Markus Zaehringer

Open versus endovascular repair of para-anastomotic aneurysms in patients who were morphological candidates for endovascular treatment.

Purpose: To compare the outcomes of open versus endovascular repair of para-anastomotic aneurysms (PAA) in the aortic and iliac arteries in a cohort of patients who fulfilled morphological criteria for endovascular repair. Methods: A retrospective review of 31 consecutive patients with PAA treated between 1985 and 2002 identified 26 (84%) patients who would have been candidates for endovascular repair based on preoperative computed tomography and angiography. Of these 26 patients, 10 (9 men; median age 65 years, range 60–75) underwent endovascular repair; the remaining 16 patients (14 men; median age 61.5 years, range 49–78) had open repair. The baseline data and outcome measures were compared between the treatment groups. Results: The patient groups were well matched for age, sex, weight, risk factors, comorbidities, aneurysm length, and elapsed time from initial graft placement. Both groups had technically successful PAA repairs; however, median blood loss (300 versus 1000 mL; p = 0.05) and procedural time (100 versus 215 minutes; p<0.001) were significantly reduced in the endovascular group. Median transfusion volume was significantly greater (1000 versus 0 mL; p = 0.01) in the surgically treated patients. The median stay in ICU was similar (18 versus 24 hours in the surgical cohort). Length of stay was significantly shorter in the endovascular group: 7.5 versus 17.0 days (p = 0.001) after the repair and 11 versus 22 days (p = 0.01) for overall hospitalization. One (10%) patient in the endovascular group died from a myocardial infarction on the third postoperative day. In the open group, there were 3 (19%) procedure-related deaths. Conclusions: Patients with PAA who were endograft candidates but who were treated with open repair experienced more morbidity and had more complications than patients treated with stent-grafts. If long-term follow-up demonstrates durable results, stent-graft repair may become the therapy of choice in PAAs.

Percutaneous Treatment of a Splenic Artery Pseudoaneurysm by Thrombin Injection

Pseudoaneurysms in the visceral arteries are rare complications of pancreatitis. In the reported case, a 42-year-old man with a splenic pseudoaneurysm was successfully treated by computed tomography (CT)-guided direct thrombin injection into the pseudoaneurysm lumen. Selective catheterization of the splenic artery had proven technically impossible. During the procedure, contrast medium was injected via a pigtail catheter into the aorta for planning, correct positioning of the needle tip, and control imaging after injection. CT examinations 1 day, 3 weeks, and 6 months after treatment demonstrated complete occlusion shrinkage of the pseudoaneurysm, and the patient was symptom-free.

Endovascular γ-irradiation to prevent recurrent femoral in-stent restenosis

Abstract We report about a patient with twice recurrence of femoral in-stent restenoses. Centered endoluminal γ-irradiation with 192 iridium was performed immediately after the second stent recanalization. The irradiation dose was 14 Gy calculated at 2-mm depth of vessel wall. One-year follow-up demonstrates neither clinical nor angiographic evidence of restenosis.

Successful treatment of a type-II endoleak with percutaneous CT-guided thrombin injection in a patient after endovascular abdominal aortic aneurysm repair

The persistence of blood flow outside the graft but inside the aneurysm sac after endovascular treatment of the AAA is called endoleak. Strategies of treatment vary depending on the type of endoleak. Type-II endoleaks are usually treated by intraarterial embolization of the feeding vessels; however, this may be tedious, time-consuming, and sometimes impossible. We treated a 77-year-old man with a type-II endoleak after uneventful endograft (Zenith, Cook, William Europe, Denmark) placement with CT-guided injection of thrombin. A small endoleak originating from a persistent flow through a lumbar artery was detected by contrast-enhanced helical CT (Fig. 1) and intraarterial angiography. Selective catheterization of the lumbar artery via the internal iliac artery was twice technically impossible. Firstly, a pigtail catheter was placed in the aorta. After the patient was positioned in a prone position, a helical CT scan was performed while contrast medium was injected (30 ml, 5 ml/s) via the pigtail catheter in order to confirm the localization of the endoleak. A CT-guided puncture was performed with a 22-cm-long needle (diameter 0.7 mm; Fig. 2). L E T T E R T O T H E E D I T O R

Comparison of Magnetic Resonance Imaging and Computed Tomography of 8 Aortic Stent-Graft Models

Purpose: To report the systematic comparison of magnetic resonance imaging (MRI) with contrast-enhanced computed tomography (CT) for evaluating 8 different aortic stent-graft models. Methods: MR angiography (MRA) was performed using a 1.5-T whole body system within 2 days of a CT examination (4 detector row scanner) on 8 patients with one of these stent-graft models: AneuRx, Endofit, PowerLink, Excluder, LifePath, Talent, Vanguard, or Zenith. Using a 4-point scale (maximum score 112 points), 4 independent readers (1 vascular surgeon and 3 radiologists) rated the impact of stent-related artifacts on the diagnostic quality of each imaging method for 28 parameters: length, diameter, collateral aortic side branches, stent-graft prostheses, and contrast. Each examiner also scored his personal diagnostic confidence with each stent-graft model. Results: The scores for diagnostic confidence in the CT imaging were 4 points for each stent-graft, with the exception of the LifePath (3 points). The diagnostic confidence in the MR images was mainly poor, with a median score of only 1; however, 3 stent-grafts (AneuRx, Excluder, and Vanguard) received ≥3 points. The total scores for comparative assessment were significantly different (p<0.05) between CT imaging (111.5) and MR (58.5). CT studies of all stent-grafts received > 101 points, while only 3 devices acquired >80 points (AneuRx, Excluder, and Vanguard). Bland-Altman analysis showed that the reliability of the 4 readers was higher using the CT method. The total assessment scores of the stent-graft systems were related only on the different imaging methods (p<0.0001) and not to the different readers (p=0.983). Conclusions: CT and MRI are fast, reliable means of providing all relevant information for stent-graft surveillance. Of 8 different stent-graft models, only 3 could be adequately assessed by MRA. Therefore, the potential advantages of the MR technique (e.g., use of minimally nephrotoxic contrast media, lack of ionizing radiation) are available only to a small proportion of patients.

Experimental and clinical evaluation of the PARIS centering catheter for delivery of endovascular gamma-irradiation of femoropopliteal stenoses.

PURPOSE To investigate the effect of aortic bifurcation and iliac geometry on centered endovascular irradiation (CEI) of femoropopliteal arteries and evaluate procedure-related complications. MATERIALS AND METHODS In an experimental tubing model, crossover delivery of the dummy wire by an afterloader using different sheaths (Type I: noncrossover; Type II: crossover, length 40 cm; Type III: crossover, length 65 cm) was examined at simulated angles between 20 degrees -100 degrees (aortic bifurcation) and 0 degrees -100 degrees (iliac vessels). In the clinical phase, 28 heparin-anticoagulated patients underwent percutaneous transluminal angioplasty (PTA) for femoropopliteal stenoses followed by CEI (192-iridium, 14 Gray at 2 mm depth of the vessel wall) delivered with the centering catheter (crossover from contralateral leg using a 65-cm-long 8F sheath in 13 patients, noncrossover from ipsilateral leg using a 10-cm 8F sheath in 15 patients). Measurement of the aortic bifurcation angle before advancement of the crossover sheath and rating of iliac artery tortuosity on both sides was retrospectively performed on angiograms. Fifteen controls received no post-PTA CEI. RESULTS Experimental delivery of the dummy wire was not possible at aortic angles less than 40 degrees with Type I, 60 degrees with Type II, and 30 degrees with Type III sheaths. Advancement of the centering catheter was possible in all patients. CEI failed in two patients with crossover (aortic angle <40 degrees ) and in one obese patient with antegrade approach because advancement of the dummy wire was impossible. Thromboembolism rate was 4.6% during irradiation (2.3% after PTA alone). CONCLUSIONS CEI in femoropopliteal arteries has a risk of procedure-related thromboembolic complications. Efficacy is affected by vessel geometry.