T I Omari

Publications (3)8.58 Total impact

• Article: Automated impedance-manometry analysis detects esophageal motor dysfunction in patients who have non-obstructive dysphagia with normal manometry.

  N Q Nguyen, R H Holloway, A J Smout, T I Omari
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  ABSTRACT: Background  Automated integrated analysis of impedance and pressure signals has been reported to identify patients at risk of developing dysphagia post fundoplication. This study aimed to investigate this analysis in the evaluation of patients with non-obstructive dysphagia (NOD) and normal manometry (NOD/NM). Methods  Combined impedance-manometry was performed in 42 patients (27F : 15M; 56.2 ± 5.1 years) and compared with that of 24 healthy subjects (8F : 16M; 48.2 ± 2.9 years). Both liquid and viscous boluses were tested. MATLAB-based algorithms defined the median intrabolus pressure (IBP), IBP slope, peak pressure (PP), and timing of bolus flow relative to peak pressure (TNadImp-PP). An index of pressure and flow (PFI) in the distal esophagus was derived from these variables. Key Results  Diagnoses based on conventional manometric assessment: diffuse spasm (n = 5), non-specific motor disorders (n = 19), and normal (n = 11). Patients with achalasia (n = 7) were excluded from automated impedance-manometry (AIM) analysis. Only 2/11 (18%) patients with NOD/NM had evidence of flow abnormality on conventional impedance analysis. Several variables derived by integrated impedance-pressure analysis were significantly different in patients as compared with healthy: higher PNadImp (P < 0.01), IBP (P < 0.01) and IBP slope (P < 0.05), and shorter TNadImp_PP (P = 0.01). The PFI of NOD/NM patients was significantly higher than that in healthy (liquid: 6.7 vs 1.2, P = 0.02; viscous: 27.1 vs 5.7, P < 0.001) and 9/11 NOD/NM patients had abnormal PFI. Overall, the addition of AIM analysis provided diagnoses and/or a plausible explanation in 95% (40/42) of patients who presented with NOD. Conclusions & Inferences  Compared with conventional pressure-impedance assessment, integrated analysis is more sensitive in detecting subtle abnormalities in esophageal function in patients with NOD and normal manometry.
  Neurogastroenterology and Motility 10/2012; · 3.41 Impact Factor
• Article: Susceptibility to dysphagia after fundoplication revealed by novel automated impedance manometry analysis.

  J C Myers, N Q Nguyen, G G Jamieson, J E Van't Hek, K Ching, R H Holloway, J Dent, T I Omari
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  ABSTRACT: Conventional measures of esophageal pressures or bolus transport fail to identify patients at risk of dysphagia after laparoscopic fundoplication. Liquid and viscous swallows were evaluated with impedance/manometry in 19 patients with reflux disease before and after surgery. A new method of automated impedance manometry (AIM) analysis correlated esophageal pressure with impedance data and automatically calculated a range of pressure and bolus movement variables. An iterative analysis determined whether any variables were altered in relation to dysphagia. Standard measures of esophago-gastric junction pressure, bolus presence time, and total bolus transit time were also evaluated. At 5 months postop, 15 patients reported some dysphagia, including 7 with new-onset dysphagia. For viscous boluses, three AIM-derived pressure-flow variables recorded preoperatively varied significantly in relation to postoperative dysphagia. These were: time from nadir esophageal impedance to peak esophageal pressure (TNadImp-PeakP), median intra-bolus pressure (IBP, mmHg), and the rate of bolus pressure rise (IBP slope, mmHgs(-1) ). These variables were combined to form a dysphagia risk index (DRI=IBP×IBP_slope/TNadImp-PeakP). DRI values derived from preoperative measurements were significantly elevated in those with postoperative dysphagia (DRI=58, IQR=21-408 vs no dysphagia DRI=9, IQR=2-19, P<0.02). A DRI >14 was optimally predictive of dysphagia (sensitivity 75% and specificity 93%). Before surgery, a greater and faster compression of a swallowed viscous bolus with less bolus flow time relates to postoperative dysphagia. Thus, susceptibility to postfundoplication dysphagia is related to a pre-existing sub-clinical variation of esophageal function.
  Neurogastroenterology and Motility 05/2012; 24(9):812-e393. · 3.41 Impact Factor
• Article: Nasopharyngeal pH monitoring in chronic sinusitis patients using a novel four channel probe.

  I W Y Wong, T I Omari, J C Myers, G Rees, S B Nair, G G Jamieson, P J Wormald
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  ABSTRACT: To determine the prevalence of acid reflux into the nasopharynx in patients with chronic sinusitis. Prospective study of patients presenting to a specialist rhinology practice with chronic sinusitis. Forty patients with chronic sinusitis underwent ambulatory 24 hour pH testing. The mean age of the patients was 56.3 years (25 Female, 15 Male). The studies were performed using a specially developed bifurcated 4 channel pH probe, incorporating 2 circumferential sensors positioned at the naso- and hypo-pharynx, and 2 unidirectional sensors positioned at the proximal and distal esophagus. The circumferential band sensors yielded a stable recording largely free of artefact allowing meaningful recordings to be obtained from thirty-seven patients. Twelve patients (32.4%) were diagnosed with gastroesophageal reflux. A total of 809 reflux episodes were recorded. Of these, 596 (73.7%) reached the distal esophagus, with 187 (23.1%) and 24 (3.0%) reaching the proximal esophagus and hypopharynx respectively. Only 2 episodes (0.2%) were recorded in the nasopharynx. This occurred in 2 of 37 patients (5%). Acid reflux into the nasopharynx is a rare event in patients with chronic sinusitis even though a significant proportion (32.4%) have abnormal 24 hour pH studies. It is likely that alternative mechanisms other than direct acid contact are involved in the pathogenesis of chronic sinusitis.
  The Laryngoscope 10/2004; 114(9):1582-5. · 1.75 Impact Factor