Selective Intra-procedural AAA sac Embolization During EVAR Reduces the Rate of Type II Endoleak.

OBJECTIVE: The pre-treatment presence of at least six efferent patent vessels (EPV) from the AAA sac and/or AAA thrombus volume ratio (VR%) <40% are considered to be positive predictive factors for persistent type II endoleak (ELIIp). The aim of the present study was to evaluate the effectiveness of sac embolization during EVAR in patients with pre-operative morphological risk factors (p-MRF) for ELIIp. METHODS: Patients undergoing EVAR and intra-procedural AAA sac embolization (Group A, 2012-2013) were retrospectively selected and compared with a control group of patients with the same p-MRF, who underwent EVAR without intra-procedural sac embolization (Group B, 2008-2010). The presence of ELIIp was evaluated by duplex ultrasound at 0 and 6 months, and by contrast enhanced ultrasound at 12 months. The association between AAA diameter, age, COPD, smoking, anticoagulant therapy, and AAA sac embolization with ELIIp was evaluated using multiple logistic regression. The primary endpoint was the effectiveness of the intra-procedural AAA sac embolization for ELIIp prevention. Secondary endpoints were AAA sac evolution and freedom from ELIIp and embolization related re-interventions at 6-12 months. RESULTS: Seventy patients were analyzed: 26 Group A and 44 Group B; the groups were homogeneous for clinical/morphological characteristics. In Group A the median number of coils positioned in AAA sac was 4.1 (IQR 1). There were no complications related to the embolization procedures. A significantly lower number of ELIIp was detected in Group A than in Group B (8/26 vs. 33/44, respectively, p < .001) at discharge, and this was confirmed at 6-12 months (7/26 vs. 30/44 respectively, p = .001, and 5/25 vs. 32/44, respectively, p < .001). On multivariate analysis, intra-procedural AAA sac embolization was the only factor independently associated with freedom from ELIIp at 6 (OR 0.196, 95% CI 0.06-0.63; p = .007) and 12 months (OR 0.098, 95% CI 0.02-0.35; p < .001). No differences in median AAA sac diameter shrinkage were detected between the two groups at 6-12 months (p = .42 and p = .58, respectively). Freedom from ELIIp related and embolization related re-interventions was 100% in both groups, at 6 and 12 months. CONCLUSION: Selective intra-procedural AAA sac embolization in patients with p-MRF is safe and could be an effective method to reduce ELIIp. Further studies are mandatory to support these results at long-term follow up.

Could four-dimensional contrast-enhanced ultrasound replace computed tomography angiography during follow up of fenestrated endografts? Results of a preliminary experience.

OBJECTIVE: To evaluate four-dimensional contrast-enhanced ultrasound (4D-CEUS) as an alternative imaging method to computed tomography angiography (CTA) during follow up of fenestrated endovascular aneurysm repair (FEVAR) for juxta- and para-renal abdominal aortic aneurysms (AAA). METHODS: Between October 2011 and March 2012, all consecutive patients who underwent FEVAR follow up were included in the study and evaluated with both 4D-CEUS and CTA. The interval between the two examinations was always ≤ 30 days. Endpoints were the comparison of postoperative AAA diameter, AAA volume, presence of endoleaks, revascularized visceral vessel (RVV) visualization, and patency. Comparative analysis was performed using Bland-Altman plots and McNemar's Chi-square test. RESULTS: Twenty-two patients (96% male, 4% female; mean age 74 ± 7 years; American Society of Anesthesiologists grade III/IV 82%/18%) were enrolled. Seventy-eight RVV (fenestrations: 60; scallops: 17; branches: 1) were analyzed. The mean AAA diameter evaluated by 4D-CEUS and CTA was 45 ± 10 mm (range 30-69 mm) and 48 ± 9 mm (range 32-70 mm), respectively. The mean difference was 3 ± 3 mm. The mean AAA volume evaluated by 4D-CEUS and CTA was 150 ± 7 cc (range 88-300 cc) and 159 ± 68 cc (range 80-310 cc), respectively. The mean difference was 7 ± 4 cc; a Bland-Altman plot revealed agreement in AAA diameter and volume evaluation (p < .01) between 4D-CEUS and CTA. The observed agreement for the detection of endoleaks was 95%. McNemar's Chi-square test confirmed that 4D-CEUS and CTA were equivalent (p > .05) at detecting endoleaks. The first segment of six (8%) RVVs (four renal and two superior mesenteric arteries) was not directly visualized by 4D-CEUS owing to obesity, but the contrast enhancement into the distal part of vessel or into the relative parenchyma gave indirect information about their patency. McNemar's Chi-square test demonstrated the superiority of CTA (p = .031) in visualizing RVVs. The patency of 77/78 RVVs was confirmed with both techniques. McNemar's Chi-square test confirmed that 4D-CEUS and CTA were equivalent in their ability to detect visceral vessel patency. CONCLUSIONS: The data suggest that 4D-CEUS is as accurate as CTA in the evaluation of postoperative AAA diameter and volume, endoleak detection, and RVV patency after FEVAR. Four-dimensional CEUS could provide hemodynamic information regarding RVVs, and reduce radiation exposure and renal impairment during follow up. Obesity limits the diagnostic accuracy of 4D-CEUS.

Contralateral carotid occlusion in endovascular and surgical carotid revascularization: a single centre experience with literature review and meta-analysis.

OBJECTIVE/BACKGROUND: The influence of contralateral carotid occlusion (CCO) on the outcome of carotid endarterectomy (CEA) and stenting (CAS) is debated. This study aims to evaluate CEA and CAS results in patients with CCO. METHODS: All carotid revascularizations from 2005 to 2011 were analyzed, focusing on the role of CCO on 30-day cerebral events and death (CED). A meta-analysis was performed to evaluate the results of the literature by random effect. RESULTS: Of the 1,218 carotid revascularizations performed in our institution, 706 (57.9%) were CEA and 512 (42.1%) were CAS. CED occurred in 3.6% of the CEAs and 8.2% of the CASs (p = .001). CCO was present in 37 (5.2%) CEAs and 38 (7.4%) CASs. In CEA, CCO patients had a higher CED compared with the non-CCO patients (16.2% vs. 2.9%, p = .001), as confirmed by multiple regression analysis (OR [odds ratio]: 5.1[1.7-14.5]). In CAS, CED was not significantly different in the CCO and non-CCO patients (2.6% vs. 8.7%, p = 0.23). The comparative analysis of the CCO patients showed a higher CED in CEA compared with that in CAS (16.2% vs. 2.6%, p = 0.04). Meta-analysis of 33 papers (27 on CEA and 6 on CAS) revealed that CCO was associated with a higher CED in CEA, but not in CAS (OR: 1.82 [1.57-2.11]; OR: 1.22 [0.60-2.49], respectively). CONCLUSION: CCO can be considered as a risk factor for CED in CEA, but not in CAS. CAS appears to be associated with lower CED than CEA in CCO patients.

Pancreatic injury during AAA repair: a comparison between EVAR and open repair.

OBJECTIVES: Enzymatic pancreatic injury (EPI) in abdominal aortic aneurysm (AAA) treatment has been scarcely studied in the literature. Aim of this work was to compare perioperative EPI in AAA patients treated by endovascular repair (EVAR) or open repair (OR). METHODS: Forty AAA patients consecutively treated with either EVAR (GI, 20 pts) or OR (GII, 20 pts) were prospectively evaluated in terms of epidemiology, comorbidities and technical details. Serum levels of amylase, lipase and pancreatic isoamylase were assessed before treatment (T0), before aortic clamping/endograft deployment (T1), 1, 2, and 6 hours after aortic declamping/endograft deployment (T2, T3, T4) and 24, 48, and 72 hours after the procedure (T5, T6, T7). GI and GII were compared by Mann Whitney test with significance set at p < 0.05. RESULTS: GI patients were significantly older and with higher frequency of preoperative renal insufficiency than GII ones (p = 0.001 and 0.047 respectively). Other characteristics were not significantly different. Pancreatic enzymes values at T0 were within normal parameters in all patients. Total serum amylase was significantly greater at T4 (p = 0.003), T5 (p = 0.010), T6 (p = 0.003), T7 (p = 0.011) and isoamylase at T3 (p = 0.052), T4 (p = 0.037), T5 (p = 0.016) and T6 (p = 0.014) in GII compared with GI. Amylase and isoamylase peak occurred 24 hours after the procedure. Lipase was significantly different in the two groups only in T4 (p = 0.028). No acute pancreatitis occurred in the whole study group. CONCLUSIONS: EVAR significantly reduces EPI compared with OR in the AAA treatment.

Identification of carotid 'vulnerable plaque' by contrast-enhanced ultrasonography: correlation with plaque histology, symptoms and cerebral computed tomography.

INTRODUCTION: Indication to carotid revascularisation is commonly determined by percent of stenosis as well as neurological symptoms and clinical conditions. High plaque embolic potential is defined as 'vulnerability'; however, its characterisation is not universally used for carotid revascularisation. We investigated the role of contrast-enhanced ultrasonography (CEUS) to identify carotid vulnerable plaque. METHODS: Patients undergoing carotid endarterectomy were preoperatively evaluated by cerebral computed tomography (CT) scan and CEUS. Contrast microbubbles detected within the plaque indicated neovascularisation and were quantified by decibel enhancement (dB-E). Plaques were histologically evaluated for five features: (microvessel density, fibrous cap thickness, extension of calcification, inflammatory infiltrate and lipid core) and blindly scored 1-5 to assess plaque vulnerability. Analysis of variance (ANOVA), Fisher's and Student's t-test were used to correlate patients' characteristics, histological features and dB-E. RESULTS: In 22 patients, dB-E (range 2-7.8, mean 4.85 ± 1.9 SD) was significantly greater in symptomatic (7.40 ± 0.5) vs. asymptomatic (3.5 ± 1.4) patients (p = 0.002). A higher dB-E was significantly associated with thinner fibrous cap (<200 µm, 5.96 ± 1.5 vs. 3 ± 1, p = 0.01) and greater inflammatory infiltrate (3.2 ± 0.9 vs. 6.4 ± 1.2, p = 0.03). Plaques with vulnerability score of 5 had significantly higher dB-E compared with those with vulnerability score of 1 (7.6 ± 0.2 vs. 2.5 ± 0.6, respectively, p = 0.001). Preoperative ipsilateral embolic lesions at CT were correlated with higher dB-E (5.96 ± 1.5 vs. 3.0 ± 1.0, p = 0.01). CONCLUSION: CEUS with dB-E is indicative of the extent of plaque neovascularisation. It can be used therefore as a marker for vulnerable plaque.

Pain management in peripheral arterial obstructive disease: oral slow-release oxycodone versus epidural l-bupivacaine.

OBJECTIVES: To compare the effectiveness of oral slow-release oxycodone (group OX, n=18) with that of epidural l-bupivacaine (group LRA, n=13) for the control of moderate/severe pain of advanced-stage peripheral arterial obstructive disease (PAOD) patients. DESIGN: Observational and retrospective analysis of advanced stage and hospitalised PAOD patients treated for pain management for at least 7 days prior to surgery or discharged from the hospital without surgery. METHODS: The outcome measures were pain intensity using the visual analogue scale under static, (VASs) and dynamic (VASd) conditions; vital signs, treatment side effects and patient satisfaction. RESULTS: In both groups, pain control was satisfactory and VAS scores median were VASs<3 and VASd<4; under dynamic conditions, pain control was better in the LRA group (p<0.01). Against few and transient side effects, most patients (n=30) found both pain treatments good or excellent. Results should be confirmed by studies with larger samples. CONCLUSIONS: In the perioperative setting, the epidural infusion of local anaesthetics, such as l-bupivacaine, is an effective technique for pain control in PAOD patients; for patients with contraindication for this technique or for non-surgical or outpatients, slow-release oxycodone is suggested as a possible alternative for the control of severe pain in these patients.

Ring-stents supported infrarenal aortic endograft fits well in abdominal aortic aneurysms with tortuous anatomy.

AIM: Abdominal aortic aneurysms (AAA) with severe angulation of the neck or of the iliac arteries are often unsuitable for endovascular repair with conventional endografts. We evaluated the performance of a ring-stent abdominal endograft (AnacondaTM Vascutek, Terumo, Scotland) in a consecutive series of infrarenal AAA. METHODS: Preoperative, procedural and follow-up data of patients treated with AnacondaTM endograft between September 2005 and September 2009 were prospectively enrolled. Patients were divided in Group A (proximal neck angle > or =60 degrees or iliac arteries angle > or =90 degrees ) and Group B (all others). Main endpoints were technical and clinical success (primary and assisted) and late outcome in the two groups. Results were compared by Kaplan-Meier life table analysis with log-rank test (Mantel-Cox). RESULTS: One hundred twenty-seven patients, with a mean age of 73.5+/-6.9 years, have been included in this series. Mean aneurysm size was 56.7+/-10.4 mm. A severe angulation of the proximal aortic neck or/and of the iliac arteries was present in 44 cases (Group A), absent in 83 cases (Group B). The mean follow-up was 18.2+/-16.3 months. Overall primary technical success was achieved in 100% of the patients. At twenty-four months survival, primary and assisted clinical success were 94.2%, 88.2% and 91.3% in Group A and 80.3%, 83.7% and 95.2% in Group B respectively. No significant differences were found between the two groups. The only factor significantly associated with decreased survival was preoperative renal insufficiency. Iliac limb patency 24 months after EVAR in severely and non-severely angulated iliac axis was 96.7% and 98.1% respectively, with no significant difference between the groups. Only one proximal type I endoleak was detected in a patient with severe angulation of proximal aortic neck. No significant correlation between proximal type I endoleak and severe neck angulation was found. CONCLUSION: Aneurysms with severe neck or iliac arteries angulation can be treated by a ring-stent endograft with results similar to those of AAA with more favourable anatomy.

The advantages of Anaconda endograft for AAA.

AIM: The Anaconda endograft (Vascutek, Terumo, Inchinnan, Scotland) is an infrarenal, trimodular stent-graft with peculiar characteristics in terms of implant, proximal sealing and fixation of the main body and iliac legs. This endograft can be used in infrarenal abdominal aortic aneurysm (AAA) with an aortic neck >or=15 mm in length. The authors evaluated the mid-term outcome of the Anaconda endograft in the treatment of infrarenal AAA also in cases with tortuous anatomy. METHODS: Between September 2005 and September 2008, 100 patients (94 males, 6 females) with mean age of 73.9+/-5.2 years (range 55-89) were considered eligible for treatment with Anaconda endograft (proximal neck length >or=15 mm). The mean aneurysm size was 55.2+/-3.4mm (range 45-99 mm). An angulation of the aortic neck greater than 60 degrees was present in 19 cases. The iliac arteries were severely angulated >60 degrees in 61 patients. The mean follow-up was 23.2+/-11.0 months (range 1.4-38.6). RESULTS: Primary technical success was achieved in 100% of the patients. Six patients died during follow-up, none for aneurysm-related causes. Survival rate was 87.9% at 24 months of follow-up. Primary and assisted clinical success were respectively 80.8% and 93.7% at 24 months with a freedom from reintervention of 88.8%. No cases of endograft migration were observed and only one case of type I proximal endoleak was recorded in the mid-term follow-up. The univariate and the multivariate analysis did not show an increased risk in patients with angulated proximal neck or iliac arteries. CONCLUSIONS: As evidenced in this clinical study, the mid-term outcomes of Anaconda endograft are satisfactory concerning the treatment of AAA with a minimum neck length of 15 mm. This device proved in the mid-term to effectively protect the patient treated from aneurysm rupture. Presence of even severe tortuosity of the proximal neck and of the iliac arteries did not affect outcomes. Considering these results showing the safety of Anaconda endograft, the authors suggest its employment also in cases with difficult anatomy.

Mesenchymal stem cell interaction with a non-woven hyaluronan-based scaffold suitable for tissue repair.

The fabrication of biodegradable 3-D scaffolds enriched with multipotent stem cells seems to be a promising strategy for the repair of irreversibly injured tissues. The fine mechanisms of the interaction of rat mesenchymal stem cells (rMSCs) with a hyaluronan-based scaffold, i.e. HYAFF(R)11, were investigated to evaluate the potential clinical application of this kind of engineered construct. rMSCs were seeded (2 x 10(6) cells cm(-2)) on the scaffold, cultured up to 21 days and analysed using appropriate techniques. Light (LM), scanning (SEM) and transmission (TEM) electron microscopy of untreated scaffold samples showed that scaffolds have a highly porous structure and are composed of 15-microm-thick microfibres having a rough surface. As detected by trypan blue stain, cell adhesion was high at day 1. rMSCs were viable up to 14 days as shown by CFDA assay and proliferated steadily on the scaffold as revealed by MTT assay. LM showed rMSCs in the innermost portions of the scaffold at day 3. SEM revealed a subconfluent cell monolayer covering 40 +/- 10% of the scaffold surface at day 21. TEM of early culture showed rMSCs wrapping individual fibres with regularly spaced focal contacts, whereas confocal microscopy showed polarized expression of CD44 hyaluronan receptor; TEM of 14-day cultures evidenced fibronexus formation. Immunohistochemistry of 21-day cultures showed that fibronectin was the main matrix protein secreted in the extracellular space; decorin and versican were seen in the cell cytoplasm only and type IV collagen was minimally expressed. The expression of CD90, a marker of mesenchymal stemness, was found unaffected at the end of cell culture. Our results show that HYAFF(R)11 scaffolds support the adhesion, migration and proliferation of rMSCs, as well as the synthesis and delivery of extracellular matrix components under static culture conditions without any chemical induction. The high retention rate and viability of the seeded cells as well as their fine modality of interaction with the substrate suggest that such scaffolds could be potentially useful when wide tissue defects are to be repaired as in the case of cartilage repair, wound healing and large vessel replacement.

Kissing balloon technique for angioplasty of popliteal and tibio-peroneal arteries bifurcation.

INTRODUCTION: Kissing balloon technique with two low-profile catheters (KBT) could be the treatment of choice for diseased infrapopliteal artery bifurcation in critical limb ischemia (CLI). REPORT: From April to December 2006, 8 patients with CLI and tibial artery disease located in the infrapopliteal bifurcation were treated with KBT. Technical success was achieved in all patients without major or minor complications. DISCUSSION: Angioplasty of the bifurcation of the popliteal and tibio-peroneal trunk using KBT is a safe and effective procedure in CLI.

Preliminary results of Anaconda aortic endografts: a single center study.

OBJECTIVE: To evaluate the peri-operative results of Anaconda endograft in the first 49 cases treated in a single centre. METHODS: The study was carried out prospectively on cases of infrarenal abdominal aortic aneurysm (AAA) treated with Anaconda endograft. The characteristics of the proximal aortic neck and of the iliac access vessels were considered. The following operative results were assessed: the main body oversizing, the need to correct the positioning of the main body, the use of iliac extensions, the use of ballooning, the covering of patent hypogastric arteries, the presence of endoleaks and the need for conversion. Peri-operative (30 days) mortality and morbidity were also considered. RESULTS: Of the 49 cases treated, 44 were males with a mean age of 73 years (range: 55-89 yrs; SD+/-7 yrs). The mean diameter of the AAA was 56 mm (range 45-91 mm; SD+/-11); 4 cases had common iliac aneurysms with a diameter >3 cm. The mean neck diameter and length were 23 mm (range 19-28 mm; SD+/-3) and 25 mm (range 15-50 mm; SD+/-10) respectively. An aortic neck angle between 40 degrees and 70 degrees was present in 10 cases (20%) (mean 58 degrees; SD+/-15 degrees), and 20 cases (41%) had iliac tortuosity with an angle greater than 60 degrees (mean 85 degrees; SD+/-25 degrees). There were no cases of conversion or intra-operative death. One (2%) peri-operative death occurred, for reasons not related to the endograft. There were two cases of iliac limb thrombosis. CT at one month showed 12 cases (25%) of type II endoleak. There were no cases of type I or type III endoleaks. CONCLUSIONS: The preliminary data of this series demonstrates that the Anaconda endograft has good peri-operative results in the treatment of infrarenal AAAs with a neck length not less than 15 mm.

Ruptured pancreaticoduodenal artery aneurysm. A case report and review of the literature.

Pancreaticoduodenal artery aneurysms (PDAA) are very rare (2% of the visceral aneurysms) but characterized by a high mortality rate if ruptured. Here a case of ruptured PDAA with an atypical clinical presentation that simulated an acute hepatobiliar syndrome is reported. A 60-year-old female presented with epigastric pain, nausea, gastric vomiting, elevated levels of hepatic enzymes, normal hemoglobin and cholelithiasis on echography. With persistent pain and progressively decreasing hemoglobin, an urgent contrast computed tomography was performed and revealed a large retroperitoneal hematoma that appeared to come from a branch of the superior mesenteric artery (SMA). A selective SMA-angiography showed a small aneurysm of the antero-superior pancreaticoduodenal artery with signs of hemorrhage. The patient underwent surgical ligature of the PDAA, after superselective transcatheter arterial embolization appeared technically impossible. The postoperative period was characterized by a progressive normalization of the hepatic values and hemoglobin and a post-operative angiogram confirmed the total exclusion of the PDAA and the integrity of the posterior pancreaticoduodenal arch. The pre-operative diagnosis of PDAA is usually very difficult. Symptoms can be vague or misleading, as in our case. Angiography is the most accurate diagnostic tool to locate a ruptured PDAA. Moreover, it can be immediately used for urgent endovascular treatment. Post-operative angiography is essential to confirm the total exclusion of the PDAA and demonstrate visceral circulation.

Interaction between vascular prostheses and rifampicin in the prevention of the grafts infection. An experimental study.

Infections caused by synthetic prostheses are relatively rare (1.5-6%) but serious complication in vascular surgery. There is no doubt that during and immediately after surgery bacterial contamination may occur. An in vitro study was carried out in the Vascutek laboratories, which revealed a high affinity between prostheses in Dacron gel and Rifampicin. This affinity, the result of an ionic bond, was demonstrated by the fact that after 5 days Rifampicin was still present on the prostheses. Encouraged by this result, an experimental study was carried out in sheep. Five sheep were operated on making a prosthetic graft in both of the common carotid arteries: on one side a Gelseal Dacron prosthesis was implanted after being soaked for 15 minutes in a solution containing 1 mg/ml Rifampicin. A Knitted Dacron prosthesis was implanted in the contralateral carotid artery, again after pretreatment with Rifampicin. Explants were made after 2, 24, 48, 72 and 96 hours, and the concentration of Rifampicin on the prostheses was assessed on the basis of the diameter of the inhibition area on Staphylococcus aureus cultures. The results showed that the Gelseal Dacron prostheses maintained Rifampicin concentrations with an antibacterial activity up to 72 hours; this property disappears with the Knitted Dacron prostheses after only 24 hours. These results confirm the high affinity of Gelseal Dacron and Rifampicin also in in vivo experimental models.

Peripheral aneurysms in the differential diagnosis of soft tissue sarcomas.

The authors present four cases of peripheral aneurysm: 1 true aneurysm towards the superficial femoral artery, and 3 aneurysms of the popliteal artery, 1 of which true and 2 false. The criteria used for differential diagnosis with soft tissue sarcomas is analyzed and the importance of a complete diagnosis before planning incisional biopsy is emphasized.

[Carotid restenosis: clinical significance and indications for reintervention]. / Le restenosi carotidee: significato clinico e indicazioni al reintervento.

Carotid restenosis is defined as a new > 50% diameter-reducing lesion present in sites of previous surgery. The clinical aspects of this complication are strongly connected with their anatomopathologic evolution: fibromuscular hyperplasia in early recurrent disease, atherosclerotic degeneration in the later lesions. Routine postendarterectomy duplex surveillance is able to detect this pathologic evolution. On 570 surgically treated carotid artery a postoperative duplex surveillance was made at 3, 6, 12 months and then yearly. Totally 42 cases of recurrent stenosis (7.3%) were present: in seven cases (16.6%) with a complicated restenosis the patients were symptomatic. In 27 cases (64.2%) restenosis was < 75%, in 8 cases (19.2%) > 75%. Indication to surgery was given for all the complicated restenosis and for high grade stenosis (> 75%). In the 27 cases of restenosis < 75% a conservative therapy together with duplex surveillance was applied: in none of these cases the restenosis increased in an average follow-up of 13.7 months. In the reoperated cases we didn't observe any mortality nor postoperative stroke. With regard to their mainly hyperplastic origin, carotid restenosis are low symptomatic and with a quite benign evolution. Surgical reintervention is to be limited to the symptomatic cases and to the asymptomatic high grade stenosis cases. A particular attention should be reserved to the morphologic characteristics of the lesion in order to detect the atherosclerotic degeneration that might cause cerebral symptoms.

[Thoraco-abdominal aneurysms of type IV]. / Aneurismi toraco-addominali di IV tipo.

AIM OF THE STUDY: Aims of the study were: 1. to evaluate the results of surgical treatment of type IV thoraco-abdominal aneurysms (TAA), with relationship to other types, 2. to evaluate results obtained with an approach different from the traditional thoraco-phreno laparatomy, with specific attention to postoperative respiratory function. MATERIAL AND METHODS: We have retrospectively compared type IV TAA with all other types of thoraco-abdominal aneurysms electively treated between January 1st, 1994 and May 31st, 2003. Data on perioperative mortality, spinal cord ischemia and renal failure (both temporary and permanent) occurring in the first 30 postoperative days were considered. Protection from spinal cord ischemia was accomplished through liquor drainage and prostaglandin E1 (PGE1) infusion. When the aneurysm extension was limited to the celiac axis an extrapleuric access with removal of XI rib was performed. In this subgroup of patients we have considered postoperative recovery time of respiratory function (intubation time, number of days in intensive care unit, postoperative pulmonary complications) postoperative renal failure, perioperative mortality and morbidity. RESULTS: Seventy-eight TAA have been treated in the period of time of the study. Twenty cases were type IV TAA (25.6%) of which 2 due to chronic dissection. Cumulative postoperative mortality has been 19.2%. The single perioperative death in the group of type IV TAA (5%) occurred in post-operative day 15 for multiple organ failure. No spinal cord ischemia occurred in this group. Temporary renal failure occurred in 3 cases (15%) with one case requiring dialysis. In 10 cases (50%) an extrapleuric access with removal of XI rib was performed, with adequate control of the proximal aorta. Postoperative respiratory failure requiring and intubation time longer than 12 hours occurred in 2 cases (20%). In the remaining 8 cases the mean intubation time was 5.3 hours (range 4-8 hrs). Tracheostomy was not necessary in any case. Mean time of intensive care unit stay was 3.5 days (range 0-15 days). CONCLUSION: The appropriate treatment of type IV TAA leads to low mortality and morbidity with results similar to those of pararenal aneurysms rather than those of other TAA forms. Left extrapleuric access when feasible allows faster recovery of a normal respiratory function.

Fluidodynamic evaluation of arteriovenous fistulae for hemodialysis.

Arteriovenous fistulae (AVF) are commonly used in dialysis treatment of uremic patients. However, many AVF create problems and have to be re-examined. Problems arise in the cannulation site and must be treated with antibiotics, and stenosis, both in the arterial and in the venous side of the AVF. In the worst case, the AVF must be replaced for treatment to continue. However, this can only be repeated once before the AVF site is no longer viable. This increases the discomfort, the morbidity and the mortality of the dialysis patient. Several kinds of AVF were studied to determine whether flow disturbances give rise to these complications. Many studies have already demonstrated the importance of hemodynamic factors in vascular disease pathogenesis. These factors include: the pulsatility of flow, the elasticity of the vessel, the non-Newtonian blood, flow behavior and, very importantly for AVF, the vessel geometry. In model studies, intimal changes have been observed in bends and bifurcations, regions of vessel construction and vessel stenosis. In these regions, blood flow changes abruptly and this contributes to arterial disease. We prepared several one-to-one, true-to-scale elastic silicon rubber models of different AVF. The AVF models were based on angiographic studies of chronic dialysis patients and on AVF from the arms of cadavers. The models had a similar compliance to that of the human blood vessel. Flow was visualized using photoelasticity apparatus and a birefringent blood-like fluid. This method is suitable to analyze the spatial configuration of flow profiles, to differentiate laminar flow from disturbed flow, and to visualize flow separation, vortex formation and secondary flow. It was found that AVF create disturbances that are not found under normal physiological flow conditions. The X-formed AVF was very unsatisfactory, creating significant flow disturbances. The AVF had high velocity fluctuations. These could lead, for example, to aneurysm formation. A better configuration would be an end-to-end AVF. However, this formation creates other complications. For example, there is not enough blood to the hand and parts of the hand lose feeling. The recommended AVF would be an end-to-side anastomosis. In this case, attention is needed for placement geometry, to minimize additional flow disturbances. Several models as well as patient angiographic studies are discussed.

Bypass to the ankle and foot in the era of endovascular therapy of tibial disease. Results and factors influencing the outcome.

AIM: Endovascular therapy (ET) is the treatment of choice for critical limb ischemia (CLI) and tibial arteries disease (TAD) in focal lesions with restorable run-off; ankle and foot bypass (BPG) is indicated in patients unfit for ET with foot or ankle arteries suitable for surgery. The aim of this study was to evaluate limb salvage (LS), primary patency (PP) and survival (S) of patients underwent BPG in the era of ET for TAD and to define the correlated prognostic factors. METHODS: Between February 2000 and November 2008, patients with CLI and TAD were collected prospectively in a data-base (demographics, Fontaine's stage, Texas University Wound Classification [TUC]of ulcers, risk-factors, TAD, techniques of foot revascularization and surgical factors). BPG was performed in tibial arteries occlusion longer than 4 cm or focal occlusion without line-flow to pedal arteries. Clinical and Duplex-ultrasound follow-up was performed at discharge, 1, 3, 6 months and every 6 months. LS, PP, and S rates were assessed with Kaplan-Meier method; factors influencing outcomes were sought by multivariate Cox proportional hazards model analysis. RESULTS: A total of 410 revascularizations were performed in patients with CLI and TAD; BPG in 153 patients (mean age: 69.3±10.6, male/female=117/36, diabetes mellitus=75.2% hyperlypidemia=54.9%, hypertension=87.6%, renal disease=32.7%, coronary arteries disease=51.6%, Fontaine stage IV=96.1%, TUC grade-III=65.4%, TUC stage-D=51%). All autologous grafts in 96.7% (non-reversed saphenous vein=74.5%, reversed=7.2%, composite vein graft=12.4%, arm's veins=2.6%). LS and S after 1 month were 88.2% and 97.1%, respectively. Mean follow-up was 23 months. At 12 and 36 months: LS 76.7% and 70.9%, PP 62.3% and 52.9%, S 91.5% and 74.6%. LS was negatively associated with age (HR=1.041 [95%CI=1.005-1.079]), infected ulcers (HR=3.377 [95%CI=1.571-7.258]), run-off arteries diameter <1.8 mm (HR=5.854[95% CI=2.274-15.070]). PP was negatively associated with hyperlipidemia (HR=2.555 [95% CI=1.418-4.603]), female gender (HR=2.125[95% CI=1.182-3.823]), run-off arteries diameter <1.8 mm (HR=6.165 [95% CI=2.774-13.699]), reversed saphenous graft (HR=3.105 [95% CI=1.166-8.272]), composite vein graft (HR=2.930 [95% CI=1.406-6.107]) and homograft (HR=2.762 [95% CI=1.040-7.333]); instead it is positively related with hypertension (HR=4.229 [95% CI=2.089-8.563]). S was negatively correlated with renal disease (HR=3.035 [95% CI=1.363-6.756]). CONCLUSION: BPG may be a reasonable first treatment for CLI patients with TAD unfit for ET; female gender, hyperlipidemia, use of reversed saphenous, composite vein or alternative grafts, foot infection and renal disease are associated with worse outcome.

Proximal aortic neck angle does not affect early and late EVAR outcomes: an AnacondaTM Italian Registry analysis.

AIM: The aim of this paper was to evaluate early and 3-year results of the endovascular repair (EVAR) for abdominal aortic aneurysm (AAA) using the AnacondaTM endograft in patients with severe proximal aortic neck angle. METHODS: A retrospective analysis of the AnacondaTM Italian Registry was carried out. Two groups of patients were identified according to the presence of a severe (Group A, GA: ≥ 60°) or an absent (Group B, GB: <45°) proximal aortic neck angle. Preoperative, procedural and follow-up data were evaluated. Mortality, proximal type I endoleak, freedom from iliac leg thrombosis and conversion to open repair were analyzed at 30-day and 3-year follow-up. The results of GA and GB were compared. RESULTS: From 2005 to 2012, 1030 patients were enrolled in the Registry. Sixty-five patients (6.3%) were included in GA and 737 (71.5%) in GB. The mean age and AAA diameter were respectively 76.8 years and 62.7 mm in GA and 77.2 years and 56.5 mm in GB (P=NS). The ASA ≥ 3 was reported in the 95.3% of GA vs. 81% of GB (P=0.005). The endograft main-body was repositioned in 35% of cases in GA and 20.7% in GB (P=0.008); there were no differences in the main-body ballooning and proximal aortic cuff placement. There were no statistical differences in 30-day mortality (GA 1.5% vs. GB 1.3%), proximal type I endoleaks (GA 1.5% vs. GB 0.8%), iliac leg thrombosis (GA 1.5% vs. GB 1.4%) and conversion to open repair (GA 3% vs. GB 0.6%). The 3-year survival was 95.4% in GA and 94.7% in GB (P=NS). Freedom from proximal type I endoleak, iliac leg thrombosis and conversion to open repair were respectively 98.5%, 95.4%, and 95.4% in GA and 97.8%, 96.9%, and 98.5% in GB (P=NS). CONCLUSION: The AnacondaTM Italian Registry reports good results in terms of clinical success at 3-year follow-up. AAA with severe proximal aortic neck can be treated with similar outcomes to AAA with favorable neck anatomy. The endograft repositionability is a benefit in cases with severe neck angle.