A Murine Model of Hemodialysis Access-related Hand Dysfunction

Chronic kidney disease is a major public health problem, and the prevalence of end-stage renal disease (ESRD) requiring chronic renal replacement therapies such as hemodialysis continues to increase. Autogenous arteriovenous fistula (AVF) placement remains a primary vascular access option for ESRD patients. Unfortunately, approximately half of the hemodialysis patients experience dialysis access-related hand dysfunction (ARHD), ranging from subtle paresthesia to digital gangrene. Notably, the underlying biologic drivers responsible for ARHD are poorly understood, and no adequate animal model exists to elucidate the mechanisms and/or develop novel therapeutics for the prevention/treatment of ARHD. Herein, we describe a new mouse model in which an AVF is created between the left common iliac artery and vein, thereby facilitating the assessment of limb pathophysiology. The microsurgery includes vessel isolation, longitudinal venotomy, creation of arteriovenous anastomosis, and venous reconstruction. Sham surgeries include all the critical steps except for AVF creation. Iliac AVF placement results in clinically relevant alterations in central hemodynamics, peripheral ischemia, and impairments in hindlimb neuromotor performance. This novel preclinical AVF model provides a useful platform that recapitulates common neuromotor perturbations reported by hemodialysis patients, allowing researchers to investigate the mechanisms of ARHD pathophysiology and test potential therapeutics.

Safety of Cerebrospinal Fluid Drainage for Spinal Cord Ischemia Prevention in Thoracic Endovascular Aortic Repair

Objective

Spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR) is associated with permanent neurologic deficit and decreased survival. Prophylactic cerebrospinal fluid (CSF) drainage (CSFD) in TEVAR is controversial. We evaluated the usage of CSFD in TEVAR at our tertiary aortic center.

Methods

Our institutional TEVAR database was reviewed to determine the frequency of CSFD usage/complications. Complications were categorized as mild (headache/CSF leak not requiring intervention, urinary retention), moderate (headache/CSF leak requiring intervention, drain malfunction requiring replacement), or severe (intrathecal hemorrhage, CSFD-attributable neurologic deficit). The relationships between CSFD complications and patient/procedural characteristics, CSFD placement timing, and survival were analyzed.

Results

Nine hundred thirty-six TEVAR procedures were performed in 869 patients from 2011 to 2020. Three hundred ninety CSFD drains were placed in 373 (41.7%) TEVAR patients. Most CSFD drains (89.5%) were pre-TEVAR. Most post-TEVAR drains were placed for new SCI symptoms (n = 21). Twenty-five patients (6.4%) suffered 32 CSFD complications. Most (n = 17) were mild in severity. Severe CSFD complications occurred in 5/432 (1.1% CSF drains) patients. No patient/procedural characteristics were predictive of CSFD complications. Post implant CSFD placement for new SCI symptoms conferred an increased risk of CSFD complication (odds ratio, 6.9; 95% CI, 2.42-19.6; P < .01). The long-term survival of the CSFD complication cohort did not differ from the overall population.

Conclusions

Post-TEVAR CSFD placement for new SCI symptoms was associated with substantially greater risk of CSFD complications. Avoidance of post-implant therapeutic drain placement might be the key to prevention of CSFD complications, favoring a strategy of selective pre-implant drain placement in patients at higher risk for SCI.

Abstract 361: Bidirectional Mendelian Randomization Investigating The Causal Relationship Between Major Depressive Disorder And Peripheral Artery Disease

Background: Observational studies have demonstrated strong bi-directional associations between depression and peripheral artery disease (PAD), and patients suffering from PAD who have depressive symptoms are known to have worse outcomes. Whether these associations represent causal pathways remains unknown but has important implications for disease management.

Methods: We performed causal inference experiments using bi-directional Mendelian randomization. We employed summary statistics from the 2019 Psychiatric Genomics Consortium meta-analysis of major depressive disorder (MDD) comprised of 807,553 participants (246,363 cases) of European ancestry and the VA Million Veteran Program GWAS of PAD comprised of 243,060 participants (31,307 cases) of multiple ancestries to test the association between genetic liability to MDD and genetic liability to PAD. Genetic instruments for each exposure were constructed using independent (r 2 < 0.1 by 1000 Genomes EUR LD reference panel) variants associated with the exposure at genome-wide significance (p < 5x10 -8 ). Inverse-variance weighted MR was used as the primary analysis method, with weighted-median MR, MR-PRESSO, and Steiger filtering based MR performed as sensitivity analyses. F-statistics were calculated to assess weak-instrument bias. The Egger bias-intercept test was used to detect evidence of horizontal pleiotropy.

Results: Increased genetic liability to MDD was associated with increased genetic liability to PAD (OR 1.2, 95%CI 1.1 - 1.3, p=.0001). We could not detect an effect of genetic liability to PAD on the genetic liability to MDD (OR 1.03, 95%CI 0.99 - 1.08). The results of sensitivity analyses that make different instrumental variable assumptions were consistent with these findings.

Conclusions: These results suggest a causal relationship in which MDD increases the risk of PAD, but do not provide evidence to support the causal role of PAD in MDD. Ongoing analyses are focused on identifying potential mediators of the association between MDD and PAD and performing causal inference for the effect of other mental health traits on PAD.

Long-term age-stratified survival following endovascular and open abdominal aortic aneurysm repair

OBJECTIVE

The long-term survival differences between endovascular and open repair for abdominal aortic aneurysms and specifically the impact of age on these differences remain a topic of debate. Therefore, we compared the long-term mortality between endovascular and open abdominal aneurysm repair for patients of different ages.

METHODS

This was a retrospective cohort study of prospectively collected data from patients undergoing elective endovascular or open repair for infrarenal abdominal aortic aneurysms within the Vascular Quality Initiative multi-national clinical registry (2003-2021). The primary outcome was long-term all-cause mortality comparing endovascular and open repair for patients aged <65 years, between 65-79 years, and those aged ≥80. In addition, we investigated the interaction between repair modality and ten-year hazard of mortality for sex, aneurysm diameter, and several pre-operative comorbid conditions within each age category. To account for non-random assignment of treatment, we used propensity scores and inverse probability weighted Cox proportional hazard analysis.

RESULTS

We identified 48,074 patients undergoing elective infrarenal abdominal aneurysm repair (89% endovascular) within the study period, including 7,940 patients aged <65, 29,555 aged between 65-79, and 10,579 aged ≥80 years. EVAR was associated with a higher propensity score-adjusted long-term hazard of mortality compared to open repair in the cohort aged <65 years (hazard ratio [HR]: 1.39; 95% confidence interval [CI]: 1.04-1.86; P=.026). The mortality was similar in the age cohort between 65-79 (HR: 0.94; 95%CI: 0.79-1.10; P=.43), while EVAR was associated with a lower hazard of mortality in the cohort aged ≥80 years (HR: 0.63; 95%CI: 0.46-0.86; P=.004). In patients aged <65, the hazard of mortality was higher with endovascular compared with open repair in those with female sex (HR: 4.40; 95%CI: 1.75-11.0), an aneurysm diameter >65mm (HR: 2.19; 95%CI: 1.11-4.34), and absence of coronary artery disease (HR: 1.26; 95%CI: 0.83-1.91), congestive heart failure (HR: 1.41; 95%CI: 1.03-1.92), and renal dysfunction (HR: 1.46; 95%CI: 1.04-2.05). In the patient cohort aged ≥80, a lower hazard of mortality for endovascular vs. open repair was observed for male patients, or those with small aneurysms or certain comorbidities.

CONCLUSIONS

In a selected group of young patients with a substantial life expectancy, the long-term mortality is higher with endovascular compared to open repair for infrarenal abdominal aortic aneurysms. Long-term mortality with endovascular repair is similar in the middle cohort and lower in the elderly cohort compared to open repair.

Association of Statin and Antiplatelet Use with Survival in Patients with AAA with and without Concomitant Atherosclerotic Occlusive Disease

OBJECTIVES

Statin therapy has been associated with improved clinical outcomes in patients undergoing treatment for vascular disease. Current guidelines do not address statin therapy in isolated abdominal aortic aneurysm (AAA) in the absence of other atherosclerotic cardiovascular disease (ASCVD). This study aims to elucidate effects of statin therapy, either as monotherapy or combined with antiplatelet agents, on the long-term mortality of patients with and without ASCVD who undergo elective AAA repair.

METHODS

A retrospective review was performed on all AAA patients treated electively with endovascular (EVAR) and open aortic repair (OAR) in the Society for Vascular Surgery Vascular Quality Initiative from 2003-2020. Long-term mortality was evaluated based on the presence of statin and antiplatelet medication use at discharge stratified by those with and without a history of ASCVD. Unadjusted survival was estimated by Kaplan Meier methodology. Cox proportional hazards modeling was used to determine mortality risk after adjusting for key factors.

RESULTS

A total of 47,012 AAA repairs were selected for analysis: 80.7% EVAR (N=40,153) and 19.3% OAR (N=6,859). EVAR patients on combined statin/antiplatelet (AP) therapy had significantly better survival irrespective of whether they had known ASCVD. In the presence of ASCVD, EVAR patients on statin alone had improved survival compared to those not on a statin (10.9±0.5 vs 10.5±0.4 years, Log Rank <.001), with survival being even greater among those receiving combined statin/AP therapy (12.2±0.2 vs 10.5±0.4 years, Log Rank <.001). In the absence of ASCVD, EVAR patients on statin alone also had better mean survival compared to patients not on a statin (8.7±0.5 vs 8.4±0.4 years, Log Rank<.001), with higher survival among statin/AP therapy patients (9.4±0.2 years vs 8.7±0.5 years, Log Rank <.001). Comparison of adjusted survival via Cox multivariable regression demonstrated a protective effect of statins (HR=0.737, p=0.04, vs no medication) and combined statin/AP therapy (HR=0.659, p=0.001, vs no medication) in patients with ASCVD history. A similar protective effect (statin: HR 0.826, p=0.05. Combination statin/AP: HR 0.726, p<.001, vs no medication) was identified in patients without ASCVD history. Within the OAR cohort, statin therapy was not associated with improved survival among patients without ASCVD; however, combined statin/AP therapy had a protective effect for patients with a known ASCVD diagnosis. Based on KM analysis, OAR patients with ASCVD on combined statin/AP therapy had significantly higher mean survival compared to isolated statin therapy (12.7±0.2 vs 10.3±0.65 years) and no medical therapy (10.5±0.8 years, Log Rank <.001). In KM analysis, OAR patients without known ASCVD indications (N=3591) had no significant survival differences based on the presence of combined statin/AP therapy (8.4 ± .07 vs. 8.5 ± .11 years, Log Rank=.638).

CONCLUSION

Isolated statin therapy and combined statin/AP therapy showed significant survival benefit in all EVAR and OAR patients with ASCVD indications, as well as among EVAR patients without a known ASCVD diagnosis. OAR patients without ASCVD did not have a significant survival benefit from statin therapy, but low numbers in this group may have confounded the findings. Combined statin/AP therapy appears to have significant post-repair survival benefits even in isolated AAA without ASCVD, as demonstrated in post-EVAR patients in this study. Expansion of statin use recommendations within aneurysm treatment guidelines may be warranted.

Interventional- and amputation-stage muscle proteomes in the chronically threatened ischemic limb

BACKGROUND

Despite improved surgical approaches for chronic limb-threatening ischemia (CLTI), amputation rates remain high and contributing tissue-level factors remain unknown. The purpose of this study was twofold: (1) to identify differences between the healthy adult and CLTI limb muscle proteome, and (2) to identify differences in the limb muscle proteome of CLTI patients prior to surgical intervention or at the time of amputation.

METHODS AND RESULTS

Gastrocnemius muscle was collected from non-ischemic controls (n = 19) and either pre-interventional surgery (n = 10) or at amputation outcome (n = 29) CLTI patients. All samples were subjected to isobaric tandem-mass-tag-assisted proteomics. The mitochondrion was the primary classification of downregulated proteins (> 70%) in CLTI limb muscles and paralleled robust functional mitochondrial impairment. Upregulated proteins (> 38%) were largely from the extracellular matrix. Across the two independent sites, 39 proteins were downregulated and 12 upregulated uniformly. Pre-interventional CLTI muscles revealed a robust upregulation of mitochondrial proteins but modest functional impairments in fatty acid oxidation as compared with controls. Comparison of pre-intervention and amputation CLTI limb muscles revealed mitochondrial proteome and functional deficits similar to that between amputation and non-ischemic controls. Interestingly, these observed changes occurred despite 62% of the amputation CLTI patients having undergone a prior surgical intervention.

CONCLUSIONS

The CLTI proteome supports failing mitochondria as a phenotype that is unique to amputation outcomes. The signature of pre-intervention CLTI muscle reveals stable mitochondrial protein abundance that is insufficient to uniformly prevent functional impairments. Taken together, these findings support the need for future longitudinal investigations aimed to determine whether mitochondrial failure is causally involved in amputation outcomes from CLTI.

S100A8 and S100A9 are elevated in chronically threatened ischemic limb muscle and induce ischemic mitochondrial pathology in mice

Objective

The objective of the present study was to determine whether elevated levels of S100A8 and S100A9 (S100A8/A9) alarmins contribute to ischemic limb pathology.

Methods

Gastrocnemius muscle was collected from control patients without peripheral arterial disease (PAD; n = 14) and patients with chronic limb threatening limb ischemia (CLTI; n = 14). Mitochondrial function was assessed in permeabilized muscle fibers, and RNA and protein analyses were used to quantify the S100A8/A9 levels. Additionally, a mouse model of hindlimb ischemia with and without exogenous delivery of S100A8/A9 was used.

Results

Compared with the non-PAD control muscles, CLTI muscles displayed significant increases in the abundance of S100A8 and S100A9 at both mRNA and protein levels (P < .01). The CLTI muscles also displayed significant impairment in mitochondrial oxidative phosphorylation and increased mitochondrial hydrogen peroxide production compared with the non-PAD controls. The S100A8/A9 levels correlated significantly with the degree of muscle mitochondrial dysfunction (P < .05 for all). C57BL6J mice treated with recombinant S100A8/A9 displayed impaired perfusion recovery and muscle mitochondrial impairment compared with the placebo-treated mice after hindlimb ischemia surgery. These mitochondrial deficits observed after S100A8/A9 treatment were confirmed in the muscle cell culture system under normoxic conditions.

Conclusions

The S100A8/A9 levels were increased in CLTI limb muscle specimens compared with the non-PAD control muscle specimens, and the level of accumulation was associated with muscle mitochondrial impairment. Elevated S100A8/A9 levels in mice subjected to hindlimb ischemia impaired perfusion recovery and mitochondrial function. Together, these findings suggest that the inflammatory mediators S100A8/A9 might be directly involved in ischemic limb pathology.

Despite improvements in the surgical management of chronic limb threatening limb ischemia (CLTI), the rates of major adverse limb events have remained high. Skeletal muscle has emerged as a strong predictor of outcomes in peripheral arterial disease (PAD)/CLTI; however, a complete understanding of muscle pathology in CLTI is lacking. This study identified elevated S100A8 and S100A9 alarmin proteins as a characteristic of CLTI muscle specimens and that the S100A8/A9 levels are associated with the degree of mitochondrial impairment in patient limb muscle specimens. Using a mouse model of PAD, treatment with S100A8/A9 exacerbated ischemic limb pathology, including impaired limb perfusion recovery and muscle mitochondrial impairment. Taken together, these findings connect the inflammatory milieu in the CLTI limb to exacerbated limb muscle outcomes via mitochondrial alterations.

Development of a murine iliac arteriovenous fistula model for examination of hemodialysis access-related limb pathophysiology

OBJECTIVE

Hemodialysis access-related hand dysfunction is a common clinical feature of patients with chronic kidney disease (CKD) after arteriovenous fistula (AVF) placement. The heterogeneity in symptoms and the lack of a predictive association with changes in hemodynamic alterations precipitated by the AVF suggest that other factors are involved in the mechanisms responsible for causing hand and limb dysfunction postoperatively. To the best of our knowledge, no suitable animal models have provided a platform for performing preclinical experiments designed to elucidate the biologic drivers of access-related hand dysfunction. Therefore, our objective was to develop a novel murine AVF model that could be used to study dialysis access-related limb dysfunction.

METHODS

Male 8-week-old C57BL/6J mice (n = 15/group) were exposed to either an adenine-supplemented diet to induce CKD or casein-based chow (control). Four weeks after the diet intervention, the mice were randomly assigned to receive an iliac AVF (n = 10/group) or sham surgery (n = 5/group) on the left hindlimb. The mice were sacrificed 2 weeks after surgery, and AVF specimens and hindlimb skeletal muscles were collected for further analysis.

RESULTS

Before AVF or sham surgery, the glomerular filtration rates were significantly reduced and the blood urea nitrogen levels were significantly elevated in the CKD groups compared with the controls (P < .05). AVF surgery was associated with an ∼80% patency rate among the survivors (four control and three CKD mice died postoperatively). Patency was verified by changes in hemodynamics using Doppler ultrasound imaging and altered histologic morphology. Compared with sham surgery, AVF surgery reduced ipsilateral hindlimb perfusion to the tibialis anterior muscle (20%-40%) and paw (40%-50%), which remained stable until euthanasia. Analysis of gastrocnemius muscle mitochondrial respiratory function uncovered a significant decrease (40%-50%) in mitochondrial function in the AVF mice. No changes were found in the muscle mass, myofiber cross-sectional area, or centrally nucleated fiber proportion in the extensor digitorum longus and soleus muscles between the sham and AVF mice.

CONCLUSIONS

The results from the present study have demonstrated that iliac AVF formation is a practical animal model that facilitates examination of hemodialysis access-related limb dysfunction. AVF surgery produced the expected hemodynamic changes, and evaluation of the limb muscle revealed a substantial mitochondrial impairment that was present without changes in muscle size.

Multicenter Mid-Term Outcomes of the Chimney Technique in the Elective Treatment of Degenerative Pararenal Aortic Aneurysms

PURPOSE

Chimney endovascular abdominal aortic aneurysm repair (CHEVAR) has predominantly been described as an alternative technique for the management of urgent presentations of degenerative pararenal aortic aneurysms (dPAAs). However, the role of CHEVAR in the treatment of asymptomatic patients remains unknown. The aim of current multinational study was to evaluate the outcomes of elective CHEVAR of dPAAs.

MATERIAL AND METHODS

Retrospective analysis of 267 consecutive dPAA patients treated with elective CHEVAR at 13 European and US centers from 2008 to 2014. Primary endpoints were 30 days and out of hospital CHEVAR-related mortality. Secondary endpoints included persistent type Ia endoleak or endotension, angiographically confirmed occlusion and/or high-grade chimney graft (CG) or involved splanchnic vessel stenosis identified at index procedure and/or during follow-up, as well as CHEVAR-related re-intervention.

RESULTS

Mean follow-up time was 25.5±13.3 months. The 442 visceral vessels were involved and mean number of CGs per patient was 1.63±0.7. 436 targeted vessels were successfully cannulated. The aortic graft intentionally covered 6 renal arteries and immediate technical success was 98.6%. The 30 days mortality was 1.9% (n=5), while the in-hospital complication rate was 10.1% (n=27) including 3 strokes, 1 permanent dialysis, and 1 intestinal ischemia. No 30 day type Ia endoleaks were detected and 3.2% of CGs (n=14, including the intentionally covered) had evidence of occlusion and/or stenosis. The overall CHEVAR-related mortality was 2.2% (n=6). Freedom from primary and secondary type Ia endoleak/endotension rates at 3 years was 93.0% and 98.0%, respectively. Primary and secondary CG patency was 87.0% and 89.0%. Primary and secondary endovascular freedom from any endpoint at 3 years was 81.0% and 94.0% respectively.

CONCLUSION

Elective use of CHEVAR in the management of dPAAs seems to be durable. These results are comparable to published outcomes with other total endovascular strategies, which justifies an expanded role for CHEVAR in the treatment of asymptomatic patients presenting with dPAAs.

Arteriovenous Fistula Maturation, Functional Patency, and Intervention Rates

Importance

National initiatives have emphasized the use of autogenous arteriovenous fistulas (AVFs) for hemodialysis, but their purported benefits have been questioned.

Objective

To examine AVF usability, longer-term functional patency, and remedial procedures to facilitate maturation, manage complications, or maintain patency in the Hemodialysis Fistula Maturation (HFM) Study.

Design, Setting, and Participants

The HFM Study was a multicenter (n = 7) prospective National Institutes of Health National Institute of Diabetes and Digestive and Kidney Diseases cohort study performed to identify factors associated with AVF maturation. A total of 602 participants were enrolled (dialysis, kidney failure: 380; predialysis, chronic kidney disease [CKD]: 222) with AVF maturation ascertained for 535 (kidney failure, 353; CKD, 182) participants.

Interventions

All clinical decisions regarding AVF management were deferred to the individual centers, but remedial interventions were discouraged within 6 weeks of creation.

Main Outcomes and Measures

In this case series analysis, the primary outcome was unassisted maturation. Functional patency, freedom from intervention, and participant survival were summarized using Kaplan-Meier analysis.

Results

Most participants evaluated (n = 535) were men (372 [69.5%]) and had diabetes (311 [58.1%]); mean (SD) age was 54.6 (13.6) years. Almost two-thirds of the AVFs created (342 of 535 [64%]) were in the upper arm. The AVF maturation rates for the kidney failure vs CKD participants were 29% vs 10% at 3 months, 67% vs 38% at 6 months, and 76% vs 58% at 12 months. Several participants with kidney failure (133 [37.7%]) and CKD (63 [34.6%]) underwent interventions to facilitate maturation or manage complications before maturation. The median time from access creation to maturation was 115 days (interquartile range [IQR], 86-171 days) but differed by initial indication (CKD, 170 days; IQR, 113-269 days; kidney failure, 105 days; IQR, 81-137 days). The functional patency for the AVFs that matured at 1 year was 87% (95% CI, 83.2%-90.2%) and at 2 years, 75% (95% CI, 69.7%-79.7%), and there was no significant difference for those receiving interventions before maturation. Almost half (188 [47.5%]) of the AVFs that matured had further intervention to maintain patency or treat complications.

Conclusions and Relevance

The findings of this study suggest that AVF remains an accepted hemodialysis access option, although both its maturation and continued use require a moderate number of interventions to maintain patency and treat the associated complications.

EVAR Conversion is an Increasingly Common Indication for Open AAA Repair

OBJECTIVE

Although EVAR re-intervention is common, conversion to open repair(EVAR-c) occurs less frequently but can be associated with significant technical complexity and perioperative risk. There is a paucity of data highlighting the evolution of peri-procedural results surrounding EVAR-c and change in practice patterns, especially for referral centers that increasingly manage EVAR failures. The purpose of this analysis was to perform a temporal analysis of our EVAR-c experience and describe changes in patient selection, operative details and outcomes.

METHODS

A retrospective single center review of all open AAA repairs was performed(2002-2019) and EVAR-c procedures were subsequently analyzed. EVAR-c patients(n=184) were categorized into two different eras(2002-2009, n=21; 2010-2019, n=163) for comparison. Logistic regression and Cox proportional hazards modeling were used for risk-adjusted comparisons.

RESULTS

A significant increase in EVAR-c as an indication for any type of open aneurysm repair was detected(9%→27%;p<.001). Among EVAR-c patients, no change in age or individual comorbidities was evident[mean age: 71±9 years]; however, the proportion of female subjects(p=.01) and ASA classification >3 declined(p=.05). There was no difference in prevalence[50% vs. 43%;p=.6] or number[median-1.5(0, 5)] of pre-admission EVAR re-interventions; however, time to re-intervention decreased(median: 23[6,34] vs. 0[0,22] months;p=.005). In contrast, time to EVAR-c significantly increased(median: 16[9,39]vs. 48[20,83]-months;p=.008). No difference in frequency of non-elective presentation[mean-52%;p=.9] or indication was identified but a trend toward increasing mycotic EVAR-c was observed(5% vs. 15%;p=.09). Use of retroperitoneal exposure(14% vs. 77%;p<.0001), suprarenal cross-clamp application[6286%;p=.04] and visceral-ischemia time(median: 0[0,11] vs. 5[0,20]min;p=.05) all increased. In contrast, estimated blood loss(P-trend=.03) and procedure-time(p=.008) decreased. The unadjusted elective 30-day mortality rate improved but did not reach statistical significance[elective: 10% vs. 5%;p=.5] with no change for non-elective operations[18% vs. 16%;p=.9]. However, a significantly decreased risk of complications was evident(OR 0.88, 95%CI .8-.9;p=.01). One and 3-year survival was similar over time.

CONCLUSION

EVAR-c is now a common indication for open AAA repair. Patients frequently present non-electively and at increasingly later intervals after their index EVAR. Despite increasing technical complexity, decreased complication risk and comparable survival can be anticipated when patients are managed at a high-volume aortic referral center.

Improved perioperative mortality after secondary aorto-enteric fistula repair and lessons learned from a 20-year experience

BACKGROUND

Secondary aorto-enteric fistulas (SAEFs) are rare but represent one of the most challenging and devastating problems for vascular surgeons. Several issues surrounding SAEF treatment remain unresolved, including optimal surgical reconstruction and conduit choice. We performed an audit of our experience with SAEFs and highlight aspects of care that have affected outcomes over time with the intent to identify factors associated with best outcomes.

METHODS

We performed a single center, retrospective review of all consecutive SAEF repairs (1999-2019), defined as presence of a false communication between an enteric structure and pre-existing aortic graft. The primary endpoint was 30-day mortality. Secondary endpoints included incidence of complications and overall survival. Time-dependent outcome comparison was performed. Cox proportional hazards modeling and life-table analysis estimated risk and freedom from endpoints.

RESULTS

A total of 57 patients (63% male; n = 36) presented with SAEF (median age, 69 years; interquartile range [IQR], 61-74 years). Median follow-up time was 10 months (interquartile range, 3-21 months. The most common presenting symptoms were gastrointestinal bleeding (60%; n = 34) and abdominal pain (56%; n= 3 2). For the overall cohort, 30% (n = 17) underwent extra-anatomic bypass with aortic ligation, 30% (n = 17) rifampin-soaked Dacron graft, 26% (n = 15) femoral vein (eg, neoaortoiliac system), and 14% (n = 8) cryopreserved aortic allograft. The enteric communication involved the duodenum in 85% (n = 48), and a double-layer hand-sewn primary repair was most commonly employed (61%; n = 35). Thirty-day mortality was 35% (n = 20) with no significant difference between 90 days (39%; n = 22) and 180 days (42%; n = 24). Morbidity was 70% (n = 40), with gastrointestinal (30%; n = 17; leak [9%]), pulmonary (25%; n = 14), and renal (21%) complications being most common. Incidence of reoperation for any vascular and/or gastrointestinal-related complication was 56% (n = 32). One-year and 3-year survival was 54% ± 6% and 48% ± 8%, respectively. Over time, 30- and 90-day mortality improved (odds ratio, 0.1; 95% confidence interval, 0.4-0.5; P = .002) despite no change in patient factors, operative strategy, conduit choice, or morbidity rate. Prehospital history of gastrointestinal bleeding was associated with worse survival (hazard ratio, 2.0; 95% confidence interval, 1.0-3.9; P = .06); however, reconstruction strategy (in-situ vs extra-anatomic bypass), postoperative gastrointestinal and/or vascular complication, omental flap use, and preoperative endovascular aneurysm repair history were not associated with outcome.

CONCLUSIONS

In conclusion, we observed improved short-term mortality despite no significant change in patient presentation or postoperative complications. This highlights increasing institutional experience in selecting the optimal surgical strategy and improved ability to rescue patients experiencing adverse postoperative events. An individualized approach to reconstruction and conduit choice can lead to best outcomes after SAEF management when patients are treated at a high-volume aortic surgery center.

Skeletal myopathy in CKD: a comparison of adenine-induced nephropathy and 5/6 nephrectomy models in mice

Preclinical animal models of chronic kidney disease (CKD) are critical to investigate the underlying mechanisms of disease and to evaluate the efficacy of novel therapeutics aimed to treat CKD-associated pathologies. The objective of the present study was to compare the adenine diet and 5/6 nephrectomy (Nx) CKD models in mice. Male and female 10-wk-old C57BL/6J mice (n = 5-9 mice/sex/group) were randomly allocated to CKD groups (0.2-0.15% adenine-supplemented diet or 5/6 Nx surgery) or the corresponding control groups (casein diet or sham surgery). Following the induction of CKD, the glomerular filtration rate was reduced to a similar level in both adenine and 5/6 Nx mice (adenine diet-fed male mice: 81.1 ± 41.9 µL/min vs. 5/6 Nx male mice: 160 ± 80.9 µL/min, P = 0.5875; adenine diet-fed female mice: 112.9 ± 32.4 µL/min vs. 5/6 Nx female mice: 107.0 ± 45.7 µL/min, P = 0.9995). Serum metabolomics analysis indicated that established uremic toxins were robustly elevated in both CKD models, although some differences were observed between CKD models (i.e., p-cresol sulfate). Dysregulated phosphate homeostasis was observed in the adenine model only, whereas Ca2+ homeostasis was disturbed in male mice with both CKD models. Compared with control mice, muscle mass and myofiber cross-sectional areas of the extensor digitorum longus and soleus muscles were ∼18-24% smaller in male CKD mice regardless of the model but were not different in female CKD mice (P > 0.05). Skeletal muscle mitochondrial respiratory function was significantly decreased (19-24%) in CKD mice in both models and sexes. These findings demonstrate that adenine diet and 5/6 Nx models of CKD have similar levels of renal dysfunction and skeletal myopathy. However, the adenine diet model demonstrated superior performance with regard to mortality (∼20-50% mortality for 5/6 Nx vs. 0% mortality for the adenine diet, P < 0.05 for both sexes) compared with the 5/6 Nx surgical model.NEW & NOTEWORTHY Numerous preclinical models of chronic kidney disease have been used to evaluate skeletal muscle pathology; however, direct comparisons of popular models are not available. In this study, we compared adenine-induced nephropathy and 5/6 nephrectomy models. Both models produced equivalent levels of muscle atrophy and mitochondrial impairment, but the adenine model exhibited lower mortality rates, higher consistency in uremic toxin levels, and dysregulated phosphate homeostasis compared with the 5/6 nephrectomy model.

Editor's Choice - Variation in Intact Abdominal Aortic Aneurysm Repair Outcomes by Country: Analysis of International Consortium of Vascular Registries 2010 - 2016

OBJECTIVE

Outcomes for intact abdominal aortic aneurysm (AAA) repair vary over time and by healthcare system, country, and surgeon. The aim of this study was to analyse peri-operative mortality for intact AAA repair in 11 countries over time and compare outcomes by gender, age, and geographical location.

METHODS

Prospective data on primary repair of intact AAA were collected from 11 countries through the International Consortium of Vascular Registries (ICVR) and analysed for two time periods, 2010 - 2013 and 2014 - 2016. The primary outcome was peri-operative mortality after endovascular aneurysm repair (EVAR) and open surgical repair (OSR). Multivariable logistic regression models were used to adjust for differences in patient characteristics.

RESULTS

A total of 103 715 patients were included. The percentage of patients undergoing EVAR increased from 63.6% to 71.2% (p < .001) over the study period. This proportion varied by country from 35% in Hungary to 81% in the United States. Overall peri-operative mortality decreased from 2.1% to 1.6 % (p < .001). Mortality also declined significantly over time for both OSR 4.2% to 3.6 % (p = .002) and EVAR 1.0% to 0.7% (p = .002). Mortality was significantly higher for female than male patients (3.0% vs. 1.6% p < .001). The percentage of patients > 80 years old undergoing AAA repair remained constant at 23.6% (p = .91). Peri-operative mortality was higher for patients > 80 years than for those < 80 years old (2.7% vs. 1.6% p < .001). Forty-six per cent (n = 275) of all EVAR deaths occurred in the over 80s.

CONCLUSION

The proportion of AAA repairs performed using EVAR has increased over time. Peri-operative mortality continues to decline for both OSR and EVAR. Outcomes however were significantly worse for both women and those aged over 80, so efforts should be focused on these patient groups to further reduce elective AAA mortality rates.

Surgeon experience versus volume differentially affects lower extremity bypass outcomes in contemporary practice

BACKGROUND

Calls for minimum case thresholds to guide surgeon credentialing paradigms are increasing in contemporary practice. To date, the volume-outcome relationship and the role of surgeon experience as a proxy for quality have remained primarily focused on nonvascular extirpative surgery and aneurysm repair. However, it is unclear whether these data can be rightly extrapolated to predict lower extremity bypass (LEB) outcomes. Thus, the purpose of the present study was to examine whether the annualized case volume vs surgeon experience is more consequential in predicting for successful LEB reconstruction.

METHODS

A total of 25,852 procedures with sufficient 1-year follow-up data from the Society for Vascular Surgery Vascular Quality Initiative infrainguinal bypass registry (2003-2019) were reviewed for chronic limb threatening ischemia among patients undergoing infrageniculate reconstruction. The procedures were categorized according to surgeon years of practice experience at surgery (ie, 0-5, 6-10, 11-15, >15 years) and the number of LEB procedures performed by the surgeon during the year of surgery (volume quartiles: 1-8, 9-14, 15-21, and >21). Mixed effects logistic and Cox regression models were used to assess the effects of experience, volume, and their interaction on outcomes.

RESULTS

Increasing practice experience was more significantly associated with a reduction of in-hospital complications (odds ratio, 0.97; 95% confidence interval [CI], 0.96-0.99; P = .002) and the risk of major adverse limb events (odds ratio, 0.94; 95% CI, 0.92-0.97; P < .0001) compared with the volume. Increasing experience and volume were both associated with increased freedom from thrombosis (hazard ratio, 0.95; 95% CI, 0.93-0.98; P = .001). In contrast, neither experience nor volume had any significant association with early mortality. However, a higher volume was associated with diminished long-term survival (hazard ratio, 1.04; 95% CI, 1.0-1.1; P = .01). The most experienced surgeons (>15 years' experience) were significantly more likely to perform LEB for rest pain (P < .0001). No significant differences were found in the bypass rates among patients with tissue loss. The most experienced and highest volume surgeons were more likely to use an autogenous and/or composite conduit, in situ reconstruction, and/or pedal targets (P < .05). Similarly, more experienced and higher volume surgeons had less blood loss and shorter procedure times (P < .0001). Overall, the most experienced surgeons (>15 years' experience) were significantly more likely to have a higher volume with a diminished risk for all LEB outcomes.

CONCLUSIONS

Surgeon experience appears to have the most important role in predicting for overall LEB performance with improved in-hospital outcomes and major adverse limb events. The more experienced surgeons performed more complex reconstructions with fewer complications. These findings have significant clinical and educational implications as our most experienced surgeons approach retirement. Mentorship strategies to facilitate ongoing technical development among less experienced surgeons are imperative to sustain optimal limb salvage outcomes and have significant ramifications regarding expectations for regulatory and credentialing paradigms.

Effect of ischemia-reperfusion on outcomes after open mesenteric bypass for chronic mesenteric ischemia

OBJECTIVE

Significant physiologic perturbations can occur in patients with chronic mesenteric ischemia (CMI) undergoing open mesenteric bypass (OMB). These events have frequently been attributed to ischemia-reperfusion events and have been directly implicated in the occurrence of multiple organ dysfunction (MOD). Scoring systems (MOD score [MODS] and sequential organ failure assessment [SOFA]) have been derived within the critical care field to provide a composite metric for these pathophysiologic changes. The purpose of the present study was to describe the early pathophysiologic changes that occur after OMB for CMI and determine whether these are predictive of the outcomes.

METHODS

Patients with CMI who had undergone elective OMB from 2002 to 2018 at a single institution were reviewed. Changes in the hemodynamic, pulmonary, hepatic, renal, and hematologic parameters in the first 96 hours postoperatively were analyzed. The MODSs and SOFA scores were calculated. Cox regression was used to determine the association of the MODSs and SOFA scores with the outcomes.

RESULTS

The use of OMB was analyzed for 72 patients (age, 66 ± 11 years; 68% women; body mass index, 23.8 ± 6 kg/m²; 48 ± 34-lb weight loss in 59%). Previous mesenteric stent placement or bypass had been performed in 39% [stenting in 21; bypass in 8; (one patient had both)]. An antegrade configuration (93%) was most common (retrograde configuration, 7%), with revascularization of the superior mesenteric artery/celiac vessels in 85% (superior mesenteric artery only in 15%). Postoperative pathophysiologic and metabolic changes were common, and the mean MODSs and SOFA scores were 3.6 ± 2.4 (range, 1-10) and 4.0 ± 2.7 (range, 1-13), respectively. The median length of stay was 14 days (interquartile range, 9-21). The 30-day mortality was 4% (n = 3) and in-hospital morbidity was 53% (n = 38; gastrointestinal, 25%; infectious, 22%; cardiac, 18%; pulmonary, 18%; renal, 11%). The clinical follow-up period was 16 ± 20 months. The MODSs and SOFA scores correlated linearly with overall mortality (MODS: odds ratio [OR], 1.4; 95% confidence interval [CI], 1.2-1.7; P < .01; SOFA score: OR, 1.4; 95% CI, 1.2-1.7; P < .01 per unit), with a score of ≥5 the inflection point most predictive of mortality (MODS: OR, 3.9; 95% CI, 1.6-9.9; P ≤ .01; SOFA score: OR, 2.8; 95% CI, 1.2-6.6; P = .02). The 1- and 3-year primary bypass patency and freedom from reintervention was 91% ± 5% and 83% ± 7%, respectively, with no association with the MODSs or SOFA scores. The 1- and 3-year survival was 86% ± 4% and 71% ± 6% with significantly worse outcomes for patients with higher MODSs and/or SOFA scores.

CONCLUSIONS

Most CMI patients undergoing OMB will experience significant metabolic derangements resulting from sequelae of the ischemia-reperfusion phenomenon postoperatively. These can be objectively assessed in the early postoperative period using simply applied scoring systems to reliably predict the early and long-term outcomes. A derivation of the MODS and/or SOFA score after OMB for CMI can identify the most vulnerable patients at the greatest risk of mortality. (J Vasc Surg 2021;XX:XX-X.).

Trends in the use of cerebrospinal drains and outcomes related to spinal cord ischemia after thoracic endovascular aortic repair and complex endovascular aortic repair in the Vascular Quality Initiative database

BACKGROUND

Spinal cord ischemia (SCI) is a dreaded complication of thoracic and complex endovascular aortic repair (TEVAR/cEVAR). Controversy exists surrounding cerebrospinal fluid drain (CSFD) use, especially preoperative prophylactic placement, owing to concerns regarding catheter-related complications. However, these risks are balanced by the widely accepted benefits of CSFDs during open repair to prevent and/or rescue patients with SCI. The importance of this issue is underscored by the paucity of data on CSFD practice patterns, limiting the development of practice guidelines. Therefore, the purpose of the present analysis was to evaluate the differences between patients who developed SCI despite preoperative CSFD placement and those treated with therapeutic postoperative CSFD placement.

METHODS

All elective TEVAR/cEVAR procedures for degenerative aneurysm pathology in the Society for Vascular Surgery Vascular Quality Initiative from 2014 to 2019 were analyzed. CSFD use over time, the factors associated with preoperative prophylactic vs postoperative therapeutic CSFD placement in patients with SCI (transient or permanent), and outcomes were evaluated. Survival differences were estimated using the Kaplan-Meier method.

RESULTS

A total of 3406 TEVAR/cEVAR procedures met the inclusion criteria, with an overall SCI rate of 2.3% (n = 88). The SCI rate decreased from 4.55% in 2014 to 1.43% in 2018. Prophylactic preoperative CSFD use was similar over time (2014, 30%; vs 2018, 27%; P = .8). After further exclusions to evaluate CSFD use in those who had developed SCI, 72 patients were available for analysis, 48 with SCI and prophylactic CSFD placement and 24 with SCI and therapeutic CSFD placement. Specific to SCI, the patient demographics and comorbidities were not significantly different between the prophylactic and therapeutic groups, with the exception of previous aortic surgery, which was more common in the prophylactic CSFD cohort (46% vs 23%; P < .001). The SCI outcome was significantly worse for the therapeutic group because 79% had documented permanent paraplegia at discharge compared with 54% of the prophylactic group (P = .04). SCI patients receiving a postoperative therapeutic CSFD had had worse survival than those with a preoperative prophylactic CSFD (50% ± 10% vs 71% ± 9%; log-rank P = .1; Wilcoxon P = .05).

CONCLUSIONS

Prophylactic CSFD use with TEVAR/cEVAR remained stable during the study period. Of the SCI patients, postoperative therapeutic CSFD placement was associated with worse sustained neurologic outcomes and overall survival compared with preoperative prophylactic CSFD placement. These findings highlight the need for a randomized clinical trial to examine prophylactic vs therapeutic CSFD placement in association with TEVAR/cEVAR.

Impaired muscle mitochondrial energetics is associated with uremic metabolite accumulation in chronic kidney disease

Chronic kidney disease (CKD) causes progressive skeletal myopathy involving atrophy, weakness, and fatigue. Mitochondria have been thought to contribute to skeletal myopathy; however, the molecular mechanisms underlying muscle metabolism changes in CKD are unknown. We employed a comprehensive mitochondrial phenotyping platform to elucidate the mechanisms of skeletal muscle mitochondrial impairment in mice with adenine-induced CKD. CKD mice displayed significant reductions in mitochondrial oxidative phosphorylation (OXPHOS), which was strongly correlated with glomerular filtration rate, suggesting a link between kidney function and muscle mitochondrial health. Biochemical assays uncovered that OXPHOS dysfunction was driven by reduced activity of matrix dehydrogenases. Untargeted metabolomics analyses in skeletal muscle revealed a distinct metabolite profile in CKD muscle including accumulation of uremic toxins that strongly associated with the degree of mitochondrial impairment. Additional muscle phenotyping found CKD mice experienced muscle atrophy and increased muscle protein degradation, but only male CKD mice had lower maximal contractile force. CKD mice had morphological changes indicative of destabilization in the neuromuscular junction. This study provides the first comprehensive evaluation of mitochondrial health in murine CKD muscle to our knowledge and uncovers several unknown uremic metabolites that strongly associate with the degree of mitochondrial impairment.

Complicated acute type B aortic dissection: update on management and results

BACKGROUND

The role of thoracic endovascular aortic repair (TEVAR) has evolved and is now firmly established as a mainstay of therapy for acute complicated type B aortic dissection (acTBAD). However, several important issues remain unresolved including the optimal timing, sizing, graft selection, coverage length and utilization of adjunctive therapies to address false lumen perfusion. Therefore, the purpose of this study was to provide a contemporary perspective on the management and results for TEVAR of acTBAD.

METHODS

All TEVAR patients (N.=159) with acTBAD from a single high-volume, academic medical center were analyzed. Comparative results across time-dependent cohorts (2005-2009 [N.=43] vs. 2010-2014 [N.=56] vs. 2015-2020 [N.=60]) are presented.

RESULTS

30-day mortality was 13%(N.=21) with a trend towards improvement over time (2005-2009, 18% vs. 2010-2020, 12%; P=0.1). Similarly, incidence of postoperative complications also declined: 2005-2009, 70% vs. 2010-2020, 36%(P-trend=0.08). One and 2-year freedom from aorta-related reintervention was 78±7% and 73±9% and did not differ across cohorts (log-rank P=0.5). Respective one and 5-year survival was 75±3% and 64±7%, but significantly improved with time (log-rank P<0.001). The corresponding one and five-year freedom from aorta-related mortality was 82±4% and 78±7% but did not change during the study interval (log-rank P=0.3).

CONCLUSIONS

Outcomes for TEVAR of acTBAD continue to improve over time. This time-dependent analysis delineates how results have changed due to increasing experience, technologic evolution, and maturation of the peer reviewed evidence. These results along with the evidence-based review provided herein, provide an update on the management and results of TEVAR of acTBAD while highlighting specific controversies unique to the management of this challenging clinical problem.

Association between thoracoabdominal aneurysm extent and mortality after complex endovascular repair

OBJECTIVE

Traditional open surgical repair of thoracoabdominal aortic aneurysms (TAAAs) has historically resulted in 30-day mortality rates ranging from 6% to 20%, depending on the Crawford anatomic extent. Although short-term survival is important, long-term survival is essential for patients to benefit from these often elective and potentially morbid procedures. The aneurysm extent affects the long-term survival after open repair; however, effect on endovascular repair is unknown and could influence the decision process for repair. We evaluated the association between aneurysm extent and survival and identified patient and perioperative factors associated with mortality after endovascular repair.

METHODS

A retrospective cohort of patients treated for TAAAs recorded in the Society for Vascular Surgery Vascular Quality Initiative thoracic and complex endovascular aneurysm repair registry were evaluated. All patients treated for asymptomatic degenerative aneurysms from 2010 to 2019 were included. Crawford extent I to V was defined according to the proximal and distal landing zones documented in the registry. Patients without extension into the visceral aorta were used for comparison and categorized as having extent 0a or 0b, depending on the distal landing zone in the thoracic aorta. Kaplan-Meier plots were used to estimate survival, and Cox proportional hazard regression models were created to identify the predictors of mortality.

RESULTS

From 2010 to 2019, 15,333 patients were entered into the registry, of whom 2062 met the inclusion criteria. The Crawford extent was 0a for 379, 0b for 848, I for 81, II for 98, III for 130, IV for 454, and V for 72. Three groups were created in accordance with the similar outcomes noted on a preliminary analysis: (1) extent 0a and 0b; (2) extent I, II, and III; and (3) extent IV and V. The mean survival time for the extent 0a and 0b group was 70.7 ± 1.43 months and was 48.6 ± 1.65 months for the extent I, II, and III group and 57.6 ± 1.24 months for the extent IV and V group. The corresponding 1-year mortality was 8.4%, 18.4%, and 7.8%. Cox regression analysis identified the following preoperative factors were associated with mortality: chronic obstructive pulmonary disease (odds ratio [OR], 1.70; P < .001), Crawford extent I to III (OR, 1.64; P = .015), preexisting chronic kidney disease (OR, 1.37; P = .024), and age per year (OR, 1.03; P < .001). A number of postoperative factors were also associated with mortality.

CONCLUSIONS

Similar to open TAAA repair, patients with more extensive aortic disease treated with endovascular repair had worse 1-year and long-term survival. The extent of aortic disease and anticipated postoperative survival should factor prominently into the surgical decision-making process for elective endovascular TAAA repair.

Genetic Architecture of Abdominal Aortic Aneurysm in the Million Veteran Program

Supplemental Digital Content is available in the text.

Abdominal aortic aneurysm (AAA) is an important cause of cardiovascular mortality; however, its genetic determinants remain incompletely defined. In total, 10 previously identified risk loci explain a small fraction of AAA heritability.

Remodeling, Reintervention, and Survival After Endovascular Repair of Chronic Type B Dissection

BACKGROUND

The efficacy of thoracic endovascular aortic repair (TEVAR) of chronic type B aortic dissection (cTBAD) is controversial. Only limited evidence describes temporal anatomic changes after TEVAR for cTBAD and their relationship to outcomes. We sought to investigate early aortic remodeling events after TEVAR for cTBAD with thoracic aneurysm and determine the association with reintervention and survival.

METHODS

Records from 95 cTBAD patients undergoing TEVAR from 2005 to 2017 were reviewed. Using 3-dimensional centerline analysis, anatomic phenotyping of the thoracoabdominal aorta was performed. Reverse aortic remodeling (RAR) was defined by a ≥5-mm reduction in maximal thoracic aortic diameter. Kaplan-Meier analysis estimated freedom from reintervention and survival.

RESULTS

Visceral segment dissection involvement was present in 89% of patients (n = 85), and the mean preoperative thoracic diameter was 63 mm (SD, 10). Complete thoracic false lumen thrombosis occurred in 71% of patients (n = 67), whereas abdominal false lumen thrombosis was documented in 60% (n = 57) by 6 months. RAR occurred in 41%. Aortic reintervention rate was 39% (n = 37). The 1- and 3-year freedom from reintervention was significantly higher in subjects experiencing early RAR (log-rank P = .02), but reintervention did not impact overall survival (log-rank P = .9). Similarly, overall survival was similar between patients with or without RAR (log-rank P = .4).

CONCLUSIONS

Early RAR is associated with decreased rates of reintervention; however, overall survival is not impacted by these changes. TEVAR for cTBAD results in a high rate of reintervention, which mandates vigilant surveillance protocols.

Surgical Treatment of True Superior Mesenteric Artery Aneurysms

BACKGROUND

Superior mesenteric artery aneurysms (SMAAs) are a rare clinical problem that can be associated with significant morbidity and mortality. The optimal surgical approach for both mycotic and degenerative SMAAs remains poorly defined. The study was designed to review our institutional experience and develop a treatment algorithm.

METHODS

A single-institution, retrospective review was performed to document presentation, treatment, and outcomes of patients undergoing surgical repair of SMAAs from 2003 to 2020. The primary end-point was 30-day mortality, and secondary end-points included complications, patency, freedom from reinfection, freedom from reintervention, and survival.

RESULTS

Eighteen patients (mean age: 46 ± 16 yrs; 50% male; mean diameter 2.4 ± 2.0 cm) underwent treatment of mycotic (50%) or degenerative (50%) SMAAs. Abdominal pain (66%) was the most common presenting symptom, and the diagnosis was confirmed with CT arteriography. Endocarditis secondary to intravenous drug abuse was responsible for most (88%) of the mycotic SMAAs, with a majority (66%) having positive cultures and Streptococcus being the most common organism. The majority (61%) of patients underwent urgent or emergent repair with aneurysmectomy and interposition saphenous vein bypass being the most common treatment of mycotic SMAAs while aneurysmectomy and prosthetic bypass were used most frequently for degenerative aneurysms. The operative mortality rate was 6% with a major complication rate of 17% (n = 3 patients: respiratory failure/reintubation-1, pulmonary embolism-1, necrotizing pancreatitis/graft disruption and death-1). The single death occurred in a patient with a degenerative aneurysm that developed postoperative pancreatitis and multiple organ dysfunction. The mean clinical follow-up time was 25 ± 48 (95% CI 1-48) months. The estimated primary patency, freedom from reinfection, and freedom from reintervention were 93 ± 7 %, 94 ± 5%, and 94 ± 5%, respectively, at 1 year. The overall mean survival was 55 ± 51 (95% CI 30-80) months with an estimated survival at 3 years of 77 ± 10%.

CONCLUSIONS

SMAAs associated with both degenerative and mycotic etiologies can be treated using a variety of surgical approaches with acceptable morbidity and mortality. Mycotic SMAAs should likely be repaired, regardless of size, while the indications for asymptomatic, degenerative aneurysms remain to be defined by further natural history studies.

Contemporary management and outcomes of complex vascular surgical groin wound infections

OBJECTIVE

Vascular surgical groin wound infection (VS-GWI) has multiple causes and frequently is manifested as a limb- or life-threatening problem, resulting in significant morbidity and mortality. For patients undergoing operative extirpation, in situ repair, extra-anatomic bypass, or ligation can be used; however, limited data exist describing comparative results of the different operative choices or conduit subtypes. Therefore, we sought to describe our experience with management of VS-GWI and to detail outcomes of the different strategies.

METHODS

Patients (2003-2017) undergoing surgical treatment of VS-GWI (Szilagyi grade III) secondary to primary infectious arteritis or infected pseudoaneurysm after percutaneous intervention as well as previous prosthetic graft placement were reviewed. The primary end point was major adverse limb events (MALEs; major amputation, graft occlusion, or unplanned reintervention). Secondary end points included 30-day mortality, wound healing, amputation-free survival (AFS), and all-cause mortality. Cox proportional hazards modeling was used to determine relative risk of end points; Kaplan-Meier methodology was employed to estimate freedom from outcomes.

RESULTS

There were 149 patients (age, 65 ± 11 years; body mass index, 27 ± 6 kg/m²; 70% male; 32% diabetes) identified, of whom 120 (81%) had unilateral and 29 (19%) had bilateral VS-GWI. Indications included infected prosthetic bypass (88% [n = 131]; infrainguinal, 107; suprainguinal, 24) and primary infectious femoral artery complications (12% [n = 18]). A majority underwent single-stage operations (87% [n = 129]). In situ reconstruction occurred in 87% (n = 129); 9% (n = 13) underwent ligation, and 6% (n = 7) received extra-anatomic revascularization. Autogenous conduit was used most commonly (68% [n = 101/149]; 88% single stage), of which 81% (n = 80) were femoral vein. The remaining patients received cadaveric (15% [n = 23]; 87% single stage) or prosthetic (8% [n=12]; 67% single stage) grafts. Adjunctive myocutaneous flap was used in 37% (n = 54). Length of stay was 19 ± 15 days and 30-day mortality was 7% (n = 10), with no difference between conduit repair types. All femoral wounds healed (mean follow-up, 17 ± 11 months); however, 33% (n = 49) underwent reoperation (unplanned graft reintervention, 33%; graft occlusion, 16%; wound débridement, 15%; major amputation, 11%). Reinfection occurred in 17% (n = 27), with no difference between groups. MALE rate was 22% (n = 33; most were arterial reinterventions, 19%), with no difference in single-stage vs multistage, in situ vs extra-anatomic, or autogenous vs nonautogenous conduit strategies Predictors of MALE included younger age (hazard ratio [HR], 1.6 per decade; 95% confidence interval [CI], 1.1-2.5; P = .02) and lower body mass index (<25 kg/m²; HR, 1.6 per BMI category; 95% CI, 1.1-2.5; P = .02). Overall, 1- and 3-year freedom from MALE, AFS, and survival were as follows: MALE, 74% ± 5% and 63% ± 6%; AFS, 68% ± 4% and 58% ± 5%; survival, 78% ± 3% and 70% ± 4%. Autogenous conduit use was associated with better survival (HR, 0.5; 95% CI, 0.3-0.8; 1-year: 83% ± 4% vs nonautogenous, 78% ± 4%; 3-year: 68% ± 8% vs 53% ± 9%; log-rank, P = .006).

CONCLUSIONS

An individualized approach to operative strategy and conduit choice leads to comparable outcomes in this challenging group of patients. VS-GWI can be safely managed with in situ, autogenous reconstruction in a majority of patients with acceptable mortality, excellent wound healing rates, and improved overall survival. However, a significant proportion of patients experience reinfection and MALEs, the preponderance of which are arterial reintervention, mandating need for close follow-up and graft surveillance.

A comparison of administrative data and quality improvement registries for abdominal aortic aneurysm repair

OBJECTIVE

Databases are essential in evaluating surgical outcomes and gauging the implementation of new techniques. However, there are important differences in how data from administrative databases and surgical quality improvement (QI) registries are collected and interpreted. Therefore, we aimed to compare trends, demographics, and outcomes of open and endovascular abdominal aortic aneurysm (AAA) repair in an administrative database and two QI registries.

METHODS

We identified patients undergoing open and endovascular repair of intact and ruptured AAAs between 2012 and 2015 within the National Inpatient Sample (NIS), the National Surgical Quality Improvement Program (NSQIP), and the Vascular Quality Initiative (VQI). We described the differences and trends in overall AAA repairs for each data set. Moreover, patient demographics, comorbidities, mortality, and complications were compared between the data sets using Pearson χ² test.

RESULTS

A total of 140,240 NIS patients, 10,898 NSQIP patients, and 26,794 VQI patients were included. Ruptured repairs composed 8.7% of NIS, 11% of NSQIP, and 7.9% of VQI. Endovascular aneurysm repair (EVAR) rates for intact repair (range, 83%-84%) and ruptured repair (range, 51%-59%) were similar in the three databases. In general, rates of comorbidities were lower in NIS than in the QI registries. After intact EVAR, in-hospital mortality rates were similar in all three databases (NIS 0.8%, NSQIP 1.0%, and VQI 0.8%; P = .06). However, after intact open repair and ruptured repair, in-hospital mortality was highest in NIS and lowest in VQI (intact open: NIS 5.4%, NSQIP 4.7%, and VQI 3.5% [P < .001]; ruptured EVAR: NIS 24%, NSQIP 20%, and VQI 16% [P < .001]; ruptured open: NIS 36%, NSQIP 31%, and VQI 26% [P < .001]). After stratification by intact and ruptured presentation and repair strategy, several discrepancies in morbidity rates remained between the databases. Overall, the number of cases in NSQIP represents 7% to 8% of the repairs in NIS, and the number of cases in VQI grew from 12% in 2012 to represent 23% of the national sample in 2015.

CONCLUSIONS

NIS had the largest number of patients as it represents the nationwide experience and is an essential tool to evaluate trends over time. The lower in-hospital mortality seen in NSQIP and VQI questions the generalizability of the studies that use these QI registries. However, with a growing number of hospitals engaging in granular QI initiatives, these QI registries provide a valuable resource to potentially improve the quality of care provided to all patients.

Safety and efficacy of a hybrid approach for repair of complicated aberrant subclavian arteries

OBJECTIVE

Aberrant subclavian artery (ASA), a well-described aortic arch anomaly, is frequently associated with dysphagia and development of Kommerell diverticulum (KD) with aneurysmal degeneration. Historically, open repair has been performed, which can be associated with significant morbidity. More recently, hybrid approaches using different arch vessel revascularization techniques in combination with thoracic endovascular aortic repair (hybrid TEVAR) have been described, but there is a paucity of literature describing outcomes. The objective of this analysis was to describe our experience with management of complicated ASAs using hybrid TEVAR, further adding to the literature describing approaches to and outcomes of hybrid ASA repair.

METHODS

A retrospective, single-institution review was performed of all patients treated for ASA complications using hybrid TEVAR (2002-2018). The primary end point was technical success, defined as absence of type I or type III endoleak intraoperatively and within 30 days postoperatively. Secondary end points included complications, reintervention, and survival. Centerline measurement of KD diameters (maximum diameter = opposing aortic outer wall to diverticulum apex) was employed. Kaplan-Meier methodology was used to estimate secondary end points.

RESULTS

Eighteen patients (1.4% of 1240 total TEVAR procedures; male, 67%; age, 59 ± 13 years) were identified (left-sided arch and right ASA, 94% [n = 17]; right-sided arch and left ASA, n = 1 [6%]; retroesophageal location and associated KD, 100%); median preoperative KD diameter was 60 mm (interquartile range [IQR], 37-108 mm). Operative indications included diverticulum diameter (61%), dysphagia (17%), rupture (11%), rapid expansion (6%), and endoleak after TEVAR (6%). All procedures used some combination of supraclavicular revascularization and TEVAR (staged, 50% [n = 9]), whereas partial open arch reconstruction was used in 17% (n = 3). There were no perioperative deaths or spinal cord ischemic events. Major complications occurred in 22% (n = 4): nondisabling stroke, one; arm ischemia, one; upper extremity neuropathy, one; and iatrogenic descending thoracic aortic dissection, one. Technical success was 83%, but 44% (n = 8) had an endoleak (type I, n = 3; type II, n = 5 [intercostal, n = 2; aneurysmal subclavian artery origin, n = 3]) during follow-up (median, 4 months; IQR, 1-15 months). Two endoleaks resolved spontaneously, three were treated, and three were observed (1-year freedom from reintervention, 75% ± 10%). Median KD diameter decreased by 7 mm (IQR, 1-12 mm), and 78% (n = 14) experienced diameter reduction or stability in follow-up. The 1- and 3-year survival was 93% ± 6% and 84% ± 10%, respectively.

CONCLUSIONS

Hybrid open brachiocephalic artery revascularization with TEVAR appears to be safe and reasonably effective in management of ASA complications as evidenced by a low perioperative complication risk and reasonable positive aortic remodeling. However, endoleak rates raise significant concerns about durability. Therefore, if this technique is employed, the mandatory need for surveillance and high rate of reintervention should be emphasized preoperatively. This analysis represents a relatively large series of a hybrid TEVAR technique to treat ASA complications, but greater patient numbers and longer follow-up are needed to further establish the role of this procedure.

Timing of thoracic endovascular aortic repair for uncomplicated acute type B aortic dissection and the association with complications

OBJECTIVE

Previous publications have clearly established a correlation between timing of thoracic endovascular aortic repair (TEVAR) and complications after treatment of complicated acute type B aortic dissection (ATBAD). However, the temporal association of TEVAR with morbidity after uncomplicated presentations is poorly understood and has not previously been examined using real-world national data. Therefore, the objective of this analysis was to determine whether TEVAR timing of uncomplicated ATBAD (UATBAD) is associated with postoperative complications.

METHODS

The Vascular Quality Initiative TEVAR and complex endovascular aneurysm repair registry was analyzed from 2010 to 2019. Procedures performed for non-dissection-related disease as well as for ATBAD with malperfusion or rupture were excluded. Because of inherent differences between timing cohorts, propensity score matching was performed to ensure like comparisons. Univariate and multivariable analysis after matching was used to determine differences between timing groups (symptom onset to TEVAR: acute, 1-14 days; subacute, 15-90 days) for postoperative mortality, in-hospital complications, and reintervention.

RESULTS

A total of 688 cases meeting inclusion criteria were identified. After matching 187 patients in each of the 1- to 14-day and 15- to 90-day treatment groups, there were no statistically significant differences between groups. On univariate analysis, the 1- to 14-day treatment group had a higher proportion of cases requiring reintervention within 30 days (15.3%) compared with UATBAD patients undergoing TEVAR within 15 to 90 days (5.2%; P = .02). There was also a difference (P = .007) at 1 year, with 33.8% of the 1- to 14-day UATBAD patients undergoing reintervention compared with 14.5% for the 15- to 90-day group. There were no statistically significant differences on multivariable analysis for long-term survival, complications, or long-term reintervention. There was a trend toward significance (P = .08) with the 1- to 14-day group having 2.3 times the odds of requiring an in-hospital reintervention compared with the 15- to 90-day group.

CONCLUSIONS

Timing of TEVAR for UATBAD does not appear to predict mortality or postoperative complications. However, there is a strong association between repair within 1 to 14 days and higher risk of reintervention. This may in part be related to the 1- to 14-day group's representing an inherently higher anatomic or physiologic risk population that cannot be entirely accounted for with propensity analysis. The role of optimal timing to intervention should be incorporated into future study design of TEVAR trials for UATBAD.

Design of the PReferences for Open Versus Endovascular Repair of Abdominal Aortic Aneurysm (PROVE-AAA) Trial

For patients with abdominal aortic aneurysm (AAA), randomized trials have found endovascular AAA repair (EVAR) is associated with lower perioperative morbidity and mortality than open surgical repair (OSR). However, OSR has fewer long-term aneurysm-related complications, such as endoleak or late rupture. Patients treated with EVAR and OSR have similar survival rates within two years after surgery, and OSR does not require intensive surveillance. Few have examined if patient preferences are aligned with the type of treatment they receive for their AAA. Although many assume that patients may universally prefer the less-invasive nature of EVAR, our preliminary work suggests that patients who value the lower risk of late complications may prefer OSR. In this study, called The PReferences for Open Versus Endovascular Repair of Abdominal Aortic Aneurysm (PROVE-AAA) trial, we describe a cluster-randomized trial to test if a decision aid can better align patients' preferences and their treatment type for AAA. Patients enrolled in the study are candidates for either endovascular or open repair and are followed up at VA hospitals by vascular surgery teams who regularly perform both types of repair. In Aim 1, we will determine patients' preferences for endovascular or open repair and identify domains associated with each repair type. In Aim 2, we will assess alignment between patients' preferences and the repair type elected and then compare the impact of a decision aid on this alignment between the intervention and control groups. This study will help us to accomplish two goals. First, we will better understand the factors that affect patient preference when choosing between EVAR and OSR. Second, we will better understand if a decision aid can help patients be more likely to receive the treatment strategy they prefer for their AAA. Study enrollment began on June 1, 2017. Between June 1, 2017 and November 1, 2018, we have enrolled 178 of a total goal of 240 veterans from 20 VA medical centers and their vascular surgery teams across the country. We anticipate completing enrollment in PROVE-AAA in June 2019, and study analyses will be performed thereafter.