Georg Kretschmer

Endoluminal Stent–Grafts for Infrarenal Abdominal Aortic Aneurysms

BACKGROUND The treatment of aortic aneurysms with endovascular stents or stent-graft prostheses is receiving increasing attention as an alternative to major abdominal surgery. To define the clinical value of this technique, we prospectively studied the use of stent-graft endoprostheses made of nitinol and covered with polyester fabric for the treatment of infrarenal abdominal aortic aneurysms. METHODS We treated a total of 154 patients at three academic hospitals. Twenty-one patients with aortic aneurysms not involving the aortic bifurcation received straight stent-grafts, and 133 patients with aortic aneurysms involving the bifurcation and the common iliac arteries received bifurcated stent-grafts. After a unilateral surgical arteriotomy, the endoprostheses were advanced through the femoral arteries and placed under fluoroscopic guidance. Computed tomography and intraarterial angiography were performed during an average follow-up of 12.5 months. RESULTS The primary success rate, defined as complete exclusion of the abdominal aortic aneurysm from the circulation, was 86 percent in the group receiving straight grafts and 87 percent in the group receiving bifurcated grafts. In three patients the procedure had to be converted to an open surgical operation. Minor (n=13) or major (n=3) complications associated with the procedure (including 1 death) occurred in 10 percent of the patients. All patients had a postimplantation syndrome, with leukocytosis and elevated C-reactive protein levels. CONCLUSIONS Our results suggest that endovascular treatment of infrarenal abdominal aortic aneurysms is technically feasible and can effectively exclude abdominal aortic aneurysms from the circulation. With further refinement, endoluminal repair may emerge as an interventional strategy to treat infrarenal aortic aneurysms, especially in patients at high surgical risk.

MR angiography vs CT angiography in the follow-up of nitinol stent grafts in endoluminally treated aortic aneurysms

Abstract. Our objective was to evaluate the accuracy of contrast-enhanced 3D MR angiography (MRA) in the follow-up of patients with endoluminally treated aortic aneurysms and correlate these findings with uni- or biphasic CT angiography (CTA). Forty MR angiograms in 32 patients with implanted aortic nitinol stent grafts were compared to CTA. Twenty-two MR examinations were correlated with arterial-phase CTA (uniphasic), and 18 MR examinations were correlated with biphasic CTA. Uniphasic CTA demonstrated three type-1/type-3 endoleaks and four reperfusion (type-2) endoleaks. In addition, MRA depicted two type-2 reperfusion endoleaks that were missed by CTA. Using biphasic CTA, two type-1/type-3 endoleaks and three reperfusion (type-2) endoleaks were detected; of those, delayed scanning detected three reperfusion (type-2) endoleaks missed during arterial-phase CTA. In addition to the findings by CTA, MRA depicted another type-2 reperfusion endoleak. Magnetic resonance angiography is at least as sensitive as uni- or biphasic CTA for detecting endoleaks and may consequently offer advantages in patients with contraindications to iodinated contrast agents.

Endovascular Stent Grafting Versus Open Surgical Operation in Patients With Infrarenal Aortic Aneurysms

Background— Although transfemoral endovascular aneurysm management (TEAM) of infrarenal abdominal aortic aneurysms (AAA) is widely performed, open graft replacement is still considered the standard of care. The aim of this study was to investigate whether clear indications for TEAM can be established in patients with significant comorbidities without investigating differences in relative procedure efficacy or durability. Methods and Results— A propensity score–based analysis of 454 consecutive patients treated electively for AAA from January 1995 through December 2000 was performed. Of those 454 patients, 248 received open surgery and 206 received TEAM. In-hospital mortality rates (MRs) were compared. After adjusting for propensity scores, a Cox proportional hazard model (COX) was employed to test the influence of the respective treatment on postoperative 900-day survival estimates (SEs). Several potential preoperative risk factors were used as covariates. The MR of all patients was 3.7%. Explorative anal...

Endovascular AAA treatment: Expensive prestige or economic alternative?

OBJECTIVES To compare the costs of endovascular aneurysm treatment versus open surgery during the perioperative period. METHODS Retrospective analysis of a consecutive series of 44 patients undergoing infrarenal abdominal aneurysm repair from February 1995 to March 1996 at a university teaching hospital. RESULTS No endovascular procedure was converted to open repair. Operative time was shorter for endovascular treatment (207.6 min vs. 229.1 min, n.s.), as well as postoperative intensive care unit stay (ICU, 22.7 h vs. 55.0 h, p = 0.017) and the postoperative recovery period (5.6 days vs. 13.3 days, p < 0.001). Open surgery generated significantly more costs (25,374.07 ECU vs. 22,268.78 ECU, p < 0.001), despite evaluation and a more expensive endovascular procedure (10,699.48 ECU vs. 4032.01 ECU, p < 0.001). During the study, costs for open surgery exceeded the cost for endovascular treatment by 13.95%. CONCLUSIONS Endovascular aneurysm treatment is cost effective and less expensive than open surgery. The main reason for cost saving is faster patient recovery after surgery, associated with a shorter LOS in the patients treated with endovascular procedure.

INFLUENCE OF POSTOPERATIVE ANTICOAGULANT TREATMENT ON PATIENT SURVIVAL AFTER FEMOROPOPLITEAL VEIN BYPASS SURGERY

To examine whether anticoagulants given after autologous saphenous bypass surgery influenced patient survival 119 patients who received such a graft for obliterative arterial disease were recruited for a controlled clinical trial. Patients were randomly assigned to start, in the second postoperative week, phenprocoumon (60 patients) or no treatment (59 patients). The median duration of survival for all patients was greater than 60 months, and the 75%-quartile was 39.0 (SE of the median 3.9) months. 10 patients died in the treated group and 20 in the control group. The treated group had a greater probability of survival (p less than 0.023, Breslow; p less than 0.043, Mantel). Graft occlusions occurred in 11 patients in the treatment group and in 17 controls. When these patients were excluded from the analysis, the difference in probability of survival between the two groups remained significant (p less than 0.009, Breslow; p less than 0.013, Mantel).

The relationship between the common femoral artery, the inguinal crease, and the inguinal ligament: A guide to accurate angiographic puncture

The variability of the extraperitoneal puncture space between the inguinal ligament and the inguinal crease was evaluated in 100 patients. The distance between the inguinal crease and the inguinal ligament varied from 0 to 11 cm (average 6.7 cm±1.9 SD), the average value for women (7.5 cm±1.9 SD) being significantly greater than that for men (6.3 cm±1.9 SD, p=0.0128). The bifurcation of the common femoral artery was found below the inguinal crease in 20%, at the same levelin 3.5%, and above it in 76.5% of cases. Consideration of these results will help avoid intraperitoneal puncture and improve the rate of successful antegrade puncture of the femoral artery.

Endovascular Therapy of Inflammatory Aortic Aneurysms: A Meta-Analysis

Purpose: To report a meta-analysis of results from endovascular aneurysm repair (EVAR) of inflammatory aortic aneurysms (IAA). Methods: A comprehensive literature review was performed to identify all studies reporting the results of EVAR in patients with IAA. To be included in the analysis, an article had to provide a minimum follow-up of 6 months, information about primary technical success, details of immediate and long-term complications, and evaluation of at least one of the basic outcome criteria: changes in aneurysm sac diameter, periaortic fibrosis (PAF), and/or renal impairment. All studies were reviewed by 2 independent observers for the inclusion criteria. Data were retrieved on the technical and clinical success, outcome criteria, mortality in follow-up, and reinterventions from 14 articles selected from among 701 initially identified. Results: The 14 articles encompassed 46 patients (45 men [97.8%]; mean age 65 years, range 59–75) with a mean follow-up of 18 months after endovascular repair of IAAs located in the abdominal aorta. The primary technical success rate was 95.6% (44/46) and the 30-day clinical success rate was 93.4% (43/46). The median aneurysm sac diameter regression was 11 mm. Of 43 patients with PAF prior to the intervention, 22 (51.2%) patients showed complete regression, 18 (41.8%) remained unchanged, and 3 (7.0%) showed progression after EVAR. Renal impairment disappeared in 11 (45.8%) of 24 patients. Reinterventions were reported in 8 patients. The procedure-related and follow-up mortality rates were 0% and 13.0%, respectively. Conclusions: EVAR of IAA is feasible, excludes the aneurysm effectively, and reduces PAF and renal impairment in most patients with very low periprocedural and midterm mortality and an acceptable reintervention rate.

Endovascular management of “Endoleaks” after transluminal infrarenal abdominal aneurysm repair

PURPOSE To investigate the reasons for endoleaks after transluminal infrarenal abdominal aneurysm management and the potential for transluminal interventions in subsequent management. METHODS Prospective analysis of 50 consecutive patients undergoing endovascular aneurysm repair at a single institution with Stentor and Vanguard grafts from March 1995 to March 1997. SETTING Academic teaching hospital. RESULTS Two procedures were converted for other reasons than leak. In the remaining 48 successful procedures endoleaks were detected in 11 (22.9%): proximal aortic leak (2.1%), distal aortic leak (8.3%), iliac leak (12.5%). Leaks were treated at the initial procedure in five patients, resulting in 87.5% excluded aneurysms. Twelve and a half per cent were discharged with a primary leak. Redo was performed on all iliac leaks within 7 weeks. All aortic leaks showed spontaneous thrombosis within 3 months, but reappeared with local aneurysm expansion. Aortic redo-procedures were performed by proximal tubular extension or converting a tube graft into a bifurcation graft. All rescue procedures were successful. Secondary leaks have been observed twice in this series, both treated by endovascular means. CONCLUSIONS Endovascular treatment of primary and secondary endoleaks is possible, and may be a safe alternative to a difficult open procedure.

Improved Survival After Abdominal Aortic Aneurysm Rupture by Offering Both Open and Endovascular Repair

BACKGROUND In the treatment of ruptured abdominal aortic aneurysm (rAAA), the results of open graft replacement (OGR) have remained constant but discouraging for the last 4 decades. Provided suitable anatomy, elective endovascular abdominal aortic aneurysm repair (EVAR) is less invasive and leads to improved perioperative mortality. Thus, it is reasonable to assume that endovascular treatment should improve the results of rAAA therapy. OBJECTIVE To determine whether the use of both endovascular and open repair of rAAA leads to improved results. DESIGN A single-center, retrospective analysis of 89 patients suffering from rAAA treated either by EVAR or OGR. PATIENTS From October 1999 until July 2006, a consecutive series of patients with rAAA were analyzed. Time was divided into 2 periods of 41 months. During the first period, 42 patients were treated by OGR exclusively. Period 2 started with the availability of an EVAR protocol to treat rAAA; 31 patients received open repair while 16 patients underwent EVAR. MAIN OUTCOME MEASURES Kaplan-Meier survival estimates were calculated and compared. RESULTS Survival estimates showed a statistically significant reduction in overall postoperative mortality following the introduction of EVAR (P < .03). The 90-day overall mortality rate was reduced from 54.8% to 27.7% during the second period (P < .01). Survival of patients older than 75.5 years was especially improved (75% vs 28.6%; P < .01). There was a parallel pattern of significant reduction of the mortality rate after OGR to 29% (P < .03). CONCLUSION Offering both EVAR and OGR to patients with rAAA leads to significant improvements in postoperative survival.

Endovascular Repair of Inflammatory Aortic Aneurysms: Long-Term Results

OBJECTIVE Our objective was to report the long-term follow-up results of endovascular aneurysm repair of inflammatory aortic aneurysms. CONCLUSION Endovascular aneurysm repair of inflammatory aortic aneurysms excludes the aneurysm and seems to reduce the size of the aneurysmal sac and the extent of periaortic fibrosis with acceptable periinterventional and long-term morbidity.