False-negative upper extremity ultrasound in the initial evaluation of patients with suspected subclavian vein thrombosis due to thoracic outlet syndrome (Paget-Schroetter syndrome).

OBJECTIVE: To assess the utilization and consequences of upper extremity Duplex ultrasound in the initial diagnostic evaluation of patients with suspected subclavian vein (SCV) thrombosis and venous thoracic outlet syndrome (VTOS). METHODS: A retrospective single-center review was conducted for patients that underwent primary surgical treatment for VTOS between 2008 and 2017, in whom an upper extremity ultrasound had been performed as the initial diagnostic test (n = 214). Clinical and treatment characteristics were compared between patients with positive and false-negative ultrasound studies. RESULTS: There were 122 men (57%) and 92 women (43%) that had presented with spontaneous idiopathic arm swelling, including 28 (13%) with proven pulmonary embolism, at a mean age of 30.7 ± 0.8 years (range 14-69). Upper extremity ultrasound had been performed 23.8 ± 12.2 days after the onset of symptoms, with confirmation of axillary-SCV thrombosis in 169 patients (79%) and negative results in 45 (21%). Of the false-negative ultrasound study reports, only 8 (18%) acknowledged limitations in visualizing the central SCV. Definitive diagnostic imaging (DDI) had been obtained by upper extremity venography in 175 (82%), computed tomography angiography in 24 (11%), and magnetic resonance angiography in 15 (7%), with 142 (66%) undergoing catheter-directed axillary-SCV thrombolysis. The mean interval between initial ultrasound and DDI was 48.9 ± 14.2 days with no significant difference between groups, but patients with a positive ultrasound were more likely to have DDI within 48 hours than those with a false-negative ultrasound (44% vs 24%; P = .02). At the time of surgical treatment, the SCV was widely patent following paraclavicular decompression and external venolysis alone in 74 patients (35%). Patch angioplasty was performed for focal SCV stenosis in 76 (36%) and bypass graft reconstruction for long-segment axillary-SCV occlusion in 63 (29%). Patients with false-negative initial ultrasound studies were significantly more likely to require SCV bypass reconstruction than those with a positive ultrasound (44% vs 25%; P = .02). CONCLUSIONS: Duplex ultrasound has significant limitations in the initial evaluation of patients with suspected SCV thrombosis, with false-negative results in 21% of patients with proven VTOS. This is rarely acknowledged in ultrasound reports, but false-negative ultrasound studies have the potential to delay definitive imaging, thrombolysis, and further treatment for VTOS. Initial false-negative ultrasound results are associated with progressive thrombus extension and a more frequent need for SCV bypass reconstruction at the time of surgical treatment.

Effort thrombosis of the subclavian artery as a consequence of a unique anomaly.

Congenital anatomic anomalies and variations are frequent in the thoracic outlet and may be associated with clinical symptoms. Arterial thoracic outlet syndrome (TOS) is characterized by subclavian artery compression and vascular pathology, almost always in the presence of a bony abnormality. We describe here a patient with arterial thromboembolism following a fall on the outstretched arm, who was found to have subclavian artery stenosis and post-stenotic dilatation in the absence of a bony abnormality. Surgical exploration revealed a previously undescribed anomaly in which the subclavian artery passed through the costoclavicular space in front of the anterior scalene muscle, where it was subject to bony compression between the first rib and clavicle. Successful treatment was achieved by scalenectomy, first rib resection and interposition bypass graft reconstruction of the affected subclavian artery. This newly acknowledged anatomical variant adds to our understanding of the diverse factors that may contribute to development of TOS.

Ipilimumab-induced Guillain-Barré Syndrome Presenting as Dysautonomia: An Unusual Presentation of a Rare Complication of Immunotherapy.

Immune-related adverse events are common and well-documented in patients treated with ipilimumab, a cytotoxic T-lymphocyte antigen-4 monoclonal antibody approved for the treatment of metastatic and stage III melanoma. Neurological complications are rare, but widely variable and potentially devastating. Here, we discuss a case of a patient who was treated with a single dose of ipilimumab for resected stage III melanoma. She subsequently developed pandysautonomia that manifested as a tonically dilated pupil, gastrointestinal dysmotility, urinary retention, and profound orthostatic hypotension. Guillain-Barré syndrome was diagnosed on electromyography. She was treated with intravenous immunoglobulin, droxidopa, and supportive care, with prolonged but eventual recovery. Given the broadening use of ipilimumab in the treatment of advanced and metastatic melanoma, awareness and recognition of its profound immune-mediated adverse effects are essential.

A comparison of patency and interventions in thigh versus Hemodialysis Reliable Outflow grafts for chronic hemodialysis vascular access.

OBJECTIVE: With improvements in medical management and survival of patients with end-stage renal disease, maintaining durable vascular access is increasingly challenging. This study compared primary, assisted primary, and secondary patency, and procedure-specific complications, and evaluated whether the number of interventions to maintain or restore patency differed between prosthetic femoral-femoral looped inguinal access (thigh) grafts and Hemodialysis Reliable Outflow (HeRO; Hemosphere Inc, Minneapolis, Minn) grafts. METHODS: A single-center, retrospective, intention-to-treat analysis was conducted of consecutive thigh and HeRO grafts placed between May 2004 and June 2015. Medical history, interventions to maintain or restore patency, and complications were abstracted from the electronic medical record. Data were analyzed using parametric and nonparametric statistical tests, Kaplan-Meier survival methods, and multivariable proportional hazards regression and logistic regression. RESULTS: Seventy-six (43 thigh, 33 HeRO) grafts were placed in 61 patients (54% male; age 53 [standard deviation, 13] years). Median follow-up time in the intention-to-treat analysis was 21.2 months (min, 0.0; max, 85.3 months) for thigh grafts and 6.7 months (min, 0.0; max, 56.3 months) for HeRO grafts (P = .02). The groups were comparable for sex, age, coronary artery disease, diabetes mellitus, peripheral vascular disease, and smoking history (all P ≥ .12). One thigh graft (2%) and five HeRO (15%) grafts failed primarily. In the intention-to-treat analysis, patency durations were significantly longer in the thigh grafts (all log-rank P ≤ .01). Point estimates of primary patency at 6 months, 1 year, and 3 years were 61%, 46%, and 4% for the thigh grafts and 25%, 15%, and 6% for the HeRO grafts. Point estimates of assisted primary patency at 6 months, 1 year, and 3 years were 75%, 66%, and 54% for the thigh grafts and 41%, 30%, and 10% for the HeRO grafts. Point estimates of secondary patency at 6 months, 1 year, and 3 years were 88%, 88%, and 70% for the thigh grafts and 53%, 43%, and 12% for the HeRO grafts. There were no differences in ischemic (P = .63) or infectious (P = .79) complications between the groups. Multivariable logistic regression demonstrated that after adjusting for follow-up time, HeRO grafts were associated with an increased number of interventions (P = .03). CONCLUSIONS: Thigh grafts have significantly better primary, assisted primary, and secondary patency compared with HeRO grafts. There is no significant difference between thigh grafts and HeRO grafts in ischemic or infectious complications. Our logistic regression model demonstrated an association between HeRO grafts and an increased number of interventions to maintain or restore patency. Although HeRO grafts may extend the use of the upper extremity, thigh grafts provide a more durable option for chronic hemodialysis.