Secure occlusion of large blood vessels and ductal structures is critical to all surgeries and remains a challenge in many minimally invasive procedures. This study compares in vivo use of the Amsel Occluder (AO) for secure laparoscopic blood vessel and duct closure, with one of the many commercially available hemoclips (Ligaclip®), in the porcine model.

BACKGROUND:Secure vessel occlusion is critical to the success of all surgical and interventional procedures. The purpose of this study was to compare in vivo the use of the Amsel Vessel Occluder (AVO), a novel occlusion clip device for secure blood vessel closure, with one of the many commercially available hemoclips, the Ligaclip, in the porcine model. METHODS:Vessel closure of arteries and veins was performed on 10 swine to compare the ease of use, safety, and efficacy of the AVO with the Ligaclip as well as the tissue response at 7 and 30 d. After heparinization, the targeted vessels (carotid/femoral/brachial arteries and jugular/femoral/brachial veins) were occluded with two clips, either two AVO's or two Ligaclip's, and the vessels transected between the two clips. Any bleeding was recorded. At sacrifice, gross and histopathologic findings were examined for evidence of bleeding or injury to adjacent structures. The tissue response and healing were evaluated by a prospective randomized histopathologic study for the effects of any biological incompatibilities. At time of sacrifice, occluded vessel segments were subjected to nonphysiological pressures ("holding" pressures) to compare efficacy of occlusion in fresh, nonoccluded vessels, and the ability to dislodge the clips once applied. RESULTS:Twenty veins and 20 arteries between 2-mm and 7-mm outer diameter were occluded in 10 pigs. Each vessel was occluded with either AVO or Ligaclip. Our study confirmed easy and safe AVO application with no dislodgment of any AVO clips once deployed. The AVO showed no intraoperative or postoperative bleeding (AVO = 0/40), while one Ligaclip dislodged resulting in a fatal hemorrhage 16 h after surgery (Ligaclip = 1/40), and on two occasions where, with obvious slippage of the Ligaclip, immediately after deployment, additional clips were placed. The holding pressures for the two clips were similar but unlike the AVO, the Ligaclip was easily dislodged. Histopathologic examination showed no difference in the tissue response and healing of the two clips. CONCLUSIONS:The AVO is simple to deploy and securely maintains occlusion by transfixing the targeted vessel, unlike the widely used, nontransfixing Ligaclip, that has a tendency to dislodge. As such, the Amsel secure vessel occluder opens up numerous treatment opportunities in both the venous and arterial systems to minimize open, laparoscopic, robotic surgical and interventional procedures, and reduce patient morbidity and its associated health care costs.

BACKGROUND:Secure, permanent occlusion of the great and small saphenous veins, their tributaries, and perforators is critical for the successful treatment of varicose veins. Current minimally invasive methods replacing surgery are all endoluminal and involve heat (radiofrequency or laser), chemicals (sclerosants and glues), or a combination of mechanical and chemical interventions. This study evaluated in a porcine model the performance of a percutaneous delivery of the Amsel Vessel Occluder (AVO; Amsel Medical Corp, Cambridge, Mass) using ultrasound guidance. The AVO has received United States Food and Drug Administration premarket 510(k) clearance for use in open surgical procedures for tubular structures with diameters of 2 to 7 mm. METHODS:The AVO, a novel mechanical occlusion clip similar to a transfixion suture, is delivered through an 18-gauge hypodermic needle. The AVO is subsequently expanded on either side of the vessel wall, collapsed, and locked together to effect secure vascular occlusion, thus transfixing the targeted vessel. The targeted vessels in five swine (weight >60 kg) under general anesthesia were identified, and the vessel size was measured. Patency of the targeted vessels was confirmed on duplex ultrasound imaging. Each animal provided multiple vessels for percutaneous AVO occlusion. Occlusion was confirmed by duplex ultrasound imaging and by direct examination of the occluded vessel after open surgical exploration. RESULTS:Thirty vessel occlusions were performed percutaneously, including the common and superficial femoral arteries and veins (n = 24), the carotid artery (n = 4), and the external jugular vein (n = 1) and external jugular vein tributary (n = 1). Measured vessel sizes ranged from 1.8 to 12.7 mm. After vessel transfixion, occlusion was achieved in <30 seconds. A second AVO, if necessary, was delivered to completely occlude the targeted vessel where the vessel was >7 mm diameter (n = 2; external jugular vein, 12.7 mm; carotid artery, 7 mm), or where the initial AVO did not occlude the vessel because of nontransfixion (n = 1). Surgical exposure after occlusion confirmed that all targeted vessels were successfully occluded and demonstrated no evidence of injury to any of the adjacent structures. CONCLUSIONS:This study confirms that the AVO can be effectively delivered percutaneously under ultrasound guidance to occlude blood vessels in the porcine model and may be a useful, time-saving, and cost-effective adjunct to current primary methods of treating reflux in the saphenous veins, their tributaries, or perforators for the treatment of symptomatic varicose veins.

Secure vessel occlusion is critical to the success of all surgical and interventional procedures. This study tested both in vitro and in vivo, the Amsel Vessel Occluder (AVO), a novel occlusion clip device for secure blood vessel closure. The AVO, delivered through a fine (18-gauge) hypodermic needle, transfixes the targeted vessel, and delivers expandable proximal and distal elements on either side of the vessel wall, which lock together for secure vessel occlusion. In vitro device testing was conducted on 5-mm silicon tubing. Standard corrosion analysis, material biocompatibility, and cytotoxicity were performed on the implantable elements. In vivo studies on three swine compared safety and efficacy of the AVO with the medium/large Ligaclip (J & J) for 1 week. The targeted vessels (carotid/femoral arteries; jugular/femoral veins) were divided between two AVO or two Ligaclips. In vitro testing (n = 11) confirmed a holding pressure of 450 mmHg (11 of 11), excellent clip closure repeatability (11 of 11), and release mechanism function (11 of 11). Once applied, the AVO was secure and could not be dislodged (none of 11). The Ligaclip was easily dislodged (11 of 11). No corrosion was observed, and material biocompatibility and cytoxicity (n = 12) were within accepted ranges. In vivo studies (six arteries; six veins) confirmed easy AVO application and superiority in security. The AVO showed no postoperative bleeding (AVO, zero of six), whereas one Ligaclip dislodged, resulting in a fatal hemorrhage 16 hours after surgery (Ligaclip, one of six). The AVO is simple to deploy and securely maintains occlusion by transfixing the targeted vessel, unlike the widely used, nontransfixing Ligaclip that has a tendency to dislodge. As such, the Amsel secure vessel occluder opens up numerous treatment opportunities in both the venous and arterial systems to minimize open, laparoscopic, robotic surgical, and interventional procedures, and reduce patient morbidity.

Early detection and treatment of rupture-prone vulnerable atherosclerotic plaques is critical to reducing patient mortality associated with cardiovascular disease. The combination of reflectance, fluorescence, and Raman spectroscopy-termed multimodal spectroscopy (MMS)-provides detailed biochemical information about tissue and can detect vulnerable plaque features: thin fibrous cap (TFC), necrotic core (NC), superficial foam cells (SFC), and thrombus. Ex vivo MMS spectra are collected from 12 patients that underwent carotid endarterectomy or femoral bypass surgery. Data are collected by means of a unitary MMS optical fiber probe and a portable clinical instrument. Blinded histopathological analysis is used to assess the vulnerability of each spectrally evaluated artery lesion. Modeling of the ex vivo MMS spectra produce objective parameters that correlate with the presence of vulnerable plaque features: TFC with fluorescence parameters indicative of collagen presence; NC∕SFC with a combination of diffuse reflectance β-carotene∕ceroid absorption and the Raman spectral signature of lipids; and thrombus with its Raman signature. Using these parameters, suspected vulnerable plaques can be detected with a sensitivity of 96% and specificity of 72%. These encouraging results warrant the continued development of MMS as a catheter-based clinical diagnostic technique for early detection of vulnerable plaques.

Angioscopy is the only imaging technology that allows direct in vivo visualization of the interior of blood vessels in real-life colors. This capability to detect and quantify endoluminal findings and delineate subtle variations of the different normal and abnormal endoluminal states has only begun to be appreciated. The evolution and clinical application of the endoluminal techniques in the treatment of occlusive arterial disease and the performance of the distal bypass to the tibial and pedal arteries have highlighted the deficiencies of the arteriogram in providing accurate and clinically relevant information regarding the endoluminal state.

Early detection and treatment of vulnerable atherosclerotic plaques, the lesions most prone to rupture, is critical to reducing patient mortality associated with cardiovascular disease. The combination of reflectance, fluorescence, and Raman spectroscopy - termed multimodal spectroscopy (MMS) - provides complementary and depth-sensitive information about tissue composition. We assessed the hypothesis that MMS can detect morphological features of vulnerable plaque: thin fibrous cap (TFC), necrotic core (NC), superficial foam cells (SFC), intralesional hemorrhage (IH), and thrombus. Methods. In vivo and ex vivo MMS spectra were collected from 12 patients undergoing peripheral vascular surgeries. The data collection was facilitated by means of a novel MMS probe catheter and a portable clinical instrument developed in our laboratory. During carotid endarterectomies, MMS spectra were collected in vivo from the intimal surface of the plaque with the probe held normal to the artery wall. During femoral bypasses, MMS spectra were collected in vivo either through the proximal anastomosis site from the posterior artery wall or adjacent to the incision. A tissue specimen was excised for additional MMS spectral collection ex vivo. Histopathological analysis was performed by a blinded cardiovascular pathologist to assess the vulnerability of each spectrally evaluated tissue site using a quantitative index based on the dimension or severity of the following: TFC, NC, SFC, IH, and thrombus. Across the total set of 76 evaluated tissue locations, MMS is shown to have the ability to detect vulnerability features including a TFC, NC or SFCs, and thrombus. A TFC is detected by measuring the relative amount of collagen assessed by fluorescence, a large NC or SFCs are detected through the combination of beta-carotene absorption and the Raman spectral signature of lipids, and thrombus is detected through its Raman signature. The results indicate that rupture-prone vulnerable plaques could be detected with a sensitivity of 96% and specificity of 72%. In conclusion, these encouraging results will help bring MMS into the clinical arena as a powerful, catheter-based diagnostic technique for early detection of vulnerable plaques.

The rupture of vulnerable atherosclerotic plaque accounts for the majority of clinically significant acute cardiovascular events. Because stability of these culprit lesions is directly related to chemical and morphological composition, Raman spectroscopy may be a useful technique for their study. Recent developments in optical fiber probe technology have allowed for the real-time in vivo Raman spectroscopic characterization of human atherosclerotic plaque demonstrated in this work. We spectroscopically examine 74 sites during carotid endarterectomy and femoral artery bypass surgeries. Of these, 34 are surgically biopsied and examined histologically. Excellent signal-to-noise ratio spectra are obtained in only 1 s and fit with an established model, demonstrating accurate tissue characterization. We also report the first evidence that Raman spectroscopy has the potential to identify vulnerable plaque, achieving a sensitivity and specificity of 79 and 85%, respectively. These initial findings indicate that Raman spectroscopy has the potential to be a clinically relevant diagnostic tool for studying cardiovascular disease.

ObjectiveThere is an urgent and compelling need to reduce the morbidity and expense of maintaining hemodialysis vascular access patency. This large, long-term, retrospective, multicenter study, which compared access patency of autogenous arteriovenous fistulas (AVF) and synthetic bridge grafts (AVG) created with conventional sutures or nonpenetrating clips, was undertaken to resolve conflicting results from previous smaller studies.DesignPatency data for 1385 vascular access anastomoses (clipped or sutured) was obtained from 17 hospitals and dialysis centers (Appendix). Five hundred eighteen AVF (242 clip, 276 suture) and 827 AVG (440 clip, 384 suture) were analyzed. Statistical comparisons were made with Kaplan-Meier survival analysis, log-rank test, two-sample t test, and X2 test. The Cox proportional hazards model was used to confirm Kaplan-Meier analysis.ResultsAccess patency (primary, secondary, overall, and intention to treat) was significantly improved in access anastomoses constructed with clips. In the intention-to-treat group, primary patency at 24 months was 0.54 for clipped AVF and 0.34 for sutured AVF, and was 0.36 for clipped AVG and 0.17 for sutured AVG. At 24 months, primary patency rate for AVF successfully used for dialysis was 0.67 for clips and 0.48 for sutures, and for AVG was 0.39 for clips and 0.19 for sutured constructs. Interventions necessary to maintain patency were significantly fewer in clipped anastomoses.ConclusionReplacing conventional suture with clips significantly reduces morbidity associated with maintaining permanent hemodialysis vascular access. This beneficial effect may be due to the biologic superiority of interrupted, nonpenetrating vascular anastomoses.

The incidence rate of treated end-stage renal disease in the united states is 180 per million and continues to rise at a rate of 7.8% per year. Arteriovenous hemodialysis access (AV access) creation and maintenance are two of the most difficult issues associated with the management of patients on hemodialysis. The 1-year complication rate of a primary prosthetic AV access for hemodialysis ranges from 33% to 99%. Various investigators report on patency and complications of AV access. However, it is rather difficult to compare outcomes because of the wide variety of access materials, configurations, locations, risk factors, and quality of inflow and outflow vessels. Although there have been reporting standards for dialysis access endovascular interventions and for central venous access placement, standards regarding surgical access placement and its revision are lacking. The "Dialysis Outcome Quality Initiative," published by the National Kidney Foundation, provides recommendations for optimal clinical practices aimed at improving dialysis outcome and patient survival. This reporting standards document is not meant to be a "practice guidelines" or "best practices" document. Rather, the purpose of this document is to provide standardized definitions related to AV access procedures and to recommend reporting standards for patency and complications, to be used by surgeons, nephrologists, and interventional radiologists, that will permit meaningful comparisons among AV access procedures. The terms, definitions, and categories featured in this article have been approved by the Committee on Reporting Standards of the Society for Vascular Surgery and the American Association for Vascular Surgery and should be observed in preparing manuscripts on AV accesses for submission to the Journal Of Vascular Surgery.

Purpose: Near-infrared Raman spectroscopy provides an important new means of analyzing the chemical composition of the arterial wall. The objective of this study was to show that Raman spectroscopy can be used to evaluate the lipid and calcium salt contents of human peripheral arteries. The results extend a recently developed Raman-based method for analyzing the chemical composition of coronary arteries.Methods and Results: We studied 167 segments of carotid and femoral artery wall in various pathologic states. The Raman spectra from these samples was accurately modeled. The resulting chemical concentrations were compared with the amounts of cholesterol and calcium mineral determined at histologic evaluation by an experienced cardiovascular pathologist. Strong correlations between spectroscopic measurements and morphologic findings were demonstrated and validated the applicability of the method to peripheral arteries.Conclusions: Raman spectroscopy can provide reliable histochemical information about peripheral and coronary arteries. Such information may help identify rupture-prone plaques before the onset of symptoms and allow aggressive and directed intervention. Accurate knowledge of the chemical composition of a lesion may be useful in selecting the most appropriate treatment.

Purpose: Surgical outcome data are generally reported as raw morbidity and mortality rates, which do not necessarily reflect quality of surgical care. The Society for Vascular Surgery has led this area with recommendations by the Ad Hoc Committee on Reporting Standards to establish standardized methods of outcome assessment in vascular surgery. The purpose of this study was to evaluate a new method for evaluating the overall quality of surgical care, which includes surgeon, nursing, and hospital system performance. The goal of the method is to identify problem areas in surgical practice that can be targeted for focused improvement to improve outcome.Methods: A database of more than 9000 general and vascular surgical cases was compiled over a 3-year period. Every postoperative complication was tabulated prospectively by a surgical nurse on a daily basis. Fifty clinically significant complication types specific for vascular surgery patients were identified from a list of 151 postoperative events by a panel of vascular surgeons and were grouped into nine broad categories (vascular, cardiac, pulmonary, etc.). These complications reflect the entire continuum of postoperative care, including surgeon, nursing, and hospital system performance. Each complication type was further stratified into four grades (mild, moderate, severe, death) and assigned a SCOUT severity score from 0 to 100 (0, no complication; 100, death) by the panel of surgeons. For ease of data collection and monitoring of outcome, a software program was developed to run on a laptop computer and includes medical history, risk factors, pertinent laboratory data, and the preassigned SCOUT severity scores for measuring outcome. In this study, 170 major vascular procedures performed over the previous 12-month period were prospectively evaluated using the SCOUT method in an attempt to more easily identify problem areas of practice. In-hospital morbidity and 30-day mortality results were examined.Results: One hundred sixteen postoperative complications mere identified in the 170 patients, with an overall morbidity rate of 51% and a 30-day mortality rate of 1.8%. Fifty-three percent of the complications were ''mild'' and required minimal intervention or observation only. Abdominal aortic aneurysm repair was associated with the highest morbidity rate (mean SCOUT score, 384.35), whereas distal extremity bypass grafting had the lowest morbidity rate (mean SCOUT score, 114.4). However, subgroup analysis demonstrated that cardiac events accounted for 52% of the morbidity associated with distal extremity bypass but only 34.7% of the morbidity associated with abdominal aortic aneurysm repair (p < 0.05).Conclusions: The SCOUT score is a new technical quality of care measure that can objectively quantify surgeon and other hospital system-related performance. The SCOUT score allows the surgeon to identify problem areas that can then be targeted for improvement to positively affect outcome.

This brief case report describes the successful outcome after surgical excision of multiple adventitial cysts of the popliteal artery in a 75-year-old man with rapidly worsening claudication. It highlights several unsettled points concerning the diagnosis, cause, and management of cystic adventitial disease of the popliteal artery and compares duplex ultrasound, computed tomography, and magnetic resonance angiography in the noninvasive diagnosis and treatment of this condition.

The purpose of this retrospective study was to review our experience with a consecutive group of end-stage renal disease (ESRD) patients using simple strategies to increase the use of autogenous vascular access, and determine whether the current trend of using synthetic bridge-graft fistula (BGF) rather than autogenous arteriovenous fistula (AVF), could be reversed, despite an aging population and broadening criteria for hemodialysis. All patients for vascular access surgery had careful preoperative clinical examination of the arm veins with outflow occlusion to determine the venous anatomy and continuity. Where no veins were apparent or their continuity in doubt, selective preoperative venography was performed. Where veins were unsatisfactory for forearm AVF, new or modified surgical procedures to use both the basilic and cephalic veins in the upper arm were performed. Intraoperative angioscopy was used to monitor vein quality and surgical technique. Ninety-eight primary vascular access procedures were performed in 76 patients, 75 (76.5%) AVF (forearm, n = 41; upper arm, n = 34) and 23 (23.5%) BGF. Forty-one of 76 (54%) had already had at least one previous access procedure prior to this study. More than one access procedure was needed in 16 patients. Preoperative venography was performed in 22 (22.4%) and intraoperative angioscopy in 45 (45.9%) of the 98 procedures. The number of revisions required to maintain patency was significantly higher for BGF (37 revisions in 14/23) than AVF (16 revisions in 13/75) (p<0.0001, Poisson test) with an annualized secondary revision rate of 1.168 for BGF and 0.173 for AVF (p<0.0001, Poisson test). AVF had both longer primary (p=0.0001, log rank test) and secondary patency (p=0.038, log rank test) than BGF. AVF as the primary vascular access can be significantly increased and the current trend of using BGF reversed with the use of simple clinical strategies to evaluate the suitability of the arm veins for vascular access.