Lipectomy as an alternative for superficialization of autologous AVF in obese patients: experience of a referral center in Amazon.

Background: The preferred vascular access for hemodialysis is a native arteriovenous fistula (AVF) because it offers the best results in the short and long terms, lower morbidity and mortality, and has additional advantages in relation to central venous catheters or arteriovenous grafts. However, obesity can present an additional challenge because of the barrier of subcutaneous cellular tissue covering the surface of the vein to be punctured. Objectives: The authors review their experience with excision of subcutaneous tissue (lipectomy) overlying upper arm cephalic vein arteriovenous fistulas in obese patients. Methods: Consecutive vascular access patients undergoing lipectomy for cannulation with difficult access because of vein depth were reviewed. Cephalic vein depth was measured by ultrasound in all cases. Results: Twenty-two patients were reviewed (15 men and 7 women), with a mean body mass index of 34.0 kg/m2 (range: 28-40 kg/m2). Mean age was 58.4 years. The mean preoperative vein depth of 7.9 mm (range: 7.0-10.0 mm) was reduced to 4.7 mm (range: 3.0-6.0 mm) (P 0.01). The mean follow-up period for patients was 13.2 months. Four patients were lost to follow-up and four died during the period due to causes unrelated to vascular access. Conclusions: Obesity should not be a limiting factor to creation of a native AVF, since lipectomy is a relatively simple option for superficialization, enabling functioning native and deep arteriovenous fistulas in obese patients.

Arteriovenous Fistula Histology, Hemodynamics, and Wall Mechanics: A Case Report of Successful and Failed Access in a Single Patient.

The low 1-year patency rate of mature arteriovenous fistulas (AVFs) remains a significant clinical problem. Although vessel properties and biomechanics have been suggested to affect AVF function, understanding their roles in AVF patency failure is challenging owing to the heterogeneity within the patient population, including demographics and comorbid conditions. In this study, we present a case of a patient with 2 upper-arm AVFs with different 1-year patency outcomes and investigate whether they had different histologic features before the AVF creation surgery and biomechanics at 1 day and 6 weeks after the AVF creation surgery using magnetic resonance imaging-based fluid structure interaction simulations. Despite both AVFs being in the upper arm, created <1 year apart by the same surgeon, and having similar preoperative vessel diameters, the 1-year patent AVF had less preoperative intimal collagen and higher wall shear stress 1 day after AVF creation, when compared with the AVF that failed by 1 year. Thus, a low intimal collagen content before the AVF surgery and higher wall shear stress immediately after the AVF creation surgery may be important for long-term AVF patency and should be investigated with larger cohorts.

Vascular access surgery training in the United Kingdom is currently perceived (by trainees) to be inadequate.

INTRODUCTION: Vascular access surgery (VAS) involves the creation and maintenance of arteriovenous access to facilitate haemodialysis. The prevalence of haemodialysis is rising despite increases in kidney transplants on a yearly basis. There is currently only one access surgery fellowship accredited by the Royal College of Surgeons of England. We aimed to establish the experience and perceived competence in access surgery of senior vascular surgery trainees. METHODS: A short questionnaire (SurveyMonkey) was used to survey all senior (ST6-ST8) vascular surgery trainees in Health Education England (HEE) vascular surgery training programmes. The short survey asked trainees to report their: (1) training grade; (2) training deanery; (3) experience of access surgery; and (4) whether senior trainees thought they would be able to independently undertake primary access surgery post-completion of training (post Certificate of Completion of Training). The survey was circulated via HEE deaneries and the vascular surgery trainees' society: the Rouleaux Club. RESULTS: Twenty-eight senior (ST6-ST8) vascular surgery trainees responded to the survey: 29.6% were ST6 level, 33.3% were ST7 and 37.1% were ST8. Deanery respondence was evenly spread, although London was overrepresented (37.1%). In total, 28.6% had been involved in fewer than 10 cases, 35.7% in 10-25 cases, and 35.7% in more than 25 cases. Almost 54% of senior vascular surgery trainees believed they would not be able to undertake independent access surgery once they had completed training. CONCLUSIONS: Competence in access surgery is an increasing requirement of a consultant vascular surgeon. More formalised training is required to adequately train the next generation of vascular surgeons.

Vascular access surgery training in the United Kingdom is currently perceived (by trainees) to be inadequate.

INTRODUCTION: Vascular access surgery (VAS) involves the creation and maintenance of arteriovenous access to facilitate haemodialysis. The prevalence of haemodialysis is rising despite increases in kidney transplants on a yearly basis. There is currently only one access surgery fellowship accredited by the Royal College of Surgeons of England. We aimed to establish the experience and perceived competence in access surgery of senior vascular surgery trainees. METHODS: A short questionnaire (SurveyMonkey) was used to survey all senior (ST6-ST8) vascular surgery trainees in Health Education England (HEE) vascular surgery training programmes. The short survey asked trainees to report their: (1) training grade; (2) training deanery; (3) experience of access surgery; and (4) whether senior trainees thought they would be able to independently undertake primary access surgery post-completion of training (post Certificate of Completion of Training). The survey was circulated via HEE deaneries and the vascular surgery trainees' society: the Rouleaux Club. RESULTS: Twenty-eight senior (ST6-ST8) vascular surgery trainees responded to the survey: 29.6% were ST6 level, 33.3% were ST7 and 37.1% were ST8. Deanery respondence was evenly spread, although London was overrepresented (37.1%). In total, 28.6% had been involved in fewer than 10 cases, 35.7% in 10-25 cases, and 35.7% in more than 25 cases. Almost 54% of senior vascular surgery trainees believed they would not be able to undertake independent access surgery once they had completed training. CONCLUSIONS: Competence in access surgery is an increasing requirement of a consultant vascular surgeon. More formalised training is required to adequately train the next generation of vascular surgeons.

Association of anesthetic modality and other variables on 1-year functional patency of cephalic-based arteriovenous fistulae.

OBJECTIVES: Some studies suggest that regional (RA) provides better patency for arteriovenous fistula (AVF) for hemodialysis (HD) access as compared to Local (LA) and General Anesthesia (GA). This study evaluates the impact of anesthetic modality on long term fistula function at 12 months. METHODS: A retrospective review of patients undergoing cephalic vein-based HD access in consecutive cases between 2014 and 2019 was conducted from five safety net hospitals. The primary endpoint was functional patency at 12 months. Subset analysis individually evaluated cephalic based lower forearm and wrist versus upper arm AVFs. Bivariate and multivariate logistic regression models evaluated the relationship between anesthetic modality and fistula function at 12 months. RESULTS: There were 818 cephalic based fistulas created during the study period. The overall 12-month functional patency rate was 78.7%, including an 81.3% patency for upper arm AVF and 73.3% for wrist AVF (p=0.009). There was no statistically significant difference among patients with functional and nonfunctional AVFs at 12 months with respect to anesthetic modality when comparing regional, local, and general anesthesia (p=0.343). Multivariate regression analysis identified that history of AVF/AVG (OR 0.24, p=0.007), receiving intraoperative systemic anticoagulation (OR 2.49, p<0.001), and vein diameter (OR 1.85, p=0.039) as independently associated with AVF functional patency at 12 months. CONCLUSION: There was no association between anesthetic modality and functional patency of cephalic based-AVF at 12 months. Further studies are needed to better define which patients may benefit from regional anesthesia.

Effect of early cannulation with metal needles on arteriovenous fistula patency in patients undergoing hemodialysis.

BACKGROUND: Autogenous arteriovenous fistula (AVF) is the preferred vascular access mode. However, the earliest possible time for AVF puncture and whether premature puncture affects the AVF patency rate remain unclear. METHODS: In this multicenter retrospective cohort study, adult uremic patients who underwent AVF surgery for the first time at Taizhou Hospital or Enze Hospital of Zhejiang Province between September 1, 2018 and August 31, 2021 were enrolled. All patients were followed up for 1 year after puncture, and the status of fistula establishment and puncture, subsequent patency, loss to follow-up, renal transplantation, conversion to peritoneal dialysis, abandonment of the fistula, and death, were recorded. RESULTS: A total of 465 patients with AVFs were included in this study, including 59 (12.7%) patients with fistulas that were cannulated within 30 days. In the early puncture group, the levels of serum creatinine and urea nitrogen were higher, while the levels of hemoglobin and albumin were lower, suggesting that these patients needed urgent dialysis. Furthermore, the rate of non-cuffed catheter use was higher, while the rate of cuffed catheter use was lower, and femoral vein puncture was preferred over internal jugular vein puncture. The mean duration of catheter indwelling was shorter in the early puncture group (19 vs 70 days, p < 0.001). The estimated AVF primary and cumulative functional patency at 12 months was 81.1% versus 82.3% and 98.3% versus 98.7% in the early puncture and control groups, respectively. Kaplan-Meier analysis revealed no significant difference in AVF primary and cumulative functional patency between the two groups. CONCLUSIONS: In patients with an established fistula in urgent need of hemodialysis, to avoid new catheterization, a puncture can be performed within 30 days in those with well-developed blood vessels after adequate ultrasound and clinical evaluation without affecting the patency of the fistula.

Minimizing delays to hemodialysis access maturation: A quality improvement analysis.

INTRODUCTION: Pre-operative process optimization can expedite time-to-intervention and reduce overall health care costs. We hypothesized that the longest delay to hemodialysis (HD) access creation would be from pre-operative vessel mapping (mandatory in our practice), and that this would be correlated with increased catheter days. METHODS: One hundred thirty patients (24 inpatients, 106 outpatients) who received initial hemodialysis (HD) access from 01/01/2017 to 12/31/2021, at the Veterans Affairs Puget Sound, Seattle, Washington, were identified. Median time differences between pre-operative events were compared between inpatients and outpatients using the Mann-Whitney U test. Outpatients were then stratified by time of catheter-based HD initiation (no catheter, pre-referral catheter, post-referral catheter) and compared. The impacts of mapping-related delays on catheter use were evaluated using regression. RESULTS: Inpatients had shorter referral to access maturation times (125 days inpatient vs 146 days outpatient; p = 0.03). This was driven by shorter referral to mapping (2 days inpatient vs 27 days outpatient; p < 0.01) and mapping to pre-surgical evaluation (1-day inpatient vs 6 days outpatients; p < 0.01) times. Pre-surgical evaluation to OR times represented the longest pre-operative delay in both groups (51 days inpatient vs 29 days outpatient; p = 0.59). Among outpatients, tunneled catheter placement post-referral resulted in longer maturation times (74 days no catheter vs 67 days pre-referral vs 149 days post-referral; p < 0.01) but not additional pre-operative delays. No trend existed between increased mapping times and catheter-based dialysis duration (R2 = 0.08). CONCLUSION: Preoperative vein mapping contributed up to 21% of referral to maturation times but was not associated with increased tunneled catheter duration. While tunneled catheter placement impacted access maturation it did not cause additional pre-operative delays. Earlier referrals for access creation and reduction of outpatient wait-time from referral to OR and increased AV graft placement may minimize catheter days in our system thereby mitigating the added delays caused by pre-operative vein mapping.

MSCTA imaging analysis of autologous arteriovenous fistula dysfunction in maintenance hemodialysis patients.

OBJECTIVE: To observe the multi-slice spiral CT angiography (MSCTA) imaging features of arteriovenous fistula dysfunction in patients undergoing maintenance hemodialysis and analyze the significance of the imaging examination. METHODS: Altogether 90 patients with end-stage renal disease treated by maintenance hemodialysis in General Hospital of China Resources & Wisco from June 2020 to February 2023 were divided into a normal function group (n=68) and a dysfunction group (n=22) according to the function of autogenous arteriovenous fistula. The clinical data of the two groups were recorded. The MSCTA was performed in each patient, and the manifestations of arteriovenous fistula dysfunction were analyzed. Additionally, the vascular access stenosis, vascular access lumen stenosis, arteriovenous diameter, blood flow, and hemodynamic indices were tested, and the value of MSCTA in predicting arteriovenous fistula function was analyzed by Logistic regression. RESULTS: The degree of vascular access stenosis and vascular access lumen stenosis in the normal group were less than those in the dysfunctional group (P<0.05). The arteriovenous diameter, blood flow, blood flow velocity at anastomotic vein end, dialysis adequacy (spKt/V), and von Willebrand factor (vWF) function in the normal group were larger than those in the dysfunction group, and the radial artery shear force was lower than in the dysfunction group, with statistical significance (P<0.05). Among the arteriovenous fistula dysfunction, there were 3 patients with anastomotic + outflow vein stenosis, 4 patients with outflow vein stenosis, 9 patients with inflow artery + anastomosis + outflow vein stenosis, and 6 patients with superior vena cava stenosis. Logistic regression analysis showed that slow blood flow velocity at the venous end of anastomosis and high shear force of radial artery were influencing factors of arteriovenous fistula dysfunction, and the area under ROC curve of blood flow velocity at the venous end of anastomosis plus shear force of radial artery was 0.93, with a sensitivity of 0.87 and a specificity of 0.85. CONCLUSION: MSCTA can be used to evaluate the dysfunction of autologous arteriovenous fistula in patients undergoing maintenance hemodialysis, and provide important reference information for the formulation of the next best clinical treatment plan.

Embolisation of a high - flow renal arteriovenous fistula with the use of simultaneous transvenous and transarterial approach and balloon-assisted coil embolization.

BACKGROUND: Renal arteriovenous fistula (RAVF) is a rare vascular malformation, which can be asymptomatic or may cause hemorrhage, hypokalaemic hypertension, heart failure and hematuria. Endovascular embolization is a minimally invasive method which can preserve renal parenchyma. In our case, balloon assisted coil embolization with simultaneous transvenous and transarterial approach was used. A remodelling balloon, which is routinely used in neurovascular procedures, was chosen in order to eliminate the risk of coil migration and preserve feeding artery and renal parenchyma. CASE PRESENTATION: We present a case of successful balloon - assisted coil embolization of a high flow renal arteriovenous fistula in a 25-year-old male patient via simultaneous transarterial and transvenous approach with preservation of the feeding artery. CONCLUSION: Endovascular embolisation is a safe and effective treatment of RAVFs with low risk of complications. Simultaneous transarterial and transvenous coil deployment with the use of a flow control balloon catheter can eliminate the risk of coil migration and coil protrusion into the parent artery with permanent RAVF occlusion and renal parenchyma preservation.

Tigroid Enhancement: A Characteristic Enhancement Pattern of the Cerebellar Hemisphere on MRI With Intracranial Dural Arteriovenous Fistulas.

PURPOSE: This study aims to investigate a characteristic cerebellar hemisphere enhancement pattern on magnetic resonance imaging (MRI) that could aid in early and specific diagnosis of intracranial dural arteriovenous fistulas (DAVFs). MATERIALS AND METHODS: Pretreatment MR images of 57 patients with intracranial DAVFs between January 1, 2017, and February 28, 2023, were retrospectively analyzed. A total of 128 patients with confirmed alternative cerebellar lesions during the same period were included as a control group. All patients underwent enhanced MRI with a 3.0T scanner. The presence or absence of parallel enhanced linear striations on the surface of the cerebellar lesions was documented. Statistically significant differences were determined by the Fisher exact test. RESULTS: Cerebellar lesions were identified in 4 intracranial DAVF patients (7.0%). All 4 patients were male, with an average age of 64 years (range: 58-76 years). The pretreatment MR images of all 4 DAVF patients with cerebellar lesions demonstrated the characteristic tigroid enhancement pattern. Tortuous flow voids were present in the MR images of 3 of the 4 patients. Tigroid enhancement pattern was not observed in the remaining 53 intracranial DAVF patients and all control patients. The differences in the incidence of the pattern were significant (p=0.01). CONCLUSION: A characteristic tigroid enhancement pattern of the cerebellar hemisphere on MRI may aid in the early and specific diagnosis of intracranial DAVFs, allowing timely treatment and improving outcomes. CLINICAL IMPACT: The identification of a characteristic tigroid enhancement pattern on MRI for cerebellar hemisphere lesions holds significant promise for clinical practice. This pattern serves as a distinctive marker aiding in the early and specific diagnosis of intracranial dural arteriovenous fistulas (DAVFs). Clinicians can now utilize this innovative finding to expedite diagnostic workflows, enabling timely intervention and management strategies. The incorporation of this novel imaging feature enhances diagnostic accuracy, potentially reducing misdiagnosis rates and preventing delays in treatment initiation. Ultimately, this advancement may lead to improved patient outcomes and quality of care in neurosurgical and neuroradiological practice.

Computational fluid-structure interaction analysis of the end-to-side radio-cephalic arteriovenous fistula.

BACKGROUND AND OBJECTIVE: In the current work, we present a descriptive fluid-structure interaction computational study of the end-to-side radio-cephalic arteriovenous fistula. This allows us to account for the different thicknesses and elastic properties of the radial artery and cephalic vein. METHODS: The core of the work consists in simulating different arteriovenous fistula configurations obtained by virtually varying the anastomosis angle, i.e. the angle between the end of the cephalic vein and the side of the radial artery. Since the aim of the work is to understand the blood dynamics in the very first days after the surgical intervention, the radial artery is considered stiffer and thicker than the cephalic vein. RESULTS: Our results demonstrate that both the diameter of the cephalic vein and the anastomosis angle play a crucial role to obtain a blood dynamics without re-circulation regions that could prevent fistula failure. CONCLUSIONS: When an anastomosis angle close to the perpendicular direction with respect to the radial artery is combined with a large diameter of the cephalic vein, the recirculation regions and the low Wall Shear Stress (WSS) zones are reduced. Conversely, from a structural point of view, a low anastomosis angle with a large diameter of the cephalic vein reduces the mechanical stress acting on the vessel walls.

Case Report: Vascular access in paediatric haemodialysis patients-creating and maintaining the patency of an arteriovenous fistula.

Introduction: Paediatric vascular access is a demanding field. The need for a multidisciplinary team is mandatory in children with end-stage kidney disease (ESKD). Central venous catheters (CVCs) remain the preferred option worldwide. Recent emerging data demonstrated the benefits of using arteriovenous fistulas (AVFs) in the paediatric population for long-term vascular access. The small vessel size in children represents a surgical challenge for vascular access. Case presentation: We report three cases from our haemodialysis department and the difficulty in maintaining permanent vascular access. The first case is an adolescent girl who required a change in vascular approach after multiple central venous catheter (CVC) infections and catheter thrombosis secondary to thrombophilia. Three AVFs were performed but failure occurred early. The patient was also diagnosed with a complex vascular thrombosis with total occlusion of the inferior vena cava and completed distal thrombosis of the superior vena cava. A permanent CVC was placed in the right jugular vein with the tip in the azygos vein. The second case is of an adolescent boy with systemic vasculitis with multiple CVC infections secondary to immunosuppression. The first thrombosis of two right AVFs occurred early with the development of a pseudo-aneurysm that required surgical intervention. The left brachial-cephalic fistula required surgery for closing the collaterals, repositioning and superficialisation. The third case is an adolescent boy with one surgical stage brachial-basilic left AVF and difficulties in venous puncturing. Conclusion: Vascular access in paediatric haemodialysis remains a demanding field. There is a need for a multidisciplinary team, consisting of a vascular surgeon and an interventional radiologist specialising in children.

Vascular access route venture of the chronic hemodialysis patient: A prospective cohort study.

OBJECTIVES: This study aimed to collect evidence to improve the arteriovenous fistula practice by investigating vascular access routes and by identifying the factors influencing the preferred types of vascular access routes for the first-time hemodialysis in our center. METHODS: We performed an epidemiological, prospective, cohort study. The study included 308 patients, who underwent hemodialysis for the first time between March 2023 and August 2023 in our hemodialysis center. We evaluated biochemical parameters, preferred vascular access routes for the first-time hemodialysis, planned/emergency hemodialysis status, the qualifications of the healthcare provider, who inserted the central venous catheter, if applicable, the presence of hypervolemia, anticoagulant use, nephrology follow-up findings, and in-hospital mortality in all patients and in those, who continued with chronic hemodialysis. RESULTS: The number of patients, who continued with chronic hemodialysis, was 167 (54.2%) and a temporary internal jugular central venous catheter was the most commonly preferred vascular access route for the first-time hemodialysis (47.3%). A central venous catheter was most commonly inserted by a nephrologist (53.7%) in chronic hemodialysis patients. Of the patients continuing with chronic hemodialysis, 45.5% were followed up in the nephrology outpatient clinic, 9.6% initiated hemodialysis on a planned basis, and 8.4% initiated hemodialysis with an arteriovenous fistula. A temporary internal jugular central venous catheter was commonly preferred when patients were followed up in the nephrology clinic and when the insertion was performed by a nephrologist; a transient femoral central venous catheter was commonly preferred in case of hypervolemia (p < .001, p < .001, and p = .028, respectively). Age, gender, etiology, anticoagulant use, or biochemical test results did not act on the selection of the access site for the insertion of central venous catheter at the time of the first hemodialysis treatment. The access site for central venous catheter was not associated with in-hospital mortality (p = .644). In the overall patient group, the in-hospital mortality was significantly low in patients followed up in the nephrology clinic (p = .014). CONCLUSION: The use of pre-emptive arteriovenous fistula for the first hemodialysis treatment occurs much less commonly than expected. Hemodialysis initiation rates with pre-emptive arteriovenous fistula lag behind nephrology outpatient follow-up rates.

Measurement of sinus wall thickness and wall enhancement index in dural arteriovenous fistulae by magnetic resonance vessel wall imaging.

BACKGROUND: Dural sinus wall thickness and wall enhancement index (WEI) of dural arteriovenous fistulae (DAVFs) have not been well characterized. This study aimed to measure the sinus wall thickness and WEI by using magnetic resonance vessel wall imaging (MR-VWI). METHODS: A total 27 DAVF patients and 30 normal healthy individuals were enrolled in this study. All participants were scanned by a 3 T MR scanner with the black blood sequence. The wall thickness and the WEI of the great cerebral vein, the intracranial main dural sinuses with DAVFs, and the contralateral sinuses were measured by two independent neuroradiologists. RESULTS: The DAVF-affected sinuses had significantly thicker walls (2.277 ±â€¯0.311 mm vs. 1.446 ±â€¯0.188 mm, P < 0.001) and significantly higher WEI (2.253 ±â€¯0.462 vs. 1.173 ±â€¯0.418, P < 0.001) compared to the contralateral ones. They also had significantly thicker walls (2.277 ±â€¯0.311 mm vs. 1.643 ±â€¯0.173 mm, P < 0.001) and significantly higher WEI (2.253 ±â€¯0.462 vs. 1.124 ±â€¯0.254, P < 0.001) compared to the normal controls. Neither the sinus wall thickness (r = -0.317, P = 0.107) nor the WEI (r = 0.019, P = 0.923) was significantly correlated with the Cognard types in DAVF patients. The WEI of the DAVF draining vein was significantly higher compared to the static venous wall (1.972 ±â€¯0.629 vs. 0.532 ±â€¯0.243, P < 0.001). CONCLUSION: T1-CUBE MRI is useful in measuring sinus all thickness and WEI of DAVFs, providing a new method for diagnosing this disease.

Zero upper arm hemodialysis fistulas: utopian or realistic goal?

BACKGROUND: Although distal native fistula is the best first-line vascular access (VA), upper arm fistula (UAF) prevalence is increasing worldwide, except in Japan. Our previous survey on 50% of hemodialysis patients (HP) revealed a prevalence of UAF of less than 5%, which is lower than the findings published by the DOPPS 5 study in our country. We analyzed the VA prevalence on 100% of HPs from our department. METHODS: In December 2021, we investigated the prevalence of vascular access of 1295 hemodialysis patients from 17 dialysis factories. VAs were classified according to location into distal forearm fistula (DFF), middle-proximal forearm fistula (MPFF), and UAF. The department manages VA using a Hub and Spoke model. The hub performs simple and complex VA including Graft placement, the Percutaneous Transluminal Angioplasty (PTA) of fistulas and central stenosis, and the surgical and endovascular rescue of thrombosed or stenotic fistulas. The spokes perform mainly simple DFFs. RESULTS: The mean age of 1295 HP (35% females and 21% diabetics) was 69 ± 12.4 years; 506 (39%) were over 75 years old. The prevalence of DFF, MPFF, UAF, GRAFT, and CVC was 63.5%, 10.1%, 3%, 0.7%, and 22.5%, respectively. Data comparison between our two surveys revealed a lower MPFF, UAF, and GRAFT prevalence and increased CVC prevalence. Patients aged 75 years or older, women, and diabetics showed a higher frequency of CVC and a lower prevalence of DFF. CONCLUSIONS: The findings confirm the low prevalence of UAF found in our prior survey, demonstrating that UAFs can be reduced to 5% or less, as seen in Japanese experience.

The prevalence of early contained vascular injury of spleen.

Contained vascular injuries (CVI) of spleen include pseudoaneurysms (PSA) and arterio-venous fistulae (AV-fistulae), and their reported prevalence varies. Our purpose was to assess the prevalence of early splenic CVI seen on admission CT in patients with splenic trauma admitted to a single level 1 trauma center in 2013-2021, and its detection in different CT protocols. A retrospective, single-center longitudinal cohort study. Nine-year data (2013-2021) of all patients with suspected or manifest abdominal trauma were retrieved. All patients, > 15 years with an ICD code for splenic trauma (S36.0XX) were included. CT and angiographic examinations were identified. Reports and images were reviewed. Splenic CVI CT criterion was a focal collection of vascular contrast that decreases in attenuation with delayed imaging. Number of CVIs and treatment was based on medical records and/or available angioembolization data. Of 2805 patients with abdominal trauma, 313 patients (313/2805; 11.2%) fulfilled the study entry criteria. 256 patients (256/313; 81.8%) had a CT examination. Sixteen patients had splenectomy before CT, and the final study group included 240 patients (240/313; 76.7%). Median New Injury Severity Score (NISS) was 27 and 87.5% of patients had NISS > 15. Splenic CVI was found in 20 patients, which yields a prevalence of 8.3% (20/240; 95% CI 5.2-12.6%). In those cases with both late arterial and venous phase images available, CVI was seen in 14.5% of cases (18/124, 95% CI 8.6-22.0%). None of the patients with CVI died within 30 days of the injury. The prevalence of early splenic CVI in patients with a splenic trauma was 8.3-14.5% (95% CI 5.2-22.0%). Our data suggests that both arterial and venous phase are needed for CT diagnosis. The 30-day outcome in terms of mortality was good.

Elevated Leukocyte Glucose Index Is Associated with Long-Term Arteriovenous Fistula Failure in Dialysis Patients.

(1) Background: Arteriovenous fistula (AVF) is the preferred type of vascular access for dialysis in patients with end-stage kidney disease (ESKD). However, the primary patency of AVF at one year is under 70% due to several risk factors and comorbidities. Leukocyte glucose index (LGI), a new biomarker based on blood leukocytes and glucose values, has been found to be associated with poor outcomes in cardiovascular disease. The aim of this study is to analyze the impact of LGI on the long-term primary patency of AVF following dialysis initiation. (2) Methods: We conducted a retrospective observational study in which we initially enrolled 158 patients with ESKD admitted to the Vascular Surgery Department of the Emergency County Hospital of Targu Mures, Romania, to surgically create an AVF for dialysis between January 2020 and July 2023. The primary endpoint was AVF failure, defined as the impossibility of performing a chronic dialysis session due to severe restenosis or AVF thrombosis. After follow-up, we categorized patients into two groups based on their AVF status: "functional AVF" for those with a permeable AVF and "AVF failure" for those with vascular access dysfunction. (3) Results: Patients with AVF failure had a higher prevalence of atrial fibrillation (p = 0.013) and diabetes (p = 0.028), as well as a higher LGI value (1.12 vs. 0.79, p < 0.001). At ROC analysis, LGI had the strongest association with the outcome, with an AUC of 0.729, and an optimal cut-off value of 0.95 (72.4% sensitivity and 68% specificity). In Kaplan-Meier survival analyses, patients in the highest tertile (T3) of LGI had a significantly higher incidence of AVF failure compared to those in tertile 1 (p = 0.019). Moreover, we found that patients with higher baseline LGI values had a significantly higher risk of AVF failure during follow-up (HR: 1.48, p = 0.003). The association is independent of age and sex (HR: 1.65, p = 0.001), cardiovascular risk factors (HR: 1.63, p = 0.012), and pre-operative vascular mapping determinations (HR: 3.49, p = 0.037). (4) Conclusions: In conclusion, high preoperative values of LGI are positively associated with long-term AVF failure. The prognostic role of the biomarker was independent of age, sex, cardiovascular risk factors, and pre-operative vascular mapping determinations.

Accuracy of 3.0T magnetic resonance angiography for the detection of arteriovenous fistula dysfunction in hemodialysis patients requiring interventional therapy: a prospective study.

Background: Color Doppler ultrasonography (CDUS) is feasible to detect arteriovenous fistula (AVF) dysfunction in hemodialysis patients but is not sufficient to map the structure of fistula required for interventions. This study is designed to evaluate the diagnostic accuracy of three-dimensional time-of-flight magnetic resonance angiography (TOF-MRA) at 3.0T versus CDUS for AVF dysfunction, by using digital subtraction angiography (DSA) as reference. Methods: This prospective study enrolled 68 consecutive patients with dysfunctional AVF who underwent both CDUS and TOF-MRA at Shanghai Sixth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine. The analysis of the dysfunctional AVFs was divided into three regions: the feeding artery, fistula and draining veins. In the whole- and per-regional-based analyses, two observers who were blinded to the clinical and DSA results independently analyzed all CDUS and TOF-MRA datasets. The image quality and stenosis severity of the lesions on TOF-MRA were evaluated. A receiver operating characteristic curve was applied to analyze the detection of AVF dysfunction with TOF-MRA. Results: A total of 204 vessel regions were evaluated. The whole-region-based image quality of TOF-MRA was poorer in patients with a total occlusion (1.8±0.8) than in those with stenosis (2.7±0.6, P<0.001). In the whole-region analyses, TOF-MRA had higher sensitivity [99.1% (94.6-100.0%) vs. 82.9% (74.6-89.0%), P<0.001] and similar specificity [93.1% (85.0-97.1%) vs. 94.3% (86.5-97.9%), P=0.755] than CDUS. The per-region-based analyses showed that TOF-MRA yielded higher sensitivity [fistula region, 98.1% (88.4-99.9%) vs. 80.8% (67.0-89.9%); P=0.004; draining vein region, 100.0% (92.5-100.0%) vs. 85.0% (72.9-2.5%); P=0.003] and similar specificity [fistula region, 88.2% (62.3-97.8%) vs. 88.2% (62.3-97.9%); P>0.99; draining vein region, 100.0% (59.8-100.0%) vs. 87.5% (46.7-99.3%); P>0.99] than CDUS. Sensitivity and specificity of TOF-MRA were comparable to those of CDUS in feeding artery region. Conclusions: TOF-MRA is a feasible and accurate method to display AVF dysfunction in hemodialysis patients, and this method might fulfill the endovascular treatment planning requirements.

Mitochondrial targeted catalase improves muscle strength following arteriovenous fistula creation in mice with chronic kidney disease.

Hand dysfunction is a common observation after arteriovenous fistula (AVF) creation for hemodialysis access and has a variable clinical phenotype; however, the underlying mechanism responsible is unclear. Grip strength changes are a common metric used to assess AVF-associated hand disability but has previously been found to poorly correlate with the hemodynamic perturbations post-AVF placement implicating other tissue-level factors as drivers of hand outcomes. In this study, we sought to test if expression of a mitochondrial targeted catalase (mCAT) in skeletal muscle could reduce AVF-related limb dysfunction in mice with chronic kidney disease (CKD). Male and female C57BL/6J mice were fed an adenine-supplemented diet to induce CKD prior to placement of an AVF in the iliac vascular bundle. Adeno-associated virus was used to drive expression of either a green fluorescent protein (control) or mCAT using the muscle-specific human skeletal actin (HSA) gene promoter prior to AVF creation. As expected, the muscle-specific AAV-HSA-mCAT treatment did not impact blood urea nitrogen levels (P = 0.72), body weight (P = 0.84), or central hemodynamics including infrarenal aorta and inferior vena cava diameters (P > 0.18) or velocities (P > 0.38). Hindlimb perfusion recovery and muscle capillary densities were also unaffected by AAV-HSA-mCAT treatment. In contrast to muscle mass and myofiber size which were not different between groups, both absolute and specific muscle contractile forces measured via a nerve-mediated in-situ preparation were significantly greater in AAV-HSA-mCAT treated mice (P = 0.0012 and P = 0.0002). Morphological analysis of the post-synaptic neuromuscular junction uncovered greater acetylcholine receptor cluster areas (P = 0.0094) and lower fragmentation (P = 0.0010) in AAV-HSA-mCAT treated mice. Muscle mitochondrial oxidative phosphorylation was not different between groups, but AAV-HSA-mCAT treated mice had lower succinate-fueled mitochondrial hydrogen peroxide emission compared to AAV-HSA-GFP mice (P < 0.001). In summary, muscle-specific scavenging of mitochondrial hydrogen peroxide significantly improves neuromotor function in mice with CKD following AVF creation.

Omentin reduces venous neointimal hyperplasia in arteriovenous fistula through hypoxia-inducible factor-1 alpha inhibition.

Arteriovenous fistula (AVF) failure often involves venous neointimal hyperplasia (VNH) driven by elevated hypoxia-inducible factor-1 alpha (HIF-1α) in the venous wall. Omentin, known for its anti-inflammatory and anti-hyperplasia properties, has an uncertain role in early AVF failure. This study investigates omentin's impact on VNH using a chronic renal failure (CRF) rabbit model. The CRF rabbit model of AVF received omentin-expressing adenoviral vector or control ß-gal vector to assess omentin's effects on VNH. Human vascular smooth muscle cells (HVSMCs), stimulated with tumor necrosis factor-α (TNF-α), were exposed to recombinant human omentin (Rh-OMT) to study its influence on cell proliferation and migration. The AMP-activated protein kinase (AMPK) inhibitor compound C and the mammalian target of rapamycin (mTOR) activator MHY1485 were employed to explore omentin's mechanisms in VNH reduction through HIF-1α inhibition. Omentin treatment reduced VNH in CRF rabbits, concomitant with HIF-1α down-regulation and the suppression of downstream factors, including vascular endothelial growth factor and matrix metalloproteinases. Rh-OMT inhibited TNF-α-induced HVSMC proliferation and migration by modulating both cell cycle and cell adhesion proteins. Additionally, omentin reduced HIF-1α expression through the AMPK/mTOR pathway activation. Notably, the blockade of AMPK/mTOR signaling reversed omentin-mediated inhibition of VNH, cell proliferation, and migration, both in vivo and in vitro. In conclusion, omentin mitigates VNH post-AVF creation by restraining HIF-1α via AMPK/mTOR signaling. Strategies boosting circulating omentin levels may offer promise in averting AVF failure.