Real-world data of popliteal artery aneurysm treatment: Analysis of the POPART registry.

OBJECTIVE: Popliteal artery aneurysm (PAA) is a rare disease with a prevalence of 0.1% to 1%. Within previous years, endovascular repair (ER) of PAAs has been performed more frequently despite the lack of high-level evidence compared with open surgical repair (OSR). In 2014, the POPART registry was initiated to validate the current treatment options for PAA repair. METHODS: POPART is a multinational multicenter registry of the peri- and postoperative outcomes of ER and OSR for PAAs. Data sets were recorded using the online survey tool SurveyMonkey (available at: https://www.surveymonkey.com/). Regular monitoring and plausibility checks of the data sets are performed to ensure reliability. The aim of the present study was to report the findings from the POPART registry, which includes data from 41 centers. RESULTS: From June 2014 to August 2019, 794 cases had been recorded in the POPART registry. OSR had been performed in 662 patients and ER in 106 patients; 23 patients had been treated conservatively. Of the 106 patients in the primary ER group, 4 had required conversion to OSR. The ER patients were significantly older (ER, median, 71 years; OSR, median, 67 years; P < .05). No other significant differences were present in the demographic data, comorbidities, or aneurysm morphology between the two groups. Of the 662 patients in the OSR group, 50.3% were symptomatic compared with 29.2% of the 106 patients in the ER group (P < .05). Emergency treatment because of acute ischemia, critical ischemia, or rupture was necessary for 149 patients (22.5%) in the OSR group and 11 patients (10.3%) in the ER group. The most frequent postoperative complications were impaired wound healing (OSR, n = 47 [7.1%]; ER, n = 3 [2.8%]; P > .05) and major bleeding (OSR, n = 26 [3.9%]; ER, n = 3 [2.8%]; P > .05). The in-hospital length of stay was significantly longer for the OSR group than for the ER group (median, 10 days; range, 3-65 days; vs median, 7 days; range, 1-73 days). The overall patency for the OSR and ER groups after 12 and 24 months was 83.2% and 44.7% (P < .005) and 74.2% and 29.1% (P < .005), respectively. The outcomes with a prosthetic graft vs an autologous vein were significantly poorer in the OSR group (primary patency, 71.4% vs 88.1% at 12 months). CONCLUSIONS: To evaluate new treatment techniques such as ER for PAAs, real-world data are of essential importance. The present analysis of the first results for the POPART registry shows good perioperative results for endovascular treatment of PAA in asymptomatic patients with good outflow vessels. The perioperative complication rate is low and the postoperative hospital stay is shorter than after OSR. However, the patency rates after 12 and 24 months are low in the ER group compared to patients treated with open repair. More follow-up data is required for further interpretation; the completion of the data sets in the registry is ongoing.

Protected and Unprotected Radiation Exposure to the Eye Lens During Endovascular Procedures in Hybrid Operating Rooms.

OBJECTIVE: Radiation cataract has been observed at lower doses than previously thought, therefore the annual limit for equivalent dose to the eye lens has been reduced from 150 to 20 mSv. This study evaluated radiation exposure to the eye lens of operators working in a hybrid operating room before and after implementation of a dose reduction program. METHODS: From April to October 2019, radiation exposure to the first operator was measured during all consecutive endovascular procedures performed in the hybrid operating room using BeOSL Hp(3) eye lens dosimeters placed both outside and behind the lead glasses (0.75 mm lead equivalent). Measured values were compared with data from a historic control group from the same hospital before implementation of the dose reduction program. RESULTS: A total of 181 consecutive patients underwent an endovascular procedure in the hybrid operating room. The median unprotected eye lens dose (outside lead glasses) of the main operator was 0.049 mSv for endovascular aortic repair (EVAR) (n = 30), 0.042 mSv for thoracic endovascular aortic repair (TEVAR) (n = 23), 0.175 mSv for complex aortic fenestrated or branched endovascular procedures (F/BEVAR; n = 15), and 0.042 mSv for peripheral interventions (n = 80). Compared with the control period, EVAR had 75% lower, TEVAR 79% lower, and F/BEVAR 55% lower radiation exposure to the unprotected eye lens of the first operator. The lead glasses led to a median reduction in the exposure to the eye lens by a factor of 3.4. CONCLUSION: The implementation of a dose reduction program led to a relevant reduction in radiation exposure to the head and eye lens of the first operator in endovascular procedures. With optimum radiation protection measures, including a ceiling mounted shield and lead glasses, more than 440 EVARs, 280 TEVARs, or 128 FEVARs could be performed per year before the dose limit for the eye lens of 20 mSv was reached.

TEVAR Following FET: Current Outcomes of Rendezvous Procedures in Clinical Practice.

BACKGROUND: The treatment of extensive thoracic/thoracoabdominal aortic pathologies with arch involvement remains a challenging task in aortic surgery. The introduction of the frozen elephant trunk (FET) technique offered a link between open surgery and thoracic endovascular aortic repair (TEVAR). Despite a decade of experience, data on the complementary use of these techniques are scant. The aim of this study was to evaluate TEVAR following FET in clinical reality. METHODS: Between November 2006 and June 2018, 20 patients (9 females; median age of 69 years) underwent endovascular second-stage completion after FET. The clinical outcomes, technical feasibility, and morphological findings were analyzed retrospectively. RESULTS: Eleven of the 20 interventions were intended "rendezvous procedures" in a multistage approach; 4 were elective reinterventions, and 5 were emergency complication repairs. The median interval between FET and TEVAR was 231 days (11 days-7.4 years). The technical success rate was 100%. During a median follow-up (FU) period of 58.3 months, the overall survival rate was 95%, with one in-hospital death. Neurological complications occurred in three cases (spinal cord injury: n = 1; stroke: n = 2). Computed tomography angiography showed overall regression in the median diameter of the proximal descending aorta (from 57 to 48.5 mm). CONCLUSION: TEVAR as a second-stage intervention after FET is a feasible option, with satisfactory results at medium-term FU. In extensive thoracoabdominal aortic disease without proximal landing zones, the complementary use of both techniques in a multistage approach should be considered.

Two-dimensional-three-dimensional registration for fusion imaging is noninferior to three-dimensional- three-dimensional registration in infrarenal endovascular aneurysm repair.

BACKGROUND: Fusion imaging is a tool for intraoperative three-dimensional (3D) guidance in endovascular aneurysm repair (EVAR). In many aortic centers, the registration for location is based on an intraoperative 3D dataset acquired by means of cone-beam computed tomography (3D-3D registration). Another registration method is based on two two-dimensional (2D) images (lateral and posteroanterior) acquired with the use of intraoperative fluoroscopy for registration with a computed tomographic angiogram (2D-3D registration). The aim of the present study was to compare 2D-3D registration with 3D-3D registration regarding noninferiority in accuracy and to describe radiation exposure and ease of use of both modalities. METHODS: From December 2014 to September 2015, 50 sequentially enrolled patients received EVAR with the use of fusion imaging using 2D-3D registration. No adjustments were made until the first angiography with inserted stent graft. The deviation of fusion imaging to the actual position of the lower renal artery compared with digital subtraction angiography was measured. A historic cohort of 101 patients treated with EVAR and fusion imaging with 3D-3D registration (3D-3D cohort) served as the control group for this study. RESULTS: Craniocaudal deviation did not differ significantly (4.6 ± 4.4 mm in the 2D-3D cohort vs 3.6 ± 3.9 mm in the 3D-3D cohort; P = .17). The difference of the means was 1.05 mm with a 95% confidence interval of -2.45 to 0.34 and a P value for the noninferiority test of .0249, indicating that 2D-3D registration was noninferior in terms of a margin of δ = 2.5 mm. 2D-3D registration was significantly faster with significantly less additional radiation necessary: 0.45 ± 0.28 vs 45.7 ± 9.1 Gy·cm2 in the 3D-3D cohort (P < .001); 2.3 ± 1.3 vs 5.3 ± 4.3 minutes in the 3D-3D cohort (P < .001). CONCLUSIONS: Fusion imaging during EVAR with the use of 2D-3D registration is feasible in routine EVAR. Our findings of two consecutive cohorts with the same clinical, hardware, and software setup used for the procedures underscore that the accuracy of 2D-3D registration is noninferior to that of a 3D-3D registration workflow, with advantages in terms of radiation exposure, intraoperative time demand, and ease of use.

Endograft migration after thoracic endovascular aortic repair.

OBJECTIVE: The objective of this study was to evaluate the incidence, timing, and potential risk factors of late endograft migration after thoracic endovascular aortic repair (TEVAR). METHODS: A retrospective analysis was conducted of 123 patients receiving TEVAR for thoracic aortic aneurysms (TAAs), dissections, penetrating aortic ulcer, intramural hematoma, or traumatic transection between January 2005 and December 2015 with a minimum imaging-based follow-up of 6 months. Imaging analysis was performed by three independent readers. Migration was defined according to the reporting standards as a stent graft shift of >10 mm relative to a primary anatomic landmark or any displacement that led to symptoms or required therapy. A standardized measurement protocol in accordance with the reporting guidelines was used. Median follow-up was 3 years (range, 0.5-10 years). RESULTS: Migration occurred in nine (7.3%) patients and took place at the proximal landing zone (n = 1), overlapping zone (n = 4), or distal landing zone (n = 5), resulting in type I or type III endoleaks in 44% (n = 4/9) of the cases. All cases of migration with endoleaks underwent reintervention; 75% (n = 3/4) of the migration associated with endoleaks could have been identified on previous imaging before an endoleak occurred. Freedom from migration was 99.1% after 1 year, 94.0% after 3 years, and 86.1% after 5 years. Aortic elongation and TAA were identified as predisposing factors for migration (P = .003 and P = .01, respectively). No influence of the proximal landing zone (zone 0-4), type of aortic arch (I-III), or type of endograft on the incidence of migration was found. CONCLUSIONS: Graft migration after TEVAR occurs in a relevant proportion of patients, predominantly in patients with TAA and aortic elongation. Follow-up imaging of these patients should be specifically evaluated regarding the occurrence of migration.

Long-term results after open repair of inflammatory infrarenal aortic aneurysms.

OBJECTIVE: The objective of this study was to investigate the long-term outcome after open repair of inflammatory infrarenal aortic aneurysms. METHODS: A total of 62 patients (mean age, 68.9 ± 8.8 years; 91.9% male) undergoing open surgery for inflammatory aortic aneurysm from 1995 until 2014 in a high-volume vascular center were retrospectively evaluated. The patients' demographics, preoperative and postoperative clinical characteristics, imaging measurements, and procedural data were collected. Study end points were preoperative and postoperative sac diameter, evolution of periaortic fibrosis and development of hydroureteronephrosis detected by computed tomography (CT) scan, and mortality and morbidity after 30 days and at the time of maximum follow-up. RESULTS: The mean abdominal aortic aneurysm diameter was 67.3 ± 16.7 mm. A total of 30 patients (48.4%) were asymptomatic, 27 patients (43.5%) were symptomatic, and 5 patients (8.1%) were treated for ruptured aneurysm. In 25 patients (40.3%), an aorta-aortic tube graft was implanted; in 37 patients (59.7%), an aortic bifurcation graft was used. Median operating time was 208 minutes (range, 83-519 minutes). Median aortic clamping time was 31 minutes (range, 14-90 minutes); in 25 patients (40.3%), suprarenal aortic cross-clamping was necessary. Hydroureteronephrosis was preoperatively diagnosed by CT scan in 16 patients (25.8%), with the need for a ureteral stent in 11 patients (17.7%). Aneurysm- and procedure-associated 30-day mortality was 11.3% (n = 7), with septic multiple organ failure in four patients and cardiac arrest in three patients. The overall perioperative complication rate was 33.9% (n = 21 patients). Median follow-up was 71.0 months (range, 0.2-231.6 months). At 1 year, 2 years, 4 years, and 6 years, overall survival was 83.4%, 79.6%, 79.6%, and 72.6%, respectively. Six patients (9.7%) required a reintervention during follow-up, predominantly aneurysm related and caused by aortoenteric fistula and graft infection (three of five patients). Median maximum thickness of preoperative perianeurysmal inflammation on CT was 10 mm (range, 2-22 mm), which decreased in 15 of 16 (94%) patients with available postoperative CT scans. Postoperative median thickness of perianeurysmal inflammation on CT was 6 mm (range, 0-13 mm). Hydroureteronephrosis persisted in two of nine (22.2%) patients at the end of follow-up. CONCLUSIONS: Surgery in patients with inflammatory abdominal aortic aneurysms is associated with a substantial amount of perioperative complications. After surgery, the perianeurysmal inflammation decreases in most patients on follow-up CT. However, because the inflammatory process does not totally resolve, patients require lifelong surveillance for hydroureteronephrosis and development of aortoenteric fistulas.

How Precise Are Preinterventional Measurements Using Centerline Analysis Applications? Objective Ground Truth Evaluation Reveals Software-Specific Centerline Characteristics.

PURPOSE: To evaluate different centerline analysis applications using objective ground truth from realistic aortic aneurysm phantoms with precisely defined geometry and centerlines to overcome the lack of unknown true dimensions in previously published in vivo validation studies. METHODS: Three aortic phantoms were created using computer-aided design (CAD) software and a 3-dimensional (3D) printer. Computed tomography angiograms (CTAs) of phantoms and 3 patients were analyzed with 3 clinically approved and 1 research software application. The 3D centerline coordinates, intraluminal diameters, and lengths were validated against CAD ground truth using a dedicated evaluation software platform. RESULTS: The 3D centerline position mean error ranged from 0.7±0.8 to 2.9±2.5 mm between tested applications. All applications calculated centerlines significantly different from ground truth. Diameter mean errors varied from 0.5±1.2 to 1.1±1.0 mm among 3 applications, but exceeded 8.0±11.0 mm with one application due to an unsteady distortion of luminal dimensions along the centerline. All tested commercially available software tools systematically underestimated centerline total lengths by -4.6±0.9 mm to -10.4±4.3 mm (maximum error -14.6 mm). Applications with the highest 3D centerline accuracy yielded the most precise diameter and length measurements. CONCLUSION: One clinically approved application did not provide reproducible centerline-based analysis results, while another approved application showed length errors that might influence stent-graft choice and procedure success. The variety and specific characteristics of endovascular aneurysm repair planning software tools require scientific evaluation and user awareness.

Intraoperative contrast-enhanced cone beam computed tomography to assess technical success during endovascular aneurysm repair.

BACKGROUND: The aim of the study was to analyze the use of contrast-enhanced cone beam computed tomography (ceCBCT) during endovascular aneurysm repair (EVAR) and to compare this imaging modality with standard completion digital subtraction angiography (cDSA) and postoperative computed tomography angiography (CTA) regarding the detection of endograft-associated complications. METHODS: Between September 2012 and April 2015, ceCBCT was used in 98 EVAR patients in addition to cDSA and CTA. Endoleaks, intraluminal thrombus and limb stenoses, contrast agent use, and radiation exposure were recorded for all modalities. RESULTS: cDSA detected 16 (16.3%) endoleaks; ceCBCT, 35 (35.7%) endoleaks; and CTA, 22 (22.4%) endoleaks. All endoleaks identified by cDSA or CTA were also seen on ceCBCT. ceCBCT detected intraluminal thrombus in three patients (none in cDSA or CTA) and previously undetected limb stenoses in three patients. It prompted intraoperative interventions in 7 of 98 patients (7.1%). Replacing cDSA and CTA by ceCBCT would have caused a 39% reduction of in-hospital contrast agent volume in this cohort. CONCLUSIONS: ceCBCT can reliably detect all endograft-associated complications during EVAR. It offers the chance for immediate revision of remediable problems in a relevant proportion of patients and could thus reduce early reintervention rates. ceCBCT can safely replace early follow-up CTA and thereby reduce in-hospital use of contrast media.

Feasibility and accuracy of fusion imaging during thoracic endovascular aortic repair.

OBJECTIVE: To evaluate accuracy and feasibility of fusion imaging during thoracic endovascular aortic repair (TEVAR). METHODS: From January 2013 to January 2015 fusion imaging was used in 18 TEVAR procedures. Patients were prospectively enrolled for the survey and informed consent was obtained. Planning of the procedure and computed tomography (CT) angiography (CTA) segmentation with determination of all relevant surgical landmarks that should be displayed on fusion imaging was done using the preoperative CTA data. The registration was done with an intraoperative noncontrast-enhanced cone beam CT and CTA (three-dimensional [3D]-3D registration; n = 15) or with two fluoroscopic images in anteroposterior and lateral projection and the CTA (two-dimensional-3D registration; n = 3). An intraoperative digital subtraction angiography was performed to adjust fusion imaging and to allow accuracy measurement. RESULTS: Fusion imaging was possible in all included patients. The median dose for noncontrast-enhanced cone beam CT imaging was 28.6 Gy/cm(2) (range, 17.9-43.3) and 0.46 Gy cm(2) for two fluoroscopic images in the two-dimensional-3D group. Full accuracy was achieved in two cases (11%), with a median deviation of 11.7 mm (range, 0.0-37.2). Manual realignment was possible in all cases. CONCLUSIONS: This early experience shows that fusion imaging is feasible in TEVAR procedures using different registration methods. However, it shows a significant deviation in thoracic procedures because of different sources of error, making confirmation of fusion overlay with a digital subtraction angiography necessary in any case.

Fusion Imaging to Support Endovascular Aneurysm Repair Using 3D-3D Registration.

PURPOSE: To evaluate the feasibility and accuracy of fusion imaging (FI) during endovascular aneurysm repair (EVAR). METHODS: FI was performed in 101 consecutive EVAR patients (median age 72 years; 93 men) using automatic registration of the preoperative computed tomography angiography (CTA) with an intraoperative noncontrast cone beam CT (nCBCT; 3D-3D registration). Operative landmarks defined on the CTA were then overlaid in 3 dimensions on fluoroscopy images. Accuracy was measured as the deviation of the position of the lowest renal artery between the FI and angiography. Factors potentially influencing accuracy (α angle, ß angle, anesthesia, tortuosity index, neck calcification, neck length, CTA slice thickness, and conventional or sac sealing stent-graft) were analyzed in a multivariate linear regression model. RESULTS: Median procedure time for nCBCT was 3 minutes (range 2-20), with 4 minutes (range 0.4-15) for registration. An automatic registration tool was used successfully in 90 (89%) patients. Median craniocaudal deviation of the FI was 3 mm (range 0-15). Full accuracy (<1-mm deviation) was seen in 23 (23%) patients, 1- to 3-mm deviation in 23 (23%), 4- to 5-mm deviation in 22 (22%), and >5-mm deviation in 33 (33%). Caudal deviation potentially resulting in renal coverage was seen in 9 (9%). Lateral plus craniocaudal deviation was a median 5.8 mm (range 0-22). The position of the lowest renal artery compared to the FI was left and cranial in 62 (61%). Aneurysm morphology (ß angle, p=0.04), CTA slice thickness (p=0.02), and the use of 2 stiff guidewires in endovascular aneurysm sealing (p=0.01) influenced the overlay accuracy. CONCLUSION: Fusion imaging can be integrated into a daily workflow adding little to the procedure time. Craniocaudal accuracy (<5 mm) was achieved in 68% of cases, allowing optimal C-arm and angiographic catheter positioning or cannulation of target vessels in most patients. However, the accuracy of FI does not allow a noncontrast EVAR procedure without confirmation of FI overlay by a minimal contrast injection or vessel cannulation.

Comparison of Radiation Exposure Associated With Intraoperative Cone-Beam Computed Tomography and Follow-up Multidetector Computed Tomography Angiography for Evaluating Endovascular Aneurysm Repairs.

PURPOSE: To compare the radiation exposure associated with intraoperative contrast-enhanced cone-beam computed tomography (ceCBCT) acquisitions to standard 3-phase multidetector computed tomography (MDCT) angiography used for assessing technical success after endovascular aortic repair (EVAR). METHODS: Effective doses (EDs) were calculated for 66 EVAR patients (mean age 71 years; 61 men) with a mean 27.7-kg/m(2) body mass index (range 17-49) who had both intraoperative ceCBCT and postoperative 3-phase MDCT angiography between November 2012 and April 2015. In addition, EDs were directly determined using thermoluminescent dosimeters (TLDs) embedded in anthropomorphic phantoms with body mass indexes of 22 and 30 kg/m(2) Effective doses were calculated by summing doses recorded by all TLDs corresponding to a specific tissue type before applying the International Commission on Radiological Protection (ICRP) 60 and 103 weighting factors. EDs were compared with each other for both imaging modalities as well as to TLD measurements. RESULTS: Average EDs of the patient collective were 4.9±1.1 mSv for ceCBCT, 2.6±1.2 mSv for single-phase MDCT (46% decrease, covering solely the area of the implanted endograft), and 13.6±5.5 mSv for comprehensive 3-phase MDCT examinations (178% increase, anatomical coverage from the aortic arch to femoral artery bifurcation). EDs determined in phantom measurements ranged from 3.1 to 4.5 mSv for ceCBCT, amounting to 2.6 mSv for a single MDCT phase (15% to 40% decrease) using ICRP 60 conversion factors. Applying ICRP 103 factors resulted in higher values for ceCBCT and slightly lower ones for MDCT. CONCLUSION: ceCBCT offers the chance for immediate intraoperative revisions of endograft-related problems. Requiring only a single-phase acquisition, ceCBCT is associated with a considerable reduction in ED (50%-75%) compared to standard 3-phase MDCT angiography after EVAR. On the other hand, MDCT has a larger field of view and is associated with less radiation exposure for a single phase (reduction of 20%-60%) if only the stented region is covered; however, MDCT angiography also uses larger amounts of contrast.

Single-center experience in the management of spontaneous isolated abdominal aortic dissection.

OBJECTIVE: This study aims to report the management of patients with spontaneous isolated dissection of the abdominal aorta (sIAAD). METHODS: A cohort of 18 consecutive patients (12 male, mean age 58 years) with sIAAD was treated between 1990 and 2009. Dissection was asymptomatic in ten and symptomatic in eight patients. Retrospective data analysis from patient charts was performed. Follow-up included clinical examination, ultrasound, and/or CT-angiography. Mean follow-up was 54 months (range 1-211). RESULTS: In total, eight out of 18 received invasive treatment. All asymptomatic patients initially underwent conservative treatment and surveillance. Spontaneous false lumen thrombosis occurred in four (40 %), and three patients showed relevant aneurysmatic progression and underwent elective invasive treatment (open n = 2, endovascular n = 1), representing a crossover rate of 30 %. Late mortality was 20 % (n = 2) in this group. In symptomatic patients, five underwent urgent treatment due to persistent abdominal or back pain (n = 4) or contained rupture (n = 1); one was treated for claudication. The remaining two patients presented with irreversible spinal cord ischemia and were treated conservatively. Three patients were treated by open surgery and three by endovascular interventions (two stentgrafts, one Palmaz XXL stent). Early and late morbidity and mortality was 0 % in this group. There were no reinterventions CONCLUSION: The majority of patients with sIADD require invasive treatment, with EVAR being the preferable treatment option today. In asymptomatic IADD, primary surveillance is justifiable, but close surveillance due to expansion is necessary.

Follow-up outcomes of hybrid procedures for thoracoabdominal aortic pathologies with special focus on graft patency and late mortality.

OBJECTIVE: The purpose of this study was to analyze midterm results of bypass patency and overall and aortic-related mortality rates of hybrid aortic procedures for thoracoabdominal aortic pathologies. METHODS: A retrospective study was performed considering prospectively collected data in two centers. From January 2001 to December 2012, 45 patients (33 men; mean age, 67.8 ± 7.6 years) received hybrid aortic procedures for thoracoabdominal aortic diseases (31 atherosclerotic aneurysms, 7 chronic expanding type B aortic dissections, 2 penetrating aortic ulcers, and 5 pseudoaneurysms), corresponding to 155 revascularized visceral abdominal arteries. Elective/emergency and staged/simultaneous approaches were 31 of 14 and 28 of 17, respectively. Patient demographics, clinical risk factors, and aortic morphological and procedural data were collected. End points were technical success, 30-day morbidity, reintervention and mortality, bypass graft patency, freedom from reintervention, and overall and aortic-related mortality during midterm follow-up. Mean follow-up was 2.2 ± 2.4 years. RESULTS: Technical success was achieved in 86.6% (39/45) of patients. Thirty-day morbidity rate was 60% (paraplegia/paraparesis: 13.3%, stroke: 6.7%, renal failure: 31.3%, permanent dialysis: 4.4%). Thirty-day freedom from reintervention rates were 67.1% and 78.5%, respectively. Thirty-day occlusion of revascularized visceral vessels occurred in 11 (7.1%, 11/155) target arteries. In-hospital mortality rate was 24.4%. Primary graft patency after 1, 2, and 4 years was 89.7%, 85.3%, and 79%, respectively. Bypass thrombosis or stenosis developed in nine (6.8%, 9/132) vessels during follow-up. Of these, three patients required reintervention and one died. Freedom from reintervention rates after 1, 2, and 4 years were 45.6%, 45.6%, and 34.2%, respectively. Overall and aortic-related mortality rates after 1, 2, and 4 years were 32.6%, 41.4%, and 45.3% and 9.1%, 13.9%, and 13.9%, respectively. CONCLUSIONS: A hybrid procedure for thoracoabdominal aortic pathologies in high-risk patient is feasible but carries a significant rate of early and midterm reintervention and death. Long-term surveillance of the visceral bypass is necessary because one-third of the patients will have bypass-related complications.

State-of-the-art aortic imaging: Part II - applications in transcatheter aortic valve replacement and endovascular aortic aneurysm repair.

Transcatheter aortic valve replacement (TAVR) as well as thoracic and abdominal endovascular aortic repair (TEVAR and EVAR) rely on accurate pre- and postprocedural imaging. This review article discusses the application of imaging, including preprocedural assessment and measurements as well as postprocedural imaging of complications. Furthermore, the exciting perspective of computational fluid dynamics (CFD) based on cross-sectional imaging is presented. TAVR is a minimally invasive alternative for treatment of aortic valve stenosis in patients with high age and multiple comorbidities who cannot undergo traditional open surgical repair. Given the lack of direct visualization during the procedure, pre- and peri-procedural imaging forms an essential part of the intervention. Computed tomography angiography (CTA) is the imaging modality of choice for preprocedural planning. Routine postprocedural follow-up is performed by echocardiography to confirm treatment success and detect complications. EVAR and TEVAR are minimally invasive alternatives to open surgical repair of aortic pathologies. CTA constitutes the preferred imaging modality for both preoperative planning and postoperative follow-up including detection of endoleaks. Magnetic resonance imaging is an excellent alternative to CT for postoperative follow-up, and is especially beneficial for younger patients given the lack of radiation. Ultrasound is applied in screening and postoperative follow-up of abdominal aortic aneurysms, but cross-sectional imaging is required once abnormalities are detected. Contrast-enhanced ultrasound may be as sensitive as CTA in detecting endoleaks.

BMI-Adapted Double Low-Dose Dual-Source Aortic CT for Endoleak Detection after Endovascular Repair: A Prospective Intra-Individual Diagnostic Accuracy Study.

PURPOSE: To assess the diagnostic accuracy of BMI-adapted, low-radiation and low-iodine dose, dual-source aortic CT for endoleak detection in non-obese and obese patients following endovascular aortic repair. METHODS: In this prospective single-center study, patients referred for follow-up CT after endovascular repair with a history of at least one standard triphasic (native, arterial and delayed phase) routine CT protocol were enrolled. Patients were divided into two groups and allocated to a BMI-adapted (group A, BMI < 30 kg/m2; group B, BMI ≥ 30 kg/m2) double low-dose CT (DLCT) protocol comprising single-energy arterial and dual-energy delayed phase series with virtual non-contrast (VNC) reconstructions. An in-patient comparison of the DLCT and routine CT protocol as reference standard was performed regarding differences in diagnostic accuracy, radiation dose, and image quality. RESULTS: Seventy-five patients were included in the study (mean age 73 ± 8 years, 63 (84%) male). Endoleaks were diagnosed in 20 (26.7%) patients, 11 of 53 (20.8%) in group A and 9 of 22 (40.9%) in group B. Two radiologists achieved an overall diagnostic accuracy of 98.7% and 97.3% for endoleak detection, with 100% in group A and 95.5% and 90.9% in group B. All examinations were diagnostic. The DLCT protocol reduced the effective dose from 10.0 ± 3.6 mSv to 6.1 ± 1.5 mSv (p < 0.001) and the total iodine dose from 31.5 g to 14.5 g in group A and to 17.4 g in group B. CONCLUSION: Optimized double low-dose dual-source aortic CT with VNC, arterial and delayed phase images demonstrated high diagnostic accuracy for endoleak detection and significant radiation and iodine dose reductions in both obese and non-obese patients compared to the reference standard of triple phase, standard radiation and iodine dose aortic CT.

Clinical significance of type II endoleaks after thoracic endovascular aortic repair.

BACKGROUND: To evaluate the clinical significance of type II endoleaks (ELII) after thoracic endovascular aortic repair (TEVAR). METHODS: From January 1997 to June 2012, a total of 344 patients received TEVAR in our institution. ELII was diagnosed in 30 patients (8.7%; 13 males; median age: 65 years, range: 24 to 84 years), representing the study population of this retrospective, single-center analysis. Mean follow-up was 29.5 months (range, 8 months to 9.5 years). RESULTS: Primary ELII was observed in all but two cases (28/30; 93.3%). The most common sources of ELII were the left subclavian artery (LSA; 13/30; 43.3%) and intercostal/bronchial vessels (13/30; 43.3%), followed by visceral arteries (4/30; 13.4%). Overall mortality was 33.3% (10/30). ELII-related death (secondary rupture) was observed in 20% (2/10). Reintervention (RI) procedures for ELII were performed in 9 of 30 patients (30.0%); 5 of 9 (55.6%) in cases with ELII via the LSA. Indications for RI were diameter expansion in five and extensive leakage in four cases. Treatment was successful in five patients (55.6%) but failed in four cases (44.4%). In 12 of 21 (57.1%) untreated patients, ELII sealed during follow-up. In conservatively treated patients, an increase in aortic diameter has been only observed in a patient with secondary ELII. CONCLUSIONS: The results presented herein suggest that the clinical impact of ELII after TEVAR must not be underestimated. Albeit a transient finding in most cases, ELII is associated with a relevant RI rate, particularly in cases involving the LSA. RI seems indicated in patients with increasing aortic diameter and/or extensive leakage. Careful surveillance of all patients with ELII is recommended.

State-of-the-art aortic imaging: part I - fundamentals and perspectives of CT and MRI.

Over the last two decades, imaging of the aorta has undergone a clinically relevant change. As part of the change non-invasive imaging techniques have replaced invasive intra-arterial digital subtraction angiography as the former imaging gold standard for aortic diseases. Computed tomography (CT) and magnetic resonance imaging (MRI) constitute the backbone of pre- and postoperative aortic imaging because they allow for imaging of the entire aorta and its branches. The first part of this review article describes the imaging principles of CT and MRI with regard to aortic disease, shows how both technologies can be applied in every day clinical practice, offering exciting perspectives. Recent CT scanner generations deliver excellent image quality with a high spatial and temporal resolution. Technical developments have resulted in CT scan performed within a few seconds for the entire aorta. Therefore, CT angiography (CTA) is the imaging technology of choice for evaluating acute aortic syndromes, for diagnosis of most aortic pathologies, preoperative planning and postoperative follow-up after endovascular aortic repair. However, radiation dose and the risk of contrast induced nephropathy are major downsides of CTA. Optimisation of scan protocols and contrast media administration can help to reduce the required radiation dose and contrast media. MR angiography (MRA) is an excellent alternative to CTA for both diagnosis of aortic pathologies and postoperative follow-up. The lack of radiation is particularly beneficial for younger patients. A potential side effect of gadolinium contrast agents is nephrogenic systemic fibrosis (NSF). In patients with high risk of NSF unenhanced MRA can be performed with both ECG- and breath-gating techniques. Additionally, MRI provides the possibility to visualise and measure both dynamic and flow information.

Direct percutaneous sac injection for postoperative endoleak treatment after endovascular aortic aneurysm repair.

BACKGROUND: This study presents the short-term and midterm results of direct percutaneous sac injection (DPSI) for postoperative endoleak treatment after endovascular aortic aneurysm repair (EVAR). METHODS: Between March 1994 and November 2011, EVAR was performed in 986 patients. The median follow-up was 63 ± 45 months (range, 0-211 months). A retrospective analysis was performed. DPSI was used in 21 patients for 19 type II endoleaks and two endoleaks of undefined origin (EOUO), of which 12 (57%) were after failure of a previous endovascular treatment attempt. RESULTS: DPSI using thrombin (n = 16), coils (n = 7), gelfoam (n = 6), or glue (n = 3), or a combination, was technically feasible in all patients. Saccography during DPSI revealed a previously undetected type I endoleak in three patients. Immediate DPSI success was achieved in 16 of 18 procedures (88.9%), with two complications. Glue incidentally intravasated in the inferior vena cava, causing a clinically nonsignificant subsegmental pulmonary artery embolism in one patient, and the temporary development of a type III endoleak, possibly from graft puncture, in another. During a median follow-up of 39 months (interquartile range, 13-88 months) after DPSI, recurrent endoleaks were observed in nine patients (50.0%), one type I endoleak due to graft migration, five type II endoleaks, and three EOUO. The occurrence of a re-endoleak during follow-up was significantly associated with dual-antiplatelet medication (0% in patients without re-endoleak vs 44.4% in patients with re-endoleak; P = .023) and with a nonsignificant trend for the use of aspirin alone (33.3% in patients without re-endoleak vs 80% in patients with re-endoleak; P = .094). Re-endoleak occurred in 33.3% of the patients without antiplatelet medication and in 100% of patients with dual-antiplatelet medication (P = .026). Thrombin was used as the sole embolic agent during the initial DPSI in all patients with dual-antiplatelet therapy. No other factor was significantly associated with re-endoleaks. Reintervention was deemed necessary in six patients within a median of 10 months (interquartile range, 4-16 months) after DPSI, including six additional DPSI treatments in four patients with type II re-endoleaks, cuff placements in one type I endoleak, and endograft relining in one EOUO. CONCLUSIONS: This initial experience suggests that DPSI is feasible as a technique for endoleak treatment after EVAR. However, complications and endoleak recurrence remain a concern. The role of antiplatelet therapy and different embolic agents on long-term embolization success needs to be studied in more detail.

Bivalirudin used as alternative anticoagulant in carotid artery stenting: a single center observational study.

PURPOSE: To analyze and report the safety and effectiveness of bivalirudin in a large patient population undergoing carotid artery stenting (CAS). METHODS: Between January 2001 and November 2010 extracranial CAS was performed in 272 patients in our institution. These patients were stratified according to the anticoagulant used during the CAS procedure into 2 groups (bivalirudin n = 217 vs. unfractionated heparin [UFH] n = 55) and analyzed regarding bleeding complications and periprocedural (within 30 days) stroke and myocardial infarction (MI) rates. RESULTS: The combined end-point of death, stroke, and MI occurred in 12 patients (4.4%) with no significant difference between the groups (bivalirudin 4.6% vs. UFH 3.6% P value 0.96). Stroke rates were 1.8% in the bivalirudin and 1.8% in the UFH group (P value 1.00), with 4/5 strokes being nondisabling. Periprocedural MI was observed in 7 patients (2.1%) with no significant differences between the groups (bivalirudin 2.7% vs. UFH 1.8%, P value 0.94). Bleeding complications occurred in 13/272 patients (4.7%) with no significant difference between the groups (bivalirudin 3.6% vs. UFH 9.0%, P value 0.15). The first activated clotting time after administration of the anticoagulants was therapeutic in 209/217 (96%) in the bivalirudin group and in 30/55 (55%) in the UFH group (P < 0.001). CONCLUSIONS: In this single-center study, bivalirudin was a safe and efficient anticoagulation strategy for CAS and could be considered a therapeutic alternative to UFH.

Current clinical practice in postoperative endovascular aneurysm repair imaging surveillance.

PURPOSE: To investigate the current clinical practice in postoperative endovascular aneurysm repair (EVAR) imaging surveillance. MATERIALS AND METHODS: Corresponding authors of EVAR publications during the years 2006-2011 and subscribers to an endovascular journal were invited to complete a 27-question online survey related to institutional demographics, standard post-EVAR imaging surveillance, and imaging protocols in special circumstances (eg, renal insufficiency). RESULTS: The survey was completed by 515 of 9,631 physicians performing EVAR from 52 countries. Of respondents, 65.3% were affiliated with experienced centers where EVAR has been performed for > 10 years or with > 50 EVAR procedures performed per year. Computed tomography (CT) angiography was the modality used most often for standard surveillance with a maximum time interval between studies of 12 months in 78.8% of centers out to 5 years. Experienced centers were more likely to delay follow-up imaging to 1 year after an unremarkable initial post-EVAR imaging study (P < .001), to extend surveillance intervals > 12 months (P = .043), and to use ultrasound (P < .01) for surveillance. After the detection of a type II endoleak, CT angiography was favored for follow-up by 59.4% of the respondents. Experienced centers were more likely to favor ultrasound (P = .006) and to schedule this follow-up examination later (after 6-12 months, P < .001). Of respondents, 62.8% used a glomerular filtration rate threshold of < 30 mL/min for not performing contrast-enhanced CT scan. In patients with renal insufficiency, most respondents performed ultrasound with or without a concomitant noncontrast CT scan. CONCLUSIONS: CT is the most frequently used method of long-term surveillance after EVAR. Use of ultrasound for long-term surveillance, extension of follow-up time intervals, or both were most often reported in experienced centers.