Adam J. Doyle

A comprehensive review of Paget-Schroetter syndrome

Venous thoracic outlet syndrome progressing to the point of axilosubclavian vein thrombosis, variously referred to as Paget-Schroetter syndrome or effort thrombosis, is a classic example of an entity which if treated correctly has minimal long-term sequelae but if ignored is associated with significant long-term morbidity. The subclavian vein is highly vulnerable to injury as it passes by the junction of the first rib and clavicle in the anterior-most part of the thoracic outlet. In addition to extrinsic compression, repetitive forces in this area frequently lead to fixed intrinsic damage and extrinsic scar tissue formation. Once primary thrombosis is recognized, catheter-directed thrombolytic therapy is usually successful if initiated within ten to 14 days of clot formation, but often unmasks an underlying lesion. The vast majority of investigators believe that decompression of the venous thoracic outlet, usually by means of first rib excision, partial anterior scalenectomy, resection of the costoclavicular ligament, and thorough external venolysis, is necessary, although opinion is less uniform as to the need for and method of treatment of the venous lesion itself. Using this algorithm, long-term success rates of 95 to 100% have been reported by many investigators. This review, in addition to discussing the overall treatment algorithm in more detail, attempts to point out controversies that still exist and research directions, both clinical and basic, that need to be pursued. Prospective randomized trials addressing this entity are surprisingly lacking, and although there is consensus based on experience, it may be necessary to step back and rigorously explore several aspects of this entity.

Costoclavicular Venous Decompression in Patients With Threatened Arteriovenous Hemodialysis Access

BACKGROUND Autologous arteriovenous fistulas are frequently threatened by central venous obstruction. Although this is frequently ascribed to indwelling catheters and neointimal venous remodeling, we believe that extrinsic compression of the subclavian vein as it passes through the costoclavicular junction (CCJ) may play a significant role in a subset of dialysis patients. METHODS We reviewed our experience with CCJ decompression for arteriovenous fistula dysfunction at our institution. Decompression followed principles for venous thoracic outlet syndrome: bony decompression with thorough venolysis, followed by central venography through the fistula and endoluminal treatment, if necessary. Patients underwent transaxillary first rib resection, or claviculectomy in the supine position in cases when reconstruction was anticipated. In all cases, the minimum exposure included 360° mobilization of the subclavian vein with resection of surrounding cicatrix to the jugular/innominate junction. RESULTS A total of 10 patients requiring decompression between November 2008 and February 2010 were included. All had severe arm swelling, four had dialysis dysfunction (postcannulation bleeding or maturation failure), two had severe arm pain, and one had a pseudoaneurysm. All patients had subclavian vein stenosis at the CCJ by venography or intravascular ultrasound. The majority of patients had balloon dilation (mean: 2.3 attempts) without success. Six patients underwent transaxillary first rib resection and four had medial claviculectomy. No patients required surgical venous reconstruction. In all, 80% of fistulas remained functionally patent, and all but one patient (who underwent ligation) had complete relief of upper arm edema. Median hospital length of stay was 2 days and mean follow-up was 7 months (range, 1-13). There was no mortality or significant morbidity. Five patients later required central venoplasty (four subclavian, mean: 1.8 attempts and one innominate) and three had stents placed (two subclavian, one innominate). CONCLUSION A significant number of patients with threatened AV access owing to central venous obstruction have lesions attributable to compression at the CCJ. Surgical decompression by means of first rib or clavicular resection and thorough external venoloysis allowed symptom-free functional salvage in 80% of these patients, all of whom would have lost their access otherwise. Because surgical reconstruction is seldom needed, the transaxillary approach may be preferable to claviculectomy. This lesion should be specifically looked for, and principles of venous thoracic outlet syndrome treatment seem to apply and be effective.

Aortic anatomic severity grade correlates with resource utilization

BACKGROUND Potential cost effectiveness of endovascular aneurysm repair (EVAR) compared with open aortic repair (OAR) is offset by the use of intraoperative adjuncts (components) or late reinterventions. Anatomic severity grade (ASG) can be used preoperatively to assess abdominal aortic aneurysms, and provide a quantitative measure of anatomic complexity. The hypothesis of this study is that ASG is directly related to the use of intraoperative adjuncts and cost of aortic repair. METHODS Patients who undergo elective OAR and EVAR for abdominal aortic aneurysms were identified over a consecutive 3-year period. ASG scores were calculated manually using three-dimensional reconstruction software by two blinded reviewers. Statistical analysis of cost data was performed using a log transformation. Regression analyses, with a continuous or dichotomous outcome, used a generalized estimating equations approach with the sandwich estimator, being robust with respect to deviations from model assumptions. RESULTS One hundred forty patients were identified for analysis, n = 33 OAR and n = 107 EVAR. The mean total cost (± standard deviation) for OAR was per thousand (k)

Differential expression of Hedgehog/Notch and transforming growth factor-β in human abdominal aortic aneurysms

38.3 ± 49.3, length of stay (LOS) 13.5 ± 14.2 days, ASG score 18.13 ± 3.78; for EVAR, mean total cost was k

Cross-sectional area for the calculation of carotid artery stenosis on computed tomographic angiography.

24.7 ± 13.0 (P = .016), LOS 3.0 ± 4.4 days (P = .012), ASG score 15.9 ± 4.13 (P = .010). In patients who underwent EVAR, 25.2% required intraoperative adjuncts, and analysis of this group revealed a mean total cost of k

Chronic Mesenteric Ischemia in a 26-Year-Old Man: Multivessel Median Arcuate Ligament Compression Syndrome

31.5 ± 15.9, ASG score 18.48 ± 3.72, and LOS 3.9 ± 4.5, which were significantly greater compared with cases without adjunctive procedures. An ASG score of ≥15 correlated with an increased propensity for requirement of intraoperative adjuncts; odds ratio, 5.75 (95% confidence interval, 1.82-18.19). ASG >15 was also associated with chronic kidney disease, end stage renal disease, hypertension, female sex, increased cost, and use of adjunctive procedures. CONCLUSIONS Complex aneurysm anatomy correlates with increased total cost and need for adjunctive procedures during EVAR. Preoperative assessment with ASG scores can delineate patients at greater risk for increased resource use. Patient comorbid factors are associated with anatomic complexity defined according to ASG. A critical examination of the relationship between anatomic complexity and finances is required within the context of aggressive endovascular treatment strategies and shifts toward value-based reimbursement.

Hybrid repair of an abdominal aortic aneurysm in a patient with a horseshoe kidney

OBJECTIVE The molecular mechanisms leading to the development of abdominal aortic aneurysms (AAAs) remain poorly understood. The aim of this study was to determine the expression of Sonic Hedgehog (SHh), transforming growth factor β (TGF-β), and Notch signaling components in human aneurysmal and nonaneurysmal aorta in vivo. METHODS Paired tissue samples were obtained from aneurysmal and nonaneurysmal (control) segments of the aortic wall of eight patients with suitable anatomy undergoing open repair of infrarenal AAAs. Protein and messenger RNA (mRNA) expression levels were determined by Western blot and quantitative real-time polymerase chain reaction analysis. RESULTS Aneurysm development resulted in a significant reduction in vascular smooth muscle (vSMC) differentiation genes α-actin and SMC22α at both mRNA and protein levels. In parallel experiments, an 80.0% ± 15% reduction in SHh protein expression was observed in aneurysmal tissue compared with control. SHh and Ptc-1 mRNA levels were also significantly decreased, by 82.0% ± 10% and 75.0% ± 5%, respectively, in aneurysmal tissue compared with nonaneurysmal control tissue. Similarly, there was a 50.0% ± 9% and 60.0% ± 4% reduction in Notch receptor 1 intracellular domain and Hrt-2 protein expression, respectively, in addition to significant reductions in Notch 1, Notch ligand Delta like 4, and Hrt-2 mRNA expression in aneurysmal tissue compared with nonaneurysmal tissue. There was no change in Hrt-1 expression observed in aneurysmal tissue compared with control. In parallel experiments, we found a 2.2 ± 0.2-fold and a 5.6 ± 2.2-fold increase in TGF-β mRNA and protein expression, respectively, in aneurysmal tissue compared with nonaneurysmal tissue. In vitro, Hedgehog signaling inhibition with cyclopamine in human aortic SMCs resulted in decreased Hedgehog/Notch signaling component and vSMC differentiation gene expression. Moreover, cyclopamine significantly increased TGF-β1 mRNA expression by 2.6 ± 0.9-fold. CONCLUSIONS These results suggest that SHh/Notch and TGF-β signaling are differentially regulated in aneurysmal tissue compared with nonaneurysmal tissue. Changes in these signaling pathways and the resulting changes in vSMC content may play a causative role in the development of AAAs.

Correlation of intravascular ultrasound and computed tomography scan measurements for placement of intravascular ultrasound-guided inferior vena cava filters

OBJECTIVE The use of cross-sectional area (CSA) measurements obtained from computed tomographic angiography (CTA) for the calculation of carotid artery stenosis has been suggested but not yet validated in a large population. The objective of this study was to determine whether CTA-derived CSA measurements were able to predict carotid stenosis with a level of confidence similar to CTA-derived diameter measurements, using Strandness criteria applied to carotid duplex ultrasound (CDUS) as a surrogate for true stenosis. METHODS A retrospective review was conducted to identify patients who underwent both CDUS and CTA between 2000 and 2009. Percent stenosis was calculated using the North American Symptomatic Carotid Endarterectomy Trial (NASCET) formula with diameter measurements and again with CSA measurements. A nonparametric correlation coefficient was calculated to detect correlation between the two groups. Two-dimensional receiver-operating characteristic curves with corresponding area under the curve (AUC) statistics were generated for >50% stenosis and >80% stenosis. Three-dimensional receiver-operating characteristic plots with corresponding volume under the surface (VUS) statistics were generated to measure the comparative accuracy of diameter-based and CSA-based stenosis for <50%, 50%-79%, and >80% stenosis. RESULTS A total of 575 vessels in 313 patients were included in the study. Spearmans correlation coefficient between diameter and CSA-derived stenosis was ρ = 0.938 (95% confidence interval [CI], 0.927-0.947; P < .0001). For diameter-derived stenosis, AUC was 0.905 (95% CI, 0.878-0.932; P < .0001) for >50% stenosis and 0.950 (95% CI, 0.928-0.972; P < .0001) for 80%-99% stenosis. For CSA-derived percent stenosis, the AUC was 0.908 (95% CI, 0.882-0.935; P < .0001) for >50% stenosis and 0.935 (95% CI, 0.908-0.961; P < .0001) for 80%-99%. The nonparametric estimate for VUS in the diameter-based stenosis group was 0.761, whereas in the CSA-based group, the VUS was 0.735. The difference between VUS was 0.026 (95% CI, -0.022 and 0.077; P = .318). CONCLUSIONS These data support the use of CTA as an accurate method of calculating carotid artery stenosis based on agreement with Strandness criteria applied to CDUS velocities. When additional imaging beyond CDUS is necessary, we report no significant difference between diameter and CSA measurements obtained from CTA for preoperative evaluation of carotid disease.

Outcomes After Treatment of VTOS

BACKGROUND Chronic mesenteric ischemia (CMI) is a rare diagnosis for patients in their third decade of life. Other conditions can mimic the signs and symptoms of CMI, including median arcuate ligament syndrome (MALS), primary arteritides, and congenital anomalies. Here, we present the case of a 26-year-old man who presented with CMI and multivessel mesenteric occlusive disease. METHODS A 26-year-old man presented with a 6-month history of 40-pound weight loss, postprandial abdominal pain, and food fear. His physical examination showed a scaphoid abdomen with no tenderness. Findings from laboratory evaluation were normal. Computed tomography angiogram revealed celiac artery (CA) occlusion and >80% superior mesenteric artery (SMA) stenosis, with a large marginal artery of Drummond supplying collateral circulation. RESULTS A retroperitoneal exposure of the perivisceral aorta was performed. Surgical exposure revealed compression of both CA and SMA by the MAL. The total distance of caudal arterial displacement was >3 cm. Both the CA and SMA were chronically stenotic/occluded secondary to this compression. After division of the MAL, a retrograde aortoceliac and aortomesenteric bypass was performed for mesenteric revascularization. The patient recovered uneventfully and was discharged home on the third day after surgery tolerating a full diet. CONCLUSIONS MALS is a pathologic entity that can affect more than the CA. This case demonstrates multivessel, mesenteric arterial insufficiency secondary to MALS sufficient to promote IMA collateralization of the SMA circulation. In young patients with CMI, multivessel MALS must be considered. In addition to MAL release, arterial revascularization may be necessary owing to stenoses from chronic compression.

Superior 3-Year Value of Open and Endovascular Repair of Abdominal Aortic Aneurysm with High-Volume Providers

Prior reports of conventional open abdominal aortic aneurysm repair in the setting of a horseshoe kidney have been challenging and complicated by renal infarction, neuralgia, and collecting system disruption. We aimed to demonstrate the efficacy of an alternative repair method consisting of visceral debranching followed by endovascular aneurysm repair.