Trainee Experience in Simulation-Based Education of Open Vascular Surgery.

BACKGROUND: Simulation continues to be an important adjunct to vascular surgery training, yet the optimal implementation of simulation to complement conventional surgical training continues to evolve. This study aims to find areas for improvement in current simulation-based training of open vascular skills by characterizing the experience of vascular trainees attending a national simulation-based course. METHOD: This was a survey study conducted at the simulation course of the Annual UCLA/SVS Symposium: A Comprehensive Review and Update of What's New in Vascular and Endovascular Surgery, a national vascular surgery meeting. The survey consisted of 17 questions and was administered on paper or electronically via the Audience Response System, before the start of the course. The survey assessed the participants' experience in formal training, simulation training, and comfort with open surgical procedures. RESULTS: Between 2013 and 2018, the survey was completed by 150 participants of which 65% were vascular fellows. Only 48% of the participants had formal training in suturing and surgical instruments. Most participants had formal training in basic vascular techniques and advanced vascular operations. In 71%, simulation was incorporated into basic technique training and 60% in open surgical training. Simulation training was most commonly utilized in learning anastomotic techniques and open abdominal aortic aneurysm repair. Simulation skills were deemed translatable to the operating room by 59% of participants. Most participants were comfortable performing open vascular procedures. However, 68% of participants were uncomfortable performing an abdominal aortic aneurysm repair. CONCLUSIONS: There continues to be a significant portion of trainees who do not undergo a simulation-based education. Current simulation training is being targeted to meet trainee needs in open vascular surgery, specifically open aneurysm repair. Nonetheless, trainees continue to have doubts regarding applicability of simulation-based skills to the operating theater. Further studies investigating access to simulation education as well as its translatability are needed.

Midterm evaluation of perigraft arterial sac embolization in endovascular aneurysm repair.

OBJECTIVE: Management of clinically significant endoleaks (ELs) remains costly, time-consuming, and morbid. Unresolved ELs can result in rupture and mortality after endovascular aneurysm repair (EVAR). Perigraft arterial sac embolization (PASE) has been used to treat ELs diagnosed at the time of EVAR or during surveillance. METHODS: A retrospective review of prospectively maintained databases was conducted. The databases were compiled from two institutions between 2006 and 2016. PASE was performed for type I, type II, or type III EL with a thrombin, contrast medium, and Gelfoam (Pfizer, New York, NY) slurry prepared as previously described. PASE was administered either at the time of EVAR (primary) or during surveillance (secondary). Safety end points included nontarget embolization, defined as neurologic or enteric clinical sequelae from lumbar artery or visceral artery embolization, allergic reaction, peripheral embolization, or rupture. Efficacy end points included successful resolution of EL and cessation of aneurysm sac growth on computed tomography (CT) scans with contrast enhancement. RESULTS: A total of 66 patients included in the study were treated with PASE. Primary PASE was performed in 38 patients (58%) and secondary in 28 (42%). Within the total cohort, the average clinical and CT scan follow-up was 1.7 years (0.1-11.6 years). Four patients required open repair for residual high-pressure ELs (one type IIIB and three type I; 6%). Of the 95% of patients who did not require open conversion, aneurysm growth did not occur during the follow-up period. In the overall cohort, PASE was successful in 88% of type I EL and 73% of patients with type II EL. There was no evidence of recanalization after thrombosis of culprit vessel for EL. No patients suffered nontarget embolization, spinal ischemia, allergic reaction, post-EVAR rupture, or colonic ischemia. CONCLUSIONS: Primary and secondary PASE proved to be a safe, effective, and durable tool in sac management in conjunction with EVAR. Treating ELs during or after EVAR with PASE has minimized the incidence of EL on CT scan and halted aneurysm growth in our cohort. Further studies are needed to confirm the long-term durability of PASE in reducing secondary interventions after EVAR.

Endovascular Reconstruction of Subclavian Artery Aneurysms in Patients with Arterial Thoracic Outlet Syndrome.

BACKGROUND: Subclavian artery aneurysms associated with thoracic outlet syndrome (TOS) have traditionally been managed by open surgical reconstruction. Endovascular subclavian artery reconstruction is novel in the setting of arterial TOS (aTOS). Our objective is to report our results with endovascular subclavian artery reconstruction in aTOS patients over a 10-year period with attention to surgical approach and late results. METHODS: Patients who underwent stent-graft reconstruction of subclavian artery aneurysms associated with aTOS between 2006 and 2016 were identified in a prospective database. Data collected included age, gender, presentation, surgical details, and outcomes. RESULTS: Over the study period, 869 TOS procedures were performed. Of these, 7 (0.8%) were aTOS related subclavian artery aneurysms managed with stent-graft repair. All presented with upper extremity pain (7) and a majority with limb-threatening ischemia (6). Other significant findings included subclavian artery aneurysm (7), cervical rib (4), and clavicular fracture (3). TOS decompression was accomplished via transaxillary cervical and first rib resection. Stent-graft deployment was performed concurrently with TOS decompression via brachial artery approach. The mean follow-up period was 24.9 months (range 1-60). Two patients required reintervention for stent thrombosis (1.5 months, 36 months) and 1 required balloon angioplasty for in-stent restenosis (24 months). Limb salvage was achieved in all patients with no major amputations, no minor amputations, and restoration of normal function in all. CONCLUSIONS: Our experience indicates that stent-graft reconstruction of subclavian artery aneurysms associated with aTOS is successful. This procedure was characterized by short surgical times, low blood loss, and no complications. It may be subject to late graft thrombosis or stenosis and requires life-long surveillance.

Underutilization of Thrombolytic Therapy for Patients Diagnosed with Acute Deep Venous Thrombosis in the Outpatient Setting.

BACKGROUND: Catheter-directed thrombolysis (CDT) has been shown to be a safe and effective treatment for the management of acute iliofemoral deep venous thrombosis (DVT). The potential benefits of this therapy include more rapid resolution of symptoms and possible reduction in the long-term sequelae. Many patients diagnosed with DVT in the inpatient setting have contraindications to lytic therapy, but less is known regarding the suitability of thrombolysis for outpatients diagnosed with acute DVT. We sought to determine the proportion of patients who were candidates for thrombolytic therapy and referred to a vascular specialist for evaluation. METHODS: A manual search of an outpatient vascular laboratory associated with a tertiary medical center was performed to identify all patients referred for the purpose of ruling out DVT between January 2013 and December 2014. Vascular laboratory studies conducted for evaluation of venous insufficiency were excluded. The electronic medical records were reviewed to evaluate for contraindications for thrombolysis. RESULTS: Over a 2-year period, there were 689 referrals to the outpatient vascular laboratory for the evaluation of patients with suspected DVT. Of the 689 referrals, 47 (6.8%) were found to have acute DVT, and 66 (9%) were found to have chronic DVT. Of the 47 patients with acute DVT, 41 involved the lower extremities. Fifteen of the 41 patients (37%) with extensive acute iliofemoral DVT had no absolute or major contraindications for CDT. Of these 15 patients, only 33% were referred to a vascular specialist (4 to vascular surgery and 1 to IR). Two patients (13%) agreed to and underwent successful CDT. CONCLUSIONS: Although the majority of patients with acute lower extremity DVT diagnosed in the outpatient vascular laboratory were not candidates for thrombolysis, one-third of those who may have benefited from CDT were referred to a vascular specialist to discuss lytic therapy. Given the potential benefits of CDT, it is imperative that patients with acute iliofemoral or extensive femoral DVT be offered an evaluation by a vascular specialist to optimize outcomes after this diagnosis.

Surgical Missteps in the Management of Venous Thoracic Outlet Syndrome Which Lead to Reoperation.

BACKGROUND: Surgical management of spontaneous subclavian thrombosis due to venous thoracic outlet syndrome (vTOS) results in durable relief of symptoms. The need to reoperate is rare. We report our experience with reoperation for vTOS. METHODS: Patients evaluated for vTOS between 1996 and 2016 were identified in a prospective database. Data recorded included demographics, initial presentation, initial surgery, recurrent presentation, reoperation, and final outcomes. RESULTS: In all, 261 patients were evaluated for vTOS, of these, 246 patients underwent first rib resections. Ten (3.8%) patients required evaluation for recurrent vTOS symptoms. Prior management included thrombolysis (4) and anticoagulation alone (6). Prior surgical approaches included infraclavicular (2), supraclavicular (2) and transaxillary (6). One operation was complicated by a hemothorax, and one a brachial plexus injury. Indication for reoperation included congestive symptoms (6) and recurrent thrombosis (4). Evaluation included chest X-rays (10), venogram (8), intra-venous ultrasound (2), and computed tomography venography (3). Significant compression by remaining rib segments were identified in all: inadequate resection of the anterior first rib (7), inadequate resection of posterior rib segment (1), and erroneous resection of second rib (2). Reoperations include 7 transaxillary approaches, 1 medial claviculectomy, and 1 paraclavicular decompression. One phrenic nerve palsy occurred following paraclavicular decompression. All underwent postoperative venography and angioplasty. At final evaluation, 8 veins are patent and congestive symptoms resolved, and 1 crushed stent could not be reopened despite decompression. CONCLUSIONS: The incidence of reoperation for first rib resection in cases of vTOS is low and appears largely due to missteps during the initial operation. Awareness of potential errors including inadequacy of resection, intraoperative disorientation, and misunderstanding of the limitations of surgical approaches will result in fewer reoperations.

Vascular TOS-Creating a Protocol and Sticking to It.

Thoracic Outlet Syndrome (TOS) describes a set of disorders that arise from compression of the neurovascular structures that exit the thorax and enter the upper extremity. This can present as one of three subtypes: neurogenic, venous, or arterial. The objective of this section is to outline our current practice at a single, high-volume institution for venous and arterial TOS. VTOS: Patients who present within two weeks of acute deep vein thrombosis (DVT) are treated with anticoagulation, venography, and thrombolysis. Those who present later are treated with a transaxillary first rib resection, then a two-week post-operative venoplasty. All patients are anticoagulated for 2 weeks after the post-operative venogram. Those with recurrent thrombosis or residual subclavian vein stenosis undergo repeat thrombolysis or venoplasty, respectively. ATOS: In patients with acute limb ischemia, we proceed with thrombolysis or open thrombectomy if there is evidence of prolonged ischemia. We then perform a staged transaxillary first rib resection followed by reconstruction of the subclavian artery. Patients who present with claudication undergo routine arterial duplex and CT angiogram to determine the pathology of the subclavian artery. They then undergo decompression and subclavian artery repair in a similar staged manner.

Up-regulation of nicotinic acetylcholine receptors in menthol cigarette smokers.

One-third of smokers primarily use menthol cigarettes and usage of these cigarettes leads to elevated serum nicotine levels and more difficulty quitting in standard treatment programmes. Previous brain imaging studies demonstrate that smoking (without regard to cigarette type) leads to up-regulation of ß(2)*-containing nicotinic acetylcholine receptors (nAChRs). We sought to determine if menthol cigarette usage results in greater nAChR up-regulation than non-menthol cigarette usage. Altogether, 114 participants (22 menthol cigarette smokers, 41 non-menthol cigarette smokers and 51 non-smokers) underwent positron emission tomography scanning using the α(4)ß(2)* nAChR radioligand 2-[(18)F]fluoro-A-85380 (2-FA). In comparing menthol to non-menthol cigarette smokers, an overall test of 2-FA total volume of distribution values revealed a significant between-group difference, resulting from menthol smokers having 9-28% higher α(4)ß(2)* nAChR densities than non-menthol smokers across regions. In comparing the entire group of smokers to non-smokers, an overall test revealed a significant between-group difference, resulting from smokers having higher α(4)ß(2)* nAChR levels in all regions studied (36-42%) other than thalamus (3%). Study results demonstrate that menthol smokers have greater up-regulation of nAChRs than non-menthol smokers. This difference is presumably related to higher nicotine exposure in menthol smokers, although other mechanisms for menthol influencing receptor density are possible. These results provide additional information about the severity of menthol cigarette use and may help explain why these smokers have more trouble quitting in standard treatment programmes.

Effect of secondhand smoke on occupancy of nicotinic acetylcholine receptors in brain.

CONTEXT: Despite progress in tobacco control, secondhand smoke (SHS) exposure remains prevalent worldwide and is implicated in the initiation and maintenance of cigarette smoking. OBJECTIVE: To determine whether moderate SHS exposure results in brain α(4)ß(2)* nicotinic acetylcholine receptor (nAChR) occupancy. DESIGN, SETTING, AND PARTICIPANTS: Positron emission tomography scanning and the radiotracer 2-[18F]fluoro-3-(2(S)azetidinylmethoxy) pyridine (also known as 2-[(18)F]fluoro-A-85380, or 2-FA) were used to determine α(4)ß(2)* nAChR occupancy from SHS exposure in 24 young adult participants (11 moderately dependent cigarette smokers and 13 nonsmokers). Participants underwent two bolus-plus-continuous-infusion 2-FA positron emission tomography scanning sessions during which they sat in the passenger's seat of a car for 1 hour and either were exposed to moderate SHS or had no SHS exposure. The study took place at an academic positron emission tomography center. Main Outcome Measure  Changes induced by SHS in 2-FA specific binding volume of distribution as a measure of α(4)ß(2)* nAChR occupancy. RESULTS: An overall multivariate analysis of variance using specific binding volume of distribution values revealed a significant main effect of condition (SHS vs control) (F(1,22) = 42.5, P < .001) but no between-group (smoker vs nonsmoker) effect. Exposure to SHS led to a mean 19% occupancy of brain α(4)ß(2)* nAChRs (1-sample t test, 2-tailed, P < .001). Smokers had both a mean 23% increase in craving with SHS exposure and a correlation between thalamic α(4)ß(2)* nAChR occupancy and craving alleviation with subsequent cigarette smoking (Spearman ρ = -0.74, P = .01). CONCLUSIONS: Nicotine from SHS exposure results in substantial brain α(4)ß(2)* nAChR occupancy in smokers and nonsmokers. Study findings suggest that such exposure delivers a priming dose of nicotine to the brain that contributes to continued cigarette use in smokers. This study has implications for both biological research into the link between SHS exposure and cigarette use and public policy regarding the need to limit SHS exposure in cars and other enclosed spaces.