Serious Failure Modes After EVAR Are Device Specific

OBJECTIVES

Type I and III endoleaks following endovascular aneurysm repair (EVAR) can lead to catastrophic events that require major re-interventions. We reviewed our experience with aortic endograft re-interventions for type I and III endoleaks and other serious failures among different devices.

METHODS

We retrospectively reviewed patients with a prior EVAR who underwent open conversion (OC) or major endovascular intervention (MEI) (re-lining, cuff/limb extension, parallel graft) for type I/III endoleaks at our institution from 2002 to 2019. Baseline characteristics, procedural details, re-interventions, and outcomes were collected.

RESULTS

A total of 229 patients (194 men) underwent re-interventions for type I and III endoleaks after EVAR (90 OC, 139 MEI) for devices implanted between 1997 and 2019. Average age at re-intervention was 78±8.5 years. A total of 135 (59%) were implanted at our institution, whereas 93 (41%) were referred. Median time to re-intervention was 4 years with 25% to 75% interquartile range (IQR) of 2.2-6.6 years. There was no significant difference in baseline demographics or type of re-interventions (OC/MEI) between device types. 42/229 (18%) presented with ruptured aneurysms, 20/229 (9%) were symptomatic, whereas the rest presented with asymptomatic radiographic findings. Type 1A endoleak was present in 146/229 (63.8%-72 with proximal migration), type IB in 46/229 (20.1%), type IIIA in 37/229 (16.6%), type IIIB in 15/229 (6.5%), and persistent aneurysm sac growth with no radiographic evidence of an endoleak in 6/229 (2.6%). Devices included most commercial products: AFX, Excluder, AneuRx, Ancure, Endurant, and Zenith. A smaller number of investigational devices accounted for the rest. Type 1A endoleak was the most common indication for re-intervention among all devices except for AFX and ancure devices, proximal migration was a frequent presentation with AneuRx. AFX devices more frequently presented with a type III and ancure devices more frequently presented with a type IB endoleak.

CONCLUSIONS

Serious failure modes after EVAR differ between endografts and occur throughout the follow-up period. This is important to guide targeted interrogation of surveillance studies and follow-up schedules, even for discontinued devices, as well as comparisons between various series and estimation of EVAR failure rates.

CLINICAL IMPACT

Surveillance after EVAR is critical for long term success of the repair, understanding of the differential modes of failure of every graft available is important in the longitudinal evaluation of these endografts. Equally important is the understanding of the modes of failure of legacy endografts that are no longer on the market but still being followed, in order to be able to tailor a surveillance regiemn and the evntual repair if needed.

A registry-based study of paclitaxel drug-coated balloon angioplasty for the treatment of in-stent restenosis of the femoral-popliteal artery

OBJECTIVE

The aim of this study was to report the results of a prospective, single-arm, registry-based study assessing the safety and performance of a paclitaxel drug-coated balloon (DCB) for the treatment of superficial femoral artery (SFA) or popliteal artery in-stent restenosis (ISR) in a United States population.

METHODS

We conducted a prospective, non-randomized, multi-center, single-arm, post-market registry of the IN.PACT Admiral DCB for the treatment of ISR lesions in the SFA or popliteal artery at 43 sites within the Society for Vascular Surgery (SVS) Vascular Quality Initiative (VQI) Registry from December 2016 to January 2020. Clinical outcomes were assessed at 12, 24, and 36 months. The primary endpoint was target lesion revascularization at 12 months. Secondary endpoints included technical success, target vessel revascularization, major limb amputation, and all-cause mortality. Results are presented as survival probabilities based on Kaplan-Meier survival estimates.

RESULTS

Patients (N = 300) were 58% male, with a mean age of 68 ± 10 years. Diabetes was present in 56%, 80% presented with claudication, and 20% with rest pain. Lesions included ISR of the SFA in 68%, SFA-popliteal in 26%, and popliteal arteries in 7%. The mean lesion length was 17.8 ± 11.8 cm. Lesions were categorized as occlusions in 43% (mean occluded length, 16 ± 10 cm). TASC type was A (17%), B (29%), C (38%), and D (15%). Technical success was 99%. Re-stenting was performed in 5% and thrombolysis in 0.6% of patients. Kaplan-Meier estimates for freedom from target lesion revascularization were 90%, 72%, and 62% at 12, 24, and 36 months. Freedom from target vessel revascularization was 88%, 68%, and 59% and freedom from major target limb amputation was 99.6%, 98.9%, and 98.9%, respectively, at 12, 24, and 36 months. Survival was 95%, 89%, and 85% at 12, 24, and 36 months.

CONCLUSIONS

This post-market registry-based study shows promising results in treating femoral-popliteal ISR with paclitaxel DCB in comparison to the results of plain balloon angioplasty reported in the literature. These results demonstrate the ability of the SVS VQI to conduct post-market evaluation of peripheral devices in partnership with industry and federal regulators.

Comparing post-maturation outcomes of arteriovenous grafts and fistulae

BACKGROUND

Though arteriovenous grafts (AVG) mature more reliably than arteriovenous fistulae (AVF) and require fewer maturation procedures (MP) to obtain functional patency, AVG are thought to have worse function after maturation. We explored differences in post-maturation outcomes between the following groups: AVF patients who did (AS-AVF) and did not (unAS-AVF) require assisted maturation and AVG patients who did (AS-AVG) and did not (unAS-AVG) require assisted maturation.

METHODS

Using the US Renal Data System (2012-2017), we retrospectively identified patients who initiated dialysis with a central venous catheter, underwent AVF or AVG placement and achieved successful two-needle cannulation. Primary patency and access abandonment after maturation were compared across groups using competing risks regression methods, generating sub-hazards ratios (sHR).

RESULTS

We identified 42,664 AVF and 12,335 AVG that met inclusion criteria. A larger proportion of AVFs required interventions: 18,408 AVF (43.2%) versus 2594 AVG (21.0%; p < 0.01). Both AS-AVG and AS-AVF patients experienced patency loss at 1 year more frequently compared with unAS-AVG (67.5% & 57.5% vs 55.2% respectively). Patency loss was lowest in unAS-AVF (38.9%). These trends were robust on adjusted analysis (unAS-AVG reference, AS-AVG sHR = 1.44, p < 0.01; AS-AVF sHR = 1.08, p < 0.01, unAS-AVF sHR = 0.67, p < 0.01). AS-AVGs were more likely to be abandoned than unAS-AVGs (11.7% unAS-AVG vs 17.2% AS-AVG). Fistulae, assisted or not, had lower unadjusted rates of 1-year abandonment than grafts (8.9% AS-AVF vs 7.3% unAS-AVF). On adjusted analysis, AVF usage was protective against abandonment (unAS-AVG, reference; AS-AVF sHR = 0.67, p < 0.01; unAS-AVF sHR = 0.59, p < 0.01) while AS-AVG was not (AS-AVG sHR = 1.32, p < 0.01).

CONCLUSIONS

unAS-AVF have the best long-term outcomes. AS-AVF lose primary patency at a higher rate than unAS-AVG. AVGs may be a better choice than AVFs if veins are marginal and likely to require assisted maturation. Further research is needed to identify anatomic and physiologic factors that affect long-term performance and influence conduit choice.

Socioeconomic factors predict successful supervised exercise therapy completion

OBJECTIVE

Supervised exercise therapy (SET) for patients with intermittent claudication (IC) can lower the risk of progression to chronic limb-threatening ischemia and amputation, while preserving and restoring functional status. Despite supporting evidence, it remains underutilized, and among those who initiate programs, attrition rates are extremely high. We hypothesize that socioeconomic factors may represent significant barriers to SET completion.

METHODS

Patients with IC referred to SET at a multi-hospital, single-institution health care system (2018-2022) from a prospectively maintained database were retrospectively analyzed. Our primary endpoint was SET program completion and graduation, defined as completion of 36 sessions. Our secondary endpoints were vascular intervention within 1 year of referral and change in ankle-brachial index (ABI). Baseline demographics were assessed using standard statistical methods. Predictors of SET graduation were analyzed using multivariable logistic regression generating adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Change in ABI was analyzed using t-test between subgroups. Reasons for attrition were tabulated. Patient Health Questionnaire-9 (PHQ-9), metabolic equivalent level, Vascular QOL, Duke Activity Status, and ABI were analyzed using paired t-tests across the entire cohort.

RESULTS

Fifty-two patients met inclusion criteria: mean age 67.85 ± 10.69 years, 19 females (36.54%), mean baseline ABI of 0.77 ± 0.16. The co-pays for 100% of patients were fully covered by primary and secondary insurance plans. Twenty-one patients (40.38%) completed SET. On multivariable analysis, residence in a ZIP code with median household income <$47,000 (aOR, 0.10; 95% CI, 0.01-0.76; P = .03) and higher body mass index (aOR, 0.81; 95% CI, 0.67-0.99; P = .04) were significant barriers to SET graduation. There were no differences in ABI change or vascular intervention within 1 year between graduates and non-graduates. Non-graduates reported transportation challenges (25.00%), lack of motivation (20.83%), and illness/functional limitation (20.83%) as primary reasons for SET attrition. Metabolic Equivalent Level (P ≤ .01) and Duke Activity Status scores (P = .04) were significantly greater after participating in a SET program.

CONCLUSIONS

Although SET participation improves lower extremity and functionality outcomes, only 40% of referred patients completed therapy in our cohort. Our findings suggest that both socioeconomic and functional factors influence the odds of completing SET programs, indicating a need for holistic pre-referral assessment to facilitate enhanced program accessibility for these populations.

Carotid Endarterectomy Should Not Be Recommended to End-Stage Kidney Disease Patients with Asymptomatic Carotid Artery Disease

BACKGROUND

Carotid endarterectomy (CEA) for asymptomatic carotid artery disease is advised for patients with low perioperative stroke risk and life expectancy of 3-5 years. We sought to explore the role of risk stratification and postoperative medical management in identifying appropriate asymptomatic candidates for CEA in the end-stage kidney disease (ESKD) population.

METHODS

We identified ESKD patients on dialysis from the United States Renal Data System that underwent CEA (2008-2014) for asymptomatic carotid artery disease. We used the Liu comorbidity index as well as a novel risk prediction model based on Cox proportional hazards model to stratify patients. The primary outcome evaluated was 3-year survival, and Kaplan-Meier methods were used to generate survival estimates. We further conducted a subanalysis of patients with Medicare part D data to determine postoperative usage of the following medications: statins, antiplatelets, and antihypertensives. We evaluated the association of medication utilization and 3-year survival using Kaplan-Meier methods and Cox proportional hazards modeling.

RESULTS

We analyzed 1,813 patients meeting inclusion criteria. The population was predominantly older (mean age 70.2 ± 9.1), White (84.8%), and had a high prevalence of cardiovascular comorbidities, such as hypertension (90.7%), diabetes (62.5%), and congestive heart failure (35.4%). Among the entire cohort, 23.0% had a Liu comorbidity index ≤8, 35.0% had index 9-12, and 42.0% had index >12. Increasing Liu comorbidity index was associated with worse survival (P < 0.01); however, even the group with Liu index ≤8 had poor 3-year survival of 58.8% (53.9-63.4). The Cox proportional hazards model identified variables for inclusion in the risk model such as age >80 (adjusted hazard ratio [aHR] = 2.49, 95% confidence interval [CI] [1.87-3.33], P < 0.001), congestive heart failure (aHR = 1.31, 95% CI [1.14-1.51], P < 0.001), and Liu comorbidity index >12(aHR = 1.89, 95% CI [1.56-2.28], P < 0.001). The risk score generated ranged from 0 to 6.5, and patients were divided into 3 groups: score ≤2 (43.4%), 2-4 (41.2%), and >4 (15.4%). Increasing risk score was associated with worse survival (P < 0.01) but even the "low-risk" group had 3-year survival of 58.5% (54.9-61.9). Subanalysis of the 1,249 (68.8% of total) patients with part D data found that statins and calcium channel blocker use was associated with improved survival, although observed rates for patients on drug were still low.

CONCLUSIONS

The overall long-term survival of ESKD patients undergoing CEA for asymptomatic carotid artery disease is low. Risk stratification and analysis of postoperative medical management did not identify a subgroup of patients with adequate 3-year survival. Hence, the preventive benefits of CEA are not realized in these patients.

A Comparison of Surgical Techniques and Outcomes for Primary Infected Abdominal Aortic Aneurysms

BACKGROUND

Primary infected abdominal aortic aneurysms (PIAAAs) are associated with high morbidity and mortality. Three repair approaches include open in-situ repair (OIR), extra-anatomic repair (EAR), and endovascular abdominal aortic aneurysm repair (EVAR). This study is one of the largest single-center case series comparing the outcomes of the different surgical approaches for PIAAA.

METHODS

This is a retrospective cohort study of all patients treated surgically for PIAAA between 2000 and 2021. PIAAA diagnosis was defined as the presence of an abdominal aortic aneurysm with evidence of infection on clinical presentation, laboratory markers, radiology, or surgically. Patients with prior aortic surgery were excluded from this study. Basic demographics were compared across the 3 surgical groups using standard statistical methods. Our primary outcomes included mortality at 1 and 5 years. Kaplan-Meier curves were generated and compared using log-rank testing. Multivariate Cox proportional hazards models were created to assess determinants of mortality.

RESULTS

A total of 43 patients were included in the full cohort. Patients undergoing EVAR more often had diabetes, end-stage renal disease, and coronary artery disease. EVAR was also more often done in patients with a saccular aneurysm rather than fusiform. (93% vs. 70% in EAR and 42% in OIR; P = 0.015). All-cause mortality rates at 1 year were not significantly different between the 3 groups. Survival at 5 years did show a significant benefit of OIR over EVAR and EAR: OIR had an 8% mortality rate with EAR having a 53% rate and EVAR having the highest (72%) mortality rate at 5 years (P = 0.03). Multivariable Cox regression analysis showed that EVAR (aHR 12.1, (95% CI 1.42 to 103.9), P = 0.02) and EAR (aHR 15.1, (95% CI 1.59 to 143.3), P = 0.0.02) had an increased 5-year mortality risk when compared to OIR.

CONCLUSIONS

Repair of primary infected aortic aneurysm is associated with high complication and mortality rates regardless of the approach. In our studied sample, OIR offered an improved long-term survival without added benefits in terms of complication rates. In infected AAA, EVAR should be considered bridging stage between the urgent situation and eventual open repair.

Aortobifemoral bypass vs covered endovascular reconstruction of aortic bifurcation

BACKGROUND

Covered endovascular reconstruction of aortic bifurcation (CERAB) is increasingly used as a first line-treatment in patients with aortoiliac occlusive disease (AIOD). We sought to compare the outcomes of patients who underwent CERAB compared with the gold standard of aortobifemoral bypass (ABF).

METHODS

The Vascular Quality Initiative was queried for patients who underwent ABF or CERAB from 2009 to 2021. Propensity scores were generated using demographics, comorbidities, Rutherford class, and urgency. The two groups were matched using 5-to-1 nearest-neighbor match. Our primary outcomes were 1-year estimates of primary patency, major adverse limb events (MALEs), MALE-free survival, reintervention-free survival, and amputation-free survival. Standard statistical methods were used.

RESULTS

A total of 3944 ABF and 281 CERAB cases were identified. Of all patients with AIOD, the proportion of CERAB increased from 0% to 17.9% between 2009 and 2021. Compared with ABF, patients who underwent CERAB were more likely to be older (64.7 vs 60.2; P < .001) and more often had diabetes (40.9% vs 24.1%; P < .001) and end-stage renal disease (1.1% vs 0.3%; P = .03). In the matched analysis (229 CERAB vs 929 ABF), ABF patients had improved MALE-free survival (93.2% [±0.9%] vs 83.2% [±3%]; P < .001) and lower rates of MALE (5.2% [±0.9%] vs 14.1% [±3%]; P < .001), with comparable primary patency rates (98.3% [±0.3%] vs 96.6% [±1%]; P = .6) and amputation-free survival (99.3% [±0.3%] vs 99.4% [±0.6%]; P = .9). Patients in the CERAB group had significantly lower reintervention-free survival (62.5% [±6%] vs 92.9% [±0.9%]; P < .001). Matched analysis also revealed shorter length of stay (1 vs 7 days; P < .001), as well as lower pulmonary (1.2% vs 6.6%; P = .01), renal (1.8% vs 10%; P < .001), and cardiac (1.8% vs 12.8%; P < .001) complications among CERAB patients.

CONCLUSIONS

CERAB had lower perioperative morbidity compared with ABF with a similar primary patency 1-year estimates. However, patients who underwent CERAB experienced more major adverse limb events and reinterventions. Although CERAB is an effective treatment for patients with AIOD, further studies are needed to determine the long-term outcomes of CERAB compared with the established durability of ABF and further define the role of CEARB in the treatment of AIOD.

Predictors of chronic thromboembolic pulmonary hypertension in patients with submassive pulmonary embolism treated with catheter-directed thrombolysis versus anticoagulation alone: A secondary analysis of the SUNSET sPE trial

OBJECTIVE

Chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary embolism (PE) is a morbid complication with suboptimal treatment. We aimed to evaluate the biomarker profile and functional outcomes in patients with submassive PE (sPE) treated with catheter-directed thrombolysis (CDT) compared with anticoagulation alone (ACA). We performed a secondary biomarker and survey analysis of the SUNSET sPE (standard vs ultrasound-assisted catheter thrombolysis for submassive pulmonary embolism) randomized trial comparing standard CDT to ultrasound-assisted thrombolysis in patients with sPE.

METHODS

As a part of the SUNSET sPE study, patients who did not receive an intervention were enrolled in the medical (ACA) arm. The biomarkers associated with CTEPH in the literature (ie, CCL2, CXCL10, PTX3, GDF-15, RAGE, BCA-1, TFPI) were collected and measured using a multiplex assay at diagnosis, discharge, and 3-month follow-up. Patients underwent a 6-minute walk test and answered quality-of-life questionnaires (pulmonary embolism quality of life; University of California, San Diego, shortness of breath questionnaire; 36-item short-form survey) at 3 months after diagnosis. Comparisons were made using the Student t test. Nonparametric tests were used when the distributions were not normal. Significance was set at P ≤ .05.

RESULTS

A total of 72 patients (age, 56 ± 15 years; 40.3% women) were included in the present analysis. Of these 72 patients, 53 underwent CDT and 19 were included in the ACA arm. The baseline right ventricle/left ventricle ratios were similar between the two groups (CST, 1.8; ACA, 1.7). The survival and complication rates were similar between the two groups. At discharge, CXCL10 (768.9 ± 148.6 pg/mL vs 3032.0 ± 1201.0 pg/mL; P = .018) and PTX3 (3203.5 ± 1298.0 pg/mL vs 12,716.2 ± 6961.5 pg/mL; P = .029) were lower in the CDT group and displayed a quicker return to baseline than in the ACA group. This trend, although not significant, was also seen with the other biomarkers. At 3 months, the 6-minute walking distance and quality-of-life scores were similar between both groups.

CONCLUSIONS

In patients with sPE, the biomarkers of CTEPH were lower with CDT compared with ACA. At 3 months, both groups demonstrated similar biomarker levels, 6-minute walking distances, and quality-of-life scores.

Midterm Outcomes of Endovascular vs. Medical Therapy for Uncomplicated Type B Aortic Dissection: Meta-Analysis of Reconstructed Time to Event Data

OBJECTIVE

To evaluate outcomes of thoracic endovascular aortic repair (TEVAR) vs. medical therapy in uncomplicated type B aortic dissections (TBAD).

DATA SOURCES

PubMed/MEDLINE, EMBASE, SciELO, LILACS, CENTRAL/CCTR, Google Scholar, and reference lists of relevant articles.

REVIEW METHODS

This was a pooled meta-analysis of time to event data extracted from studies published by December 2022 for the following outcomes: all cause mortality, aortic related mortality, and late aortic interventions. Certainty of evidence was evaluated through the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool.

RESULTS

Ten studies met the eligibility criteria (eight observational; two randomised trials), comprising 17 906 patients (2 332 patients in the TEVAR groups and 15 574 patients in the medical therapy group). Compared with patients who received medical therapy, patients who underwent TEVAR had a statistically significantly lower risk of all cause death (HR 0.79, 95% CI 0.72 - 0.87, p < .001; GRADE certainty: low) and lower risk of aortic related death (HR 0.43, 95% CI 0.30 - 0.62, p < .001; GRADE certainty: low) without statistically significant difference in the risk of late aortic interventions (HR 1.05, 95% CI 0.88 - 1.26, p = .56; GRADE certainty: low). In the subgroup analyses, TEVAR was associated with lower risk of all cause death when randomised controlled trials only were pooled (HR 0.44, 95% CI 0.23 - 0.83, p = .012; GRADE certainty: moderate), younger patients only (HR 0.56, 95% CI 0.47 - 0.67, p < .001; GRADE certainty: low), Western populations only (HR 0.85, 95% CI 0.77 - 0.93, p = .001; GRADE certainty: low) and non-Western populations only (HR 0.47, 95% CI 0.35 - 0.62, p < .001; GRADE certainty: low). For all cause mortality and aortic related mortality, restricted mean survival time was overall 396 days and 398 days longer with TEVAR (p < .001), respectively, which means that TEVAR was associated with lifetime gain.

CONCLUSION

TEVAR may be associated with better midterm survival and lower risk of aortic related death in the follow up of patients treated for uncomplicated TBAD compared with medical therapy; however, randomised controlled trials with larger sample sizes and longer follow up are still warranted.

Racial Disparities in Treatment Indications and Outcomes for Limb Ischemia

BACKGROUND

Studies suggest that the Affordable Care Act (ACA) of 2014 has improved access to vascular care and vascular outcomes among patients suffering from peripheral arterial disease (PAD). We sought to examine the racial disparities that exist in patients with PAD who have undergone lower extremity bypass (LEB) or a peripheral vascular intervention (PVI) using the Vascular Quality initiative (VQI) database.

METHODS

The VQI infrainguinal and PVI datasets were queried for patients receiving elective and urgent LEB or PVI between 2016, 2 years after ACA implementation, and in 2021. Patients undergoing interventions urgently/emergently or for aneurysm were excluded. The primary outcome was major adverse limb event (MALE-defined as any vascular reintervention or above-ankle amputation) free survival at 1 year. Standard statistical methods were utilized as appropriate.

RESULTS

A total of 17,455 LEB and 87,475 PVIs were included in this analysis. Black persons present at a younger age when compared to non-Hispanic White persons (NHW) and are more likely to have diabetes, hypertension, end-stage renal disease (ESRD), and higher rates of prior amputation. Black persons are more likely to present with chronic limb-threatening ischemia (CLTI) rather than claudication, and in a more urgent setting. Postoperative outcomes show higher rates of major amputations among racial minorities, specifically Black persons for both LEB (1.8% vs. 0.8% P < 0.001) and PVI (20.8% vs. 16.8% P < 0.001). Black persons are at higher risk of 1-year MALE for LEB (36.7% vs. 29.9% P < 0.001) and PVI (31.0% vs. 21.7%; P < 0.001). Even after adjusting for confounding variables, Black persons have a higher risk of 1-year MALE for LEB, with an adjusted hazard ratio (aHR) of 1.15 (95% CI [1.05-1.26], P = 0.003) and PVI (aHR 1.18 95% CI [1.12-1.24], P < 0.001). Other major determinates of 1-year MALE on multivariate Cox regression included CLTI (LEB aHR 1.57 95% CI [1.43-1.72], P < 0.001; PVI aHR 2.29 95% CI [2.20-2.39], P < 0.001) and history of prior amputation (LEB aHR 1.35 95% CI [1.17-1.56], P < 0.001; PVI aHR 1.5 95% CI [1.4-1.6], P < 0.001).

CONCLUSIONS

Compared to NHW persons, Black persons present with more advanced vascular disease regardless of the operative indication. Black persons are also at significantly higher risk of 1-year MALE. Despite some advances in more accessible care through the ACA of 2014, our observations suggest that Black persons still have significantly worse outcomes due to variety of variables that need further investigation.

Selective Publication within Vascular Surgery: Characteristics of Discontinued and Unpublished Randomized Clinical Trials

BACKGROUND

Discontinued and unpublished randomized clinical trials (RCTs) are common resulting in biased publication and loss of potential knowledge. The magnitude of selective publication within vascular surgery remains unknown.

METHODS

RCT relevant to vascular surgery registered (01/01/2010-10/31/2019) on ClinicalTrials.gov were included. Trials ending normally with conclusion of participant treatment and examination were considered completed whereas discontinued trials stopped early. Publications were identified through automatically indexed PubMed citations on ClinicalTrials.gov or manually identified on PubMed or Google Scholar >30 months after the completion date, the date the final participant was examined, allowing time for publication.

RESULTS

Of 108 RCT (n = 37, 837), 22.2% (24/108) were discontinued, including 16.7% (4/24) stopped prior to and 83.3% (20/24) after starting enrollment. Only 28.4% of estimated enrollment was achieved for all discontinued RCT. Nineteen (79.2%) investigators provided a reason for discontinuation, which most commonly included poor enrollment (45.8%), inadequate supplies or funding (12.5%), and trial design concerns (8.3%). Of the 20 trials terminated following enrollment, 20.0% (4/20) were published in peer-reviewed journals and 80.0% (16/20) failed to reach publication. Of the 77.8% trials completed, 75.0% (63/84) were published and 25.0% (21/84) remain unpublished. In a multivariate regression of completed trials, industry funding was significantly associated with decreased likelihood of peer-reviewed publication (OR = 0.18, (95% CI 0.05-0.71), P = 0.01). Of the discontinued and completed trials remaining unpublished, 62.5% and 61.9% failed to report results on ClinicalTrials.gov, respectively, encompassing a total of 4,788 enrollees without publicly available results.

CONCLUSIONS

Nearly 25% of registered vascular RCT were discontinued. Of completed RCT, 25% remain unpublished with industry funding associated with decreased likelihood of publication. This study identifies opportunities to report all findings for completed and discontinued vascular surgery RCT, whether industry sponsored, or investigator initiated.

Surgical and endovascular assisted maturation procedures improve cannulation after arteriovenous fistula creation, but not after arteriovenous graft placement

OBJECTIVE

After creation, arteriovenous fistulae (AVF) and arteriovenous grafts (AVG) can undergo surgical or endovascular assisted maturation (AM) procedures to enable use for hemodialysis. We sought to explore the association of interventions with successful two-needle cannulation (TNC) using the United States Renal Data System (USRDS).

METHODS

Using the 2012-2017 USRDS, we identified patients initiating hemodialysis with tunneled dialysis catheters (TDC). Successful AVF/G use was defined as two-needle cannulation (TNC). Our principal outcome was time to first TNC after AVF/G creation. Death and new access placement were competing events that precluded TNC. Competing-risks regression models were constructed to identify factors associated with cannulation. Logistic regression was used to assess the association between AM procedures and 1-year TNC and also to compare post-cannulation outcomes.

RESULTS

Among 81,143 patients, 15,880 (19.6%) had AVG and 65,263 (80.4%) had AVF. AVG patients were more likely than AVF patients to achieve TNC at 1 year on unadjusted (77.4% vs 64.0%, p < 0.001) and on multivariate analysis (sHR = 2.56 (2.49-2.63), p < 0.001). For AVFs, one AM surgical procedure was associated with improved 1-year TNC rates, but further revisions were not helpful. Endovascular AM procedures were associated with increased AVF TNC rates. Any procedure, surgical or endovascular, was detrimental to achieving TNC for AVGs.Following initial TNC, those accesses that needed AM procedures were associated with higher rates of access failure (AVF: OR = 1.32 (1.21-1.45); AVG: OR = 1.77 (1.500-2.00); p < 0.001), catheter replacement (AVF: OR = 1.27 (1.20-1.34); AVG: OR = 1.56 (1.42-1.71), p < 0.001), and additional endovascular procedures (AVF: 0.75 ± 1.22 no AM vs 1.33 ± 1.62 any AM; AVG: 1.31 ± 1.77 no AM vs 1.96 ± 2.22 any AM; all p < 0.001).

CONCLUSIONS

AVG achieved TNC after creation more reliably than AVF. A single surgery or endovascular procedures for AVFs is associated with greater rates of TNC. For AVGs, any AM procedure is associated with lower cannulation rates, and reinforces the need for careful operative technique.

Pulmonary embolism response team for hospitalized patients with submassive and massive pulmonary embolism: A single-center experience

BACKGROUND

Pulmonary embolism (PE) is a major cause of mortality with presentation varying between few or no symptoms to sudden death. This makes timely and appropriate treatment extremely important. Multidisciplinary PE response teams (PERT) have emerged to improve the management of acute PE. This study aims to describe the experience of a large multihospital single-network institution with PERT.

METHODS

A retrospective cohort study of patients admitted for submassive and massive PE between 2012 and 2019 was conducted. The cohort was divided based on time of diagnosis and hospital into two groups: non-PERT included patients treated at hospitals that did not initiate PERT and patients diagnosed before the introduction of PERT (June 1, 2014); and the PERT group included those admitted after June 1, 2014, to a hospital with PERT. Patients with low-risk PE and those who had admissions in both time periods were excluded. Primary outcomes included all-cause mortality at 30, 60, and 90 days. Secondary outcomes included causes of death, intensive care unit (ICU) admission, ICU length of stay (LOS), total hospital LOS, type of treatment, and specialty consultations.

RESULTS

We analyzed 5190 patients, with 819 (15.8%) being in the PERT group. Patients in the PERT group were more likely to receive extensive workup that included troponin-I (66.3% vs 42.3%; P < .001) and brain natriuretic peptide (50.4% vs 20.3%; P < .001). They also more often received catheter-directed interventions (12% vs 6.2%; P < .001) rather than anticoagulation monotherapy. Mortality outcomes were similar between both groups at all measured timepoints. Rates of ICU admission (65.2% vs 29.7%; P < .001), ICU LOS (median, 64.7 hours; interquartile range [IQR], 41.9-89.1 hours vs median, 38 hours; IQR, 22-66.4 hours; P < .001), and total hospital LOS (median, 5 days; IQR, 3-8 days vs median, 4 days; IQR, 2-6 days; P < .001) were all higher among the PERT group. Patients in the PERT group were more likely to receive vascular surgery consultation (5.3% vs 0.8%; P < .001) and the consultation occurred earlier in the admission when compared with the non-PERT group (median, 0 days; IQR, 0-1 days vs median, 1 day; IQR, 0-1; P = .04).

CONCLUSIONS

The data presented here showed that there was no difference in mortality after PERT implementation. These results suggest that the presence of PERT increases the number of patients receiving a full PE workup with cardiac biomarkers. PERT also leads to more specialty consultations and more advanced therapies such as catheter-directed interventions. Further research is needed to assess the effect of PERT on long-term survival of patients with massive and submassive PE.

COVID-associated acute limb ischemia during the Delta surge and the effect of vaccines

OBJECTIVE

Hypercoagulability is common in severe acute respiratory syndrome coronavirus 2 and has been associated with arterial thrombosis leading to acute limb ischemia (ALI). Our objective was to determine the outcomes of concurrent coronavirus disease 2019 (COVID-19) infection and ALI, particularly during the Delta variant surge and the impact of vaccination status.

METHODS

A retrospective review was performed of patients treated at a single health care system between March 2020 and December 2021 for ALI and recent (<14 days) COVID-19 infection or who developed ALI during hospitalization for the same disease. Patients were grouped by year as well as by pre and post Delta variant emergence in 2021 based on the World Health Organization timeline (January to May vs June to December). Baseline demographics, imaging, interventions, and outcomes were evaluated. A control cohort of all patients with ALI requiring surgical intervention for a 2-year period prior to the pandemic was used for comparison. Primary outcomes were in-hospital mortality and amputation-free survival. Kaplan-Meier survival and Cox proportional hazards analysis were performed.

RESULTS

Forty acutely ischemic limbs were identified in 36 patients with COVID-19, the majority during the Delta surge (52.8%) and after the wide availability of vaccines. The rate of COVID-19-associated ALI, although low overall, nearly doubled during the Delta surge (0.37% vs 0.20%; P = .09). Intervention (open or endovascular revascularization vs primary amputation) was performed on 31 limbs in 28 individuals, with the remaining eight treated with systemic anti-coagulation. Postoperative mortality was 48%, and overall mortality was 50%. Major amputation following revascularization was significantly higher with COVID-19 ALI (25% vs 3%; P = .006) compared with the pre-pandemic group. Thirty-day amputation-free survival was significantly lower (log-rank P < .001). COVID-19 infection (adjusted hazard ratio, 6.2; P < .001) and age (hazard ratio, 1.1; P = .006) were associated with 30-day amputation in multivariate analysis. Severity of COVID-19 infection, defined as vasopressor usage, was not associated with post-revascularization amputation. There was a higher incidence of re-thrombosis in the latter half of 2021 with the Delta surge, as reintervention for recurrent ischemia of the same limb was more common than our previous experience (21% vs 0%; P = .55). COVID-19-associated limb ischemia occurred almost exclusively in non-vaccinated patients (92%).

CONCLUSIONS

ALI observed with Delta appears more resistant to standard therapy. Unvaccinated status correlated highly with ALI occurrence in the setting of COVID-19 infection. Information of limb loss as a COVID-19 complication among non-vaccinated patients may help to increase compliance.

Stenting across inferior vena cava filters can be a safe and effective alternative to complex retrieval

OBJECTIVE

Venous stenting for acute and chronic venous disease has been increasingly used as more evidence has accumulated on the efficacy and durability of these interventions for symptomatic patients. Inferior vena cava (IVC) filters that could have been present for years will often be implicated in the obstructive pathology and removal can be challenging. The purpose of the present study was to evaluate whether stenting across an indwelling IVC filter is a safe and effective alternative to removal.

METHODS

Consecutive patients who had undergone iliocaval stenting at our institution from 2007 to 2020 were identified and divided into groups stratified by the presence of an IVC filter. The operative notes, venography findings, and the electronic health records were queried to obtain the operative details, patient characteristics, postoperative outcomes, stent patency, and survival outcomes. The primary end point was iliocaval stent patency. The patients were divided into two groups according to the presence of an IVC filter with or without overstenting. We used the χ2 test and survival analysis as appropriate.

RESULTS

A total of 224 consecutive patients were identified, of whom 71 were found to have undergone iliocaval stenting (age, 48 ± 18 years; 47.9% male; body mass index, 31 ± 9 kg/m2). Of the 71 patients, 15 had had stents placed across an indwelling IVC filter (overstented group) and 56 had not had an IVC filter present (non-overstented group). No differences were found in presentation between the overstented group (acute occlusion, 4 of 15 [26.7%]; chronic occlusion, 8 of 15 [53.3%]; and nonocclusive lesions, 3 of 15 [20%]) and the non-overstented group (acute occlusion, 29 of 56 [52%]; chronic occlusion, 18 of 56 [32%]; nonocclusive lesions, 9 of 56 [16%]; P = .2). Comparisons between the two groups revealed no differences in the baseline characteristics except for age (overstented, 57 ± 15 years; non-overstented, 46 ± 18 years; P = 0.03), preoperative anticoagulation therapy (overstented, 66.6%; non-overstented, 26.9%; P = .01), and bilateral leg symptoms (overstented, 86.7%; non-overstented, 23.2%; P < .001). Primary patency at 30 months was 85.6% in the overstented group and 86.1% in the non-overstented group (P = .78). At follow-up, no adverse events related to filter crushing were reported, and no differences were found in 30-month survival.

CONCLUSIONS

In our single-center, retrospective study of iliocaval stenting, patients who had undergone overstenting across an indwelling IVC filter had had patency rates similar to those whose stents had been placed with no IVC filter in place. Thus, complex IVC filter removal, when not possible or when the risk of operative complications is too high, can be forgone in favor of stenting across the IVC filter, with no implications on midterm patency or adverse events.

Five-year outcomes from a prospective, multicenter study of endovascular repair of iliac artery aneurysms using an iliac branch device

OBJECTIVE

We have reported the 5-year results of a pivotal prospective, multicenter study conducted in the United States of a specifically designed iliac branch endoprosthesis (IBE; W.L. Gore & Associates, Flagstaff, AZ) for endovascular repair of aortoiliac aneurysms and common iliac artery aneurysms.

METHODS

A total of 63 patients (98.4% male; mean age, 70 years) with aortoiliac or common iliac artery aneurysms had undergone implantation of a single IBE device and a bifurcated aortoiliac stent graft. Patients with bilateral common iliac artery aneurysms (n = 22; 34.9%) had undergone either staged occlusion or surgical revascularization of the contralateral internal iliac artery before study enrollment. At 5 years, 36 of the 63 patients had completed the final study follow-up examinations, including clinical examinations (n = 35) and computed tomography (n = 32), with the results evaluated by an independent core laboratory and adverse events adjudicated by a clinical events committee.

RESULTS

At 5 years, freedom from all-cause mortality was 85.7% and freedom from aneurysm-related mortality was 100%. The nine deaths that had occurred (range, 132-1898 days) were adjudicated as unrelated to the aneurysm or procedure. Primary patency of the internal and external iliac artery IBE limbs was 95.1% and 100%, respectively. No patients had experienced new-onset buttock claudication on the IBE side or self-reported new-onset erectile dysfunction. The common iliac artery diameter on the IBE side was either unchanged or had decreased by ≥5 mm in 30 of the 31 patients (96.8%) with a baseline (1 month) and 5-year (range, 1641-2006 days) computed tomography scan available. Of the 31 evaluable patients, 9 (29.0%) had had an increase of ≥5 mm in the aortic diameter, 5 of whom had had a concurrent type II endoleak. No type I or type III endoleaks or device migration were identified by the core laboratory. Six patients had undergone eight secondary interventions, including five interventions for a type II endoleak. The freedom from secondary intervention was 90.5%.

CONCLUSIONS

The 5-year results of our prospective, multicenter study have confirmed the safety, efficacy, and durability of the IBE device for the treatment of aortoiliac and iliac artery aneurysms. The device effectively prevented common iliac artery aneurysm rupture, maintained the patency of the internal iliac artery, and avoided the complications associated with internal iliac artery sacrifice. Although common iliac artery aneurysm enlargement was rare, abdominal aortic enlargement was more common, suggesting that the outcomes of endovascular aneurysm repair might be different for patients with or without associated common iliac artery aneurysms.

Abdominal aortic aneurysm monitoring via arterial waveform analysis: towards a convenient point-of-care device

Abdominal aortic aneurysms (AAAs) are lethal but treatable yet substantially under-diagnosed and under-monitored. Hence, new AAA monitoring devices that are convenient in use and cost are needed. Our hypothesis is that analysis of arterial waveforms, which could be obtained with such a device, can provide information about AAA size. We aim to initially test this hypothesis via tonometric waveforms. We study noninvasive carotid and femoral blood pressure (BP) waveforms and reference image-based maximal aortic diameter measurements from 50 AAA patients as well as the two noninvasive BP waveforms from these patients after endovascular repair (EVAR) and from 50 comparable control patients. We develop linear regression models for predicting the maximal aortic diameter from waveform or non-waveform features. We evaluate the models in out-of-training data in terms of predicting the maximal aortic diameter value and changes induced by EVAR. The best model includes the carotid area ratio (diastolic area divided by systolic area) and normalized carotid-femoral pulse transit time ((age·diastolic BP)/(height/PTT)) as input features with positive model coefficients. This model is explainable based on the early, negative wave reflection in AAA and the Moens-Korteweg equation for relating PTT to vessel diameter. The predicted maximal aortic diameters yield receiver operating characteristic area under the curves of 0.83 ± 0.04 in classifying AAA versus control patients and 0.72 ± 0.04 in classifying AAA patients before versus after EVAR. These results are significantly better than a baseline model excluding waveform features as input. Our findings could potentially translate to convenient devices that serve as an adjunct to imaging.

Endovascular repair of abdominal and thoracoabdominal aneurysms using chimneys and periscopes is associated with poor outcomes

OBJECTIVE

Chimneys and periscopes are often used to treat pararenal or thoracoabdominal aneurysms de novo or after failed open or endovascular repair. We sought to describe our institutional experience, given their limited success and questionable long-term outcomes.

METHODS

We retrospectively reviewed the electronic records for patients treated with chimneys/periscopes from 1997 through 2020. Baseline characteristics, procedural details, periprocedural complications, reinterventions, and midterm outcomes were collected.

RESULTS

Fifty-eight patients (86 vessels) were treated; the median follow-up was 32 months (range, 0.03-104 months). There were 36% (n = 21) juxta-renal, 2% (n = 1) para-visceral, and 21% (n = 12) thoracoabdominal aneurysms, and 41% (n = 24) had pararenal failure of prior endovascular aneurysm repair (n = 17) or open repair (n = 7). Stent configuration for the majority of the 86 vessels (n = 80; 93%) treated were chimney configuration (n = 6 periscopes; 7%). The most common stent graft utilized was Viabahn, and 8.1% (n = 7) were reinforced with a bare metal stent. Although the majority of the cases were elective, 36.2% (n = 21) of the cases were urgent/emergent. At the conclusion of the initial procedure, 16 of 58 patients had an endoleak (gutter, 50% [8/16]; type Ia, 25% [4/16]; and type II, 25% [4/16]). On follow-up, 14 of 58 patients developed one or more endoleaks, with the most common endoleaks being a gutter endoleak (35% [7/20]). Other endoleaks observed included 30% (6/20) type III, 15% (3/20) type Ia, 15% (3/20) type Ib, and 5% (1/20) type II. Eleven of 58 patients underwent interventions for one or more endoleak (gutter, 33% [5/15]; type Ib, 20% [3/15]; type II, 7% [1/15]; and type III, 40% [6/15]). Twelve of 58 patients returned to the operating room for one or more procedures during the index hospitalization (five laparotomies, three dialysis access, three acute limb ischemia, and four chimney/periscope interventions). Ten of 58 patients underwent angioplasty/stenting for chimney/periscope compression or occlusion during the follow-up period. Survival was 61.3% at 1 year by Kaplan-Meier analysis (75% for elective, 37% for urgent/emergent) (aneurysm-related death, 22%). Cox hazard modeling showed that aneurysm diameter (hazard ratio, 1.03; 95% confidence interval, 1.004-1.05; P = .02) and urgent/emergent interventions (hazard ratio, 3.6; 95% confidence interval, 1.33-9.74; P = .01) were predictors of mortality.

CONCLUSIONS

Endovascular repair of aortic aneurysms with chimneys/periscopes is associated with poor outcomes, including limited technical success and aneurysm exclusion, as well as high morbidity and mortality, with a high rate of reinterventions both in the immediate postoperative period and on follow-up. They should be used only when other surgical or endovascular options are not possible.

Acute Deep Vein Thrombosis Involving the Inferior Vena Cava: Interventional Perspectives

Extension of an iliofemoral thrombosis into the inferior vena cava (IVC), or from the IVC descending into the iliofemoral segments, can confer significant morbidity and mortality. Interventional management of acute deep vein thrombosis (DVT) has been controversial, but there is little doubt that certain subpopulations benefit, such as those with symptomatic IVC thrombosis. When considering an intervention, caval involvement introduces technical difficulties due to its larger diameter, high thrombus burden, bilateral limb clot extension and need for dual access. The frequent coexistence of an IVC filter increases the complexity even more. This review summarises the current indications and treatment modalities available for the management of acute DVT involving the vena cava.

Outcomes of Operative and Non-Operative Management in Blunt Thoracic Aortic Injury

OBJECTIVES

Although current guidelines for management of blunt traumatic aortic injury (BTAI) recommend intervention for grade 2 injury or higher, there is a national trend of aggressive endovascular treatment of low-grade BTAI. Little is known about the natural history of grade 1-2 injuries treated non-operatively. We hypothesized that most of these low-grade injuries remain stable with non-operative management.

METHODS

A review of blunt thoracic aortic injuries (BTAI) at a large referral Level 1 trauma center from 2004-2020 was performed. Injuries were graded on a standard 1-4 scale. Outcomes of both non-operative and TEVAR management strategies were compared, including post-trauma morbidity, mortality, re-intervention, and lesion stability.

RESULTS

176 patients with BTAI, sufficient imaging, and follow-up were identified during the time period. 36 with grade 1, 24 with grade 2, 115 with grade 3, and 1 with grade 4 injury. Of those 176 patients, 112 underwent thoracic endovascular aortic repair (TEVAR) and 64 were managed non-operatively. Most (90.2%) undergoing TEVAR had grade 3 injuries. Non-operative management was performed for 97.2% of grade 1 injuries and 62.5% of grade 2 injuries. Endovascular reintervention after TEVAR was rare (2.7%). Post-trauma morbidity within 30 days (stroke [3.6 vs. 3.1%], MI/arrhythmia [8.9 vs. 1.6%], respiratory failure [31.2 vs. 28.1%], acute kidney injury [9.8 vs. 12.5%], UTI [2.7 vs. 4.8%], GI bleeding [3.6 vs. 0.0%], PE [10.9 vs. 4.5%]) and 1-year mortality after discharge [1.8 vs. 3.1%] were comparable between operative and non-operative groups. Median [IQR] follow up was 1501 [475.6, 2804] days in the TEVAR group and 1170.5 [317, 2173] days in the non-operative group. There was no progression of lesions in patients with low-grade (1-2) injuries managed non-operatively. Resolution of grade 1-2 injury was seen in 20% of patients at 30 days, improving to 44% during long-term follow up. Fourteen patients with grade 3 injuries (12.2% of grade 3 injuries in this series) were also observed and did not require future intervention. These patients generally had smaller pseudoaneurysms with minimal periaortic hematoma. None progressed or resulted in rupture on follow-up (454.5 [81, 1199] days CT scan follow up).

CONCLUSIONS

Non-operative management of low-grade BTAI does not result in long-term aortic complications or need for reintervention. Those grade 3 injuries with smaller pseudoaneurysms and minimal periaortic hematoma may be safely observed if they can be appropriately followed, and that indications for treatment of select grade 3 injuries merits further consideration.

Contemporary management of acute and chronic mesenteric ischemia: 10-year experience from a multihospital healthcare system

OBJECTIVE

Endovascular and hybrid methods are being increasingly used to treat mesenteric ischemia. However, long-term outcomes and risk of symptom recurrence remain unknown. The objective of this study was to define predictors of post-operative morbidity, mortality, and patency loss in acute (AMI) or chronic mesenteric ischemia (CMI).

METHODS

Inpatient and follow-up records for all patients who underwent revascularization for AMI and CMI from 2010 to 2020 at a multicenter hospital system were reviewed. Patency and mortality were evaluated with Cox regression, visualized with Kaplan-Meier curves, and compared using log rank testing. Patency was further evaluated with Fine-Gray regression utilizing death as a competing risk. Post-operative major adverse events (MAE) and 30-day mortality were evaluated with logistic regression.

RESULTS

407 patients were included; 148 AMI and 259 CMI. In AMI, 30-day mortality was 31%. Open surgery was associated with lower rates of bowel resection (OR 0.23, 95% CI 0.13, 0.61). Etiology of AMI also did not change outcomes (OR 1.30, 95% CI 0.77, 2.19). Adjusted analyses indicates that a history of diabetes (OR 2.77, 95% CI 1.37, 5.61) and sepsis on presentation (OR 2.32, 95% CI 1.18, 4.58) were independently associated with increased risk of 30-day MAE. In CMI, open surgery and CKD were associated with higher MAE (OR 3.03, 95% CI 1.14, 8.05; OR 2.37, 95% CI 1.31, 4.31) while CKD (OR 3.02, 95% CI 1.10, 8.37) and inpatient status prior to revascularization (OR 2.78, 95% CI 1.01, 7.61) were associated with increased 30-day mortality. In CMI, patients in the endovascular cohort had higher rates of symptom recurrence (29% vs. 13%) with faster onset (endovascular 64 days vs. bypass 338 days).

CONCLUSIONS

AMI remains a morbid disease despite evolving revascularization techniques. An open approach should remain the gold standard as it reduces likelihood of bowel resection. In CMI, endovascular interventions have improved post-operative morbidity but result in early symptom recurrence and re-interventions. An endovascular-first approach should be standard in CMI with close surveillance.

Hospital-based Delays to Revascularization Increase Risk of Post-operative Mortality and Short Bowel Syndrome in Acute Mesenteric Ischemia

OBJECTIVE

Acute mesenteric ischemia (AMI) is a surgical emergency for which delays in treatment have been closely associated with high morbidity and mortality. Although the duration of ischemia as a determinant of outcomes for AMI is well known, the objective of this study was to identify hospital-based determinants of delayed revascularization and their effects on post-operative morbidity and mortality in AMI.

METHODS

All patients who underwent any surgery for acute mesenteric ischemia (AMI) from a multi-center hospital system between 2010 and 2020 were divided into two groups based on timeliness of mesenteric revascularization after presentation. Early revascularization (ER) was defined as having both vascular consultation ≤ 12 hours of presentation and vascular surgery performed at the patient's initial operation. Delayed revascularization (DR) was defined as having either delays to vascular consultation or vascular surgery. A retrospective review of demographic and post-operative data was performed. Effect of DR on major post-operative outcomes including 30-day and 2-year mortality, total length of bowel resection, and development of short bowel syndrome were analyzed. Effects of delayed vascular consultation alone, delayed vascular surgery alone, no revascularization during admission, and admitting service on outcomes were also examined on sub-group analyses.

RESULTS

A total of 212 patients were analyzed. 99 patients received ER while the remaining 113 patients experienced a delay to revascularization after hospital presentation. Among the DR group, 55 (25.9%) patients had delayed vascular consultation while vascular surgery was deferred until after the initial operation in 37 (17.4%) patients. 51 (24.0%) patients were never revascularized during admission. DR was a significant predictor of 30-day (odds ratio (OR) 2.09, 95% confidence interval (CI) [1.4-4.9], P=0.03) and 2-year mortality (hazard ratio (HR) 1.55, CI [1.0-2.3], P= 0.04). DR was also independently associated with increased bowel resection length (OR 7.47, P <0.01) and post-operative short bowel syndrome (OR 2.4, P=0.03) on multivariate analyses. When examined separately on sub-group analysis, both delayed vascular consultation (OR 3.38, P=0.03) and vascular surgery (OR 4.31, P <0.01) independently increased risk of 30-day mortality. Hospital discharge after AMI without mesenteric revascularization was associated with increased risk of short bowel syndrome (OR 2.94, P <0.01) and late mortality (HR 1.60, P=0.04).

CONCLUSIONS

Delayed vascular consultation and vascular surgery are both significant hospital-based determinants of post-operative mortality and short bowel syndrome in AMI. Timing-based management protocols which emphasize routine evaluation by a vascular surgeon and early, definitive mesenteric revascularization should be established and widely adopted for all patients with clinically suspected AMI at presentation.

Carotid Endarterectomy remains cost-effective for the surgical management of carotid stenosis

BACKGROUND

Transcarotid arterial revascularization (TCAR) has gained popularity as an alternative to carotid endarterectomy (CEA) and transfemoral carotid artery stenting (TFCAS) potentially combining the benefits of a minimally invasive approach with a lower risk of procedural stroke compared to TFCAS. Emerging evidence shows TCAR to have excellent perioperative outcomes. However, the cost effectiveness of TCAR is not well understood.

METHODS

Incorporating data from Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST), the Vascular Quality Initiative Surveillance Project, and local cost data, we compared the cost-effectiveness of these three treatment modalities (TFCAS, CEA, and TCAR) for both symptomatic and asymptomatic carotid stenosis using a Markov state-transition model to quantify lifetime costs in $US and effectiveness in quality-adjusted life-years (QALYs). We accounted for perioperative stroke and MI as well as long-term risks of stroke and restenosis. Based on CREST, we assumed a start age of 69 and a cost-effectiveness acceptability threshold of $100,000/QALY gained. Sensitivity analyses were performed.

RESULTS

In the base case scenario, TCAR cost $160,642/QALY gained compared to CEA, greater than the frequently cited $100,000/QALY gained threshold. TFCAS was more expensive and less effective than other strategies, largely due to a greater periprocedural stroke risk. In one-way sensitivity analysis, if TCAR stroke risk was <0.9% (base case risk 1.4%), than it was economically favorable compared to CEA at its current procedural cost. Alternatively, if TCAR procedural costs were reduced by approximately $2000 (base case $15,182), it would also become economically favorable. In a probabilistic sensitivity analysis, varying all parameters simultaneously over distributions, CEA was favored in 80% of model iterations at $100,000/QALY, with TCAR favored in 19%.

CONCLUSIONS

At current cost and outcomes, TCAR does not meet a traditional cost-effectiveness threshold to replace CEA as the primary treatment modality for carotid stenosis. TFCAS is the least cost-effective strategy for carotid revascularization. Given these observations, TCAR should be limited to select patients, specifically those at high physiologic and anatomic risk from CEA. However, TCAR can become cost-effective if its cost is reduced. Given the current outcomes and cost, CEA remains the most cost-effective treatment for carotid revascularization.

Female Gender is a Predictor of Lower Iliac Vein Stenting Patency Rates

BACKGROUND

Iliac venous stenting (IVS) for thrombotic and nonthrombotic venous disease is increasingly used as evidence of the safety, efficacy and durability of these interventions increases. Female gender has been implicated as a predictor of failure in arterial endovascular interventions. We hypothesize that female gender could be predictive of patency rates of iliac vein stenting.

METHODS

Consecutive patients who underwent IVS for thrombotic or nonthrombotic venous disease at our institution from 2007 until 2019 were identified and divided into groups based on gender. Operative notes, venograms, and the electronic health record were then queried to obtain operative details, co-morbid conditions, postoperative outcomes and stent patency. Study outcome was long term patency rate. The data was analyzed using chi-square, logistic regression, and Kaplan-Meier analysis as appropriate.

RESULTS

A total of 200 consecutive patients (231 limbs) were identified in our retrospective analysis, with a mean age of 48.8 ± 17.3, and BMI of 31.6 ± 8.6. Of those, 119 (59.5%) patients, (131 [56.8%] limbs) were female. Comparisons between the gender groups revealed no difference in age, BMI, or preoperative comorbidities. There was no difference in type of venous disease between male (85% thrombotic, 15% nonthrombotic) and female (84% thrombotic, 16% nonthrombotic), P= 0.830. The male cohort was more likely to present with leg ulceration (17% vs. 4.6%, P = 0.002), and the female cohort was more likely to present with leg edema (98.5% vs. 93.0%, P= 0.03). The male cohort had a higher rate of caval (48% vs. 33.6%, P= 0.027) and infrainguinal stent extension. (11% vs. 6.9%, P= 0.02). Females had a higher rate of left sided stenting (80.9% vs. 66/0%, P= 0.010). There was no difference in the median stent diameter used between the cohorts. Primary patency at 5 years was significantly higher for the male cohort (94.1% vs. 74.4%, P= 0.01) On adjusted multivariable cox regression female gender was a predictor of loss of primary patency within 5 years (HR, 4.04; P= 0.007).

CONCLUSIONS

In this single center retrospective analysis of IVS, male patients were found to have better primary stent patency compared to female.

Catheter Directed Interventions for pulmonary embolism: Institutional Trends over a Decade 2010-2019

OBJECTIVES

Catheter Directed Interventions (CDIs) are commonly performed for acute Pulmonary Embolism (PE). The evolving catheter types and treatment algorithms impact the utilization and outcomes of these interventions. This study aimed to investigate the changes in CDI practice and their impact on outcomes.

METHODS

Patients who underwent CDIs for PE between 2010 and 2019 at a single institution were identified from a prospectively maintained database. A PE team was launched in 2012, and in 2014 was established as an official Pulmonary Embolism Response Team (PERT). CDI annual usage trends and clinical failures were recorded. Clinical success was defined as physiologic improvement in the absence of major bleeding, perioperative stroke or other procedure-related adverse event, decompensation for sub-massive or persistent shock for massive PE, need for surgical thromboembolectomy or death. Major bleeding was defined as requiring a blood transfusion, a surgical intervention, or suffering from an intracranial hemorrhage.

RESULTS

372 patients received a CDI for acute PE during the study period: age 58.9±15.4 years, males 187 (50.3%), sub-massive PE 340 (91.4%). CDI showed a steep increase in the early PERT years, peaking in 2016 with a subsequent decline. Ultrasound-assisted thrombolysis was the predominant CDI technique peaking at 84% of all CDI in 2014. Suction thrombectomy utilization peaked at 15.2% of CDI in 2019. Mean alteplase dose with catheter thrombolysis techniques decreased from 26.8±12.5mg in 2013 to 13.9±7.5mg in 2019 (P<.001). Mean lysis time decreased from 17.2±8.3 hours in 2013 to 11.3±8.2 hours in 2019 (P<.001). Clinical success for the massive and the submassive PE cohorts was 58.1% and 91.2% respectively; the major bleed rate was 25.0% and 5.3%. There were two major clinical success peaks, one in 2015 mirroring our technical learning curve and one in 2019 mirroring our patient selection learning curve. The clinical success drop in 2018 was primarily derived from blood transfusions due to acute blood loss during suction thrombectomy.

CONCLUSIONS

CDIs for acute PE have rapidly evolved with high success rates. Multidisciplinary approaches amongst centers with appropriate expertise are advisable for the safe and successful implementation of catheter interventions.

Left Renal Vein Stenting in Nutcracker Syndrome: Outcomes and Implications

Nutcracker syndrome refers to the symptomatic extrinsic compression of the left renal vein presenting most commonly as flank pain and haematuria. While surgery remains the first-line treatment, stenting is gaining more acceptance and there are now several published case series. This article highlights the outcomes of left renal vein stenting in the setting of nutcracker syndrome.

Risk factors for acute kidney injury after pharmacomechanical thrombolysis for acute deep vein thrombosis

BACKGROUND

Pharmacomechanical thrombolysis (PMT) is an established treatment for selected patients with acute deep vein thrombosis (DVT). Despite significant clinical success, hemolysis can lead to acute kidney injury (AKI) with unknown longer term implications. Our aim was to characterize the rate of AKI after PMT and identify those patients at the greatest risk.

METHODS

A retrospective medical record review of patients with acute DVT who had undergone PMT in our institution from 2007 to 2018 was performed. The baseline demographics, comorbidities, preoperative clinical characteristics, procedural details, postoperative hospital course, and follow-up data were reviewed. The primary outcome was postoperative AKI (≥1.5 times preoperative creatinine), and longer term renal impairment. Logistic regression modeling was used to identify associated factors.

RESULTS

A total of 137 patients (mean age, 47 ± 16.6 years; 49.6% male) who had undergone PMT for treatment of acute DVT were identified (85.4% AngioJet system; Boston Scientific Corp, Marlborough, Mass). Of the 137 patients, 30 (21.9%) had developed AKI in the periprocedural period, 1 of whom had required hemodialysis in the perioperative period. The patients who had developed AKI had had significantly greater rates of preoperative coronary artery disease (23.1% vs 4.7%; P = .002), diabetes mellitus (19.2% vs 6.6%; P = .045), dyslipidemia (42.3% vs 17.9%; P = .008), and hypertension (53.6% vs 29.3%; P = .018). No significant difference was found in preoperative creatinine (0.99 vs 0.92 mg/dL; P = .65) or glomerular filtration rate (GFR; 96.9 vs 91.8 mL/min; P = .52) between the two groups. Multivariate analysis demonstrated bilateral DVT (odds ratio [OR], 4.35; 95% confidence interval [CI], 1.47-12.86; P = .008), single-session PMT (OR, 3.05; 95% CI, 1.02-9.11; P = .046), and female sex (OR, 2.85; 95% CI, 1.01-8.04; P = .048) were significant predictors of AKI. Of the 30 patients, 10 had had normal renal function at discharge and 15 and 25 patients had had normal renal function at the first and subsequent clinical follow-up visits, respectively. The remaining five patients (3.6%) had progressed to moderate (GFR, <60 mL/min) or severe (GFR, <30 mL/min) renal insufficiency, with one requiring long-term hemodialysis.

CONCLUSIONS

The use of PMT for treatment of acute DVT conferred a risk of AKI that will progress to chronic renal failure in a small fraction of affected patients. Patients with bilateral extensive DVTs have a greater risk of AKI; thus, longer priming with a thrombolytic drip before PMT should be preferred for this population.

Comparable Patency of Open and Hybrid Treatment of Venous Anastomotic Lesions in Thrombosed Haemodialysis Grafts

OBJECTIVE

Arteriovenous graft (AVG) failures are typically associated with venous anastomotic (VA) stenosis. Current evidence regarding AVG thrombosis management compares surgical with purely endovascular techniques; few studies have investigated the "hybrid" intervention that combines surgical balloon thrombectomy and endovascular angioplasty and/or stenting to address VA obstruction. This study aimed to describe outcomes after hybrid intervention compared with open revision (patch venoplasty or jump bypass) of the VA in thrombosed AVGs.

METHODS

Retrospective cohort study. Consecutive patients with a thrombosed AVG who underwent thrombectomy between January 2014 and July 2018 were divided into open and hybrid groups based on VA intervention; patients who underwent purely endovascular thrombectomy were excluded. Patient demographics, previous access history, central vein patency, AVG anatomy, type of intervention, and follow up data were recorded. Kaplan-Meier curves were used to analyse time from thrombectomy to first re-intervention (primary patency) and time to abandonment (secondary patency). Cox regression analysis was performed to evaluate predictors of failure.

RESULTS

This study included 97 patients (54 females) with 39 forearm, 47 upper arm, and 11 lower extremity AVGs. There were 34 open revisions (25 patches, nine jump bypasses) and 63 hybrid interventions, which included balloon angioplasty ± adjunctive procedures (15 stents, five cutting balloons). Technique selection was based on physician preference. Primary patency for the open and hybrid groups was 27.8% and 34.2%, respectively, at six months and 17.5% and 12.9%, respectively, at 12 months (p = .71). Secondary patency was 45.1% and 38.5% for open and hybrid treatment, respectively, at 12 months (p = .87). An existing VA stent was predictive of graft abandonment (hazard ratio 4.4, 95% confidence interval 1.2-16.0; p = .024). Open vs. hybrid intervention was not predictive of failure or abandonment.

CONCLUSION

Hybrid interventions for thrombosed AVGs are not associated with worse patency at six and 12 months compared with open revision.

Society of Interventional Radiology Clinical Practice Guideline for Inferior Vena Cava Filters in the Treatment of Patients with Venous Thromboembolic Disease: Developed in collaboration with the American College of Cardiology, American College of Chest Physicians, American College of Surgeons Committee on Trauma, American Heart Association, Society for Vascular Surgery, and Society for Vascular Medicine

PURPOSE

To provide evidence-based recommendations on the use of inferior vena cava (IVC) filters in the treatment of patients with or at substantial risk of venous thromboembolic disease.

MATERIALS AND METHODS

A multidisciplinary expert panel developed key questions to address in the guideline, and a systematic review of the literature was conducted. Evidence was graded based on a standard methodology, which was used to inform the development of recommendations.

RESULTS

The systematic review identified a total of 34 studies that provided the evidence base for the guideline. The expert panel agreed on 18 recommendations.

CONCLUSIONS

Although the evidence on the use of IVC filters in patients with or at risk of venous thromboembolic disease varies in strength and quality, the panel provides recommendations for the use of IVC filters in a variety of clinical scenarios. Additional research is needed to optimize care for this patient population.

Catheter Interventions for Acute Deep Venous Thrombosis: Who, When and How

Deep venous thrombosis (DVT) is common and can be a source of morbidity by way of pulmonary embolism and post-thrombotic syndrome. Recent trials have demonstrated both early and late symptomatic benefit in venous thrombolysis and early recanalisation of the iliocaval system of selected patients. Based on the emerging evidence, national societies have published guidelines that recommend early thrombus removal in iliofemoral DVT in patients with low bleeding risk and good life expectancy. In light of these recommendations, endovenous thrombolysis and/or thrombectomy have become more popular among vein specialists. As more venous technology becomes available, surgeons and interventionalists should take pause and ensure their patient selection and treatment algorithms parallel that of existing and emerging evidence. This article summarises current evidence, technology, and the approach used at a high-volume academic centre in treating iliofemoral DVT.