title: Building multidevice pipeline constructs of favorable metal coverage: a practical guide.
abstract: OBJECTIVE
  The advent of low-porosity endoluminal devices, also known as flow diverters, exemplified by the Pipeline in the United States, produced the greatest paradigm shift in cerebral aneurysm treatment since the introduction of detachable coils. Despite robust evidence of efficacy and safety, key questions regarding the manner of their use remain unanswered. Recent studies demonstrated that the Pipeline device geometry can dramatically affect its metal coverage, emphasizing the negative effects of oversizing the device relative to its target vessels. This follow-up investigation focuses on the geometry and coverage of multidevice constructs.
  
  
  METHODS
  A number of Pipeline devices were deployed in tubes of known diameters and photographed, and the resultant coverage was determined by image segmentation. Multidevice segmentation images were created to study the effects of telescoped devices and provide an estimate of coverages resulting from device overlap.
  
  
  RESULTS
  Double overlap yields a range of metal coverage, rather than a single value, determined by the diameters of both devices, the size of the recipient artery, and the degree to which strands of the overlapped devices are coregistered with each other. The potential variation in coverage is greatest during overlap of identical-diameter devices, for example, ranging from 24% to 41% for two 3.75-mm devices deployed in a 3.5-mm vessel. Overlapping devices of progressively different diameters produce correspondingly more uniform ranges of coverage, though reducing the maximum achievable value, for example, yielding a 33%-34% range for 3.75- and 4.75-mm devices deployed in the same 3.5-mm vessel.
  
  
  CONCLUSIONS
  Rational strategies for building multidevice constructs can achieve favorable geometric outcomes.
authors.affiliation: From the Departments of Radiology (M.S., E.R., T.B., P.K.N.), Bernard and Irene Schwartz Neurointerventional Radiology SectionNeurology (M.S., T.B.) maksim.shapiro@nyumc.org neuroangio@neuroangio.org.
authors.forename: M
authors.initials: M
authors.lastname: Shapiro
authors.affiliation: From the Departments of Radiology (M.S., E.R., T.B., P.K.N.), Bernard and Irene Schwartz Neurointerventional Radiology Section.
authors.forename: E
authors.initials: E
authors.lastname: Raz
authors.affiliation: From the Departments of Radiology (M.S., E.R., T.B., P.K.N.), Bernard and Irene Schwartz Neurointerventional Radiology SectionNeurology (M.S., T.B.).
authors.forename: T
authors.initials: T
authors.lastname: Becske
authors.affiliation: From the Departments of Radiology (M.S., E.R., T.B., P.K.N.), Bernard and Irene Schwartz Neurointerventional Radiology SectionNeurosurgery (P.K.N.); New York University Langone Medical Center, New York, New York.
authors.forename: P K
authors.initials: PK
authors.lastname: Nelson
mesh_terms: D001807:Blood Vessel Prosthesis; D004867:Equipment Design; D006801:Humans; D002532:Intracranial Aneurysm / Q000628:therapy*; D008670:Metals
chemical_list: D008670:Metals