Dirk Van Beckevoort

Universitair Ziekenhuis Leuven, Louvain, Flanders, Belgium

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Publications (6)41.36 Total impact

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    ABSTRACT: Automated impedance manometry (AIM) analysis measures swallow variables defining bolus timing, pressure, contractile vigour, and bolus presence, which are combined to derive a swallow risk index (SRI) correlating with aspiration. In a heterogeneous cohort of dysphagia patients, we assessed the impact of bolus volume and viscosity on AIM variables. We studied 40 patients (average age = 46 years). Swallowing of boluses was recorded with manometry, impedance, and videofluoroscopy. AIMplot software was used to derive functional variables: peak pressure (PeakP), pressure at nadir impedance (PNadImp), time from nadir impedance to peak pressure (TNadImp-PeakP), the interval of impedance drop in the distal pharynx (flow interval, FI), upper oesophageal sphincter (UES) relaxation interval (UES RI), nadir UES pressure (Nad UESP), UES intrabolus pressure (UES IBP), and UES resistance. The SRI was derived using the formula SRI = (FI * PNadImp)/(PeakP * (TNadImp-PeakP + 1)) * 100. A total of 173 liquid, 44 semisolid, and 33 solid boluses were analysed. The SRI was elevated in relation to aspiration. PeakP increased with volume. SRI was not significantly altered by bolus volume. PNadImp, UES IBP, and UES resistance increased with viscosity. SRI was lower with increased viscosity. In patients with dysphagia, the SRI is elevated in relation to aspiration, reduced by bolus viscosity, and not affected by bolus volume. These data provide evidence that pharyngeal AIM analysis may have clinical utility for assessing deglutitive aspiration risk to liquid boluses.
    Dysphagia 09/2012; · 1.94 Impact Factor
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    ABSTRACT: This validation study evaluates a new manometry impedance-based approach for the objective assessment of pharyngeal function relevant to postswallow bolus residue. We studied 23 adult and pediatric dysphagic patients who were all referred for a videofluoroscopy, and compared these patients with 10 adult controls. The pharyngeal phase of swallowing of semisolid boluses was recorded with manometry and impedance. Fluoroscopic evidence of postswallow bolus residue was scored. Pharyngeal pressure impedance profiles were analyzed. Computational algorithms measured peak pressure (Peak P), pressure at nadir impedance (PNadImp), time from nadir impedance to PeakP (PNadImp-PeakP), the duration of impedance drop in the distal pharynx (flow interval), upper esophaghageal sphincter (UES) relaxation interval (UES-RI), nadir UES pressure (NadUESP), UES intrabolus pressure (UES-IBP), and UES resistance. A swallow risk index (SRI) was derived by the formula: SRI=(FI × PNadImp)/(PeakP × (TNadImp-PeakP+1)) × 100. In all, 76 patient swallows (35 with residue) and 39 control swallows (12 with residue) were analyzed. Different functional variables were found to be altered in relation to residue. In both controls and patients, flow interval was longer in relation to residue. In controls, but not patients, residue was associated with an increased PNadImp (suggestive of increased pharyngeal IBP). Controls with residue had increased UES-IBP, NadUESP, and UES resistance compared with patients with residue. Residue in patients was related to a prolonged UES-RI. The SRI was elevated in relation to residue in both controls and patients and an average SRI of 9 was optimally predictive of residue (sensitivity 75% and specificity 80%). We present novel findings in control subjects and dysphagic patients showing that combined manometry and impedance recordings can be objectively analyzed to derive pressure-flow variables that are altered in relation to the bolus residual and can be combined to predict ineffective pharyngeal swallowing.
    The American Journal of Gastroenterology 05/2011; 106(10):1796-802. · 7.55 Impact Factor
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    ABSTRACT: Pharyngeal manometry and impedance provide information on swallow function. We developed a new analysis approach for assessment of aspiration risk. We studied 20 patients (30-95 years old) with suspected aspiration who were referred for videofluoroscopy, along with controls (ages 24-47 years). The pharyngeal phase of liquid bolus swallowing was recorded with manometry and impedance. Data from the first swallow of a bolus and subsequent clearing swallows were analyzed. We scored fluoroscopic evidence of aspiration and investigated a range of computationally derived functional variables. Of these, 4 stood out as having high diagnostic value: peak pressure (PeakP), pressure at nadir impedance (PNadImp), time from nadir impedance to peak pressure (TNadImp-PeakP), and the interval of impedance drop in the distal pharynx (flow interval). During 54 liquid, first swallows and 40 clearing swallows, aspiration was observed in 35 (13 patients). Compared to those of controls, patient swallows were characterized by a lower PeakP, higher PNadImp, longer flow interval, and shorter TNadImp-PeakP. A Swallow Risk Index (SRI), designed to identify dysfunctions associated with aspiration, was developed from iterative evaluations of variables. The average first swallow SRI correlated with the average aspiration score (r = 0.846, P < .00001 for Spearman Rank Correlation). An average SRI of 15, when used as a cutoff, predicted aspiration during fluoroscopy for this cohort (κ = 1.0). Pressure-flow variables derived from automated analysis of combined manometric/impedance measurements provide valuable diagnostic information. When combined into an SRI, these measurements are a robust predictor of aspiration.
    Gastroenterology 02/2011; 140(5):1454-63. · 12.82 Impact Factor
  • Gastroenterology 01/2010; 138(5). · 12.82 Impact Factor
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    ABSTRACT: We studied the long-term anatomical and functional outcome following sacrocolpopexy for apical vaginal prolapse using xenogenic grafts in a population at increased risk for graft-related complications (GRCs). Twenty-two consecutive patients with symptomatic apical prolapse were scheduled for laparoscopic sacrocolpopexy (LSC) with porcine grafts because they were presumed to be at risk for GRC, because of pre-existing vaginal ulcerations (n = 4), concomitant vaginal prolapse repair (n = 15), total hysterectomy (n = 1), or intra-operative abdominal contamination due to accidental laceration of the vagina, bowel perforation (n = 1) or the presence of infection (n = 1). Either small intestinal submucosa (n = 8) or dermal collagen (n = 14) was used. Outcome measures were GRCs, anatomical cure (<or=Stage I at any compartment), subjective cure, impact on bowel, bladder, and sexual function measured by a standardized interview. At study closure 20 (91%) patients were available for functional evaluation and 16 (73%) for anatomical evaluation at a mean follow-up period of 27.4 months. The GRC rate was 25% (n = 4) prompting reintervention in half, and including two patients with spondylodiscitis. The anatomical cure rate was 31.5%. Failures at the vault, anterior, and posterior compartments occurred in, respectively, 31%, 18.8%, and 50% of patients. The subjective cure rate was 60% and three patients (15%) underwent redo-LSC. The strategy of using xenografts in patients at risk for GRC, did not prevent these to occur and was associated with a high anatomical and functional failure rate as well as reoperation rate.
    Neurourology and Urodynamics 09/2009; 29(4):563-7. · 2.67 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 09/2007; 30(4):448 - 448. · 3.56 Impact Factor

Publication Stats

62 Citations
41.36 Total Impact Points

Institutions

  • 2011–2012
    • Universitair Ziekenhuis Leuven
      • Department of Radiology
      Louvain, Flanders, Belgium
    • University of Adelaide
      • Gastroenterology Unit
      Adelaide, South Australia, Australia
  • 2007
    • KU Leuven
      • Department of Reproduction, Development and Regeneration
      Leuven, VLG, Belgium