Clark J. Zeebregts

The relevance of aortic endograft prosthetic infection

BACKGROUND Vascular prosthetic graft infection is a severe complication after open aortic aneurysm repair. Reports of infected endografts are scarce. General treatment consensus with infected graft material is that it should be removed completely. The objective of this study was to describe the incidence of endograft infection after endovascular repair of abdominal (EVAR) and thoracic aortic aneurysm (TEVAR) and to report treatment options and their outcome. METHODS A retrospective cohort study was performed of patients endovascularly operated for abdominal and thoracic aortic aneurysm in two large hospitals (one tertiary referral center and one large community hospital) between March 1996 and June 2009. Diagnosis of infected endograft was made based on clinical findings, blood tests and cultures, imaging studies (computed tomography, fludeoxyglucose positron emission tomography), and intraoperative findings at reoperation. RESULTS Eleven patients with an infected endograft were identified in 1431 endovascular procedures. One other patient was referred from another hospital. Patients were aged 68 ± 9 years, and all but one were male. The median time from initial TEVAR/EVAR to the diagnosis of infection was 115 days (range, 7-3748 days), with 42% of patients presenting within 3 months after TEVAR/EVAR. Seven patients were diagnosed with endograft infection after elective TEVAR/EVAR and five after emergency TEVAR/EVAR. The incidence was significantly higher in patients that were treated in an emergency setting (0.56% vs 2.79%; P = .002), while there was no significant difference between TEVAR and EVAR procedures (1.37% vs 0.77%). All patients were initially treated with antibiotic therapy, which was complemented with surgical intervention in six patients. In four patients, the infected graft material was completely explanted. Isolated microorganisms included Staphylococcus species (n = 4), Streptococcus species (n = 4), Enterobacter cloacae (n = 1), Escherichia coli (n = 1), Pseudomonas aeruginosa (n = 1), and Listeria monocytogenes (n = 1). Median time of follow-up was 201 days (range, 6-2023 days). During the study period, three out of 12 patients died, of which two were treated conservatively (P = ns). At their last follow-up visit, seven of nine patients still used antimicrobial therapy. CONCLUSIONS The incidence of endograft infection is below 1%, with a mortality rate of 25%. Although consensus is that infected graft material should always be removed, this study shows no significant difference in mortality between the conservatively- and the surgically-managed group, possibly related to the small sample size. There may be a role for conservative treatment in selected cases of patients with an infected endograft.

Visceral stent patency in fenestrated stent grafting for abdominal aortic aneurysm repair

OBJECTIVE Fenestrated endovascular abdominal aortic aneurysm repair (F-EVAR) has been introduced for treatment of aneurysms in which visceral arteries are incorporated. Patency of target vessels has been reported to be excellent. Results of the use of stent grafts to accommodate visceral arteries in F-EVAR are presented in this study, including an overview of factors that affect outcome. METHODS All patients treated with fenestrated stent grafts in a single center between November 2001 and October 2011 were reviewed. Patients treated for suprarenal, juxtarenal, and infrarenal short-necked aortic aneurysms were included. Patients with thoraco-abdominal aneurysms or aneurysms treated with grafts with fixed side branches were excluded. Polytetrafluoroethylene covered stents were used routinely since June 2005. Target vessels and stents were examined using computed tomography angiography reconstructions. Primary end points were primary patency, defined as the absence of occlusion, and loss of renal function. Secondary end points were technical success, stenosis (defined as a ≥50% angiographic diameter reduction), stent fracture, and mortality. RESULTS A total of 138 patients with a median age of 73 years (range, 50-91 years) met the inclusion criteria. Median computed tomography angiography follow-up was 13 months (range, 1-97 months). In total, 392 target vessels were provided with 140 scallops and 252 fenestrations. Visceral stents (-grafts) were placed in 254 target vessels. Technical success was obtained in 249 arteries (98.0%). Overall stent patency of target vessels was 95.7% at 1 year and 88.6% at 4 years. Renal artery stent patency was 97.4% at 1 year and 91.2% at 4 years (96.8% and 89.1% for uncovered stents; 97.3% and 92.4% for covered stents, respectively). There was no significant difference in patency between covered and uncovered stents in renal arteries (P = .71). Renal artery stenosis occurred in 26 stented arteries (11.3%) and occlusion in seven arteries. Renal artery stent stenosis occurred significantly more in uncovered than in covered stents (P = .04). Stent fractures occurred more in uncovered than in covered stents (P = .01) and was associated with a significantly lower visceral stent patency rate (P < .01). During follow-up, 13 patients developed permanent renal function impairment (9.4%), of which two required permanent dialysis (1.4%). Renal dysfunction was significantly associated with renal stent occlusion or stenosis (P < .01). CONCLUSIONS Patency rates of visceral artery stent (-grafts) in F-EVAR were 95.7% at 1 year and 88.6% at 4 years. Patency rates were affected by stent fractures, which occurred more in uncovered compared with covered stents. Renal artery stent stenosis occurred more in uncovered compared with covered stents. Renal dysfunction was significantly associated with renal stent occlusion or stenosis.

Fenestrated and branched endograft repair of juxtarenal aneurysms after previous open aortic reconstruction

OBJECTIVE Para-anastomotic aortic aneurysms and progressive aneurysmal degeneration of the aorta after previous open aortic reconstruction pose a challenging clinical scenario. Due to the proximity to the visceral arteries, endovascular exclusion is typically not an option. However, the development of fenestrated and branched endografts has provided a less invasive means of repair. We sought to evaluate our experience using fenestrated endografts in the management of juxtarenal aortic aneurysms after previous open aortic reconstruction. METHODS This is an analysis of patients who have undergone fenestrated endovascular repair specifically for juxtarenal aneurysms in the setting of previous infrarenal open aortic surgery. Patients were treated with customized Cook (William A. Cook Australia, Ltd, Brisbane, Australia) endografts manufactured based on preoperative 3-dimensional (3-D) imaging. All patients underwent repair under the direction of a single surgeon. RESULTS Eighteen patients were treated from March 2004 to November 2008. All patients had a previous open aortic reconstruction, and 3 patients had two prior reconstructions. The mean time since the last operation was 8.5 years (range, 1-15 years). Mean patient age was 72-years-old (range, 57-80 years). All patients were considered high risk for open surgery due to pre-existing medical co-morbidities and/or the redo nature of their surgery. The mean number of fenestrations per patient was three vessels, including proximal graft scallops. All but one operation (94%) was completed by totally endovascular means. One operation required a planned celiotomy for retrograde access to a left renal artery. Of 56 target vessels, all were successfully revascularized using a combination of: fenestrations with stents (12), or stent grafts (25), as well as graft scallops (18), and directional graft branches with a bridging stent graft (1). Mean operative time was 215 minutes (range, 135-420 minutes) and mean blood loss was 560 cc (range, 100-1500 cc). Thirty-day and 1-year mortality was 0 and 11%, respectively. Perioperative complications occurred in 2 patients. One patient developed a congestive heart failure exacerbation and myocardial infarction, and the other patient a groin wound infection. Mean follow-up time was 23 months and cumulative primary patency was 95% (53/56 vessels), with no follow-up interventions. CONCLUSION Endovascular treatment of juxtarenal aneurysms after prior aortic reconstruction is a viable alternative to open repair with high success and low reintervention rates. These devices will broaden the available treatment modalities for these conditions, and will likely significantly decrease the complication rate of treatment in these high-risk patients.

Thirty-day outcome and quality of life after endovascular abdominal aortic aneurysm repair in octogenarians based on the Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE)

OBJECTIVE To determine 30-day outcome and quality of life after elective endovascular abdominal aortic aneurysm repair in octogenarians. METHODS From March 2009 to May 2011, 1200 patients with abdominal aortic aneurysms were treated with endovascular aneurysm repair (EVAR) using the Endurant stent graft were included in the Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE) registry. Among these, 926 (77%) were aged <80 years, and 274 (23%) were aged ≥ 80 years. Quality of life was assessed using composite EuroQoL 5-Dimensions Questionnaire index scores. RESULTS Gender was unequally distributed, with more female patients among the octogenarians (P = .043). Octogenarians had a significantly higher American Society of Anesthesiologists classification (P < .001) and differed significantly in baseline risk factors. The younger cohort was more likely to smoke (P < .001) and be alcoholics (P = .005). Octogenarians had larger aortic aneurysm (P = .010) and left iliac artery diameters (P = .017) and greater infrarenal neck angulation (P = .01). The technical success rate was >99% for both cohorts. Octogenarians were more often operated on under general anesthesia (P = .028), had a longer procedure duration (P = .001), and an increased length of hospitalization; both total (P < .001) and postprocedure (P < .001). All-cause mortality and major adverse event rates were similar in the two groups (P = .835 and P = .186, respectively). There was no difference in the number of secondary endovascular procedures or aneurysm rupture at 30 days. At discharge, both groups had reduced health status dimensions, except anxiety/depression, when compared with baseline. At 30 days, the octogenarian group had a lower composite EuroQoL 5-Dimensions Questionnaire index compared with the younger group, indicating a slower recovery (0.83 ± 0.20 vs 0.87 ± 0.16; P = .003). CONCLUSIONS Octogenarians can be safely treated using the Endurant stent graft with a high technical rate of success, low perioperative mortality, and no reduction in quality of life. Octogenarians did, however, appear to recover more slowly than younger patients with respect to certain quality of life components. Long-term data are needed to confirm these results.

Dutch experience with the fenestrated Anaconda endograft for short-neck infrarenal and juxtarenal abdominal aortic aneurysm repair

OBJECTIVE In the past decennium, the management of short-neck infrarenal and juxtarenal aortic aneurysms with fenestrated endovascular aneurysm repair (FEVAR) has been shown to be successful, with good early and midterm results. Recently, a new fenestrated device, the fenestrated Anaconda (Vascutek, Renfrewshire, Scotland), was introduced. The aim of this study was to present the current Dutch experience with this device. METHODS A prospectively held database of patients treated with the fenestrated Anaconda endograft was analyzed. Decision to treat was based on current international guidelines. Indications for FEVAR included an abdominal aortic aneurysm (AAA) with unsuitable neck anatomy for EVAR. Planning was performed on computed tomography angiography images using a three-dimensional workstation. RESULTS Between May 2011 and September 2013, 25 patients were treated in eight institutions for juxtarenal (n = 23) and short-neck AAA (n = 2). Median AAA size was 61 mm (59-68.5 mm). All procedures except one were performed with bifurcated devices. A total of 56 fenestrations were incorporated, and 53 (94.6%) were successfully cannulated and stented. One patient died of bowel ischemia caused by occlusion of the superior mesenteric artery. On completion angiography, three type I endoleaks and seven type II endoleaks were observed. At 1 month of follow-up, all endoleaks had spontaneously resolved. Median follow-up was 11 months (range, 1-29 months). There were no aneurysm ruptures or aneurysm-related deaths and no reinterventions to date. Primary patency at 1 month of cannulated and stented target vessels was 96%. CONCLUSIONS Initial and short-term results of FEVAR using the fenestrated Anaconda endograft are promising, with acceptable technical success and short-term complication rates. Growing experience and long-term results are needed to support these findings.

Current state of experimental imaging modalities for risk assessment of abdominal aortic aneurysm

BACKGROUND Abdominal aortic aneurysm (AAA) is a major cause of death in developed countries. Patients often lack clinical symptoms, most acute AAA patients do not survive rupture, and subsequent surgical repair has a significant postoperative mortality. Diagnostics for AAAs are currently centered on aneurysm diameter, but recent studies claim this method to be insufficiently accurate. More accurate diagnostic criteria need to be indentified to minimize the amount of unnecessary interventions and to provide earlier diagnosis of rupture-prone AAAs. METHODS A literature study using the MEDLINE database followed by manual cross-referencing provided original studies concerning AAA diagnostics. RESULTS The currently validated imaging modalities such as ultrasound, computed tomography, and magnetic resonance imaging allow AAA research to develop in several directions. Some studies investigate whether clinically visible entities like thrombus, calcification, and vascular anatomy could be implemented directly into clinical practice through use of ultrasound or computed tomography. Experimental studies on intravascular ultrasound, positron emission tomography-computed tomography, ultrasound particle image velocimetry and superparamagnetic particles in magnetic resonance imaging propose new methodologies to benefit AAA research. Other studies focus on available technology toward inflammation, metabolism, and the effects of hemodynamics on vascular integrity. CONCLUSIONS Contradictory outcomes, low availability of experimental imaging modalities, and an often small population size hamper research in this field. Introducing new techniques and biomarkers in current or experimental modalities may prove to be the next step in the development of new diagnostic criteria for the risk assessment of AAA rupture. Until then, the AAA diameter remains the gold standard as a clinical risk factor.

Predicting postoperative delirium after vascular surgical procedures

OBJECTIVE The objective of this study was to determine the incidence of and specific preoperative and intraoperative risk factors for postoperative delirium (POD) in electively treated vascular surgery patients. METHODS Between March 2010 and November 2013, all vascular surgery patients were included in a prospective database. Various preoperative, intraoperative, and postoperative risk factors were collected during hospitalization. The primary outcome variable was the incidence of POD. Secondary outcome variables were any surgical complication, hospital length of stay, and mortality. RESULTS In total, 566 patients were prospectively evaluated; 463 patients were 60 years or older at the time of surgery and formed our study cohort. The median age was 72 years (interquartile range, 66-77), and 76.9% were male. Twenty-two patients (4.8%) developed POD. Factors that differed significantly by univariate analysis included current smoking (P = .001), increased comorbidity (P = .001), hypertension (P = .003), diabetes mellitus (P = .001), cognitive impairment (P < .001), open aortic surgery or amputation surgery (P < .001), elevated C-reactive protein level (P < .001), and blood loss (P < .001). Multivariate logistic regression analysis revealed preoperative cognitive impairment (odds ratio [OR], 16.4; 95% confidence interval [CI], 4.7-57.0), open aortic surgery or amputation surgery (OR, 14.0; 95% CI, 3.9-49.8), current smoking (OR, 10.5; 95% CI, 2.8-40.2), hypertension (OR, 7.6; 95% CI, 1.9-30.5) and age ≥80 years (OR, 7.3; 95% CI, 1.8-30.1) to be independent predictors of the occurrence of POD. The combination of these parameters allows us to predict delirium with a sensitivity of 86% and a specificity of 92%. The area under the curve of the corresponding receiver operating characteristics was 0.93. Delirium was associated with longer hospital length of stay (P < .001), more frequent and increased intensive care unit stays (P = .008 and P = .003, respectively), more surgical complications (P < .001), more postdischarge institutionalization (P < .001), and higher 1-year mortality rates (P = .0026). CONCLUSIONS In vascular surgery patients, preoperative cognitive impairment and open aortic or amputation surgery were highly significant risk factors for the occurrence of POD. In addition, POD was significantly associated with a higher mortality and more institutionalization. Patients with these risk factors should be considered for high-standard delirium care to improve these outcomes.

Modest utility of quantitative measures in (18)F-fluorodeoxyglucose positron emission tomography scanning for the diagnosis of aortic prosthetic graft infection

BACKGROUND The clinical dilemma in suspected aortic graft infection (AGI) is how to noninvasively obtain a reliable proof of infection. In addition to confirming the presence of infection, obtaining information regarding the extent of infection to select a proper strategy for reoperation is also necessary. Therefore, developing a more reliable noninvasive physiologic approach to detect infected prostheses is required. (18)F-fluorodeoxyglucose positron emission tomography scanning ((18)F-FDG PET) has been suggested to have a pivotal role in the detection of AGI. In this study, we assessed the contribution of two (semi) quantitative parameters-maximal standardized uptake value (SUVmax) and tissue-to-background ratio (TBR)-and of two visual parameters-fluorodeoxyglucose (FDG) distribution patterns and visual grading scale-in the final confirmation of the diagnosis of AGI. METHODS Patients with a central aortic prosthetic graft and symptoms clinically suggestive of AGI were gathered from a prospectively maintained database. Included were those who underwent (18)F-FDG PET scanning combined with computed tomography angiography and in whom periprosthetic samples were taken at some stage in the diagnostic process. AGI was considered proven in case of a positive culture and compared with a group with negative cultures. Positive predictive values (PPVs) and negative predictive values (NPVs) were calculated. Receiver operating characteristics curves were used to assess the ability of SUVmax and TBR to identify the presence and absence of AGI (ie, accuracy). RESULTS In 37 of 77 patients with suspected AGI, (18)FDG-PET and perigraft material for culturing was obtained. The tissue culture was positive in 21 of these 37 patients (56.7%). Mean ± standard deviation SUVmax for proven infection was 8.1 ± 3.7 (range, 3.6-18.5) and TBR was 5.9 ± 2.7 (range, 1.7-13.0). The area under the curve for SUVmax was 0.78 (95% confidence interval, 0.63-0.93). A cutoff value of 8 yielded a PPV of 80% and a NPV of 54%. The area under the curve for TBR was 0.70 (95% confidence interval, 0.52-0.87). A cutoff value of 6 yielded a PPV of 73% and NPV of 52%. The PPVs for the visual grading scale and (18)F-FDG distribution patterns were 75% and 61%, respectively; the NPVs were 77% and 67%, respectively. CONCLUSIONS Our study, performed in a small sample of patients suspected of AGI, showed that the diagnostic abilities of quantitative and visual (18)F-FDG PET parameters are modest.

A limited and customized follow-up seems justified after endovascular abdominal aneurysm repair in octogenarians

OBJECTIVE The objective of this study was to determine whether long-term follow-up after endovascular aneurysm repair (EVAR) is justified in octogenarians. METHODS Between September 1996 and October 2011, all patients, including octogenarians, treated for an abdominal aortic aneurysm (AAA) by EVAR were included in a prospective database. Patients older than 80 years and with a nonruptured infrarenal aneurysm treated electively or urgently were included in the study (study group [SG]). Patients with ruptured aneurysms and patients who died during surgery or within the first postoperative month were excluded from further analysis. The control group (CG) consisted of patients younger than 80 years, matched for gender and AAA diameter. All patients were evaluated 4 to 8 weeks after EVAR and then annually thereafter. Follow-up data were complemented by review of the computerized hospital registry and charts and by contact of the patients general practitioner or referring hospital. Primary outcomes were stent- or aneurysm-related complications and interventions. Secondary outcomes were additional surgical complications and patient survival. RESULTS A total number of 193 patients (SG, n = 97; CG, n = 96) were included for analysis. Median age was 80 years, and 88.6% were male. Median follow-up time was 33.6 months (interquartile range [IQR], 12.9-68.3). Stent- and procedure-related postoperative complications were comparable between groups (SG, 41.2%; CG, 39.6%; P = .82). Median time to complication was 2.3 months (IQR, 0.2-19.4) in the SG compared with 18.1 months (IQR, 6.8-50.5) in the CG. The 2-year complication-free survival rates were 58% (SG) and 60% (CG). Interventions were performed significantly less frequently in octogenarians (SG, 8.2%; CG, 19.8%; P < .05). Median time to intervention was 11.1 months (IQR, 2.0-31.0) in the SG compared with 54.3 months (IQR, 15.0-93.2) in the CG. The 2-year intervention-free survival rates were 90% (SG) and 92% (CG). During follow-up, 98 patients died (SG, n = 54; CG, n = 44); median time to death was 31.8 months (IQR, 13.3-66.0) in the SG compared with 44.4 months (IQR, 15.0-77.7) in the CG. One aneurysm-related death occurred in the CG. The 2- and 5-year survival rates were 71% and 32% for the SG compared with 77% and 66% for the CG (P < .05). CONCLUSIONS Because of the low incidence of secondary procedures and AAA-related deaths in octogenarians, long-term and frequent follow-up after EVAR seems questionable. An adapted and shortened follow-up seems warranted in this patient group.

Outcome and quality of life after endovascular abdominal aortic aneurysm repair in octogenarians

OBJECTIVE This study determined outcome and quality of life (QOL) in octogenarians, compared with patients aged <80 years, 1 year after endovascular aortic aneurysm repair (EVAR). METHODS From March 2009 until April 2011, 1263 patients in the Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE) registry with an abdominal aortic aneurysm were treated with EVAR using the Endurant endograft (Medtronic Cardiovascular, Santa Rosa, Calif). The patients were grouped according to those aged ≥80 years (290 [22.9%]) and those aged <80 years (973 [77.1%]) at the time of the procedure. QOL was assessed using composite EuroQoL 5-Dimensions Questionnaire (EQ-5D) index scores. Baseline, perioperative, and follow-up data were analyzed at 1 year. RESULTS Octogenarians had poorer anatomic characteristics. The technical success rate was almost 99% for both cohorts, with no deaths. The duration of the implant procedure was significantly longer in the elderly patients (P = .002), with significant differences in overall (P < .001) and postprocedure (P < .001) hospital stays in favor of the younger group. At 1 year, there was a significant difference in all-cause mortality (P = .002) and in the number of major adverse events (P = .003), including secondary rupture (P = .01), to the detriment of octogenarians. There were no significant differences in conversion to open surgery or in overall secondary endovascular procedures. The octogenarians scored lower in their overall health care perception (P < .001) but with no significant difference in the EQ-5D index. Compared with the group aged <80 years, they had still not completely recovered their QOL after 1 year (P = .01). CONCLUSIONS Octogenarians are more difficult to treat by EVAR than younger patients due to poorer anatomic suitability and a higher incidence of complications. Recovery of QOL in octogenarians takes longer (>12 months) than expected.