Acute Insulin Resistance and Rapid Alterations in Neuronal Derived Blood Exosome Concentration After Branched Endovascular Aortic Aneurysm Repair.

OBJECTIVE: Hyperglycaemia following branched endovascular repair (BEVAR) of extensive aortic aneurysms is associated with post-operative lower extremity weakness (LEW). Insulin administration to maintain euglycaemia appears to decrease LEW rates. The purpose of this study was to examine changes in insulin receptor content of neuron derived blood exosomes (NDEs) after BEVAR. METHODS: Ten patients with a range of post-operative lower extremity neurological deficits after elective BEVAR were included in the study. Blood samples were collected pre-operatively, immediately after aneurysm repair, and on post-operative day 1. NDE insulin receptor substrate proteins were quantified by enzymevlinked immunosorbent assays. RESULTS: NDE levels of phosopho-serine312-type 1 insulin receptor substrate ([P-Ser312-IRS1], an inhibitor of insulin signalling) increased sevenfold in the immediate post-operative period (from 7.90 ± 0.89 to 58.54 ± 6.77 pg/mL; p < .001), whereas those of pan-tyrosine-phospho insulin receptor substrate ([P-panTyr-IRS1], which facilitates insulin signalling), rose only 50% (from 0.41 ± 0.07 to 0.63 ± 0.10 pg/mL; p = .03). As a result, the mean ratio of P-Ser312-IRS1 to P-panTyr-IRS1, which reflects the level of insulin resistance, increased fivefold immediately post-operatively (from 22.31 ± 3.28 to 106.33 ± 11.83; p < .001) and returned to normal levels by the next day (18.72 ± 1.87). CONCLUSION: BEVAR is associated with an acute state of insulin resistance within neuronal tissue. Further studies in a larger cohort of patients are needed to understand the potential interconnected processes of insulin resistance, hyperglycaemia, and spinal cord ischaemia after extensive endovascular aortic procedures.

Multibranched endovascular aortic aneurysm repair in patients with and without chronic aortic dissections.

OBJECTIVE: The objective of this study was to compare multibranched endovascular aneurysm repair (MBEVAR) of postdissection thoracoabdominal aortic aneurysms (TAAAs) and pararenal aortic aneurysms (PRAAs) with MBEVAR of degenerative TAAAs and PRAAs and to assess the role played by the preoperative correction of potential complicating factors, such as true lumen compression and false lumen origin of vital branches, using adjunctive maneuvers. METHODS: From July 2005 to July 2017, there were 162 patients who underwent elective MBEVAR of TAAAs and PRAAs. Data on demographics, procedural details, and outcomes were collected prospectively. RESULTS: The mean age was 73 ± 8 years, and 119 of 162 (74%) were men; 19 of 162 (12%) had prior aortic dissections. Patients with dissections were younger (65 ± 11 years vs 74 ± 7 years; P = .002) and were less likely to have smoked (13/19 [68%] vs 135/143 [94%]; P = .002) or to have peripheral artery disease (0/19 [0%] vs 35/143 [24%]; P = .01) compared with those without dissections. Patients with prior dissections were more likely to have Crawford type II (10/19 [53%] vs 22/143 [15%]; P = .001) and type III (6/19 [32%] vs 16/143 [11%]; P = .03) TAAAs and were more likely to require at least one pre-MBEVAR adjunctive procedure (14/19 [74%] vs 55/143 [38%]; P = .006) compared with those without dissection. There was no difference in perioperative death, stroke, or paraplegia rates between the two groups. Median follow-up was 2.4 years (interquartile range, 0.8-4.7) and did not differ significantly between the two groups. There were no significant differences in branch vessel occlusion, endoleak rate, or aneurysm-related death between the two groups. CONCLUSIONS: Patients with chronic type B aortic dissection are more likely to have extensive aneurysms and more likely to require adjunctive procedures to provide the appropriate anatomic substrate for MBEVAR, but this does not appear to affect the conduct of MBEVAR or its outcomes.

Late graft failure is rare after endovascular aneurysm repair using the Zenith stent graft in a cohort of high-risk patients.

OBJECTIVE: Device-specific data on the long-term efficacy of endovascular aneurysm repair (EVAR) are limited by the constant evolution of stent graft design. Whereas some modifications, such as barb-mediated fixation, probably enhance durability, others, such as thin-walled fabric, are of less certain benefit. The purpose of this study was to examine 15 years of a single-center experience of EVAR using the Zenith stent graft (Cook Medical, Bloomington, Ind). METHODS: Retrospective analysis was conducted of 325 high-risk patients who underwent elective EVAR with Zenith stent grafts between October 1998 and December 2005 under a physician-sponsored investigational device exemption. Patients' charts and death registries were reviewed to identify late stent graft failures and causes of death. Late stent graft failures were defined as type I or type III endoleaks; enlarging aneurysm sac requiring revision; and limb kinking or occlusion, stent graft infection, renal artery occlusion, or aneurysm rupture occurring >30 days after the index procedure. RESULTS: The mean age at treatment was 75.9 ± 7.4 years, and 300 of 325 (92%) were men. The mean aneurysm diameter was 60 ± 9 mm, and the median main body stent graft diameter was 28 mm (range, 22-32 mm). During a median follow-up time of 5.6 years (interquartile range, 2.6-8.7 years), there were six (2%) aneurysm-related deaths caused by the following: one stent graft infection, one infection of a femoral-femoral bypass graft placed after limb occlusion, one infection of a stent graft placed to treat a type IB endoleak, and three aneurysm ruptures. There were 19 (6%) late stent graft failures occurring at a median time of 4.0 years (range, 39 days-14.6 years) after the procedure. Patients with late stent graft failure were more likely to have had impaired renal function (creatinine concentration ≥2 mg/dL; 21% vs 6%; P = .03) and less likely to have had cardiac disease (42% vs 67%; P = .04) at the time of the index procedure. There was no significant association between late stent graft failure and age, sex, aneurysm size, stent graft diameter, diabetes, smoking, or lung disease. Kaplan-Meier estimated overall survival was 60% at 5 years, 29% at 10 years, and 12% at 15 years. Kaplan-Meier estimated freedom from aneurysm-related mortality was 98% at 5 years, 97% at 10 years, and 97% at 15 years. CONCLUSIONS: Late-occurring stent graft failures and aneurysm-related death are rare after EVAR using the Zenith stent graft, especially in high-risk patients whose comorbidities diminish life expectancy.

The impact of prior aortic surgery on outcomes after multibranched endovascular aortic aneurysm repair.

OBJECTIVE: The purpose of this study was to evaluate the impact of prior aortic surgery on outcomes after multibranched endovascular aneurysm repair (MBEVAR) of thoracoabdominal aortic aneurysms (TAAAs) and pararenal aortic aneurysms (PRAAs). METHODS: From July 2005 to October 2016, there were 153 patients who underwent elective endovascular repair of TAAA and PRAA using multibranched stent grafts. Data on demographics, procedural details, and outcomes were collected prospectively. RESULTS: The mean age was 73 ± 8 years, and 113 of 153 (74%) were men. Mean aneurysm diameter was 67 ± 9 mm. Before MBEVAR, 68 of 153 (44%) patients had undergone a prior aortic surgery; 49 of 68 (72%) had prior open aortic surgery, 15 of 68 (22%) had prior endovascular aortic surgery, and 4 of 68 (6%) had both. There were no significant differences in age, sex, preoperative aneurysm diameter, or medical comorbidities (coronary artery disease, lung disease, diabetes mellitus, or hypertension) in patients with previous aortic surgery compared with those without. Patients with previous aortic surgery had higher fluoroscopy times (131 ± 59 vs 118 ± 54 minutes; P = .18) and procedural times (370 ± 101 vs 345 ± 118 minutes; P = .27) during MBEVAR, but these differences did not reach statistical significance. Patients without previous aortic intervention had higher rates of postoperative paraplegia (9/85 [11%]) vs (0/68 [0%]; P = .005) compared with those with previous aortic surgery. Of 153 patients, 3 (2%) had a postoperative stroke, and this was not different between the two groups. Median follow-up time was 2.5 years (interquartile range, 1.0-4.5 years) and did not differ between those with and those without previous aortic surgery. Kaplan-Meier estimated 5-year freedom from aneurysm-related mortality and overall mortality was 90% and 48%, respectively, and did not differ between the two groups. There was also no difference in branch vessel occlusion between the two groups. CONCLUSIONS: A high proportion of patients undergoing MBEVAR for TAAA or PRAA have already undergone prior open or endovascular aortic procedures, but this does not appear to increase the complication rate or affect midterm clinical outcomes. Patients with prior aortic surgery who undergo MBEVAR have lower rates of paraplegia compared with those without prior surgery, which may be due to effective recruitment of collateral circulation.

Low-profile versus standard-profile multibranched thoracoabdominal aortic stent grafts.

OBJECTIVE: This study compared midterm results using low-profile stent grafts (LPSGs; 18F) and standard-profile stent grafts (SPSGs; 22F-24F) for endovascular pararenal and thoracoabdominal aortic aneurysm (TAAA) repair. METHODS: From July 2005 to March 2015, 134 asymptomatic patients underwent endovascular repair of a pararenal or TAAA using multibranched aortic stent grafts. In March 2011, we started using a LPSG with nitinol stents and thin-walled polyester fabric. Prospectively collected data on operative repair, complications, and outcomes were compared between the two groups. RESULTS: LPSGs were used in 37 patients (8 women [21.6%]; mean ± standard deviation age, 72.5 ± 8 years) and SPSGs in 97 patients (25 [26%] women; mean age, 73 ± 8 years). Medical comorbidities, aneurysm size, and aneurysm extent were similar in the LPSG and SPSG groups. Mean follow-up time was longer in the SPSG group (3.1 ± 2 years) than in the LPSG group (1.3 ± 0.9 years; P < .001). Operative time, renal failure, stroke, myocardial infarction, and perioperative death were not significantly different between the two groups (P > .05). Aneurysm-related death, rupture, stent graft migration, type I or III endoleaks, aneurysm enlargement >5 mm, branch vessel occlusion, and reintervention rates were similar between the two groups (P > .05). However, the combined outcome of conduit use or access artery injury occurred at a lower rate in the LPSG group than in the SPSG group (16% vs 36%; P = .03). Women experienced significantly higher rates of conduit use and access artery injury than men after repair with SPSGs (64% vs 26%, respectively; P = .001) but similar rates after repair with the LPSG (25% vs 14%, respectively; P = .45). CONCLUSIONS: LPSGs had similar safety profile and midterm outcomes compared with the SPSGs for treatment of pararenal and TAAA. The substitution of LPSGs for SPSGs lowered the number of patients who required conduit insertion to avoid access artery injury, especially in women, thereby reducing an otherwise striking gender difference.

Standard off-the-shelf versus custom-made multibranched thoracoabdominal aortic stent grafts.

OBJECTIVE: The complex aortic branch anatomy in thoracoabdominal aortic aneurysms (TAAAs) and pararenal aortic aneurysms (PRAAs) presents a challenge for endovascular repair. The multibranched endovascular device has durable midterm results with use of a custom branch stent graft (CSG) configuration. The midterm results with use of the standard branch stent graft (SSG) configuration are unknown, but it has the advantage of off-the-shelf technology. The goal of this study was to compare the midterm outcomes of CSG and SSG multibranched endovascular devices. METHODS: From July 2005 to September 2014, 133 patients underwent elective endovascular repair of TAAA and PRAA in a prospective trial. Beginning in December 2008, SSGs were used in those with suitable anatomy. RESULTS: Fifty patients (mean age, 71 ± 7 years; 11 women [22%]) were treated using SSGs, and 83 patients (mean age, 74 ± 9 years; 22 women [26.5%]) underwent repair using CSGs. The SSG and CSG groups were similar with regard to aneurysm size, aneurysm extent, and medical comorbidities, with the sole exception of lung disease, which was more common in the SSG group. All stent grafts were deployed as intended, with no conversions to open repair. Mean ± standard deviation follow-up (days) was 694 ± 525 for the SSG group and 942 ± 764 for the CSG group (P = .045). There were no significant differences in aneurysm-related death, renal failure requiring dialysis, stroke, endoleak, visceral or renal branch occlusion, lower extremity weakness, or reintervention (P > .05 for each). The volume of contrast material was significantly lower in those with SSGs compared with CSGs (P = .016), but there were no significant differences in operative or fluoroscopy times. Time to treatment (days from consent to surgery) was significantly lower in SSG patients compared with CSG patients (P = .01). CONCLUSIONS: For patients with suitable anatomy, the use of SSGs for TAAA and PRAA repair results in significantly shorter wait times to surgery and is as safe, effective, and durable in the midterm compared with CSGs.

Endovascular rescue after inadvertent false lumen stent graft implantation.

We report a case of a 58-year-old patient with a complicated type B aortic dissection who developed acute visceral malperfusion after placement of a thoracic aortic stent graft from the true to the false lumen. He underwent an urgent endovascular revision that involved septal fenestration and distal extension of the stent graft into the true lumen.

Lower extremity weakness after endovascular aneurysm repair with multibranched thoracoabdominal stent grafts.

OBJECTIVE: We conducted our study to describe the incidence, presentation, management, risk factors, and outcomes of lower extremity weakness (LEW) after elective endovascular aneurysm repair with multibranched thoracoabdominal stent grafts. METHODS: Excluding symptomatic patients and those with aortic dissection, between July 2005 and October 2013, 116 patients with aortic aneurysms were treated in a prospective, single-center trial of multibranched endovascular aneurysm repair. LEW that resolved within 30 days of operation was classified as transient. Persistent LEW was defined as inability to walk or stand 30 days after surgery. Perioperative spinal cord protection measures included bypass as needed to maintain flow to the subclavian and internal iliac arteries, cerebrospinal fluid drainage, and permissive hypertension. RESULTS: Postoperative LEW occurred in 24 of 116 patients (20.6%). In 15 (12.9%), LEW was transient with full recovery. Nine patients (7.7%) had persistent LEW, three with paraparesis and six with paraplegia. Five of 24 patients (21%) awoke from anesthesia with LEW. Symptoms of LEW developed within 72 hours of operation in 14 of 24 (58%). Late-onset LEW (≥72 hours postoperatively) always occurred in the presence of a precipitating hypotensive event (5 of 24; 21%). Univariate analysis showed no association between LEW and Crawford type, staged repair, aneurysm extent, or postoperative endoleak. Baseline glomerular filtration rate <30 mL/min/1.73 m(2) (odds ratio [OR], 4.2; 95% confidence interval [CI], 1.2-14.6; P = .03), fluoroscopy time >190 minutes (OR, 3.6; 95% CI, 1.0-12.7; P = .04), and sustained hypotension (OR, 2.9; 95% CI, 1.1-7.7; P = .04) were identified as independent risk factors for LEW in multivariate analysis. CONCLUSIONS: Most episodes of LEW after multibranched endovascular aneurysm repair are transient and do not occur in the operating room. Adjunctive strategies to maintain spinal perfusion, including cerebrospinal fluid drainage and permissive hypertension, may help prevent permanent LEW.

Visceral branch occlusion following aneurysm repair using multibranched thoracoabdominal stent-grafts.

PURPOSE: To identify risk factors for late-occurring branch occlusion following multibranched endovascular repair of thoracoabdominal and pararenal aortic aneurysm. METHOD: Out of 120 patients who underwent multibranched endovascular aneurysm repair between September 2005 and May 2013, 100 (78 men; mean age 72.4 ± 7.4 years) met the criteria for inclusion in the current retrospective analysis. Demographic data were gleaned from a prospectively maintained database. Mean aneurysm diameter was 66.7 ± 11.7 mm. Multiplanar reconstructions of postoperative computed tomographic angiography were used to measure 6 parameters of renal branch morphology. RESULTS: All 100 patients had undergone successful placement of multibranched aortic stent-grafts with a total of 95 celiac branches, 100 superior mesenteric artery (SMA) branches, and 187 renal branches. During a mean follow-up of 25.6 months, there were no stent fractures or stent separations, no SMA occlusions, and only 2 (2.1%) celiac artery occlusions, neither of which required reintervention. In contrast, there were 18 (9.6%) renal branch occlusions in 16 patients, all men (p=0.02). Patients with renal branch occlusions were significantly more likely to have a history of myocardial infarction (p=0.004). The mean renal artery length was significantly greater in the occlusion group compared to the non-occlusion group (47.5 ± 13.6 vs. 39.4 ± 14.2, p=0.03). No other aspect of branch morphology was significantly different between the occlusion and non-occlusion groups. CONCLUSION: Renal branch occlusion was by far the commonest late failure mode after multibranched endovascular aneurysm repair. The current study provides no basis for a change in patient selection or stent-graft design, only a change in the components used to construct renal branches. It is too early to tell the effect this will have.

Assessing the anatomic applicability of the multibranched endovascular repair of thoracoabdominal aortic aneurysm technique.

BACKGROUND: Multibranched endovascular aneurysm repair (MBEVAR) has the potential to lower the morbidity and mortality rates of thoracoabdominal aneurysm repair, but the applicability of the technique is unknown. Our aim was to estimate the prevalence of anatomic suitability for MBEVAR. METHODS: Retrospective review of patients referred for a prospective trial of MBEVAR between November 2005 and July 2012. Anatomic suitability was assessed on three-dimensional computed tomography scan reconstructions according to the current criteria for a custom-made stent graft or a fixed, off-the-shelf stent graft in both standard (22F) and low-profile (18F) delivery systems. RESULTS: A total of 250 contrast-enhanced computed tomography scans were reviewed, 49 of which were excluded due to inadequate aneurysm size. Of 201 candidates for repair, 149 (74%) were men and 86 (43%) had Crawford classification type IV/paravisceral aneurysms; 109 (58%) were anatomically suitable for a single-stage repair with a custom-made, low-profile stent graft. Another 58 (29%) could have been made suitable for MBEVAR with an adjunct procedure, including angiogram with visceral or renal artery stenting (n = 23), carotid-subclavian bypass (n = 5), or iliac bypass for device insertion (n = 17), or to preserve internal iliac artery flow because of an iliac aneurysm (n = 9), or dissection (n = 8). There was no association between suitability and gender, aneurysm diameter, or type. However, women were significantly more likely to need a conduit or low-profile device (P = .003). Patients with type B aortic dissections were significantly less likely to have anatomy suitable for repair (P = .035) and more likely to require a multistage repair. Thirty-four patients would have been unsuitable for repair because of renal artery anatomy (n = 14), visceral artery anatomy (n = 4), lack of a proximal landing zone due to an arch aneurysm (n = 7), or inadequate access arteries (n = 9). The low-profile device increased the number of patients who would have been suitable for a single-stage repair by 16. The off-the-shelf graft has the advantage of a faster assessment-to-treatment time, but only 64 patients would have been suitable for a single-stage repair and another 30 could have been made suitable with an adjunct procedure. CONCLUSIONS: Most patients would have been suitable or could have been made suitable for a thoracoabdominal stent graft using current anatomic criteria. The applicability of MBEVAR will continue to change as the experience with the technique grows and devices evolve, as evidenced by the potential reduction in iliac bypasses after the introduction of a low-profile device and the ability to treat symptomatic or urgent patients with the off-the-shelf device.

Efficacy and durability of endovascular thoracoabdominal aortic aneurysm repair using the caudally directed cuff technique.

OBJECTIVE: This study determined early and intermediate results of multibranched endovascular thoracoabdominal (TAAA) and pararenal aortic aneurysm (PRAA) repair using a uniform operative technique. METHODS: Eighty-one patients (mean age, 73 ± 8 years, 19 [23.5%] women) underwent endovascular TAAA repair in a prospective trial using self-expanding covered stents connecting axially oriented, caudally directed cuffs to target aortic branches. Mean aneurysm diameter was 67 ± 10 mm. Thirty-nine TAAA (48.1%) were Crawford type II, III, or V; 42 (51.9%) were type IV or pararenal. Thirty-three procedures (40.7%) were staged. The insertion approach was femoral for aortic components and brachial for branch components. Follow-up assessments were performed at 1, 6, and 12 months, and yearly thereafter. RESULTS: All devices (n = 81) and branches (n = 306) were successfully inserted and deployed, with no conversions to open repair. Overall mortality was 6.2% (n = 5), including three perioperative (3.7%) and two late treatment-related deaths (2.5%). Permanent paraplegia occurred in three patients (3.7%), and transient paraplegia/paraparesis occurred in 16 (19.8%). Four patients (4.9%) required dialysis postoperatively, three permanently and one transiently. Women accounted for 67% of the paraplegia, 75% of the perioperative dialysis, and 60% of the perioperative or treatment-related deaths. During a mean follow-up of 21.2 months, no aneurysms ruptured, but four (4.9%) enlarged: two were successfully treated, one was unsuccessfully treated, and one was not treated. No late onset spinal cord ischemia symptoms developed. Of the five patients starting dialysis during follow-up, two resulted from renal branch occlusion. Sixteen branches occluded (nine renal, two celiac) or developed stenoses (four renal, one superior mesenteric artery), requiring stenting. Primary patency was 94.8%, and primary-assisted patency was 95.1%. Thirty-two patients (39.5%) underwent 42 reinterventions. Of 25 early reinterventions (≤ 45 days), 10 were to treat access or insertion complications, and 5 were for endoleak. Of 17 late reinterventions, eight were for endoleak and five were for branch stenosis/occlusion. New endoleaks developed in two patients during follow-up. Overall, 73 of 81 patients (90.1%) were treated without procedure-related death, dialysis, paralysis, aneurysm rupture, or conversion to open repair. CONCLUSIONS: Total endovascular TAAA/PRAA repair using caudally directed cuffs is safe, effective, and durable in the intermediate term. The most common form of late failure, renal artery occlusion, rarely had a clinically significant consequence (dialysis). The trend toward worse outcome in women needs further study.

The transition from custom-made to standardized multibranched thoracoabdominal aortic stent grafts.

OBJECTIVE: The purpose of this study was to compare the branch morphology and short-term outcome of endovascular aneurysm repair using multibranched thoracoabdominal custom-made stent grafts (CSGs) vs standard stent grafts (SSGs). METHODS: Data on patient demographics, aortic morphology, component use, and outcome were collected prospectively. Final branch length (cuff to target artery orifice) and branch angle (cuff orientation to target artery orientation) were determined using 3-D reconstruction of computed tomographic angiograms (CTAs). RESULTS: Between January 2008 and March 2010, 28 patients underwent endovascular aneurysm repair using 14 CSGs and 14 SSGs. Two patients were excluded from analysis: one patient in the CSG group had yet to undergo CTA, and one patient in the SSG group had crossed renal branches due to problems traversing a previously reconstructed aortic arch. All the stent grafts were implanted successfully. There were no perioperative deaths. There were no statistically significant differences between the CSG (n = 13) and SSG (n = 13) groups in terms of patient age (74.4 ± 7.9 years vs 73.5 ± 6.0 years), aneurysm diameter (66.1 ± 9.0 mm vs 71.2 ± 9.0 mm), operative time (311 ± 94 minutes vs 286 ± 57 minutes), fluoroscopy time (108 ± 43 minutes vs 101 ± 30 minutes), contrast volume (98 ± 39 minutes vs 91 ± 27 minutes), blood loss (458 ± 205 mL vs 433 ± 193 mL), mean branch angle (22.8 ± 19.0 degrees vs 22.0 ± 17.6 degrees), or branch length (25.3 ± 12.1 mm vs 23.4 ± 10.2 mm). CONCLUSION: The substitution of SSG for CSG had no effect on the complexity of the procedure, the branch morphology, or the perioperative outcome. The availability of an off-the-shelf SSG will broaden the application of endovascular thoracoabdominal aortic aneurysm repair by eliminating manufacturing delays.

Valve-in-valve hemodynamics of 20-mm transcatheter aortic valves in small bioprostheses.

BACKGROUND: Transcatheter aortic valve (TAV) implantation is a treatment for selected patients with failing bioprostheses. We previously showed that currently available SAPIEN (Edwards Lifesciences, Irvine, CA) TAV sizes did not yield acceptable valve-in-valve (VIV) hemodynamics in small degenerated bioprostheses because optimal TAV function requires full stent expansion to its nominal size. The study objective was to determine (1) if 20-mm TAVs provide acceptable hemodynamics in small degenerated bioprostheses and (2) the effect of TAV spatial orientation on valvular hemodynamics and coronary flows. METHODS: Twelve 20-mm TAVs were created for implantation within 19-mm and 21-mm degenerated Carpentier-Edwards Perimount (Edwards Lifesciences) and porcine bioprostheses. Degenerated valves were sutured into human homograft roots and mounted in a pulse duplicator. TAVs were implanted within bioprostheses as VIV in standard orientation, in which TAV and bioprosthetic commissures were aligned, and later with 60-degree rotation. RESULTS: The 20-mm TAVs migrated retrograde into the left ventricle after VIV in the 21-mm Perimount bioprostheses. However, 20-mm TAVs in 19-mm Perimount (54.9±5.4 to 23.5±3.9 mm Hg, p=0.006) and 21-mm porcine bioprostheses (35.2±8.9 to 16.8±4.1 mm Hg, p=0.03) significantly reduced mean gradients. No significant reduction in pressure gradient occurred after VIV in 19-mm degenerated porcine bioprostheses. Mild regurgitation was observed after VIV. VIV with standard and 60-degree TAV orientation did not significantly alter hemodynamics or coronary flows. CONCLUSIONS: Valve-in-valve hemodynamics with 20-mm TAV improved for 19-mm Perimount and 21-mm porcine but not 19-mm porcine bioprostheses. No significant differences in hemodynamics were noted by orientation with TAV and bioprosthesis commissural alignment or 60-degree rotation.