Factors associated with successful median arcuate ligament release in an international, multi-institutional cohort.

OBJECTIVE: Prior research on median arcuate ligament syndrome has been limited to institutional case series, making the optimal approach to median arcuate ligament release (MALR) and resulting outcomes unclear. In the present study, we compared the outcomes of different approaches to MALR and determined the predictors of long-term treatment failure. METHODS: The Vascular Low Frequency Disease Consortium is an international, multi-institutional research consortium. Data on open, laparoscopic, and robotic MALR performed from 2000 to 2020 were gathered. The primary outcome was treatment failure, defined as no improvement in median arcuate ligament syndrome symptoms after MALR or symptom recurrence between MALR and the last clinical follow-up. RESULTS: For 516 patients treated at 24 institutions, open, laparoscopic, and robotic MALR had been performed in 227 (44.0%), 235 (45.5%), and 54 (10.5%) patients, respectively. Perioperative complications (ileus, cardiac, and wound complications; readmissions; unplanned procedures) occurred in 19.2% (open, 30.0%; laparoscopic, 8.9%; robotic, 18.5%; P < .001). The median follow-up was 1.59 years (interquartile range, 0.38-4.35 years). For the 488 patients with follow-up data available, 287 (58.8%) had had full relief, 119 (24.4%) had had partial relief, and 82 (16.8%) had derived no benefit from MALR. The 1- and 3-year freedom from treatment failure for the overall cohort was 63.8% (95% confidence interval [CI], 59.0%-68.3%) and 51.9% (95% CI, 46.1%-57.3%), respectively. The factors associated with an increased hazard of treatment failure on multivariable analysis included robotic MALR (hazard ratio [HR], 1.73; 95% CI, 1.16-2.59; P = .007), a history of gastroparesis (HR, 1.83; 95% CI, 1.09-3.09; P = .023), abdominal cancer (HR, 10.3; 95% CI, 3.06-34.6; P < .001), dysphagia and/or odynophagia (HR, 2.44; 95% CI, 1.27-4.69; P = .008), no relief from a celiac plexus block (HR, 2.18; 95% CI, 1.00-4.72; P = .049), and an increasing number of preoperative pain locations (HR, 1.12 per location; 95% CI, 1.00-1.25; P = .042). The factors associated with a lower hazard included increasing age (HR, 0.99 per increasing year; 95% CI, 0.98-1.0; P = .012) and an increasing number of preoperative diagnostic gastrointestinal studies (HR, 0.84 per study; 95% CI, 0.74-0.96; P = .012) Open and laparoscopic MALR resulted in similar long-term freedom from treatment failure. No radiographic parameters were associated with differences in treatment failure. CONCLUSIONS: No difference was found in long-term failure after open vs laparoscopic MALR; however, open release was associated with higher perioperative morbidity. These results support the use of a preoperative celiac plexus block to aid in patient selection. Operative candidates for MALR should be counseled regarding the factors associated with treatment failure and the relatively high overall rate of treatment failure.

Utility of Hook Sign in the Diagnosis of Median Arcuate Ligament Syndrome.

BACKGROUND: Median arcuate ligament syndrome (MALS) is a clinical syndrome caused by compression of the celiac artery by the median arcuate ligament that often manifests with nonspecific abdominal pain. Identification of this syndrome is often dependent on imaging of compression and upward bending of the celiac artery by lateral computed tomography angiography, the so-called "hook sign." The purpose of this study was to assess the relationship of radiologic characteristics of the celiac artery to clinically relevant MALS. METHODS: An institutional review board-approved retrospective chart review from 2,000 to 2,021 of 293 patients at a tertiary academic center diagnosed with celiac artery compression (CAC) was performed. Patient demographics and symptoms of 69 patients who were diagnosed with symptomatic MALS were compared to 224 patients without MALS (but with CAC) per electronic medical record review. Computed tomography angiography images were reviewed and the fold angle (FA) was measured. The presence of a hook sign (defined as a visual FA < 135°), as well as stenosis (defined as >50% of luminal narrowing on imaging) were recorded. Wilcoxon rank-sum test and Chi-squared test were used for comparative analysis. Logistic model was run to relate the presence of MALS with comorbidities and radiographic findings. RESULTS: Imaging was available in 59 patients (25 males, 34 females) and 157 patients (60 males, 97 females) with and without MALS, respectively. Patients with MALS were more likely to have a more severe FA (120.7 ± 33.6 vs. 134.8 ± 27.9, P = 0.002). Males with MALS were also more likely to have a more severe FA compared with males without MALS (111.1 ± 33.7 vs. 130.4 ± 30.4, P = 0.015). In patients with body mass index (BMI) >25, MALS patients also had narrower FA compared with patients without MALS (112.6 ± 30.5 vs. 131.7 ± 30.3, P = 0.001). The FA was negatively correlated with BMI in patients with CAC. The hook sign and stenosis were associated with diagnosis of MALS (59.3% vs. 28.7%, P < 0.001, and 75.7% vs. 45.2%, P < 0.001, respectively). In logistic regression, pain, stenosis, and a narrow FA were statistically significant predictors of the presence of MALS. CONCLUSIONS: The upward deflection of the celiac artery in patients with MALS is more severe compared with patients without MALS. Consistent with prior literature, this bending of the celiac artery is negatively correlated with BMI in patients with and without MALS. When demographic variables and comorbidities are considered, a narrow FA is a statistically significant predictor of MALS. Regardless of MALS diagnosis, a hook sign was associated with narrower FA. While demographics and imaging findings may inform MALS diagnosis, clinicians should not rely on a visual assessment of a hook sign but should quantitatively measure the anatomic bending angle of the celiac artery to assist with the diagnosis and understand the outcomes.

Higher Inpatient Mortality for Women after Intervention for Lifestyle Limiting Claudication.

BACKGROUND: Sex-related differences in outcomes have been identified in patients with peripheral artery disease (PAD). We hypothesized that women with PAD would have equivalent inpatient mortality with men after vascular intervention. METHODS: Patients with a primary diagnosis of critical limb ischemia (CLI) or lifestyle-limiting claudication (LLC) receiving endovascular (EV) or open surgical repair from 2003-2012 were identified from the Nationwide Inpatient Sample. Demographics, comorbidities, and inpatient mortality were analyzed by chi-squared tests of independence and independent-samples t-tests. Logistic regression analysis was performed to identify predictors of inpatient mortality. SPSS 24 software was used with P < 0.05 considered statistically significant. RESULTS: We identified 139,435 (59,432 women and 80,003 men) individuals meeting the aforementioned criteria. Women were older than men (71.5 years vs. 68.2, P < 0.001). There were no differences in racial distribution but women had lower rates of diabetes (38.6% vs. 39.7%, P < 0.001), chronic obstructive pulmonary disease (17.9% vs. 19.5%, P < 0.001), and coronary artery disease (38.6% vs. 47.4%, P < 0.001), while having a higher rate of hypertension (60.0% vs. 56.1%, P < 0.001). There was no sex-related difference in the rate of chronic renal failure. Women had higher inpatient mortality than men after vascular intervention (1.3% vs. 1.1%, P < 0.001). When stratified by surgical technique, women also had higher inpatient mortality after EV repair (1.0% vs. 0.8%, P < 0.05) and open repair (1.9% vs 1.3%, P < 0.001). When separated by admitting diagnosis, women with CLI had higher inpatient mortality than men after open surgery (2.3% vs. 1.9%, P < 0.05) but not after EV intervention. Women with LLC had higher inpatient mortality after both open (0.6% vs. 0.3%, P < 0.05) and EV surgery (0.3% vs. 0.1%, P < 0.05). Regression analysis revealed female sex as an independent predictor of inpatient mortality in patients with LLC (OR, 1.74; 95% CI 1.30-2.32, P < 0.001) but not CLI. CONCLUSIONS: Women had higher inpatient mortality than men after vascular intervention for PAD. Women were also older and more likely to have EV intervention than men. Subgroup analysis suggests that these sex-related differences in inpatient mortality are more pronounced in patients with LLC than with CLI. Furthermore, regression analysis shows that sex is a significant predictor for patients diagnosed with LLC but not with CLI. Treatment guidelines should include consideration of sex in their indications for revascularization, particularly for patients diagnosed with LLC.

Endovascular interventions decrease length of hospitalization and are cost-effective in acute mesenteric ischemia.

OBJECTIVE: Acute mesenteric ischemia (AMI) continues to be one of the most devastating diagnoses requiring emergent vascular intervention. There is a national trend toward increased use of endovascular procedures, with improved survival for the treatment of these patients. Our aim was to evaluate whether this trend has changed the treatment of AMI and the subsequent impact on length of hospitalization and hospitalization costs. METHODS: We identified all patients admitted for AMI from the National Inpatient Sample from 2004 to 2014 who received open surgical revascularization (OPEN) or an endovascular intervention (ENDO). Primary end points included length of hospital stay and cost of hospitalization. Our secondary end points included acute kidney injury (AKI), in-hospital mortality, and routine discharge. RESULTS: Among 10,381 discharges identified in the data set, 3833 (37%; 97.5% confidence interval [CI], 35%-39%) were male patients with a mean age of 69 years (range, 18-98 years); 4543 (44%; 97.5% CI, 41%-47%) patients were treated ENDO, and 5839 (56%; 97.5% CI, 53%-59%) patients were treated OPEN. Although a higher proportion of patients in the ENDO group (28%; 97.5% CI, 24%-31%) vs the OPEN group (14%; 97.5% CI, 11%-16%) had a moderate to severe Charlson Comorbidity Index (P < .0001), ENDO was associated with a lower mortality rate (12.3% [97.5% CI, 9.8%-14.8%] vs 33.1% [97.5% CI, 29.9%-36.2%]; P < .0001) and a lower mean hospitalization cost ($41,615 [97.5% CI, $38,663-$44,567] vs $60,286 [97.5% CI, $56,736-$63,836]; P < .0001). After propensity-adjusted logistic regression analysis, OPEN retained a significant association with higher mortality than ENDO (odds ratio, 3.0; 97.5% CI, 2.2-4.1) and with higher costs (mean, $9196; 97.5% CI, $3797-$14,595). Patients in the OPEN group had higher risk for AKI (P < .0001) and discharge to a skilled nursing facility (P < .0001) rather than home. CONCLUSIONS: Although the rate of ENDO continues to rise nationally, it still has not surpassed OPEN revascularization in the face of AMI. Patients treated endovascularly demonstrated one-third the rate of in-hospital mortality (odds ratio, 3.0; 97.5% CI, 2.2-4.1), an increased hazard ratio for discharge alive (hazard ratio, 2.27; 97.5% CI, 2.00-2.58), and a cost saving of $9196 (97.5% CI, $3797-$14,595) per hospitalization. Furthermore, they were less likely to develop AKI and to be discharged home after hospitalization.

Improved mortality in treatment of patients with endovascular interventions for chronic mesenteric ischemia.

OBJECTIVE: Chronic mesenteric ischemia (CMI) continues to be a devastating diagnosis. There is a national trend toward increased use of endovascular procedures with improved survival for the treatment of these patients. Our aim was to evaluate whether this trend has changed CMI patients' length of hospitalization and health care cost. METHODS: We identified all patients admitted for CMI from the National Inpatient Sample (NIS) from 2000 to 2014. Our primary end points included length of hospital stay (LOS) and cost of hospitalization (COH). Our secondary end points included mortality assessment of the CMI hospitalization. RESULTS: There were 15,475 patients admitted for CMI. The mean age of patients was 71 years, and 4022 (26.0%) were male. There were 10,920 (70.6%) patients treated endovascularly (ENDO) and 4555 (29.4%) patients treated in an open fashion (OPEN). Although a higher proportion of patients in the ENDO (43.3%) group vs OPEN (33.1%) had a Charlson Comorbidity Index score of ≥2 (P < .0001), they had a lower mortality rate (2.4% vs 8.7%; P < .0001), lower mean LOS (6.3 vs 14.0 days; P < .0001), and lower COH ($21,686 vs $42,974; P < .0001). After adjusting for clinical and hospital factors, OPEN continued to demonstrate higher mortality than ENDO (odds ratio, 7.2; 95% confidence interval, 4.9-10.6; P < .0001), longer LOS (mean, +9.7 days; P < .0001), and higher COH (mean, +$25,834; P < .0001). CONCLUSIONS: The rate of ENDO continues to rise nationally in the treatment of CMI patients. After adjusting for clinical and hospital factors, patients in the ENDO group tend to have lower in-hospital mortality of 2.4% and lower LOS by 10 days, and they incur a cost saving of >$25,000 compared with patients in the OPEN group. ENDO should be considered first line of therapy for patients with CMI.

Increased mortality in octogenarians treated for lifestyle limiting claudication.

OBJECTIVE: Treatment for lifestyle limiting claudication (LLC) that is due to infra-inguinal peripheral artery disease relies on either bypass, angioplasty, and/or stenting. Given the enthusiasm and shift toward more endovascular therapy for treatment of LLC, we sought to analyze whether octogenarians benefit from infra-inguinal interventions in the same manner as their younger counterparts. METHODS: We identified all patients admitted for elective treatment of LLC from the Nationwide Inpatient Sample from 2003 to 2012, who received open surgical or endovascular intervention for infra-inguinal peripheral arterial disease. These patients were divided into two groups including those between the ages 60-80 years (younger cohort) and those older than 80 years (octogenarians). Primary end-points included morbidity and mortality and the secondary end-points were length of hospital stay (LOS) and disposition after dismissal. RESULTS: Among 59,323 discharges identified in the dataset, 34,658 (58%) were males. There were 50,323 (85%) patients in the younger cohort and 9,000 (15%) octogenarians. The mean age was 69.9 ± 5.7 years and 84.2 ± 3.0 years for the younger cohort and octogenarians, respectively. The mean Charlson comorbidity index (CCI) was higher in our younger cohort (2.1 ± 1.1, P < 0.001). Octogenarians mainly treated with open surgery prior to 2004 are now treated endovascularly and this trend has remained stable. The younger cohort's treatment modality has fluctuated through the study period and most recently is treated mainly with open surgery. The rate of acute kidney injury, exacerbation of congestive heart failure and mortality was higher in octogenarians (P < 0.001). The rate of infectious wound complications was higher in the younger cohort (P < 0.05). Octogenarians have longer LOS and are dismissed in higher percentage to a skilled nursing facility (P < 0.001). On binary logistic regression analysis, age over 80 years, female sex, higher CCI and having an open as opposed to an endovascular procedure are independent predictors of in-hospital mortality. CONCLUSIONS: Although endovascular techniques seem to dominate the care for octogenarians with LLC, the overall morbidity and mortality rates are significantly higher in this patient population. Other options such as medical management and/or supervised exercise therapy should be explored in this patient group.

Regulation of Yes-Associated Protein by Laminar Flow.

BACKGROUND: The cells lining the endothelium of blood vessels are recognized as playing critical roles in vascular health and disease. The mechanisms that regulate endothelial cells (ECs) proliferation and release of mediators remain poorly understood but represent a potential source of disease modulation. Actin-cytoskeleton remodeling and cell shape have been suggested as key regulators of phosphorylation of yes-associated protein (YAP) which controls cellular growth and proliferation. Because different types of flow have been shown to affect cell shape and cytoskeleton differently, we hypothesized that the level of phosphorylated yes-associated protein (pYAP; serine 127) decreases in EC exposed to pulsatile uniform flow or steady laminar flow, whereas exposure to pulsatile disturbed flow causes an increase or no change. METHODS: Human umbilical vein endothelial cells (HUVECs) were exposed to pulsatile uniform flow, pulsatile disturbed flow, or steady laminar flow and analyzed by immunoblotting. RESULTS: Exposure of HUVECs to steady laminar flow caused a significant decrease in the levels of pYAP (69.7 + 2.6%, P < 0.05), whereas total YAP levels remained nearly unchanged. Conversely, exposure to either pulsatile uniform or disturbed flow caused a significant decrease in the levels of both pYAP (63.2 + 10.9% and 69.8 + 11.9%, respectively; P < 0.05) and total YAP (57.1 + 17.8% and 58.4 + 16.3%, respectively; P < 0.05). Addition of MG132, a ubiquitin-proteasome system inhibitor, failed to significantly inhibit the decrease in the levels of total YAP in HUVECs exposed to either pulsatile uniform or disturbed flow. CONCLUSIONS: Flow causes a decrease in pYAP. The observed decrease in total YAP levels with pulsatile flow is due to degradation via a proteasome-independent mechanism. This may be a potential target for intervention for disease states such as atherosclerosis and intimal hyperplasia.

Acute Limb Ischemia in an 8-Year-Old Patient: A Case Report.

We report the case of an 8-year-old patient with a history of nephrotic syndrome, who presented to the emergency department with right foot pain. The patient's mother described intermittent pain that woke her son from sleep and was accompanied by the foot turning purple and becoming cold to touch. Physical examination revealed capillary refill of over 10 seconds in the right and less than 2 seconds in the left foot. Ankle-brachial indices (ABIs) were 0.0 on the right and 0.96 on the left. The patient was admitted and started on therapeutic intravenous heparin. After consultation with his parents, right lower extremity angiography and thrombolysis was performed over 2 days. He subsequently underwent fasciotomy and amputation of the tip of all 5 toes. Eighteen months later, there is no leg length discrepancy, he is walking with foot inserts and has normal ABIs bilaterally.

Explantation of infected aortic aneurysm and endograft with ascending aorta to mesenteric bypass for mesenteric ischemia.

A 65-year-old man presented with an infected perivisceral aortic aneurysm after previous treatment of an abdominal aortic aneurysm with an endograft. On presentation, he was septic and had occlusion of the celiac, superior mesenteric, inferior mesenteric, and bilateral renal arteries. He underwent a three-stage procedure: first, axillobifemoral bypass; then resection of the thoracoabdominal aorta; and finally bypass from the ascending aorta to the celiac and superior mesenteric arteries with a rifampin-soaked Gelsoft graft (Vascutek, Renfrewshire, Scotland). The abdominal pain resolved, and the patient remains symptom free 10 months postoperatively. This rare surgical revascularization technique offered a nontraditional solution to a difficult surgical issue.

Percutaneous endovascular aneurysm repair in morbidly obese patients.

OBJECTIVE: Endovascular aneurysm repair (EVAR) with percutaneous femoral access (PEVAR) has several potential advantages. Morbidly obese (MO) patients present unique anatomical challenges and have not been specifically studied. This study examines the trends in the use of PEVAR and its surgical outcomes compared with open femoral cutdown (CEVAR) in MO patients. METHODS: The American College of Surgeons National Surgical Quality Improvement Program files for the years 2005 to 2013 were reviewed. The study included all MO patients (body mass index [BMI] ≥40 kg/m2) undergoing EVAR. Patients were categorized as having CEVAR if they had any one of 11 selected Current Procedural Terminology (American Medical Association, Chicago, Ill) codes describing an open femoral procedure. The PEVAR group included any remaining patients who had only codes for EVAR and endovascular procedures. Linear correlation was used to evaluate temporal trends in the use of PEVAR among MO patients. Baseline comorbidities and surgical outcomes were compared between the PEVAR and CEVAR groups using χ2 tests or t-tests. RESULTS: There were 833 MO patients (470 CEVAR and 363 PEVAR) constituting 3.0% of all patients undergoing EVAR. The use of PEVAR in MO patients significantly increased from 27.3% of total EVARs in the years 2005 to 2006 to 48.6% in 2013 (P = .039). The two groups had similar baseline characteristics, including age, BMI, comorbidities, and emergency procedures, except for history of severe chronic obstructive pulmonary disease (29.6% CEVAR vs 22.6% PEVAR; P = .024). PEVAR patients had shorter duration of anesthesia (244 vs 260 minutes; P = .048) and shorter total operation time (158 vs 174 minutes; P = .002). PEVAR patients had significantly decreased wound complications (5.5% vs 9.4%; P = .039). There was a trend towards PEVAR patients being more likely to be discharged home than to a facility (93.6% vs 87.8%; P = .060). There was no difference in any other complication or mortality. A subgroup analysis of 109 superobese patients with BMI ≥50 kg/mg2 (59 CEVAR and 50 PEVAR) demonstrated no significant differences in outcomes between groups. CONCLUSIONS: PEVAR is increasingly used in MO patients and decreases operating time and rates of wound infection compared with CEVAR. The advantages of PEVAR seem to be lost in the superobese patients.

Clinical Decision Analysis and Markov Modeling for Surgeons: An Introductory Overview.

This study addresses the use of decision analysis and Markov models to make contemplated decisions for surgical problems. Decision analysis and decision modeling in surgical research are increasing, but many surgeons are unfamiliar with the techniques and are skeptical of the results. The goal of this review is to familiarize surgeons with techniques and terminology used in decision analytic papers, to provide the reader a practical guide to read these papers, and to ensure that surgeons can critically appraise the quality of published clinical decision models and draw well founded conclusions from such reports.First, a brief explanation of decision analysis and Markov models is presented in simple steps, followed by an overview of the components of a decision and Markov model. Subsequently, commonly used terms and definitions are described and explained, including quality-adjusted life-years, disability-adjusted life-years, discounting, half-cycle correction, cycle length, probabilistic sensitivity analysis, incremental cost-effectiveness ratio, and the willingness-to-pay threshold.Finally, the advantages and limitations of research with Markov models are described, and new modeling techniques and future perspectives are discussed. It is important that surgeons are able to understand conclusions from decision analytic studies and are familiar with the specific definitions of the terminology used in the field to keep up with surgical research. Decision analysis can guide treatment strategies when complex clinical questions need to be answered and is a necessary and useful addition to the surgical research armamentarium.

Use of hyperspectral imaging to assess endothelial dysfunction in peripheral arterial disease.

BACKGROUND: Hyperspectral imaging (HSI) is a technology that with limited training can noninvasively measure oxygenated hemoglobin (oxyHb) and deoxygenated hemoglobin concentrations in the skin to create an oxygenation map. This pilot study determined whether HSI could be used to demonstrate vascular dysfunction in the upper extremity of patients with peripheral artery disease (PAD) and coronary artery disease (CAD). METHODS: This prospective study included 93 consecutive, consented patients presenting to the vascular clinic, with and without diagnosed arterial disease, and healthy volunteers. Patients underwent HSI at the upper arm, forearm, and palm before and after cuff occlusion (50 mm Hg above systolic) for 5 minutes. Medical records of enrolled patients were reviewed for demographic data, medications, surgical history, and other pertinent information. RESULTS: Significant changes occurred with oxyHb, with minimal to no effects on deoxygenated hemoglobin. The highest values of oxyHb were detected in the upper arm, followed by the forearm and hand. The absolute and percentage change in oxyHb measured in the upper arm and forearm was significantly reduced in controls aged >40 years compared with controls aged <40 years. Significant differences were noted in the upper arm oxyHb absolute change in response to cuff occlusion comparing PAD or CAD (n = 47) vs the older control cohort (P = .028). When the 23 patients with PAD only were separated out, the upper arm oxyHb response to cuff occlusion is even more significantly impaired (P < .01) compared with controls. CONCLUSIONS: Our study suggests the ability of HSI to assess the presence of PAD or CAD based on systemic vascular dysfunction at sites remote from the clinically diseased vascular bed. This could enable early screening and tracking of arterial disease patients before the development of clinically advanced disease.

PECAM-1 phosphorylation and tissue factor expression in HUVECs exposed to uniform and disturbed pulsatile flow and chemical stimuli.

INTRODUCTION: We analyzed the relationship between platelet endothelial cell adhesion molecule-1 (PECAM-1) activation and tissue factor (TF) RNA expression in human umbilical vein endothelial cells (HUVECs) exposed to mechanical and chemical stimulation. METHODS: Fifty percent confluent and 100% confluent HUVEC cultures were exposed to pulsatile forward flow, as a model for uniform flow, or pulsatile to-and-fro flow, as a model for disturbed flow, using a parallel-plate flow chamber system for up to 4 hours in the presence or absence of 4 U/mL thrombin. Protein lysates were immunoprecipitated for PECAM-1 and then immunoblotted with anti-phospho-tyrosine antibody. TF RNA expression was determined using quantitative reverse transcription polymerase chain reaction. RESULTS: HUVECs exposed to disturbed flow induced higher TF expression at 4 hours than HUVECs exposed to uniform flow in sparse cultures (16.8 ± 5.8 vs 5.1 ± 1.2; P < .05). HUVECs exposed to disturbed flow and thrombin induced higher TF RNA expression at 4 hours than cultures exposed to uniform flow and thrombin in both confluent (47.0 ± 6.0 vs 30.2 ± 4.9; P < .05) and sparse (72.3 ± 10.7 vs 49.8 ± 4.7; P < .05) cultures. In confluent HUVEC cultures, PECAM-1 is minimally phosphorylated by disturbed and uniform flow, while in sparse HUVEC cultures, PECAM-1 phosphorylation at 15 minutes is greater in both disturbed and uniform flow (2.0 ± 0.2 and 2.1 ± 0.4 respectively; P < .05). Thrombin treatment of static HUVECs exhibited greater PECAM-1 phosphorylation at 15 minutes in confluent compared with sparse cultures (3.0 ± 0.5 vs 2.3 ± 0.1; P < .05). PECAM-1 phosphorylation of HUVECs exposed to both flow and thrombin is significantly higher in sparse cultures compared with either flow or thrombin stimulation alone but was suppressed in confluent cultures. CONCLUSIONS: The significantly higher TF RNA expression induced by disturbed flow and cell confluence indicates that suppression of PECAM-1 phosphorylation may be an important contributory mechanical signal pathway that promotes TF expression when HUVECs are exposed to disturbed flow.

Consequences of hypogastric artery ligation, embolization, or coverage.

OBJECTIVE: Interruption of the hypogastric artery by ligation, embolization, or coverage frequently results in ischemic complications. The aim of this study was to compare the rate and risk factors for the development of ischemic complications after interruption of the hypogastric artery in obstetrics and gynecology (OBG), vascular surgery, oncology, and trauma patients. METHODS: MEDLINE, Ovid, and Scopus were searched for articles containing data of patients who underwent interruption of the hypogastric artery. Based on the indication, details of the procedure, and complications developed, data were categorized and a systematic review was done to evaluate any significant differences. RESULTS: A total of 394 patients (median age, 48.5 years) from 124 papers were included in the study; 31% of the study population was male and 69% was female. Indication for interruption was OBG related in 53.3%, vascular surgery related in 25.1%, oncology related in 17.5%, and trauma related in 4.1% of patients. Overall ischemic complication rate was 22.6%, comprising buttock claudication in 12.2%, buttock necrosis in 4.8%, erectile dysfunction in 2.7%, spinal cord ischemia in 4.0%, colonic ischemia in 2.5%, and bladder necrosis in 0.8%. Complications were fewer in patients younger than the median age of 48.5 years (12.8%) compared with those older than the median age (36.3%; P < .01), women compared with men (13.1% vs 41.7%; P < .01), OBG patients compared with vascular surgery patients (9.5% vs 37.4%; P < .01), patients after ligation compared with embolization (9.4% vs 31.0%; P < .01), and proximal interruption compared with distal interruption (19.6% vs 51.4%; P < .01). No significant difference in complications was seen after bilateral interruption compared with unilateral interruption (20.6% vs 27.1%; P > .05). Similarly, no significant difference in complication rate was seen with the type of embolization material used. Among OBG patients, ligations resulted in fewer complications compared with embolization (4.1% vs 16.7%; P < .01). Among vascular surgery patients, bilateral embolization resulted in a higher rate of complications compared with bilateral ligation (83.3% vs 30.5%; P < .01). Among oncology patients, fewer complications were seen after proximal interruption compared with distal interruption (25.5% vs 75%; P = .01). No significant differences in outcome were seen with regard to gender, laterality, and material used for embolization when patients were compared within each specialty. CONCLUSIONS: Interruption of the hypogastric artery is relatively safe in young and OBG patients compared with vascular surgery and oncology patients. Ligation of the hypogastric arteries is preferred to embolization, and proximal embolization should be preferred to distal embolization to decrease the risk of ischemic complications. Randomized controlled trials with larger sample size are needed to definitively elucidate clear risk factors for development of complications after hypogastric artery interruption.

Cost-effectiveness of endovascular repair, open repair, and conservative management of splenic artery aneurysms.

OBJECTIVE: Open repair (OPEN) and conservative management (CONS) have been the treatments of choice for splenic artery aneurysms (SAAs) for many years. Endovascular repair (EV) has been increasingly used with good short-term results. In this study, we evaluated the cost-effectiveness of OPEN, EV, and CONS for the treatment of SAAs. METHODS: A decision analysis model was developed using TreeAge Pro 2013 software (TreeAge Inc, Williamstown, Mass) to evaluate the cost-effectiveness of the different treatments for SAAs. A hypothetical cohort of 10,000 55-year-old female patients with SAAs was assessed in the reference-case analysis. Perioperative mortality, disease-specific mortality rates, complications, rupture risks, and reinterventions were retrieved from a recent and extensive meta-analysis. Costs were analyzed with the 2014 Medicare database. The willingness to pay was set to $60,000/quality-adjusted life years (QALYs). Outcomes evaluated were QALYs, costs from the health care perspective, and the incremental cost-effectiveness ratio (ICER). Extensive sensitivity analyses were performed and different clinical scenarios evaluated. Probabilistic sensitivity analysis was performed to include the uncertainty around the variables. A flowchart for clinical decision-making was developed. RESULTS: For a 55-year-old female patient with a SAA, EV has the highest QALYs (11.32; 95% credibility interval [CI], 9.52-13.17), followed by OPEN (10.48; 95% CI, 8.75-12.25) and CONS (10.39; 95% CI, 8.96-11.87). The difference in effect for 55-year-old female patients between EV and OPEN is 0.84 QALY (95% CI, 0.42-1.34), comparable with 10 months in perfect health. EV is more effective and less costly than OPEN and more effective and more expensive compared with CONS, with an ICER of $17,154/QALY. Moreover, OPEN, with an ICER of $223,166/QALY, is not cost-effective compared with CONS. In elderly individuals (age >78 years), the ICER of EV vs CONS is $60,503/QALY and increases further with age, making EV no longer cost-effective. Very elderly patients (age >93 years) have higher QALYs and lower costs when treated with CONS. The EV group has the highest number of expected reinterventions, followed by CONS and OPEN, and the number of expected reinterventions decreases with age. CONCLUSIONS: EV is the most cost-effective treatment for most patient groups with SAAs, independent of the sex and risk profile of the patient. EV is superior to OPEN, being both cost-saving and more effective in all age groups. Elderly patients should be considered for CONS, based on the high costs in relation to the very small gain in health when treated with EV. The very elderly should be treated with CONS.

Open repair, endovascular repair, and conservative management of true splenic artery aneurysms.

OBJECTIVE: True splenic artery aneurysms (SAAs) are a rare but potentially fatal pathology. For many years, open repair (OPEN) and conservative management (CONS) were the treatments of choice, but throughout the last decade endovascular repair (EV) has become increasingly used. The purpose of the present study was to perform a systematic review and meta-analysis evaluating the outcomes of the three major treatment modalities (OPEN, EV, and CONS) for the management of SAAs. METHODS: A systematic review of all studies describing the outcomes of SAAs treated with OPEN, EV, or CONS was performed using seven large medical databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to ensure a high-quality review. All articles were subject to critical appraisal for relevance, validity, and availability of data regarding characteristics and outcomes. All data were systematically pooled, and meta-analyses were performed on several outcomes, including early and late mortality, complications, and number of reinterventions. RESULTS: Original data of 1321 patients with true SAAs were identified in 47 articles. OPEN contained 511 patients (38.7%) in 31 articles, followed by 425 patients (32.2%) in CONS in 16 articles and 385 patients (29.1%) in EV in 33 articles. The CONS group had fewer symptomatic patients (9.5% vs 28.7% in OPEN and 28.8% in EV; P < .001) and fewer ruptured aneurysms (0.2% vs 18.4% in OPEN and 8.8% in EV; P < .001), but no significant differences were found in existing comorbidities. CONS patients were usually older and had smaller-sized aneurysms than patients in the OPEN and EV groups. The only identified difference in baseline characteristics between OPEN and EV was the number of ruptured aneurysms (18.4% vs 8.8%; P < .001). OPEN had a higher 30-day mortality than EV (5.1% vs 0.6%; P < .001), whereas minor complications occurred in a larger number of the EV patients. EV required more reinterventions per year (3.2%) compared with OPEN (0.5%) and CONS (1.2%; P < .001). The late mortality rate was higher in patients treated with CONS (4.9% vs 2.1% in OPEN and 1.4% in EV; P = .04). CONCLUSIONS: EV of SAA has better short-term results compared with OPEN, including significantly lower perioperative mortality. OPEN is associated with fewer late complications and fewer reinterventions during follow-up. Patients treated with CONS showed a higher late mortality rate. Ruptured SAAs are predictors of a significantly higher perioperative mortality compared with nonruptured SAAs in the OPEN and EV groups.

A clinical decision model for selecting the most appropriate therapy for uncomplicated chronic dissections of the descending aorta.

OBJECTIVE: The optimal treatment for patients with uncomplicated chronic Stanford type B aortic dissections (chTBADs) is still matter of debate. The purpose of this study was to design a decision tool to guide the surgeon in determining the preferred treatment option. METHODS: A Markov decision-analysis model compared chTBAD patients treated with initial open surgical repair (OSR), thoracic endovascular aortic repair (TEVAR), and optimal medical therapy (OMT), followed during follow-up by OSR (OMT-OSR) or TEVAR (OMT-TEVAR), if indicated. Procedural risks, aortic growth and rupture rates, outcomes, and quality of life values were derived from the best available evidence in the literature. A chTBAD treatment strategy decision tool was developed, including the four key variables of age, sex, surgical risk, and maximum initial aortic diameter. Primary outcome was quality-adjusted life-years (QALYs). RESULTS: For the reference patient cohort, 55-year-old men with chTBAD with a maximum aortic diameter of 5.0 cm, medium risk for surgery, and a threshold for surgery of 6.0 cm during follow-up, OSR yielded higher QALYs, with 10.06 QALYs (95% credibility interval [CI], 9.52-10.56 QALYs) vs 9.92 QALYs (95% CI, 9.23-10.58 QALYs) after TEVAR and 9.64 QALYs (95% CI, 9.38-9.88 QALYs) and 9.40 QALYs (95% CI, 9.11-9.69 QALYs) for OMT-OSR and OMT-TEVAR. The difference between OSR and OMT-OSR was 0.42 QALYs (95% CI, 0.01-0.81 QALYs) and between TEVAR and OMT-TEVAR was 0.52 QALYs (95% CI, 0.04-0.68 QALYs). This showed that intervention is preferred over OMT. A change of the four variables resulted in a change of preferred treatment. In general, OSR was the preferred treatment in younger patients with a larger aortic diameter and in low-risk patients. TEVAR was preferred in elderly patients with large aortic diameter and if the aortic diameter threshold for repair decreased. OMT was the optimal therapy in high-risk patients, elderly patients, or in patients with small aortic diameters. CONCLUSIONS: This decision-analysis model shows that there is no "one-size-fits-all" treatment for uncomplicated chTBADs. For the reference patient cohort, intervention is preferred over OMT. Age is the most important deciding factor, followed by initial aortic diameter. Immediate OSR is the preferred treatment option in younger patients with a large initial aortic diameter and in low-risk patients. Immediate TEVAR is preferred in elderly patients with a large initial aortic diameter and in patients with a lower threshold for OSR. OMT should be considered in high-risk patients, in patients with small initial aortic diameters, and in patients aged >80 years, unless their initial aortic diameter is >5.5 cm. However, the differences in some patient groups are clinically insignificant, allowing a major role for patient preferences and hospital-specific considerations. This clinical decision model may guide chTBAD treatment.

Decision analysis model of open repair versus endovascular treatment in patients with asymptomatic popliteal artery aneurysms.

OBJECTIVE: Repair is indicated of asymptomatic popliteal artery aneurysms (aPAAs) that are >2 cm. Endovascular PAA repair with covered stents (stenting) is increasingly used. It is, however, unclear when an endovascular approach is preferred to traditional open repair with great saphenous vein bypass (GSVB). The goal of this study was to assess the treatment options for aPAAs using decision analysis. METHODS: A Markov model was developed and a hypothetic cohort of patients with aPAAs was analyzed. GSVB, stenting, and nonoperative management with optimal medical treatment (OMT) were compared. Operative mortality, patency rates, quality-of-life values, and costs were determined by comprehensive review of the best available evidence. The main outcome was quality-adjusted life-years (QALYs). Secondary outcomes were cost-effectiveness and number of reinterventions. RESULTS: For a 65-year-old male patient with a 2.0-cm aPAA and without significant comorbidities, probabilistic sensitivity analysis shows that intervention is preferred over OMT (5.77 QALYs, 95% credibility interval [CI], 5.43-6.11; OMT). GSVB treatment for this patient results in slightly higher QALYs than stent placement, with a predicted 8.43 QALYs (GSVB: 95% CI, 8.21-8.64) vs 8.07 QALYs (stenting: 95% CI, 7.84-8.29), a difference of 0.36 QALYs (95% CI, 0.14-0.58). Furthermore, costs are higher for stenting ($40,464; 95% CI, $34,814-$46,242) vs GSVB ($21,618; 95% CI, $15,932-$28,070), and more reinterventions are required after stenting (1.03 per patient) vs GSVB (0.52 per patient), making GSVB the preferred strategy for all outcomes considered. Stenting is preferred in patients who are at high risk for open repair (>6% 30-day mortality) or if the 5-year primary patency rates of stenting increase to 80%. For very old patients (>95 years) and patients with a very short life expectancy (<1.5 years), OMT yields higher QALYs. CONCLUSIONS: GSVB is the preferred treatment in 65-year-old patients with aPAAs for all outcomes considered. However, patients at high risk for open repair or without suitable vein should be considered as candidates for endovascular repair. Very elderly patients and patients with a short life expectancy are best treated with OMT. Further improvement of endovascular techniques that increase patency rates of endovascular stents could make this the preferred therapy for more patients in the future.

A comparison of open and endovascular revascularization for chronic mesenteric ischemia in a clinical decision model.

OBJECTIVE: Open revascularization (OR) has been the treatment of choice for chronic mesenteric ischemia (CMI) for many years, but endovascular revascularization (EV) has been increasingly used with good short-term results. In this study, we evaluated the comparative effectiveness and cost-effectiveness of EV and OR in patients with CMI refractory to conservative management. METHODS: A Markov-state transition model was developed using TreeAge Pro 2012 (TreeAge Inc, Williamstown, Mass) to simulate a hypothetical cohort of 10,000 65-year-old female patients with CMI requiring treatment with either OR or EV. Data for the model, including perioperative and long-term overall mortality risks, disease-specific mortality risks, complications, and reintervention and patency rates, were retrieved from original studies and systematic reviews about CMI. Costs were analyzed with the 2013 Medicare database. Outcomes evaluated were quality-adjusted life-years (QALYs), costs from the health care perspective, and the incremental cost-effectiveness ratio. Extensive sensitivity analyses were performed and different clinical scenarios evaluated. Probabilistic sensitivity analysis was performed to assess robustness of the model. RESULTS: For a reference-case 65-year-old female patient with CMI and an average risk for operation, EV is preferred with 10.03 QALYs (95% credibility interval [CI], 9.76-10.29) vs 9.59 after OR (95% CI, 9.29-9.87). The difference is comparable to 5 months in perfect health: 0.44 QALY (95% CI, 0.13-0.76). For 65-year-old men, this was 8.71 QALYs (95% CI, 8.48-8.94) for EV vs 8.42 (95% CI, 8.14-8.63) for OR. Sensitivity analysis showed that for younger patients, EV results in a higher increase in QALYs compared with older patients. Total expected reinterventions per patient are 1.70 for EV vs 0.30 for OR. Total expected health care costs for the reference-case patient were $39,942 (95% CI, $28,509-$53,380) for OR and $38.217 (95% CI, $29,329-$48,309) for EV. For men, this was $39,375 (95% CI, $28,092-$52,853) for OR and $35,903 (95% CI, $27,685-$45,597) for EV. For patients younger than 60 years, EV is a more expensive treatment strategy compared with OR, but with an incremental cost-effectiveness ratio for EV of less than $60,000/QALY. For patients 60 years and older, EV dominated OR as preferential treatment because effectiveness was higher than for OR and costs were lower. CONCLUSIONS: The results of this decision analysis model suggest that EV is favored over OR for patients with CMI in all age groups. Although EV is associated with more expected reinterventions, EV appears to be cost-effective for all age groups.

Endovascular vs. open repair of complicated acute type B aortic dissections.

Purpose : To assess the comparative effectiveness of thoracic endovascular aortic repair (TEVAR) vs. open surgical repair (OSR) of complicated acute type B aortic dissections (cABAD) using decision analysis. Methods : A decision analysis comparing TEVAR and OSR for cABAD included variables extracted from the best-available evidence. Main outcomes were quality-adjusted life years (QALYs), presented with the 95% credibility intervals (CI), and number of reinterventions over the remaining lifetime. Different clinical scenarios, including age, gender, and risk profile were analyzed. Parameter uncertainty was analyzed using probabilistic sensitivity analysis. Results : In the reference case, a cohort of 55-year-old men, TEVAR was preferred over OSR: 7.07 QALYs (95% CI 6.77 to 7.38) vs. 6.34 QALYs (95% CI 6.04 to 6.66) for OSR. The difference of 0.73 QALYs (95% CI 0.29 to 1.17) is equal to 8.5 months in perfect health. TEVAR was more effective in all analyzed cases and age groups. Perioperative mortality was the most important variable affecting the difference between OSR and TEVAR, followed by the relative risk and percentage of aortic-related complications. Total expected reinterventions were 0.43/patient (TEVAR) and 0.35/patient (OSR). Conclusion : The results of this decision model for the treatment of cABAD suggest that TEVAR is preferred over OSR. Although a higher number of reinterventions is expected, the total effectiveness of TEVAR is higher for all age groups. OSR should be reserved for patients whose aortic anatomy is unsuitable for endovascular repair.