Congenital absence of inferior vena cava

Abstract

In their report, M Ruggeri and colleagues (Feb 10, p 441)1Ruggeri M Tosetto A Castaman G Rodeghiero F Congenital absence of the inferior vena cava: a rare risk factor for idiopathic deep vein thrombosis.Lancet. 2001; 357: 441Summary Full Text Full Text PDF PubMed Scopus (185) Google Scholar point out the clinical relevance of the congenital absence of the inferior vena cava (IVC) in young patients (<30 years) as a potential independent risk factor for deep vein thrombosis (DVT). In the past 23 months, we have assessed 21 young patients with objectively documented acute venous thromboembolism (15 with isolated DVT, four with isolated pulmonary embolism, and two with DVT and pulmonary embolism). As part of a diagnostic screening in the emergency room,2Siragusa S Porta C Tatoni P et al.A combined approach applied by emergency department physicians in the initial management of acute deep vein thrombosis.Haematologica. 2000; 85: 290Google Scholar in case of non-compressibility of the common femoral vein,3Lensing AWA Prandoni P Brandjes D et al.Detection of deep vein thrombosis by real time B-mode ultrasonography.N Engl J Med. 1989; 320: 342-345Crossref PubMed Scopus (813) Google Scholar we apply an ultras on ographic investigation of the legs from distal veins to the inferior vena cava (IVC). Because of this approach, aplasia or agenesia of the IVC have been suspected and subsequently confirmed by computed tomography in two cases (9–5% [95% CI 2·7–21·7]).4Bass JE Redwine MD Kramer LA Huynh PT Harris JH Spectrum of congenital anomalies of the inferior vena cava: sectional imaging findings.Radiographics. 2000; 20: 639-652Crossref PubMed Scopus (471) Google Scholar The table shows the clinical characteristics of the patients. Patient 1 had an evident compensatory enlargement of the vena azygos. This patient was referred to us because of signs and symptoms of acute DVT with respiratory failure; perfusion-ventilation lung scanning confirmed the presence of pulmonary embolism. Patient 2 was a young woman who developed bilateral leg swelling in absence of evident risk factors. In these two cases, the mutation for factor V Leiden (G1691 A) was diagnosed.TableCharacteristics of patients with acute VTE, AIVC, and thrombophiliaCharacteristicsPatient12SexMaleFemaleAge at DVT diagnosis2824(years)Veins affectedLeft (femoral-iliac)BilateralSymptomatic PEYesNoCoagulation abnormalitiesYes*Factor V Leiden.Yes*Factor V Leiden.Total months on oral anticoagulantsCurrent12 monthsTotal follow-up11 months19 monthsRecurrence after anticoagulation··NoVTE=venous thromboembolism; AIVC=absence of inferior vena cava; DVT=deep vein thrombosis; PE=pulmonary embolism.* Factor V Leiden. Open table in a new tab VTE=venous thromboembolism; AIVC=absence of inferior vena cava; DVT=deep vein thrombosis; PE=pulmonary embolism. The prevalence of the acute IVC in our young population is apparently higher than that reported by Ruggeri and colleagues. Although our approach required computed tomography, only in the case of suspected IVC alterations, this approach seems to be effective for detecting at least an equal number of acute IVC than that detected by routine computed tomography.1Ruggeri M Tosetto A Castaman G Rodeghiero F Congenital absence of the inferior vena cava: a rare risk factor for idiopathic deep vein thrombosis.Lancet. 2001; 357: 441Summary Full Text Full Text PDF PubMed Scopus (185) Google Scholar In conclusion, acute IVC seems to be a not so rare a finding in young patients with confirmed acute venous thormboembolism. Potential advantages of ultrasonography over computed tomography for detecting acute IVC and the weight of congenital thrombophilia in these patients should be investigated in larger series.