Pooyan Sadeghi

University of Iowa, Iowa City, Iowa, United States

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Publications (4)21.64 Total impact

  • Source
    Satish S C Rao · Siddharth Singh · Pooyan Sadeghi
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    ABSTRACT: To examine whether endoscopic mucosal clipping prevents probe migration. Ambulatory colonic manometry can provide useful pathophysiologic information regarding colonic motor function. However, probe displacement during prolonged recording can be problematic. Thirty healthy volunteers underwent 24-hour ambulatory colonic manometry with colonoscopic-assisted probe placement, and fluoroscopic confirmation of the location of most proximal sensor at hepatic flexure. Participants were randomized to 2 groups; in 14 participants (m/f=8/6), the probe was anchored to the colonic mucosa using mucosal clips and in 16 participants, (m/f=9/7), the probe was left unattached in the colon. Magnitude of transducer displacement was assessed by fluoroscopic localization. The difference between the number of transducers in each segment at the beginning (x) and at the end (y) of each study was summed up and divided by 2, to calculate the "displacement score" and this was taken as the main outcome measure. In participants without clipping, the mean (s.d.) displacement score was 1.6 (0.9), implying displacement of transducers by 1.6 colonic segments relative to their initial location. In contrast, there was no displacement of transducers in those who received clipping. Clipping caused no adverse events. Endoscopic mucosal clipping is safe and effective for prevention of probe displacement, and ensures more accurate temporospatial resolution of data for prolonged colonic manometry recording.
    Preview · Article · Feb 2010 · Journal of clinical gastroenterology
  • Satish S.C. Rao · Pooyan Sadeghi · Jennifer Beaty · Renae Kavlock
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    ABSTRACT: The colonic neuromuscular dysfunction in patients with constipation and the role of colonic manometry is incompletely understood. To study prolonged colonic motility and assess its clinical significance. Twenty-four-hour ambulatory colonic manometry was performed in 21 patients with slow-transit constipation and 20 healthy controls by placing a 6-sensor solid-state probe up to the hepatic flexure. Quantitative and qualitative manometric analysis was performed in 8-h epochs. Patients were followed up for 1 yr. Constipated patients showed fewer pressure waves and lower area under the curve (p < 0.05) than controls during daytime, but not at night. Colonic motility induced by waking or meal was decreased (p < 0.05) in patients. High-amplitude propagating contractions (HAPCs) occurred in 43% of patients compared to 100% of controls and with lower incidence (1.7 vs 10.1, p < 0.001) and propagation velocity (p < 0.04). Manometric features suggestive of colonic neuropathy were seen in 10, myopathy in 5, and normal profiles in 4 patients. Seven patients with colonic neuropathy underwent colectomy with improvement. The rest were managed conservatively with 50% improvement at 1 yr. Patients with slow-transit constipation exhibited either normal or decreased pressure activity with manometric features suggestive of colonic neuropathy or myopathy as evidenced by absent HAPC or attenuated colonic responses to meals and waking. In refractory patients, colonic manometry may be useful in characterizing the underlying pathophysiology and in guiding therapy.
    No preview · Article · Jan 2005 · The American Journal of Gastroenterology
  • Source
    S. S. C. Rao · P Sadeghi · K Batterson · J Beaty
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    ABSTRACT: The pathophysiology of slow transit constipation is poorly understood. Both decreased and increased distal colonic motility have been reported. In healthy humans, a 3 cycles per minute (cpm), periodic rectal motor activity (PRMA) has been described. Our aim was to investigate the characteristics of PRMA and to assess its role in the pathogenesis of constipation. A six-sensor solid-state probe was placed with the tip sensor in the mid-transverse colon, without sedation, and prolonged colonic motility was recorded in nine patients with slow transit constipation (1M, 8F) and in 11 healthy subjects (3M, 8F). Subjects were free to ambulate. We examined the frequency, nocturnal vs. diurnal variation, and characteristics of PRMA, and its relationship to proximal colonic motility. All subjects showed PRMA. The rhythm was similar (2.5-4 cpm) in both groups. However, constipated patients exhibited a greater (P < 0.001) number of PRMA cycles than controls. The duration of each cycle and amplitude of pressure waves during PRMA were also greater (P < 0.05) at night in patients compared with controls. In patients, 40% of PRMA cycles were associated with a proximal colonic motor event compared with 81% in controls (P < 0.02). The area under the curve of all colonic pressure waves and incidence of specialized propagating pressure waves was lower (P < 0.05) in patients during daytime. When compared with controls, constipated patients exhibited reduced daytime colonic pressure waves and a higher frequency of PRMA. Most of the PRMA was unrelated to proximal colonic activity in constipated patients in contrast with findings in control patients. In addition to decreased colonic motility, this excessive and unco-ordinated phasic rectal activity may further impede stool transport and contribute to the pathogenesis of slow transit constipation.
    Preview · Article · Dec 2001 · Neurogastroenterology and Motility
  • S.S.C. Rao · P Sadeghi · J Beaty · R Kavlock · K Ackerson
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    ABSTRACT: Our aim was to investigate motor activity of the healthy, relatively unprepared colon in the ambulatory state. Twenty-five age- and gender-matched adults had a six-sensor solid-state probe inserted into the proximal transverse colon without sedation. Subjects ambulated freely and ate standard meals. In 528 h of recording, we found a lower (P < 0.05) area under the curve during the night. Waking induced a threefold increase in motility, whereas meals induced a twofold increase. Women showed less activity (P < 0.05) in the transverse/descending colon than men. The transverse/descending colon showed more (P < 0.05) activity than the rectosigmoid colon. Seven patterns were recognized; predominantly, they were simultaneous, propagated, or periodic bursts of 3-cycles/min (cpm) waves. A specialized propagating pressure wave with a high amplitude (>105 mmHg) and a prolonged duration (>14 s) occurred in all subjects (mean 10/day), mostly after waking, after meals, or with defecation. A 3-cpm motor activity was seen in the rectosigmoid region predominantly at night. The colon exhibits a wide spectrum of pressure activity around the clock, with gender and regional differences and circadian rhythm. This comprehensive study provides qualitative and quantitative normative data for colonic manometry.
    No preview · Article · Apr 2001 · AJP Gastrointestinal and Liver Physiology