Faculty Bibliography

OBJECTIVE:Aberrant subclavian artery (aSCA) is a rare anatomic variant whose association with other aortic branch variations and aortic pathology has yet to be established. Knowledge of such an association could be relevant to recommendations for screening and awareness as associated variations are important for operative planning. We describe the incidence of aSCA variations, its association with aortic pathology, and a proposed classification system. METHODS:The thoracic cross-sectional imaging database at Keck Hospital of the University of Southern California from 2006 to 2018 was queried for presence of aSCA. Studies were evaluated for aSCA laterality, variant anatomy, and aortic and branch vessel disease. Medical records were reviewed for associated symptoms and diagnoses. The primary outcome was association of aSCA with aortic pathology (aneurysm or dissection). Secondary outcomes were comparison of right and left aSCA, comparison between the sexes, and creation of a proposed classification system. RESULTS:Of 98,580 axial imaging studies, 810 studies (0.82%) were identified with aSCA in 312 unique patients. Right aSCA made up the majority of cases (90.1%). All aSCAs had a retroesophageal course. Kommerell's diverticulum (KD) was present in 184 (59%) with an average diameter of 1.67 cm (range, 1.2-3.3 cm). KD was more frequent (84% vs 56%; P = .0003) and larger (2.05 cm vs 1.61 cm; P < .0001) in left aSCA patients. When present, KD was more often symptomatic in left aSCA compared with right aSCA (77.4% vs 49.1%; P = .005). Dysphagia, chest pain, reflux, and asthma were all more common in left aSCA patients. KD was also more common in men (73.3% vs 50%; P < .0001) and larger in men (1.81 cm vs 1.54 cm; P < .0001) but with no difference in symptoms between sexes. Our proposed classification system based on aortic arch branching is as follows: type 1, left arch with right aSCA (59.9%); type 2, left arch with common carotid trunk and right aSCA (30.1%); type 3, right arch with left aSCA (9.6%); and type 4, right arch with common carotid trunk and left aSCA (0.3%). Subtypes describe the right vertebral artery (RVA) and left vertebral artery (LVA) origin: subclavian (s, RVA 90.1%, LVA 96.8%), carotid (c, RVA 9.6%, LVA 0.3%), or arch (a, RVA 0.3%, LVA 2.9%). Overall, 9.9% (31/312) had associated aortic pathology, although the study was underpowered to detect a difference between right aSCA and left aSCA (9.3% vs 16.1%; P = .213). Type 3 and type 4 arches more often have associated aortic pathology, KD, and symptoms. CONCLUSIONS:aSCAs are frequently symptomatic and commonly associated with aortic dissection and aneurysm. Our proposed classification scheme depicts all four aSCA arch variants and accounts for vertebral artery origin variation. These variants are common, and vertebral anatomy can differ greatly. Knowledge of these anatomic variations is critical to planning for endovascular and open repair of aortic arch pathology.

OBJECTIVE:Upper extremity and neck access is commonly used for complex endovascular aortic repairs. We sought to compare perioperative stroke and other complications of (1) arm/neck (AN) and femoral or iliac access versus femoral/iliac (FI) access alone, (2) right- versus left-sided AN, and (3) specific arm versus neck access sites. METHODS:Patients entered in the thoracic endovascular aortic repair/complex endovascular aortic repair registry in the Vascular Quality Initiative from 2009 to 2018 were analyzed. Patients with a missing access variable and aortic arch proximal landing zone were excluded. The primary outcome was perioperative in-hospital stroke. Secondary outcomes were other postoperative complications and 1-year survival. Kaplan-Meier curves and log-rank test were used for survival analysis. RESULTS:Of 11,621 patients with 11,774 recorded operations, 6691 operations in 6602 patients met criteria for analysis (1418 AN, 5273 FI). AN patients had a higher rate of smoking history (83.6% vs 76.1%; P < .0001), and prior stroke (12.6% vs 10.1%; P = .01). Operative time (280 ± 124 minutes vs 157 ± 102 minutes; P < .0001), contrast load (141 ± 82 mL vs 103 ± 67 mL; P < .0001), and estimated blood loss (300 mL vs 100 mL; P < .0001) were larger in the AN group, indicative of greater complexity cases. Overall, AN had a higher rate of stroke (3.1% vs 1.8%; P = .003) compared with FI and on multivariable analysis AN access was found to be an independent risk factor for stroke (odds ratio, 1.97; P = .0003). There was no difference in stroke when comparing right- and left-sided AN access (2.8% vs 3.2%; P = .71). Stroke rates were similar between arm, axillary, and multiple access sites, but were significantly higher in patients with carotid access (2.6% vs 3.5% vs 13% vs 3.7%; P = .04). AN also had higher rates of puncture site hematoma, access site occlusion, arm ischemia, and in-hospital mortality (7.1% vs 4.2%; P < .0001). At 1 year, AN had a lower survival rate (85.1% vs 88.1%; P = .03). CONCLUSIONS:Upper extremity and neck access for complex aortic repairs has a higher risk of stroke compared with femoral and iliac access alone. Right-sided access does not have a higher stroke rate than left-sided access. Carotid access has a higher stroke rate than axillary, arm, and multiple arm/neck access sites.

For trauma patients with noncompressible truncal hemorrhage (NCTH), aortic occlusion (AO) is attempted with either resuscitative thoracotomy (RT) or the resuscitative endovascular balloon occlusion of the aorta (REBOA). However, it is often challenging to identify the group of patients who would benefit from AO procedures. We hypothesized that patients who met simple clinical criteria would have better outcomes following AO procedures. This is a retrospective cohort study using the Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery database (November 2013-August 2019) which included patients who arrived with signs of life and underwent AO procedures (RT or zone 1 REBOA). Outcomes were compared between patients who met the criteria (admission vital signs: Glasgow Coma Scale (GCS) ≥9 and systolic blood pressure <90 mm Hg) and those who did not. Subgroup analyses were then conducted on patients who had a REBOA placed and those who underwent RT. A total of 998 patients met our inclusion criteria. Of those, a REBOA was placed in 364 patients (37%), while 634 (64%) underwent RT. The overall mortality rate in the criteria (+) group was significantly lower than that in the criteria (-) group (62 vs. 79%, P < .001). In patients who survived beyond the emergency department following AO procedures, those who met the criteria underwent hemorrhage control procedures more frequently (83% vs. 57%, P < .001). Our data suggest that simple clinical criteria could guide the provider for proceeding with AO in patients with suspected NCTH.

We describe a technique for antegrade in situ laser fenestration that has several advantages in the setting of ruptured thoracoabdominal aortic aneurysms. This technique involves rapid aneurysm sealing by deployment of aortic stent graft, followed by sequential incorporation of branch vessels using a laser probe through steerable sheath. The advantages of this technique include (1) rapid seal of the ruptured aneurysm, (2) preservation of the visceral and renal branch perfusion, (3) use of an off-the-shelf device, and (4) the ability to be performed without general anesthesia.

Persistent false lumen flow is common after thoracic endovascular aortic repair of type B aortic dissection and may contribute to continued aortic aneurysmal degeneration. We report an innovative technique of intercostal artery embolization within the false lumen for a patient who had incomplete false lumen thrombosis and progressive aortic enlargement after thoracic endovascular aortic repair of chronic type B aortic dissection. Technical success was facilitated by use of on-table cone beam computed tomography angiography, virtual vessel marking, and modern endovascular tools. The patient had no complications from the procedure. Postoperative imaging demonstrated complete thoracic false lumen thrombosis and favorable aortic remodeling with reduction in maximal aortic diameter.

We believe that the rapid and widespread adoption of resuscitative endovascular balloon occlusion of the aorta as well as enthusiasm for catheter-based strategies has led to increased interest in basic endovascular techniques among trauma surgeons. The aim of this article was to describe the most commonly performed endovascular procedures for trauma patients, the basic capital equipment and room set up, and a parsimonious inventory of disposable supplies needed to perform each procedure. Together, these make a standardized trauma-specific endovascular inventory. LEVEL OF EVIDENCE: Economic/decision, level V.

The Society for Vascular Surgery Lower Extremity Threatened Limb Classification System has been developed to stratify amputation risk on the basis of extent of the wound, level of ischemia, and severity of foot infection (WIfI). However, there are no currently validated metrics to assess, grade, and consider functional status, especially ambulatory status, as a major consideration during limb salvage efforts. Therefore, we propose an adjunct to the current WIfI system to include the patient's ambulatory functional status after initial assessment of limb threat. We propose a functional ambulatory score divided into grade 0, ambulation outside the home with or without an assistive device; grade 1, ambulation within the home with or without an assistive device; grade 2, minimal ambulation, limbs used for transfers; and grade 3, a person who is bed-bound. Adding ambulatory function as a supplementary assessment tool can guide clinical decision making to achieve optimal future functional ambulatory outcome, a patient-centered goal as critical as limb preservation. This adjunct may aid limb preservation teams in rapid, effective communication and clinical decision making after initial WIfI assessment. It may also improve efforts toward patient-centered care and functional ambulatory outcome as a primary objective. We suggest a score of functional ambulatory status should be included in future trials of patients with chronic limb-threatening ischemia.

BACKGROUND:Despite current guidelines suggesting a benefit for dual antiplatelet therapy (DAPT) following peripheral vascular intervention (PVI), there are limited data on antiplatelet prescribing patterns post-procedure. We attempted to determine variables associated with DAPT prescription following lower extremity PVI. METHODS:Retrospective analysis of patients undergoing lower extremity PVI in the Vascular Quality Initiative (2017-2018) was performed. Participants not on anticoagulation or DAPT before the procedure were considered for the final analysis. Postdischarge antiplatelet therapy regimen rates were determined (none, aspirin only, P2Y12 inhibitor only, and DAPT). Multivariate logistic regression was performed to determine variables associated with DAPT initiation compared with those discharged on single-agent or no antiplatelet therapy. RESULTS:A total of 16 597 procedures were included for analysis, with 49% initiated on DAPT post-PVI. Male sex (odds ratio [OR], 1.12 [95% CI, 1.05-1.20]), smoking (OR, 1.20 [95% CI, 1.09-1.32]), and coronary artery disease (OR, 1.19 [95% CI, 1.11-1.27]) were associated with an increased likelihood of post-PVI DAPT prescription. Procedures requiring multiple types of interventions (OR, 1.28 [95% CI, 1.15-1.42]), stent placement (OR, 1.16 [95% CI, 1.06-1.27]), and with complications (OR, 1.31 [95% CI, 1.14-1.52]) were also positively associated with DAPT prescription. CONCLUSIONS:In patients not already receiving anticoagulation or on DAPT at the time of lower extremity PVI, prescription of DAPT following intervention is ≈50%. Multiple factors were associated with the decision for DAPT versus single antiplatelet therapy, and further study is required to understand how this affects postintervention adverse limb and cardiovascular events.

OBJECTIVE:Mycotic aortic aneurysms and aortic graft infections (aortic infections [AIs]) are rare but highly morbid conditions. Open surgical repair is the "gold standard" treatment, but endovascular repair (EVR) is increasingly being used in the management of AI because of the lower operative morbidity. Multiple organisms are associated with AI, and bacteriology may be an important indication of mortality. We describe the bacteriology and associated outcomes of a group of patients treated with an EVR-first approach for AI. METHODS:All patients who underwent EVR for native aortic or aortic graft infections between 2005 and 2016 were retrospectively reviewed. Primary end points were 30-day mortality and overall mortality. The primary exposure variable was bacteria species. Logistic regression analysis was used to determine association with mortality. Kaplan-Meier survival analysis was used to estimate survival. RESULTS:A total of 2038 EVRs were performed in 1989 unique and consecutive patients. Of those, 27 patients had undergone EVR for AI. Thirteen presented ruptured (48%). Eighteen (67%) were hemodynamically unstable. Ten had a gastrointestinal bleed (37%), whereas others presented with abdominal pain (33%), fever (22%), chest or back pain (18.5%), and hemothorax (3.7%). Twenty patients had a positive blood culture (74%), with the most common organism being methicillin-resistant Staphylococcus aureus (MRSA) isolated in 37% (10). Other organisms were Escherichia coli (3), Staphylococcus epidermidis (2), Streptococcus (2), Enterococcus faecalis (1), vancomycin-resistant Enterococcus (1), and Klebsiella (1). Thirteen patients had 4 to 6 weeks of postoperative antibiotic therapy, six of whom died after therapy. Fourteen were prescribed lifelong therapy; 10 died while receiving antibiotics. On univariate analysis for mortality, smoking history (P = .061) and aerodigestive bleeding on presentation (P = .109) approached significance, whereas MRSA infection (P = .001) was strongly associated with increased mortality. On multivariate analysis, MRSA remained a strong, independent predictor of mortality (adjusted odds ratio, 93.2; 95% confidence interval, 1.9-4643; P = .023). Overall 30-day mortality was 11%, all MRSA positive. At mean follow-up of 17.4 ± 28 months, overall mortality was 59%. Overall survival at 1 year, 3 years, and 5 years was 49%, 31%, and 23%. Kaplan-Meier survival analysis demonstrated that MRSA-positive patients had a significantly lower survival compared with other pathogens (1-year, 20% vs 71%; 5-year, 0% vs 44%; P = .0009). CONCLUSIONS:In our series of AI, the most commonly isolated organism was MRSA. MRSA is highly virulent and is associated with increased mortality compared with all other organisms, regardless of treatment. Given our results, EVR for MRSA-positive AI was not a durable treatment option.