The selection of patients for ambulatory endovascular aneurysm repair of elective asymptomatic abdominal aortic aneurysm

Ambulatory Surgery Ensemble: Predicting Adult and Pediatric Same-Day Surgery Cases Across Specialties

Objective

To develop an ensemble model using case-posting data to predict which patients could be discharged on the day of surgery.

Background

Few models have predicted which surgeries are appropriate for day cases. Increasing the ratio of ambulatory surgeries can decrease costs and inpatient bed utilization while improving resource utilization.

Methods

Adult and pediatric patients undergoing elective surgery with any surgical specialty in a multisite academic health system from January 2021 to December 2023 were included in this retrospective study. We used surgical case data available at the time of case posting and created 3 gradient-boosting decision tree classification models to predict case length (CL) less than 6 hours, postoperative length of stay (LOS) less than 6 hours, and home discharge disposition (DD). The models were used to develop an ambulatory surgery ensemble (ASE) model to predict same-day surgery (SDS) cases.

Results

The ASE achieved an area under the receiver operating characteristic curve of 0.95 and an average precision of 0.96. In total, 139,593 cases were included, 48,464 of which were in 2023 and were used for model validation. These methods identified that up to 20% of inpatient cases could be moved to SDS and identified which specialties, procedures, and surgeons had the most opportunity to transition cases.

Conclusions

An ensemble model can predict CL, LOS, and DD for elective cases across multiple services and locations at the time of case posting. While limited in its inclusion of patient factors, this model can systematically facilitate clinical operations such as strategic planning, surgical block time, and case scheduling.

Feasibility and Cost Analysis of Ambulatory Endovascular Aneurysm Repair

PURPOSE

We sought to compare the costs of ambulatory endovascular aneurysm repair (a-EVAR) and inpatient EVAR (i-EVAR) at up to 1-year of follow-up.

MATERIALS AND METHODS

A retrospective cohort study of consecutive patients undergoing elective EVAR between April 2016 and December 2018 at two academic centers. Patients planned for a-EVAR were compared with i-EVAR. Costs at 30 days and 1 year were extracted. These included operating room (OR) use, bed occupancy, laboratory and imaging, emergency department (ED) visits, readmissions, and reinterventions. Baseline characteristics were compared. Multiple regression model was used to identify predictors of increased EVAR costs. Repeated measures analysis of variance (ANOVA) was used to compare cost differences at 30 days and 1 year via an intention-to-treat analysis. Bonferroni post hoc test compared between-group differences. A p value<0.05 was considered statistically significant.

RESULTS

One hundred seventy patients were included. Most underwent percutaneous EVAR (>94%) under spinal anesthesia (>84%). Ambulatory endovascular aneurysm repair was successful in 84% (84/100). Ambulatory endovascular aneurysm repair patients (76±8 years) were younger than i-EVAR (78±9 years). They also had a smaller mean aneurysm diameter (56±6 mm) compared with i-EVAR (59±6 mm). Emergency department visits, readmissions, and reinterventions were similar up to 1 year (all p=NS). Ambulatory endovascular aneurysm repair costs showed a non-statistically significant reduction in total costs at 30 days and 1 year by 27% and 21%, respectively. Patients younger than 85 years and males had a 30-day cost reduction by 34% (p=0.027) and 33% (p=0.035), respectively with a-EVAR.

CONCLUSIONS

Same-day discharge is feasible and successful in selected patients. Patients younger than 85 years and males have a short-term cost benefit with EVAR done in the ambulatory setting without increased complications or reinterventions.

CLINICAL IMPACT

This study shows the overall safety of ambulatory EVAR with proper patient selection. These patient had similar post-intervention complications to inpatients. Same day discharge also resulted in short-term reduction in costs in male patients and patients younger than 85 years.

Development and Evaluation of an Enhanced Recovery Protocol to Reduce Length of Stay following Elective Endovascular Aneurysm Repair

BACKGROUND

Elective endovascular abdominal aortic aneurysm repair (EVAR) can be performed safely with a short postoperative length of stay (LOS). We aimed to develop and assess the impact of an enhanced recovery protocol (ERP) on LOS after elective EVAR.

METHODS

Pre-ERP development single center retrospective review of elective EVAR procedures from January 2012 to December 2019. ERP was developed by targeting factors associated with prolonged LOS (>2 days) elucidated from semistructured interviews and Bayesian additive regression tree analysis. Post-ERP development, a subsequent retrospective review of elective EVAR performed from January 2018 to June 2021 was performed to evaluate LOS before and after ERP. Primary outcome was LOS.

RESULTS

Two hundred sixteen patients underwent elective infrarenal EVAR from 2012 to 2019. Periprocedural factors identified as associated with LOS >2 days included noncommercial insurance (43.6% vs. 26.5%; P = 0.01), preoperative anemia (hemoglobin 12.56 g/dL vs. 13.57 g/dL; P = 0.001), worse renal function (creatinine 1.31 mg/dL vs. 1.01/dL; P = 0.004), open femoral access (74.4% vs. 26.5%; P < 0.001), intensive care unit (ICU) stay (2.7 days vs. 0.9 days; P < 0.001), postoperative anemia (9.8 g/dL vs. 11.9 g/dL; P < 0.001), postoperative creatinine (1.55 mg/dL vs. 0.97 mg/dL; P < 0.001), and beta blocker need on discharge (45.5% vs. 25%; P = 0.003) as significant between patients with short and prolonged LOS groups. Semistructured interviews revealed postoperative day 1 complete blood count/chemistry, postoperative physical therapy evaluation, ICU admission, urinary retention, patient expectations, and unavailability of transportation home as modifiable factors that delayed early discharge. A 14-component ERP was created to target the factors identified from combined qualitative and quantitative results. Post-ERP development, 74 elective EVAR patients were reviewed from 2018 to 2021 (37 pre-ERP and 37 post-ERP). Following ERP development, the mean LOS was reduced from 2.6 (standard deviation: 1.9) to 1.3 days (standard deviation: 1.3); P < 0.01. There were no significant differences in 30-day readmission, postoperative complications, emergency room visits, or 90-day mortality before and after the ERP was used.

CONCLUSIONS

Practice and procedural factors can be modified through an informed and safe process to reduce LOS after elective EVAR. LOS following elective EVAR was safely reduced following the use of a systematically developed ERP.

What is Happening in the Ambulatory Space? Past Challenges and Future Directions

Despite reimbursement pressures and scrutiny of procedural appropriateness, the demand for peripheral vascular ambulatory services remains strong. Improvements in minimally invasive technologies, coupled with a supportive regulatory environment and considerable preference for ambulatory services among purchasers, patients, and providers, have resulted in the rapid proliferation of ambulatory facilities in a number of markets. Emerging ecosystem dynamics, notably the rapid growth of Medicare Advantage and the growing presence of private equity and venture capital within healthcare, will likely have an impact on future growth trends but will not fundamentally alter the incentives driving the ambulatory shift. Indeed, it is likely that the dynamics currently at work within peripheral vascular services will become come to characterize a variety of other services, as more care shifts away from the hospital.

[Inpatient rehabilitation for patients 65 years and older with abdominal aortic aneurysm repair: Indications and long-term outcome]

BACKGROUND

In Germany, there is no data available on the frequency of inpatient rehabilitation (IR) after elective endovascular (EVAR) and open (OAR) abdominal aortic aneurysm (AAA) repair.

OBJECTIVE

To report for the first time on the outcome of patients 65 years and older and thus of retirement age with and without IR after AAA repair in a retrospective analysis of routine data from all eleven regional companies of the AOK health insurance fund (AOK-Gesundheit).

METHODS

Anonymized data of 16,358 patients 65 years and older with intact abdominal aortic aneurysm treated with EVAR (n = 12,960) or OAR (n = 3,398) between 01/01/2010 and 12/31/2016 were analyzed. Patients with postoperative IR (n = 1,531) were compared to those without postoperative IR (n = 14,827) with respect to general patient characteristics, comorbidities, perioperative and postoperative outcomes, and survival. The average follow-up of patients with postoperative and without postoperative IR was 49.9 months and 51.8 months, respectively.

RESULTS

5.4% of EVAR patients, but 24.6% of OAR patients were referred to IR (p < 0.001). Patients with IR were sicker than those without IR. Parameters significantly influencing the use of IR included OAR vs EVAR (Odds Ratio [OR] 6.03), condition after cerebral infarction (OR 1.53), and women vs men (OR 1.49). Perioperative influencing parameters were cerebral infarction (OR 2.40), blood transfusions (OR 2.21) and complex critical care (OR 2.15). After nine years, the Kaplan-Meier estimated survival was 41.9% for patients with vs 43.4% for those without IR in the EVAR group (p = 0.178). For OAR, it was 50.2% for patients with IR vs 49.8% for patients without IR (p = 0.006). In multivariate regression analysis, postoperative IR had a significant effect on long-term survival in OAR but not in EVAR patients.

CONCLUSION

There are no generally binding guidelines for the indication of IR after AAA repair. It should therefore be a requirement for the future that the fitness of each patient with elective AAA repair be determined with a score before and after the procedure in order to make indications for AHB more comparable. The score should be documented in the hospital discharge letter.

Changes in Anesthesia Can Reduce Periprocedural Urinary Retention After EVAR

BACKGROUND

Enhanced recovery after surgery (ERAS) programs provide a streamlined approach for expedient postoperative care of high-volume procedures. Endovascular aortic repair (EVAR) has become standard treatment for abdominal aortic aneurysms and implementation of an early recovery program is warranted. Postoperative urinary retention (POUR) remains a problem lending to longer hospital stays and patient discomfort. We aim to demonstrate the utility of monitored anesthetic care (MAC) plus local anesthesia as a modality to minimize urinary retention following EVAR.

METHODS

Single-center retrospective review from January 2017 to March 2020 of all patients undergoing standard elective EVAR under general anesthesia or MAC anesthesia. Local anesthetic at vessel access sites was used in all patients under MAC. Ruptured pathology and female sex were excluded from analysis. Patient characteristics, operative details, prostate measurements, and outcomes were abstracted from the electronic medical record. Urinary retention was defined as any requirement of straight catheterization, urinary catheter replacement, or discharge with urinary catheter. Chi square tests and logistic regression were used to determine predictors associated with POUR and increased hospital length of stay.

RESULTS

Among 138 patients who underwent EVAR, eight (5.8%) were excluded due to ruptured pathology. Of the cohort, 113 (86.9%) were male with mean age of 73 years. Excluding female patients, 63 (55.8%) male patients underwent general anesthesia and 50 (44.3%) underwent MAC. Male patients under general anesthesia were more likely to have intra-operative urinary catheter placement when compared to MAC (82.5% vs. 36%, respectively; P < 0.001). POUR was identified in 17 patients (13.1%) of the entire study population with 15 events (88.2%) occurring in males. Excluding patients who were admitted to the ICU, twenty-two (19.5%) male patients stayed past postoperative day (POD) one, of which those who developed POUR were more likely to experience compared to those without POUR (45.6% vs. 9.7%, respectively; P = 0.001). On multivariable analysis, male patients who received MAC had a lower risk of developing POUR (OR 0.09, 95% CI 0.02-0.50). POUR was not associated with elective urinary catheter placement nor with pre-existing conditions such as diabetes, urinary retention, benign prostatic hypertrophy (BPH), or use of BPH medications. Additionally, neither prostate size nor volume was associated with developing POUR among male patients.

CONCLUSION

MAC plus local anesthesia is associated with decreased rates of POUR after elective EVAR in male patients. ERAS pathways during elective EVAR interventions should implement MAC plus local anesthesia as an acceptable anesthetic option, where appropriate, in order to reduce urinary retention rates and subsequently decrease hospital length of stay in this patient cohort.

Midterm outcomes of 455 patients receiving the AFX2 endovascular graft for the treatment of abdominal aortic aneurysm: A retrospective multi-center analysis

Since being introduced into clinical practice the AFX family of endografts has undergone labelling updates, design and manufacturing changes to address a Type III failure mode. The published literature on the performance of the current endograft-AFX2 -is limited to small series with limited follow up. The present study reports the largest series of patients implanted with AFX2 for the treatment of abdominal aortic aneurysms. The study was a retrospective, 5 center study of patients receiving an AFX2 endograft from January 2016 until Dec 2020. Electronic case report forms were provided to four of the centers, with one additional site providing relevant outcomes in an independent dataset. Relevant outcomes were reported via Kaplan-Meier analysis and included all-cause mortality, aneurysm-related mortality, post EVAR aortic rupture, open conversion, device related reinterventions and endoleaks. Among a cohort of 460 patients, 405 underwent elective repair of an AAA, 50 were treated for a ruptured AAA, and 5 were aorto-iliac occlusive disease cases. For the elective cohort (mean age 73.7y, 77% male, mean AAA diameter 5.4cm), the peri-operative mortality was 1.7%. Freedom from aneurysm-related mortality was 98.2% at 1,2,3 and 4 years post-operatively, there were no post-operative aortic ruptures, and 2 patients required open conversion. Freedom from Type Ia endoleaks was 99.4% at 1, 2, 3 and 4 years. Freedom from Type IIIa and Type IIIb endoleaks were 100% and 100% (year 1), 100% and 99.6% (year 2), 99.4% and 99.6% (year 3), 99.4% and 99.6% (year 4) respectively. Freedom from all device-related reintervention (including Type II endoleaks) at 4 y was 86.8%. The AFX2 endograft appears to perform to a satisfactory standard in terms of patient centric outcomes in mid-term follow up. The Type Ia and Type III endoleaks rates at 4y appear to be within acceptable limits. Further follow up studies are warranted.

Need for routine preoperative insertion of indwelling urinary catheter prior to endovascular repair of abdominal aortic aneurysm

OBJECTIVE

Evaluate outcomes following urinary catheter (UC) vs. no urinary catheter (NUC) insertion in elective endovascular repair (EVAR) of abdominal aortic aneurysm (AAA).

METHODS

Retrospective record review of all elective EVAR at a university affiliated medical center over a 5-year period. Statistical analysis included Chi Sq, Independent Student T Test.

RESULTS

Six surgeons performed 272 elective EVAR. Three surgeons preferred selective insertion of indwelling UC, such that 86 (32%) EVAR were completed without indwelling urinary catheters (NUC). Differences between NUC vs. UC included; male: (86% vs. 70%; P= 0.004), CAD: (45% vs.33%; p= .046), conscious sedation: (36% vs. 8%; P < 0.001), bilateral percutaneous EVAR (PEVAR): (100% vs. 90%; P= 0.01), within Proglide^TM IFU guidelines (87% vs 75%; P= .05), major adverse operative event (MAOE): (3.5% vs. 10%; P= 0.05) and mean operative time (185 ± 73 vs. 140 ± 37; P < 0.001). Intra-operative catheterization was never required among NUC. Postoperative adverse urinary events (AUE) were more common among UC (11.4% vs. 8.1%; P= 0.41); with longer times to straight catheterization/reinsertion (1575 ± 987 vs 522 ± 269 minutes; P= 0.015) and lower likelihood of eligibility for same day discharge (SDD); (41% vs.59%; P= 0.008). Ineligibility for SDD was due to AUE in 18% of UC patients.

CONCLUSION

Selective preoperative UC insertion should be considered for EVAR, with particular consideration to no preoperative catheterization in men meeting Proglide IFU. Adverse urinary events occurred less frequently among NUC and were identified/ treated earlier. Moreover, AUEs were the most common reason for potential SDD ineligibility among UC patients. Selective policies may facilitate SDD.

Outpatient Percutaneous Endovascular Abdominal Aortic Aneurysm Repair: A Single-Center Experience

PURPOSE

To evaluate the safety of outpatient percutaneous endovascular abdominal aortic repair (PEVAR) versus inpatient PEVAR without or with adjunct procedures.

MATERIALS AND METHODS

Between January 2012 and June 2019, a cohort of 359 patients comprising 168 (46.8%) outpatients and 191 (53.2%) inpatients who had undergone PEVAR were enrolled. All the patients were asymptomatic but had indications for endovascular aortic repair, ie, fit for intravenous anesthesia and anatomically feasible with standard devices. Patient sex, age, comorbidities, smoking status, type of anesthesia, adjunct procedures, type of graft device, operative times, mortality, complications, and readmissions were analyzed.

RESULTS

Median follow-up period was 16.5 months (interquartile range, 9-31 months). Except for a higher percentage of tobacco use (42.6% vs 28.8%; P = .04), dyslipidemia (39.7% vs 19.2%; P < .01), and use of local anesthesia (99.4% vs 82.2%; P < .01) in the outpatients, there was no significant difference in the type of graft and adjunct procedures used. No outpatient mortality occurred. There was no difference in the number, severity, and onset of complications (all P > .05). Outpatient unexpected same-day admission, 30-day readmission, and emergency department visit rates were 4.8%, 2.4% (P = .13), and 10% (P < .01), respectively. Operative times for outpatient PEVAR without adjunct procedures were shorter (P < .01).

CONCLUSIONS

Outpatient PEVAR can be performed with a safety profile similar to that of inpatient PEVAR. The unexpected same-day admission, 30-day readmission, and emergency department visit rates were low. The outpatient PEVARs without adjunct procedures took less time.