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It was reported in the article "variability in aneurysm sac regression after endovascular aneurysm repair based on a comprehensive registry of patients in eastern ontario" (2019) by jetty et al published in the journal of vascular surgery, that seven patients experienced post operative complications and required intervention following an unknown zenith flex (tffb) device placement."methods: study design and setting.The ottawa hospital is a tertiary care university teaching hospital and is the only institution providing vascular surgical care in its local health region, with a catchment of 1.3 million.A database of all evars performed since its introduction at our institution in 1999, was created by the surgical team and has been prospectively maintained since 2013.Fields in the database are populated, by trained vascular research personnel, using the electronic hospital records, imaging database office paper charts, and billing records.The design of this observational study based on routinely collected data was retrospective in the sense that data were analyzed after they were captured.Some data, however, were captured prospectively after protocol development." "participants.All patients with intact or ruptured and fusiform or saccular infrarenal aaas undergoing their first endovascular repair from january 1999 to may 2015 were identified through a simple query of the registry.Patients undergoing endovascular repair for isolated iliac, thoracic, or traumatic aneurysms were excluded.Branched and fenestrated endograft repairs as well as hybrid repairs were also excluded.Patients universally underwent preoperative computed tomography (ct) imaging.Evar procedures were exclusively performed in an operating room suite by a team composed of vascular surgeons and interventional radiologists.Our standard protocol for follow-up is both enhanced ct imaging and duplex ultrasound examination in our own blood flow laboratory by dedicated vascular technologists at intervals of 1, 6, 12, 18, and 24 months, and then yearly.Toward the end of the study period the frequency of the ct imaging was decreased beyond 12 months after evar as we became more comfortable with monitoring nonexpanding aneurysm sacs with ultrasound examination alone." "variables and measurement.The variables in this study include clinical characteristics (age, sex, aaa diameter, preoperative rupture status), procedure date, surgeon, and make/configuration of endograft device.The outcomes measured include mean sac size at selected time intervals (preoperative; 6, 12, and 18; and 2, 5, 10, and >10 years), time to sac regression of greater than 5 mm, and time to sac expansion of greater than 5 mm.We also measured 30-day mortality and the reintervention rate.Preoperative aaa diameter, postoperative sac size, and endoleak determination were in accordance with society for vascular surgery reporting standards for evar.Both major and minor axes were measured from adventitia to adventitia on ct imaging viewed on digital workstations by radiologists.Similar measurements were obtained on transverse duplex scans perpendicular to the centerline of the aneurysm, by registered sonographers in our intersocietal accreditation commission vascular laboratory.Only the minor axis measurement was used to determine changes in sac size diameter.The presence of an endoleak was determined using early and delayed phase contrast ct imaging, and duplex ultrasound examination.Contrast enhanced duplex imaging was used when the source of the leak was indeterminate or in the presence of an expanding sac with no evidence of endoleak by conventional methods." "bias and study size.Given the exploratory, observational nature of this study, the number of patients enrolled in this study was determined by availability in the registry, rather than a predefined calculation of sample size.We attempted to minimize bias from misclassification and measurement error by relying on standard protocols and data entry procedures as described.Performance bias was minimized through blinded observers recording sac diameters and endoleaks to the specific endograft device.Any other potential sources of bias, such as confounding by selection (eg, the use of device by anatomy), or bias from preferential follow-up of patients with complications, is addressed in the discussion section." "statistical methods.Aaa diameters and post-evar sac sizes are presented as a continuous variable (mean and 95% confidence intervals).Sac regression or expansion was calculated using two methods.In method 1, absolute change (preoperative aaa diameter [a] minus current sac diameter [b]] was calculated and in method 2, the relative change (preoperative sac diameter [a] minus the current sac diameter [b] divided by [preoperative sac (a) minus stent diameter (c)]) was calculated.The relative change measurement takes into account the total potential for maximum sac regression up to the point of the stent diameter.For all subsequent univariate and multivariate analyses, sac regression was calculated using absolute change (method 1).Sac regression was determined at the following intervals: 0 to 6 months, 6 to 12 months, 12 to 18 months, 18 moths to 2 years, 2 to 5 years, 5 to 10 years, and more than 10 years.Sac regression as a function of date of procedure (divided into 3-year intervals) was also analyzed.Time to a greater than 5-mm sac regression and a greater than 5-mm sac expansion was determined using kaplan-meier analysis and sidak multiple comparison adjustment.Hazard ratios (hrs) were calculated using multivariable analysis with cox proportional hazards modelling.Means and absolute changes were used for these calculations.Devices with fewer than 10 procedures performed were omitted from all statistical comparisons.Differences in mean sac size among endograft devices were analyzed through a one-way analysis of variance (anova) using a fixed-effect model with adjustments for multiple pairwise comparisons using tukey¿s method.All analyses were performed using statistical software." "this study is reported using the reporting of studies conducted using observational routinely collected data (record) extension to the strengthening the reporting of observational studies in epidemiology (strobe) statement.This study was approved by the ottawa health science network research ethics board (approval # 20150832-01h)." "results: participants and descriptive data.From 1999 to 2015, a total of 3027 patients underwent an index aaa procedure at the ottawa hospital, of which 1967 were open repairs and 1060 were evars.Of these, 97 were performed for confirmed ruptured aaas.Procedures were performed by seven different surgeons.Five endograft devices (cook zenith, n = 398; competitor one, n = 375; competitor two, n = 183; cook zenith lp, n = 52; and competitor three, n = 23) were used in 97% of the procedures (1031/1060).The remaining stent graft devices used were the competitor four (n = 5), competitor five (n =5), competitor six (n = 3), competitor seven (n = 6), and combinations of these (n = 10).The mean preoperative aaa diameter was 61.2 mm (60.3-61.8).There were no detectable differences between endograft devices with respect to age, preoperative aaa diameter, or rupture diagnosis.There was a greater proportion of females treated with the zenith lp device (p =.04) compared with the other devices.Clinical characteristics are shown in table i.Intraoperative data.Intraoperative details are summarized in table ii.Anova testing did not reveal differences between endograft devices with respect to mean endograft diameter or individual surgeons¿ preference for a particular endograft device (data not shown).There were, however, significant differences when considering other intraoperative device characteristics including use of aortouniiliac configuration (p <.0001), number of components (p <.0001), proximal extensions (p =.049), and large bare metal stents (p =.02).There was no detectable difference in persistent intraoperative type i endoleaks between any of the endograft devices." "outcome data.Approximately one-half of the patient population (n =521) had a minimum of 5 years of follow-up imaging, being censored by the end of the study date, death, or loss to follow-up.Absolute mean sac regression increased from - 1.3 mm (95% ci, -1.5 to -1.1) at 6 months, -9.0mm (95% ci, -7.97 to -10.3) at 2 years, and to -14.9 mm (95% ci, 21.1-8.7) beyond 10 years, with most of sac regression occurring within the first 2 years (fig 1).When calculating the percent of the total potential sac regression (method 2), the majority of expected total sac regression was achieved by 2 years, in that an average of 26.6% (95% ci, 23.7-29.5) of the sac regressed at 2 years, and only increasing to 29.8% (95% ci, 26.8-33.2) and 30.0% (95% ci, 21.6-38.0) at 5 and 10 years, respectively.Anova testing demonstrated greater sac regression in evars performed with four or more components vs three or fewer (-12.1mmvs -8.2mmat 2 years; p =.013), as well as evars performed by surgeons with formal endovascular training fellowships (-11.0 mm vs -4.4 mm at 10 years; p =.048).With respect to era of implantation, sac regression consistently improved with time, with the greatest sac regression seen in endograft devices implanted from 2009 to 2011 (vs 2003-2005) at 2 years (p =.018), and a reversal of the trend toward inferior sac regression for endografts implanted afterward, from 2012 to 2015 (p = ns)." "kaplan-meier analysis revealed that approximately 80% of patients in our cohort achieved sac regression of greater than 5 mm by 4 years (fig 2).Zenith, zenith lp, and competitor one and competitor two endografts demonstrated the shortest time to a greater than 5-mm sac regression among devices used in more than 10 patients.Significant p values after sidak adjustment for multiple comparisons using the log-rank test are listed (fig 3), with no detectable difference between the zenith and competitor two endografts.Only 90 of the 1060 patients (8.5%) experienced sac expansion of greater than 5 mm at some point during their follow-up period, with no statistically significant endograft-specific differences in type i or type ii endoleak rates.We further explored endograft-specific sac regression in the setting of no type i endoleak.The zenith endograft demonstrated statistically significant increased sac regression at all intervals with significant p values for anova testing (fig 4).Moreover, using kaplan-meier analysis, a statistically significant difference was identified between devices, when comparing freedom from sac expansion of more than 5 mm (zenith vs competitor two; p =.017)." "sac regression with subsequent delayed sac expansion.Early sac regression was associated with decreased probability for subsequent delayed sac expansion.Of the patients who experienced sac regression of greater than 5 mm within 1 and 2 years, only 2.9% and 2.6% experienced subsequent sac expansion of greater than 5 mm, respectively.In contrast, of the patients who did not experience sac regression within 1 and 2 years, 10.1% and 10.7% experienced subsequent sac expansion, respectively (p <.0001)." "multivariate analysis.Cox proportional hazard modeling was performed using time to a greater than 5-mm sac regression as the dependent outcome variable, while controlling for age, sex, preoperative aaa diameter, surgeon, presence of type i endoleak, and make of endograft device (using competitor two as the reference).Statistically significant predictors of sac regression included age less than 75 years (hr, 1.4; p =.001), female sex (hr, 1.4; p =.003), aaa diameter of greater than 70 mm (hr, 1.6; p <.0001), absence of type i endoleak (hr, 4.6; p <.0001), and both the zenith (hr, 2.0; p <.0001) and competitor one (hr, 1.6; p =.001) devices.Similar cox proportional hazard modelling was performed using time to a greater than 5-mm sac expansion as the dependent outcome variable.Statistically significant positive predictors of sac expansion also included female sex (hr, 1.8; p =.027), and the presence of a type i endoleak (hr, 9.1; p <.0001), with the zenith endograft (hr, 0.35; p ¼=.0002) as a significant negative predictor." "mortality and reinterventions.Overall 30-day mortality occurred in 0.8% of elective evars (n ¼ 21/963) vs 13.4% in emergent evars (n ¼ 13/97; ie, for ruptured aaas).Reinterventions are summarized in table iii.Overall, endograft-specific differences were not observed for minor reinterventions (embolizations, proximal/distal extensions, aortouniiliac conversions, large metal stent insertions, bypasses, or groin complications).A total of 29 patients (2.7%) experienced a major endograft reintervention or complication, which included open surgical conversions (explantation or with graft preservation) for expanding sac, graft infection, or late rupture.A statistically significant difference was seen for this variable when comparing endograft devices performed in more than 10 patients (two competitor three [8.7%] and nine competitor two [4.9%] endografts required open surgical conversion or late aneurysm rupture; p =.034)." "discussion: this observational cohort study is the first to report post-evar sac regression as a time-dependent variable at multiple intervals over a 15-year study period.This study demonstrated that the majority of patients (approximately 80%) achieved sac regression of more than 5 mm within 4 years and majority of absolute sac regression within the first 2 years.A large observational study conducted in japan reported similar results of early sac regression with 1- and 5-year cumulative sac regression (>5 mm) in 50% and 62% of patients respectively.Anatomic variables (such as aortic neck diameter and angulation) outside of the ifu guidelines have been implicated as predictors of evar failure, often using reintervention, endoleak, conversion, aneurysm-related mortality, and sac expansion rates as markers.Although necessarily mean successful evar or obviate the chance of sac rupture." "our study specifically looked at sac behavior as the main outcome measure.This factor is being increasingly recognized as a potentially better indicator of success after evar, although successful exclusion of the sac may not necessarily result in sac regression, because there may be other influencing factors beyond the presence or absence of an endoleak.Undeniably, the presence of a type i endoleak was most profoundly associated with sac expansion, as demonstrated in our multivariable regression model.However, the association between the absence of type i endoleak and sac regression was significant but less profound.Our study identified female sex, younger patients, and patients with larger aneurysms as having higher rates of sac regression.These findings are similar to those in a recent report published by the vascular study group of new england looking at a registry of patients from 2003 to 2011 to identify evar patients with 1-year ct scan follow-up.Paradoxically, we also identified female sex as a risk factor for sac expansion.We postulate that females may have aneurysm sacs that are more susceptible to hemodynamic and biological processes that influence post implantation sac behavior.Other studies have implicated thrombus burden, statin therapy, and even platelet count as influencing sac regression." "most notably, however, we identified a statistically significant variability in sac regression between various endograft devices, even after controlling for multiple variables including presence or absence of endoleak, similar to results from a recent smaller cohort study from japan.32 the goal of this particular study was not necessarily to identify a superior endograft device, but rather to identify that there may be factors related to different endograft designs that influence sac behavior after implantation.The role of different graft materials and stent graft designs have been previously studied with respect to variation in sac regression patterns.Graft material porosity has been previously linked to type v endoleaks and sac expansion for early iterations of the competitor four device, which has since undergone a redesign and subsequent resolution of this problem.We postulate that there still exists unexplained differences in post implantation sac behavior as a result of variances in material and stent designs amongst modern endograft devices.Differences in material porosity and thickness may lead to ultrafiltration of plasma, altered cellular ingrowth, or even microtears with subsequent bleeding.In addition, disparities in postimplant inflammatory response between various endograft devices may affect biological wall activity, wall stiffness, and subsequent sac regression.Finally, our study identified that early sac regression of greater than 5 mm within 1 to 2 years after implantation was associated with a significantly lower probability for delayed sac expansion.Although small, this proportion of patients with delayed sac expansion (<3%) is the incentive for pursuing indefinite surveillance in the form of yearly ultrasound examinations at our center.Intervals and modalities for imaging should likely be individualized to patients and centers¿ experience, especially in the setting of continued evolution in device technology and tolerance to treat anatomies outside of ifu.Also, we observed a considerably lower proportion (8.5%) of patients experiencing sac expansion (>5 mm) at 5 years compared with most other reports in the literature.A plausible explanation may lie in our vascular center¿s traditionally conservative approach to evar with an estimated overall ifu compliance rate of 79% and an average of 35% evar rate during the study period.The rate of evar use has since increased to 60% based on our own unpublished audit data.Interestingly, we observed that sac regression steadily improved during the study period, but decreased after 2011, possibly as a result of liberalization of evar outside of the ifu." "the strength of this study is that it is based on a single, comprehensive registry of patients from a single group practice, coupled with a strong regional follow-up program.In addition, it used a prespecified protocol and analysis plan before finalizing data collection, along with standard protocols for measurement of sac behavior and preoperative aortic diameter.The vast majority of these used duplex measurement, which is recognized as an accurate and consistent means of measurement.Using multivariable analysis coupled with survival analysis also allowed us to control for important factors that may influence outcomes and recognize the time dependency of sac behavior." "there are some important limitations to our study that warrant mention, however.First, we were unable to account for some potentially important covariates in our multivariable analysis.We were able to control for surgeon; however, we could not control for surgeons¿ preferences for using particular devices in particular anatomic situations and thus increasing the risk of bias.In addition, although the effect of placing endografts outside of the ifu has been implicated in sac expansion, it is unclear if this practice is associated with sac regression.Regardless, we attempted to overcome this potentially important bias by controlling for the presence of type ia and ib endoleaks, which we felt to be one important predictor for outside ifu stent grafting.A second potential weakness of our study is the much lower numbers associated with the use of some devices, as well as choice of device being dependent on when the procedure was undertaken (ie, device availability).This factor could lead to a much higher likelihood of type ii error, especially when using adjustments for multiple comparisons.In addition, some devices are no longer available commercially.Although we did address this factor by eliminating comparisons based on small numbers, we feel in general that there were significant contemporary data available for three widely used devices (zenith, competitor one, and zenith lp) to draw robust conclusions." "conclusions: this study demonstrated a pattern of sac diameter change after evar, with the majority of sac regression occurring within the first 2 years.Variability in sac regression was influenced by nonanatomic variables including age, sex, original aaa diameter, and specific endograft device, even after controlling for the presence or absence of endoleak.We hope that our study findings contribute to a burgeoning literature on post-evar implantation sac behavior patterns and determination of optimal surveillance imaging intervals.The biophysical relationship between specific endograft design and materials, and sac regression is yet to be determined, but continued exploration in this area will hopefully contribute in the evolution of stent graft technology." this report captures seven patients that experienced post operative complications and required intervention following an unknown zenith flex (tffb) device placement.The major endograft reintervention or complication includes open surgical conversions (explantation or with graft preservation) for expanding sac, migration, graft infection, or late rupture.This information can be found in the journal article on page 1476, table iii, postoperative reinterventions, and in the footnotes of the table.Additional events from this article are referenced in reports with patient identifiers: (b)(6).Literature citation: jetty, p., husereau, d., kansal, v., zhang, t., & nagpal, s.(2019).Variability in aneurysm sac regression after endovascular aneurysm repair based on a comprehensive registry of patients in eastern ontario.Journal of vascular surgery, 70(5), 1469¿1478.Https://doi.Org/10.1016/j.Jvs.2019.01.091.
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Correction: annex a investigation ¿ evaluation on 02oct2023 cook became aware of a journal article, ¿variability in aneurysm sac regression after endovascular aneurysm repair based on a comprehensive registry of patients in eastern ontario¿ written by prasad jetty, md.As reported in the literature the purpose of the journal article was to determine the rate of overall long-term sac regression after evar and the influence of nonanatomic factors, and endograft devices used at their center (the ottawa hospital).This complaint focused on the seven patients that experienced major post operative complications and required reintervention after a zenith flex aaa endovascular graft bifurcated main body (unknown tffb) was placed in the index procedure.The major endograft reintervention or complication includes open surgical conversions (explantation or with graft preservation) for expanding sac, migration, graft infection, or late rupture.This information can be found in table iii of the literature.Reviews of documentation including the complaint history, drawing, quality control procedures, specifications, manufacturing instructions (mi), and instructions for use (ifu) of the complaint device were conducted during the investigation.The complaint device was not returned; therefore, no physical examinations could be performed.Also, no imaging was provided.However, a document-based investigation evaluation was performed.A review of the device master record (dmr) concluded sufficient inspection activities are in place to identify this failure mode prior to distribution.The customer did not provide the lot number for the complaint device.Cook reviewed the sales history for this customer and was unable to identify the complaint lot.The device history record could not be reviewed.Based on this information, the device was manufactured to specification.There is no evidence of nonconforming material in house or in the field.Cook also reviewed product labeling.The product ifu, t_zaaaf36_rev 6 ¿zenith flex aaa graft with the h&l one-shot introduction system,¿ provides the following information to the user related to the reported failure mode: "4 warnings and precautions 4.1 general ¿ additional endovascular interventions or conversion to standard open surgical repair following initial endovascular repair should be considered for patients experiencing an enlarging aneurysm, unacceptable decrease in fixation length (vessel and component overlap) and/or endoleak.An increase in aneurysm size and/or persistent endoleak or migration may lead to aneurysm rupture.¿ patients experiencing reduced blood flow through the graft limb and/or leaks may be required to undergo secondary interventions or surgical procedures.4.2 patient selection, treatment and follow-up ¿ the zenith flex aaa endovascular graft is designed to treat aortic neck diameters no smaller than 18 mm and no larger than 32 mm.The zenith flex aaa endovascular graft is designed to treat proximal aortic necks (distal to the lowest renal artery) of at least 15 mm in length.Iliac artery distal fixation site greater than 10 mm in length and 7.5 - 20 mm in diameter (measured outer wall to outer wall) is required.These sizing measurements are critical to the performance of the endovascular repair.¿ key anatomical elements that may affect successful exclusion of the aneurysm include severe proximal neck angulation (>60 degrees for infrarenal neck to axis of aaa or >45 degrees for suprarenal neck relative to the immediate infrarenal neck); short proximal aortic neck (<15 mm); an inverted funnel shape (greater than 10% increase in diameter over 15 mm of proximal aortic neck length); and circumferential thrombus and/or calcification at the arterial implantation sites, specifically the proximal aortic neck and distal iliac artery interface.In the presence of anatomical limitations, a longer neck may be required to obtain adequate sealing and fixation.Irregular calcification and/or plaque may compromise the attachment and sealing at the fixation sites.Necks exhibiting these key anatomical elements may be more conducive to graft migration or endoleak.¿ adequate iliac or femoral access is required to introduce the device into the vasculature.Access vessel diameter (measured inner wall to inner wall) and morphology (minimal tortuosity, occlusive disease and/or calcification) should be compatible with vascular access techniques and delivery systems of a 16 french to 22 french vascular introducer sheath.Vessels that are significantly calcified, occlusive, tortuous, or thrombus-lined may preclude placement of the endovascular graft and/or may increase the risk of embolization.A vascular conduit technique may be necessary to achieve success in some patients.¿ the zenith flex aaa endovascular graft with the h&l one-shot introduction system is not recommended in patients who cannot tolerate contrast agents necessary for intraoperative and postoperative follow-up imaging.All patients should be monitored closely and checked periodically for a change in the condition of their disease and the integrity of the endoprosthesis.¿ multiple large, patent lumbar arteries, mural thrombus and a patent inferior mesenteric artery may all predispose a patient to type ii endoleaks.Patients with uncorrectable coagulopathy may also have an increased risk of type ii endoleak or bleeding complications.Diameters utilizing ct, diameter measurements should be determined from the outer wall to outer wall vessel diameter (not lumen measurement) to help with proper device sizing and device selection.The contrast-enhanced spiral ct scan must start 1 cm superior to the celiac axis and continue through the femoral heads at an axial thickness slice of 3 mm or less.Lengths ¿ the long-term performance of endovascular grafts has not yet been established.All patients should be advised that endovascular treatment requires life-long, regular follow-up to assess their health and the performance of their endovascular graft.Patients with specific clinical findings (e.G., endoleaks, enlarging aneurysm or changes in the structure or position of the endovascular graft) should receive enhanced follow-up.Specific follow-up guidelines are described in section 12, imaging guidelines and postoperative follow-up.¿ after endovascular graft placement, patients should be regularly monitored for perigraft flow, aneurysm growth or changes in the structure or position of the endovascular graft.At a minimum, annual imaging is required, including: 1) abdominal radiographs to examine device integrity (separation between components, stent fracture or barb separation) and 2) contrast and non-contrast ct to examine aneurysm changes, perigraft flow, patency, tortuosity and progressive disease.If renal complications or other factors preclude the use of image contrast media, abdominal radiographs and duplex ultrasound may provide similar information.4.4 device selection ¿ strict adherence to the zenith flex aaa endovascular graft ifu sizing guide is strongly recommended when selecting the appropriate device size (tables 10.5.1 through 10.5.2).Appropriate device oversizing has been incorporated into the ifu sizing guide.Sizing outside of this range can result in endoleak, fracture, migration, device infolding or compression 4.5 implant procedure ¿ appropriate procedural imaging is required to successfully position the zenith flex aaa endovascular graft and assure accurate apposition to the aortic wall.¿ inaccurate placement and/or incomplete sealing of the zenith flex aaa endovascular graft within the vessel may result in increased risk of endoleak, migration or inadvertent occlusion of the renal or internal iliac arteries.Renal artery patency must be maintained to prevent/reduce the risk of renal failure and subsequent complications.5.2 potential adverse events adverse events that may occur and/or require intervention include, but are not limited to: ¿ aneurysm enlargement ¿ aneurysm rupture and death ¿ endoleak ¿ endoprosthesis: improper component placement; incomplete component deployment; component migration; suture break; occlusion; infection; stent fracture; graft material wear; dilatation; erosion; puncture; perigraft flow; barb separation and corrosion 8 patient counseling information ¿ physicians must advise each patient that it is important to seek prompt medical attentions if he/she experiences signs of limb occlusion, aneurysm enlargement or rupture.Signs of graft limb occlusion include pain in the hip(s) or leg(s) during walking or at rest or discoloration or coolness of the leg.Aneurysm rupture may be asymptomatic, but usually presents as: pain; numbness; weakness in the legs; any back, chest, abdominal or groin pain; dizziness; fainting; rapid heartbeat or sudden weakness.Physicians should refer patients to the patient guide regarding risks occurring during or after implantation of the device.Procedure-related risks include cardiac, pulmonary, neurologic, bowel and bleeding complications.Device related risks include occlusion, endoleak, aneurysm enlargement, fracture, potential for reintervention and open surgical conversion, rupture, and death 10.5 device sizing guidelines the choice of diameter should be determined from the outer wall to outer wall vessel diameter and not the lumen diameter.Undersizing or oversizing may result in incomplete sealing or compromised flow.11 directions for use anatomical requirements ¿ proximal aortic neck lengths should be a minimum of 15 mm with a diameter measured outer wall to outer wall of 18 ¿ 32 mm.Final angiogram 1.Position angiographic catheter just above the level of the renal arteries.Perform angiography to verify that the renal arteries are patent and that there are no endoleaks.Verify patency of internal iliac arteries.2.Confirm there are no endoleaks or kinks and verify position of proximal gold radiopaque markers.Remove the sheaths, wires, and catheters.- note: if endoleaks or other problems are observed, refer to the suggested instructions for use for the zenith aaa endovascular graft ancillary components.3.Repair vessels and close in standard surgical fashion.12 imaging guidelines and postoperative follow-up 12.1 general ¿ the long-term performance of endovascular grafts has not yet been established.All patients should be advised that endovascular treatment requires life-long, regular follow-up to assess their health and the performance of their endovascular graft.Patients with specific clinical (e.G., endoleaks, enlarging aneurysm or changes in the structure or position of the endovascular graft) should receive additional follow-up.Patients should be counseled on the importance of adhering to the follow-up schedule.Both during the first year and at early intervals thereafter.Patients should be told that regular and consistent follow-up is a critical part of ensuring the ongoing safety and effectiveness of endovascular treatment of aaas.12.4 ultrasound imaging may be performed in place of contrast ct when patient factors preclude the use of image contrast media.Ultrasound may be paired with non-contrast ct.A complete aortic duplex is to be videotaped for maximum aneurysm diameter, endoleaks, stent patency and stenosis.Included on the videotape should be the following information as outlined below: ¿ transverse and longitudinal imaging should be obtained from the level of the proximal aorta demonstrating mesenteric and renal arteries to the iliac bifurcations to determine if endoleaks are present utilizing color flow and color power angiography (if accessible).¿ spectral analysis confirmation should be performed for any suspected endoleaks.¿ transverse and longitudinal imaging of the maximum aneurysm should be obtained.12.6 additional surveillance and treatment additional surveillance and possible treatment is recommended for: ¿ aneurysms with type i endoleak ¿ aneurysms with type iii endoleak ¿ aneurysms enlargement, = 5mm of maximum diameter (regardless of endoleak status) ¿ migration ¿ inadequate seal length" based on the information provided, no product returned, and the results of the investigation, cook was unable to determine a definitive cause for the event.The appropriate personnel have been notified.Cook will continue to monitor for similar complaints.Per the risk assessment no further action is required.This report is required by the fda under 21 cfr part 803 and is based on unconfirmed information submitted by others.Neither the submission of this report nor any statement contained herein is intended to be an admission that any cook device is defective or malfunctioned, that a death or serious injury occurred, nor that any cook device caused, contributed to, or is likely to cause or contribute to a death or serious injury if a malfunction occurred.
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