pela I/R. Esses recursos seriam de especial interesse para o aproveitamento de fígados marginais, cuja falência microcirculatória compromete sobremaneira sua utilização para o transplante hepático.(AU)