ZENITH FLEX AAA ENDOVASCULAR GRAFT BIFURCATED MAIN BODY
Report
- Report Number
- 1820334-2025-00552
- Event Type
- Injury
- Date Received
- May 15, 2025
- Report Date
- September 9, 2025
- Manufacturer
- COOK INC
- Product Code
- MIH
- PMA / PMN Number
- P020018
- Adverse Event
- Yes
- Product Problem
- Yes
- Report Source
- Manufacturer report
- Reporter Location
- FI
- Reporter Occupation
- PHYSICIAN
- Health Professional
- Yes
Narratives
INVESTIGATION-EVALUATION ON 08MAY2025 COOK BECAME AWARE OF THE PUBLICATION OF JOURNAL ARTICLE ¿POSSIBLE IMPLICATIONS OF DEVICE-SPECIFIC VARIABILITY IN POST-ENDOVASCULAR ANEURYSM REPAIR SAC REGRESSION AND ENDOLEAKS FOR SURVEILLANCE CATEGORIZATION¿ WRITTEN BY SUVI VÄÄRÄMÄKI, MD, PHD, ILKKA UURTO, MD, PHD, AND VELIPEKKA SUOMINEN, MD, PHD, TAMPERE, FINLAND. PER THE LITERATURE SIGNIFICANT SAC REGRESSION DURING EARLY SURVEILLANCE HAS BEEN SHOWN TO BEST PREDICT REINTERVENTION-FREE LONG-TERM SURVEILLANCE AFTER ENDOVASCULAR ANEURYSM REPAIR (EVAR). FURTHERMORE, A PERSISTENT ENDOLEAK HAS BEEN RELATED TO A WORSE OUTCOME. INDIVIDUALIZED SURVEILLANCE ALGORITHMS BASED ON THESE FINDINGS HAVE BEEN SUGGESTED. THERE ARE NO STUDIES COMPARING THE PERFORMANCE OF DIFFERENT STENT GRAFTS REGARDING SAC REGRESSION, THE PRESENCE OF TYPE II ENDOLEAKS, AND THEIR POSSIBLE IMPLICATIONS FOR INDIVIDUALIZED SURVEILLANCE. THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE DEVICE-SPECIFIC DIFFERENCES AND HOW THESE MAY AFFECT PATIENT CATEGORIZATION FOR SURVEILLANCE. THE RETROSPECTIVE STUDY INCLUDED ALL PATIENTS ASSIGNED TO ELECTIVE TREATMENT OF AN ABDOMINAL AORTIC ANEURYSM (AAA) USING STANDARD ENDOVASCULAR AORTIC REPAIR (EVAR) IN ONE ACADEMIC INSTITUTION BETWEEN 2005 AND 2015, COMPRISING A TOTAL OF 435 PATIENTS. THE INITIAL INDICATION FOR TREATMENT WAS AN ANEURYSM WITH A DIAMETER OF 55 MM OR GREATER IN MEN AND 50 MM OR GREATER IN WOMEN, OR AN INCREASE OF 5 MM IN DIAMETER OVER A PERIOD OF 6 MONTHS. PATIENTS WERE TREATED WITH THREE DIFFERENT STENT GRAFTS: ENDURANT (MEDTRONIC), EXCLUDER (W.L. GORE & ASSOCIATES), AND ZENITH (COOK INC). DURING THE SURVEILLANCE, 23.2% OF THE PATIENTS (N = 101) UNDERWENT REINTERVENTIONS FOR GRAFT-RELATED COMPLICATIONS (ZENITH: N = 52, 24.8%; EXCLUDER: N = 33, 22.0%; AND ENDURANT: N =16, 21.3%) (TABLE III). THESE INCLUDED 11 RAAAS (2.5%). NINE OF THE RUPTURES WERE CONFIRMED IN COMPUTED TOMOGRAPHY ANGIOGRAPHY (CTA), AND TWO HAD A CLINICAL DIAGNOSIS WITHOUT AN AUTOPSY. THESE LATTER TWO PATIENTS HAD UNCOMPLICATED SURVEILLANCE. REINTERVENTIONS AND ANEURYSM RUPTURES IN EVERY POST-EVAR YEAR ARE PRESENTED IN FIGURE 2 OF THE LITERATURE ARTICLE. PER THE LITERATURE IN SIX RUPTURED ABDOMINAL AORTIC ANEURYSM (RAAA) CASES, A PERSISTENT TYPE II ENDOLEAK, COMBINED IN FOUR OF THEM WITH SAC EXPANSION, LED TO LOSS OF PROXIMAL SEALING AND FURTHER TYPE 1A ENDOLEAK. IN TWO CASES, A PERSISTENT TYPE II ENDOLEAK CAUSED SAC EXPANSION, BUT NO TREATMENT WAS OFFERED BECAUSE OF PATIENTS¿ HIGH AGE AND DEMENTIA. ONE PATIENT HAD PRIMARY TYPE II ENDOLEAK, BUT HE WAS NOT UNDER SURVEILLANCE BECAUSE OF WIDESPREAD CANCER. IN ONE CASE, SIGNIFICANT SAC EXPANSION WAS NOTED BEFORE RAAA WITHOUT A DETECTABLE ENDOLEAK, BUT THIS PATIENT WAS CONSIDERED A POOR CANDIDATE FOR OPEN CONVERSION, AND NO TREATMENT WAS OFFERED. IN ONE CASE, BOTH TYPE IA AND IB LED TO RAAA WITHOUT PREVIOUS TYPE II ENDOLEAK OR SIGNIFICANT SAC EXPANSION. ENDOLEAKS WERE CONFIRMED SEVEN MONTHS BEFORE THE RUPTURE OCCURRED, BUT PATIENTS REFUSED FURTHER PROCEDURES. WITHIN THE LITERATURE A CHART WAS PROVIDED LABELED TABLE 3. THE TABLE PROVIDES THE NUMBER OF PATIENTS WITH ENDOVASCULAR ANEURYSM REPAIR (EVAR)-RELATED COMPLICATIONS REQUIRING REINTERVENTIONS STRATIFIED BY STENT GRAFTS. THIS REPORT WILL FOCUS ON THE SEVEN PATIENTS WHO HAD A TYPE 1A ENDOLEAK ON AN UNKNOWN ZENITH FLEX AAA ENDOVASCULAR GRAFT BIFURCATED MAIN BODY (TFFB), WHERE A RUPTURE OCCURRED, AND A PROXIMAL CUFF WAS REQUIRED. REVIEWS OF DOCUMENTATION INCLUDING THE DRAWING, QUALITY CONTROL, SPECIFICATIONS, MANUFACTURING INSTRUCTIONS (MI), AND INSTRUCTIONS FOR USE (IFU), WERE CONDUCTED DURING THE INVESTIGATION. THE COMPLAINT DEVICE WAS NOT RETURNED; THEREFORE, NO PHYSICAL EXAMINATIONS COULD BE PERFORMED. ADDITIONALLY, A DOCUMENT-BASED INVESTIGATION EVALUATION WAS PERFORMED. A REVIEW OF THE DEVICE MASTER RECORD (DMR) CONCLUDED THAT SUFFICIENT INSPECTION ACTIVITIES ARE IN PLACE TO IDENTIFY THIS FAILURE MODE PRIOR TO DISTRIBUTION. A REVIEW OF THE DEVICE HISTORY RECORD (DHR) WAS UNABLE TO BE COMPLETED DUE TO A LACK OF LOT NUMBER INFORMATION. IT SHOULD BE NOTED THAT THIS DEVICE IS SUPPLIED VIA A ONE-DEVICE LOT. BASED ON THE AVAILABLE INFORMATION, COOK HAS CONCLUDED THAT THE DEVICE WAS MANUFACTURED TO SPECIFICATION AND THAT THERE IS NO EVIDENCE SUGGESTING NONCONFORMING PRODUCTS EXIST EITHER IN HOUSE OR IN THE FIELD. COOK ALSO REVIEWED PRODUCT LABELING. THE IFU PACKAGED WITH THE DEVICE CONTAINS THE FOLLOWING IN RELATION TO THE REPORTED FAILURE MODE: 2 INDICATIONS FOR USE THE ZENITH FLEX AAA ENDOVASCULAR GRAFT WITH THE Z-TRAK INTRODUCTION SYSTEM IS INDICATED FOR THE ENDOVASCULAR TREATMENT OF PATIENTS WITH ABDOMINAL AORTIC OR AORTOILIAC ANEURYSMS HAVING MORPHOLOGY SUITABLE FOR ENDOVASCULAR REPAIR, INCLUDING: ¿ ADEQUATE ILIAC/FEMORAL ACCESS COMPATIBLE WITH THE REQUIRED INTRODUCTION SYSTEMS. ¿ NON-ANEURYSMAL INFERNAL AORTIC SEGMENT (NECK) PROXIMAL TO THE ANEURYSM: ¿ WITH A LENGTH OF AT LEAST 15 MM ¿ WITH A DIAMETER MEASURED OUTER WALL TO OUTER WALL OF NO GREATER THAN 32 MM AND NO LESS THAN 18MM, ¿ WITH AN ANGLE LESS THAN 60 DEGREES RELATIVE TO THE LONG AXIS OF THE ANEURYSM, AND ¿ WITH AN ANGLE LESS THAN 45 DEGREES RELATIVE TO THE AXIS OF THE SUPRARENAL AORTA. ¿ ILIAC ARTERY DISTAL FIXATION SITE GREATER THAN 10 MM IN LENGTH AND 7.5-20 MM IN DIAMETER (MEASURED OUTER WALL TO OUTER WALL) 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 INTERVENTION 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. ¿ MULTIPLE LARGE, PATENT LUMBAR ARTERIES, MURAL THROMBUS AND A PATIENT 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. 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. 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 ¿ 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: ¿ AORTIC DAMAGE, INCLUDING PERFORATION, DISSECTION, BLEEDING, RUPTURE AND DEATH ¿ ANEURYSM ENLARGEMENT ¿ ANEURYSM RUPTURE AND DEATH ¿ AORTIC DAMAGE, INCLUDING PERFORATION, DISSECTION, BLEEDING, RUPTURE AND DEATH ¿ ENDOLEAK ¿ SURGICAL CONVERSION TO OPEN REPAIR 8 PATIENT COUNSELING INFORMATION 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 RISK 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 ¿ ILIOFEMORAL ACCESS VESSEL SIZE AND MORPHOLOGY (MINIMAL THROMBUS, CALCIUM AND/OR TORTUOSITY) SHOULD BE COMPATIBLE WITH VASCULAR ACCESS TECHNIQUES AND ACCESSORIES. ARTERIAL CONDUIT TECHNIQUES MAY BE REQUIRED. ¿ PROXIMAL AORTIC NECK LENGTHS SHOULD BE A MINIMUM OF 15 MM WITH A DIAMETER MEASURED OUTER WALL TO OUTER WALL OF 18-32 MM. ¿ ILIAC ARTERY DISTAL FIXATION SITE SHOULD BE GREATER THAN 10 MM IN LENGTH AND 7.5-20 MM IN DIAMETER (MEASURED OUTER WALL TO OUTER WALL). 12.4 ULTRASOUND 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. BASED ON THE INFORMATION PROVIDED, NO PRODUCT WAS RETURNED, AND THE RESULTS OF THE INVESTIGATION A DEFINITIVE ROOT CAUSE FOR THIS EVENT COULD NOT BE ESTABLISHED. 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 INCLUDES INFORMATION KNOWN AT THIS TIME. A FOLLOW-UP REPORT WILL BE SUBMITTED SHOULD ADDITIONAL RELEVANT INFORMATION BECOME AVAILABLE. 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 OR THAT A DEATH OR SERIOUS INJURY OCCURRED; NOR IS IT ADMISSION THAT ANY COOK DEVICE CAUSED, CONTRIBUTED TO, OR IS LIKELY TO CAUSE OR CONTRIBUTE TO A DEATH OR SERIOUS INJURY IF A MALFUNCTION OCCURRED.
B3: DATE OF EVENT: JAN2005 TO DEC2020. D6A: IMPLANT DATE (B)(6) 2005 TO (B)(6) 2015. E1: PHONE: (B)(6). H3 - DEVICE EVALUATED BY MFG: DEVICE NOT RETURNED TO MANUFACTURER. THIS REPORT INCLUDES INFORMATION KNOWN AT THIS TIME. A FOLLOW-UP REPORT WILL BE SUBMITTED SHOULD ADDITIONAL RELEVANT INFORMATION BECOME AVAILABLE. 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 OR THAT A DEATH OR SERIOUS INJURY OCCURRED; NOR IS IT ADMISSION THAT ANY COOK DEVICE CAUSED, CONTRIBUTED TO, OR IS LIKELY TO CAUSE OR CONTRIBUTE TO A DEATH OR SERIOUS INJURY IF A MALFUNCTION OCCURRED.
NO ADDITIONAL INFORMATION REGARDING PATIENT AND/OR EVENT DETAILS HAS BEEN RECEIVED SINCE THE PREVIOUS MEDWATCH REPORT WAS SENT.
COOK WAS INFORMED OF SEVEN PATIENTS WHO HAD TYPE IA ENDOLEAKS ON AN UNKNOWN ZENITH FLEX AAA ENDOVASCULAR GRAFT BIFURCATED MAIN BODY. THIS WAS PRESENTED IN THE ARTICLE TITLED "POSSIBLE IMPLICATIONS OF DEVICE-SPECIFIC VARIABILITY IN POST-ENDOVASCULAR ANEURYSM REPAIR SAC REGRESSION AND ENDOLEAKS FOR SURVEILLANCE CATEGORIZATION" IN THE JOURNAL OF VASCULAR SURGERY. THE LONG-TERM EFFICACY OF ENDOVASCULAR ANEURYSM REPAIR (EVAR) REMAINS A CONCERN DESPITE FAVORABLE EARLY OUTCOMES, AND SURVEILLANCE IMAGING IS THEREFORE CONSIDERED MANDATORY AFTER EVAR. MANY PATIENTS ARE LOST TO FOLLOW-UP, AND EXISTING SURVEILLANCE PROTOCOLS HAVE A WIDE HETEROGENEITY. LIFELONG ANNUAL IMAGING SURVEILLANCE ALSO PLACES A BURDEN ON HEALTH CARE RESOURCES, AS APPROXIMATELY 77% OF ELECTIVE PATIENTS WITH AN ABDOMINAL AORTIC ANEURYSM (AAA) UNDERGO EVAR. SURVEILLANCE IMAGING AFTER EVAR IS PERFORMED TO IDENTIFY PATIENTS WITH POSSIBLE COMPLICATIONS IN GENERAL, AND SPECIFICALLY THOSE WHO WOULD BENEFIT FROM A REINTERVENTION TO PREVENT RUPTURE. MULTIPLE FACTORS HAVE BEEN IDENTIFIED TO PREDICT THE LATE FAILURE OF EVAR, SUCH AS LARGE PREOPERATIVE AAA SIZE, POOR SEALING, PERSISTENT TYPE II ENDOLEAK, AND INSTRUCTIONS FOR USE (IFU) ADHERENCE. AT THE SAME TIME, SEVERAL STUDIES HAVE SHOWN THAT PATIENTS WITH SIGNIFICANT SAC REGRESSION IN THE EARLY POSTOPERATIVE PHASE WILL EXPERIENCE FEWER COMPLICATIONS. HOWEVER, PARTICIPATION IN POST-EVAR SURVEILLANCE TO FIND LATE COMPLICATIONS IS CURRENTLY CONSIDERED EQUALLY IMPORTANT REGARDLESS OF PRE- AND POSTOPERATIVE FINDINGS, ALTHOUGH CONTROVERSY ALSO EXISTS. THERE ARE STUDIES ASSESSING THE RISK FACTORS FOR REINTERVENTIONS BASED ON PREOPERATIVE FINDINGS AS WELL AS IMAGING FINDINGS IN LATER SURVEILLANCE. SOME STUDIES SUGGEST THAT CATEGORIZATION FOR INDIVIDUALIZED SURVEILLANCE COULD BE BASED ON THE FIRST COMPUTED TOMOGRAPHY ANGIOGRAPHY (CTA) AFTER EVAR, WHEREAS OTHER AUTHORS RECOMMEND RELYING ON LATER CATEGORIZATION. THERE ARE ALSO DISCREPANCIES IN THE CURRENT GUIDELINES FOR POST-EVAR SURVEILLANCE. NO STUDIES HAVE BEEN PUBLISHED COMPARING THE PERFORMANCE OF DIFFERENT STENT GRAFTS REGARDING SAC REGRESSION AND THE PRESENCE OF TYPE II ENDOLEAKS AS WELL AS THEIR POSSIBLE IMPLICATIONS FOR INDIVIDUALIZED SURVEILLANCE. THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE DEVICE SPECIFIC DIFFERENCES IN SAC REGRESSION AND ENDOLEAKS DURING POST-EVAR SURVEILLANCE AND TO DETERMINE HOW THESE MAY AFFECT THE PATIENTS¿ CATEGORIZATION FOR INDIVIDUALIZED SURVEILLANCE. PATIENTS AND METHODS. THIS RETROSPECTIVE STUDY INCLUDED ALL PATIENTS ASSIGNED TO ELECTIVE TREATMENT OF AN AAA USING STANDARD EVAR IN ONE ACADEMIC INSTITUTION BETWEEN 2005 AND 2015, COMPRISING A TOTAL OF 435 PATIENTS. THE INITIAL INDICATION FOR TREATMENT WAS AN ANEURYSM WITH A DIAMETER OF 55 MM OR GREATER IN MEN AND 50 MM OR GREATER IN WOMEN, OR AN INCREASE OF 5 MM IN DIAMETER OVER A PERIOD OF 6 MONTHS. PATIENTS WERE TREATED WITH THREE DIFFERENT STENT GRAFTS: ENDURANT (MEDTRONIC), EXCLUDER (W.L. GORE & ASSOCIATES), AND ZENITH (COOK INC). AFTER INSTITUTIONAL APPROVAL OF THE STUDY, DATA WERE COLLECTED RETROSPECTIVELY THROUGH A REVIEW OF ELECTRONIC MEDICAL RECORDS. ALL CTAS WERE REANALYZED FOR THE STUDY. ALL PROCEDURES WERE PERFORMED BY A VASCULAR SURGEON TOGETHER WITH AN INTERVENTIONAL RADIOLOGIST IN A HYBRID SUITE. THE NUMBER OF TREATING SPECIALISTS WAS LIMITED TO A FEW VASCULAR SURGEONS AND INTERVENTIONAL RADIOLOGISTS. PATIENTS WERE FOLLOWED CONTINUOUSLY UNTIL THE END OF 2020 ACCORDING TO A PREARRANGED PROGRAM, INCLUDING CTA AT 1 AND 24 MONTHS AND COLOR DOPPLER ULTRASONOGRAPHY ANNUALLY. IN THE CASE OF SAC ENLARGEMENT, AN ADDITIONAL CTA WAS SCHEDULED TO DETECT A POSSIBLE ENDOLEAK. INDICATIONS FOR A REINTERVENTION INCLUDED A TYPE I, III, AND IV ENDOLEAK, MIGRATION, THROMBOSIS, ENDOTENSION, AND AAA RUPTURE. THE INDICATION FOR TREATING A TYPE II ENDOLEAK AT THE TIME OF THE STUDY WAS A 5-MM INCREASE IN AAA SAC SIZE. DEATHS WERE ASCERTAINED BY RECORD LINKAGE BETWEEN THE STUDY POPULATION AND THE NATIONAL CAUSES OF DEATH REGISTER ON THE BASIS OF THE PERSONAL IDENTIFICATION CODE UNIQUE TO EVERY RESIDENT. THE PRIMARY ENDPOINTS WERE DEVICE-SPECIFIC DIFFERENCES IN SAC REGRESSION AND ENDOLEAKS AT 30 DAYS AND 2 YEARS. WE DETERMINED THE SAFETY OF EARLY (30 DAYS) AND LATE (2 YEARS) CATEGORIZATION FOR INDIVIDUALIZED SURVEILLANCE BY CALCULATING THE SPECIFICITY AND SENSITIVITY, AS WELL AS THE NEGATIVE PREDICTIVE VALUE (NPV) FOR EACH DEVICE TO PREDICT REINTERVENTION-FREE SURVEILLANCE. PATIENTS¿ OUTCOMES WERE ANALYZED USING THE PEARSON X2 TEST OR THE FISHER EXACT TEST AND THE KRUSKAL-WALLIS TEST, WHERE APPROPRIATE (SPSS 26.0 FOR WINDOWS). A P VALUE OF < .05 WAS CONSIDERED STATISTICALLY SIGNIFICANT. CONFIDENCE INTERVALS FOR SENSITIVITY AND SPECIFICITY, AS WELL AS NPV, WERE CALCULATED BY MEANS OF THE CLOPPER-PEARSON METHOD USING THE MED-CALC STATISTICAL SOFTWARE (MEDCALC SOFTWARE LTD). RESULTS THE IMPLANTED GRAFTS INCLUDED THE COOK ZENITH (48.3%; N = 210), GORE EXCLUDER (34.5%; N = 150), AND MEDTRONIC ENDURANT (17.2%; N = 75). ROUTINE EMBOLIZATION OF PATENT INFERIOR MESENTERIC ARTERY (IMA) WAS DONE DURING THE EVAR PROCEDURE. THE IMA WAS PATENT IN 298 PATIENTS (68.5%), AND EMBOLIZATION WAS PERFORMED IN 179 CASES (59.3%). EMBOLIZATION OF THE IMA WAS ATTEMPTED IN AN ADDITIONAL 45 CASES. THE MAIN REASON FOR ABSTAINING FROM THE EMBOLIZATION WAS A SIGNIFICANT OSTIUM STENOSIS OR A LACK OF VISUALIZATION IN ANGIOGRAM. BASELINE PATIENT AND AAA-RELATED CHARACTERISTICS ARE PRESENTED IN TABLE I. THE MEAN FOLLOW-UP TIME WAS 70.0 MONTHS (STANDARD DEVIATION, 32 MONTHS). THIRTY-DAY FINDINGS. THIRTY-DAY MORTALITY WAS 1.5% (N = 5), WITH NO SIGNIFICANT DIFFERENCES BETWEEN THE DEVICES (P =.397). IMAGING DATA FOR THOSE SURVIVING THE FIRST 30 DAYS WERE AVAILABLE IN 98.4% OF THE CASES (N=424). IN 80.0% OF THE CASES (N = 339), NO ENDOLEAK WAS DETECTED IN THE 30-DAY CTA, AND NONE OF THE PATIENTS HAD SIGNIFICANT SAC SHRINKAGE (> OR EQUAL TO 5MM). THE DETECTED ENDOLEAK INCLUDED TYPE I (N = 9) AND II (N = 67). AN ENDOLEAK WAS FOUND MOST OFTEN WITH THE EXCLUDER STENT GRAFT (33.6%) AND MOST INFREQUENTLY WITH ENDURANT (4.1%), AND THIS FINDING WAS STATISTICALLY SIGNIFICANT (P < .001) (TABLE I). THE DEVICE-SPECIFIC ENDOLEAK FINDINGS WERE AS FOLLOWS: EXCLUDER: TYPE I, N = 5 AND TYPE II, N = 44; ZENITH: TYPE I, N = 3 AND TYPE II, N = 30; AND ENDURANT: TYPE I, N = 1 AND TYPE II, N = 2). TWO-YEAR FINDINGS. AT 2 YEARS, 86.0% OF THE PATIENTS (N = 374) WERE ALIVE, AND THERE WERE NO SIGNIFICANT DIFFERENCES IN MORTALITY RATES BETWEEN THE DEVICES (P = .417). IMAGING DATA WERE AVAILABLE FOR 92.5% OF THE PATIENTS (N = 346). OF THESE PATIENTS, 78.9% (N = 273) WERE FREE OF ANY ENDOLEAKS. THE DIFFERENCE BETWEEN THE DEVICE IN ENDOLEAK RATES WAS SIGNIFICANT AT 2 YEARS (P = .001) (TABLE I). THE ENDOLEAKS INCLUDED TYPE I (2.9%; N = 10) AND TYPE II (18.2%; N = 63). OF PATIENTS WITH A TYPE II ENDOLEAK, 54.0% (N = 34) HAD A PERSISTENT EARLY ENDOLEAK, AND 46.0% (N = 29) HAD DEVELOPED A NEW-ONSET TYPE II ENDOLEAK AT 2 YEARS. IN FURTHER SURVEILLANCE, 10.6% OF THE ENDOLEAK-FREE PATIENTS (N = 29) HAD A COMPLICATION REQUIRING A REINTERVENTION. OF THE EARLY ENDOLEAKS, 34.2% (N = 25) HAD RESOLVED SPONTANEOUSLY BY 2 YEARS. AT 2 YEARS, 53.5% OF THE PATIENTS (N =185) SHOWED AT LEAST 5-MM SAC REGRESSION WHEN COMPARED WITH THE PREOPERATIVE CTA. THE MEDIAN SHRINKAGE WAS 11.0 MM AMONG ALL EVAR PATIENTS WHO HAD ANY SAC REGRESSION AT 2 YEARS. THERE WAS NO SIGNIFICANT DIFFERENCE IN SAC SHRINKAGE RATE BETWEEN THE DEVICES (P = .096), BUT THE MEDIAN SHRINKAGE (MM) WAS MOST PRONOUNCED WITH EXCLUDER AND ZENITH DEVICES (P = .017) (TABLE II). SAFETY OF EARLY (30-DAY) CATEGORIZATION FOR INDIVIDUALIZED SURVEILLANCE. OF THE PATIENTS WITH NO ENDOLEAK AT 30 DAYS, 13.6% (N = 46) DEVELOPED A COMPLICATION THAT REQUIRED A REINTERVENTION DURING FURTHER SURVEILLANCE. THE SENSITIVITY FOR REINTERVENTION-FREE LONG-TERM SURVEILLANCE BASED ON A NEGATIVE 30-DAY ENDOLEAK FINDING WAS 44.8%, WITH SPECIFICITY OF 80.2%. A NEGATIVE ENDOLEAK FINDING PREDICTED REINTERVENTION-FREE LONG-TERM SURVEILLANCE WITH A PROBABILITY (NPV) OF 81.1%. THERE WAS WIDE VARIETY IN SENSITIVITY, SPECIFICITY, AND NPV BETWEEN THE DEVICES (TABLE II). SAFETY OF LATE (2-YEAR) CATEGORIZATION FOR INDIVIDUALIZED SURVEILLANCE. OF THE PATIENTS WITH NO ENDOLEAK AT 2 YEARS, 11.8% (N = 32) DEVELOPED A COMPLICATION REQUIRING A REINTERVENTION DURING FURTHER SURVEILLANCE. CATEGORIZATION BASED ON A NEGATIVE 2-YEAR ENDOLEAK FINDING HAD A SENSITIVITY OF 63.3%, SPECIFICITY OF 91.4%, AND NPV OF 89.4% FOR PREDICTING REINTERVENTION-FREE SURVEILLANCE. IN LONG TERM SURVEILLANCE, 5.7% OF THE PATIENTS WITH SIGNIFICANT SAC REGRESSION (> OR EQUAL TO 5 MM) AT 2 YEARS HAD A COMPLICATION REQUIRING A REINTERVENTION. CATEGORIZATION BASED ON A POSITIVE 2-YEAR SAC SHRINKAGE (> OR EQUAL TO 5 MM) RESULT HAD A SENSITIVITY OF 87.3% AND SPECIFICITY OF 66.3% FOR PREDICTING REINTERVENTION-FREE SURVEILLANCE. A POSITIVE SAC SHRINKAGE (> THAN OR EQUAL TO 5 MM) RESULT PREDICTED REINTERVENTION-FREE LONG-TERM SURVEILLANCE WITH 94.6% PROBABILITY. THE COMBINATION OF SAC REGRESSION (> THAN OR EQUAL TO 5 MM) AND NO ENDOLEAK AT 2 YEARS YIELDED A LONG-TERM REINTERVENTION RATE OF 3.2% (FIG 1). THIS CATEGORIZATION WAS ASSOCIATED WITH A SENSITIVITY OF 90.0%, SPECIFICITY OF 65.53%, AND NPV OF 95.6% FOR REINTERVENTION-FREE LONG-TERM SURVEILLANCE. FOUR PATIENTS WHO WERE INITIALLY TREATED WITH AN EXCLUDER DEVICE HAD A SHRINKING ANEURYSM SAC WITH AN ENDOLEAK AT 2 YEARS. THREE OF THESE PATIENTS REQUIRED REINTERVENTIONS DURING FURTHER SURVEILLANCE. A POSITIVE ENDOLEAK FINDING COMBINED WITH POSITIVE SAC REGRESSION WAS NOT FOUND WITH ANY OTHER DEVICE MODEL. THE CATEGORIZATION OF PATIENTS BASED ON ENDOLEAK-FREE STATUS AND SAC REGRESSION (> OR EQUAL TO 5 MM) FINDINGS RESULTED IN FAVORABLE OUTCOMES REGARDLESS OF THE DEVICE THAT HAD BEEN USED, AS THE NPV WAS HIGH WITH ALL THREE DEVICES (TABLE II). A PARTICULARLY HIGH NPV WAS ACHIEVED WITH THE EXCLUDER DEVICE. NO PATIENTS WITH AN EXCLUDER DEVICE AND A SHRINKING AAA WITH NO ENDOLEAK AT 2 YEARS UNDERWENT REINTERVENTIONS AFTER THAT POINT. ONE PATIENT WITH A SHRINKING AAA AND NO ENDOLEAK AT 2 YEARS LATER DIED OF A RUPTURED AAA (RAAA) AFTER UNCOMPLICATED SURVEILLANCE AT 3 YEARS WITHOUT A CTA OR AUTOPSY CONFIRMATION, LOWERING THE NPV FROM 100% TO 98.2%. COMPLICATIONS AND REINTERVENTIONS. DURING THE SURVEILLANCE, 23.2% OF THE PATIENTS (N = 101) UNDERWENT REINTERVENTIONS FOR GRAFT-RELATED COMPLICATIONS (ZENITH: N = 52, 24.8%; EXCLUDER: N = 33, 22.0%; AND ENDURANT: N = 16, 21.3%) (TABLE III). THESE INCLUDED 11 RAAAS (2.5%). NINE OF THE RUPTURES WERE CONFIRMED IN CTA, AND TWO HAD A CLINICAL DIAGNOSIS WITHOUT AN AUTOPSY. THESE LATTER TWO PATIENTS HAD UNCOMPLICATED SURVEILLANCE. REINTERVENTIONS AND ANEURYSM RUPTURES IN EVERY POST-EVAR YEAR ARE PRESENTED IN FIG 2. IN SIX RAAA CASES, A PERSISTENT TYPE II ENDOLEAK, COMBINED IN FOUR OF THEM WITH SAC EXPANSION, LED TO LOSS OF PROXIMAL SEALING AND FURTHER TYPE 1A ENDOLEAK. IN TWO CASES, A PERSISTENT TYPE II ENDOLEAK CAUSED SAC EXPANSION, BUT NO TREATMENT WAS OFFERED BECAUSE OF PATIENTS¿ HIGH AGE AND DEMENTIA. ONE PATIENT HAD PRIMARY TYPE II ENDOLEAK, BUT HE WAS NOT UNDER SURVEILLANCE BECAUSE OF WIDESPREAD CANCER. IN ONE CASE, SIGNIFICANT SAC EXPANSION WAS NOTED BEFORE RAAA WITHOUT A DETECTABLE ENDOLEAK, BUT THIS PATIENT WAS CONSIDERED A POOR CANDIDATE FOR OPEN CONVERSION, AND NO TREATMENT WAS OFFERED. IN ONE CASE, BOTH TYPE IA AND IB LED TO RAAA WITHOUT PREVIOUS TYPE II ENDOLEAK OR SIGNIFICANT SAC EXPANSION. ENDOLEAKS WERE CONFIRMED 7 MONTHS BEFORE RUPTURE, BUT PATIENTS REFUSED FURTHER TREATMENT. THE FOCUS OF THIS REPORT IS THE SEVEN PATIENTS WHO HAD TYPE IA ENDOLEAKS ON AN UNKNOWN ZENITH FLEX AAA ENDOVASCULAR GRAFT BIFURCATED MAIN BODY WHERE A RUPTURE OCCURRED AND THE PATIENTS REQUIRED REINTERVENTION TO PLACE A PROXIMAL CUFF. REFERENCE: VÄÄRÄMÄKI, S., UURTO, I., & SUOMINEN, V. (2023). POSSIBLE IMPLICATIONS OF DEVICE-SPECIFIC VARIABILITY IN POST-ENDOVASCULAR ANEURYSM REPAIR SAC REGRESSION AND ENDOLEAKS FOR SURVEILLANCE CATEGORIZATION. JOURNAL OF VASCULAR SURGERY, 78(5), 1204¿1211. HTTPS://DOI.ORG/10.1016/J.JVS.2023.07.001Z.
Devices
| Seq | Brand | Generic | Product Code | Manufacturer | Model | Lot | UDI-DI |
|---|---|---|---|---|---|---|---|
| 1886061 | ZENITH FLEX AAA ENDOVASCULAR GRAFT BIFURCATED MAIN BODY | MIH, SYSTEM, ENDOVASCULAR GRAFT, AORTIC ANEURYSM TREATMENT | MIH | COOK INC |
Patients
| Seq | Age | Sex | Outcome | Treatment |
|---|---|---|---|---|
| 1 | NA | Unknown | Required Intervention |