Christine E. Hovis

Prevalence of missed adenomas in patients with inadequate bowel preparation on screening colonoscopy

BACKGROUND The prevalence of missed polyps in patients with inadequate bowel preparation on screening colonoscopy is unknown. OBJECTIVE To determine the prevalence of missed adenomas in average-risk patients presenting for screening colonoscopy who are found to have inadequate bowel preparation. DESIGN Retrospective chart review. Endoscopy and pathology reports were examined to determine the characteristics of polyps. Data from repeat colonoscopies were collected through 2010. SETTING Outpatient endoscopy center at an academic medical center. PATIENTS This study involved patients who underwent outpatient average-risk screening colonoscopy between 2004 and 2009 documented to have inadequate bowel preparation and who had colonoscopy to the cecum. MAIN OUTCOME MEASUREMENTS Initial adenoma detection rate and adenoma detection rate on follow-up examination. RESULTS Inadequate bowel preparation was reported on 373 patients, with an initial adenoma detection rate of 25.7%. Of 133 patients who underwent repeat colonoscopy, 33.8% had at least 1 adenoma detected, and 18.0% had high-risk states detected (≥ 3 adenomas, 1 adenoma ≥ 1 cm, or any adenoma with villous features or high-grade dysplasia). Per-adenoma miss rate was 47.9%. Among patients with at least 1 adenoma on repeat colonoscopy, 31.1% had no polyps on initial colonoscopy; mean time between colonoscopies was 340 days. Among patients with high-risk states, 25.0% had no polyps seen on initial colonoscopy; mean time between colonoscopies was 271 days. LIMITATIONS Retrospective design. CONCLUSION Adenomas and high-risk lesions were frequently detected on repeat colonoscopy in patients with inadequate bowel preparation on initial screening colonoscopy, suggesting that these lesions were likely missed on initial colonoscopy.

Synthesis, Stability, and Antimicrobial Studies of Electronically Tuned Silver Acetate N-Heterocyclic Carbenes

A series of methylated imidazolium salts with varying substituents on the 4 and 5 positions of the imidazole ring were synthesized. These salts were reacted with silver acetate to afford their corresponding silver N-heterocyclic carbene (NHC) complexes. These complexes were then evaluated for their stability in water as well as for their antimicrobial efficacy against a variety of bacterial strains associated with cystic fibrosis and chronic lung infections.

The antimicrobial efficacy of sustained release silver–carbene complex-loaded l-tyrosine polyphosphate nanoparticles: Characterization, in vitro and in vivo studies

The pressing need to treat multi-drug resistant bacteria in the chronically infected lungs of cystic fibrosis (CF) patients has given rise to novel nebulized antimicrobials. We have synthesized a silver-carbene complex (SCC10) active against a variety of bacterial strains associated with CF and chronic lung infections. Our studies have demonstrated that SCC10-loaded into L-tyrosine polyphosphate nanoparticles (LTP NPs) exhibits excellent antimicrobial activity in vitro and in vivo against the CF relevant bacteria Pseudomonas aeruginosa. Encapsulation of SCC10 in LTP NPs provides sustained release of the antimicrobial over the course of several days translating into efficacious results in vivo with only two administered doses over a 72 h period.

Obesity as a risk factor for sedation-related complications during propofol-mediated sedation for advanced endoscopic procedures

BACKGROUND There are limited data on the safety of anesthesia-assisted endoscopy by using propofol-mediated sedation in obese individuals undergoing advanced endoscopic procedures (AEPs). OBJECTIVE To study the association between obesity (as measured by body mass index [BMI]) and the frequency of sedation-related complications (SRCs) in patients undergoing AEPs. DESIGN Prospective cohort study. SETTING Tertiary referral center. PATIENTS A total of 1016 consecutive patients undergoing AEPs (BMI <30, 730 [72%]; 30-35, 159 [16%]; >35, 127 [12%]). INTERVENTION Monitored anesthesia sedation with propofol alone or in combination with benzodiazepines and/or opioids. MAIN OUTCOME MEASUREMENTS SRCs, airway maneuvers (AMs), hypoxemia, hypotension requiring vasopressors, and early procedure termination were compared across 3 groups. RESULTS There were 203 AMs in 13.9% of patients, hypoxemia in 7.3%, need for vasopressors in 0.8%, and premature termination in 0.6% of patients. Increasing BMI was associated with an increased frequency of AMs (BMI <30, 10.5%; 30-35, 18.9%; >35-26.8%; P < .001) and hypoxemia (BMI <30, 5.3%; 30-35, 9.4%; >35, 13.4%; P = .001); there was no difference in the frequency of need for vasopressors (P = .254) and premature termination of procedures (P = .401). On multivariable analysis, BMI (odds ratio [OR] 2.0; 95% CI, 1.3-3.1), age (OR 1.1; 95% CI, 1.0-1.1), and American Society of Anesthesiologists class 3 or higher (OR 2.4; 95% CI, 1.1-5.0) were independent predictors of SRCs. In obese individuals (n = 286), there was no difference in the frequency of SRCs in patients receiving propofol alone or in combination (P = .48). LIMITATIONS Single tertiary center study. CONCLUSIONS Although obesity was associated with an increased frequency of SRCs, propofol sedation can be used safely in obese patients undergoing AEPs when administered by trained professionals.

A Screening Instrument for Sleep Apnea Predicts Airway Maneuvers in Patients Undergoing Advanced Endoscopic Procedures

BACKGROUND & AIMS Among patients undergoing advanced endoscopy, unrecognized obstructive sleep apnea (OSA) could predict sedation-related complications (SRCs) and the need for airway maneuvers (AMs). By using an OSA screening tool, we sought to define the prevalence of patients at high risk for OSA and to correlate OSA with the frequency of AMs and SRCs. METHODS We enrolled 231 consecutive patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) (n = 176) and endoscopic ultrasound (n = 55). Propofol-based sedation and patient monitoring were performed by a nurse anesthetist and an anesthesiologist. A previously validated screening tool for OSA (STOP-BANG) was used to identify patients at high risk for OSA (score, > or =3 of 8; SB+) or low risk (SB-). AMs were defined as a chin lift, modified mask ventilation, nasal airway, bag-mask ventilation, and endotracheal intubation. SRCs were defined as any duration of pulse oximetry less than 90%, systolic blood pressure less than 90 mm Hg, apnea, or early procedure termination. RESULTS The prevalence of SB+ was 43.3%. The frequency of hypoxemia was significantly higher among patients with SB+ than SB- (12.0% vs 5.2%; relative risk [RR], 1.83; 95% confidence interval [CI], 1.32-2.54). The rate of AMs was also significantly higher among SB+ (20.0%) compared with SB- (6.1%) patients (RR, 1.8; 95% CI, 1.3-2.4). These rates remained significant after adjusting for American Society of Anesthesiologists class 3 or higher (RR, 1.70; 95% CI, 1.28-2.2 for AMs; RR, 1.63; 95% CI, 1.19-2.25 for hypoxemia). Each element of the STOP-BANG was reported more commonly in SB+ patients (P < .0001 for each comparison). CONCLUSIONS A significant number of patients undergoing advanced endoscopic procedures are at risk for OSA. AMs and hypoxemia occur at an increased frequency in these patients.

Sensitivity of endoscopic ultrasound, multidetector computed tomography, and magnetic resonance cholangiopancreatography in the diagnosis of pancreas divisum: a tertiary center experience.

Objectives There are limited data comparing imaging modalities in the diagnosis of pancreas divisum. We aimed to: (1) evaluate the sensitivity of endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP), and multidetector computed tomography (MDCT) for pancreas divisum; and (2) assess interobserver agreement (IOA) among expert radiologists for detecting pancreas divisum on MDCT and MRCP. Methods For this retrospective cohort study, we identified 45 consecutive patients with pancreaticobiliary symptoms and pancreas divisum established by endoscopic retrograde pancreatography who underwent EUS and cross-sectional imaging. The control group was composed of patients without pancreas divisum who underwent endoscopic retrograde pancreatography and cross-sectional imaging. Results The sensitivity of EUS for pancreas divisum was 86.7%, significantly higher than the sensitivity reported in the medical records for MDCT (15.5%) or MRCP (60%) (P < 0.001 for each). On review by expert radiologists, the sensitivity of MDCT increased to 83.3% in cases where the pancreatic duct was visualized, with fair IOA (&kgr; = 0.34). Expert review of MRCPs did not identify any additional cases of pancreas divisum; IOA was moderate (&kgr; = 0.43). Conclusions Endoscopic ultrasound is a sensitive test for diagnosing pancreas divisum and is superior to MDCT and MRCP. Review of MDCT studies by expert radiologists substantially raises its sensitivity for pancreas divisum.

Training in EUS-Guided Fine Needle Aspiration: Safety and Diagnostic Yield of Attending Supervised, Trainee-Directed FNA from the Onset of Training

Background. The optimal time to initiate hands-on training in endoscopic ultrasound fine needle aspiration (EUS-FNA) is unclear. We studied the feasibility of initiating EUS-FNA training concurrent with EUS training. Methods. Three supervised trainees were instructed on EUS-FNA technique and allowed hands-on exposure from the onset of training. The trainee and attending each performed passes in no particular order. During trainee FNA, the attending provided verbal instruction as needed but no hands-on assistance. A blinded cytopathologist assessed the adequacy (cellularity) and diagnostic yield of individual passes. Primary outcomes compared cellularity and diagnostic yield of attending versus fellow FNA passes. Results. We analyzed 305 FNA sites, including pancreas (51.2%), mediastinal/upper abdominal lymph node (LN) (28.5%) and others (20.3%). The average proportion of fellow passes with AC was similar to attending FNA—pancreas: 70.3 versus 68.8%; LN: 79.0 versus 81.7%; others 65.5 versus 68.7%; P > 0.05); these did not change significantly during the training period. Among cases with confirmed malignancy (n = 179), the sensitivity of EUS-FNA was 78.8% (68.4% fellow-only versus 69.6% attending only). There were no EUS-FNA complications. Conclusions. When initiated at the onset of EUS training, attending-supervised, trainee-directed FNA is safe and has comparable performance characteristics to attending FNA.

Diagnostic Endoscopic Mucosal Resection (EMR) Leads to a Change in Histologic Diagnosis in Barrett's Esophagus (BE) Patients With Visible and Flat Neoplasia

BACKGROUND: Radiofrequency ablation (RFA) is an endoscopic ablation modality used to treat Barretts esophagus (BE) with the goal of eliminating dysplasia and metaplasia. Factors associated with stricture formation or incomplete eradication of intestinal metaplasia (EIM) are poorly understood. AIM: To determine the factors associated with stricture formation or incomplete EIM. METHODS: This was a retrospective study of all patients treated with RFA for BE at a tertiary care referral center between June 2006 and November 2010. Pertinent information was extracted from medical records, including: demographics, history of BE (pre-ablation histology, duration of pre-treatment dysplasia), medication and substance use, indicators of GERD activity (symptoms, presence of erosive esophagitis), upper endoscopy findings (Prague criteria, hiatus hernia), ablation outcomes (elimination of metaplasia and dysplasia), and complications (perforation, stricture, bleeding, and hospitalization). Outcomes related to RFA were described for all patients as well as stratified by pre-ablation histology. Comparative analysis of patients with and without stricture and complete and incomplete elimination of dysplasia were performed with non-parametric tests (Fishers exact test for categorical data, Wilcoxon rank-sum test for continuous data) to determine associated factors. RESULTS: Among 113 patients who received RFA for BE (22 low-grade dysplasia, 77 high-grade dysplasia, 14 intramucosal carcinoma), 83 (73.5%) completed treatment with 95.2% complete elimination of dysplasia and 85.5% complete EIM. Of the remaining 30 subjects, 22 had ongoing treatment, 6 were lost to follow up, one had treatment delay for antireflux surgery and 1 opted for esophagectomy. Nine patients (8.0%) experienced a treatment-related complication, including8 strictures and 1 post-procedure hemorrhage. Stricture formation was associated with receiving endoscopic mucosal resection (75.0% vs. 36.2%, p=0.05) and number of EMR sessions (mean 1.4 vs. 0.4, p=0.007). A trend toward stricture formation existed with number of focal RFA treatments (mean 3.3 vs. 2.2, p=0.09), active NSAID use (75.0% vs. 44.8%, p=0.14) and prior peptic stricture (25.0% vs. 7.6%, p=0.15). Incomplete EIM was associated with ongoing GERD symptoms (75.0% vs. 33.8%, p=0.01) while increased Prague M length had a trend toward association (mean 6.6 vs. 4.5cm, p=0.11). CONCLUSIONS: RFA at a tertiary referral center is both safe (8.0% with complications, mostly benign strictures) and efficacious (95.2% elimination of dysplasia, 85.5% elimination of intestinal metaplasia). Previous EMR is associated with stricture formation while ongoing GERD symptoms are associated with incomplete elimination of intestinal metaplasia. These findings should be considered in planning treatment protocols for patients with BE.