Open Repair of AAA in a High Volume Center

Benchmarking a Center of Excellence in Vascular Surgery: Using Acute Physiology and Chronic Health Evaluation II to Validate Outcomes in a Tertiary Care Institute

OBJECTIVE

The Society of Vascular Surgery (SVS) has made it a top priority to implement verification of vascular "centers of excellence". Our institutional aortic network was established in 2008 in order to standardize care of patients with suspected acute aortic pathology. The implementation and success of this program has been previously reported. We sought to use our experience as a benchmark for which to develop prognostic modeling to quantify clinical status upon admission and help predict outcomes. Our objective was to validate the Acute Physiology and Chronic Health Evaluation (APACHE) II scoring system using a cohort of aortic emergencies transferred by an organized transfer network.

METHOD

This was a retrospective, single institution review of patients transferred through an institutional aortic network for acute aortic pathology from 2017-2018. Demographics, comorbidities, aortic diagnosis, APACHE II score, as well as 30-day mortality were recorded. Associations with 30-day mortality were evaluated using two-sample t-tests, ANOVA models, Pearson chi-square tests and Fisher exact tests. Receiver operating characteristic (ROC) curves were fit overall and by pathology to predict 30-day mortality by Apache II total score.

RESULTS

There were 395 consecutive transfers were identified. The mean age was 64.7 years. Diagnoses included Type A Dissection (n = 134), Type B (n = 81), Aortic Aneurysm (n = 122), and PAU/IMH (n = 27). Mean APACHE II score on arrival was 12. Overall there were 53 deaths (13.4%) in the cohort. Patients that died had significantly higher Apache II total scores (11.3 vs 16.5, P < .001). The area under the receiver operator characteristic (ROC) curve (AUC) was .66 for the full cohort, indicating a poor clinical prediction test.

CONCLUSION

APACHE II score is a poor predictor of 30-day mortality in a large transfer network accepting all aortic emergencies. The authors believe further refining a prognostic model for diverse population will not only help in predicting outcomes but to objectively quantify illness severity in order to have a basis for comparison among institutions and verification of "centers of excellence".

Endovascular Abdominal Aortic Aneurysm Repair with Ovation Alto stent graft: Protocol of the ALTAIR study (ALTo endogrAft Italian Registry). (Preprint)

Background

Since 2010, the Ovation Abdominal Stent Graft System has offered an innovative sealing option for abdominal aortic aneurysm (AAA) by including a sealing ring filled with polymer 13 mm from the renal arteries. In August 2020, the redesigned Ovation Alto, with a sealing ring 6 mm closer to the top of the fabric, received CE Mark approval.

Objective

This registry study aims to evaluate intraoperative, perioperative, and postoperative results in patients treated by the Alto stent graft (Endologix Inc.) for elective AAA repair in a multicentric consecutive experience.

Methods

All consecutive eligible patients submitted to endovascular aneurysm repair (EVAR) by Alto Endovascular AAA implantation will be included in this analysis. Patients will be submitted to EVAR procedures based on their own preferences, anatomical features, and operators experience. An estimated number of 300 patients submitted to EVAR with Alto stent graft should be enrolled. It is estimated that the inclusion period will be 24 months. The follow-up period is set to be 5 years. Full data sets and cross-sectional images of contrast-enhanced computed tomography scan performed before EVAR, at the first postoperative month, at 24 or 36 months, and at 5-year follow-up interval will be reported in the central database for a centralized core laboratory review of morphological changes. The primary endpoint of the study is to evaluate the technical and clinical success of EVAR with the Alto stent graft in short- (90-day), mid- (1-year), and long-term (5-year) follow-up periods. The following secondary endpoints will be also addressed: operative time; intraoperative radiation exposure; contrast medium usage; AAA sac shrinkage at 12-month and 5-year follow-up; any potential role of patients’ baseline characteristics, valuated on preoperative computed tomography angiographic study, and of device configuration (number of component) in the primary endpoint.

Results

The study is currently in the recruitment phase and the final patient is expected to be treated by the end of 2023 and then followed up for 5 years. A total of 300 patients will be recruited. Analyses will focus on primary and secondary endpoints. Updated results will be shared at 1- and 3-5-year follow-ups.

Conclusions

The results from this registry study could validate the safety and effectiveness of the new design of the Ovation Alto Stent Graft. The technical modifications to the endograft could allow for accommodation of a more comprehensive range of anatomies on-label.

Trial Registration

ClinicalTrials.gov NCT05234892; https://clinicaltrials.gov/ct2/show/NCT05234892

International Registered Report Identifier (IRRID)

PRR1-10.2196/36995

Open surgical conversion and management of patients with ruptured abdominal aortic aneurysm after previous endovascular aneurysm repair

Introduction/Objective. The objective was to present the results and technical considerations from high-volume center when performing late open surgical conversion (LOSC) after endovascular aneurysm repair (EVAR) in ruptured abdominal aortic aneurysm (RAAA) patients. Methods. This was a single center retrospective study. LOSC was performed whenever eventual endovascular reintervention failed, was not feasible due to hostile anatomy and unavailability of specific endograft materials, or when patient was hemodynamically unstable necessitating emergent surgery. Results. All previously implanted EVARs had bimodular configuration with suprarenal fixation. Total endograft explantation was performed in 40% of patients. Hospital mortality was 20%. Both patients who died had total endograft explantation with supraceliac clamp lasting more than 30 minutes. 30-day mortality was 30%, with one more patient who died from pulmonary embolism after hospital discharge and two hospital deaths were due to myocardial infarction. Conclusion. LOSC due to RAAA after previous EVAR carries greater mortality for the patient, suggesting multifactorial impacts on the outcome. The appropriate choice of surgical method and technical success are of ultimate importance, with total graft explantation having negative impact on patient?s survival.

Intraoperative hypotension and complications after vascular surgery: A scoping review

BACKGROUND

Intraoperative hypotension during major surgery is associated with adverse health outcomes. This phenomenon represents a potentially important therapeutic target for vascular surgery patients, who may be uniquely vulnerable to intraoperative hypotension. This review summarizes current evidence regarding the impact of intraoperative hypotension on postoperative complications in patients undergoing vascular surgery, focusing on potentially modifiable procedure- and patient-specific risk factors.

METHODS

A scoping review of the literature from Embase, MEDLINE, and PubMed databases was conducted from inception to December 2019 to identify articles related to the effects of intraoperative hypotension on patients undergoing vascular surgery.

RESULTS

Ninety-two studies met screening criteria; 9 studies met quality and inclusion criteria. Among the 9 studies that defined intraoperative hypotension objectively, there were 9 different definitions. Accordingly, the reported incidence of intraoperative hypotension ranged from 8% to 88% (when defined as a fall in systolic blood pressure of >30 mm Hg or mean arterial pressure <65). The results demonstrated that intraoperative hypotension is an independent risk factor for longer hospital length of stay, myocardial injury, acute kidney injury, postoperative mechanical ventilation, and early mortality. Vascular surgery patients with comorbid conditions that confer increased vulnerability to hypoperfusion and ischemia appear to be susceptible to the adverse effects of intraoperative hypotension.

CONCLUSION

There is no validated, consensus definition of intraoperative hypotension or other hemodynamic parameters associated with increased risk for adverse outcomes. Despite these limitations, the weight of evidence suggests that intraoperative hypotension is common and associated with major postoperative complications in vascular surgery patients.

The Polymer-Based Technology in the Endovascular Treatment of Abdominal Aortic Aneurysms

An abdominal aortic aneurysm (AAA) is a dilatation of the abdominal aorta that progressively grows until it ruptures. Treatment is typically recommended when the diameter is more than 5 cm. The EVAR (Endovascular aneurysm repair) is a minimally invasive procedure that involves the placement of an expandable stent graft within the aorta to treat aortic disease without operating directly on the aorta. For years, stent grafts' essential design was based on metallic stent frames to support the fabric. More recently, a polymer-based technology has been proposed as an alternative method to seal AAA. This review underlines the two platforms that are based on a polymer technology: (1) the polymer-filled endobags, also known as Endovascular Aneurysm Sealing (EVAS) with Nellix stent graft; and (2) the O-ring EVAR polymer-based proximal neck sealing device, also known as an Ovation stent graft. Polymer characteristics for this particular aim, clinical applications, and durability results are hereby summarized and commented critically. The technique of inflating endobags filled with polymer to exclude the aneurysmal sac was not successful due to the lack of an adequate proximal fixation. The platform that used polymer to create a circumferential sealing of the aneurysmal neck has proven safe and effective.

Open Surgical Treatment of Acute Spontaneous Isolated Abdominal Aortic Dissection

BACKGROUND

The aim of this paper is to report our single-center experience in the open surgical treatment of acute spontaneous infrarenal isolated abdominal aortic dissection (siIAAD).

METHODS

This was a single center retrospective study. Between January 2015 and 2020 ten patients were treated due to acute siIAAD with open surgery. There were no patients treated for chronic siIAAD in this time period. Patients who had concomitant thoracic aortic involvement were excluded from this report.

RESULTS

The group consisted of 7 male and 3 female patients. History of hypertension was present in nine patients and six were active smokers. The abdominal/back pain was described in 9 patients, two had acute limb ischemia and three had aortic rupture. Median dissection length was 91 mm (65.7 - 106), median distance from the lowest renal artery was 30 mm (20.7 - 49.3) and median abdominal aortic diameter was 58.5 mm (32.5 - 66.2). Supracoeliac clamp was used in three cases with a ruptured aorta and suprarenal in two patients. The mean duration of proximal clamping time was 24.3 ± 7.49 min. One patient died of postoperative acute myocardial infarction, one suffered nonfatal pulmonary embolism and one had deep venous thrombosis. No aortic-related deaths and/or reinterventions occurred during the median follow-up of 32 months.

CONCLUSIONS

Acute siIAAD is a rare event which affects mostly male smokers with hypertension. Open surgery is a technically demanding procedure with acceptable complication rates and should be performed in specialized high-volume centers for the treatment of aortic disease. Future efforts to establish a multicenter registry to evaluate the prevalence of the disease and treatment options could provide better and more comprehensive guidelines for the treatment of acute siIAAAD.

Predictors of Operative Mortality of 928 Intact Aortoiliac Aneurysms

BACKGROUND

The aim of this study is to identify preoperative and intraoperative factors associated with in-hospital mortality of intact abdominal aortoiliac aneurysm repair.

METHODS

In this observational study, prospectively collected information included demographics, risk factors, comorbidities, aneurysm characteristics (including special aneurysm presentation, i.e., inflammatory, mycotic/infected, aortocaval fistula), investigations, and operative variables. Receiver operating characteristic) curve analysis of the Glasgow aneurysm score (GAS) and the Vascular Study Group of New England (VSGNE) score was performed in the subgroup of bland aneurysms undergoing isolated elective repair.

RESULTS

A total of 928 cases with intact aortoiliac aneurysms had an elective (n = 882) or urgent (n = 46) repair, associated with an in-hospital mortality of 1.7% and 8.7%, respectively (P = 0.01). Open repair (n = 514) was a predictor of higher mortality (3.3% vs. 0.5% for endovascular aneurysm repair [EVAR], n = 414, odds ratio [OR] 7.1, P = 0.003), and so was the pre-EVAR era (4.8% vs. 1.3% in the EVAR era, OR 4.0, P = 0.004). Other significant predictors included the presence of abdominal/back pain (7.5% vs. 1.3%, OR = 6.0, P = 0.001), preoperative angiography (7% vs. 1.6%, OR = 4.5, P = 0.01), special aneurysm presentation (10.9% vs. 1.5%, OR = 8.1, P < 0.001), concomitant major procedures (19% vs. 1.7%, OR = 14.0, P < 0.001), serious intraoperative complications (9.1% vs. 1.5%, OR = 6.6, P = 0.001), median number of transfused units of blood intraoperatively (2 and 0 for cases with and without mortality, respectively, P < 0.001), and procedure duration (270 and 150 min for cases with and without mortality, respectively, P < 0.001). Open repair (OR = 4.5, P = 0.05), special aneurysm presentation (OR = 6.58, P = 0.001), and concomitant major procedures (OR = 14.3, P < 0.001) were independent predictors of higher mortality. ROC curve analysis for the GAS (P = 0.87) and VSGNE score (P = 0.10) failed to demonstrate statistical significance in the subgroup of bland aneurysms undergoing isolated elective repair.

CONCLUSIONS

Our study has demonstrated independent risk factors for mortality, which should be considered when contemplating aortoiliac aneurysm repair. We failed to externally validate the GAS and VSGNE score.

Improved outcomes from endovascular aortic repair in younger patients: Towards improved risk stratification

Objectives

Abdominal aortic aneurysms are conventionally treated by open repair surgery. While endovascular aortic repair improves survival in high-risk patients, younger patients (40–65 years) potentially at lower risk with asymptomatic abdominal aortic aneurysms undergoing endovascular aortic repair usually have poorer post-operative outcomes and require longer term follow-up. In this study, clinical data on younger patients were analyzed to investigate whether endovascular aortic repair leads to poorer short- and long-term outcomes.

Methods

This was a systematic review and meta-analysis of articles comparing clinical outcomes in patients aged 40–65 years undergoing open repair or endovascular aortic repair and published between 2000 and 2017. In-hospital mortality, long-term mortality, and post-operative complication data were retrieved from eligible studies and clinical outcomes were compared. Twenty-one retrospective cohort analyses were included, accounting for 250,837 patients (149,051 endovascular aortic repair; 101,786 open repair). Risk ratios were pooled using the DerSimonian and Laird random effects model. All statistical analyses were performed in Review Manager 5.3.

Results

Younger patients with asymptomatic abdominal aortic aneurysms undergoing endovascular aortic repair had a significantly reduced 30-day mortality (odds ratio (OR) = 0.40, 95% confidence intervals (CI) 0.28–0.57; p  < 0.00001), long-term mortality (OR = 0.37, 95% CI 0.17–0.82; p  = 0.01), incidence of reintervention (OR = 0.47, 95% CI 0.34–0.66; p  < 0.0001), and incidence of renal failure (OR = 1.58, 95% CI 1.37–1.82; p  < 0.00001).

Conclusions

Endovascular aortic repair may improve short- and long-term survival and reduce post-operative complications in younger patients with asymptomatic abdominal aortic aneurysms.

Ischemic colitis following infrarenal abdominal aortic aneurysm treatment: Results from a tertiary medical center

OBJECTIVE

The aim of this study was to investigate the effects of ruptured aneurysm on morbidity and mortality in patients with ischemic colitis (IC) and resection following infrarenal abdominal aortic aneurysms (AAA) surgery.

METHODS

Between January 2012 and December 2016, patients who underwent resection for ischemic colitis in our clinic were retrospectively reviewed. Data on the ruptured condition of the aneurysm, the emergency or elective form of aneurysm surgery, treatment method for the aneurysm (EVAR-open) were obtained. The patients were compared and divided into two groups as those with ruptured aneurysm and those without.

RESULTS

A total of 275 infrarenal AAA cases were treated by the cardiovascular surgery clinic between January 2012 and December 2016. Fourteen patients (5%) developed ischemic colitis requiring resection. Four (1.8%) patients with EVAR and 10 (17.5%) patients with open surgery were operated because of IC. No statistically significant difference was observed between the two groups in terms of demographic data and surgical procedures. The intergroup comparison did not reveal any statistically significant difference among gastrointestinal (GIS) symptoms, the time period until surgery, the involved colon segment, and the surgical procedures performed. The mortality rate in ruptured AAA group was 83.3%, while it was 62.5% in the non-ruptured AAA group. In spite of the fact that the mortality rate was high in the ruptured group, it was not statistically significant (p=0.393).

CONCLUSION

IC is a complication of AAA surgery with a high mortality rate. Rupture in abdominal aortic aneurysm increasing mortality in IC patients. This complication with a high mortality rate following open AAA surgery should be noted by surgeons and we believe that the liberal utilization of laparotomy and early intervention in suspected cases will decrease mortality rates.

Intraoperative hypotension and the risk of postoperative adverse outcomes: a systematic review

BACKGROUND

Intraoperative hypotension is a common side effect of general anaesthesia and might lead to inadequate organ perfusion. It is unclear to what extent hypotension during noncardiac surgery is associated with unfavourable outcomes.

METHODS

We conducted a systematic search in PubMed, Embase, Web of Science, and CINAHL, and classified the quality of retrieved articles according to predefined adapted STROBE and CONSORT criteria. Reported strengths of associations from high-quality studies were classified into end-organ specific injury risks, such as acute kidney injury, myocardial injury, and stroke, and overall organ injury risks for various arterial blood pressure thresholds.

RESULTS

We present an overview of 42 articles on reported associations between various absolute and relative intraoperative hypotension definitions and their associations with postoperative adverse outcomes after noncardiac surgery. Elevated risks of end-organ injury were reported for prolonged exposure (≥10 min) to mean arterial pressures <80 mm Hg and for shorter durations <70 mm Hg. Reported risks increase with increased durations for mean arterial pressures <65-60 mm Hg or for any exposure <55-50 mm Hg.

CONCLUSIONS

The reported associations suggest that organ injury might occur when mean arterial pressure decreases <80 mm Hg for ≥10 min, and that this risk increases with blood pressures becoming progressively lower. Given the retrospective observational design of the studies reviewed, reflected by large variability in patient characteristics, hypotension definitions and outcomes, solid conclusions on which blood pressures under which circumstances are truly too low cannot be drawn. We provide recommendations for the design of future studies. CLINICAL REGISTRATION NUMBER: (PROSPERO ID). CRD42013005171.

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.