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Biomedical subjects

P F Crookes

Publications and source records attributed to P F Crookes.

53 records · Page 3Linked to original sources

The effect of symptoms and nonspecific motility abnormalities on outcomes of surgical therapy for gastroesophageal reflux disease.

The outcome of Nissen fundoplication in patients with a nonspecific motility abnormality compared with the outcome in patients with normal motility is unknown. One hundred consecutive patients who underwent primary Nissen fundoplication were evaluated before and a median of 50 months after operation, with emphasis on the presence of a preoperative motility disorder and its relationship to preoperative and postoperative symptoms. Compared with patients who had normal motility, patients with a nonspecific motility abnormality had a greater prevalence and severity of heartburn and regurgitation before operation. These patients also had a greater esophageal exposure to gastric juice on pH monitoring as a result of poorer esophageal clearance function. The prevalence and severity of preoperative dysphagia was not related to the presence of a motility disorder. A 90% or a 95% actuarial success rate was achieved in the relief of heartburn and regurgitation over a 96-month period in patients with and without a motility abnormality. The overall actuarial success rate was 93%. Dysphagia was rarely caused or made more severe by the procedure; if present before the operation, it was relieved in most patients. The prevalence of persistent postoperative dysphagia was similar in patients with and without a motility abnormality. The success of Nissen fundoplication in properly selected patients is not affected by the presence of a nonspecific motility disorder.

Deglutition Disorders↗

Manometry of individual segments of the distal esophageal sphincter. Its relation to functional incompetence.

The major components of the lower esophageal sphincter, the pressure it exerts, its total length, and the length of sphincter affected by abdominal pressure are usually expressed as means of several recordings from different radial segments of the sphincter. In segmental manometry, the individual readings for these components in each segment, rather than the mean values, are analyzed. We used segmental manometry to study 50 normal volunteers and 200 patients with symptoms suggestive of gastroesophageal reflux. Of the latter, 100 had increased esophageal acid exposure and 100 did not. An increased number of defective segments was associated with a greater prevalence of increased esophageal acid exposure. Segmental analysis disclosed the same number (52) of defective sphincters (defined as sphincters with two or more defective segments) in the 100 patients with increased acid exposure as did standard analysis. However, the relationship between a defective lower esophageal sphincter and the number of reflux episodes was clearer when a defective sphincter was defined using standard analysis. Segmental analysis of the lower esophageal sphincter has no clear advantage over standard analysis.

Adolescent↗

Pharyngeal swallowing. The major factor in clearance of esophageal reflux episodes.

OBJECTIVE: This study defined the clearance mechanisms of naturally occurring reflux episodes in normal subjects and patients with gastroesophageal reflux disease. SUMMARY BACKGROUND: Previous studies on acid clearance have been performed in the laboratory setting in supine subjects using acid instillation and stationary motility. The mechanisms of clearance have not been studied using ambulatory pH and motility monitoring. METHODS: A new system capable of monitoring simultaneously for 24 hours pharyngeal pressure, esophageal motility, and pH was used to study the clearance of naturally occurring reflux episodes in 10 normal subjects and 18 patients with gastroesophageal reflux disease. Esophageal contraction waves were classified as primary (i.e., initiated by a pharyngeal swallow) and secondary (i.e., unrelated to a pharyngeal swallow). RESULTS: A total of 1288 reflux episodes were analyzed, during which 2781 contraction waves occurred. Clearance (i.e., restoration of pH to > 4) occurred after primary peristalsis in 83% of reflux episodes. An additional 11% were cleared by pharyngeal swallows without an esophageal body response. Secondary waves were rare and when they occurred, only 19% were peristaltic. Secondary peristalsis cleared only 9 of the 1288 reflux episodes. Patients and normal subjects cleared reflux episodes similarly. Baseline swallowing frequency was 0.87/min during the daytime and increased to 2.59/min (p < 0.01) during daytime reflux episodes. Swallowing frequency in response to nighttime reflux episodes was less (1.42/min; p < 0.05). CONCLUSIONS: Pharyngeal swallowing is the most important mechanism for esophageal acid clearance. Secondary waves are rare, usually disorganized, and unimportant in clearing a reflux episode. During sleep, the mechanisms of clearance are depressed.

Adolescent↗

Value of physiologic assessment of foregut symptoms in a surgical practice.

BACKGROUND: The aim of this study was to evaluate the reliability of symptoms in the diagnosis of gastroesophageal reflux disease and esophageal motility disorders as assessed by functional tests. METHODS: In 365 patients referred for suspected esophageal functional disease, symptomatic assessment was compared with the results of esophageal manometry and ambulatory 24-hour pH monitoring of the distal esophagus. RESULTS: Based on the patients' chief complaint, the symptomatic diagnosis was gastroesophageal reflux (44%), esophageal motor disorder (26%), chest pain of esophageal origin (9%), reflux and aspiration (8%), and abdominal pathology (12%). The symptomatic diagnosis was considerably altered by the results of the esophageal function tests: gastroesophageal reflux and motility disorders were found in all symptomatic diagnostic groups and a large number of patients in each group tested normal. The sensitivity and specificity of symptom-based diagnoses for functional disease were low. CONCLUSIONS: The results of this study showed that symptoms are an unreliable guide of esophageal abnormality, illustrating the need for objective testing in these patients, particularly to avoid inappropriate medical or surgical therapy.

Adolescent↗

Concentration of refluxed acid and esophageal mucosal injury.

The hallmark of gastroesophageal reflux disease (GERD) is an increase in esophageal exposure to gastric juice. This exposure can result in complications such as esophagitis, stricture, and Barrett's esophagus. The aim of this study is to determine if there are specific pH exposure patterns that are associated with the development of these complications. The 24-hour esophageal pH data for 50 normal subjects and 154 patients with proven GERD were analyzed for time spent at different pH intervals. Increased esophageal acid exposure at a given interval occurred when the cumulative time of exposure exceeded the 95th percentile of that measured in the 50 normal subjects for that interval. The greatest prevalence of mucosal damage was found in the those patients with increased esophageal exposure to pH 0 to 2, corresponding to the known pKa of pepsin. This exposure was not related to a hypersecretory state. In addition, mucosal injury was associated with an increased esophageal exposure to pH 7 to 8. We conclude that mucosal injury in patients with GERD is related to the exposure time to gastric juice with a pH of less than 2 or greater than 7.

Adult↗

Reoperation for failed antireflux surgery.

The management of patients with an unsatisfactory result following antireflux surgery is often problematical. Ten such patients with failed antireflux surgery, for whom medical management had also subsequently failed, underwent reoperation via a thoraco-abdominal approach. The anatomical cause of the surgical failure was determined pre-operatively in most cases by endoscopy, radiology, manometry and 24-hour pH monitoring. The most common reason for failure was a slipped Nissen fundoplication. A tight wrap, a disrupted wrap and a fundoplication hernia were less common causes. At follow-up, only one patient had a poor result. Reoperation for failed antireflux surgery can yield good results and is facilitated by pre-operative definition of the cause of failure and wide operative exposure.

Adult↗

Familial hypocalciuric hypercalcaemia as a differential diagnosis of hyperparathyroidism: studies in a large kindred and a review of surgical experience in the condition.

We have studied 46 members of a large kindred with familial hypocalciuric hypercalcaemia (FHH) after a neck exploration failed to cure hypercalcaemia in an asymptomatic patient. Serum calcium, serum phosphate, plasma parathormone and vitamin D metabolites do not distinguish affected members from patients with hyperparathyroidism. Because of the continuing debate as to whether or not FHH is a variant of, or distinct from, hyperparathyroidism, we have carried out a review of surgical experience with subtotal parathyroidectomy in hyperparathyroidism secondary to parathyroid hyperplasia and in FHH. Whereas the procedure is successful in 90 per cent of the former cases only one case of FHH has been cured by it. This provides evidence for the two conditions being aetiologically distinct. Before patients with asymptomatic hypercalcaemia are referred for parathyroid surgery the calcium:creatinine clearance ratio should be measured using a 2 h urine sample collected after an overnight fast and a fasting blood sample. If this ratio is less than 0.01 then screening of first degree relations should be undertaken before any parathyroid surgery is performed. Unnecessary surgery can therefore be avoided.

Adult↗

Investigation of non-cardiac chest pain--which oesophageal test?

Five different tests were used to evaluate oesophageal function in 22 patients who presented to a cardiac unit with acute chest pain but whose cardiological investigations were negative. Eight patients had an abnormality on oesophagoscopy, 10 had an abnormal pH monitoring study, six had a positive acid infusion test, 10 had an abnormal manometric study and six had an abnormal oseophageal transit scintiscan. Concordance for the three tests of gastro-oesophageal reflux disease was low at 28%, and for the two tests of oesophageal motility only 55%. Only two patients had normal results in all five tests.

Adult↗

Suppression of gastric acid secretion in patients with gastroesophageal reflux disease results in gastric bacterial overgrowth and deconjugation of bile acids.

The aim of this study was to test the hypothesis that gastric bacterial overgrowth is a side effect of acid suppression therapy in patients with gastroesophageal reflux disease (GERD) and that the bacteria-contaminated gastric milieu is responsible for an increased amount of deconjugated bile acids. Thirty patients with GERD who were treated with 40 mg of omeprazole for at least 3 months and 10 patients with GERD who were off medication for at least 2 weeks were studied. At the time of upper endoscopy, 10 ml of gastric fluid was aspirated and analyzed for bacterial growth and bile acids. Bacterial overgrowth was defined by the presence of more than 1000 bacteria/ml. Bile acids were quantified via high-performance liquid chromatography. Eleven of the 30 patients taking omeprazole had bacterial overgrowth compared to one of the 10 control patients. The median pH in the bacteria-positive patients was 5.3 compared to 2.6 in those who were free of bacteria and 3.5 in the control patients who were off medication. Bacterial overgrowth only occurred when the pH was >3.8. The ratio of conjugated to unconjugated bile acids changed from 4:1 in the patients without bacterial overgrowth to 1:3 in those with bacterial growth greater than 1000/ml. Proton pump inhibitor therapy in patients with GERD results in a high prevalence of gastric bacterial overgrowth. The presence of bacterial overgrowth markedly increases the concentration of unconjugated bile acids. These findings may have implications in the pathophysiology of gastroesophageal mucosal injury.

Anti-Ulcer Agents↗

Static and dynamic function of the lower esophageal sphincter before and after laparoscopic Nissen fundoplication.

The means by which fundoplication protects against reflux is disputed. We studied the resting and dynamic features of the lower esophageal sphincter (LES) and 24-hour pH monitoring in 26 patients before and after laparoscopic Nissen fundoplication. Resting features were LES pressure, abdominal length, and total length. Dynamic function was assessed by the residual pressure in the LES during a swallow measured as the bolus flowed though the LES. All patients experienced near-total relief of heartburn and all but one had normal postoperative acid scores. Resting LES characteristics were restored to normal. Mean residual pressure on swallowing was 7.1+/-3.2 mm Hg in the patients postoperatively compared with 1.2+/-1 mm Hg preoperatively and 4.0+/-2.4 mm Hg in normal subjects. Eighteen of 26 patients had residual LES pressure within the normal range (<8.2 mm Hg). There was a tendency for residual pressures to be lower as experience with the procedure was gained. Incomplete LES relaxation is not necessary for effective functioning of a Nissen fundoplication. In construction of a Nissen fundoplication, creating a large retroesophageal window and deliberate dissection of the back of the posterior fundus from the left crus allows the creation of an effective antireflux procedure with restoration of static LES parameters to normal and minimal limitation of LES relaxation.

Adult↗

Gastroesophageal reflux disease and mucosal injury with emphasis on short-segment Barrett's esophagus and duodenogastroesophageal reflux.

Gastroeosphageal reflux disease has been associated with long segments of Barrett's esophagus </=3 cm), but little is known about its association with shorter segments. The aim of this study was to evaluate anatomic and physiologic alterations of the cardia and esophageal exposure to gastric and duodenal juice in patients with short and long segments of Barrett's esophagus. Furthermore, these patients were compared to each other and to patients with erosive esophagitis and those with no mucosal injury. Two hundred sixty-two consecutive patients with foregut symptoms were divided into the following four groups based on endoscopic and histologic findings: group 1, no mucosal injury; group 2, erosive esophagitis; group 3, short-segment Barrett's esophagus; and group 4, long-segment Barrett's esophagus. Esophageal exposure time to acid and bilirubin, lower esophageal sphincter characteristics, and endoscopic anatomy of the cardia were compared between the groups. Patients with short-segment Barrett's esophagus had elevated esophageal acid and bilirubin exposure, decreased lower esophageal sphincter pressure and length, and a high incidence of hiatal hernia. These abnormalities were similar to those in patients with esophagitis and in general less profound than those found in patients with long-segment Barrett's esophagus. The length of intestinal metaplasia was higher in patients with a defective lower esophageal sphincter. Short-segment Barrett's esophagus is a complication of severe gastroesophageal reflux disease and is associated with the reflux of both gastric and duodenal juice similar to that seen in patients with long-segment Barrett's esophagus.

Adult↗

Outcome after laparoscopic fundoplication is not dependent on a structurally defective lower esophageal sphincter.

With the advent of laparoscopic surgery and the recognition that gastroesophageal reflux disease often requires lifelong medication, patients with normal resting sphincter characteristics are now being considered for surgery. The outcome of these patients after fundoplication is unknown and formed the basis of this study. The study population consisted of 123 patients undergoing laparoscopic Nissen fundoplication between 1992 and 1996. All patients had increased esophageal acid exposure on 24-hour esophageal pH monitoring. Patients were divided into those with a normal (n = 36) and those with a structurally defective (n = 87) lower esophageal sphincter (LES), based on LES resting pressure (normal >6 mm Hg), overall length (normal >2 cm), and abdominal length (normal >1 cm), and their outcomes were assessed. Each group was subsequently divided into patients presenting with a primary symptom that was "typical" (heartburn, regurgitation, or dysphagia) or "atypical" (gastric, respiratory, or chest pain) of gastro-esophageal reflux, and outcome was assessed. Median duration of follow-up was 18 months after surgery. Overall, laparoscopic fundoplication was successful in relieving symptoms of gastroesophageal reflux in 90% of patients. Patients with a typical primary symptom had an excellent outcome irrespective of the resting status of the LES (95% and 97%, respectively). Atypical primary symptoms were significantly more common in patients with a normal LES (29%) than in those with a structurally defective LES (10%; P <0.05), and these symptoms were less likely (50%) to be relieved by antireflux surgery. Laparoscopic antireflux surgery is highly successful and not dependent on the status of the resting LES in patients with increased esophageal acid exposure and primary symptoms "typical" of gastroesophageal reflux. Antireflux surgery should be applied cautiously in patients with atypical primary symptoms.

Adult↗

Multivariate analysis of factors predicting outcome after laparoscopic Nissen fundoplication.

Laparoscopic Nissen fundoplication has been applied with increasing frequency in the treatment of gastroesophageal reflux disease. The aim of this study was to determine the variables that predict outcome of laparoscopic Nissen fundoplication. A multivariate analysis was performed on data from 199 consecutive patients undergoing laparoscopic Nissen fundoplication. Variables included age, sex, body mass index, primary symptoms, clinical response to acid suppression therapy, erosive esophagitis, 24-hour esophageal pH score, and the percentage of time the esophageal pH was less than 4 on 24-hour pH monitoring, lower esophageal sphincter competence, status of the esophageal body motility, hiatal hernia, carditis, intestinal metaplasia of cardiac epithelium limited to the gastroesophageal junction, and Barrett's esophagus of any length. Clinical outcome was obtained from all patients at a median follow-up of 15 months (range 6 to 74 months) after surgery. One hundred seventy-three patients had an excellent or good outcome (87%) and 26 had a fair or poor outcome. Three factors were significantly predictive of a successful outcome: an abnormal 24-hour pH score (odds ratio = 5.4; 95% confidence interval [CI] = 1. 9-15.3), a typical primary symptom (odds ratio = 5.1; 95% CI = 1. 9-13.6), and a clinical response to acid suppression therapy (odds ratio = 3.3; 95% CI = 1.3-8.7). We conclude that 24-hour pH monitoring provides the strongest outcome predictor of laparoscopic Nissen fundoplication and that outcome is based more on the correct identification of the disease than on its severity.

Adolescent↗

Manual verification of computer analysis of 24-hour esophageal motility.

The application of solid-state technology to intraesophageal pressure monitoring over an entire circadian cycle has resulted in large amounts of data that require computer analysis. Recently available commercial software has yet to be validated. The aim of this study was to compare the analysis of ambulatory esophageal manometry by an automated computer program with manual analysis and make the software modifications necessary to validate the automated system for clinical use. Computer-aided analysis of a large number of esophageal contractions recorded during ambulatory esophageal manometry was compared with manual analysis by four experienced physicians. Good correlations were found between manual and computerized measurements of contraction amplitude and duration (r = 0.99 and r = 0.73, respectively). Software modifications resulted in correct identification of 94% of contractions and correct classification of 93.3% of these waves as peristaltic or simultaneous. These results demonstrate that the evaluated program for automated analysis of ambulatory esophageal manometry is accurate and reliable for research and clinical applications.

Circadian Rhythm↗