title: Aortic stent-grafting with transrenal fixation: use of newly designed spiral Z-stent endograft.
abstract: OBJECTIVE
  To evaluate the feasibility and efficacy of a newly designed stent-graft placed across the renal arteries for exclusion of abdominal aortic aneurysms (AAAs) with short or tortuous proximal necks.
  
  
  METHODS
  Among a group of AAA patients treated with endovascular grafting, 5 had tortuous proximal necks and 13 had necks <20 mm (mean 13 mm). In these 18 cases, a 2- to 3-cm uncovered segment of the stent-graft was placed transrenally using a catheter inserted into the renal artery as a guide for graft margin positioning. A newly designed stent-graft was constructed from a custom-made spiral Z-stent covered with a thin-walled Dacron material; the endografts were deployed through 16-F (aortoaortic model) or 18-F sheaths (bifurcated devices). Renal function was assessed by preoperative and postoperative measurement of urea nitrogen and creatinine. Aneurysm exclusion and renal artery patency were evaluated during follow-up using spiral computed tomography and angiography.
  
  
  RESULTS
  The stent-grafts were correctly placed at the intended site in all 18 patients. Renal function was not affected except transiently in 1 patient who developed bilateral renal artery stenoses 24 hours after the procedure; Palmaz stents were deployed in each renal artery to reestablish satisfactory blood flow. Of the 33 renal arteries crossed by the bare stent-graft segment, all were patent over a mean 14-month follow-up (range 7-24), including the patient with Palmaz stents implanted for postprocedural renal stenosis. Complete aneurysm exclusion was maintained in 15 (83%) of 18 patients; proximal leaks persisted in 3 patients, including 2 with severely angled proximal necks.
  
  
  CONCLUSIONS
  Transrenal placement of the uncovered leading edge of custom-made spiral Z-stent-based endografts appears feasible and clinically effective in the treatment of AAAs with short or tortuous proximal necks.
authors.affiliation: Department of Radiology and Oncoradiology, Nara Medical University, Kashihara, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kichikawa
authors.forename: H
authors.initials: H
authors.lastname: Uchida
authors.forename: M
authors.initials: M
authors.lastname: Maeda
authors.forename: K
authors.initials: K
authors.lastname: Ide
authors.forename: Y
authors.initials: Y
authors.lastname: Kubota
authors.forename: S
authors.initials: S
authors.lastname: Sakaguchi
authors.forename: K
authors.initials: K
authors.lastname: Nishimine
authors.forename: W
authors.initials: W
authors.lastname: Higashiura
authors.forename: T
authors.initials: T
authors.lastname: Nagata
authors.forename: H
authors.initials: H
authors.lastname: Sakaguchi
authors.forename: T
authors.initials: T
authors.lastname: Yoshioka
authors.forename: H
authors.initials: H
authors.lastname: Ohishi
authors.forename: T
authors.initials: T
authors.lastname: Ueda
authors.forename: N
authors.initials: N
authors.lastname: Tabayashi
authors.forename: S
authors.initials: S
authors.lastname: Taniguchi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation*; D020099:Coated Materials, Biocompatible; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D011093:Polyethylene Terephthalates; D011474:Prosthesis Design; D012077:Renal Artery; D012189:Retrospective Studies; D013193:Stainless Steel; D015607:Stents; D014057:Tomography, X-Ray Computed; D018608:Ultrasonography, Doppler
chemical_list: D020099:Coated Materials, Biocompatible; D011093:Polyethylene Terephthalates; D013193:Stainless Steel