Complex Endovascular Procedures Research Articles

Assessing the institutional learning curve for pararenal aortic repair using the fenestrated Anaconda endograft.

Custom-made fenestrated aortic endografts allow exclusion of pararenal aortic aneurysms while maintaining blood flow to aortic branches. Meticulous device planning and precise deployment of the main body are essential to allow successful cannulation of the fenestrations. This study investigates whether a learning curve can be observed with more reliable cannulation and connection of fenestrations over time at a single department of vascular and endovascular surgery with multiple surgeons trained to use the device. A retrospective analysis of data from all patients undergoing primary fenestrated endovascular aneurysm repair during the study period was performed. Outcome measures included case volume and average number of fenestrations over time, average fluoroscopy dose area product per calendar year and primary unconnected fenestration and 30-day mortality rates. Between 1 January 2013 and 31 December 2016, 89 patients with no history of endovascular aneurysm repair underwent fenestrated endovascular aneurysm repair at our institution. The number of fenestrations per case increased over time, averaging 2.6 in 2013 and 3.3 in 2016. Primary unconnected fenestration and 30-day mortality rates were 5.6%. Primary-assisted technical success was 93.3%, secondary-assisted technical success was 94.4%. Fluoroscopy dose area product declined over the study period. Thirty-day mortality and primary unconnected fenestration rates did not significantly change over the study period. Albeit the reduction in lethal complications and primary technical success rates were not statistically significant, a lower percentage of unconnected fenestrations and 30-day mortality per calendar year were observed over time. At the same time, an increasing complexity of performed cases, as reflected by an increasing number of fenestrations per case, was observed. Complications associated with this complex endovascular procedure are potentially lethal and remain an unfortunate reality and may not be entirely dependent on overcoming a learning curve. A higher volume of cases performed over the study period and a reduction in fluoroscopy use can be considered a representation of the institutional development and learning curve for the Anaconda fenestrated endograft at a department with prior complex endovascular aortic repair experience, but due to limitations of the current retrospective observation, deserve further consideration in future trials, ideally designed in a prospective fashion.

Optimizing imaging and reducing radiation exposure during complex aortic endovascular procedures.

Improvements in endovascular technologies and development of custom-made fenestrated and branched endografts currently allow clinicians to treat complex aortic lesions such as thoraco-abdominal and aortic arch aneurysms once treatable with open repair only. These advances are leading to an increase in the complexity of endovascular procedures which can cause long operation times and high levels of radiation exposure. This in turn places pressure on the vascular surgery community to display more superior interventional skills and radiological practices. Advanced imaging technology in this context represents a strong pillar in the treatment toolbox for delivering the best care at the lowest risk level. Delivering the best patient care while managing the radiation and iodine contrast media risks, especially in frail and renal impaired populations, is the challenge aortic surgeons are facing. Modern hybrid rooms are equipped with a wide range of new imaging applications such as fusion imaging and cone-beam computed tomography (CBCT). If these technologies contribute to reducing radiation, they can be complex and intimidating to master. The aim of this review is to discuss the fundamentals of good radiological practices and to describe the various imaging tools available to the aortic surgeon, both those available today and those we anticipate will be available in the near future, from equipment to software, to perform safe and efficient complex endovascular procedures.

Artificial vascular models for endovascular training (3D printing)

The endovascular technique has led to a revolution in the care of patients with vascular disease; however, acquiring and maintaining proficiency over a broad spectrum of procedures is challenging. Three-dimensional (3D) printing technology allows the production of models that can be used for endovascular training. This article aims to explain the process and technologies available to produce vascular models for endovascular training, using 3D printing technology. The data are based on the group experience and a review of the literature. Different 3D printing methods are compared, describing their advantages, disadvantages and potential roles in surgical training. The process of 3D printing a vascular model based on an imaging examination consists of the following steps: image acquisition, image post-processing, 3D printing and printed model post-processing. The entire process can take a week. Prospective studies have shown that 3D printing can improve surgical planning, especially in complex endovascular procedures, and allows the production of efficient simulators for endovascular training, improving residents’ surgical performance and self-confidence.

Image Fusion and 3-Dimensional Roadmapping in Endovascular Surgery

Practitioners of endovascular surgery have historically used 2-dimensional (2D) intraoperative fluoroscopic imaging, with intravascular contrast opacification, to treat complex 3-dimensional (3D) pathology. Recently, major technical developments in intraoperative imaging have made image fusion techniques possible, the creation of a 3D patient-specific vascular roadmap based on preoperative imaging which aligns with intraoperative fluoroscopy, with many potential benefits. First, a 3D model is segmented from preoperative imaging, typically a computed tomography scan. The model is then used to plan for the procedure, with placement of specific markers and storing of C-arm angles that will be used for intraoperative guidance. At the time of the procedure, an intraoperative cone beam computed tomography is performed, and the 3D model is registered to the patient's on-table anatomy. Finally, the system is used for live guidance in which the 3D model is codisplayed with overlying fluoroscopic images. There are many applications for image fusion in endovascular surgery. We have found it to be particularly useful for endovascular aneurysm repair (EVAR), complex EVAR, thoracic EVAR, carotid stenting, and for type 2 endoleaks. Image fusion has been shown in various settings to lead to decreased radiation dose, less iodinated contrast use, and shorter procedure times. In the future, fusion models may be able to account for vessel deformation caused by the introduction of stiff wires and devices, and the user-dependent steps may become more automated. In its current form, image fusion has already proven itself to be an essential component in the planning and success of complex endovascular procedures.

Pros and Cons of 3D Image Fusion in Endovascular Aortic Repair: A Systematic Review and Meta-analysis

Purpose: To systematically review and meta-analyze the added value of 3-dimensional (3D) image fusion technology in endovascular aortic repair for its potential to reduce contrast media volume, radiation dose, procedure time, and fluoroscopy time. Methods: Electronic databases were systematically searched for studies published between January 2010 and March 2016 that included a control group describing 3D fusion imaging in endovascular aortic procedures. Two independent reviewers assessed the methodological quality of the included studies and extracted data on iodinated contrast volume, radiation dose, procedure time, and fluoroscopy time. The contrast use for standard and complex endovascular aortic repairs (fenestrated, branched, and chimney) were pooled using a random-effects model; outcomes are reported as the mean difference with 95% confidence intervals (CIs). Results: Seven studies, 5 retrospective and 2 prospective, involving 921 patients were selected for analysis. The methodological quality of the studies was moderate (median 17, range 15–18). The use of fusion imaging led to an estimated mean reduction in iodinated contrast of 40.1 mL (95% CI 16.4 to 63.7, p=0.002) for standard procedures and a mean 70.7 mL (95% CI 44.8 to 96.6, p<0.001) for complex repairs. Secondary outcome measures were not pooled because of potential bias in nonrandomized data, but radiation doses, procedure times, and fluoroscopy times were lower, although not always significantly, in the fusion group in 6 of the 7 studies. Conclusion: Compared with the control group, 3D fusion imaging is associated with a significant reduction in the volume of contrast employed for standard and complex endovascular aortic procedures, which can be particularly important in patients with renal failure. Radiation doses, procedure times, and fluoroscopy times were reduced when 3D fusion was used.

Ascorbic acid ameliorates renal injury in a murine model of contrast-induced nephropathy

BackgroundContrast induced nephropathy (CIN) is the commonest cause of iatrogenic renal injury and its incidence has increased with the advent of complex endovascular procedures. Evidence suggests that ascorbic acid (AA) has a nephroprotective effect in percutaneous coronary interventions when contrast media are used. A variety of biomarkers (NGAL, NGAL:creatinine, mononuclear cell infiltration, apoptosis and RBP-4) in both the urine and kidney were assayed using a mouse model of CIN in order to determine whether AA can reduce the incidence and/or severity of renal injury.MethodsTwenty-four BALB/c mice were divided into 4 groups. Three groups were exposed to high doses of contrast media (omnipaque) in a well-established model of CIN, and then treated with low or high dose AA or placebo (saline). CIN severity was determined by measurement of urinary neutrophil gelatinase-associated lipocalin (NGAL):creatinine at specific time intervals. Histological analysis was performed to determine the level of mononuclear inflammatory infiltration as well as immunohistochemistry to determine apoptosis in the glomeruli by staining for activated caspase-3 and DNA nicking (TUNEL assays). Reverse transcriptase PCR (rtPCR) of mRNA transcripts prepared from mRNA extracted from mouse kidneys was also performed for both lipocalin-2 (Lcn2) encoding NGAL and retinol binding protein-6 (RBP4) genes. NGAL protein expression was also confirmed by ELISA analysis of kidney lysates.ResultsUrinary NGAL:creatinine ratio was significantly lower at 48 h with a 44% and 62% (204.3μg/mmol versus 533.6μg/mmol, p = 0.049) reduction in the low and high dose AA groups, respectively. The reduced urinary NGAL:creatinine ratio remained low throughout the time period assessed (up to 96 h) in the high dose AA group. In support of the urinary analysis ELISA analysis of NGAL in kidney lysates also showed a 57% reduction (12,576 ng/ml versus 29,393 ng/ml) reduction in the low dose AA group. Immunohistochemistry for apoptosis demonstrated decreased TUNEL and caspase-3 expression in both low and high dose AA groups.ConclusionsAscorbic acid reduced the frequency and severity of renal injury in this murine model of CIN. Further work is required to establish whether AA can reduce the incidence of CIN in humans undergoing endovascular procedures.

Feasibility of three-dimensional magnetic resonance angiography-fluoroscopy image fusion technique in guiding complex endovascular aortic procedures in patients with renal insufficiency

ObjectiveThree-dimensional image fusion of preoperative computed tomography (CT) angiography with fluoroscopy using intraoperative noncontrast cone-beam CT (CBCT) has been shown to improve endovascular procedures by reducing procedure length, radiation dose, and contrast media volume. However, patients with a contraindication to CT angiography (renal insufficiency, iodinated contrast allergy) may not benefit from this image fusion technique. The primary objective of this study was to evaluate the feasibility of magnetic resonance angiography (MRA) and fluoroscopy image fusion using noncontrast CBCT as a guidance tool during complex endovascular aortic procedures, especially in patients with renal insufficiency. MethodsAll endovascular aortic procedures done under MRA image fusion guidance at a single-center were retrospectively reviewed. The patients had moderate to severe renal insufficiency and underwent diagnostic contrast-enhanced magnetic resonance imaging after gadolinium or ferumoxytol injection. Relevant vascular landmarks electronically marked in MRA images were overlaid on real-time two-dimensional fluoroscopy for image guidance, after image fusion with noncontrast intraoperative CBCT. Technical success, time for image registration, procedure time, fluoroscopy time, number of digital subtraction angiography (DSA) acquisitions before stent deployment or vessel catheterization, and renal function before and after the procedure were recorded. The image fusion accuracy was qualitatively evaluated on a binary scale by three physicians after review of image data showing virtual landmarks from MRA on fluoroscopy. ResultsBetween November 2012 and March 2016, 10 patients underwent endovascular procedures for aortoiliac aneurysmal disease or aortic dissection using MRA image fusion guidance. All procedures were technically successful. A paired t-test analysis showed no difference between preimaging and postoperative renal function (P = .6). The mean time required for MRA-CBCT image fusion was 4:09 ± 01:31 min:sec. Total fluoroscopy time was 20.1 ± 6.9 minutes. Five of 10 patients (50%) underwent stent graft deployment without any predeployment DSA acquisition. Three of six vessels (50%) were cannulated under image fusion guidance without any precannulation DSA runs, and the remaining vessels were cannulated after one planning DSA acquisition. Qualitative evaluation showed 14 of 22 virtual landmarks (63.6%) from MRA overlaid on fluoroscopy were completely accurate, without the need for adjustment. Five of eight incorrect virtual landmarks (iliac and visceral arteries) resulted from vessel deformation caused by endovascular devices. ConclusionsFerumoxytol or gadolinium-enhanced MRA imaging and image fusion with fluoroscopy using noncontrast CBCT is feasible and allows patients with renal insufficiency to benefit from optimal guidance during complex endovascular aortic procedures, while preserving their residual renal function.

Evidence overview: anatomical criteria determining patients at high risk for carotid stenting.

Carotid artery stenting (CAS) is a complex endovascular procedure that may be an alternative for carotid endarterectomy in selected patients. This paper provides an overview of the anatomical and lesion characteristics that are related to an increase in complications with CAS procedures, in order to provide criteria to select patients that will benefit most from CAS.

Is volume important in aneurysm treatment outcome?

Several studies have suggested that surgical procedures performed at high-volume centers may result in superior outcome. Technically more demanding procedures such as aortic aneurysm repair appear to demonstrate a stronger relationship with volume. The present chapter reviewed the literature using the MEDLINE database to identify studies investigating the effect of volume in aortic aneurysm repair outcomes. The great majority of studies identified shows an advantage for high-volume hospitals with regard to perioperative mortality of abdominal (AAA), thoracic (TAA) and thoracoabdominal (TAAA) aortic aneurysm repair. A similar advantage is shown for high-volume surgeons. The volume advantage appears to be less evident for simple endovascular procedures (EVAR & TEVAR), compared to more complex endovascular (F/BEVAR) and open surgical procedures. Superior outcomes observed in high-volume hospitals are not only explained by increased surgeons' experience, but importantly also by a more effective management of intra- and postoperative complications. Confounding factors to be taken into account are the timing of the studies in relation to positive evolution of outcomes in several high-risk procedures, and patient cohorts selected in regions with very low- and very high-volume hospitals only.

New image-processing and noise-reduction software reduces radiation dose during complex endovascular procedures

A new proprietary image-processing system known as AlluraClarity, developed by Philips Healthcare (Best,The Netherlands) for radiation-based interventional procedures, claims to lower radiation dose while preserving image quality using noise-reduction algorithms. This study determined whether the surgeon and patient radiation dose during complex endovascular procedures (CEPs) is decreased after the implementation of this new operating system. Radiation dose to operators, procedure type, reference air kerma, kerma area product, and patient body mass index were recorded during CEPs on two Philips Allura FD 20 fluoroscopy systems with and without Clarity.Operator dose during CEPs was measured using optically stimulable, luminescent nanoDot (Landauer Inc, Glenwood, Ill) detectors placed outside the lead apron at the left upper chest position. nanoDots were read using a microStar ii (Landauer Inc) medical dosimetry system. For the CEPs in the Clarity group, the radiation dose to surgeons was also measured by the DoseAware (Philips Healthcare) personal dosimetry system. Side-by-side measurements of DoseAware and nanoDots allowed for cross-calibration between systems. Operator effective dose was determined using a modified Niklason algorithm. To control for patient size and case complexity, the average fluoroscopy dose rate and the dose per radiographic frame were adjusted for body mass index differences and then compared between the groups with and without Clarity by procedure. Additional factors, for example, physician practice patterns, that may have affected operator dose were inferred by comparing the ratio of the operator dose to procedural kerma area product with and without Clarity. Aone-sided Wilcoxon rank sum test was used to compare groups for radiation doses, reference air kermas, and operating practices for each procedure type. The analysis included 234 CEPs; 95 performed without Clarity and 139 with Clarity. Practice patterns of operators during procedures with and without Clarity were not significantly different. For all cases, procedure radiation dose to the patient and the primary and assistant operators were significantly decreased in the Clarity group by 60% compared with the non-Clarity group. By procedure type, fluorography dose rates decreased from 44% for fenestrated endovascular repair and up to 70% with lower extremity interventions. Fluoroscopy dose rates also significantly decreased, from about 37% to 47%, depending on procedure type. The AlluraClarity system reduces the patient and primary operator's radiation dose by more than half duringCEPs. This feature appears to be an effective tool in lowering the radiation dose while maintaining image quality.

IF13. Outcomes of the Candy-Plug Technique to Achieve Thrombosis of Thoracic False-Lumen Postdissection Aneurysms

False lumen (FL) perfusion and aneurysmal degeneration of the thoracic aorta limits the response to endovascular treatment in patients with chronic aortic dissection by retrograde flow arising from distal entry tears. Aim of the study is to evaluate the “candy-plug” FL embolization technique to prevent back-flow in chronic aortic dissection aneurysms. The “candy-plug” stent graft is a custom-made endograft at the shape of a candy with proximal and distal diameters of up to 50 mm that taper down at the middle of the graft to 16 mm (Fig 1). With the adjunct of a regular plug, complete FL occlusion can be achieved. Between 2013 and 2015, 12 patients (11 males; mean age, 65 ± 11years; American Society of Anesthesiologists 3/4) with chronic type B dissection (CTBD) received candy-plug endografts for residual type A aortic dissection (n = 6) or CTBD aneurysms (n = 6) in conjunction with extension of aortic stent grafting of the true lumen (TL) to the celiac trunk. Eleven procedures were elective and one acute. All procedures were technically successful in occluding FL perfusion, and only one patient required additional embolization techniques at the level of the candy-plug (Fig 2). There was no 30-day mortality, but one patient with transient spinal cord injury recovered. At a mean follow-up of 12 ± 6 months (range, 1-26), there were two reinterventions due to persisting retrograde FL perfusion. On later follow-up, one patient underwent visceral debranching and thoracoabdominal stenting. Two further patients required fenestrated endografts of the abdominal aorta for expansion of the abdominal chronic aortic dissection aneurysm. There was only one late death in the patient with conversion to hybrid procedure. FL embolization of chronic dissection aneurysms with a candy-plug endograft presents a useful tool that expands the material options for FL embolization. Application of this technique achieves complete FL thrombosis in most patients, who would otherwise require open surgery or complex endovascular procedures with fenestrated/branched abdominal endografts.Fig 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Radiation Dose During Complex Endovascular Procedures

Radiation Dose During Complex Endovascular Procedures

Axillary Artery Deployment of Endovascular Aortic Repair Iliac Limb for Preservation of Internal Iliac Artery Blood Flow

The axillary artery approach has been used for access for complex endovascular aortic procedures such as thoracic endovascular aortic repair with poor anatomy for traditional deployment as well as for fenestrated and branched abdominal aortic endografts. We report the first case of an iliac graft limb deployment through the axillary artery during an endovascular aortic repair for maintenance of anterograde internal iliac flow in a patient with a symptomatic abdominal aortic aneurysm and chronic occlusion of both the external iliac and common femoral arteries.

Radiation exposure to eye lens and operator hands during endovascular procedures in hybrid operating rooms

The purpose of this study was to evaluate the radiation exposure of vascular surgeons' eye lens and fingers during complex endovascular procedures in modern hybrid operating rooms. Prospective, nonrandomized multicenter study design. One hundred seventy-one consecutive patients (138 male; median age, 72.5 years [interquartile range, 65-77 years]) underwent an endovascular procedure in a hybrid operating room between March 2012 and July 2013 in two vascular centers. The dose-area product (DAP), fluoroscopy time, operating time, and amount of contrast dye were registered prospectively. For radiation dose recordings, single-use dosimeters were attached at eye level and to the ring finger of the hand next to the radiation field of the operator for each endovascular procedure. Dose recordings were evaluated by an independent institution. Before the study, precursory investigations were obtained to simulate the radiation dose to eye lens and fingers with an Alderson phantome (RSD, Long Beach, Calif). Interventions were classified into six treatment categories: endovascular repair of infrarenal abdominal aneurysm (n = 65), thoracic endovascular aortic repair (n = 32), branched endovascular aortic repair for thoracoabdominal aneurysms (n = 17), fenestrated endovascular aortic repair for complex abdominal aortic aneurysm, (n = 25), iliac branched device (n = 8), and peripheral interventions (n = 24). There was a significant correlation in DAP between both lens (P < .01; r = 0.55) and finger (P < .01; r = 0.56) doses. The estimated fluoroscopy time to reach a radiation threshold of 20 mSv/y was 1404.10 minutes (90% confidence limit, 1160, 1650 minutes). According to correlation of the lens dose with the DAP an estimated cumulative DAP of 932,000 mGy/m(2) (90% confidence limit, 822,000, 1,039,000) would be critical for a threshold of 20 mSv/y for the eyes. Radiation protection is a serious issue for vascular surgeons because most complex endovascular procedures are delivering measurable radiation to the eyes. With the correlation of the DAP obtained in standard endovascular procedures a critical threshold of 20 mSv/y to the eyes can be predicted and thus an estimate of a potential harmful exposure to the eyes can be obtained.

Carbon Dioxide Angiography: Scientific Principles and Practice.

Carbon dioxide (CO2) is a colorless, odorless gas which occurs naturally in the atmosphere and human body. With the advent of digital subtraction angiography, the gas has been used as a safe and useful alternative contrast agent in both arteriography and venography. Because of its lack of renal toxicity and allergic potential, CO2 is a preferred contrast agent in patients with renal failure or contrast allergy, and particularly in patients who require large volumes of contrast medium for complex endovascular procedures. Understanding of the unique physical properties of CO2 (high solubility, low viscosity, buoyancy, and compressibility) is essential in obtaining a successful CO2 angiogram and in guiding endovascular intervention. Unlike iodinated contrast material, CO2 displaces the blood and produces a negative contrast for digital subtraction imaging. Indications for use of CO2 as a contrast agent include: aortography and runoff, detection of bleeding, renal transplant arteriography, portal vein visualization with wedged hepatic venous injection, venography, arterial and venous interventions, and endovascular aneurysm repair. CO2 should not be used in the thoracic aorta, the coronary artery, and cerebral circulation. Exploitation of CO2 properties, avoidance of air contamination and facile catheterization technique are important to the safe and effective performance of CO2 angiography and CO2-guided endovascular intervention.

Surgeon radiation dose during complex endovascular procedures

Surgeon radiation dose during complex fluoroscopically guided interventions (FGIs) has not been well studied. We sought to characterize radiation exposure to surgeons during FGIs based on procedure type, operator position, level of operator training, upper vs lower body exposure, and addition of protective shielding. Optically stimulable, luminescent nanoDot (Landauer, Inc, Glenwood, Ill) detectors were used to measure radiation dose prospectively to surgeons during FGIs. The nanoDot dosimeters were placed outside the lead apron of the primary and assistant operators at the left upper chest and left lower pelvis positions. For each case, the procedure type, the reference air kerma, the kerma-area product, the relative position of the operator, the level of training of the fellow, and the presence or absence of external additional shielding devices were recorded. Three positions were assigned on the right-hand side of the patient in decreasing relative proximity to the flat panel detector (A, B, and C, respectively). Position A (main operator) was closest to the flat panel detector. Position D was on the left side of the patient at the brachial access site. The nanoDots were read using a microSTARii medical dosimetry system (Landauer, Inc) after every procedure. The nanoDot dosimetry system was calibrated for scattered radiation in an endovascular suite with a National Institute of Standards and Technology traceable solid-state radiation detector (Piranha T20; RTI Electronics, Fairfield, NJ). Comparative statistical analysis of nanoDot dose levels between categories was performed by analysis of variance with Tukey pairwise comparisons. Bonferroni correction was used for multiple comparisons. There were 415 nanoDot measurements with the following case distribution: 16 thoracic endovascular aortic repairs/endovascular aneurysm repairs, 18 fenestrated endovascular aneurysm repairs (FEVARs), 13 embolizations, 41 lower extremity interventions, 10 fistulograms, 13 visceral interventions, and 3 cerebrovascular procedures. The mean operator effective dose for FEVARs was higher than for other case types (P < .03), 20 μSv at position A and 9 μSv at position B. For all case types, position A (9.0 μSv) and position D (20 μSv) received statistically higher effective doses than position B (4 μSv) or position C (0.4 μSv) (P < .001). However, the mean operator effective dose for position D was not statistically different from that for position A. The addition of the lead skirt significantly decreased the lower body dose (33 ± 3.4 μSv to 6.3 ± 3.3 μSv) but not the upper body dose (6.5 ± 3.3 μSv to 5.7 ± 2.2 μSv). Neither ceiling-mounted shielding nor level of fellow training affected operator dose. Surgeon radiation dose during FGIs depends on case type, operator position, and table skirt use but not on the level of fellow training. On the basis of these data, the primary operator could perform approximately 12 FEVARs/wk and have an annual dose <10 mSv, which would not exceed lifetime occupational dose limits during a 35-year career. With practical case loads, operator doses are relatively low and unlikely to exceed occupational limits.

Feasibility and Safety of Renal and Visceral Target Vessel Cannulation Using Robotically Steerable Catheters During Complex Endovascular Aortic Procedures

Purpose: To evaluate the safety and success of target vessel cannulation in the visceral aortic segment using the Magellan robotic catheter system (RCS) during complex endovascular aortic procedures. Methods: Robotic navigation was attempted for access to 37 target vessels in 15 patients (14 men; mean age 75±10 years) during 16 fenestrated and/or branched stent-grafting procedures and 1 endovascular repair requiring the chimney technique. For each target vessel, robotic navigation was attempted for a maximum of 15 minutes; if cannulation was unsuccessful in that time, manual catheters were employed. Safety was evaluated by recording intraoperative adverse events, intraoperative complications related to robotic navigation, and postoperative complications. Technical success of robotic cannulation, wire cannulation times, and times for inserting the leader over the wire in the target vessels were recorded to assess RCS performance. Results: Successful robotic cannulation was achieved for 30 (81%) of the 37 target vessels, with a median wire cannulation time of 263 seconds (range 40–780) and a median 15 seconds (range 5–450) for inserting the leader over the wire. No intraoperative complications related to robotic navigation were observed. Seven of 27 arteries accessed via 7 fenestrations could not be cannulated within 15 minutes; all were cannulated successfully using conventional catheters (mean cannulation time 31±7 minutes). All 10 target vessels accessed via branches and chimney stents were successfully cannulated with the RCS. Conclusion: Cannulation of target vessels with the RCS during complex endovascular aortic procedures is feasible and safe. The robotic system was particularly effective for branched and chimney stents.

Angulation of the C-Arm During Complex Endovascular Aortic Procedures Increases Radiation Exposure to the Head

Angulation of the C-Arm During Complex Endovascular Aortic Procedures Increases Radiation Exposure to the Head

Covered stents for endovascular repair of iatrogenic injuries of iliac and femoral arteries.

The growing number of complex endovascular procedures is expected to increase the risk of iatrogenic injuries of peripheral arteries. A strategy of percutaneous transluminal angioplasty (PTA) with covered stent (CS) may represent a valuable alternative to open surgery. However, systematic evaluations of CS in this setting represent a scientific gap. In the present study, we investigate the procedural and clinical outcomes associated with PTA and CS implantation to repair iatrogenic injuries of peripheral arteries. All patients undergoing PTA with CS for endovascular repair of iatrogenic injuries of peripheral arteries between August 2010 and July 2013 at our Institution were retrospectively analyzed. The primary endpoint was the technical success. Secondary endpoints were in-hospital mortality and cumulative death, target lesion revascularization (TLR), amputation and major stroke at 12-month follow-up. During the period of observation, a total of 30 patients underwent PTA with either self-expandable (43.3%) or balloon-expandable CS (56.7%) for iatrogenic injuries of peripheral arteries. Injuries consisted of perforation/rupture (76.7%), arteriovenous fistula (16.7%) and pseudoaneurysm (6.7%) of iliac-femoral arteries. Technical success was achieved in all cases. Median follow-up was 409days [210-907]. The incidence of in-hospital mortality was 10.0%. At 12-month follow-up, the incidence of death, TLR, amputation and major stroke was 20.0%, 17.0%, 3.3% and 6.7%, respectively. The use of covered stents for endovascular repair of iatrogenic injuries of peripheral arteries shows a high technical success and may be alternative to surgery. Further studies with larger populations are needed to confirm these preliminary findings.

Radiation Safety in Vascular Surgery

Modern vascular surgeons perform an ever-increasing number of complex endovascular procedures, largely based on patient preference, decreased length of stay, and improved outcome. With the upsurge of endovascular cases, concern has grown regarding the harmful effects of radiation exposure delivered to the patient and the operator. Surgeon education on the appropriate use of fluoroscopic operating factors coupled with appropriate training in radiation safety has been shown to decrease radiation dose. This review elucidates dose terminology and metrics, possible radiation-induced injuries, risk factors for deterministic injury, and radiation safety principles and techniques. Tables provide practical tips to lower patient and operator radiation dose during fluoroscopically guided intervention, and National Council on Radiation Protection &amp; Measurements recommended dose limits for occupational exposure. Figures illustrate reference air kerma, radiation-induced skin injury, effects of image receptor and table position, and operator exposure. This review contains 4 figures, 3 tables, and 53 references.