Chapter 163 - Congenital occlusion/absence IVC Flashcards
Incidence of absence IVC (AIVC)
0.3-0.5%
% of people under 30 with DVT that have AIVC
5%
When does AIVC usually happen at what age
2nd decade of life
Pathogenesis of AIVC causing DVT
low flow state + second hit (thrombophilia, other usual risks for DVT)
Association of AIVC with other congenital problems
1) Atrial septal defect
2) polysplenia
3) dysgenesis of lungs
Embryology of IVC
3 primitive veins form collaterals and connect via auto anastomosis
1) supracardinal
2) subcardinal
3) postcardinal
IVC segments and its embryologic origin
1) hepatic - hepatic sinusoids
2) prerenal - subcardinal
3) post renal - supracardinal
4) renal collar - subcardinal and postcardinal
azygous/hemiazygous - supracardinal
IVC anomaly types and embryologic cause
1) isolated left IVC: regression of right supracardinal with persistent left supracardinal
2) double IVC: both left and right supracardinal veins persist
3) segment or total atresia: failure of one or multiple segment anastomosis
Presentation of AIVC
1) incidental
2) DVT
Diagnosis of AIVC
1) clinical
2) duplex
3) axial imaging (CT/MRI)
4) conventional venogram
Duplex signs of AIVC
1) lack of respiratory phasity
2) signs of chronic DVT on usual US
3) lots of collaterals
4) direct insonation of iliocaval veins
Disadvantages of US for AIVC
1) operator dependent
2) patient factors: size, gas, cooperation
Axial imaging for AIVC pro of each
Both: anatomic characterization
CT: faster, better size resolution
MRI: time resolution better, no contrast needed
Venography in AIVC
1) real-time
2) intervene at the same time
3) anatomy deneation
Treatment of AIVC
Indication: symptom driven, not for prevention of PE
Compression + AC (lifelong)
Thrombolysis within 2-4 weeks
Surgery
CAVENT trial
1) anticoagulation vs tpa in iliofem DVT
2) better patency 47 vs 66% at 5 years in tpa
3) better freedom from PTS 41 vs 55% with tpa
tpa risk of bleeding
5-10%
In severe DVT should add this therapy
pharmacomechanical thrombectomy
faster restoration of flow
In refractory DVT from tpa need
Open reconstruction; stenting unlikely useful in AIVC
1) autologous or homograft
2) prosthetic needs lifelong anticoagulation
3) fistula not needed and can cause high output cardiac failure
Goal of treatment in AIVC
Restore previous venous collaterals with tpa and long term anticoagulation
