Antiplatelet Therapy in Carotid Artery Stenting and Carotid Endarterectomy in the Asymptomatic Carotid Surgery Trial-2

OBJECTIVE

Strokes are infrequent but potentially serious complications following carotid intervention, but antiplatelet therapy can reduce these risks. There are currently no specific guidelines on dose or duration of peri-procedural antiplatelet treatment for patients undergoing carotid intervention. Within the ongoing Asymptomatic Carotid Surgery Trial-2 (ACST-2), this study aimed at assessing the current use of antiplatelet therapy before, during, and after CEA and CAS in patients with asymptomatic carotid stenosis.

METHODS

Questionnaires were sent to ACST-2 collaborators seeking information about the use of antiplatelet therapy during the pre-, peri-, and post-operative periods in patients undergoing carotid intervention at 77 participating sites and also whether sites tested for antiplatelet therapy resistance.

RESULTS

The response rate was 68/77 (88%). For CAS, 82% of sites used dual antiplatelet therapy (DAPT) pre-operatively and 86% post-operatively with a mean post-procedural duration of 3 months (range 1-12), while 9% continued DAPT life-long. For CEA only 31% used DAPT pre-operatively, 24% post-operatively with a mean post-procedural duration of 3 months (range 1-5), while 10% continued DAPT life-long. For those prescribing post-procedural mono antiplatelet (MAPT) therapy (76%), aspirin was more commonly prescribed (59%) than clopidogrel (6%) and 11% of centres did not show a preference for either aspirin or clopidogrel. Eleven centres (16%) tested for antiplatelet therapy resistance.

CONCLUSION

There appears to be broad agreement on the use of antiplatelet therapy in ACST-2 patients undergoing carotid artery stenting and surgery. Although evidence to help guide the duration of peri-procedural antiplatelet therapy is limited, long-term treatment with DAPT appears similar between both treatment arms.

Neural damage biomarkers during open carotid surgery versus endovascular approach

BACKGROUND

Carotid endarterectomy (CEA) is the gold standard for treating severe carotid artery stenosis, whereas carotid artery stenting (CAS) represents an endovascular alternative. The objective of this study was to assess the potential neural damage following open or endovascular carotid surgery measured by peripheral blood concentration of 3 biomarkers: S100β, matrix metalloproteinase-9 (MMP-9), and d-dimer.

METHODS

Data for this prospective investigation were obtained from the Carotid Markers study (January 2010-2011), which sought to measure the levels of specific biomarkers of neuronal damage and thrombosis on candidates to CEA or CAS presenting at the Department of Vascular Surgery of the Nuovo Ospedale S. Agostino Estense of Modena (Italy) at baseline and at 24 hr after surgery. Relevant medical comorbidities were noted.

RESULTS

A total of 113 consecutive patients were enrolled in the study, 41 in the endarterectomy group and 72 in the endovascular group. The baseline levels of the studied biomarkers did not show any statistically significant difference between the groups with the exception of MMP-9, which showed higher concentrations in the endovascular group (median 731 vs. 401, P = 0.0007), while 24 hr after surgery the endarterectomy group featured significantly higher peripheral blood concentrations of MMP-9, S100β, and d-dimer. Conversely, no significant difference was detected in the endovascular group except the d-dimer level.

CONCLUSIONS

Neural damage biomarkers demonstrated a substantial difference between open and endovascular carotid surgery, which, if performed in selected patients, may become a less invasive alternative to CEA.

INCRAFT® Stent-Graft System: one-year outcome of the INNOVATION Trial

AIM

Endovascular repair has surpassed open surgical treatment as the most common procedure in patients with abdominal aortic aneurysms (AAA), yet its applicability remains limited to those with aortoiliac anatomy suitable for the introduction and deployment of the devices. The current study was performed to assess the safety and efficacy of INCRAFT® (Cordis Corporation, Bridgewater, NJ), an ultra-low-profile device for the treatment of AAA.

METHODS

The INNOVATION study is a first in human prospective, multicenter trial involving 6 centers in Europe. From March 2010 to June 2011 60 patients with asymptomatic AAA were treated with the INCRAFT® bifurcated Stent-Graft System. The main inclusion criteria were a proximal aortic neck of 15 mm or more in length and up to 27 mm in diameter; iliac landing zones greater than 10 mm in length and between 9 and 18 mm in diameter; an access vessel large enough to accept the 14F outer diameter of the delivery system; and an aortic bifurcation >18 mm in diameter. The primary endpoint was technical success at one-month; one-year safety endpoints included the absence of device- or procedure-related major adverse events; absence of type I or III endoleaks; and maintenance of device integrity through one year of follow-up.

RESULTS

Among 60 patients treated at six centers, the primary endpoint was met in 56 of 58 patients (97%; 95% CI, 88-100%) who came back for one month follow-up, two patients did not come back for their one month follow-up assessments but remained enrolled in the study. Fifty-six had one-year follow-up data showing 100% freedom from aneurysm enlargement with absence of type I and III endoleaks in all patients. There were two patients (3.6%) with a type Ia endoleak which was successfully treated with secondary endovascular intervention in both occasions. Core laboratory evaluation of the postoperative imaging studies documented absence of endograft migration, stent fracture, or limb occlusion. A single patient (1.8%) died within one year due to sepsis unrelated to the AAA.

CONCLUSION

The results of the INNOVATION study with the INCRAFT® Stent-Graft are encouraging, with satisfactory clinical outcome and device durability through one-year of follow-up. The INCRAFT® device is a novel ultra-low-profile endograft that holds promise to broaden the patient population eligible for endovascular aneurysm repair.

BRAVISSIMO: 12-month results from a large scale prospective trial

The BRAVISSIMO study is a prospective, non-randomized, multi-center, multi-national, monitored trial, conducted at 12 hospitals in Belgium and 11 hospitals in Italy. This manuscript reports the findings up to the 12-month follow-up time point for both the TASC A&B cohort and the TASC C&D cohort. The primary endpoint of the study is primary patency at 12 months, defined as a target lesion without a hemodynamically significant stenosis on Duplex ultrasound (>50%, systolic velocity ratio no greater than 2.0) and without target lesion revascularization (TLR) within 12 months. Between July 2009 and September 2010, 190 patients with TASC A or TASC B aortoiliac lesions and 135 patients with TASC C or TASC D aortoiliac lesions were included. The demographic data were comparable for the TASC A/B cohort and the TASC C/D cohort. The number of claudicants was significantly higher in the TASC A/B cohort, The TASC C/D cohort contains more CLI patients. The primary patency rate for the total patient population was 93.1%. The primary patency rates at 12 months for the TASC A, B, C and D lesions were 94.0%, 96.5%, 91.3% and 90.2% respectively. No statistical significant difference was shown when comparing these groups. Our findings confirm that endovascular therapy, and more specifically primary stenting, is the preferred treatment for patients with TASC A, B, C and D aortoiliac lesions. We notice similar endovascular results compared to surgery, however without the invasive character of surgery.

How to simplify the approach to the supra-aortic trunks

Carotid artery stenting (CAS) represents a valid alternative to carotid endarterectomy (CEA). Possible embolization during the approach and the cannulation of the supra-aortic arterial trunks remains an important obstacle to CAS. This risk is increased in elderly patients and complex anatomies. In order to achieve satisfactory technical and clinical outcomes, a thorough understanding of the patients' individual anatomy of the arch and the access vessels is essential. The cannulation of the common carotid artery represents the key maneuver for the entire CAS procedure. This review article will present the currents techniques and devices actually use in order to facilitate the approach to the supra-aortic vessels.

The Bolton Treovance abdominal stent-graft: European clinical trial design

Endovascular aortic repair (EVAR) has emerged as a promising, less invasive alternative to conventional open surgery for the treatment of infrarenal abdominal aortic aneurysms (AAAs). In the last 20 years, the application rate of EVAR and its clinical results have significantly improved thanks to the evolution of stent-grafts and endovascular delivery systems. However, further development is still needed to reduce the incidence of complications and secondary re-interventions. The Treovance abdominal aortic stent-graft (Bolton Medical, Barcelona, Spain) is a new-generation endovascular device, developed to increase flexibility, lower profile, improve deployment and sealing mechanisms. In particular, it is provided with some innovative features as a double layer of proximal barbs (suprarenal and infrarenal) for supplemental fixation, dull barbs between modules to avoid potential leg disconnections, detachable outer sheath provided with a new-design hemostatic valve, and a double improved mechanism (slow motion and "pin and pull") for precise stent-graft deployment. A European prospective, non-randomized, multi-institutional, "first-in-human" trial (the ADVANCE trial) was conducted from March to December 2011 to assess the safety and performance of the Treovance stent-graft system before commercialization. Thirty patients with anatomically suitable non-ruptured AAAs were enrolled at five clinical sites in Italy, Spain, and Germany. EVAR was completed successfully in all patients. The stent-graft was delivered and deployed safely even in heavily angulated or calcified anatomies. No 30-day device-related complications nor deaths were observed. Preliminary experience with the Treovance abdominal stent-graft within the ADVANCE trial was satisfactory with regard to technical success and perioperative clinical results. Follow-up data are needed to assess mid- and long-term clinical outcomes, along with durability of this new-generation endovascular device.

Endovascular preservation of pelvic circulation with external iliac-to-internal iliac artery "cross-stenting" in patients with aorto-iliac aneurysms: a case report and literature review

Endovascular success depends heavily upon anatomical suitability for secure graft placement. Common iliac artery (CIA) aneurysms frequently extend close to the iliac bifurcation, requiring distal fixation in the external iliac artery (EIA), in turn excluding the internal iliac artery (IIA). The preservation of circulation to at least one IIA artery is highly recommended. We report an endovascular technique for complete preservation of the hypogastric arteries of an aorto-iliac aneurysm extending into the iliac bifurcation and hypogastric artery. A left CIA aneurysm involving the iliac bifurcation was excluded with a covered Fluency stent-graft (Bard Inc., New Jersey, USA) deployed from the EIA into the IIA followed by the internal deployment of a Luminex uncovered stent (Bard Inc.) extended into one branch of the hypograstric artery. IVUS evaluation was essential in determining precise aneurysm and sealing zone measurements. Complete preservation of hypogastric circulation was achieved. The placement of the uncovered stent effectively extended the sealing zones without covering either of the hypogastric distal branches and concurrently corrected the Fluency stent kinking due to severe arterial tortuosity. In CIA aneurysms involving the IIA, an uncovered stent can extend the sealing zones, whilst maintaining complete preservation of pelvic circulation and offers support to the covered stent-graft. IVUS seems necessary for precise neck evaluation.

Endovascular treatment of an early arch aneurysm rupture after open thoracoabdominal aortic repair

Optimal treatment for synchronous aortic aneurysms is still debated. Staged repair is advocated as the standard of care. Its disadvantage however is the consistent risk of rupture of the untreated aortic segment during recovery; moreover a considerable percentage of patients either refuse the second stage or is lost to follow-up. We present the case of a patient with a ruptured aortic arch aneurysm after open-surgery for a type III thoracoabdominal aortic aneurysm. Our therapeutic decision is described and discussed, with all the related advantages and disadvantages.

A new idea for a safer approach to the supra-aortic trunks: the Piton™ catheter

Carotid artery disease is among the most common causes of stroke, and stroke is the third leading cause of death in industrialized countries. Thus the personal health and socioeconomic burden of carotid artery disease is significant. Carotid artery disease accounts for approximately 5-12% of new strokes in patients amenable to revascularization therapy. Atherosclerosis is the main reason for stroke and accounts for approximately one third of all cases. Carotid stenting is nowadays considered a valid standard alternative to surgical carotid endarterectomy, especially in patients having a high perioperative risk. The first carotid balloon angioplasty was carried out in 1979 and the first carotid balloon-expandable bare metal stents were implanted 10 years later, in 1989. However, carotid stenting at that time was associated with major complications, due to extrinsic compression and subsequent to the steel stents used. The Piton™ GC (carotid guide catheter) is intended to facilitate the introduction and placement of interventional devices (e.g., guidewires, stent delivery systems, dilation balloons, angiographic- or micro-catheters, etc.) into the human vasculature to treat vascular obstructive disease, including but not limited to the supra-aortic vessels.

Analgesia and endocrine surgical stress: effect of two analgesia protocols on cortisol and prolactin levels during abdominal aortic aneurysm endovascular repair

OBJECTIVES

Endovascular abdominal aortic aneurysm (AAA) repair was performed with local anaesthesia and intravenous analgesia. The objective of the study was to evaluate how two analgesia protocols affected stress response, measured as cortisol, 17-OH progesterone (17OHP) and prolactin (PRL) concentration during the procedure.

METHODS

44 patients undergoing elective AAA endovascular repair were included to either receive regular boluses of fentanyl midazolam or remifentanil continuous infusion, analgesia was monitored by Visual Analogue Scale (VAS) measurement; cortisol, 17OHP and PRL were sampled preoperatively, at skin incision, endovascular prosthesis release and skin suture.

RESULTS

42 patients were included. Mean VAS values were lower in the remifentanil group 0.50±0.68 vs 1.48±1.20, p=0.002 at incision, 0.24±0.58 vs 1.45±1.18, p<0.001 prosthesis release, 0.51±0.90 vs 1.73±1.45, p=0.002 suture. No statistically significant difference was found among cortisol and 17OHP levels; PRL was significantly lower in the fentanyl-midazolam group (23.83±16.92 ng/ml vs 40.81±22.45 p=0.009 at prosthesis release and 28.23±15.05 vs 41.37±14.54, p=0.007 at suture).

CONCLUSIONS

Although statistically significant VAS difference had a limited clinical impact due to its small entity. The group that experienced less pain showed a more intense PRL response, while cortisol and 17OHP did not reach statistical significance.

Mechanical thrombectomy in in-stent restenosis: preliminary experience at the iliac and femoropopliteal arteries with the Rotarex System

AIM

Iliac and femoropopliteal arterial stenting remains controversial due to frequent restenosis. This study aims to evaluate the efficacy of a mechanical rotational thrombectomy procedure with the Rotarex Mechanical Thrombectomy System (Straub Medical, Wangs, CH) and percutaneous transluminal angioplasty (PTA) in terms of technical success, patency rates and limb salvage.

METHODS

From May 2006 to March 2010, 32 selected patients with sub-acute or chronic in-stent restenosis at the iliac or femoropopliteal arteries were treated with a Rotarex and then PTA procedure.

RESULTS

Technical success was 100%. Intra-procedural complications included a superficial femoral artery (SFA) dissection (1), SFA (1) and external iliac (1) perforations and a groin hematoma (1). There was no incidence of embolization in this series. One patient required reintervention (3.1%); an attempted surgical bypass and amputation. Secondary reinterventions were required in 17 patients (53.1%). Limb salvage rate at 12 months was 90.6%. Primary patency at 30 days was 96.8%. Primary, primary assisted and secondary patency rates at 6 months were 75%, 75% and 89.6% and at 12 months were 58.1%, 58.1% and 75.5%, respectively. Late mortality was 18.75% at an average follow-up of 13.1 months (3-45) due to the severe disease state of these patients..

CONCLUSION

This treatment seems promising in terms of technical success and embolization risk. Reinterventions are frequently required but mid-term limb salvage rates are encouraging. Larger, randomised studies are needed to determine the cost/benefit advantage and long-term results.

Management of thoracic endograft infection

Thoracic endovascular aortic repair (TEVAR) has emerged as a promising, less invasive alternative to conventional open surgery for the treatment of thoracic aortic pathology. Most surveillance after TEVAR concentrates on the technical aspects of the procedure, including endoleak, device migration and endograft rupture; so far, the knowledge on endograft infectious complications is limited to anecdotal reports. Several etiopathogenetic factors may play a role in thoracic endograft infections (TEIs), including perioperative contamination, hematogenous seeding, and local bacterial translocation. Moreover, fistulization with the esophagus or the bronchial tree is a common mechanism of secondary TEI, and it represents a dramatic event requiring a multidisciplinary management. Risk factors assessment and prevention have a key role in avoiding the development of new TEIs. When a TEI is established, treatment is demanding, and includes several medical therapies associated with various surgical options. Patients are usually severely compromised by sepsis, and in most cases they are considered unfit for surgery for general clinical conditions or local concerns. Thus, results of different therapeutic strategies for TEI are still burdened with very high morbidity and mortality. In this paper, we reviewed the English literature regarding the main strategies proposed for operative management of TEI, we reported and analyzed our personal series of 7 patients treated at our institution for TEI from 1999 to 2009, and we summarized results from the data collected during a recent Italian multicenter national survey, performed to investigate aortoesophageal and aortobronchial fistulae treated with TEVAR or developed following TEVAR.

Endovascular treatment of descending thoracic aneurysms

INTRODUCTION

Current strategies for repair of descending thoracic aortic aneurysms consist of open repair with surgical graft replacement or thoracic endovascular aortic repair. We review and update our overall experience in aortic thoracic diseases and specifically analyzed our outcomes with thoracic endovascular aortic repair in patients with descending thoracic aortic aneurysms.

METHODS

From 1993 to present a total of 1144 patients were treated in our Center for pathology involving the thoracic aorta. Since 1998, 322 patients underwent thoracic endovascular aortic repair, and among this group, in 188 cases the descending aorta was involved. In 74% of patients treated for a descending thoracic aortic lesion, a degenerative aneurysm was observed.

RESULTS

In patients with descending thoracic aortic aneurysms receiving thoracic endovascular aortic repair, our technical success rate, i.e. deployment of endograft with complete exclusion of the lesion/minimal endoleak, was 99.5% (one case required emergent open conversion) with a perioperative mortality of 2.6% (five patients). The rate of spinal cord ischemia, manifesting either as paraplegia or paraparesis, was 4.7%. Delayed onset spinal cord ischemia ameliorated with adequate arterial pressure and cerebrospinal fluid drainage.

CONCLUSIONS

Our experience of selected patients undergoing thoracic endovascular aortic repair of descending thoracic aorta aneurysms is satisfactory with very low mortality and morbidity. A large use of thoracic endovascular aortic repair is foreseen in the next future.

Advancements in the Mo.Ma system procedure during carotid artery stenting

AIM

The aim of this paper was to reduce the incidence of clamping intolerance, asystolia, immediate mortality and neurological complications associated with carotid artery stenting (CAS) using the Mo.Ma system (Invatec, Roncadelle Brescia, Italy) embolic protection device (EPD).

METHODS

CAS was perfomed using the Mo.Ma system in 312 patients between January 2002-October 2009. From October 2008 variations to the standard technique were introduced. A total of 214 patients were treated with the standard technique, and 88 with the new technique. Improvements include the engagement of the guidewire's floppy tip through the lesion whilst the cerebral blood flow is maintained, a slow release post-dilation (1 atm/2 s), a quicker manual aspiration procedure following post-dilation, a redirection of blood flow into the external carotid artery (ECA) with the post-dilation balloon inflated in the internal carotid artery (ICA), and a further manual aspiration and the subsequent release of the Mo.Ma system.

RESULTS

This study reports reduced incidence of clamping intolerance (7.9% vs. 4.5%), asystolia (0 vs. 1.9%), immediate mortality (0 vs. 0.9%) and neurological complications (1.1% vs. 3.7%). The only neurological complication associated with the new technique was a transient ischemic attack (TIA).

CONCLUSIONS

The new variations of the standard Mo.Ma technique seem rational in the improvement of the safety and efficacy of CAS using an EPD, in reducing the incidence of clamping intolerance and asystolia, immediate mortality and neurological complications. This series indicates a positive trend for this revised technique, but a multicentre registry is required to validate these promising results.

Carotid Endarterectomy: experience in 8743 cases

INTRODUCTION

Recently published case series of patients undergoing carotid endarterectomy suggested a reduction in the rate of perioperative neurologic events when compared to those reported in the large randomized trials performed in the 1990s, without great differences between high and low risk patients.

METHODS

As a major center of Vascular Surgery we prospectively collected data on 8743 carotid endarterectomy procedures (eversion technique 75%, patch closure 17.5%) performed in the period 1992-2009.

RESULTS

Perioperative mortality was 0.32% (27/8743) with myocardial infarction being the most frequent cause (9 patients). Perioperative neurological morbidity was 1.04% (91/8743) with 51 major and 40 minor strokes. In 201 cases (2.3%) a cervical hematoma (suture-line bleeding in 41 cases and or diffuse oozing in 160 cases) in the early postoperative period necessitated urgent wound revision. In 262 (3.0%) cases we observed permanent or transient lesions of cranial nerves in the postoperative period. There was no significant difference in the combined ipsilateral stroke and perioperative death rate in octogenarian patients (2.1% in octogenarians and 1.2% in younger patients, p>0.05), even though an increasing trend was evident.

CONCLUSIONS

Carotid endarterectomy has a reduced rate of perioperative complications when compared to those previously reported in literature. The low complication rate is related to improved preoperative patients evaluation, surgeons' increasing experience and to surgical and anesthesiological techniques. Carotid angioplasty and stenting should have their results compared to these real world results of carotid endarterectomy in order to asses their reliability when treating extracranial cerebrovascular disease.

Alginate microparticles for Polymyxin B Peyer's patches uptake: microparticles for antibiotic oral administration

Microparticles with size less than 3 microm, able to be taken up by M cell of Peyer's patches for the drug delivery to the Gut Associated Limphoid Tissue (GALT), were developed in order to improve oral bioavailability of Polymyxin B (PMB). Less than 3 microm alginate microparticles resistant to gastro-intestinal media were prepared by spray-drying technique and cross-linking by calcium ions and chitosan. The cross-linked microparticles were evaluated for PMB content by spectrophotometric method, alginate/PMB interaction by rheological study, cross-linking degree by EDS analysis and PMB activity by microbiological assay. By modulating the polymer cross-linking degree, cationic PMB interacted on alginate chains leading to a proper PMB loading as well as antibiotic retention in gastric environment and sustained delivery in intestinal fluid. Moreover, the procedure resulted suitable for PMB biological activity preservation.

Effectiveness and safety of carotid endarterectomy under remifentanil

AIM

The aim of this study was to evaluate the effectiveness and safety of carotid endarterectomy (CEA) with conscious sedation under remifentanil (Remifentanil anesthesia - RA) vs conventional loco-regional anesthesia (Conventional-LRA) in the current practice of a vascular surgery unit.

METHODS

We introduced the ''Remifentanil-RA'' in our practice according to a two-step protocol. In the first step we performed a pilot prospective study to assess the procedure's safety and reproducibility in our setting on 60 consecutive patients with symptomatic and/or high-grade (>70%) internal carotid artery stenosis and alternately assigning them either to ''Remifentanil-RA'' or ''Conventional-LRA'' CEA. In the second step we analysed our routine operative records as to effectiveness and safety on 533 patients who consecutively underwent ''Remifentanil-RA'' CEA. We compared them with 533 age- and sex-matched historical controls who underwent ''Conventional-LRA'' CEA.

RESULTS

The patients' mean age was 71.2+/-6.8 vs 71.8+/-6.1 (''Remifentanil-RA'' vs ''Conventional-LRA''). About 73% of them were male and 56% had a symptomatic carotid stenosis. Neither the pilot study nor second step comparison showed differences in outcome measures. We found only higher peri-operative nausea/ vomit (3.6% vs 0.4% ''Remifentanil-RA'' vs ''Conventional-LRA'', P<0.0002) and fewer re-operations for post-operative hematomas (3% vs 5.4% respectively, P=0.048).

CONCLUSIONS

We found that ''Remifentanil-RA'' CEA was safe, effective and satisfactory. Nevertheless, with the potential problems of intubation and those already found with side effects, a randomized control trial (RCT) is needed in order to prove that this method is superior to ''Conventional-LRA'' CEA.

PRIAMUS--proximal flow blockage cerebral protectIon during carotid stenting: results from a multicenter Italian registry

AIM

The aim of this Italian prospective registry was to evaluate the applicability and efficacy of the Mo.Ma Device (Invatec, Roncadelle, Italy) for the prevention of cerebral embolization during carotid artery stenting (CAS) in a real world population.

METHODS

In 4 Italian centers, 416 patients (300 men; mean age 71.6+/-9 years) between October 2001 and March 2005 were enrolled in a prospective registry. Two-hundred and sixty-four symptomatic (63.46%) with >50% diameter stenosis and 152 (36.54%) asymptomatic patients with >70% diameter stenosis were included. The Mo.Ma Proximal Flow Blockage Embolic Protection System was used to perform protected CAS, achieving cerebral protection by endovascular clamping of the common carotid artery (CCA) and of the external carotid artery (ECA).

RESULTS

Technical success, defined as the ability to establish protection with the Mo.Ma device and to deploy the stent, was achieved in 412 cases (99.03%). The mean duration of flow blockage was 4.91+/-1.1 min. Transient intolerances to flow blockage were observed in 24 patients (5.76%), but in all cases the procedure was successfully completed. No peri-procedural strokes and deaths were observed. Complications during hospitalization included 16 minor strokes (3.84%), 3 transient ischemic attacks (0.72%), 2 deaths (0.48%) and 1 major stroke (0.24%). This resulted in a cumulative rate at discharge of 4.56% all strokes and deaths, and of 0.72% major strokes and deaths. All the patients underwent thirty-day follow-up. At thirty-day follow-up, there were no deaths and no minor and major strokes, confirming the overall cumulative 4.56% incidence of all strokes and deaths rate, and of 0.72% rate of major strokes and deaths at follow up. In 245 cases (58.89%) there was macroscopic evidence of debris after filtration of the aspirated blood.

CONCLUSIONS

This Italian multicenter registry confirms and further supports the efficacy and applicability of the endovascular clamping concept with proximal flow blockage in a broad patient series. Results match favorably with current available studies on carotid stenting with cerebral protection.

First Clinical Experiences with an Endovascular Clamping System for Neuroprotection During Carotid Stenting

OBJECTIVES

This report evaluates the feasibility and efficacy of an endovascular blood flow blockage technique to prevent intracerebral embolization of plaque debris during carotid artery stenting.

METHODS

Forty-two patients were enrolled in five clinical sites in Germany and Italy with either an asymptomatic internal carotid artery stenosis > or =75% (mean 87%) or a symptomatic stenosis > or =60% (mean 85%). Cerebral protection during the stenting procedure was achieved using an endovascular clamping technique, obtained by occlusion of the external and common carotid artery via two independently inflatable balloons integrated in the Mo.Ma system. Blood with particulate plaque debris was aspirated before flow was restored. The patient's clinical and the neurological status were assessed during intervention, at discharge, and at 3 months follow-up.

RESULTS

Stenting was performed in all but one patient. The mean flow occlusion time was 10.6+/-6.5 min. Transient clamping intolerance was observed in five patients (12%). In two patients, neurological deficits persisted for 2 and 12 h, respectively. Two minor strokes (4,7%) occurred at 5 and 72 h after the procedure. No major strokes or deaths were observed at 3 months follow-up.

CONCLUSIONS

This first clinical experience with the Mo.Ma device substantiates the feasibility of endovascular clamping in preventing cerebral embolization during carotid artery stenting.

Alginate microparticles for enzyme peroral administration

In order to protect protein and peptide drugs against inactivation by different barriers in the gastro-intestinal tract and to improve their absorption, alginate microparticles as a carrier of L-lactate dehydrogenase, were developed by spray-drying technique. However, alginate complexation and spray-drying conditions led to enzyme activity loss. Such a drawback was overcome by using protectant additives (carboxymethylcellulose sodium salt, polyacrylic acid sodium salt, lactose) preventing the enzyme inactivation by both interaction with alginate and experimental conditions, lactose having the most protective effect. Nevertheless, only polyacrylic acid sodium salt provided a microparticulate structure required for the target of the Peyer's patches.

Protein immobilization in crosslinked alginate microparticles

Oral administration of peptide and protein drugs requires their protection from the acidic and enzymatic degradation in the gastro-intestinal environment and their targeting to the absorption zone. For this purpose, an alginate microsystem, as a carrier of bovine serum albumin (BSA), as a model protein, was developed using a spray-drying technique. A hardening process with Ca2+ and chitosan (CS) provided a system with resistance to the gastro-intestinal barriers and of appropriate size for targeting to the Peyer's patches. The present work aims to evaluate the effects of the ratio of sodium alginate (Na-A) and BSA as well as the pH of the crosslinking medium on the microsystem properties. Microparticle morphological and dimensional characteristics did not change significantly with the formulation variables. BSA loading at a pH value less than the protein isoelectric point (pI) was higher than that at a pH similar to the pI owing to an electrostatic interaction between the charged protein and the polyanionic alginate. The maximum encapsulation efficiency was obtained at the highest Na-A/BSA ratio. Protein release in a simulated gastro-intestinal fluid was not affected by the preparative variables, but was controlled by the pH-dependent nature of the polymer material. Polyacrylamide gel electrophoresis (PAGE) demonstrated the stability of the protein to both the preparative conditions and the gastro-intestinal pH values.

Chitosan-alginate microparticles as a protein carrier

The oral administration of peptidic drugs requires their protection from degradation in the gastric environment and the improvement of their absorption in the intestinal tract. For these requirements, a microsystem based on cross-linked alginate as the carrier of bovine serum albumin (BSA), used as a model protein, was proposed. A spray-drying technique was applied to BSA/sodium alginate solutions to obtain spherical particles having a mean diameter less than 10 microm. The microparticles were hardened using first a solution of calcium chloride and then a solution of chitosan (CS) to obtain stable microsystems. The cross-linking process was carried out at different CS concentrations and pH values of the cross-linking medium. The CS concentration affected the BSA loading in the microparticles prepared at a pH value less than the protein isoelectric point (pI). Moreover, the BSA loading at a pH value less than the pI was higher than that at a pH similar to the pI regardless of the CS concentration. This finding could be attributable to the formation of a BSA/alginate complex. The evaluation of the interaction between BSA and alginate at different pH values by means rheological measurements confirmed this hypothesis. This approach may represent a promising way to devise a microcarrier system with appropriate size for targeting the Peyer's patches, with appropriate immobilization capacity, and suitable for the oral administration of peptidic drugs.

[Thyroid metastasis of a renal carcinoma. 3 clinical cases]

The clinical finding of metastasis to the thyroid is a very rare event. When a metastasis from a renal carcinoma is diagnosed, it is usually the distant evidence of a tumour discovered and removed surgically months or years before, or it may be the first clinical sign of an as yet undiagnosed asymptomatic renal tumour. A case of massive retrosternal goiter in a 65-year-old patient, operated on for a right renal carcinoma (nephrectomy 6 years before), is reported. The goiter, causing compression symptoms and dyspnoea, was treated by total thyroidectomy. The pathological diagnosis was metastasis from renal carcinoma. The authors present a second case of nodular goiter, in a 79-year-old woman, 9 years after a right nephrectomy for a renal carcinoma. The expanding nodule, diagnosed intraoperatively as carcinoma, was treated by total thyroidectomy. The postoperative pathological diagnosis was metastasis from renal carcinoma. The authors report a third case of an expanding nodule of the thyroid, in a 65-year-old patient, diagnosed intraoperatively as a metastasis from renal carcinoma, treated by right lobectomy and isthmusectomy. An abdominal CT scan revealed a renal asymptomatic tumor, treated by right nephrectomy. The diagnosis can be established by means of fine needle aspiration biopsy preoperatively or intra- or postoperative histology. Surgical therapy may resolve the compression symptoms and improve the prognosis.

Mechanisms of myocardial ischemia in a patient with left main coronary artery atresia

This report describes the different clinical and instrumental manifestations of coronary ischemia in a patient with left main coronary artery atresia. Exercise test and thallium-201 perfusion scintigraphy during isometric exercise test were negative for angina and electrocardiographic changes. Conversely, dipyridamole infusion caused severe angina, marked ST-segment changes and diffuse thallium-201 uptake abnormalities. This peculiar anatomical condition offers the opportunity of high-lighting the role played by the microcirculation in determining myocardial ischemia.

PVP solid dispersions for the controlled release of furosemide from a floating multiple-unit system

The poor bioavailability of orally dosed furosemide (FUR) is due to the presence of a biological window in the upper gastrointestinal tract. The purpose of the present study was to develop and optimize in vitro a multiple-unit floating system with increased gastric residence time for FUR. The incomplete release of FUR from the units, related to its low water solubility, led to the preparation and evaluation of different FUR samples to be incorporated into the units. The complete dose release over the actual intragastric residence time of the system (about 8 hr) was achieved by loading both the core and the membrane forming the units with a 1:5 FUR/polyvinylpyrrolidone (FUR/PVP) solid dispersion. Physicochemical analyses suggested the predominant role of the amorphous state of FUR in producing enhanced drug solubility and dissolution rate, which led to the desired release profile from the floating units.

Eversion versus conventional carotid endarterectomy: late results of a prospective multicenter randomized trial

OBJECTIVE

The durability of carotid endarterectomy (CEA) may be affected by carotid restenosis. The data from randomized trials show that the highest incidence of restenosis after CEA occurs from 12 to 18 months after surgery. The optimal CEA technique to reduce perioperative complications and restenosis rates is still undefined. This study examines the long-term clinical outcome and incidence of recurrent stenosis in patients who undergo eversion CEA. Previously published perioperative results of this study did not show statistically significant differences in study endpoints between the eversion and standard techniques.

METHODS

From October 1994 to March 1997, 1353 patients with surgical indications for carotid stenosis were randomly assigned to undergo eversion (n = 678) or standard CEA (n = 675; primary closure, 419; patch, 256). Withdrawal from the assigned treatment occurred in 1.6% of the patients (in 13 assigned to eversion CEA, and in nine assigned to standard CEA). The clinical and duplex scan follow-up examination was 99% complete, and the mean follow-up interval was 33 months (range, 12 to 55 months). The primary outcomes were perioperative and late major stroke and death, carotid restenosis (stenosis >/= 50% of the lumen diameter detected at duplex scanning), and carotid occlusion. The primary evaluation of study outcomes was conducted on the basis of an intention-to-treat analysis.

RESULTS

Restenosis was found at duplex scanning in 56 patients (19 in the eversion group, and 37 in the standard group). Within the standard group, the restenosis rates were 7.9% in the primary closure population and 1.5% in the patched population. Of the patients with restenosis, 36% underwent cerebral angiography that confirmed restenosis in all cases. The cumulative restenosis risk at 4 years was significantly lower in the group that underwent treatment with eversion CEA as compared with the standard group (3.6% vs 9.2%; P =.01), with an absolute risk reduction of 5. 6% and a relative risk reduction of 62%. Eighteen patients would have had to undergo treatment with eversion CEA to prevent one restenosis during the 4-year period. The incidence rate of ipsilateral stroke was 3.3% in the eversion population and 2.2% in the standard group. There were no significant differences in the cumulative risks of ipsilateral stroke (3.9% for eversion, and 2.2% for standard; P =.2) and death (13.1% for eversion, and 12.7% for standard; P =.7)) in the two groups. Of the 18 variables that were examined for their influence on restenosis, eversion CEA (hazard ratio, 0.3; 95% confidence interval, 0.2 to 0.6; P =.0004) and patch CEA (hazard ratio, 0.2; 95% confidence interval, 0.07 to 0.6; P =. 002) were negative independent predictors of restenosis with multivariate Cox proportional hazards regression analysis.

CONCLUSION

The EVEREST (EVERsion carotid Endarterectomy versus Standard Trial) showed that eversion CEA is safe, effective, and durable. No statistically significant differences were found in late outcome between the eversion and standard techniques at the available follow-up examination.

Endoluminal repair of infrarenal abdominal aortic aneurysms using a modular stent-graft: one-year clinical results from a European multicentre trial

This is a report of a prospective study to evaluate the safety and efficacy of the Medtronic AneuRx stent-graft. Patients with an infrarenal aneurysm with a proximal neck length of greater than 10 mm and a neck diameter not greater than 26 mm and iliac artery diameters of at least 6 mm were accepted for endovascular repair using the Medtronic AneuRx modular stent-graft. A total of 104 patients were included in the study. Transfemoral placement of the bifurcated stent-graft was successful in 102 of 104 patients. Two conversions were performed. The mean operating time was 148 min (range 75-480) and the mean blood loss was 605 ml (range 100-2900). The mean follow-up was 15 months (range 12-21). Complications were rare and no kinking or migration occurred. At follow-up, four endoleaks persisted after 12 months. The Medtronic AneuRx stent-graft is a safe and efficacious alternative to open abdominal aortic aneurysm repair with excellent early results.

European multicentre experience with modular device (Medtronic Aneurx) for the endoluminal repair of infrarenal abdominal aortic aneurysms

OBJECTIVE

Transfemoral endoluminal repair of AAA, introduced for the first time in the early 90's, has become a very promising alternative to conventional open repair and more and more centers are reporting satisfactory postoperative results in a high percentage of cases. Straight and bifurcated grafts represent the devices available on the market at present and aortic, as well as iliac aneurysmal lesions can be safely treated through a transfemoral approach. The possibility to indicate an endovascular AAA repair is related to the configuration (length and size) of the proximal and distal necks, tortuosity and calcification of the access arteries and to vascular and non-vascular comorbidities, which afflict the patients. The objective of our study was to evaluate the early and late postoperative results in a series of patients affected by infrarenal AAA, who underwent endoluminal repair.

MATERIALS AND METHODS

From December 1996 to 31 October 1997 in 5 different European Centers, 100 Medtronic AneuRx bifurcated stent grafts were implanted for infrarenal abdominal aortic aneurysms. The diameter of the AAA varied from 33 to 77 mm (average 64 mm) and the mean age of the patients was 70.8 years (51-87 years). In one patient with a 33 mm diameter of the aneurysm, the surgical procedure was indicated because the size of the aneurysm had increased by 5 mm, compared to the previous control made 2 months before. In addition the aneurysm became symptomatic. There were 92 male and 8 female patients. The average time of the surgical procedure was 150 minutes (75-480 minutes) with an average blood loss of 570 ml (100-2,600 ml).

Effect of lesions of the nucleus basalis magnocellularis and of treatment with posatirelin on cholinergic neurotransmission enzymes in the rat cerebral cortex

The effect of 4 and 8 weeks of treatment with the thyrotropin releasing hormone (TRH), analogue posatirelin (L-6-ketopiperidine-2-carbonyl-L-leucyl-proline amide), on the changes of cholinergic neurotransmission enzymes, choline acetyltransferase (ChAT) and acetylcholinesterase (AChE), caused by lesions of the nucleus basalis magnocellularis (NBM), was investigated in the rat frontal cortex. ChAT and AChE were demonstrated with immunohistochemical and histochemical techniques, respectively associated with image analysis and microdensitometry. Monolateral and bilateral lesions of NBM area caused a significant loss of ChAT-immunoreactive nerve cell bodies in the NBM, as well as a remarkable decrease of ChAT-immunoreactive fibres and of AChE reactivity in the frontal cortex ipsilateral to the lesion or of both sides, respectively. The number of ChAT-immunoreactive nerve cell bodies in the lesioned NBM was higher in posatirelin-treated rats for 8 weeks in comparison with control NBM-lesioned rats. Moreover, the compound increased the number of ChAT-immunoreactive fibres in the frontal cortex of monolaterally and bilaterally NBM-lesioned rats at 8 weeks after lesion, but was without effect on these fibres in sham-operated rats. The same is true for AChE reactivity, developed in the neuropil of the frontal cortex, which was restored in part by an 8-week treatment with posatirelin in NBM-lesioned rats. These findings suggest that treatment with posatirelin rescues cholinergic neurons of the NBM and cholinergic projections to the cerebral cortex affected by lesioning of the NBM. The functional relevance of these observations and their possible applications should be evaluated in future studies.

Polysaccharide film-coating process for freely swellable hydrogels

In order to control the drug release from coated hydrogels by preventing membrane fractures, an intramembrane freely swellable matrix device was designed by enclosing a void space between a crosslinked poly(vinyl alcohol) (PVA) matrix and a calcium alginate membrane. The highly swellable PVA matrix loaded with diltiazem hydrochloride was obtained by means of a simplified procedure of the polymer crosslinking reaction using glutaraldehyde in solution with ammonium persulfate. The undried swollen matrix was coated with a calcium alginate membrane employing an ionotropic gelation of sodium alginate induced by calcium ions. The subsequent drying process generated a void space separating the inner core from the membrane. The resulting calcium alginate membrane, which was uniform and compact in the structure, increased in thickness according to the coating time. Coating times exceeding 5 min allowed modification of the drug release profile providing, after a short burst period, sustained and constant rate phases in both simulated gastric fluid and simulated intestinal fluid. Because the inner hydrogel expanded freely inside the device, the unstressed and intact membrane could act as the rate-controlling factor in the drug release process. Owing to the pH-dependent behavior of the membrane, most of the drug was delivered in intestinal fluid. Therefore, the device proposed could be advantageously used for drug targeting to the small intestine.

Experience with the Stentor endograft at four Italian centers

PURPOSE

To report the outcome of an Italian multicenter trial of endovascular abdominal aortic aneurysm (AAA) exclusion using the Stentor device.

METHODS

Between April 1995 and July 1996, 66 patients (63 men; average age 69 years, range 53 to 84) with infrarenal AAAs meeting the inclusion criteria were enrolled. The average diameter of the aneurysm was 4.6 cm (range 4.2 to 7). Three (4.5%) of the 66 AAAs were anastomotic aneurysms.

RESULTS

Sixteen (25%) tubular and 50 (76%) bifurcated endograft procedures were attempted; 4 (6.1%) were converted and 1 terminated owing to technical faults with the bifurcated graft's second limb. One tube graft was too short and failed to exclude an anastomotic aneurysm. Sixty (91%) endograft procedures were completed successfully. Six (9.1%) vascular complications occurred, three in one patient who subsequently died of pulmonary embolism 72 hours postoperatively (1.5% mortality). There were four (6.1%) proximal endoleaks; two sealed spontaneously in < 1 month, and a third was converted (7.6% conversion rate). The fourth is being observed. Clinical success (aneurysm exclusion with no death or endoleak) at 30 days was 86.3% (57/66). In the 23-month follow-up of 57 eligible patients, 2 patients died of unrelated causes and 1 graft limb thrombosed, requiring a crossover femoral bypass. One patient was converted to surgical repair at 5 months postoperatively when increasing aneurysm size signaled an undisclosed endoleak (1.8% late conversion rate). Five other secondary endoleaks were treated with endovascular techniques.

CONCLUSIONS

The Stentor was technically feasible in 10% to 40% of AAA candidates in this study, although deployment of the second limb was problematic in the bifurcated device. Introduction of the second-generation Vanguard endograft brought this study to an end.

A randomized study on eversion versus standard carotid endarterectomy: study design and preliminary results: the Everest Trial

PURPOSE

The EVEREST Trial was designed to determine whether the surgical technique influences the durability and complications of carotid endarterectomy (CEA). The current report focuses on the study design and preliminary results.

METHODS

EVEREST is a randomized multicenter trial. A total of 1353 patients with carotid stenosis requiring surgical treatment were randomly assigned to received standard (n = 675) or eversion (n = 678) CEA. Primary end points included carotid occlusion, major stroke, death, and restenosis rate.

RESULTS

The rate of perioperative major stroke and death (1.3 for each study group) and the incidence of early carotid occlusion (0.6% for eversion vs 0.4% for standard) were similar. No significant differences were found between eversion and standard CEA with respect to incidence of perioperative transient ischemic accident, minor stroke, cranial nerve injuries, neck hematoma, myocardial infarction, or surgical defects as detected with intraoperative quality controls. Clamping time was significantly shorter for eversion CEA compared with patch standard procedures (31.7 +/- 15.9 vs 34.5 +/- 14.4 minutes, p = 0.02). A shunt was inserted in 11% of patients undergoing eversion CEAs and in 16% of patients undergoing standard procedures. Overall 30-day events occurred in 13.3% of the eversion group and in 11.4% of the standard group (p = 0.3). At a mean follow-up of 14.9 months (range, 1 to 38 months), 16 (2.4%) restenoses occurred in the eversion group and 28 (4.1%) occurred in the standard group (odds ratio, 0.56; 95% confidence interval, 0.3 to 1.1; p = 0.08).

CONCLUSION

The preliminary results of the EVEREST Trial suggest that eversion CEA is a safe and rapid procedure with low major complication rates. No significant differences in restenosis rates were observed between eversion and standard CEA at the available follow-up. Longer-term results are necessary to assess whether the eversion technique influences the durability of CEA.

Effect of treatment with the neuroactive peptide posatirelin on microanatomical changes of frontal cortex and hippocampus caused by lesions of the locus coeruleus

The influence of monolateral and bilateral lesions of the Locus coeruleus (LC) on the number of nerve cell and glial fibrillary acidic protein (GFAP)-immunoreactive astrocyte profiles, on silver-gold impregnated fibres and on tyrosine hydroxylase (TH) immunoreactivity was assessed in the rat frontal cortex and hippocampus. The influence of treatment for 4 and 8 weeks with a 10 mg/kg/day dose of the neuroactive peptide posatirelin on the above parameters was also investigated. Lesions of the LC decreased the number of nerve cell profiles in the frontal cortex 8 weeks after lesioning and were without effect on nerve cell profiles in the frontal cortex 4 weeks after lesioning and in the hippocampus at both 4 and 8 weeks after LC lesioning. Glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes were not affected by lesions of LC. Silver-gold impregnated fibres were decreased in the frontal cortex but not in the hippocampus of LC-lesioned rats at 8 weeks after lesioning. TH immunoreactivity, which was localized in nerve fibre-like structures both in the frontal cortex and in the hippocampus was decreased in the frontal cortex and in the hippocampus from the 4th week after LC lesioning. Treatment with posatirelin was without effect on the number of nerve cell and of GFAP-immunoreactive astrocyte profiles at both 4 and 8 weeks after LC lesioning, with the exception of nerve cells of the frontal cortex in monolaterally-lesioned rats which were increased 8 weeks after lesioning. The compound increased silver-gold impregnated fibres in the frontal cortex of monolaterally lesioned rats after 8 weeks of treatment, but did not affect TH immunoreactivity both in the frontal cortex or in the hippocampus. The above results suggest that treatment with posatirelin exerts a neuroprotective effect on the frontal cortex consisting of the partial restoration of some microanatomical changes caused by lesions of LC. The possible significance of this effect is discussed.

The Italian trial of endovascular AAA exclusion using the Parodi endograft

PURPOSE

To report the outcome of the prospective 11-center Italian Parodi Trial using straight and tapered endografts for the endovascular exclusion of abdominal aortic aneurysms (AAA).

METHODS

From April 1994 to July 1995, 27 patients were evaluated and selected for endovascular AAA exclusion. The Parodi devices were delivered through femoral arteriotomies using 18 to 22F introducers and deployed by balloon expansion of the terminal stents.

RESULTS

Of 27 cases attempted, 24 endografts (15 tube, 9 aortomonoiliac) were implanted (1 deployment and 2 access failures [11.1%] were converted). Three endoleaks (12.5%) were treated intraoperatively with covered stents, two successfully, and the third sealed within 30 days. Three (12.5%) of the 24 treated patients died in-hospital of device-(n = 2) and procedure-related (n = 1) causes; the remaining 21 patients were discharged within 8 days. Of the 8 aortomonoiliac grafts in follow-up, only 1 (12.5%) failed in the mean 23-month (range 18 to 30) follow-up: however, 4 (31%) of 13 tube graft patients were converted to surgery within 18 months. Of the 16 (66.7%) surviving endografts at 2 years, 6 (38%) showed no change in the AAA diameter, while 10 (62%) had shrunk.

CONCLUSIONS

The tube graft was applicable in only about 5% of cases, and accurate endograft sizing and distal fixation were problematic. The aortomonoiliac design was not appealing to surgeons but fared better in the long term. Given the advent of newer endograft models, the Italian Parodi Trial has been terminated.

[Carotid endarterectomy using the classical technique and by eversion]

After a brief introduction on the history of the surgical treatment of carotid stenosis the authors illustrate both the classical endarterectomy and the eversion endarterectomy. The constant search for a technique which could be of easy execution and also reduce the risk of complication (especially late ones, such as restenosis), brought the authors to adopt the eversion endarterectomy with reimplantation of internal carotid artery. From 1990 through 1995, 1034 carotid endarterectomies were performed, of which 611 with eversion technique and 423 with others techniques. The average follow-up was 38 months. The eversion endarterectomy group had lower neurological morbidity and mortality rates, both early and late. Even more important, they had a lower incidence rate of hemodynamically relevant restenosis (0.37% in the eversion endarterectomy group vs 1.97% in the other group).