title: Persistence in Coil-Embolized Pulmonary Arteriovenous Malformations with Feeding Artery Diameters of 3 mm or Less: A Retrospective Single-Center Observational Study.
abstract: OBJECTIVE
  To assess persistence in coil-embolized pulmonary arteriovenous malformations (PAVMs) with feeding artery diameters ≤ 3 mm.
  
  
  METHODS
  Fifty-eight patients (21 male, 37 female; mean age, 43 y; range, 13-71 y) with 141 simple-type PAVMs treated from 2004 to 2014 were analyzed retrospectively. Inclusion criteria were one or more PAVMs with feeding artery diameters ≤ 3 mm ("small PAVMs"), treatment with coil embolization, and presence of a follow-up chest computed tomographic (CT) angiogram at approximately 6 months. Feeding artery diameter, total coil length, and coil nest-to-PAVM sac distance were measured on arteriographic images. Coil packing density was estimated. Persistence was defined as less than 70% reduction in PAVM sac size and was assessed for each PAVM with respect to previous arteriogram or CT angiogram. Each variable was statistically tested for association with persistence.
  
  
  RESULTS
  On follow-up CT arteriography, 111 of 141 PAVMs (79%) showed a 70% or greater reduction in size of the sac and were deemed not persistent. The remaining 30 (21%) with unchanged or minimally reduced sac sizes were classified as persistent. Feeding artery diameter, coil size, quantity of coils, shape of coils, coil nest length, compaction, and visible packing density did not affect persistence, but coil nest-to-sac distance was directly correlated with persistence (P < .006). This result held true even with nest-to-sac distances of less than 1 cm.
  
  
  CONCLUSIONS
  Small PAVMs have a high persistence rate after coil embolotherapy. Most previously described risk factors for PAVM persistence do not seem to apply to these PAVMs, with the exception of coil nest-to-sac distance.
authors.affiliation: Perelman School of Medicine, School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Elliot J
authors.initials: EJ
authors.lastname: Stein
authors.affiliation: Biostatistics Consulting Unit, Office of Nursing Research, School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Jesse L
authors.initials: JL
authors.lastname: Chittams
authors.affiliation: Biostatistics Consulting Unit, Office of Nursing Research, School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Mary
authors.initials: M
authors.lastname: Miller
authors.affiliation: Department of Radiology, Division of Interventional Radiology, and Hereditary Hemorrhagic Telangiectasia Center of Excellence, Hospital of the University of Pennsylvania, Perelman School of Medicine, 1 Silverstein, 3400 Spruce St., Philadelphia, PA19104. Electronic address: scott.trerotola@uphs.upenn.edu.
authors.forename: Scott O
authors.initials: SO
authors.lastname: Trerotola
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001165:Arteriovenous Malformations / Q000000981:diagnostic imaging / Q000628:therapy*; D000072226:Computed Tomography Angiography; D004621:Embolization, Therapeutic / Q000009:adverse effects / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D015143:Philadelphia; D010690:Phlebography; D011651:Pulmonary Artery / Q000002:abnormalities* / Q000000981:diagnostic imaging; D011667:Pulmonary Veins / Q000002:abnormalities* / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult