Endovascular treatment for nontraumatic rupture of the descending thoracic aorta: long-term results.

BACKGROUND: This study evaluated the long-term results of thoracic endovascular aortic repair (TEVAR) of nontraumatic rupture of the descending thoracic aorta. METHODS: This was a retrospective and observational single-center study. During the 10-year study period, 21 patients (6 males) with an average age of 66.1 ± 12.4 (range 31-81) years underwent emergency TEVAR for nontraumatic rupture of the descending thoracic aorta. The underlying aortic pathologies causing the rupture were degenerative aneurysms in 11 patients, complicated type B dissection in nine, and erosion hemorrhage due to neoplasia in one patient. RESULTS: The 30-day mortality rate was 9.5% (2/21). Two patients died postoperatively: one from a repeat aortic rupture and the other from pneumonia. Two patients underwent early endovascular reintervention. After a median follow-up of 65.6 ± 50.4 (range 1.5-44) months, 10 patients died, resulting in a late mortality of 52.6% (10/19). Six patients (31.5%) developed major complications requiring late reintervention. There was no mortality with reintervention. CONCLUSIONS: Endovascular treatment of the descending thoracic aorta in patients with nontraumatic rupture is a promising treatment option in an emergency setting with a relatively low mortality rate. Despite encouraging early results, TEVAR is associated with a high reintervention rate and poor survival due to nonaortic or procedure-related mortality in the long term.

Secondary interventions after endovascular thoracic aortic repair.

BACKGROUND: Endovascular stent grafting of the descending thoracic aorta has evolved rapidly and is now the standard of care for certain patient subsets. However, the durability of this technique is limited by the development of technique-specific complications at mid-term follow-up. The aim of this study was to evaluate the incidence, techniques, and outcomes of secondary intervention for complications after stent grafting of the descending thoracic aorta. METHODS: Between March 2001 and November 2011, 152 patients underwent endovascular thoracic aortic repair (TEVAR). We identified 19 (12.5%) patients from this cohort who required secondary interventions. RESULTS: The indications for TEVAR were type B aortic dissection in 12 patients, thoracic aortic aneurysm in six patients, and intramural hematoma in one patient. The mean time between TEVAR and secondary intervention was 20.49 ± 24.90 months (range, 1.2-83 months). A secondary endovascular intervention was required in eleven patient, six patients required secondary surgical therapy, and hybrid procedures were performed in two patients. Endoleaks were the most common indication for a secondary intervention. The 30-day mortality rate was 10.5% (2/19). Two perioperative deaths were observed following surgical therapy. During the mean follow-up of 78.06 ± 37.37 months (range, 23-142 months) after TEVAR, four unrelated deaths occurred, two patients were lost to follow-up, and four patients required a further intervention. CONCLUSIONS: Secondary intervention after endovascular stent grafting of the descending thoracic aorta was not infrequently required and can be performed with acceptable risks. However, serial, systematic follow-up is essential to detect late complications and to perform secondary procedures, preferably under elective circumstances.

Development of a temperature sensitive drug release system for polymeric implant devices.

A low density polyethylene (LDPE) model surface was coated with poly(amino-p-xylylene) (amino-ppx) via chemical vapour deposition (CVD) polymerization. The functional surface was used to immobilize a polymeric drug release system consisting of poly(N-isopropylacrylamide) (NIPAAm)-co-poly(acrylic acid) (AAc). The coupled drug release system was used to incorporate the thrombin inhibitor r-hirudin. For the investigation of the concentration of incorporated r-hirudin and the release profile over a given period of time r-hirudin was labelled with 123I as well as fluorescein isothiocyanate (FITC). Using an incubation solution concentration of 0.2% at pH 5 and an ionic strength of 0.7 M a maximum concentration of 2.21 (+/- 0.11) nmol/cm2 of r-hirudin was detected. FITC-r-hirudin was almost quantitatively (2.08 +/- 10 nmol/cm2; 94%) released from the surface coating within a period of 14 days.

Bilateral renal fornix rupture following intraarterial contrast medium application for infrarenal aortic stent placement.

A 74-year-old male claudicant who had a significant abdominal aortic stenosis was hydrated before aortic stent placement because of an elevated creatinine level. During the intervention the patient experienced acute abdominal pain with vomiting. No vascular cause was detected. Due to persistent pain, plain radiography and an abdominal CT scan were performed a few hours after the procedure. Images revealed a bilateral renal fornix rupture with a large retroperitoneal fluid collection. The patient was treated conservatively with ureteral double-J placement and percutaneous nephrostomy. The further course was uneventful and the patient was discharged 2 weeks later free of symptoms. Renal fornix rupture is a very rare complication after contrast medium application that can be treated without surgery.

Inhibition of neointimal proliferation with 188Re-labeled self-expanding nitinol stent in a sheep model.

PURPOSE: To evaluate a self-expanding rhenium 188 (188Re) radiochemically labeled radioactive stent in sheep. MATERIALS AND METHODS: A self-expanding nitinol stent (30 mm in length, 8 mm in diameter) coated with a functionalized polymer layer was radiolabeled with 188Re. Fifty prostheses, 25 of which were radioactive (mean radioactivity, 20 MBq +/- 3.8 [SD]) and 25 of which were nonradioactive, were implanted into the external iliac arteries of 25 sheep. Stent patency was assessed with angiography. Neointimal formation was assessed with intravascular ultrasonography and histologic examination 1 month (in all sheep) and 3 months (in 12 sheep) after implantation. The results were analyzed by using repeated-measures analysis of variance with two repeated factors and paired t tests for comparison at each measuring point. RESULTS: All stents were placed successfully. Data in one animal had to be excluded from the study. After 3 months, a mean neointimal area reduction of 70 mm2 +/- 55 (SD) was observed inside the radioactive stents, and a mean lumen reduction of 126 mm2 +/- 39 was observed inside the nonradioactive control stents (P =.022). An edge effect was observed in the radioactive stents in that they showed an amount of neointimal formation at the edges that was similar to that seen in control stents. This neointimal formation accounted for the maximum lumen loss in the vascular segment with the stent. CONCLUSION: As compared with a nonradioactive stent, a beta particle-emitting stent, through endovascular irradiation, significantly inhibits neointimal formation inside the stent but not at the stent edges.