Outcomes of balloon-assisted maturation with large-diameter balloons.

OBJECTIVES: Balloon-assisted maturation (BAM) is a well-established technique for maturation of inadequate arteriovenous fistulas (AVF). The objective of this study was to evaluate outcomes of initial BAM using large-diameter angioplasty balloons. METHODS: Charts of patients who underwent BAM between 2018 and 2021 at a single academic institution were reviewed. AVF maturation rate was the primary outcome. Secondary outcomes included procedural complications, re-intervention rates, post-procedure vein diameter, and time to catheter-free hemodialysis (HD). Outcomes of patients that underwent initial BAM with ⩾7 mm diameter balloons (Group I) were compared to those of patients that had initial BAM with <7 mm balloons (Group II). RESULTS: Group I (n = 149) was a significantly younger cohort and had more men compared to Group II (n = 90). There were no significant differences associated with procedural details and complication rates. Median vein diameter was larger (5.9 mm, IQR: 5-6.4) in Group I compared to Group II (5.1 mm, IQR: 4.2-5.9; p = 0.03) on post-procedure Duplex ultrasound. There was also a higher incidence of vein stenosis in Group II. The overall maturation rate was higher in Group I (97% vs 88%, p = 0.003), and a larger proportion of patients in Group II required more than one BAM to achieve maturation (33% vs 16%, p = 0.002). The median time to catheter-free HD after first BAM was 29 days (IQR: 19-47) in Group I and 42 days (IQR: 24-75) in Group II (p = 0.002). At 60 days after first BAM, the incidence of catheter-free HD was 83% in Group I versus 67% in Group II (p = 0.001). CONCLUSIONS: Our study demonstrates that the ability to utilize large angioplasty balloons during initial BAM is associated with higher rates of AVF maturation with fewer re-interventions and shorter time to catheter-free dialysis. AVFs that can tolerate this procedure often have more favorable baseline characteristics.

Sex Disparities in Arteriovenous Fistula Maturation Outcomes.

BACKGROUND: The end-stage kidney disease life-plan aims to individualize hemodialysis (HD) access selection in patients requiring renal replacement therapy. Paucity of data on risk factors for poor arteriovenous fistula (AVF) outcomes limits the ability of physicians to guide their patients on this decision. This is especially true for female patients, who are known to have worse AVF outcomes when compared to male patients. The goal of this study was to identify risk factors associated with poor AVF maturation outcomes in female patients that will help guide individualized access selection. METHODS: A retrospective review of 1,077 patients that had AVF creation between 2014 and 2021 at an academic medical center was performed. Maturation outcomes were compared between 596 male and 481 female patients. Separate multivariate logistic regression models were created for the male and female cohorts to identify factors associated with unassisted maturation. AVF was considered mature if it was successfully used for HD for 4-week sessions without need for further interventions. Unassisted fistula was defined as an AVF that matured without any interventions. RESULTS: The male patients were more likely to receive more distal HD access; 378 (63%) male versus 244 (51%) female patients had radiocephalic AVF, P < 0.001. Maturation outcomes were significantly worse in female patients; 387 (80%) AVFs matured in females and 519 (87%) in male patients, P < 0.001. Similarly, the rate of unassisted maturation was 26% (125) in female patients versus 39% (233) in male patients, P < 0.001. Mean preoperative vein diameters were similar in both groups; 2.8 ± 1.1 mm in male versus 2.7 ± 0.97 mm in female patients, P = 0.17. Multivariate logistic regression analysis of the female patients revealed that Black race (odds ratio [OR]: 0.6, 95% confidence interval [CI]: 0.4-0.9, P = 0.045), radiocephalic AVF (OR: 0.6, 95% CI: 0.4-0.9, P = 0.045), and preoperative vein diameter <2.5 mm (OR: 1.4, 95% CI: 10.33-0.901.1-1.7, P = 0.014) were independent predictors of poor unassisted maturation in this cohort. In male patients, preoperative vein diameter <2.5 mm (OR: 1.4, 95% CI: 1.2-1.7, P < 0.001) and need for HD prior to AVF creation (OR: 0.6, 95% CI: 0.3-0.9, P = 0.018) were independent predictors of poor unassisted maturation. CONCLUSIONS: Black women with marginal forearm veins may have worse maturation outcomes, and upper arm HD access should be considered when advising patients on their end-stage kidney disease life-plan.

Early Follow-Up after Arteriovenous Fistula Creation is Associated with Improved Access-Related Outcomes.

BACKGROUND: Up to 60% of arteriovenous fistulas (AVF) require intervention to assist maturation, which prolongs the time until it can be used for hemodialysis (HD). Current guidelines recommend early postoperative AVF examination to detect and address immaturity to decrease time to maturation. This study evaluates how the timing of postoperative follow-up to assess AVF maturity affects patients' outcomes. METHODS: All patients who underwent AVF creation between 2017 and 2021 in an academic medical center were retrospectively reviewed, excluding patients lost to follow-up or not on HD. Outcomes were compared between patients that had delayed follow-up to assess AVF maturity, >8 weeks post surgery, versus early follow-up, <8 weeks post-surgery. AVF evaluation for maturity consisted of physical examination and duplex ultrasound. Primary endpoints were time to first cannulation (interval from AVF creation to first successful cannulation) and time to catheter-free dialysis (interval from AVF creation to central venous catheter removal). RESULTS: A total of 400 patients were identified: 111 in the delayed follow-up group and 289 in the early follow-up group. The median time to follow-up was 78 days (interquartile range [IQR], 66-125) in the delayed follow-up group versus 39 days (IQR, 36-47) in the early follow-up group, (P < 0.0001). The maturation rate was 87% in the delayed follow-up group versus 81% in the early follow-up group, (P = 0.1) and both groups had similar rates of interventions to assist maturation (66% vs. 57%, P = 0.2). The early follow-up group had a significantly shorter median time to first cannulation (50 vs. 88 days; P < 0.0001) and shorter time to catheter-free HD (75 vs. 118 days; P <0.0001). At 4 months after AVF creation, the incidence of first cannulation was 74% in the early follow-up group versus 63% in the delayed follow-up group (P = 0.001). Similarly, the incidence of catheter-free dialysis was 65% in the early follow-up group versus 50% in the delayed follow-up group at 4 months postoperatively, (P = 0.036). CONCLUSIONS: Early postoperative follow-up for evaluation of fistula maturation is associated with reduced time to first successful cannulation of AVF for HD and reduced time to catheter-free dialysis.

Transradial access for balloon-assisted maturation of arteriovenous fistulas.

Balloon-assisted maturation (BAM) of arteriovenous fistulas has conventionally been performed via direct fistula access. The transradial approach has not been well described for BAM, although its use has been reported throughout the cardiology literature. The purpose of the present study was to assess the outcomes of transradial access for its use with BAM. A retrospective review of 205 patients with transradial access for BAM was performed. One sheath was inserted into the radial artery distal to the anastomosis. We have described the procedural details, complications, and outcomes. The procedure was considered technically successful if transradial access had been established and the AVF had been ballooned with at least one balloon without major complications. The procedure was considered clinically successful if no further interventions had been required for AVF maturation. The average time for BAM via transradial access was 35 ± 20 minutes, with 31 ± 17 mL of contrast used. No access-related perioperative complications, including access site hematoma, symptomatic radial artery occlusion, or fistula thrombosis, had occurred. The technical success rate was 100%, and the rate of clinical success was 78%, with 45 patients requiring additional procedures to achieve maturation. Transradial access is an efficient alternative to trans-fistula access for BAM. It is technically easier and allows for better visualization of the anastomosis.

The effect of nutrition on stroke risk: A systematic review.

Background: An estimated 33% reduction in cardiovascular events can be achieved when incorporating whole grains, fruits, vegetables, poultry, nuts, and vegetable oils in the diet along with reduced consumption of refined carbohydrates, processed meats, and sugar sweetened beverages. We performed a systematic review to analyze the impact of nutritional intervention on stroke risk, as there is no current consensus concerning dietary recommendation for primary and secondary stroke prevention. Methods: A literature search of the PubMed database from January 2010 to June 2020 was performed using combinations of the following search terms: carotid disease, carotid artery disease, carotid stenosis, carotid intima-media thickness (CIMT), diet, nutrition, micronutrition, embolic stroke, and stroke. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 checklist. Results: 28 studies met our inclusion criteria. Multiple studies showed an inverse relationship between consumption of vegetables and fruits and stroke risk. Vitamin B12 or a combination of B Vitamins was the most common supplement studied in stroke prevention. Only one RCT showed the use of B12 (500 micrograms/day) correlated with lower CIMT at follow up in healthy vegetarians. Discussion: The key findings from this systematic review indicate that adopting a diet rich in fruits and vegetables earlier in life may lower stroke risk compared with meats and fat intake. B vitamins also appear to confer some protection against stroke. However, not enough data exists to support the use of multivitamins, calcium, soy products and other supplements for primary or secondary stroke prevention.

Intraoperative vascular mapping improves patient eligibility for arteriovenous fistula creation.

BACKGROUND: We assessed the utility of intraoperative vein mapping performed by the operating surgeon for evaluating vessel suitability for arteriovenous fistula (AVF) creation. METHODS: In a retrospective review of 222 AVFs, vein diameter measurements were compared between intraoperative and preoperative mapping in the same anatomical location. AVF creation was based on intraoperative vein diameter ≥2 mm, using a distal to proximal and superficial veins first approach. Potential selection of access type based on preoperative findings alone was analyzed. RESULTS: The mean diameter of the veins used for AVF creation measured 3.6 ± 0.8 mm on intraoperative duplex versus 2.5 ± 0.9 mm when the same veins were measured on preoperative duplex. Based on preoperative mapping alone, 23% of patients would have received a more proximal AVF and 5% would have needed a graft. AVFs created more distally based on intraoperative findings had similar maturation rates compared to the rest of the cohort, 79% versus 84% (p = 0.2). CONCLUSIONS: Intraoperative vein mapping can be used to evaluate vessel suitability for AVF and compared to pre-operative vein mapping may increase the eligibility of distal veins for fistula creation while reducing the need for AV grafts.

Knowledge gaps in surgical management for aortic dissection.

Aortic dissection (AD) is recognized as a potentially fatal condition and its standard treatment has been surgical intervention for acute type A AD (TAAD) and complicated acute type B AD (TBAD), and medical management for uncomplicated acute type B AD. Due to rapidly evolving device technologies and minimally invasive surgical techniques that have lowered perioperative risk, there are paradigm shifts for the indications and treatment options for both TAAD and TBAD. In this article, we will discuss the current indications and treatment options for TAAD and TBAD by chronicity of the disease, which comprises four categories: acute TAAD, chronic (repaired) TAAD, acute TBAD, and chronic TBAD. We will also discuss the knowledge gaps in the current surgical management strategies and literature evidence. Open surgical intervention remains the reference standard for acute TAAD and chronic TAAD with complications until an endoprosthesis that will suit the complex anatomy of aortic root, ascending aorta, and aortic arch is developed. Thoracic endovascular aortic repair is now the first line for complicated acute and chronic TBADs. However, we need a larger trials to support the safety and durability of the procedures in patients with uncomplicated TBAD. Without additional data, patients are left to choose between existing treatment options, such as open surgical repair and stent-grafting.