Smaller Sheath Research Articles

Four French sheath-based transradial cerebral angiographies in the elderly: A single neurointerventionalist's experience.

Catheter angiography via transradial access (TRA) is better at reducing access site complications and morbidity than via transfemoral access (TFA). The rate of periprocedural complications increases in elderly populations and using a smaller sheath can help reduce access site complications. The aim of this study was to assess the feasibility and safety of 4 F sheath-based TRA cerebral angiography in elderly patients (≥65 years) and compare it to TFA cerebral angiography. The medical records of elderly patients undergoing diagnostic cerebral angiography with a single neurointerventionalist via TRA (57 cases, from July 2019 to December 2020) versus TFA (69 cases, from January 2018 to June 2019) were retrospectively reviewed. All TRA angiographies were performed via right radial artery access with a 4 F sheath and a 4 F Simmons 2 catheter. There were no significant differences (TRA vs. TFA) in age (71.1 ± 4.0 vs. 72.1 ± 4.6 years, p = 0.189), accessed vessels (3.9 ± 0.5 vs. 3.9 ± 0.6, p = 0.852), fluoroscopy time (7.1 ± 3.3 vs. 7.6 ± 3.5 min, p = 0.068), and radiation exposure (42.1 ± 15.8 vs. 47.0 ± 13.7 Gy-cm2, p = 0.067). However, the procedure duration was significantly shorter in the TRA group (17.2 ± 3.9 vs. 19.0 ± 6.0 min, p = 0.003). Painful groin hematoma occurred in 2 of the 69 cases (2.9%) in the TFA group. In the TRA group, access site complications were not occurred; however, catheter kinks occurred in 2 of 57 cases (3.5%). The 4 F sheath-based TRA is a feasible option for diagnostic cerebral angiography in elderly patients. However, care should be taken during catheter manipulation.

Vascular Access Site Complications Do Not Correlate With Large Sheath Diameter in TAVI Procedures With New Generation Devices.

Background: Vascular complications after transfemoral transcatheter aortic valve implantation (TAVI) are associated with morbidity and mortality. However, consistent predictors have not been identified yet. The size of the implantation sheath seems to play a role, though especially with new generation TAVI devices and their improved sheaths and delivery systems this remains uncertain.Objectives: This study aimed to determine the incidence and predictors of access site-related vascular complications (VC) in the era of new generation TAVI devices.Methods and Results: Four hundred consecutive patients receiving TAVI in an experienced tertiary care center were analyzed. VC occurred in 89 patients (22.25%) with the majority being minor VC (21%) and only 1.25% major VC. Possible predictors for VC were tested, and only peri-interventional dual antiplatelet therapy (DAPT) showed to be predictive for VC [OR 2.11 (95% CI 1.10–4.06, p = 0.025)]. The female gender [OR 0.75 (95% CI 0.44–1.3), p = 0.31], sheath to femoral artery ratio >1.05 [OR 1.18 (95% CI 0.66–2.08, p = 0.58)], calcification of the access site vessel [OR 0.83 (95% CI 0.48–1.42, p = 0.48)], known peripheral artery disease [OR 0.95 (95% CI 0.4–2.25, p = 0.9)], and BMI ≥ 25 kg/m2 [OR 0.69 (95% CI 0.41–1.19, p = 0–19)] were not predictive of VC. The larger sheath with 20 French even showed less VC than the smaller sheath with 16 French [OR 0.43 (95% CI 0.25–0.74, p = 0.002)].Conclusions: Overall, the rate of major and minor VC was low in this study population (for major VC: rate of 1.25%). Predefined risk factors were not associated with the occurrence of VC, except for peri-interventional treatment with DAPT. Especially, larger sheath size could not be identified as a predictor for VC in the setting of TAVI procedures performed with contemporary devices.

Percutaneous Transhepatic Treatment for Obstructing Retained Surgical Biliary Stents After Pediatric Liver Transplantation Without Placement of Biliary Drain

Percutaneous Transhepatic Treatment for Obstructing Retained Surgical Biliary Stents After Pediatric Liver Transplantation Without Placement of Biliary Drain

Abstract No. 215 Percutaneous cholecystolithotomy: a single-institution experience with SpyGlass DS cholangioscopy

Percutaneous cholecystolithotomy using cholecystoscopy can be an alternative to cholecystectomy in high surgical risk patients with calculous cholecystitis. The purpose of this study is to describe our experience of percutaneous cholecystolithotomy using Spyglass direct visualization cholangioscopy (SpyGlass DS, 10F, Boston Scientific). The Institutional Review Board approved this retrospective study with a waiver of informed consent. Between January 1, 2018, and September 9, 2020, 18 patients (M:F = 13:5, mean 73 years) underwent percutaneous cholecystolithotomy using SpyGlass DS cholangioscopy for calculous cholecystitis. Percutaneous cholecystolithotomy was performed with SpyGlass DS cholangioscopy after placement of 16F sheath. Stone fragmentation was performed with EHL probe and stones were removed using baskets or saline flushing technique. Procedure details, technical success, complications, and clinical follow up were retrospectively analyzed. Eighteen patients underwent 28 percutaneous cholecystolithotomy procedures using SpyGlass DS cholangioscopy including seven patients for a second and three patients for a third cholecystolithotomy session. Conscious sedation was used in the majority of cases 86% (n = 24) versus general anesthesia 14% (n = 4) for the procedure. The median time interval between cholecystostomy tube placement and 1st cholecystolithotomy was 78 days. Overall technical success rate (removal of all stones) was 78% (14/18 patients) after repeat cholecystolithotomy. The median time from cholecystostomy tube placement to final tube removal was 111 days. Cause of technical failure were large, impacted stones (n = 3) and cystic duct occlusion (n = 1). There were three procedure related complications (acute pancreatitis causing mortality (n = 1), fistula to the skin requiring surgical excision (n = 1), bile leak requiring replacement of cholecystostomy tube due to gallbladder dyskinesia (n = 1)). There is no recurrence of symptomatic cholecystitis in patients with technical success. Three patients died because of reasons unassociated with the procedure during follow up. Percutaneous cholecystolithotomy using SpyGlass DS cholangioscopy can be performed with smaller sheath (16F) than conventional cholangioscopy (24F sheath) and can be a very useful alternate minimally invasive technique for gallstone management with high technical success rates.

Mini percutaneous nephrolithotomy. How good it is - a single centre experience

Background: Percutaneous nephrolithotomy (PCNL) is one of the 1st line treatment options for managing renal stones. Miniaturization of this technique has been developed to decrease the morbidity of this technique without compromising the results. Mini PCNL (mPCNL) involves the use of small calibre sheath and nephroscope to tackle renal stones of small to moderate size. The aim of this study is to present the efficacy and technical advantages of mPCNL in managing renal stones.Methods: This was a retrospective single centre study of mPCNL in managing renal stones. Results: From July 2015 to July 2020 192 mPCNL procedures were done at our centre in 175 patients. The median number of stones was 1(1-3) and the average size of calculus was 18.5 mm (6-35) mm. Mean operative time in our study was 46 (35-92) minutes. Fever developed in 15 (7.8%) patients which was managed by parenteral antibiotics, none of our patients required ICU admission. Haemothorax developed in 2 (1%) patients and both of them were managed by tube thoracostomy. We achieved complete clearance in 183 (95.3%) cases. In 9 (4.7%) patients residual calculi were manged by flexible ureteroscopy at 1 month. Conclusions: mPCNL is an effective procedure for management of patients with renal stones with the advantages of less blood loss, short hospital stay and excellent stone clearance rate.

Small Ureteral Access Sheath in Treating Paediatric Urolithiasis: A Single Centre Experience.

IntroductionUrolithiasis is not commonly encountered in the pediatric population. The adoption of ureteral access sheaths (UAS) facilitates the passage to the pediatric ureter and limits the harm and ureteral injury. However, the debate continues regarding whether or not to use UAS in children.ObjectiveTo assess the safety and outcomes of using UAS in the treatment of pediatric renal and ureteral stones.Study DesignThis was a prospective cohort study of 14 pediatric patients who underwent flexible ureteroscopy (fURS) with the use of UAS for symptomatic renal and ureteric stones.ResultsOf the fourteen enrolled patients, nine (64.3%) were males, and five (35.7%) were females with an average age of 9.5 years. Eleven (78.6%) of the patients were rendered stone-free. The average operative time was 55.7 min. None of the patients developed any complications. The stone-free rate was significantly higher with stone burdens of ≤10 mm (p ≤ 0.05).ConclusionThe use of UAS in children facilitates the passage of a flexible ureteroscope without complications. The procedure is considered to be efficient and safe with minimal morbidity.

Use of Amplatz Sheath in Percutaneous Nephrolithotomy and effect of its various sizes: Randomized Controlled Trial

Background: Nephrostomy tract itself is the most common source of hemorrhage during percutaneous nephrolithotomy, which can be avoided by puncturing through the calyx with minimal angulation between calyceal system and the nephroscope shaft. Smaller the sheath diameter, lesser would be the bleeding. Our objective was to compare mean change in hemoglobin (HB) level in patients undergoing percutaneous nephrolithotomy (PCNL) with 24 versus 30 French Amplatz sheath. Methods: In this study, 142 patients were randomly divided into Group A undergoing procedure with 24 French Amplatz sheath; and Group B with 30 French sheath. At the end of procedure in both groups, nephrostomy tube was kept for 24 hours. On first post-operative day, patients’ HB was checked and compared with pre-operative data, along with blood transfusion rates. SPSS 20 was used for data analysis and p-value < 0.05 was considered significant. Results: Median age and interquartile range of Group-A and Group-B patients was (40; 18) and (41; 21) years respectively. While stone size of Group-A and Group-B patients reported as (2.0; 0.60) and (2.1; 0.70) cm. The operative time and interquartile ratio of Group-A and Group-B patients was (75; 45) and (85; 45) minutes and we found significant change in HB of Group-A (0.90; 0.80) with Group-B patients (1.90; 0.70) gm/dl respectively [p = 0.000]. Conclusion: It was observed that use of 24 French Amplatz sheath lead to less renal hemorrhage and less hemoglobin drop compared to standard 30 French Amplatz sheath. Thus, small size Amplatz sheath in percutaneous nephrolithotomy may be considered effective and safe option for treatment of renal stones.

Outcomes of routine use of percutaneous access with large-bore introducer sheaths (>21F outer diameter) during endovascular aneurysm repair

ObjectiveThe objective of this study was to evaluate the performance of percutaneous femoral access with large-bore sheaths (>21F outer diameter) mainly employed for thoracic and thoracoabdominal aortic endovascular treatment and to stratify the outcomes on the basis of the introducer size. MethodsBetween December 2015 and December 2018, all consecutive patients who received endovascular repair through a percutaneous approach with a suture-mediated vascular closure device (VCD) and the preclose technique were included in a retrospective single-center study called Totally Percutaneous Approach to Endovascular Treatment of Aortic Aneurysms (PEVAR-PRO). The morphologic characteristics of the access vessels and patients' demographics were recorded, and 30-day closure success was defined as the primary end point. Analysis of the closure success comparing large-bore sheaths vs small-bore sheaths (≤21F outer diameter) was performed after 1:1 propensity score matching of preoperative confounding variables. ResultsThe closure success rate of the entire study cohort was 94% (622 femoral accesses in 360 patients; median age, 74 years; 84% male). Univariate analysis identified eight different factors associated with failure, but only two remained significant on multivariate analysis: diabetes (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.3-6.2; P = .011) and common femoral artery stenosis >50% (OR, 4.5; 95% CI, 1.3-13.7; P = .019). After propensity score matching (1:1, 172 femoral accesses per group), closure success rate was not significantly different between large-bore and small-bore sheaths (90.7% vs 93.0%; P = .43). Multivariate analysis of the large-sheath group identified two factors associated with failure: small (<9 mm) femoral arteries (OR, 6.9; 95% CI, 1.5-31.6; P = .13) and access vessel calcifications involving more than one-third of the circumference (OR, 7.9; 95% CI, 2.1-29.4; P = .002). Neither previous femoral cutdown (44 accesses [23%]) nor percutaneous closure with VCDs (38 accesses [20%]) affected the closure success rate in the large-sheath group. Closure failure did not significantly increase the need for postoperative blood transfusions or hospital length of stay. ConclusionsOff-label use of VCDs and the preclose technique for percutaneous approach with large-bore sheaths needed for complex aortic endovascular procedures is safe and feasible. Closure success rate is not significantly different from that obtained with on-label application of VCDs with smaller sheaths.

Short Durations of Radial Hemostatic Device After Diagnostic Transradial Cardiac Catheterization: The PRACTICAL-2 Randomized Trial

BackgroundRadial artery occlusion (RAO) is the most common complication following transradial approach (TRA) for cardiac catheterisation. Our aim was to assess if decreasing radial hemostatic device (RHD) time reduces the risk of RAO among individuals receiving small sheath sizes with no adjunctive heparin. MethodsWe randomised 450 individuals undergoing diagnostic cardiac catheterization via TRA to 3 durations of RHD time: 10, 20, or 30 minutes. After these time periods, the RHD was gradually released over 20 minutes. The primary efficacy end point was forearm hematoma grade ≥ 2 (5-10 cm) and the primary safety end point was RAO (as determined by Doppler ultrasound) 1 hour after RHD removal (before discharge). ResultsThe mean age was 66 years and 64% were male. Five-French sheaths were used in all patients. Hematoma grade ≥ 2 occurred in only 1 patient, who was in the 20-minute group (P = 0.39). RAO occurred in 6.7% of patients in the 10-minute group, 10.7% in the 20-minute group and 6% in the 30-minute group (P = 0.26). ConclusionsAmong patients receiving small-caliber sheaths without adjunctive heparin, the incidence of forearm hematoma and RAO are low. Shorter durations of RHD time did not further reduce the risk of these complications.

MP46-13 RISK FACTORS OF SYSTEMIC INFLAMMATORY RESPONSE SYNDROME FOLLOWING RETROGRADE INTRARENAL SURGERY IN PATIENTS WITH UROLITHIASIS

You have accessJournal of UrologyInfections/Inflammation/Cystic Disease of the Genitourinary Tract: Kidney & Bladder I (MP46)1 Apr 2020MP46-13 RISK FACTORS OF SYSTEMIC INFLAMMATORY RESPONSE SYNDROME FOLLOWING RETROGRADE INTRARENAL SURGERY IN PATIENTS WITH UROLITHIASIS Wen Zhong* and Guohua Zeng Wen Zhong*Wen Zhong* More articles by this author and Guohua ZengGuohua Zeng More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000901.013AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: To evaluate the risk factors of systemic inflammatory response syndrome (SIRS) following retrograde intrarenal surgery (RIRS). METHODS: A total of 260 patients who underwent RIRS were included in this retrospective study. 21 out of 260 patients who developed postoperative SIRS were categorized as SIRS group and the rest 239 patients were categorized as non-SIRS group. Two-tailed t-test was used to determine significance of change in continuous variables whereas categorical data were compared with the Chi-squared test or Fisher’s exact test for proportions. Multivariable logistic regression analysis was performed to identify the potential risk factors of SIRS as after adjusting for covariates that were statistically significant in the univariate analysis. RESULTS: 157 (60.4%) patients were males, and 103(39.6%) patients were females. The mean age was 48.4±12.2 years and the mean stone burden was 1.7±0.7 cm. Preoperative positive midstream urine culture was noted in 47(18.1%) patients and solitary kidney was found in 31(11.9%) patients. The mean lithotripsy time was 34.3±13.0 minutes and the mean operation time was 45.4±12.9 minutes. Twenty one (8.1%) patients developed postoperative SIRS. Two patients developed clinical septic shock and recovered after treatment in intensive care unit (ICU). Multivariable logistic regression analysis showed that sex (OR=0.047, 95%CI=0.009-0.238, p < 0.001), irrigation method (OR=0.059, 95%CI=0.008-0.446, p=0.006), access sheath (OR=0.200, 95%CI=0.045-0.878,p=0.033), infection stone (OR=3.769, 95%CI=0.829-17.134, p=0.086), stone burden (OR=2.789, 95%CI=0.761-10.225, p=0.122), irrigation flow rate (OR=1.240, 95%CI=1.137-1.352, p < 0.001), and lithotripsy time (OR=0.935, 95%CI=0.856-1.021, p=0.133) were identified as independent risk factors of SIRS after RIRS. The equation was: Logit P=-9.404-3.050*Sex-2.826* (Irrigation method)-1.611* (Access sheath)+1.327* (Infection stone) +1.026* (Stone burden)+0.215* (Irrigation flow rate)-0.068* (Lithotripsy time). CONCLUSIONS: Females, infection stone, large stone burden, irrigation with high flow rate, small size access sheath and prolonged operation time were important risk factors of SIRS after RIRS. Syringe injection was regarded as a good method to provide irrigation with low flow rate and low pressure, and larger size access sheath can provide better drainage during RIRS, therefore to be preferred for RIRS procedures. The operation time should be seriously controlled in patients with high risk factors for SIRS, and staged procedures strategy should be preferred. Source of Funding: None © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e678-e678 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Wen Zhong* More articles by this author Guohua Zeng More articles by this author Expand All Advertisement PDF downloadLoading ...

Increased ischemic complications in fenestrated and branched endovascular abdominal aortic repair compared with standard endovascular aortic repair

ObjectiveIschemic complications (including in the lower extremity, visceral, spinal, and pelvic territories) following standard endovascular aortic repair (EVAR) are well recognized but fortunately uncommon. The incidence of such complications following fenestrated and branched aortic repair (F/BEVAR) has not been well defined in the literature. The objective of this study was to compare the incidence of ischemic complications between EVAR and F/BEVAR and to elucidate potential risk factors for these complications. MethodsWe identified all patients who underwent EVAR from 2003 to 2017 or F/BEVAR from 2012 to 2017 in the national Vascular Quality Initiative database. We assessed differences in perioperative ischemic outcomes with methods including logistic regression and inverse probability of treatment propensity score weighting, using a composite end point of lower extremity ischemia, intestinal ischemia, stroke, or new dialysis as the primary end point. ResultsThe data comprised 35,379 EVAR patients and 3374 F/BEVAR patients. F/BEVAR patients were more likely to be female, have had previous aneurysm repairs, and be deemed unfit for open aneurysm repair; they were less likely to have ruptured aneurysms; and they had higher estimated blood losses, contrast volumes, and fluoroscopy and procedure times. The incidence of any ischemic event (7.7% vs 2.2%) as well as the incidences of the component end points of lower extremity ischemia (2.3% vs 1.0%), intestinal ischemia (2.7% vs 0.7%), stroke (1.5% vs 0.3%), and new hemodialysis (3.1% vs 0.4%) were all significantly increased (all P < .001) in F/BEVAR compared with standard EVAR. After propensity adjustment, F/BEVAR conferred increased odds of any ischemic complication (1.8), intestinal ischemia (2.0), lower extremity ischemia (1.3), new hemodialysis (10.2), and stroke (2.3). ConclusionsRates of lower extremity ischemia, intestinal ischemia, new dialysis, and stroke each range from 0% to 1% for standard EVAR and 1% to 3% for F/BEVAR. The incidence of perioperative ischemic complications following F/BEVAR is significantly increased compared to EVAR. The real-world data in this study should help guide decision-making for surgeons and patients as well as serve as one metric for progress in device and technique development. Improvements in ischemic complications may come from continued technology development such as smaller sheaths, improved imaging to decrease procedure time and contrast volume, embolic protection, and increased operator skill with wire and catheter manipulation

A Technique to Flush Out Stone Fragments Through a Ureteral Access Sheath During Retrograde Intrarenal Surgery

Background: Retrograde intrarenal surgery (RIRS) has become the preferred treatment option for selected renal stones <20 mm. However, laser fragmentation of stones often results in residual small fragments that may prompt subsequent stone events. We describe a simple technique to facilitate removal of these fragments. Case Presentation: A 68-year-old woman underwent elective RIRS for a 13 mm right renal pelvic stone. After laser fragmentation of the stone there were numerous <2 mm fragments too small to allow removal by a standard retrieval basket (i.e., NCircle® and NCompass® Nitinol Stone Extractors, Cook Medical, Bloomington, IN). A smaller ureteral access sheath (UAS) was advanced into the kidney within the preexisting larger UAS and, using a connecting piece from a Foley catheter, stone fragments were suctioned out through the smaller sheath. Stone-free status was corroborated endoscopically and with postoperative CT. Conclusion: Stone fragments were flushed from the kidney using a simple irrigation technique through a coaxial UAS.

Percutaneous Access with Larger Introducers Sheaths (&gt;21f) During Endovascular Repair of Thoracic and Thoraco-Abdominal Pathology: A Propensity Matched Analysis

Introduction: To evaluate the feasibility and safety of an off-label percutaneous approach during the endovascular treatment of thoracic and thoracoabdominal pathology with large sheaths (>21F), even in the presence of predictors of technical failure. Methods: From December 2015 to December 2018, all patients receiving a percutaneous approach for endovascular treatment of aortic pathology (EVAR: 389 cases - 60.9%; TEVAR: 163 cases - 25.5 %, FEVAR= 87 cases - 13.6%) were enrolled in an ambispective study called PEVAR-PRO (clinicaltrials.gov: NCT03484013). The entire retrospective arm of the study was analyzed to identify the predictors of technical failure at univariate analysis. The identified predictors were used to create a 1:2 propensity matched cohort to compare the technical success rate of cases receiving a large sheath (LS) to small sheath (SS) percutaneous closure. All the enrolled PEVAR-PRO patients received two suture-mediated vascular closure devices, employing the “pre-close technique” with ProGlide (Abbott Vascular, Santa Clara, Calif) and the 30-day technical success was defined as a successful hemostasis without evidence of bleeding, pseudoaneurysm formation, arterial occlusion or dissection requiring secondary intervention. Results: The univariate analysis of the 639 femoral arteries in 363 patients (Male 84%, median age: 72 years IQR: 68-78) enrolled in the study observed that the failure predictors were: Diabetes (RR: 3.4, p< .001), SVS score >12 (RR: 2.3; p=.017), common femoral artery stenosis ≥5 0% (RR: 6.0, p< .001), femoral calcifications involving more than 33% of the vessel circumference (RR: 2.6, p=.002) and femoral anterior calcifications (RR: 2.3, p=.031). At univariate analysis a borderline lower technical success (90.8% vs 95.0%, p=.057) was observed comparing LS group (191 cases) to SS group (448 cases). After 1: 2 propensity score matching we obtained a SS group (n=346 patients: male 85%, median age: 75 years IQR: 70-79) and LS group (n=173 male: 80%, median age: 71 years IQR: 65-77) with no significative differences regarding other preoperative risk factors. The technical success rate did not differ between the two groups (LS group 90.8% vs SS Group 94.2%, RR: 1.6, IC95%: 0.85-3.01, p=.143). Interestingly, in LS group a technical failure for bleeding (6 cases - 38%) or vessel occlusion (11 cases - 62%) did not show an increased need for postoperative blood transfusions (11.4% vs 7.8%). Moreover, a previous open (42 cases - 24.3%) femoral or percutaneous (35 cases - 20.2%) access did not affect the technical success rate (open: 90.5% vs 90.8% and percutaneous: 88.6% vs 91.3%). Conclusion: An off-label percutaneous approach with pre-close technique to thoracic and thoraco-abdominal aortic pathology employing large sheath (> 21F) is feasible and safe even in presence of redo accesses. Technical success rate is not different when compared to an in-label use of the closure devices even after propensity matching toward failure predictors. Prospective controlled studies are needed to include large sheath access into the instructions for use of the device. Disclosure: Nothing to disclose

A Novel Internal and External Bypass Method to Safeguard Cerebral Blood Flow During Aortic Arch Endovascular Repair Requiring Triple In Situ Fenestrations

Purpose: To report a novel internal and external blood bypass method for cerebral protection during in situ triple-fenestrated stent-graft repair in the aortic arch. Technique: A method was devised to combine internal and external blood bypass circuits to preserve cerebral blood flow when all 3 supra-aortic branches are covered by the stent-graft. Long 14-F to 18-F introducers are placed retrogradely into the right and left common carotid arteries (CCAs). Smaller sheaths are placed antegradely into the internal carotid arteries (ICAs) bilaterally and into the right CCA introducer, which has had an aperture cut into it for flow to pass into the smaller sheath. The right CCA introducer is positioned in the ascending aorta to supply the innominate artery; the smaller sheath in the right CCA introducer is positioned at the aperture. The small sheath in the right CCA is connected to the left ICA sheath, and the left CCA fenestration is made and stented. The left ICA sheath is connected to the right ICA sheath, and the right CCA introducer is pulled back to the origin of the innominate artery and the smaller sheath removed. The fenestrations for the innominate and left subclavian arteries are opened sequentially. In 8 patients, complete bypass to maintain brain perfusion was performed for an average 17.6±6.9 minutes; intraoperative transcranial Doppler monitoring during flow bypass showed no notable decline in intracranial blood flow velocity. Two patients suffered stroke; one recovered completely. Conclusion: A cerebral protection strategy that integrates internal and external blood flow bypass techniques to maintain adequate brain blood flow is simple and feasible for in situ triple-fenestration aortic arch stent-graft repairs. However, neurological complications were not avoided with this method; thus, further research and development are required.

Is mini-percutaneous nephrolithotomy the way to go for renal stones? Yes!

Is mini-percutaneous nephrolithotomy the way to go for renal stones? Yes!

Thromboembolic and Bleeding Complications in Transcatheter Aortic Valve Implantation: Insights on Mechanisms, Prophylaxis and Therapy

Transcatheter aortic valve implantation (TAVI) has emerged as an important alternative to surgical aortic valve repair (SAVR) for patients with severe aortic stenosis. This rapidly advancing field has produced new-generation devices being delivered with small delivery sheaths, embolic protection devices and improved retrieval features. Despite efforts to reduce the rate of thrombotic complications associated with TAVI, valve thrombosis and cerebral ischaemic events post-TAVI continue to be a significant issue. However, the antithrombotic treatments utilised to prevent these dreaded complications are based on weak evidence and are associated with high rates of bleeding, which in itself is associated with adverse clinical outcomes. Recently, experimental data has shed light on the unique mechanisms, particularly the complex haemodynamic changes at sites of TAVI, that underpin the development of post-TAVI thrombosis. These new insights regarding the drivers of TAVI-associated thrombosis, coupled with the ongoing development of novel antithrombotics which do not cause bleeding, hold the potential to deliver newer, safer therapeutic paradigms to prevent post-TAVI thrombotic and bleeding complications. This review highlights the major challenge of post-TAVI thrombosis and bleeding, and the significant issues surrounding current antithrombotic approaches. Moreover, a detailed discussion regarding the mechanisms of post-TAVI thrombosis is provided, in addition to an appraisal of current antithrombotic guidelines, past and ongoing clinical trials, and how novel therapeutics offer the hope of optimizing antithrombotic strategies and ultimately improving patient outcomes.

Evolution of transcatheter aortic valve implantation: from planning to robotic systems

Since its introduction in 2002, transcatheter aortic valve implantation (TAVI) has evolved dramatically and is now standard of care for intermediate risk patients with aortic stenosis. The development of innovative transcatheter heart valves and refinement of technical skills have contributed to the decrease in complication rates associated with TAVI. Increased experience, smaller sheaths, rigorous pre-procedural planning and improved vascular closing techniques have resulted in markedly lower rates of vascular complications. The next step was the simplification of the procedure, which contributed to a further decrease in complications, reduced procedural time, and shorter hospital stay. Change-over from general anaesthesia to conscious sedation, refusal from predilatation, and use of the radial approach instead of the contralateral femoral approach are all instrumental in achieving optimal results. Prospects for development include visual assist systems and robotic systems that can potentially optimize the transcatheter aortic valve implantation process, improve safety and effectiveness of the procedure.

Screening of Mutants Related to the C4 Photosynthetic Kranz Structure in Foxtail Millet

C4 plants exhibit significantly higher photosynthetic, water and nutrient use efficiency compared with C3 plants. Kranz anatomy is associated with many C4 plants in which bundle sheath cells surround the veins and are themselves surrounded by mesophyll cells. This specialized Kranz anatomy is elucidated as an important contributor to C4 photosynthetic activities in C4 plant. Characterizing the molecular basis of Kranz structure formation has become a key objective for studies of C4 photosynthesis. However, severe mutants that specifically disrupt Kranz anatomy have not been identified. In this study, we detected 549 stable ethyl methane sulfonate-induced foxtail millet (cultivar Yugu1) mutants related to leaf development and photosynthesis among 2,709 mutants screened (M3/M4 generation). The identified mutants included 52 that had abnormal leaf veins (with abnormal starch accumulation based on iodine staining). Each of the 52 mutants was characterized through an analysis of leaf morphology, and through microscopic observations of leaf tissue sections embedded in resin and paraffin. In total, 14 mutants were identified with abnormal Kranz structures exemplified by small bundle sheath cell size. Additional phenotypes of the mutants included poorly differentiated mesophyll and bundle sheath cells, increased vein density and the absence of chloroplasts in the bundle sheath cells. Kranz structure mutations were accompanied by varying leaf thickness, implying these mutations induced complex effects. We identified mutations related to Kranz structure development in this trial, which may be useful for the mapping and cloning of genes responsible for mediating Kranz structure development.

Virginity-sparing management of blind hemivagina in obstructed hemivagina and ipsilateral renal anomaly syndrome

To demonstrate the hymen-sparing management of a blind hemivagina in obstructed hemivagina and ipsilateral renal anomaly (OHVIRA) syndrome with the use of transrectal ultrasound (TRUS)-guided vaginoscopic septoplasty supported by pre- and postoperative diagnostics with the use of a novel ultrasound technique: 3-dimensional saline-solution infusion contrast sonovaginocervicography (3D-SVC) with virtual speculoscopy. Video presentation of surgical and ultrasound techniques. University hospital and two private centers. We are demonstrating four cases with blind hemivagina as a component of OHVIRA syndrome and varying level and features of obstruction including: 1) hemihydrocolpos; 2) hemihematocolpos; 3) "old blood" deposits in small hemivagina; and 4) narrow hymenal opening. The patients were diagnosed preoperatively by means of 3D-SVC with the use of TRUS. Surgery was planned according to available data from ultrasound and 3D-SVC, and the place of incision of the vaginal septum and blinded hemivagina with cervix were performed with the use of TRUS guidance. Wide septal incision was performed with the use of a monopolar or bipolar resectoscope with needle Collin electrode, and after incision the occult second of double cervix or part of septate cervix was visualized, and the septum was excised with the use of a loop electrode. In narrow hymenal opening, a small diagnostic sheath was used for wide septal incision. Anatomic results in the vagina were assessed with the use of 3D-SVC 2months after surgery. Agreement between imaging from preoperative diagnostics with the use of 3D-SVC and intraoperative findings, and anatomic (hymenal integrity, obstruction, status of vagina and cervix) and clinical outcomes (pain). In these four cases, 3D-SVC accurately recognized the morphology of blind hemivagina, oblique vaginal septa, and double or septate cervix. Successful minimally invasive wide septoplasty with preservation of hymen were performed with the use of hysteroscope and TRUS guidance. Concomitant laparoscopy was performed if endometriosis and hematosalpinx were present. No peri- or late postoperative complications occurred. Patients were discharged within 3hours or within 12hours in case of laparoscopy. Anatomic results were optimal (lack of septum) or suboptimal (wide opening) after septum resection and incision, respectively, without recurrence of obstruction according to 3D-SVC. Pain was not noticed 2months after the primary surgery. 3D-SVC is a useful and accurate technique in diagnosis, surgery planning, and postoperative assessment in women with blind hemivagina and intact hymen. TRUS-guided vaginoscopic septoplasty is a reasonable alternative to traditional vaginal surgery and allows hymen preservation.

Numerical simulation of casing deformation during volume fracturing of horizontal shale gas wells

Casing deformation problems occur frequently during volume fracturing of shale gas wells. It is crucial to assess the casing deformation near heel (the beginning of the horizontal wellbore trajectory) where natural faults exist among 84.6% of the deformation positions in some shale plays. Based on the source mechanism, the fault slip distance was derived from microseismic inversion. Then, three-dimensional physical and finite element models were established using a stage finite element model procedure to investigate the influences of fault slippage on casing stress and displacement. Other factors such as pump rate, fracturing pressure, formation anisotropy, formation elastic modulus, cement sheath elastic modulus, casing size, and cement sheath thickness were taken into consideration. The results show that (1) fault slippage is an important mechanism of casing deformation near heel. The casing has a higher risk of deformation under the conditions of fault slippage combined with high external stress and internal pressure. (2) Under different slip distances, the casing Mises stress dramatically increases with an increase in the cement sheath and formation elastic moduli and the ratio of the casing diameter to the thickness Dout/t. (3) The high pump rate, high inner casing pressure, large formation anisotropy, and small cement sheath thickness can aggrandize casing stress. The calculated casing displacements using this model obtained good agreement when compared to the deformations of the actual wells. Countermeasures such as avoiding natural fault areas, using cement with an elastic modulus smaller than 10 GPa, using a higher grade and smaller diameter casing with a value of Dout/t smaller than 12.7 can be effective to prevent casing deformation during multi-fracturing operation.