Revealing the Rare: Prenatal Diagnosis of Inferior Vena Cava Aneurysm
Miraç Özalp1, Murat İbrahim Toplu 2, Doğan Çağrı Tanrıverdi3, Türkay Sarıtaş3
1 Associate professor, M.D., Prof.Dr.Cemil Taşcıoğlu City Hospital, Department of Perinatology, İstanbul, Turkey, ozalpmirac@gmail.com
Orcid No: 0000-0002-2255-1642
2 M.D., Prof.Dr.Cemil Taşcıoğlu City Hospital, Department of Gynecology and Obstetrics, İstanbul, Turkey, mitoplu@gmail.com
Orcid No: 0000-0003-1358-9099
3 M.D. Prof.Dr.Cemil Taşcıoğlu City Hospital, Department of Pediatric Cardiology, İstanbul, Turkey, dctanriverdi@outlook.com
Orcid No:0000-0002-9871-1155
3 Professor, M.D., Prof.Dr.Cemil Taşcıoğlu City Hospital, Department of Pediatric Cardiology, İstanbul, Turkey, turkaysaritas@yahoo.com
Orcid No: 0000-0003-0434-2545
Corresponding Author: Murat İbrahim Toplu
Prof.Dr.Cemil Taşcıoğlu City Hospital, Department of Gynecology and Obstetrics,
İstanbul, Turkey
Telephone: +905317262517
e-mail: mitoplu@gmail.com
Abstract
This case report highlights the prenatal diagnosis of a rare saccular inferior vena cava (IVC) aneurysm. A 25-year-old gravida 4 para 1 patient underwent detailed ultrasonography at 20 weeks of gestation, revealing a 15 x 10 x 14 mm infrarenal IVC aneurysm. Genetic analysis identified a de novo 2p16.3 deletion of uncertain significance. Serial imaging showed progressive aneurysm dilation and mild cardiomegaly. Postnatal CT angiography confirmed the aneurysm, and anticoagulant therapy was initiated. This report underscores the importance of detailed prenatal imaging and genetic evaluation in the identification and management of rare vascular anomalies, contributing to the understanding of their clinical implications.
Inferior vena cava (IVC) aneurysm, a scarce condition, presents with a diverse range of anatomical and clinical manifestations1. Since its initial documentation by Oh et al. in 1973, 59 IVC aneurysms have been sporadically reported in the literature, as comprehensively reviewed by Wu et al. in 20182,3. These cases, spanning an age range of 2 to 89 years, underscore the unusual nature of this condition. This report discusses a unique case of IVC aneurysm identified in the prenatal period.
A 25-year-old gravida 4 para 1 patient with a history of cesarean section presented at 20 weeks of gestation for a detailed ultrasound scan. No prenatal screening tests had been conducted, and no additional features were noted in the patient’s medical history. Ultrasound examination revealed a saccular IVC aneurysm measuring 15 x 10 x 14 mm, extending from the right infrarenal region to the upper border of the bladder (Figure 1) (Videoclip S1-S2). The portal veins, ductus venosus, and hepatic veins appeared normal. Fetal echocardiography identified no abnormalities except for an echogenic cardiac focus in the left ventricle. After counseling, amniocentesis was performed at 23 weeks based on the couple’s decision. Microarray analysis revealed a 35.7 kB heterozygous deletion in the 2p16.3 region, classified as a variant of uncertain significance (VUS). Literature indicates partially overlapping pathogenic findings in this region 4,5. The clinical exome panel detected no pathogenic variants or VUS. Analysis of the parents’ peripheral blood samples showed no similar changes, and the deletion was deemed de novo.
Routine assessments throughout pregnancy, including Doppler parameters, TORCH serology, and oral glucose tolerance test results, were within normal limits. At 33 weeks, the fetal IVC aneurysm measured 23 x 21 x 26 mm, and the heart-to-chest circumference ratio was 65%, suggesting cardiomegaly (Figure S1). The foramen ovale flap extended distally to the mitral valve by 8.5 mm, and a foramen ovale aneurysm was observed (Figure S2). From this examination onward, the fetal abdominal circumference remained consistently above the 97th percentile. At 35 weeks, the patient presented to the emergency department in active labor and delivered a live female infant weighing 2830 g by cesarean section. On the first postnatal day, computed tomography angiography confirmed a 15 mm saccular aneurysm in the IVC, while the thoracic and abdominal aorta and branches appeared normal (Figure 2). The newborn was started on anticoagulant therapy, and follow-up is ongoing. Written informed consent was obtained from the family for publication.
IVC aneurysms, although rare, span a broad spectrum of clinical presentations, ranging from asymptomatic incidental findings to life-threatening conditions 6. To the best of current knowledge, this case represents the first documented instance of an IVC aneurysm diagnosed in the prenatal period. Thompson et al. proposed a classification for IVC aneurysms based on etiology, categorizing them as Type 1 congenital, Type 2 acquired, and Type 3 secondary to arteriovenous fistula 7. Gradman et al. further classified IVC aneurysms by anatomical and embryological characteristics into four types: Type 1 includes aneurysms of the suprahepatic IVC without venous obstruction; Type 2 involves aneurysms with interruptions above or below the hepatic vein; Type 3 represents infrarenal IVC aneurysms without venous obstruction; and Type 4 includes all other IVC aneurysms 8. In this case, the IVC aneurysm was infrarenal and congenital. Types 2-4 are associated with higher complication rates, including aneurysm rupture, thrombosis in the deep leg veins or the IVC, and pulmonary embolism 3,9. Treatment options for IVC aneurysms include conservative management, ligation, endovascular stent-graft, and end-to-end anastomosis; however, due to the rarity of IVC aneurysms, no consensus has been reached regarding treatment strategies 6,9. Decisions on conservative or surgical management should consider thromboembolism risk, associated conditions, clinical scenarios, surgical risks, and patient preferences holistically.
None of the authors have any conflicts of interest to declare.