Gary W. Lemmon

A vascular laboratory protocol for improving and managing after-hours suspected acute deep venous thrombosis

This study reviews the clinical and workforce impact of a suggested protocol designed for the management of suspected acute deep venous thrombosis (DVT) in patients seen after standard vascular laboratory business hours. The protocol included the use of Wells score, D-dimer and a single dose of therapeutic anticoagulant to defer venous duplex ultrasound (VDU) testing until routine business hours unless contraindicated. Information was collected on medical history, physical exam and the timing of any diagnostic studies and treatment provided. Over 15% of studies done after-hours were deemed unnecessary by our protocol and in every individual the results were negative for an acute DVT. There were no adverse events from a one-time dose of anticoagulant. Limiting emergency VDU coverage to evaluate for acute DVT based on a management protocol can eliminate unnecessary after-hours VDU testing without having a negative impact on patient care.

Dialysis access steal syndromes

Dialysis-associated steal syndromes remain a vexing problem for the busy vascular access surgeon. Those factors associated with ischemia include the elderly, diabetic, female, preexisting cardiac disease and brachial anastomosis, and previous ipsilateral access. A constellation of symptoms and findings based on underlying arterial disease and flow characteristics are necessary to provide prompt diagnosis and initiate treatment. Although a digital brachial index (DBI) >1 and transcutaneous oxygen tension (TCPO(2) ) measurements >60 mm Hg accurately predict a patient not at risk, no DBI or TCPO2 levels below that accurately predict if a patient will develop dialysis-associated ischemia. The goal of the vascular access surgeon is to provide prompt recognition and treatment of the disorder to maximize both limb salvage and access salvage. Continuation of angio access in the same extremity can be accomplished in most individuals.

Institutional experience with the Zenith Fenestrated aortic stent graft

Objective: The Zenith Fenestrated (ZFEN; Cook Medical, Bloomington, Ind) aortic stent graft system was approved for commercial use by the Food and Drug Administration in April 2012. We report our single‐center experience of 100 consecutive patients treated with the ZFEN platform from October 2012 to March 2017. Methods: A retrospective review of our prospectively maintained fenestrated endovascular aneurysm repair (FEVAR) database at a tertiary care academic institution located in the Midwest United States was performed for descriptive analysis. All continuous variables are reported as a mean ± standard deviation and compared using two‐sided Student t‐tests. Categorical variables were compared using two‐sided Fisher exact tests. Results: All but one of the procedures were elective in nature. Overall intraoperative characteristics included a mean blood loss (estimated blood loss) of 388 ± 385 mL, fluoroscopy time of 63 ± 30 minutes, radiation dose of 437 ± 272 rad, contrast material volume of 99 ± 36 mL, and operative time of 236 ± 87 minutes. Average number of visceral arteries stented was 2.1 ± 0.5. Technical success was achieved in 98% of the patients. Statistically significant (P < .05) improvement in estimated blood loss (2.1‐fold) was observed in the second half of our series. Interestingly, no improvements were made in terms of fluoroscopy time, radiation exposure, contrast material use, or operative time. However, procedural difficulty increased in the last half by number of visceral arteries stented as a surrogate (1.9 vs 2.2; P < .05). Mean length of stay was 3.6 ± 4.3 days. Perioperative mortality at 30 days was 2%. Perioperative morbidity included a 5% incidence of any bowel ischemia, 1% of spinal cord ischemia, 3% of renal failure requiring hemodialysis, 1% of stroke, and 4% of myocardial infarction. Average follow‐up was 1.7 ± 1.4 years. Reintervention during the follow‐up phase was 20%. Of the 209 visceral arteries stented, we noted 6 instances of stent thrombosis, 6 of kinking or stenosis, and 1 of stent fracture in follow‐up. Endoleak, most commonly type II, was present or could not be excluded in 15% of all FEVARs at last available computed tomography angiography. Conclusions: In our experience, FEVAR with the ZFEN system continues to be safe and effective. There is a significant rate of reintervention observed, and close monitoring is fundamental to maintaining good clinical results.

Use of the Zenith Fenestrated platform to rescue failing endovascular and open aortic reconstructions is safe and technically feasible

Objective: Proximal neck dilation is a serious long‐term complication directly causing the failure of endovascular aneurysm repair (EVAR) and open surgical repair (OSR) of abdominal aortic aneurysms. However, the implantation of a fenestrated device presents the opportunity for proximal extension of the aortic reconstruction into a healthy segment while maintaining patency of the visceral vessels. The objective of this investigation was to report perioperative and follow‐up outcomes using the Zenith Fenestrated (ZFEN; Cook Medical, Bloomington, Ind) aortic stent system in salvaging previous aortic repairs undergoing type IA endoleak or aneurysmal degeneration of the proximal neck. Methods: We performed a retrospective review of a prospectively maintained institutional database capturing all fenestrated EVAR (FEVAR) cases with the ZFEN platform. Fenestrated cases were classified as primary FEVAR or reoperative FEVAR (rFEVAR) after previous EVAR or OSR. Cohort comparisons were performed using Fisher exact tests and Student t‐tests for categorical and continuous variables, respectively. Results: Between October 2012 and March 2017, a total of 103 patients diagnosed with abdominal aortic aneurysm with an inadequate proximal seal zone for traditional EVAR were treated with ZFEN. In 12 patients, FEVAR was performed as a reoperation after previous EVAR (n = 6) or OSR (n = 6). The indications for rFEVAR were proximal neck dilation (>55 mm) after OSR (n = 6), type IA endoleak after EVAR (n = 5), and proximal neck dilation after EVAR without endoleak (n = 1). No difference in ability to achieve technical success was observed between primary FEVAR and rFEVAR (97.8% vs 100%; P = 1.00). In addition, there were no differences in estimated blood loss (363 vs 500 mL; P = .25) and intraoperative use of contrast material (97.3 vs 104.0 mL; P = .55). However, a significant increase in fluoroscopy time (61.1 vs 79.8 minutes; P = .04), radiation exposure (415.9 vs 606.3 rad; P = .02), and operative time (228.4 vs 287.6 minutes; P = .03) in the rFEVAR cohort was observed. In the 30‐day perioperative period, there were no significant differences with regard to mortality (2.2% vs 0%; P = 1.0), major adverse cardiovascular events (5.5% vs 0%, P = 1.0), and stent‐related adverse events (2.2% vs 0%; P = 1.0). There were no differences in rates of perioperative (5.5% vs 0%; P = 1.0) or follow‐up reintervention after a mean follow‐up duration of 20.8 months (18.6% vs 25.0%; P = .70). Conclusions: FEVAR with the ZFEN platform of failed and failing aortic reconstructions due to disease progression is safe and feasible without increased morbidity and mortality in select patients. These preliminary results support the inclusion of ZFEN as a treatment option for aortic reintervention.

Outcomes associated with a transcarotid artery revascularization-centered protocol in high-risk carotid revascularizations using the ENROUTE neuroprotection system

Objective This investigation describes the perioperative and early follow‐up results associated with transcarotid artery revascularization (TCAR) in patients not participating in the Safety and Efficacy Study for Reverse Flow Used During Carotid Artery Stenting Procedure II (ROADSTER‐2) registry using the ENROUTE neuroprotection system (ENPS; Silk Road Medical, Sunnyvale, Calif). Methods A retrospective review was performed capturing all TCAR/ENPS procedures in patients deemed to be at high risk for complications after traditional carotid endarterectomy. All patients enrolled in the ROADSTER‐2 registry were excluded, leaving only those treated outside trial regulations for analysis. Preoperative demographics, intraoperative variables, and perioperative and follow‐up outcomes were abstracted and reported herein. Results From December 2015 to January 2018, there were 75 carotid arteries treated at our institution. All interventions were performed on carotid arteries that were symptomatic with ≥50% stenosis (46.7%) or asymptomatic with ≥80% stenosis (53.3%) by duplex ultrasound and computed tomography angiography. Technical success in our series was 97.3% (73/75), with treatment failures attributed to one case of common carotid artery dissection and another secondary to stent maldeployment in the external carotid artery. Perioperative (30‐day) ipsilateral stroke rate was 2.7% (n = 2), myocardial infarction incidence was 0%, and mortality rate was 2.7% (n = 2). We did not observe any cranial nerve injuries. After a mean follow‐up of 8.0 ± 6.7 months, no carotid stents required reintervention. However, we noted one instance of minor (<50%) in‐stent stenosis and one asymptomatic stent thrombosis. One additional ipsilateral stroke was observed on follow‐up, probably from a cardiac source. Conclusions We report that dynamic reverse‐flow TCAR using the ENPS continues to be safe, feasible, and efficacious with minimal risks of postoperative stroke, myocardial infarction, and mortality outside of ROADSTER‐2 regulations.

Perioperative Outcomes are Adversely Affected by Poor Pretransfer Adherence to Acute Limb Ischemia Practice Guidelines

BACKGROUNDnThe accepted treatment for acute limb ischemia (ALI) is immediate systemic anticoagulation and timely reperfusion to restore blood flow. In this study, we describe the retrospective assessment of pretransfer management decisions by referring hospitals to an academic tertiary care facility and its impact on perioperative adverse events.nnnMETHODSnA retrospective analysis of ALI patients transferred to us via our Level I Vascular Emergency Program from 2010 to 2013 was performed. Patient demographics, comorbidities, Rutherford ischemia classification, time to anticoagulation, and time to reperfusion were tabulated and analyzed for correlation to incidence of major adverse limb events (MALEs), mortality, and bypass patency in the perioperative period (30-day postoperative). All intervals were calculated from the onset of symptoms and categorized into 3 subcohorts (<6xa0hr, 6-48xa0hr, and >48xa0hr).nnnRESULTSnEighty-seven patients with an average age of 64.0 (±16.2) years presented to outlying hospitals and were transferred to us with lower extremity ALI. The mean delay from symptom onset to initial referring physician evaluation was 18.3xa0hr. At that time of evaluation, 53.8% had Rutherford class IIA ischemia and 36.3% had class IIB ischemia. Seventy-six patients (87.4%) were started on heparin previous to transfer. However, only 44 patients (57.9%) reached therapeutic levels as measured by activated partial thromboplastin time before definitive revascularization. A delay of anticoagulation initiation >48xa0hr from symptom onset was associated with increased 30-day reintervention rates compared with the <6xa0hr group (66.7% vs. 23.5%; Pxa0<xa00.05). However, time to reperfusion had no statistically significant impact on MALE, 30-day mortality, or 30-day interventional patency in our small cohorts. Additionally, patients with a previous revascularization had a higher 30-day reintervention rate (46.5%; Pxa0<xa00.05).nnnCONCLUSIONSnThe practice of timely therapeutic anticoagulation of patients referred for ALI from community facilities occurs less frequently than expected and is associated with an increased perioperative reintervention rate.

Cryopreserved Homografts in Infected Infrainguinal Fields Are Associated with Frequent Reinterventions and Poor Amputation-Free Survival

BACKGROUNDnSingle-length saphenous vein continues to be the conduit of choice in infected-field critical limb ischemia. However, half of these individuals have inadequate vein secondary to previous use or chronic venous disease. We reviewed our outcomes of infected-field infrainguinal bypasses performed with cryopreserved homografts (CHs), a widely accepted alternative to autogenous vein in this setting.nnnMETHODSnThis is a retrospective, institutional descriptive analysis of infected-field infrainguinal revascularizations between 2012 andxa02015.nnnRESULTSnTwenty-four operations were performed in the same number of patients for limb ischemia with signs of active infection. The mean age of the cohort examined was 62.5xa0±xa014.4 (standard deviation) years. Mean Society of Vascular Surgery risk score was 3.9 with a baseline Rutherfords chronic ischemia score of 4.3 at presentation. Emergent procedures constituted 29% of cases, and the remainder cases were urgent procedures. The CH bypass captured was a reoperative procedure in all but one of the patients. Culture positivity was present in 75% of cases with Staphylococcus aureus (29%), the most commonly isolated organism. Thirty-day mortality and major adverse cardiovascular events were both 4%. Amputation-free survival (AFS) was 75% at 30 days. Similarly, 30-day reintervention was 38% with debridement (43%) and bleeding (29%), the most common indications. Average duration of follow-up was 27.9xa0±xa020.4xa0months (range: 0.5-60.4). Mean length of stay was 14.8xa0days. Reinfection requiring an additional procedure or antibiotic regimen separate from the index antibiotic course was 13%. Primary patency and AFS at 1 year was 50% and 58%, respectively. Primary patency and AFS at 2 years was 38% and 52%, respectively. Limb salvage at 1 and 2 years was 70% and 65%, respectively. Fifteen patients (63%) required reintervention during the follow-up period with 40% of those subjects undergoing multiple procedures.nnnCONCLUSIONSnCHs remain a marginal salvage conduit in the setting of infection and no autogenous choices. Therefore, clinicians should individualize usage of this high-cost product in highly selected patients only.

Staged endovascular repair of an abdominal aortic aneurysm adjacent to a chronic high-flow iliocaval traumatic arteriovenous fistula

Large-vessel chronic traumatic arteriovenous fistulas are a rare complication after trauma. Delayed presentation can consist of one or more features of high-output cardiac failure, pulsatile abdominal mass, bruit, limb ischemia, and venous congestion. We describe a patient with a complex iliocaval fistula secondary to a remote gunshot wound associated with a large 8.5-cm aortic aneurysm. Informed consent of the patient was obtained for publication of the case.

Results of nonoperative management of acute limb ischemia in infants

Objective: Acute limb ischemia (ALI) in infants poses a challenge to the clinician secondary to poor operative outcomes, limb loss risk, and lifelong morbidity. This retrospective study reviewed a 10‐year institutional experience with the nonoperative management of ALI in infants. Methods: Infants (aged ≤12 months) diagnosed with ALI by duplex ultrasound and treated with initial nonoperative management at a tertiary care childrens hospital were identified through vascular laboratory arterial duplex ultrasound records and International Classification of Diseases and Current Procedural Terminology codes associated with ALI. Demographics of the patients, injury characteristics, treatment administered, and outcomes were abstracted by chart review and presented using descriptive statistics. Results: During the study period, a total of 25 (28% female) infant patients were diagnosed with ALI. The average age for this cohort was 3.5 ± 3.2 months (standard deviation). Most cases were secondary to iatrogenic injury (88%) from arterial cannulation. Injury sites were more concentrated to the lower extremities (84%) compared with the upper. Absence of Doppler signals was noted in 64% of infants, whereas limb cyanosis was observed in 60% at the time of presentation. Infants were initially treated with anticoagulation (80%) when possible. Two patients failed to respond to nonoperative management and required thrombolysis secondary to progression of thrombus burden while anticoagulated. There were no major (above‐ankle) amputations at 30 days. Three deaths occurred within 30 days; all were unrelated to limb ischemia. In the 30‐day survivors, overall duration of follow‐up was 53.5 ± 38.5 months. One infant required above‐knee amputation 6 weeks after diagnosis, resulting in an overall limb salvage rate of 96% on follow‐up. Long‐term morbidity included two patients with a chronic wound of the affected limb and one patient with limb length discrepancy. No subjects reported claudication at the latest follow‐up appointment. In addition, all patients were independently ambulatory except for one adolescent girl who was using a walker with leg braces. Conclusions: In contrast to the adult population, ALI in infants can be managed with anticoagulation alone with good results. Long‐term follow‐up continues to demonstrate excellent functional results and minimal disability.

Institutional Cost of Unplanned 30-Day Readmission Following Open and Endovascular Surgery

Background: Vascular surgical patients have a high rate of readmission, and the cost of readmission for these patients has not been described. Herein, we characterize and compare institutional index hospitalization and 30-day readmission cost following open and endovascular vascular procedures. Methods: The American College of Surgeons National Surgical Quality Improvement Program database was used to identify inpatient open and endovascular procedures at a single institution, from January 2011 through June 2012. Variable and fixed costs for index hospitalization and unplanned 30-day readmissions were obtained using SAP BusinessObjects. Patient characteristics and outcome variables were analyzed using Student t tests or Wilcoxon rank-sum nonparametric tests for continuous variables and Fisher exact tests for categorical variables. Results: One thousand twenty-six inpatient procedures were included in the analysis. There were 605 (59%) open and 421 (41%) endovascular procedures with a 30-day unplanned readmission rate of 16.9% and 17.8%, respectively (P = .679). The mean index hospitalization costs for open and endovascular procedures were US