Percutaneous drainage and combined praziquantel-albendazole therapy: a novel approach for the treatment of simple echinococcal liver cysts.

Cystic echinococcosis (CE) is a worldwide helminthic zoonosis causing serious disease in humans. The WHO Informal Working Group on Echinococcosis recommends a stage-specific treatment approach of hepatic CE that facilitates the decision on what therapy option is most appropriate. Percutaneous aspiration, instillation of a scolicide, e.g., ethanol or hypertonic saline, and subsequent re-aspiration (PAIR) have been advocated for treating medium-size unilocular WHO-stage CE1 cysts. PAIR can pose a risk of toxic cholangitis because of spillage of ethanol in the case of a cysto-biliary fistula or of life-threatening hypernatriaemia when hypertonic saline is used. The purpose of our study is to develop an alternative, safe, minimally invasive method to treat CE1 cysts, avoiding the use of toxic topic scolicides.We opt for percutaneous drainage (PD) in four patients: the intrahepatic drainage catheter is placed under CT-fluoroscopy, intracystic fluid is aspirated, and the viability of intracystic echinococcal protoscolices is assessed microscopically. Oral praziquantel (PZQ) is added to albendazole (ABZ) instead of using topical scolicidals.Protoscolices degenerate within 5 to 10 days after PZQ co-medication at a cumulative dosage of 250 to 335 mg/kg, and the cysts collapse. The cysts degenerate, and no sign of spillage nor relapse is observed in the follow-up time of up to 24 months post-intervention.In conclusion, PD combined with oral PZQ under ABZ coverage is preferable to PAIR in patients with unilocular echinococcal cysts.

[Management of Injuries to the Parenchymal Abdominal Organs]. / Management von Verletzungen parenchymatöser Abdominalorgane.

The most common organs affected by abdominal trauma are the spleen and the liver, often in combination. Pancreatic injuries are rare. In the case of blunt abdominal trauma, which is much more common, a clinical and laboratory examination as well as sonography should be performed. In the initial assessment, the circulatory situation must be screened. If there is haemodynamic instability and presentation of free fluid, an emergency laparotomy is indicated. If the situation is stable or stabilised and a pathological sonography is present, it is essential to perform triphasic contrast enhanced computed tomography, which is also mandatory in polytraumatised patients. If a renal injury is suspected, a late venous phase should be attached. In addition to the classification of the injury, attention should be paid to possible vascular injury or active bleeding. In this case, angiography with the possibility of intervention should be performed. Endoscopic treatment is possible for injuries of the pancreatic duct. If the imaging does not reveal any intervention target and a circulation is stable, a conservative approach is possible with continuous monitoring using clinical, laboratory and sonographic controls. Most injuries can be successfully treated by non-operative management (NOM).There are various surgical options for treating the injury, such as local and resecting procedures. There is also the option of "damage control surgery" with acute bleeding control and second look. Complex surgical procedures should be performed at centres. Postoperative complications arise out of elective surgery.In the less common case of penetrating abdominal trauma, the actual extent of the injury cannot be estimated from the visible wound. Here again, the circulatory situation determines the next steps. An emergency laparotomy should be carried out in case of instability. If the condition is stable, further diagnostics should be performed using contrast enhanced computed tomography. If penetration through the peritoneum cannot be clearly excluded, diagnostic laparoscopy should be performed.

Use of Chimney Technique Does Not Improve the Outcome of Endovascular Aneurysm Repair in Patients With a Hyperangulated and Short Proximal Aortic Neck.

PURPOSE: We hypothesized that extending the proximal landing zone with the chimney technique could be beneficial in patients with a hyperangulated proximal aortic neck, defined as more > 60 degrees. MATERIAL AND METHODS: We retrospectively analyzed the outcome of prospectively collected data of patients treated by endovascular aneurysm repair (EVAR) for infrarenal aortic aneurysm with a hyperangulated proximal aortic neck. In all, 104 out of 130 patients were treated without (Group A) and 24 with the chimney endovascular aortic repair (ChEVAR, Group B). Primary outcome was technical and clinical success according to the reporting standards of the Society of Vascular Surgery. RESULTS: The use of the chimney technique was associated with a significantly longer operation duration (167 vs. 93 min, p < .001), longer fluoroscopy time (44 vs.30 min, p = < .001), and larger amount of contrast medium used (149 vs. 127 ml, p = .03) but did not significantly improve technical (79.2% vs. 87.7%) and clinical success (54.2% vs. 68.9%). Aneurysm-related mortality was higher in group B (8.3% vs. = 0%, p < .001). Type IA endoleak was high in both groups at completion angiography (11.3% in Group A vs. 12.5% in Group B) and at follow-up (10.4% in Group A vs. 4.5% in Group B) without significant difference between the groups. CONCLUSIONS: Our data did not show a benefit of the primary use of the chimney technique in patients with a hyperangulated and short neck, although more studies are required to support this conclusion. Other strategies or new technologies are required for improving EVAR results in aneurysm patients with severe angulated proximal and short neck.

Cannulation of Visceral Vessels Using a Steerable Sheath in Fenestrated and Branched Aortic Endografts.

BACKGROUND: A critical step in the endovascular treatment of complex aortic aneurysms is the cannulation and stenting of renovisceral vessels, especially in cases with a complex anatomy or atherosclerotic lesions. This study aimed to demonstrate the results of renovisceral vessel cannulation using a steerable sheath in fenestrated or branched endovascular aortic procedures (FB-EVAR). METHODS: Patients undergoing elective FB-EVAR for asymptomatic thoracoabdominal or juxtarenal aneurysm at a single tertiary referral center from 2016 to 2019 were included in this study. Underlying pathologies, renovisceral target vessels (TV), technical success (TS), freedom from reintervention (FFR), and TV patency were assessed. Target vessels were categorized as challenging or nonchallenging TV. RESULTS: Fifty-three patients (median age 73 (Q1, Q3 (68-80)); 43 male (81%)) who underwent elective FB-EVAR were included. Indications comprised thoracoabdominal aneurysms (Crawford I-IV) (n = 26; 49%), juxtarenal aneurysms (n = 23; 43.5%) and penetrating aortic ulcers (PAU) (n = 4; 7.5%). Two patients (4%) had prior open aortic surgery, and three patients (6%) had undergone a failed standard EVAR before. Of the 196 treated TV, 131 (67%) were categorized as challenging. Cannulation was successful in 194 of 196 vessels (99%). A total of 3 TV (1.5%) showed periprocedural complications. No significant difference was found in the rate of intraoperative complications between challenging versus nonchallenging TV (P = 0.457). One patient died within 30 days of the procedure (1.9%). No stroke or intestinal ischemia occurred. After 12, 24, and 36 months, the survival rate was 87%, 87%, and 81%, respectively. Primary patency after 12 months was 98.6%, and 97.9% of vessels remained FFR during follow-up. CONCLUSIONS: Transfemoral, retrograde cannulation of renovisceral vessels using a steerable sheath is feasible and safe and provides good mid-term results, especially in cases with challenging renovisceral vessels. The potential complications of antegrade vascular access can be avoided.

Long-term Results of Thoracic Endovascular Aortic Repair Using a Low-Profile Stent-Graft.

PURPOSE: To evaluate the long-term results associated with the Zenith Alpha thoracic stent-graft, which was designed to address challenging access vessel anatomy. MATERIALS AND METHODS: A retrospective analysis was conducted of 44 consecutive patients (mean age 72.5±8.3 years; 25 men) treated in a single center between August 2010 and October 2014 with a minimum follow-up of 5 years in survivors. The Zenith Alpha thoracic stent-graft was used to treat thoracic aortic aneurysms (n=37), thoracoabdominal aortic aneurysm (n=5), or penetrating aortic ulcer (n=2). Ten patients (23%) were American Society of Anesthesiologists class IV, and 9 (20%) had nonelective procedures. Access vessel anatomy was demanding (mean minimum diameter 5.4 mm, tortuosity index 1.3). The primary endpoint at 5 years was ongoing clinical success (freedom from aneurysm-/procedure-related death, secondary intervention, type I or III endoleak, infection, thrombosis, aneurysm expansion, rupture, or conversion). Secondary endpoints were freedom from all-cause mortality, device migration, stent fractures, fabric erosions, endoleaks, neurological events, and access vessel complications. RESULTS: The ongoing clinical success was 84% (37 of 44 patients) owing to 4 aneurysm-related deaths (9%), 3 type I or III endoleaks (1 in a deceased patient), and 1 aneurysm expansion without detectable endoleak. There were 3 access vessel complications (7%), and no postoperative neurological events. Migration was observed in 2 cases (5%). There were no stent fractures or fabric tears. CONCLUSION: Despite the alterations in stent-graft design and material to reduce profile, the Zenith Alpha thoracic stent-graft showed favorable long-term results even in multimorbid patients with demanding iliac anatomy.

Fatigue Resistance of the Advanta V12/iCast and Viabahn Balloon-Expandable Stent-Graft as Bridging Stents in Experimental Fenestrated Endografting.

PURPOSE: Bridging stents undergo millions of cycles during respiratory movements of the kidneys throughout the patient's life. Thus, understanding the response of fabric and endoskeleton of the stent to cyclic loading over the time is crucial. In this study, we compare the fatigue resistance of the Viabahn Balloon-Expandable stent-graft (VBX) with the widely used Advanta V12/iCast under prolonged stress induction. MATERIALS AND METHODS: A polyester test sheet with 10 fenestrations was used simulating a fenestrated endograft. Five 6×59 mm VBX stent-grafts and five 6×58 mm Advanta stent-grafts were implanted into 6×6 mm fenestrations. The stents were flared with a 10×20 mm PTA (percutaneous transluminal angioplasty) catheter and connected with a fatigue stress machine. All stent-grafts were evaluated by microscopy and radiography at baseline and after regular intervals until 50,000,000 cycles were applied, simulating a life span of approximately 75 months. Freedom from fracture (FF), freedom from initial polytertafluoroethylene (PTFE) changes (FIC), and from PTFE breakpoint (FBP, all-layer defect) were calculated. RESULTS: Digital radiographic images did not show any stent fracture in both groups after 50,000,000 cycles. The VBX stent-graft was free from any all-layer defects at the conclusion of 50,000,00 cycles resulting in a significant higher FBP compared with Advanta V12 (50,000,000 vs 33,400,000; p<0.01). All-layer defects were observed only in the Advanta group. Two of 5 Advanta stents showed early penetration of the nitinol ring causing a defect of PTFE. Regarding FIC, there was no significant difference between the stents (3,400,000 in VBX vs 3,200,000 in Advanta). CONCLUSIONS: In fatigue tests simulating respiration movements, VBX and Advanta V12 performed equally well in terms of fracture resistance and freedom from initial PTFE changes. VBX maintained freedom from PTFE breakpoint throughout the full 50,000,000 cycles. All-layers defects were detected only in Advanta and were mainly caused by penetration of the nitinol ring through the PTFE.

Performance of the Gore VBX Balloon Expandable Endoprosthesis as Bridging Stent-Graft in Branched Endovascular Aortic Repair for Thoracoabdominal Aneurysms.

PURPOSE: Bridging stent stability is crucial for efficacy and safety of branched aortic endovascular repair (bEVAR) of thoracoabdominal aortic aneurysms (TAAAs). In this study, we assess the performance of the new Viabahn Balloon-Expandable endoprosthesis (VBX) in bEVAR. Based on our learning curve we give recommendations for a safe and effective use of the device. MATERIALS AND METHODS: We prospectively collected the data of patients with TAAAs undergoing bEVAR between December 2017 and December 2019. All patients with implantation of at least 1 VBX stent-graft as bridging stent were included in our single-center analysis. Demographic, comorbidity, and computed tomography angiography (CTA) data of 112 patients were retrospectively evaluated. Primary endpoint was a composite of branch-related technical success and freedom from target vessel instability. Secondary endpoints were clinical and ongoing clinical success. RESULTS: Primary endpoint: technical success was achieved in all patients (100%) with a freedom from target vessel instability of 96.3% after a median follow-up of 18 months. Overall mortality was 13.4% (n=15) and 13 patients underwent secondary interventions, 12 of them are still alive and 1 suffered from aneurysm sac expansion, consequently an ongoing clinical success of 75.9% was reached. After modification of the implantation technique during the course of the study by selecting longer stent lengths after accurate estimation of vessel curvature and expected adaptation of the flexible endoskeleton to the specific anatomical conditions, no type Ic endoleaks were observed in the last 70 cases. CONCLUSIONS: The VBX stent-graft can be safely used as bridging stent for branched thoracoabdominal repair. However, learning curve should be considered to avoid type Ic endoleak and edge stenosis. Based on this experience longer landing zones and 2-step deployment of VBX are useful for successful bridging also of challenging target vessels.

Preliminary Clinical and Radiologic Outcome of Matched Patients with Thoracoabdominal Aortic Aneurysms Treated by Low-Profile vs Standard Profile Branched Aortic Endografts.

BACKGROUND: Durability of low-profile branched aortic stent-grafts (LPSG) in the treatment of patients with thoracoabdominal aortic aneurysms (TAAA) remains unclear. Objective of this study is to compare the outcomes of LPSG with standard profile branched aortic stent-grafts (SPSG). METHODS: Between January 2016 and January 2020, 225 consecutive patients with TAAA were treated by branched endovascular aortic repair (BEVAR). Twenty-four patients who were treated with a LPSG were compared to 24 patients who received SPSG as a control group. Control patients were selected according to aneurysm size (maximum aneurysm diameter) and extension (Crawford classification) as well as availability of adequate preoperative and postoperative CT-angiograms at 24 months. The primary endpoint was ongoing clinical success defined as successful implantation and freedom from aneurysm- or procedure-related death, secondary intervention, type I or III endoleak, infection, thrombosis, aneurysm expansion or rupture and conversion. Secondary endpoints were radiological changes of the branched endograft (migration, shortening, scoliosis, lordosis, and fracture). RESULTS: After a median follow-up of 22.6 (LPSG) and 26.2 months (SPSG), no significant difference was found in terms of technical success (100% in both groups), late mortality (4.2% vs 0%), aneurysm diameter increase (4.2% in both groups) and reinterventions (25% vs 37.5%). Infection, thrombosis, aneurysm expansion or rupture and conversion were not observed. Radiological analysis of aortic graft remodeling showed no fracture and no significant migration, shortening, scoliosis and lordosis of the LPSG (6.1 mm, 7.5 mm, 12.8° and 6.1°) compared to SPSG (3.9 mm, 5.1 mm, 7.9° and 5.6°) after 2 years. CONCLUSION: The clinical and radiological findings of the present study showed no increased mortality and complications for the matched patients who underwent treatment with low-profile vs standard-profile BEVAR. This study provides preliminary evidence of safety and efficacy of low-profile branched endografts in patients with demanding iliac access vessels.

Outcomes of bridging stent grafts in fenestrated and branched endovascular aortic repair.

OBJECTIVE: Until today, no dedicated bridging stent graft (BSG) has been available for use in fenestrated and branched endovascular aneurysm repair (F/BEVAR). The purpose of this study was to evaluate the clinical performance of the well-known Advanta/iCast V12 (Getinge Maquet, Rastatt, Germany) and the new Viabahn VBX (W. L. Gore & Associates, Flagstaff, Ariz) balloon-expandable stent graft in F/BEVAR. METHODS: Retrospective analysis of prospectively collected data was performed. Inclusion criteria were treatment with fenestrated or branched endografts for complex aortic diseases, implantation of at least one VBX stent graft as a BSG in one of the target vessels, and clinical or radiologic follow-up of 6 months. The primary end point of the study was technical success of all BSGs, defined as placement of the BSG in the desired position with absence of endoleak on final angiography. Secondary end points were freedom from perioperative major adverse events and freedom from reinterventions and mortality at 6 months. Procedural and postoperative data were analyzed. RESULTS: Between December 2017 and July 2018, there were 50 patients (40 male; mean age, 71 years) included. A total of 145 VBX stent grafts were implanted, followed by 57 Advanta V12, 29 Viabahn, and 28 bare-metal stents. There were 126 branches (celiac trunk, 27; superior mesenteric artery, 25; renal arteries, 74) sealed exclusively with VBX. Technical success rate was 98.6%. There were six device-related reinterventions due to type IC endoleaks (n = 4), target vessel stenosis distal to the BSG, and stent graft occlusion in a left renal artery in one case. The perioperative and aneurysm-related mortality was 0%; the 6-month all-cause mortality was 2%. CONCLUSIONS: The used BSGs demonstrated promising preliminary results in F/BEVAR. Further evaluation is mandatory to determine durability of the VBX.

Late outcomes of different hypogastric stent grafts in aortoiliac endografting with iliac branch device: Results from the pELVIS Registry.

OBJECTIVE: The objective of this study was to evaluate long-term results of self-expanding vs balloon-expandable hypogastric stent grafts in conjunction with iliac branch devices (IBDs) for aortoiliac aneurysm repair in a multicenter experience (pErformance of iLiac branch deVIces for aneurysmS involving the iliac bifurcation [pELVIS] Registry). METHODS: All patients electively treated for aortoiliac aneurysm with the Cook IBD (Cook Medical, Bloomington, Ind) in nine European centers were reviewed. Clinical and imaging data were prospectively collected in each center, and a multicenter database was created and interrogated. The primary outcome was the primary patency of the IBDs. For the purpose of this investigation, three subgroups were identified: patients receiving a hypogastric balloon-expandable stent graft (BESg); those with a self-expanding stent graft (SESg); and those with any stent graft plus relining with a bare-metal stent (RESg). RESULTS: Between 2005 and 2017, there were 691 patients who underwent 747 elective endovascular repairs of aortoiliac aneurysms (n = 518 [75.0%]) or isolated iliac aneurysms (n = 173 [25.0%]) with Cook IBDs (n = 56 bilateral) in nine European centers. Mean age was 72 years (range, 41-93 years); 658 (95.2%) patients were male. In 364 patients (52.7%), BESg was used; in 127 (18.4%), SESg; and in 200 (28.9%), RESg. At 30 days, there were 3 (0.4%) perioperative deaths, 3 (0.4%) technical failures, 7 (1.0%) graft thromboses, 30 (4.3%) reinterventions, and 1 (0.1%) conversion to open repair. After a mean follow-up of 32 months (range, 0-128 months), 28 (3.7%) IBD occlusions and 17 (2.3%) IBD-related endoleaks occurred. In 10 patients, iliac diameter increased >5 mm (1.4%). Overall primary patency was 99.2% at 1 month, 97.9% at 12 months, and 95.1% at 72 months. Primary patency was not significantly different in the BESg vs SESg or RESg cohorts (P = .4). During follow-up, there were 126 (18.2%) reinterventions, 93 (13.5%) of which were IBD related, including 11 (1.6%) conversions. Overall, freedom from reintervention and conversion was 90.4% at 12 months and 71.0% at 72 months. IBD-related reinterventions during follow-up in the three cohorts were not significantly different (P = .3) Overall survival was 71.3% at 72 months without differences between the subgroups. At multivariate analysis, aneurysmal hypogastric artery (P < .001; Exp [B] = 4.44) and bilateral treatment (P = .02; Exp [B] = 1.87) were associated with an increase in late failure. CONCLUSIONS: In this wide real-world experience, long-term results of endovascular treatment of aortoiliac aneurysms with the IBD are favorable, with a low rate of late graft occlusion and aneurysm-related death. No significant differences in clinical outcomes were observed in patients receiving hypogastric BESg vs SESg or endovascular relining.

One-Year Results From the SURPASS Observational Registry of the CTAG Stent-Graft With the Active Control System.

Purpose: To report the outcomes from the observational SURPASS registry, which was created to assess the performance of the Conformable TAG (CTAG) stent-graft with the Active Control System (ACS) in patients undergoing thoracic endovascular aortic repair (TEVAR) in a real-world setting. Materials and Methods: The SURPASS registry (ClinicalTrials.gov; identifier NCT03286400) was an observational, prospective, single-arm, post-market, international study that enrolled patients undergoing TEVAR using the CTAG with ACS for both acute and chronic thoracic aortic disease between October 2017 and July 2018. The CTAG with ACS features 2-stage deployment of the stent-graft and an optional angulation mechanism that modifies only the proximal end of the stent-graft. During the observation period, 127 patients (mean age 67.1±12.1 years, range 27-86; 92 men) were enrolled and treated for an array of aortic pathologies, including chronic and acute lesions and 4 ruptured descending thoracic aneurysms. The primary outcome of this study was technical success; secondary outcomes were clinical success and major adverse events at 30 days and 12 months. The numbers of 2-stage device deployments and applications of the angulation mechanism were recorded, along with the reasons for use. Results: Technical success of the TEVAR was 97.6% owing to unintentional partial coverage of supra-aortic branches in 3 cases (the vessels were patent on imaging). The stent-graft was repositioned at its intermediate diameter in 79 patients (62.2%), and the angulation feature was applied in 64 cases (50.4%), mainly to improve proximal wall apposition and orthogonality in the aorta. The desired effect was achieved in 60 cases (93.8%). There was no device compression, bird-beak configuration, fracture, or graft occlusion. The 30-day and 12-month clinical success rates were 97.6% and 92.9%, respectively. There were 3 aorta-related deaths at 30 days and a further 3 at 12 months. Fatalities were due to a retrograde type A dissection (0.8%), paraplegia, bowel ischemia, sepsis in the setting of a mycotic aneurysm, aneurysm rupture post aortoesophageal fistula, and multiorgan dysfunction syndrome. Three endoleaks (2 type Ia and 1 type III) required reintervention. Conclusion: In the SURPASS registry, the use of the CTAG device with ACS showed promising outcomes despite the challenging pathologies. The new delivery system enables a controlled staged delivery with in situ adjustments during positioning, facilitating the treatment of complex aortic disease.

Comparison of the Biomechanical Properties of the Advanta V12/iCast and Viabahn Stent-Grafts as Bridging Devices in Fenestrated Endografts: An In Vitro Study.

Purpose: To compare experimentally the biomechanical properties of the Viabahn Balloon-Expandable Stent Graft (VBX) with the widely used Advanta V12/iCast in the role of bridging stent-grafts for fenestrated endovascular aortic repair. Materials and Methods: Test sheets made of polyester having 2 rows of 5 fenestrations in 6-mm and 8-mm diameters were used to simulate a commercially made fenestrated aortic endograft. In total, 40 stent-grafts measuring 6×39 mm and 8×39 mm (10 of each size for each stent-graft) were implanted in fenestration sheets immersed in a 37°C water bath. After flaring, all stent-grafts were evaluated using microscopy and radiography. Biomechanical evaluation included pullout and the shear stress force testing; results are reported in Newtons (N) as the median (minimum-maximum). Results: After flaring, no damage or fracture to the stent-graft structures were detected. Pullout forces for the 6-mm stent-grafts were 27.1 N (20.0-28.9) for the VBX and 16.6 N (14.7-19.2) for the Advanta (p=0.008). Pullout forces for the 8-mm stent-grafts were 20.1 N (14.8-21.5) for the VBX and 15.8 N (12.4-17.5) for the Advanta (p=0.095). The shear stress forces necessary to dislocate the device at 150% stent diameter displacement was 12.5 N (VBX) vs 14.7 N (Advanta) for the 6-mm devices and 23.3 N (VBX) vs 20.2 N (Advanta) for the 8-mm stents (p>0.99 and p=0.222, respectively). Conclusion: In vitro tests simulating external pull and shear forces on bridging stent-grafts implanted in fenestrations showed that the VBX had resistance to dislocation equivalent to a well-known control device.

In Vitro Evaluation of the Gore Viabahn Balloon-Expandable Stent-Graft for Fenestrated Endovascular Aortic Repair.

PURPOSE: To evaluate the safety and integrity of a new stent-graft as a potential bridging device in fenestrated stent-grafts using an in vitro fenestrated model. MATERIALS AND METHODS: Polyester test sheets with ten 6-mm- or 8-mm-diameter fenestrations were used to simulate a fenestrated main body endoprosthesis. In total, 50 Viabahn balloon-expandable (VBX) stent-grafts of varying lengths (29 and 39 mm) and diameters (6, 7, and 8 mm) were implanted in the fitting fenestrations. After release, the 6- and 7-mm-diameter stent-grafts were flared with a 10×20-mm angioplasty balloon; a 12×20-mm balloon was used in the 8-mm-diameter devices. Safety of the devices was defined as absence of fractures detected on radiography or computed tomography (CT), as well as material failure detected by microscopy and water permeability testing. The forces (in Newtons, N) needed for perpendicular dislocation (pullout force) and axial dislocation (shear stress force) were also evaluated. RESULTS: Forty VBX stent-grafts were subjected to digital radiographic imaging and multiplanar CT. None showed any stent fracture. Subsequent microscopy indicated no damage to the fabric or separation of the graft after flaring. Ten VBX stent-grafts underwent water permeability testing after flaring; no water passed through the graft wall during a 10-minute period under an intraluminal pressure at 120 mm Hg. Testing of 25 VBX stent-grafts revealed initial pullout forces between 11.3 and 31 N. Shear stress tests showed that the average force needed to dislocate the stent-grafts by 50% of their diameter ranged between 5.75 and 6.91 N (mean 6.1±0.5 N) for the 6-mm stents and between 3.31 and 5.4 N (mean 4.4±0.8) for the 8-mm stents. CONCLUSION: This preliminary study demonstrated the applicability of the VBX as a bridging stent-graft in a simulated fenestration model. A comparison with other stent-grafts and clinical assessment are required.

CTA Assessment of Midterm Morphological Changes to Chimney Grafts Used in the Treatment of Juxtarenal Aortic Aneurysms.

Purpose: To evaluate chimney stent-graft position and morphological changes of the aneurysm sac as visualized by postoperative computed tomography angiography (CTA) over a minimum 24-month follow-up period. Materials and Methods: Twenty-one patients (mean age 75.7±8.6 years; 20 men) with juxtarenal aortic aneurysms who underwent successful chimney endovascular aneurysm repair (ch-EVAR) with the Endurant stent-graft and had 2 postoperative CTAs separated by at least 24 months were included in the study. CTA-based measurements of aortic stent-graft migration, target vessel angle, and chimney angle were compared between the serial scans. Results: During a mean follow-up of 34.9 months (range 24-69.2), the mean migration of the aortic stent-grafts was under 5 mm (2.76±2.4 mm). The average migration distance per year was 1.15 mm. The aneurysm diameter reduced a mean 3.25 mm (p=0.048). The right renal artery angle moved significantly upward 6.72° (p=0.025), while the right renal chimney stent-graft moved significantly downward 7.83° (p=0.042). The left renal artery angle also moved upward 1.87° (p=0.388) and the corresponding chimney moved downward 5.68° (p=0.133). During the study period, no type I/III endoleak or chimney occlusion was observed. Conclusion: Midterm morphometric assessment of ch-EVAR using CTA showed significant aneurysm sac shrinkage and a stable 3-year position of the abdominal devices, with the mean downward migration of the aortic stent-graft being <5 mm in the majority of cases. The chimney grafts seem to be prone to take an oblique rather than parallel configuration during follow-up. However, there was no relevant clinical consequence related to this phenomenon.

Performance of BeGraft and BeGraft+ Stent-Grafts as Bridging Devices for Fenestrated Endovascular Aneurysm Repair: An In Vitro Study.

Purpose: To investigate 2 generations of balloon-expandable covered stents as potential bridging devices using an in vitro model of stent-graft fenestrations. Materials and Methods: Twenty BeGraft and 20 BeGraft+ cobalt-chromium stents covered in expanded polytetrafluoroethylene (ePTFE) in 6- and 8-mm diameters were tested in sheets mimicking stent-graft fenestrations. Microscopy and radiography were employed to evaluate stent morphology after flaring. In vitro bench tests measured maximum pullout (perpendicular displacement) and the shear stress (axial displacement) forces needed to dislocate the stents. Results: No alteration of ePTFE coverage was detected in the flared stents. Digital radiography and computed tomography showed marked alteration of the stent geometry, which was more pronounced in the BeGraft group. No fractures were detected. Median (minimum-maximum) pullout forces for the 6-mm stent-grafts were 17.1 N (15.8-19.6) for the BeGraft device and 30.4 N (20.2-31.9) for the BeGraft+ device (p=0.006). Median (minimum-maximum) pullout forces for the 8-mm stent-grafts were 11.3 N (11-12.1) for the BeGraft device and 21.8 N (18.2-25.5) for the BeGraft+ device (p<0.001). The shear stress test showed median forces of 10.5 vs 15.28 N at 150% of the stent diameter for the 6-mm BeGraft and BeGraft+ stent-grafts, respectively, and 15.23 vs 20.72 N at 150% stent diameter for the 8-mm models (p=0.016 and 0.017, respectively). Conclusion: Flaring changed the stent geometry but did not provoke stent fractures. The BeGraft+ is superior to the BeGraft in terms of pullout and shear stress forces, demonstrating greater resilience.

In Vitro Evaluation of Balloon-Expandable Chimney Grafts in the Renal Arteries Combined With the Endurant Endograft.

Purpose: To compare balloon-expandable covered stents (BECS) available for use as renal chimney grafts to the Advanta V12 approved for use with the Endurant endograft. Materials and Methods: A silicone model was manufactured based on preoperative computed tomography angiography (CTA) scans of a patient with a 7-cm juxtarenal aneurysm treated with an Endurant bifurcated endograft and an Advanta V12 covered stent for the 6-mm-diameter right renal artery. The model was placed in a flow box filled with a 37°C blood-mimicking solution equipped with a pulsatile pumping system (140/60 mm Hg). The tested BECS were the Advanta V12, the VBX, and the BeGraft+. A 36-mm-diameter Endurant II endograft with a 16-mm-diameter contralateral limb and a 6×59-mm BECS chimney graft were used in 9 consecutive tests (3 for each combination). After each implantation, the model was placed in the CT scanner, and 2 radiologists blinded to the test device independently measured the gutter areas and the patent chimney graft lumen at the level of the Endurant's suprarenal stent, at the level of the chimney's maximum curvature, and 10 mm inside the renal artery. The intraclass correlation coefficients (ICC) were calculated to assess interreader reliability. Results: The mean gutter areas were 19.3±7, 20.2±8, and 22.3±8 mm2 for the Advanta, VBX, and BeGraft+, respectively (all p>0.05). At the level of the aortic endograft's suprarenal stent struts, the mean diameter of the Advanta V12, VBX, and BeGraft+ were 4.46±0.3, 4.12±0.4, and 4.12±0.3 mm, respectively (all p>0.05). At the level of the maximum chimney graft angulation, the mean diameters were 3.77±0.3, 4.16±0.1, and 3.74±0.3 mm, respectively (all p>0.05). In the right renal artery, the mean diameters were 3.91±0.2, 4.05±0.9, and 4.3±0.4 mm, respectively (all p>0.05). The ICCs varied between 0.7 and 0.9, indicating good agreement between readers. Conclusion: These in vitro findings showed comparable results between the Advanta V12 and the available BECS used in conjunction with the Endurant endograft according to the instructions for use. Further clinical evaluation is needed to confirm these results.

Radiation doses for endovascular aortic repairs performed on mobile and fixed C-arm fluoroscopes and procedure phase-specific radiation distribution.

OBJECTIVE: The objective of this study was to analyze radiation risk to patients during endovascular aneurysm repair (EVAR) using mobile C-arm (MA) or fixed C-arm (FA) fluoroscopes and to describe the dose distribution during the different phases of the procedure. METHODS: Patients treated with EVAR using a single stent graft system between November 2009 and June 2016 were included in this study. The patients were divided into one of two groups (MA or FA) according to the type of C-arm used in the procedure. Data regarding patients' demographics and the total amount of contrast agent (CA) used, dose-area product, and fluoroscopy time for the procedures were prospectively recorded. Based on the dose report from the FA system, five standard and two optional phases of the procedure were identified to determine the dose distribution. RESULTS: Overall, 160 patients were included (mean age, 73.30 ± 8.97 years; 146 men); of these, 107 were treated with an MA system and 53 were treated with an FA system. The mean amounts of CA used were 108.55 ± 42.28 mL in the MA group and 85.37 ± 38.79 mL in the FA group (P = .0014). The mean total dose-area product values were 49.93 ± 38.06 Gy·cm2 in the MA group and 168.34 ± 146.92 Gy·cm2 in the FA group (P < .0001). There was no significant difference in fluoroscopy time between the groups. Per-phase analysis demonstrated that identification of the proximal landing zone and main body deployment required the most radiation, accounting for 24% of the total radiation dose. Overall, 47.6% of the exposure was due to digital subtraction angiography. CONCLUSIONS: Use of an FA system can significantly reduce the amount of CA needed but may also lead to higher radiation doses in EVAR procedures. Dose monitoring remains crucial for the safety of both patients and operators. A detailed analysis of dose distribution is possible with modern systems, which may improve the quality of monitoring in the future.

Computer-aided endovascular aortic repair using fully automated two- and three-dimensional fusion imaging.

OBJECTIVE: To assess the usability of a fully automated fusion imaging engine prototype, matching preinterventional computed tomography with intraoperative fluoroscopic angiography during endovascular aortic repair. METHODS: From June 2014 to February 2015, all patients treated electively for abdominal and thoracoabdominal aneurysms were enrolled prospectively. Before each procedure, preoperative planning was performed with a fully automated fusion engine prototype based on computed tomography angiography, creating a mesh model of the aorta. In a second step, this three-dimensional dataset was registered with the two-dimensional intraoperative fluoroscopy. The main outcome measure was the applicability of the fully automated fusion engine. Secondary outcomes were freedom from failure of automatic segmentation or of the automatic registration as well as accuracy of the mesh model, measuring deviations from intraoperative angiography in millimeters, if applicable. RESULTS: Twenty-five patients were enrolled in this study. The fusion imaging engine could be used in successfully 92% of the cases (n = 23). Freedom from failure of automatic segmentation was 44% (n = 11). The freedom from failure of the automatic registration was 76% (n = 19), the median error of the automatic registration process was 0 mm (interquartile range, 0-5 mm). CONCLUSIONS: The fully automated fusion imaging engine was found to be applicable in most cases, albeit in several cases a fully automated data processing was not possible, requiring manual intervention. The accuracy of the automatic registration yielded excellent results and promises a useful and simple to use technology.

The PROTAGORAS study to evaluate the performance of the Endurant stent graft for patients with pararenal pathologic processes treated by the chimney/snorkel endovascular technique.

OBJECTIVE: The chimney/snorkel endovascular aortic repair (ch-EVAR) is gaining ever-greater acceptance in the treatment of pararenal pathologic processes. However, the published experience includes mainly short-term clinical results with combinations of several abdominal devices and types of chimney grafts. The aim of this study was the midterm evaluation of the Endurant stent graft (Medtronic, Santa Rosa, Calif) as a standard abdominal device for ch-EVAR. METHODS: Between January 2009 and January 2013, prospectively collected data of high-risk patients with pararenal pathologic processes who underwent ch-EVAR with placement of the Endurant abdominal device were analyzed. The chimney graft intended for use was a balloon-expandable covered stent. Main outcome measures were aneurysm sac regression and chimney graft patency. RESULTS: A total of 187 snorkel/chimney grafts were successfully placed in 128 patients (mean age, 76.6 years). The technical success was 100%. The mean preoperative proximal neck length and aneurysm size were 4.7 mm and 64.8 mm (range, 48-135 mm), respectively. The postoperative new neck length after use of chimney grafts was 18.7 ± 6.3 mm. The mean aneurysm sac decreased significantly (60.8 mm; 95% confidence interval, 2.036-7.084; P = .001) after a mean radiologic follow up of 24.6 ± 17.4 months. Thirty-day mortality and midterm mortality were 0.8% and 17.2%, respectively. Two patients (1.6%) with single chimneys presented with late new onset of type Ia endoleak and underwent additional tube and multiple chimney placement. Primary chimney graft patency was 95.7%. Freedom from chimney graft-related reinterventions was 93.1%. CONCLUSIONS: Standard use of the Endurant abdominal device for ch-EVAR in >120 patients is associated with high technical success, significant aneurysm sac regression, and low incidence of secondary procedures after 2-year radiologic follow-up. These results will give significant impetus to device selection, facilitating the standardization of technique.

Treatment of Femoropopliteal Artery Disease with Polymer-Coated Drug-Eluting Stent: 5-Year Results of a Prospective, Non-Randomized Study Including the Halo Phenomenon.

PURPOSE: To investigate the long-term results of the Eluvia drug-eluting stent (DES) implantation for femoropopliteal arterial disease, including the 'halo' phenomenon. Long-term data of DES is scarce. A focal reaction ('halo') following Eluvia DES deployment has been described. However, the long-term clinical impact of this phenomenon remains unclear. METHODS: This prospective, non-randomized, single-arm study included 130 consecutive patients treated with an Eluvia DES for symptomatic femoropopliteal disease between March 2016 and December 2018. Clinical outcomes and imaging were assessed after 6 months and annually thereafter for up to 5 years. The primary outcome measure was primary patency. Secondary outcomes were freedom from clinically driven target lesion revascularization (CD-TLR), freedom from major amputation, overall survival and amputation-free survival rates. RESULTS: The primary patency was 65% at 5 years. The freedom from CD-TLR and from major amputation at 5 years was 79 and 96%, respectively. The overall survival and amputation-free survival rates were 88 and 83% at 60 months, respectively. Out of the 27 patients with a halo sign, two showed an increased (7.4%) and 6 (22.2%) a decreased diameter. In 19 cases (70.4%), the diameter remained unchanged at the latest follow-up. The presence of the 'halo' sign was associated with increased primary patency (87% versus 59%, HR: 2.48, 95%CI 1.19-5.16, P = .015). CONCLUSIONS: The presented patient cohort treated with the Eluvia DES for femoropopliteal artery lesions indicates durable efficacy and a good safety profile regardless of the halo phenomenon. The results need to be confirmed in a larger patient cohort. LEVEL OF EVIDENCE III: Non-randomized controlled cohort/follow-up study.