Aneurisma gigante de aorta ascendente y síndrome de vena cava superior / Giant ascending aortic aneurysm and superior vena cava syndrom

Introducción: el aneurisma gigante de aorta es una entidad poco frecuente y puede cursar asintomático por años o con manifestaciones inespecíficas. El diagnóstico es imagenológico, siendo la tomografía contrastada y la angiografía por resonancia magnética los procedimientos de elección. Tiene alta mortalidad con pronóstico variable. Reporte de caso: se presenta el caso de un aneurisma gigante de aorta manifestado como síndrome de vena cava superior en una mujer de 88 años con múltiples patologías de base, quien por las características del aneurisma y sus antecedentes patológicos no fue candidata a intervención quirúrgica. Discusión: es relevante considerar esta patología en el abordaje de pacientes con síndrome de vena cava superior, para definir la posibilidad de intervención quirúrgica y mejorar el pronóstico de los pacientes. Conclusión: el aneurisma gigante de la aorta es una patología poco frecuente con clínica inespecífica, cuyo tratamiento por lo general es quirúrgico, con alta morbimortalidad a largo plazo si el diagnóstico es tardío.

Introduction: giant aortic aneurysm (AA) is a rare condition which may be asymptomatic for years or present with non-specific symptoms. Diagnosis is by imaging tests such as contrast tomography and magnetic resonance angiography of the aorta, which are considered first line for definitive diagnosis. It carries high mortality and variable prognosis. Case: herein we present a case of giant aortic aneurysm revealed by superior vena cava syndrome in an 88-year-old female patient with multiple underlying pathologies. She was not a candidate for AA surgical repair due to the features of the aneurysm and her past medical history. Discussion: it is relevant to consider AA in the approach to the patient with superior vena cava syndrome, to define treatment by surgical repair for improving prognosis. Conclusion: giant aortic aneurysm is a rare condition with non-specific features, usually treated surgically, carrying high long-term morbidity and mortality if diagnosis is delayed.

Causas anatómicas inusuales de malposición de catéteres venosos centrales / Unusual anatomical causes of malposition of central venous catheters

Resumen: La malposición de los catéteres venosos centrales se asocia a importantes riesgos, a menudo infraestimados. Aunque se han descrito algunos factores que pueden favorecer la malposición, generalmente su causa no llega a diagnosticarse y parece ser de origen multifactorial. Presentamos dos casos de malposición de catéteres venosos centrales motivadas por causas anatómicas inusuales, diagnosticadas en el perioperatorio. En el primer caso, se diagnostica una agenesia de vena cava superior en el transcurso de una sustitución mitral por esternotomía, que lógicamente se asocia con una malposición de la vía central insertada. La utilización de catéteres y dispositivos a través de venas yugulares y subclavias en pacientes con esta infrecuente patología implica importantes limitaciones y complicaciones potenciales graves. En el segundo caso, la existencia de un bocio no diagnosticado provoca la malposición bilateral y simultánea de dos catéteres venosos canalizados, en el contexto de una situación de emergencia, en ambas venas yugulares internas.

Abstract: Malposition of central venous catheters is associated with important and underestimated risks. Although some factors have been related with malposition, its cause is generally not diagnosed, and it seems to have multifactorial origin. We present two cases of central venous catheter malposition due to unusual anatomical causes, diagnosed in the perioperative period. In the first case, superior vena cava agenesis was diagnosed during mitral replacement by sternotomy, which was logically associated with malposition of the inserted central line. The use of catheters and devices through jugular and subclavian veins in patients with this infrequent pathology is associated with important limitations and serious potential complications. In the second case, an undiagnosed goiter causes bilateral and simultaneous malpositioning of two inserted central venous catheters, in the context of an emergency situation, in both internal jugular veins.

Evaluation of Inferior and Superior Vena Cava and the Vena Cava Ratio in Growth Restricted Fetuses.

OBJECTIVE: To evaluate the changes in the diameters of superior vena cava (SVC) and inferior vena cava (IVC) and to measure the ratio between SVC and IVC in growth-restricted fetuses and compare these results with normally grown fetuses. METHODS: Twenty-three consecutive patients with fetal growth restriction (FGR) (Group I) and 23 pregnant gestational age-matched controls (Group II) between 24 and 37 weeks of gestation were enrolled in the study between January 2018 and October 2018. The diameter of the SVC and IVC from inner wall to inner wall was measured in all patients by sonographic examination. The ratio between the diameter of the SVC and IVC was also measured in each patient to eliminate the gestational age factor. We have named this ratio the "vena cava ratio" (VCR). All parameters were compared between the two groups. RESULTS: The diameter of the SVC was significantly greater in the fetuses with FGR (2.6-7.7 [5.4]) than in controls (3.2-5.6 [4.1]; P = .002; P < .01). The diameter of the IVC was significantly less in the fetuses with FGR (1.6-4.5 [3.2]) than in controls (2.7-5 [3.7]; P = .035; P < .05). The VCR was between 1.1 and 2.3 and the median value was 1.8 in Group I. The VCR was between 0.8 and 1.7 and the median value was 1.2. VCR was significantly higher in fetuses with FGR (P = .001 P < .01). CONCLUSION: This study shows that VCR is higher in fetuses with growth restriction. Further studies are needed to clarify the association between VCR and antenatal prognosis and postnatal results.

Efficacy and Safety of Adjunctive and Primary Use of the TightRail Mechanical Cutting Sheath for Lead Extraction.

BACKGROUND: Rotational cutting tools are increasingly used in transvenous lead extraction. There are limited data on their safety and efficacy, particularly when used adjunctively for stalled progression. The aim of this study was to evaluate the utilization, safety, and effectiveness of mechanical rotational cutting tools for transvenous lead extraction. METHODS: Patients undergoing transvenous lead extraction at a single tertiary center (April 2015 to January 2021, n=586) were included in this retrospective analysis. The study characterized the 251 patients (42.8%) whose cases involved the TightRail mechanical cutting tool. RESULTS: Among 251 patients, 526 leads were extracted and TightRail was used for 70.5%. The TightRail was used adjunctively with the laser for 65.2% of leads, 97.8% of the time as the second tool after stalled progression. Using a multivariable logistic regression model, we found that active-fixation leads (odds ratio, 2.78 [95% CI, 1.62-4.78]; P=0.0002), dual-coil leads (odds ratio, 3.39 [95% CI, 1.87-6.16]; P<0.0001), and lead dwell time (odds ratio, 1.16 [95% CI for 1-year increase, 1.11-1.21]; P<0.0001) were factors independently associated with adjunctive TightRail use. Stalled progression requiring TightRail occurred most often in the innominate vein and superior vena cava (59.3%). The clinical success rate was 96.8%, and the rate of major adverse events was 2.8%. Only 1 major adverse event was observed during TightRail use. CONCLUSIONS: Rotational cutting with TightRail was used in 42.8% of transvenous lead extractions, predominantly in an adjunctive manner after stalled laser progression in the innominate vein and superior vena cava, and more frequently for dual-coil and leads with longer dwell times. Adjunctive TightRail use carries a low risk of major complications.

Superior Mediastinal Syndrome Misdiagnosed as Foreign Body Aspiration: A Case Report.

Superior mediastinal syndrome is a life-threatening pediatric oncological emergency that requires high level of awareness and clinical suspicion to avoid misdiagnosis and devastating outcomes. Early diagnostic evaluation and management of underlying etiology are of utmost significance for optimal results. In children, it is most commonly caused by non-Hodgkin's lymphoma and T-cell lymphoblastic leukemia. We report a case of a six-year-old boy with superior mediastinal syndrome secondary to T-cell acute lymphoblastic leukemia, initially misdiagnosed as foreign body aspiration and underwent a procedure with a life-threatening outcome.

Device Closure of Superior Sinus Venosus Atrial Septal Defects: A single centre experience.

Sinus venosus atrial septal defects present a wide variety of anatomical features and are frequently associated with partial anomalous pulmonary venous drainage of one or more right pulmonary veins. Surgical correction used to be the standard treatment. In recent times, transcatheter correction of superior sinus venosus atrial septal defects has come into vogue. The transcatheter closure of these defects with covered stents at a tertiary care centre in Oman between 2018 and 2023 is reported.

Implante de marcapasos a través de la vena cava superior izquierda persistente por ausencia de vena cava superior derecha. Reporte de un caso / Pacemaker implantation through the persistent left superior vena cava due to the absence of the right superior vena cava. Report of a case / Implante de marcapasso pela veia cava superior esquerda persistente devido à ausência da veia cava superior direita. Relato de um caso

Resumen: Introducción: la persistencia de la vena cava superior izquierda (PVCSI) tiene una prevalencia de 0.21% en la población general. Presentación del caso: masculino de 67 años de edad diagnosticado con bloqueo auriculoventricular (AV) de tercer grado y que requirió colocación de marcapasos; sin embargo, debido a la ausencia de la vena cava superior derecha, corroborado por angiotomografía, se colocó marcapasos definitivo a través de la vena cava superior izquierda persistente. Conclusión: la persistencia de la vena cava superior izquierda (PVCSI) es la anomalía venosa torácica más común. Puede causar una serie de síntomas clínicamente significativos, incluso en un corazón con anatomía normal. La colocación de marcapasos dificulta la fijación del electrodo debido al recorrido tortuoso que genera.

Abstract: Introduction: the persistence of the left superior vena cava (PLSVC) has a prevalence of 0.21% in the general population. Case presentation: 67-year-old male diagnosed with third-degree AV block, requiring pacemaker placement. However, due to the absence of a right superior vena cava, corroborated by CT angiography, a definitive pacemaker was placed through a persistent left superior vena cava. Conclusion: the persistence of the left superior vena cava (PLSVC) is the most common thoracic venous anomaly. It can cause a number of clinically significant symptoms, even in a heart with normal anatomy. Pacemaker placement makes electrode fixation difficult due to tortuous travel.

Resumo: Introdução: a persistência da veia cava superior esquerda (PVCSI) tem uma prevalência de 0.21% na população geral. Apresentação do caso: Homem de 67 anos com diagnóstico de bloqueio AV de terceiro grau, necessitando de colocação de marcapasso. No entanto, devido à ausência da veia cava superior direita, corroborada pela angiotomografia, colocou-se marcapasso definitivo através da veia cava superior esquerda persistente. Conclusão: a persistência da veia cava superior esquerda (PVCSI) é a anomalia venosa torácica mais comum. Pode causar uma série de sintomas clinicamente significativos, mesmo em um coração com anatomia normal. A colocação do marcapasso dificulta a fixação do eletrodo devido ao trajeto tortuoso.

Oclusão percutânea da comunicação interatrial do tipo seio venoso com stent coberto: a importância dos métodos de imagem para impressão de modelos tridimensionais e a melhor tomada de decisão clínica / Percutaneous occlusion of sinus venosus atrial septal defect using a covered stent: the importance of imaging methods for printing three-dimensional models and better clinical decision-making

A comunicação interatrial do tipo seio venoso superior geralmente acompanha-se de uma conexão venosa anômala de veia ou veias pulmonares superiores ou médias direitas, que drenam diretamente na veia cava superior ou, ainda, na junção cavoatrial. Relatamos o caso de uma paciente do sexo feminino, de 62 anos, com diagnóstico de comunicação interatrial do tipo seio venoso, com sobrecarga das câmaras direitas, para quem foi planejado o procedimento de oclusão percutânea do defeito por meio da realização prévia de tomografia cardiovascular e, sequencialmente, estudo anatômico tridimensional, com o software de acesso público 3D Slicer. Além disso, foi realizada a impressão do modelo em resina para inspeção e simulação de implante de um stent. A paciente foi tratada de maneira percutânea com um stent Chetham-Platinum coberto de 60mm de extensão, com oclusão total do defeito, ausência de shunts residuais e direcionamento do fluxo da veia pulmonar superior direita para o átrio esquerdo por comunicação posterior entre os átrios, condição essencial para a realização desse tipo de procedimento. O planejamento do procedimento de oclusão percutânea da comunicação interatrial do tipo seio venoso passa por avaliação criteriosa dos exames de imagem. A impressão de modelos virtuais ou físicos, derivados da angiotomografia cardíaca, é fundamental para estudo detalhado do defeito e das estruturas anatômicas associadas, minimizando a ocorrência de complicações.

A superior sinus venosus atrial septal defect is usually accompanied by an anomalous venous connection to a right superior or middle pulmonary vein or veins, draining directly into the superior vena cava or even into the cavoatrial junction. This is a case report of a 62-year-old female patient, diagnosed with a sinus venosus atrial septal defect, with overload of the right chambers, for whom a percutaneous occlusion procedure was planned, using a previous cardiovascular tomography and, sequentially, a three-dimensional anatomical study, with the publicly available software 3D Slicer. In addition, a resin model was printed for inspection and simulation of a stent implantation. The patient was treated percutaneously with a 60-mm covered Chetham-Platinum stent, with total occlusion of the defect, absence of residual shunts, and draining flow from the right superior pulmonary vein to the left atrium, through a posterior communication between the atria, a sine qua non prerequisite to perform this type of procedure. Planning of the percutaneous occlusion procedure of the sinus venosus atrial septal defect involves careful evaluation of imaging tests. The printing of virtual or physical models, derived from computed tomography angiography of the heart, is essential for a detailed study of the defect and associated anatomical structures, minimizing the occurrence of complications.

[Superior vena cava syndrome associated with bilateral angle closure glaucoma]. / A vena cava superior szindrómához társuló kétoldali zárt zugú glaucoma.

Superior vena cava syndrome is a set of symptoms resulting from partial or complete blockage of the superior vena cava. In the majority of cases, it develops secondary to lung tumors and lymphoma. It is characterized by edema of the head, neck, and upper limbs, large veins, and dyspnoea. Ophthalmological changes related to the syndrome rarely occur: eyelid swelling, conjunctival chemosis and suffusion have been described previously, and in one case, elevated episcleral pressure was also reported. Our 57-year-old female patient's superior vena cava syndrome was resolved with stent placement, and her small cell lung tumor was treated with chemotherapy. As part of the syndrome, he complained of bilateral blurred vision with a history of 4 months. During his examination, we found a bilateral closed angle, an intraocular pressure of 60 mmHg on both sides, and severe visual impairment. We performed a lens exchange combined with better semolysis, which achieved a significant reduction in intraocular pressure and managed to preserve the remaining visual acuity. After Nd:YAG laser iridotomy on the left eye, we started antiglaucoma drop treatment to reduce pain. After phacoemulsification, the morphology of the anterior chamber in the right eye improved significantly, which could be quantified by anterior segment optical coherence tomography. The ophthalmic parameters remained stable during the treatment of the underlying disease. The purpose of this publication is to draw attention to the ophthalmic symptoms of vena cava syndrome as well as to present the ophthalmic condition that sometimes accompanies the syndrome causing rapid, severe visual impairment, which, to our knowledge, has not been described before. Orv Hetil. 2022; 163(49): 1967-1971.

Prospective Evaluation of the Correlation Between Gated Cardiac Computed Tomography Detected Vascular Fibrosis and Ease of Transvenous Lead Extraction.

BACKGROUND: Difficulty of lead extraction does not track well with procedural complications, but several small retrospective studies have lead fibrosis on computed tomography as an important indicator of difficult lead extraction. The purpose of the present study was to apply a standardized gated cardiac computed tomography (CT) protocol to assess fibrosis and study it prospectively to examine the need for powered sheaths and risk outcomes. METHODS: We performed a prospective, blinded, multicenter, international study at high-volume lead extraction centers and included patients referred for transvenous lead extraction with at least one lead with a dwell time >1 year and ability to receive a cardiac CT. The degree of fibrosis (as measured by amount of lead adherence to vessel wall) was graded on a scale of 1 to 4 by dedicated CT readers in 3 zones (vein entry to superior vena cava, superior vena cava, and right atrium to lead tip). The primary outcome of the study was number of extractions requiring powered sheaths at zone 2 for each fibrosis group. RESULTS: A total of 200 patients were enrolled in the trial with 196 completing full gated CT and lead extraction analysis. The primary endpoint of powered sheath (laser and mechanical) sheath use was significantly higher in patients with higher fibrosis seen on CT (scores 3+4; 67.8%) at the zone 2 compared to patients with lower fibrosis (scores 1+2; 38.6%; P<0.001). There were 5 major complications with 3 vascular lacerations all occurring in zone 2 in the study. CONCLUSIONS: Gated, contrasted CT can predict the need for powered sheaths by identification of fibrosis but did not identify an absolute low-risk cohort who would not need powered sheaths. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03772704.

Vena Cava Superior Syndrome Six Years after Central Venous Catheter Removal in a Patient on Hemodialysis.

Vena cava superior (VCS) syndrome is rarely seen as a complication of central-venous-catheter placement. Usually, the syndrome appears when the presence of the catheter causes intraluminal obstruction or thrombosis. In this case report, however, we describe a patient on intermittent hemodialysis who had been free of any venous central line for over 6 years, presented with a VCS syndrome. The CT scan showed an absent VCS without extravascular compression. Previous catheter placement was diagnosed as the case of the VCS syndrome. It is important to realize that VCS syndrome can occur late after removal of central venous catheters, and thus, clinicians should be aware of its symptoms in any patient who has had an upper central line in the past medical history.

Persistent left superior vena cava as an incidental finding in the introduction of a transient pacemaker: A case report / Vena cava superior izquierda persistente como hallazgo incidental en la introducción de un marcapasos transitorio: informe de un caso

The persistent left superior vena cava is the most common venous anomaly in the systemic drainage in adults and tends to be asymptomatic. The persistent left superior vena cava causes rhythm disorders such as tachyarrhythmias or bradyarrhythmias. We report a case of persistent left superior vena cava diagnosed in a 53-year-old female patient admitted due to an acute coronary syndrome associated with unstable bradycardia. A transvenous peacemaker impressed the left atrium; therefore, a transthoracic echocardiogram was required to diagnose persistent left superior vena cava. The patient needed management with percutaneous intervention; she had an adequate evolution and subsequent discharge from the intensive care unit

La vena cava superior izquierda persistente es la anomalía venosa más frecuente en el drenaje sistémico en adultos; tiende a ser asintomática, pero causa trastornos del ritmo como taquiarritmias o bradiarritmias. Se presenta un caso de vena cava superior izquierda persistente diagnosticada en una paciente de 53 años hospitalizada por un síndrome coronario agudo asociado a bradicardia inestable. Un marcapasos transvenoso dejó una impresión en la aurícula izquierda, por lo que se requirió un ecocardiograma transtorácico para diagnosticar la vena cava superior izquierda persistente. La paciente necesitó una intervención percutánea con una adecuada evolución y se le dio el alta de la unidad de cuidados intensivos.

Síndrome de vena cava superior: una serie de casos consecutivos en pacientes internados en un hospital terciario universitario / Superior vena cava syndrome: a consecutive case series of in-hospital patients in a tertiary teaching hospital

Introducción: el síndrome de vena cava superior resulta de la obstrucción del flujo sanguíneo a través de este vaso. Casi la totalidad de los casos en la actualidad se asocian con tumores malignos. Existen controversias acerca del manejo apropiado de este cuadro. Actualmente, las terapias endovasculares son consideradas de elección. Materiales y métodos: se recolectaron y describieron, a partir de datos de la historia clínica electrónica, los casos de pacientes mayores de 18 años internados ­de forma consecutiva, que desarrollaron el síndrome­ en el Hospital Italiano de Buenos Aires en 2021. Se constataron las características basales, los tratamientos recibidos y los desenlaces clínicos intrahospitaliarios de cada uno de ellos. Resultados: un total de cinco pacientes fueron incluidos en el presente estudio y seguidos durante su instancia intrahospitalaria. Todos los casos descriptos fueron secundarios a enfermedades oncológicas. La mayoría de los pacientes presentaron un cuadro de moderada gravedad según las escalas utilizadas. En cuatro de cinco pacientes se optó por terapias endovasculares y dos de ellos fallecieron durante la internación. Discusión: existen controversias respecto del tratamiento óptimo del síndrome de vena cava superior, y heterogeneidad en la práctica clínica. Los estudios futuros deberían centrarse en identificar a aquellos pacientes que más probablemente se beneficien de las estrategias terapéuticas endovasculares, anticoagulantes o antiagregantes. (AU)

Introduction: superior vena cava syndrome results from an obstruction of blood flow through this vessel. Currently, almost all cases are associated with malignancies. There are controversies about the optimal management of this syndrome. Endovascular therapies are considered the first-line therapy. Material and methods: we collected clinical, laboratory and pharmacological data from patients admitted at the Hospital Italiano de Buenos Aires, between January 1st and November 1st 2021 with a diagnosis o superior vein cava syndrome. Baseline characteristics, treatment strategies and clinical outcomes were recorded. Results: a total of five patients were included in the present study. All cases were malignancy-related. Most of the patientsdeveloped moderate symptoms. Four out of five patients were treated with endovascular therapies and two patients died during hospitalization. Discussion: controversies regarding optimal management of the superior vena cava syndrome remain. Future research should focus on identifying those patients who are most likely to benefit from endovascular, anticoagulant or antiplatelet therapeutic strategies. (AU)

Double-sided superior vena cava: developmental considerations associated with the thymic veins / Vena cava superior de doble cara: consideraciones de desarrollo asociadas con las venas tímicas

SUMMARY: The superior vena cava is usually located only on the right side, but persistence of the left superior vena cavais observed in about 0.3 to 0.5 % of adults. A routine dissection of the cadaver of a 91-year-old Japanese female, whose cause of death was sepsis due to cholecystitis, was performed at Nagasaki University and revealed a double-sided superior vena cava. On the right side, the superior vena cava opened to the right atrium, while on the left, it opened into the extended coronary sinus. Veins in the left head, neck and upper limb regions joined to form the persistent left superior vena cava, with eventual drainage into the expanded coronary vein. An anastomosing branch occurred between each superior vena cava, and two thymic veins opened to the anastomosing branch. The azygos vein in the azygos venous system opened into the right superior vena cava, whereas a hemi-azygos vein opened into the azygos vein. The accessory hemi-azygos vein also opened into the azygos vein and opened cranially into the left superior vena cava. The left supreme intercostal vein also opened into the left superior vena cava. Several studies have reported a persistent left superior vena cava and the various considerations for its occurrence. Here, we propose a new hypothesis for the embryonic development of the persistent left superior vena cava with the thymic vein. This hypothesis essentially states that the left brachiocephalic vein fails to mature due to inadequate venous return from the thymic vein during the embryonic period, and the left superior vena cava then remains to maintain venous return from the left head, neck and upper limb. We also discuss the clinical significance of the persistent left superior vena cava.

RESUMEN: Usualmente la vena cava superior se localiza solo en el lado derecho, sin embargo en aproximadamente 0,3 a 0,5 % de los adultos se observa la persistencia de la vena cava superior izquierda. En la Universidad de Nagasaki se realizó una disección de rutina del cadáver de una mujer japonesa de 91 años, cuya causa de muerte fue sepsis debido a una colecistitis. El cuerpo presentaba una vena cava superior doble. En el lado derecho, la vena cava superior llegaba al atrio derecho, mientras que en el lado izquierdo drenaba al seno coronario. Las venas de las regiones de la cabeza, el cuello y del miembro superior izquierdo formaban la vena cava superior izquierda persistente, con drenaje hacia la vena coronaria. Se observó una rama anastomótica entre cada vena cava superior y dos venas tímicas drenaban a la rama anastomótica. La vena ácigos drenaba a la vena cava superior derecha, mientras que una vena hemiácigos drenaba a la vena ácigos. La vena hemiácigos accesoria también drnaba en la vena ácigos y cranealmente lo hacia la vena cava superior izquierda. La vena intercostal suprema izquierda drenaba en la vena cava superior izquierda. Varios estudios han informado una vena cava superior izquierda persistente y las diversas consideraciones para su aparición. Aquí, proponemos una nueva hipótesis para el desarrollo embrionario de la vena cava superior izquierda persistente con la vena tímica, que esencialmente establece que la vena braquiocefálica izquierda no se dearrolla debido a un retorno venoso inadecuado de la vena tímica durante el período embrionario, y se mantiene la vena cava superior izquierda para el retorno venoso de la cabeza, el cuello y el miembro superior izquierdo. Además se informa de la importancia clínica de la persistencia de la vena cava superior izquierda.

Using CT to evaluate mediastinal great vein invasion by thymic epithelial tumors: measurement of the interface between the tumor and neighboring structures.

OBJECTIVES: For thymic epithelial tumors, simple contact with adjacent structures does not necessarily mean invasion. The purpose of our study was to develop a simple noninvasive technique for evaluating organ invasion using routine pretreatment computed tomography (CT). METHODS: This retrospective study analyzed the pathological reports on 95 mediastinal resections performed between January 2003 and June 2020. Using CT images, the length of the interface between the primary tumor and neighboring structures (arch distance; Adist) and maximum tumor diameter (Dmax) was measured, after which Adist/Dmax (A/D) ratios were calculated. Receiver operating characteristic (ROC) curves were used to analyze the Adist and A/D ratios. RESULTS: An Adist cut-off of 37.5 mm best distinguished between invaded and non-invaded mediastinal great veins based on ROC curves. When Adist > 37.5 mm was used for diagnosis of invasion of the brachiocephalic vein (BCV) or superior vena cava (SVC), the sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under the ROC curve for diagnosis of invasion were 61.9%, 92.5%, 81.25%, 82.2%, 81.97%, and 0.76429, respectively. Moreover, there were significant differences between BCV/SVC Adist > 37.5 mm and ≤ 37.5 mm for 10-year relapse-free survival and 10-year overall survival (p < 0.01). CONCLUSIONS: When diagnosing invasion of the mediastinal great veins based on Adist > 37.5 mm, we achieved a higher performance level than the conventional criteria such as irregular interface with an absence of the fat layer. Measurement of Adist is a simple noninvasive technique for evaluating invasion using CT. Key Points • Simple contact between the primary tumor and adjacent structures on CT does not indicate direct invasion. • Using CT images, the length of the interface between the primary tumor and neighboring structures (arch distance; Adist) is a simple noninvasive technique for evaluating invasion. • Adist > 37.5 mm can be a supportive tool to identify invaded mediastinal great veins and surgical indications for T3 and T4 invasion by thymic epithelial tumors.