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214 result(s) for "Endoleak - diagnostic imaging"
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Endovascular aortic repair with sac embolization for the prevention of type II endoleaks (the EVAR-SE study): study protocol for a randomized controlled multicentre study in Germany
Background Beyond a certain threshold diameter, abdominal aortic aneurysms (AAA) are to be treated by open surgical or endovascular aortic aneurysm repair (EVAR). In a quarter of patients who undergo EVAR, inversion of blood flow in the inferior mesenteric artery or lumbar arteries may lead to type II endoleak (T2EL), which is associated with complications (e.g. AAA growth, secondary type I endoleak, rupture). As secondary interventions to treat T2EL often fail and may be highly invasive, prevention of T2EL is desirable. The present study aims to assess the efficacy of sac embolization (SE) with metal coils during EVAR to prevent T2EL in patients at high risk. Methods Over a 24-month recruitment period, a total of 100 patients undergoing EVAR in four vascular centres (i.e. Klinikum rechts der Isar of the Technical University of Munich, University Hospital Augsburg, University Hospital Dresden, St. Joseph’s Hospital Wiesbaden) are to be included in the present study. Patients at high risk for T2EL (i.e. ≥ 5 efferent vessels covered by endograft or aneurysmal thrombus volume <40%) are randomized to one group receiving standard EVAR and another group receiving EVAR with SE. Follow-up assessments postoperatively, after 30 days, and 6 months involve contrast-enhanced ultrasound scans (CEUS) and after 12 months an additional computed tomography angiography (CTA) scan. The presence of T2EL detected by CEUS or CTA after 12 months is the primary endpoint. Secondary endpoints comprise quality of life (quantified by the SF-36 questionnaire), reintervention rate, occurrence of type I/III endoleak, aortic rupture, death, alteration of aneurysm volume, or diameter. Standardized evaluation of CTA scans happens through a core lab. The study will be terminated after the final follow-up visit of the ultimate patient. Discussion Although preexisting studies repeatedly indicated a beneficial effect of SE on T2EL rates after EVAR, patient relevant outcomes have not been assessed until now. The present study is the first randomized controlled multicentre study to assess the impact of SE on quality of life. Further unique features include employment of easily assessable high-risk criteria, a contemporary follow-up protocol, and approval to use any commercially available coil material. Overcoming limitations of previous studies might help SE to be implemented in daily practice and to enhance patient safety. Trial registration ClinicalTrials.gov NCT05665101. Registered on 23 December 2022.
Contrast-Enhanced Ultrasound vs. CT Angiography in Fenestrated EVAR Surveillance: A Single-Center Comparison
Purpose To evaluate contrast-enhanced ultrasound (CEUS) as an effective alternative to computed tomographic angiography (CTA) during follow-up after fenestrated endovascular aneurysm repair (EVAR) of juxtarenal aortic aneurysms. Methods Between January 2008 and April 2011, 62 patients (all men; mean age 72 years) underwent fenestrated EVAR follow-up with both CTA and CEUS. In a retrospective analysis, the first CTA and CEUS postoperative examinations after EVAR were compared for endoleak detection, aneurysm sac diameter, and target vessel patency. The examinations were performed within 30 days of the procedure and the interval between the 2 scans was <7days. Only fenestrated endografts with up to 3 fenestrations (with or without a scallop) were eligible so that the entire implant could be visualized with standard abdominal ultrasound. Results The mean diameters of the aneurysm sac were 56.58 ± 8.56 mm with CEUS and 57.70 ± 8.59 mm with CTA. The mean difference in aneurysm sac diameter was –1.13 ± 3.19 mm (95% CI –0.34 to –1.92), with CTA measurements tending to be slightly larger. Bland-Altman plots showed good agreement between the imaging modalities with respect to aneurysm sac diameter (Spearman correlation coefficient rs=0.921, p<0.01). Endoleaks were detected by CTA in 7 (11.3%) of 62 patients and by CEUS in 6 (9.7%). In 59 (95.16%) cases, the tests agreed, and their equivalence was confirmed by binomial distribution testing. There was complete agreement between CEUS and CTA in the assessment of target vessels (144/146 patent target arteries; 1 had a significant stenosis and another was thrombosed). Conclusion CEUS is as accurate as CTA in endoleak detection, abdominal aortic aneurysm diameter measurement, and the evaluation of target vessels during surveillance of fenestrated stent-grafts. Although it cannot yet be proposed as the only imaging modality during follow-up, CEUS could be usefully employed with the self-evident advantage of reducing lifetime exposure to ionizing radiation.
Early Follow-Up After Endovascular Aneurysm Repair: Is the First Postoperative Computed Tomographic Angiography Scan Necessary?
Purpose To examine whether initial postoperative computed tomographic angiography (CTA) is needed in all patients undergoing endovascular aneurysm repair (EVAR). Methods A total of 105 consecutive patients underwent EVAR with standard infrarenal devices in our department between November 2009 and May 2011. Five patients were excluded due to severe renal insufficiency, leaving 100 (85 men; median age 73 years, range 46–91) eligible for prospective enrollment in a triple-modality early postoperative follow-up protocol [intraoperative completion angiography, postoperative duplex ultrasonography (DUS), and plain abdominal radiography). Findings were compared for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) against the first postoperative CTA results for the detection of endoleaks or other signs of EVAR failure. Results There were 10 inconclusive DUS examinations. In the remaining 90 patients, DUS had 75.0% sensitivity, 95.4% specificity, 85.7% PPV, and 91.5% NPV for the detection of endoleaks. The intraoperative angiogram, DUS, and abdominal radiograph combined resulted in 87.5% sensitivity and 95.4% specificity, with a 65.6% PPV and 94.8% NPV for the detection of endoleaks. In 2 patients who required a reintervention for endoleak in the early postoperative period, both endoleaks were correctly detected by the triple-modality early postoperative follow-up protocol. Conclusion An early follow-up protocol consisting of an intraoperative completion angiogram, DUS, and abdominal radiograph shows a high sensitivity and NPV for the detection of endoleaks and should detect early migration or kinking of the stent-graft. An initial postoperative CTA is not necessary for most patients undergoing EVAR and should be reserved for those individuals in whom the aforementioned modalities are inconclusive or show signs of endoleak or other EVAR failure.
Experimental feasibility of spectral photon-counting computed tomography with two contrast agents for the detection of endoleaks following endovascular aortic repair
ObjectivesAfter endovascular aortic repair (EVAR), discrimination of endoleaks and intra-aneurysmatic calcifications within the aneurysm often requires multiphase computed tomography (CT). Spectral photon-counting CT (SPCCT) in combination with a two-contrast agent injection protocol may provide reliable detection of endoleaks with a single CT acquisition.MethodsTo evaluate the feasibility of SPCCT, the stent-lined compartment of an abdominal aortic aneurysm phantom was filled with a mixture of iodine and gadolinium mimicking enhanced blood. To represent endoleaks of different flow rates, the adjacent compartments contained either one of the contrast agents or calcium chloride to mimic intra-aneurysmatic calcifications. After data acquisition with a SPCCT prototype scanner with multi-energy bins, material decomposition was performed to generate iodine, gadolinium and calcium maps.ResultsIn a conventional CT slice, Hounsfield units (HU) of the compartments were similar ranging from 147 to 168 HU. Material-specific maps differentiate the distributions within the compartments filled with iodine, gadolinium or calcium.ConclusionSPCCT may replace multiphase CT to detect endoleaks without sacrificing diagnostic accuracy. It is a unique feature of our method to capture endoleak dynamics and allow reliable distinction from intra-aneurysmatic calcifications in a single scan, thereby enabling a significant reduction of radiation exposure.Key Points• SPCCT might enable advanced endoleak detection.• Material maps derived from SPCCT can differentiate iodine, gadolinium and calcium.• SPCCT may potentially reduce radiation burden for EVAR patients under post-interventional surveillance.
Late Open Conversion Following Failure of EVAR and TEVAR: “State of the Art”
Abdominal endovascular aneurysm repair (EVAR) and thoracic endovascular aneurysm repair (TEVAR) have changed the aortic surgery, due to several advantages in terms of reduced morbidity and mortality. However, increasing rate of late complications requiring secondary procedures has been observed over time. Even if the majority of them may be treated by means of endovascular techniques, late open surgical conversion (LOSC) is required in specific situations. This paper aims to provide our single-center experience with LOSCs and an updated review of the literature. From 1995 to 2020, indications and outcomes of patients treated with LOSC for failed EVAR and TEVAR, at our institutions, were analyzed. LOSC was required to treat a broad range of complications that were classified into two main groups: “disease related” and “stent-graft (SG) related.” Among the 121 patients treated with LOSC after EVAR, endoleak (75.2%) represented the most common indication. The overall 30-day mortality rate was 3.3%. A higher mortality rate was associated with infection after EVAR (p. 006). Among the 81 patients treated with LOSC after TEVAR, endoleak (32.1%) was the most common indication. The overall 30-day mortality rate was 13.6% with a higher incidence in the SG-related group (p. 02). LOSC is associated with an increased surgical complexity, in both the abdominal and thoracic area, that results in higher morbidity and mortality rates compared with standard open repair. Depending on the indication to LOSC, specific surgical maneuvers are required to improve clinical outcomes.
Long-Term Outcomes Following Transarterial Embolisation of Proximal Type I Endoleaks Post-EVAR
PurposeTo describe the long-term outcomes following transarterial embolisation for type Ia endoleaks (ELIa) in patients who failed or were unsuitable for standard endovascular/surgical options.Materials and MethodsA retrospective single-centre observational study was performed between October 2010 and April 2018. Technical success rates and long-term outcomes were evaluated. A sub-analysis was performed comparing outcomes of covered aortic endografts and Nellix endovascular aneurysm sealing systems.ResultsA total of 34 transcatheter embolisations were performed for ELIa in 27 patients (13 endografts and 14 patients with Nellix systems). A combination of Onyx and coils was used most frequently (18/34), followed by Onyx alone (14/34) and coils alone (2/34). Technical success was achieved in 33/34 (97%) procedures . Seven early complications occurred with no immediate mortality, 5 of which involved migration/reflux of embolic into the endograft—all successfully managed via endovascular approach. Following the surveillance period (mean 25 months), 13/26 (50%) of patients were free from recurrent endoleak. Sac expansion occurred in 42% (11/26). 21/26 patients died; 6 due to aneurysm sac rupture, 10 due to unrelated causes, and 5 had no cause of death available. No significant difference in survival was found between patients with an endograft or Nellix graft—Chi-squared value − 0.011 (p < 0.05 = 3.84).ConclusionsTranscatheter embolisation for type Ia endoleaks is a safe and effective option in a select patient cohort—where traditional endovascular and surgical options are unsuitable or have failed. The procedure may prevent recurrence in some whilst delaying rupture and death in others.
Effectiveness of Intra-operative Contrast-Enhanced Ultrasound Assessment to Optimize Type II Endoleak Embolization
PurposeTo analyze the effectiveness of type II endoleaks (T2E) embolization using intra-operative contrast-enhanced ultrasound (CEUS).MethodsConsecutive patients treated for T2E underwent a standardized protocol with trans-arterial or trans-lumbar access, large volume embolization, onlay fusion, and intra-operative CEUS. Technical success was defined by exclusion of endoleak by CEUS.ResultsTwenty-six patients (mean age 81 ± 11 years old; 89% male) were treated. The mean aneurysm sac enlargement was 11 ± 8 mm from T2E diagnosis. Embolization was performed using Onyx® 18 in all patients with adjunctive coils in 13 patients (50%). After the first embolization, CEUS documented residual T2E in 13 patients (50%). Ten patients (38%) had additional embolization, which successfully eradicated the T2E in seven of them. Technical success was 50% after the first embolization attempt and 77% after additional attempts guided by CEUS (P = 0.080). There was no mortality. Median imaging follow-up was 22 months. Among the 20 patients with no residual T2E on completion CEUS, 16 (80%) had sac stabilization and none required additional interventions for T2E. Of the six patients with residual T2Es on CEUS, three had sac stabilization (50%) and one required additional reintervention for T2E. There was one late aortic rupture at 56 months.ConclusionOne in two patients treated by T2E embolization had residual endoleak on intra-operative CEUS after a first embolization attempt, decreasing to one in four patients after multiple attempts. A negative completion CEUS following embolization was associated with higher rates of sac stabilization and no need for additional T2E embolization.
Endoleak detection using single-acquisition split-bolus dual-energy computer tomography (DECT)
Objectives To assess a single-phase, dual-energy computed tomography (DECT) with a split-bolus technique and reconstruction of virtual non-enhanced images for the detection of endoleaks after endovascular aneurysm repair (EVAR). Methods Fifty patients referred for routine follow-up post-EVAR CT and a history of at least one post-EVAR follow-up CT examination using our standard biphasic (arterial and venous phase) routine protocol (which was used as the reference standard) were included in this prospective trial. An in-patient comparison and an analysis of the split-bolus protocol and the previously used double-phase protocol were performed with regard to differences in diagnostic accuracy, radiation dose, and image quality. Results The analysis showed a significant reduction of radiation dose of up to 42 %, using the single-acquisition split-bolus protocol, while maintaining a comparable diagnostic accuracy (primary endoleak detection rate of 96 %). Image quality between the two protocols was comparable and only slightly inferior for the split-bolus scan (2.5 vs. 2.4). Conclusions Using the single-acquisition, split-bolus approach allows for a significant dose reduction while maintaining high image quality, resulting in effective endoleak identification. Key Points • A single-acquisition, split-bolus approach allows for a significant dose reduction . • Endoleak development is the most common complication after endovascular aortic repair (EVAR) . • CT angiography is the imaging modality of choice for aortic aneurysm evaluation .