PubMed Health⌕ Search

Biomedical subjects

R A Knox

Publications and source records attributed to R A Knox.

16 recordsLinked to original sources
PubMed1989

Vertical gastric plication: an operation for gastro-oesophageal reflux.

An operation has been devised to prevent gastro-oesophageal reflux in which a vertical partition is made parallel to the proximal gastric lesser curvature. The technique, which can be simply, safely and rapidly performed, prevents reflux in the following ways: 1. Increasing the effective length of the 'intra-abdominal oesophagus'; 2. Increasing the crural sling and mucosal flap valve effect; 3. Sharpening the angle of entry into the gastric reservoir; 4. Creating a flutter valve and markedly reducing the gastric cross-sectional area along which reflux can occur. The stomach is neither opened nor divided. The efficacy of the operation was investigated in six dogs which had their lower oesophageal sphincter excised by circular myomectomy before vertical gastric plication. Pre- and postoperative manometric and oesophageal pH studies were performed. Vertical gastric plication prevented the oesophagitis produced by circular myomectomy alone. The operation has been performed in 26 patients over a 2-year period. Assessment has been by clinical methods, ambulatory 24 h pH studies and endoscopy. Twenty-one patients were classified in Visick grades I and II and ambulatory pH recordings showed a marked reduction in reflux in 13 of 14 patients. The operation is technically simple, quick and safe to perform, being accurately and scientifically reproducible.

Animals↗
PubMed1986

Carcinoma of the ampulla of Vater.

Experience in treating tumours of the ampulla of Vater in the North West region of the UK is reviewed. The results of local resection, radical resection and palliative bypass in 61 cases have been compared. Local resection in this series offers a better survival than radical procedures at one, two, three, and five years. The operative mortality for radical procedures was 30 per cent. There were no operative deaths in those patients having a local resection. No patient having palliative bypass surgery survived more than 18 months.

Aged↗
PubMed1986

Management of the septic complications of diverticular disease.

One hundred and five patients underwent surgical treatment of septic complications of diverticular disease. In nine cases, operation was carried out for acute large bowel obstruction and in the remainder for peritonitis. An inflammatory mass and/or localized abscess was found in 23 cases. Free pus without evidence of 'communicating' perforation was found in a further 33 and 'communicating' perforation in 40. Treatment by primary resection or by transverse colostomy and drainage were both associated with significantly lower mortality from sepsis than treatment by drainage alone. In cases without 'communicating' perforation, there was no difference in mortality between primary resection and transverse colostomy with drainage. Although the advantage of primary resection was most apparent in cases with 'communicating' perforation, it did not reach statistical significance. In three cases treated primarily without resection the pathology was subsequently found to be that of carcinoma. In 'favourable' circumstances, i.e. without 'communicating' perforation, defunctioning colostomy with drainage has an acceptably low mortality rate and may be undertaken by a less experienced surgeon to avoid a difficult resection. Ideally these problems should be dealt with by an experienced surgeon; we prefer to treat the septic complications of diverticular disease by primary resection.

Abscess↗
PubMed1983

The influence of ultrasonic Duplex scanning on the management of carotid artery disease.

In order to assess the influence of a non-invasive test such as Duplex scanning on the management of patients with suspected carotid artery disease, we reviewed the data on all new referrals (n = 491) during a year. The patients were grouped according to the reason for the referral: 1, patients with focal neurological symptoms lasting less than 24 h (n = 156); 2, patients with focal neurological symptoms lasting longer than 24 h (n = 107); 3, patients with non-focal neurological symptoms (n = 147); 4, patients with asymptomatic bruits (n = 81). For all four groups there was a statistically significant relationship (chi 2; P less than 0 . 005) between the reporting of the presence of a high grade stenosis (more than 50 per cent diameter reduction) and the likelihood that the patient would undergo arteriography. The finding of a high grade stenosis on the arteriogram resulted in a greater number of patients undergoing carotid artery surgery. The results of this study indicate that the report of the non-invasive test influenced the decision-making process in the management of patients with suspected carotid artery disease.

Carotid Artery Diseases↗
PubMed1982

A simple parameter for accurate detection of severe carotid disease.

The value of the ratio of the peak systolic velocity in the internal carotid artery to the end diastolic velocity in the common carotid artery in quantifying the severity of carotid arteriosclerosis has been investigated in 86 diseased vessels and 30 normal vessels. The ratio permitted gradation of disease into 60 per cent stenosis and greater with 95 per cent accuracy, 65 per cent stenosis and greater with 97 per cent accuracy and greater than 90 per cent stenosis with 100 per cent accuracy. The values for 30 normal sides studied fell below those of the 60 per cent stenosis group. The ratio has a value in predicting the severity of disease in the internal carotid artery in those with a 60 per cent stenosis and greater.

Blood Flow Velocity↗
PubMed1981

Importance of noninvasive ultrasonic-Doppler testing in the evaluation of patients with symptomatic carotid bruits.

An ultrasonic Duplex scanner was used to estimate the site and degree of extracranial arterial disease in two groups of patients with asymptomatic bruits. In the first 100 patients only the extent of disease was assessed with 37% of the sides with bruits having high-grade stenoses (greater than 50% diameter reduction) and one-half having lesions which narrowed the internal carotid artery by less than 50%. Seven percent were found to be normal. The remaining 6% had occlusion of the internal carotid artery. In a second group of 81 patients, the effect of the reported findings of the Duplex scan on patient management was reviewed. Only 13 patients underwent angiography and 11 of these were in patients with high-grade stenoses. Five carotid endarterectomies were performed and in each case, the patient had bilateral high-grade lesions. The implications of this diagnostic approach are discussed as well as the need for prospective studies of patients who present with an asymptomatic bruit.

Arteriosclerosis↗
PubMedDate not supplied

Empirical findings relating sample volume size to diagnostic accuracy in pulsed Doppler cerebrovascular studies.

Ultrasonic duplex scanning has a sensitivity of 97% in detecting disease of the carotid bulb. However, the specificity is much less, being 37%. The error in distinguishing normal arteries from those with minimal disease appears to be in part related to the size of the sample volume of the pulsed Doppler. This paper addresses the importance of the features of scan head design in relation to distinguishing normal and diseased arteries.

Blood Flow Velocity↗
PubMedDate not supplied

Computer based classification of carotid arterial disease: a prospective assessment.

A minicomputer based pattern recognition method has been used to prospectively classify the category of disease involvement of 105 carotid arteries. The system utilized spectral patterns obtained from a combined B-mode/pulsed Doppler unit. All decisions are based upon comparison of an unknown, averaged waveform with a series of vessels with known severity of disease. The variability in the computer decision as compared to arteriography is discussed.

Adult↗