Increasing Complexity in the Open Surgical Repair of Abdominal Aortic Aneurysms

Facilitators and Barriers to Implementation of Simulation Based Education in Vascular Surgery in Europe

OBJECTIVE

This study explored the status and availability of simulation based education (SBE) for learning vascular surgical procedures identified in the 2019 General Needs Assessment in vascular surgery in Europe (GNA-2019) and identified facilitators and barriers to SBE implementation in vascular surgery.

METHODS

A three round iterative survey was distributed via the European Society for Vascular Surgery and the Union Européenne des Médecins Spécialistes. Members from leading committees and organisations within the European vascular surgical community were invited to participate as key opinion leaders (KOLs). Three online survey rounds explored demographics, SBE availability, and facilitators and barriers to SBE implementation.

RESULTS

Overall, 147 KOLs (target population 338) accepted invitation to round 1, representing 30 European countries. The dropout rates for rounds 2 and 3 were 29% and 40%, respectively. Most respondents (88%) were senior, consultant level or higher. No mandatory SBE training was required in their department before training on patients, according to 84% of the KOLs. There was high consensus on the need for structured SBE (87%) and mandatory SBE (81%). SBE is available for the top three prioritised procedures in GNA-2019 (basic open skills, basic endovascular skills, and vascular imaging interpretation) in 24, 23, and 20 of the 30 represented European countries, respectively. The highest ranking facilitators were structured SBE programmes, availability of simulation equipment locally and regionally, good quality simulators, and having a dedicated person running the SBE. The highest ranked barriers were lack of structured SBE curriculum, equipment costs, lack of SBE culture, no or limited dedicated time for faculty to teach in SBE, and clinical work overload.

CONCLUSION

Based largely on the opinions of KOLs in vascular surgery in Europe, this study revealed that SBE is needed in vascular surgery training and that systematic and structured programmes are required to ensure successful implementation.

Contemporary Indications for Open Abdominal Aortic Aneurysm Repair in the Endovascular Era

INTRODUCTION AND OBJECTIVES

Despite the emergence of endovascular aneurysm repair (EVAR) as the most common approach to abdominal aortic aneurysm repair, open aneurysm repair (OAR) remains an important option. This study seeks to define the indications for OAR in the EVAR era and how these indications effect outcomes.

METHODS

A retrospective cohort study was performed of all OAR at a single institution from 2004 to 2019. Pre-operative computed tomography scans and operative records were assessed to determine the indication for OAR. These reasons were categorized into anatomical contraindications; systemic factors (connective tissue disorders, contraindication to contrast dye); and patient/surgeon preference (patients who were candidates for both EVAR and OAR). Perioperative and long-term outcomes were compared between the groups.

RESULTS

370 patients were included in the analysis; 71.6% (265/370) had at least one anatomic contraindication to EVAR; 36% had two or more contraindications. The most common anatomic contraindications were short aortic neck length (51.6%), inadequate distal seal zone (19.2%), and inadequate access vessels (15.7%). The major perioperative complication rate was 18.1% and the 30-day mortality was 3.0%. No single anatomic factor was identified as a predictor of perioperative complications. Sixty-one patients (16.5%) had OAR based on patient/surgeon preference; these patients were younger; had lower incidences of coronary artery disease and chronic obstructive pulmonary disease; and they were less likely to require suprarenal cross clamping compared with patients who had anatomic and/or systemic contraindications to EVAR. The patient/surgeon preference group had a lower incidence of perioperative major complications (8.2% versus 20.1%, p=0.034), shorter length of stay (6 versus 8 days, p<0.001) and zero 30-day mortalities. The multivariable adjusted risk for 15-year mortality was lower for patient/surgeon preference patients (adjusted hazard ratio 0.44 [95% confidence interval 0.24-0.80], p=0.007) compared to those anatomic/systemic contraindications.

CONCLUSIONS

Within a population of patients who did not meet instruction for use (IFU) criteria for EVAR, no single anatomic contraindication was a marker for worse outcomes with OAR. Patients who were candidates for both aortic repair approaches but elected to have open surgical repair due to patient/surgeon preference have very low 30-day mortality and morbidity, and superior long-term survival rates compared with those patients who had OAR due to anatomic and/or systemic contraindications to EVAR.

Comparison of contemporary and historical outcomes of elective and ruptured open abdominal aortic aneurysm repair

BACKGROUND

Recently, open abdominal aortic aneurysm (AAA) repair (OSR) has become less common and will often be reserved for patients with more complex aortic anatomy. Despite improvements in patient management, the reduced surgical volume has raised concerns for potentially worsened outcomes in the contemporary era (2014-2019) compared with an earlier era in which OSR was more widely practiced (2005-2010). In the present study, we compared the 30-day outcomes of open AAA repair between these two eras.

METHODS

The American College of Surgeons National Quality Improvement Program general database was queried for open AAA repair using the Current Procedural Terminology and International Classification of Diseases, 9th and 10th, codes. The cases were stratified into two groups by operation year: 2005 to 2010 (early) and 2014 to 2019 (contemporary). In each era, the cases were further divided into elective and ruptured groups. The 30-day outcomes, including mortality, major morbidity, postoperative sepsis, and unplanned reoperation, were compared between the contemporary and early eras in the elective and ruptured groups. Preoperative variables with a P value <.25 were adjusted for in the multivariate analysis.

RESULTS

In the contemporary and early eras, 3749 and 3798 patients had undergone elective OSR and 1148 and 907 had undergone ruptured OSR, respectively. These samples were of similar sizes owing to the National Quality Improvement Program sampling process and our relatively strict inclusion criteria. In the contemporary era, fewer patients were elderly and fewer were smokers or had hypertension or dyspnea in the elective and rupture cohorts. More patients had had American Society of Anesthesiologists class >3 in the elective contemporary era (39% vs 24%; P < .0001). The contemporary elective repair group demonstrated increased 30-day mortality (3.7% vs 3.2%; adjusted odds ratio [aOR], 1.36; P = .006), major adverse cardiac events (5.7% vs 3.4%; aOR, 1.87; P < .0001), and bleeding requiring transfusion (58.5% vs 13.7%; aOR, 8.96; P < .0001). The incidence of pulmonary complications (12.1% vs 15.2%; aOR, 0.80; P = .02) and sepsis (3.7% vs 8.4%; aOR, 0.47; P < .0001) had decreased in the contemporary era, with a similar rate of unplanned reoperations (8.4% vs 7.7%; aOR, 1.16; P = .09). The incidence of renal complications in the contemporary era had increased, with a statistically significant difference. However, the absolute increase of <0.5% was likely not clinically relevant (5.5% vs 5.1%; aOR, 1.23; P = .049). In the ruptured cohort, contemporary repair was associated with increased 30-day mortality (41.4% vs 40%; aOR, 1.53; P < .0001), major adverse cardiac events (25.8% vs 12.8%; aOR, 2.49; P < .0001), and bleeding requiring transfusion (88.2% vs 27%; aOR, 23.03; P < .0001). The incidence of pulmonary complications (36.9% vs 48.1%; aOR, 0.67; P < .0001), sepsis (14.6% vs 23%; aOR, 0.75; P = .03), and unplanned reoperations (18.1% vs 22.7%; aOR, 0.74; P = .008) had decreased in the contemporary OSR group. No differences were detected in the incidence of renal complications.

CONCLUSIONS

The 30-day mortality has worsened after open AAA repair in the elective and rupture settings despite the improvements in perioperative management over the years. These complications likely stem from increased bleeding events and major cardiac events, which were increased in the contemporary era.

Effects of hospital preference for endovascular repair on postoperative mortality after elective abdominal aortic aneurysm repair: analysis of the Dutch Surgical Aneurysm Audit

BACKGROUND

Increased use of endovascular aneurysm repair (EVAR) and reduced open surgical repair (OSR), has decreased postoperative mortality after elective repair of abdominal aortic aneurysms (AAAs). The choice between EVAR or OSR depends on aneurysm anatomy, and the experience and preference of the vascular surgeon, and therefore differs between hospitals. The aim of this study was to investigate the current mortality risk difference (RD) between EVAR and OSR, and the effect of hospital preference for EVAR on overall mortality.

METHODS

Primary elective infrarenal or juxtarenal aneurysm repairs registered in the Dutch Surgical Aneurysm Audit (2013-2017) were analysed. First, mortality in hospitals with a higher preference for EVAR (high-EVAR group) was compared with that in hospitals with a lower EVAR preference (low-EVAR group), divided by the median percentage of EVAR. Second, the mortality RD between EVAR and OSR was determined by unadjusted and adjusted linear regression and propensity-score (PS) analysis and then by instrumental-variable (IV) analysis, adjusting for unobserved confounders; percentage EVAR by hospital was used as the IV.

RESULTS

A total of 11 997 patients were included. The median hospital rate of EVAR was 76.6 per cent. The overall mortality RD between high- and low-EVAR hospitals was 0.1 (95 per cent -0.5 to 0.4) per cent. The OSR mortality rate was significantly higher among high-EVAR hospitals than low-EVAR hospitals: 7.3 versus 4.0 per cent (RD 3.3 (1.4 to 5.3) per cent). The EVAR mortality rate was also higher in high-EVAR hospitals: 0.9 versus 0.7 per cent (RD 0.2 (-0.0 to 0.6) per cent). The RD following unadjusted, adjusted, and PS analysis was 4.2 (3.7 to 4.8), 4.4 (3.8 to 5.0), and 4.7 (4.1 to 5.3) per cent in favour of EVAR over OSR. However, the RD after IV analysis was not significant: 1.3 (-0.9 to 3.6) per cent.

CONCLUSION

Even though EVAR has a lower mortality rate than OSR, the overall effect is offset by the high mortality rate after OSR in hospitals with a strong focus on EVAR.

Thirty-day outcomes of open abdominal aortic aneurysm repair by proximal clamp level in patients with normal and impaired renal function

OBJECTIVE

Open surgical repair (OSR) of abdominal aortic aneurysms (AAAs) has often been reserved in contemporary practice for complex aneurysms requiring a suprarenal or supraceliac proximal clamp level. The present study investigated the associated 30-day outcomes of different proximal clamp levels in OSR of complex infrarenal/juxtarenal AAA in patients with normal renal function and those with chronic renal insufficiency (CRI).

METHODS

All patients undergoing elective OSR of infrarenal and juxtarenal AAA were identified in the American College of Surgeons National Surgical Quality Improvement Program-targeted AAA database from 2012 to 2018. The patients were stratified into two cohorts (normal renal function [estimated glomerular filtration rate, ≥60 mL/min] and CRI [estimated glomerular filtration rate, <60 mL/min and no dialysis]) before further substratification into groups by the proximal clamp level (infrarenal, inter-renal, suprarenal, and supraceliac). The 30-day outcomes, including mortality, renal and pulmonary complications, and major adverse cardiovascular event rates, were compared within each renal function cohort between proximal clamp level groups using the infrarenal clamp group as the reference. Supraceliac clamping was also compared with suprarenal clamping.

RESULTS

A total of 1284 patients with normal renal function and 524 with CRI were included in the present study. The proximal clamp levels for the 1808 patients were infrarenal for 1080 (59.7%), inter-renal for 337 (18.6%), suprarenal for 279 (15.4%), and supraceliac for 112 (6.2%). In the normal renal function cohort, no difference was found in 30-day mortality with any clamp level. Increased 30-day acute renal failure was only observed in the supraceliac vs infrarenal clamp level comparison (5.9% vs 1.5%; adjusted odds ratio [aOR], 3.97; 95% confidence interval [CI], 1.04-5.18; P = .044). In the CRI cohort, supraceliac clamping was associated with an increased rate of renal composite complications (22.7% vs 5.6%; aOR, 8.81; 95% CI, 3.17-24.46; P < .001) and ischemic colitis (13.6% vs 3.0%; aOR, 4.78; 95% CI, 1.38-16.62; P = .014) compared with infrarenal clamping and greater 30-day mortality (13.6% vs 2.4%; aOR, 6.00; 95% CI, 1.14-31.55; P = .034) and renal composite complications (22.7% vs 10.8%; aOR, 2.87; 95% CI, 1.02-8.13; P = .047) compared with suprarenal clamping. Suprarenal clamping was associated with greater renal dysfunction (10.8% vs 5.6%; aOR, 2.77; 95% CI, 1.08-7.13; P = .035) compared with infrarenal clamping, with no differences in mortality. No differences were found in 30-day mortality or morbidity for inter-renal clamping compared with infrarenal clamping in either cohort. No differences were found in major adverse cardiovascular events with higher clamp levels in either cohort.

CONCLUSIONS

In elective OSR of infrarenal and juxtarenal AAAs for patients with CRI, this study found a heightened mortality risk with supraceliac clamping and increased renal morbidity with suprarenal clamping, though these effects were not present for patients with normal renal function. Every effort should be made to keep the proximal clamp level as low as possible, especially in patients with CRI.

Cross-clamp location affects short-term survival in patients undergoing open abdominal aortic aneurysm repair

INTRODUCTION

Open abdominal aortic aneurysm (oAAA) repair in the era of advanced endovascular aortic techniques is used in challenging anatomy. The impact of the location of the proximal aortic cross-clamp (suprarenal [SR] vs infrarenal [IR]) on outcomes remains to be determined. The aim of this study was to analyze the effect of proximal aortic cross-clamp location on short-term and overall survival after oAAA repair in a contemporary series.

METHODS

A retrospective cohort study was performed comparing the outcomes of patients undergoing oAAA repair with SR and IR aortic cross-clamping using the Vascular Quality Initiative registry from January 2003 to September 2018. Our primary end point was short-term mortality.

RESULTS

There were 7601 patients who underwent oAAA repair. Their mean age was 69.3 ± 8.5 years and 5555 patients (73.1%) were male. The aortic cross-clamp location was IR in 4044 patients (53.2%). The SR group had increased maximum AAA diameter (58 mm vs 56 mm; P < .0001), hypertension (85.5% vs 82.0%; P < .0001), preoperative creatinine (1.11 vs 1.08; P = .001), and were more likely to be in American Society of Anesthesiologists class IV (37.4% vs 30.6%; P < .0001). Postoperative renal failure occurred significantly more often in the SR group (24.4 vs 11.4%; P < .0001). Short-term mortality was 2.7% in the IR group and 4.7% in the SR group (P < .0001). Kaplan-Meier survival estimates were 93.7% and 83.8% in the IR group and 90.9% and 81.2% in the SR group at 1 and 5 years, respectively (P = .007). Multivariable analysis demonstrated that SR cross-clamping was significantly associated with short-term mortality (hazard ratio, 1.38; 95% confidence interval, 1.07-1.78; P = .01); however, it did not affect overall survival (hazard ratio, 1.13; 95% confidence interval, 1.00-1.28; P = .06).

CONCLUSIONS

A SR cross-clamp location is associated with an increased short-term mortality in patients undergoing oAAA repair. Overall survival is not affected by a SR cross-clamp location.

Has Anatomic Complexity of Abdominal Aortic Aneurysms Undergoing Open Surgical Repair Changed after the Introduction of Endovascular Treatment? Systematic Review and Meta-analysis of Comparative Studies

BACKGROUND

At a time when endovascular aneurysm repair (EVAR) is increasingly used to treat abdominal aortic aneurysms (AAAs), lesions undergoing open surgical repair (OSR) may present significant differences compared with those treated before wide EVAR availability. We aim to record discrepancies in AAAs surgically treated before and after the introduction of EVAR.

METHODS

We conducted a systematic review of the literature and meta-analysis of comparative studies. The MEDLINE, CENTRAL, and OpenGrey databases were searched up to October 2017. Outcome measures were anatomic complexity, procedural details, and postoperative outcomes. The random-effects model was used to calculate combined overall effect sizes. Data are presented as odds ratio (OR) or mean difference (MD) with 95% confidence intervals (CIs).

RESULTS

Five observational studies were included. These involved 1,091 patients treated in the pre-EVAR era and 802 in the post-EVAR era. In general, patients undergoing OSR during the first period presented more comorbidities. Increased anatomic complexity was found among patients in the second group as demonstrated by the increased rate of suprarenal clamping (10.5% vs. 22.3%; OR, 0.34; 95% CI, 0.24-0.50), left renal vein division (10.3% vs. 18.8%; OR, 0.46; 95% CI, 0.25-0.88), iliac aneurysm (28.3% vs. 44.9%; OR, 0.48; 95% CI, 0.37-0.64), and iliac occlusive disease (13.1% vs. 20.2%; OR, 0.59; 95% CI, 0.39-0.88). Intraoperative use of blood products was greater during the latter period, but this difference did not reach statistical significance. Procedural duration was slightly increased in the same group. Morbidity and mortality were similar among the groups.

CONCLUSIONS

After the wide availability of endoluminal grafting, more compromised patients tend to be managed with EVAR, leaving a fitter patient population to undergo OSR. At the same time, anatomic complexity of AAAs undergoing open surgery has considerably increased, requiring advanced proximal aortic surgical expertise to deal with these complex aortic pathologies Overall, morbidity and mortality remained unchanged, possibly due to the counterbalancing effects of these factors.

The perioperative effect of concomitant procedures during open infrarenal abdominal aortic aneurysm repair

BACKGROUND

Open repair of abdominal aortic aneurysms (AAAs) is occasionally performed in conjunction with additional procedures; however, how these concomitant procedures affect outcome is unclear. This study determined the frequency of additional procedures during elective open AAA repair and the effect on perioperative outcomes.

METHODS

All elective infrarenal open AAA repairs between January 2003 and November 2014 in the Vascular Study Group of New England (VSGNE) were identified. Patients were grouped by concomitant procedures, which included no concomitant procedure, renal artery bypass, lower extremity bypass, other abdominal procedure, or thromboembolectomy. Analyses were performed using multivariable logistic regression.

RESULTS

Of 1314 patients who underwent elective AAA repair, 153 (11.6%) had a concomitant procedure, including renal bypass in 27 (2.1%), lower extremity bypass in 28 (2.1%), other abdominal procedures in 64 (4.9%), and thromboembolectomy in 48 (3.7%). Independent risk factors for 30-day mortality were renal bypass (odds ratio [OR], 7.2; 95% confidence interval [CI], 1.9-27.7), other abdominal procedures (OR, 4.8; 95% CI, 1.6-14.1), and thromboembolectomy (OR, 8.8; 95% CI, 3.1-24.9). Deterioration of renal function was predicted by renal bypass (OR, 5.1; 95% CI, 2.1-12.4) and thromboembolectomy (OR, 3.7; 95% CI, 1.8-7.6). Lower extremity bypass and thromboembolectomy were predictive of postoperative leg ischemia (OR, 8.9; 95% CI, 2.7-29.0; OR, 11.2; 95% CI, 4.4-28.8, respectively), and thromboembolectomy was also predictive of postoperative bowel ischemia (OR, 4.4; 95% CI, 1.6-12.0).

CONCLUSIONS

Performing additional procedures during infrarenal open AAA repair is associated with increased morbidity and mortality in the postoperative period. Careful deliberation of the operative risks and the necessity of the additional interventions are therefore advised during operative planning. This study also highlights the importance of avoiding perioperative thromboembolic events.

A cross-sectional retrospective analysis of the regionalization of complex surgery

Background

The Veterans Health Administration (VHA) system has assigned a surgical complexity level to each of its medical centers by specifying requirements to perform standard, intermediate or complex surgical procedures. No study to similarly describe the patterns of relative surgical complexity among a population of United States (U.S) civilian hospitals has been completed.

Methods

Design: single year, retrospective, cross-sectional.

Setting/Participants: the study used Florida Inpatient Discharge Data from short-term acute hospitals for calendar year 2009. Two hundred hospitals with 2,542,920 discharges were organized into four quartiles (Q 1, 2, 3, 4) based on the number of complex procedures per hospital. The VHA surgical complexity matrix was applied to assign relative complexity to each procedure. The Clinical Classification Software (CCS) system assigned complex procedures to clinically meaningful groups. For outcome comparisons, propensity score matching methods adjusted for the surgical procedure, age, gender, race, comorbidities, mechanical ventilator use and type of admission.

Main Outcome Measures: in-hospital mortality and length-of-stay (LOS).

Results

Only 5.2% of all inpatient discharges involve a complex procedure. The highest volume complex procedure hospitals (Q4) have 49.8% of all discharges but 70.1% of all complex procedures. In the 133,436 discharges with a primary complex procedure, 374 separate specific procedures are identified, only about one third of which are performed in the lowest volume complex procedure (Q1) hospitals. Complex operations of the digestive, respiratory, integumentary and musculoskeletal systems are the least concentrated and proportionately more likely to occur in the lower volume hospitals. Operations of the cardiovascular system and certain technology dependent miscellaneous diagnostic and therapeutic procedures are the most concentrated in high volume hospitals. Organ transplants are only done in Q4 hospitals. There were no significant differences in in-hospital mortality rates and the longest lengths of stay were found in higher volume hospitals.

Conclusions

Complex surgery in Florida is effectively regionalized so that small volume hospitals operating within the range of complex procedures appropriate to their capabilities provide no increased risk of post surgical mortality.

Renal and abdominal visceral complications after open aortic surgery requiring supra-renal aortic cross clamping

PURPOSE

The aim of this study was to assess renal or abdominal visceral complications after open aortic surgery (OAS) requiring supra-renal aortic cross clamping (SRACC).

METHODS

We retrospectively reviewed the medical records of 66 patients who underwent SRACC. Among them, 17 followed supra-celiac aortic cross clamping (SCACC) procedure, 42 supra-renal, and 7 inter-renal aorta. Postoperative renal, hepatic or pancreatic complications were investigated by reviewing levels of serum creatinine and hepatic and pancreatic enzymes. Preoperative clinical and operative variables were analyzed to determine risk factors for postoperative renal insufficiency (PORI).

RESULTS

Indications for SRACC were 25 juxta-renal aortic occlusion and 41 aortic aneurysms (24 juxta-renal, 12 supra-renal and 5 type IV thoraco-abdominal). The mean duration of renal ischemic time (RIT) was 30.1 ± 22.2 minutes (range, 3 to 120 minutes). PORI developed in 21% of patients, including four patients requiring hemodialysis (HD). However, chronic HD was required for only one patient (1.5%) who had preoperative renal insufficiency. RIT ≥ 25 minutes and SCACC were significant risk factors for PORI development by univariate analysis, but not by multivariate analysis. Serum pancreatic and hepatic enzyme was elevated in 41% and 53% of the 17 patients who underwent SCACC, respectively.

CONCLUSION

Though postoperative renal or abdominal visceral complications developed often after SRACC, we found that most of those complications resolved spontaneously unless there was preexisting renal disease or the aortic clamping time was exceptionally long.