Novel approach in using ultrasound in treating acute limb ischemia.

BACKGROUND: It is imperative to gain safe access into the occluded targeted vessel and begin treating acute extremity limb ischemia. Often the origin of the targeted native artery or bypass graft will have a flush occlusion making it difficult to cannulate. This paper looks at the novel use of portable ultrasound to evaluate the origin of the artery or bypass graft to help facilitate the start of thrombolysis. METHODS: We reviewed our last 2 years of acute limb ischemia in our patients with high risk factors and comorbidities. We reviewed the use of ultrasound in these cases from the initial use of gaining femoral access to real time ultrasound and fluoroscopic guidance into the targeted native artery or bypass graft to begin needed thrombolysis. RESULTS: We had 26 acute limb ischemia in 10 patients with native arterial circulation and in 16 patients with either saphenous or prosthetic bypass grafts. Ultrasound was used in gaining safe access with no complications in 22 contralateral and 2 antegrade femoral and 4 direct-graft accesses. Ultrasound was used in 6 of these cases to help gain access in the occluded graft (4 cases) and saphenous veins (2 cases). It was successful in all cases but one case which had bleeding. CONCLUSIONS: Ultrasound is increasing in its application including acute limb ischemia with flush occlusions of native arteries and bypass grafts.

First Clinical Experience With Targeted REnal Nerve Demodulation (TREND-1) Using a Neurotropic Agent for the Treatment of Sympathetic Hypertension.

AIMS: To evaluate the feasibility and safety of a novel targeted neuromodulatory treatment for sympathetic hypertension involving a one-time local injection of neurotropic agents near renal nerves. METHODS AND RESULTS: Seven patients suffering from uncontrolled hypertension per ESH-ESC guidelines were treated using a single dose of NW2013, a neurotropic Na+/K+ ATPase antagonist. A microneedle catheter was used to administer 1.2 mL of NW2013 (0.6 mL per artery) to the perivascular space surrounding renal arteries using percutaneous endovascular procedures under fluoroscopic guidance. All patients were successfully treated without any procedural complications. Patients were followed for 12 months post procedure, and office and 24-hour ambulatory blood pressure measurements were made. Both office and ambulatory blood pressures were lower at 24 hours, 1 month, and 3 months after treatment. The decrease in office blood pressure was greater than the decrease in ambulatory blood pressure. A reduction in medication regimen was also observed in 2 patients. One patient suffered a cerebrovascular event after 6-month follow-up and died from stroke, unrelated to the treatment. Overall, the reduction in office and ambulatory blood pressure was sustained over the course of 12 months. CONCLUSIONS: Treatment of hypertension using local administration of NW2013 near renal nerves appears to be feasible and safe. Large, controlled, randomized, and blinded clinical studies with monitoring of patient compliance to daily oral medication are recommended to further establish the efficacy of this novel treatment.

Wall apposition assessment and performance comparison of distal protection filters.

PURPOSE: To assess the wall apposition of 3 distal protection filters used in carotid artery stenting (CAS) for cerebral protection and quantify the effect on the in vitro capture efficiency of the filters under simulated physiological flow conditions. METHODS: The 3 distal protection filters (Angioguard XP, FilterWire EZ, and RX Accunet) were deployed in silicone flow models of 5.0-, 5.5-, and 6.0-mm inner diameter and were tested at a mean flow rate characteristic of the human internal carotid artery while injecting polydispersed microspheres simulating plaque emboli. The injected microspheres had a diameter larger than the pore size of the devices tested, so it was conjectured that any microspheres missed by the device traveled between the device basket and the vessel wall. Varying the diameter of the vessel phantom within the recommended vessel diameter treatment range for each device simulated the variability of vessel diameter in vivo, allowing the quantification of device wall apposition. RESULTS: None of the devices tested completely prevented distal embolization in the flow model. The RX Accunet device has the best overall wall apposition, yielding gaps of 0.075% of the vessel cross-sectional area. The FilterWire EZ device had the best overall average filtration rate, failing to capture only 0.8% of plaque particles. There were no statistically significant differences in the wall apposition assessment or the capture efficiency of the RX Accunet and FilterWire EZ devices. CONCLUSION: Several complications related to apposition of the filter basket on the vessel wall and device retrieval were detected in all the devices. It is inferred that the adaptability of the filter basket to conform to the vessel cross section at the site of deployment is the primary design variable responsible for distal embolization during CAS with cerebral protection.

Type 2 endoleaks after abdominal aortic aneurysm stent grafting with systematic mesenteric and lumbar coil embolization.

We evaluated the results of our policy of systematic coil embolization of the inferior mesenteric artery (IMA) and/or lumbar arteries (LAs) prior to endovascular abdominal aortic aneurysm (AAA) repair (EVAR). We retrospectively reviewed all patients undergoing EVAR over a 4-year period at one hospital. Results were analyzed using uni- and multivariate analyses. Fifty-five male patients with an average age of 71 years were evaluated. Follow-up averaged 15 +/- 13 months. The IMA was either coiled or occluded in 30 cases. One or more LAs were coiled in 29 patients. An average of 1.3 LAs per patients were coiled (range 0-6). There were no immediate or late complications from coiling. At last follow-up, 14 AAAs showed no change in diameter, one increased by 2 mm, and the remainder (n = 40) decreased by 7.5 +/- 6 mm in maximal diameter. Only five (9%) type 2 endoleaks were detected during follow-up. Three were associated with AAA size increase. Four of the five were treated with additional coiling, with good results. By logistic regression, neither endoleak occurrence nor AAA shrinkage correlated with LA or IMA coiling. However, by multivariate analysis, completeness of lumbar coiling correlated negatively with aneurysm shrinkage (p = 0.04) and IMA coiling correlated positively with aneurysm shrinkage (p = 0.04). Coil embolization of the IMA and/or LAs prior to EVAR can be safely accomplished in a large number of cases and is associated with a low incidence of type 2 endoleaks. We cannot at present demonstrate a benefit to LA embolization in terms of endoleak prevention or AAA shrinkage. However, IMA embolization may be of benefit in terms of AAA shrinkage.

Distal embolic protection during femoropopliteal atherectomy.

We report on a series of 10 consecutive cases of superficial femoral and popliteal artery atherectomy with the SilverHawk device, carried out for the treatment of peripheral vascular atherosclerosis. All cases were done with the use of a distal embolic protection device. Debris were retrieved in the filter in each case. Implications are discussed, along with a review of the available literature on this device.

Early experience in the application of distal protection devices in treatment of peripheral vascular disease of the lower extremities.

The objectives of this study were to reduce the risk of showering distal vessels with thromboemboli created during percutaneous interventions of the arteries in the lower extremities. Distal protection devices have been used in coronary and carotid interventions. Hence, using similar techniques, these filters and occlusion balloons were advanced past the targeted lesions and distally into femoral and popliteal arteries. Once opened, these devices allowed standard angioplasty and stent placement and captured the dislodged thromboemboli. Five cases were performed with the distal protection devices. One case used the distal occlusion balloon and four with the filter system. All five passed the lesion and were deployed. All five devices were retrieved without incident and were retrieved with substantial debris. There were no adverse events. The use of distal protection to treat high-risk or unstable lesions in the lower extremities shows great promise. Further case will be needed to evaluate the device for feasibility and safety.

History and current status of endovascular management for the extracranial carotid and supra-aortic vessels.

Few procedures in the history of medicine have been more controversial than carotid artery stenting (CAS) for the management of carotid artery occlusive disease. Introduced just as the randomized trials were establishing carotid endarterectomy as the gold standard for carotid interventions, CAS has finally reached the point in its development when dedicated stenting systems are being tested in randomized clinical trials. Assisted by the concomitant use of distal protection devices, CAS has shown equipoise with endarterectomy in terms of safety at 30 days. This review summarizes the completed and ongoing CAS trials and the applications of endovascular techniques in the supra-aortic vessels.

Updated review of the global carotid artery stent registry.

The purpose of this article was to review and update the current status of carotid artery stent placement in the world. Surveys of major interventional centers in Europe, North and South America, and Asia were initially completed in June 1997. Subsequent updates from these 24 centers in addition to 29 new centers have been obtained to bring up to date the information. The survey asked the various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 12392 procedures involving 11243 patients. There was a technical success of 98.9% with 12254 carotid arteries treated. Complications that occurred during the carotid stent placement or within a 30-day period following placement were recorded. Overall, there was transient ischemic attack rate of 3.07%, minor strokes of 2.14%, major strokes of 1.20%, and procedure-related deaths of 0.64%. The combined minor and major strokes and procedure-related death rate was 3.98% based on procedure number. With nonprocedure-related death rate of 0.77%, the total stroke and death rate was 4.75%. Subsets of questions were directed at the new use of distal embolic protection devices; there were 6753 cases done without protection and which incurred a 5.29% rate of strokes and procedure-related deaths. In the 4221 cases with cerebral protection, there was a 2.23% rate of strokes and procedure-related deaths. Restenosis rates of carotid stenting have been 2.7%, 2.6%, and 2.4% at 1, 2, and 3 years, respectively. The rate of neurologic events after stent placement has been 1.2%, 1.3%, and 1.7% at 1, 2, and 3 years, respectively. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative for vascular surgery, especially for patients who are high risk for standard carotid endarterectomy. The periprocedure risks for major and minor strokes and death are generally acceptable at this early stage of development and have shown an improvement with technological developments, including distal embolic protection.

Endovascular treatment of innominate artery stenosis in a bovine aortic arch--a case report.

Recent reports have established the feasibility and safety of percutaneous transluminal angioplasty and stent placement in the treatment of innominate artery occlusive disease. Although the long-term durability of these endovascular approaches has not been clearly established, they are particularly attractive in patients who are not considered good candidates for surgical reconstruction. The authors present a case involving a morbidly obese Hispanic woman who had undergone previous coronary artery bypass and complained of right visual symptoms, dizziness, and right upper extremity claudication. Because of her unusual bovine anatomy and the desire to avoid reoperating in her chest, a unique approach with a left subclavian-to-carotid bypass and innominate artery angioplasty and stenting was used.

Evaluation of a model to predict poor survival in patients undergoing elective TIPS procedures.

PURPOSE: To validate a previously published model to predict the probability of patient death within 3 months after an elective transjugular intrahepatic portosystemic shunt (TIPS) procedure. The model is implemented with use of a nomogram or a formula. MATERIALS AND METHODS: Patients who underwent an elective TIPS procedure between May 1, 1999, and May 1, 2001, were selected. Patients who underwent emergency TIPS creation and patients with serum creatinine levels greater than 3.0 mg/dL were excluded. A total of 72 patients met the inclusion criteria. The patients were divided into two groups: group A (ethanol-induced cirrhosis; n = 23) and group B (non-ethanol-induced cirrhosis; n = 49). The model was applied and the predicted probability of death was compared to actual patient survival. A high risk score (R > or = 1.8) is associated with a high risk of death within 3 months after TIPS creation. Survival curves were estimated with use of Kaplan-Meier product limit estimates and were compared with use of the log-rank test. The model's accuracy was evaluated with use of the c-statistic. P values lower than.05 indicated statistical significance. RESULTS: The technical success rate was 98.7%. The 3-month survival rate for the whole group was 79.7%. The predicted mortality rate was higher than the observed mortality rate. The c-statistic was 0.65 for the formula and 0.66 for the nomogram. Patients with a risk score of at least 1.8 had a 3-month survival rate of 54.6% and patients with a risk score lower than 1.8 had a 3-month survival rate of 84.9% (P =.037). CONCLUSION: These results confirm that, after an elective TIPS procedure, patients with risk scores of at least 1.8 have a significantly lower 3-month survival rate than patients with risk scores lower than 1.8.