A RARE CASE OF HISTOPLASMA CAUSING OBLITERATION OF THE SUPERIOR VENA CAVA AND SUBSEQUENT DEVELOPMENT OF COLLATERAL CIRCULATION

ABSTRACT

SESSION TITLE Critical Cardiovascular Disorders SESSION TYPE Rapid Fire Case Reports PRESENTED ON 10/18/2022 1015 am - 1110 am INTRODUCTION: Physicians are educated on the traditional pathways of sanguineous return of the head and neck through the superior vena cava (SVC). There are known causes of disruption of this system such as SVC syndrome and malignancy causing compression, delayed transit or invasion of these vessels. While compensatory angiogenesis is not a new concept, it has been primarily documented in cases involving coronary artery circulation or congenital heart defects. Here, we present a rare case of the development of left-sided collateral flow in lieu of a right sided SVC with connection to the IVC as a complication of histoplasma infection. CASE PRESENTATION Our patient was a 67-year female with a past medical history of histoplasmosis, asthma and diabetes who presented with a chief complaint of shortness of breath. Shortly following admission, she was diagnosed with COVID19. In the course of her diagnostic evaluation, she was noted to have significant abnormalities of her thoracic vasculature. More specifically, she had developed calcified granulomas that included a large old calcified granuloma of her right hilum that caused a complete obliteration of her SVC and right middle lobe airways. Her right middle lobe airways had evidence of chronic scarring with development of left sided collateral circulation. Her collateral flow went through her innominate vein into her azygos system and from there into her inferior vena cava and back to her heart. DISCUSSION: It is well established in the literature that histoplasma can lead to scarring and granulomatous changes within lung parenchyma. Our case is unique in the location where the patient developed a granuloma. The close proximity to the SVC over time led to the complete obliteration of the vessel and as a compensatory mechanism her body developed collateral circulation to the left side via her azygous vein and IVC. While we were unable to find similar cases in the literature specifically caused by histoplasma, other phenomena have led to the development of collateral circulation within the lungs. Specifically, Genta et. al. published a case report of an acute pulmonary vein occlusion leading to the development of collateral circulation through the patients' bronchial veins and into the azygous & hemiazygos system similar to our patient. One of the clinical implications for this patient during her hospitalization was the severity of her illness with COVID19. She did require treatment in the intensive care unit. This prompted a discussion among the treatment team regarding developing a plan of action for central line placement should this patient have required vasopressor support. CONCLUSIONS: This case stresses the importance of understanding primary anatomy in order to comprehend potential variants and predict future consequences for patients. It also highlights how sequela of chronic conditions can impact treatment plans. Reference #1 Yu CH, Chen MR. Clinical investigation of systemic-pulmonary collateral arteries. Pediatr Cardiol. 2008 Mar;29(2)334-8. doi 10.1007/s00246-007-9086-y. Epub 2007 Sep 18. PMID 17876652. Reference #2 Schaper W. Development of the collateral circulation History of an idea. Exp Clin Cardiol. 2002 Fall;7(2-3)60-3. PMID 19649224;PMCID PMC2719163. Reference #3 Genta PR, Ho N, Beyruti R, Takagaki TY, Terra-Filho M. Pulmonary vein thrombosis after bilobectomy and development of collateral circulation. Thorax. 2003 Jun;58(6)550-1. doi 10.1136/thorax.58.6.550. PMID 12775876;PMCID PMC1746717. DISCLOSURES No relevant relationships by Alessandra Carrillo No relevant relationships by Chetachi Odelugo No relevant relationships by Shil Punatar No relevant relationships by Ravi Sundaram