One-year patient survival correlates with surgeon volume after elective open abdominal aortic surgery

Longitudinal outcomes of forearm versus upper arm arteriovenous fistulas

BACKGROUND

National guidelines recommend forearm arteriovenous fistulas (AVFs) over upper arm AVFs as the initial permanent vascular access for hemodialysis if consistent with the end-stage kidney disease (ESKD) Life-Plan, but comparative outcomes are underexplored. Our objective was to assess longitudinal outcomes of forearm vs upper arm AVFs in patients with advanced kidney disease.

METHODS

Using multicenter data from three prospective studies (Hemodialysis Fistula Maturation [HFM] Study, PATENCY-1 [A Study of PRT-201 Administered Immediately After Radiocephalic Arteriovenous Fistula (AVF) Creation in Patients With Chronic Kidney Disease], and PATENCY-2), we conducted a cohort study of 1516 patients who underwent upper extremity AVF creation (2014-2019). Demographic factors, comorbidities, procedural details, and 3 years of longitudinal follow-up were captured. Outcomes included primary, primary-assisted, and secondary patency at 3 years, successful AVF use, and access-related hand ischemia (ARHI) interventions. Forearm vs upper arm AVF outcomes were compared using Cox regression and logistic regression models. Subgroup analyses included outcomes stratified by site volume using model interaction terms.

RESULTS

The study population included 1059 forearm AVFs and 457 upper arm AVFs; mean age was 56.2 ± 13.4 years and 25.2% were female. The overall primary, primary-assisted, and secondary patency rates at 3 years was 26.2% (95% confidence interval [CI], 23.6%-29.1%), 57.6% (95% CI, 54.6%-60.9%), and 66.5% (95% CI, 63.6%-69.5%), respectively, with no significant differences between forearm and upper arm AVFs. Successful AVF use at 12 months was also similar between forearm (66.1%) and upper arm AVFs (70.0%) (odds ratio, 1.02; 95% CI, 0.71-1.48; P = .91). Forearm AVFs had lower risk of ARHI interventions (hazard ratio [HR], 0.36; 95% CI, 0.18-0.71; P = .003) compared with upper arm AVFs. Subgroup analyses showed that compared with upper arm AVFs, patients who received forearm AVFs at low volume sites (≤30 access creations per year) were at greater risk for loss of primary-assisted (HR, 2.03; 95% CI, 1.21-3.41; P < .001) and secondary patency (HR, 2.53; 95% CI, 1.33-4.83; P < .001). Patients receiving forearm AVFs at low volume sites also had lower AVF use at 12 months (odds ratio, 0.52; 95% CI, 0.21-1.31; P value of interaction = .03).

CONCLUSIONS

Although forearm AVFs demonstrate similar long-term patency and usability as upper arm AVFs, they are associated with lower rates of ARHI. However, outcomes for forearm AVFs seem to have associations with institutional volume-significantly poorer results are seen at low-volume centers. System-level efforts are needed to improve outcomes for forearm AVFs, which serve as a critical lifeline for end-stage kidney disease patients.

Fenestrated and Branched Endovascular Aortic Repair and Mortality at Hospitals Without Investigational Device Trials

Importance

Fenestrated and branched endovascular aortic repairs (F/BEVAR) have been adopted by many centers. However, national trends of F/BEVAR use remain unclear, particularly at sites who perform them without an US Food and Drug Adminstration (FDA)-approved investigational device exemption (IDE).

Objective

To quantify the use of F/BEVAR in the US and to determine if mortality was different at IDE vs non-IDE sites.

Design, Setting, and Participants

This retrospective cohort study examined 100% fee-for-service Medicare claims data from 2016 to 2023. Participants were patients who underwent endovascular treatment of the visceral aorta incorporating 2 or more visceral artery endoprostheses. Hospitals with vs without an IDE were identified using hospitals' Employer Identification Number as a time varying exposure.

Exposure

F/BEVAR.

Main Outcomes and Measures

Trends in the center-level F/BEVAR case volume stratified by IDE status were assessed using cumulative incidence curves. Mortality outcomes at 30 days and 3 years were compared using Kaplan-Meier methods and Cox proportional hazards models with adjustment for baseline patient characteristics.

Results

From 2016 to 2023, 8017 patients were treated with F/BEVAR at 549 hospitals. The median (IQR) age was 75.8 (71.3-80.8) years; 5795 patients (72.3%) were male and 2222 (27.7%) female. A total of 2226 F/BEVAR (27.8%) were performed at 22 hospitals with an IDE. The number of patients treated with F/BEVAR increased from 771 in 2016 to 1251 in 2023. The median (IQR) annual case volume per hospital was significantly higher at IDE sites (22.3 [11.0-30.4] vs 1.2 [1.0-2.0] cases/y; P < .001); 18 IDE sites (90.0%) and 20 non-IDE sites (3.7%) completed 9 or more cases per year. The 30-day mortality (3.0% vs 4.9%) but not 3-year mortality (26.0% vs 27.1%) was lower for patients treated at hospitals with vs without an IDE. After risk adjustment, both 30-day (odds ratio, 0.47; 95% CI, 0.32-0.69) and midterm mortality (hazard ratio, 0.81; 95% CI, 0.69-0.95) were lower for patients treated at IDE sites.

Conclusions and Relevance

The use of F/BEVAR is increasing across the United States, with the majority of cases being performed outside of IDE studies and at low-volume centers. F/BEVAR performed at non-IDE centers are associated with higher adjusted 30-day and midterm mortality. Transparent outcome reporting and identification of process measures from IDE sites may help achieve more equity in patient outcomes.

Implementation of a vascular acute care surgery model is associated with improved surgeon efficiency and 2-year mortality after lower extremity intervention

OBJECTIVE

Vascular surgeons work long, unpredictable hours with repeated exposure to high-stress situations. Inspired by general surgery acute care surgery models, we sought to organize the care of vascular emergencies with the implementation of a vascular acute care surgery (VACS) model. Within this model, a surgeon is in-house without elective cases and assigned for consultations and urgent operative cases on a weekly basis. This study examined the impact of a VACS model on postoperative mortality and surgeon efficiency.

METHODS

This was a retrospective cohort analysis of institutional Vascular Quality Initiative data from July 2014 to July 2023. Patients undergoing lower extremity bypass, peripheral vascular intervention, or amputation were included. There was a washout period from January 2020 to January 2022 to account for COVID-19 pandemic practice abnormalities. Patients were separated into pre- or post-VACS groups. The primary clinical outcomes were 30-day and 2-year mortality. Secondary clinical outcomes included 30-day complications and 30-day and 1-year major adverse limb events (MALE). Separate analyses of operating room data from July 2017 to February 2024 and fiscal data from fiscal year 2019 to fiscal year 2024 were conducted. A washout period from January 2020 to January 2022 was applied. Efficiency outcomes included monthly relative value units (RVUs) per clinical fraction full-time equivalent (cFTE) and daytime (0730-1700, Monday-Friday) operating room minutes. Patient factors and operative efficiency were compared using appropriate statistical tests. Regression modeling was performed for the primary outcomes.

RESULTS

There were 972 and 257 patients in the pre- and post-VACS groups, respectively. Pre-VACS patients were younger (66.8 ± 12.0 vs 68.7 ± 12.7 years; P = .03) with higher rates of coronary artery disease (34.6% vs 14.8%; P < .01), hypertension (88.4% vs 82.2%; P = .01), and tobacco history (84.4% vs 78.2%; P = .02). Thirty-day mortality (2.4% pre-vs 0.8% post-VACS; P = .18) and Kaplan-Meier estimation of 2-year mortality remained stable after VACS (P = .07). VACS implementation was not associated with 30-day mortality but was associated with lower 2-year mortality hazard on multivariable Cox regression (hazard ratio [HR], 0.5; 95% confidence interval [CI], 0.3-0.9; P = .01). Operative efficiency improved post-VACS (median, 850.0; interquartile range [IQR], 765.7-916.3 vs median, 918.0; IQR, 881.0-951.1 RVU/cFTE-month; P = .03). Daytime operating minutes increased (469.1 ± 287.5 vs 908.2 ± 386.2 minutes; P < .01), whereas non-daytime minutes (420.0; IQR, 266.0-654.0 vs 469.5; IQR, 242.0-738.3 minutes; P = .40) and weekend minutes (129.0; IQR, 0.0-298.0 vs 113.5; IQR, 0.0-279.5 minutes; P = .59) remained stable.

CONCLUSIONS

A VACS model leads to improvement in surgeon operative efficiency while maintaining patient safety. The adoption of a vascular acute care model has a positive impact on the delivery of comprehensive vascular care.

The Utility of Three-Dimensional Printing in Physician-Modified Stent Grafts for Aortic Lesions Repair

Background: Three-dimensional (3D) printing is becoming increasingly popular around the world not only in engineering but also in the medical industry. This trend is visible, especially in aortic modeling for both training and treatment purposes. As a result of advancements in 3D technology, patients can be offered personalized treatment of aortic lesions via physician-modified stent grafts (PMSG), which can be tailored to the specific vascular conditions of the patient. The objective of this systematic review was to investigate the utility of 3D printing in PMSG in aortic lesion repair by examining procedure time and complications. Methods: The systematic review has been performed using the PRISMA 2020 Checklist and PRISMA 2020 flow diagram and following the Cochrane Handbook. The systematic review has been registered in the International Prospective Register of Systematic Reviews: CRD42024526950. Results: Five studies with a total number of 172 patients were included in the final review. The mean operation time was 249.95± 70.03 min, and the mean modification time was 65.38 ± 10.59 min. The analysis of the results indicated I2 of 99% and 100% indicating high heterogeneity among studies. The bias assessment indicated the moderate quality of the included research. Conclusions: The noticeable variance in the reviewed studies' results marks the need for larger randomized trials as clinical results of 3D printing in PMSG have great potential for patients with aortic lesions in both elective and urgent procedures.

Decreasing prevalence of centers meeting the Society for Vascular Surgery abdominal aortic aneurysm guidelines in the United States

OBJECTIVE

Based on data supporting a volume-outcome relationship in elective aortic aneurysm repair, the Society of Vascular Surgery (SVS) guidelines recommend that endovascular aortic repair (EVAR) be localized to centers that perform ≥10 operations annually and have a perioperative mortality and conversion-to-open rate of ≤2% and that open aortic repair (OAR) be localized to centers that perform ≥10 open aortic operations annually and have a perioperative mortality ≤5%. However, the number and distribution of centers meeting the SVS criteria remains unclear. This study aimed to estimate the temporal trends and geographic distribution of Centers Meeting the SVS Aortic Guidelines (CMAG) in the United States.

METHODS

The SVS Vascular Quality Initiative was queried for all OAR, aortic bypasses, and EVAR from 2011 to 2019. Annual OAR and EVAR volume, 30-day elective operative mortality for OAR or EVAR, and EVAR conversion-to-open rate for all centers were calculated. The SVS guidelines for OAR and EVAR, individually and combined, were applied to each institution leading to a CMAG designation. The proportion of CMAGs by region (West, Midwest, South, and Northeast) were compared by year using a χ2 test. Temporal trends were estimated using a multivariable logistic regression for CMAG, adjusting by region.

RESULTS

Overall, 67,865 patients (49,264 EVAR; 11,010 OAR; 7591 aortic bypasses) at 336 institutions were examined. The proportion of EVAR CMAGs increased nationally by 1.7% annually from 51.6% (n = 33/64) in 2011 to 67.1% (n = 190/283) in 2019 (β = .05; 95% confidence interval [CI], 0.01-0.09; P = .02). The proportion of EVAR CMAGs across regions ranged from 27.3% to 66.7% in 2011 to 63.9% to 72.9% in 2019. In contrast, the proportion of OAR CMAGs has decreased nationally by 1.8% annually from 32.8% (n = 21/64) in 2011 to 16.3% (n = 46/283) in 2019 (β = -.14; 95% CI, -0.19 to -0.10; P < .01). Combined EVAR and OAR CMAGs were even less frequent and decreased by 1.5% annually from 26.6% (n = 17/64) in 2011 to 13.1% (n = 37/283) in 2019 (β = -.12; 95% CI, -0.17 to -0.07; P < .01). In 2019, there was no significant difference in regional variation of the proportion of combined EVAR and OAR CMAGs (P = .82).

CONCLUSIONS

Although an increasing proportion of institutions nationally meet the SVS guidelines for EVAR, a smaller proportion meet them for OAR, with a concerning downward trend. These data question whether we can safely offer OAR at most institutions, have important implications about sufficient OAR exposure for trainees, and support regionalization of OAR.

Operation time and clinical outcomes for open infrarenal abdominal aortic aneurysms to remain stable in the endovascular era

Objective

Endovascular aortic repair (EVAR) has become a routine procedure worldwide. Ultimately, the increasing number of EVAR cases entails changing conditions for open surgical repair (OSR) regarding patient selection, complexity, and surgical volume. This study aimed to assess the time trends of open abdominal aortic aneurysm (AAA) repair in a high-volume single center in Austria over a period of 20 years, focusing on the operation time and clinical outcomes.

Materials and methods

A retrospective analysis of all patients treated for infrarenal AAAs with OSR or EVAR between January 2000 and December 2019 was performed. Infrarenal AAA was defined as the presence of a >10-mm aortic neck. Cases with ruptured or juxtarenal AAAs were excluded from the analysis. Two cohorts of patients treated with OSR at different time periods, namely, 2000-2009 and 2010-2019, were assessed regarding demographical and procedure details and clinical outcomes. The time periods were defined based on the increasing single-center trend toward the EVAR approach from 2010 onward.

Results

A total of 743 OSR and 766 EVAR procedures were performed. Of OSR cases, 589 were infrarenal AAAs. Over time, the EVAR to OSR ratio was stable at around 50:50 (p = 0.488). After 2010, history of coronary arterial bypass (13.4% vs. 7.2%, p = 0.027), coronary artery disease (38.1% vs. 25.1%, p = 0.004), peripheral vascular disease (35.1% vs. 21.3%, p = 0.001), and smoking (61.6% vs. 34.3%, p < 0.001) decreased significantly. Age decreased from 68 to 66 years (p = 0.023). The operation time for OSR remained stable (215 vs. 225 min, first vs. second time period, respectively, p = 0.354). The intraoperative (5.8% vs. 7.2%, p = 0.502) and postoperative (18.3% vs. 20.8%, p = 0.479) complication rates also remained stable. The 30-day mortality rate did not change over both time periods (3.0% vs. 2.4%, p = 0.666).

Conclusion

Balanced EVAR to OSR ratio, similar complexity of cases, and volume over the two decades in OSR showed stable OSR time without compromise in clinical outcomes.

Impact of Preoperative Visceral Fat Area Measured by Bioelectrical Impedance Analysis on Clinical and Oncologic Outcomes of Colorectal Cancer

BACKGROUND

Some studies have shown that an increase in visceral fat is associated with postoperative clinical and oncologic outcomes. However, no studies have used bioelectrical impedance analysis (BIA) to determine the effects of visceral fat on the oncologic outcomes of colorectal cancer (CRC). This study aimed to investigate the impact of preoperative visceral fat area measured by bioelectrical impedance analysis on clinical and oncologic outcomes of colorectal cancer Methods: This study included 203 patients who underwent anthropometric measurements by BIA before surgical treatment for CRC between January 2016 and June 2020.

RESULTS

According to the cut-off level of VFA by receiver operating characteristic curve analysis, 85 (40.5%) patients had a low VFA, and 119 (59.5%) had a high VFA. Multivariate analysis found that preoperative CRP (hazard ratio (HR), 3.882; 95% confidence interval (CI), 1.001-15.051; p = 0.050) and nodal stage (HR, 7.996; 95% CI, 1.414-45.209; p = 0.019) were independent prognostic factors for overall survival, while sex (HR, 0.110; 95% CI, 0.013-0.905; p = 0.040), lymphovascular invasion (HR, 3.560; 95% CI, 1.098-11.544; p = 0.034), and VFA (HR, 4.263; 95% CI, 1.280-14.196; p = 0.040) were independent prognostic factors for disease-free survival (DFS).

CONCLUSIONS

Preoperative VFA measured by BIA had no significant impact on postoperative clinical outcomes and was an independent prognostic factor for disease-free survival.

Surgeon volume and established hospital perioperative mortality rate together predict for superior outcomes after open abdominal aortic aneurysm repair

BACKGROUND

In 2018, the Society for Vascular Surgery (SVS) published hospital volume guidelines for elective open abdominal aortic aneurysm (AAA) repair, recommending that elective open surgical repair of AAAs should be performed at centers with an annual volume of ≥10 open aortic operations of any type and a documented perioperative mortality of ≤5%. Recent work has suggested a yearly surgeon volume of at least seven open aortic cases for improved outcomes. The objective of the present study was to assess the importance of hospital volume and surgeon volume at these cut points for predicting 1-year mortality after open surgical repair of AAAs.

METHODS

We evaluated patients who had undergone elective open AAA repair using the New York Statewide Planning and Research Cooperative System database from 2003 to 2014. The effect of the SVS guidelines on postoperative mortality and complications was evaluated. Confounding between the hospital and surgeon volumes was identified using mixed effects multivariate Cox proportional hazards analysis. The effect of the interactions between hospital volume, established hospital perioperative survival, and surgeon volume on postoperative outcomes was also investigated.

RESULTS

The cohort consisted of 7594 elective open AAA repairs performed by 542 surgeons in 137 hospitals during the 12-year study period. Analysis of the 2018 guidelines using the Statewide Planning and Research Cooperative System database revealed 1-year and 30-day mortality rates of 9.2% (range, 8.3%-10.1%) and 3.5% (range, 2.9%-4.1%) for centers that were within the SVS guidelines and 13.6% (range, 12.5%-14.7%) and 6.9% (range, 6.1%-7.8%) for those that were outside the guidelines, respectively (P < .001 for both). Multivariate survival analysis revealed a hazard ratio for a surgeon volume of ≥7, hospital volume of ≥10, and hospital 3-year perioperative mortality of ≤5% of 0.80 (95% confidence interval [CI], 0.70-0.93; P = .003), 0.91 (95% CI, 0.77-1.08; P = .298), and 0.72 (95% CI, 0.62-0.82; P < .001), respectively. Additionally, procedures performed by surgeons with a yearly average volume of open aortic operations of at least seven and at hospitals with an established elective open AAA repair perioperative mortality rate of ≤5% showed improved 1-year (33.2% relative risk reduction; P < .001) and 30-day (P = .001) all-cause survival and improved postoperative complication rates.

CONCLUSIONS

These data have demonstrated that centers that meet the SVS AAA volume guidelines are associated with improved 1-year and 30-day all-cause survival. However, the results were confounded by surgeon volume. A surgeon open aortic volume of at least seven procedures and an established hospital perioperative mortality of ≤5% each independently predicted for 1-year survival after open AAA repair, with the hospital volume less important. These results indicate that surgeons with an annual volume of at least seven open aortic operations of any type should perform elective open AAA repair at centers with a documented perioperative mortality of ≤5%.

Survival following abdominal aortic aneurysm repair in North Queensland is not associated with remoteness of place of residence

Objective

To assess whether survival and clinical events following elective abdominal aortic aneurysm (AAA) repair were associated with remoteness of residence in North Queensland, Australia.

Methods

This retrospective cohort study included participants undergoing elective AAA repair between February 2002 and April 2020 at two hospitals in Townsville, North Queensland, Australia. Outcomes were all-cause survival and AAA-related events, defined as requirement for repeat AAA repair or AAA-related mortality. Remoteness of participant’s place of residence was assessed by the Modified Monash Model classifications and estimated distance from the participants’ home to the tertiary vascular centre. Cox proportional hazard analysis examined the association of remoteness with outcome.

Results

The study included 526 participants undergoing elective repair by open (n = 204) or endovascular (n = 322) surgery. Fifty-four (10.2%) participants had a place of residence at a remote or very remote location. Participants' were followed for a median of 5.2 (inter-quartile range 2.5–8.3) years, during which time there were 252 (47.9%) deaths. Survival was not associated with either measure of remoteness. Fifty (9.5%) participants had at least one AAA-related event, including 30 (5.7%) that underwent at least one repeat AAA surgery and 23 (4.4%) that had AAA-related mortality. AAA-related events were more common in participants resident in the most remote areas (adjusted hazard ratio 2.83, 95% confidence intervals 1.40, 5.70) but not associated with distance from the participants’ residence to the tertiary vascular centre

Conclusions

The current study found that participants living in more remote locations were more likely to have AAA-related events but had no increased mortality following AAA surgery. The findings emphasize the need for careful follow-up after AAA surgery. Further studies are needed to examine the generalisability of the findings.