The challenge of maintaining necessary vascular and endovascular services at a referral center in Northern Italy during the COVID-19 outbreak.

OBJECTIVES: The Padova Hospital Vascular Surgery Division is located in Veneto, one of the area of the Northern Italy most hit by the Coronavirus disease 2019 outbreak. The aim of this paper is to describe the protocols adopted and to evaluate their impact during the acute phase of Coronavirus spread, focusing on the management of elective and urgent/emergent surgery, outpatients activity, and also health staff preservation from intra-hospital Coronavirus disease 2019 infection. METHODS: Several measures were progressively adopted in the Padova University Hospital to front the Coronavirus disease 2019 outbreak, with a clear strong asset established by 9 March 2020, after the Northern Italy lockdown. Since this date, the Vascular Surgery Unit started a "scaled-down" activity, both for elective surgical procedures and for the outpatient Clinical activities; different protocols were developed for health preservation of staff and patients. We compared a two months period, 30 days before and 30 days after this time point. In particular, emergent vascular surgery was regularly guaranteed as well as urgent surgery (to be performed within 24 h). Elective cases were scheduled for "non-deferrable" pathology. A swab test protocol for COVID-19 was applied to health-care professionals and hospitalized patients. RESULTS: The number of urgent or emergent aortic cases remained stable during the two months period, while the number of Hospital admissions via Emergency Room related to critical limb ischemia decreased after national lockdown by about 20%. Elective vascular surgery was scaled down by 50% starting from 9 March; 35% of scheduled elective cases refused hospitalization during the lockdown period and 20% of those contacted for hospitalization where postponed due to fever, respiratory symptoms, or close contacts with Coronavirus disease 2019 suspected cases. Elective surgery reduction did not negatively influence overall carotid or aortic outcomes, while we reported a higher major limb amputation rate for critical limb ischemia (about 10%, compared to 4% for the standard practice period). We found that 4 out of 98 (4%) health-care providers on the floor had an asymptomatic positive swab test. Among 22 vascular doctors, 3 had a confirmed Coronavirus disease 2019 infection (asymptomatic); a total of 72 swab were performed (mean = 3.4 swab/person/month) during this period; no cases of severe Coronavirus disease 2019 (deaths or requiring intensive care treatment) infection were reported within this period for the staff or hospitalized patients. CONCLUSIONS: Elective vascular surgery needs to be guaranteed as possible during Coronavirus disease 2019 outbreak. The number of truly emergent cases did not reduce, on the other side, Emergency Room accesses for non-emergent cases decreased. Our preliminary results seem to describe a scenario where, if the curve of the outbreak in the regional population is flattened, in association with appropriate hospitals containment rules, it may be possible to continue the activity of the Vascular Surgery Units and guarantee the minimal standard of care.

Editor's Choice - Outcomes of Self Expanding PTFE Covered Stent Versus Bare Metal Stent for Chronic Iliac Artery Occlusion in Matched Cohorts Using Propensity Score Modelling.

OBJECTIVES: The aim was to compare outcomes of self expanding PTFE covered stents (CSs) with bare metal stents (BMSs) in the treatment of iliac artery occlusions (IAOs). METHODS: Between January 2009 and December 2015, 128 iliac arteries were stented for IAO. A CS was implanted in 78 iliac arteries (61%) and a BMS in 50 (49%). After propensity score matching, 94 limbs were selected and underwent stenting (47 for each group). Thirty day outcomes and midterm patency were compared; follow-up results were analysed with Kaplan-Meier curves. RESULTS: Overall, iliac lesions were classified by limb as TASC B (19%), C (21%), and D (60%). Technical success was 98%. Comparing CS versus BMS, the early cumulative surgical complication rate (12% vs. 12%, p = 1.0) and 30 day mortality rate (2% vs. 2%, p = 1.0) were equivalent. At 36 months (average 23 ± 17), overall primary patency was similar between CS and BMS (87% vs. 66%, p = .06), and this finding was maintained after stratification by TASC B (p = .29) and C (p = .27), but for TASC D, CSs demonstrated a higher patency rate (CS, 88% vs. BMS, 54%; p = .03). In particular, patency was in favour of CSs for IAOs > 3.5 cm in length (p = .04), total lesion length > 6 cm (p = .04), and IAO with calcification > 75% of the arterial wall circumference (p = .01). CONCLUSIONS: Overall, the use of self expanding CS for IAOs has similar early and midterm outcomes compared with BMS. Even if further confirmatory studies are needed, CSs seem to have higher midterm patency rates than BMSs for TASC D lesions, IAOs with a total lesion length > 6 cm, occlusion length > 3.5 cm, and calcification involving > 75% of the arterial wall circumference. These specific anatomical parameters may be useful to the operator when deciding between CS and BMS during endovascular planning.

Hemothorax Management After Endovascular Treatment For Thoracic Aortic Rupture.

OBJECTIVES: The aim was to describe and analyze the management of hemothorax (HTX) and the occurrence of respiratory complications after endovascular repair of thoracic aortic rupture (TEVAR). METHODS: This was a multicenter study with retrospective analysis. Between November 2000 and December 2012, all patients with confirmed HTX due to rupture of the descending thoracic aorta treated with TEVAR were included. Respiratory function (acid base status, Pao2, Paco2, lactate, and respiratory index) was monitored throughout hospitalization. Primary endpoints were survival and post-operative respiratory complications. RESULTS: Fifty-six patients were treated. The mean age was 62 ± 21 years (range 18-92 years). Etiology included traumatic rupture (n = 23, 41%), atherosclerotic aneurysm (n = 20, 36%), Debakey type IIIa dissection (n = 8, 14%), and penetrating aortic ulcer (n = 5, 9%). The primary technical success of TEVAR was 100%. The in hospital mortality rate was 12.5% (n = 7). Hemothorax was drained in 21 (37.5%) cases. In hospital respiratory complications occurred in 23 (41%) patients who required a longer intensive care unit stay (days 2.3 ± 0.7 vs. 1.9 ± 0.8, p = .017), and hospitalization (26 ± 17 vs. 19 ± 17, p = .021). Those who developed post-operative respiratory complications had lower pre-operative PO2 values (mmHg, 80 ± 24 vs. 91 ± 21, p = .012). Respiratory complications and in hospital mortality did not differ among aortic pathologies (p = .269 and p = 1.0, respectively), nor did in hospital mortality differ between patients with and without respiratory complications (13% vs. 12%; p = .990). CONCLUSIONS: Thoracic aortic rupture still has a high mortality rate. Respiratory complications have not been eliminated by endovascular repair. HTX evacuation may have had a positive influence on the survival in these patients. Although traumatic and degenerative ruptures are two significantly different scenarios, survival and respiratory outcomes were similar and were not affected by the underlying aortic disease.

Surgical infrarenal "neo-neck" technique during elective conversion after EVAR with suprarenal fixation.

OBJECTIVES: Conversion of a previous endovascular aneurysm repair (EVAR) with suprarenal fixation is a challenging situation even in the elective setting. The outcomes of a technique based on preservation of the first proximal covered stent of the endograft, used as a "neo-neck" for proximal anastomosis, are presented. METHODS: From 2001 to 2014, nine patients underwent elective conversion of a previous suprarenally fixed EVAR. After supraceliac clamping, the aneurysm sac was opened and the endograft identified; the fabric was cut beyond the first covered stent together with its native aortic wall in order to create a "neo-neck." An aortic balloon was inflated into the visceral aorta to avoid back bleeding. A Dacron bifurcated tube graft (Intergard, Maquet) was then sutured to the neo-neck mimicking endobanding, passing the stitches into the aortic wall and the first covered stent. RESULTS: The mean age was 68 years (range, 52-84 years). The stent grafts removed were four Zenith (Cook Medical), three Endurant (Medtronic), and two E-vita (Jotec). The indication for conversion was type 1A (n = 2), type 2 (n = 2), and type 3 (n = 1) endoleak, complete endograft thrombosis (n = 2), and abdominal pain with sac enlargement with no radiological sign of endoleak (n = 2). Blood loss was 1,428 mL (range 500-3,000 mL); the visceral ischemic time to perform the proximal anastomosis was 23.5 min ± 2.3 min). The post-operative complication rate was 11% (n = 1/9) related to a case of sac wall bleeding requiring re-intervention; mortality at 30 days was 0%. At 22 months (range, 8-41) the computed tomography angiogram demonstrated no signs of leaks or anastomotic pseudoaneurysm. CONCLUSION: Preservation of the proximal covered stent of an endograft with suprarenal fixation used as an infrarenal "neo-neck" with incorporation of the aorta to the suture line during elective surgical explantation simplifies the procedure, and can be achieved with very low early morbidity and mortality; furthermore, it seems to be durable over mid-term follow up.

Long-term outcomes and sac volume shrinkage after endovascular popliteal artery aneurysm repair.

OBJECTIVES: The aim was to evaluate long-term outcomes and sac volume shrinkage after endovascular popliteal artery aneurysm repair (EVPAR). METHODS: This study was a retrospective review of all EVPAR cases between 1999 and 2012. Sac volume shrinkage, long-term patency, limb salvage, and survival were evaluated using Kaplan-Meier estimates. The association of anatomical and clinical characteristics with patency was evaluated using multivariate analysis. RESULTS: Forty-six EVPAR were carried out in 42 patients (mean age 78 years, 86% male; mean sac volume 45.5 ± 3.5 mL). In 93% of cases (n = 43) the procedure was elective, while in 7% of cases it was for rupture (n = 2) or acute thrombosis (n = 1). Of the 43 patients who underwent elective repair, 58% were asymptomatic and 42% symptomatic (14 claudication, 3 rest pain, and 1 compression symptoms). Technical success was 98%. Mean duration of follow-up was 56 ± 21 months. Primary patency at 1, 3, and 5 years was 82% (SE 2), 79% (SE 4), and 76% (SE 4), while secondary patency was 90% (SE 5), 85% (SE 4), and 82% (SE 1) respectively; at 5 years there was 98% limb salvage and an 84% survival rate. During follow-up 11 limbs had stent graft failure: six required conversion, one underwent amputation, and four continued with mild claudication. Of those with graft failure, 63% (7/11) occurred within the first year of follow-up. The mean aneurysm sac volume shrinkage between preoperative and 5-year post-procedure measurement was significant (45.5 ± 3.5 mL vs. 23.0 ± 5.0 mL; p < .001). Segment coverage >20 cm was a negative predictor for patency (HR 2.76; 95% CI 0.23; p = .032). CONCLUSIONS: EVPAR provides successful aneurysm exclusion with good long-term patency, excellent limb salvage, and survival rates. Close surveillance is nevertheless required, particularly during the first postoperative year. Patients requiring long segment coverage (>20 cm) may be at increased risk for failure.

Parallel endografts in the treatment of distal aortic and common iliac aneurysms.

OBJECTIVES: Endovascular treatment of distal abdominal aortic aneurysms (D-AAA) and bilateral common iliac artery aneurysms (BCIAA) may present technical challenges for standard EVAR. Parallel iliac leg endografts (ILEs) of standard aortic devices and covered stents have been successfully employed to treat patients with D-AAA and BCIAA. The perioperative and long-term results of this straightforward endovascular technique are presented. METHODS: Beginning in 2009, patients deemed unfit for open surgery underwent parallel endografts D-AAA and BCIAA exclusion. Avoiding the use of a main body, ILEs are simultaneously delivered from both femoral arteries, landing parallel into the aortic neck (parallel grafts: PG). Distal landing zones including external iliac arteries (EIAs) are reached using appropriate ILEs. A third parallel covered stent graft (Viabahn, Gore) is delivered from a left brachial approach to maintain prograde blood flow to one internal iliac artery (IIA) when needed. RESULTS: Eighteen patients were successfully treated using parallel endografts, nine for BCIAA and nine for D-AAA. All D-AAA presented an irregular saccular shape, including three penetrating aortic ulcers and two pseudoaneurysms of previous aortic grafts. Prograde flow to one IIA was successfully maintained using a Viabahn graft in five patients with BCIAA. Mean aneurysm size was 50 mm in D-AAA and 43 mm in BCIAA. One patient required a perioperative ILE extension to treat a type Ib endoleak. One patient suffered a minor stroke 24 hours after the procedure. Two type II endoleaks were observed postoperatively. Five patients died of non-aneurysm related causes during follow-up. No new endoleaks, graft displacements or occlusions were observed during follow-up (median: 26 months, range 12-42 months). CONCLUSIONS: Successful exclusion of D-AAA and BCIAA was achieved in high-risk patients using parallel endografts, allowing antegrade blood flow to one IIA when needed. Commercially available endografts were used in a simple and effective approach, with excellent follow-up results.

Platelets express and release osteocalcin and co-localize in human calcified atherosclerotic plaques.

BACKGROUND: Although vascular-calcification mechanisms are only partially understood, the role of circulating calcifying cells and non-collagenous bone matrix proteins in the bone-vascular axis is emerging. In spite of the fact that platelets represent a cellular interface between hemostasis, inflammation and atherosclerosis, and have a myeloid precursor, a possible involvement in the modulation of vascular calcification has rarely been investigated. We investigated if osteocalcin (OC) is released by platelets and described OC expression in patients with carotid artery occlusive disease. METHODS: Expression and release of OC were determined by Western blot, immunofluorescence, fluorescence-activated cell sorting (FACS) and ELISA in human resting and activated platelets and megakaryocytes. Co-localization of platelet aggregates, macrophages, OC and calcifications was studied in carotid endarterectomy specimens and normal tissues. RESULTS: Human platelets expressed OC and co-localized with CD63 in δ-granules. Upon activation with an endogenous mechanism, platelets released OC in the extracellular medium. Expression of OC in megakaryocytes suggested lineage specificity. The OC count in circulating platelets and the released amount were significantly higher in patients with carotid artery occlusive disease than in healthy controls (P < 0.0001) in spite of similar serum levels. In atherosclerotic plaques, OC strongly overlapped with CD41+ platelets in the early stage of calcification, but this was not seen in normal tissues. CD68+OC+ cells were present at the periphery of the calcified zone. CONCLUSIONS: Given the active role played by platelets in the atherosclerotic process, the involvement of OC release from platelets in atherosclerotic lesions and the impact of genetic and cardiovascular risk factors in mediating bone-marrow preconditioning should be investigated further.

Restenosis: a challenge for vascular surgeon.

From the beginning of the cardiovascular surgery to the endovascular era restenosis represents the main problem of several spreading vascular disciplines. It can be considered as an excessive wound healing reaction of target vessel of revascularization procedures, that leads to a new narrowing of the vascular lumen. Restenosis still represents the main limiting factor of the long-term success of revascularization procedures. Prevention and strict follow-up are well established techniques in order to reduce restenosis rate and clinical impact of this condition. New drugs as cilostazol have been proven beneficial for patients with de novo lesions of peripheral arteries and cilostazol seems to avoid restenosis process in the majority of patients.

Unusual inflow sources and device introduction sites in aortic arch debranching.

AIM: Aim of the study was to evaluate a single center experience on hybrid treatment for thoracic aortic diseases, including aortic arch and ascending aorta endografting needing a total debranching from descending thoracic aorta and an antegrade endograft deployment from left ventricle. METHODS: Between January 2004 and December 2010 48 patients underwent thoracic aorta endografting, with coverage of at least one supra-aortic artery, because of atherosclerotic, dissecting and post-traumatic aneurysms or complications of previous aortic surgery. Supra-aortic trunks revascularization was obtained from ascending aorta, common carotid arteries and, in three cases, from descending thoracic aorta since the unavailability of common inflow sites. In three cases the antegrade endograft introduction through left ventricle (transapical approach, 2 cases) or ascending aorta (one case) was the only possibility for a safe deployment. RESULTS: Three groups have been identified on the basis of the proximal landing zone. Group A (27 patients): zone 2; Group B (9 patients): zone 1; Group C (12 patients): zone 0. The 30 days mortality was respectively 7.4%, 0% and 16%. Post operative paraplegia occurred in the 7.4% of group A, respiratory insufficiency and infections were the main post-operative complications with an incidence reaching 30% in each group. CONCLUSION: Hybrid procedures on aortic arch represent a possible treatment for cases unfit for open surgery despite the complication rates and mortality are not negligible. In selected cases, the endografting can be extended up to beyond the landing zone 0 where an antegrade transventricular endograft deployment and a supra-aortic perfusion from descending thoracic aorta represent a feasible option.

Open repair for ruptured abdominal aortic aneurysm: is it possible to predict survival?

The aim of the study was to determine variables that could be used to predict survival in patients with ruptured abdominal aortic aneurysm (RAAA) and to assess the accuracy of the Glasgow Aneurysm Score (GAS) and the Acute Physiology Chronic Health Evaluation II (APACHE-II). From January 1998 to July 2006, 103 patients underwent operations for RAAA. For each patient, 44 variables were retrospectively recorded in a database. Data were analyzed with univariate and multivariate methods. In the univariate analysis significant predictors of death were hypotension (p=0.001), preexisting peripheral vascular disease (p<0.001), renal insufficiency (p=0.037), chronic obstructive pulmonary disease (p=0.028), level of HCO(3)(-) (p<0.001), intraperitoneal rupture (p=0.001), blood transfused (p<0.001), cardiac complications (p<0.001), and APACHE-II score (p=0.001). Multivariate analysis confirmed statistical significance for coexisting peripheral vascular disease (p<0.001), diastolic blood pressure at admission <60 mm Hg (p=0.039), APACHE-II score >18.5 (p=0.025), HCO(3)(-) <21 mg/dL (p<0.001), and intraperitoneal rupture of the aneurysm (p=0.011) as predictors of death. Results of the study suggested that different factors can be helpful in identifying those patients whose operative risk is prohibitive. APACHE-II, contrary to GAS, is an accurate system to predict postoperative death after repair for RAAA.

Role of the genetic study in the management of carotid body tumor in paraganglioma syndrome.

Diagnosis of carotid body tumor (CBT) was made in a 36 years old woman. The pre-operative examination included genetic analysis of the succinate dehydrogenase that showed a mutation in his subunit D responsible of multiple paraganglioma at slow growth. Subsequently a thoraco-abdominal CT and indium(111) octreotide body scan were performed and another paraganglioma was detected in the anterior mediastinum. CBT was surgically removed; differently the thoracic lesion due to his benign genetic profile was not treated. During a 3-years follow-up the thoracic paraganglioma as expected, didn't increase. Genetic analysis of succinate dehydrogenase, should be performed in the management of CBT.

Endovascular treatment of asymptomatic popliteal aneurysms: 8-year concurrent comparison with open repair.

AIM: The aim of this prospective comparative study was to compare the results of 8-years experience of endovascular treatment (ET) of popliteal aneurysms (PAs) using the Hemobahn/Viabahn endograft with those achieved with open repair (OR). Endpoints were primary and secondary patency rate. METHODS: The study was a prospective randomized clinical trial from January 1999 to December 2003 and a prospective comparative study from January 2004 to December 2006. Patients with an asymptomatic aneurismal lesion in the popliteal artery 2 cm at angio-computed tomography were included in the study. Indication for ET was PA (proximal and distal neck length >1 cm); contraindications were: 1) age <50 years; 2) poor distal run-off; 3) contraindication to antiplatelet, anticoagulant or thrombolytic therapy. RESULTS: Between January 1999 and December 2006, of a total of 42 patients with 48 PA, 27 were treated with OR (group A) and 21 with ET (group B). The primary patency rate was 100% in group A and 80.9% in group B at 12 months and 71.4% and 88.1%, respectively, at 72 months; the secondary patency rate at 72 months was 88.15% and 85.9% in groups A and B, respectively. No statistical differences were observed at the log-rank test. During the entire study period, 3 (14.3%) patients in group B required conversion to open surgery because of endograft occlusion. CONCLUSION: Within the power limitations of this study, ET for asymptomatic PA in patients with suitable anatomy can be considered safe, with long-term results comparable with those of OR.

Glasgow aneurysm score predicts the outcome after emergency open repair of symptomatic, unruptured abdominal aortic aneurysms.

OBJECTIVE: To determine the predictor factors of in-hospital postoperative mortality in patients presenting with symptomatic but not ruptured abdominal aortic aneurysm (AAA) at our institution. PATIENTS AND METHODS: Forty-two patients who underwent urgent open repair for symptomatic, non-ruptured AAA were evaluated retrospectively. RESULTS: Five patients (11.9%) died during the in-hospital stay. History of coronary artery disease (p=0.014), cerebrovascular diseases (p=0.015), renal failure according to Glasgow Aneurysm Score (GAS) criteria (p=0.001), serum creatinine concentration (p=0.026), and the GAS (p=0.008) were predictive of postoperative death. The ROC curve analysis showed that the Glasgow Aneurysm Score had an area under the curve of 0.870 (95%C.I. 0.71-1, S.E. 0.08, p=0.008), and its best cut-off value in predicting postoperative death was 90.0 (specificity 89.2%, sensitivity 80.0%). The postoperative mortality rate of patients with a Glasgow Aneurysm Score below 90 was 2.9%, whereas it was 50% for those with a score >or=90 (p=0.003, O.R. 33.0). CONCLUSION: This study shows that the Glasgow Aneurysm Score is a good predictor of postoperative mortality and morbidity after urgent repair of symptomatic, non-ruptured AAA and can be useful in identifying those patients whose operative risk is prohibitive. Its simplicity makes it a clinically important tool, particularly, in the emergency setting. Patients having a score less than 90 can safely undergo urgent open repair. Thorough evaluation and improvement of preoperative status followed preferably by an endovascular repair is indicated for those with a score >or=90.

Hyaluronan biodegradable scaffold for small-caliber artery grafting: preliminary results in an animal model.

OBJECTIVE: To evaluate a new Hyaluronan-based graft. MATERIAL AND METHODS: Hyaluronan-based grafts (HYAFF 11trade mark tube, diameter 2 mm, length 1.5 cm) were implanted in an end-to-end fashion in the abdominal aorta of 15 rats. Histology, immunohistochemistry and electron microscopy were used to evaluate the results at 7, 21, and 90 days. RESULTS: At day 7, new tissue was observed in the graft coming from both the proximal and distal ends of the aorta. The luminal surface of the regenerating tissue was covered by endothelial cells (CD34(+), VEGFR-2(+), vWF(+)). At day 21, regenerating tissue joined at the centre of the tube. The neo-vessel was formed by smooth muscle cells (Myosin Light Chain Kinase) as well as elastic, and collagen fibres. At day 90 a stable artery segment was formed and the biomaterial was almost completely degraded. Infiltration of neutrophils and lymphocytes was not observed. All animals survived the observation period and there were no signs of stenoses or aneurysms. CONCLUSION: The hyaluronan-based graft allowed complete regeneration of a newly formed vascular tube in which all the cellular and extracellular components are present and organized in a well defined architecture similar to native artery.

Is carotid endarterectomy in octogenarians more dangerous than in younger patients?

AIM: The risk for developing stroke increases with the advancing age, peaking over age 80. In elderly patients, carotid endarterectomy may provide prophylaxis against stroke. Aim of our study was to compare patients 80 years or older with patients younger than 80 undergoing carotid endarterectomy. Endpoints were perioperative mortality and morbidity. METHODS: From January 1996 to December 2002, 1 659 patients underwent a 1 733 carotid endarterectomy for a symptomatic or asymptomatic significant carotid lesion. Among them, 125 patients were 80 years or older. We analyzed death and stroke rate from cerebrovascular accidents, TIA as well as non cerebrovascular complications and death rate postoperatively and in the long term follow-up. The Pearson's chi-squared(2) test was used for the statistical analysis on risk factors, morbidity and mortality. The Log rank test was used for cumulative stroke-free and survival rates between the 2 groups (level of confidence p<0.05). RESULTS: Risk factors were similar in both groups. No statistical difference was observed in the stroke, TIA, mortality and stroke free rates between the 2 groups. CONCLUSIONS: The results of our study show that perioperative and postoperative mortality and morbidity as well as the long-term stroke-free rate does not differ significantly in patients 80 years or older compared to patients younger than 80 undergoing carotid endarterectomy.

Effect of fluid ingestion on neuromuscular function during prolonged cycling exercise.

OBJECTIVES: To investigate the effects of fluid ingestion on neuromuscular function during prolonged cycling exercise. METHODS: Eight well trained subjects exercised for 180 minutes in a moderate environment at a workload requiring approximately 60% maximal oxygen uptake. Two conditions, fluid (F) and no fluid (NF) ingestion, were investigated. RESULTS: During maximal voluntary isometric contraction (MVC), prolonged cycling exercise reduced (p<0.05) the maximal force generating capacity of quadriceps muscles (after three hours of cycling) and root mean square (RMS) values (after two hours of cycling) with no difference between the two conditions despite greater body weight loss (p<0.05) in NF. The mean power frequency (MPF) for vastus lateralis muscle was reduced (p<0.05) and the rate of force development (RFD) was increased (p<0.05) only during NF. During cycling exercise, integrated electromyographic activity and perceived exertion were increased in both conditions (p<0.05) with no significant effect of fluid ingestion. CONCLUSIONS: The results suggest that fluid ingestion did not prevent the previously reported decrease in maximal force with exercise duration, but seems to have a positive effect on some indicators of neuromuscular fatigue such as mean power frequency and rate of force development during maximal voluntary contraction. Further investigations are needed to assess the effect of change in hydration on neural mechanisms linked to the development of muscular fatigue during prolonged exercise.

Influence of exercise duration and hydration status on cognitive function during prolonged cycling exercise.

The purpose of the present study was to examine the influence of submaximal aerobic exercise duration on simple and complex cognitive performance. Eight well-trained male subjects agreed to participate in this study (trial group). A control group of eight regularly trained male subjects was included for comparative purposes. For the trial group, the experiment involved a critical flicker fusion test (CFF) and a map recognition task performed before, every 20 min during, and immediately after, a 3-h cycling task at an intensity corresponding to approximately 60 % of VO2max. Data were obtained over two experimental sessions with fluid ingestion (F) or no fluid (NF) ingestion. For the control group the experiment was the same but without exercise and fluid ingestion. In the trial group, a significant effect of hydration status was observed on physiological parameters (p <0.05). No effect was found on cognitive performance. A significant decrease in CFF performance was observed after 120 min of exercise when compared with the first 20 min (respectively for CFFmdi: 2.6 vs. 3.8 Hz), irrespective of experimental condition. A significant improvement in speed of response (respectively: 3291 vs. 3062 msec for 20 and 120 min, respectively) and a decrease in error number (21.5 % vs. 6.0 % for 20 and 120 min, respectively) during the map recognition task were recorded between 80 min and 120 min when compared with the first 20 min of exercise. After 120 min the number of recorded errors was significantly greater indicating a shift in the accuracy-speed trade-off (6.0 % vs. 14.1 % for 120 and 180 min, respectively). These results provide some evidence for exercise-induced facilitation of cognitive function. However this positive effect disappears during prolonged exercise--as evidenced within our study by an increase in errors during the complex task and an alteration in perceptual response (i.e. the appearance of symptoms of central fatigue).

Effect of long duration exercise on the ratings of perceived exertion and perceived difficulty of walking and running at the ventilatory threshold.

AIM: The purpose of this study was to examine if the relationship between physiological changes classically observed with exercise duration and some subjective workload measures would be affected by the complexity of the locomotion mode (running vs racewalking). METHODS: The study was conducted on 24 well trained subjects (12 long distance runners and 12 racewalkers) divided in 3 groups (runners, racewalkers and control). Energy cost of locomotion (C), heart rate (HR), minute ventilation (V(E)), lactate concentration [La], ratings of perceived exertion (RPE 6-20 scale) and ratings of perceived difficulty (RPD 1(-1)5 scale) were recorded during 2 10-min submaximal tests on a treadmill before and immediately after a 3 hour exercise (racewalking or running) conducted at the velocity ventilatory threshold (vVT). RESULTS: No significant variations in physiological parameters and perceived measures were observed in G(c). A significant increase (p<0.05) in energy cost of walking (mean: +9.4%) and running (mean: +7.5%) at the end of exercise was observed. A significant interaction of locomotion mode and exercise duration was found on perceived exertion and perceived difficulty. In racewalkers RPD significantly increased with duration whereas no significant effect was found for RPE. Conversely a significant increase in RPE was found after 3 hours in runners without any significant change in RPD. CONCLUSIONS: This experiment suggests that, for a complex task, the classical relationship between RPE and metabolic load increase during prolonged exercise could be affected by changes in RPD. In this study, stability in RPE and increase in RPD observed in racewalkers may reflect an attentional focus dissociated from internal sensations and directed toward maintaining the required race walking gait.

Synchronous carotid endarterectomy and retrograde endovascular treatment of brachiocephalic or common carotid artery stenosis.

OBJECTIVES: To retrospectively evaluate the safety and the long-term results of retrograde brachiocephalic and common carotid angioplasty and stenting (AS) performed for >70% stenosis synchronously with the carotid endarterectomy (CEA). PATIENTS: Sixteen patients operated between April 1999 and March 2002. RESULTS: 14/16 procedures were successful. There was no neurological morbidity or mortality. Per-operative angiography showed the optimal stent positioning and patency of both proximal and distal arteries in all patients. In the follow-up, all patients showed patency of the treated vessels without restenosis and the absence of any cerebrovascular symptoms. CONCLUSION: Intra-operative retrograde AS combined with CEA is an effective, safe and durable alternative to conventional surgery when a tandem significant proximal lesion is identified in a patient with an high grade carotid stenosis.