Utility of Intra-operative Cone Beam Computed Tomography in Endovascular Treatment of Aorto-iliac Occlusive Disease.

OBJECTIVE: Endovascular treatment of aorto-iliac occlusive disease (AIOD) is well established, but to maintain long-term patency, secondary interventions are common. Multiple stents and iliac artery tortuosity often make it difficult to evaluate stent compression intra-operatively and this might be a cause for later failure. Completion angiography (CA) and pressure gradient (PG) measurement are often used to assess the final intra-operative result. The purpose of this study was to evaluate the role of intra-operative cone beam computed tomography (CBCT) to optimize the primary operation results. METHOD: Fifty-three patients (28 females) were enrolled in a prospective study. All patients underwent endovascular aorto-iliac revascularization. Final intra-operative results were evaluated with additional CBCT, after CA and PG were found to be satisfactory. Imaging findings and imaging based adjunctive procedures were recorded. RESULTS: One hundred and sixty five stents were placed because of AIOD. Twenty patients underwent adjunctive procedures after the primary stenting. In 24.5% (13/53) cases, adjunctive procedures were indicated solely by the CBCT findings, as both standard CA and PG were normal. Twenty-six of the 53 patients had kissing stents placed at the aortic bifurcation. Of the kissing stent patients, 34.6% required adjunctive procedures and in two thirds these stent compressions were detected only by CBCT. CONCLUSION: The use of CBCT revealed a significant number of stent compressions that were not found with CA and PG. When performing endovascular procedures at the aortic bifurcation, CBCT is an excellent intra-operative evaluation method to assess the configuration of deployed stents. In this study, CBCT improved the technical results intra-operatively, which might influence the long-term patency positively.

Intra-operative cone beam computed tomography can help avoid reinterventions and reduce CT follow up after infrarenal EVAR.

OBJECTIVE/BACKGROUND: Re-interventions after endovascular abdominal aortic aneurysm repair (EVAR) are common and therefore a strict imaging follow up protocol is required. The purpose of this study was to evaluate whether cone beam computed tomography (CBCT) can detect intra-operative complications and to compare this with angiography and the 1 month CT follow up (computed tomography angiography [CTA]). METHODS: Fifty-one patients (44 men) were enrolled in a prospective trial. Patients underwent completion angiography and CBCT during infrarenal EVAR. Contrast was used except when pre-operative renal insufficiency was present or if the maximum contrast dose threshold was reached. CBCT reconstruction included the top of the stent graft to the iliac bifurcation. Endoleaks, kinks, or compressions were recorded. RESULTS: CBCT was technically successful in all patients. Twelve endoleaks were detected on completion digital subtraction angiography (CA). CBCT detected 4/5 type 1 endoleaks, but only one type 2 endoleak. CTA identified eight type 2 endoleaks and one residual type I endoleak. Two cases of stent compression were seen on CA. CBCT revealed five stent compressions and one kink, which resulted in four intra-operative adjunctive manoeuvres. CTA identified all cases of kinks or compressions that were left untreated. Two of them were corrected later. No additional kinks/compressions were found on CTA. Groin closure consisted of 78 fascia sutures, nine cut downs, and 11 percutaneous sutures. Seven femoral artery pseudoaneurysms (<1 cm) were detected on CTA, but no intervention was needed. CONCLUSION: CA is better than CBCT in detecting and categorizing endoleaks but CBCT (with or without contrast) is better than CA for detection of kinks or stentgraft compression. CTA plus CBCT identified all significant complications noted on the 1 month follow up CTA. The use of intra-operative CA and CBCT could replace early CTA after standard EVAR thus reducing overall radiation and contrast use. Technical development might further improve the resolution and usefulness of CBCT.

Optimizing imaging for aortic repair.

Imaging is an integral part of an aortic program. Careful preoperative planning is essential to successful evaluation and treatment of aortic pathology. Computed tomography angiography (CTA) is the dominant modality for such preoperative planning. The use of a dedicated workstation for 3D postprocessing is very favorable and is considered mandatory when treating complex aortic pathology. Intraoperative imaging during aortic repair still depends heavily on standard fluoroscopy and angiography. However, the introduction of image fusion has the potential to reduce the use of both contrast and radiation, for the benefit of both patients and operators. Using cross-sectional imaging intraoperatively also has the potential to reduce the need for early imaging follow-up and to reduce the technical failures of endovascular aneurysm repair (EVAR). Imaging follow-up after EVAR has changed dramatically since the introduction of minimally invasive aortic repair. CTA remains the gold standard but a significant shift towards ultrasound surveillance has occurred. With the introduction of newer generation EVAR devices, results have improved and a trend towards less rigorous follow-up is expected.

Endoleaks after EVAR and TEVAR: indications for treatment and techniques.

Endoleaks after endovascular aortic repair (EVAR) are a common cause of treatment failure and secondary interventions. Endoleak classification is important to determine both prognosis as well as need for treatment. With increasingly complex endovascular aortic procedures, endoleak classification according to the original classification has become more difficult. A classification into direct and indirect endoleaks as well as precise anatomical description is often more pragmatic. This manuscript outlines mechanisms of endoleak formation and their treatment.

Automated extraction of acetylgestagens from kidney fat by matrix solid phase dispersion.

A new extraction method for the acetylgestagens medroxyprogesterone acetate (MPA), chloromadinone acetate and megestrol acetate, from kidney fat, has been developed. The method is a combination of matrix solid phase dispersion and solid phase extraction and is simpler and safer than previous methods, especially as it can be automated. The recovery was estimated as 59 +/- 5% (mean +/- standard deviation) for MPA. For screening purposes detection can be achieved using a commercially available enzyme immunoassay kit giving detection limits in the range of 1.0-2.0 ng g-1.

Liquid silicone in the treatment of retinal detachment.

Liquid silicone was used in the surgical treatment of 46 eyes with complex retinal detachment. Forty-six eyes have been followed up for at least 6 months. In 27 of these eyes (58.7%) the retina was totally or partially attached at the 6-month follow-up. Visual improvement was found in 20 of the 46 eyes (43.5%). These results are encouraging considering the poor prognosis of the operated eyes. There were few severe complications during an observation time of 6 months. Liquid silicone was found to be a valuable help in the surgical treatment of severe forms of retinal detachment.