Progressive shortfall in open aneurysm experience for vascular surgery trainees with the impact of fenestrated and branched endovascular technology

Impact of the endovascular revolution on vascular training through analysis of national data case reports

BACKGROUND

In the last couple of decades, there has been a shift in use of endovascular procedures in vascular surgery. We aim to examine the impact of this endovascular shift on vascular trainees, determine whether the surgical experiences of trainees in the integrated residency and fellowship program changed over time, and identify differences between the two training paradigms.

METHODS

Data were extracted from the Accreditation Council for Graduate Medical Education National Data Case Logs for the vascular surgery fellowship (1999-2021) and integrated residency (2012-2021) programs. Every procedure was categorized as open or endovascular, then designated into the following subcategories: thoracic aneurysm repairs, cerebrovascular, abdominal aneurysm repairs, venous, vascular access, peripheral arterial disease, visceral, or miscellaneous. We compared the prevalence of open and endovascular cases in the fellowship and integrated residency using data from overlapping years (2012-2021). In addition, we compared the mean number of cases per trainee per year within designated time intervals. The vascular surgery fellowship was grouped into three intervals: 1999 to 2006, 2006 to 2013, and 2013 to 2021; the integrated vascular surgery residency was grouped into two intervals: 2012 to 2017 and 2017 to 2021. Data were standardized to represent the average number of cases per trainee per year.

RESULTS

Within the fellowship, we found a 362.37% increase in endovascular procedures (mean, 56.80 ± 32.57 vs 262.63 ± 9.91; P < .001), although there was only a 32.47% increase in open procedures (220.19 ± 4.55 vs 291.68 ± 8.20) between the first and last time intervals. There was a decrease in abdominal aneurysm repair (24.46 ± 7.30 vs 13.85 ± 0.58; P < .001) and visceral (6.41 ± 0.44 vs 5.80 ± 0.42; P = .039) open procedures. For the integrated residency, there was an increase in open procedures by 8.52% (352.18 ± 8.23 vs 382.20 ± 5.84; P < .001). Residents had greater total, open, and endovascular procedures per year than fellows (all P < .001). Chief residents had approximately one-half as many cases as vascular fellows per year. Fellows performed more open abdominal aneurysm repair (14.04 ± 0.80 vs 12.40 ± 1.32; P = .007) and visceral (5.83 ± 0.41 vs 4.88 ± 0.46; P > .001) procedures than residents. Overall, 52% to 53% of cases performed by trainees per year were open procedures in both the fellowship and integrated residency (288.56 ± 12.10 vs 261.27 ± 10.13, 365.52 ± 17.23 vs 319.58 ± 6.62; both P < .001). Within the subcategories, only cerebrovascular, vascular access, and miscellaneous had more open procedures performed per trainee.

CONCLUSIONS

Vascular surgery training has incorporated new endovascular techniques and technologies while maintaining operative training in open procedures. Despite changes in vascular surgery training, trainees are still performing more open procedures than endovascular procedures per year. However, there are evolving deficits in specific types of procedures.

Temporal Trends and Outcomes of Abdominal Aortic Aneurysm Care in the United States

BACKGROUND

Endovascular aortic aneurysm repair (EVAR) has had a dynamic impact on abdominal aortic aneurysm (AAA) care, often supplanting open AAA repair (OAR). Accordingly, US AAA management is often highlighted by disparities in patient selection and guideline compliance. The purpose of this analysis was to define secular trends in AAA care.

METHODS

The Society for Vascular Surgery Vascular Quality Initiative was queried for all EVARs and OARs (2011-2021). End points included procedure utilization, change in mortality, patient risk profile, Society for Vascular Surgery-endorsed diameter compliance, off-label EVAR use, cross-clamp location, blood loss, in-hospital complications, and post-EVAR surveillance missingness. Linear regression was used without risk adjustment for all end points except for mortality and complications, for which logistic regression with risk adjustment was used.

RESULTS

In all, 66 609 EVARs (elective, 85% [n=55 805] and nonelective, 15% [n=9976]) and 13 818 OARs (elective, 70% [n=9706] and nonelective, 30% [n=4081]) were analyzed. Elective EVAR:OAR ratios were increased (0.2 per year [95% CI, 0.01-0.32]), while nonelective ratios were unchanged. Elective diameter threshold noncompliance decreased for OAR (24%→17%; P=0.01) but not EVAR (mean, 37%). Low-risk patients increasingly underwent elective repairs (EVAR, +0.4%per year [95% CI, 0.2-0.6]; OAR, +0.6 points per year [95% CI, 0.2-1.0]). Off-label EVAR frequency was unchanged (mean, 39%) but intraoperative complications decreased (0.5% per year [95% CI, 0.2-0.9]). OAR complexity increased reflecting greater suprarenal cross-clamp rates (0.4% per year [95% CI, 0.1-0.8]) and blood loss (33 mL/y [95% CI, 19-47]). In-hospital complications decreased for elective (0.7% per year [95% CI, 0.4-0.9]) and nonelective EVAR (1.7% per year [95% CI, 1.1-2.3]) but not OAR (mean, 42%). A 30-day mortality was unchanged for both elective OAR (mean, 4%) and EVAR (mean, 1%). Among nonelective OARs, an increase in both 30-day (0.8% per year [95% CI, 0.1-1.5]) and 1-year mortality (0.8% per year [95% CI, 0.3-1.6]) was observed. Postoperative EVAR surveillance acquisition decreased (67%→49%), while 1-year mortality among patients without imaging was 4-fold greater (9.2% versus imaging, 2.0%; odds ratio, 4.1 [95% CI, 3.8-4.3]; P<0.0001).

CONCLUSIONS

There has been an increase in EVAR and a corresponding reduction in OAR across the United States, despite established concerns surrounding guideline adherence, reintervention, follow-up, and cost. Although EVAR morbidity has declined, OAR complication rates remain unchanged and unexpectedly high. Opportunities remain for improving AAA care delivery, patient and procedure selection, guideline compliance, and surveillance.

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.

Patterns in Complex Aortic Vascular Surgery Training and Early Career Practice

BACKGROUND

Recent literature has suggested a decreasing experience with open aortic surgery among recent vascular surgery graduates. While trainees have a wide exposure to endovascular aortic repair, experience with both endovascular and open management of thoracoabdominal aneurysms, as well as the early career surgeon comfort with these procedures, remains unknown. Thus, we sought to evaluate early practice patterns in the surgical treatment of complex aortic surgery among recent US vascular surgery graduates.

METHODS

An anonymous survey was distributed among all vascular surgeons who completed vascular surgery residency or fellowship in 2020. Self-reported data assessed the number and type of cases performed in training, surgeon experience in early practice, and surgeon desire for additional training in these areas.

RESULTS

A total of 62 surgeons completed the survey with a response rate of 35%. Seventy-nine percent of respondents completed fellowship training (as compared to integrated residency), and 87% self-described as training in an academic environment. Sixty-six percent performed less than 5 open thoracoabdominal aortic surgeries and 58% performed less than 5 4-vessel branched/fenestrated aortic repairs (F/BEVARs), including 56% who completed less than 5 physician modified endovascular grafts repairs. Only 11% of respondents felt adequately prepared to perform open thoracoabdominal operations following training. For both open and F/BEVAR procedures, more than 80% respondents plan to perform such procedures with a partner in their current practice, and the majority desired additional open (61%) and endovascular (59%) training for the treatment of thoracoabdominal aneurysms.

CONCLUSIONS

The reported infrequency in open thoracoabdominal and multivessel F/BEVAR training highlights a desire and utility for an advanced aortic training paradigm for surgeons wishing to focus on this area of vascular surgery. Further research is warranted to determine the optimal way to provide such training, whether through advanced fellowships, junior faculty apprenticeship models, or regionalization of this highly complex patient care. The creation of these programs may provide pivotal opportunity, as vascular surgery and the management of complex aortic pathology continues to evolve.

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.

The role of big data, risk prediction, simulation, and centralization for emergency vascular problems: Lessons learned and future directions

Vascular specialists remain in high demand in current practice and commonly oversee care delivery for a variety of clinical emergencies. Accordingly, the contemporary vascular surgeon must be facile with treating a spectrum of problems, including a complex, heterogeneous group of acute arteriovenous thromboembolic and bleeding diatheses. It has been documented previously that there are substantial current workforce limitations placing constraints on vascular surgical care provision. Moreover, with the aging at-risk population, there remains a considerable national urgency to improve timely diagnoses, specialty consultation, and appropriate transfer of patients to centers of excellence capable of providing a comprehensive compendium of emergency vascular services. Clinical decision aids, simulation training, and regionalization of nonelective vascular problems are all strategies that have been increasingly recognized to address these service gaps. Notably, clinical research in vascular surgery has traditionally focused on identification of patient- and procedure-related factors that influence outcomes by using resource-intensive causal inference methodology. By comparison, large data sets have only more recently been recognized to be a valuable tool that can provide heuristic algorithms to address more complex health care problems. Such data can be manipulated to generate clinical risk scores and decision aids, as well as robust outcome descriptions, which stand to inform stakeholders regarding best practice. The purpose of this review was to provide a robust overview of the lessons derived from the application of big data, risk prediction, and simulation in the management of vascular emergencies.

The Impact of Endovascular Repair of Abdominal Aortic Aneurysms on Vascular Surgery Training in Open Aneurysm Repair

BACKGROUND

Since the introduction of endovascular aneurysm repair (EVAR) in 1992, the number of open AAA repair (OAR) cases continue to decline. The consequence of reduced OAR cases raises valid concerns related to patient safety and the future training of vascular surgeons that need to be appropriately addressed. Our objective is to analyze trends in OAR and EVAR cases and to assess their implications on the quality of vascular surgery training.

METHODS

We analyzed the Accreditation Council for Graduate Medical Education (ACGME) case log database for total clinical experience in OAR and EVAR for graduating vascular surgery fellows (VSFs) finishing 5 + 2 programs between 2002 and 2019 and vascular surgery integrated residents (VSRs) between 2013 and 2019. VSF case totals were calculated by combining average total cases of open and endovascular supra- and infrarenal AAA repair during fellowship years combined with total cases performed during their general surgery residency. VSR case totals included only the cases performed during the 5-year residency period. Isolated Iliac and thoracic aortic aneurysms were excluded from our analysis.

RESULTS

The average number of OAR cases per trainee has decreased by 60% (from 36.9 to 14.7) with a rate of 1.4 cases per year (P < 0.001) for VSF. Meanwhile, EVAR average cases have increased by 102% (from 22 to 44.4). However, there were 2 different trends exhibited with EVAR over the study period. Between 2002 and 2007, EVAR cases tended to increase by 5.9 cases per year (P < 0.001). Whereas, between 2007 and 2019, there was a slightly decreased trend in EVAR cases by 0.3 cases per year (P = 0.01). For VSR, while no significant trend was observed in the mean number of OAR cases (Coef. -0.3, P = 0.2) due to the limited time frame, the proportion of open cases was significantly lower compared to endovascular cases. Additionally, there were 2 different trends exhibited with EVAR over the study period. Between 2013 and 2015, EVAR cases tended to increase by 1.7 cases per year (P = 0.1). Whereas, between 2015 and 2019, there was a slightly decreased trend in EVAR cases by 0.2 cases per year (P = 0.007).

CONCLUSIONS

A significant reduction in average OAR cases and an increase in EVAR cases were observed over the study period. Vascular surgery training programs may need to introduce further training programs in open surgical repair to ensure vascular surgery trainees have the required technical skills and expertize to perform such a high-risk procedure safely and independently.

Role of Simulated Training for Carotid Endarterectomy: A Systematic Review

Vascular surgery trainees often do not get to perform carotid endarterectomy (CEA) directly on the patients as it requires meticulous surgical technique and has a high risk of procedure-related complications. Hence, the role of simulation in training future vascular surgeons becomes essential. This review aims to assess the types and utility of simulators available for CEA. In this systematic review, all the studies performed on CEA simulation were included. The purpose of this review was to assess different types of simulators and their usefulness for CEA. We identified 122 articles, of which 10 were eligible for review. A variety of simulators, ranging from animal models, virtual reality simulators and commercially designed models with high fidelity options were used. Technical competence was the major domain assessed in the majority of the studies (n=8), whereas four studies evaluated anatomical and procedural knowledge. Blinding was done in five studies for assessment purposes. The majority of studies (n=9) found the simulation to be an effective tool for achieving technical competence. This review shows the potential usefulness of simulation in acquiring technical skills and procedural acumen for CEA. The available literature is unfortunately too diverse to have a common recommendation.

Psoas Muscle Area as a Prognostic Factor for Survival in Patients Undergoing EVAR Conversion

OBJECTIVE

EVAR conversion(EVAR-c) is increasingly reported and known to be technically complex and physiologically demanding. It has been proposed that pragmatic anthropomorphic measures such as psoas muscle area(PMA) may reliably quantify levels of preoperative frailty and be used to inform point of care clinical decision making and patient discussions for a variety of complex operations. To date, there is mixed data supporting use of PMA as a prognostic factor in fenestrated endovascular and open AAA repairs; however, no literature exists evaluating the impact of preoperative PMA on EVAR-c results. Therefore, the purpose of this study was to review our EVAR-c experience and evaluate the association of PMA with perioperative and long-term mortality outcomes.

METHODS

A retrospective single-center review of all AAA repairs was performed(2002-2019) and EVAR-c procedures were subsequently analyzed(n=153). Cross-sectional PMA at the mid-body of the L3 vertebrae was measured. The lowest PMA tertile was used as a threshold value to designate patients as having "low" PMA(n=51) and this cohort was subsequently compared to subjects with "normal" PMA(n=102). Cox proportional hazards modeling was used to estimate covariate association with all-cause mortality.

RESULTS

Patients with low PMA were older(77 vs. 72 years;p=.002), more likely to be female(27% vs. 5%;p<.001), and had reduced BMI(26 vs. 29kg/m²;p=.002). Time to conversion, total number of EVAR reinterventions prior to conversion and elective EVAR-c presentation incidence were similar; however, patients with low PMA had larger aneurysms(8.3 vs. 7.5cm;p=.01) and increased post-EVAR sac growth(2.3 vs. 1cm;p=.005). Unadjusted inpatient mortality was significantly greater for low PMA patients(16% vs. normal PMA, 5%, p=.02). Similarly, the total number of complications was higher among low PMA subjects(1.5±1.9 vs. normal PMA, 0.9±1.5;p=.02). Although frequency of major adverse cardiovascular events and new onset inpatient hemodialysis were similar, low PMA patients had a more than four-fold increased likelihood of having persistent requirement of hemodialysis at discharge(18% vs. 4%,p=.01). The low PMA group had decreased survival at 1 and 5 years, respectively(77±5%, 65±6% vs. normal PMA, 86±3%, 82%±5%;log-rank p=.03). Low PMA was an independent predictor of mortality with every 100mm² increase in PMA being associated with a 15% reduction in mortality(HR 0.85,95% CI, .74-.97;p=.02).

CONCLUSION

Among EVAR-c patients, subjects with low preoperative PMA had higher rates of postoperative complications and worse overall survival. PMA assessments may be a useful adjunct to supplement traditional risk-stratification strategies when patients are being considered for EVAR-c.

Can We Still Teach Open Repair of Abdominal Aortic Aneurysm in The Endovascular Era? Single-Center Analysis on The Evolution of Procedural Characteristics Over 15 Years

OBJECTIVE

In many vascular centers an endovascular first policy for the treatment of abdominal aortic aneurysms (AAA) has resulted in endovascular aortic repair (EVAR) outnumbering open aortic repair (OAR). The declining routine in OAR raises the question whether this might influence procedural outcomes and diminish surgical expertise for current and future vascular surgeons. We aimed to analyze OAR outcomes, AAA morphology and procedural details over the past 15 years while an endovascular first approach was successively implemented.

PARTICICPANTS AND DESIGN

All patients operated for (i)ntact infra-/juxtarenal AAA between January 1, 2005 and December 31, 2019 were identified. Outcome parameters were length of stay (hospital/ICU), in-hospital mortality and medical/surgical complications. Operative details were clamping zone, access and graft configuration. AAA anatomy including neck and iliac parameters was analyzed with Endosize©. Logistic regression, uni- and multivariate analysis were applied.

RESULTS

293 patients received elective OAR for iAAA. Baseline characteristics (age, sex, hypertension, smoking, occlusive disease, coronary disease, hyperlipidemia, diabetes, renal insufficiency and obesity) did not change over time. The number of OAR dropped significantly (-0.5 cases/year p = 0.02). The procedure time (2005-2007: 192.2 ± 87.5min to 2017-2019: 235.6 ± 88.2min; p = 0.0001) and the length of stay (2005-2007: 12.0 ± 7.9 to 2017-2019: 17.0 ± 23.1; p = 0.03) increased significantly, whereas the in-hospital mortality, length of ICU stay and complication rates didn't, nor did AAA anatomy. Upon multivariate analysis, annual number of OAR and any additional anastomosis significantly influenced procedure time, trainee involvement, for example, did not. Hospital length-of-stay depended on patient age (p = 0.002), complication rates (p < 0.0001) and procedure time (p = 0.006).

CONCLUSION

Mortality and complication rates for OAR have remained low and constant. With the increase of EVAR, the absolute number of OARs has decreased significantly. However, the total procedure time has increased and depends significantly on the annual number of OARs in total and per surgeon. This might influence outcome parameters and should be implanted in future surgical education.

Virtual Simulation of Intra-operative Decision-Making for Open Abdominal Aortic Aneurysm Repair: A Mixed Methods Analysis

OBJECTIVE

To create and pilot test a novel open abdominal aortic aneurysm (AAA) repair virtual simulation focused on intraoperative decision-making. To identify if the simulation replicated real-time intra-operative decision-making and discover how learners' respond to this type of simulation.

DESIGN

An explanatory sequential mixed methods study. We developed a step-by-step outline of major intra-operative decision points within a standard open AAA repair. Perioperative and intraoperative decision-making trees were developed and coded into an online virtual simulation. The simulation was piloted. Quantitative data was collected from the simulation platform. We then performed a qualitative thematic analysis on feedback from interviewed participants.

SETTING

Four academic general and vascular surgical training programs across the US.

PARTICIPANTS

Seventeen vascular and general surgery trainees and 6 vascular surgery faculty.

RESULTS

Participants spent on average 27 minutes (range: 8-45 minutes) interacting with the interface. 93% of participants reported feeling they were making real intraoperative decisions. 85% said it added to their knowledge base. 96% requested additional simulations. 22 interviews were completed: 241 primary codes were collapsed into 21 parent codes, and 6 emerging themes identified. Themes included the benefit of how (1) "Virtual Learning Could Standardize the Training Experience"; how (2) "Dealing with the Unexpected" as a trainee is an important part of surgical education growth, and that this (3) "Choose Your Own Adventure" virtual format simulates this intraoperative growth experience. Participants requested a (4) "Looping Feature Feedback Diagram" for future simulation iterations and highlighted that (5) "Fancier is Not Necessarily More Educational." Finally, many trainees wondered about (6) "The Attending Impact" from the simulation: if faculty would notice a difference between trainees who did vs did not utilize the simulation for case preparation.

CONCLUSIONS

Operative simulation training should focus on both technical skills and intra-operative decision-making, particularly "dealing with the unexpected." The learners' responses indicate that a low-fidelity, scalable, virtual platform can effectively deliver knowledge and allow for intra-operative decision-making practice in a remote learning environment.

Cadaver Simulation is Associated with Increased Comfort in Performing Open Vascular Surgery Among Integrated Vascular Surgery (0+5) Residents and Recent Graduates

BACKGROUND

With the evolution in vascular surgery toward increased endovascular therapy and decreased open surgical training, comfort with open procedures by current trainees is declining. A proposed method to improve this discomfort is simulator training. We hypothesized that open, cadaver, and endovascular surgery simulation would be associated with increased self-perceived comfort in performing corresponding procedures.

METHODS

Integrated (0 + 5) vascular surgery residents and recent graduates in the United States were asked to complete a survey quantifying comfort via a Likert scale with procedures and experience with simulation training. Simulation groups were then matched using coarsened exact matching. Ordinal logistic regression assessed the association between simulation experience and comfort in performing procedures.

RESULTS

Surveys were completed by 68 trainees and 20 attending surgeons in their first 5 years of practice. On unmatched analyses, there were no significant differences in comfort in performing any open or endovascular aorto-mesenteric or peripheral vascular procedures between respondents who reported experience with open or endovascular simulation, respectively. However, respondents who reported cadaver simulation experience (58%, 51/88) had a significantly higher reported comfort score performing open juxtarenal aortic repair (2.4 vs. 1.7), superior mesenteric artery thrombectomy or bypass (2.5 vs. 1.9), inferior vena cava or iliac vein repair (2.2 vs. 1.7), axillary-femoral artery bypass (3.4 vs. 2.5), femoral-popliteal artery bypass (3.7 vs. 2.8), and inframalleolar artery bypass (2.8 vs. 2.1; all P < 0.05). After matching on training level, number of abdominal cases completed, and number of open vascular cases completed, ordinal logistic regression demonstrated that previous cadaver simulation was significantly associated with increased comfort in performing open aortic repairs, venous repair, visceral revascularization, and peripheral bypasses.

CONCLUSIONS

In this nationally representative sample, cadaver, but not open or endovascular, simulation was associated with increased comfort in performing open vascular surgery. Providing cadaver simulation to trainees may help to improve comfort levels in performing open surgery. Integrated vascular surgery training programs should consider implementing these experiences into their curriculum.

Trends in annual open abdominal aortic surgical volumes for vascular trainees compared to annual national volumes in the endovascular era

OBJECTIVE

Prior analysis predicted a shortfall in open abdominal aortic repair (OAR) experience for vascular trainees resulting from the rapid adoption of and increased anatomic suitability of endovascular aortic repair (EVAR) technology. We explored how EVAR has transformed contemporary open aortic surgical education for vascular trainees.

METHODS

We examined ACGME case volumes of open abdominal aortic aneurysm (AAA) repair and reconstruction for aorto-iliac occlusive disease (AIOD) via aorto-iliac/femoral bypass (AFB) from integrated vascular surgery residents (VSR) and fellows (VSF) graduating 2006-2017 and compared them to national estimates of total OAR (open AAA repair + AFB) in the Agency for Healthcare Research and Quality National Inpatient Sample based on ICD-9 and ICD-10 procedural codes. Changes over time were assessed using Chi-square test, Student's t-test, and linear regression.

RESULTS

During the twelve-year study period, the national annual total OAR and open AAA repair estimates decreased: total OAR by 72.5% (2006: estimate (standard error) 24,255 (1185) vs. 2017: 6,690 (274); p<0.001) and open AAA repair by 84.7% (2006: 18,619 (924) vs. 2017: 2,850 (168); p<0.001); AFB estimates decreased by 33.0% (p<0.001). The percentage of total OAR, open AAA repair, and AFB performed at teaching hospitals significantly increased from ∼55 to 80% (all p<0.001). There was a 40.9% decrease in open AAA repairs logged by graduating VSF (mean 18.6 vs. 11) but only a 6.9% decrease in total OAR cases (mean 27.6 vs. 25.7) due to increasing AFB volumes (mean 9.0 vs. 14.7). VSR graduates consistently logged an average of ∼10 open AAA repairs and there was a 31.0% increase in total OAR (mean 23.2 vs. 30.4), again secondary to rising AFB volumes (mean 11.4 vs 17.5). Although there was an absolute decrease in open aortic experience for VSF, the rate of decline for total OAR case volumes was not significantly different after VSR programs were established (p=0.40).

CONCLUSIONS

As incidence decreases nationally, OAR is shifting towards teaching hospitals. While open AAA procedures for trainees are declining due to EVAR, open aortic reconstruction for AIOD is rising and plays an important role in ensuring that vascular trainees continue to have satisfactory OAR experience sufficient for meeting minimum graduation requirements. Strategies to maintain and maximize the education and experience from these cases should be top priority for vascular surgery program directors.

Open vascular surgery training in the endovascular era: 5-year experience with cadaver laboratory

BACKGROUND

Vascular cadaver laboratory (CAD LAB) courses included vascular exposure techniques and simulations of open procedures. Aim of the study was to demonstrate the benefit of cadaver laboratory (CAD LAB) courses to improve trainees' experience in open surgical vascular procedures.

METHODS

Between 2014 and 2020, 162 vascular surgeons or medical trainees (mean age 28 years) participated in vascular CAD LAB courses in Italy and France. Outcomes were measured using the Linkert survey, performed pre- and post-course to evaluate self-efficacy/confidence, surgical experience and resident perception of the course with a range score from 0 to 5 for each point. Anatomical knowledge improvement was measured using a questionnaire with multiple answers pre- and post-course. The course was considered to have yielded a positive result if the post-course Linkert survey score increased by ≥2 points, or in the case of an increase of at least 30% above the baseline value of the multiple questionnaires.

RESULTS

Post-course questionnaires were positive for all outcomes evaluated. Participants' perception of the usefulness of the CAD LAB evaluation was 4.8 out of 5. For the vascular CAD LAB, participant anatomical knowledge improved overall from an average of 55% to 93% (P < .001), and self-efficacy/confidence improved from 2.3 to 4.5 out of 5 (P < .001). Regarding the different operative procedures, the greatest self-efficacy/confidence improvement was recorded in carotid endarterectomy and aortic procedures (+50% and +66% respectively; P < .001). The city location (Italy vs. France) did not affect the results.

CONCLUSIONS

CAD LAB courses were shown to be effective in increasing participants' self-efficacy, confidence, and anatomical knowledge in open vascular surgical procedures.

Late Type 1A Endoleaks: Associated Factors, Prognosis and Management Strategies

BACKGROUND

Unlike periprocedural Type 1A endoleaks, late appearing proximal endoleaks have been poorly described.

METHODS

We studied all elective EVAR from 2010 -2018 in a single institution. Late endoleaks were defined as those appearing after 1 year. We used Cox regression to study factors associated with late Type 1A endoleaks and survival.

RESULTS

Of 477 EVAR during the study period, 411 (86%) had follow-up imaging, revealing 24 Type 1A endoleaks; 4 early and 20 late. Freedom from Type 1A endoleaks was 99%, 92-81% at 1, 5 and 8 years with a median time to occurrence of 2.5 years (.01-8.2 years). On completion angiogram, only 10% of patients with a late Type 1A had a proximal endoleak, and 60% had no endoleak. Only 21% of late Type 1As were diagnosed on routine 1-year CT angiogram, but 79% had stable or expanding sacs. Two thirds (65%) of the patients eventually diagnosed with late Type 1A endoleaks had previously been treated for other endoleaks, mostly Type 2 (10/13). Age (HR 1.07/year [1.02-1.12], P = 0.01), neck diameter >28mm (HR 3.5 [1.2-10.3], P = 0.02), neck length <20mm (HR 3.0 [1.1-8.6], P = 0.04), and neck angle>60 degrees (HR 3.4 [1.5-7.9], P = 0.004) were associated with higher rates of Type 1A endoleak, but not female sex, endograft, or the use of suprarenal fixation. 2 patients had proximal degeneration and 5 experienced graft migration. There were 2 ruptures (10%), and 13 patients underwent repair with 5 open conversions. Median survival after late Type 1A repair was 6.6 years (0-8.4 years).

CONCLUSION

Late appearing Type 1A endoleaks have a high rate of rupture and present significant diagnostic and management challenges. Careful surveillance is needed in patients with hostile neck anatomy and those who undergo intervention for other endoleaks. Adverse neck anatomy may be better suited for open repair or fenestrated/branched devices rather than conventional EVAR.

Trends in General Surgery Operative Experience Obtained by Integrated Vascular Surgery Residents

OBJECTIVE

When the integrated vascular surgery training pathway was introduced, training was comprised of nearly equal amounts of core general surgery and vascular surgery experience. However, specific requirements for case numbers or types were not defined. Over time, the time spent on core general surgery requirements has been reduced, most recently in 2018, from 24 to 18 months. We sought to determine trends in general surgery case volume and type over the past 10 years for vascular surgery residents.

METHODS

We conducted a retrospective review of the Accreditation Council for Graduate Medical Education case log data for integrated vascular surgery graduates from 2012-2018. We evaluated trends in mean numbers of cases, categorized as general surgery open (GS-open), general surgery laparoscopic (GS-laparoscopic), vascular surgery open (VS-open), and vascular surgery endovascular (VS-endo). Cases were also categorized by anatomic region as head/neck, thoracic, or abdominal.

RESULTS

The mean number of total head/neck, thoracic, or abdominal cases logged by graduating integrated vascular surgery trainees was 263.5. This total, as well as the proportion of general surgery cases (35%-38%, p = 0.99) has remained constant over time. The type of general surgery cases has changed significantly, with an upward trend in the mean number of GS-open cases and downward trend in mean GS-laparoscopic cases (GS-open p = 0.006, GS-laparoscopic p = 0.048). Among head/neck and thoracic subgroups, no significant changes were observed, while in the abdominal subgroup, there has been a significant increase in GS-open over time (p = 0.005). Additionally, the number of open vascular abdominal aortic cases has remained stable, with an average of 36.82 per graduating trainee per year.

CONCLUSIONS

In the 10 years since the introduction of integrated vascular surgery programs, total case volume and proportion of general surgery cases have remained remarkably stable. The type of general surgery cases has shifted though, with a decrease in GS-laparoscopic cases, replaced primarily by open abdominal cases. These changes likely reflect integrated vascular residents actively seeking out these opportunities during their core rotations and a willingness by general surgery partners to provide these opportunities. At the program level, these data may help guide program directors' choices about the specific core rotations they incorporate into their curriculum. At the national level, this information may contribute to future discussions regarding the optimal number of core general surgery rotation requirements.

Evaluation of Circulating Endothelial Progenitor Cells in Abdominal Aortic Aneurysms after Endovascular Aneurysm Repair

Background and Objectives

Circulating endothelial progenitor cells (EPCs) participate in vascular repair and predict cardiovascular outcomes. The aim of this study was to investigate the correlation between EPCs and abdominal aortic aneurysms (AAAs).

Methods and Results

Patients (age 67±9.41 years) suffering from AAAs (aortic diameters 58.09±11.24 mm) were prospectively enrolled in this study. All patients received endovascular aneurysm repair (EVAR). Blood samples were taken preoperatively and 14 days after surgery from patients with aortic aneurysms. Samples were also obtained from age-matched control subjects. Circulating EPCs were defined as those cells that were double positive for CD34 and CD309. Rat models of AAA formation were generated by the peri-adventitial elastase application of either saline solution (control; n=10), or porcine pancreatic elastase (PPE; n=14). The aortas were analyzed using an ultrasonic video system and immunohistochemistry. The levels of CD34^＋/CD309^＋ cells in the peripheral blood mononuclear cell populations were measured by flow cytometry. The baseline numbers of circulating EPCs (CD34^＋/CD309^＋) in the peripheral blood were significantly smaller in AAA patients compared with control subjects. The number of EPCs doubled by the 14th day after EVAR. A total of 78.57% of rats in the PPE group (11/14) formed AAAs (dilation ratio >150%). The numbers of EPCs from defined AAA rats were significantly decreased compared with the control group.

Conclusions

EPC levels may be useful for monitoring abdominal aorta aneurysms and rise after EVAR in patients with aortic aneurysms, and might contribute to the rapid endothelialization of vessels.

Short-term outcomes of open surgical abdominal aortic aneurysm repair from the Dutch Surgical Aneurysm Audit

Background

The sharp decrease in open surgical repair (OSR) for abdominal aortic aneurysm (AAA) has raised concerns about contemporary postoperative outcomes. The study was designed to analyse the impact of complications on clinical outcomes within 30 days following OSR.

Methods

Patients who underwent OSR for intact AAA registered prospectively between 2016 and 2019 in the Dutch Surgical Aneurysm Audit were included. Complications and outcomes (death, secondary interventions, prolonged hospitalization) were evaluated. The adjusted relative risk (aRr) and 95 per cent confidence intervals were computed using Poisson regression. Subsequently, the population-attributable fraction (PAF) was calculated. The PAF reflects the expected percentage reduction of an outcome if a complication were to be completely prevented.

Results

A total of 1657 patients were analysed. Bowel ischaemia and renal complications had the largest impact on death (aRr 12·44 (95 per cent c.i. 7·95 to 19·84) at PAF 20 (95 per cent c.i. 8·4 to 31·5) per cent and aRr 5·07 (95 per cent c.i. 3·18 to 8.07) at PAF 14 (95 per cent c.i. 0·7 to 27·0) per cent, respectively). Arterial occlusion had the greatest impact on secondary interventions (aRr 11·28 (95 per cent c.i. 8·90 to 14·30) at PAF 21 (95 per cent c.i. 14·7 to 28·1) per cent), and pneumonia (aRr 2·52 (95 per cent c.i. 2·04 to 3·10) at PAF 13 (95 per cent c.i. 8·3 to 17·8) per cent) on prolonged hospitalization. Small effects were observed on outcomes for other complications.

Conclusion

The greatest clinical impact following OSR can be made by focusing on measures to reduce the occurrence of bowel ischaemia, arterial occlusion and pneumonia.

Trends in operative case volumes of Canadian vascular surgery trainees

OBJECTIVE

Vascular surgery has evolved with increasing use of endovascular therapies and a decline in open surgery. The influence of these changes, in addition to a new vascular surgery training program introduced in 2012, on case volumes of vascular trainees is not known. We sought to evaluate trends in operative case volumes of Canadian vascular surgery trainees.

METHODS

A survey was administered to graduates of the Canadian Royal College-accredited Vascular Fellowships (VFs) and Integrated Vascular Surgery Residency (IVSR) programs (2007-2019) to record cases performed during their final 2 years of training. Procedures of interest were open abdominal aortic aneurysm (oAAA) repair, open thoracic/thoracoabdominal aortic (oTAA/TAAA) repair, lower extremity bypass (LEB), carotid endarterectomy (CEA), lower extremity endovascular intervention (LEEI), and endovascular abdominal, advanced, and thoracic aortic repair (EVAR, aEVAR, and TEVAR). Case volumes were analyzed overall, and by graduation year, type of training program, and resident demographics.

RESULTS

A total of 60 participants (10% female) from all the 10 Canadian training institutions responded (response rate, 63%). There was a declining trend in overall procedures performed since the introduction of IVSR in 2012 (median, 427 [interquartile range (IQR), 304-496] in 2007-2012 vs median, 342 [IQR, 279-405] in 2013-2019; P = .055), driven by a significant decline in open vascular surgery cases (median, 273 [IQR, 221-339] in 2007-2012 vs median, 156 [IQR, 128-181] in 2013-2019; P = .001). Case volumes of oAAA, LEB, and CEA declined by 44%, 40%, and 45%, respectively. Compared with vascular fellows, IVSR residents logged ∼2.5 times more aEVARs (median, 8; IQR, 2-11 vs median, 19; IQR, 8-27; P = .001) and ∼1.5 times more LEEIs (median, 60; IQR, 40-99 vs median, 93; IQR, 69-120; P = .018). Trainees were most confident (range, 90%-100%) in performing oAAA, EVAR, LEB, LEEI, and CEA after training, and least confident in performing oTAA/TAAA and aEVAR (20% and 49% confidence, respectively).

CONCLUSIONS

Operative case volumes of Canadian vascular surgery trainees since the introduction of IVSR program in 2012 have decreased, driven by declining exposure to open cases. However, trainees continue to receive adequate operative exposure to perform most standard vascular procedures confidently upon graduation.

Association and interplay of surgeon and hospital volume with mortality after open abdominal aortic aneurysm repair in the modern era

OBJECTIVE

Operative volume has been used as a marker of quality. Research from previous decades has suggested minimum open abdominal aortic aneurysm (AAA) repair volume requirements for surgeons of 9 to 13 open AAA repairs annually and for hospitals of 18 open AAA repairs annually to purportedly achieve acceptable results. Given concerns regarding the decreased frequency of open repairs in the endovascular era, we examined the association of surgeon and hospital volume with the 30- and 90-day mortality in the Vascular Quality Initiative (VQI) registry.

METHODS

Patients who had undergone elective open AAA repair from 2013 to 2018 were identified in the VQI registry. We performed a cross-sectional evaluation of the association between the average hospital and surgeon volume and 30-day postoperative mortality using a hierarchical Bayesian model. Cross-level interactions were permitted, and random surgeon- and hospital-level intercepts were used to account for clustering. The mortality results were adjusted by standardizing to the observed distribution of relevant covariates in the overall cohort. The outcomes were compared to the Society for Vascular Surgery guidelines recommended criteria of <5% perioperative mortality.

RESULTS

A total of 3078 patients had undergone elective open AAA repair by 520 surgeons at 128 hospitals. The 30- and 90-day risks of postoperative mortality were 4.1% (n = 126) and 5.4% (n = 166), respectively. The mean surgeon volume and hospital volume both correlated inversely with the 30-day mortality. Averaged across all patients and hospitals, we found a 96% probability that surgeons who performed an average of four or more repairs per year achieved <5% 30-day mortality. Substantial interplay was present between surgeon volume and hospital volume. For example, at lower volume hospitals performing an average of five repairs annually, <5% 30-day mortality would be expected 69% of the time for surgeons performing an average of three operations annually. In contrast, at higher volume hospitals performing an average of 40 repairs annually, a <5% 30-day mortality would be expected 96% of the time for surgeons performing an average of three operations annually. As hospital volume increased, a diminishing difference occurred in 30-day mortality between lower and higher volume surgeons. Likewise, as surgeon volume increased, a diminishing difference was found in 30-day mortality between the lower and higher volume hospitals.

CONCLUSIONS

Surgeons and hospitals in the VQI registry achieved mortality outcomes of <5% (Society for Vascular Surgery guidelines), with an average surgeon volume that was substantially lower compared with previous reports. Furthermore, when considering the development of minimal surgeon volume guidelines, it is important to contextualize the outcomes within the hospital volumes.

Understanding value and patient complexity among common inpatient vascular surgery procedures

OBJECTIVE

Vascular surgery patients are highly complex, second only to patients undergoing cardiac procedures. However, unlike cardiac surgery, work relative value units (wRVU) for vascular surgery were undervalued based on an overall patient complexity score. This study assesses the correlation of patient complexity with wRVUs for the most commonly performed inpatient vascular surgery procedures.

METHODS

The 2014 to 2017 National Surgical Quality Improvement Program Participant Use Data Files were queried for inpatient cases performed by vascular surgeons. A previously developed patient complexity score using perioperative domains was calculated based on patient age, American Society of Anesthesiologists class of ≥4, major comorbidities, emergent status, concurrent procedures, additional procedures, hospital length of stay, nonhome discharge, and 30-day major complications, readmissions, and mortality. Procedures were assigned points based on their relative rank and then an overall score was created by summing the total points. An observed to expected ratio (O/E) was calculated using open ruptured abdominal aortic aneurysm repair (rOAAA) as the referent and then applied to an adjusted median wRVU per operative minute.

RESULTS

Among 164,370 cases, patient complexity was greatest for rOAAA (complexity score = 128) and the least for carotid endarterectomy (CEA) (complexity score = 29). Patients undergoing rOAAA repair had the greatest proportion of American Society of Anesthesiologists class of ≥IV (84.8%; 95% confidence interval [CI], 82.6%-86.8%), highest mortality (35.5%; 95% CI, 32.8%-38.3%), and major complication rate (87.1%; 95% CI, 85.1%-89.0%). Patients undergoing CEA had the lowest mortality (0.7%; 95% CI, 0.7%-0.8%), major complication rate (8.2%; 95% 95% CI, 8.0%-8.5%), and shortest length of stay (2.7 days; 95% CI, 2.7-2.7). The median wRVU ranged from 10.0 to 42.1 and only weakly correlated with overall complexity (Spearman's ρ = 0.11; P < .01). The median wRVU per operative minute was greatest for thoracic endovascular aortic repair (0.25) and lowest for both axillary-femoral artery bypass (0.12) and open femoral endarterectomy, thromboembolectomy, or reconstruction (0.12). After adjusting for patient complexity, CEA (O/E = 3.8) and transcarotid artery revascularization (O/E = 2.8) had greater than expected O/E. In contrast, lower extremity bypass (O/E = 0.77), lower extremity embolectomy (O/E = 0.79), and open abdominal aortic repair (O/E = 0.80) had a lower than expected O/E.

CONCLUSIONS

Patient complexity varies substantially across vascular procedures and is not captured effectively by wRVUs. Increased operative time for open procedures is not adequately accounted for by wRVUs, which may unfairly penalize surgeons who perform complex open operations.

Self-Perceived Comfort Performing Vascular Surgery Procedures among Senior Vascular Surgery Trainees and Recent Graduates

OBJECTIVE

In the last two decades, vascular surgery training evolved from exclusively learning open skills to learning endovascular skills in addition to a functional reduction in training duration with 0+5 residency programs. The implications for this on trainee evolution to independence are unknown. We aimed to assess self-perceived comfort performing open and endovascular procedures and to identify predictors of high comfort among senior vascular surgery trainees and recent graduates.

METHODS

Junior and senior 0+5 vascular surgery residents, traditional fellows, and attendings in their first 4 years of practice were asked to complete a survey assessing the number of vascular procedures performed to date, comfort performing these procedures on a Likert scale, and validated scales of self-efficacy and grit. Groups were then matched by training level and age. Logistic regression identified independent predictors of the top quartile of self-perceived comfort performing procedures.

RESULTS

Surveys were completed by 92 trainees and 71 attending surgeons in their first 4 years of practice. After matching, completing ≥7 open juxtarenal aortic repairs (OR = 4.73, 95% CI = 1.59-14.07) and a higher self-efficacy score (OR = 3.24, 95% CI = 1.20-8.76), were independent predictors of top quartile comfort performing open vascular procedures. 0+5 residency training inversely correlated with top quartile comfort performing open vascular operations (OR = 0.12, 95% CI = 0.03-0.47). Completing ≥7 complex EVARs (OR = 3.94, 95% CI = 1.61-9.59) and a higher self-efficacy personality score (OR = 2.76, 95% CI = 1.09-7.02) were predictors of top quartile comfort performing endovascular procedures.

CONCLUSION

In this nationally representative survey, both trainees and junior attendings completed a paucity of complex open vascular cases, which corresponded to reduced comfort performing these procedures. Furthermore, 0+5 residency training was associated with lower self-perceived comfort performing open vascular surgery, a trend that persisted through the first years of practice. Endovascular comfort did not show a similar correlation.

A Canadian multicenter experience describing outcomes after endovascular abdominal aortic aneurysm repair stent graft explantation

BACKGROUND

Most studies describing the outcomes after endovascular abdominal aortic aneurysm repair (EVAR) explantation have been from single, high-volume, centers. We performed a multicenter cross-Canadian study of outcomes after EVAR stent graft explantation. Our objectives were to describe the outcomes after late open conversion and EVAR graft explantation at various Canadian centers and the techniques and outcomes stratified by the indication for explant.

METHODS

The Canadian Vascular Surgery Research Group performed a retrospective multicenter study of all cases of EVAR graft explantation at participating centers from 2003 to 2018. Data were collected using a standardized, secure, online platform (RedCap [Research Electronic Data Capture]). Univariate statistical analysis was used to compare the techniques and outcomes stratified the indication for graft explantation.

RESULTS

Patient data from 111 EVAR explants collected from 13 participating centers were analyzed. The mean age at explantation was 74 years, the average aneurysm size was 7.5 cm, and 28% had had at least one instructions for use violation at EVAR. The average time between EVAR and explantation was 42.5 months. The most common indication for explantation was endoleak (n = 66; type Ia, 46; type Ib, 2; type II, 9; type III, 2; type V, 7), followed by infection in 20 patients; rupture in 18 patients (due to type Ia endoleak in 10 patients, type Ib in 1, type II in 1, type III in 2, and type V in 1), and graft thrombosis in 7 patients. The overall 30-day mortality was 11%, and 45% of the patients had experienced at least one major perioperative complication. Mortality was significantly greater for patients with rupture (33.3%) and those with infection (15%) compared with patients undergoing elective explantation for endoleak (4.5%; P = .003). The average center volume during the previous 15 years was 8 cases with a wide range (2-19 cases). A trend was seen toward greater mortality for patients treated at centers with fewer than eight cases compared with those with eight or more cases (19% vs 9%). However, the difference did not reach statistical significance (P = .23). Overall, 41% of patients had undergone at least one attempt at endovascular salvage before explantation, with the highest proportion among patients who had undergone EVAR explantation for endoleak (51%). Only 22% of patients with rupture had undergone an attempt at endovascular salvage before explantation.

CONCLUSIONS

The performance of EVAR graft explantation has increasing in Canada. Patients who had undergone elective explantation for endoleak had lower mortality than those treated for either infection or rupture. Thus, patients with an indication for explanation should be offered surgery before symptoms or rupture has occurred. A trend was seen toward greater mortality for patients treated at centers with lower volumes.

Simulation Based Training and Assessment in Open Vascular Surgery: A Systematic Review

OBJECTIVE

The aim of this study was to systematically review the literature and give evidence based recommendations for future initiatives for simulation based training (SBT) and assessment in open vascular surgery.

DATA SOURCES

PubMed, Embase, and the Cochrane Library.

REVIEW METHODS

A systematic review of PubMed, Embase, and the Cochrane Library was performed, with the last search on 31 March 2020, to identify studies describing SBT and assessment in open vascular surgery. Kirkpatrick's levels for efficacy of training were evaluated. Validity evidence for assessment tools was evaluated according to the recommended contemporary framework by Messick.

RESULTS

Of 2 844 studies, 51 were included for data extraction. A high degree of heterogeneity in reporting standards and varying types of simulation was found. Vascular anastomosis was the most frequently simulated technical skill (43%). Assessment was mostly carried out using the Objective Structured Assessment of Technical Skills (55%). Validity evidence for assessment tools was found using outdated frameworks, and only one study used Messick's framework. Self directed training is valuable, the low trainer to trainee ratio is important to maximise efficiency, and experienced vascular surgeons are the most effective trainers.

CONCLUSION

Carefully designed and structured SBT is effective and can improve technical skills, especially in less experienced trainees. However, the supporting evidence lacks homogeneity in the reporting standards and types of simulations. Pass/fail standards that support proficiency based learning and studies investigating skills transfer should be the focus in future studies. Validity evidence of assessment tools needs to be addressed using contemporary frameworks.

Simulation for technical skill acquisition in open vascular surgery

BACKGROUND

Simulation has an increasingly prominent role in modern vascular surgery training. However, it is important to understand how simulation is most effectively delivered to best use the time and resources available. The aim of this narrative review is therefore to critically appraise open technical skill acquisition in the operating room environment and provide recommendations for the future development of evidence-based simulation for open vascular surgery.

METHODS

A systematic search strategy was used to retrieve relevant studies from PubMed, Medline, Web of Science, EMBASE, and the Cochrane databases in July 2019. Included papers were independently screened by two reviewers. Data were subsequently extracted using a standardized proforma and thematically analyzed.

RESULTS

Thirteen studies were included. All demonstrated that simulation is effective in improving confidence and/or competence in performing open technical skills when assessed by previously validated metrics. However, not all participants or course schedules achieved equal benefit, with distributed practice for junior trainees over several weeks achieving a greater improvement in technical skill compared with senior trainees or longer course schedules for some tasks.

CONCLUSIONS

Simulation can be an effective adjunct to traditional operative experience for technical skill acquisition in open vascular surgery. Future work should focus on developing models to address a wider range of training needs, as well as further defining the optimum schedule for the style, content, and timing of simulation for specific learner groups.

Learning Curves and Competences of Vascular Trainees Performing Open Aortic Repair in a Simulation-Based Environment

BACKGROUND

The aim of this study was to analyze learning curves and competency gains of novice vascular trainees when performing open aortic repair in a simulation-based environment.

METHODS

This was a prospective study of 16 vascular trainees performing infrarenal open aortic repair on an inanimate abdominal aortic aneurysm simulator with pulsatile pressure and flow. Each participant performed 4 procedures as a primary surgeon while getting structured feedback by a supervising experienced vascular surgeon. All sessions were video recorded and were anonymously and independently assessed by 3 rater-trained experts on an online platform using the newly validated open abdominal aortic aneurysm repair of technical expertise assessment tool. All supervisor interferences and procedure time was noted.

RESULTS

Reliability between raters was excellent (intraclass correlation coefficient = 0.92). Participants' mean scores almost doubled during the course between the first (13.4, 95% confidence interval [CI], 6.8-20) and fourth session (29.8, 95% CI, 26.3-33.3) with a mean difference of 14.6 (P < 0.001). Supervisor interference also decreased significantly from mean 3.0 (95% CI, 1.5-3.6) in the first to 0.7 (95% CI, 0.4-1.0) in the fourth session (P = 0.004). Procedure time decreased with a mean of 24 minutes: from 81 min (95% CI, 71.8-90.3) to 57 min (95% CI, 51.1-63.2, P < 0.001). There was a significant negative correlation between procedure time and the Open Abdominal Aortic Aneurysm Repair of Technical Expertise score (Pearson's r = -0.72, P < 0.01). Only half of the participants passed the pass/fail score of 27.7 points during the course.

CONCLUSIONS

Novice vascular trainees achieve skills and competencies in open aortic repair in a simulated setting with dedicated supervision and feedback and can become ready for supervised surgery on real patients. Learning rates are individual, and it is important to construct training programs with emphasis on proficiency and not merely attending a course.

Mortality for Open Abdominal Aortic Aneurysm Repair before and after Endovascular Aortic Repair (EVAR)

The purpose of this study was to determine whether endovascular aortic repair (EVAR) has impacted inhospital mortality for patients undergoing open repair (OR). From 1982 through 2016, 1572 repairs were performed for abdominal aortic aneurysms (AAAs). Both ORs and EVARs were performed by the author at two large, tertiary-care, community-based hospitals. In Period I (1982–1999, n = 863), all AAA repairs were performed open. In Period II (2000–2016; n = 709), repairs were performed both by ORs and EVARs. Demographics were similar between study groups. Mortality for elective repairs in Periods I and II were as follows: I = 1.2 per cent (open, n = 9/756) versus II = 1.7 per cent (open, n = 4/241) versus II = 1.2 per cent (EVAR, n = 5/420). Mortality for patients with ruptured AAAs in Periods I and II were as follows: I = 31.8 per cent (open, n = 34/107) versus II = 32 per cent (open, n = 8/25) versus II = 13 per cent (EVAR, n = 3/23). The results of this study demonstrate that the introduction of EVARs has not negatively impacted the inhospital mortality for elective ORs or emergent AAAs for one vascular surgeon who completed training before EVARs became available.

National temporal trends and determinants of cost of abdominal aortic aneurysm repair

INTRODUCTION

In recent decades, there has been a shift in the management of aortic abdominal aneurysm from open intervention (open aortic aneurysm repair) to an endovascular approach (endovascular aortic aneurysm repair). This shift has yielded clinical as well as socioeconomic reverberations. In our current study, we aim to analyze these effects brought about by the switch to endovascular treatment and to scrutinize the determinants of cost variations between the two treatment modalities.

METHODS

The National (Nationwide) Inpatient Sample database was queried for clinical data ranging from 2001 to 2013 using International Classification of Disease, 9th Revision (ICD-9) codes for open and endovascular aortic repair. Clinical parameters and financial data related to the two treatment modalities were analyzed. Temporal trends of index hospitalization costs were determined. Multivariate linear regression was used to characterize determinants of cost for endovascular aneurysm repair and open abdominal aortic aneurysm repair.

RESULTS

A total of 128,154 aortic repairs were captured in our analysis, including 62,871 open repairs and 65,283 endovascular repairs. Over the assessed time period, there has been a decrease in the cost of elective endovascular aortic aneurysm repair from $34,975.62 to $31,384.90, a $3,590.72 difference (p < 0.01), while the cost of open aortic repair has increased from $37,427.77 to $43,640.79 by 2013, a $6,212.79 increase (p < 0.01). The cost of open aortic aneurysm repair disproportionately increased at urban teaching hospitals, where by 2013, it costs $50,205.59, compared to $34,676.46 at urban nonteaching hospitals, and $34,696.97 at rural institutions. Urban teaching hospitals were found to perform an increasing proportion of complex open aneurysm repairs, involving concomitant renal and visceral bypass procedures. On multivariate analysis, strong determinants of cost increase for both endovascular aortic aneurysm repair and open aortic aneurysm repair are rupture status, prolonged length of stay, occurrence of complications, and the need for disposition to a nursing facility or another acute care institution.

CONCLUSION

As the vascular community has shifted from an open repair of abdominal aortic aneurysm to an endovascular approach, a number of unforeseen clinical and economic effects were noted. We have characterized these ramifications to help guide further clinical decision and resource allocation.

Hospital Volume Matters: The Volume-Outcome Relationship in Open Juxtarenal AAA Repair

OBJECTIVE

We studied whether the volume-outcome relationship would persist in more complex aortic operations.

BACKGROUND

Despite the added complexity of the involvement of the renal arteries in open juxtarenal abdominal aortic aneurysm (AAA) repair, the volume effect in these difficult operations has yet to be defined.

METHODS

We identified all patients in the Vascular Quality Initiative (VQI) who underwent open AAA repair from 2003 to 2016. We calculated each hospital's average annual volume for total open AAA repairs, and total open juxtarenal AAA repairs. We compared adjusted perioperative and long-term survival across quintiles of hospital volume, and constructed models including both volume metrics to evaluate the cross-volume effects.

RESULTS

Of 8880 total open AAA repairs, there were 3470 open juxtarenal cases. Centers with low (<4), medium (4-14), and high (>14) volumes of open juxtarenal repair demonstrated adjusted perioperative mortality of 9.0%, 4.9%, and 3.9%, respectively (P < 0.01). When both volume metrics were considered, open juxtarenal volume, but not total open AAA volume was associated with perioperative mortality (lowest quintile of juxtarenal volume: OR 2.36 [1.29-4.30], P < 0.01). Hospital volume was not associated with adjusted long-term mortality. High volume centers were more likely to use renal protective strategies such as mannitol and cold renal perfusion (both P < 0.01). Low volume centers performed a similar proportion of cases each year, but 22 centers (13%) did stop performing repairs during the study period.

CONCLUSION

Hospitals with low annualized volumes of open juxtarenal repair have higher perioperative mortality, irrespective of their total open aortic volume. Complex open AAA repairs should be performed at experienced centers, and future efforts should focus on centralization of complex aortic care.

Ensuring Competency in Open Aortic Aneurysm Repair - Development and Validation of a New Assessment Tool

OBJECTIVE

The aims of this study were to develop a procedure specific assessment tool for open abdominal aortic aneurysm (AAA) repair, gather validity evidence for the tool and establish a pass/fail standard.

METHODS

Validity was studied based on the contemporary framework by Messick. Three vascular surgeons experienced in open AAA repair and an expert in assessment and validation within medical education developed the OPEn aortic aneurysm Repair Assessment of Technical Expertise (OPERATE) tool. Vascular surgeons with varying experiences performed open AAA repair in a standardised simulation based setting. All procedures were video recorded with the faces anonymised and scored independently by three experts in a mutual blinded setup. The Angoff standard setting method was used to establish a credible pass/fail score.

RESULTS

Sixteen novices and nine experienced open vascular surgeons were enrolled. The OPERATE tool achieved high internal consistency (Cronbach's alpha .92) and inter-rater reliability (Cronbach's alpha .95) and was able to differentiate novices and experienced surgeons with mean scores (higher score is better) of 13.4 ± 12 and 25.6 ± 6, respectively (p = .01). The pass/fail score was set high (27.7). One novice passed the test while six experienced surgeons failed.

CONCLUSION

Validity evidence was established for the newly developed OPERATE tool and was able to differentiate between novices and experienced surgeons providing a good argument that this tool can be used for both formative and summative assessment in a simulation based environment. The high pass/fail score emphasises the need for novices to train in a simulation based environment up to a certain level of competency before apprenticeship training in the clinical environment under the tutelage of a supervisor. Familiarisation with the simulation equipment must be ensured before performance is assessed as reflected by the low scores in the experienced group's first attempt.

Difficult Intraoperative Heparinization Following Andexanet Alfa Administration

Direct oral anticoagulants are now commonplace, and reversal agents are recently becoming available. Andexanet alfa (AnXa), approved by the United States Food and Drug Administration in 2018, is a novel decoy molecule that reverses factor Xa inhibitors in patients with major hemorrhage. We present a case of a 70-year-old man taking rivaroxaban with hemodynamic instability from a ruptured abdominal aortic aneurysm. He received AnXa prior to endovascular surgery, and intraoperatively he could not be heparinized for graft placement. Consideration should be given to the risks and benefits of AnXa administration in patients who require anticoagulation after hemorrhage has been controlled.

Meta-analysis of fenestrated endovascular aneurysm repair versus open surgical repair of juxtarenal abdominal aortic aneurysms over the last 10 years

Background

Juxtarenal abdominal aortic aneurysms pose a significant challenge whether managed endovascularly or by open surgery. Fenestrated endovascular aneurysm repair (FEVAR) is now well established, but few studies have compared it with open surgical repair (OSR). The aim of this systematic review was to compare short- and long-term outcomes of FEVAR and OSR for the management of juxtarenal aortic aneurysms.

Methods

A literature search was conducted of the Ovid Medline, EMBASE and PubMed databases. Reasons for exclusion were series with fewer than 20 patients, studies published before 2007 and those concerning ruptured aneurysms. Owing to variance in definitions, the terms 'juxta/para/suprarenal' were used; thoracoabdominal aortic aneurysms were excluded. Primary outcomes were 30-day/in-hospital mortality and renal insufficiency. Secondary outcomes included major complication rates, rate of reintervention and rates of endoleak.

Results

Twenty-seven studies were identified, involving 2974 patients. Study designs included 11 case series, 14 series within retrospective cohort studies, one case-control study and a single prospective non-randomized trial. The pooled early postoperative mortality rate following FEVAR was 3·3 (95 per cent c.i. 2·0 to 5·0) per cent, compared with 4·2 (2·9 to 5·7) per cent after OSR. After FEVAR, the rate of postoperative renal insufficiency was 16·2 (10·4 to 23·0) per cent, compared with 23·8 (15·2 to 33·6) per cent after OSR. The major early complication rate following FEVAR was 23·1 (16·8 to 30·1) per cent versus 43·5 (34·4 to 52·8) per cent after OSR. The rate of late reintervention after FEVAR was higher than that after OSR: 11·1 (6·7 to 16·4) versus 2·0 (0·6 to 4·3) per cent respectively.

Conclusion

No significant difference was noted in 30-day mortality; however, FEVAR was associated with significantly lower morbidity than OSR. Long-term durability is a concern, with far higher reintervention rates after FEVAR.

Learning Curve Analysis to Determine Operative Requirements for Young Vascular Surgeons Learning Open Abdominal Aortic Aneurysm Repair

BACKGROUND

Since endovascular aneurysm repair has become predominant, the issue of training young vascular surgeons in open abdominal aortic aneurysm (AAA) surgery has received significant attention. Through learning curve analysis, we aimed to determine the number of cases needed for young surgeons to achieve satisfactory open surgical skills.

METHODS AND RESULTS

A total of 562 consecutive patients who underwent open repair either by an attending surgeon (group A) or 6 young vascular surgeons (group Y) were included and assessed with regards to the preparation, clamp, and total operation times. Although some of the patients' characteristics were different, the surgical procedures were comparable between the 2 groups. There was a clear trend towards a decrease in each 10 successive cases in group Y. The operation times in group A were constant at 72±30 (preparation), 48±10 (clamp), and 231±59 min (total), which were achieved by young vascular surgeons in 10, 30, and 10 cases, respectively. In the cumulative sum analysis, 25-27 cases were necessary for young vascular surgeons to enhance their surgical skills. The complication rate in group Y was no higher than that in group A.

CONCLUSIONS

Young vascular surgeons can safely learn open AAA repair without increasing operation time or complications. Approximately 30 cases would be necessary to gain satisfactory surgical skills.

Thirty-Day Outcomes After Open Revascularization for Acute Mesenteric Ischemia From the American College of Surgeons National Surgical Quality Improvement Program

BACKGROUND

Open revascularization for acute mesenteric ischemia (AMI) is associated with high perioperative morbidity and mortality; however, results from contemporary studies are varied. Therefore, we evaluated 30-day mortality after open revascularization for AMI and identified preoperative factors associated with mortality.

METHODS

We performed a retrospective cohort study of patients in the American College of Surgeons National Surgical Quality Improvement Program database undergoing open mesenteric revascularization for AMI from 2005 to 2017. The primary outcome was 30-day mortality. We used multivariable logistic regression to identify preoperative factors independently associated with 30-day mortality.

RESULTS

The study cohort included 918 patients; their median age was 70 years (interquartile range: 59-80 years), 62% were female, and 90% were white. Thirty-day mortality after open revascularization for AMI was 32%, specifically 35% after embolectomy, 31% after thromboendarterectomy, and 28% after mesenteric bypass. Mortality was higher in patients requiring concomitant bowel resection (38% vs. 29%, respectively, P < 0.01). The preoperative factor most strongly associated with 30-day mortality was disseminated cancer (odds ratio = 8.8, 95% confidence interval = 2.4-32, P = 0.001). Other factors independently associated with mortality were renal dysfunction, preoperative intubation, preoperative blood transfusion, diabetes, elevated preoperative international normalized ratio, elevated preoperative white blood cell count, and increasing age.

CONCLUSIONS

In this retrospective cohort study using a real-world, nationwide cohort, open revascularization for AMI was associated with high mortality, with nearly one-third of patients dying within 30 days of their operation. The factors identified to be independently associated with 30-day mortality, particularly disseminated cancer, preoperative renal dysfunction, and elevated preoperative WBC count, are an important tool for preoperative risk stratification.

Transabdominal open abdominal aortic aneurysm repair is associated with higher rates of late reintervention and readmission compared with the retroperitoneal approach

OBJECTIVE

Limited data exist comparing the transabdominal and retroperitoneal approaches to open abdominal aortic aneurysm (AAA) repair, especially late mortality and laparotomy-related reinterventions and readmissions. Therefore, we compared long-term rates of mortality, reintervention, and readmission after open AAA repair through a transabdominal compared with a retroperitoneal approach.

METHODS

We identified all patients in the Vascular Quality Initiative (VQI) undergoing open AAA repair from 2003 to 2015. Patients with rupture or supraceliac clamp were excluded. We used the VQI linkage to Medicare to ascertain rates of long-term outcomes, including rates of AAA-related and laparotomy-related (ie, hernia, bowel obstruction) reinterventions and readmissions. We used multivariable Cox regression to account for differences in comorbidities, aneurysm details, and operative characteristics.

RESULTS

We identified 1282 patients in the VQI with linkage to Medicare data, 914 (71%) who underwent a transperitoneal approach and 368 (29%) who underwent a retroperitoneal approach. Patients who underwent a retroperitoneal approach were slightly more likely to have preoperative renal insufficiency but were otherwise similar in terms of demographics and comorbidities. They more often had a clamp above at least one renal artery (61% vs 36%; P < .001) and underwent concomitant renal revascularization (9.5% vs 4.3%; P < .001). Patients who underwent a transabdominal approach more often presented with symptoms (14% vs 9.0%; P < .01) and had a femoral distal anastomosis (15% vs 7.1%; P < .001). There was no difference in 5-year survival (62% vs 61%; log-rank, P = .51). However, patients who underwent a transabdominal approach experienced higher rates of repair-related reinterventions and readmissions (5-year: 42% vs 34%; log-rank, P < .01), even after adjustment for demographic and operative differences (hazard ratio, 1.5; 95% confidence interval, 1.1-1.9; P < .01).

CONCLUSIONS

A transabdominal exposure for AAA repair is associated with higher rates of late reintervention and readmission than with the retroperitoneal approach, which should be considered when possible in operative decision-making.