[Surgery for complicated accessory lobe of the azygos vein]. / Khirurgiya oslozhnennoi dobavochnoi doli neparnoi veny.

Congenital anomalies of respiratory system are quite diverse and not all of them are subject to surgical treatment. One example is accessory lobe of the azygos vein. This anomaly usually has no clinical manifestations and requires only follow-up, as well as attention in surgery on the right half of the chest for some other disease. This situation changes when complications occur, for example, purulent-inflammatory process. Therapy is not always effective, and lung tissue destruction requires surgical treatment. Progressive destruction complicates diagnosis and choosing surgical tactics. We present a rare case of severe purulent-inflammatory complication with abscess in accessory lobe of v. azygos. Anatomical abnormalities following this congenital pulmonary anomaly can cause difficulties in surgeries for other intra-thoracic diseases. The situation is especially relevant for thoracoscopic access. This report will be useful for radiologists, pulmonologists and thoracic surgeons.

CT findings of an incidental segmental aplasia of the caudal vena cava with azygos continuation in a guinea pig (Cavia porcellus).

Background: Segmental aplasia of the caudal vena cava (CVC) with azygos continuation is a congenital malformation macroscopically described in mammals including humans, dogs, and rodents. It is usually detected as an incidental finding and the final diagnosis is reached by computed tomography (CT), fluoroscopy, or post-mortem dissection. Case Description: A 3-year-old guinea pig (Cavia porcellus) presented with subacute dyspnea. A computed tomographic examination was performed for the evaluation of subtle pulmonary changes previously suspected on conventional radiography, and a segmental aplasia of the CVC with azygos continuation was identified as an incidental finding. Conclusion: According to database negative results, this is the first report describing a segmental aplasia of the CVC and azygos continuation in a guinea pig by CT.

Case of Isolated Absence of the Azygos Vein: Evaluation Using Photon-counting Detector CT.

The isolated absence of the azygos vein was incidentally found on computed tomography (CT) examination in a 60-year-old female. The exact anomaly can be evaluated on high-resolution images of 0.4-mm slice thickness with low keV using photon-counting detector CT. The azygos vein, including the azygos arch, was absent, and a mildly dilated hemiazygos vein flowed to the left brachiocephalic vein through the left superior intercostal vein. A hemiazygos vein connected the left renal vein at the level of the first lumbar vertebra. This patient was the second patient to undergo evaluation using volume rendering images. High-resolution maximum-intensity projection images were useful for assessing the anatomy. Radiation dose was decreased compared with that in conventional CT.

RF catheter ablation of AVNRT in a patient with interrupted inferior vena cava anomaly with hemiazygos continuity with persistent left superior vena cava.

Intrahepatic interruption of the inferior vena cava (IVC) with continued hemizygous is a very rare abnormality and sometimes it may be accompanied by other cardiovascular abnormalities. Continuation of the hemizygous vein draining into the right atrium through the left superior vena cava (LSVC) is much rarer. In this paper, we have presented a patient who had simultaneous IVC interrupted with persistent LSVC and suffered from Atrioventricular nodal reentrant tachycardia (AVNRT). Finally, radiofrequencies (RF) catheter ablation for AVNRT was successfully performed through a left subclavian vein access.

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.

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.

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.

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

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