Philippe W.M. Cuypers

Emergency treatment of symptomatic or ruptured abdominal aortic aneurysms: the role of endovascular repair.

Purpose: To report the initial experience with endovascular aortic repair (EVAR) in patients with ruptured or symptomatic abdominal aortic aneurysms (AAA) and to compare the results with conventional open surgery. Methods: Between May 1999 and December 2001, 24 patients (21 men; mean age 75 years, range 56–89) with ruptured or symptomatic AAA underwent EVAR using a specially designed aortomonoiliac endograft. Six patients were selected based on device and operator availability; the subsequent 18 patients were treated under a modified management protocol that offered stent-graft repair to all symptomatic AAA patients. The results of this new treatment protocol were analyzed on an intention-to-treat basis for the last 8 months of the study. The 30-day outcomes in all patients treated with emergency EVAR were compared with 40 consecutive, contemporaneous patients undergoing open surgery for symptomatic or ruptured AAA. Results: No early conversions to open surgery were performed. Significantly decreased operative blood loss and intensive care stay (p<0.05 for both) were observed in EVAR patients. The mortality rate for EVAR patients was 17% compared to 32% in conventionally treated patients (NS). Among patients with ruptured AAA, the 30-day mortality rates were 24% (4/17) and 41% (12/29) for EVAR and open surgery, respectively (NS). Of 26 unselected patients who were treated prospectively under the modified protocol, the majority (81%, 21/26) had anatomy suitable for endovascular repair; however, only 18 (69%) underwent EVAR owing to a short infrarenal neck (n=2) or device/operator unavailability (n=6). Conclusions: EVAR is a feasible treatment in the majority of patients with ruptured or symptomatic AAA. The 30-day mortality appears to be similar between conventionally treated patients and those undergoing endovascular repair.

Vein graft surveillance: Is graft revision without angiography justified and what criteria should be used?

PURPOSE The objective of this study was to assess the accuracy of color-flow duplex surveillance parameters to detect infrainguinal vein graft stenoses and to investigate whether graft revision without angiography is justified. METHODS In a prospective study in which three centers participated, the data of graft surveillance in 300 patients were analyzed. For the evaluation of surveillance criteria all patients underwent a digital subtraction angiography if a graft stenosis was suspected. To create a control group, in patients with normal grafts a consented digital subtraction angiography was performed also. From these data the accuracy of seven duplex and three ankle blood pressure-derived variables was assessed. The relation between various surveillance criteria and continued graft patency was determined with life table analysis with the transient state method. RESULTS The mean follow-up period was 20 months (range, 1 to 40 months). At univariate and multivariate analysis the peak systolic velocity (PSV) ratio provided the best correlation with angiographic stenoses > or = 70% (PSV ratio cutoff 3.0: sensitivity 80%, specificity 84%). This finding did not differ between the participating centers. With life table methods it was demonstrated that the best combination of efficacy (limitation of the number of unnecessary revisions), safety (minimal number of correctable lesions missed), and reduction of angiograms was obtained by a two-parameter surveillance algorithm. This algorithm included a PSV ratio < 2.5 to delineate patients in whom a conservative approach without angiography or revision was appropriate, a PSV ratio > or = 4.0 to indicate patients in whom vein graft revision without angiography could be scheduled, and a group with PSV ratios between 2.5 and 4.0 in whom angiography was to be performed to determine clinical management on the basis of the stenosis severity. This algorithm had a positive predictive value of 93% and a negative predictive value of 89%. In addition, it resulted in a reduction of the number of angiograms of 49% compared with a policy of angiographies in all patients with a PSV ratio > or = 2.5. CONCLUSIONS The best criterion to identify a failing graft is the PSV ratio. With a two-parameter algorithm for vein graft surveillance, the incidence of unnecessary revisions and of missed high-grade lesions was acceptably low, whereas the number of angiograms was reduced by one half.

Editor's Choice - Use of Disposable Radiation-absorbing Surgical Drapes Results in Significant Dose Reduction During EVAR Procedures

OBJECTIVES Because of the increasing number of interventional endovascular procedures with fluoroscopy and the corresponding high annual dose for interventionalists, additional dose-protecting measures are desirable. The purpose of this study was to evaluate the effect of disposable radiation-absorbing surgical drapes in reducing scatter radiation exposure for interventionalists and supporting staff during an endovascular aneurysm repair (EVAR) procedure. MATERIALS This was a randomized control trial in which 36 EVAR procedures were randomized between execution with and without disposable radiation-absorbing surgical drapes (Radpad: Worldwide Innovations & Technologies, Inc., Kansas City, US, type 5511A). Dosimetric measurements were performed on the interventionalist (hand and chest) and theatre nurse (chest) with and without the use of the drapes to obtain the dose reduction and effect on the annual dose caused by the drapes. RESULTS Use of disposable radiation-absorbing surgical drapes resulted in dose reductions of 49%, 55%, and 48%, respectively, measured on the hand and chest of the interventionalist and the chest of the theatre nurse. CONCLUSIONS The use of disposable radiation-absorbing surgical drapes significantly reduces scatter radiation exposure for both the interventionalist and the supporting staff during EVAR procedures.

Outpatient treatment of arterial inflow stenoses of dysfunctional hemodialysis access fistulas by retrograde venous access puncture and catheterization

OBJECTIVE To determine the feasibility of endovascular treatment of inflow stenoses in arteriovenous fistulae (AVFs) through retrograde venous access catheterization. METHODS We included all 22 dysfunctional AVFs with arterial inflow stenoses at access imaging between January 2002 and September 2006. Following retrograde venous access puncture, an interventional radiologist intended to cross the arteriovenous anastomosis and advance a catheter into the aortic arch. After depiction of the complete vascular access tree, angioplasty and/or stent placement was aimed for stenoses with a >50% luminal diameter reduction at digital subtraction angiography (DSA). RESULTS In one radiocephalic AVF, a catheter could not be positioned into the aortic arch after retrograde venous access puncture. DSA depicted 28 inflow stenoses in the remaining 21 patients (11 radiocephalic AVFs and 10 brachiocephalic AVFs). Clinical improvement was obtained in 18 out of 19 patients with a technically successful intervention (<30% residual stenosis after angioplasty or stent placement). Following endovascular therapy, access flow of 12 patients with a low flow access improved from 431 +/- 150 ml/min to 818 +/- 233 ml/min, and four patients with steal symptoms became symptom free. One nonmaturing fistula could be salvaged by angioplasty, and access cannulation problems were solved in another patient following angioplasty. Brachial artery stent placement did not reduce steal symptoms in one case, whereas two patients, in whom stent placement was not thought desirable, showed a >30% residual arterial stenosis after angioplasty. No complications were observed at DSA and endovascular intervention. CONCLUSION Retrograde venous access puncture and catheterization, as an alternative to a potentially more hazardous brachial artery or more invasive femoral artery approach, should be considered for the visualization of the arterial inflow and endovascular treatment of inflow stenoses.

Performance of the Endurant stent graft in challenging anatomy

OBJECTIVE This study aimed to compare perioperative and postoperative outcomes after endovascular repair of abdominal aortic aneurysms (AAAs) in patients with various neck morphologic features. METHODS Data from the Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE) were used for the analyses. Patients were categorized into three different groups according to proximal aortic neck anatomy: regular (REG), intermediate (INT), and challenging (CHA). REG was defined as AAAs with a proximal neck ≥15 mm combined with a suprarenal angulation (α) ≤45 degrees and an infrarenal neck angulation (ß) ≤60 degrees. INT was defined as AAAs with a proximal neck of 10 to 15 mm combined with α ≤45 degrees and ß ≤60 degrees or with a proximal neck of >15 mm combined with α ≤60 degrees and ß = 60 to 75 degrees or α = 45 to 60 degrees and ß ≤75 degrees. CHA was defined as infrarenal necks that exceed at least one of the three defining factors. RESULTS Overall, 925 patients (75.9%) had REG anatomy, 189 patients (15.5%) had INT anatomy, and 104 patients (8.5%) had CHA anatomy. Patient demographics and risk factors were similar. There was a significant difference in AAA diameter between the REG and CHA groups (59.4 mm vs 65.2 mm; P < .001). Technical success was similar among groups (REG 99.1% vs INT 99.5% vs CHA 97.1%). There were no differences in mortality or the need for secondary procedures within 30 days or at 1 year. A significantly higher rate of type I endoleaks within 30 days was seen in CHA compared with REG (adjusted odds ratio, 0.15; 95% confidence interval, 0.05-0.46) and INT (adjusted odds ratio, 0.08; 95% confidence interval, 0.01-0.70), but there was no difference at 1-year follow-up. CONCLUSIONS This real-world, global experience shows promising results and indicates that endovascular AAA repair with the Endurant stent graft (Medtronic Vascular, Santa Rosa, Calif) is safe and effective in patients with challenging aortic neck anatomy. However, long-term follow-up of patients is required to confirm results.

Retrograde catheterization of haemodialysis fistulae and grafts: angiographic depiction of the entire vascular access tree and stenosis treatment

BACKGROUND The European Best Practice Guidelines on Vascular Access propose magnetic resonance angiography (MRA) of dysfunctional dialysis fistulae and grafts if visualization of the complete arterial inflow and outflow vessels is needed. In a prospective multi-centre study we determined the technical success rate of complete vascular access tree depiction by digital subtraction angiography (DSA) as an alternative to MRA. Instead of a more invasive brachial artery of femoral artery approach, we performed a retrograde catheterization of the venous outflow or graft, and stenoses were treated in connection with DSA. METHODS A catheter was advanced into the central arterial inflow after retrograde puncture of the venous outflow or graft for depiction of the complete inflow, access region and complete outflow. Access DSA through femoral artery puncture was done if the retrograde approach failed to depict the complete vascular access tree. Stenoses with a luminal diameter reduction >or=50% were treated, if possible, in connection with DSA. RESULTS A total of 116 dysfunctional haemodialysis fistulae and 50 grafts were included. Retrograde DSA depicted the complete vascular tree in 162 patients (97.6%). The arteriovenous anastomosis of four fistulae could not be negotiated by a catheter. DSA demonstrated 247 significant stenoses: 30, 128 and 89 were located in the arterial inflow (12.1%), AV anastomosis and graft region (51.8%) and venous outflow (36.0%), respectively. Ten patients (6.0%) had no stenosis. Eight (4.8%), 55 (33.1%) and 33 (19.9%) patients demonstrated stenoses in only inflow, access region or outflow, respectively. Stenoses in two or three vascular territories were present in 53 (31.9%) and 7 (4.2%) patients, respectively. A technically successful endovascular intervention was obtained in 135 of the 139 patients (97.1%) who underwent angioplasty and/or stent placement. Additional sheath insertion by antegrade outflow puncture was needed in 46 patients (33.1%) for the treatment of coexisting venous outflow stenoses, located downstream from the retrograde positioned sheath. Two minor complications were observed at DSA/angioplasty. CONCLUSION As an alternative to MRA, full retrograde DSA is safe and effective for stenosis detection and stenosis treatment. However, access evaluation by a non-invasive imaging modality such as colour duplex ultrasound will be sufficient in most cases as proximal inflow stenoses are encountered in a minority of patients. Full retrograde DSA, including complete arterial inflow depiction, may then be reserved for cases with an unsuccessful outcome following endovascular intervention of stenoses depicted at ultrasound.

Effects of Anesthesia Type on Perioperative Outcome After Endovascular Aneurysm Repair.

Purpose: To examine outcomes of endovascular aortic aneurysm repair (EVAR) using general, regional, or local anesthesia. Methods: From March 2009 to April 2011, patients were enrolled from 79 sites in 30 countries worldwide and treated with an Endurant Stent Graft System. Data were compared among 3 groups based on the method of anesthesia: general anesthesia (GA) was used in 785 (62%) patients, regional anesthesia (RA) in 331 (27%) patients, and local anesthesia (LA) in 145 (11%) patients. Multivariate logistic regression analysis was performed to adjust for possible confounding factors; outcomes are presented as the odds ratio and 95% confidence interval. Results: There were intercontinental differences in the distribution of type of anesthesia used for EVAR. Higher ASA (American Society of Anesthesiologists) classification was associated with predominant use of GA. Procedure time was reduced in LA (80.4±40.0 minutes) compared with RA (94.2±41.6 min, adjusted p=0.001) and GA (105.3±46.0 minutes, adjusted p<0.001). Intensive care unit (ICU) admission was less frequent for RA than for GA (adjusted OR 0.71, 95% CI 0.53 to 0.97, p=0.030) and LA (adjusted OR 0.51, 95% CI 0.33 to 0.79, p=0.002). Postoperative hospital stay was significantly shorter for RA and LA compared with GA (adjusted p=0.003 and p=0.010, respectively). There were no significant differences in systemic and surgical complications. Mortality rates within 30 days did not differ among the groups. Conclusion: Type of anesthesia used during EVAR has no influence on perioperative mortality and morbidity. The use of local or regional anesthesia during EVAR appeared to be beneficial concerning procedure time, ICU admission, and postoperative hospital stay.

Infrarenal abdominal aortic aneurysm with concomitant urologic malignancy: treatment results in the era of endovascular aneurysm repair.

During diagnostic workup for urologic malignancies, an abdominal aortic aneurysm (AAA) is identified in a proportion of patients. In the era of open AAA repair, these patients presented a surgical dilemma with regard to the sequence of the operations: cancer treatment first or AAA repair first? Previous assessments have concluded that irrespective of the followed strategy, the early and mediumterm mortality from the two operative procedures in this patient category was significant. With the introduction of endovascular aneurysm repair (EVAR), the mortality and morbidity associated with the treatment of both pathologic conditions may be more favorable than with open aneurysm repair. The objective of this study was to assess, in an institutional series of patients receiving EVAR, the early and long-term survival and complication rates in patients with urologic malignancies. In a series of 385 patients receiving EVAR, 14 had a concomitant urologic malignancy: renal cell carcinoma (5 patients), prostate carcinoma (6 patients), and carcinoma of the bladder (3 patients). The first-month mortality was nil. Long-term survival was 80%, 83%, and 67% for the three tumor types, respectively. EVAR offers improved treatment in patients with concomitant AAA and urologic malignancy and should be considered the first choice for these patients.

Long-term survival and secondary procedures after open or endovascular repair of abdominal aortic aneurysms

Objective Randomized trials have shown an initial survival benefit of endovascular over conventional open abdominal aortic aneurysm repair but no long‐term difference up to 6 years after repair. Longer follow‐up may be required to demonstrate the cumulative negative impact on survival of higher reintervention rates associated with endovascular repair. Methods We updated the results of the Dutch Randomized Endovascular Aneurysm Management (DREAM) trial, a multicenter, randomized controlled trial comparing open with endovascular aneurysm repair, up to 15 years of follow‐up. Survival and reinterventions were analyzed on an intention‐to‐treat basis. Causes of death and secondary interventions were compared by use of an events per person‐year analysis. Results There were 178 patients randomized to open and 173 to endovascular repair. Twelve years after randomization, the cumulative overall survival rates were 42.2% for open and 38.5% for endovascular repair, for a difference of 3.7 percentage points (95% confidence interval, −6.7 to 14.1; P = .48). The cumulative rates of freedom from reintervention were 78.9% for open repair and 62.2% for endovascular repair, for a difference of 16.7 percentage points (95% confidence interval, 5.8‐27.6; P = .01). No differences were observed in causes of death. Cardiovascular and malignant disease account for the majority of deaths after prolonged follow‐up. Conclusions During 12 years of follow‐up, there was no survival difference between patients who underwent open or endovascular abdominal aortic aneurysm repair, despite a continuously increasing number of reinterventions in the endovascular repair group. Endograft durability and the need for continued endograft surveillance remain key issues.

A 15-Year Single-Center Experience of Endovascular Repair for Elective and Ruptured Abdominal Aortic Aneurysms

Purpose: To evaluate the differences in technical outcomes and secondary interventions between elective endovascular aneurysm repair (el-EVAR) procedures and those for ruptured aneurysms (r-EVAR). Methods: Of the 906 patients treated with primary EVAR from September 1998 until July 2012, 43 cases were excluded owing to the use of first-generation stent-grafts. Among the remaining 863 patients, 773 (89.6%) patients (mean age 72 years; 697 men) with asymptomatic or symptomatic abdominal aortic aneurysms (AAAs) were assigned to the el-EVAR group; 90 (10.4%) patients (mean age 73 years; 73 men) were assigned to the r-EVAR group based on blood outside the aortic wall on preoperative imaging. The primary study outcome was technical success; secondary endpoints, including freedom from secondary interventions and late survival, were examined with Kaplan-Meier analyses. Results: At baseline, r-EVAR patients had larger aneurysms on average (p<0.001) compared to el-EVAR patients. Technical success was comparable (p=0.052), but there were more type Ia endoleaks at completion angiography in the r-EVAR group (p=0.038). As anticipated, more patients died in the first month in the r-EVAR group (18.9% vs 2.2% el-EVAR, p<0.001). At 5 years, there was an overall survival of 65.1% for the el-EVAR patients vs 48.1% in the r-EVAR group (p<0.001). The freedom from AAA-related mortality was 95.7% for el-EVAR and 71.0% for r-EVAR (p<0.001). Five-year freedom from type I/III endoleaks was significantly lower in the r-EVAR group (78.7% vs 90.0%, p=0.003). Five-year freedom from secondary intervention estimates were not significantly different (el-EVAR 84.2% vs r-EVAR 78.2%, p=0.064). Conclusion: Within our cohort of primary EVAR patients, r-EVAR cases showed comparable stent-graft–related technical outcome. Although there was a higher incidence of type Ia endoleaks on completion angiography in the r-EVAR group, the overall secondary intervention rate was comparable to el-EVAR.