Publications by authors named "Darve Robinson"

5 Publications

  • Page 1 of 1

Rationale and Design for the Remote Ischemic Preconditioning for Carotid Endarterectomy Trial.

Ann Vasc Surg 2019 Oct 12;60:246-253. Epub 2019 Jun 12.

UPMC, Division of Vascular Surgery, Pittsburgh, PA.

Background: While the perioperative stroke rate after carotid endarterectomy (CEA) is low, "silent" microinfarctions identified by magnetic resonance imaging (MRI) are common and have been correlated with postoperative neurocognitive decline. Our study will investigate the role of remote ischemic preconditioning (RIPC) as a potential neuroprotective mechanism. RIPC is a well-tolerated stimulus that, through neuronal and humoral pathways, generates a systemic environment of greater resistance to subsequent ischemic insults. We hypothesized that patients undergoing RIPC before CEA will have improved postoperative neurocognitive scores compared with those of patients undergoing standard care.

Methods: Patients undergoing CEA will be randomized 1:1 to RIPC or standard clinical care. Those randomized to RIPC will undergo a standard protocol of 4 cycles of RIPC. Each RIPC cycle will involve 5 min of forearm ischemia with 5 min of reperfusion. Forearm ischemia will be induced by a blood pressure cuff inflated to 200 mm Hg or at least 15 mm Hg higher than the systolic pressure if it is >185 mm Hg. This will occur after anesthesia induction and during incision/dissection but before manipulation or clamping of the carotid; thus, patients will be blinded to their assignment. Before carotid endarterectomy, all patients will undergo baseline neurocognitive testing in the form of a Montreal Cognitive Assessment (MoCA) and National Institutes of Health (NIH) Toolbox. MoCA testing only will be conducted on postoperative day 1 in the hospital. The full neurocognitive testing battery will again be conducted at 1-month follow-up in the office. Changes from baseline will be compared between arms at the follow-up time points. Assuming no drop-ins or dropouts and a 10% loss to follow-up, we would need a sample size of 43 patients for 80% power per treatment arm. The primary endpoint, change in MoCA scores, will be analyzed using a random effects model, and secondary outcomes will be analyzed using either linear or logistic regression where appropriate.

Conclusions: RIPC, if shown to be effective in protecting patients from neurocognitive decline after CEA, represents a safe, inexpensive, and easily implementable method of neuroprotection.
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October 2019

Increasing use of open conversion for late complications after endovascular aortic aneurysm repair.

J Vasc Surg 2019 06 21;69(6):1766-1775. Epub 2018 Dec 21.

Division of Vascular Surgery, Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pa.

Objective: Open procedures are often required for late complications after endovascular aneurysm repair (EVAR). Our aim was to describe the indications for open interventions and their postoperative outcomes and to specifically examine our experience with limited conversions in which problem endoleaks are targeted without endograft explantation.

Methods: We reviewed patients from 2002 to 2017 who underwent any surgical abdominal aortic operation after a previous EVAR. Baseline characteristics, preoperative imaging, procedural details, and postoperative outcomes were reviewed. The primary end point was 30-day mortality.

Results: There were 102 patients who underwent open conversion 3.8 ± 3.1 years after EVAR. The numbers increased significantly in recent years, with 18 cases performed in 2016; 48.5% of patients had undergone 1.9 ± 1.0 prior endovascular interventions. The indication for surgical conversion was an endoleak in 85 patients and infection in 15. One patient had a limb occlusion and another a proximal aneurysm. The 30-day mortality was 6.2% in 65 patients treated electively for endoleak but higher in 20 ruptures (40.0%) and 15 infections (40.0%). In a multivariate logistic regression model, independent predictors of 30-day mortality were rupture (odds ratio [OR], 6.70; 95% confidence interval [CI], 1.75-25.60; P = .005), endograft infection (OR, 8.48; 95% CI, 1.99-36.20; P = .004), and use of a supraceliac clamp (OR, 4.80; 95% CI, 1.47-15.66; P = .009). Transient acute kidney injury (12.8%) and prolonged intubation (11.8%) were the most common postoperative complications. In 65 patients treated for endoleak without rupture, 37 underwent endograft explantation, whereas 28 had a graft-preserving intervention (branch vessel ligation for type II endoleak in 26, external banding of the aneurysm neck for type IA endoleak in 8). Mortality was 8.1% when the endograft was explanted and 3.6% when it was not (P = .63). During 3.0 ± 3.5 years of follow-up, there was one reintervention after endograft explantation (for rupture secondary to type IB endoleak) and two reinterventions after graft preservation (for a new type IA endoleak and a new type II endoleak). Survival was 87.4% at 1 year and 70.9% at 5 years.

Conclusions: Open conversion is playing an increasing role in the management of late EVAR complications. Endoleaks treated electively by open conversion are reasonably safe and show good midterm durability, even with graft-preserving interventions that avoid endograft explantation.
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June 2019

Risk factors for perioperative mortality after revascularization for acute aortic occlusion.

J Vasc Surg 2018 12 23;68(6):1789-1795. Epub 2018 Jun 23.

Division of Vascular Surgery, Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pa.

Objective: Acute aortic occlusion (AAO) is a life-threatening event necessitating prompt revascularization to the pelvis and lower extremities. Because of its uncommon nature, outcomes after revascularization for AAO are not well characterized. Our aim was to describe the perioperative morbidity and mortality associated with revascularization and to identify the patients at highest risk.

Methods: A retrospective chart review was performed of patients who presented to our institution from 2006 to 2017 with acute distal aortic occlusion. Patients with a prior aortofemoral bypass were excluded, but those with aortoiliac stents were included. Baseline demographics and comorbidities, preoperative clinical presentation and imaging, procedural details, and postoperative hospital course were reviewed. The primary outcome was 30-day mortality, and major complications were evaluated as secondary outcomes. Logistic regression models were constructed to identify factors associated with 30-day mortality.

Results: We identified 65 patients who underwent revascularization for AAO. Median age was 63 years (range, 35-89 years), and 64.6% were male; 56.4% of patients presented within 24 hours of symptom onset, and 43.8% were treated within 6 hours of presentation. There were particularly high rates of prior coronary artery disease (62.3%) and chronic obstructive pulmonary disease (41.0%); 18.5% had prior iliac stents. Preoperative imaging in 44 patients showed occlusion of the inferior mesenteric artery in 36.0% and both internal iliac arteries in 34.7%. Treatments for revascularization included axillobifemoral bypass (55.4%), aortoiliac thromboembolectomy (15.4%), aortobifemoral bypass (13.9%), and aortoiliac stenting (15.4%). Overall 30-day mortality was 27.7% and was not affected by treatment modality. Mortality was highest in patients older than 60 years (40.5% vs 10.7%; P = .01) and those presenting with lactate elevation (45.5% vs 5.9%; P = .004) or motor deficit in at least one extremity (36.6% vs 9.5%; P = .03). Univariate predictors of 30-day mortality were age ≥60 years (odds ratio [OR], 5.68; 95% confidence interval [CI], 1.45-22.26; P = .01), presentation with motor deficit (OR, 5.48; 95% CI, 1.12-26.86; P = .04), presentation with elevated lactate level (OR, 13.33; 95% CI, 1.58-11.57; P = .02), history of prior stroke (OR, 4.80; 95% CI, 1.21-18.97; P = .03), and bilateral internal iliac artery occlusion (OR, 7.11; 95% CI, 1.54-32.91; P = .01). At least one postoperative complication was observed in 78.5% of patients, including acute kidney injury (56.9%, with 21.5% requiring hemodialysis), respiratory complications (46.2%), cardiovascular complications (33.9%), major amputation (15.4%, bilateral in 7.7%), and bowel ischemia (10.8%).

Conclusions: Even with prompt revascularization and despite the chosen treatment modality, AAO carries high risk of mortality and numerous life-threatening complications. Older patients presenting with elevated lactate levels, motor deficit, and bilateral internal iliac artery occlusions are at the highest risk of perioperative mortality. These factors may aid in risk stratification and managing expectations in this critically ill population.
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December 2018

Implementation of drug-eluting stents for the treatment of femoropopliteal disease provides significant cost-to-system savings in a single-state outpatient simulation.

J Vasc Surg 2018 11 18;68(5):1465-1472. Epub 2018 May 18.

Division of Vascular Surgery, Department of Surgery, UPMC, Pittsburgh, Pa.

Objectives: Initial data on drug-eluting stents (DES) shows that they may increase the durability of endovascular treatment of superficial femoral artery disease compared with traditional bare-metal stents (BMS). Observed decreased target lesion revascularization (TLR) rates have potential for cost savings despite an increased initial cost. The purpose of this study was to run a simulation model of progressive transition from BMS to DES over 5 years evaluating the overall cost impact of that transition.

Methods: Florida State Ambulatory Databases were searched for all patients undergoing superficial femoral artery stenting in 2013 using Current Procedural Terminology codes 37226 and 37227. A simulation model was developed to estimate the impact of a progressive transition from BMS to DES over a 5-year horizon in this patient population. Cost estimates were determined from available cost charge ratio data. For the 5-year model, 2013 served as the initial year with each subsequent year based on the expected number of interventions per year. Up to one TLR per patient was assumed for the model. The 5-year TLR rates for DES and other parameter estimates were based on pooled data from the literature. Institutional data were used to estimate that up to 48% of superficial femoral artery lesions would fit the instructions for use for the Zilver PTX (Cook Medical, Bloomington, Ind), which is currently the only DES approved by the U.S. Food and Drug Administration for peripheral interventions. The net budget impact was expressed as the difference in total costs (primary stenting and reinterventions) for a scenario where BMS is progressively replaced by Zilver PTX compared with a scenario of BMS only. Multiple sensitivity analyses were performed on the base scenario.

Results: We identified 4107 peripheral interventions in the first year that fit our study. The overall cost for these procedures in Florida database was $51,362,142.00. In the base case scenario, DES was introduced slowly into the population at a rate of 8% per year up to 48% at the end of the model. This strategy resulted in an overall cost savings of $1,688,953.72 compared with the model with BMS alone. Sensitivity analyses including slower adoption of DES up to only 24% at 5 years, a 20% increase in TLR rates per year for the DES, and a 10% reduction in TLR rates per year for BMS still resulted in a net savings. As long as the additional cost of a DES compared with BMS is less than $677, the DES model remains less expensive.

Conclusions: The adoption of DES in lieu of traditional BMS can lead to significant cost savings in a single state model over a short time horizon.
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November 2018

Daytime Sleepiness, Circadian Preference, Caffeine Consumption and Khat Use among College Students in Ethiopia.

J Sleep Disord Treat Care 2013 Dec;3(1)

Addis Continental Institute of Public Health, Addis Ababa, Ethiopia.

Objectives: To estimate the prevalence of daytime sleepiness and circadian preferences, and to examine the extent to which caffeine consumption and Khat (a herbal stimulant) use are associated with daytime sleepiness and evening chronotype among Ethiopian college students.

Methods: A cross-sectional study was conducted among 2,410 college students. A self-administered questionnaire was used to collect information about sleep, behavioral risk factors such as caffeinated beverages, tobacco, alcohol, and Khat consumption. Daytime sleepiness and chronotype were assessed using the Epworth Sleepiness Scale (ESS) and the Horne & Ostberg Morningness /Eveningness Questionnaire (MEQ), respectively. Linear and logistic regression models were used to evaluate associations.

Results: Daytime sleepiness (ESS≥10) was present in 26% of the students (95% CI: 24.4-27.8%) with 25.9% in males and 25.5% in females. A total of 30 (0.8%) students were classified as evening chronotypes (0.7% in females and 0.9% in males). Overall, Overall, Khat consumption, excessive alcohol use and cigarette smoking status were associated with evening chronotype. Use of any caffeinated beverages (OR=2.18; 95%CI: 0.82-5.77) and Khat consumption (OR=7.43; 95%CI: 3.28-16.98) increased the odds of evening chronotype.

Conclusion: The prevalence of daytime sleepiness among our study population was high while few were classified as evening chronotypes. We also found increased odds of evening chronotype with caffeine consumption and Khat use amongst Ethiopian college students. Prospective cohort studies that examine the effects of caffeinated beverages and Khat use on sleep disorders among young adults are needed.
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December 2013