Luciano Pedrini

Failure of thrombolytic therapy to improve long-term vascular patency

PURPOSE Few data are available on long-term follow-up of arterial segments subjected to thrombolysis. We reviewed all cases of vascular occlusion treated with urokinase to identify early success and determine the influence of postlysis intervention and the nature of the thrombosed segment (i.e., artery vs graft) on long-term patency. METHODS Data on 134 cases (58 arteries, 76 grafts) treated with high-dose urokinase infusion in the lower limbs over a 7-year period were analyzed. Limbs were divided into five groups on the basis of therapy after lytic infusion to determine long-term efficacy: group I, success with no additional therapy; group II, percutaneous angioplasty alone; group III, limited surgical procedure (operative angioplasty, jump graft); group IV, extensive procedure (new bypass); and group V, revascularization after lytic failure. Long-term results were assessed by life-table analysis and groups compared by log-rank test (Mantel-Haenszel). RESULTS Initial patency was established in 87 (64.9%) of 134 cases with 5 deaths (3.7%), 11 amputations (8.2%), and 16 complications (11.9%). Follow-up was available in 68.6% of cases for a mean of 10.9 months. No difference was seen between grafts and native arteries. Patency was analyzed at 6, 12, 18, and 24 months. The 24-month patency rate after lysis alone (group I-25.9%) was inferior (p < 0.05) to results after lysis and any subsequent intervention (groups II, III, and IV). The type of intervention did not influence subsequent patency. Twenty-four-month patency of procedures performed after failed thrombolysis (group V, 41.4%) was not different from those after successful lysis (groups I to IV). Twenty-four-month patency in groups II and III (minor interventions, 62.9%) was not significantly different from that of groups IV and V (major interventions, 53.2%) (p > 0.25). CONCLUSIONS Operative intervention is required to produce long-term arterial patency, even after successful thrombolysis. No statistically significant benefit of thrombolysis on vascular patency was seen in our series.

Is Near-Infrared Spectroscopy a Reliable Method to Evaluate Clamping Ischemia during Carotid Surgery?

Guidelines do not include cerebral oximetry among monitoring for carotid endarterectomy (CEA). The purpose of this study was to evaluate the reliability of near-infrared spectroscopy (NIRS) in the detection of clamping ischemia and in the prevention of clamping-related neurologic deficits using, as a cutoff for shunting, a 20% regional cerebral oxygen saturation (rSO2) decrease if persistent more than 4 minutes, otherwise a 25% rSO2 decrease. Bilateral rSO2 was monitored continuously in patients undergoing CEA under general anesthesia (GA). Data was recorded after clamping, declamping, during shunting and lowest values achieved. Preoperative neurologic, CT-scan, and vascular lesions were recorded. We reviewed 473 cases: 305 males (64.5%) mean age 73.3 ± 7.3. Three patients presented transient ischemic deficits at awakening, no perioperative stroke or death; 41 (8.7%) required shunting: 30 based on the initial rSO2 value and 11 due to a decrease during surgery. Using the ROC curve analysis we found, for a >25% reduction from baseline value, a sensitivity of 100% and a specificity of 90.6%. Reliability, PPV, and NPV were 95.38%, 9%, and 100%, respectively. In conclusion, this study indicates the potential reliability of NIRS monitoring during CEA under GA, using a cutoff of 25% or a cutoff of 20% for prolonged hypoperfusion.

Abdominal Aortic Hypoplasia: Clinical and Technical Considerations

Hypoplasia of the distal abdominal aorta, first described by Quain in 1847, is rarely associated with atherosclerotic occlusive disease. The condition usually occurs early in life; the principal clinical features are hypertension and arterial insufficiency of the lower extremities which is often well tolerated. Some 20 patients had operations for abdominal aortic hypoplasia; 16 underwent prosthetic reconstruction and four had aortoiliac endarterectomy with angioplasty. Reconstructive techniques were influenced by narrow renal arteries and by the presence of extensive atheroma. The long-term prognosis is often poor, especially in patients with extensive disease.

Intraoperative cerebral monitoring in carotid surgery

We have used and studied intraoperative cerebral monitoring in order to prevent intraoperative and early postoperative cerebral ischaemia. The techniques examined have included stump pressure measurement, the evaluation of somatosensory evoked potentials (SEPs) and completion intraoperative angiography. Stump pressure was measured in 920 patients and a safety level of 50 mmHg confirmed. Below this value, non-shunted patients were three times more likely to have cerebrovascular accident (CVA). SEPs were prospectively monitored in 72 patients and a mean decrease of N20-P25 in complex amplitude was seen in patients with a positive CT scan. In particular, pathological SEPs were found in 53% of patients with a positive CT scan, and in 54% of those with a contralateral carotid occlusion. In these patients, the N20-P25 amplitude fell progressively in the first 4 min. Using SEPs, the indication for shunting was 42% lower than with the measurement of back pressure and no patient with normal SEPs had a postoperative neurological deficit. The data obtained under local anaesthesia in 25 patients monitored by stump pressure and SEPs did not give better results. Intraoperative completion angiography performed routinely since 1978 has made it possible to reduce the need for immediate reoperation from 10-2%.

Hospitalization rates and post-operative mortality for abdominal aortic aneurysm in Italy over the period 2000-2011.

Background Recent studies have reported declines in incidence, prevalence and mortality for abdominal aortic aneurysms (AAAs) in various countries, but evidence from Mediterranean countries is lacking. The aim of this study is to examine the trend of hospitalization and post-operative mortality rates for AAAs in Italy during the period 2000–2011, taking into account the introduction of endovascular aneurysm repair (EVAR) in 1990s. Methods This retrospective cohort study was carried out in Emilia-Romagna, an Italian region with 4.5 million inhabitants. A total of 19,673 patients hospitalized for AAAs between 2000 and 2011, were identified from the hospital discharge records (HDR) database. Hospitalization rates, percentage of OSR and EVAR and 30-day mortality rates were calculated for unruptured (uAAAs) and ruptured AAAs (rAAAs). Results Adjusted hospitalization rates decreased on average by 2.9% per year for uAAAs and 3.2% for rAAAs (p<0.001). The temporal trend of 30-day mortality rates remained stable for both groups. The percentage of EVAR for uAAAs increased significantly from 2006 to 2011 (42.7 versus 60.9% respectively, mean change of 3.9% per year, p<0.001). No significant difference in mortality was found between OSR and EVAR for uAAAs and rAAAs. Conclusions The incidence and trend of hospitalization rates for rAAAs and uAAAs decreased significantly in the last decade, while 30-day mortality rates in operated patients remained stable. OSR continued to be the most common surgery in rAAAs, although the gap between OSR and EVAR recently declined. The EVAR technique became the preferred surgery for uAAAs since 2008.

Prevention of Reperfusion Syndrome in Acute Muscular Ischaemia with Free Radical Scavengers and Membrane-Protecting Compounds: An Experimental Study:

The prevention of oxidant-induced damage following reperfusion was experimentally evaluated. Two pharmacological regimens containing different combinations of antioxidant factors and membrane-stabilizing compounds, such as α-tocopherol (vitamin E), methionine, dexamethasone, mannitol and cysteine, were administered. The reduced/oxidized glutathione (GSH/GSSG) ratio in muscle was used to evaluate oxidative stress. Ischaemia was induced by occluding the aorta and the inferior vena cava with an irrigation-occlusion catheter. After 4h of ischaemia, five sheep were reperfused without any treatment (control group) and five treated with an endoaortic bolus administered at declamping (treatment 1). In five other sheep, treatment started during ischaemia (treatment 2). Ischaemia and, in particular, reperfusion significantly reduced the muscle GSH content, compared with the basal value in the control group; thus the GSH/GSSG ratio decreased significantly in the control group from 10.5(2.2) (mean(s.e.) basal value) to 0.687(0.3) at reperfusion (P<0.009). Both treatments 1 and 2 significantly prevented a reduction in GSH content induced by reperfusion following ischaemia; the GSH/GSSG ratio (10.5(2.2) basal value) increased to 19.67(4.6) with reperfusion in the treatment group 1, mainly because of a lower decrease of GSH and a lower level of GSSG while it did not change in treatment group 2 (10.7(5.0)). Levels of creatine phosphokinase did not change in the treated groups, although they increased significantly in the control group (P<0.006). Although oxidative stress is not the only cause of damage in revascularization, this study confirms the protective ability of treatment with free radical scavengers and membrane-stabilizing compounds.

Local haemofiltration with free radical scavenger treatment during revascularisation of severe muscular ischaemia induced in sheep limbs

Many treatments have been proposed for the prevention of the revascularisation syndrome following embolectomy or thrombectomy in patients with severe ischaemia. These include the administration of diuretics, bicarbonate, buffer solutions, free radical scavengers, washing out the venous blood from the ischaemic leg, or systemic dialysis. The aim of our study was to investigate the effect of combining haemofiltration with a treatment using compound oxy-radical scavengers in order to prevent or to reduce the appearance of the revascularisation syndrome. The study was performed on 13 sheep. Eight animals underwent 4 h of aortic and vena cava occlusion using irrigation-occlusion catheters, followed by normal reperfusion (control group). Five sheep underwent the same period of ischaemia, followed by 1 h of local haemofiltration and re-oxygenation and 2 h of normal revascularisation. The priming solution for the ECC circuit consisted of 500 ml of 20% mannitol and 500 ml of 18/1000 HCO3- contained: superoxide dismutase (150,000 I.U.), methylprednisolone, 1 g, and heparin, 10,000 I.U. After the 3rd h of ischaemia, 2.1 g of acetate alpha-tocopherol (30 mg kg-1) were injected i.m. The treatment produced good protection against oxidative stress, shown by an increase in the glutathione ratio (GSH/GSSG), and reduced muscular damage, confirmed by a moderate increase in creatine phosphokinase (CPK) levels (significantly higher in the control group). Diuresis was significantly higher in the treated group, and the acid-basic and potassium balance returned to normal more rapidly. Our data suggest that this combined treatment could be effective in the prevention of the ischaemia-reperfusion syndrome.

Spinal cord stimulation or prostacyclin in unrevascularizable arteriopathy of lower limbs (SPINAL) study: interim analysis results

License. The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. Permissions beyond the scope of the License are administered by Dove Medical Press Limited. Information on how to request permission may be found at: http://www.dovepress.com/permissions.php Journal of Vascular Diagnostics 2014:2 23–37 Journal of Vascular Diagnostics

SEPs monitoring during carotid surgery: reliability and limitations

Carotid endarterectomy (TEA) remains the treatment of choice for carotid disease characterized by stenosing, hemodynamically significant or embolizing atherosclerotic plaque. One of the greatest risks during surgery is carotid clamping when cerebral ischemia may occur if collateral circulation does not maintain adequate perfusion.