Surveillance and medical therapy following endovascular treatment of chronic cerebrospinal venous insufficiency.

The debate regarding the possible link between chronic cerebrospinal venous insufficiency and multiple sclerosis (MS) is continuously becoming more and more contentious due to the current lack of level 1 evidence from randomized trials. Regardless of this continued uncertainty surrounding the safety and efficacy of this therapy, MS patients from Canada, and other jurisdictions, are traveling abroad to receive central venous angioplasty and, unfortunately, some also receive venous stents. They often return home with few instructions regarding follow-up or medical therapy. In response we propose some interim, practical recommendations for post-procedural surveillance and medical therapy, until further information is available.

Hybrid open and endovascular therapy for a proximal subclavian artery aneurysm.

A 57-year-old male presented with a large proximal right subclavian artery aneurysm that had been the source of upper extremity emboli on two occasions. A combined open and endovascular approach was undertaken involving a common carotid to vertebral artery autogenous bypass via a supraclavicular incision and endovascular repair of the aneurysm from a transbrachial approach. The patient did well postoperatively and recovered fully following a short hospitalization.

Prevention of contrast-induced nephropathy in vascular surgery patients.

Presently, only hydration and N-acetylcysteine have been shown to be effective in decreasing the incidence of radiographic contrast-induced nephropathy. We investigated the role of N-acetylcysteine and various hydration protocols in vascular surgery patients undergoing angiography. A single-center, randomized, placebo-controlled trial was conducted in patients with stable, preexisting renal dysfunction undergoing elective, outpatient angiography. Patients were randomized to outpatient oral hydration and N-acetylcysteine, inpatient hydration plus N-acetylcysteine, or our standard therapy of inpatient intravenous hydration alone. Two of twenty-eight (7%) patients who received outpatient oral hydration and N-acetylcysteine developed contrast-induced nephropathy, while two of 25 (8%) who recieved inpatient hydration plus N-acetylcysteine developed contrast-induced nephropathy and two of 25 (8%) who received standard therapy of inpatient intravenous hydration alone developed contrast-induced nephropathy. There was no statistical difference in incidence of contrast-induced nephropathy between the groups. No statistically significant independent risk factors were identified among the patients who developed contrast-induced nephropathy. N-Acetylcysteine did not confer additional benefit to patients treated with inpatient intravenous hydration. Outpatient oral hydration plus N-acetylcysteine was as effective at preventing contrast-induced nephropathy as inpatient therapies and avoided costly hospital admission.

Midterm results of endovascular infrarenal abdominal aortic aneurysm repair in high-risk patients.

Short-term and midterm clinical outcomes after endovascular repair of abdominal aortic aneurysms (AAAs) have been well documented. Evaluation of longer term outcomes is now possible. Here we describe our initial 100 high-risk patients treated with endovascular aneurysm repair (EVAR), all with a minimum of 5 years of follow-up. A retrospective review of prospectively recorded data in a departmental database was undertaken for the first 100 consecutive EVAR patients with a minimum of 5 years (range, 60-105 months) of follow-up performed between December 1997 and June 2001. Information was obtained from surgical follow-up visits and family doctors' offices. Endovascular repair of AAA in high-risk patients can be achieved with acceptably low postoperative mortality and morbidity. Longer term results in this high-risk cohort suggest that EVAR is effective in preventing aneurysm-related deaths at 5 years and beyond. All late mortalities were due to patients' comorbid diseases.

Midterm follow-up of inflammatory abdominal aortic aneurysms following endovascular repair.

The role of endovascular therapy in the management of inflammatory aneurysms of the infrarenal abdominal aorta has been controversial. Review of our endovascular database identified six patients who have undergone treatment for preoperatively diagnosed inflammatory abdominal aortic aneurysms. Outcomes measured were primary success of the procedure, variation in computed tomographic (CT) scan-defined perianeurysmal fibrosis, change in aneurysm size, development of endoleak, requirement of reintervention, aneurysm rupture, and progression or resolution of symptoms. At a median follow-up of 20 months (range 4-56 months), endovascular repair has been successful in all six patients. All patients demonstrated CT reduction of perianeurysmal fibrosis, with a median of 47% absolute reduction (range 33-69%, p = 0.014). All patients had aneurysm sac shrinkage, with a mean of 41% (range 6-86%, p = 0.04). There were no aneurysm ruptures or persistent endoleaks. Of the three patients who presented with abdominal or back pain, all are now symptom-free. One patient required reintervention for limb thrombosis of a bifurcated graft after 2 years. In conclusion, endovascular treatment of an inflammatory abdominal aortic aneurysm is safe and effective and the treatment of choice in anatomically suitable patients.

Cumulative sum failure analysis of the learning curve with endovascular abdominal aortic aneurysm repair.

PURPOSE: The purpose of this study was to evaluate the importance of experience and the learning curve with endovascular abdominal aortic aneurysm (AAA) repair. METHODS: A retrospective analysis was performed of all elective endovascular AAA repairs attempted by an individual surgeon and radiologist over a 4-year period. The primary outcome variable was achievement and 30-day maintenance of initial clinical success as defined by the Society for Vascular Surgery/American Association of Vascular Surgery reporting standards. Following standard statistical analysis, the cumulative sum (CUSUM) method was used to analyze the learning curve, with a predetermined acceptable failure rate of 10% and calculated 80% alert and 95% alarm lines. RESULTS: Ninety-six elective endovascular AAA repairs were attempted by this team between 1998 and 2002 (mean age 74 +/- 0.8 years; mean aneurysm diameter 5.98 +/- 0.8 cm). Initial clinical success was achieved and maintained in 85 of 96 patients (88.5%). Although results were acceptable throughout the study period, improved results with respect to the target failure rate (10%) were not achieved until 60 patients were treated. The learning or CUSUM curves did not differ for different device manufacturers, with improved results being achieved following 20 implantations of each device. The results did differ when comparing aortouniiliac grafts (n = 27) and bifurcated grafts (n = 64). Results with bifurcated grafts remained consistent throughout the study period, whereas with aortouniiliac grafts, results improved after only a few procedures in comparison with the target failure rate. CONCLUSION: Success rates with endovascular aneurysm repair will improve with an individual's experience. The CUSUM method is a valuable tool in the evaluation of this learning curve, which has credentialing and training implications. Although acceptable results were obtained throughout the study period, this analysis indicates that 60 endovascular aneurysm repairs, or 20 with an individual device, are necessary before optimal rates of initial clinical success can be achieved. These results can be achieved more readily with aortouniiliac grafts than with bifurcated grafts.

Regular monitoring of access flow compared with monitoring of venous pressure fails to improve graft survival.

Regular vascular access blood flow (Qa) surveillance is recommended to detect graft stenosis; however, there is little evidence that monitoring and correcting with angioplasty improves graft survival. This blinded, randomized, controlled trial of 112 patients studied time to graft thrombosis and graft loss, comparing monthly Qa plus standard surveillance (dynamic venous pressure and physical examination) (treatment group) to standard surveillance alone (control group). Only the treatment group was referred for angiogram if Qa <650 ml/min or a 20% decrease in Qa from baseline. Percutaneous angioplasty was performed for stenosis >50%. The rate of graft thrombosis per patient-year at risk was 0.41 and 0.51 in the control and treatment groups, respectively. Fifty-one interventions (0.93/patient-years at risk) were performed in the treatment group versus 31 interventions (0.61/patient-years at risk) in the control group. There was no difference in time to graft loss (P = 0.890). In a multivariate analysis, aspirin (ASA) therapy at baseline was associated with an 84% reduction in risk of graft thrombosis (odds ratio [OR], 0.14; P = 0.002). Higher baseline Qa (OR, 0.84; P = 0.05) and longer interval since graft insertion (OR, 0.97; P = 0.07) were associated with a decrease in graft thrombosis. Results reveal that graft surveillance that uses Qa increases the detection of stenosis, compared with standard surveillance; however, intervention with angioplasty does not improve the time to graft thrombosis or time to graft loss.