Faculty Bibliography

BACKGROUND:Management of patients with chronic limb-threatening ischemia (CLTI) and extensive foot necrosis presents a challenge for limb salvage. Our study evaluates preoperative risk factors that contributed to durability and efficacy of limb salvage after open transmetatarsal amputation (TMA) in patients with critical limb-threatening ischemia. METHODS:We abstracted data from patients who underwent open TMA at Los Angeles County-University of Southern California Medical Center and Keck Hospital of University of Southern California from 2009 to 2018. Multivariable logistic regression analysis, adjusting for preoperative risk factors, was used to examine predictors of major adverse limb events (MALE). The aim was to evaluate outcomes following open TMA with MALE as the primary outcome. Our hypotheses were that outcomes would be worse for patients with foot infections and renal failure. RESULTS:Forty-three open TMAs were done in 39 patients during the study period. The cohort had a mean age of 63 ± 11.6 years, 89% had a history of diabetes, 95% hypertension (HTN), 54% had end-stage renal disease (ESRD), and 26% were current smokers. MALE occurred in 39% of the cohort. Sex, race, indication, HTN, smoking status, and history of prior ipsilateral revascularization or minor amputations were not associated with MALE (P > 0.05). Multivariate logistic regression found ESRD to be an independent predictor of MALE (odds ratio 7.43, 95% confidence interval 1.12-49.17, P = 0.038) after adjusting for clinically significant covariates. CONCLUSIONS:Open TMA provides acceptable rates of limb salvage for complex patients with CLTI. ESRD is an independent risk factor for MALE following open TMA in these patients. Vigilant follow-up is essential for this morbid patient population given poorer outcomes after forefoot amputation.

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.

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.

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.

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.

BACKGROUND:Popliteal vascular injuries are common and frequently associated with limb loss. Although many studies have evaluated the treatment and outcomes of popliteal artery injuries (PAI), there is little available evidence regarding popliteal venous injuries (PVI). As such, substantial debate remains regarding the benefit of repair over ligation of PVI. The objectives of this study were to compare in-hospital outcomes of repair versus ligation of isolated PVI, as well as to determine nonvascular factors associated with worse outcomes. METHODS:Patients in the National Trauma Databank from 2007 to 2014 with at least one PVI were evaluated. First, patients with concomitant PVI and PAI were compared with patients with isolated PVI. Second, outcomes were compared between ligation and repair of isolated PVI. To limit the impact of concomitant injuries and focus on the impact of venous injury management, we defined isolated PVI as cases without concomitant PAI and with Abbreviated Injury Scale severity score of less than 3 for all body regions other than lower extremity. Patients dead on arrival and those with less than 18 years of age were excluded. The primary outcomes were in-hospital mortality, amputation, and in-hospital amputation-free survival (AFS). Secondary outcomes included lower extremity compartment syndrome, fasciotomy, acute kidney injury, pulmonary embolism, deep venous thrombosis, and inferior vena cava filter placement. RESULTS:Overall, 1819 patients (0.03%) had a PVI and after exclusion 1213 met the criteria for initial analysis. Of those, 308 had isolated PVI, and 905 had combined PVI and PAI. Patients with combined PVI and PAI had higher rates of amputation (15.2% vs 6.8%; P < .001), fasciotomy (64.5% vs 30.8%; P < .001), compartment syndrome (14.8% vs 8.8%; P = .006), and a lower AFS (82.9% vs 91.8%; P < .001) than patients with isolated PVI. There was no difference in in-hospital mortality, amputation, or in-hospital AFS between ligation and repair of isolated PVI. On multivariable logistic regression of isolated PVI, ligation was not independently associated with in-hospital AFS, amputation, or mortality. CONCLUSIONS:Ligation of isolated PVI was not an independent predictor of in-hospital mortality, lower extremity amputation, or in-hospital AFS. Ligation also did not result in higher rates of fasciotomy, acute kidney injury, or pulmonary embolism.

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.

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.