Access-based customer journeys.

Despite the popularity of access-based platforms, the understanding of customer journeys remains anchored in traditional market contexts that overlook prosumers' extended value-chain roles, interconnected experiences, and instrumental sociality in access-based consumption. Using a qualitative study on the access-based platform Rent the Runway, the authors discuss the nature of customer journeys in access-based platforms and showcase how customers perform these journeys. The study reveals two key elements: (1) systemic dynamics, which encompass just-in-time circularity and tightly coupled customer interdependencies, and (2) job crafting, which involves customer work practices that allow pain point avoidance, circulation flow adjustments, and journey stickiness increases. Job crafting can create unpredictable disruptions in other customer journeys and affect systemic flows. This investigation expands research on customer experience management and journey design by developing an access-based platform journey model differentiated from ownership- and service-based platform models, showcasing its systemic instability dynamics, and elaborating how to manage these customer journeys. Supplementary Information: The online version contains supplementary material available at 10.1007/s11747-023-00942-6.

Degradation phenomena on last generations of polyethylene terephthalate knitted vascular prostheses.

Objectives: The aim of this study was to analyze a series of new generations of explanted knitted polyethylene terephthalate (PET) vascular grafts (VGs) presenting nonanastomotic degradations according to preoperative computed tomography angiography (CTA) when available in order to better understand the mechanisms leading to rupture. Methods: Explanted knitted PET VGs were collected as part of the Geprovas European Collaborative Retrieval Program. VGs implanted after 1990 presenting a nonanastomotic rupture of the fabric were included. Clinical data and pre-explantation CTA data when available were retrieved for each VG. The ruptures were characterized by macroscopic examination and optical microscopy according to a standardized protocol. Results: Nineteen explants were collected across 11 European centers, 13 were implanted as infrainguinal bypasses, 3 at the aortic level, and 1 as an axillobifemoral bypass. The mean implantation duration was 9.2 years. Pre-explantation CTA data were available for 8 VGs and showed false aneurysms at the adductor canal level on 4 VGs, at the inguinal ligament level on 2 VGs, and in the proximal or middle third thigh level on 3 VGs. Examination revealed longitudinal ruptures on 9 explanted VGs (EVGs), transversal ruptures on 15 EVGs, 45°-oriented ruptures on 5 EVGs, V-shaped ruptures on 7 EVGs, and punctiform ruptures on 2 EVGs. Ruptures involved the remeshing line on 11 EVGs, the guideline on 10 EVGs, and the crimping valley on 15 EVGs.At the microscopic level, two main degradation phenomena could be identified: a decrease in the density of the meshing and local ruptures of the PET fibers. Fourteen EVGs presented a loosening of the remeshing line and 17 EVGs an attenuation of the crimping. Conclusions: New-generation PET VG degradation seems to result from both anatomic constraints and intrinsic textile structure phenomena.

Vascular grafts collagen coating resorption and healing process in humans.

Background: The objective of the present study was to evaluate the bioresorption rate of collagen coating (CC) sealed on textile vascular grafts (VGs) and their healing in humans using histologic analysis of explanted VGs. Methods: A total of 27 polyester textile VGs had been removed during surgery from 2012 to 2020. The segments underwent histologic assessment. The CC bioresorption rate was assessed using morphometric analysis to determine the internal and external capsule thickness, inflammatory reaction degree, presence of neovessels, and endothelial cell layer. Results: A total of 27 VGs were explanted from 25 patients because of infection (n = 5; 18.5%), thrombosis (n = 7; 25.9%), stenosis (n = 2; 7.4%), rupture (n = 4; 14.8%), aneurysmal degeneration (n = 3; 11.1%), revascularization (n = 4; 14.8%), or another cause (n = 2; 7.4%), with a median implantation duration of 291 days (interquartile range [IQR], 48-911 days). VGs with remaining CC (n = 7; 26%) had been explanted earlier than had those without (n = 20; 74%; 1 day [IQR, 1-45 days] vs 516 days [IQR, 79-2018 days]; P = .001). After 1 year, no remaining CC was detected on the analyzed VG sections. VGs implanted for <90 days had had a greater CC maximal thickness (63.90 µm [IQR, 0-83.25 µm] vs 0 µm [IQR, 0-0 µm]; P = .006) and a greater CC surface coverage (180° [IQR, 0°-360°] vs 0° [IQR, 0°-0°]; P = .002) than those implanted for >90 days. VGs implanted for >90 days had a greater external capsule thickness (889.2 µm [IQR, 39.6-1317 µm] vs 0 µm [IQR, 0-0 µm]; P = .002), a higher number of inflammatory mononuclear cells and giant cells (168 cells [IQR, 110-310 cells] vs 0 cells [IQR, 0-94 cells]; P < .0001) and a higher number of neovessels (4 [IQR, 0-5] vs 0 [IQR, 0-0]; P = .001) than those implanted for <90 days. Conclusions: CC had a slow bioresorption rate in humans. Complete healing was never achieved, with no endothelial coverage observed. This finding implies that CC might not help graft healing.

Degradation Phenomena on "Homemade" Explanted Aortic Textile Endografts.

OBJECTIVE: In the 1990s, the concept of "homemade" endografts (EGs) using commercially available materials was proposed in clinical practice for endovascular abdominal aortic repair (EVAR). The aim of this study was to analyse the ageing phenomena of these EGs in light of explant analyses. METHODS: The study focused on five explanted homemade EGs collected from 2012 to 2014. The explants were assessed in accordance with the ISO 9001/13485 certified standard protocol, which included naked eye evaluation, organic remnant cleaning, and microscopic and endoscopic examinations and analysis (magnification range from 20% to 200%). The observations report followed a classification based on 12 features assessing the fabric cover, the stitch filament, and the stents. RESULTS: The reasons for explantation were type 1 endoleak in three cases and aneurysm sac growth in two. The implantation duration ranged from 56 to 202 months. Sixty three per cent of the fabric surface lesions (holes and tears) were related to abrasion between the fabric and the stents. Up to 33% of the knots used to connect adjacent stents were broken on one EG. Other defects including running suture rupture and stent corrosion were also observed. The overall hole cumulated surface ranged from 0.377 mm2 (56 month of implantation) up to 3.21 mm2 (78 month of implantation). CONCLUSION: In this study, various ageing phenomena on homemade textile EGs were identified and classified. The main damaging mechanisms were related to abrasion stress leading to tears and holes in the fabric, stitch ruptures, and detachment of stent segments responsible for serious EG deformations and further degradation.

Disruption of a Covered Nitinol Self Expanding Stent Graft Implanted in the Common Femoral Artery.

INTRODUCTION: Common femoral artery aneurysm is a rare condition and can be treated by open or endovascular surgery. There is a general understanding that open surgery is the recommended option because of the anatomical location and the biomechanical constraints posed by hip flexion. REPORT: The case of a 66 year old man treated with an endograft for an asymptomatic abdominal aortic aneurysm followed by the implantation of a nitinol covered stent graft (Fluency™, Bard Peripheral Vascular, Temple, AZ) for a 25 mm diameter left common femoral artery aneurysm is reported. Two years later, follow up revealed a rupture of the nitinol covered stent graft, requiring an open iliofemoral reconstruction. DISCUSSION: Systematic analysis with protocolised cleaning, and macroscopic and microscopic evaluation (Keyence VHX-600 digital microscope) of the explanted nitinol covered stent graft showed membrane perforation at the level of an acute angle formed by the struts.

The Impact of EndoAnchor Penetration on Endograft Structure: First Report of Explant Analysis.

OBJECTIVE: The adjunctive use of Heli-FX EndoAnchors (EAs) in endovascular aneurysm repair has been proposed for the treatment or prevention of type Ia endoleaks. The aim of this study was to evaluate the impact of the penetration of EAs on endograft textile structure from two aortic endografts that had been explanted for persistent type Ia endoleak despite the implantation of EAs. METHODS: An Aorfix aortic endograft was implanted in an 85 year old man. Six months later, six EAs were implanted for Ia endoleak. The endograft was explanted as an emergency seven months later for aneurysm rupture. An Endurant II aortic endograft was implanted in an 80 year old man. Seven EAs were implanted 24 months later for type Ia endoleak. A proximal cuff extension with bilateral renal and superior mesenteric artery chimneys was performed 18 months later to treat a persistent type Ia endoleak. Endograft explantation was performed six months later owing to persistent type Ia endoleak and aneurysm sac enlargement. Explant analysis in both cases was performed at GEPROVAS. RESULTS: Systematic analysis of both explants, including the 13 EAs, revealed the following lesions: (1) alteration of textile structure directly linked to several penetrations of the fabric with the same EA and tears of the textile fibres in two cases; (2) tears of the binding threads as the EA had passed through them in five cases; and (3) interactions between EA and endograft stents in four cases. CONCLUSION: The site of EA penetration into the endograft might contribute to endograft fabric damage and to a loss of stability of the endograft at the level of the aortic neck.

Non-Anastomotic Complete ePTFE Axillobifemoral Bypass Disruption and Thrombosis Following Shoulder Dislocation.

Complete disruption of an expanded polytetrafluoroethylene (ePTFE) vascular graft is rare. This is a report of a case of a 70 year old man presenting with left shoulder dislocation, which was reduced immediately. Two weeks later, the patient presented with Rutherford 2b bilateral lower limb ischaemia related to the thrombosis of an ePTFE axillobifemoral bypass. The graft was implanted five years earlier for treatment of an aorto-enteric fistula secondary to an infected aortobifemoral bypass. A non-anastomotic pseudoaneurysm associated with complete disruption of the ePTFE graft was found. Systematic analysis of the explant showed that the rupture occurred at the level of a ringed external support and that ongoing tears also occurred on the posterior wall of the graft at the level of this external support. In conclusion, complete analysis of failure mechanisms even from an isolated report is mandatory.

Explanted Vascular and Endovascular Graft Analysis: Where Do We Stand and What Should We Do?

OBJECTIVE/BACKGROUND: Since the late 1950s, major advances in vascular surgical practice have been closely associated with the introduction of novel vascular implants. These devices have been constructed from a variety of materials and have been designed to be implanted in several different ways. Despite a rigorous regulatory process, regular failures continue to be observed. A systematic review of the literature and of the Geprovas registry was performed in order to improve understanding of the failures. METHODS: A systematic review was performed via a search of the MEDLINE and Embase databases. Full text, English, German, or French language studies without any chronological limit were included. The reference lists of included studies, as well as the first 20 related items, were scanned for other potentially relevant studies. RESULTS: Data extraction allowed the evaluation of 184 publications; 72 publications met the inclusion criteria. Only 12 publications reported sufficient data for structural, histopathological, and epidemiological analysis. However, explant analysis allowed the understanding of degenerative phenomena: "warp knitted" replaced "weft knitted" polyethylene terephthalate grafts, decreasing the risk of dilatation or rupture; inter-nodal distance was modified in order to improve polytetrafluoroethylene graft incorporation capacities; and index of saturation, endograft fabric/stent interactions, and stent fatigue phenomena have been extensively studied in an attempt to improve endovascular device durability. CONCLUSION: A general lack of depth of reporting of explants remains. Dedicated systematic explant analysis programs are the key to improving the performance of future generations of devices.