Effect of a Decision Aid on Agreement Between Patient Preferences and Repair Type for Abdominal Aortic Aneurysm: A Randomized Clinical Trial

Importance

Patients with abdominal aortic aneurysm (AAA) can choose open repair or endovascular repair (EVAR). While EVAR is less invasive, it requires lifelong surveillance and more frequent aneurysm-related reinterventions than open repair. A decision aid may help patients receive their preferred type of AAA repair.

Objective

To determine the effect of a decision aid on agreement between patient preference for AAA repair type and the repair type they receive.

Design, Setting, and Participants

In this cluster randomized trial, 235 patients were randomized at 22 VA vascular surgery clinics. All patients had AAAs greater than 5.0 cm in diameter and were candidates for both open repair and EVAR. Data were collected from August 2017 to December 2020, and data were analyzed from December 2020 to June 2021.

Interventions

Presurgical consultation using a decision aid vs usual care.

Main Outcomes and Measures

The primary outcome was the proportion of patients who had agreement between their preference and their repair type, measured using χ2 analyses, κ statistics, and adjusted odds ratios.

Results

Of 235 included patients, 234 (99.6%) were male, and the mean (SD) age was 73 (5.9) years. A total of 126 patients were enrolled in the decision aid group, and 109 were enrolled in the control group. Within 2 years after enrollment, 192 (81.7%) underwent repair. Patients were similar between the decision aid and control groups by age, sex, aneurysm size, iliac artery involvement, and Charlson Comorbidity Index score. Patients preferred EVAR over open repair in both groups (96 of 122 [79%] in the decision aid group; 81 of 106 [76%] in the control group; P = .60). Patients in the decision aid group were more likely to receive their preferred repair type than patients in the control group (95% agreement [93 of 98] vs 86% agreement [81 of 94]; P = .03), and κ statistics were higher in the decision aid group (κ = 0.78; 95% CI, 0.60-0.95) compared with the control group (κ = 0.53; 95% CI, 0.32-0.74). Adjusted models confirmed this association (odds ratio of agreement in the decision aid group relative to control group, 2.93; 95% CI, 1.10-7.70).

Conclusions and Relevance

Patients exposed to a decision aid were more likely to receive their preferred AAA repair type, suggesting that decision aids can help better align patient preferences and treatments in major cardiovascular procedures.

Trial Registration

ClinicalTrials.gov Identifier: NCT03115346.

The Application of Split-Thickness Skin Graft as an Autogenous Arterial Conduit in a Goat (Capra Hircus) Model

Adequate autogenous vein is often the limiting factor in achieving a successful infrainguinal bypass. Attempts have been made to find alternative conduits; however, these alternatives have demonstrated inferior patency rates. We attempt to show that a split-thickness skin graft conduit provides a feasible autogenous arterial conduit. Neoconduits were prepared with an autogenous split-thickness skin graft (STSG) tubularized for a length of 5-6 centimeters with an appropriate caliber match to native artery. The deep dermal side of the graft was randomized to form either the external surface or the luminal surface. The neoconduit was placed as an interposition graft in the left common carotid artery. Grafts were studied in vivo with duplex ultrasonography and ex vivo by histopathology and immunohistochemistry. Feasibility study involved 4 animals with grafts harvested for study at 24 hours (n= 2) and 7 days (n= 2). Two subsequent groups were studied to evaluate 3-month (n= 8) and 6-month (n= 5) patency. All grafts (n= 4) in the feasibility phase of the study were patent at the time of harvest without evidence of aneurysmal degeneration. In the subsequent 8 goats, grafts with the deep dermal side forming the extraluminal surface (n= 4) had a propensity to ulcerate and rupture or to become aneurysmal (75%). The patency rate of these grafts at 6 weeks was 25%. In contrast, grafts with the deep dermal side forming the intraluminal surface (n= 4) demonstrated 75% patency at 6 weeks. Because of these results the remaining goats underwent placement of neoconduits with the deep dermal side forming the luminal surface. These grafts maintained a patency rate of 80% at 6 months. Neoconduits implanted with a diameter greater than 1.5 times the native arterial diameter became aneurysmal. Histopathology demonstrated neointimal formation in all grafts patent for longer than 7 days. Immunohistochemical staining for Factor VIII/von Willebrand’s factor (vWF) was reactive in the endoluminal cells of these grafts. Immunohistochemical staining for a-smooth muscle actin demonstrated reactivity in conduits patent for greater than 1 month. Split-thickness skin may provide a feasible source for autogenous conduit in arterial reconstructions and warrants further study. Technical factors affecting patency include orientation of the deep dermal surface of the STSG and the diameter of the neoconduit at the time of implantation.

Vein diameter is the major predictor of fistula maturation

OBJECTIVES

Preoperative duplex ultrasound mapping of veins and arteries has been widely advocated to maximize the creation of native arteriovenous fistula (AVF) for hemodialysis access, but reliable diameter criteria have not been established. We sought to determine patient and anatomic variables predictive of fistula maturation in patients receiving their initial permanent hemodialysis access.

METHODS

All patients undergoing dialysis access creation from January 2003 to June 2007 were retrospectively reviewed. We analyzed fistula type and functional maturation rates (Society for Vascular Surgery [SVS] reporting standards) based on patient characteristics and findings on physical examination, preoperative vein mapping studies, or venography. Maturation and patency rates were determined by Kaplan Meier analysis. The following factors were analyzed: age, race, gender, body-mass index (BMI), fistula site, preoperative duplex vein diameter, diabetes, hyperlipidemia, HTN, prior central catheter placement, HIV, and history of IV drug abuse.

RESULTS

From January 2003 to June 2007, 298 vascular access procedures were performed. One hundred ninety-five (65%) were initial hemodialysis access procedures, among which a native AVF was created in 185 (95%); 158 patients with posterior radiocephalic AVF (PRCAVF, n = 24), wrist radiocephalic AVF (WRCAVF, n = 72), or brachiocephalic AVF (BCAVF, n = 62) had adequate follow-up and were included in the analysis. PRCAVF, WRCAVF, and BCAVF had 54%, 66%, and 81% maturation rates, respectively. Both the type of fistula type (P = .032) and vein size (P = .002) significantly affected maturation by univariate analysis. In contrast, by multivariate logistic regression analysis, vein diameter was the sole independent predictor of fistula functional maturation (P = .002).

CONCLUSION

In this series of 158 patients undergoing initial hemodialysis access creation, native AVF creation was performed in 95%. In contrast to previous reports, age, gender, diabetes, and BMI had no significant effect on functional maturation. By multivariate logistic regression analysis, vein diameter was the sole independent predictor of functional fistula maturation.

Current assessment of endovascular therapy for infrainguinal arterial occlusive disease in patients with diabetes

Endovascular therapy has increasingly become the initial clinical option for the treatment of lower-extremity peripheral arterial occlusive disease not only for patients with claudication but also for those with critical limb ischemia. Despite this major clinical practice paradigm shift, the outcomes of endovascular therapy for peripheral arterial disease are difficult to evaluate and compare with established surgical benchmarks because of the lack of prospective randomized trials, incomplete characterization of indications for intervention, mixing of arterial segments and extent of disease treated, the multiplicity of endovascular therapy techniques used, the exclusion of early treatment failures, crossover to open bypass during follow-up, and the frequent lack of intermediate and long-term patency and limb salvage rates in life-table format. These data limitations are especially problematic when one tries to assess the outcomes of endovascular therapy in patients with diabetes. The purpose of the present article is to succinctly review and objectively analyze available data regarding the results of endovascular therapy in patients with diabetes.

Comparison of the effects of open and endovascular aortic aneurysm repair on long-term renal function using chronic kidney disease staging based on glomerular filtration rate

OBJECTIVE

It has been suggested that endovascular aneurysm repair (EVAR) in concert with serial contrast-enhanced computed tomography (CT) surveillance adversely impacts renal function. Our primary objectives were to assess serial renal function in patients undergoing EVAR and open repair (OR) and to evaluate the relative effects of method of repair on renal function.

METHODS

A thorough retrospective chart review was performed on 223 consecutive patients (103 EVAR, 120 OR) who underwent abdominal aortic aneurysm (AAA) repair. Demographics, pertinent risk factors, CT scan number, morbidity, and mortality were recorded in a database. Baseline, 30- and 90-day, and most recent glomerular filtration rate (GFR) were calculated. Mean GFR changes and renal function decline (using Chronic Kidney Disease [CKD] staging and Kaplan-Meier plot) were determined. EVAR and OR patients were compared. CKD prevalence (>or=stage 3, National Kidney Foundation) was determined before repair and in longitudinal follow-up. Observed-expected (OE) ratios for CKD were calculated for EVAR and OR patients by comparing observed CKD prevalence with the expected, age-adjusted prevalence.

RESULTS

The only baseline difference between EVAR and OR cohorts was female gender (4% vs 12%, P = .029). Thirty-day GFR was significantly reduced in OR patients (P = .047), but it recovered and there were no differences in mean GFR at a mean follow-up of 23.2 months. However, 18% to 39% of patients in the EVAR and OR groups developed significant renal function decline over time depending on its definition. OE ratios for CKD prevalence were greater in AAA patients at baseline (OE 1.28-3.23, depending upon age group). During follow-up, the prevalence and severity of CKD increased regardless of method of repair (OE 1.8-9.0). Deterioration of renal function was independently associated with age >70 years in all patients (RR 2.92) and performance of EVAR compared with OR (RR 3.5) during long-term follow-up.

CONCLUSIONS

Compared with EVAR, OR was associated with a significant but transient fall in GFR at 30 days. Renal function decline after AAA repair was common, regardless of method, especially in patients >70 years of age. However, the renal function decline was significantly greater by Kaplan-Meier analysis in EVAR than OR patients during long-term follow-up. More aggressive strategies to monitor and preserve renal function after AAA repair are warranted.

Endovascular common iliac aneurysm exclusion with antegrade hypogastric artery flow preservation: a novel approach

Open surgical repair of iliac aneurysms has been usually associated with significant morbidity and mortality. The introduction of novel endovascular techniques has expanded the currently available options to treat these aneurysms. However, the use of endoluminal stent grafts to treat common iliac artery aneurysms by landing their distal end into the hypogastric artery in patients where flow into the latter artery is crucial to avoid end-organ ischemia has only been rarely reported in the past. A case report of a common iliac aneurysm case treated with a novel therapeutic approach, not previously reported is herein presented. Three telescopically-overlapping Hemobahn/Viabahn polytetrafluoroethylene (PTFE)-covered endoprosthesis (W.L. Gore & Associates, Flagstaff, AZ) were used with success.

Aortic Paraprosthetic-colonic Fistulae: A Review of the Literature

BACKGROUND

Aortic graft-colonic fistulae are a rare complication of aortic reconstructive surgery.

METHODS AND FINDINGS

A comprehensive review of this entity was performed based on the available literature from 1950 until 2006. Available reports were analyzed with respect to demographics, prior surgical intervention and its indication, prosthetic material used during the initial intervention, clinical presentation, the time interval in between the initial operation and symptoms, the method of treatment of the aortic graft-colonic fistula and its outcome.

An economic appraisal of lower extremity bypass graft maintenance

OBJECTIVE

Infrainguinal graft surveillance leads to intervention on the basis of duplex-identified stenoses. We have become increasingly concerned about the high frequency with which such revisions are required to maximize graft patency and limb salvage rates. The economic implications of these procedures have not been carefully analyzed or justified.

METHODS

We retrospectively reviewed 155 consecutive autogenous infrainguinal bypass grafts performed for chronic leg ischemia in 141 patients. All patients were enrolled in a prospective surveillance program using color flow duplex imaging. Full economic appraisal (cost analysis, cost-effect analysis, and cost-benefit analysis) was performed for all graft surveillance and limb salvage-related interventions through use of standard accounting and valuation techniques.

RESULTS

Mean follow-up was 27 months. Five-year assisted primary patency (72%) and limb salvage rates (91%) were calculated by means of life table analysis. A total of 61 grafts required 86 revisions. Within 1 year of implantation, 36% of the grafts required revision. During this first year, the mean cost per graft enrolled was $9417. Time intervals after the initial year demonstrated a reduced annual revision rate (6%) and cost ($1725 per graft). The mean 5-year cost of graft maintenance ($16,318) approached that of the initial bypass graft ($19,331). The sum of the initial cost of bypass graft and 5-year graft maintenance cost ($35,649) was similar to the cost of amputation ($36,273). Grafts revised for duplex-detected stenoses (n = 46), in comparison with those revised after thrombosis (n = 15), had an improved 1-year patency (93% vs 57%; P <.01), required fewer amputations (2% vs 33%; P <.01), less frequently required multiple graft revisions (P =.06), and generated fewer expenses (at 12 months after revision, $17,688 vs $45,252, P <.01).

CONCLUSION

The cost associated with graft maintenance is significant, particularly within the first year, and demands consideration. Revision of a duplex-identified stenosis was significantly less costly than revision after graft thrombosis. Compared with the cost of limb amputation, limb salvage-related expenses appear to be justified.

Temporary arterial shunts to maintain limb perfusion after arterial injury: an animal study

BACKGROUND

Temporary shunt placement can quickly restore perfusion after extremity arterial injury. This study examined the adequacy of limb blood flow with shunt use, non-heparin-bonded shunt patency over prolonged periods, and the safety of this technique.

METHODS

Common iliac arteries were divided and 4.0-mm Silastic Sundt shunts placed in 16 anesthetized pigs. Eight (group I) had shunts placed immediately; eight others (group II) were shunted after an hour of limb ischemia and hemorrhagic shock. Physiologic parameters and femoral artery blood flow in both hindlimbs were continuously monitored. Limb lactic acid generation, oxygen utilization, and hematologic and metabolic effects were serially evaluated for 24 hours.

RESULTS

Shunts remained patent in 13 of 16 pigs. Shunts thrombosed in two group I animals because of technical errors, but functioned well after thrombectomy and repositioning. Patency could not be maintained in one animal that died from shock. Flow in group I shunted limbs was 57 (+/-11 SD) % of control. For group II animals in shock, shunted limb flow initially averaged 46 +/- 15% of control, but 4 hours after shunt placement, the mean limb blood flow was the same as in group I. Increased oxygen extraction compensated for the lower flow. Lactic acid production was not increased in comparison to control limbs.

CONCLUSION

Shunts provided adequate flow in this model of extremity trauma. Correctly placed shunts stayed patent for 24 hours, without anticoagulation, if shunt placement followed resuscitation.

The correlation of early flow disturbances with the development of infrainguinal graft stenosis: a 10-year study of 341 autogenous vein grafts

PURPOSE

Although duplex surveillance of infrainguinal bypass grafts is widely accepted, the optimal frequency and intensity of graft surveillance remains controversial. Earlier reports have suggested that grafts can be stratified into high-risk and low-risk groups based on the presence or absence of early graft flow disturbances. The purpose of this study was to provide long-term data in determining whether early graft flow disturbances detected by means of duplex scanning can predict the development of intrinsic vein graft stenosis.

METHODS

We reviewed a series of patients undergoing prospective duplex graft surveillance after autogenous infrainguinal bypass grafting procedures from 1987 to 1997. Patients included in the study underwent at least one duplex scan within 3 months of graft implantation and were observed for a minimum of 6 months. Grafts were categorized as abnormal when a focal flow disturbance with a peak systolic velocity greater than 150 cm/s was identified within 3 months of graft implantation.

RESULTS

Of 341 vein grafts in 296 patients who met inclusion criteria, 89 grafts (26%) required revision for intrinsic stenosis; the mean follow-up period was 35 months (range, 6 months to 10 years). Early flow disturbances were detected in 84 (25%) grafts. Grafts with early flow disturbances were more likely to ultimately require revision (43% vs 21%; P =. 0001) and required initial revision earlier (8 months vs 16 months; P =.019). Eighty-two percent of initial graft revisions occurred in the first 2 postoperative years; 69% occurred in the first year. However, an annual 2% to 4% incidence of late-appearing graft stenosis persisted during long-term follow-up. An additional 24 patients (7% of grafts) required an inflow or outflow reconstruction.

CONCLUSION

Grafts with early postoperative flow disturbances detected by means of duplex scanning have nearly three times the incidence of graft-threatening stenosis and an earlier requirement for revision, when compared with normal grafts. This suggests that the biology and etiology of these lesions may differ. These data support not only aggressive efforts to detect early graft lesions to stratify grafts at highest risk, but also continued lifelong graft surveillance to detect late-appearing lesions, inflow and outflow disease progression, and maximize graft patency.

Treatment of patients with venous thromboembolism and malignant disease: should vena cava filter placement be routine?

PURPOSE

It has been proposed that inferior vena cava filter placement should be the initial treatment of deep venous thrombosis (DVT) or pulmonary embolus (PE) in patients with coexisting malignant disease. We have chosen instead to selectively place filters only in patients with either a contraindication to anticoagulation therapy or a subsequent complication from anticoagulation therapy. The treatment efficacy and mortality rates in patients with concomitant malignant disease and venous thromboembolism using this approach was determined.

METHODS

We retrospectively reviewed all patients at our institution with malignant disease in whom venous thromboembolism developed between August 1991 through August 1996 and identified 166 patients with PE (n = 8), DVT (n = 147), and DVT/PE (n = 11). Of these patients, 138 (83.1%) were initially treated with anticoagulation therapy, and 28 (16.9%) had primary filter placement because of contraindications to anticoagulation therapy (10 for intracranial tumors, 11 for recent or upcoming operations, 6 for recent hemorrhage, and 1 for a malignant bloody pericardial effusion).

RESULTS

Thirty-two (23%) of the 138 patients who initially underwent anticoagulation therapy subsequently required a filter for the following reasons: bleeding (n = 15, 10.9%); recurrent thromboembolism (n = 6, 4.3%); heparin-induced thrombocytopenia (n = 1, 0.7%); and perceived high risk for bleeding with continued anticoagulation therapy (n = 11, 8%). Both bleeding and recurrent thromboembolism developed in 1 patient. Sixty patients (36%) received filters. No major technical complications occurred from filter placement. Major recurrent thromboembolic complications developed in 10 patients: DVT (n = 6, 10%), PE (n = 2, 3.3%), inferior vena cava thrombosis and phlegmasia cerulea dolens (n = 1, 1.7%), superior vena cava thrombosis (n = 1, 1.7%). Venous gangrene developed in 1 patient with DVT. The 1-year actuarial survival rates for patients treated with filter and anticoagulation therapy were 35% and 38%, respectively (P = NS).

CONCLUSION

In summary, our experience suggests that 64% of patients with malignant disease and venous thromboembolism are effectively treated with anticoagulation alone; 17% require primary filter placement for standard indications, and an additional 19% require subsequent filter placement because of complications (primarily bleeding) or failure of anticoagulation therapy. Although technical complications of filter placement are low, serious life-threatening or limb-threatening thromboembolic complications developed in 17% of patients. Survival was poor in all patients, regardless of treatment. These data support a conservative approach of routine anticoagulation therapy with selective filter placement.