Faculty Bibliography

OBJECTIVE:We investigated the association of tunneling technique on patency and amputation in patients undergoing lower extremity bypass for limb ischemia. METHODS:The National Vascular Quality Initiative database infrainguinal bypass module from 2008 to 2017 was queried for analysis. We excluded cases with non-great saphenous vein grafts, grafts using multiple segments, aneurysmal disease indications, bypass locations outside the femoral to below the knee popliteal artery or tibial arteries, and missing data on tunneling type and limb ischemia. The main exposure variable was the tunneling type, subcutaneously vs subfascially. Our primary outcomes were primary patency and amputation. The secondary outcomes included primary-assisted patency and secondary patency. Univariate and multivariate logistic regression models were used. RESULTS:A total of 5497 bypass patients (2835 subcutaneous and 2662 subfascial) were included. Age, race, graft orientation (reversed vs not reversed), bypass donor and recipient vessels, harvest type, end-stage renal disease, smoking, coronary artery bypass graft, congestive heart failure, P2Y12 inhibitor at discharge, surgical site infection at discharge, and indication (rest pain vs tissue loss vs acute ischemia) were analyzed for an association with the tunneling technique (P < .05). Multivariate analyses demonstrated that the tunneling type was not associated with primary patency, primary-assisted patency, secondary patency, or major amputation (P > .05). CONCLUSIONS:Compared with subfascial tunneling, the superficial tunneling technique was not associated with primary patency or major amputation in limb ischemia patients undergoing infrainguinal bypass with a single-segment great saphenous vein.

OBJECTIVES/OBJECTIVE:Endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms have been performed widely in an increasing number of centers, utilizing custom-manufactured or physician-modified stent grafts containing fenestrations and side-arm branches for visceral and renal artery incorporation. Alternatively, inner branch configurations may be useful in complex anatomy, where application of fenestrations or side-arm branches can be challenging. Our study aims to evaluate the incidence of target vessel instability when incorporated with inner branch configurations, and report clinical outcomes of patients who underwent fenestrated/branched endovascular aortic repairs (F-BEVAR) containing one or more inner branches. METHODS:We reviewed patients who underwent F-BEVAR with at least one inner branch configuration for complex abdominal or thoracoabdominal aortic aneurysms at Keck Hospital of University of Southern California from 2014 to 2020. Endpoints were mortality, major adverse events (MAE), technical success, and target vessel instability. Target vessel instability was assessed using follow-up computed tomography (CT) and duplex imaging. RESULTS:Out of the 175 patients who underwent F-BEVAR for complex abdominal and TAAA during the study period, 17 patients had at least one inner branch configuration. All were deemed high-risk for open repair with multiple cardiovascular and/or pulmonary comorbidities. Eight (47%) patients had extent I, II, III thoracoabdominal aortic aneurysms, and 10 (59%) had prior aortic repairs. A total of 68 target vessels were incorporated (mean = 4 vessels/patient, range=1~6), of which 40% were inner branch configurations, most commonly for renal arteries. Technical success was 94.1%. There was one perioperative mortality due to massive myocardial infarction, as well as one patient who needed temporary hemodialysis. No device-related mortalities were observed. At 30 days, primary inner branch patency was 100% with no target vessel instability or reintervention. At mean follow-up of 5.8 months, the overall survival was 94% with one patient who expired from unknown cause. Overall primary inner branch patency was 96.3%, due to occlusion of a long lumbar artery branch with no clinical sequelae. CONCLUSION/CONCLUSIONS:Inner branch configurations can provide a safe alternative technique of branch incorporation during complex endovascular aortic repair.

INTRODUCTION/BACKGROUND:Aortic graft infection remains a considerable clinical challenge, and it is unclear which variables are associated with adverse outcomes among patients undergoing partial resection. METHODS:A retrospective, multi-institutional study of patients who underwent partial resection of infected aortic grafts from 2002 to 2014 was performed using a standard database. Baseline demographics, comorbidities, operative, and postoperative variables were recorded. The primary outcome was mortality. Descriptive statistics, Kaplan-Meier (KM) survival analysis, and Cox regression analysis were performed. RESULTS:One hundred fourteen patients at 22 medical centers in 6 countries underwent partial resection of an infected aortic graft. Seventy percent were men with median age 70 years. Ninety-seven percent had a history of open aortic bypass graft: 88 (77%) patients had infected aortobifemoral bypass, 18 (16%) had infected aortobiiliac bypass, and 1 (0.8%) had an infected thoracic graft. Infection was diagnosed at a median 4.3 years post-implant. All patients underwent partial resection followed by either extra-anatomic (47%) or in situ (53%) vascular reconstruction. Median follow-up period was 17 months (IQR 1, 50 months). Thirty-day mortality was 17.5%. The KM-estimated median survival from time of partial resection was 3.6 years. There was no significant survival difference between those undergoing in situ reconstruction or extra-anatomic bypass (P = 0.6). During follow up, 72% of repairs remained patent and 11% of patients underwent major amputation. On univariate Cox regression analysis, Candida infection was associated with increased risk of mortality (HR 2.4; P = 0.01) as well as aortoenteric fistula (HR 1.9, P = 0.03). Resection of a single graft limb only to resection of abdominal (graft main body) infection was associated with decreased risk of mortality (HR 0.57, P = 0.04), as well as those with American Society of Anesthesiologists classification less than 3 (HR 0.35, P = 0.04). Multivariate analysis did not reveal any factors significantly associated with mortality. Persistent early infection was noted in 26% of patients within 30 days postoperatively, and 39% of patients were found to have any post-repair infection during the follow-up period. Two patients (1.8%) were found to have a late reinfection without early persistent postoperative infection. Patients with any post-repair infection were older (67 vs. 60 years, P = 0.01) and less likely to have patent repairs during follow up (59% vs. 32%, P = 0.01). Patients with aortoenteric fistula had a higher rate of any post-repair infection (63% vs. 29%, P < 0.01) CONCLUSION: This large multi-center study suggests that patients who have undergone partial resection of infected aortic grafts may be at high risk of death or post-repair infection, especially older patients with abdominal infection not isolated to a single graft limb, or with Candida infection or aortoenteric fistula. Late reinfection correlated strongly with early persistent postoperative infection, raising concern for occult retained infected graft material.

OBJECTIVE:Traumatic popliteal vascular injuries are associated with the highest risk of limb loss of all peripheral vascular injuries. A method to evaluate the predictors of amputation is needed because previous scores could not be validated. In the present study, we aimed to provide a simplified scoring system (POPSAVEIT [popliteal scoring assessment for vascular extremity injuries in trauma]) that could be used preoperatively to risk stratify patients with traumatic popliteal vascular injuries for amputation. METHODS:A review of patients sustaining traumatic popliteal artery injuries was performed. Patients requiring amputation were compared with those with limb salvage at the last follow-up. Of these patients, 80% were randomly assigned to a training group for score generation and 20% to a testing group for validation. Significant predictors of amputation (P < .1) on univariate analysis were included in a multivariable analysis. Those with P < .05 on multivariable analysis were assigned points according to the relative value of their odds ratios (ORs). Receiver operating characteristic curves were generated to determine low- vs high-risk scores. An area under the curve of >0.65 was considered adequate for validation. RESULTS:A total of 355 patients were included, with an overall amputation rate of 16%. On multivariate regression analysis, the risk factors independently associated with amputation in the final model were as follows: systolic blood pressure <90 mm Hg (OR, 3.2; P = .027; 1 point), associated orthopedic injury (OR, 4.9; P = .014; 2 points), and a lack of preoperative pedal Doppler signals (OR, 5.5; P = .002; 2 points [or 1 point for a lack of palpable pedal pulses if Doppler signal data were unavailable]). A score of ≥3 was found to maximize the sensitivity (85%) and specificity (49%) for a high risk of amputation. The receiver operating characteristic curve for the validation group had an area under the curve of 0.750, meeting the threshold for score validation. CONCLUSIONS:The POPSAVEIT score provides a simple and practical method to effectively stratify patients preoperatively into low- and high-risk major amputation categories.

OBJECTIVE:Despite the increasing use of endovascular therapy for traumatic arterial injuries, little is known about the outcomes of endovascular repair of superficial femoral artery (SFA) and popliteal artery (PA) injuries. In the present study, we compared the characteristics and outcomes of endovascular vs open repair of traumatic SFA and PA injuries. METHODS:We performed a retrospective National Trauma Data Bank analysis of trauma patients with a blunt or penetrating injury of the SFA and/or PA who had undergone endovascular or open repair from 2007 to 2014. Multivariate logistic regression was used to compare the outcomes, with propensity score matching used for sensitivity analysis. RESULTS:The incidence of SFA and PA injuries was 0.2%, with an overall increase in the annual use of endovascular stent repair from 3.2% in 2007 to 7.6% in 2014 (P = .002). A total of 2,873 patients with an isolated SFA and/or PA injury were included in the present study, of whom 163 (5.7%) had undergone endovascular repair. SFA injuries were more frequently treated with endovascular repair (70% vs 27%) and PA injuries were more often associated with open repair (41.1% vs 54.7%). Open repair was more frequently associated with a concomitant femur fracture or knee dislocation (30.7% vs 38.8%; P = .039). Endovascular repair was not associated with worse in-hospital amputation-free survival (AFS) compared with open repair on univariate analysis (91.1% vs 89.7%; P = .573) or multivariate logistic regression (odds ratio [OR], 1.053; 95% confidence interval [CI], 0.551-2.012; P = .876). Propensity score matching revealed that in-hospital mortality was higher (OR, 3.69; 95% CI, 1.37-9.82; P = .01) and fasciotomy was lower (OR, 0.23; 95% CI, 0.14-0.37; P < .001) in the endovascular repair group, with no significant differences in AFS (OR, 0.86; 95% CI, 0.48-1.67; P = .65). CONCLUSIONS:Endovascular repair of SFA and PA injuries has in-hospital AFS comparable to that for open repair, supporting the increasing use of endovascular repair for traumatic SFA and PA injuries in appropriately selected cases. Given the unexpected finding of increased in-hospital mortality after endovascular repair, further studies are necessary to determine the appropriate patient selection and the durability of endovascular repair.

We previously described a transfemoral antegrade in situ laser fenestration technique (in situ fenestrated endovascular abdominal aortic aneurysm repair) for ruptured thoracoabdominal aortic aneurysms. In the present report, we have described an alternative technique of caudally directed in situ fenestrated endografts using upper extremity access for branch vessel incorporation. This technique involves partial deployment of the aortic stent graft in the thoracic aorta to achieve proximal control, followed by sequential branch incorporation using a laser probe through a steerable sheath, from the upper extremity access. The advantages of the technique include rapid proximal aortic control before branch incorporation without target vessel prestenting and separation of in situ fenestration from the target branch vessel origin, facilitating cannulation of angulated branch vessels.

BACKGROUND:Several studies have reported lower mortality and morbidity after thoracic endovascular aortic repair (TEVAR) when compared to open surgical repair (OSR) in the treatment of type B aortic dissection (TbAD). However, there are few studies in the literature on the cost of both treatment options. Thus, the aim of this study is to focus on in-hospital outcomes and cost associated with TbAD repair procedures in a national database in the United States. METHODS:A retrospective review of the Premier Healthcare Database (PHD) between June 2009 and March 2015 was performed. ICD-9-CM codes were used to identify patients who underwent OSR or TEVAR for TbAD. Endpoints included in-hospital adverse events, in-hospital mortality and hospitalization cost. Logistic regression models and generalized linear models were used to assess the impact of treatment type on the main outcomes. RESULTS:Out of 1752 patients with TbAD, 54.3% underwent OSR and 45.7% underwent TEVAR. Patients in the TEVAR group were older [median age, 64 (IQR 54-73) vs. 59 (IQR 49-70), P < 1] and more likely to have preexisting comorbidities. IAE rates were 78.6% for the OSR group compared to 43.1% for the TEVAR group, P < 0.001. Patients in the OSR group showed significantly higher in-hospital mortality (15.3% vs. 5.9%, P < 0.001). After adjusting for potential confounders, OSR was associated with a 5-fold increase in IAE [aOR(95%CI): 4.8 (3.8-6.1), P < 0.001] and a 3-fold increase in in-hospital mortality [aOR(95%CI): 3.3 (2.1-5.1), P < 0.001]. In regards to charges related to the hospital stay, total cost was significantly higher among patients undergoing OSR $53,371 ($39,029-$80,471) vs. TEVAR $45,311 ($31,479-$67,960), P < 0.001. CONCLUSION/CONCLUSIONS:The present study shows that TEVAR presents an advantage in terms of morbidity, mortality and cost when compared to OSR in the treatment of TbAD. However, long-term cost-effectiveness of both procedures remains unknown. Further research is warranted to see whether the superiority of TEVAR is maintained over time.

OBJECTIVE:Inferior vena cava (IVC) injuries have a high mortality rate that may be related to the location of injury and type of repair. Previous studies have been either single center series or database studies lacking granular detail. These have reported conflicting results. We aimed to perform a systematic review and meta-analysis of published literature evaluating ligation versus repair. METHODS:Studies published in English on MEDLINE or EMBASE from 1946 through October 2018 were examined to evaluate mortality among patients treated with ligation versus repair of IVC injuries. Studies were included if they provided mortality associated with ligation versus repair and reported IVC injury by level. Risk of bias was assessed regarding incomplete and selective outcome reporting with Newcastle-Ottawa score of 7 or higher to evaluate study quality. We used a random-effects model with restricted maximum likelihood estimation method in R using the Metafor package to evaluate outcomes. RESULTS: = 0%) were also associated with higher mortality. CONCLUSIONS:In this meta-analysis, ligation of IVC injuries was associated with increased mortality compared to repair, but not specifically for infrarenal IVC injuries. Suprarenal IVC injury, and blunt mechanism was associated with increased mortality compared to infrarenal IVC injury and penetrating mechanism, respectively. Data are limited regarding acute renal injury and venous thromboembolic events after IVC ligation and may warrant multicenter studies. Standardized reporting of IVC injury data has not been well established and is needed in order to enable comparison of outcomes across institutions. In particular, reporting of injury location, severity, and repair type should be standardized. A contemporary prospective, multicenter study is needed in order to definitively compare surgical technique.

OBJECTIVE:Recent studies have suggested that the low risk of stroke and death associated with transcarotid artery revascularization (TCAR) is partially attributable to a robust dynamic flow reversal system and the avoidance of the atherosclerotic aortic arch during stenting. However, the benefits of flow reversal compared with distal embolic protection (DEP) in reducing stroke or death in TCAR have not been studied. METHODS:All patients undergoing carotid artery stenting (CAS) via the transcarotid route with either dynamic flow reversal (TCAR) or DEP (TCAS-DEP) in the Vascular Quality Initiative from September 2016 to November 2019 were analyzed. Both multivariable logistic regression and nearest neighbor propensity score-matched analysis were performed to explore the differences in outcomes between the two procedures. The primary outcome was in-hospital stroke or death. The secondary outcomes were stroke, death, myocardial infarction (MI), and the composite of stroke, death, and MI. A secondary analysis was performed to compare transcarotid stenting with DEP vs transfemoral CAS with DEP to evaluate the effects of crossing the aortic arch. RESULTS:A total of 8426 patients were identified (TCAS-DEP, n = 287; 3.4%). TCAR was associated with a lower risk of in-hospital stroke or death (1.6% vs 5.2%; odds ratio [OR], 0.35; 95% confidence interval [CI], 0.20-0.64; P = .001), stroke (1.4% vs 4.2%; OR, 0.37; 95% CI, 0.20-0.68; P = .002), and stroke/death/MI (2.0% vs 5.2%; OR, 0.41; 95% CI, 0.23-0.71; P = .001) compared with TCAS-DEP. Among the 274 pairs of patients identified with propensity score matching, TCAR was associated with a lower risk of stroke/death (1.1% vs 4.7%; risk ratio [RR], 0.23; 95% CI, 0.06-0.81; P = .021) and stroke (0.4% vs 4.0%; RR, 0.09; 95% CI, 0.01-0.70; P = .006) compared with TCAS-DEP but no differences in stroke/death/MI (1.8% vs 4.7%; RR, 0.38; 95% CI, 0.15-1.02; P = .077). The secondary analysis found no differences in stroke between TCAS-DEP and transfemoral CAS with DEP (4.9% vs 3.7%; RR, 1.3; 95% CI, 0.36-1.63; P = .65). CONCLUSIONS:Compared with TCAS-DEP, TCAR was associated with a lower risk of perioperative stroke or death and stroke. This finding implies that dynamic flow reversal might provide better neuroprotection than does a distal embolic filter in reducing the perioperative risk of stroke. Avoiding the aortic arch did not confer any reduction in the stroke rate. The present findings serve to separate the clinical benefit of dynamic flow reversal from that of avoiding the aortic arch during TCAR.