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)

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

The Kawashima Operation With Simultaneous Preparation for Transcatheter Fontan-Kreutzer Completion.

Patients with functionally single ventricle and interrupted inferior vena cava may develop progressive cyanosis soon after the Kawashima operation. Therefore, early redirection of the hepatic venous return to the pulmonary circulation is recommended. To avoid performing an early redo sternotomy, we propose to prepare these patients for the interventional Fontan-Kreutzer at the time of the Kawashima operation using a technical modification of the approach reported by Prabhu and coworkers in 2017. The technique described here uses an expanded polytetrafluoroethylene conduit interposed between the hepatic veins and the right pulmonary artery. This graft is everted and divided into two portions with a pericardial patch. The lower one is widely opened and anastomosed side-to-side to the atrium. A few months after the operation, percutaneous Fontan-Kreutzer completion can easily be performed using covered stents to open the patch and at the same time close the opening between the conduit and the atrium.

The first reported case of factor V Leiden mutation with agenesis of superior vena cava: A case report.

RATIONALE: Total absence of superior vena cava (ASVC) is a very rare anomaly, and the patient usually suffers from superior vena cava syndrome (SVCS) or conduction disturbances. PATIENT CONCERNS: We report a 36-year-old white male, born and living in Brazil, without comorbidities presented to hematologist thrombotic episodes even under anticoagulant therapy. On his first hematologic appointment, he had no active complaints except by the fullness after meals, and his physical examination presented remarkable collateral circulation in the chest. DIAGNOSES: Congenital ASVC associated with factor V Leiden mutation. OUTCOMES: In his magnetic resonance angiography of the thorax, a great amount of collateral circulation and communication of the azygos and hemiazygos veins with inferior vena cava were evident, as well as the absence of the upper cava vein. Furthermore, heterozygous genetic mutation was found for Leiden factor V. LESSONS: This case gives us the lesson that we need to include ASVC in the differential diagnosis of SVCS. The importance of the V-Leiden factor as a joint risk with this congenital defect for venous thromboembolism episodes was also highlighted.

Anatomical variations of the azygos venous system: classification and clinical relevance / Variaciones anatómicas del sistema venoso ácigos: clasificación y relevancia clínica

The azygos venous system is highly variable in terms of its origin, course, communications, tributaries and termination of the associated veins: this study aimed to classify these anatomical variations. Thirty Thiel-embalmed cadavers aged 48­98 years (18 female, 12 male) were examined. The vertebral level of termination and diameter of the azygos, hemiazygos, accessory hemiazygos and the left superior intercostal veins were determined, as well as the termination level of the right superior intercostal vein. The azygos system was classified into 3 types; primitive (type 1), transitional (type 2) and unicolumnar (type 3). Type 2 was further divided into 5 subgroups (A to E) according to the number of retroaortic communications. Type one was observed in 3 % (n=1), type 2 in 87 % (n=26) and type 3 in 10 % (n=3) of specimens. The vertebral level of termination of the azygos, hemiazygos, accessory hemiazygos, right superior intercostal and left superior intercostal veins were between T2 and T3, T6 and T10, T5 and T9, T2 and T4, and T2 and T4 respectively. Identification and understanding these variations are important during preoperative radiological investigations and surgical procedures, especially spinal surgery between T7 and T12 using a left thoracotomy approach, to avoid injuries which may lead to postoperative hematomas.

El sistema venoso ácigos es muy variable en función de su origen, comunicaciones, afluentes y terminación de venas asociadas. Este estudio tuvo como objetivo clasificar las variaciones anatómicas relacionadas con el sistema venoso ácigos. Se examinaron treinta cadáveres embalsamados con la técnica de Thiel, con edades comprendidas entre 48-98 años (18 mujeres, 12 hombres). Se determinó el nivel vertebral de terminación y el diámetro de las venas ácigos, hemiácigos, hemiácigos accesoria e intercostales superiores izquierdas, así como el nivel de terminación del lado derecho de la vena intercostal superior. El sistema ácigos se clasificó en 3 tipos; primitivo (tipo 1), de transición (tipo 2) y unicolumnar (tipo 3). El tipo 2 se dividió en 5 subgrupos (A a E) de acuerdo con el número de comunicaciones retroaórticas. El tipo 1 se observó en 3 % (n = 1), el tipo 2 en 87 % (n = 26) y tipo 3 en 10 % (n = 3) de las muestras. El nivel vertebral de terminación de las venas ácigos, hemiácigos, hemiácigos accesoria, intercostal derecho superior e intercostales superiores izquierda se presentaron entre T2 y T3, T6 y T10, T5 y T9, T2 y T4 y T2 y T4, respectivamente. La identificación y comprensión de estas variaciones anatómicas son importantes durante las investigaciones radiológicas preoperatorias y de los procedimientos quirúrgicos, especialmente en cirugía de columna vertebral, entre los niveles T7 y T12, utilizando un abordaje de toracotomía izquierda, para evitar lesiones que pueden conducir a hematomas postoperatorios.

Pre-aortic inter-azygos veins: two case reports / Venas interácigos pre-aórticas: reporte de dos casos

This report describes two cases of multiple anomalies associated with the azygos venous system. In Case 1, the hemiazygos vein drained the 9th to 11th left posterior intercostal veins. At T9 vertebral level, the interazygos vein passed obliquely and anterior to the aorta to drain into the azygos vein on the right. In Case 2, the common venous trunk formed by the accessory hemiazygos and hemiazygos veins passed anterior to the aorta to drain into the azygos vein at T9 vertebral level. These findings represent pre-aortic inter-azygos veins, which is a rare variation of the azygos venous system. Pre-aortic inter-azygos veins can mimic pathologies such as enlarged lymph nodes, tumors and aneurysms leading to misinterpretation of radiographs, computerized tomography and magnetic resonance scans. Surgeons need to be aware of this type of variation so as to avoid injury of any anomalous passing venous vessels.

Este informe describe dos casos de múltiples anomalías asociadas con el sistema venoso ácigos. En el caso 1, la vena ácigos drena las 9 y 11 venas intercostales posteriores izquierdas. A nivel de la 9 vértebra torácica, la vena interácigos pasó oblicuamente y anterior a la aorta para drenar en la vena ácigos del lado derecho. En el caso 2, el tronco venoso común formado por las venas hemiácigos accesoria y hemiácigos pasaron anterior a la aorta para drenar en la vena ácigos a nivel de la 9 vértebra torácica. Estos resultados representan venas interácigos pre-aórticas, que es una rara variación del sistema venoso ácigos. Las venas interácigos pre-aórticas pueden imitar patologías, como agrandamiento de nódulos linfáticos, tumores y aneurismas que conducen a una mala interpretación de las exploraciones por radiografías, tomografía computarizada y resonancia magnética. Los cirujanos deben ser conscientes de estos tipos de variaciones para evitar lesionarlos.

Anatomic variation of thorax drainage: absence of accessory hemiazygos vein

Formed by the azygos, hemiazygos and accessory hemiazygos veins, this system is responsible for the venous drainage of the thorax and partially of the abdomen. Abnormalities of this system are not uncommon, and many are referred to in literature. The complete agenesis of the accessory hemyazigos vein is associated with complete regression of the left posterior cardinal vein or atrophy of the left subcardinal vein. The reported case consists of the complete absence of the accessory hemiazygos vein, culminating in the drainage of the 4th, 5th, 6th, 7th and 8th left posterior intercostal veins directly into the azygos vein of a male cadaver. The importance of the theme is due to the necessity of recognizing patterns and frequencies of these variations when facing procedures addressing the mediastinum or the major vessels.

Ausência de veia cava inferior: relato de caso / Absence of the inferior vena cava: case report

A ausência congênita de veia cava inferior é achado incomum e ocasional durante exames complementares ou cirurgias do abdome. Em razão de a maioria dos pacientes sem outras malformações serem assintomáticos, há dificuldade em estimar a prevalência dessas anomalias. O objetivo deste trabalho foi relatar o caso de um paciente de 28 anos, sexo masculino, referido para radiografia de tórax devido a quadro de febre alta (39ºC) não-responsiva à medicação. Radiografia de tórax sugeriu dilatação de veia ázigos. Em inquérito dirigido para sintomas cardiovasculares, referiu dor torácica (durante atividade física e em repouso) e dispneia ocasionais durante o sono associada ao período em que intensificou a prática de exercícios. Realizada tomografia computadorizada sem contraste e, posteriormente, contrastada. As mesmas não esclareceram o caso, fazendo-se necessário angiotomografia, a qual evidenciou ausência de veia cava inferior torácica.

The congenital absence of the inferior vena cava is a rare and occasional finding at complementary exams or abdominal surgeries. As the majority of patients without other malformations are asymptomatic, it is hard to estimate the prevalence of these anomalies. Our goal was to report a case of a 28-year-old patient, male, referred to thorax X-ray due to high fever state (39ºC), nonresponder to medication. The X-ray suggested azygos vein dilatation. The interview about cardiovascular symptoms revealed thoracic pain during both physical exercises and at rest, and occasional dyspnea during sleep related to the period of intensification of physical exercises. Computadorized tomography with and without contrast did not solve the case, what explain the request of an angiotomography, that showed absence of thoracic inferior vena cava.

Partial absence of the inferior vena cava associated with bowel malformation.

A 6-year-old female child sought medical service due to a gastrointestinal malformation. During medical follow-up, partial absence of the inferior vena cava was diagnosed, a rare congenital alteration affecting the vascular drainage from the inferior segment of the body. Imaging exams were accomplished, contributing to evaluation and description of the case. Conservative treatment with oral anticoagulant was maintained. The patient presents good evolution after long-term cardiovascular follow-up.

Azygos vein diverticulum.

A 47-year-old woman, diagnosed with a diverticulum of the arch of the azygos vein, underwent surgical treatment. With nonspecific symptomatology, she presented one of the most uncommon anomalies of the large veins.

Interrupción de la vena cava inferior / Inferior vena cava interruption: US, CT and MR features

La interrupción de la vena cava inferior (VCI), con continuación con el sistema ácigos-hemiácigos, es una entidad poco común, con una incidencia de presentación del 0,6 por ciento. La más frecuente es la ausencia del segmento suprarrenal, que constituye el 90 por ciento de estas anomalías y sólo un 6 por ciento compromete el segmento renal e infrarrenal. Esta entidad puede asociarse a poliesplenia o asplenia y a situs inversus, aunque también puede presentarse aisladamente. Presentamos un paciente de sexo masculino, de 51 años, que presenta interrupción del segmento intrahepático de la VCI, con continuación de las venas ácigos y hemiácigos asociada a poliesplenia

Interrupción de la vena cava inferior / Inferior vena cava interruption: US, CT and MR features

La interrupción de la vena cava inferior (VCI), con continuación con el sistema ácigos-hemiácigos, es una entidad poco común, con una incidencia de presentación del 0,6 por ciento. La más frecuente es la ausencia del segmento suprarrenal, que constituye el 90 por ciento de estas anomalías y sólo un 6 por ciento compromete el segmento renal e infrarrenal. Esta entidad puede asociarse a poliesplenia o asplenia y a situs inversus, aunque también puede presentarse aisladamente. Presentamos un paciente de sexo masculino, de 51 años, que presenta interrupción del segmento intrahepático de la VCI, con continuación de las venas ácigos y hemiácigos asociada a poliesplenia (AU)

Lobo acessorio da veia azigos: estudo anatomo-radiologico e importancia clinico-cirurgica / Acessory lobe of azigos vein : anatomical radiologic study and clinical and surgical importance

A anomalia causada pela alteracao do trajeto da veia azigos propicia a formacao de um lobo acessorio que pode acometer ambos os pulmoes. O conhecimento previo desta variacao anatomica auxilia o medico na escolha da conduta clinico-cirurgica. Os autores propoem uma revisao de literatura associada ao relato de um caso