Myocardial damage in high-risk patients undergoing elective endovascular or open infrarenal abdominal aortic aneurysm repair.

OBJECTIVE: Dobutamine stress echocardiography (DSE) provides an objective assessment of the presence and extent of coronary artery disease. Therefore we compared cardiac outcome in patients at high-cardiac risk undergoing open or endovascular repair of infrarenal AAA using preoperative DSE results. METHODS: Consecutive patients with >or=3 cardiac risk factors (age >70 years, angina pectoris, myocardial infarction, heart failure, stroke, renal failure, and diabetes mellitus) undergoing infrarenal AAA repair were reviewed retrospectively. All underwent cardiac stress testing using DSE. Postoperatively data on troponin release and ECG were collected on day 1, 3, 7, before discharge, and on day 30. The main outcome measures were perioperative myocardial damage and myocardial infarction or cardiovascular death. RESULTS: All 77 patients (39 endovascular, 38 open) had a history of cardiac disease. The number and type of cardiac risk factors were similar in both groups. Also DSE results were similar: 55 vs 56%, 24 vs 28%, and 21 vs 18% had no, limited, or extensive stress induced myocardial ischemia respectively. The incidence of perioperative myocardial damage (47% vs 13%, p=0.001) and the combination of myocardial infarction or cardiovascular death (13% vs 0%, p=0.02) was significantly lower in patients receiving endovascular repair. CONCLUSION: In patients with similar high cardiac risk, endovascular repair of infrarenal aortic aneurysms is associated with a reduced incidence of perioperative myocardial damage.     

Fenestrated endovascular aneurysm repair is associated with lower perioperative morbidity and mortality compared with open repair for complex abdominal aortic aneurysms

ObjectiveThe Zenith Fenestrated Endovascular Graft (ZFEN; Cook Medical, Bloomington, Ind) has expanded the anatomic eligibility of endovascular aneurysm repair (EVAR) for complex abdominal aortic aneurysms (AAAs). Current data on ZFEN mainly consist of single-institution experiences and show conflicting results. Therefore, we compared perioperative outcomes after repair using ZFEN with open complex AAA repair and infrarenal EVAR in a nationwide multicenter registry.MethodsWe identified all patients undergoing elective AAA repair using ZFEN, open complex AAA repair, and standard infrarenal EVAR between 2012 and 2016 within the American College of Surgeons National Surgical Quality Improvement Program targeted vascular module. Open complex AAA repairs were defined as those with a juxtarenal or suprarenal proximal AAA extent in combination with an aortic cross-clamping position that was above at least one renal artery. The primary outcome was perioperative mortality, defined as death within 30 days or within the index hospitalization. Secondary outcomes included postoperative renal dysfunction (creatinine concentration increase of >2 mg/dL from preoperative value or new dialysis), occurrence of any complication, procedure times, blood transfusion rates, and length of stay. To account for baseline differences, we calculated propensity scores and employed inverse probability-weighted logistic regression.ResultsWe identified 6825 AAA repairs—220 ZFENs, 181 open complex AAA repairs, and 6424 infrarenal EVARs. Univariate analysis of ZFEN compared with open complex AAA repair demonstrated lower rates of perioperative mortality (1.8% vs 8.8%; P = .001), postoperative renal dysfunction (1.4% vs 7.7%; P = .002), and overall complications (11% vs 33%; P < .001). In addition, fewer patients undergoing ZFEN received blood transfusions (22% vs 73%; P < .001), and median length of stay was shorter (2 vs 7 days; P < .001). After adjustment, open complex AAA repair was associated with higher odds of perioperative mortality (odds ratio [OR], 4.9; 95% confidence interval [CI], 1.4-18), postoperative renal dysfunction (OR, 13; 95% CI, 3.6-49), and overall complication rates (OR, 4.2; 95% CI, 2.3-7.5) compared with ZFEN. Compared with infrarenal EVAR, ZFEN presented comparable rates of perioperative mortality (1.8% vs 0.8%; P = .084), renal dysfunction (1.4% vs 0.7%; P = .19), and any complication (11% vs 7.7%; P = .09). Furthermore, after adjustment, there was no significant difference between the odds of perioperative mortality, postoperative renal dysfunction, or any complication between infrarenal EVAR and ZFEN.ConclusionsZFEN is associated with lower perioperative morbidity and mortality compared with open complex AAA repair, and outcomes are comparable to those of infrarenal EVAR. Long-term durability of ZFEN compared with open complex AAA repair warrants future research.     

肾动脉下腹主动脉瘤腔内治疗后并发症的防治

目的　总结肾动脉下腹主动脉瘤腔内治疗后常见并发症的预防与处理。　方法对已施行腔内治疗的 71例肾下腹主动脉瘤患者的临床资料进行回顾性分析 ,讨论常见并发症发生的原因、处理、结果及预后。　结果　 71例接受腔内治疗的肾动脉下腹主动脉瘤患者技术成功率1 0 0 % ,无中转开腹手术者。原发性内漏 8例 ,神经并发症合并急性血栓形成 1例。一过性缺血性肠炎 2例。无肾动脉梗死、肢体栓塞等并发症。平均随访时间 (2 6± 5)个月。围手术期病死率 1 3 % (1 /71 ) ,总病死率 4 2 % (3/ 71 )。死亡原因 2例为急性心肌梗死 ,1例为急性心功能衰竭。随访过程中发现 3例原发性内漏转为持续性内漏 ,另发现继发性内漏 4例。本组患者 1个月后内漏发生率 9 8%(7/ 71 )。 2例继发性Ⅰ型内漏随访中瘤体增大 ,1例进行二期腔内治疗。　结论　动脉瘤的腔内治疗具有创伤小、技术操作可行、效果肯定的优点 ,内漏血是该技术主要并发症。对漏血量及瘤体有增大趋势的内漏应积极处理     

Endovascular vs open AAA repair: similar effects on renal proximal tubular function.

AIM: To compare the effect of open and endovascular repair on renal function. MATERIALS AND METHODS: In a prospective, non-randomized study twenty-four abdominal aortic aneurysms (AAA) treatable with either method were repaired, 15 using endovascular device (ENDO group) and nine with open surgery with infrarenal aortic cross-clamping (OPEN group). All the patients had standardised general anaesthesia, intravascular fluid therapy and monitoring. Renal function tests and cardiovascular measurements were performed at predetermined intervals. RESULTS: N-acetyl-beta-D-glucosaminidase indexed to urinary creatinine (U-NAG/crea), a sensitive marker of renal proximal tubular damage, increased similarly in both groups at the end of surgery (two-way ANOVA, p < 0.05). No patient developed clinical renal impairment, on the contrary, creatinine clearance was increased, serum cystatin C (a sensitive marker of renal glomerular filtration) and serum creatinine concentration decreased at 24 hours postoperatively (Wilcoxon paired test, p < 0.05). Intraoperative blood loss and the amount of administered crystalloids were higher in the OPEN than in the ENDO group (Mann-Whitney U-test, p < 0.05). The cardiovascular measurements were comparable between the groups. The mean (SD) amount of radio-contrast media given was 3.1 (1.1) ml/kg in the ENDO group. CONCLUSIONS: Our results indicate that endovascular AAA repair does not protect renal proximal tubular function. A temporary renal tubular dysfunction was found both in open and in endovascular AAA repair which did not lead to permanent changes in renal function.     

Preoperative glomerular filtration rate and outcome following open abdominal aortic aneurysm repair

Estimated glomerular filtration rate (eGFR) can be readily calculated from serum creatinine values. It is a more sensitive prognostic indicator than serum creatinine alone in patients undergoing thoracoabdominal or endovascular abdominal aortic aneurysm repair. The value of eGFR in patients undergoing open abdominal aortic aneurysm repair remains unclear. The preoperative eGFR was calculated for patients undergoing elective open infrarenal aortic aneurysm repair. Postoperative complications, perioperative mortality, and long-term survival were compared across eGFR and serum creatinine quartiles. The eGFR identified preoperative renal dysfunction in 33% of patients, whereas serum creatinine identified renal impairment in only 11%. The eGFR correlated with perioperative morbidity and long-term survival. Serum creatinine did not correlate with perioperative mortality or long-term survival. However, it did correlate with postoperative morbidity. The eGFR is a more sensitive index of preoperative renal function than serum creatinine and correlates with survival. It should replace serum creatinine as the standard index of renal function before open abdominal aortic aneurysm repair.     

Endovascular AAA repair in patients with renal insufficiency: strategies for reducing adverse renal events

Vascular imaging, usually employing nephrotoxic contrast agents is relied upon for all aspects of endovascular AAA repair causing some to consider renal insufficiency a relative contraindication. We sought to determine if endovascular AAA evaluation and repair could be successfully accomplished by minimally or non-nephrotoxic modalities.Records and results for 98 consecutive patients undergoing endovascular AAA repair were reviewed. Patients requiring dialysis preoperatively were excluded (N=3).The average volume of iodinated contrast agent employed for intraoperative imaging was 152 cc (35-420 cc). Twenty patients (20%) had baseline renal insufficiency (serum creatinine > or =1.3 mg/dl). A rise in serum creatinine above baseline was observed in 23 (24%) patients following repair; for 15 (16%) this was permanent. Creatinine rise occurred in patients with both normal (15) and abnormal (8) baseline values (P=0.09). Rise in creatinine was independent of contrast volume employed and of the use of infrarenal vs suprarenal device fixation (P>0.05). Two (2%) patients required permanent dialysis, one of which had a normal baseline creatinine and unclear etiology for renal failure, the other had a baseline creatinine of 2 and required device placement over an accessory renal artery. Strategies to minimize the use of nephrotoxic contrast for patients with renal insufficiency included the use of MRA, rather than contrast-CT for pre and postoperative imaging (7, 35%) and use of Gadolinium rather than iodinated contrast for performance of intraoperative arteriography (5, 25%). Endovascular grafts were successfully designed and implanted based upon MRA as the sole preoperative imaging modality in every case in which it was attempted (7). Mortality was not significantly different between those with and without abnormal baseline renal function (P>0.05). Adverse events (access failures, arterial injuries, blood loss, endoleaks) were not significantly correlated with baseline renal insufficiency, rise in creatinine from baseline, use of MRA or intraoperative Gadolinium angiography (P>0.05).Pre- and postoperative evaluation and performance of endovascular AAA repair can be accomplished in patients with renal insufficiency without increasing the rate of mortality or adverse events employing a strategy which minimizes the use of nephrotoxic contrast agents, relying upon Gadolinium arteriography and MRA. Endovascular grafts can be successfully planned and followed employing MRA as the sole imaging modality.     

Abdominal aortic aneurysm repair in patients with preoperative renal failure

The purpose of this study was to determine the effect of preoperative renal failure on the outcome of patients undergoing infrarenal abdominal aortic aneurysm (AAA) repair. Of 251 patients undergoing AAA repair from 1977 to 1984, 10% had evidence of preoperative chronic renal failure. These patients were classified according to their preoperative serum creatinine values; group I had preoperative creatinine levels of 2 to 4 mg/dl, group II had creatinine levels greater than 4 mg/dl but no history of hemodialysis, and group III consisted of patients on chronic hemodialysis before operation. One of 16 patients in group I developed transient high-output renal failure postoperatively. Four of the six patients in group II (67%) developed significant postoperative deterioration of renal function and required acute hemodialysis. Of the four patients in group III maintained on chronic hemodialysis preoperatively, one died of sepsis from an ischemic colon. This experience suggests that patients with mild renal dysfunction (serum creatine value less than 4 mg/dl) can undergo elective AAA repair without additional morbidity. Patients on hemodialysis before operation can also safely undergo surgical repair of their AAAs electively if dialyzed the day before operation. Patients with severe renal dysfunction (serum creatinine greater than 4 mg/dl) who are not on hemodialysis should be considered for dialysis preoperatively in an attempt to reduce the high incidence of serious postoperative renal functional deterioration and subsequent morbidity.     

The incidence of hypomagnesaemia following abdominal aortic aneurysm surgery

IntroductionMagnesium is important for cardiac function. Hypomagnesaemia is associated with a higher incidence of arrhythmias and poorer outcomes in cardiac surgery. No studies have investigated the incidence or impact of postoperative hypomagnesaemia after abdominal aortic aneurysm (AAA) surgery. We aim to assess the incidence of hypomagnesaemia after AAA repair in our population.MethodsRetrospective analysis was performed of patients who underwent elective AAA surgery at a single vascular centre. The last 110 patients undergoing open or endovascular AAA repair were identified. The hospital pathology system was used to identify the immediate postoperative serum magnesium levels as well as patient demographics and admission details. Hypomagnesaemia was defined as serum magnesium of <0.7mmol/l.ResultsA total of 211 patients were studied and there were 3 deaths. Of the patients included, 101 underwent open elective AAA repair and 110 underwent endovascular repair. In the elective open repair group, 73 patients (73%) were hypomagnesaemic. In the endovascular repair group, 35 (32%) had hypomagnesaemia. A t-test showed a statistically significant difference in hypomagnesaemia between the open and endovascular groups (p<0.001).ConclusionsAAA surgery is associated with a high incidence of postoperative hypomagnesaemia, which is significantly greater among open repair patients. This is likely to have an effect on cardiac activity and lead to cardiac complications such as arrhythmias and poorer postoperative outcomes, especially in the open AAA repair subgroup. This stresses the importance of serum magnesium and cardiac monitoring in the postoperative phase. A prospective study is proposed to further investigate these findings, and their potential implications on perioperative morbidity and mortality.     

Will endovascular repair replace open surgery for abdominal aortic aneurysm repair?

OBJECTIVE: To evaluate of the impact of endovascular aneurysm repair on the rate of open surgical repair and on the overall treatment of abdominal aortic aneurysms (AAAs). METHODS: All patients with AAA who were treated during two consecutive 40-month periods were reviewed. During the first period, only open surgical repair was performed; during the subsequent 40 months, endovascular repair and open surgical repair were treatment options. RESULTS: A total of 727 patients with AAA were treated during the entire period. During the initial 40 months, 268 patients were treated with open surgical repair, including 216 infrarenal (81%), 43 complex (16%), and 9 ruptured (3%) aortic aneurysms. During the subsequent 40 months, 459 patients with AAA were treated (71% increase). There was no significant change in the number of patients undergoing open surgical repair and no significant difference in the rate of infrarenal (238 [77%]) and complex (51 [16%]) repairs. A total of 353 patients were referred for endovascular repair. Of these, 190 (54%) were considered candidates for endovascular repair based on computed tomography or arteriographic morphologic criteria. Analyzing a subgroup of 123 patients, the most common primary reasons for ineligibility for endovascular repair were related to morphology of the neck in 80 patients (65%) and of the iliac arteries in 35 patients (28%). A total of 149 patients underwent endovascular repair. Of these, the procedure was successful in 147 (99%), and 2 (1%) patients underwent surgical conversion. The hospital death rate was 0%, and the 30-day death rate was 1%. During a follow-up period of 1 to 39 months (mean 12 +/- 9), 21 secondary procedures to treat endoleak (20) or to maintain graft limb patency (1) were performed in 17 patients (11%). There were no aneurysm ruptures or aneurysm-related deaths. CONCLUSIONS: Endovascular repair appears to have augmented treatment options rather than replaced open surgical repair for patients with AAA. Patients who previously were not candidates for repair because of medical comorbidity may now be safely treated with endovascular repair.     

Changes in the Proximal Neck of Abdominal Aortic Aneurysms Early after Endovascular Treatment

Long-term success of endovascular treatment of infrarenal abdominal aortic aneurysms (AAA) depends on secure attachment of the stent to the proximal and distal necks of the aneurysm. The purpose of this retrospective study was to detect changes in the proximal neck early after endovascular treatment of infrarenal AAA. Between November 1997 and December 1998, we performed endovascular treatment of infrarenal AAA in 43 patients. A bifurcated modular stent (AneuRx by Medtronic) was used in all patients. An oversized stent with a diameter 10% greater than the preoperative diameter of the proximal neck of the AAA was used in all cases. Follow-up examinations were carried out at 1, 6, and 12 months using plain roentgenography, color Doppler ultrasound, and CT scan with contrast injection. Statistical analysis was performed using the Student's t-test. Deterioration of the aortic neck is the result of a variety of mechanisms. The natural history of the infrarenal neck of AAA following endovascular repair (as well as conventional open repair) is progressive enlargement. Stenting could be an added risk factor for expansion. Strict follow-up is essential for early detection of this complication.     

Predictors of survival following open and endovascular repair of abdominal aortic aneurysms

Clinical decision making for asymptomatic abdominal aortic aneurysms (AAAs) weighs risk of aneurysm rupture, treatment hazards, and overall survival expectations. AAA diameter is the primary parameter in assessing rupture risk. Perioperative risk assessment has been extensively studied, and in-hospital mortality has been reduced to less than 8% with higher-risk open repair and less than 3% with endovascular repair. The purpose of this report is to determine risk factors that predict 2-year survival following open and endovascular AAA repair. We studied 334 patients enrolled in a multicenter clinical trial evaluating an endovascular graft in comparison to standard open repair of infrarenal AAA. Demographic, medical history, physical examination, laboratory, anatomic, procedural, and standardized risk score system variables were analyzed in a multivariable Cox proportional hazard model. Overall survival was 89% at 2 years. Heart disease, cancer, and stroke were the most common causes of death, and no deaths were due to AAA rupture. Cox modeling demonstrated that there were several independent predictors for death after AAA repair: smaller body mass index (p=0.005), Society for Vascular Surgery pulmonary risk score >or=1 (p=0.005), history of erectile dysfunction (p=0.008), history of heart valve replacement (p=0.008), lower preoperative platelet count (p=0.012), larger ratio of AAA diameter/proximal neck diameter (p=0.020), and lower ankle-brachial index (p=0.031). Age, gender, and open or endovascular treatment group are not significant independent risk factors for 2-year mortality in this study. Clinical, laboratory, and anatomic factors predict survival after open and endovascular repair of AAAs. With progressive reduction of in-hospital mortality, assessment of patient longevity after AAA repair has become a more important factor in clinical decision making. Use of valid predictors of patient survival will optimize resource utilization and improve overall patient outcomes. Better selection of patients for any method of repair may improve overall utility more than choice of open or endovascular techniques.     

Analysis of renal function after aneurysm repair with a device using suprarenal fixation (Zenith AAA Endovascular Graft) in contrast to open surgical repair

PURPOSE: This study was undertaken to assess the effect on renal function of open surgery and endovascular abdominal aortic aneurysm (AAA) repair with suprarenal fixation with the Zenith device. METHODS: Data for 279 patients with similar preoperative comorbid conditions were prospectively analyzed after AAA repair. One hundred ninety-nine patients underwent endografting with the Zenith AAA Endovascular Graft, which incorporates suprarenal fixation (Zenith standard risk group, ZSR), and 80 patients underwent open surgery (standard surgical risk group, SSR). Endovascular repair was also performed in 100 patients considered poor candidates for open repair (Zenith high risk group, ZHR). Serum creatinine concentration (SCr) and anatomic defects were assessed before the procedure, before discharge, and at 1, 6, 12, and 24 months in all patients who underwent endovascular repair, and before the procedure and at 1 and 12 months in patients who underwent open surgical repair (only SCr was measured before discharge). Renal function was also analyzed, with a creatinine clearance calculation (Cockcraft-Gault). Renal insufficiency was defined as an increase in SCr greater than 30% from a preoperative baseline value, any SCr concentration in excess of 2.0 mg/dL, or any need for dialysis. Cumulative renal infarction and arterial occlusion rates were calculated with computed tomographic, ultrasonographic, and angiographic data, and reported as cumulative values. RESULTS: Despite the initially superior renal function in the ZSR group at the pre-discharge evaluation (P =.01), there were no differences at 12 months with respect to rise in SCr greater than 30% (ZSR, 16%, vs SSR, 12%; P =.67), SCr rise greater than 2.0 mg/dL (ZSR, 2.5%, vs SSR, 3.4%; P =.66), incidence of renal artery occlusion (ZSR, 1%, vs SSR, 1.4%; P >.99), or infarction (ZSR, 1.5%, vs SSR, 1.4%; P >.99). Only one patient in each group required hemodialysis. Of note, both groups of patients demonstrated a reduction in creatinine clearance over 12 months, which then stabilized or improved by 24 months for ZSR patients. CONCLUSIONS: Renal dysfunction occurs in a subset of patients regardless of type of repair (open or endovascular with suprarenal fixation). The cause of renal dysfunction after open or endovascular repair with a suprarenal stent is probably multifactorial. The observed dysfunction occurs in a small number of patients, and the effect in the endovascular group (no data for the surgical group at 24 months) appears to be transient. The initial dysfunction, apparent in both groups over 12 months of follow-up, stabilizes or improves at 12 to 24 months.     

An analysis of standard open and endovascular surgical repair of abdominal aortic aneurysms in octogenarians

While elective open abdominal aortic aneurysm (AAA) repair has been shown to be safe in selected octogenarians, very little is known about the role of endovascular AAA exclusion in this high-risk cohort. A retrospective review of our vascular surgical registry from January 1996 to December 2001 revealed 51 octogenarians that underwent infrarenal AAA repair. Since 1999 all octogenarians who presented for AAA repair were evaluated for preferential endovascular stent graft placement. Over the 6-year period, 35 patients underwent standard open repair while 16 patients were found to be anatomic candidates for and were treated with an endovascular stent graft. Hospital and office charts were reviewed to compare the endovascular cohort to the standard open cohort. Factors considered included patient comorbidities, perioperative data, and operative outcomes. Statistical analysis was done using Wilcoxon rank sum test and Fisher exact test. The median age for the entire group was 83 years. There were 11 females in the open group and 1 female in the endovascular group. There were no statistically significant differences in preoperative patient comorbidities between groups. Total mortality for the entire series was 11.8 per cent but this included 5 ruptured AAAs, all of which patients died, and 11 additional AAAs that were symptomatic, of which 1 patient died. Total nonruptured mortality for the entire series was 2.2 per cent (0% for the endo-group and 3.3% for the open group). There were statistically significant differences between the endovascular versus the open groups when comparing aneurysm diameter (5.6 cm vs. 6.2 cm; P = 0.016), estimated blood loss (225 cc vs. 2100 cc; P < 0.001), ICU days (0 vs. 3; P < 0.001), length of hospital stay (2 days vs. 12 days; P < 0.001), and patients with blood transfusions (1 vs. 27; P < 0.001). When comparing postoperative morbidities, 4 of the endovascular patients (25%) and 25 of the open patients (68.6%) had a complication (P = 0.006). In conclusion, endovascular stent graft treatment of nonruptured infrarenal AAAs in octogenarians led to significantly better outcomes and should probably be considered the preferred treatment whenever anatomically appropriate. Endovascular exclusion of ruptured AAAs may potentially improve future outcomes in this high-risk group.     

Elective treatment of abdominal aortic aneurysm with endovascular or open repair: the first decade

OBJECTIVES: The development of endovascular aneurysm repair (EVAR) as an alternative to open repair of abdominal aortic aneurysms (AAA) has led to an increasing number of patients being treated by this less-invasive technique. It was anticipated that EVAR would reduce the operative mortality and morbidity compared with open repair. This study examined the initial 10-year experience in one center when both techniques were available to determine if there were advantages to one technique or the other, putting the results into the perspective of routine clinical care of patients with infrarenal AAA. METHODS: From June 1996 to May 2005, 677 patients underwent elective repair of their infrarenal AAA, of which 417 were treated with open repair and 260 by EVAR. Demographic and aneurysm-specific data, comorbidities, operative morbidity, mortality, and late outcome were analyzed. RESULTS: Open repair patients were 2 years younger (71 vs 74 years, P < .001), had larger aneurysms (6.01 +/- 1.38 cm vs 5.45 +/- 0.99 cm, P < .001), greater familial predisposition, a higher incidence of current smokers, and a higher incidence of chronic obstructive pulmonary disease than the EVAR group. There were no differences in renal function, hypertension, coronary artery disease, or heart failure between the two groups. Overall operative mortality was 3.1%; operative mortality per group was 3.5% for open and 2.7% for EVAR (P = .627). Procedure-related outcomes showed significant differences in operative blood loss and length of hospital stay in favor of EVAR, and 95% of the EVAR patients were discharged home vs 83% in the open repair group (P < .001). A Kaplan-Meier log-rank analysis showed no difference in early or long-term survival between open repair and EVAR (P = .20), but did show a difference in mid-term (3-year) survival favoring open repair (P < .002). Survival analysis by age (<70 and > or =70 years) showed no difference between treatment groups. CONCLUSIONS: Open repair and EVAR are both performed safely in patients treated for elective infrarenal AAA. EVAR has the perioperative advantages of reduced blood loss, reduced length of intensive care unit and hospital stay, and increased number of patients discharged to home. The mid-term survival advantage of open repair has been observed in other reports and deserves further study.     

Iliorenal artery bypass grafting to facilitate endovascular abdominal aortic aneurysm repair

Effective endovascular repair of an infrarenal abdominal aortic aneurysm (AAA) requires adequate proximal and distal landing zones to allow secure endograft attachment. We report a patient with an infrarenal AAA originating 3 mm below the left renal artery with cardiac morbidity that precluded open AAA repair. Left renal artery relocation with retroperitoneal iliorenal bypass grafting was performed to lengthen the proximal landing zone, which facilitated successful endovascular AAA repair. Postoperative surveillance after 3 years showed aneurysm reduction with a patent iliorenal bypass graft. This case underscores the utility of a combined open and endovascular approach in treatment of a challenging aortic aneurysm.     

Zenith AAA endovascular graft: intermediate-term results of the US multicenter trial

PURPOSE: The intent of this study was to assess the safety and effectiveness of the Zenith AAA Endovascular Graft compared with conventional aneurysm repair. MATERIAL AND METHODS: The study was conducted in a prospective, multicenter, nonrandomized, concurrent control manner. Physiologically similar patients with infrarenal abdominal aortic aneurysms (AAAs) underwent either open surgery or repair with the Zenith AAA Endovascular Graft. Separate analyses of physiologically challenged patients were performed. Follow-up was conducted at hospital discharge and at 1, 6, and 12 months (endovascular repair group) or 1 and 12 months (open surgical repair group). Evaluation included computed tomography, abdominal radiography, laboratory tests, and physical examination. Mortality (AAA-related and overall), morbidity, in-hospital recovery, renal function, and secondary interventions were assessed. Patients in the endovascular repair group were evaluated for change in aneurysm size, endoleak, graft migration, conversion, rupture, and device integrity. Statistical analyses were performed with the Kaplan-Meier method, Blackwelder test, propensity score assessment, two-sample t test, Yates-corrected Pearson chi(2) test, and Fisher exact test. RESULTS: Conventional open surgery was used in 80 patients, and 200 patients underwent repair with the Zenith AAA Endovascular Graft. Technical success was accomplished in 98.8% of patients in the open repair group and 99.5% in the endovascular repair group. Patients in the endovascular repair group had fewer significant adverse events within 30 days (80% vs 57%; P <.001). All-cause mortality was similar (endovascular, 3.5%; open surgery, 3.8%). Aneurysm-related mortality was higher with conventional surgery at 12 months (3.8% vs 0.5%; P =.04). In-hospital recovery and procedural measures were better for endovascular repair in all categories (P <.001). The incidence of endoleak was 17% at 30 days, 7.4% at 12 months, and 5.4% at 24 months. Aneurysm shrinkage (>5 mm) was noted in more than two thirds of patients at 12 months and three fourths of patients at 24 months. Renal dysfunction rate did not differ between groups. Migration (>5 mm) was detected in four (2%) patients through 12 months; none was greater than 10 mm or associated with adverse events through 24 months. Three conversions were performed within 12 months, one because of aneurysm rupture. Secondary procedures were more common in the endovascular group (11% vs 2.5%; P =.03). In total, 351 patients had endografts implanted, and 6 patients were noted to have barb separations through 12-month follow-up. No stent fractures were noted. CONCLUSIONS: The Zenith AAA Endovascular Graft is safe and effective for treatment of infrarenal AAAs. The high likelihood of decrease in aneurysm size provides evidence that treatment of aneurysms with this device reverses the natural history of aneurysmal disease. The importance of long-term follow-up is underscored by the small but defined incidence of barb separation and the potential for unforeseen failure modes.     

Extensive spinal cord ischemia following endovascular repair of an infrarenal abdominal aortic aneurysm: a rare complication

Postoperative paraplegia secondary to spinal cord ischemia (SCI) is an extremely rare and devastating complication of endovascular repair in abdominal aortic aneurysm (AAA) surgery. The reported incidence is only 0.21 % worldwide. This case of postoperative paraplegia occurred in a 60-year-old man immediately following endovascular repair of an infrarenal AAA. Postoperative magnetic resonance imaging showed multiple foci of SCI involvement from C5 to L1. However, neither cerebral spinal fluid drainage nor steroid therapy was effective; he was eventually admitted with no improvement in his neurological status. The mechanism remains multifactorial until now and needs more attention in perioperative management. We report the first case involved in the most significantly extensive SCI after endovascular repair of an infrarenal AAA.     

Relationship of proximal fixation to postoperative renal dysfunction in patients with normal serum creatinine concentration

OBJECTIVES: This study was performed to determine whether there is deterioration in renal function during follow-up in patients who have undergone endovascular aneurysm repair (EVAR), as recommended by the device manufacturers; to determine whether suprarenal fixation correlates with impairment of renal function; and to explore the potential implication of life-long surveillance of renal function with contrast-enhanced computed tomography. METHODS: One hundred forty-six consecutive patients underwent EVAR at our institution. Data from 113 of these patients who were free from preoperative renal insufficiency or postoperative renal disease were analyzed. Fifty-three patients received infrarenal (IR) fixation devices, and 60 patients received suprarenal (SR) fixation devices. All SR fixation devices were placed under investigational device exemption protocols. The average follow-up was 688 days. Sixty-five consecutive patients who had undergone open repair of an abdominal aortic aneurysm (AAA) served as the control group. RESULTS: Preoperative creatinine concentration, intraoperative blood loss, contrast volume, and number of contrast-enhanced procedures were not significantly different between the IR and SR groups. Two renal artery occlusions (1 SR, 1 IR; P=NS) were identified, and 8 renal infarcts (5 SR, 3 IR; P=NS). There was an increase in mean creatinine concentration in the open AAA, IR, and SR fixation groups at each time point in the analysis. Mean elevation in creatinine concentration at 12, 24, and 36 months was 0.10, 0.10, and 0.04 mg/dL, respectively, for open AAA repair; 0.20, 0.21, and 0.28 mg/dL for IR fixation; and 0.15, 0.21, and 0.12 mg/dL for SR fixation. At life table analysis, renal impairment at 36 months was seen in 36% +/- 9% of patients in the IR group, 25% +/- % of patients in the SR group, and 19% +/- 6% of patients in the open AAA group (P=.04 for IR fixation vs open AAA repair). CONCLUSIONS: A decrease in kidney function is seen after EVAR, regardless of fixation level, that is independent of renal disease and renal arterial occlusion. In patients with normal renal function the site of proximal fixation does not affect postoperative creatinine concentration. The decrease in renal function is likely related to the repetitive administration of contrast agent.     

Impact of endovascular repair on open aortic aneurysm surgical training.

PURPOSE: The purpose of this study was to determine the impact of an endovascular stent-graft program on vascular training in open aortic aneurysm surgery. METHODS: The institutional and vascular surgery fellow experience in aortic aneurysm repair during a 6-year period was reviewed. The 3-year period before introduction of endovascular repair was compared with the 3-year period after introduction of endovascular repair. All patients undergoing abdominal aortic aneurysm (AAA) or thoracoabdominal aortic aneurysm repairs were entered prospectively into a vascular registry and retrospectively analyzed to evaluate the changing patterns in aortic aneurysm treatment and surgical training. RESULTS: Between July 1994 and June 2000, a total of 588 patients with AAA or thoracoabdominal aneurysms were treated at Stanford University Medical Center. There were 296 (50%) open infrarenal AAA repairs, 87 (15%) suprarenal AAA repairs, 47 (8%) thoracoabdominal aneurysm repairs, and 153 (26%) endovascular stent-grafts. The total number of aneurysms repaired per year by vascular fellows before the endovascular program was 71.3 +/- 4.9 (range, 68-77) and increased to 124.7 +/- 35.6 (range, 91-162) after introduction of endovascular repair (P <.05). This increase was primarily caused by the addition of endovascular stent-graft repairs by vascular fellows (51.0 +/- 29.0/year [range, 23-81]). There was no change in the number of open infrarenal aortic aneurysm repairs per year, 53.0 +/- 6.6 (range, 48-56) before endovascular repair versus 47.0 +/- 1.7 (range, 46-49) after (P = not significant). There was a significant increase in the number of suprarenal AAA repairs per year by vascular fellows, 10.0 +/- 1.0 (range, 9-11) before endovascular repair compared with 19.0 +/- 6.5 (range, 13-26) after (P <.05). There was no change in the number of thoracoabdominal aneurysm repairs per year between the two groups, 8.0 +/- 3.0 (range, 4-11) before endovascular repair compared with 7.6 +/- 2.3 (range, 5-9) after. CONCLUSIONS: Introduction of an endovascular aneurysm stent-graft program significantly increased the total number of aneurysms treated. Although the number of open aneurysm repairs has remained the same, the complexity of the open aneurysm experience has increased significantly for vascular fellows in training.     

Evaluation of the effect of endovascular options on infrarenal abdominal aortic aneurysm repair

Endovascular devices designed to exclude flow to infrarenal abdominal aortic aneurysms (AAA) were approved by the Food and Drug Administration in the United States in 1999. This action allowed widespread use of this technology for AAA exclusion. The purpose of this report is to examine trends for use of these modalities, rates of rupture of AAA, and to compare results of open AAA repair with endovascular repair. Results were collected for all hospitals, except for Veterans Administration hospitals, by a state-wide repository. Data for the years 1996 through 1998 and 2001 through 2002 were evaluated, and data from 1999 through 2000 were excluded because no separate codes were available to distinguish between open and endovascular repair. The information gathered is based on the All Patient Refined Diagnostic Related Group (APRDRG; 3M, St. Paul, MN). An average of 718 open, elective AAA was performed between 1996 and 1998. This dropped to 503 open repairs from 2001 to 2002 (P < 0.005). During that same interval, 308 endovascular elective AAA repairs were performed, therefore the total rate of elective repair increased by 100. The average rate of ruptured AAA repairs from 1996 to 1998 was 121 per year, and this dropped to 89 from 2001 to 2002 (P < 0.005). The mortality of open AAA repair during the 1996 to 1998 and 2001 to 2002 intervals was unchanged (4.7%). Mortality from endovascular AAA repair between 2001 and 2002 was 1.9 per cent (P = 0.003). Major morbidity was 14.5 per cent for open, elective AAA repair and 6.3 per cent for endovascular elective repair from 2001 to 2002 (P < 0.001). These data suggest that the advent of endovascular AAA repair has contributed to a reduction in the rate of ruptured AAA repairs, an increase in total procedures performed, and a significant decrease in perioperative deaths and major complications when compared with open AAA repair.