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Objective: Strain has become a viable index for evaluating abdominal aortic aneurysm stability after endovascular aneurysm repair (EVAR). In addition, literature has shown that healthy aortic tissue requires a degree of strain to maintain homeostasis. This has led to the hypothesis that too much strain reduction conferred by a high degree of graft oversizing is detrimental to the aneurysm neck in the seal zone of abdominal aortic aneurysms after EVAR. We investigated this in a laboratory experiment by examining the effects that graft oversizing has on the pressure-normalized strain ( ε ρ + ¯ /pulse pressure [PP]) reduction using four different infrarenal EVAR endografts and our ultrasound elastography technique. Approximate graft oversizing percentages were 20% (30 mm phantom-graft combinations), 30% (28 mm phantom-graft combinations), and 50% (24 mm phantom-graft combinations). Methods: Axisymmetric, 10% by mass polyvinyl alcohol phantoms were connected to a flow simulator. Ultrasound elastography was performed before and after implantation with the four different endografts: (1) 36 mm polyester/stainless steel, (2) 36 mm polyester/electropolished nitinol, (3) 35 mm polytetrafluoroethylene (PTFE)/nitinol, and (4) 36 mm nitinol/polyester/platinum-iridium. Five ultrasound cine loops were taken of each phantom-graft combination. They were analyzed over two different cardiac cycles (end-diastole to end-diastole), yielding a total of 10 maximum mean principal strain ( ε ρ + ¯ ) values. ε ρ + ¯ was divided by pulse pressure to yield pressure-normalized strain ( ε ρ + ¯ /PP). An analysis of variance was performed for graft comparisons. We calculated the average percent ε ρ + ¯ /PP reduction by manufacturer and percent oversizing. These values were used for linear regression analysis. Results: Results from one-way analysis of variance showed a significant difference in ε ρ + ¯ /PP between the empty phantom condition and all oversizing conditions for all graft manufacturers (F(3, 56) = 106.7 [graft A], 132.7 [graft B], 106.5 [graft C], 105.7 [graft D], P < .0001 for grafts A-D). There was a significant difference when comparing the 50% condition with the 30% and 20% conditions across all manufacturers by post hoc analysis (P < .0001). No significant difference was found when comparing the 20% and 30% oversizing conditions for any of the manufacturers or when comparing ε ρ + ¯ /PP values across the manufacturers according to percent oversize. Linear regression demonstrated a significant positive correlation between the percent graft oversize and the all-graft average percent ε ρ + ¯ /PP reduction ( R 2  = 0.84, P < .0001). Conclusions: This brief report suggests that a 10% increase in graft oversizing leads to an approximate 5.9% reduction in ε ρ + ¯ /PP on average. Applied clinically, this increase may result in increased stiffness in axisymmetric vessels after EVAR. Further research is needed to determine if this is clinically significant.

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Purpose: Iliac limb occlusion (ILO) is a serious complication of endovascular abdominal aneurysm repair (EVAR). This study aimed to identify predictive factors for ILO derived from aortoiliac morphology, endovascular procedure-related parameters, and aneurysmal remodeling characteristics. Patients and Methods: Patient demographics, pre-EVAR anatomical characteristics of the aneurysm, endovascular procedure details, and post-EVAR aneurysmal remodeling outcomes were analyzed and compared using univariate analysis. Statistically significant factors were subsequently subjected to Cox regression and Kaplan-Meier analyses. Results: Between January 2013 and April 2022, 66 patients were included in this study. Fourteen patients presented with ILO and were compared with 52 control patients with patent endograft limb over at least 1-year of follow-up. The tortuosity indices of the common iliac artery (CIA) and endograft iliac limb to vessel oversizing were significantly larger in the ILO group than in the patent endograft limb group. The CIA index of tortuosity ≥1.08, and endograft iliac limb to vessel oversizing ≥18.8% were independent predictors for ILO. During the follow-up of all patients, the proximal aortic neck and CIA diameters increased, aneurysm sac diameter decreased, and aortic neck and aortic length increased. The aortoiliac length increased over time in patients with patent endograft limb but not in patients with ILO. A change in the lowest renal artery-left iliac bifurcation distance ≦0.07 mm increased the risk of ILO. Conclusion: ILO is predisposed to occur when the CIA index of tortuosity ≥1.08 and endograft iliac limb to vessel oversizing ≥18.8% are present. Significant aortoiliac remodeling, including proximal aortic neck dilatation, neck straightening, aneurysmal sac regression, iliac artery enlargement, and aortic lengthening, occurs after EVAR. Aortoiliac elongation was observed in patients with patent endograft limb, but not in patients with ILO. ILO was associated with a change in the lowest renal artery-left iliac bifurcation from the postoperative measurements ≦ 0.07 mm.

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OBJECTIVES: Valve oversizing has been associated with reduced paravalvular leaks (PVL) and valve migration risk. However, no optimal cut-off oversizing value has been defined for the Evolut system (Medtronic). The aim of this study was to assess the relationship between the degree of oversizing and moderate-to-severe PVL and determine the optimal oversizing cut-off value. METHODS: We conducted a multicenter study that included 740 consecutive patients with multidetector computed tomography (CT) data. Valve size was selected according to manufacturer recommendations, with oversizing ranging from 10% to 30%. The primary endpoint was moderate-to-severe PVL. RESULTS: The median age was 84 years (79-87 years), with 58.4% women, and a median EuroSCORE II of 4.1% (2.4-7.3%). Moderate-to-severe PVL was observed in 7.0% of the patients. An inverse relationship was found between oversizing and both PVL (11.3%, 8.6%, 5.4%, and 2.7% for quartiles Q1 to Q4; P = .007) and the need for post-dilation (P = .016). The multivariable analysis showed an association between oversizing and PVL (OR: 0.915 for each 1%-increase, P = .002). The optimal oversizing cut-off value to predict PVL was 20%, and PVL was significantly higher in patients with oversizing less than 20% (10.5% vs.4.2%, P less than .001). There were no differences in major clinical events according to the degree of oversizing, and a higher oversizing did not translate into an increased risk of permanent pacemaker (18.4% vs18.3%, P = .976). CONCLUSIONS: In TAVR with the Evolut valve, a higher oversizing was associated with lower rates of moderate-to-severe PVL and a lower need for post-dilation, with no negative impact on procedural and early clinical outcomes. A 20% oversizing threshold could be suggested to reduce PVLs. Further prospective studies are warranted to validate optimal oversizing for this valve system.

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BACKGROUND: Transcatheter Aortic Valve Implantation (TAVI) has a growing target population after being indicated even in low-surgical-risk patients with severe symptomatic aortic stenosis. However, postoperative outcomes can be compromised due to para-valvular leakage (PVL). A lot of procedural steps have been investigated to decrease this partially avoidable operational hazard. Oversizing is a main technique to decrease the PVL, despite being itself a risky step. Many studies have been conducted to identify the optimum degree of oversizing. However, studies about oversizing by more than 20% are scarce. We aimed to evaluate the safety and efficacy of oversizing equal to or more than 20%. RESULTS: 209 patients who underwent TAVI using the self-expandable valve Evolut R were initially included. 66 patients were excluded because of the baseline conduction disturbance and lack of sufficient data, so 143 patients, 60 females and 83 males, were enrolled in our study as two groups based on the degree of oversizing: Group A included 97 patients with an oversizing index (OI) of less than 20%, and Group B included 46 patients with an OI of 20% or more. We conducted a new technique for more accurate measuring of the OI in the context of the implantation depth, and our patients were categorized using this technique. Our findings have met our primary end point in terms of the safety and efficacy of oversizing by 20% or more. There was no significant difference between both groups in terms of new-onset conduction disturbance (NOCD), with zero cases of annular rupture or coronary encroachment. In terms of efficacy, The incidence of significant PVL (grade 2 or more) in group B was less than in group A (P value 0.007). The ROC curve found that the minimum depth of implantation-derived oversizing (DIDO) to predict no significant PVL was less than 17%. CONCLUSION: Prosthesis oversizing by 20% using the self-expandable Evolut R valve is safe and effective, with no significant effect on the conduction system, coronary encroachment, or annular injury, and warrants a greater reduction in the incidence of significant PVL.

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Consideration for oversizing the proximal stent graft is suggested in endovascular aortic repair. However, a special recommendation for the proximal oversizing ratio (OSR) in patients with ruptured abdominal aortic aneurysm (rAAA) is ambiguous. This study aims to evaluate the effect of different degrees of the proximal oversizing ratio (OSR) on risk of type IA endoleak (TIAEL) in hemodynamically stable and unstable patients with rAAA undergoing emergency endovascular aortic repair (EVAR). Our study included 134 rAAA patients undergoing emergent EVAR, and we did not observe a significant association between hemodynamic instability and risk of T1AEL (HR 3.89, 95%CI 0.40-37.75, p = 0.24). All three T1AELs in the hemodynamically unstable subgroup were observed in patients with OSR ≤ 30%, but no significant difference was found regarding T1AEL between patients with OSR > 30% and OSR ≤ 30% (0.00% vs. 11.11%, p = 0.19). As for hemodynamically stable patients, OSR > 20% was associated with a significantly decreased risk of T1AEL (HR 0.03, 95%CI 0.01-0.53, p = 0.016). In conclusion, a proximal OSR > 20% is associated with a decreased risk of T1AEL in hemodynamically stable patients, while an OSR > 30% did not add an additional advantage of lowering the risk of T1AEL in hemodynamically unstable patients.

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Background: Shoulder arthroplasty humeral stem design has evolved to include various shapes, coatings, lengths, sizes, and fixation methods. While necessary to accommodate patient anatomy characteristics, this creates a surgical paradox of choice. The relationship between the surgeon's selection of short-stem implant size and construct stiffness, resistance to subsidence and micromotion has not been assessed. Methods: Eight paired cadaveric humeri were reconstructed with surgeon-selected (SS) and 2-mm diametrically larger (SS+2) short-stemmed press-fit implants. Each reconstruction was subjected to 2000 cycles of 90° forward flexion loading, and stem subsidence and micromotion were measured using optical tracking. Compressive stiffness of the stem-bone reconstruction was then assessed by applying a load in-line with the stem axis that resulted in 5 mm of stem subsidence. Results: Increasing stem size by 2 mm resulted in the construct stiffness more than doubling compared to SS stems (-741 ± 243 N/mm vs. -334 ± 120 N/mm; P = .003; power = 0.971). These larger stems also subsided significantly less than their SS counterparts (SS: 1.2 ± 0.6 mm; SS+2: 0.5 ± 0.5 mm; P = .029; power = 0.66), though there were no significant changes in micromotion (SS: 169 ± 59 µm; SS+2: 187 ± 52 µm; P = .506; power = 0.094). Conclusions: The results of this study highlight the importance of proper short-stem sizing, as a relatively small 2 mm increase in diametral size was observed to significantly impact construct stiffness, which could increase the risk of stress shielding and implant loosening. Future work should focus on developing tools that objectively quantify bone quality and aid surgeons in selecting the appropriate size short-stem humeral implants for a particular patient.

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Objective: This article aims to investigate the incidence rate of retrograde type A aortic dissection (RTAD) and the risk factors of RTAD in relation to thoracic endovascular aortic repair (TEVAR). Methods: Patients with thoracic aortic disease who underwent TEVAR at Henan Provincial People's Hospital from January 2004 to December 2019 were enrolled in the present research. The risk factors associated with RTAD following TEVAR using univariate and multiple logistic regression analyses. Results: During the study period, A total of 1,688 TEVAR patients were included in this study, and of these, 1,592 cases were included in the type B aortic dissection (TBAD) group, and 96 cases were included in the non-TBAD group. There were 1,230 cases of aortic dissection and 362 cases of aortic intramural hematoma and/or penetrating ulcer in the TBAD group. The non-TBAD group included 68 cases of thoracic aortic aneurysm, 21 cases of thoracic aortic pseudoaneurysm, and seven cases of congenital aortic coarctation. The overall incidence rate of RTAD was 1.1% (18/1,688) in patients, all of which occurred in the TBAD group. The cohort comprised 18 RTAD patients with an average age of 56.78, consisting of 13 males and 5 females. Among them, 13 individuals exhibited hypertension. Ten instances happened within the TEVAR perioperative period, including two cases during the surgery, six cases occurred within three months, two cases occurred after one year, and the longest interval was 72 months following TEVAR. TEVAR was successfully implemented in 17 patients, while the operation technique was temporarily altered in one case. The new entry position for RTAD was identified as the proximal region of the stent graft (SG) in 13 patients, while in five cases, the entry site was more than 2 cm away from the proximal region of the SG. 17 cases were at the greater curvature of the aorta, and one case was at the lesser curvature. Multivariate logistic regression analysis revealed that the SG oversizing ratio is a relevant risk factor for RTAD. However, ascending aortic diameter, aortic arch type, SG type, and anchored region were not directly related to the occurrence of RTAD. Conclusion: RTAD is a rare yet catastrophic complication. It could occur both during the procedure, early and late postoperative periods. Maintaining an appropriate SG oversizing ratio is crucial to minimize the risk of RTAD.

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Objective: The optimal degree of proximal thoracic endograft oversizing when aiming for durable sealing in prosthetic grafts is unknown. The aim of the present study was to create an in vitro model for testing different oversized thoracic endografts in a reproducible and standardized manner and, subsequently, determine the optimal oversizing range when planning procedures with a proximal landing in prosthetic zones in the descending thoracic aorta or aortic arch. Methods: An in vitro model consisting of a fixed 24-mm polyethylene terephthalate (Dacron; DuPont) graft sutured proximally and distally to two specifically designed 40-mm rings, with four force sensing resistors attached at four equally distant positions and a USB camera attached proximally for photographic and video documentation was used for deployment of Zenith TX2 (Cook Medical Inc) dissection platform endografts with diameters between 24 and 36 mm. After deployment, ballooning with a 32-mm compliant balloon was performed to simulate real-life conditions. The assessment of oversizing included visual inspection, calculation of the valley areas created between the prosthetic wall and the stent graft fabric, distance between the stent graft peaks, the radial force exerted by the proximal sealing stent, and the pull-out force necessary for endograft extraction. Results: A total of 70 endografts were deployed with the oversizing ranging from 0% to 50%: 10 × 24 mm, 10 × 26 mm, 10 × 28 mm, 10 × 30 mm, 10 × 32 mm, 10 × 34 mm, and 10 × 36 mm. Two cases of infolding occurred with 50% oversizing. The valley areas increased from 8.79 ± 0.23 mm2 with 16.7% oversizing to 14.26 ± 0.45 mm2 with 50% oversizing (P < .001). A significant difference was found in the pull-out force required for endografts with <10% oversizing vs ≥10% oversizing (P < .001). The difference reached a plateau at ∼4 N with oversizing of >15%. The mean radial force of the proximal sealing stent was greater after remodeling with a compliant balloon (0.55 ± 0.02 N vs 0.60 ± 0.02 N after ballooning; P < .001). However, greater oversizing did not lead to an increase in the radial force exerted by the proximal sealing stent. Conclusions: The findings from the present study offer additional insight into the mechanics of oversized stent grafts in surgical grafts. In endografts with the Zenith stent design (TX2), oversizing of <16.7% resulted in reduced resistance to displacement forces, and oversizing of >50% was associated with major infolding in 20% of cases. Long-term in vitro and in vivo testing is required to understand how these mechanical properties affect the clinical outcomes of oversizing.

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PURPOSE: The purpose of this study was to assess the impact of oversizing in thoracic endovascular aortic repair (TEVAR) on early and long-term survival and major adverse events in patients with uncomplicated type B aortic dissection (TBAD). METHODS: Between January 2010 and December 2018, 226 patients who were diagnosed with uncomplicated TBAD and received TEVAR were analyzed retrospectively. The patients were divided into ≤5% oversizing (n=153) and >5% oversizing (n=73) groups. Primary end points were all-cause and aortic-related mortalities. Secondary end points were procedure-related complications, including retrograde type A aortic dissection (RTAD), endoleak, distal stent-induced new entry (SINE), and late reintervention. All-cause and aortic-related mortalities were assessed using the Kaplan-Meier survival method, while procedure-related complications were evaluated using a competing risk model with all-cause death as a competing risk. RESULTS: Mean oversizing was 2.1%±1.5% in the ≤5% oversizing group and 9.6%±4.1% in the >5% oversizing group. Differences in the 30-day mortality and adverse events between the 2 groups were statistically insignificant. The freedom from all-cause mortality was comparable between the ≤5% oversizing group and the >5% oversizing group (≤5%: 93.3% at 5 years, >5%: 92.3% at 5 years, p=0.957). No significant difference was observed between both groups in the freedom from aortic-related mortality (≤5%: 95.0% at 5 years, >5%: 96.7% at 5 years, p=0.928). However, the competing risk analyses revealed that the cumulative incidence of RTAD was statistically significantly greater in the >5% oversizing group than in the ≤5% oversizing group (≤5%: 1(0.7%) at 5 years, >5%: 6(6.9%) at 5 years, p=0.007). All RTADs occurred within a year of TEVAR. The differences in the cumulative incidences of type I endoleak, distal SINE, and late reintervention were not significant between the 2 groups. CONCLUSION: The differences in the 5-year all-cause mortality and aortic-related mortality between patients with uncomplicated TBAD who received TEVAR with ≤5% oversizing and those who got TEVAR with >5% oversizing were insignificant. However, oversizing >5% was considerably associated with an increased risk of RTAD within a year of TEVAR, suggesting that oversizing ≤5% may be the appropriate size for TEVAR in patients with uncomplicated TBAD. CLINICAL IMPACT: For patients with uncomplicated TBAD, choosing oversizing ≤5% in endovascular treatment is beneficial to reduce the risk of postoperative retrograde type A aortic dissection. This finding provides a basis for stent size selection in endovascular repair. In addition, one year after TEVAR is the main time period for postoperative retrograde type A aortic dissection, and attention should be paid to the management and follow-up of this period.

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BACKGROUND: The potential benefit of using larger or smaller transcatheter heart valves (THV) in patients with borderline aortic annulus measurement (BAM) remains uncertain. The objective of this study was to evaluate the clinical outcomes associated with the selection of larger or smaller THV in the context of BAM. METHODS: This was a multicenter observational study including patients who underwent transcatheter aortic valve replacement with the SAPIEN 3 or SAPIEN 3 Ultra-valve systems (Edwards Lifesciences, Irvine, CA) from April 2014 to June 2021. BAM was defined according to the manufacturer sizing chart and included the following annulus areas: 314 to 346, 400 to 430, 500 to 546 mm2. A 1:1 propensity score matching was used to compare outcomes of patients with larger or smaller THV. RESULTS: From a total of 2467 patients, BAM was identified in 852 patients (34.5%). A larger and smaller THV was selected in 338 (39.7%) and 514 patients (60.3%) patients, respectively. The choice of a larger THV was associated (before and after propensity matching) with a higher risk of new-onset left bundle branch block (HR, 2.25 [95% CI, 1.39-3.65; P=0.001) and permanent pacemaker implantation (HR, 1.86 [95% CI, 1.11-3.09]; P=0.016) without any impact on gradients or the risk of moderate or severe paravalvular regurgitation at discharge (HR, 0.78 [95% CI, 0.41-1.45]; P=0.427). The risk of periprocedural complications such as aortic rupture and tamponade was low (<1%) and similar between groups. CONCLUSIONS: In patient with BAM, selecting a larger SAPIEN 3/Ultra THV increased the risk of conduction disturbances without any benefit on valve hemodynamics and clinical outcomes.

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Subclinical leaflet thrombosis has been increasingly recognized following transcatheter aortic valve replacement (TAVR). Determining the risk factors is vital in preventing clinical leaflet thrombosis and ensuring long-term value durability. Clinical data have indicated that regional stent under-expansion of transcatheter aortic valves (TAVs), particularly self-expanding devices, may be associated with an increased risk of subclinical leaflet thrombosis. This study aimed to determine the effects of regional TAV frame under-expansion on leaflet kinematics, leaflet structural characteristics, and explore its impact on the likelihood of leaflet thrombosis. In this study, mild and moderate regional frame under-expansion of a 26-mm CoreValve were examined using experimental testing and computational simulations. The results indicated that regional TAV frame under-expansion impairs leaflet kinematics and reduces the range of motion in leaflets with an angle less than 120°. The reduced range of motion can increase blood stasis on the surface of the TAV leaflets. The results also demonstrated that regional frame under-expansion induced localized high-stress regions in the leaflets close to the fixed boundary edge. The increased mechanical stress can lead to accelerated tissue degeneration. The study improves our understanding of the effects of regional stent under-expansion in TAVR. Post-procedural balloon dilatation of self-expanding TAVs can potentially be advantageous in reducing leaflet distortion and normalizing leaflet stress distribution. Large-scale, prospective, and well-controlled studies are needed to further investigate regional TAV frame under-expansion effects on subclinical leaflet thrombosis and long-term valve durability.

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Background: To characterize the difference in aortic dimensions during the cardiac cycle with electrocardiogram (ECG)-gated computed tomography angiography (CTA) and to determine whether other parameters in comparison to diameter could potentially provide a more accurate size reference for stent selection at the aortic arch and the proximal thoracic descending aorta. Methods: The CTA imaging of 90 patients during the cardiac cycle was reviewed. Three anatomic locations were selected for analysis (level A: 1 cm proximal to the innominate artery; level B: 1 cm distal to the left common carotid artery; and level C: 1 cm distal to the left subclavian artery). We measured the maximum diameter, the minimum diameter, the lumen area, the lumen perimeter, and the diameter derived from the lumen area, and the changes of each parameter at each level during the cardiac cycle were compared. Results: The mean age was 60.9 ± 12.4 years (range, 16-78 years). There was a significant difference in the aortic dimensions during the cardiac cycle (p < 0.001). The diameter derived from the lumen area at all three levels was changed least over time when compared to the area, perimeter, and the maximum aortic diameter (all p < 0.01). Conclusion: The aortic dimensional differences during the cardiac cycle are significant. The aortic diameter derived from the lumen area over other parameters may provide a better evaluation for selecting the size of the stent at the aortic arch and the proximal thoracic descending aorta. A prospective study comparing these different measurement parameters regarding the outcomes is still needed to evaluate the clinical implications.

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Despite being commonly employed to treat peripheral artery disease, self-expanding Nitinol stents are still associated with relatively high incidence of failure in the mid- and long-term due to in-stent restenosis or fatigue fracture. The practice of stent oversizing is necessary to obtain suitable lumen gain and apposition to the vessel wall, though it is regarded as a potential cause of negative clinical outcomes when mis-sizing occurs. The objective of this study was to develop a computational model to provide a better understanding of the structural effects of stent sizing in a patient-specific scenario, considering oversizing ratio OS, defined as the stent nominal diameter to the average vessel diameter, between 1.0 and 1.8. It was found that OS < 1.2 resulted in problematic short-term outcomes, with poor lumen gain and significant strut malapposition. Oversizing ratios that were in the range 1.2 ≤ OS ≤ 1.4 provided the optimum biomechanical performance following implantation, with improved lumen gain, reduced incomplete stent apposition and favourable predicted long-term fatigue performance. Excessive oversizing, OS > 1.4, did not provide any further benefit in outcomes, showing limited increases in lumen gain and unfavourable long-term performance, with higher mean strain values predicted from the fatigue analysis. Therefore, our findings predict that the optimal oversizing ratio for self-expanding Nitinol stents is in the range of 1.2 ≤ OS ≤ 1.4, which is similar to clinical observations, with this study providing detailed insight into the biomechanical basis for this.

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PURPOSE: The study aims to evaluate visual outcome, central corneal thickness, and rebubbling rate in a cohort with oversized DMEK grafts after failed penetrating keratoplasty (PK). The unique feature of the study is a descemetorhexis diameter larger than the full-thickness graft, i.e., peripheral to the PK interface. METHODS: A monocentric, retrospective evaluation of all patients with endothelial graft failure after PK treated with an oversized DMEK graft and descemetorhexis outside of the PK interface (i.e., in host tissue) between January 2015 and July 2019 at the Department of Ophthalmology at the University of Düsseldorf (Germany) was performed. RESULTS: Eleven eyes of 10 patients were identified. Mean age was 69 years. On average (arithmetic mean ± standard deviation), 1.7 ± 1.0 previous PKs have been performed per eye in this cohort. The mean time between last PK and DMEK was 10.1 ± 7.3 years (range 2 to 23 years). In all cases, the graft diameter exceeded the diameter of the previous PK and descemetorhexis was performed in host tissue, that is, peripheral to the graft-host interface. Rebubbling was performed in 18.2% of the patients (n = 2 eyes) because of central graft detachment. Mean central corneal thickness showed a statistically significant improvement at 5.3 ± 3.5 months after surgery from 688.23 ± 151.01 to 527.75 ± 88 µm (p = 0.002). Visual acuity increased significantly by 5 lines from 1.24 ± 0.5 logMAR (range from 0.5 to 2) to 0.73 ± 0.76 logMAR (range from 0.1 to 2) within 3 months (p = 0.006). Excluding patients without visual potential and transplant failure, visual acuity improved significantly by 8 lines (p < 0.001), and stayed stable until the last follow-up at 15.1 ± 11.4 months (range 6 to 39 months, p < 0.001, n = 8) after surgery. CONCLUSION: DMEK can be successfully used to treat endothelial cell failure after PK, and can provide good postoperative results with regards to visual acuity. This study shows that stripping of Descemet's membrane (DM) peripheral to the PK interface is surgically feasible. Overlapping, larger DMEK grafts with more endothelial cells can be used without increasing rebubbling rates and may potentially improve long-term graft survival.

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Rapid deployment valve has expanded surgical indication for high-risk patients with aortic stenosis despite its accommodated risk for conduction disorder (CD). The purpose of this study was to evaluate the degree of oversizing in association with postoperative CD. During June 2019 to September 2021, 25 patients underwent aortic valve replacement with Edwards INTUITY. Device size selection was evaluated intraoperatively using provided sizers. Oversizing was evaluated retrospectively by measuring the difference of the dimension of the annulus and left ventricular outflow tract (LVOT) compared to the dimensions of the device used by preoperative-computed tomography. Although there was no incidence of pacemaker implantation, seven patients (28.0%) experienced CD after surgery. There was no difference in device area and annulus area (CD: - 37 ± 22.7 mm2 vs. no CD: - 56 ± 63.6 mm2, p = 0.47), and device circumference and annulus circumference (CD: - 4.4 ± 2.77 mm vs. no CD: - 6.9 ± 5.60 mm, p = 0.26) in patients with and without CD. However, there was a significant difference in area of the device skirt and sub-annular area at the LVOT (CD: 114 ± 28.4 mm2 vs. no CD: - 8 ± 80.0 mm2, p < 0.001), and circumference of device skirt and the LVOT (CD: 3.9 ± 2.08 mm vs. no CD: - 4.6 ± 5.24 mm, p < 0.001) between the two groups. Receiver operating characteristic curve analysis showed that an area difference of 77.7 mm2 and circumference difference of 0.91 mm at LVOT were associated with postoperative CD with specificities of 0.83, 0.78 and sensitivity of 1.0, 1.0, respectively. Preoperative measurement of the LVOT may be useful in evaluating the risk of postoperative CD in patients receiving rapid deployment valve.

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INTRODUCTION: Aortic neck dilation post endovascular aneurysm repair (EVAR) has been implicated in the long-term development of endoleak and the subsequent re-intervention. Optimal endograft sizing is a vital aspect to successful repair. This study looked at percentage of graft oversizing as well as type of fixation on aortic neck dilation. METHODS: We retrospectively evaluated all EVARs completed at Loyola's University from 2006 to 2015 after IRB approval. Patients without follow-up scans within a year were excluded. We collected demographics, comorbidities, graft type, size, aortic neck diameter, maximum sac size diameters from the pre-operative and follow-up scans. We reviewed and collected data on 432 patients but analyzed 154. We measured the largest aortic diameter on axial images 1 cm above and 1 cm below the lowest renal artery. Change in supra and infrarenal aortic measurements were evaluated by calculating the mm difference from each scan compared to the pre-operative scan. Linear mixed effects models were used to estimate patients' mean differences over time. RESULTS: We compared three groups of neck fixation grafts. Those with active suprarenal fixation had a significant change in suprarenal aortic diameter at four-year follow-up (1.86 mm, CI:0.65-3.06), compared to those with active infrarenal (0.22 mm, CI: -0.67 to -1.11) or passive suprarenal fixation (1.52 mm, CI: -0.11 to -3.15) (Fig. 1). Those with active suprarenal fixation were the only ones to have significant increase in suprarenal aortic diameter (P = 0.0026). Degree of oversizing was also divided into three groups. Oversizing by <10% had less impact on the suprarenal aorta than >15% oversizing at 4 years (0.41 mm, CI: -0.31 to -1.14 vs. 3.26 mm, CI: 1.63-4.88, P < 0.001) (Fig. 2). Oversizing had a more pronounced effect on the infrarenal aorta: 3.01 mm, CI: 2.18-3.83; 5.95 mm, CI: 3.26-8.64; and 5.05 mm, CI: 3.41-6.69 for <10%, 10-15%, and >15% oversizing at four years, respectively. CONCLUSION: Stent-grafts with active fixation below the renal arteries as well as oversizing by <10% seem to have the least effect on aortic neck dilation over time. These factors should be considered when performing EVARs, as aortic neck dilation could lead to endoleak and need for further intervention. Further research defining the optimal stent-graft type, self-expanding versus balloon expandable, type of fixation and degree of oversizing.

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Objective: To evaluate the predictors of new-onset conduction disturbances in bicuspid aortic valve patients using self-expanding valve and identify modifiable technical factors. Background: New-onset conduction disturbances (NOCDs), including complete left bundle branch block and high-grade atrioventricular block, remain the most common complication after transcatheter aortic valve replacement (TAVR). Methods: A total of 209 consecutive bicuspid patients who underwent self-expanding TAVR in 5 centers in China were enrolled from February 2016 to September 2020. The optimal cut-offs in this study were generated from receiver operator characteristic curve analyses. The infra-annular and coronal membranous septum (MS) length was measured in preoperative computed tomography. MSID was calculated by subtracting implantation depth measure on postoperative computed tomography from infra-annular MS or coronal MS length. Results: Forty-two (20.1%) patients developed complete left bundle branch block and 21 (10.0%) patients developed high-grade atrioventricular block after TAVR, while 61 (29.2%) patients developed NOCDs. Coronal MS <4.9 mm (OR: 3.08, 95% CI: 1.63-5.82, p = 0.001) or infra-annular MS <3.7 mm (OR: 2.18, 95% CI: 1.04-4.56, p = 0.038) and left ventricular outflow tract perimeter <66.8 mm (OR: 4.95 95% CI: 1.59-15.45, p = 0.006) were powerful predictors of NOCDs. The multivariate model including age >73 years (OR: 2.26, 95% CI: 1.17-4.36, p = 0.015), Δcoronal MSID <1.8 mm (OR: 7.87, 95% CI: 2.84-21.77, p < 0.001) and prosthesis oversizing ratio on left ventricular outflow tract >3.2% (OR: 3.42, 95% CI: 1.74-6.72, p < 0.001) showed best predictive value of NOCDs, with c-statistic = 0.768 (95% CI: 0.699-0.837, p < 0.001). The incidence of NOCDs was much lower (7.5 vs. 55.2%, p < 0.001) in patients without Δcoronal MSID <1.8 mm and prosthesis oversizing ratio on left ventricular outflow tract >3.2% compared with patients who had these two risk factors. Conclusion: The risk of NOCDs in bicuspid aortic stenosis patients could be evaluated based on MS length and prosthesis oversizing ratio. Implantation depth guided by MS length and reducing the oversizing ratio might be a feasible strategy for heavily calcified bicuspid patients with short MS.

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OBJECTIVES: This study sought to investigate the impact of computed tomography (CT)-based area and perimeter oversizing on the incidence of paravalvular regurgitation (PVR) and valve hemodynamics in patients treated with the SAPIEN 3 transcatheter heart valve (THV). BACKGROUND: The incremental value of considering annular perimeter or left ventricular outflow tract measurements and the impact of THV oversizing on valve hemodynamics are not well defined. METHODS: The PARTNER 3 (Placement of Aortic Transcatheter Valves 3) trial included 495 low-surgical-risk patients with severe aortic stenosis who underwent THV implantation. THV sizing was based on annular area assessed by CT. Area- and perimeter-based oversizing was determined using systolic annular CT dimensions and nominal dimensions of the implanted THV. PVR, effective orifice area, and mean gradient were assessed on 30-day transthoracic echocardiography. RESULTS: Of 485 patients with available CT and echocardiography data, mean oversizing was 7.9 ± 8.7% for the annulus area and 2.1 ± 4.1% for the perimeter. A very low incidence of ≥moderate PVR (0.6%) was observed, including patients with minimal annular oversizing. Incidence of ≥mild PVR and need for procedural post-dilatation were inversely related to the degree of oversizing. For patients with annular dimensions suitable for 2 THV sizes, the larger THV with both area and perimeter oversizing was associated with the lowest incidence of ≥mild PVR (12.0% vs 43.4%; P < 0.0001). Left ventricular outflow tract area oversizing was not associated with PVR. THV prosthesis size, rather than degree of oversizing, had greatest impact on effective orifice area and mean gradient. CONCLUSIONS: In low-surgical-risk patients, a low incidence of ≥moderate PVR was observed, including patients with minimal THV oversizing. The degree of prosthesis oversizing had the greatest impact on reducing mild PVR and incidence of post-dilatation, without impacting valve hemodynamics. In selected patients with annular dimensions in between 2 valve sizes, the larger THV device oversized to both the annular area and perimeter reduced PVR and optimized THV hemodynamics.

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El objetivo de este estudio ha sido evaluar mediante modelos in vitro, dos configuraciones distintas de stent paralelo: en 2 y 3 chimeneas viscerales (chEVAR) y en configuración tipo sándwich para preservar la arteria hipogástrica y analizar cuál es la mejor combinación de materiales, el grado óptimo de sobredimensión y la mejor técnica de medición de esta última. Respecto a la configuración en 2-3 chimeneas, los resultados mostraron una mejor adaptación general de los componentes a sobredimensiones crecientes con una menor tasa de compresión en las combinaciones de alta fuerza radial aunque a expensas de un significativo peor sellado. Respecto a la configuración en sándwich, los resultados mostraron también una reducción de las zonas de mal sellado a mayor sobredimensión aunque a expensas de una mayor compresión y de un mayor replegado, sin diferencias significativas con los distintos dispositivos utilizados. Respecto a la medición de la sobredimensión, se obtuvo una correlación prácticamente perfecta entre la sobredimensión de áreas (clásicamente descrita) con la de perímetros y de diámetros. En conclusión, los resultados de este estudio in vitro pueden ser de utilidad en la planificación de procedimientos reales de EVAR con stent paralelo ante la ausencia de evidencia actual que soporte unas recomendaciones específicas.(AU)

The aim of this study was evaluate using in vitro models, two different configurations of parallel stenting: 2 and 3 visceral chimneys (chEVAR) and in a sandwich configuration to preserve the hypogastric artery, analysing which is the best combination of materials, the optimal oversizing and the best measurement method. Regarding 2-3 chimney configuration, our results showed a better adaptation of the devices with increasing oversizing with a lower compression rate in high radial force combinations, although with a significantly worse sealing. Regarding sandwich configuration, our results also showed gutter area reduction when increasing oversizing although higher compression rate and inflodin, without significant differences between the devices used. Regarding oversizing measuring methods, a practically perfect correlation was obtained between area oversizing (classically described) and perimeter and diameter oversizing. In conclusion, the results of this in vitro study may be useful in planning real EVAR procedures with parallel stenting in the absence of current evidence to support specific recommendations.(AU)

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