title: Distal macro- and microembolization during subintimal recanalization of femoropopliteal chronic total occlusions.
abstract: OBJECTIVE
  To investigate the phenomenon of distal embolization during subintimal angioplasty with or without stenting of femoropopliteal chronic total occlusions (CTOs).
  
  
  METHODS
  This prospective study included 40 consecutive patients (35 men; mean age 65.4±9.3 years) who underwent subintimal angioplasty alone (n=14) or with stenting (n=26) of CTOs in the femoropopliteal segment. A Spider protection filter was used to capture any possible macro- or microemboli generated during balloon inflation/stenting. Arterial outflow was angiographically checked during each consecutive procedural step. All filters were examined on site for macroscopic material, while the first 20 filters underwent further histopathological qualitative and semiquantitative analysis using a 0+ to 3+ score.
  
  
  RESULTS
  There was no angiographically or clinically evident distal embolization. Macroscopic particulate debris was not detected in any filter. Histopathology confirmed the absence of macroemboli but revealed microembolic material (diameter <100 μm) in all filters (20/20). The mean number of particles detected was 9.4±4.5 (range 5-17). Histopathological findings included fibrin conglomerates (20/20), trapped erythrocytes (19/20), inflammatory cells (16/20), calcification minerals (6/20), extracellular matrix (6/20), cholesterol clefts (6/20), and endothelial cells (6/20). Captured material was classified as fresh and old thrombus in 7/20 and 4/20 cases, respectively. Semiquantitative analysis demonstrated that the collected microparticles consisted primarily of fibrin conglomerates (median score 2+), trapped erythrocytes (median score 1+), and inflammatory cells (median score 1+).
  
  
  CONCLUSIONS
  Macroscopically evident emboli were not detected following subintimal angioplasty or stenting of femoropopliteal CTOs. Microscopic debris was present in all filters. The clinical significance of the phenomenon remains to be determined.
authors.affiliation: 1 Department of Interventional Radiology, Patras University Hospital, School of Medicine, University of Patras, Greece.
authors.forename: Stavros
authors.initials: S
authors.lastname: Spiliopoulos
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Theodosiadou
authors.forename: Vasilios
authors.initials: V
authors.lastname: Koukounas
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Katsanos
authors.forename: Athanasios
authors.initials: A
authors.lastname: Diamantopoulos
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Kitrou
authors.forename: Panagiota
authors.initials: P
authors.lastname: Ravazoula
authors.forename: Dimitris
authors.initials: D
authors.lastname: Siablis
authors.forename: Dimitris
authors.initials: D
authors.lastname: Karnabatidis
mesh_terms: D000368:Aged; D000800:Angioplasty, Balloon / Q000009:adverse effects* / Q000295:instrumentation; D002908:Chronic Disease; D003251:Constriction, Pathologic; D057505:Embolic Protection Devices; D004617:Embolism / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D005263:Femoral Artery; D006115:Greece; D006801:Humans; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000175:diagnosis / Q000628:therapy*; D011150:Popliteal Artery; D011446:Prospective Studies; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome
keywords: balloon angioplasty; distal embolization; femoropopliteal disease; peripheral angioplasty; peripheral protection filter; recanalization; stent; subintimal angioplasty