Stefan Schulte

Spinal Cord Stimulation in the Treatment of Peripheral Vascular Disease: Results of a Single-Center Study of 258 Patients

This report is of a retrospective study of data from 258 patients who received spinal cord stimulation (SCS) for the treatment of peripheral vascular disease as a result of arteriosclerosis. The patients’ clinical outcomes were monitored over a period of 18 months. In patients with a low baseline transcutaneous oxygen pressure (TcPO2) value of <10 mm Hg, limb survival at 18 months of follow-up (estimated by use of Kaplan-Meier survival analysis) was 77.8%, and this was even higher, at 89.5%, in patients with a medium baseline TcPO2 value of 10-30 mm Hg. This successful treatment was accompanied by a sustained increase in TcPO2 values to approximately 30 mm Hg in both of these groups. In looking at diabetic and nondiabetic patients, there is no difference in limb survival as a result of the treatment. It is concluded that SCS is an effective therapy in improving limb survival in patients with peripheral vascular disease. In addition, TcPO2 values at baseline may be a useful predictor of treatment outcome.

Endovascular Treatment of Iatrogenic and Traumatic Carotid Artery Dissection

This paper reports on the early and midterm results of endovascular treatment of acute carotid artery dissections, its specific problems, and its limitations. We encountered seven patients with symptomatic extracranial carotid artery dissection, three cases of which occurred after carotid endarterectomy, two after carotid angioplasty and stenting, and two after trauma. Balloon-expandable and self-expanding stents were placed using a transfemoral approach. Success in restoring the carotid lumen was achieved in all patients. No procedure-related complications occurred. All patients experienced significant clinical improvement while in the hospital and achieved complete long-term recovery. At follow-up (mean, 22.4 months), good luminal patency of the stented segments was observed. In conclusion, in this small series, primary stent-supported angioplasty seems to be a safe and effective strategy in the treatment of selected patients having acute traumatic extracranial carotid artery dissection, with excellent early and midterm results. Larger series and longer-term follow-up are required before definitive recommendations can be made.

Two-dimensional versus three-dimensional CT angiography in analysis of anatomical suitability for stentgraft repair of abdominal aortic aneurysms:

Background The morphological analysis prior to endovascular abdominal aneurysm repair (EVAR) plays an important role in long-term outcomes. Post-imaging analysis of computed tomographic angiography (CTA) by three-dimensional reconstruction with central lumen line detection (CLL 3D-CTA) enables measurements to be made in orthogonal slices. This might be more precise than equal post-imaging analysis in axial slices by two-dimensional computed tomographic angiography (2D-CTA). Purpose To evaluate the intra- and interobserver variability of CLL 3D-CTA and 2D-CTA post-imaging analysis methods and the agreement between them in pre-EVAR suitability analysis of patients with abdominal aortic aneurysm (AAA). Material and Methods Anonymized CTA data-sets from 70 patients with AAA were analyzed retrospectively. Length measurements included proximal and distal aortic neck lengths and total distance from the lower renal artery to the higher iliac bifurcation. Width measurements included proximal and distal neck diameters, maximum AAA diameter and common iliac diameters just above the iliac bifurcations. The measurements were performed in random order by two vascular surgeons, twice per method with 1-month interval between readings. In the CLL 3D-CTA method we used semi-automated CLL detection by software and manual measurements on CTA slices perpendicular to CLL. The equal measurements in 2D-CTA were performed manually on axial CTA slices using a DICOM viewer workstation. The intra- and interobserver variability, as well as the agreement between the two methods were assessed by Bland-Altman test and bivariate correlation analysis. Results The intraobserver variability was significantly higher in 2D-CTA measurements for both readers. The interobserver variability was significant in 2D-CTA measurements of proximal neck dimensions while the agreement in CLL 3D-CTA analysis between the two readers was excellent in all studied parameters. The agreement between the two suitability analysis techniques was poor for both readers, especially in measurements of proximal necks dimensions and in total aortoiliac length (p = 0.001). Conclusion In pre-EVAR morphological evaluation of AAAs the CLL-3D CTA post-imaging analysis has better intra- and interobserver correlation than 2D-CTA and might represent a useful tool for the proper selection of endografts type and size.

Surgical outcome of degenerative versus postreconstructive extracranial carotid artery aneurysms.

OBJECTIVES Extracranial carotid artery aneurysms (ECAAs) are rare vascular lesions, and large series with short-term and long-term outcomes are seldom reported. This study compared the clinical presentation and conventional treatment outcomes of different ECAA types according to their etiology. METHODS We retrospectively reviewed the data of 55 consecutive patients (47 men, 8 women) with 61 ECAAs who were treated from January 1986 to December 2007 by conventional surgical techniques. The patients were a mean age of 65 +/- 11 years (range, 30-92 years). Thirty-two ECAAs (52.5%) occurred postoperatively after previous carotid endarterectomy, of which 26 patients had 29 degenerative aneurysms (47.5%). Clinical presentation included cerebral stroke in three patients (4.9%) and transient ischemic attack in 26 (42.7%). Mean follow-up was 42.7 +/- 22.0 months. Statistical analysis was performed within and between degenerative and post-reconstructive ECAA subgroups of patients. RESULTS Open aneurysm resection included 27 extended polytetrafluoroethylene interposition grafts, 12 venous grafts, and 22 closures using synthetic patch. Cumulative 1-year primary patency rates were 86.9% for the degenerative ECAAs and 96% for the postoperative ECAAs, with respective secondary patency rate at 5 years of 80% and 93.3%. The 5-year patency rate was 88.9% for synthetic grafts compared with 66.7% for vein grafts and 86.4% for synthetic patches. These differences were not statistically significant (P > .05). Complications for the degenerative ECAAs included two reconstruction thromboses <30 days, two cerebral strokes, and one myocardial infarction. The patients with postoperative ECAAs experienced one early thrombosis and two strokes postoperatively. Two patients (3.6%) from the degenerative ECAA subgroup died of cardiac decompensation (n = 1) and cerebral ischemic event (n = 1). CONCLUSIONS Despite the different trends, no significant differences were found between degenerative ECAA and postoperative ECAA patients in clinical presentation, localization, and surgery outcomes. The good middle-term and long-term patency rates of synthetic graft reconstruction justify its use in the treatment of ECAAs, and it is less time consuming and technically demanding compared with vein interposition graft.

Spinal Cord Stimulation for Peripheral Vascular Disorders

Publisher Summary This chapter focuses on the use of spinal cord stimulation (SCS) for treating peripheral vascular disorders (PAD). PAD includes a diverse group of disorders that lead to progressive stenosis or occlusion of the aorta and its noncoronary branch arteries, including the carotid, upper extremity, visceral, and lower extremity arteries. The most common cause of lower extremity PAD worldwide is atherosclerosis and thus the epidemiology and clinical consequences of PAD are closely associated with classic atherosclerosis risk factors such as smoking, diabetes, hypertension, hyperlipidemia, and family history. Spinal cord stimulation (SCS) provides good pain relief (60–80% of the patients), provides an improvement in claudication distance, and provides an improvement in activities of daily living (ADLs). These apparent benefits have been attributed to improvement of the microcirculation in the affected limb. The careful selection of patients on the basis of their local microcirculation and positive response to a period of trial stimulation can further improve the probability of limb salvage. The most frequent reported complications are lead migration or dislocation of the lead, resulting in loss of paresthesia coverage over the affected limb or unwanted stimulation, and lead fracture. To avoid these complications, surgeon implanters must attend to appropriate careful fixation of the electrode array to the thoracolumbar fascia. In cases of lead migration, the lead can easily be replaced surgically, under fluoroscopic guidance.

Technically Challenging Cases for Endovascular Repair of Aortic Aneurysms

Aortic aneurysms and treatment thereof continue to challenge the vascular surgeon. The natural history of aneurysms has been well documented, and the indica- tion for treatment extensively discussed [56]. The goal of treatment is to prevent aneurysm rupture and distal embolization. It is well known that aneurysm size is the most important criterion determining the main risk, namely rupture. Arterial hypertension is the second most important parameter that influences this risk, according to Laplace’s law (tension on the wall is produced by the product of pressure and radius). As experience has accu- mulated, the durability of open surgical therapy, which was introduced over 50 years ago, has also been well doc- umented [29]. In contrast, there are very few data on the long-term durability of endovascular aneurysm repair (EVAR), which was introduced as a new approach about 15 years ago [45].