title: Extreme below-the-knee interventions: retrograde transmetatarsal or transplantar arch access for foot salvage in challenging cases of critical limb ischemia.
abstract: OBJECTIVE
  To describe advanced retrograde access (transmetatarsal or transplantar arch) for endovascular treatment of critical limb ischemia (CLI) and foot salvage.
  
  
  METHODS
  From September 2011 to March 2012, 28 CLI patients (24 men; mean age 71.9 ± 10.6 years) being treated for foot salvage had failed antegrade recanalization, and percutaneous retrograde access at the pedal or plantar artery was unavailable. Advanced retrograde access techniques were required to recanalize the target vessel to restore blood flow to the compromised tissue. After local administration of verapamil to control spasm, the first dorsal metatarsal artery was preferentially accessed with a 21-G needle. When the first metatarsal artery was occluded and not fluoroscopically viewable, the plantar arch was punctured directly. After puncture, a 0.018- or 0.014-inch guidewire and microsheath were inserted for retrograde recanalization of the foot and tibial arteries with balloons sized to the target vessels.
  
  
  RESULTS
  Retrograde transmetatarsal artery access was performed in 25 cases and direct transplantar arch access in 3. Technical success (ability to deliver the balloon across the lesion and inflate it at nominal pressure) was achieved in 24 (86%) cases, with <50% residual stenosis and no complications. The 4 technical failures were due to spasm or no true lumen re-entry after successful transmetatarsal (n=3) and transplantar arch access. During a mean 5-month follow-up (range 1-8), clinical improvement was obtained in the patients having technically successful tibial and foot artery recanalization; the transcutaneous pressure improved from 12.5 ± 6.7 to 49.8 ± 9.5 mmHg. There were no major and only 8 minor amputations. Amputation-free survival estimated by Kaplan-Meier analysis was 71% at 6 months. In patients with failed advanced access, the clinical condition did not improve.
  
  
  CONCLUSIONS
  The advanced retrograde access technique appears feasible and beneficial as a rescue strategy in challenging patients with a failed antegrade approach who are unsuitable for retrograde pedal/plantar access.
authors.affiliation: Interventional Radiology Unit, Foot & Ankle Clinic, Policlinico Abano Terme, Italy. marianopalena@hotmail.com
authors.forename: Luis Mariano
authors.initials: LM
authors.lastname: Palena
authors.forename: Marco
authors.initials: M
authors.lastname: Manzi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical; D000800:Angioplasty, Balloon / Q000009:adverse effects / Q000379:methods*; D016638:Critical Illness; D018572:Disease-Free Survival; D005240:Feasibility Studies; D005260:Female; D005528:Foot / Q000098:blood supply*; D006801:Humans; D007511:Ischemia / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D053208:Kaplan-Meier Estimate; D023821:Limb Salvage; D008297:Male; D008875:Middle Aged; D011677:Punctures; D012039:Regional Blood Flow; D013997:Time Factors; D016896:Treatment Outcome; D014654:Vascular Patency