Prospective evaluation of the utility of magnetic resonance imaging in patients with non-MRI-conditional pacemakers and defibrillators.

BACKGROUND: Magnetic resonance imaging (MRI) in patients with legacy cardiovascular implantable electronic devices (CIEDs) in situ is likely underutilized. We hypothesized the clinical benefit of MRI would outweigh the risks in legacy CIED patients. METHODS: This is a single-center retrospective study that evaluated and classified the utility of MRI using a prospectively maintained database. The outcomes were classified as aiding in diagnosis, treatment, or both for the patients attributable to the MRI. We then assessed the incidence of adverse effects (AE) when the MRI was performed. RESULTS: In 668, MRIs performed on 479 patients, only 13 (1.9%) MRIs did not aid in the diagnosis or treatment of the patient. Power-on reset events without clinical sequelae in three scans (0.45%) were the only AE. The probability of an adverse event happening without any benefit from the MRI scan was 1.1 × 10-4 . A maximum benefit in diagnosis using MRI was obtained in ruling out space-occupying lesions (121/185 scans, 65.4%). Scans performed in patients for elucidating answers to queries in treatment were most frequently done for disease staging at long term follow-up (167/470 scans, 35.5%). Conservative treatment (184/470 scans, 39%) followed by medication changes (153/470 scans, 28.7%) were the most common treatment decisions made. CONCLUSIONS: The utility of MRI in patients with non-MRI-conditional CIEDs far outweighs the risk of adverse events when imaging is done in the context of a multidisciplinary program that oversees patient safety.

Safety of thoracic magnetic resonance imaging for patients with pacemakers and defibrillators.

BACKGROUND: During magnetic resonance imaging (MRI), cardiac implantable electronic device (CIED) leads can be antennae to focus energy onto myocardium, leading to heating and arrhythmias. Clinical data on thoracic MRI safety for patients with legacy devices are limited. OBJECTIVE: The purpose of this study was to identify patients undergoing thoracic MRI with legacy devices, compare the incidence of adverse events of those patients with control patients undergoing brain MRI with legacy devices, and compare paired cardiac troponin T (cTnT) values. METHODS: In this single-center study, we reviewed a prospectively collected database of patients with CIED undergoing MRI from January 25, 2008, through February 28, 2017. RESULTS: Of 952 patients (1290 scans), 120 patients (12.6%) underwent 134 thoracic MRI scans with legacy CIEDs (median [range] age 61.98 [21.24-86.96] years; male 71.1%). Median (range; interquartile range [IQR]) age of leads across devices was 3.5 (1.6-7.1; 5.5) years; implantable cardioverter-defibrillators (ICDs) were oldest (median [range; IQR], 3.7 [1.1-8.0; 6.9] years). No difference was observed in incidence of adverse events between groups. Paired cTnT values were compared for 19 patients (19 scans) with no difference between pre- and postimaging values. No significant difference was present in device setting values before and after MRI (mean follow-up 72.5 days). Incidence of adverse events was no different after adjustment for ICD coil number. CONCLUSION: Thoracic MRI is relatively safe in an institutional multidisciplinary program. It does not represent greater risk than brain MRI for patients with legacy CIEDs.

Mortality After Magnetic Resonance Imaging of the Brain in Patients With Cardiovascular Implantable Devices.

BACKGROUND: Use of magnetic resonance imaging (MRI) brain is restricted in patients with cardiovascular implantable electronic devices (CIEDs). We proposed to determine whether mortality difference exists for patients with non-MRI-conditional CIEDs undergoing brain MRI compared with controls. METHODS AND RESULTS: Retrospective analysis of prospectively collected data was performed to compare all-cause mortality in patients with CIEDs undergoing brain MRI (CIED-MRI) with 3 control groups matched for age, sex, imaging year, and type of CIED: (1) no CIED, brain MRI (no-CIED-MRI); (2) CIED, brain computerized tomography (CT) scan (CIED-CT); and (3) no CIED, brain CT (no-CIED-CT). The primary outcome was a significant difference (P<0.05) between estimated mortality rates. Secondary outcomes were changes in device function before and after brain MRI. The estimated all-cause mortality at 5 years for the CIED-MRI group [mean age (±SD), 68.2 years (15.3 years); 61.2% men] was not significantly different from patients who underwent CT with or without a device (CIED-CT group: hazard ratio, 0.814; 95% confidence interval, 0.593-1.117; P=0.2; no-CIED-CT group: hazard ratio, 1.149; 95% confidence interval, 0.818-1.613; P=0.4). There was a significant increase in mortality between CIED-MRI and no-CIED-MRI groups (hazard ratio, 1.463; 95% confidence interval, 1.019-2.099; P=0.04). CONCLUSIONS: Brain MRI in patients with CIEDs does not carry an increased mortality risk compared with brain CT and can be performed with adherence to appropriate procedural protocols.

Safety of magnetic resonance imaging in patients with legacy pacemakers and defibrillators and abandoned leads.

BACKGROUND: During magnetic resonance imaging (MRI), abandoned leads may act as antennae that result in tissue heating and arrhythmia induction. OBJECTIVE: The purpose of this study was to assess the safety of MRI in patients with abandoned leads, with the addition of cardiac troponin T (cTnT) assessment to screen for myocardial damage. METHODS: We reviewed our prospectively collected database of patients with cardiovascular implantable electronic devices (CIEDs) undergoing MRI between 2008 and 2017 at Mayo Clinic, Rochester, MN, and selected patients who had abandoned leads. We compared the adverse events in this population with an age, sex, and site of MRI-matched cohort of patients selected from this database. We evaluated paired (before/after) cTnT values using MRI in these patients. RESULTS: Of 952 patients, 80 (8.4%) underwent 97 MRI scans with CIEDs in situ with 90 abandoned leads in place during the scans. The median age was 66 years (interquartile range 22.3 years) 66.1 years (interquartile range, Q1,Q3: 53.6, 75.9) with 66.3% (53 patients) men. There was no clinical or electrical evidence of CIED dysfunction, arrhythmias, or pain. Paired samples for the measurement of cTnT values were available in 40 patients undergoing 44 MRI examinations. The mean difference between the pre- and postimaging values was -0.002 ± 0.006 ng/mL (interquartile range 0). There was no difference after adjustment for total number of leads per patient and total number of implantable cardioverter-defibrillator coils. CONCLUSION: There was no evidence of myocardial injury as measured by paired cTnT. The risk of MRI with abandoned leads appears low, suggesting a favorable risk-benefit profile in patients with CIEDs and abandoned leads who are considered for MRI.

Magnetic Resonance Imaging in Nondependent Pacemaker Patients with Pacemakers and Defibrillators with a Nearly Depleted Battery.

BACKGROUND: Magnetic resonance imaging (MRI) in patients with non-MRI-conditional cardiac implantable electronic devices (CIEDs) has been shown to be safe when performed under closely monitored protocols. However, the safety of MRI in patients with devices with a nearly depleted battery has not been reported. METHODS: Prospective data were collected between January 2008 and May 2015 in patients with non-MRI-conditional CIEDs undergoing clinically indicated MRI under institutional protocol. Patients who were pacemaker dependent were excluded. Patients whose devices were at elective replacement indicator (ERI) at the time of MRI or close to ERI (ERI or replacement for battery depletion within 3 months of scan) were identified through database review and analyzed for clinical events. RESULTS: MRI scans (n = 569) were performed in 442 patients. Of these, we identified 13 scans performed with a nearly depleted battery in nine patients. All scans with implantable cardioverter defibrillators (ICDs, n = 9) were uneventful. However, two scans with pacemakers close to ERI resulted in a power-on-reset (PoR) event. One scan with a pacemaker close to ERI that was programmed to DOO mode reached ERI during MRI and automatically changed to VVI mode. Additionally, one scan with a pacemaker at ERI did not allow programming. All pacemakers with events were implanted before 2005. CONCLUSION: Patients with pacemakers and ICDs with a nearly depleted battery can safely undergo MRI when patients are not pacemaker dependent. Attention should be paid because old devices can result in PoR or ERI during MRI, which may lead to oversensing and inhibition of pacing.

Age-related changes in the pancreas identified by EUS: a prospective evaluation.

BACKGROUND: EUS is an important modality for the diagnosis of pancreatic disease. An understanding of normal pancreatic ductal and parenchymal variation in asymptomatic individuals is essential to improve EUS accuracy. The primary aim of this study was to determine age-related pancreatic parenchymal and ductular changes identifiable on EUS in individuals with no history or symptoms of pancreaticobiliary disease. Secondary aims were to define demographic and clinical factors associated with identifiable pancreatic parenchymal and ductular changes, and to determine the main pancreatic-duct diameter and pancreatic-gland width according to age. METHODS: Patients referred for either upper endoscopy or EUS for an indication unrelated to pancreaticobiliary disease were prospectively enrolled. Patients were stratified by age (<40, 40-60, >60 years). Each patient was assessed for the presence of EUS findings for chronic pancreatitis. Logistic regression was used to identify factors associated with an abnormality. RESULTS: A total of 120 patients (63 men, 57 women; median age, 52 years, interquartile range [IQR] 40-61 years) were prospectively evaluated. At least one parenchymal and/or ductular abnormality was identified in 28% of the patients, with a trend of increasing abnormality with age: <40 years (23%), 40 to 60 years (25%), and >60 years (39%); p = 0.13. No patient had more than 3 abnormal EUS features. Hyperechoic stranding (n = 22) was the most common finding in all age groups. The odds for any abnormality in men (relative to women) was significantly higher (OR 2.9: 95% CI[1.2, 6.8], p = 0.01), with 38% of men and 18% of women having an abnormality. Smoking, low alcohol intake, body mass index, and endoscopic finding were not significantly associated with an abnormal EUS. The overall median pancreatic-gland width and main pancreatic duct diameter were 15 mm (IQR 6-25 mm) and 1.7 mm (IQR 0.9-4.3 mm), respectively. CONCLUSIONS: The frequency of EUS abnormalities in patients without clinical evidence of chronic pancreatitis increases with age, particularly after 60 years of age. The threshold number of EUS criteria for the diagnosis of chronic pancreatitis is variable. However, the typically used standard of 3 or more criteria appears appropriate. A higher number of threshold criteria may be needed in males and to a lesser extent in patients over 40 years of age, which should be related to clinical history and other structural or functional studies. Ductal or parenchymal calculi, ductal narrowing, ductal dilatation, or more than 3 abnormalities appear to be more specific features for the EUS diagnosis of chronic pancreatitis at any age.

Evaluation of a new curved linear array echoendoscopy system for EUS.

BACKGROUND: EUS-FNA can be used to accurately diagnose and stage GI and pulmonary neoplasms. This study evaluated the performance characteristics of a new compact linear EUS system during EUS-FNA. METHODS: A total of 37 patients enrolled in this prospective pilot study underwent clinically indicated EUS-FNA and/or celiac plexus neurolysis with the compact EUS system. RESULTS: The mean time to perform a radial and linear array EUS with FNA and/or celiac plexus neurolysis was 24 minutes shorter with the compact EUS system compared with that for an historical control procedure in which a conventional linear EUS unit was used (p = 0.0007). The EUS images and visualization of the needle during EUS-FNA were rated good to excellent in greater than 95% of the patients. With respect to ease of esophageal intubation, duodenal intubation, and general maneuverability, the performance of the new linear echoendoscope, compared with a radial scanning videoechoendoscope, was the same or better in, respectively, 85%, 87%, and 100% of procedures. The video image quality of the new linear array echoendoscope was superior to that of the radial scanning videoechoendoscope in all patients. No complications were encountered. CONCLUSIONS: EUS-FNA and celiac plexus neurolysis can be performed safely with the new compact EUS system. The efficiency of this procedure is enhanced compared with historical experience with other instruments. Although image quality is sufficient for EUS-FNA and celiac plexus neurolysis, the compact unit cannot be used as a "stand-alone" system for routine diagnostic EUS, and its use must be complemented by standard radial imaging.

Prospective risk assessment of bacteremia and other infectious complications in patients undergoing EUS-guided FNA.

BACKGROUND: There are few data regarding the risk of bacteremia with EUS-guided FNA. This study prospectively evaluated the frequency of bacteremia and other infectious complications after EUS-guided FNA. METHODS: Patients referred for EUS-guided FNA of the upper GI tract lesions were considered for enrollment. Patients were excluded if there was an indication for preprocedure administration of antibiotics based on ASGE guidelines, had taken antibiotics within the prior 7 days, or if they had a pancreatic cystic lesion. Blood cultures were obtained immediately before the procedure, after routine endoscopy/radial EUS, and 15 minutes after EUS-guided FNA. RESULTS: Fifty-two patients underwent EUS-guided FNA at 74 sites (mean 1.4 sites/patient) totaling 266 passes of the fine needle (mean 5.1 FNA/patient). Coagulase negative Staphylococcus was grown in cultures from 3 patients (5.8%; 95% CI [1%, 15%]) and was considered a contaminant. Three patients (5.8%; 95% CI [1%, 15%]) developed bacteremia: Streptococcus viridans (n = 2), unidentified gram-negative bacillus (n = 1). No signs or symptoms of infection developed in any patient. CONCLUSION: EUS-guided FNA of solid lesions in the upper GI tract should be considered a low-risk procedure for infectious complications that does not warrant prophylactic administration of antibiotics for prevention of bacterial endocarditis.

Preliminary experience with an EUS-guided trucut biopsy needle compared with EUS-guided FNA.

BACKGROUND: EUS-guided FNA is a sensitive method for the diagnosis of malignancy. However, EUS-FNA is often laborious and usually requires the presence of a cytopathologist or cytotechnician. The development of an EUS-guided Trucut biopsy (EUS-TCB) needle may simplify the procedure and expand the application of EUS-directed procurement of biopsy specimens. The aim of this study was to determine the feasibility of using the EUS-TCB for the diagnosis of intraintestinal and extraintestinal lesions and compare the results with this needle with those of EUS-FNA. METHODS: The EUS-TCB and EUS-FNA were used to evaluate patients with known or suspected intraintestinal or extraintestinal mass lesions and/or lymphadenopathy. Patient records were retrospectively reviewed to determine the accuracy and safety of both techniques. RESULTS: Nineteen patients had tissue samples obtained with both the EUS-TCB and EUS-FNA from 20 sites (2 sites in 1 patient) between December 2001 and March 2002. Accuracy was higher with EUS-TCB than EUS-FNA, although the difference was not significant (85% vs. 60%), despite performing fewer passes with the former (mean [SD] 2.0 [0.7], range 1-4; vs. mean 3.3 [1.5], range 1-10; p < 0.05). No complications were identified. CONCLUSIONS: This preliminary study suggests EUS-TCB can safely be used to obtain biopsy specimens of intraintestinal and extraintestinal mass lesions and lymphadenopathy. Its use may reduce the number of needle passes compared with EUS-FNA. This may reduce costs by shortening the procedure, diminishing the need for an onsite cytopathologist or technician, and lowering the frequency of nondiagnostic procedures. Prospective studies are needed to verify these findings.

Evaluation of indeterminate bile duct strictures by intraductal US.

BACKGROUND: Cholangiography and tissue sampling (brush cytology, biopsy) are the standard nonsurgical techniques for determining whether a bile duct stricture is benign or malignant. The aim of this study was to determine whether intraductal US is of assistance in distinguishing benign from malignant biliary strictures. METHODS: A retrospective review was undertaken of 30 patients with indeterminate bile duct strictures who underwent ERCP and tissue sampling from September 1999 to November 2000. A 20 MHz over-the-guidewire intraductal US catheter probe was used during ERCP for further examination of the strictures. Final diagnoses of malignant strictures (18 patients) were confirmed histopathologically; confirmation of benign stricture (12 patients) was based on negative tissue sampling plus extended clinical follow-up. RESULTS: Based on retrospective blinded review, the diagnosis by ERCP was correct in 67% of patients, by tissue sampling in 68%, by combined ERCP/tissue sampling in 67%, and by intraductal US in 90% (p = 0.04 vs. ERCP/tissue sampling) of cases. No complication of intraductal US or ERCP was recorded. CONCLUSIONS: Intraductal US is safe and can improve on the ability at ERCP to distinguish benign from malignant biliary strictures.

Initial experience with EUS-guided trucut needle biopsies of perigastric organs.

BACKGROUND: The aims of this study were to determine the feasibility, safety, and yield of a 19-gauge EUS-guided-trucut needle for obtaining biopsy specimens of perigastric organs. METHODS: The study was performed in swine under general anesthesia. EUS-guided trucut needle biopsy specimens were obtained from the spleen, liver, pancreas body, and left kidney. Biopsy specimens were assessed for size, fragmentation, and representation of the target organ. OBSERVATIONS: Twenty-eight biopsy specimens were obtained from the 4 target organs with two needles. Median biopsy length was 6 mm (spleen), 4 mm (liver), 6 mm (left kidney), and 2 mm (pancreas body). Of all the specimens, 75% to 100% had tissue representative of the target organ. EUS visualization of the needle was excellent and no complications were identified. CONCLUSIONS: Use of the trucut needle under EUS guidance to obtain biopsy specimens of perigastric organs appears safe and yields specimens that are representative of the target organ sampled. Further study of the utility and safety of this needle in humans is warranted.

A prospective, blinded assessment of the impact of preoperative staging on the management of rectal cancer.

BACKGROUND & AIMS: The influence of preoperative staging of rectal carcinoma on therapeutic decisions is uncertain. The use of fine-needle aspiration (FNA) of perirectal nodes in this setting has not been evaluated. The aim of this prospective, blinded study of patients with rectal cancer was to assess the impact of preoperative staging on treatment decisions and compare the tumor (T), nodal (N) staging performance characteristics of pelvic computed tomography (CT), rectal endoscopic ultrasonography (EUS), and EUS FNA. METHODS: Eighty consecutive patients with newly diagnosed rectal cancer were prospectively evaluated. Therapy decisions were recorded after sequential disclosure of staging information to the patient's surgeon. RESULTS: In 31% of patients (95% confidence interval, 21%-42%), EUS staging information changed the surgeon's original treatment plan based on CT alone. The further addition of FNA changed therapy in one patient. T staging accuracy was 71% (CT) and 91% (EUS) (P = 0.02); N staging accuracy was 76% (CT), 82% (EUS), and 76% (EUS FNA) (P = NS). CONCLUSIONS: Preoperative staging with EUS results in more frequent use of preoperative neoadjuvant therapy than if staging was performed with CT alone. The addition of FNA only changed the management of one patient, whereas FNA did not significantly improve N staging accuracy over EUS alone. FNA seems to offer the most potential for impacting management in those patients with early T stage disease, and its use should be confined to this subgroup of patients. EUS is more accurate than CT for determining T stage of rectal carcinoma.

Occult lymph node metastases as a predictor of tumor relapse in patients with node-negative esophageal carcinoma.

BACKGROUND & AIMS: Esophageal carcinoma is an aggressive disease with a very poor prognosis. Early tumor relapse after surgical resection in patients with node-negative esophageal carcinoma suggests that occult metastases may have been missed at the original pathologic examination. The aim of this study was to determine the prevalence of immunohistochemically detected occult lymph node microscopic metastases in patients with pathologic N0 esophageal carcinoma and the impact of these occult metastases on relapse-free survival. METHODS: All patients (n = 124) with pathologic N0 esophageal carcinoma undergoing resection at our institution between January, 1994, and October, 1998, constituted the study population. Esophagectomy specimens were reevaluated by immunohistochemistry (monoclonal antibody against cytokeratin AE1/AE3). Clinical and pathologic features were summarized, and patient relapse-free survival was estimated. RESULTS: Among the total of 124 patients, occult lymph node microscopic metastases were identified by immunohistochemistry in 14 patients (11%) (T1 mucosa, 4%; T1 submucosa, 6%; T2, 22%; and T3, 14%). Patients were followed for a median of 3.2 years. Relapse-free survival was not significantly associated with the presence of occult lymph node microscopic metastases as detected by immunohistochemistry (P = 0.12). Advanced T stage (T3; P < 0.001) and lymphovascular invasion (P < 0.001) were found to be associated with tumor relapse. CONCLUSIONS: In the present study, occult lymph node microscopic metastases in pathologic N0 esophageal carcinoma patients were less frequent than previously reported. T stage and lymphovascular invasion were significantly associated with relapse-free survival, although a significant association with occult lymph node metastases was not detected.