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Biomedical subjects

D F Worsley

Publications and source records attributed to D F Worsley.

At least 19 recordsLinked to original sources
PubMed2001

Laparoscopic Heller myotomy improves esophageal emptying and the symptoms of achalasia.

HYPOTHESIS: Laparoscopic Heller esophageal myotomy improves esophageal clearance and symptoms of achalasia in the early and late postoperative periods. DESIGN: We followed up 98 consecutive patients attending a referral center between February 1, 1994, and July 1, 2000, who underwent laparoscopic myotomy. Operative time, complications, and length of stay were recorded. Postoperative outcomes were assessed using Van Trappen symptom scores (1 indicates no symptoms; 2, symptoms occurring less than once a week; 3, symptoms occurring more than once weekly; and 4, persistent symptoms) and scintigraphic esophageal transit studies. RESULTS: Of 98 patients, 91 underwent anterior fundoplication. There were no open conversions and 1 mucosal perforation, which was closed laparoscopically without complications. Mean operative times and postoperative days were 3.2 hours and 4.3 days, respectively, in the first 32 patients and 1.7 hours and 2.3 days, respectively, in the last 32 patients (P<.001). Postoperative complications included pneumothorax (4% of patients), atelectasis (5%), and delayed gastric emptying (1%). Seventy-five percent of patients gained weight after surgery. At longest follow-up, 91% of patients were satisfied with the outcome of the procedure. Mean Van Trappen scores for dysphagia improved from 4.0 in the preoperative period to 1.2 at early and late follow-up (P<.001). Fluid retention at 10 minutes in the upright position was 47% in the preoperative period and improved at early and late follow-up to 21% and 20%, respectively (P<.001). CONCLUSIONS: Laparoscopic Heller myotomy can safely reverse the symptoms of achalasia and improve esophageal transit. These benefits, realized during the early postoperative period, were maintained at longest follow-up.

Adolescent↗
PubMed2001

Radionuclide imaging of acute pulmonary embolism.

From the prospective and outcome-based studies that have been carried out in the past few years, the following conclusions regarding the diagnostic evaluation of patients with suspected PE can be made: 1. A normal V/Q scan interpretation excludes the diagnosis of clinically significant PE. 2. Patients with a very-low- or low-probability V/Q scan interpretation and a low clinical likelihood of PE do not require angiography or anticoagulation. 3. Patients with a very-low- or low-probability V/Q scan interpretation, an intermediate or high clinical likelihood of PE, and negative serial noninvasive venous studies of the lower extremities do not require anticoagulation or angiography. If serial noninvasive venous studies of the lower extremities are positive, patients should be treated. 4. Clinically stable patients with an intermediate-probability V/Q scan interpretation require noninvasive venous studies of the legs and, if negative, require CT angiography or pulmonary angiography for a definite diagnosis. 5. Clinically stable patients with a high-probability V/Q scan interpretation and a high clinical likelihood of PE require treatment and need no further diagnostic tests to confirm the diagnosis. 6. Clinically stable patients with a high-probability V/Q scan interpretation and a low or intermediate clinical likelihood of PE require noninvasive venous studies of the legs and, if negative, often require CT angiography or pulmonary CT for a definitive diagnosis.

Acute Disease↗
PubMed2000

Ventilation-perfusion-chest radiography match is less likely to represent pulmonary embolism if perfusion is decreased rather than absent.

PURPOSE: The authors' goal was to determine whether the prevalence of pulmonary embolism in patients with matching ventilation-perfusion (V-Q) defects and chest radiographic opacities differs depending on the degree of perfusion deficit (absent versus decreased). METHODS: The authors performed a retrospective analysis of the data obtained from the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study. In 233 patients, angiograms were of diagnostic quality for 275 lung zones that showed matching V-Q defects and chest radiographic opacities (triple matches). Of these, V-Q scans and chest radiographs from 217 patients with triple matches in 255 lung zones were retrieved and reviewed. Areas corresponding to chest radiographic opacities were scored as having either decreased perfusion or absent perfusion by consensus. Information regarding the presence or absence of pulmonary embolism in corresponding lung zones was obtained from the PIOPED database. RESULTS: The overall prevalence of pulmonary embolism in all lung zones with triple matches was 27% (69 of 255). Of the 255 areas of triple matches, the perfusion was decreased in 153 (60%) and absent in 102 (40%). The prevalence of pulmonary embolism in areas of triple matches with decreased perfusion and triple matches with absent perfusion was 13% (20 of 153) and 48% (49 of 102), respectively (P = 0.0001 by the chi-square test). When these were divided further by lung zones, triple matches with decreased perfusion and triple matches with absent perfusion in the upper-middle lung zone were associated with a prevalence of 0% (O of 44), and 25% (9 of 36), respectively. The prevalence of pulmonary embolism in areas of triple matches with decreased perfusion and triple matches with absent perfusion in the lower lung zone was 18% (20 of 109), and 61% (40 of 66), respectively. CONCLUSIONS: A V-Q/chest radiographic match is less likely to represent pulmonary embolism if perfusion is decreased rather than absent. The overall prevalence of pulmonary embolism associated with all triple matches in all lung zones varied from very low (0% in this series) to upper intermediate (61 %), depending on whether perfusion was decreased or absent and also on the location of the triple match.

Databases, Factual↗
PubMed2000

Alveolar epithelial integrity in athletes with exercise-induced hypoxemia.

The effect of incremental exercise to exhaustion on the change in pulmonary clearance rate (k) of aerosolized (99m)Tc-labeled diethylenetriaminepentaacetic acid ((99m)Tc-DTPA) and the relationship between k and arterial PO(2) (Pa(O(2))) during heavy work were investigated. Ten male cyclists (age = 25 +/- 2 yr, height = 180.9 +/- 4.0 cm, mass = 80.1 +/- 9.5 kg, maximal O(2) uptake = 5. 25 +/- 0.35 l/min, mean +/- SD) completed a pulmonary clearance test shortly (39 +/- 8 min) after a maximal O(2) uptake test. Resting pulmonary clearance was completed >/=24 h before or after the exercise test. Arterial blood was sampled at rest and at 1-min intervals during exercise. Minimum Pa(O(2)) values and maximum alveolar-arterial PO(2) difference ranged from 73 to 92 Torr and from 30 to 55 Torr, respectively. No significant difference between resting k and postexercise k for the total lung (0.55 +/- 0.20 vs. 0. 57 +/- 0.17 %/min, P > 0.05) was observed. Pearson product-moment correlation indicated no significant linear relationship between change in k for the total lung and minimum Pa(O(2)) (r = -0.26, P > 0.05). These results indicate that, averaged over subjects, pulmonary clearance of (99m)Tc-DTPA after incremental maximal exercise to exhaustion in highly trained male cyclists is unchanged, although the sampling time may have eliminated a transient effect. Lack of a linear relationship between k and minimum Pa(O(2)) during exercise suggests that exercise-induced hypoxemia occurs despite maintenance of alveolar epithelial integrity.

Adult↗
PubMed1997

Laparoscopic esophageal myotomy and anterior partial fundoplication for the treatment of achalasia.

BACKGROUND: The purpose of this study was to determine the initial results of laparoscopic esophageal myotomy and anterior fundoplication in the treatment of 26 patients with achalasia. METHODS: Operative time, complications, and length of hospitalization were recorded for each patient. Postoperative outcomes were assessed by a standardized patient questionnaire, 24-hour esophageal pH studies, and esophageal transit studies. RESULTS: Twenty-six consecutive patients with class IV dysphagia underwent a laparoscopic esophageal myotomy and anterior partial fundoplication, with a single incidence of intraoperative esophageal perforation. The mean operative time was 3.5 hours. The median length of hospitalization was 5 days. Of the 21 patients for whom follow-up was available (median follow-up, 4 months), 19 (90%) were satisfied and 2 (10%) were somewhat satisfied with their surgery. After operation, 14 of the 21 patients (67%) reported no dysphagia (class I), whereas 6 (28%) had class II dysphagia (less than once per week) and only 1 (5%) had class III dysphagia (greater than once per week). Liquid-phase esophageal transit studies (n = 14) revealed a significant improvement in esophageal clearance in the supine position from 18% before operation to 44% after operation (p = 0.006). Distal esophageal acid exposure was normal in 6 of 7 patients. CONCLUSIONS: These early results suggest that laparoscopic esophageal myotomy and anterior partial fundoplication provides efficacious treatment of achalasia.

Adult↗
PubMed1997

Pulmonary embolism: prospective comparison of spiral CT with ventilation-perfusion scintigraphy.

PURPOSE: To compare prospectively the accuracy of spiral computed tomography (CT) with that of ventilation-perfusion scintigraphy for diagnosing pulmonary embolism. MATERIALS AND METHODS: Within 48 hours of presentation, 142 patients suspected of having pulmonary embolism underwent spiral CT, scintigraphy, and (when indicated) pulmonary angiography. Pulmonary angiography was attempted if interpretations of spiral CT scans and of scintigrams were discordant or indeterminate and intermediate-probability, respectively. RESULTS: In the 139 patients who completed the study, interpretations of spiral CT scans and of scintigrams were concordant in 103 patients (29 with embolism, 74 without). In 20 patients, intermediate-probability scintigrams were interpreted (six with embolism at angiography, 14 without); diagnosis with spiral CT was correct in 16. Interpretations of spiral CT scans and those of scintigrams were discordant in 12 cases; diagnosis with spiral CT was correct in 11 cases and that with scintigraphy was correct in one. Spiral CT and scintigraphic scans of four patients with embolism did not show embolism. Sensitivities, specificities, and kappa values with spiral CT and scintigraphy were 87%, 95%, and 0.85 and 65%, 94%, and 0.61, respectively. CONCLUSION: In cases of pulmonary embolism, sensitivity of spiral CT is greater than that of scintigraphy. Interobserver agreement is better with spiral CT.

Adolescent↗
PubMed1997

Pulmonary nodules: differential diagnosis using 18F-fluorodeoxyglucose single-photon emission computed tomography.

OBJECTIVE: The objective of this study was to prospectively evaluate the feasibility and efficacy of single-photon emission computed tomography (SPECT) with 18F-fluorodeoxyglucose (FDG) for differentiating malignant from benign pulmonary nodules. SUBJECTS AND METHODS: Twenty-six patients with 28 radiologically indeterminate focal pulmonary lesions were examined. Fasting patients were injected with 5 MBq/kg of FDG (maximum dose, 370 MBq). Imaging was performed with dual-head SPECT cameras equipped with 511-keV collimators. RESULTS: Seventeen of 21 pathologically malignant nodules showed FDG uptake on SPECT imaging (sensitivity, 81%). None of the seven benign modules showed uptake (specificity, 100%). SPECT imaging with FDG was positive in all 16 malignant nodules that were larger than or equal to 2 cm in diameter. However, only one (20%) of five nodules smaller than 2 cm in diameter showed positive on SPECT imaging. CONCLUSION: Using current technology, we found FDG SPECT imaging useful for distinguishing benign from malignant pulmonary nodules that were larger than or equal to 2 cm in diameter. However, because of the relatively low sensitivity of SPECT, smaller malignant nodules were not adequately revealed.

Deoxyglucose↗
PubMed1996

Comparison of diagnostic performance with ventilation-perfusion lung imaging in different patient populations.

PURPOSE: To determine if patient age, chest radiographic abnormalities, or history of cardiopulmonary disease or venous thromboembolism affected diagnostic performance with ventilation-perfusion (V-P) imaging. MATERIALS AND METHODS: Receiver operating characteristic (ROC) analyses were performed on the final V-P imaging interpretation data obtained during the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study. Diagnostic performance with V-P imaging was not substantially different in patients with varying ages, an abnormal chest radiograph, or a history of venous thromboembolism or cardiopulmonary disease. CONCLUSION: Because diagnostic performance with V-P imaging in detection of pulmonary embolism was similar among the patient populations examined, an abnormal chest radiograph or history of venous thromboembolism or cardiopulmonary disease does not appear to adversely affect overall diagnostic performance in evaluation of acute pulmonary embolism.

Adult↗
PubMed1995

Identification of viable myocardium with technetium-99m-MIBI infusion.

A 50-yr-old man was evaluated using standard stress/rest 99mTc-methoxyisobutylisonitrile (MIBI) perfusion imaging, rest thallium infusion imaging and rest 99mTc-MIBI infusion imaging prior to revascularization. Resting 99mTc-MIBI infusion imaging demonstrated hibernating myocardium which was not detected with standard stress/rest 99mTc-MIBI imaging. The implication from this observation is that resting 99mTc-MIBI infusion scintigraphy can provide useful information when evaluating patients for the presence of hibernating myocardium. A prospective comparison of resting 99mTc-MIBI infusion scintigraphy with other noninvasive techniques used to identify viable myocardium may be warranted.

Coronary Artery Bypass↗
PubMed1995

Comprehensive analysis of the results of the PIOPED Study. Prospective Investigation of Pulmonary Embolism Diagnosis Study.

UNLABELLED: The goals of this review were to summarize the published data from the National Heart, Lung and Blood Institute sponsored Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study, present new data from the entire population and provide a comprehensive criteria for ventilation-perfusion (V/Q) lung scan interpretation. METHODS: Data from the PIOPED frequent user tape and journal articles published between 1990 and 1994 and indexed on Medline that presented data from the PIOPED study were reviewed. RESULTS: A normal V/Q lung scan excludes the diagnosis of clinically significant PE. The usefulness of the V/Q lung scan was optimized when interpreted as representing a very low, low or high probability of PE with a concordant clinical likelihood of PE. Patients with a V/Q lung scan interpreted as representing an intermediate probability of PE or patients with discordant clinical likelihood of PE and lung scan interpretation will often require further investigations to diagnose or exclude acute venous thromboembolism. CONCLUSION: The results of the PIOPED study support the use of V/Q lung scanning in the diagnostic evaluation of patients with suspected PE. Amendments to the original PIOPED interpretation criteria should reinforce the role of V/Q lung scanning in patients with suspected PE.

Adult↗
PubMed1994

Scintigraphic appearance of albuterol-induced inhibition of hypoxic pulmonary vasoconstriction.

Alveolar hypoxia is known to result in localized pulmonary arterial vasoconstriction. As a consequence, blood is diverted from poorly ventilated alveoli, maintaining ventilation-perfusion (V/Q) matching and thereby reducing the deleterious effects on gas exchange. An incomplete alveolar hypoxic vasoconstrictive response can be easily demonstrated by radionuclide V/Q lung scanning. A case of albuterol-induced inhibition of hypoxic pulmonary vasoconstriction is described in a patient with steroid-dependent asthma. The utility of V/Q lung scanning as a simple, noninvasive test to detect this phenomenon in patients with primary airway disorders who deteriorate despite appropriate therapy is also briefly discussed.

Administration, Inhalation↗
PubMed1994

Ventilation-perfusion lung scanning in the evaluation of pulmonary hypertension.

UNLABELLED: The objective of this study was to define the sensitivity, specificity and accuracy of ventilation-perfusion (V/Q) lung scanning in distinguishing chronic thromboembolic pulmonary hypertension (PHT) from other nonembolic causes of PHT. METHODS: The V/Q lung scans from 75 patients in whom a confirmed cause of PHT was established were retrospectively reviewed. Twenty-five patients (33%) had chronic thromboembolic PHT, whereas 35 patients (47%) and 15 patients (20%) suffered from primary PHT and secondary nonthromboembolic PHT, respectively. RESULTS: A high-probability V/Q scan interpretation had a sensitivity of 96% and a specificity of 94% for detecting patients with thromboembolic PHT. The combination of high- and intermediate-probability V/Q scan interpretations had a sensitivity of 100% for detecting patients with thromboembolic PH; however, the specificity decreased to 86%. Of the 35 patients with primary PHT, all but one patient had low-probability V/Q scan interpretations. CONCLUSION: In this series, a low-probability V/Q scan interpretation effectively excluded the diagnosis of chronic thromboembolic PHT. In patients with an intermediate- or high-probability V/Q scan interpretation, pulmonary angiography was required to confirm the diagnosis of chronic thromboembolic PHT and determine whether surgical intervention was indicated. The V/Q lung scan appears to be a highly sensitive test for chronic thromboembolism in the diagnostic evaluation of patients with PHT. However, its role needs to be defined further by application to a prospectively recruited cohort of patients with PHT.

Adolescent↗