Arterial Embolisms and Thrombosis in Upper Extremity Ischemia.

OBJECTIVE: Upper extremity ischemia (UEI) is an uncommon condition that can lead to permanent disability. There is a limited understanding of the etiology, management, and outcomes of the disease. METHODS: We retrospectively reviewed the charts of all patients who were diagnosed with "embolism and/or thrombosis of arteries of upper extremity" at our institution from January 2005 to December 2013. RESULTS: Patients diagnosed with embolisms were older (P < .001), more likely to undergo thromboembolectomy (P < .001), had higher rates of hypertension (P = .001), and had longer lengths of hospital stay (P = .002). There were no significant differences in complications or mortality at 30 days and up to 1 year. CONCLUSION: At our center, embolism was found to be the most common etiology for UEI followed by thrombosis and stenosis. Patients presented with embolism were older, were more likely to undergo thromboembolectomy, and had higher rates of hypertension and longer hospital stays.

A systematic review for the screening for peripheral arterial disease in asymptomatic patients.

BACKGROUND: Peripheral arterial disease (PAD) is common and associated with significant morbidity and mortality. PAD can be detected through a noninvasive measurement of the ankle-brachial index (ABI). METHODS: We conducted a systematic review of several electronic bibliographic databases for studies that evaluated ABI as a screening test for PAD in asymptomatic individuals. We conducted random-effects meta-analysis, reporting pooled hazard ratios (HRs) when appropriate. RESULTS: We included 40 individual studies, 2 systematic reviews, and 1 individual-patient data meta-analysis. We found no studies comparing ABI screening with no screening in terms of patient-important outcomes (mortality, amputations). The yield of PAD screening averaged 17% (range, 1%-42%) and was 1% to 4% in lower risk populations. Patients with PAD had higher adjusted risk of all-cause mortality (HR, 2.99; 95% confidence interval, 2.16-4.12) and of cardiovascular mortality (HR, 2.35; 95% confidence interval, 1.91-2.89). Data on benefits, harms, and cost-effectiveness of screening were limited; however, ABI screening was associated with additional prognostic information and risk stratification for heart disease. The overall quality of evidence supporting screening was low. CONCLUSIONS: The current available evidence demonstrates that PAD is common in patients with multiple cardiovascular risk factors and is associated with significant morbidity and mortality, but it does not support the benefit of routine ABI screening.

A systematic review of treatment of intermittent claudication in the lower extremities.

BACKGROUND: Peripheral arterial disease is common and is associated with significant morbidity and mortality. METHODS: We conducted a systematic review to identify randomized trials and systematic reviews of patients with intermittent claudication to evaluate surgery, endovascular therapy, and exercise therapy. Outcomes of interest were death, amputation, walking distance, quality of life, measures of blood flow, and cost. RESULTS: We included eight systematic reviews and 12 trials enrolling 1548 patients. Data on mortality and amputation and on cost-effectiveness were sparse. Compared with medical management, each of the three treatments (surgery, endovascular therapy, and exercise therapy) was associated with improved walking distance, claudication symptoms, and quality of life (high-quality evidence). Evidence supporting superiority of one of the three approaches was limited. However, blood flow parameters improved faster and better with both forms of revascularization compared with exercise or medical management (low- to moderate-quality evidence). Compared with endovascular therapy, open surgery may be associated with longer length of hospital stay and higher complication rate but resulted in more durable patency (moderate-quality evidence). CONCLUSIONS: In patients with claudication, open surgery, endovascular therapy, and exercise therapy were superior to medical management in terms of walking distance and claudication. Choice of therapy should rely on patients' values and preferences, clinical context, and availability of operative expertise.

Hyperbaric oxygen treatment outcome for different indications from a single center.

BACKGROUND: Hyperbaric oxygen (HBO) is used as an adjunctive therapy for a variety of indications. However, there is a lack of high-quality research evaluating HBO treatment outcomes for different indications available in the current literature. METHODS: We retrospectively reviewed all patients who underwent HBO therapy at a single hyperbaric center from January 2010 to December 2013 using predetermined criteria to analyze successful, improved, or failed treatment outcomes for the following indications: chronic refractory osteomyelitis, diabetic foot ulcer, failed flap or skin graft, osteoradionecrosis, soft tissue radiation necrosis, and multiple coexisting indications. RESULTS: Among the included 181 patients treated with adjunctive HBO at our center, 81.8% had either successful or improved treatment outcomes. A successful or improved outcome was observed in 82.6% of patients treated for chronic refractory osteomyelitis (n = 23), 74.1% for diabetic foot ulcer (n = 27), 75.7% for failed flap or skin graft (n = 33), 95.7% for osteoradionecrosis (n = 23), 88.1% for soft tissue radiation necrosis (n = 42), and 72.4% for multiple coexisting indications (n = 29). Among 4 patients treated for other indications, 100% of the cases were either successful or improved. CONCLUSIONS: This study has provided a comprehensive outcome survey of using HBO for the previously mentioned indications at our center. It supplements the literature with more evidence to support the consideration of HBO in different indications.

The success and safety of endovenous ablation in patients with previous superficial venous thrombosis: a retrospective case-control study.

OBJECTIVES: Retrospective case-control study to determine the failure and endovenous heat-induced thrombosis (EHIT) rates of endovenous ablation (EVA) in patients with a history of superficial venous thrombosis (SVT). METHODS: Study and control groups each consisted of 73 patients with or without the history of SVT, who underwent EVA between June 2010 and July 2012. All patients were followed with venous duplex ultrasound. Procedural failure and EHIT rates were considered primary outcomes. RESULTS: There was no difference in EHIT or failure rates between study and control groups (P = 1.00). There was no difference in EHIT or failure rates between patients with and without the history of venous thromboembolism (VTE), with and without the history of VTE and/or SVT, with and without the history of thrombophilia, and on and off anticoagulation for either group or the combined study population. For the combined study population, failure rate was higher in patients with a history of VTE. CONCLUSIONS: Although EVA seems to be safe and effective in patients with a history of SVT, vein access in this patient group might require multiple attempts.

Chronic venous ulcer: minimally invasive treatment of superficial axial and perforator vein reflux speeds healing and reduces recurrence.

BACKGROUND: Chronic venous ulcer (CVU) is common and is responsible for significant health care expenditures worldwide. Compression is the mainstay of treatment, but long-term compliance with this therapy is often inconsistent, particularly in the elderly and infirm. Surgical ablation of axial and perforator reflux has been used as an adjunct to compression to reduce recurrence rates and assist healing. These surgical techniques are being replaced by minimally invasive procedures, such as thermal ablation and foam sclerotherapy, in the treatment of uncomplicated venous disease. The role for these techniques in the treatment of CVU is just beginning to be defined. METHODS: Eighty-six patients with CVU with 95 active ulcers (Clinical, Etiology, Anatomy, Physiology-CEAP clinical class 6) presenting to a multispecialty wound clinic were retrospectively reviewed and analyzed by leg. All patients underwent duplex scanning for venous insufficiency. Ulcer dimensions at each visit were recorded and used to calculate healing rates. Presence or absence of ulcer recurrence at 1-year follow-up was recorded. Ulcers treated with compression alone ("compression group") were compared with those treated with compression and minimally invasive interventions, such as thermal ablation of superficial axial reflux and ultrasound-guided foam sclerotherapy (UGFS) of incompetent perforating veins and varicosities ("intervention group"). RESULTS: The average age in the intervention and compression groups was 67 and 71 years, respectively (P = not significant [NS]). Body mass index was 32.4 ± 9.5 and 33.6 ± 11.8 kg/m(2), in the compression and intervention groups, respectively (P = not significant [NS]). Ulcers were recurrent in 42% of the intervention group and 26% of the compression group (P = NS). In the intervention group, 33% had radiofrequency ablation of axial reflux, 31% had UGFS of perforators, and 29% had both treatments. The only complication of intervention was a single case of cellulitis requiring hospitalization. Compared with the compression group, the ulcers in the intervention group healed faster (9.7% vs. 4.2% per week; P = 0.001) and showed fewer recurrences at 1-year follow-up (27.1% vs. 48.9 %; P < 0.015). Multivariate analysis showed use of intervention was the strongest determinant of healing with a coefficient of variation of 7.432, SE 2.406, P = 0.003. Analysis of just the intervention group before and after intervention using matched pairs showed acceleration of healing after intervention from ranging from a median of 1.2% (interquartile range [IQR], 14.3) to 9.7% (IQR, 11.3) per week (P ≤ 0.001). CONCLUSIONS: Minimally invasive ablation of superficial axial and perforator vein reflux in patients with active CVU is safe and leads to faster healing and decreased ulcer recurrence when combined with compression alone in the treatment of CVU.

Comparative effectiveness of the treatments for thoracic aortic transection [corrected].

OBJECTIVES: To synthesize the available evidence regarding the outcomes associated with nonoperative management, open repair, and endovascular repair of thoracic aortic transection. METHODS: We searched electronic databases (MEDLINE, EMBASE Cochrane, Web of Science, and Scopus) for studies that enrolled patients with aortic transection and measured the outcomes of interest. Two reviewers determined study eligibility and extracted data. We estimated the event rate associated with the different approaches from case series and the relative risk from comparative studies. Estimates from each study were pooled using the random effects model. RESULTS: We found 139 studies that fulfilled the inclusion criteria, the majority of which were noncomparative surgical case series, retrospective, and none were randomized. Studies included 7768 patients, the majority of which were males. The mortality rate was significantly lower in patients who underwent endovascular repair, followed by open repair and nonoperative management (9%, 19%, and 46%, respectively, P < .01). No significant difference in event rate across the three groups was noted for the outcomes of anterior stroke, posterior stroke, or any stroke. The risk of spinal cord ischemia and end-stage renal disease were higher in open repair compared with the other 2 groups (9% vs 3% and 3%, P = .01 for spinal cord ischemia and 8% vs 5% and 3%, P = .01 for end-stage renal disease). Compared with endovascular repair, open repair was associated with an increased risk of graft infection and systemic infections. Meta-analyses of comparative studies demonstrated that compared with open repair, endovascular repair is associated with reduced mortality and spinal cord ischemia (relative risk, 0.61; 95% confidence interval, 0.46-0.80; and relative risk, 0.34; 95% confidence interval, 0.16-0.74; respectively). Inferences are limited by methodological quality, survival, and publication biases. CONCLUSIONS: Very low-quality evidence suggests that, compared with open repair or nonoperative management, endovascular repair of thoracic aortic transection is associated with better survival and decreased risk of spinal cord ischemia, renal injury, and graft and systemic infections. Nonoperative management is associated with the least favorable outcomes.

Outcomes related to antiplatelet or anticoagulation use in patients undergoing carotid endarterectomy.

BACKGROUND: The number of cases involving patients undergoing vascular procedures who are prescribed clopidogrel or warfarin as treatment options continues to rise. Our aim was to examine outcomes related to antiplatelet or anticoagulation therapy in patients undergoing carotid endarterectomy (CEA). METHODS: A retrospective review of 260 consecutive patients undergoing CEA. Data including patient demographics, operative details, perioperative use of aspirin (ASA), clopidogrel, or warfarin, and early and/or late outcome(s) were collected. Endpoints included postoperative morbidity and/or mortality rate(s) and bleeding complications. RESULTS: The study included 152 men and 108 women (mean age = 69.3 years), with a mean follow-up of 406 days. In all, 46% of endarterectomies were for a symptomatic disease. The technique of eversion endarterectomy was applied in 126 (48.5%), Dacron-patch in 112 (43.1%), and bovine pericardial-patch in 14 (5.4%) of the cases. Among the patients, 171 were taking ASA, 50 were taking clopidogrel ± ASA, and 10 were taking warfarin (mean INR = 1.62; range, 1.2-2.1); the remaining 29 were not on any antiplatelet therapy. All patients who were on warfarin therapy underwent an eversion endarterectomy. Overall, there were 19 (7.3%) complications (12 major and seven minor). The 30-day stroke rate and stroke death rate was 0.7% and 1.1%, respectively. Patients taking clopidogrel developed more number of neck hematomas (16% vs. 1.7%, p = 0.0004) compared with patients who were on ASA alone. For patients taking clopidogrel, Dacron-patch repair resulted in more hematomas than eversion endarterectomy (35% vs. 4.2%, p = 0.012). There was no difference in the incidence of neck hematoma on the basis of endarterectomy technique in patients who were on ASA alone. The patients taking warfarin neither had a perioperative complication nor developed a neck hematoma. CONCLUSIONS: In this study, clopidogrel use during CEA resulted in a significant risk for developing a neck hematoma, particularly when using a Dacron-patch. The risk of a neck hematoma in patients who were on clopidogrel was much less when an eversion endarterectomy was performed.

Imaging features of invasion and preoperative and postoperative tumor burden in previously untreated glioblastoma: Correlation with survival.

BACKGROUND: A paucity of data exists concerning the prognostic usefulness of preoperative and postoperative imaging after resection of glioblastoma multiforme (GBM). This study aimed to connect outcome with imaging features of GBM. METHODS: Retrospective computer-assisted volumetric calculations quantified central necrotic (T0), gadolinium-enhanced (T1) and increased T2-weighted signal volumes (T2) in 70 patients with untreated GBM. Clinical and treatment data, including extent of resection (EOR), were obtained through chart review. T1 volume was used as a measure of solid tumor burden; and T2 volume, as an indicator of invasive isolated tumor cell (ITC) burden. Indicators of invasiveness included T2:T1 ratios as a propensity for ITC infiltration compared to solid tumor volumes and qualitative analysis of subependymal growth and infiltration of the basal ganglia, corpus callosum or brainstem. Cox multivariate analysis (CMVA) was used to identify significant associations between imaging features and survival. RESULTS: In the 70 patients studied, significant associations with reduced survival existed for gadolinium-enhancing tumor crossing the corpus callosum (odds ratio, 3.14) and with increased survival with gross total resection (GTR) (GTR median survival, 62 weeks versus 37 and 34 weeks for sub-total resection and biopsy, respectively). For a selected "GTR-eligible" subgroup of 52 patients, prolonged survival was associated with smaller preoperative gadolinium-enhancing volume (T1) and actual GTR. CONCLUSION: Some magnetic resonance (MR) imaging indicators of tumor invasiveness (gadolinium-enhancing tumor crossing the corpus callosum) and tumor burden (GTR and preoperative T1 volume in GTR-eligible subgroup) correlate with survival. However, ITC-infiltrative tumor burden (T2 volume) and "propensity" for ITC invasiveness (T2:T1 ratio) did not impact survival. These results indicate that while the ITC component is the ultimate barrier to cure for GBM, the pattern of spread and volumes of gadolinium-enhancing solid tumor are more robust indicators of prognosis.

The effect of left subclavian artery coverage on morbidity and mortality in patients undergoing endovascular thoracic aortic interventions: a systematic review and meta-analysis.

OBJECTIVES: Thoracic endografts (stent grafts) have emerged as a less invasive modality to treat various thoracic aortic lesions. The intentional coverage of the left subclavian artery (LSA) during the placement of these endografts is associated with several complications including stroke, spinal cord ischemia, and arm ischemia. In this review, we synthesize the available evidence regarding the complications associated with LSA coverage. METHODS: We searched electronic databases (MEDLINE and EMBASE) from January 1990 through February 2008 for studies that included patients who received thoracic endografts and had intentional LSA coverage. Eligible studies had a control group that either received the endograft without LSA coverage or had primary revascularization prior to coverage. Two independent reviewers determined trial eligibility and extracted descriptive, methodological and outcome data from each eligible study. Meta-analyses estimated Peto odds ratio (OR) and 95% confidence intervals (CI) to describe the strength of association between coverage and complications; the I(2) statistic described the proportion of inconsistency of treatment effect among studies not due to chance. RESULTS: We found 51 eligible observational studies. LSA coverage was associated with significant increase in the risk of arm ischemia (OR 47.7; CI, 9.9-229.3; I(2) = 72%, 19 studies) and vertebrobasilar ischemia (OR 10.8; CI, 3.17-36.7; I(2) = 0%; eight studies); and nonsignificant increase in the risk of spinal cord ischemia (OR 2.69; CI, 0.75-9.68; I(2) = 40%; eight studies) and anterior circulation stroke (OR 2.58; CI, 0.82-8.09; I(2) = 64%, 13 studies). There were no significant associations between LSA coverage and death, myocardial infarction, or transient ischemic attacks. The incidence of phrenic nerve injury as a complication of primary revascularization was 4.40% (CI, 1.60%-12.20%). Data on perioperative infection were sparse and rarely reported. CONCLUSIONS: Very low quality evidence suggests that LSA coverage increases the risk of arm ischemia, vertebrobasilar ischemia, and possibly spinal cord ischemia and anterior circulation stroke.

Timing of referral for vascular access placement: a systematic review.

OBJECTIVE: This review was conducted to determine the optimal timing for referring patients with end-stage renal disease to vascular surgery for access placement. METHODS: A systematic review of the electronic databases (MEDLINE, EMBASE, Current Contents, Cochrane CENTRAL and Web of Science) was conducted through March 2007. Randomized and observational studies were eligible if they compared an early referral cohort with a late referral cohort in terms of patient-important outcomes such as death, access-related sepsis, and hospitalization related to access complications. RESULTS: We found no studies that fulfilled eligibility criteria. CONCLUSION: At the present time, the optimal timing for referral to vascular surgery for vascular access placement is based on expert opinion and choices made by patients and physicians.

Autogenous versus prosthetic vascular access for hemodialysis: a systematic review and meta-analysis.

OBJECTIVES: The autogenous arteriovenous access for chronic hemodialysis is recommended over the prosthetic access because of its longer lifespan. However, more than half of the United States dialysis patients receive a prosthetic access. We conducted a systematic review to summarize the best available evidence comparing the two accesses types in terms of patient-important outcomes. METHODS: We searched electronic databases (MEDLINE, EMBASE, Cochrane CENTRAL, Web of Science and SCOPUS) and included randomized controlled trials and controlled cohort studies. We pooled data for each outcome using a random effects model to estimate the relative risk (RR) and its associated 95% confidence interval (CI). We estimated inconsistency caused by true differences between studies using the I(2) statistic. RESULTS: Eighty-three studies, of which 80 were nonrandomized, met eligibility criteria. Compared with the prosthetic access, the autogenous access was associated with a significant reduction in the risk of death (RR, 0.76; 95% CI, 0.67-0.86; I(2) = 48%, 27 studies) and access infection (RR, 0.18; 95% CI, 0.11-0.31; I(2) = 93%, 43 studies), and a nonsignificant reduction in the risk of postoperative complications (hematoma, bleeding, pseudoaneurysm and steal syndrome, RR 0.73; 95% CI, 0.48-1.16; I(2) = 65%, 31 studies) and length of hospitalization (pooled weighted mean difference -3.8 days; 95% CI, -7.8 to 0.2; P = .06). The autogenous access also had better primary and secondary patency at 12 and 36 months. CONCLUSION: Low-quality evidence from inconsistent studies with limited protection against bias shows that autogenous access for chronic hemodialysis is superior to prosthetic access.

Surveillance of arteriovenous hemodialysis access: a systematic review and meta-analysis.

OBJECTIVES: Hemodialysis centers regularly survey arteriovenous (AV) accesses for signs of dysfunction. In this review, we synthesize the available evidence to determine to what extent proactive vascular access monitoring affects the incidence of AV access thrombosis and abandonment compared with clinical monitoring. METHODS: We searched electronic databases (MEDLINE, EMBASE, Cochrane CENTRAL, Web of Science, and SCOPUS) and sought references from experts, bibliographies of included trials, and articles that cited included studies. Two reviewers independently assessed trial quality and extracted data. We used random effects meta-analysis to estimate the pooled relative risk (RR) and 95% confidence interval (CI) across studies and conducted subgroup analyses to explain heterogeneity. The I(2) statistic was used to assess heterogeneity of treatment effect among trials. RESULTS: Nine studies (1363 patients) compared a strategy of surveillance vs clinical monitoring. A vascular intervention to maintain or restore patency was provided to both groups if needed. Surveillance followed by intervention led to a nonsignificant reduction of the risk of access thrombosis (RR, 0.82; 95% CI, 0.58-1.16; I(2) = 37%) and access abandonment (RR, 0.80; 95% CI, 0.51-1.25; I(2) = 60%). Three studies (207 patients) compared the effect of vascular interventions vs observation in patients with abnormal surveillance result. Vascular interventions after an abnormal AV access surveillance led to a significant reduction of the risk of access thrombosis (RR, 0.53; 95% CI, 0.36-0.76) and a nonsignificant reduction of the risk of access abandonment (RR, 0.76; 95% CI, 0.43-1.37). CONCLUSION: Very low quality evidence yielding imprecise results suggests a potentially beneficial effect of AV access surveillance followed by interventions to restore patency. This inference, however, is weak and will require randomized trials of AV access surveillance vs clinical monitoring for rejection or confirmation.

Benign superior vena cava syndrome: stenting is now the first line of treatment.

BACKGROUND: Endovascular repair (EVR) is emerging as first-line treatment for patients with superior vena cava (SVC) syndrome of benign etiology, but data on its durability remain scarce. The aims of this study were to assess the efficacy and durability of EVR and compare results of EVR with open surgical reconstruction (OSR). METHODS: Data from 70 consecutive patients undergoing treatment for benign SVC syndrome between November 1983 and November 2006 were retrospectively reviewed. RESULTS: There were 30 males and 40 females (mean age, 41 years; range, 5-75 years). Etiology included indwelling catheters or pacemaker wires in 35 patients, mediastinal fibrosis in 31, idiopathic thrombosis in 2, hypercoagulable disorder in 1, and postsurgical thrombosis in 1. In 42 patients, OSR was done through a median sternotomy: repair was with spiral saphenous vein in 22, expanded polytetrafluoroethylene (ePTFE) in 13, femoral vein grafts in 6, and human allograft in 1. Fifteen OSRs followed failed EVR interventions. EVR was attempted in 32 patients and was successful in 28 (88%): 19 had stenting, 14 had percutaneous transluminal balloon angioplasty (PTA), 2 had thrombolytic therapy with PTA, and 3 had stenting. All four technical failures subsequently underwent OSR. There were no early deaths in either group. Periprocedural morbidity was 19% after OSR and 4% in the EVR group. Six early surgical graft failures were successfully treated with surgical revision; one restenosis after EVR was restented. During a mean follow-up of 4.1 years (range, 0.1-17.5 years) after OSR, 11 patients underwent 18 secondary interventions. Mean follow-up after EVR was 2.2 years (range, 0.2-6.4 years), and nine patients underwent 21 secondary EVR interventions. Primary, assisted primary, and secondary patency rates of surgical bypass grafts were, respectively, 45%, 68%, and 75% at 3 and 5 years. Primary, assisted primary and secondary patency rates after EVR were 44%, 96%, and 96% at 3 years. Assisted primary patency was significantly higher in vein grafts than in ePTFE grafts (P = .05). Assisted primary and secondary patency was significantly higher in patients undergoing stenting compared with PTA (P = .02). At last follow-up, 93% of patients in both OSR and EVR groups had significant relief from symptoms. CONCLUSIONS: OSR of benign SVC syndrome is effective, with durable long-term relief from symptoms. EVR is less invasive but equally effective in the mid-term, albeit at the cost of multiple secondary interventions, and is an appropriate primary treatment for benign SVC syndrome. OSR remains an excellent choice for patients who are not suitable for EVR or in whom the EVR fails.

Bone marrow-derived cells fuse with normal and transformed intestinal stem cells.

Transplanted adult bone marrow-derived cells (BMDCs) have been shown to adopt the phenotype and function of several nonhematopoietic cell lineages and promote tumorigenesis. Beyond its cancer enhancing potential, cell fusion has recently emerged as an explanation of how BMDCs regenerate diseased heptocytes, contribute to Purkinje neurons and skeletal and cardiac muscle cells, and participate in skin and heart regeneration. Although bone marrow-derived epithelial cells also have been observed in the intestine, fusion as a mechanism has not been investigated. Here, we show that transplanted BMDCs fuse with both normal and neoplastic intestinal epithelium. Long-term repopulation by donor-derived cells was detected in all principal intestinal epithelial lineages including enterocytes, goblet cells, Paneth cells, and enteroendocrine cells, suggesting that the fusion partners of the BMDCs are long-lived intestinal progenitors or stem cells. Fusion of BMDCs with neoplastic epithelium did not result in tumor initiation. Our findings suggest an unexpected role for BMDCs in both regeneration and tumorigenesis of the intestine.

Forty-eight-hour pH monitoring increases sensitivity in detecting abnormal esophageal acid exposure.

Ambulatory 24-hour esophageal pH measurement is the standard for detecting abnormal esophageal acid exposure (AEAE), but it has a false negative rate of 15% to 30%. Wireless 48-hour pH monitoring (Bravo; Medtronic, Shoreview, MN) may allow more accurate detection of AEAE versus 24-hour pH monitoring. Forty-eight-hour wireless data were reviewed from 209 patients at three different tertiary care referral centers between 2003 and 2005. Manometric or endoscopic determination of the lower esophageal sphincter helped place the Bravo probe 5 to 6 cm above the lower esophageal sphincter. A total of 190 studies in 186 patients had sufficiently accurate data. There were 114 women and 72 men with an average age of 51 years. AEAE was defined by a Johnson-DeMeester score greater than 14.7 and was obtained in 115 of 190 studies (61%). Only 64 of 115 patients (56%) demonstrated AEAE for both days of the study, whereas 51 of 115 patients (44%) demonstrated AEAE in a single 24-hour period. There was no difference in the prevalence of AEAE on day 1 versus day 2 only (26% vs. 18%, P = .26). Compared with 24-hour alone data, 48-hour data showed 22% more patients with AEAE. Frequent day-to-day variability in patients with AEAE may be missed by a single 24-hour pH test. Forty-eight-hour pH testing may increase detection accuracy and sensitivity for AEAE by as much as 22%.