As open abdominal aortic aneurysm (AAA) repair (OAR) rates decline in the endovascular era, the endorsement of minimum volume thresholds for OAR is increasingly controversial, as this may affect ...credentialing and training. The purpose of this analysis was to identify an optimal centre volume threshold that is associated with the most significant mortality reduction after OAR, and to determine how this reflects contemporary practice.
This was an observational study of OARs performed in 11 countries (2010 – 2016) within the International Consortium of Vascular Registry database (n = 178 302). The primary endpoint was post-operative in hospital mortality. Two different methodologies (area under the receiving operating curve optimisation and Markov chain Monte Carlo procedure) were used to determine the optimal centre volume threshold associated with the most significant mortality improvement.
In total, 154 912 (86.9%) intact and 23 390 (13.1%) ruptured AAAs were analysed. The majority (63.1%; n = 112 557) underwent endovascular repair (EVAR) (OAR 36.9%; n = 65 745). A significant inverse relationship between increasing centre volume and lower peri-operative mortality after intact and ruptured OAR was evident (p < .001) but not with EVAR. An annual centre volume of between 13 and 16 procedures per year was associated with the most significant mortality reduction after intact OAR (adjusted predicted mortality < 13 procedures/year 4.6% 95% confidence interval 4.0% – 5.2% vs. ≥ 13 procedures/year 3.1% 95% CI 2.8% – 3.5%). With the increasing adoption of EVAR, the mean number of OARs per centre (intact + ruptured) decreased significantly (2010 – 2013 = 35.7; 2014 – 2016 = 29.8; p < .001). Only 23% of centres (n = 240/1 065) met the ≥ 13 procedures/year volume threshold, with significant variation between nations (Germany 11%; Denmark 100%).
An annual centre volume of 13 – 16 OARs per year is the optimal threshold associated with the greatest mortality risk reduction after treatment of intact AAA. However, in the current endovascular era, achieving this threshold requires significant re-organisation of OAR practice delivery in many countries, and would affect provision of non-elective aortic services. Low volume centres continuing to offer OAR should aim to achieve mortality results equivalent to the high volume institution benchmark, using validated data from quality registries to track outcomes.
Spinal cord ischemia (SCI) is a dreaded complication of thoracic endovascular aortic repair (TEVAR). There are limited national data describing the incidence and influence of in-hospital SCI recovery ...on survival. Moreover, no robust preoperative SCI risk assessment models currently exist. The purpose of this analysis was to analyze the Vascular Quality Initiative to determine the national incidence, survival association, and preoperative predictors of SCI after TEVAR.
All Vascular Quality Initiative TEVAR procedures (June 2014-June 2019) were reviewed. The primary end point was development of in-hospital SCI, defined as any new neurologic deficit or paralysis not attributable to intracranial disease. Secondary end points were disease-specific SCI rates and long-term out-of-hospital survival. Functional outcomes (transient vs permanent SCI) were independently determined by treating physicians. Kaplan-Meier analysis and Cox proportional hazards methodology were used to assess the association of SCI with survival. A logistic regression model of candidate preoperative SCI predictors was created, and bootstrapped backward elimination (retaining predictors with ≥50% selection frequency) was used for model reduction. Model fit and performance statistics were validated by adjustment for Efron's optimism.
The overall rate of SCI was 3.7% (n = 422/11,473; transient, 1.6% n = 179; permanent, 2.1% n = 243). Patients who developed any SCI had significantly lower Kaplan-Meier survival estimate compared with those without SCI (1-year survival: SCI, 65%; no SCI, 87%; P < .0001), and patients with permanent SCI had notably worse survival than patients with transient SCI (1-year survival: permanent SCI, 54%; transient SCI, 80%; P < .0001). Disease-specific incidence of any SCI was as follows: aneurysm, 3.4%; dissection, 5.3%; aneurysm from dissection, 4.1%; trauma, 1.1%; penetrating ulceration, 2.4%; intramural hematoma, 5.7%; penetrating ulceration and intramural hematoma, 4.3%; and aortic thrombus, 4.8%. Several factors were selected on multivariable analysis as the most robust preoperative predictors of any SCI, including distal landing zone 5 to zone 10, nonelective case, creatinine concentration >1.38 mg/dL, smoking history, American Society of Anesthesiologists class, adjunctive procedure, nonwhite race, and preoperative hypertension (area under the curve = 0.72; Nagelkerke R2 = 0.06).
SCI is a devastating complication after TEVAR that is associated with worse overall survival, particularly when no functional recovery occurs by hospital discharge. Disease-specific, real-world benchmarks for SCI rates are provided that may inform quality initiatives focused on reducing this complication. Importantly, this analysis is the first description of a preoperative prediction model derived from national data for determining SCI risk after TEVAR. These predictors should be used to identify high-risk patients to balance the risk of SCI and its associated increased short-term mortality with the risk of the underlying disease. Furthermore, all available adjunctive measures should be implemented in these high-risk patients to reduce risk of SCI.
AbstractObjectiveFailure to rescue (FTR), a patient safety indicator (PSI) defined, codified, and adjudicated by the Agency for Healthcare Research and Quality, is classified as a preventable ...inpatient death following major complications. FTR has been reported to be a significant driver of postoperative mortality after open abdominal aortic aneurysm (OAAA) repair. The association between hospital volume (HV) and mortality is well known; however, the mechanisms responsible for these improved outcomes and relative contribution to observed interhospital variation is poorly understood. Similarly, HV influence on specific complications predictive of FTR is unknown; therefore, we sought to determine how HV influences risk and contributes to interhospital variation in PSI events leading to FTR and/or in-hospital mortality after OAAA repair. MethodsThe Vizient database (174 academic/nonacademic hospitals) was queried for all OAAA repairs (elective, n = 2827; nonelective, n = 1622) completed from 2012 to 2014. The primary endpoint was combined FTR and/or in-hospital 30-day mortality. Risk-adjusted rates of complications, Agency for Healthcare Research and Quality-designated PSIs, and FTR were determined. Additional modeling identified PSIs associated with FTR, whereas HV effects on PSIs and FTR were evaluated using mixed-effect models accounting for interhospital variation. Proportion of variation attributable to HV was estimated by contrasting hospital random effect variances in the presence/absence of volume effects. ResultsThe combined overall FTR/in-hospital 30-day mortality rate was 9.3% (n = 414). For elective and nonelective cases, the overall FTR and 30-day mortality rates were: FTR, 1.6%, 4.9%; and 30-day in-hospital mortality, 3.4%, 17.5%, respectively. HV significantly influenced FTR/30-day in-hospital mortality ( P < .0001). FTR/30-day mortality odds for hospitals with 3-year volumes of 50, 100, 150, and 200 cases were 1.4, 2.0, 2.7, and 3.0 times lower, respectively, than hospitals performing ≤25 cases/3 years. The proportion of interhospital variation attributed to HV was greatest for FTR/30-day mortality (62%). Procedural volume accounted for 41% and 38% of interhospital variation in postoperative bleeding and myocardial infarction, respectively. Preoperative predictors of FTR included coagulopathy, arrhythmia (nonelective cases); congestive heart failure, obesity (elective cases); and age, neurological disease, hypertension, and valvular disease (all cases). ConclusionsOAAA FTR/30-day in-hospital mortality strongly correlated with annual case volume with higher volume centers having the lowest risk. Notably, HV accounted for a significant proportion of the observed variation in FTR and specific complications providing direct evidence for how the volume-outcome relationship may influence perioperative mortality. These findings can inform stakeholders to strategically enable them to implement processes of care directed at the most vulnerable patients that are designed to reduce the likelihood of preventable adverse events and death after OAAA repair. Furthermore, these results underscore the need to regionalize OAAA repair and potentially other complex operations, to HV centers because of their improved ability to rescue patients experiencing complications associated with postoperative mortality.
Thoracic endovascular aortic repair (TEVAR) has become a mainstay of therapy for acute and chronic type B aortic dissection (TBAD). Dynamic aortic morphologic changes, untreated dissected aorta, and ...persistent false lumen perfusion have significant consequences for reintervention after TEVAR for TBAD. However, few reports contrast differences in secondary aortic intervention (SAI) after TEVAR for TBAD or describe their influence on mortality. This analysis examined incidence, timing, and types of SAI after TEVAR for acute and chronic TBAD and determined their impact on survival.
All TEVAR procedures for acute and chronic TBAD (2005-2016) were retrospectively reviewed. Patients with staged (<30 days) or concomitant ascending aortic arch repair or replacement were excluded. Acuity was defined by symptom onset (0-30 days, acute; >30 days, chronic). SAI procedures were grouped into open (intended treatment zone or remote aortic site), major endovascular (TEVAR extension or endograft implanted at noncontiguous site), and minor endovascular (side branch or false lumen embolization) categories. Kaplan-Meier methodology was used to estimate freedom from SAI and survival. Cox proportional hazards were used to identify SAI predictors.
TEVAR for TBAD was performed in 258 patients (acute, 49% n = 128; chronic, 51% n = 130). Mean follow-up was 17 ± 22 months with an overall SAI rate of 27% (n = 70; acute, 22% 28; chronic, 32% 42; odds ratio, 1.7; 95% confidence interval, 0.9-2.9; P = .07. Median time to SAI was significantly less after acute than after chronic dissection (0.7 0-12 vs 7 0-91 months; P < .001); however, freedom from SAI was not different (1-year: acute, 67% ± 4%, vs chronic, 68% ± 5%; 3-year: acute, 65% ± 7%, vs chronic, 52% ± 8%; P = .7). Types of SAI were similar (acute vs chronic: open, 61% vs 55% P = .6; major endovascular, 36% vs 38% P = .8; minor endovascular, 21% vs 21% P = 1). The open conversion rate (either partial or total endograft explantation: acute, 10% 13/128; chronic, 15% 20/130; P = .2) and incidence of retrograde dissection (acute, 6% 7/128; chronic, 4% 5/130; P = .5) were similar. There was no difference in survival for SAI patients (5-year: acute + SAI, 55% ± 9%, vs acute without SAI, 67% ± 8% P = .3; 5-year: chronic + SAI, 72% ± 6%, vs chronic without SAI, 72% ± 7% P = .7). Factors associated with SAI included younger age, acute dissection with larger maximal aortic diameter at presentation, Marfan syndrome, and use of arch vessel adjunctive procedures with the index TEVAR. Indication for the index TEVAR (aneurysm, malperfusion, rupture, and pain or hypertension) or remote preoperative history of proximal arch procedure was not predictive of SAI.
SAI after TEVAR for TBAD is common. Acute TBAD has a higher proportion of early SAI; however, chronic TBAD appears to have ongoing risk of remediation after the first postoperative year. SAI types are similar between groups, and the occurrence of aorta-related reintervention does not affect survival. Patients' features and anatomy predict need for SAI. These data should be taken into consideration for selection of patients, device design, and surveillance strategies after TEVAR for TBAD.
Objectives Successful surgical management of thoracic aortic aneurysms (TAA) and thoracoabdominal aortic aneurysms (TAAA) has historically relied upon open surgical repair (OSR). More recently, the ...advent and application of thoracic endovascular stent graft aneurysm repair (TEVAR) permutations have become increasingly performed in contemporary practice. To better determine the effect of TEVAR techniques on OSR, we examined national and regional trends in treatment use. Methods All Medicare patients from 1998 through 2007 undergoing isolated TAA and TAAA repair were analyzed using a clinically validated algorithm using diagnostic International Classification of Disease 9th revision (ICD-9; 441.1, 441.2, 441.6, 441.7, 441.9) codes and procedural (ICD-9 OSR: 38.35, 38.45 and TEVAR: 39.73, 39.79) codes. Differential rates of OSR and TEVAR were compared across census tract regions during the study interval. Results Total complex aortic repairs increased by 60%, from 10.8 to 17.8/100,000, between 1998 and 2007 ( P < .001). A dramatic increase occurred in TEVAR (not performed in 1998, 5.8/100,000 in 2007) during the study period, but OSR rates remained stable during the same interval (10.7 to 12.0/100,000 in 2007, P = NS). There was substantial regional variation for both OSR and TEVAR. This regional variation was greater in OSR (range, 8.8-16.7/100,000) than in TEVAR (range, 4.5-6.9/100,000). Conclusions Degenerative TAA and TAAA aneurysms are being repaired in the United States at an increasing rate. This reflects the rapid acceptance of TEVAR, which apparently supplements rather than supplants OSR. There appears to be greater regional variation in OSR compared with TEVAR. These data may have significant implications for those interested in the effect of new technologies on health care and cost containment.
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.
Ruptured abdominal aortic aneurysms (rAAA) remain one of the most clinically challenging and technically complex emergencies in contemporary vascular surgery practice. Over the past 30 years, a ...variety of changes surrounding the treatment of rAAA have evolved including improvements in diagnosis, development of coordinated referral networks to transfer patients more efficiently to higher volume centers, deliberate de-escalation of pre-hospital resuscitation, modification of patient and procedure selection, implementation of clinical pathways, as well as enhanced awareness of certain high-impact postoperative complications. Despite these advances, current postoperative outcomes remain sobering since morbidity and mortality rates ranging from 25%-50% persist among modern published series. Some of the most impactful variation in rAAA management has been fostered by the rapid proliferation of endovascular repair (EVAR) along with service alignment at selected centers to improve timely revascularization. Indeed, clinical care pathways and emergency response networks are now increasingly utilized which has led to improved outcomes contemporaneously. Moreover, evolution in pre- and post-operative physiologic resuscitation has also contributed to observed improvements in rAAA outcomes. Due to different developments in care provision over time, the purpose of this review is to describe the modern management of rAAA, while providing historical perspectives on patient, procedure and systems-based practice elements that have evolved care delivery paradigms in this complex group of patients.
PDF
