Repaired coarctation of the aorta does not affect four-dimensional flow metrics in bicuspid aortic valve disease.

OBJECTIVES: The objective of this study was primarily to compare four-dimensional flow magnetic resonance imaging metrics in the ascending aorta (AA) of patients with right-left fusion type bicuspid aortic valve (RL-BAV) and repaired coarctation of the aorta (CoA) to RL-BAV without CoA. Metrics of patients with RL-BAV were also compared to the matched group of patients with common tricuspid aortic valve (TAV). METHODS: Eleven patients with RL-BAV and CoA, 11 patients with RL-BAV without CoA and 22 controls with TAV were investigated. Peak velocity (cm/s), peak flow (ml/s) and flow displacement (%) were analysed at 5 pre-defined AA levels. In addition, regional wall shear stress (WSS, mN/m2), circumferential WSS (WSSc) and axial WSS (WSSa) at all levels were quantified in 6 sectors of the aortic circle. Averaged WSS values on each level (WSSavg, WSSc, avg and WSSa, avg) were calculated as well. RESULTS: Peak velocity at the proximal tubular AA was significantly lower in BAV and CoA group (P = 0.047) compared to BAV without CoA. In addition, the WSSa, avg was found to be higher for the BAV and CoA group at proximal AA respectively (P = 0.040). No other significant differences were found between these groups. BAV group's peak velocity was higher at every level (P < 0.001-0.004) compared to TAV group. Flow displacement was significantly higher for the BAV group at every level (P < 0.001) besides at the most distal level. All averaged WSS values were significantly higher in BAV patients in distal AA (P < 0.001-0.018). CONCLUSIONS: Repaired CoA does not relevantly alter four-dimensional flow metrics in the AA of patients with RL-BAV. However, RL-BAV majorly alters flow dynamics in the AA when compared to patients with TAV. CLINICAL TRIAL REGISTRATION NUMBER: https://www.clinicaltrials.gov/study/NCT05065996, Unique Protocol ID 5063566.

Long-term outcome after implementation of endovascular-first strategy to treat acute mesenteric ischemia.

OBJECTIVE: To evaluate the rationale of an aggressive endovascular-first strategy to treat elderly patients with acute mesenteric ischemia (AMI) by studying long-term survival, readmissions, and patients' discharge to home vs nursing facility a decade after an episode of AMI. METHODS: The retrospective study cohort included 66 consecutive patients (all-comers) treated for arterial occlusive AMI between 2009 and 2013. Endovascular revascularization (EVR) was attempted in 50 patients (EVR+), whereas 16 patients were treated without attempted revascularization (EVR-). All patients were followed until death or September 2022. Studied outcomes included discharge status, long-term survival and cause of death and readmissions related to AMI. RESULTS: The mean age of all 66 patients was 78 ± 10 years: 79 ± 9 years in the EVR+ group and 76 ± 12 years in the EVR- group. EVR was technically successful in 44 patients (88%); three patients underwent subsequent open revascularization after EVR failure. One-third required bowel resection after EVR. The 30-day mortality for all patients was 44%; 32% in the EVR+ group and 81% in the EVR- group. Only two survivors were permanently institutionalized, whereas all others were discharged to the same place they lived prior to the AMI episode. There were four AMI-related readmissions during the follow-up; all were in the EVR+ group. Two patients underwent reinterventions for recurrent AMI. One-year survival was 52% for EVR+ and 19% for EVR- patients. Five-year survival rates were 18% and 13%, respectively. The causes of deaths were mesenteric ischemia in 22, other cardiovascular event in 21, and non-cardiovascular cause in 19 patients. Four patients were alive at the end of the follow-up. CONCLUSIONS: In this unselected elderly population with AMI, the aggressive strategy to attempt EVR resulted in a high revascularization rate and favorable outcomes. The high proportion of patients returning to their prior living status and low readmission rate after survival from AMI encourages active treatment of high-functioning elderly patients.

Friendly Neck Anatomy Does Not Prevent Neck-Related Adverse Events After EVAR.

BACKGROUND: Life-long follow-up after endovascular aneurysm repair (EVAR) is costly and burdensome to the patient. Follow-up should be stratified based on the risk of EVAR failure. Aneurysm neck is thought to be the single most important risk factor. This study investigated neck anatomy as a predictor of neck-related adverse events after EVAR. METHODS: This retrospective single-center study included consecutive patients undergoing elective EVAR for infrarenal abdominal aortic aneurysms between 2011 and 2016 (n = 222) who were followed with yearly imaging until December 2020. Hostile neck was defined as neck length ≤15 mm, width ≥28 mm, angulation ≥60°, calcification, or thrombus ≥50% of circumference or conical neck based on preoperative computed tomography angiography. Neck-related adverse event was defined as aneurysm rupture, any neck-related reintervention or type 1a endoleak during follow-up. RESULTS: Ninety (41%) patients had hostile neck and 132 (59%) had friendly neck. There were no differences in 30-day mortality (1% vs. 1%, P = 0.78), major adverse events (20% vs. 16%, P = 0.43) or reinterventions during the hospital stay (8% vs. 4%, P = 0.20) between patients with hostile and friendly neck. Estimated survival at 1 year was 89 ± 3% for hostile neck and 95 ± 2% for friendly neck patients (P < 0.01). Five-year survival estimates were 51 ± 6% and 66 ± 4%, respectively. Aneurysm-related mortality was higher after 6 years in patients with hostile neck (P < 0.01). Twenty-four patients (11%) suffered neck-related adverse events with mean time-to-event of 3.3 ± 2.8 years; there were no differences between the groups stratified by neck anatomy. Incidentally, preoperative aneurysm diameter was found to be an independent risk factor for neck-related adverse events and aneurysm-related mortality; 53 patients (24%) had aneurysm diameter ≥70 mm, which was associated with nearly 4-fold risk of neck-related complications during the follow-up. CONCLUSIONS: Friendly neck anatomy may not protect from neck-related adverse events after EVAR in the long-term. Especially patients with large aneurysms should be followed closely.

Wall Shear Stress Predicts Media Degeneration and Biomechanical Changes in Thoracic Aorta.

Objectives: In thoracic aortic aneurysm (TAA) of the ascending aorta (AA), AA is progressively dilating due to the weakening of the aortic wall. Predicting and preventing aortic dissections and ruptures in TAA continues to be challenging, and more accurate assessment of the AA dilatation, identification of high-risk patients, and timing of repair surgery are required. We investigated whether wall shear stress (WSS) predicts pathological and biomechanical changes in the aortic wall in TAA. Methods: The study included 12 patients with bicuspid (BAV) and 20 patients with the tricuspid aortic valve (TAV). 4D flow magnetic resonance imaging (MRI) was performed a day before aortic replacement surgery. Biomechanical and histological parameters, including assessing of wall strength, media degeneration, elastin, and cell content were analyzed from the resected AA samples. Results: WSSs were greater in the outer curves of the AA compared to the inner curves in all TAA patients. WSSs correlated with media degeneration of the aortic wall (ρ = -0.48, p < 0.01), elastin content (ρ = 0.47, p < 0.01), and aortic wall strength (ρ = -0.49, p = 0.029). Subsequently, the media of the outer curves was thinner, more rigid, and tolerated lower failure strains. Failure values were shown to correlate with smooth muscle cell (SMC) density (ρ = -0.45, p < 0.02), and indicated the more MYH10+ SMCs the lower the strength of the aortic wall structure. More macrophages were detected in patients with severe media degeneration and the areas with lower WSSs. Conclusion: The findings indicate that MRI-derived WSS predicts pathological and biomechanical changes in the aortic wall in patients with TAA and could be used for identification of high-risk patients.

Use of paclitaxel-coated balloons in clinical setting is not associated with increased mortality compared with plain balloon angioplasty in femoropopliteal lesions.

OBJECTIVE: To investigate mortality and causes of death associated with the use of paclitaxel-coated balloon (PCB) compared with plain balloon (PB) angioplasty in the treatment of femoropopliteal artery lesions in real-world clinical setting. METHODS: This retrospective, single-center study included patients who underwent percutaneous femoropopliteal artery angioplasty without stenting between years 2014 and 2020. Patients were stratified into PCB and PB groups according to the index procedure. Those who had undergone any prior or subsequent intervention using drug-eluting technology were excluded from the PB group. Long-term survival was estimated up to 5 years using the Kaplan-Meier method, and risk factors for all-cause mortality were assessed in a multivariable analysis. Causes of death were retrieved from a national registry. RESULTS: The study included 139 patients treated with PB and 190 with PCB. Patients treated with PCB had a higher prevalence of chronic pulmonary disease (27% vs 17%; P = .02) and were less often on anticoagulant therapy (34% vs 48%; P = .01) compared with patients in the PB group. Those treated with PB were more likely to have chronic limb-threatening ischemia (CLTI; 82% vs 72%; P = .04). Ipsilateral perioperative amputation rate was significantly higher in the PB group (7% vs 1%; P = .01). There were no major differences in other 30-day outcomes between the groups and no differences in the rates of reinterventions and ipsilateral amputations during a mean follow-up time of 2.7 ± 1.9 years. Survival at 1 year in the PCB group was 83% ± 3% compared with 73% ± 4% in the PB group (P = .0001). The 5-year survival estimates were 56% ± 5% and 37% ± 5%, respectively. PCB use was independently associated with decreased risk of mortality (hazard ratio [HR], 0.70; 95% confidence interval [CI], 0.50-0.97). Independent risk factors for increased mortality were age (HR, 1.04 per year; 95% CI, 1.02-1.06), cardiac insufficiency (HR, 1.60; 95% CI, 1.12-2.27), chronic renal insufficiency (HR, 2.04; 95% CI, 1.47-2.85), anticoagulation therapy (HR, 1.65, 95% CI, 1.16-2.34), and CLTI (HR, 2.85; 95% CI, 1.51-5.39). In the PCB group, 63% of deaths were due to cardiovascular causes compared with 42% in the PB group (P < .01). CONCLUSIONS: The use of PCB is safe, and there is no concern of increased mortality after the procedure based on the 5-year survival estimates.

Radiographically quantified sarcopenia and traditional cardiovascular risk assessment in predicting long-term mortality after endovascular aortic repair.

OBJECTIVE: This study evaluated radiographically quantified sarcopenia and the patient's comorbidity burden based on traditional cardiovascular risk assessment as potential predictors of long-term mortality after endovascular aortic repair (EVAR). METHODS: The study included 480 patients treated with standard EVAR for intact infrarenal abdominal aortic aneurysms. Patient characteristics, comorbidities, aneurysm dimensions, and other preoperative risk factors were collected retrospectively. Preoperative computed tomography was used to measure psoas muscle area (PMA) at the L3 level. Patients were divided into three groups based on American Society of Anesthesiologists (ASA) score and PMA. In the high-risk group, patients had sarcopenia (PMA <8.0 cm2 for males and <5.5 cm2 for females) and an ASA score of 4. In the medium-risk group, patients had either sarcopenia or an ASA score of 4. Patients in the low-risk group had no sarcopenia and the ASA score was less than 4. Risk factors for long-term mortality were determined using multivariable analysis. Kaplan-Meier survival estimates were calculated for all-cause mortality. RESULTS: Patients in the high- and medium-risk groups were older than those in the low-risk group (77 ± 7, 76 ± 6, and 74 ± 8 years, respectively, P < .01). Patients in the high-risk group had higher prevalence of coronary artery disease, pulmonary disease, and chronic kidney disease. There were no differences in 30-day or 90-day mortality between the groups. The independent predictors of long-term mortality were age, ASA score, PMA, chronic kidney disease, and maximum aneurysm sac diameter. The estimated 1-year mortality rates were 5% ± 2% for the low-risk, 5% ± 2% for the medium-risk, and 18% ± 5% for the high-risk group (P < .01). Five-year mortality estimates were 23% ± 4%, 36% ± 3%, and 60% ± 6%, respectively (P < .01). The mean follow-up time was 5.0 ± 2.8 years. CONCLUSIONS: Both ASA and PMA were strong predictors of increased mortality after elective EVAR. The combination of these two can be used as a simple risk stratification tool to identify patients in whom aneurysm repair or the intensive long-term surveillance after EVAR may be unwarranted.

Finnish flow diverter study: 8 years of experience in the treatment of acutely ruptured intracranial aneurysms.

BACKGROUND: Flow diversion of acutely ruptured intracranial aneurysms (IAs) is controversial due to high treatment-related complication rates and a lack of supporting evidence. We present clinical and radiological results of the largest series to date. METHODS: This is a nationwide retrospective study of acutely ruptured IAs treated with flow diverters (FDs). The primary outcome was the modified Rankin Scale (mRS) score at the last available follow-up time. Secondary outcomes were treatment-related complications and the aneurysm occlusion rate. RESULTS: 110 patients (64 females; mean age 55.7 years; range 12-82 years) with acutely ruptured IAs were treated with FDs between 2012 and 2020 in five centers. 70 acutely ruptured IAs (64%) were located in anterior circulation, and 47 acutely ruptured IAs (43%) were blister-like. A favorable functional outcome (mRS 0-2) was seen in 73% of patients (74/102). Treatment-related complications were seen in 45% of patients (n=49). Rebleeding was observed in 3 patients (3%). The data from radiological follow-ups were available for 80% of patients (n=88), and complete occlusion was seen in 90% of aneurysms (79/88). The data from clinical follow-ups were available for 93% of patients (n=102). The overall mortality rate was 18% (18/102). CONCLUSIONS: FD treatment yields high occlusion for acutely ruptured IAs but is associated with a high risk of complications. Considering the high mortality rate of aneurysmal subarachnoid hemorrhage, the prevention of rebleeding is crucial. Thus, FD treatment may be justified as a last resort option.

Flow displacement and decreased wall shear stress might be associated with the growth rate of an ascending aortic dilatation.

OBJECTIVES: Our goal was to evaluate whether four-dimensional (4D) flow magnetic resonance imaging (MRI) can predict the growth rate of dilatation of the ascending aorta (AA) in patients with a tricuspid, normally functioning aortic valve. METHODS: In this prospective clinical study, aortic 4D flow MRI was performed at the Kuopio University Hospital on 30 patients diagnosed with AA dilatation (maximum diameter >40 mm) between August 2017 and July 2020. The MRI was repeated after a 1-year follow-up, with AA dimensions and 4D flow parameters analysed retrospectively at both time points. The standard error of measurement was used to assess the statistical significance of the growth rate of AA dilatation. Flow displacement (FD) was transformed to a class-scaled parameter using FD ≥5% as a threshold. RESULTS: Statistically significant growth [median 2.1 mm (1.5-2.2 mm); P = 0.03] was detected in 6 male patients (20%); the AA diameter remained unchanged [0.2 mm (-0.3 to 0.9 mm)] in 24 patients (80%). An increased FD at the baseline was associated with significant growth during the 1-year follow-up in the proximal AA. An association was detected between decreased total wall shear stress and significant aortic growth in the inner curve of the sinotubular junction [529 mPa (449-664 mPa) vs 775 mPa (609-944 mPa); P = 0.03] and the anterior side of the proximal aortic arch [356 mPa (305-367 mPa) vs 493 mPa (390-586 mPa); P < 0.001]. CONCLUSIONS: FD and decreased wall shear stress seem to be associated with significant growth of AA dilatation at the 1-year follow-up. Thus, 4D flow MRI might be useful in assessing risk for AA diameter growth in patients with a tricuspid aortic valve.

Long-term outcome over a decade after first rib resection for neurogenic thoracic outlet syndrome.

OBJECTIVES: The aim was to determine long-term outcomes over a decade after first rib resection (FRR) in patients with neurogenic thoracic outlet syndrome (NTOS). A secondary aim was to investigate correlation of residual rib stump with long-term symptoms. METHODS: This ambispective cohort included patients who underwent transaxillary FRRs for NTOS between 1998 and 2007. Short-term outcomes at 3-month clinical follow-up were retrospectively collected from medical records. Patients who agreed to participate in the study were invited to a long-term clinical follow-up in 2019. Disabilities of Arm, Shoulder, and Hand Score and Cervical Brachial Symptom Questionnaire were used. A chest X-ray limited to a clavicular projection was taken, and the length of the residual first rib was measured. RESULTS: Twenty patients {mean age 41.8 [standard deviation (SD): 10.3 years]} who underwent 27 FRRs participated in the study. The mean follow-up time was 14.9 (SD: 3.6) years. Excellent or good recovery was noted after 16 (59.3% of operated arms) operations in the short-term follow-up and 22 (81.5%) operations in the long-term follow-up. No reoperations were necessary for residual symptoms. The mean Cervical Brachial Symptom Questionnaire score was 26.7 (SD: 28.2) (maximum 120), and the Disabilities of Arm, Shoulder, and Hand Score was 21.1 (SD: 18.4) (maximum 100) points. Twenty-six patients (96.3%) had a noticeable residual first rib stump. The mean length of the residual first rib was 28.9 (SD: 9.5) mm. More than 30-mm rib stump did not indicate a worse long-term outcome. CONCLUSIONS: This study showed good long-term outcome without symptom recurrence after FRR for NTOS. In most patients, after surgery, quality of life and ability to work improved. Residual rib stump length was not associated with the treatment outcome.

High prevalence of ascending aortic dilatation in a consecutive coronary CT angiography patient population.

OBJECTIVES: To clarify the prevalence and risk factors of ascending aortic (AA) dilatation according to ESC 2014 guidelines. METHODS: This study included 1000 consecutive patients scheduled for diagnostic coronary artery computed tomographic angiography. AA diameter was retrospectively measured in 3 planes: sinus valsalva, sinotubular junction, and tubular part. The threshold for AA dilatation was set to > 40 mm which has been suggested as an upper normal limit for AA diameter in ESC 2014 guidelines on aortic diseases. Aortic size index (ASI) using the ratio between aortic diameter and body surface area (BSA) was applied as a comparative measurement. The threshold for AA dilatation was set to the upper limit of normal distribution exceeding two standard deviations (95%). Risk factors for AA dilatation were collected from medical records. RESULTS: The patients' mean age was 52.9 ± 9.8 years (66.5% women). The prevalence of AA dilatation was 23.0% in the overall study population (52.5% males) and 15.1% in the subgroup of patients with no coronary artery disease or bicuspid (BAV)/mechanical aortic valve (n = 365). According to the normal-distributed ASI values, the threshold for sinus valsalva was defined as 23.2 mm/m2 and for tubular part 22.2 mm/m2 in the subgroup. Higher BSA was associated with larger AA dimensions (r = 0.407, p < 0.001). Male gender (p < 0.001), BAV (p < 0.001), hypertension (p = 0.009) in males, and smoking (p < 0.001) appeared as risk factors for AA dilatation. CONCLUSIONS: The prevalence of AA dilatation is high with current ESC guidelines for normal AA dimension, especially in males. Body size is strongly associated with AA dimensions; it would be more reliable to use BSA-adjusted AA diameters for the definition of AA dilatation. KEY POINTS: • The prevalence of AA dilatation is high in patients who are candidates for coronary CT angiography. • Body size is strongly associated with AA dimensions.

Effect of Endovascular Treatment Rate on Population Level Outcomes and Survival After Intact Abdominal Aortic Aneurysm Repair.

OBJECTIVES: The aim was to study outcomes of endovascular aneurysm repair (EVAR) and open surgical repair (OSR) of abdominal aortic aneurysms (AAAs) in four geographically adjacent populations with identical demographics and variable EVAR rates. METHODS: This was a multicentre cohort study based on local and national registry data from an area of 815 000 inhabitants. The study involved 527 consecutive patients with an intact AAA treated with EVAR (n = 327) or OSR (n = 200) between 2010 and 2016. The catchment area was divided into four health care districts (populations A, B, C, and D) with one central hospital in each district. Each hospital decided independently between OSR and EVAR for patients within their population; OSR was performed in all hospitals while EVAR was centralised in one of them. Patient demographics and treatment outcomes were extracted from local registries. Population demographics, overall AAA incidence, and mortality data were retrieved from a national database. RESULTS: The rate of new intact AAA diagnosis varied between 20 and 29 per 100 000 inhabitants/year with the highest incidence in population D (p < .001). The intact AAA repair rates were 9.8, 8.9, 9.9, and 8.7 per 100 000 inhabitants/year for populations A, B, C, and D, respectively (p = .64). There were no significant differences in mean age (73.6 ± 8.0 years) or mean aortic diameter (62 ± 13 mm) between the treated patient populations. Groups A and B had high EVAR rates (74% and 72%, respectively) whereas the EVAR rates were lower in groups C and D (50% and 38%, respectively) (p < .001). The 30 day mortality rates were 2%, 2%, 4%, and 1% (p = .55), and complication rates were 17%, 12%, 15%, and 11% (p = .39) for A, B, C and D, respectively. There were no significant differences in mortality, complication or re-intervention rates between the groups during the mean follow up of 3.3 ± 2.0 years. CONCLUSIONS: At population level, high EVAR rates had no measurable effect compared with lower EVAR rates on the outcomes in patients with intact AAA.

Pharmacomechanical Thrombectomy in Paget-Schroetter Syndrome.

PURPOSE: The purpose of the study was to evaluate feasibility of pharmacomechanical thrombectomy (PMT) in the treatment of Paget-Schroetter syndrome (PSS) followed by thoracoscopic or open surgical decompression of the subclavian vein. METHODS: Twenty-two out of 27 consecutive patients with PSS received PMT using the Trellis-8 peripheral infusion system (Covidien) between 2010 and 2014. Subsequent surgery was performed in 18 of those patients, 9 patients were treated with thoracoscopic, 7 patients with subclavicular, and 2 patients with transaxillary first rib resection, 4 patients were treated with PMT and anticoagulation alone. Technical success, complications, and patency were registered. RESULTS: PMT was successful in 21 (95 %) patients; 1 patient with unsatisfactory lysis received further catheter-directed thrombolysis, which, however, did not improve the result. The mean endovascular procedure time was 105 ± 33 min (range 70-200 min), and the required median amount of thrombolytic agent was 500,000 international unit (IU; range 250,000-1,000,000 IU). Adjunctive balloon venoplasty and aspiration were used in 18 (82 %) and 7 (32 %) cases, respectively. One patient had an intimal tear of the subclavian vein that was discovered and repaired during surgery. There were no other complications related to the endovascular procedure. At follow-up, 18 of 21 patients (86 %) with follow-up imaging available had patent subclavian vein, and all except 1 of the 22 patients were asymptomatic. The mean follow-up time was 25 ± 17 months. CONCLUSIONS: In experienced hands, PMT is effective for early thrombus removal in PSS. Surgical decompression must be considered after PMT.

Interpretation of Abdominal CT Findings in Patients Who Develop Acute on Chronic Mesenteric Ischemia.

BACKGROUND: We studied whether ischemia-specific computed tomography (CT) findings are consistently detectable in patients who develop acute on chronic mesenteric ischemia (AOCMI), whereas absent in chronic mesenteric ischemia (CMI). METHODS: Consecutive patients with symptomatic angiography-verified atherosclerotic obstruction of the superior mesenteric artery (SMA) were categorized as AOCMI (n = 27) or CMI (n = 20). Three experienced radiologists blindly evaluated the contrast-enhanced CTs for vascular and intestinal findings. Kappa statistics was used to test interobserver agreement. RESULTS: Two observers had substantial agreement (k = 0.66) that two thirds of AOCMI patients showed ischemia-specific CT findings (decreased bowel wall enhancement, pneumatosis, or thrombotic SMA clot); the third observer agreed only fairly regarding pneumatosis and thrombosis (k = 0.3-0.4). All observers had substantial agreement (k = 0.65-0.71) that most patients with AOCMI had unspecific intestinal findings such as mesenteric fat stranding in up to 96%, bowel lumen dilatation in 93%, and bowel wall thickening in 70%, while only few patients with CMI had such findings (due to chronic ischemic colitis) (P < 0.001). CONCLUSION: One third of AOCMI patients presented without any ischemia-specific CT signs. However, any intestinal abnormality in CT together with SMA obstruction should raise suspicion of intestinal ischemia. Furthermore, clinicians need to be aware of the interobserver variability in the CT interpretation.

Antegrade in situ fenestration of aortic stent graft: in-vivo experiments using a pig model.

BACKGROUND: Short proximal neck of an abdominal aortic aneurysm is associated with risk of treatment failure during abdominal aortic repair. Important side branches, such as renal arteries, cannot be covered without serious consequences. PURPOSE: To test the feasibility of preoperative fenestration of abdominal aortic stent grafts with a re-entry catheter and steerable sheath to preserve the patency of renal arteries in an animal model. MATERIAL AND METHODS: Three domestic pigs were anesthetised and a stent graft placed in the abdominal aorta, covering the renal arteries. An attempt was made to fenestrate the renal arteries through the prosthesis using the Outback re-entry catheter supported by the Channel Steerable sheath. The hole that was created was dilated and stented. The specimens were visually analyzed after sacrifice. RESULTS: In one pig, the graft material was successfully traversed and a guide wire advanced in the renal arteries. Due to insufficient guide wire support and a poor balloon profile, dilatation of the fenestration failed. In another pig, the procedure was technically successful, but a long warm ischemia time for the left kidney caused infarction. In the third experiment, the procedure had to be discontinued due to a technical failure of the Outback device. CONCLUSION: Fenestration of a stent graft with a re-entry device through a steerable sheath is technically feasible in vivo. However, without further refinement of the instrumentation, the technique cannot be recommended in elective cases of abdominal aortic repair, but if the renal arteries are covered accidentally during endovascular treatment, the technique may be a valuable salvage option if surgical revascularization is not considered as an option.