Silicone-covered self-expanding metallic stents for the palliation of malignant esophageal obstruction and esophagorespiratory fistulas: experience in 32 patients and a review of the literature

Esophagogastric malignancies often are manifested with progressive dysphagia or esophagorespiratory fistulas. Palliative modalities currently available have significant limitations. A modified Gianturco-Rösch silicone-covered self-expanding metallic Z stent was used in 32 consecutive patients with malignant esophageal obstruction (n = 24) or esophagorespiratory fistulas (n = 8). The stent was placed successfully in all patients. Dysphagia improved by at least two grades in 21 of the 24 patients (87.5%); the mean dysphagia grade fell from 3.21 to 1.08. Six of the 8 patients with fistulas were able to resume a normal diet, and the other 2 were able to eat solids without symptoms of aspiration. Complications occurred in 10/32 patients (31%) and included stent migration (4 patients), food impaction (2 patients), membrane disruption with tumor ingrowth (1 patient), tumor overgrowth (1 patient), early pressure necrosis with hemorrhage (1 patient), and late pressure necrosis with sepsis (1 patient). The latter 2 patients died, giving a mortality rate of 6.3%. Many complications were managed with endoscopic or interventional radiologic techniques. Although randomized prospective clinical trials are needed, the silicone-covered Gianturco-Rösch Z stent offers promise for the effective palliation of malignant esophageal obstruction and esophagorespiratory fistulas.

Effects of insulin on the cardiovascular integrating mechanisms of brain stem in cats

In 65 cats anesthetized with alpha-chloralose and urethane, the effects of insulin on cardiovascular responses to stimulation of various structures in the brain stem were studied. The threshold dose of insulin injected intravenously that produced systemic hypoglycemia was 5-10 U/kg. Subthreshold hypoglycemic doses of insulin were used intracerebroventricularly (0.25 U/kg) or intracerebrally (2 mU in 200 nl). Sixty minutes after intravenous insulin, when serum glucose concentrations decreased from 158 to 43 mg/100 ml, pressor responses to stimulation of the periaqueductal gray of midbrain (PAG), locus coeruleus (LC), dorsal medulla (DM), ventrolateral medulla (VLM), and parvocellular reticular nucleus (PVC) decreased significantly. Depressor and bradycardiac response to stimulation of paramedian reticular nucleus or dorsal motor nucleus of vagus (DMV) decreased significantly as well. Thirty minutes after intracerebroventricular insulin, pressor responses of PAG, DM, and the bradycardiac response of DMV decreased significantly. Thirty minutes after intracerebral insulin, pressor responses and renal nerve activities of LC (but not PAG), VLM, DM, and PVC decreased significantly. A similar but faster onset (5 min) of depression of cardiovascular responses on stimulating the LC, VLM, DM, and PVC was observed in another six acutely midcollicular-decerebrate cats recovered from halothane anesthesia. These findings suggest that insulin directly inhibits the vasomotor structures of the brain stem and decreases the pressor responses to stimulation.

Transaxillary endoscopic sympathectomy--a report of experience in 150 patients with palmar hyperhidrosis

We report our 1-year experience with transaxillary endoscopic sympathectomy in 150 patients with palmar hyperhidrosis (PH). The double-puncture technique of video laparoscopy was used in a transaxillary approach to perform the sympathectomy by either electrocautery (EC; 93.3%) or electroresection (ER; 7.7%). The procedure was successfully completed in 299 operated limbs and required conversion to open surgery in 1 operated limb because of extensive pleural adhesions. The mean operative time of EC was significantly less than that of ER. In a total of 29 procedures, there were three technical complications. Most patients (92.7%) were discharged after an overnight hospital stay. On the seventh postoperative day, the cure rate was 99.3%. During the mean follow-up period of 200.1 days, there was no recurrence in 130 patients. Apparent compensatory hyperhidrosis occurred in 28 patients (21.5%). In conclusion, transaxillary endoscopic sympathectomy offers a simple and effective treatment to patients with PH, resulting in a shorter hospital stay and convalescent period.

The anatomic basis and clinical applications of flaps based on the posterior tibial vessels

The vascular anatomy of the posterior tibial vessels has been studied in 20 legs of 10 cadavers. The number, size and distribution of the direct cutaneous and direct muscle branches of the posterior tibial vessels were recorded. For analysis, the leg was divided into four equal segments, Zone I being the most distal and Zone IV the most proximal. The direct cutaneous branches were found to cluster mainly around Zone II. The direct muscle branches to the soleus and flexor digitorum longus muscles arose chiefly in Zones II and III. Based on this knowledge, we performed fasciocutaneous, island soleus muscle, musculo-fasciocutaneous and flexor digitorum longus muscle flaps based on the posterior tibial vessels in 12 patients. Four were free fasciocutaneous flaps and eight were pedicled flaps. All flaps survived and there were no major complications. Delayed wound healing was encountered in three patients.

Achalasia associated with hiatal hernia: prevalence and potential implications

Although hiatal hernia is reported with a 40-50% frequency in the general population, its occurrence and potential implications in achalasia are less well known. We reviewed the medical records and radiographic examinations of 120 patients with achalasia to assess the prevalence of hiatal hernia and its importance in evaluation and management of this motility disorder. Hiatal hernia was present in only 10 (8.3%) patients. Age, sex distribution, prevalence of dysphagia and regurgitation, and lower esophageal sphincter pressure measured manometrically were not significantly different in patients having hiatal hernia compared to those without hernia. Most patients (88%) underwent pneumatic dilatation and five esophageal perforations occurred, but all in patients without hiatal hernia. In conclusion, hiatal hernia is uncommon in patients with achalasia for reasons not known. Age, sex, symptoms, and results of esophageal manometry were not significantly different in those with hiatal hernia. Finally, the presence of hiatal hernia is not a contraindication to treatment of achalasia by pneumatic dilatation.

Prevalence of upper gastrointestinal disease in relation to age: radiologic and clinical implications

Reports of 1126 endoscopies were reviewed to determine the age-related prevalence of upper gastrointestinal (UGI) diseases as a guide to radiologists performing UGI examinations. Results indicate that (1) there were positive findings in 78% of all endoscopic examinations, and thus most symptomatic patients can be expected to have at least one UGI abnormality; (2) many patients with UGI symptoms have two or more reportable disease processes; (3) the prevalence of serious or life-threatening disease, such as cancer or large ulcers, rises steadily with age; and (4) after age 60, approximately 60% of symptomatic patients have a serious UGI disease. Based on these findings, radiologists should not hesitate to make the diagnosis of multiple abnormalities and should expect to diagnose at least one abnormality in most symptomatic patients having an UGI study. Also, because of the high prevalence of serious lesions in the elderly, endoscopy should be considered for the initial examination of an elderly patient if poor physical status would render the radiologic examination difficult or unreliable.

Gastroesophageal reflux disease: correlation of esophageal pH testing and radiographic findings

In an attempt to ascertain radiologic efficacy in patients with evidence of gastroesophageal reflux disease (GERD) at pH testing, radiographic findings were correlated with pH values obtained with an esophageal monitor worn for a 24-hour period in 112 patients. Fifteen (30%) of 50 patients with abnormal pH test results had esophagitis diagnosed radiographically, compared with six (10%) of 62 with normal pH test results (P < .05). The severity of abnormal pH monitoring results was classified but did not correlate significantly with the prevalence of esophagitis diagnosed radiographically. Hiatal hernia was also more common (80% vs 60%) in patients with abnormal pH test results (40 of 50 patients) than in those with normal results (37 of 62 patients) (P < .05). Pharyngeal, laryngeal, and pulmonary symptoms were common indications for evaluation, and 14 of 27 (52%) patients with hoarseness had an abnormal pH tracing. Only a minority of patients with evidence of GERD as defined by abnormal pH test results had reflux esophagitis diagnosed radiographically.

Coexistence of autonomic and somatic mechanisms in the pressor areas of medulla in cats

The effects of electrical stimulation and microinjection of sodium glutamate (0.5 M) in the sympathetic pressor areas of the dorsal medulla (DM), ventrolateral medulla (VLM), and parvocellular nucleus (PVC) on the knee jerk, crossed extension, and evoked potential of the L5 ventral root produced by intermittent electrical stimulation were studied in 98 adult cats anesthetized with chloralose and urethane. During electrical and glutamate stimulation of these pressor areas, in addition to the rise of systemic arterial blood pressure marked inhibition of the spinal reflex was produced, indicating presence of neuronal perikarya responsible for these actions. Mild to moderate augmentation of spinal reflexes was also observed during brain stimulation but only in a few cases. The magnitude of the somatic effects among the pressor areas of the VLM, DM, and PVC subsequent to glutamate activation was about the same. Induced spinal reflex inhibition, independent from the baroreceptor and vagal influence, remained essentially unaltered after acute midcollicular decerebration. The inhibition was also observed in cats decerebellated 8-10 days in advance. The inhibition was not affected after bilateral electrolytic- or kainic-acid-induced lesions in the paramedian reticular nucleus (PRN). On the contrary, PRN-induced spinal reflex inhibition was attenuated after bilateral lesions in the DM or VLM. Data suggest that there coexists neuronal subpopulations in the VLM, DM, and PVC that can affect both the sympathetic pressor systems and spinal reflexes.

Normal 24-hr ambulatory esophageal pH values. Influence of study center, pH electrode, age, and gender

Although the most sensitive and specific test for diagnosing gastroesophageal reflux disease, normal standards for prolonged esophageal pH monitoring are based on small sample sizes with questions raised about the effects of pH electrode, older age, gender, and methods of data analysis on pH variables. Recently three groups have established normal data bases using similar methodology. Multiple regression and nonparametric analyses showed that the values for the six traditional pH parameters were comparable across study centers. Therefore, the groups were combined for a total study population of 110 healthy subjects (47 men, 63 women, mean age 38 years with a range of 20-84 years). Further nonparametric analyses revealed the following: (1) type of pH electrode (antimony vs glass) is not significantly related to parameters of physiologic acid reflux; (2) age is not independently related to pH parameters; (3) men tend to have more physiologic reflux than women; and (4) older men tend to experience longer episodes of reflux than younger men and women. There was a significant effect of gender and a significant interaction between age and gender on the number of episodes greater than 5 min (P = 0.008). Nearly significant differences were found for percentage of total acid exposure time (P = 0.03), total reflux episodes (P = 0.02), and the longest reflux episode (P = 0.02). We believe these normal esophageal pH values can be used confidently as standards in any laboratory, and consideration should be given to developing separate standards for men and women.

Randomized, double-blind, placebo-controlled crossover trial of pirenzepine in patients with gastroesophageal reflux

A muscarinic receptor subtype 1 (M1) antagonist, pirenzepine, recently has been shown to be relatively free of the usual anticholinergic side effects on esophageal smooth muscle and thus has been implicated for the treatment of gastroesophageal reflux disease (GERD). However, the effect of pirenzepine on GERD remains to be defined. Thirteen patients who demonstrated GERD in a baseline 24-hr ambulatory intraesophageal pH monitoring study were randomized in a double-blind crossover fashion to receive pirenzepine and placebo. An ambulatory 24-hr intraesophageal pH monitor was used to assess reduction in reflux (esophageal pH less than 4.0) with respect to position (upright vs supine), to total number of reflux episodes, and to episodes greater than 5 min. A significant effect for pirenzepine was seen for episodes greater than 5 min (t = 2.61, P = 0.023) and a trend towards significance was seen for total (upright and supine positions combined) percent time of reflux (t = 2.13, P = 0.055). Although not statistically significant, pirenzepine consistently showed greater reduction in all parameters of reflux tested. A greater reduction in percent time of reflux in supine vs upright positions (pirenzepine: 58.9% vs 21.4%; placebo: 43.6% vs 7.3%) may be clinically important in prevention of esophageal injury due to reflux in the recumbent position. Pirenzepine may provide a unique alternative for some GERD patients who may be refractory to other therapies of GERD.

Radiographic evaluation of achalasia immediately after pneumatic dilatation with the Rigiflex dilator

Radiographic evaluation of the lower esophagus was done immediately after pneumatic dilatation using the Rigiflex dilator in 34 patients (24 men, 10 women; mean age, 55 years) with achalasia. The dilator was positioned across the esophagogastic junction using fluoroscopy and the balloon was inflated for 1 min. The esophagus was intubated and injected sequentially with water-soluble and barium contrast materials. Radiographic analysis included changes in the appearance of the caliber and contour of the esophagogastric junction, rate of esophageal emptying, and presence of complications. In 23 patients with predilatation esophagrams, the mean esophagogastric junction caliber increased from 4.7-7.6 mm following dilatation. The postdilatation esophagrams in 33 patients showed a smooth contour in 22 (67%) and immediate esophageal emptying in 26 (79%). Esophageal perforation occurred in one (3%) patient and intramural hematoma in one (3%). Clinical follow-up (mean, 7 months) was available in 29 patients and 23 (79%) had symptomatic improvement. Five of the six patients who did not improve clinically all had previous Heller myotomy, pneumatic dilatation, or both.

Exercise increases the circulating concentration of the N-terminus of the atrial natriuretic factor prohormone in normal individuals

Recently two peptides consisting of amino acids (aa) 1 to 30 and 31 to 67 of the N-terminus of the 126 aa prohormone of atrial natriuretic factor (proANF), as well as atrial natriuretic factor (ANF, aa 99 to 126; C-terminus), were found to have vasodilatory and natriuretic properties. These peptides, as well as ANF, circulate in humans as part of the N-terminus of the prohormone. To determine the effect of graded exercise on the circulating concentrations of the N-terminus and C-terminus of the ANF prohormone in normal persons, 12 healthy individuals (mean age 45 +/- 2 years) were evaluated before, for 2 hours after, and during bicycle exercise at a work loads of 25, 50, 75, 100, 125, 150, and 175 W. Both the N- and C-terminus of the ANF prohormone were released simultaneously with graded exercise in direct proportion to the intensity of the work load, measured objectively via maximal oxygen consumption (VO2max), respiratory quotient, and heart rate. Both the N-terminus and C-terminus of the ANF prohormone had strong positive correlations (p less than 0.001) with blood pressure, heart rate, VO2max, and respiratory quotient. Following exercise, the C-terminus returned to preexercise levels within 30 minutes, while the N-terminus remained significantly elevated at 30 and 60 minutes postexercise, reflecting the longer half-life of the N-terminus in the circulation.

Corneal wound healing after 193-nm excimer laser keratectomy

As part of a human trial of phototherapeutic keratectomy, we performed anterior keratectomy using excimer laser 193-nm ablation on patients with superficial corneal opacities. We examined the ultrastructural changes in the corneas of four patients who underwent penetrating keratoplasty 6 to 15 months after excimer laser ablation. The four cases included macular dystrophy, recurrent keratoconus in a graft, and corneal scarring (two eyes). Light microscopy showed epithelial thickening, absence of Bowman's layer, and superficial stromal scarring in the area of ablation. Ultrastructural study showed that the epithelial basement membrane had focal discontinuities. At the margin of the ablation superficial collagen bundles terminated abruptly in a steplike configuration. The anterior stroma was scarred, with loss of lamellar structure and an increase in number of fibrocytes. The laser-induced scar was 10 to 15 microns thick in the two eyes without a stromal scar before laser ablation. The stroma underlying the scarred areas and that in the untreated area appeared normal. Linear collagen-like fibers were present in the posterior aspect of Descemet's membrane. Laser-induced scarring may be an important factor in limiting visual improvement in patients undergoing phototherapeutic keratectomy.

Enteral feeding tubes: placement by using fluoroscopy and endoscopy

Fluoroscopy and endoscopy are both effective for guiding placement of enteral feeding tubes, but the relative advantages and limitations of the two methods are less clear. Consequently, we studied 104 consecutive patients referred for primary fluoroscopic placement of a Frederick-Miller feeding catheter. Success rate, fluoroscopic and room times, and tube position were determined. Unsuccessful fluoroscopic placement was followed immediately by an endoscopic attempt. The success rate for fluoroscopic placement was 90% (94/104), with the tube placed into the jejunum in 53% and into the duodenum in 47%. The fluoroscopic and room times for successful fluoroscopic placements were 8.6 +/- 5.6 min (mean +/- SD) and 21.7 +/- 8.4 min, respectively. For the 10 unsuccessful placements, the fluoroscopic and room times were 16.2 +/- 5.4 min (mean +/- SD) and 45.6 +/- 18.4 min, respectively. Both time differences were significant statistically. Endoscopic placement was successful in all seven patients in whom it was attempted, with a mean time of 13.4 min. The tubes placed endoscopically were in the jejunum in 29% and in the duodenum in 71%. Our results show that fluoroscopic and endoscopic placement of enteral feeding tubes is highly effective. Fluoroscopic time in successful cases is usually less than 15 min. Endoscopic placement of feeding tubes is successful after fluoroscopic failure.

Diffuse esophageal spasm. A rare motility disorder not characterized by high-amplitude contractions

Diffuse esophageal spasm (DES) has frequently been described as a motility disorder characterized by simultaneous, high-amplitude contractions. We reviewed the results of esophageal manometry testing on a total of 1480 patients referred to our lab over 36 months. Lower esophageal sphincter (LES) pressure was determined by a mean of four station pull-through. Esophageal body motility was assessed following 10 wet swallows. In our lab a diagnosis of DES is made when greater than 10% but less than 100% of contractions are simultaneous. Manometric findings of DES were rare, with an overall prevalence of 4% (56/1480). Of the 56 patients with a manometric diagnosis of DES, high-amplitude (mean greater than or equal to 180 mm Hg) peristaltic contractions were found in only two (4%). No simultaneous contractions with amplitude greater than or equal to 180 mm Hg were seen. Pressures of simultaneous contractions were consistently lower than peristaltic contractions. A hypertensive LES pressure (greater than or equal to 45 mm Hg) was present in 5/56 DES patients (9%). Poor LES relaxation was found in 7/56 DES patients (13%). We conclude that DES is a rare manometric finding, regardless of the reason for referral, and that the occurrence of high-amplitude contractions in DES is equally rare.

Use of a marshmallow bolus for evaluating lower esophageal mucosal rings

Sixty-three patients (35 women, 28 men; mean age 55 yr) with lower esophageal mucosal ring shown radiographically were examined with a semi-solid bolus consisting of a portion of a standard marshmallow. The most common symptom was dysphagia, present in 46 (73%) patients. Impaction of the marshmallow bolus by the ring occurred in 40 (63%) of the 63 patients, and produced symptoms in 27 (68%) of these 40 patients. Nine (14%) rings were detected radiographically only with a solid bolus; eight of these patients had dysphagia and seven rings were 20 mm or less in caliber. Impaction related to ring caliber, and was found in all 17 (100%) rings that were 13 mm or less in diameter, in 17/24 (71%) 14- to 19-mm rings, and in 6/22 (27%) rings 20 mm or more in caliber. Endoscopy in 23 patients detected 16 (70%) rings, and also depended on ring caliber: less than or equal to 13 mm, 6/6 (100%); 14-19 mm, 5/9 (56%); greater than or equal to 20 mm, 5/8 (63%). Marshmallow impaction occurred in 17 (74%) of 23 patients who had endoscopy; three of the 23 patients had normal endoscopy. In conclusion, radiographic examination supplemented by the use of a marshmallow bolus best detects lower esophageal mucosal ring.

Transfer from ophthalmology to another service is a marker of high risk medical events

Of 3632 consecutive admissions to the Wilmer Ophthalmological Institute between July 1, 1987 and June 30, 1989, 27 patients required transfer to a medical or surgical service (0.74%). The major reasons for transfer included acute or decompensated cardiac disease (26%), poorly controlled diabetes mellitus (19%), acute renal failure (11%), coagulopathy, stroke, and hypertension (7% each). Only one transfer was a direct result of an anesthesia complication. The highest rates of transfers were associated with orbital (4.3%), enucleation/evisceration (3.1%), and glaucoma (2.3%) surgeries, while vitreoretinal surgery had the lowest rate of transfer (0.3%). Most of the transfers of patients with orbital disease were for management of related problems such as sinusitis or increased intracranial pressure.

Radiologic evaluation of esophageal motility: results in 170 patients with chest pain

The role of radiologic evaluation of esophageal motility in patients with chest pain has been studied rarely. Consequently, we compared the results of radiologic and manometric examinations of the esophagus in 170 patients (106 women, 64 men; mean age, 53 years) with chest pain. Manometry, used as the standard, was normal in 114 (67%) patients, and showed the following abnormal diagnoses in the remaining 56 (33%): nonspecific esophageal motility disorder in 27 (48%), nutcracker esophagus in 16 (29%), diffuse esophageal spasm in 11 (20%), and achalasia in two (4%). Radiologic specificity was 93% (106/114) and overall sensitivity only 36% (20/56). Sensitivity increased to 50% by excluding those with nutcracker esophagus, a purely manometric diagnosis. Of the 20 patients in whom nonspecific esophageal motility disorder and diffuse esophageal spasm were undetected on radiologic examination, minimal manometric criteria for diagnosis were available in 18. Our results show that radiologic recognition of normal esophageal peristalsis is excellent. However, the vast majority of patients with chest pain do not appear to have abnormal esophageal motility on radiologic evaluation.

Prospective randomized comparison of Brown-McHardy and microvasive balloon dilators in treatment of achalasia

We report the results of a randomized prospective study comparing a standard bougie rubber balloon dilator [Brown-McHardy (BMH)] and a newer polyethylene dilator passed over a guide wire [Microvasive Rigiflex (MVR)]. Twenty achalasia patients (15M, 5F, mean age 45.4 yr) considered candidates for either dilator were randomized. Symptom assessment, body weight, and upright radionuclide solid esophageal emptying study were measured before and 6 months after pneumatic dilatation. All dilatations were performed by one of three experienced gastroenterologists under fluoroscopic guidance. Overall success occurred with 10/10 BMH and 7/10 MVR. One patient not improved with MVR had myotomy; the other two were successfully treated by BMH. No complications occurred with either dilator.

Inhibition of spinal reflexes by paramedian reticular nucleus

The inhibitory actions of the paramedian reticular nucleus (PRN), and its neighbouring structures, i.e., midline raphe nuclei (MRN) and dorsal medullary depressor area (DMD) on the knee jerk (KnJ) and crossed extension movement (CEM) induced by central sciatic stimulation and on the L5 ventral root response (EVRR) evoked by central tibial stimulation, were studied in cats under urethane (400 mg/kg) and alpha-chloralose (40 mg/kg) anesthesia alone, IP or further paralyzed with atracurium besylate (0.5 mg/kg/30 min), IV. Electrical stimulation of the above areas with rectangular pulses (80 Hz, 1.0 msec, 100-200 microA) decreased systemic arterial blood pressure (SAP) in an average value of: 36 +/- 3 mmHg for PRN; 19 +/- 2 mmHg for MRN; and 23 +/- 3 mmHg for DMD. The KnJ and CEM were almost completely suppressed by simultaneous PRN stimulation. The EVRR, including mono- and polysynaptic spinal reflexes with transmission velocity from 10 to 60 m/sec or above, were also suppressed. MRN stimulation only inhibited the KnJ, CEM and polysynaptic spinal reflexes with transmission velocities between 25 and 60 m/sec, but facilitated spinal reflexes with conduction velocities below 10 m/sec. On the other hand, DMD stimulation resulted in small suppression of KnJ, CEM and inhibition of polysynaptic spinal reflexes with conduction velocities between 25 and 60 m/sec. Even though MRN and DMD partially inhibited polysynaptic spinal reflexes, the magnitude of such inhibition was much smaller than that produced by PRN (-20% and -22% vs. -48%). The above-mentioned PRN effects on SAP and EVRR persisted in chronic animals decerebellated 9-12 days before.(ABSTRACT TRUNCATED AT 250 WORDS)

Ancillary tests in the diagnosis of gastroesophageal reflux disease

This article reviews some of the diagnostic procedures for gastroesophageal reflux disease other than the procedures of choice, endoscopy and prolonged intraesophageal pH monitoring. The author discusses the roles of the acid perfusion (Bernstein) test, radiology, manometry, and radionuclide scintigraphy in the diagnosis and management of gastroesophageal reflux disease.

Comparison of lower esophageal sphincter manometrics and gastroesophageal reflux measured by 24-hour pH recording

We compared lower esophageal sphincter (LES) pressures to parameters of acid reflux measured during 24-h pH monitoring in 81 patients being evaluated for possible reflux disease. Mid-respiratory LES pressures were significantly higher (p less than 0.05) in patients with normal amounts of reflux than in those with abnormal reflux. This difference did not occur with LES pressure measured by end-expiratory station pull-through (SPT) or rapid pull-through (RPT). There was no significant difference in total length or intra-abdominal portion of LES between the two groups. However, the product of LES pressure and total LES length was greater (p less than 0.05) for patients with normal reflux than for these with abnormal reflux. No difference was noted in the percentage of abnormal contractions in the distal esophagus between groups. These studies support the following conclusions: 1) LES pressure may be a more important protective mechanism against reflux than LES length. 2) Mid-respiratory SPT technique appears to identify the LES antireflux barrier better than either end-expiratory SPT or RPT techniques. 3) Acid exposure time seems to be a better measure of gastroesophageal reflux than the number of reflux episodes.

The prevalence of abnormal esophageal test results in patients with cardiovascular disease and unexplained chest pain

The purpose of our study was to assess the prevalence of esophageal test abnormalities in patients with known cardiovascular disease and persistent chest pain. We performed a retrospective review of symptoms, manometry, and provocative test results performed on patients with undiagnosed chest pain. The 220 patients with angiographically determined cardiac disease and persistent chest pain were divided into three groups: coronary artery disease (125 patients), mitral valve prolapse (38 patients), and coronary bypass/angioplasty (57 patients). A comparison group consisted of 159 patients with noncardiac chest pain. All patients underwent esophageal manometry and placebo-controlled provocative testing (acid perfusion test and edrophonium chloride test). The prevalence of esophageal motility disorders in the noncardiac chest pain group (27%) was similar to that in the coronary artery disease (24%), mitral valve prolapse (37%), and coronary bypass/angioplasty (30%) groups. The frequency of nutcracker esophagus (11% to 16%) and diffuse esophageal spasm (2% to 7%) was remarkably constant. The prevalence of any positive provocative result in the noncardiac chest pain group (27%) was similar to that in the coronary artery disease (19%), mitral valve prolapse (32%), and coronary bypass/angioplasty (20%) groups. Furthermore, completely negative results of esophageal investigation occurred in 55%, 62%, 42%, and 59% of the respective patient groups.

Manometry and radiology. Complementary studies in the assessment of esophageal motility disorders

The relationship between radiological and manometric findings in esophageal motility disorders is poorly understood. Therefore, 20 subjects (4 normal; 13 diffuse spasm; 3 other motility disorders) were studied using synchronous manometry and videofluoroscopy with alternate 5-ml and 10-ml barium swallows. A total of 181 swallows were analyzed. Concordance between manometry and fluoroscopy was excellent for individual swallows (98%), groups of 5 swallows (97%), and final diagnoses (90%). Contraction onset intervals less than 0.8 s apart over 5 cm (velocity greater than 6.25 cm/s) were critical in determining abnormal bolus transit (98% sensitivity and positive predictive value). Radiologically, segmental tertiary activity (complete luminal obliteration) was always associated with disrupted primary peristalsis, but nonsegmental tertiary activity was often seen with normal bolus transit and did not have a specific manometric correlate. Four patterns of interrupted peristalsis radiologically were found--segmental tertiary contractions, a generalized esophageal contraction, absence of motor activity, or discoordinated "to-and-fro" movement. Surprisingly, nearly complete barium clearance occurred by the first two mechanisms in two thirds of swallows. Thus, the authors believe radiology and manometry are both excellent studies for identifying abnormal esophageal peristalsis. In difficult cases, these tests give complementary information because radiology assesses bolus movement while manometry provides quantitative pressure data.

Thymic carcinomas: histopathological varieties and immunohistochemical study

Thirteen cases of primary thymic carcinomas are described. The patients' ages ranged from 19 to 64 years, with a median of 40 years. Nine of them were male. Chest pain with or without cough was the main presenting symptom. No patient had myasthenia gravis. Five histological types were identified; two were undifferentiated (lymphoepithelioma-like) carcinoma, one was a clear-cell carcinoma, two were mixed squamous and small-cell carcinoma, and six were squamous cell carcinoma. All the tumors were variably positive for anti-keratin antibody AE1 and AE3, but negative for AE2. Anti-neuron specific enolase antibody was useful in identifying and confirming the small-cell carcinoma component of the mixed carcinomas. Anti-epithelial membrane antigen antibody aided in revealing the glandular structures in mixed adenosquamous and small-cell carcinomas. Thymic carcinomas were histopathologically differentiated from thymomas by their malignant cytological appearance, increased mitotic activity, and central tumor necrosis. All six patients with pure squamous-cell carcinoma were still alive, with a median survival time of 27 months. All but one of the other patients of different histological types died, the exception being a recent case of mixed adenosquamous and small-cell carcinoma; their median survival was 19.5 months, or 18 months when the latter surviving case is included. The prognosis of patients with pure squamous-cell carcinoma was better.

Chronic hoarseness secondary to gastroesophageal reflux disease: documentation with 24-h ambulatory pH monitoring

Gastroesophageal reflux (GER) has been implicated in otolaryngologic problems, particularly chronic hoarseness that cannot be attributed to other causes. To study this relationship, we used 24-h ambulatory intraesophageal or dual pharyngoesophageal pH monitoring in 33 patients with chronic hoarseness and laryngeal lesions suggestive of acid irritation. Twenty-six of the patients (78.8%) had pH evidence of severe GER, being at least three times greater than the upper limit of normal. In contrast to 19 patients with proven esophagitis, this GER was worse in the upright position. Of 15 patients with both pharyngeal and esophageal probes, three had esophagopharyngeal reflux, and two had atypical unexplained pharyngeal decreases in pH to below 4.0. Less than half of the 33 patients had the typical symptoms of GER, and standard esophageal tests usually yielded normal findings. Occult GER, predominantly in the upright position, appears to be common and severe in patients with chronic hoarseness, who have laryngeal lesions suggestive of GER. The causative mechanisms are not clear. The 24-h esophageal pH monitor is useful in screening this potentially treatable problem.

Radiographic and manometric correlation in achalasia with apparent relaxation of the lower esophageal sphincter

We compared the clinical, radiographic, and manometric findings in 10 patients with atypical achalasia showing complete lower esophageal sphincter (LES) relaxation to 39 patients with classic achalasia (i.e., incomplete LES relaxation). Those with atypical achalasia were younger (46.1 vs 60.6 years), had dysphagia of shorter duration (18.7 vs 45.7 mos), had lost less weight (8.2 vs 21.5 lbs), and had less esophageal dilatation (2.8 vs 3.9 cm). However, the mean LES pressures (34.5 vs 37.7 mmHg) and the esophagogastric junction calibers (4.5 vs 4.8 mm) were similar. Radionuclide esophageal emptying studies were done in 15 patients (6 with atypical achalasia; 9 with classic achalasia) and were abnormal in all. Most patients in both groups (90 and 92%) responded well to pneumatic dilatation. We conclude that achalasia with apparent LES relaxation may represent an early form of this motor disorder and that the radiographic findings remain characteristic except for less dilatation of the esophagus.

Esophageal motility: assessment with synchronous video tape fluoroscopy and manometry

Synchronous video tape fluoroscopy and manometry of the esophagus was performed in 11 subjects (seven men and four women; mean age, 49 years). Four had normal and seven had abnormal esophageal motility (diffuse esophageal spasm, n = 4; nonspecific esophageal motility disorder, n = 3) that was shown by previous manometry. A digital timer appeared on the video tape recording and marked the manometric tracing synchronously. Alternate 5-mL and 10-mL barium boluses were recorded for a total of 10 swallows per patient. Video tape examinations were reviewed prospectively, and the status of primary peristalsis and presence and severity of tertiary activity were noted. A total of 98 swallows (58 normal, 40 abnormal) were correlated, and a 96% agreement was found in assessing primary peristalsis. Overall results of fluoroscopic examinations of each subject during all swallows showed complete agreement with those of manometry; segregating the swallows into groups of five showed 92% concordance. Severe tertiary activity was invariably seen with abnormal primary peristalsis at fluoroscopy.

Does sleeping on a waterbed promote gastroesophageal reflux?

We conducted a randomized prospective study with extended intraesophageal pH monitoring on two consecutive nights to test the hypothesis that a waterbed (WB) might increase recumbent acid exposure compared to a regular bed (RB). We studied 10 controls (mean age 29 years; five males, five females) with no history of reflux symptoms more than two times per month. We also studied 10 reflux patients (mean age 42 years; seven males, three females) with symptoms at least five days a week and documented recumbent reflux, with or without upright reflux, by previous 24 hr pH study. A standard meal (56% fat) was provided at 6 PM. After randomization, the subjects and patients slept on the assigned bed (WB or RB) in one nearby hotel. The pH probe was removed the next morning at 8 AM. On the same day, the pH probe was inserted at 4 PM and the routine was repeated with use of the other bed. No significant difference (P greater than 0.05; paired t test) was found between the regular bed and waterbed in any measurement of recumbent reflux. Our study does not support the hypothesis that greater recumbent reflux may occur when sleeping flat on a waterbed compared to a regular bed. It does not, however, absolutely refute the possible association of waterbed use with esophagitis, since elevation of the head of a waterbed is not possible.

Positive predictive value and posttest probability of diagnosis of colonic polyp on single- and double-contrast barium enema

The positive predictive value for a radiographic diagnosis of colonic polyp, the prevalence of polypoid disease, and posttest probability relative to patient age were studied. The positive predictive value for colonic polyp on single- and double-contrast barium enema was determined for 191 polyps found radiographically in 136 patients who also underwent colonoscopy for confirmation. Of 72 polyps seen in 54 patients on single-contrast examination, 59 were confirmed endoscopically; 110 of 119 polyps seen in 82 patients on double-contrast examination were confirmed similarly, giving positive predictive values of 82% and 92%, respectively. Positive predictive values per patient, disregarding the number of polyps present, were 87% (47/54) and 90% (74/82) for the single- and double-contrast examinations, respectively. False-positive errors were due to stool, air bubbles, haustration, and misinterpretation of an appendiceal stump. By using specificities derived from our prevalence of polypoid disease and previously reported sensitivities, we drew posttest probability curves showing that predictive values depend both on the chance of disease before the test is done and on the efficacy of the test used.

Prostaglandins in the gut and their relationship to non-steroidal anti-inflammatory drugs

Prostaglandins are long-chain, saturated, oxygenated fatty acids. Relatively large quantities of prostaglandins have been found in gut mucosa, suggesting that these substances play an important role in gastrointestinal physiology. Non-steroidal anti-inflammatory drugs (NSAIDs) cause damage to the gastric, intestinal, and colonic mucosa in experimental animals and in humans. Prostaglandins protect the gastric mucosa against injury induced by NSAIDs, and this property has been labelled cytoprotection. The mechanisms of cytoprotection have been extensively evaluated and are probably multifactorial, including effects on the gastric mucosal barrier, gastric blood flow, mucus, bicarbonate, and fluid section, ionic transport, cyclic AMP, and surface-active phospholipids. Prostaglandins may also prevent NSAID-induced injury in the small intestine and colon. The mechanisms responsible for prostaglandin protection in the lower gut against injurious agents are unknown. Further studies of the role of prostaglandins in the gut and their relationship to the effects of NSAIDs are needed. The results of these investigations may lead to a better understanding of the importance of prostaglandins in the physiology of the gastrointestinal tract, and may provide information regarding actions of NSAIDs on the functional integrity of the gastric, intestinal, and colonic mucosa.

A comparison of high and low fat meals on postprandial esophageal acid exposure

Fatty foods have been identified as precipitating factors in symptomatic gastroesophageal reflux (GER). A fat meal has also been found to decrease lower esophageal sphincter pressure (LESP) in normal subjects. We used the ambulatory 24-h pH monitor to assess esophageal acid exposure in 10 normal subjects and 10 GER patients following low and high fat meals eaten in two body positions. The meals had nearly identical protein content, volumes, and calories. On successive days, patients ingested one of the meals twice, followed by random assignment to 3 h upright and 3 h recumbent position. Acid exposure for each hour over a 3-h postprandial (PP) period was assessed as the percent time pH less than 4.0. Increased upright acid exposure occurred in normals after the high fat (6.2 +/- 2.1%; mean +/- SE) compared with the low fat meal (1.5 +/- 0.5%; p less than 0.05). GER patients had greater (p less than 0.05) acid exposure than normals in all study periods, but no differences were found between low and high fat meals in either study position. High fat meals induce upright GER in normals, but do not significantly affect the abnormal amount of GER in patients. In addition, progressive increases in acid exposure were found over the 3 postprandial hours in GER patients in a recumbent position. The findings are consistent with prior data showing decreased LESP with a fat meal in normals.

Endoscopic biopsy is diagnostic in gastric antral vascular ectasia. The "watermelon stomach"

Gastric antral vascular ectasia was endoscopically diagnosed in seven patients. Pathologic characteristics of this entity were defined retrospectively, by studying endoscopic pinch biopsy slides from these seven patients and antrectomy specimens from five patients. A scoring system was developed, and the seven patients were compared prospectively with various control groups. Abnormalities of mucosal vessels (fibrin thrombi and/or ectasia) consistently distinguished patients from control antrectomies, normal biopsies, acute gastritis biopsies and atrophic gastritis biopsies (P = 0.02, all comparisons). Spindle cell proliferation into mucosa also was characteristic of gastric antral vascular ectasia, distinguishing this disease from normals, acute gastritis, and atrophic gastritis (P less than or equal to 0.039, each comparison). The presence of abnormal mucosal vessels (fibrin thrombi and/or ectasia) and spindle cell proliferation was similar in patient antrectomies compared to patient endoscopic biopsies. Therefore, we conclude that endoscopic biopsies can reliably diagnose gastric antral vascular ectasia, a vascular disorder characterized by abnormal mucosal vessels and spindle cell proliferation.

Acid perfusion test: does it have a role in the assessment of non cardiac chest pain?

Using 24 hour pH monitoring as a reference standard, the usefulness of the acid perfusion (AP) test in predicting gastro-oesophageal reflux disease (GORD) was assessed in 71 non-cardiac chest pain (NCCP) patients and 23 endoscopic oesophagitis patients. Of the 71 NCCP patients, 35 had a positive AP test (of whom 20 had an abnormal 24 hour pH) and 36 had a negative AP test (of whom 14 had an abnormal 24 hour pH study). Thus, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the AP test in this group was 59%, 59%, 57%, and 61%, respectively. The corresponding values in the oesophagitis group were 85%, 67%, 94%, and 40%. In the NCCP group when heartburn alone was used as the positive criterion the PPV rose to 74%. When chest pain with or without heartburn was used, however, the PPV dropped to 38%. A 'symptom index' was used to define the number of chest pain episodes that were caused by acid reflux. Only 48% of AP test positive patients had demonstrable acid mediated chest pain. In the NCCP population with a normal oesophageal examination (1) AP test reproduction of chest pain is poorly predictive of GORD; (2) AP test reproduction of heartburn is more predictive of GORD but does not ensure that the chest pain is caused by GORD; (3) a negative AP test does not exclude GORD and (4) only 48% of AP test positive patients have demonstrable acid mediated chest pain. The ambulatory 24 hour pH test may have rendered the AP test obsolete in the assessment of GORD as the cause of NCCP.

Diffuse esophageal spasm: radiographic and manometric correlation

Diffuse esophageal spasm (DES) is characterized by substernal chest pain, dysphagia, and a manometric pattern of frequent simultaneous contractions with intermittently normal peristalsis. The authors correlated the radiographic and manometric findings in 17 patients with DES to better clarify the role of radiography in the evaluation of this uncommon motility disorder. Incomplete or absent primary peristalsis was observed on radiographs in 13 patients (76%), and mild to severe tertiary activity was seen in 12 patients (71%). The mean estimated thickness of the esophageal wall in patients with DES was 2.6 mm compared with 2.5 mm in an age-matched control group of 17 patients with normal esophageal manometric findings (P greater than .05). The authors conclude that most patients with DES show abnormal esophageal motility on radiographs, although the findings were nonspecific and required clinical and manometric correlation. Esophageal wall thickness was normal in patients with DES and appears to be an overemphasized sign in differentiating DES from other esophageal motility disorders.

Introduction of impermeant molecules into synaptosomes using freeze/thaw permeabilization

Brief freezing as a means of transiently permeabilizing synaptosomes was explored. Rat brain synaptosomes frozen and thawed in the presence of 5% dimethyl sulfoxide, a cryoprotectant, were shown to release, in a calcium-dependent manner, previously accumulated [3H]norepinephrine and [14C]acetylcholine in response to elevated [K+]. In addition, synaptosomes subjected to freeze/thaw were shown to retain their ability to exhibit resting protein phosphorylation, as well as stimulated protein phosphorylation occurring in response to calcium influx. Brief freezing of synaptosomes in the presence of [gamma-32P]ATP and either the catalytic subunit of cyclic AMP-dependent protein kinase or calcium/calmodulin-dependent protein kinase II rendered the synaptosomal interior accessible to these agents, as reflected by the phosphorylation of substrate proteins, such as synapsin I, which reside within the nerve terminal. Inclusion of inhibitors of these protein kinases during freeze/thaw blocked synaptosomal protein phosphorylation, indicating that the inhibitors were also introduced. After freezing, the synaptosomes resealed rapidly and spontaneously, as shown by the inability of any of the agents to elicit an effect on phosphorylation when added at the end of the freezing period. The permeabilization procedure should contribute to an understanding of the functional roles of phosphoproteins, and of their associated protein kinases and protein phosphatases, in nerve terminals.

Barium enema examination: sensitivity in detecting colonic polyps and carcinomas

We analyzed the sensitivity of the barium enema examination in 128 patients with 191 endoscopically proven colonic polyps and 12 carcinomas, relative to patient age, indications, and the type of examination used. Seventy-seven patients (60%) had rectal bleeding, and 51 (40%) patients with 87 lesions, including six carcinomas, did not. Overall roentgenographic sensitivity was 88%, with a 93% detection rate in patients less than 70 years old as compared to 76% for older patients. Sensitivity of single- and double-contrast barium enema examination was 82% and 91%, respectively. There were similar detection rates for lesions 1 cm or more in size (91% vs 95% for single- and double-contrast examinations, respectively), but double-contrast examination was slightly better at detecting smaller polyps (88%, vs 70% for single-contrast examination). Compared to colonoscopy, which has an average reported false-negative rate of 12% in detecting neoplasms, the barium enema is similarly reliable, less costly, and safer.

Ambulatory 24-hour esophageal pH monitoring. Reproducibility and variability of pH parameters

If 24-hour esophageal pH monitoring is to be a useful diagnostic tool, it must reliably discriminate gastroesophageal reflux patients despite daily variations in distal esophageal acid exposure. To address this issue, we studied 53 subjects (14 healthy normals, 14 esophagitis patients, and 25 patients with atypical symptoms) with two ambulatory pH tests performed within 10 days of each other. Intrasubject reproducibility of 12 pH parameters to discriminate the presence of abnormal acid reflux was determined. As a group, the parameters of percent time with pH less than 4 (total, upright, recumbent) were most reproducible (80%). Therefore, a subject was defined as having gastroesophageal reflux disease if at least one of these three values were abnormal. Intrasubject reproducibility for the diagnosis of reflux disease was 89% for the entire sample. Among subsets, the reproducibility was 93% for the normals and esophagitis patients and 84% for the atypical symptom patients. Total percent time with pH less than 4 was the single most discriminate pH parameter (85%) and nearly equaled that of the three combined parameters (89%). The intrasubject variability of this parameter was determined by the mean +/- 2 SD of the relative differences between the two test results for all 53 subjects. Total percent time with pH less than 4 may vary between tests by a factor of 3.2-fold or less (218% higher to 69% lower). We conclude: (1) ambulatory 24-hr esophageal monitoring is a reproducible test for the diagnosis of gastroesophageal reflux disease; and (2) the large intrastudy variability in 24-hr total acid exposure may limit this test's usefulness as a measurement of therapeutic improvement.

The symptom index: a clinically important parameter of ambulatory 24-hour esophageal pH monitoring

Ambulatory 24-h esophageal pH monitoring is an accurate quantitative test of gastroesophageal reflux (GER). However, it does not answer the question: are the patients' symptoms due to GER? We developed a numerical scale to quantify the percent association between symptoms and pH less than 4--the symptom index (SI). In 100 consecutive patients with heartburn or chest pain, the SI for the chief complaint was either high (greater than 75%) or low (less than 25%) in 77% of cases. A similar bimodal distribution was seen when heartburn or chest pain symptoms were individually evaluated. There was a good association between high SI and the presence of GER (97.5%), as well as low SI and a normal 24-h pH study (81.1%). Endoscopy was normal in 89.5% of patients with low SI, but patients with high SI had esophagitis in only 69.7% of cases. The Bernstein test showed a poor association with the SI. Therefore, the SI gives clinically relevant information regarding the role of acid reflux and patient's symptoms. We believe this simple calculated index should be included in the analysis of 24-h esophageal pH studies.

Acid-induced esophagitis in cats is prevented by sucralfate but not synthetic prostaglandin E

The cytoprotective effects of liquid sucralfate and a synthetic analog of prostaglandin E1 (PGE1) on acid-induced esophagitis in cats were studied. Esophagitis was induced in adult cats using a constant infusion of 0.1 N HCl at 1 ml/min for 20 min. Animals were infused for either one or three days. Mucosal lesions were evaluated by blinded investigators using both fiberoptic endoscopy and light microscopy. Histologic changes included basal cell hyperplasia, intraepithelial leukocytosis, and subepithelial leukocytosis. Liquid sucralfate given prior to acid infusion consistently prevented acid-induced lesions in both one- and three-day infusions, demonstrated by both endoscopy and quantitative histologic scoring. Indomethacin (200 micrograms/kg) given prior to sucralfate and acid did not affect sucralfate cytoprotection. Synthetic PGE1, given in doses of 5 micrograms/kg and 100 micrograms/kg, afforded no esophageal cytoprotection. These studies indicate that sucralfate is cytoprotective against acid-induced esophageal injury in cats, an effect that does not appear to be mediated by prostaglandin. In addition, synthetic PGE1 does not confer protection in this animal model.

Consent in medical decision making: the role of communication

Informed participation in medical decisions is important because it demonstrates respect for the ethical principle of individual autonomy and increases the likelihood of reaching therapeutic goals. Twenty hospitalized patients were randomly selected and observed for six and a half hours to assess the degree to which informed participation was possible with diagnostic and therapeutic procedures. Resident physicians and patients were then interviewed about the rationale, benefit, risk, and alternative for each observed procedure. Commonly observed activities were injecting and giving oral medications, and performing invasive diagnostic procedures. Clinicians' communication involved rationale (43%) more often than benefits (34%), risks (14%), and alternatives (12%). Communication was similar when the procedures proposed were important and risky. Residents' and patients' interviews demonstrated limited congruence in shared understanding of rationale (57%), benefit (45%), risk (19%), and alternatives (25%). These results suggest that clinicians selectively impart information essential for informed patient participation, and highlight areas of clinician-patient communication in need of attention.