Treatment Location Variation for Chronic Limb-Threatening Ischemia in Patients With Kidney Failure

INTRODUCTION

End-stage kidney disease (ESKD) is an established risk factor for chronic limb-threatening ischemia (CLTI). Procedural location for ESKD patients has not been well described. This study aims to examine variation in index procedural location in ESKD versus non-ESKD patients undergoing peripheral vascular intervention for CLTI and identify preoperative risk factors for tibial interventions.

METHODS

Chronic limb-threatening ischemia (CLTI) patients were identified in the Vascular Quality Initiative (VQI) peripheral vascular intervention dataset. Patient demographics and comorbidities were compared between patients with and without ESKD and those undergoing index tibial versus nontibial interventions. A multivariable logistic regression evaluating risk factors for tibial intervention was conducted.

RESULTS

A total of 23,480 procedures were performed on CLTI patients with 13.6% (n = 3154) with ESKD. End-stage kidney disease (ESKD) patients were younger (66.56 ± 11.68 versus 71.66 ± 12.09 y old, P = 0.019), more often Black (40.6 versus 18.6%, P < 0.001), male (61.2 versus 56.5%, P < 0.001), and diabetic (81.8 versus 60.0%, P < 0.001) than non-ESKD patients. Patients undergoing index tibial interventions had higher rates of ESKD (19.4 versus 10.6%, P < 0.001) and diabetes (73.4 versus 57.5%, P < 0.001) and lower rates of smoking (49.9 versus 73.0%, P < 0.001) than patients with nontibial interventions. ESKD (odds ratio (OR) 1.67, 95% confidence interval (CI) 1.52-1.86, P < 0.001), Black race (OR 1.19, 95% CI 1.09-1.30, P < 0.001), and diabetes (OR 1.82, 95% CI 1.71-2.00, P < 0.001) were risk factors for tibial intervention.

CONCLUSIONS

Patients with ESKD and CLTI have higher rates of diabetes and tibial disease and lower rates of smoking than non-ESKD patients. Tibial disease was associated with ESKD, diabetes, and Black race.

Investigating glycemic control in patients undergoing lower extremity bypass within an enhanced recovery pathway at a single institution

BACKGROUND

Enhanced recovery pathways (ERPs) aim to lower perioperative stress to facilitate recovery. Limited fasting combined with carbohydrate loading is a common ERP element. The effect of limited fasting has not been elucidated in patients with diabetes. Given the known deleterious effects of poor glycemic control in the perioperative period, such as increased rates of surgical site infection, the associations of preoperative limited fasting with perioperative glycemic control and early outcomes after lower extremity bypass (LEB) were investigated.

METHODS

A single institutional retrospective review of patients who underwent infrainguinal LEB from 2016 to 2022 was performed. The ERP was initiated in May 2018. Patients were stratified by diabetes diagnosis and preoperative hemoglobin A1C (HbA1C) levels. Perioperative glycemic control was compared between the limited fasting and traditional fasting patients (nil per os at midnight). Limited fasting was defined as a clear liquid diet until 2 hours before surgery with recommended carbohydrate loading consisting of 400 cc of a clear sports drink (approximately 30 g of carbohydrates). All limited fasting patients were within the ERP. Early perioperative hyperglycemia (EPH) was defined as blood glucose of >180 mg/dL within the first 24 hours of surgery. Perioperative outcomes such as surgical site infection, readmission, reinterventions, and complications were also compared.

RESULTS

A total of 393 patients were included (limited fasting patients N = 135; traditional fasting patients N = 258). A trend toward EPH was seen in all limited fasting groups. Evaluating limited fasting within diabetic patients revealed that 74.5% of limited fasting-diabetic patients had EPH compared with 49.6% of traditional fasting-diabetic patients (P = .001). When stratified by the HbA1C level, a significantly higher rate of EPH was seen in the HbA1c >8.0% groups, with 90.5% in the limited fasting patients compared with 67.9% in traditional fasting patients (P = .05). Limited fasting-diabetic patients experience a longer postoperative length of stay at 5.0 days (interquartile range: 3, 9) vs 4.0 days (2, 6) in nondiabetic patients (P = .016).

CONCLUSIONS

ERP limited fasting was associated with early perioperative hyperglycemia after LEB, particularly in patients with HbA1C >8.0%. Due to the high prevalence of diabetic patients undergoing LEB under ERP, the role of limited fasting and common glycemic elements of ERP may need to be re-evaluated in this subpopulation.

Differences in Long-Term Outcomes in End-Stage Kidney Disease Patients with Chronic Limb-Threatening Ischemia

BACKGROUND

End-stage kidney disease (ESKD) is a risk factor for peripheral arterial disease and major adverse limb events following infra-inguinal bypass. Despite comprising an important patient population, ESKD patients are rarely analyzed as a subgroup and are underrepresented in vascular surgery guidelines. This study aims to compare the long-term outcomes of patients with and without ESKD undergoing endovascular peripheral vascular intervention (PVI) for chronic limb-threatening ischemia (CLTI).

METHODS

CLTI patients with and without ESKD from 2007-2020 were identified in the Vascular Quality Initiative PVI dataset. Patients with prior bilateral interventions were excluded. Patients undergoing femoral-popliteal and tibial interventions were included. Mortality, reintervention, amputation, and occlusion rates at 21 months following intervention were examined. Statistical analyses were completed with the t-test, chi-square, and Kaplan-Meier curves.

RESULTS

The ESKD cohort was younger (66.4 ± 11.8 vs. 71.6 ± 12.1 years, P < 0.001) with higher rates of diabetes (82.2 vs. 60.9%, P < 0.001) the non-ESKD cohort. Long-term follow-up was available for 58.4% (N = 2,128 procedures) of ESKD patients and 60.8% (N = 13,075 procedures) of non-ESKD patients. At 21 months, ESKD patients had a higher mortality (41.7 vs. 17.4%, P < 0.001) and a higher amputation rate (22.3 vs. 7.1%, P < 0.001); however, they had a lower reintervention rate (13.2 vs. 24.6%, P < 0.001).

CONCLUSIONS

CLTI patients with ESKD have worse long-term outcomes at 2 years following PVI than non-ESKD patients. Mortality and amputation are higher with ESKD, while the reintervention rate is lower. Development of guidelines within the ESKD population has the potential to improve limb salvage.

Aortic Visceral Segment Instability is evident following Thoracic Endovascular Aortic Repair for Acute and Subacute Type B Aortic Dissection

BACKGROUND

Anatomic remodeling within the thoracic aorta following thoracic endovascular aortic repair (TEVAR) for type B aortic dissections (TBAD) has been well documented, but less is known about the response of the untreated visceral aorta. This study aims to investigate visceral aortic behavior following TEVAR for acute or subacute TBAD and identify associations with clinical outcomes.

METHODS

A multi-center retrospective review was performed of all imaging for all patients treated with TEVAR for acute (0-14 days) and subacute (14-90 days) non-traumatic TBAD between 2006-2020. Cohort was inclusive of uncomplicated, high-risk, and complicated (defined per SVS reporting guidelines) dissections. Centerline aortic measurements of the true and false lumen and total aortic diameter (TAD) were taken at standardized locations relative to aortic anatomy within each aortic zone (zones defined by SVS reporting guidelines). Diameter changes over time were evaluated using repeated measures mixed effects linear growth modeling. Visceral segment instability (VSI) was defined as any growth in TAD ≥ 5mm within aortic zones 5 through 9.

RESULTS

A total of 82 patients were identified. Median length of imaging follow-up was 2.1 years (IQR 3.9 years), with 15% of the cohort having follow-up longer than 5 years. VSI was present in 55% of the cohort, with an average maximal increase in TAD of 10.4±6.3 mm over a median follow-up of 2.1 years (IQR 3.9 years). Roughly a third of the cohort experienced rapid VSI (growth ≥5mm in first year), and 4.8% of the cohort developed a large para-visceral aneurysm aortic (TAD≥5cm) secondary to VSI. Linear growth modeling identified significant predictable growth in TAD across all visceral zones. Zones 7 had the highest rate of TAD dilation, with a fixed effect estimated rate of 1.3 mm per year (95%-CI 0.23-2.1, p=0.022). The preoperative factor most strongly associated with VSI was ≥6 cumulative number of zones dissected (OR 6.4, 95% OR 1.07-8.6, p=0.041). Odds for aortic reintervention were significantly increased in cases where VSI led to development of a para-visceral aortic aneurysm ≥5cm development (OR 3.7, 95%-CI 1.1-13, p=0.038).

CONCLUSION

VSI was identified in the majority of patients treated with TEVAR for management of acute and subacute TBAD. Preoperative anatomic features such as extent of dissection, rather than procedural details of graft coverage, may play a more significant role in VSI occurrence. Importantly, significant TAD growth occurred in all visceral segments. These results highlight the importance of lifelong surveillance following TEVAR, and identify a subset of patients that may be at increased risk for re-intervention.

WDR76 Co-Localizes with Heterochromatin Related Proteins and Rapidly Responds to DNA Damage

Proteins that respond to DNA damage play critical roles in normal and diseased states in human biology. Studies have suggested that the S. cerevisiae protein CMR1/YDL156w is associated with histones and is possibly associated with DNA repair and replication processes. Through a quantitative proteomic analysis of affinity purifications here we show that the human homologue of this protein, WDR76, shares multiple protein associations with the histones H2A, H2B, and H4. Furthermore, our quantitative proteomic analysis of WDR76 associated proteins demonstrated links to proteins in the DNA damage response like PARP1 and XRCC5 and heterochromatin related proteins like CBX1, CBX3, and CBX5. Co-immunoprecipitation studies validated these interactions. Next, quantitative imaging studies demonstrated that WDR76 was recruited to laser induced DNA damage immediately after induction, and we compared the recruitment of WDR76 to laser induced DNA damage to known DNA damage proteins like PARP1, XRCC5, and RPA1. In addition, WDR76 co-localizes to puncta with the heterochromatin proteins CBX1 and CBX5, which are also recruited to DNA damage but much less intensely than WDR76. This work demonstrates the chromatin and DNA damage protein associations of WDR76 and demonstrates the rapid response of WDR76 to laser induced DNA damage.

ASB2 is an Elongin BC-interacting protein that can assemble with Cullin 5 and Rbx1 to reconstitute an E3 ubiquitin ligase complex

The ankyrin repeat-containing protein with a suppressor of cytokine signaling box-2 (ASB2) gene was identified as a retinoic acid-response gene and a target of the promyelocytic leukemia-retinoic acid receptor-alpha oncogenic protein characteristic of acute promyelocytic leukemia. Expression of ASB2 in myeloid leukemia cells inhibits growth and promotes commitment, recapitulating an early step known to be critical for differentiation. Here we show that ASB2, by interacting with the Elongin BC complex, can assemble with Cullin5.Rbx1 to form an E3 ubiquitin ligase complex that stimulates polyubiquitination by the E2 ubiquitin-conjugating enzyme Ubc5. This is a first indication that a member of the ASB protein family, ASB2, is a subunit of an ECS (Elongin C-Cullin-SOCS box)-type E3 ubiquitin ligase complex. Altogether, our results strongly suggest that ASB2 targets specific proteins to destruction by the proteasome in leukemia cells that have been induced to differentiate.