Biomedical subjects

Reza Shaker

Publications and source records attributed to Reza Shaker.

61 records · Page 4Linked to original sources

PubMed2002

The small-caliber esophagus: an unappreciated cause of dysphagia for solids in patients with eosinophilic esophagitis.

BACKGROUND: Dysphagia for solids usually indicates a structural esophageal abnormality. This article is a description of a group of 5 young men referred with chronic dysphagia for solids. Esophagoscopy and barium esophagogram failed to show a cause. Our evaluation showed that these patients had eosinophilic esophagitis and a "small-caliber esophagus." This article describes the clinical features, diagnosis, and management of the small-caliber esophagus. METHODS: Patients were evaluated by barium esophagogram with marshmallow challenge, esophageal manometry, Bernstein test, and EGD with biopsies. All patients underwent empiric esophageal dilation with wire-guided dilators. OBSERVATIONS: A diffusely narrow esophagus was appreciated in 3 of 5 patients radiographically, endoscopically, or both. However, the latter studies showed normal findings in 2 patients. Eosinophilic esophagitis was found in all 4 patients in whom biopsy specimens were obtained. Esophageal manometry was performed in 4 patients and showed normal findings in all. The feature that most confirmed the diagnosis of small-caliber esophagus in all patients was the unusually long rents (8 to 17 cm) in the esophageal wall after empiric dilation. Dilation relieved the symptoms in all cases. CONCLUSIONS: The small-caliber esophagus is a cause of dysphagia for solids in young men with eosinophilic esophagitis. It frequently defies detection by routine diagnostic studies. The clue to diagnosis lies in endoscopic reinspection after dilation and the finding of unusually long rents in the esophageal wall.

Adolescent↗

PubMed2002

Unsedated transnasal endoscopy accurately detects Barrett's metaplasia and dysplasia.

BACKGROUND: Unsedated transnasal upper endoscopy has a diagnostic yield comparable with that of sedated conventional upper endoscopy. The ability of transnasal upper endoscopy to detect Barrett's metaplasia or dysplastic change has not been systematically evaluated. The aim of this study was to assess the feasibility of transnasal upper endoscopy for surveillance of patients with Barrett's esophagus and to evaluate its histopathologic yield for Barrett's metaplasia and dysplasia. METHODS: Thirty-two patients with Barrett's esophagus were evaluated with conventional upper endoscopy and transnasal upper endoscopy. An effort was made to recruit patients known to have dysplasia. Quadrantic biopsy specimens were taken with standard (conventional upper endoscopy) and pediatric (transnasal upper endoscopy) biopsy forceps at procedures performed at least 1 week apart. Two blinded pathologists evaluated the specimens. RESULTS: Transnasal upper endoscopy detected Barrett's metaplasia histopathologically in 31 of 32 patients. Level of agreement for presence of dysplasia in biopsy specimens obtained between conventional upper endoscopy and transnasal upper endoscopy was excellent (k = 0.79). Interobserver agreement for dysplasia in specimens obtained by conventional upper endoscopy (k = 0.61) and by transnasal upper endoscopy (k = 0.61) were similar. Intraobserver agreement between conventional upper endoscopy and transnasal upper endoscopy biopsy specimens for dysplasia by pathologist 1 (k = 0.73) and pathologist 2 (k = 0.75) were also similar. No significant adverse effects were noted. CONCLUSIONS: Transnasal upper endoscopy is feasible and accurate for identification and histopathologic confirmation of Barrett's metaplasia with a histopathologic yield for dysplasia comparable with conventional upper endoscopy.

Adult↗

PubMed2002

Autonomic dysfunction, vasomotor rhinitis, and extraesophageal manifestations of gastroesophageal reflux.

OBJECTIVE: Several recent reports suggest there may be a relationship between chronic rhinitis and extraesophageal manifestations of gastroesophageal reflux (EER). It is hypothesized that this relationship is a result of autonomic nervous system (ANS) dysfunction. STUDY DESIGN: Patients with isolated vasomotor rhinitis (VR), both VR and EER, and a control group were studied by a battery of tests designed to objectively evaluate ANS function. In addition all 3 groups underwent barium esophagogram and 4-site (proximal pharynx, distal pharynx, proximal esophagus, and distal esophagus) ambulatory pH monitoring. Adult patients fulfilling diagnostic criteria for VR, and with both VR and EER underwent objective ANS testing in a recently developed ANS testing laboratory. The control group consisted of age- and sex-matched adults without diagnostic criteria for VR or EER. RESULTS: In patients with VR only (n = 9), 2 patients had a positive esophagogram, whereas a positive pharyngeal reflux probe was found in 1 and an abnormal composite autonomic scoring scale (CASS) was found in 8 (mean VR CASS = 1.750 vs control CASS 0.556, P =.02). The group with VR and EER (n = 12) had a positive esophagogram in 10 patients, positive pharyngeal reflux by probe in 9, and all 12 had an abnormal CASS (mean CASS VR/EER = 2.909 vs CASS control = 0.556, P =.001 and vs VR CASS = 1.750, P =.05). The control patients (n = 9) had normal transesophageal gastroduodenoscopy in 8, 1 had a positive pharyngeal probe study, and all 9 had a normal CASS. In addition ANS testing in patients with diagnostic criteria for both VR/EER revealed statistically significant evidence of an adrenergic deficit as compared with control patients on the basis of mean phase II blood pressure response to Valsalva maneuver (mean phase II VR/EER = -16.730 vs control = -7.780, P =.05). In the VR only group, the phase II blood pressure decrease was greater than in control patients, but did not reach statistical significance (mean phase II VR = -9.370 vs control = -7.780, P = 0.672). CONCLUSION: Patients with VR and VR/EER have objective evidence of ANS dysfunction when compared with a group of age- and sex-matched control patients. Patients with both VR/EER demonstrate a significantly greater degree of ANS dysfunction than patients with isolated VR. The mechanism by which VR and EER interact is not entirely clear, but ANS dysfunction is objectively associated with both disorders. In addition, patients with VR/EER seem to demonstrate hypofunction of the adrenergic component of the ANS, in contrast to the generally held hypothesis that VR results from increased cholinergic activity. Further characterization of the type of ANS abnormality may allow the development of novel pharmacologic therapies for these disorders.

Adult↗

PubMed2002

Unsedated transnasal endoscopy: a new technique for accurately detecting and grading esophageal varices in cirrhotic patients.

OBJECTIVES: Endoscopic screening of cirrhotics for large esophageal varices (EV) is advocated before initiation of prophylactic therapy for variceal bleeding. Conscious sedation for conventional endoscopy is problematic in cirrhotic patients because of risk of prolonged encephalopathy. Unsedated transnasal endoscopy (T-EGD) is a new technique, which allows for unsedated examination because it is well tolerated. The aims of this study were to determine whether T-EGD is feasible for screening of cirrhotic patients for presence of EV and to compare the diagnostic yield of T-EGD with conventional endoscopy for detecting and grading of EV. METHODS: Fifteen cirrhotics with no history of variceal bleeding, known EV, severe thrombocytopenia, or recurrent epistaxis were evaluated by unsedated T-EGD using a 5.3-mm outer diameter endoscope. Immediately afterward, a different endoscopist, blinded to T-EGD findings, performed sedated conventional endoscopy in standard fashion. The presence and size of EV, gastric varices, and other findings were recorded. Patient tolerance was also evaluated. RESULTS: Both modalities detected EV in the same 10 and gastric varices in the same two patients and completely agreed on size of EV. No stigmata of recent variceal bleeding were noted. Average time for unsedated T-EGD was 5 min 6 s. All patients found both procedures acceptable overall, with no significant difference in choking, discomfort, and sore throat. One patient developed self-limited epistaxis after T-EGD. CONCLUSIONS: 1) EV are accurately detected and graded by T-EGD in cirrhotic patients. 2) T-EGD is a safe and less costly screening alternative for EV in cirrhotic patients.

Adult↗

PubMed2002

Mechanisms of airway protection during retching, vomiting, and swallowing.

We investigated the mechanisms of airway protection and bolus transport during retching and vomiting by recording responses of the pharyngeal, laryngeal, and hyoid muscles and comparing them with responses during swallowing and responses of the gastrointestinal tract. Five dogs were chronically instrumented with electrodes on the striated muscles and strain gauges on smooth muscles. Retching and vomiting were stimulated by apomorphine (5-10 ug/kg iv). During retching, the hyoid and thyroid descending and laryngeal abductor muscles were activated; between retches, the hyoid, thyroid, and pharyngeal elevating, and laryngeal adductor muscles were activated. Vomiting always occurred during the ascending phase of retching and consisted of three sequential phases of hyoid and pharyngeal muscle activation culminating in simultaneous activation of all recorded elevating and descending laryngeal, hyoid, and pharyngeal muscles. Retrograde activation of esophagus and pharyngeal muscles occurred during the later phases, and laryngeal adductor was maximally activated in all phases of the vomit. During swallowing, the laryngeal adductor activation was followed immediately by brief activation of the laryngeal abductor. We concluded that retching functions to mix gastric contents with refluxed intestinal secretions and to impart an orad momentum to the bolus before vomiting. During retches, the airway is protected by glottal closure, and between retches, it is protected by ascent of the larynx and closure of the upper esophageal sphincter. The airway is protected by maximum glottal closure during vomiting. During swallowing, the airway is protected by laryngeal elevation and glottal closure followed by brief opening of the glottis, which may release subglottal pressure expelling material from the laryngeal vestibule.

Animals↗

PubMedDate not supplied

Prevalence of gastroesophagopharyngeal acid reflux events: an evidence-based systematic review.

OBJECTIVES: To identify variables contributing to discrepant gastroesophagopharyngeal acid reflux (GEPR) findings and to critically assess the prevalence of GEPR in healthy individuals and patients with reflux laryngitis (RL). STUDY DESIGN: Quantitative systematic review. METHODS: Pharyngeal pH monitoring studies of healthy individuals and patients with RL were identified through a MEDLINE search of publications between 1966 and 2003. Pooled results of the measured pharyngeal acid exposure characteristics and the prevalence of GEPR events were analyzed. Statistical comparisons were performed using a chi 2 test. RESULTS: The study included 181 controls and 184 RL patients. Subjects' age ranged from 19 to 85 years. Gastroesophagopharyngeal acid reflux events were detected at 1, 2, and 4 cm above upper esophageal sphincter (UES) and 0.5 cm below arytenoids, with varying rates. The prevalence of GEPR ranged from 0% to 83% in controls and 27% to 86% in RL. After excluding the healthy subjects with abnormal esophageal acid exposure, prevalence of GEPR decreased from 35% to 17% (P<or=.002). Gastroesophagopharyngeal acid reflux in RL was significantly more prevalent than in the entire group of controls as well as in controls without abnormal esophageal acid exposure (P<or=.001). CONCLUSIONS: The prevalence of GEPR in controls and patients with RL varies in the studied 4 areas above the UES. The percentage of the subjects with GEPR increased as the probe was located more closely to the UES. Differences in demographic characteristics of the subjects, interventions used to select subjects, and pharyngeal pH monitoring techniques were identified as factors possibly contributing to inconsistent pharyngeal pH monitoring findings. The documented differences in methodology of existing studies make comparison of the studies difficult.

Adult↗

PubMedDate not supplied

Pharyngoglottal closure reflex: characterization in healthy young, elderly and dysphagic patients with predeglutitive aspiration.

BACKGROUND: Mechanism(s) of aspiration, a common complication of oropharyngeal dysphagia, is not completely elucidated. Since the pharyngoglottal closure reflex induces vocal cord adduction in healthy young humans, it may help prevent aspiration during premature spill of oral content. OBJECTIVE: The objective of this study was to characterize this reflex in normal young and elderly humans and dysphagic patients with predeglutitive aspiration; a potential group for developing abnormalities of this reflex. METHODS: We used a concurrent video endoscopic and manometric technique for recording of the vocal cords' response to pharyngeal water stimulation. We first studied 9 young (26 +/- 2 years) and 9 elderly (77 +/- 14 years) healthy volunteers to characterize and determine the effect of aging on the pharyngoglottal closure reflex. Subsequently, we studied 8 patients (65 +/- 16 years) with predeglutitive aspiration and 7 age-matched controls to characterize this reflex among patients with compromised airway safety during swallowing. RESULTS: The threshold volume of water for triggering both glottal closure and reflexive pharyngeal swallow in the elderly volunteers for rapid pulse injection was significantly larger than that for the young (p < 0.05). Neither glottal closure reflex nor pharyngeal reflexive swallow could be induced in any of the dysphagic patients with volumes of injected water as large as 1 ml. In contrast, in all age-matched controls, both the pharyngoglottal reflex and reflexive pharyngeal swallow were stimulated with threshold volumes of 0.3 +/- 0.07 and 0.6 +/- 0.05 ml, respectively. CONCLUSIONS: Pharyngeal stimulation by water induces vocal cord adduction in humans; the pharyngoglottal closure reflex. Although preserved, a significantly larger volume of water is required to stimulate this reflex by rapid pulse injection in the elderly, suggesting some deterioration in this age group. The pharyngoglottal closure reflex induced by rapid pulse injection is absent in dysphagic patients with predeglutitive aspiration, suggesting its contribution to airway protection against aspiration.

Adult↗