The Incidence of Thoracic Outlet Syndrome.

BACKGROUND: Thoracic outlet syndrome (TOS) refers to a constellation of compressive problems that occur at the thoracic outlet. TOS has been recognized since the 19th century, and the "modern" era of treatment, especially for neurogenic TOS, dates from at least the 1970s. Despite this, however, the incidence and prevalence of these syndromes are almost completely unknown. To attempt to answer this fundamental question, we established a prospective database of all patients who presented to our clinic with a diagnosis of potential TOS, as described below. METHODS: We established a database of all patients referred to our clinic from July 1, 2014 to May 2018. All subjective data, the tentative diagnosis, and plan at the time of the office visit were prospectively recorded. For patients with neurogenic TOS (NTOS), a standardized workup sheet was used based on the Society for Vascular Surgery's recently published reporting standards document. For patients with venous TOS (VTOS), diagnosis was made by clinical examination and ultrasound, and for those with arterial TOS (ATOS), by clinical examination, ultrasound, and cross-sectional imaging when needed. RESULTS: From July 1, 2014, to May 1, 2018, 526 patients were referred to our institution with a diagnosis of possible TOS. Of these, 432 (82%) were referred with symptoms suggestive of NTOS, 84 (16%) with symptoms suggestive of VTOS, and 10 (2%) with findings and/or symptoms suggestive of ATOS. NTOS: After evaluation as per the algorithm previously mentioned, 234 patients (54%) were judged high suspicion for NTOS, 126 (30%) moderate suspicion, and 72 (17%) low suspicion; 360 (83%) of those originally referred were felt to potentially have NTOS. Of the 84 patients with VTOS, 25 (30%) presented with acute Paget-Schroetter syndrome, 41 (48%) with subacute or chronic occlusion, and 18 (21%) with McCleery's syndrome. Finally, 8 of the 10 limbs had true ATOS; of these, 6 (75%) underwent decompression and repair and 2 (25%) endovascular intervention only. Based on referral assumptions and population density in our area, the incidence of NTOS seems to be between 2 and 3 cases per 100,000 people per year and that of VTOS between 0.5 and 1 per 100,000 people per year, ATOS being sporadic. The ratio of those with decent suspicion for NTOS and VTOS, respectively, is about 80:20, whereas that of those undergoing surgical decompression is about 75:25. CONCLUSIONS: The rates of NTOS and VTOS, as aforementioned, are approximately 25 and 8 per year in a metropolitan area of 1,000,000, respectively. Although a rare disease, these numbers are not insignificant, although are much lower than prior estimates.

Single Center Outcomes of Carotid Artery Stenting in Veterans with Prior Head and Neck Cancer.

BACKGROUND: Patients meeting criteria for intervention of carotid stenosis with a history of prior cervical radiation or neck dissection are considered "high risk" for carotid endarterectomy. This is a well-established indication for carotid artery stenting (CAS). The long-term outcomes of CAS in this population are less frequently published in the literature but are poor. The purpose of this study was to review long-term results of CAS in veteran patients with a prior history of treatment for head and/or neck cancer. METHODS: This is a retrospective review of a veteran patient population from 1998 to 2016. All patients at our institution with a prior history of treatment for head and/or neck cancer who underwent CAS were included in the analysis. During this time period, 44 patients met inclusion criteria and were treated with 57 carotid stenting interventions. The Kaplan-Meier analysis was used to determine survival and primary patency. The secondary aims were to analyze early outcomes and to identify predictive risk factors for mortality and reintervention. RESULTS: The mean follow-up was 42.9 ± 36.6 months. The cumulative survival at 1, 5, and 10 years was 91%, 67%, and 48%, respectively. The primary patency at 1, 5, and 10 years was 95%, 86%, and 86%, respectively. The reintervention rate was 11% (n = 6) with an assisted primary patency rate of 100%. No neurologic events occurred within 30 days. There were 3 strokes in late follow-up and no stroke-related deaths. Eighteen patients (41%) died during the follow-up period, 15 of whom died during the first 5 years of follow-up. Ten (66%) of those patients died of recurrent or active index cancer. On univariate analysis, tumor, node, metastasis stage IV was significantly associated with death (P = 0.02). Multivariate models were not statistically significant for predicting mortality or reintervention CONCLUSIONS: On the basis of the results in this series, CAS can be performed in these patients with low long-term rates of neurologic events and need for reintervention. However, the survival of patients with head and neck cancer undergoing CAS in this cohort is poor, which is consistent with other published series of patients undergoing CAS for head/neck cancer with at least 5-year follow-up. In this specific patient population, a more critical analysis of the patient's overall prognosis, especially as related to cancer, should be undertaken before offering CAS.

Hemodynamic events during carotid stenting are associated with significant periprocedural stroke and adverse events.

BACKGROUND: There are limited data on the impact of carotid angioplasty and stenting (CAS)-related changes in blood pressure, heart rate, and preprocedural medications on periprocedural stroke in contemporary, real-world practice. This study evaluates the risk attributable to the CAS-related hemodynamic events and the impact preprocedural medications have on mitigating this risk in a large, population-based cohort. METHODS: We studied all patients in the Vascular Quality Initiative who underwent CAS between January 2006 and December 2016. Kaplan-Meier, multivariable logistic, and Cox regression analyses were used to evaluate the impact of periprocedural hypertension, hypotension, bradycardia, and medication use on immediate periprocedural stroke (IPPS), 30-day, and 1-year stroke. RESULTS: Of the 13,698 CAS procedures studied, 1239 (9.1%), 1824 (13.3%), and 1333 (9.7%) patients experienced periprocedural hypertension, hypotension, and bradycardia, respectively. IPPS was 3.2% vs 2.1% vs 0.65% (P < .001), comparing patients with periprocedural hypertension vs hypotension vs normotension and 1.4 vs 1.0% (P = .19) for bradycardic vs nonbradycardic patients. Periprocedural hypertension was associated with a four-fold increase in IPPS (adjusted odd ratio [aOR], 3.97; 95% confidence interval [CI], 2.63-5.99; P < .001). periprocedural hypotension and bradycardia were associated with 5.5-fold (aOR, 5.56; 95% CI, 3.24-9.52; P < .001) and 2.3-fold (aOR, 2.31; 95% CI, 1.26-4.25; P = .007) increases in IPPS among patients with carotid symptoms. There was 76% decrease in IPPS for patients who did not experience a periprocedural hemodynamic event (aOR, 0.24; 95% CI, 0.16-0.35; P < .001). Unlike preprocedural beta-blockers and angiotensin-converting enzyme inhibitors, prophylactic antibradyarrhythmic agents conferred a 58% reduction in IPPS among patients with carotid symptoms (aOR, 0.42; 95% CI, 0.23-0.78; P = .006). The periprocedural hemodynamic events were also associated with 7.7-fold increase in myocardial infarction (aOR, 7.70; 95% CI, 4.77-12.45; P < .001), a 2.2-fold increase in 30-day mortality (aOR, 2.24; 95% CI, 1.61-3.12; P < .001), and a 16% increase in length of stay (aOR, 1.16; 95% CI, 0.04-2.28; P = .042). The occurrence of these hemodynamic events is higher in patients with prior cardiac disease and the difference in periprocedural outcomes extended to 1 year. CONCLUSIONS: Periprocedural hemodynamic events are associated with an increase in periprocedural stroke, myocardial infarction, death, and length of stay. Periprocedural hypertension in all patients; hypotension and bradycardia in patients with symptomatic carotid disease are associated with significant increase in IPPS. Prophylactic antibradyarrhythmic agents are associated with decrease in bradycardia and IPPS. These results heighten the need to anticipate and promptly address these CAS-related hemodynamic events, especially in susceptible patients.

Evaluation and treatment of thoracic outlet syndrome during the global pandemic due to SARS-CoV-2 and COVID-19.

The global SARS-CoV-2/COVID-19 pandemic has required a reduction in nonemergency treatment for a variety of disorders. This report summarizes conclusions of an international multidisciplinary consensus group assembled to address evaluation and treatment of patients with thoracic outlet syndrome (TOS), a group of conditions characterized by extrinsic compression of the neurovascular structures serving the upper extremity. The following recommendations were developed in relation to the three defined types of TOS (neurogenic, venous, and arterial) and three phases of pandemic response (preparatory, urgent with limited resources, and emergency with complete diversion of resources). • In-person evaluation and treatment for neurogenic TOS (interventional or surgical) are generally postponed during all pandemic phases, with telephone/telemedicine visits and at-home physical therapy exercises recommended when feasible. • Venous TOS presenting with acute upper extremity deep venous thrombosis (Paget-Schroetter syndrome) is managed primarily with anticoagulation, with percutaneous interventions for venous TOS (thrombolysis) considered in early phases (I and II) and surgical treatment delayed until pandemic conditions resolve. Catheter-based interventions may also be considered for selected patients with central subclavian vein obstruction and threatened hemodialysis access in all pandemic phases, with definitive surgical treatment postponed. • Evaluation and surgical treatment for arterial TOS should be reserved for limb-threatening situations, such as acute upper extremity ischemia or acute digital embolization, in all phases of pandemic response. In late pandemic phases, surgery should be restricted to thrombolysis or brachial artery thromboembolectomy, with more definitive treatment delayed until pandemic conditions resolve.

Arteriovenous Access superficialization: A New Technique and Review of Options.

BACKGROUND: Up to 30% of autogenous cephalic vein arteriovenous fistulas (AVFs) are too deep for reliable cannulation. Techniques to superficialize these AVFs have been described previously. This study describes a new surgical technique for AVF superficialization and provides a review of the alternative techniques. METHODS: The path of the fistula is marked using ultrasound, and transverse incisions are made along this path. The underlying tissue is separated from the dermis over this area to expose the fistula outflow vein. The mobilized vein is then elevated and "trapped" directly under the dermis by closing the superficial fascia and adipose tissue beneath it. RESULTS: Between March 2016 and February 2019, 23 patients underwent superficialization using this technique at two centers. The mean time between AVF creation and superficialization was 6.3 months, and the time to first use for hemodialysis after superficialization was 38.8 ± 27.9 days. The average presuperficialization depth was 7.1 ± 2.4 mm and average postsuperficialization depth was 3.7 ± 2.7 mm (P = 0.002). Sixteen fistulas were successfully accessed for a cannulation rate of 89%. 94.7% of fistulas remained patent at last visit, with only one thrombosed 8-10 weeks after superficialization. CONCLUSIONS: This technique appears to be both safe and effective, and results in a vein that is immediately subdermal without major contour deformity. Early outcomes are comparable to those alternative methods described in the literature.

Positive Impact of an Aortic Center Designation.

BACKGROUND: In January 2015, we created a multidisciplinary Aortic Center with the collaboration of Vascular Surgery, Cardiac Surgery, Interventional Radiology, Anesthesia and Hospital Administration. We report the initial success of creating a Comprehensive Aortic Center. METHODS: All aortic procedures performed from January 1, 2015 until December 31, 2016 were entered into a prospectively collected database and compared with available data for 2014. Primary outcomes included the number of all aortic related procedures, transfer acceptance rate, transfer time, and proportion of elective/emergent referrals. RESULTS: The Aortic Center included 5 vascular surgeons, 2 cardiac surgeons, and 2 interventional radiologists. Workflow processes were implemented to streamline patient transfers as well as physician and operating room notification. Total aortic volume increased significantly from 162 to 261 patients. This reflected an overall 59% (P = 0.0167) increase in all aorta-related procedures. We had a 65% overall increase in transfer requests with 156% increase in acceptance of referrals and 136% drop in transfer denials (P < 0.0001). Emergent abdominal aortic cases accounted for 17% (n = 45) of our total aortic volume in 2015. The average transfer time from request to arrival decreased from 515 to 352 min, although this change was not statistically significant. We did see a significant increase in the use of air-transfers for aortic patients (P = 0.0041). Factorial analysis showed that time for transfer was affected only by air-transfer use, regardless of the year the patient was transferred. Transfer volume and volume of aortic related procedures remained stable in 2016. CONCLUSIONS: Designation as a comprehensive Aortic Center with implementation of strategic workflow systems and a culture of "no refusal of transfers" resulted in a significant increase in aortic volume for both emergent and elective aortic cases. Case volumes increased for all specialties involved in the center. Improvements in transfer center and emergency medical services communication demonstrated a trend toward more efficient transfer times. These increases and improvements were sustainable for 2 years after this designation.

Postoperative Pain Management following Thoracic Outlet Decompression.

BACKGROUND: Thoracic outlet decompression (TOD) is associated with significant postoperative pain often leading to hospital length of stay out of proportion to the risk profile of the operation. We seek to describe the improvement in hospital length of stay and patient pain control with an improved multiagent pain management regimen. METHODS: We retrospectively reviewed the hospital length of stay, medication regimen/usage, operative details, and operative indications for all patients undergoing TOD from January 2012 through June 2015. During early experience, single-agent narcotic therapy was the mainstay of postoperatively pain control. Since 2014, we have adopted a regimen consisting of narcotic patient controlled analgesia, oral narcotics, and scheduled ibuprofen and valium, which is transitioned to oral narcotics/valium upon discharge. Operative approach (supraclavicular, infraclavicular, transaxial, or paraclavicular) was determined by patient anatomy and indication for procedure (neurogenic/arterial thoracic outlet syndrome or arteriovenous access dysfunction). RESULTS: Seventy-four patients were treated with TOD over the study period: 36 (49.3%) for neurogenic thoracic outlet syndrome, 23 (31.5%) for venous thoracic outlet syndrome, and 15 (19.2%) for arteriovenous access dysfunction. Prior to 2014, the mean length of stay was 4 days with a median pain score of 6. Since 2014, the mean length of stay was 2.6 (P = 0.04) with a median pain score of 4 (P = 0.005). There was no statistically significant difference in the indication for operation or operative approach between the two periods. CONCLUSIONS: Since adoption of a multiagent pain management regimen to include scheduled NSAIDs and benzodiazepines, we have reduced the mean pain score experienced by our patients as well as the hospital length of stay.

Outcomes of a Clinical Pathway for Borderline Resectable Pancreatic Cancer.

BACKGROUND: Without prospective data establishing a consensus multimodality approach to borderline resectable pancreatic adenocarcinoma, institutional treatment regimens vary. This study investigated the outcomes of the clinical pathway at the author's institution, which consists of neoadjuvant gemcitabine, docetaxel, capecitabine, and stereotactic radiotherapy followed by surgery. METHODS: The study reviewed all cases that met the National Comprehensive Cancer Network (NCCN) diagnostic criteria for borderline resectable pancreatic adenocarcinoma from 1 January 2006, to 31 December 2013. Pancreatectomy rates, margin status, pathologic response, disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS) were retrospectively examined. Standard statistical methods and Kaplan-Meier survival analysis were used for statistical comparisons. RESULTS: Of 121 patients who met criteria, 101 entered the clinical pathway, and 94 (93.1 %) completed neoadjuvant chemotherapy and radiation therapy. Of the 101 patients, 55 (54.5 %) underwent pancreatectomy, with 53 patients (96.4 %) having microscopically negative margins (R0) and 2 patients (3.6 %) having microscopically positive margins (R1). Vascular resection was required for 22 patients (40 %), with rates of 95.5 % for R0 (n = 21) and 4.5 % for R1 (n = 1). A pathologic response to treatment was demonstrated by 45 patients (81.8 %) and a complete response by 10 patients (14.5 %). Pancreatectomy resulted in a median DFS of 23 months (95 % conflidence interval [CI] 14.5-31.5), a median DSS of 43 months (95 % CI, 25.7-60.3), and a median OS of 33 months (95 % CI, 25.0-41.0) versus a median DSS and OS of 14 months (95 % CI, 10.9-17.1) for patients without pancreatectomy (DSS: P = 3.5 × 10(-13); OS: P = 4.7 × 10(-10)). CONCLUSIONS: The study demonstrated high rates for neoajduvant therapy completion (93.1 %) and pancreatectomy (54.5 %). After pancreatectomy, DSS was significantly improved (43 months), with a pathologic response demonstrated by 81.8 % and a complete response by 14.5 % of the patients. The results support further study of this borderline resectable pancreatic adenocarcinoma clinical pathway.

Reporting standards of the Society for Vascular Surgery for thoracic outlet syndrome: Executive summary.

Thoracic outlet syndrome (TOS) is a group of disorders all having in common compression at the thoracic outlet. Three structures are at risk: the brachial plexus, the subclavian vein, and the subclavian artery, producing neurogenic (NTOS), venous (VTOS), and arterial (ATOS) thoracic outlet syndromes, respectively. Each of these three are separate entities, though they can coexist and possibly overlap. The treatment of NTOS, in particular, has been hampered by lack of data, which in turn is the result of inconsistent definitions and diagnosis, uncertainty with regard to treatment options, and lack of consistent outcome measures. The Committee has defined NTOS as being present when three of the following four criteria are present: signs and symptoms of pathology occurring at the thoracic outlet (pain and/or tenderness), signs and symptoms of nerve compression (distal neurologic changes, often worse with arms overhead or dangling), absence of other pathology potentially explaining the symptoms, and a positive response to a properly performed scalene muscle test injection. Reporting standards for workup, treatment, and assessment of results are presented, as are reporting standards for all phases of VTOS and ATOS. The overall goal is to produce consistency in diagnosis, description of treatment, and assessment of results, in turn then allowing more valuable data to be presented.

Reporting standards of the Society for Vascular Surgery for thoracic outlet syndrome.

Thoracic outlet syndrome (TOS) is a group of disorders all having in common compression at the thoracic outlet. Three structures are at risk: the brachial plexus, the subclavian vein, and the subclavian artery, producing neurogenic (NTOS), venous (VTOS), and arterial (ATOS) thoracic outlet syndromes, respectively. Each of these three are separate entities, though they can coexist and possibly overlap. The treatment of NTOS, in particular, has been hampered by lack of data, which in turn is the result of inconsistent definitions and diagnosis, uncertainty with regard to treatment options, and lack of consistent outcome measures. The Committee has defined NTOS as being present when three of the following four criteria are present: signs and symptoms of pathology occurring at the thoracic outlet (pain and/or tenderness), signs and symptoms of nerve compression (distal neurologic changes, often worse with arms overhead or dangling), absence of other pathology potentially explaining the symptoms, and a positive response to a properly performed scalene muscle test injection. Reporting standards for workup, treatment, and assessment of results are presented, as are reporting standards for all phases of VTOS and ATOS. The overall goal is to produce consistency in diagnosis, description of treatment, and assessment of results, in turn then allowing more valuable data to be presented.

One-year outcomes from the international multicenter study of the Zenith Alpha Thoracic Endovascular Graft for thoracic endovascular repair.

OBJECTIVE: This study evaluated the safety and effectiveness of the Zenith Alpha Thoracic Endovascular Graft (Cook Medical, Bloomington, Ind) for the treatment of descending thoracic aortic aneurysms and large ulcers. METHODS: The Zenith Alpha Thoracic Endovascular Graft, with a 16F to 20F delivery system, was developed to address vascular access issues associated with larger-profile devices and to increase conformability in tortuous anatomy. This prospective, nonrandomized, multicenter study was conducted in Europe, Japan, and the United States. The main anatomical inclusion criteria included proximal neck seal zone of ≥20 mm, aortic arch radius of ≥20 mm, and a neck diameter of 15 to 42 mm. Patients were evaluated preprocedure, predischarge, and postdischarge 1, 6, and 12 months and yearly thereafter through 5 years. RESULTS: Between March 2010 and January 2013, 110 patients (64 men and 46 women; mean age, 72 ± 10 years) were enrolled in the study for the treatment of descending thoracic aortic aneurysms (n = 90) or ulcers (n = 20). Access was percutaneous in 36% (40 of 110) of patients. The study device was successfully implanted in all but two patients (both due to inability to gain access or advance to the target treatment site). There was no 30-day mortality. Five deaths occurred ≤1 year (only one was aneurysm-related by independent adjudication), resulting in a 95% freedom from all-cause mortality and a 99% freedom from thoracic aortic aneurysm-related mortality. At one or more time points ≤1 year, type I endoleak (all distal) was observed in 4 patients, type III endoleak in 2, and aneurysm growth in 4. Five patients experienced stroke ≤1 year (2 procedure-related). No aortic rupture, paraplegia, paralysis, or permanent spinal cord injury was observed ≤1 year. CONCLUSIONS: Early outcomes after Zenith Alpha implantation appear promising and suggest expanded thoracic endovascular aortic repair applicability in patients with smaller access vessels. Longer-term follow-up is ongoing.

Axillary Artery Access as an Adjunct for Complex Endovascular Aortic Repair.

BACKGROUND: The aim of this study was to review and compare our experience with 3 upper extremity access techniques (percutaneous single-sheath brachial, multi-sheath brachial cutdown, and axillary cutdown with conduit construction) in the setting of complex endovascular repair of paravisceral aneurysms. METHODS: We performed a retrospective review of a prospectively collected endovascular aneurysm repair database. All patients who underwent parallel stent grafting or fenestrated repair with upper extremity arterial access were included. End points included the following: (1) local access complications, (2) number of vessels successfully snorkeled, and (3) technical success. RESULTS: Fifty patients underwent treatment for paravisceral aneurysms using a combination of snorkel and fenestration techniques. All cases used one of the 3 upper extremity arterial access techniques--percutaneous single-sheath brachial, multi-sheath brachial cutdown, and axillary cutdown with conduit construction. Eighteen patients underwent open brachial exposure (15 for single vessel snorkel, 2 for two vessel snorkel, 1 for 4 vessel snorkel) with zero access site complications. Five patients underwent percutaneous brachial access (all for single vessel snorkel) with 2 brachial artery injuries and 1 median nerve injury. Twenty-seven patients underwent open axillary exposure with the conduit/sheath technique (1 for single vessel, 15 for two vessel, 6 for three vessel, and 5 for four vessel snorkel) with 2 access site hematomas requiring surgical evacuation. Successful cannulation of 95 of the 97 vessels was achieved. CONCLUSIONS: Upper extremity arterial access is required to snorkel one or more of the visceral vessels during complex endovascular pararenal aortic aneurysm repair. There are several techniques of arm access that can be used. Brachial access is appropriate when a single visceral vessel must be cannulated, and by utilizing the conduit/sheath combination presented here, it is possible to safely approach multiple visceral vessels from an axillary access. Further evolution of this technique will expand our ability to treat complex paravisceral aneurysms.

Aggressive Costoclavicular Junction Decompression in Patients with Threatened AV Access.

BACKGROUND: A substantial number of patients with threatened arteriovenous (AV) access are found to have stenoses at the costoclavicular junction (CCJ), which frequently are resistant to angioplasty and stenting. We believe that stenoses in this location will not resolve unless bony decompression is performed to relieve the extrinsic compression on the vein. This article describes our short- to medium-term results following such decompression in patients with failing fistulae. METHODS: We reviewed a prospectively maintained database to identify all patients with threatened AV access operated on for stenoses at the CCJ. Pre- and postoperative course along with long-term follow-up were analyzed. RESULTS: Between July 2012 and December 2013, 24 patients with threatened access were operated on for CCJ stenoses at our institution. Fifteen had highly dysfunctional AV fistulae otherwise felt to need ligation, 10 had significant arm and/or head swelling, and 3 required access but had no contralateral options. In 6 patients, the subclavian vein was occluded and 18 stenotic; 5 of these had stents in place through the CCJ. Decompression was performed via claviculectomy in 3 patients, 2 of whom underwent reconstruction (one jugular vein, one prosthetic bypass) and 1 was stented. The other 21 patients underwent first rib resection, 20 via an infraclavicular exposure and 1 via a supraclavicular rib resection. A variety of interventions were performed in the arm, including aneurysm plication, cephalic to deep bypass, one prophylactic distal revascularization interval ligation, and several primary fistulae. 30-Day mortality was minimal: there was one significant hematoma and one hemothorax in a patient who underwent on-table thrombolysis and there were no deaths or cardiac, neurologic, or other significant morbidity. Median length of stay was 2 days. At follow-up up to 20 (median 10) months, 4 patients died of unrelated causes and 1 patient undergoing central reconstruction with prosthetic bypass required excision of this for infection and ligation of his fistula. Two other fistulae failed. One-year assisted primary patency of the fistula was 85%, and of the central bypass, 89%. At last follow-up, the index arm continued to be used for access in 85% of patients, and overall survival was 68%. Virtually all patients experienced dramatic symptom relief. CONCLUSIONS: In this group of high-risk patients whose access was judged otherwise nonsalvageable, excellent symptom relief and long-term fistula and ipsilateral arm use can be achieved with aggressive decompression of the bony CCJ followed by endovascular intervention as needed.

Acute Paget-Schroetter syndrome: does the first rib routinely need to be removed after thrombolysis?

BACKGROUND: Most clinicians feel that treatment for patients with acute primary axillosubclavian vein thrombosis ("effort thrombosis") is catheter-directed thrombolysis followed by thoracic outlet decompression. Several investigators feel that first rib resection (FRR) is not indicated in every case. No randomized data exist to answer this question. METHODS: A MEDLINE search was done using the terms "Paget-Schroetter syndrome," "upper extremity DVT," "first rib resection," "effort thrombosis," and "primary upper extremity thrombosis," with thrombolysis used as an "AND" term. We also specifically explored references cited to support either side of this argument in the past. Analysis was limited to patients aged 18 years or older with symptoms of 14-day duration or less undergoing thrombolysis for primary axillosubclavian vein thrombosis. Those studies that did not report follow-up, duplicate series from the same institution, and those in which patients were stented were excluded. Results were analyzed on an intent-to-treat basis, with groups assigned according to each authors' prospectively described algorithm. RESULTS: Twelve series were included. Patients were divided into 3 groups according to treatment after thrombolysis: FRR (448 patients), FRR plus endovenous balloon venoplasty (FRR + PLASTY; 68 patients), and those with no further intervention after thrombolysis (rib not removed; 168 patients). Symptom relief at last follow-up was significantly more likely in the FRR (95%) and FRR + PLASTY (93%) groups than in the rib not removed (54%) group (both <0.0001) as was patency (98%, 86%, and 48%, respectively; both <0.0001 vs. rib not removed). More than 40% of patients in the rib not removed group eventually required rib resection for recurrent symptoms. No differences in symptom-free rates were seen when comparing FRR with FRR + PLASTY. CONCLUSIONS: In patients with acute effort thrombosis who undergo thrombolysis, permanent symptom relief and long-term patency are more likely to be achieved in patients who undergo FRR with or without endovenous balloon venoplasty than those whose rib is left intact.

Long-segment plication technique for arteriovenous fistulae threatened by diffuse aneurysmal degeneration: short-term results.

BACKGROUND: A substantial number of patients with autologous arteriovenous fistulas (AVFs) develop diffuse aneurysmal degeneration, which frequently interferes with successful access. These AVFs are often deemed unsalvageable. We hypothesize that long-segment plication in these patients can be performed safely with acceptable short-term AVF salvage rates. METHODS: We reviewed a prospectively maintained database to identify all patients with extensive AVF aneurysmal disease operated on for this problem. RESULTS: Thirty-five patients, 25 (71%) male and 10 (29%) female were operated on between July 2012 and January 2014. AVFs included 23 (66%) brachiocephalic, 5 (14%) radiocephalic, and 7 brachiobasilic (20%) fistulae (one first stage only but in use). The cohort had one or a combination of local pain, arm edema, cannulation issue, recurrent thrombosis, dysfunctional during dialysis, or extreme tortuousity. Time range for AVF creation to consultation ranged from 3 months to 11 years. All underwent long-segment plication over a 20-Fr Bougie with or without segmental vein resection; 3 underwent concomitant first rib resection for costoclavicular stenosis; 21 patients had tunneled catheter placement for use while healing, whereas 13 were allowed segmental use of their AVF during the perioperative period (1 patient was not yet on dialysis). Early in our experience, AVFs were left under the wound, whereas all but one repaired since early 2013 were left under a lateral flap. All patients were followed by clinical examination and duplex. In the 30-day postoperative period, 2 AVFs (5.7%) became infected requiring excision, 2 occluded (5.7%), 1 day 1 and the other at 24 days out, 1 patient developed steal and required DRIL 1 week postoperatively, and 1 patient died, unrelated to his surgery. Postoperative functional primary patency was 88% (30 of 34). Of the patients needing temporary access catheter, mean time to first fistula use was 44 days. No wound or bleeding complications have occurred in repaired AVF left under skin flaps. CONCLUSIONS: In this group of patients whose access was threatened by diffuse aneurysmal degeneration, long-segment placation allowed salvage of 88% of fistulae with relatively low morbidity. Fewer complications are associated by covering the revised fistula with intact skin.

In vitro hemodynamic model of the arm arteriovenous circulation to study hemodynamics of native arteriovenous fistula and the distal revascularization and interval ligation procedure.

BACKGROUND: Experimental modeling of arteriovenous hemodialysis fistula (AVF) hemodynamics is challenging. Mathematical modeling struggles to accurately represent the capillary bed and venous circulation. In vivo animal models are expensive and labor intensive. We hypothesized that an in vitro, physiologic model of the extremity arteriovenous circulation with provisions for AVF and distal revascularization and interval ligation (DRIL) configurations could be created as a platform for hemodynamic modeling and testing. METHODS: An anatomic, upper extremity arteriovenous model was constructed of tubing focusing on the circulation from the subclavian artery to subclavian vein. Tubing material, length, diameter, and wall thickness were selected to match vessel compliance and morphology. All branch points were constructed at physiologic angles. The venous system and capillary bed were modeled using tubing and one-way valves and compliance chambers. A glycerin/water solution was created to match blood viscosity. The system was connected to a heart simulator. Pressure waveforms and flows were recorded at multiple sites along the model for the native circulation, brachiocephalic AVF configuration, and the AVF with DR without and with IL (DR no IL and DRIL). RESULTS: A preset mean cardiac output of 4.2 L/min from the heart simulator yielded a subclavian artery pressure of 125/55 mm Hg and a brachial artery pressure of 121/54 mm Hg with physiologic arterial waveforms. Mean capillary bed perfusion pressure was 41 mm Hg, and mean venous pressure in the distal brachial vein was 17 mm Hg with physiologic waveforms. AVF configuration resulted in a 15% decrease in distal pressure and a 65% decrease in distal flow to the hand. DR no IL had no change in distal pressure with a 27% increase in distal flow. DRIL resulted in a 3% increase in distal pressure and a 15% increase in distal flow to the hand above that of DR no IL. Flow through the DR bypass decreased from 329 mL/min to 55 mL/min with the addition of IL. Flow through the AVF for both DR no IL and DRIL was preserved. CONCLUSIONS: Through the construction and validation of an in vitro, pulsatile arteriovenous model, the intricate hemodynamics of AVF and treatments for ischemic steal can be studied. DR with or without IL improved distal blood flow in addition to preserving AVF flow. IL decreased the blood flow through the DR bypass itself. The findings of the AVF as a pressure sink and the relative role of IL with DR bypass has allowed this model to provide hemodynamic insight difficult or impossible to obtain in animal or human models. Further study of these phenomena with this model should allow for more effective AVF placement and maturation while personalizing treatment for associated ischemic steal. CLINICAL RELEVANCE: The complications of arteriovenous fistula (AVF)-associated steal with its concurrent surgical treatments have been clinically described but have relatively little published, concrete hemodynamic data. A further understanding of the underlying hemodynamics is necessary to prevent the occurrence of steal and improve treatment when it occurs. Specific objectives are to study the blood flow through an AVF with varying anatomic and physiologic parameters, determine what factors contribute to the development of arterial steal distal to an AVF, and create optimal interventions to treat arterial steal from an AVF when it occurs. The long-term goal is creation of AVF tailored to patient-specific parameters, resulting in higher rates of functional fistulas with decreases in fistula-related complications. The ability to study fluid dynamics using a unique, in vitro, upper extremity pulsatile arteriovenous circulation simulator creates the ideal platform for this work.

An approach to EVAR simulation using patient specific modeling.

BACKGROUND: The Simbionix Angiomentor Procedure Rehearsal Studio (PRS) offers accurate virtual anatomy for measurement, stent graft selection, and deployment of endovascular aneurysm repair (EVAR) devices. METHODS: Selected Gore Excluder EVAR cases from our EVAR database were reviewed and DICOM data loaded into the Simbionix Angiomentor simulator using PRS software. Using centerline measurements created on PRS, neck diameter (D1), length from lowest renal artery to each iliac bifurcation (Ll and Lr), and common iliac artery diameter (Dl and Dr) were recorded. All measurements for device selection were made based on data recorded on the simulator. Simulated EVAR was then performed using PRS on a dual limb endovascular simulator. Changes in device selection based on intraoperative measurements and use of three-dimensional (3D) anatomic overlay made by the attending vascular surgeon performing the case were recorded. The devices actually used for successful repair were considered gold standard for comparison. At the completion of each virtual case, simulations were rated by an experienced vascular surgeon for realism, imaging quality, and final product on a 5-point scale. RESULTS: Ten cases with complete operative data and available computed tomography scans were chosen at random. Fifty percent of the cases (5/10) had changes in device length when using the "in vivo" 3D volume filled model and angiographic measurements. Analysis of variance revealed no significant differences between the groups in any measurement-main body diameter P = 0.960; main body length P = 0.643; and contralateral limb length P = 0.333. Review of simulation scoring showed ratings of diminished realism (average 2.3/5) due to unrealistic ease of wire passage and gate cannulation; however, simulation imaging and final product were scored favorably (3.7 and 3.4, respectively). CONCLUSIONS: The use of centerlines, angiographic measurements, and 3D modeling within the PRS software approaches real-life device selection and represents an opportunity for high fidelity patient-specific preoperative EVAR case rehearsal.

A single-institution experience: the integrated vascular surgery residency's effect on fellowship and general surgery resident case volume and diversity.

BACKGROUND: To determine whether the formation of an integrated vascular surgery residency (0 + 5) has negatively impacted the case volume and diversity of the vascular surgery fellows (5 + 2) and chief general surgeons at the same institution. METHODS: Operative data from the vascular integrated (0 + 5), independent (5 + 2), and general surgery residencies at a single institution were retrospectively reviewed and analyzed to determine vascular surgery case volumes from 2006-2012. National operative data (Residency Review Committee) were used for comparison of diversity and volume. Standard statistical methods were applied. RESULTS: During this period, the 5 + 2 fellows at our institution performed on average 741 (range, 554-1002) primary cases and 1091 (range, 844-1479) combined primary and secondary cases for the 2-year fellowship. Our integrated residency began in July 2007. Our fellows' primary case volumes remained relatively stable between 2006 and 2011, with a 4% increase in the number of cases, although their total (primary and secondary) case volumes fell 15%; by comparison, the equivalent national 50th percentile rates rose 16% during this time frame. Our institution's general surgery residents performed an average of 116 (range, 56-221) vascular cases individually during their 5-year residency from 2005-2011. From 2006-2011, the total case volume fell only 5%, while the national 50th percentile rate fell 24%. Across all years, however, resident and fellow volumes both continue to be above Accreditation Council for Graduate Medical Education minimum requirements, and the major vascular case volume at our institution in all groups studied remained statistically greater than or equal to the national 50th percentile of cases. Our first integrated resident to graduate finished in June 2012 with 931 total vascular cases and 249 general surgery cases for a total operative experience of 1180 cases during the 5-year residency. Finally, after an 8-year period (2003-2010) in which none of our general surgery residents pursued vascular training, 1 resident in each of the 2011, 2012, and 2013 graduating years has now done so. CONCLUSIONS: At our institution, the introduction of a 0 + 5 vascular residency has correlated with a modest drop (15%) in overall case volume for the 5 + 2 fellows, but the number of primary cases have actually increased slightly and they continue to meet or exceed Accreditation Council for Graduate Medical Education requirements and national 50th percentile rates. General surgery residents' vascular volumes, by contrast, have remained stable, and interest in vascular surgery by residents has increased. Our integrated vascular residents are projected to exceed the fellows' 50th percentile case volume and diversity targets during their residency experience.

Recruiting strategies for potential 0+5 vascular residency applicants.

BACKGROUND: The 0+5 integrated vascular residency training pathway was established in 2006 to allow for trainee-focused training culminating in vascular surgery certification only. An early concern was whether enough medical students could be recruited directly into a vascular internship without the exposure that a general surgery residency provides. We hypothesized that programs that send a large percentage of their general surgical graduates to vascular fellowships have models that can be adapted to medical student recruitment. METHODS: Opinions and practices were sought from program directors through survey and from trainees taking the Vascular Surgery In-Training Examination. RESULTS: Eight programs were identified that sent 20% or more of their residents to vascular fellowships over the past 5 years (projecting a mean of 1.6 residents entering vascular fellowships in 2011). Almost all such programs have a formal mentoring system in place that match mentors to residents by interest, and almost all send residents to academic meetings before their senior year. Seventy-five percent of such programs have formal vascular lecture exposure to the first and second year medical student classes, offer clinical shadowing experiences, and have time on the vascular service during the MS3 clerkship; 83% offer a third- or fourth-year elective in vascular surgery. Vascular Surgery In-Training Examination responses were collected from 156 fellows and 13 "0+5" residents. Although fellows had initially been attracted to vascular surgery by the technical aspects of the field learned during residency (43%), the most important factor initially attracting medical students was an interested mentor (46%). However, the most important factor for both residents and students in making a final decision was the technical aspects of the field (66% and 63%, respectively). CONCLUSIONS: Although residents are automatically exposed to the field during residency, students can only be exposed to vascular surgery if a conscious effort is made by interested educators. Programs that send a high proportion of students and residents into vascular surgery tend to have planned exposure at the MS1 and MS2 levels, formal clinical rotations in place at the MS3 and MS4 levels, and pay personal attention to those who display interest. A guide is presented to help specifically plan these steps. Successful recruiting of students into a 0+5 integrated training program requires specific planning and action.