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The field of vascular surgery is constantly evolving and is unsurpassed in its innovation and adoption of new technologies. Endovascular therapy has fundamentally changed the treatment paradigms for aneurysm and occlusive disease. As we continue to make advances in not only endovascular therapy, but also robotic surgery, artificial intelligence, and minimally invasive surgery, it is important that the vascular community stay at the forefront. Topics include the advantages of laparoscopic and robotic surgery over open surgery for aortic procedures, robotic versus laparoscopic aortic surgery, patient candidacy for robotic-assisted aortic surgery, and how to increase training and adoption of robotic-assisted laparoscopic aortic surgery. Future growth includes the development of new platforms and technologies, creation and validation of curriculum and virtual simulators, and conduction of randomized clinical trials to determine the best applications of robotics in vascular surgery. [ABSTRACT FROM AUTHOR]

The article deals with setting out the optimum project design of railroad switches with the aim of finding an economical, effective and purposeful solution for a project. The Life Cycle Costs method (LCC) presents the best approach for this mentioned optimization. LCC does not take into account only the acquisition costs of a building, but summarizes all costs for the examined period. The very need to optimize costs for the construction and operation is ever more in demand in the context of increasing energy prices and relentless pressure to find new saving opportunities. The article also provides a comparison of individual stages of the life cycle of a project (investment- operation- maintenance) among the separate individual branches of construction and the railroad switch structure itself. With railroad switches as opposed to other structures appearing in the transport infrastructure there results almost an equality between investment and operational costs. The specific calculation of the LCC railroad switch is carried out within the framework of a case study for the modernization of the section of the railway in the town of Ceska Lipa (northern region of the Czech Republic), where the total costs for 27 pieces of railroad switches within a 30 year evaluation period reached 6 million €. On the basis of the research undertaken there were summarized the particular steps leading to the choice of an economical, effective and purposeful variant of a railway line design with its own impact on the design of railroad switches which significantly influence the price of the construction and thus the whole LCC. [ABSTRACT FROM AUTHOR]

Biomechanical rupture risk assessment of aortic tissues is commonly based on computed stress to measured uniaxial static strength comparison. Loading of the arterial wall, however, is cyclic; thus, the static strength may not be a proper limit value. This study investigates the low cycle fatigue of porcine aortic samples tested in a circumferential direction. 7 porcine descending aorta (both thoracic and abdominal) were harvested and 56 dogbone-shaped samples were prepared. Static strength was measured, the limit of engineering stress was chosen and then force controlled cyclic loading was performed up to 100,000 cycles. Efforts were made to obtain a sufficient number of points across the entire range of 0-100,000 cycles. Data were fitted by both linear and logarithmic law and extrapolated towards 1 cycle for validation against static strength/ultimate tension. Data dispersion was evaluated via normalised root mean square error. Out of 56 samples from 7pigs, 28 samples from 4 pigs were successfully tested. There was a strong negative correlation between applied stress/tension and number of cycles to failure. The fitting of both linear and logarithmic values resulted in a similar accuracy (R 2 = 0.72 and 0.71 for stress and R 2 = 0.62 and 0.7 for tension, respectively), while predicting static failure properties was more accurate by logarithmic law. NRMSE was lower for absolute values (20–21%) than for relative values (27–30%). Absolute values of cyclic strength and tension are less dispersed than relative ones. Logarithmic fits are more robust in predicting static strength from cyclic data, while linear fits serve as a lower limit estimation. [Display omitted] • Passive low cycle fatigue properties of porcine aorta tested. • Stress/tension to number of cycles to failure relation evaluated. • Absolute values of stress/tension gives less dispersion than relative values. • Logarithmic law accurately predict static strength/ultimate tension. [ABSTRACT FROM AUTHOR]

With regards to the strategic role of transport in a country's economic development and the large investments that are required, a thorough economic appraisal of these investments is of high importance. Therefore, it is appropriate to analyze and possibly modify existing methods for evaluating the economic efficiency of road construction at the scientific level, with the support of the real practice experience. Our research concentrates on evaluation of current methods of economic appraisal, their consecutive improvement and on incorporation of the LCCA agenda into the investment decision process. Consequently, it focuses on the possibilities to improve the effectivity of both, an investment decision process and a realization phase through the proposal of very concrete measures based on results of our research and on experience of real practice construction. [ABSTRACT FROM AUTHOR]

Abstract: The paper summarizes the experience with use of thermomechanically rolled ML and normalized rolled NL steel plates in fabrication of steel structure of Apollo bridge from the year 2003 till 2005. Basic data about the bridge, used steels and their properties in compliance with EN standard as well as supplementary requirements on chemical composition and mechanical properties, especially toughness of steels and welded joints are described. The statistic evaluation of properties of used steel plates: carbon content, CEV carbon equivalent, sulphur content, yield strength Re, impact energy KV at – 30°C are outlined. The required and determined welding procedure specifications WPS are also described. It is recommended using S420ML and S460ML steels and corresponding welding consumables for construction of large steel bridges. [Copyright &y& Elsevier]

The aim of this paper is to find, in a closed form, special solutions of equations describing a one-dimensional non-stationary flow of a liquid containing dissolved gas. The special feature of these solutions is that despite the fact that they do not satisfy all initial and boundary conditions, they describe a physical characteristic qualitatively analogous to that described by the original equations. Thus these special solutions may prove useful means for judging the reliability of the original mathematical model of the problem. [ABSTRACT FROM AUTHOR]

Objective: The feasibility of laparoscopic aortic surgery with robotic assistance has been sufficiently demonstrated. Reported is the clinical experience of robot-assisted aortoiliac reconstruction for occlusive disease and aneurysm performed using the da Vinci system. Methods: Between November 2005 and June 2006, 30 robot-assisted laparoscopic aortoiliac procedures were performed. Twenty-seven patients were prospectively evaluated for occlusive disease, two patients for abdominal aortic aneurysm, and one for common iliac artery aneurysm. Dissections of the aorta and iliac arteries were performed laparoscopically using a transperitoneal direct approach technique, a modification of the Štádler method. The robotic system was used to construct anastomoses, to perform thromboendarterectomies and, in most of the cases, for posterior peritoneal suturing. Results: Robot-assisted procedures were successfully performed in all patients. The robot was used to perform both the abdominal aortic and common iliac artery aneurysm anastomoses, the aortoiliac reconstruction with patch, and to complete the central, end-to-side anastomosis in another operation. Median operating time was 236 minutes (range, 180 to 360 minutes), with a median clamp time of 54 minutes (range, 40 to 120 minutes). Operative time is defined as the time elapsed from the initial incision to final skin closure. Median anastomosis time was 27 minutes (range, 20 to 60 minutes), and median blood loss was 320 mL (range, 100 to 1500 mL). No conversion was necessary, 30-day survival was 100%, median intensive care unit stay was 1.8 days, and median hospital stay was 5.3 days. A regular oral diet was resumed after a mean time of 2.5 days. Conclusion: Robot-assisted laparoscopic surgery is a feasible technique for aortoiliac surgery. The da Vinci robotic system facilitated the creation of the aortic anastomosis and shortened aortic clamp time in comparison with our laparoscopic techniques. [Copyright &y& Elsevier]

There is a striking difference in the reported mean response of abdominal aortic aneurysm tissue in academic literature depending on the type of tests (uniaxial vs biaxial) performed. In this paper, the hypothesis variability caused by differences in experimental protocols is explored using porcine aortic tissue as a substitute for aneurysmal tissue. Nine samples of porcine aorta were created and both uniaxial and biaxial tests were performed. Three effects were investigated. (i) Effect of sample (non) preconditioning, (ii) effect of objective function used (normalised vs non-normalised), and (iii) effect of chosen procedure used for mean response calculation: constant averaging (CA) vs fit to averaged response (FAR) vs fit to all data (FAD). Both the overall shape of mean curve and mean initial stiffness were compared. (i) Non-preconditioning led to a much stiffer response, and initial stiffness was about three times higher for a non-preconditioned response based on uniaxial data compared to a preconditioned biaxial response. (ii) CA led to a much stiffer response compared to FAR and FAD procedures which gave similar results. (iii) Normalised objective function produced a mean response with six times lower initial stiffness and more pronounced nonlinearity compared to non-normalised objective function. It is possible to reproduce a mechanically inconsistent response purely by using the chosen experimental protocol. Non-preconditioned data from failure tests should be used for FE simulation of the elastic response of aneurysms. CA should not be used to obtain a mean response. [ABSTRACT FROM AUTHOR]

This study concerns procedural aspects of planar biaxial experiments on aortic tissues that have not been exhaustively addressed in the literature. The following questions are explored. First, is there a difference in the apparent mechanical properties if the experiments are conducted in a force-controlled regime or a displacement-controlled regime. Second, does it matter whether the deformations of the surface are tracked from one side of the tissue or the other (luminal vs. abluminal surface). The study provides answers to these questions with the help of a series of experiments on porcine aortic tissue, constitutive modelling and statistical analysis. It was found that the loading protocol does not substantially affect the constitutive response, while the surface orientation does. Image 1 [ABSTRACT FROM AUTHOR]

Introduction: Thoracoabdominal aortic surgery is a technically demanding and extensive treatment that has its place in the era of endovascular techniques. To ensure the best possible outcomes, it requires a well-coordinated team of surgeons, anaesthetists, intensive care physicians and other medical staff., Methods: The authors present a series of 300 patients operated on between 1 January 2003 and 15 March 2022. Although the group included sporadic cases of severe obliterating involvement of the visceral aorta, patients with thoracoabdominal aortic aneurysms (TAAA) constituted the vast majority. All known organ preservation procedures were used during the operations. The thoraco-phreno-retroperitoneal approach was chosen in almost all TAAA cases; the thoraco-phreno-transperitoneal approach was used only in two reoperations., Results: In this cohort, type II thoracoabdominal aneurysm according to Crawford classification was most common (33%). This was followed by type IV (32%), type III (15.3%), type I (8.7%), type V (6.7%) and other thoracoabdominal aortic procedures (4.3%). Thirty-day mortality rate was 9.6% (2019 - 6%, 2020 - 9.5%, 2021 - 3.8%) in this group; surgical postoperative complications occurred in 36 patients (12%). Neurological complications were reported in 16 cases (5.3%), of which postoperative paraplegia was noted 6 times (2%). Temporary postoperative dialysis due to renal insufficiency was performed in 19 patients (6.3%) and 4 patients (1.3%) have entered the chronic dialysis programme. In 67 patients (23.3%), temporary tracheostomy was done postoperatively due to prolonged withdrawal from the lung ventilator., Conclusion: Surgical treatment of the thoracoabdominal aorta is one of the most extensive procedures in vascular surgery and the mortality and morbidity rates still remain relatively high. A multidisciplinary approach, sufficient experience and a dedicated team are essential for a successful outcome of these highly specialised operations.

Introduction: Based on their experience with robot-assisted vascular surgery, the authors present some unique types of procedures they have performed in this area., Methods: From November 2005 to February 2022, a total of 560 robotic vascular procedures were performed, of which 70 were orphan operations, corresponding to 12.5%. The most common was robotic decompression of the coeliac trunk (18 times) in Dunbar syndrome, followed by robotic repair of type II endoleak after stent graft implantation (15 times) and robotic repair of splenic artery aneurysm (11 times). Less common were isolated pelvic artery aneurysm surgery (8 times), aortic thromboenderectomy and abdominal aortic patch repair (8 times) and hybrid surgery (6 times). Completely unique are renal artery reconstruction (2 times), operation of internal mammary artery aneurysm (1 time) in a patient with Marfan syndrome and paracaval biopsy (1 time) in a cancer patient., Results: In 3 cases (4.2%) the operation had to be converted to open surgery. Twice in the management of splenic artery aneurysm due to flat adhesions in the abdominal cavity and once in the endoleak operation, when due to the very fragile wall of the dilated and pulsating abdominal aortic aneurysm sac, we considered manipulation with robotic instruments to be highly risky. There was zero mortality in this cohort; one patient had to undergo laparoscopic diaphragm repair for diaphragmatic hernia at another institution after deliberation of the coeliac trunk and in one case open surgery was needed for persistent endoleak., Conclusion: The use of the robotic system can be beneficial also in less frequent procedures, offering the patients all the advantages of robotic surgery. However, the need of extensive experience in robotic surgery should be emphasized because these operations are rare and perfect anatomical knowledge of the area is necessary.

Introduction: The aim of this study was to evaluate the clinical experience with 379 robot-assisted vascular procedures performed from November 2005 to December 2016 at our institution., Methods: A total of 366 cases (96.6%) were successfully completed using the robotic surgical systems da Vinci Standard and da Vinci Xi., Results: Conversion was necessary in 13 patients (3.4%). The 30-day mortality was 0.26% and 2 (0.5%) late prosthetic infections occurred., Conclusions: From a practical point of view, the greatest advantage of robot-assisted procedures has been the speed and relative simplicity of vascular anastomosis construction. Our experience with robot-assisted surgery has demonstrated the safety and feasibility of this technique in different areas of vascular surgery.Key words: robotic vascular surgery aortic and non-aortic surgery.

Objective: The feasibility of robotically assisted laparoscopic aortic surgery has already been adequately demonstrated. Our clinical experience with robot-assisted aortoiliac reconstruction for occlusive diseases, aneurysms, and hybrid procedures performed using the Da Vinci system is described below., Methods: Between November 2005 and November 2011, we performed 225 robot-assisted laparoscopic aortoiliac procedures. One hundred seventy-four patients were prospectively evaluated for occlusive diseases, 43 patients for abdominal aortic aneurysm, two for common iliac artery aneurysm, two for splenic artery aneurysm, three for hybrid procedures, and one for endoleak II treatment after endovascular aneurysm repair. The robotic system was applied to construct the vascular anastomosis for thromboendarterectomy, for aortoiliac reconstruction with a closure patch, for dissection of the splenic artery, and for posterior peritoneal suturing. A combination of conventional laparoscopic surgeries and robotic surgeries was routinely included. A modified fully robotic approach without laparoscopic surgery was used in the last 55 cases in our series., Results: Two hundred seventeen cases (96%) were successfully completed robotically; one patient's surgery was discontinued during laparoscopy because of heavy aortic calcification. In seven patients (3%), conversion was necessary. The 30-day mortality rate was 0.4%, and nonlethal postoperative complications were observed in 10 patients (4.4%)., Conclusions: Our experience with robot-assisted laparoscopic surgery has demonstrated the feasibility of this technique for aortoiliac vascular and hybrid procedures. Compared with purely laparoscopic techniques, the Da Vinci robotic system facilitated the creation of the aortic anastomosis and shortened the aortic clamping time.

Background: Pedal bypass grafting has been the method of choice at Na Homolce Hospital's Vascular Surgery Department since 2008., Methods and Results: During the period from June 2008 to December 2011, 29 pedal bypass procedures were performed in 27 patients. No perioperative mortality was recorded. Early occlusion of the graft occurred in three patients and two patients experienced delayed occlusion. Loss of the limb as a result of graft occlusion was unavoidable in two cases and one amputation had to be performed despite a patent graft. The primary patency rate for the period under review is 82.75%, and we were able to salvage the limb in 89.65% of cases. Follow-up results for our cohort are comparable with those from other centres dealing with the same problem., Conclusions: Pedal bypass has excellent early and long-term results and makes a significant contribution to reducing the number of major amputations of the lower limbs.

Minimally invasive surgery provides an attractive alternative compared with conventional surgical approaches and is popular with patients, particularly because of its favourable cosmetic results. Vascular surgery has taken its inspiration from general surgery and, over the past few years, has also been reducing the invasiveness of its operating methods. In addition to traditional laparoscopic techniques, we most frequently encounter the endovascular treatment of aneurysms of the thoracic and abdominal aorta and, most recently, robot-assisted surgery in the area of the abdominal aorta and pelvic arteries. Minimally invasive surgical interventions also have other advantages, including less operative trauma, a reduction in post-operative pain, shorter periods spent in the intensive care unit and overall hospitalization times, an earlier return to normal life and, finally, a reduction in total treatment costs.

Introduction: The authors present a group of patients, who underwent standard procedures on thoracic (TAA) and thoracoabdominal (TAAA) aortic aneurysms from 01-01-2009 to 15-09-2010., Material and Methods: During the above time period, a total of 29 patients were operated. The authors employed as many known organ protection procedures as possible, including reduced heparinization, mild hypothermia (32-34 degrees C), sequential aortic clamping cerebrospinal drainage, left heart bypass (a biopump) with non-ischemic canylation of the femoral artery, selective visceral blood perfusion (superior mesenteric artery and coeliac trunk) and renal arteries perfusion using cold crystallic solution. For technical reasons, monitoring of somatosensory and motor evoked potentials was used only twice. In the majority of TAAA procedures, the thoracoretroperitoneal approach was used., Results: During the studied period, the overall mortality rate was 24%. In 2009, a total of 16 patients were operated, out of which 14 subjects underwent elective procedures. Two subjects underwent urgent procedures for ruptures and both of them died. In 2009, the mortality rate was 21% for planned procedures. In the following year, from January to September 15, a total of 13 patients underwent surgery, out of whom 11 underwent elective and two urgent procedures. The group's overall mortality rate was 15.4%, the mortality rate in elective surgery patients was 9% . One patient undergoing urgent surgery survived and one exited. Postoperative paraplegia was reported in one subject (3,4%), postoperative dialysis due to postoperative renal insufficiency was used in 6.9% and other postoperative complications occurred in 10,3% of the subjects., Conclusion: Mortality and morbidity rates in the surgical management of thoracoabdominal aortic aneurysms remain considerably high, although new procedures of organ protection help to reduce it. These highly specialized procedures require a multispecialty approach and a well- coordinated surgical team, specialized in this problematics.

Aim: Based on experience with 150 robot-assisted vascular reconstructions, the authors discuss current potential applications of the Da Vinci robotic system in vascular surgery, as well as a potential for further use of this new technology in vascular surgery., Material and Methodology: In vascular surgery, laparoscopic methods have never been used as much as in general surgery. Although many studies presenting interesting outcomes have been published, laparoscopic vascular surgery has not been generally accepted. Its main problems include duration of the procedure and, in particular, the vascular staple size and associated difficulties with the vascular anastomosis suturing. However, recently, there have been many revolutionary advancements in medicine, including vascular surgery. Robot-assisted surgery is the next step in the development of miniinvasive methods. From November 2005 to August 2009, the authors performed 150 robot-assisted vascular reconstructions in the aorto-iliac region. Besides aorto-femoral reconstructions, the most significant procedures also included aortic aneurysm procedures, procedures on pelvic and splenic arteries, as well as hybrid procedures., Results: In four cases (2.7%) conversion to classical procedures were required and four subjects (2.7%) developed serious postoperative complications. In a single case (0.7%), the robotic apparatus had a defect during the procedure and the procedure was completed using laparoscopy. In a single case (0.7%), the procedure had to be cancelled because of an inoperable finding on the aorta. The average duration of the procedure in this study group was 228 minutes, the average time required for anastomosis suturing was 27 minutes and the average stapling time was 39 minutes., Conclusion: Robotic systems increase accuracy, control and quality of surgical procedures and offer higher quality surgery to patients. The authors managed to reach the world primacy in the field of vascular surgery and the Czech Republic has become a significant world leader in this superspecialized surgical specialty.

The authors describe their first hybrid, combined robot-assisted surgical procedure. The procedure included robot-assisted aorto-bifemoral reconstruction and robot-assisted incisional hernioplasty in one step. The procedure has not been published in the literature yet, and it indicates that, with certain experience, concomittant management of a secondary disorder may be performed together with a minimally invasive procedure for a primary condition, with a very good outcome.

Considering frequencies of the heart cathetrization procedures, including treatment of pseudoaneurysms of the femoral artery using percutaneous thrombotization, a possibility of peripheral arterial emobolization should be considered. The authors describe management of the relatively rare complication in the treatment of postcathetrization pseudoaneurysms. According to the case review, clearing the obliterating arterial embolus of the tissue glue is technically feasible even more than 24 hours folowing the embolization.

Robotic operational systems improve accuracy, control of and skilful management of surgical procedures up to levels unachievable by a human factor itself. A surgeon is also allowed to conduct the types of miniinvasive procedures, which cannot be conducted using contemporary technologies. High degree of the procedure's safety can be achieved. Currently, the robotic surgical systems are used in top clinics worldwide and the concept of the robotic operating theatre is considered to become standard for some procedures in future. In October 2005, a multispecialist robotic centre was opened in the Hospital Na Homolce, which then created a new qualitative standard in the miniinvasive surgical management. The authors present the initial group of patients, who were operated from November 2005 to January 2006 with employement of the da Vinci robotic system, listing its pros and cons.

Some 500 aortoiliac aneurysms are mostly electively operated in the Czech Republic each year. Miniinvasive approaches already widely accepted in general surgery are gradually becoming more routine in vascular surgery as well. Better patient comfort hand in hand with reduced hospital stay represent the major advantages of these procedures. The authors present their initial experience with laparoscopic AAA resection with the use of their own modification of the transperitoneal-retroperitoneal approach. Ischemic preconditionning's techniques with regard to the expected prolonged aortic clamping time were used during surgery.

Laparoscopic techniques, which have been found useful in the general surgical procedures, have influenced the vascular surgical procedures with a certain delay. The main reason for the delay were technical difficulties of the vascular anastomosis, which resulted in a reluctant acceptance of the laparoscopic procedures by vascular surgeons. However, with respect to clear benefits of the miniinvasive procedures, including reduction of the postoperative pain, faster recovery rates and reduction of the total treatment costs, the laparoscopic procedures are finally being applied in the vascular surgery as well. The authors introduce operative results and outcome of ten laparoscopic vascular procedures for aortoiliac occlusive disease, which were conducted from September 2003 to April 2004. In five cases, iliofemoral bypasses were conducted, fourtimes unilateral aortofemoral bypasses (AF) and once an aortobifemoral bypass (ABF). All the IF and AF reconstructions were conducted via laparoscopy and the ABF reconstruction was conducted as laparoscopy-assisted.

A cohort of 14 patients with bacterial destruction of various segments of the aortic wall is presented. The Salmonella enteritidis strain was predominantly responsible. Most patients had typical history of symptomatic trias of sepsis, abdominal and/or back pain and positive blood cultures. CT scan showed pseudoaneurysm within the thoracic, subphrenic or subrenal aorta as well as acute hemorrhage in three patients. One of these was excluded from invasive treatment due to hopeless prognosis. In one patient primary aortoduodenal phistula was responsible for GI bleeding. Five patients were operated and prosthetic replacement of subrenal or iuxtarenal aortic portion together with aortorenal bypass in a couple of cases was performed. In eight patients stentgrafts (SG) of various types were deployed completed with femorofemoral crossover bypass when necessary. All patients were subject to long-standing antibiotic therapy. Two patients expired following SG insertion, all operated patients survived. Average follow-up has been 1 year (1-22 months) so far. A groin abscess was later drained in one patient. Neither CT nor isotope scanning showed persistent or recurrent infectious or hemorrhagic foci in any survivors whatsoever. The authors review and consider the doubtful indication of aortic SG deployment into the septic terrain in selected cases. Midterm results might justify its use in overly debilitated patients otherwise not eligible for radical operation due to its prohibitive risk.

The authors present a case of a complex approach to treatment of a symptomatic pseudoaneurysm of the distal anastomosis of the aorta-aortic replacement in concurrence with a carcinoma of the right kidney. The patient was acutely hospitalized in August 2003 for a two-day-history of a stomach ache. In March 1996, the patient underwent a surgical resection and the aorta-aortic replacement of the abdominal aorta aneurysm. On admission, the CT-AG scan showed a large pseudoaneurysm (5 x 4 x 8 cm) localized in the area of the distal anastomosis with a suspected leak of the contrast matter to the surrounding tissues. Furthermore, an extrarnally bulging expansion in the superior part of the right kidney with a central necrosis measuring 31 mm and the sigmoid diverticulosis were reported as accidental findings.