Introduction : Agenesis of the inferior vena cava (IVC) is a rare abnormality that occurs in less than 1% of the population. The origin of the inferior vena cava is a complex process that occurs between the sixth and eighth week of gestation. When the process of formation of the vena cava incompletely occurs or it does not occur, we have a compensatory dilatation of the azygos system to help the venous drainage of the lower segment of the body.(1,2)
Case presentation :
a 47-year-old male come to our clinic in 07/02/2019 complaining of chest pain , shortness of breath and cough for the previous 5 days . The Chest pain was retrosternal , sudden in onset and was not radiated or referred . In addition , the pain was severe , dull in character and there were no reported exacerbating factors . It was associated with shortness of breath at rest and cough . On examination , the patient was ill- looking and dyspneic with a respiratory rate of 30 . He was pale and axillary temperature was 38.1 . Blood pressure was 110/73 and the Mean Arterial Blood Pressure (MAP) was 82 . Finally , SpO2 was 90 % on room air improving to 94% with high-flow oxygen via mask .
Regarding cardiovascular examination , there was pulsations in the neck which was found to be an arterial pulsation . JVP was not raised . Pulse was 139 , sinus rhythm , good volume , normal character and there was no radio-radial or radio-femoral delay . Precordium examination was normal . Chest examination was also normal apart from some transmitted sounds and possible fine crackles over lower zones . Abdominal examination revealed tortuous , snake-like protrusions extending from the epigastrium down about 2-3 cm from the midline in the left side radiating away from the umbilicus . In addition , there are few scattered swellings in the left lumbar and the left iliac regions . (Figure 1) . These swellings were found to be engorged superficial veins . Otherwise , the rest of abdominal examination was unremarkable .
On Examination of the lower limbs , the left lower limb was swollen up to the knee and it was darker in color as compared to the other limb . Also , there were multiple crustations and scratch marks more prominent on the medial ankle extending medially just below the knee but there were no ulcers . The limb was pitting and temperature was normal . Later on , a diagnosis of DVT was confirmed using Doppler U/S scan . Clinically , the right lower limb was completely normal .
Thereafter, a set of Investigations were requested . CTPA confirmed a diagnosis of pulmonary embolism ( PE ) . CXR was normal . CT chest revealed dilated thrombosed azygos veins , subpleural honeycombing , early traction bronchiectasis , reticular interstitial thickening and lung architectural distortion . (Figure 2) . CT angiography for the lower limbs was completely normal .The patient has a previous venography that was done many years ago but unfortunately , it was not available at the moment . It showed complete absence of inferior vena cava and dilated azygous and hemi-zygous venous systems more in the right side .This finding was also noted in the abdominal CT ( Figure 3 )
BNP was high at a level of 700 pg/mL .He received fractionated heparin 60 mg and warfarin 5 mg was thereafter continued with warfarin in addition to analgesia . The patient’s condition was improved , SOB and chest pain disappeared and repeated BNP was normal at a level of 10 pg/ml . The patient has had several episodes like this before and he was admitted at least once to the hospital for treatment of Pulmonary embolism . The diagnosis is Congenital absence of Inferior vena cava complicated by recurrent lower limb DVT and PE . Further investigations were requested to rule out other causes of VTE including Coagulation factors . Unfortunately , we could not be able to view the results of these tests because the patient did not bring them back later .
Author Contribution : Mohammed I Alfaki and Asma Abdallah : Were involved in selection of the case . In addition , they worked together in writing and editing the manuscript . Samoal Dafallah : He supervised the case presentation and management . He guided the process of selection and involved in final approval of the manuscript . All authors were involved in the editing and final approval of the manuscript.