Prospective randomized study evaluating an absorbable cyanoacrylate for use in vascular reconstructions

BackgroundAn easy-to-use vascular sealant with good safety and efficacy is needed to prevent anastomotic bleeding in vascular surgery. This study evaluated the safety and efficacy of cyanoacrylate surgical sealant in establishing hemostasis of expanded polytetrafluoroethylene to arterial vascular anastomoses in arteriovenous (AV) grafts and femoral bypass grafts.MethodsThis multicenter, randomized, controlled, open-label study was conducted in a hospital setting at 12 sites: 10 in the United States and 2 in Europe. A total of 151 patients undergoing femoral bypass procedures or AV shunt procedures for hemodialysis access using expanded polytetrafluoroethylene grafts were randomized 2:1 to receive cyanoacrylate surgical sealant or the control (oxidized cellulose) between April 26, 2004, and January 18, 2005. Randomization was stratified by clinical site and type of procedure. After the anastomosis, cyanoacrylate surgical sealant or the control was applied to all anastomosis sites for patients undergoing femoral bypass procedures and to only the arterial anastomosis sites for patients undergoing AV shunt procedures. The primary end point was the elapsed time from clamp release to hemostasis. Secondary end points were the proportion of patients achieving hemostasis at t = 0 (immediate), 1, 5, or 10 minutes after clamp release, use of additional adjunctive measures to achieve hemostasis, and occurrence of adverse events.ResultsBaseline demographics and clinical characteristics showed that the two treatment groups were similar at baseline. The mean time from clamp release to hemostasis was 119.3 seconds with cyanoacrylate surgical sealant vs 403.8 seconds with the control (P < .001). Immediate hemostasis was achieved in 54.5% of patients receiving cyanoacrylate surgical sealant and in 10% of those receiving the control. The proportion of patients requiring additional adjunctive measures was lower with cyanoacrylate surgical sealant, and the occurrence of adverse events was similar in both groups.ConclusionsThis study demonstrates that cyanoacrylate surgical sealant is effective at reducing the time to hemostasis and achieving immediate hemostasis in AV shunt and femoral bypass procedures and that it is safe for internal use. Cyanoacrylate surgical sealant is an easy-to-use vascular sealant with good safety and efficacy that significantly decreases anastomotic bleeding in vascular surgery

Endovascular occlusion of right to left arteriovenous shunt associated with persistent left superior vena cava

Left-sided superior vena cava (SVC) as the result of persistence of the left superior cardinal vein in postnatal life is a rare congenital anomaly, is usually associated with other cardiac defects, and can cause symptoms of right to left shunt. We report the case of a 58-year-old Asian man with a history of end-stage renal disease and Ebstein anomaly that was corrected surgically who presented with progressively worsening disabling dyspnea. An echocardiogram with concomitant intravenous saline injection raised the suspicion of right to left shunt, a finding that was confirmed with contrast injection of the left SVC that rapidly filled the left heart chambers and subsequently the aortic arch. To treat this anomaly, we accessed the left basilic vein under ultrasound guidance and inserted a 14F sheath into the left subclavian vein. A covered stent was then prepared at the back table with three Prolene 4-0 sutures that were wrapped around the middle portion of the graft to achieve a controlled area of stenosis after deployment. The stent graft was placed along the proximal innominate vein and the contiguous part of the left SVC. Coil embolization was then performed with coils that were positioned at the stenotic area of the covered stent. An immediate venogram demonstrated residual flow into the left SVC; however, a delayed venogram 2 weeks after the procedure showed occlusion of the left SVC and the development of collaterals to the right innominate vein that was draining to a normal right SVC. The patient remained marginally hypotensive after surgery, but he soon noted a substantial improvement in his symptoms. A repeat echocardiogram with intravenous saline injection confirmed the correction of the right to left shunt. Endovascular repair of persistent left SVC is feasible and safe and can be performed with minimal morbidity

Hybrid approach to complex thoracic aortic aneurysms in high-risk patients: Surgical challenges and clinical outcomes

BackgroundEndovascular therapy is a less invasive alternative treatment for high-risk patients with thoracic aortic aneurysms. However, this technology alone is often not applicable to complex aneurysmal morphology. The purpose of this study was to evaluate the utility of hybrid strategies in high-risk patients who are otherwise unsuitable for endovascular therapy alone.MethodsDuring an 18-month period, 31 high-risk patients (mean age, 69 years; range, 52-89 years) underwent combined open and endovascular approaches for complex aneurysms, including 16 patients with ascending and arch aneurysms and 15 patients with aneurysms involving visceral vessels. Among them, 11 patients had histories of aneurysm repairs. To overcome the anatomic limitations of endovascular repairs, various adjunctive surgical maneuvers were used, including aortic arch reconstruction in 3 patients, supra-aortic trunk debranching in 13 patients (including 8 patients who required aortas as inflow sources), and visceral vessel bypasses in 15 patients (including 10 patients who required bypasses to all 3 visceral branches). Additionally, carotid artery access was obtained in 1 patient, and iliac artery conduits were created in 12 patients.ResultsTechnical success was achieved in all patients. There was one perioperative death (3.2%) due to postoperative bleeding. Two patients (6.4%) had immediate type II endoleaks, which were resolved by the 1-month follow-up. Other procedure-related complications occurred in three patients (9.6%), including renal bypass thromboses in two patients and retroperitoneal hematoma, which was successfully managed conservatively, in one patient. During a mean follow-up of 16 months, two patients died of unrelated causes, whereas the remainder of patients were asymptomatic, without aneurysm enlargement.ConclusionsOur study highlights how hybrid strategies incorporating surgical and endovascular approaches can be used successfully in treating patients with complex thoracic aortic aneurysms. This combined approach potentially expands the field of endovascular stent grafting and is an attractive solution for patients with poor cardiopulmonary reserves

Delayed neurologic deficit after endovascular abdominal aortic aneurysm repair

AbstractParaplegia or paraparesis secondary to spinal cord ischemia is an extremely rare complication after elective repair of abdominal aortic aneurysm. We report delayed paraparesis after endovascular abdominal aortic aneurysm repair in which one hypogastric artery was unintentionally occluded due to atheroembolism. A spinal catheter was immediately inserted after onset of paraplegia to promote cerebrospinal fluid drainage, which partially reversed the neurologic deficit. Our case underscores both the importance of the critical spinal collateral supply from the hypogastric artery and the role of spinal fluid drainage to maximize spinal cord perfusion in the setting of spinal cord ischemia. (J Vasc Surg 2003;37:690-2.

Spontaneous arterial thrombosis in a patient with human immunodeficiency virus infection: Successful treatment with pharmacomechanical thrombectomy

AbstractPatients with human immunodeficiency virus (HIV) have various coagulation abnormalities as well as increased risk for development of clinical thrombosis and subsequent embolic events. We report acute lower leg ischemia caused by spontaneous atheroembolism with no identifiable source in a young patient with HIV infection. Treatment included percutaneous mechanical thrombectomy and thrombolysis, which reversed the arterial ischemia. Physicians should be aware of thromboembolic disease as a possible complication of HIV

Prophylactic balloon angioplasty fails to prolong the patency of expanded polytetrafluoroethylene arteriovenous grafts: Results of a prospective randomized study

AbstractPurpose: Maintenance of hemodialysis access grafts represents an enormous social and clinical problem. Current grafts and graft salvage techniques are inadequate. Consequently, there has been increasing interest in the use of minimally invasive catheter techniques to prophylactically treat stenoses in functioning arteriovenous grafts. Prophylactic balloon angioplasty has been widely suggested as prolonging assisted primary patency. We have performed a prospective randomized trial to compare patients who underwent percutaneous transluminal angioplasty (PTA) for graft stenoses >50% with a control group that received no intervention. Our hypothesis was that to be efficacious a minimal benefit of 20% prolongation in patency would be necessary.Methods: Color flow duplex scanning was used to detect >50% stenoses in functioning expanded polytetrafluoroethylene grafts. Patients were then subjected to confirmatory angiographic evaluation. Those who had angiographic stenoses >50% were randomized to balloon angioplasty or observation. Patients were followed-up with duplex scanning every 2 months. Statistical analysis was performed using the Kaplan-Meier technique. Although demographically the patient groups were well matched, there were more prior interventions and concurrent central stenoses in the treatment group. Outcomes were graft thrombosis, graft dysfunction that precluded dialysis, and six or more PTA procedures within 18 months.Results: In the treatment and observation groups, the 6-month patency rates were 69% ± 7% and 70% ± 7%, respectively. The 12-month patency rates for the treatment and observation groups were 51% ± 6% and 47% ± 4%, respectively. There was no significant difference between these two groups ( p = 0.97), with an 80% confidence limit for detection of a difference greater than 20%.Conclusions: This study demonstrates that a generic approach of PTA to treat all polytetrafluoroethylene grafts with stenoses >50% does not prolong patency and cannot be supported

Effects of transition metal substitutions on the incommensurability and spin fluctuations in BaFe2As2 by elastic and inelastic neutron scattering

The spin fluctuation spectra from nonsuperconducting Cu-substituted, and superconducting Co-substituted, BaFe2As2 are compared quantitatively by inelastic neutron scattering measurements and are found to be indis- tinguishable. Whereas diffraction studies show the appearance of incommensurate spin-density wave order in Co and Ni substituted samples, the magnetic phase diagram for Cu substitution does not display incommensu- rate order, demonstrating that simple electron counting based on rigid-band concepts is invalid. These results, supported by theoretical calculations, suggest that substitutional impurity effects in the Fe plane play a signifi- cant role in controlling magnetism and the appearance of superconductivity, with Cu distinguished by enhanced impurity scattering and split-band behavior.Comment: 5 pages, 5 figures, Major change in the manuscrip