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.

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.

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.

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.

Long-term follow-up of neck expansion after endovascular aortic aneurysm repair.

OBJECTIVE: This study determined the rate, extent, and clinical significance of neck dilatation after endovascular aneurysm repair (EVAR). METHODS: The study included 46 patients who underwent elective EVAR using bifurcated Zenith stent grafts (Cook, Bloomington, Ind) and had at least 48 months of clinical and radiographic follow-up. Computed tomography images were analyzed on a 3-dimensional workstation (TeraRecon, San Mateo, Calif). Neck diameter was measured 10 mm below the most inferior renal artery in planes orthogonal to the aorta. Nominal stent graft diameter was obtained from implantation records. RESULTS: Median follow-up was 59 months (range, 48-120 months). Neck dilation occurred in all 46 patients. The rate of neck dilation was greatest at early follow-up intervals. At 48 months, median neck dilation was 5.3 mm (range, 2.3-9.8 mm). The extent of neck dilation at 48 months correlated with percentage of stent graft oversizing (Spearman rho = 0.61, P < .001). No type I endoleak or migration >5 mm occurred. CONCLUSIONS: After EVAR with the Zenith stent graft, the neck dilates until its diameter approximates the diameter of the stent graft. Neck dilation was not associated with type I endoleak or migration of the stent graft.

Variation in the shape and length of the branches of a thoracoabdominal aortic stent graft: implications for the role of standard off-the-shelf components.

PURPOSE: To describe variations in the shape, orientation, and length of the branches of multi-branched thoracoabdominal stent grafts. METHOD: The branches were constructed in situ by attaching a covered stent (Fluency Plus Tracheobronchial Stent Graft; Bard Peripheral Vascular, Tempe, Ariz) to each of four caudally-oriented cuffs on custom-made stent grafts. Pre- and postoperative computed tomography (CT) scans of 38 consecutively treated patients were analyzed using a three-dimensional work station to give the orientation of celiac, superior mesenteric, and right renal and left renal orifices relative to the centerline of the aorta (planned cuff orientation [PCO]) and relative to the centerline of the stent graft (actual vessel orientation [AVO]). The orientation of each cuff (actual cuff orientation [ACO]) was also measured relative to the centerline of the stent graft. These values were used to assess the degree of stent graft malorientation (ACO-PCO), or cuff-to-artery misalignment (ACO-AVO), and combined with measurements of branch length to calculate the resulting lateral displacement (arc distance [AD]) between each cuff and its corresponding arterial orifice and the angle (longitudinal branch angulation [LBA]) between the long axis of the branch and the long axis of the aorta, all in the plane of the aortic surface. RESULTS: All 136 branches were inserted as intended. None has since migrated, disconnected, or kinked. In most cases, stent graft orientation was accurate, with a mean ACO-PCO of 18.4 + 12.1 degrees. Cuff-to-artery misalignment was correspondingly low, with a mean ACO-AVO of 19.8 + 14.0 degrees. More than 30 degrees of misalignment was present in 23.2% of branches, yet only 9% (n = 12) had an LBA of >30 degrees. CONCLUSION: Moderate degrees of cuff-to-artery misalignment had no effect on the feasibility of multi-branched stent graft insertion.

Reversal of fortune: induced endoleak to resolve neurological deficit after endovascular repair of thoracoabdominal aortic aneurysm.

PURPOSE: To describe a direct anatomical treatment approach using an induced type Ib endoleak to increase spinal cord perfusion and reverse paraplegia occurring after endovascular exclusion of a type 2 thoracoabdominal aortic aneurysm (TAAA). TECHNIQUE: The approach is illustrated in an 82-year-old woman who underwent branched endovascular repair of an asymptomatic, 6.8-cm-diameter type 2 TAAA. In 4-hour procedure, 3 aortic components were implanted beginning 50 mm distal to the origin of the left subclavian artery and ending 33 mm proximal to the aortic bifurcation. Upon awakening, the patient had sluggish movement in her legs. She responded to vasoactive agents and cerebrospinal fluid (CSF) drainage, but 3 recurrent episodes of paraplegia within 24 hours and severe headache indicated that the limits of CSF drainage had been reached. The patient was taken back to the operating room, and a type Ib (distal) endoleak was created by placing a balloon-expandable stent between the distal end of the infrarenal stent-graft component and the aortic wall, partially re-establishing flow into the aneurysm. The patient had no further recurrence of lower extremity paraplegia or paraparesis. At 3.5 months postoperatively, a Palmaz stent was deployed inside the distal end of the infrarenal stent-graft component to crush and occlude the Express LD stent, re-establishing a complete seal to preclude flow into the aneurysm. The patient remains clinically stable without lower extremity neurological deficit 3 months after the last procedure and 7 months after endovascular TAAA repair. CONCLUSION: A direct anatomical approach to reverse spinal cord ischemia following endovascular TAA or TAAA repair is feasible by creating a type I or type III endoleak to afford partial, temporary reperfusion of the excluded aorta.

Outcome of renal stenting for renal artery coverage during endovascular aortic aneurysm repair.

OBJECTIVE: This study was conducted to determine the outcome of adjunctive renal artery stenting for renal artery coverage at the time of endovascular abdominal aortic aneurysm repair (EVAR). METHODS: Between August 2000 and August 2008, 29 patients underwent elective EVAR using bifurcated Zenith stent grafts (Cook, Indianapolis, Ind) and simultaneous renal artery stenting. Renal artery stenting during EVAR was performed with endograft "encroachment" on the renal artery ostium (n = 23) or placement of a renal stent parallel to the main body of the endograft ("snorkel," n = 8). Follow-up included routine contrast-enhanced computed tomography (CT), multiview abdominal radiographs, and serum creatinine measurement at 1, 6, and 12 months, and then yearly thereafter. RESULTS: Thirty-one renal arteries were stented successfully in 29 patients. The 18 patients with planned renal artery stent placement had a proximal neck length <15 mm. Mean proximal neck length was shorter in patients who underwent the "snorkel" technique (6.9 +/- 3.1 mm) compared with those with planned endograft encroachment (9.9 +/- 2.6 mm). None of the patients with unplanned endograft encroachment had neck lengths <15 mm (mean length, 26.3 +/- 10.2 mm). Mean proximal neck angulation was 42.8 degrees +/- 24.0 degrees and did not differ between the groups. One patient had a type I endoleak on completion angiography, and two additional patients had a type I endoleak on the first postoperative CT scan. All type I endoleaks resolved by the 1-month postoperative CT scan. The primary assisted patency of renal artery stents was 100% at a median follow-up of 12.5 months (range, 2 days-77.4 months). In one patient near occlusion of a renal artery stent was noted on follow-up CT scan at 9 months; patency was restored by placement of an additional stent. One patient required dialysis after sustained hypotension from a right external iliac artery injury that resulted in prolonged postoperative bleeding. Mean serum creatinine was 1.1 +/- 0.3 mg/dL at baseline, 1.2 +/- 0.5 mg/dL at 1 month of follow-up, and 1.2 +/- 0.5 mg/dL at 2 years of follow-up. There were no late type I endoleaks (>1 month postoperatively) or stent graft migrations. CONCLUSIONS: Adjunctive renal artery stenting during endovascular AAA repair using the "encroachment" and "snorkel" techniques is safe and effective. Short- and medium-term primary patency rates are excellent, but careful follow-up is needed to determine the durability of these techniques.

Systemic inflammation, coagulopathy, and acute renal insufficiency following endovascular thoracoabdominal aortic aneurysm repair.

OBJECTIVE: To characterize the inflammatory and coagulopathic response after endovascular thoracoabdominal aortic aneurysm (TAAA) repair and to evaluate the effect of the response on postoperative renal function. METHODS: From July 2005 to June 2008, 42 patients underwent elective endovascular repair of a TAAA using custom designed multi-branched stent-grafts at a single academic institution. Four patients were excluded from the analysis. White blood cell count (WBC), platelet count, prothrombin time (PT), and creatinine were measured in all patients. In the last nine patients, interleukin-6 (IL-6), protein C, Factor V, d-dimers, cystatin C, and neutrophil gelatinase-associated lipocalin (NGAL) levels were also measured. Change in lab values were expressed as a percentage of baseline values. RESULTS: The 30-day mortality rate was 5% (2/38). All patients (n = 38) had a higher WBC (mean +/- SD: 139 +/- 80%, P < .0001), lower platelet count (56 +/- 15%, P < .0001), and higher PT (median: 17%, Interquartile range (IQR) 12%-22%, P < .0001) after stent-graft insertion. Twelve of 38 patients (32%) developed postoperative acute renal insufficiency (>50% rise in creatinine). Patients with renal insufficiency had significantly larger changes in WBC (178 +/- 100% vs 121 +/- 64%, P = .04) and platelet count (64 +/- 17% vs 52 +/- 12%, P = .02) compared with those without renal insufficiency. All patients (n = 9) had significant increases in NGAL (182 +/- 115%, P = .008) after stent-graft insertion. Six of nine patients (67%) had increased cystatin C (35 +/- 43%, P = .04) after stent-graft insertion, with a greater rise in those with postoperative renal insufficiency (87 +/- 32% vs 8 +/- 13%, P = .02). IL-6 levels were markedly increased in all patients (n = 9) after repair (9840 +/- 6160%, P = .008). Protein C (35 +/- 10%, P = .008) and Factor V levels (28 +/- 20%, P = .008) were uniformly decreased, while d-dimers were elevated after repair in all patients (310 +/- 213%, P = .008). CONCLUSIONS: Leukocytosis and thrombocytopenia were uniform following endovascular TAAA repair, and the severity of the response correlated with post-operative renal dysfunction. Elevation of a sensitive marker of renal injury (NGAL) suggests that renal injury may occur in all patients after stent-graft insertion.

A standardized multi-branched thoracoabdominal stent-graft for endovascular aneurysm repair.

PURPOSE: To assess the feasibility of endovascular thoracoabdominal aortic aneurysm (TAAA) repair using a standard off-the-shelf multi-branched stent-graft. METHODS: The aortic anatomy of 66 patients (45 men; mean age 74 years, range 57-87) referred for endovascular repair of TAAA was measured using 3-dimensional reconstructed images from computed tomographic angiograms. In particular, the orientation and longitudinal position of the orifice of each celiac artery, right renal artery, and left renal artery were measured relative to the location of the superior mesenteric artery (SMA) orifice. Based on prior experience, branch insertion with a standard endograft was considered feasible under the following conditions: (1) no more than 4 indispensable (target) arteries to the abdominal viscera, (2) the celiac artery and SMA were 6 to 10 mm in diameter, (3) the renal arteries were 4 to 8 mm in diameter, (4) all target arteries were accessible from a transbrachial approach, (5) the distance between each cuff and the corresponding arterial orifice was 4 indispensable visceral or renal branches, and 3 patients had inaccessible upward directed renal artery branches. Three of the remaining 59 patients had renal arteries outside the boundaries defined by conditions 5 and 6 when the hypothetical stent-graft was positioned with its SMA cuff 25 mm proximal to the corresponding SMA orifice. However, if the stent-graft were deployed in a more caudal location, only 1 of these 3 renal arteries would have been out of range. Therefore, 58 (88%) of 66 patients met all the eligibility criteria for repair using the off-the-shelf stent-graft. CONCLUSION: A standardized, off-the-shelf, multi-branched stent-graft is applicable in 88% of cases of TAAA that would otherwise have been treated using customized stent-grafts. The use of a pre-made stent-graft has the potential to eliminate long manufacturing delays and expand the scope of endovascular repair of TAAA.

Aortic valve-in-valve implantation: impact of transcatheter- bioprosthesis size mismatch.

BACKGROUND AND AIM OF THE STUDY: Transcatheter aortic valves (TAVs) provide minimally invasive treatment for high-risk patients with severe native aortic stenosis. While the off-label application of TAV for degenerative bioprosthetic stenosis (valve-in-valve therapy) is attractive, few cases have been reported. If the rigid annulus and stent posts of bioprostheses prevent full expansion of the TAV, the hemodynamic performance may be compromised. The study aim was to evaluate the use of a 23 mm TAV within normal bioprostheses of equivalent or smaller orifice sizes. METHODS: Twelve TAVs designed to mimic the 23 mm Edwards SAPIEN valve were created using stainless steel stents and trileaflet pericardial valves. A custom-built pulse duplicator was used to measure the hemodynamic performance of the TAV within 19, 21 and 23 mm Edwards pericardial bioprostlieses. The transvalvular gradient, effective orifice area (EOA) and regurgitant volume were used to evaluate valve-in-valve therapy for each valve size. RESULTS: The TAV demonstrated similar hemodynamics to the Edwards SAPIEN valve (mean pressure gradient 6.68 +/- 2.11 mmHg and EOA 2.07 +/- 0.35 cm2). Acceptable valve-in-valve hemodynamics were achieved only in the 23 mm bioprosthesis after TAV implantation, with no significant change in mean pressure gradient (5.93 +/- 0.87 to 8.27 +/- 1.19 mmHg, p = 0.052) and EOA (2.13 +/- 0.15 to 1.79 +/- 0.15 cm2, p = 0.053). In 19 and 21 mm valves, the excess pericardial tissue relative to the stent EOA resulted in severe and moderate stenosis, respectively. The mean pressure gradient increased from 16.18 +/- 2.20 mmHg to 45.53 +/- 12.54 mmHg (p = 0.004) in 19 mm bioprostheses, and from 11.84 +/- 1.88 mmHg to 28.18 +/- 9.03 mmHg (p = 0.004) in 21 mm bioprostheses. Furthermore, the EOA was reduced from 1.28 +/- 0.1 to 0.78 +/- 0.11 cm2 (p < 0.001) in 19 mm valves, and from 1.51 +/- 0.15 to 1.01 +/- 0.19 cm2 (p < 0.001) in 21 mm bioprostheses. The TAV resulted in an increased regurgitant volume for all valve sizes. CONCLUSION: Oversized TAVs are constrained by rigid bioprostheses, creating hemodynamic complications. Patients with 19 and 21 mm Edwards pericardial bioprostheses may be poor candidates for valve-in-valve therapy with the currently available technology.