Assessing the institutional learning curve for pararenal aortic repair using the fenestrated Anaconda endograft.

OBJECTIVE: Custom-made fenestrated aortic endografts allow exclusion of pararenal aortic aneurysms while maintaining blood flow to aortic branches. Meticulous device planning and precise deployment of the main body are essential to allow successful cannulation of the fenestrations. This study investigates whether a learning curve can be observed with more reliable cannulation and connection of fenestrations over time at a single department of vascular and endovascular surgery with multiple surgeons trained to use the device. METHODS: A retrospective analysis of data from all patients undergoing primary fenestrated endovascular aneurysm repair during the study period was performed. Outcome measures included case volume and average number of fenestrations over time, average fluoroscopy dose area product per calendar year and primary unconnected fenestration and 30-day mortality rates. RESULTS: Between 1 January 2013 and 31 December 2016, 89 patients with no history of endovascular aneurysm repair underwent fenestrated endovascular aneurysm repair at our institution. The number of fenestrations per case increased over time, averaging 2.6 in 2013 and 3.3 in 2016. Primary unconnected fenestration and 30-day mortality rates were 5.6%. Primary-assisted technical success was 93.3%, secondary-assisted technical success was 94.4%. Fluoroscopy dose area product declined over the study period. Thirty-day mortality and primary unconnected fenestration rates did not significantly change over the study period. CONCLUSION: Albeit the reduction in lethal complications and primary technical success rates were not statistically significant, a lower percentage of unconnected fenestrations and 30-day mortality per calendar year were observed over time. At the same time, an increasing complexity of performed cases, as reflected by an increasing number of fenestrations per case, was observed. Complications associated with this complex endovascular procedure are potentially lethal and remain an unfortunate reality and may not be entirely dependent on overcoming a learning curve. A higher volume of cases performed over the study period and a reduction in fluoroscopy use can be considered a representation of the institutional development and learning curve for the Anaconda fenestrated endograft at a department with prior complex endovascular aortic repair experience, but due to limitations of the current retrospective observation, deserve further consideration in future trials, ideally designed in a prospective fashion.

Custom-Made Iliac Fenestrated Device.

Iliac branch devices (IBDs) are undergoing rapid popularization. They allow for treatment of an iliac aneurysm while preserving blood flow to the hypogastric artery. Certain anatomic criteria are necessary for the use of an iliac side branch device to be technically feasible. Custom-made fenestrated iliac stent grafts may provide an alternative when anatomic criteria for an IBD are not met.

Successful percutaneous access for endovascular aneurysm repair is significantly cheaper than femoral cutdown in a prospective randomized trial.

OBJECTIVE: Because of its minimally invasive nature, percutaneous femoral access for endovascular aneurysm repair (pEVAR) is currently undergoing rapid popularization. Compared with surgical cutdown for femoral access (cEVAR), it offers the advantage of faster recovery after surgery as well as a reduction in wound complications. Despite proposed advantages, the method is largely considered uneconomical because of its reliance on costly closure devices. METHODS: There were 50 patients undergoing EVAR who were enrolled in this randomized prospective single-center trial. Each patient randomly received percutaneous access in one groin and surgical access in the other. The primary end points were access duration and cost. Secondary end points were wound complications and the postoperative pain levels. RESULTS: Surgery was performed per protocol in 44 patients. Mean access times for pEVAR and cEVAR were 11.5 ± 3.4 minutes and 24.8 ± 12.1 minutes (P < .001), respectively. Total access costs were €559.65 ± €112.69 for pEVAR and €674.85 ± €289.55 for cEVAR (P = .016). Eight complications in six patients were attributed to cutdown, none to pEVAR (P = .02). The percutaneously accessed groin was significantly less painful at day 1 and day 5 after surgery (P < .001). An intention-to-treat analysis (N = 50 patients) included six cases of pEVAR conversion due to technical failure in three patients (6%) and change of the operative strategy in another three patients (eg, aortouni-iliac stent graft followed by crossover bypass). The intention-to-treat analysis showed shorter mean overall access time for pEVAR (pEVAR, 14.65 ± 10.20 minutes; cEVAR, 25.12 ± 11.77 minutes; P < .001) and no cost difference between the two methods (pEVAR, €651.29 ± €313.49; cEVAR, €625.53 ± €238.29; P = .65). CONCLUSIONS: Our data confirm proposed potential benefits attributable to the minimally invasive nature of pEVAR while demonstrating cost-effectiveness despite the additional cost of closure devices. Taking into account pEVAR failures still does not increase pEVAR costs over cEVAR. Further considering reduced postoperative pain and wound complications, the technique deserves consideration in suitable patients.

Rescue of failed endovascular aortic aneurysm repair using the fenestrated Anaconda device.

OBJECTIVE: Endovascular aortic aneurysm repair (EVAR) with a fenestrated device (FEVAR) allows an extension of the proximal sealing zone above the renal arteries to an adequate, healthier segment of the aorta. This feature makes FEVAR an option to treat patients with a diseased aortic neck or type Ia endoleak after EVAR. The aim of this investigation was to present a single-center experience with FEVAR for patients with an abdominal aortic endograft in situ compared with primary FEVAR. METHODS: A prospectively held database on FEVAR patients treated with the fenestrated Anaconda device (Vascutek/Terumo, Inchinnan, Scotland, United Kingdom) at our institution was screened for individuals who had previously undergone EVAR. RESULTS: Between April 1, 2013, and July 31, 2016, 94 fenestrated Anaconda devices were implanted at our institution. Twelve patients with prior EVAR were treated for pathology of the proximal neck: type I endoleak (n = 7), for stent migration with aneurysm progression but no visible endoleak (n = 2), and progressive aortic disease at the level of the visceral segment (n = 3). When redo cases and primary FEVARs were compared, primary technical success rates were 58.3% and 87.8% (P = .02) and primary functional success rates were 91.7% and 95.1%, respectively (P = .62). Perioperative rate of major deployment-related (14.6% and 16.7%) and systemic complications (8.5% and 8.3%) as well as 30-day mortality (6.1% and 0%; P = .5) were comparable between groups. After an average follow-up interval of 10 months (range, 0-43 months), no late occlusions of connecting stents were observed. The late reintervention rates were 11.0% and 16.7%, respectively (P = .57). CONCLUSIONS: The risk of a failure to cannulate one or more visceral arteries through the respective fenestrations was increased in patients who had previously undergone EVAR. This is most likely caused by increased friction between the fenestrated endograft and the failing graft in situ, which may impair the adaption of the unsupported Anaconda device to the aortic wall. As a consequence, fenestrations may not line up perfectly at the respective openings of the visceral or renal arteries, and folding of the fabric may be increased, making cannulation of the fenestrations more difficult.

The influence of prototype testing in three-dimensional aortic models on fenestrated endograft design.

OBJECTIVE: The fenestrated Anaconda endograft (Vascutek/Terumo, Inchinnan, UK) is intended for the treatment of abdominal aortic aneurysms with an insufficient infrarenal landing zone. The endografts are custom-made with use of high-resolution, 1-mm-slice computed tomography angiography images. For every case, a nonsterile prototype and a three-dimensional (3D) model of the patient's aorta are constructed to allow the engineers as well as the physician to test-implant the device and to review the fit of the graft. The aim of this investigation was to assess the impact of 3D model construction and prototype testing on the design of the final sterile endograft. METHODS: A prospectively held database on fenestrated endovascular aortic repair patients treated at a single institution was completed with data from the Vascutek engineers' prototype test results as well as the product request forms. Changes to endograft design based on prototype testing were assessed and are reported for all procedures. RESULTS: Between April 1, 2013, and August 18, 2015, 60 fenestrated Anaconda devices were implanted. Through prototype testing, engineers were able to identify and report potential risks to technical success related to use of the custom device for the respective patient. Theoretical concerns about endograft fit in the rigid model were expressed in 51 cases (85.0%), and the engineers suggested potential changes to the design of 21 grafts (35.0%). Thirteen cases (21.7%) were eventually modified after the surgeon's testing of the prototype. A second prototype was ordered in three cases (5.0%) because of extensive changes to endograft design, such as inclusion of an additional fenestration. Technical success rates were comparable for grafts that showed a perfect fit from the beginning and cases in which prototype testing resulted in a modification of graft design. CONCLUSIONS: Planning and construction of fenestrated endografts for complex aortic anatomies where exact fit and positioning of the graft are paramount to allow cannulation of the aortic branches are challenging. In the current series, approximately one in five endografts was modified after prototype testing in an aortic model. Eventually, success rates were comparable between the groups of patients with a good primary prototype fit and those in which the endograft design was altered. Prototype testing in 3D aortic models is a valuable tool to test the fit of a custom-made endograft before implantation. This may help avoid potentially debilitating adverse events associated with misaligned fenestrations and unconnected aortic branches.

Prognostic value of tumor progression-related gene expression in colorectal cancer patients.

PURPOSE: Colorectal cancer (CRC) is driven by genetic alterations causing its progression. Besides accepted tumor suppressor- and onco- genes, a series of genes have been identified, which contribute to transformation into a more malignant stage. We investigated whether the expression level of such genes, alone or in combination, could add to predict the prognosis of CRC patients. METHODS: Tumor samples from 118 CRC patients were screened in a retrospective analysis by qRT-PCR for expression of the four tumor progression-associated genes osteopontin (Opn), transforming growth factor ß (Tgf-ß), matrix metalloproteinase-2 (Mmp-2) and cyclooxigenase-2 (Cox-2). The resulting qRT-PCR values were related to those of housekeeping genes. All patients were clustered for similar expression levels between the four genes with R statistical software using the package pvclust, which provides bootstrap agglomerative hierarchical clustering. Clusters with similar expression of the four genes were analyzed for correlation with UICC stages and survival time. RESULTS: Expression of the four genes varied considerably within the cohort of patients. Cluster analysis of patients revealed a subgroup (n = 33) who in comparison with the other patients showed tenfold higher expression levels of all four genes (p < 0.001, respectively). However, there was no correlation between patients expressing high or low levels of these four genes and known parameters of clinical prognosis (UICC stages, survival time). CONCLUSIONS: In conclusion, tenfold increased expression levels of Opn, Tgf-ß, Mmp-2 and Cox-2 in a subset of CRC patients did not predict for a clinical outcome that is different from that of the remaining patients.