Association of frailty with post-operative survival and outcomes following hemodialysis vascular access creation.

BACKGROUND: The literature suggests that for patients to experience the purported advantages of an arteriovenous fistula (AVF) over arteriovenous graft (AVG), a minimum survival of 18 months is required. With the vascular access guideline shift away from "Fistula First" towards shared decision making, patient survival after vascular access creation is a major factor to consider in optimal access selection. The objective of this study is to examine outcomes of vascular access in patients with short survival and factors associated with short survival, including frailty. METHODS: We performed a retrospective review of 200 access procedures performed between August 2018 and November 2020 at a single institution. Maturation was defined as the date when the surgeon deemed the access ready to be used for dialysis. A modified Risk Analysis Index (RAI) score was used to calculate frailty. RESULTS: Within 3 years after access creation, 55 (27.5%) patients were recorded as dead (3YMORT). In the 3YMORT group, 5 did not follow up with the surgeon prior to death and 22/34 (65%) of AVF vs 15/16 (94%) of AVGs were deemed mature prior to death (P=0.03). Of the accesses that matured, the median days to maturation for AVF was 69 (IQR 53, 87) vs 28 (IQR 18, 32) for AVG (P<0.001). Patients in the 3YMORT group were older (70.6 vs 63.4, P=0.004) and had a lower body mass index (BMI) (24.8 vs 27.4, P=0.03). Patients in the 3YMORT group had higher prevalence of dysrhythmia (35% vs 15%, p=0.002), COPD (20% vs 10%, P=0.048) and dialysis dependence at the time of access creation (91% vs 75%, P=0.01). There was no significant difference in sex, white race, Hispanic ethnicity, coronary artery disease, congestive heart failure, previous coronary artery bypass graft or percutaneous coronary intervention, diabetes, hypertension, and peripheral arterial disease between the two groups. The 3YMORT group had a significantly higher prevalence of frailty (78% vs 49%, P=0.0002). Patients categorized as frail by the RAI had a significantly higher risk of 3YMORT (OR 3.74, 95% CI 1.82-7.66) compared to non-frail patients. Patients categorized as very frail by the RAI had an even higher risk of 3YMORT (OR 4.20, 95% CI 1.95-9.05), compared to non-frail patients. CONCLUSIONS: Patients with short life expectancy after vascular access creation may have high rates of AVF non-maturation and longer time to maturation. Factors associated with high risk of mortality within 3 years of vascular access creation correlate well with factors included in the RAI frailty score. Patients who are frail or very frail may be appropriate candidates for AVG creation over AVF considering their high risk for short life expectancy.

Population-Level Associations Between Visual Impairment and Functional Difficulties in California.

PURPOSE: The prevalence of visual impairment is increasing, and there is a need to understand the functional implications. Using the American Community Survey (ACS) data, this study examined the relationship between visual impairment and functional difficulties in California. METHODS: Using the 2010-2014 and 2015-2019 ACS 5-year estimates from the U.S. Census, data were obtained for visual impairment and functional difficulties including hearing, cognitive, ambulatory, self-care, and independent living difficulties. The prevalence of vision impairment and each functional difficulty was calculated on the Medical Service Study Area (MSSA) level in California. Unadjusted and adjusted linear regression models were performed to estimate the association between visual impairment and each functional difficulty, adjusting for age, sex, race and ethnicity, education level, English-speaking ability, poverty status, health insurance status, and urbanity of residence location. RESULTS: The prevalence of visual impairment in California was 2.3% (659,502 of 28,794,572) in 2010-2014 and 2.3% (709,353 of 30,231,767) in 2015-2019 among the population ≥ 18 years old. There were statistically significant associations between the prevalence of vision impairment and increased prevalence of all functional difficulties, with the most positive correlation observed with ambulatory difficulty (slope estimate 0.58 ± 0.072 for 2010-2014 and 0.78 ± 0.082 for 2015-2019 for ambulatory difficulty). CONCLUSIONS: There may be population-level impacts of functional consequences from vision impairment, suggesting the need for neighborhood-level investigation and policy-based interventions to address the burden of vision impairment on the population level.

Short-term mortality and revisions to promote maturation after arteriovenous fistula creation.

OBJECTIVE: Arteriovenous fistula (AVF) for hemodialysis access is traditionally considered superior to grafts due to infection resistance and purported improved patency. However, challenges to AVF maturation and limited patient survival may reduce AVF benefits. The objective of this study is to identify factors associated with risk of AVF requiring revision before maturation and/or mortality within 2 years of creation. METHODS: We performed a retrospective review of 250 AVFs created between May 2017 and November 2020 at a single institution. Maturation was defined as the date the surgeon deemed the AVF ready for use or the patient successfully used the AVF for dialysis. The Risk Analysis Index was used to calculate frailty. The primary outcome was a composite of endovascular/surgical revision to promote maturation and/or mortality within 2 years of AVF creation (REVDEAD). The primary outcome was categorized as met if the patient required a revision to promote maturation or if the patient experienced mortality within 2 years of AVF creation, or if both occurred. REVDEAD was compared with those who did not meet the primary outcome and will be referred to as NOREVDEAD. RESULTS: Survival at 2 years after AVF creation was 82%, and 54 (22%) patients underwent AVF revision. Of those, 31 (59%) patients progressed to AVF maturation. Of the 250 AVFs, 91 (36%) met the primary outcome of REVDEAD and 159 (64%) did not (NOREVDEAD). There was no difference between the REVDEAD and NOREVDEAD groups in age (P = .18), sex (P = .75), White race (P = .97), Hispanic ethnicity (P = .62), obesity (P = .76), coronary artery disease (P = .07), congestive heart failure (P = .29), diabetes mellitus (P = .78), chronic obstructive pulmonary disease (P = .10), dialysis status (P = .63), hypertension (P = .32), peripheral arterial disease (P = .34), or dysrhythmia (P = .13). There was no difference between the groups in the forearm vs the upper arm location of AVF (P = .42) or the vein diameter (P = .58). Forearm access, as opposed to upper arm AVF creation, was associated with higher rate of revision before maturation (P = .05). More patients in REVDEAD were frail or very frail (60% vs 48%, P = .05). Of the AVFs that matured, maturation required longer time in REVDEAD at 110.0 ± 9.1 days vs 78.8 ± 5.6 days (mean ± standard deviation) (P = .003). Adjusted for the vein diameter and the forearm vs the upper arm, frailty increased the odds of REVDEAD by 1.9 (95% confidence interval: 1.1, 3.3). CONCLUSIONS: Frail patients who underwent AVF were significantly more likely to die within 2 years of AVF creation with no significant association between frailty and the need for revisions to promote maturation. Forearm AVFs were more likely to require revisions; in patients who are frail, with a high likelihood of 2-year mortality, graft may be more appropriate than AVF. If AVF is being considered in a frail patient, upper arm AVFs should be prioritized over forearm AVFs.

Association Between Geographic Distribution of Eye Care Clinicians and Visual Impairment in California.

Importance: The association between availability of eye care clinicians and visual impairment, a condition presenting with increased morbidity and health care costs, has not been thoroughly studied. Objective: To examine associations between the geographic distribution of eye care clinicians and visual impairment in California. Design, Setting, and Participants: This survey-based cross-sectional study included ophthalmologists and optometrists licensed in California in 2018 and 2020 as well as respondents to the 2014 to 2018 American Community Survey (ACS) by California counties and Medical Service Study Areas (MSSAs). Data were analyzed from August 2020 to December 2021. Main Outcomes and Measures: Prevalence of visual impairment by county and MSSA. Exposures: The number of eye care clinicians was determined based on the number of member ophthalmologists of the American Academy of Ophthalmology in 2018 and optometrists listed in the 2020 Blue Book of Optometrists in California. The prevalence of visual impairment was determined using questionnaire data from the American Community Survey. Linear regression was used to assess multivariable associations between number of eye care clinicians and visual impairment by MSSA. Results: A total of 30 068 581 California residents were included; 15 253 655 (50.7%) were female, and 5 314 389 (17.7%) were 65 years and older. The overall number of eye care clinicians was 22.18 clinicians per 100 000 residents. The overall prevalence of visual impairment was 2411.07 residents with visual impairment per 100 000 residents. San Francisco County had the highest number of eye care clinicians per 100 000 residents (39.24 clinicians per 100 000 residents). Four counties had no eye care clinicians (Alpine, Mariposa, Inyo, and Sierra counties). For every increase of 1 eye care clinician per 100 000 residents, there was a mean (SE) decrease of 3.90 (1.39) persons with visual impairment per 100 000 residents in adjusted analyses. Conclusions and Relevance: In this cross-sectional study, a higher number of eye care clinicians was potentially associated with lower prevalence of visual impairment in California. Additional studies are needed to assess eye care clinician availability on a national and global scale and strategies to improve access to eye care.

Technical note: Evaluation of a silicone-based custom bolus for radiation therapy of a superficial pelvic tumor.

PURPOSE: Use of standard-of-care radiation therapy boluses may result in air-gaps between the target surface and bolus, as they may not adequately conform to each patient's unique topography. Such air-gaps can be particularly problematic in cases of superficial pelvic tumor radiation, as the density variation may result in the radiation delivered to the target site being inconsistent with the prescribed dose. To increase bolus fit and thereby dose predictability and homogeneity, we designed and produced a custom silicone bolus for evaluation against the clinical standard. METHODS: A custom bolus was created for the pelvic regions of both an anthropomorphic phantom and a pelvic patient with squamous cell carcinoma of the penile shaft. Molds were designed using computed tomography (CT) scans, then 3D-printed and cast with silicone rubber to yield the boluses. Air-gap measurements were performed on custom and standard-of-care Superflab gel sheet boluses by analyzing total volume between the bolus and target surface, as measured from CT scans. Therapeutic doses of radiation were delivered to both boluses. Radiation dose was measured and compared to the expected dose using nine optically stimulated luminescent dosimeters (OSLDs) placed on the phantom. RESULTS: Mean air-gap volume between the bolus and phantom was decreased from 314 ± 141 cm3 with the standard bolus to 4.56 ± 1.59 cm3 using the custom device. In the case of the on-treatment patient, air-gap volume was reduced from 169 cm3 with the standard bolus to 46.1 cm3 with the custom. Dosimetry testing revealed that the mean absolute difference between expected and received doses was 5.69%±4.56% (15.1% maximum) for the standard bolus and 1.91%±1.31% (3.51% maximum) for the custom device. Areas of greater dose difference corresponded to areas of larger air-gap. CONCLUSIONS: The custom bolus reduced air-gap and increased predictability of radiation dose delivered compared to the standard bolus. The custom bolus could increase the certainty of prescribed dose-delivery of radiation therapy for superficial tumors.