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When designing biomass-to-biofuel supply chains, the biomass uncertainty, seasonality and geographical dispersion that affect economic viability need to be considered. This work presents a novel methodology that can optimize the design of biofuel supply chains by adopting a decentralized network structure consisting of a mix of fixed and mobile processing facilities. The model considers a variable biomass yield profile and the mobile fast pyrolysis technology. The mixed-integer linear programming model developed identifies the optimal biofuel production and biomass harvesting schedule schemes under the objective of profit maximization. It was applied in the case study of marginal lands in Scotland, which are assumed to be planted with Miscanthus. The trade-offs observed between economies of scale against the transportation costs, the effect of the relocation costs and the contribution of storage capacity were investigated. The results showed that, in most cases, harvesting is most concentrated during the month of the highest biomass yield, provided that storage facilities are available. Storage capacity plays an important role to widen the operational time window of processing facilities since scenarios with restricted or costly storage resulted in facilities of higher capacity operating within a narrower time window, leading to higher investment costs. Relocation costs proved to have a minor share in the total transportation costs.

Public Transit (PT) systems aim to provide social, economic, and environmental benefits to modern cities offering reliable transportation service to users and ultimately reducing the problems related to traffic externalities due to car dependency. With the growing trend of urbanization and the associated phenomenon of cities’ sprawl being increasingly evident, significant attention should be given to understanding PT systems’ performance and then improving their efficiency. Considering the spatial characteristics of the PT system's performance promotes the environmentally friendly transport “character” that every city endeavors. This paper aims to incorporate the spatial spillover effects of a realistic PT system by augmenting information about the service network along with socio-economic variables, in a spatial demand-supply econometric framework. In detail, geographically separated demand and supply information on bus stops and lines was analyzed by a spatial econometric model, namely, the Spatial Lagged X (SLX) model which may be formatted so that can soundly handle, spatial and –in particular- network data like those coming from the General Transit Feed Specification (GTFS) protocol widely used in PT systems. The novelty and the importance of the proposed model rely on the ability to introduce transit network structure within the framework of spatial econometric regression, fostering the explanatory statistical analysis over networked information. The developed modeling approach was applied to the urban and rural PT system of Nicosia (Cyprus), incorporating the spatial spillover effects of the system over more than 1,500 bus stops, 40 lines, and 252 different but spatially connected postcode areas. The results of the SLX model were compared with other demand models of this form typically used, namely the Ordinary Least Square model and standard Spatial Autoregressive models, providing solid evidence of the benefits of incorporating the network structure in spatial demand modeling, giving valuable input for further planning purposes.

When designing biomass-to-biofuel supply chains, the biomass uncertainty, seasonality and geographical dispersion that affect economic viability need to be considered. This work presents a novel methodology that can optimize the design of biofuel supply chains by adopting a decentralized network structure consisting of a mix of fixed and mobile processing facilities. The model considers a variable biomass yield profile and the mobile fast pyrolysis technology. The mixed-integer linear programming model developed identifies the optimal biofuel production and biomass harvesting schedule schemes under the objective of profit maximization. It was applied in the case study of marginal lands in Scotland, which are assumed to be planted with Miscanthus. The trade-offs observed between economies of scale against the transportation costs, the effect of the relocation costs and the contribution of storage capacity were investigated. The results showed that, in most cases, harvesting is most concentrated during the month of the highest biomass yield, provided that storage facilities are available. Storage capacity plays an important role to widen the operational time window of processing facilities since scenarios with restricted or costly storage resulted in facilities of higher capacity operating within a narrower time window, leading to higher investment costs. Relocation costs proved to have a minor share in the total transportation costs. [ABSTRACT FROM AUTHOR]

Byline: Fotis N. Koumboulis, George E. Panagiotakis, Paraskevas N. Paraskevopoulos The problem of Exact Model Matching (EMM) for general left invertible neutral multidelay systems, via proportional realisable state and output feedback, is extensively solved. The necessary and sufficient conditions for the problem to have a realisable solution are established. The general analytical expression of the controllers, solving the problem, is derived. The present results are rather useful to adaptive control of distributed industrial processes described by neutral time delay models.

Urbanization is one of the most dominant economic and social changes of the 20th century. This phenomenon brings about rapid urban development, which is inextricably linked to transport development. In order to understand this relationship, it is important to analyze the spatial spillover effects of the phenomenon in the urban environment. This study analyzes the spatial performance, in terms of urban development, of 12 European Union regions from five European countries with coastal areas by incorporating spatial data such as length of road network, population distribution, land uses, and other factors. Key performance indicators have been developed for evaluating the structural development model of the regions (e.g., dense or sprawl development). In addition, the incorporation of spatial spillover effects in the evaluation of the regions was conducted by the extended spatial data envelopment analysis (SDEA) method. The results of SDEA identified the best and worst-performing regions in terms of urban growth. Finally, this study implements a target-setting approach where under-performing regions can best perform. Based on the target-setting approach, local authorities can set realistic targets for improving the structural model that the regions are following.

Objective: The clinical profile, management and outcome of infective endocarditis (IE) may be influenced by socioeconomic issues. Methods: A nationwide prospective study evaluated IE during the era of deep economic crisis in Greece. Epidemiological data and factors associated with 60-day mortality were analyzed through descriptive statistics, logistic and Cox-regression models. Results: Among 224 patients (male 72.3%, mean age 62.4 years), Staphylococcus aureus (n = 62; methicillin-resistant S. aureus (MRSA) 33.8%) predominated in the young without impact on mortality (p = 0.593), whilst Enterococci (n = 36) predominated in the elderly. Complications of IE were associated with mortality: heart failure [OR 2.415 (95% CI: 1.159–5.029), p = 0.019], stroke [OR 3.206 (95% CI: 1.190–8.632), p = 0.018] and acute kidney injury [OR 2.283 (95% CI: 1.085–4.805), p = 0.029]. A 60-day survival benefit was solely related to cardiac surgery for IE during hospitalization [HR 0.386 (95% CI: 0.165–0.903), p = 0.028] and compliance with antimicrobial treatment guidelines [HR 0.487 (95% CI: 0.259–0.916), p = 0.026]. Compared with a previous country cohort study, history of rheumatic fever and native valve predisposition had declined, whilst underlying renal disease and right-sided IE had increased (p < 0.0001); HIV infection had emerged (p = 0.002). No difference in rates of surgery and outcome was assessed. Conclusions: A country-wide survey of IE highlighted emergence of HIV, right-sided IE and predominance of MRSA in the youth during a severe socioeconomic crisis. Compliance with treatment guidelines promoted survival.

Greek cities hold important urban issues related to social injustice; lack of open spaces, pedestrian facilities, parks and greenery, access to public amenities, etc. In view of these, we investigated residents’ preferences and choices regarding their walking activities in the urban environment of Thessaloniki, Greece. In specific, we applied research with questionnaires to the residents of the municipality of Ampelokipoi-Menemeni. The research applied the Contingent Valuation Method to investigate residents’ willingness to pay (WTP) for the improvement of the existing infrastructure of public space in view of making walking and the use of local metro stations more attractive. A methodological framework was developed, including Explanatory Factor Analysis and Structural Equation Modelling, along with statistical analysis of the results. The lack of pedestrian facilities and the long walking distances are two main reasons discouraging the use of the metro. CVM application showed that almost half of the residents would be willing to contribute an amount of money for the improvement of pedestrian infrastructure. The main reasons for this were to make the use of the metro more attractive, which would also improve their living conditions and would contribute to a better quality of life. Income restrictions proved highly important to a negative WTP.

The growing competition among container port terminals enhances the pressure for optimizing their efficiency level in the performance of containers’ service. Comparing container terminals based on their performance is a complicated task due to the variety of ports’ type, scale, and service configuration. This however is an important task in the efforts of improving not only national trade transportation but also the global trade system, since valuable best practices can be identified and adopted among container terminals. Notwithstanding, available information about container port terminals’ efficiency level, based on their performance measured by the service of Twenty-foot Equivalent Units (TEUs), is yet incomplete due to the lack of information about which factors influence their efficiency the most. This additional information will support the decision-making processes of container terminals’ authorities to direct their focus on specific factors that will improve their efficiency. This paper investigates the efficiency of the top-50 global container port terminals that service the global freight supply chain in a period of 5 years (2013-2017) through a two-step procedure. First, a benchmarking analysis, namely, Data Envelopment Analysis, is implemented to estimate the efficiency level of the container port terminals. The second step involves the methodology followed in this paper which is further expanded to quantify the effects that different factors have on container terminals efficiency through the implementation of suitable Tobit regression models. The findings of this paper identify the benchmark container terminals that should be taken as examples for under-performing container port terminals and also points out the factors that must be enhanced for improving global trade system, like, number of cranes, terminal space and quay lenght.

Purpose: To report endovascular treatment of 2 patients with aneurysmal deterioration of peripheral arterial allografts. Case Report: Two men (65 and 64 years old) who had undergone an arterial allograft reconstruction for infection of prosthetic infrapopliteal bypass grafts 5 and 7 years ago, respectively, were diagnosed with asymptomatic aneurysmal deterioration of the allografts. Stent-graft repair was successful in both cases, completely excluding the aneurysms. At >or=1 year, continued aneurysm exclusion was confirmed by duplex scan, with no evidence of endoleak, migration, or stenosis. Conclusion: Endovascular treatment may be a useful therapeutic option when treating patients with late peripheral allograft deterioration. [ABSTRACT FROM AUTHOR]

The control of unstable first-order plus dead-time (UFOPDT) processes using proportional-integral (PI) and proportional-integral-differential (PID) type controllers is investigated in this brief. New tuning rules based on the exact satisfaction of gain and phase margin specifications are proposed. The tuning rules are given in the form of iterative algorithms, as well as in the form of accurate, analytical approximations. Moreover, several specific functions, related to the crossover frequencies of the Nyquist plot and to the feasible design specifications for a given process, are derived. These functions, which are particularly useful for the general design of PI- and PID-type controllers for UFOPDT processes are accurately approximated, in order to simplify the tuning procedure. With the proposed approximations, the tuning rules reported in this brief require relatively small computational effort and are particularly useful for online applications. [ABSTRACT FROM AUTHOR]

The use of pseudoderivative feedback (PDF) in the control and identification of unstable first order plus dead-time (UFOPDT) processes is investigated. Several new methods for tuning the PDF feedback controller are presented. In contrast to known tuning rules for conventional proportional integral derivative (PID) controllers, which result in excessive overshoot in the closed-loop response, the proposed control structure and tuning methods ensure a smooth response to set-point changes, fast attenuation of step-load disturbances, and satisfactory robustness against parametric uncertainty. Moreover, two simple methods for identifying the UFOPDT process parameters, based on this controller structure, are proposed in this paper. Both methods rely on a single experiment on a closed-loop system with a step change in the set point of a PDF controller. They are very accurate, as well as simpler and less sensitive than existing identification methods. Finally, an application of the proposed identification and tuning methods to an open-loop unstable bioreactor with hard input constraints and significant measurement delay is presented. [ABSTRACT FROM AUTHOR]

Background: Type 2 endoleaks (T2ELs) have been considered a benign condition and intervention is recommended when they are associated to sac expansion. The aim of this study was to report on T2EL embolization midterm outcomes, using neurointerventional material., Methods: A single-center retrospective analysis of consecutive patients treated with transarterial embolization, using neurointerventional material, for T2EL after standard endovascular aortic aneurysm repair (EVAR) between January 01, 2017 and July 30, 2022, was undertaken. Primary outcome was technical success and secondary outcome was T2EL recurrence during follow-up., Results: Twenty six patients [92.3% males, mean age 73.9 ± 7.7 years] were included. The median time between EVAR and T2EL diagnosis was 12 months (range: 1-84 months). In 38.5% of patients, T2EL was detected at first month after EVAR. The time to embolization was 18 months (range: 1-96 months). In 42.3% of cases, a patent inferior mesenteric artery was suspected to relate to T2EL formation while in 42.3% of cases, a lumbar artery. Twelve procedures (38.4%) were performed using coils and Onyx and 13 (50%), using only Onyx. Technical success was 84.6%. The mean follow-up was 24 months (range: 1-60 months), including 20 patients. In 30% of cases, an T2EL recurrence was detected. Three patients (11.5%) underwent secondary embolization., Conclusions: Transarterial embolization for T2EL, using neurointerventional material, provided acceptable technical success and T2EL recurrence rates at 2 years of follow-up. Longer follow-up data would further estimate the durability of the technique., (Copyright © 2023 Elsevier Inc. All rights reserved.)

For symptomatic buttock arteriovenous malformations (AVMs), embolization techniques and surgical resection have been suggested as treatment options. Our aim was to evaluate the feasibility and long-term results after a single surgical resection. Twelve patients had undergone surgical resection without preoperative embolization. Of the 12 patients, 11 had had incomplete procedures, 9 of whom had undergone arterial embolization 1 to 3 years previously. All the patients were symptomatic. Computed tomography scans showed AVMs located in the cellular spaces with preservation of the gluteal muscle. The median follow-up time was 80 months. On the last follow-up computed tomography scan, 67% had had no residual AVM. The use of preoperative embolization, especially with nonresorbable embolic material (Onyx; Medtronic, Dublin, Ireland), makes AVM resection and imaging follow-up more difficult because of artifacts and should be avoided., (© 2022 The Authors.)

We retrospectively reviewed 35 patients with venous malformations located in the forearm and treated by surgery in a single institution during the period 2010-19. The common complaints were pain and swelling (34 patients) and impaired function with contractures of fingers (15 patients). Twenty-four had complete resection and 11 had an incomplete resection. Associated procedures were reconstruction or lengthening of tendons in 17 patients. At the last follow-up (mean 61 months), 32 of the 35 had no residual pain and 27 had no functional sequelae. On MRI follow-up exams, 27 had no residual venous malformations. Venous malformations in the anterior compartment of the forearm can impair the function of the hand. They are developed almost exclusively in the connective tissue around tendons and muscles, deforming the musculotendinous structures and involving nerves. Surgery seems an appropriate option for the condition in this area. Level of evidence: IV.

Background: Our aim was to evaluate the benefit of surgical resection of the venous malformations (VMs) of the external female genitalia., Methods: Over the period of 2009-2019, 18 consecutive females underwent surgical resection for vulvar VM. Evaluations included preoperative Doppler ultrasound, MRI, and pre-and postoperative photographic imaging. The main outcomes were: residual pain, cosmetic distortion, residual VM, and quality of life., Results: Over a 10 year periods, 18 females, mean age 35 years (range 9-71) were included in this study. All patients were symptomatic: 16 had intermittent pain or discomfort, 1 had bleeding and 2 requested cosmetic treatment. Of these cases, there were 5 isolated vulvar VM, 12 associated VM: 3 of the clitoral hood, 3 troncular pelvic vein insufficiency and 12 of the lower limb. Eight patients had undergone previous procedures: 2 sclerotherapy treatments (1-3 sessions), 4 partial surgical resections. There were 18 single resections in the vulva (7 focal, 11 complete), 2 partial resections in clitoral hood and 2 had resection of a VM in the perirtoneovaginal canal at the same time. The mean follow-up was 42. 9 months (range 6-120). Two patients were lost to followup at 6 months. For all patients, elimination of pain and soft tissue redundancy was achieved. Two patients had persistent discomfort and 2 requested cosmetic treatment., Conclusion: Surgical resection of vulvar VM can be the best approach with few postoperative complications, good functional and cosmetic results. Appropriate preoperative evaluation is required to identify isolated VM or VM associated with ovarian vein or internal iliac vein insufficiency requiring to be treated before surgery., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Objectives: To report the outcomes of surgical treatment of calf intramuscular venous malformations (IMVMs) on pain, functional limitation, and quality of life., Methods: We retrospectively reviewed 57 consecutive patients who had surgery for IMVM of the posterior compartment of the leg between 2010 and 2015. Treatments were all done at a single institution., Results: Patients presented with pain (52), muscle contracture (14), or pulmonary embolism (4). Muscle involvement included the soleus muscle (n = 28, 49%), the gastrocnemius muscle (n = 25, 43%), and deep muscles (n = 4, 7%). Complete excision was possible in 52 patients (91%) and partial excision in 5 (9%). Thirty-five of 46 patients who had an MRI follow-up at six months had no residual venous malformation. At the final follow-up (mean 39 months), 32 of 40 patients seen had no residual pain and 37 had no residual functional impairment., Conclusion: In cases where IMVM is located in one muscle in the leg, we demonstrated that surgery yielded improvement in pain, function, and quality of life.

Background: The place of open surgery in venous malformations (VMs) of knee joint is still discussed. The aim of this study was to evaluate the benefits of surgery in terms of pain, function, and quality of life., Design: This was a retrospective observational study., Methods: Thirty-five consecutive young patients undergoing surgery for VMs of the knee between 2011 and 2014 were included. Data collection was performed using a prospective database by reviewing patient records. Pain, mobility of the joint, residual VMs as seen by magnetic resonance imaging, and quality of life were the main outcome endpoints for this study., Results: Thirty-five patients (22 females and 13 males, with a median age of 15 y, range of 5 to 20 y) were included. Twenty-seven VMs were localized in and around the knee joint, of which 8 were extensive. Indication for surgery was intermittent or permanent pain.Details of the surgical excisions of the VM are as follows: suprapatellar area in 57%, suprapatellar and infrapatellar area in 29%, infrapatellar area in 2%, limited in the femoropatellar area in 12%. Partial resection of a vastus muscle or patellar retinaculum was necessary for 19 patients.The median duration of the surgery was 4 hours (range: 2 to 7 h). The median hospital stay was 5 days; full-time physiotherapy was systematic for 2 to 3 weeks.After 6 months, 74% had no longer pain, the mobility of the joint was normal for 60%. Of the 33 patients who had a magnetic resonance imaging at 6 months, 86% (28 patients) had no residual intra-articular VMs, and 14% had focal residual VMs.At the last follow-up, 77% (27 patients) had no longer pain, 23% experienced intermittent pain with unusual activities, and 91% (32 patients) had normal mobility of the joint. Quality of life was increased significantly due to the pronounced impact on pain., Conclusion: Extensive surgical excision of knee VMs is a safe procedure with good outcomes in terms of pain, function, and quality of life., Level of Evidence: Level II-retrospective observational monocentric study.

Background: Spontaneous and isolated dissection of the superior mesenteric artery (SIDSMA) is a rare pathology, and the treatment of symptomatic forms is not consensual. The objective of this study was to analyze the management of a series of patients presenting a symptomatic SIDSMA within a structure taking care of intestinal vascular emergencies., Methods: From January 2010 to January 2014, the patients presenting a symptomatic SIDSMA were included retrospectively. The clinical and radiologic data as well as the treatment and the follow-up were analyzed., Results: Nine patients were included. Among them, 2 patients presenting with acute mesenteric ischemia were revascularized surgically in emergency, and 1 patient presenting a rupture of a superior mesenteric artery aneurysm had an arteriography followed by medical care. The 6 other patients received medical treatment. Among these, 2 patients developed mesenteric angina requiring surgical revascularization during the follow-up., Conclusions: The revascularization of spontaneous and isolated dissections of the superior mesenteric artery is indicated in the cases complicated with acute mesenteric ischemia, aneurysmal rupture, or in the event of appearance of mesenteric angina or aneurysmal evolution. It should also be discussed in the event of failure of the medical treatment., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Infection of peripheral bypass is a very severe complication associated to a high rate of morbimortality. The aim of this study was to prospectively evaluate cryopreserved arterial allografts (CAAs) performances in the treatment of this complication. Between April 1996 and June 2008, we prospectively collected data from patients presenting with major infections of peripheral bypasses who benefited from a CAA reconstruction in association with the excision of the infected bypass. CAA were taken from multi-organ donors and frozen at -80 °C. CAA mean conservation time was 115 days (±132). Over this 12-year study, 36 patients (31 men, five women, mean age = 68) benefited from CAA reconstruction for major infections of peripheral bypasses. Eighteen patients (50%) had a septic syndrome, five patients (14%) had an acute ischemia at the reconstruction time, and 12 patients (33%) had an anastomotic rupture. Emergency CAA reconstruction was performed on seven patients (19%). There were no perioperative deaths and no early amputations. Patient follow-up was complete, with a mean 42 -month duration (range, 3-116). There were no persisting or recurring infections. During the follow-up, 10 patients benefited from revision, excision, or replacement of the CAA and fifteen patients died from causes nonrelated to the initial infection. The cumulative rate of limb salvage was 87% at 3 years. Primary and secondary cumulative patency rates were 57% and 78% at 3 years, respectively. CAA reconstruction in association with infected bypass excision is an effective treatment for peripheral bypass major infections. Our results prompt us to go on with CAA reconstructions for this type of indication., (Copyright © 2010. Published by Elsevier Inc.)

Descending thoracic aorta to femoral artery bypass is an effective and safe procedure for the treatment of aortoiliac occlusive disease when an approach to the abdominal aorta is undesirable. The major limitation of this technique has resulted from the morbidity rate associated with thoracotomy in a relatively high-risk vascular surgery population. As a minimally invasive procedure, videoendoscopy has been shown to improve the patient postoperative course and comfort in the field of general and thoracic surgery. The same benefits could be expected from a videoendoscopic surgery involving the thoracic aorta. In 2003 we reported the first case of a totally videoendoscopic descending thoracic aorta-to-femoral artery bypass procedure. In this article we report our additional experience with and the modifications we have made to this technique., (Copyright (c) 2010 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Background: We report a hybrid treatment for a ruptured penetrating aortic ulcer (PAU) of the aortic arch in emergency conditions., Methods: A 74-year-old man with severe comorbidity was diagnosed with a symptomatic rupture of a PAU of the aortic arch. As he was considered unfit for conventional open repair and it was an emergency condition, an acute endovascular repair with cervical debranching of the supra-aortic trunks could be proposed. The left common carotid artery and left subclavian artery were first debranched and revascularized through cervical access, and the endovascular stent graft was then deployed via femoral access in the aortic arch. At >or=2 years the patient is safe with no sign of progression of the disease., Conclusion: Acute debranching and stent grafting is feasible in emergency conditions to treat ruptured PAU of the aortic arch, with satisfying short- and mid-term outcomes, and can be proposed to patients considered unfit for conventional open repair.

Primary vascular tumours are very rare. Most cases are leiomyosarcomas usually arising from large veins such as the inferior vena cava. Involvement of major veins in the limbs is uncommon and of small veins or tributaries extremely uncommon. We report a case of leiomyosarcoma originating from a tributary of the femoral vein in a 55-year-old woman.

We present an alternative surgical approach to popliteal artery entrapment syndrome with vascular complications in the absence of a suitable saphenous vein. Three patients (29, 35, and 78 years old) with thrombotic and/or aneurysmal lesions of the popliteal artery from popliteal artery entrapment syndrome were treated with superficial femoral artery autograft reconstruction. The procedure was performed through a medial approach. The superficial femoral artery was harvested in the upper third of the thigh and used as the conduit for reconstruction and the harvested segment was replaced by a polytetrafluoroethylene graft. At follow-up, patients were asymptomatic and duplex ultrasound revealed patent reconstruction with no morphological abnormalities.

The aim of this work was to evaluate, in terms of activity and immediate postoperative results, the modifications of our elective surgical treatment of infrarenal abdominal aortic aneurysms (AAAs) resulting from the use of stent grafts to treat AAAs, following the recommendations issued by the French Health Products Safety Agency (AFSSAPS) in December 2003. This monocentric and retrospective study used the clinical data of patients operated on for asymptomatic AAA between January 2001 and December 2006. Endovascular treatment of AAAs with aortic stent grafts was introduced in our current practice in January 2004, following the recommendations of the AFSSAPS (high-risk patients for open surgery presenting with an AAA > or =50 mm). Group I was composed of patients operated on between January 2001 and December 2003 according to the standard open technique. Group II was composed of patients operated on between January 2004 and December 2006 with either standard open surgery or endovascular surgery. The main criteria of evaluation were the number of operated patients, their American Society of Anesthesiology (ASA) score of surgical risk, and the intrahospital morbidity and mortality. The number of treated patients significantly increased between these two periods (group I n = 49, group II n = 88, with 38 endovascular treatments; p < 0.001), without any changes in average age (70 vs. 72 years), percentage of men (93.7% vs. 95.5%), and mean AAA size (57.8 vs. 56 mm) between the two groups. ASA scores were significantly higher in group II (ASA III and IV, group I = 20.4% vs. group II = 55.7%; p < 0.0001), whereas the intrahospital mortality rate (4.1% vs. 3.4%) and the rate of major postoperative complications (16.3% vs. 11%) have remained stable. In group II, the median duration of hospitalization was significantly reduced (12 vs. 9 days, p < 0.001). In conclusion, in our center, following the AFSSAPS recommendations, the introduction of endovascular treatment has enabled us to electively treat a greater number of AAA patients with higher surgical risk, without aggravating the immediate postoperative results.

Objective: This prospective, observational study evaluated the safety and efficacy of superficial femoral artery autograft reconstruction in the treatment of popliteal artery aneurysms in the absence of a suitable saphenous vein., Methods: From March 1997 to April 2007, data from patients with popliteal artery aneurysms treated by superficial femoral artery reconstruction were prospectively collected in two centers. The procedure was performed through a medial approach. The superficial femoral artery was harvested in the upper third of the thigh and used as the conduit for reconstruction, and the harvested segment was replaced by a polytetrafluoroethylene graft. The patients were observed for survival, limb salvage, and reconstruction patency. The results were calculated by the Kaplan-Meier method., Results: During the 10-year study period, 37 popliteal artery aneurysms in 32 patients (all men; median age, 71 years) were treated by reconstruction using the superficial femoral artery. Indications for surgical treatment were symptomatic or complicated aneurysms in 11 (30%). Four (11%) of the 37 popliteal artery aneurysms were thrombosed, and 33 (89%) were patent. At surgery, 35% had a single vessel runoff. Because of acute ischemia, reconstruction was performed as an emergency procedure in three patients (8%). There were no perioperative deaths, early amputations, or early thrombosis. The mean follow-up period was 36 months (range, 7-103 months). Two grafts thrombosed during follow-up. At 3 years, the primary and secondary patency rates were 86% and 96%, and overall limb salvage was 100%. Follow-up duplex ultrasonography did not detect any aneurysmal dilatation of the autograft., Conclusion: Our experience shows that superficial femoral arterial reconstruction is a safe and useful treatment option in patients with popliteal artery aneurysms who lack suitable saphenous veins. This reconstruction seems to be a good alternative to prosthetic bypass crossing the knee joint, and our results suggest that this study should be continued.

External iliac artery (EIA) dissection and especially bilateral involvement is very rare. We report the case of a 49-year-old male intense bicyclist who had presented a dissection of the left EIA responsible for claudication. He underwent an iliofemoral vein graft bypass. The histopathologic examination showed a dissection of the EIA with an otherwise normal arterial wall. Two years after he resumed his sporting activity, a dissection of the right EIA occurred with the onset of claudication. The patient underwent a right iliofemoral vein graft bypass. Histopathologic examination showed the same lesions as on the left side. Bilateral involvement of EIA dissection is possible especially when the mechanism leading to dissection is persistent. An attentive follow-up is thus to consider.

Descending thoracic aorta to femoral artery bypass is an effective and safe procedure for the treatment of aortoiliac occlusive disease when an approach to the abdominal aorta is undesirable. The major limitation of this technique has resulted from the morbidity rate associated with thoracotomy in a relatively high-risk vascular surgery population. As a minimally invasive procedure, videoendoscopy has been shown to improve the patient postoperative course and comfort in the field of general and thoracic surgery. The same benefits could be expected from a videoendoscopic surgery involving the thoracic aorta. We report what we think to be the first totally videoendoscopic descending thoracic aorta to femoral artery bypass.

Spinal cord ischemia is a major cause of complications after operative and endovascular treatment of descending thoracic or thoracoabdominal aortic aneurysms. Prior revascularization of the intercostal artery (IA) giving rise to the artery of Adamkiewicz (AA) using an artery of the thoracic wall would preserve circulation in the AA and allow obstruction of the IA at its origin. The purpose of this study was to determine the feasibility of revascularization of the IA giving rise to the AA using three thoracic wall arteries, i.e., lateral thoracic artery, thoracodorsal artery, and descending scapular artery. A total of 16 specimens from 8 cadavers (6 men and 2 women) were prepared. The length and diameter of the thoracic wall arteries were measured to ascertain the feasibility of revascularization of the IA giving rise to the AA. In addition, 12 preoperative spinal cord arteriograms were studied. We found that revascularization of the IA giving rise to the AA using thoracic wall arteries is feasible. This technique could be used to prevent spinal cord complications after treatment of descending thoracic or thoracoabdominal aortic aneurysms.

From May 91 to March 99 a consecutive series of 100 acute obstructions or perforations of the left colon or rectum were treated by primary resection with mechanical anastomosis using a double or triple stapling technique without proximal colostomy. There were 8 postoperative deaths (8%) due to sepsis, acute respiratory distress syndrome, pulmonary embolism, stroke, and cachexy. Complications occurred in 29% of surviving patients. Clinical anastomotic leaks were observed in 7%, respiratory infection in 8%, wound infection in 8% and major cardiovascular problems in 4% of patients. The median hospital stay was 19 days. The morbidity and mortality of this series did not exceed the cumulative morbidity and mortality that can be expected after staged surgery. Compared with staged surgery, immediate resection and anastomosis using an entirely mechanical suture, thereby avoiding the problems of colostomy and reducing the length of hospital stay, has significant advantages for patients.

Objective: to propose an anatomical classification of juxtarenal aortic aneurysm (JRA) that relates to their epidemiology and the result of surgical repair., Material and Methods: retrospective study of 53 JRA and 376 infrarenal aortic aneurysm (AAA) operated between January 1989 and August 1999., Results: perioperative mortality after JRA repair was 19% for type A (interrenal), 13% for type B (aneurysm of one or two renal origins) and 4% for type C (no infrarenal neck). These differences were not significant. The overall perioperative mortality after JRA repair (11%) was significantly higher than mortality of AAA (3%p<0.01). Postoperative morbidity after JRA repair was 62% for type A, 75% for type B and 33% for type C. Postoperative morbidity after type B repair was significantly more frequent than after type C (p<0.001). The overall postoperative morbidity (51%) was significantly more frequent than after AAA repair (26%p<0.01). Preoperative ischaemic heart disease, aortic clamping above the coeliac axis and aortic proximal clamping longer than 30 min were significant risk factors for death after JRA repair. Survival by life-table analysis at five years after JRA repair and AAA repair were respectively 73%+/-7% and 76%+/-3%., Conclusion: there is a less favourable outcome after JRA repair as compared to AAA repair. The complexity of the surgical procedure requires accurate preoperative morphological assessment. The proposed classification of juxtarenal aneurysms may be helpful in guiding surgical access., (Copyright 2001 Harcourt Publishers Limited.)