RT Book, Section
A1 Peck, Tyler J.
A1 Rodriguez-Lopez, Josanna M.
A2 Grippi, Michael A.
A2 Antin-Ozerkis, Danielle E.
A2 Dela Cruz, Charles S.
A2 Kotloff, Robert M.
A2 Kotton, Camille Nelson
A2 Pack, Allan I.
SR Print(0)
ID 1195008477
T1 Pulmonary Arteriovenous Malformations
T2 Fishman’s Pulmonary Diseases and Disorders, 6e
YR 2023
FD 2023
PB McGraw-Hill Education
PP New York, NY
SN 9781260473988
LK accessmedicine.mhmedical.com/content.aspx?aid=1195008477
RD 2024/04/24
AB In  the  normal  pulmonary  circulation,  blood  leaves  the  right  ventricle  of  the  heart  via  the  pulmonary  artery,  and  the  entire  blood  volume  is  routed  to  the  pulmonary  capillary  bed  adjacent  to  alveoli,  allowing  for  gas  exchange.  The  normal  diameter  of  blood  vessels  making  up  the  pulmonary  capillary  bed  is  approximately  6  µm.1  After  drainage  from  the  pulmonary  capillaries,  the  blood  then  returns  to  the  heart  via  the  pulmonary  veins.  Pulmonary  arteriovenous  malformations  (PAVMs)  are  abnormal  vascular  connections  between  pulmonary  arteries  and  pulmonary  veins,  preventing  exposure  of  blood  to  normal  pulmonary  capillaries  and  many  times  leading  to  hypoxemia  due  to  shunting  of  deoxygenated  blood  into  the  pulmonary  venous  system  and  into  the  systemic  circulation.  Additionally,  the  size  of  these  abnormal  connections  is  typically  larger  than  the  size  of  pulmonary  capillaries,  allowing  for  transmission  of  particles  in  the  blood  stream  (e.g.,  venous  thromboemboli)  from  the  venous  circulation  into  the  arterial  circulation,  leading  to  complications  like  stroke  or  septic  emboli.  Pulmonary  AVMs  are  commonly  aneurysmal  and  can  frequently  be  seen  macroscopically  on  advanced  imaging  (e.g.,  CT  angiography).