Biomedical subjects

K Matthewson

Publications and source records attributed to K Matthewson.

At least 19 recordsLinked to original sources

PubMed2001

A prospective study of the workload of a newly formed PEG advice team.

BACKGROUND: A multidisciplinary advice team may be the optimal way of providing the long-term nutritional and percutaneous endoscopic gastrostomy (PEG)-related care for patients dependent on PEG feeding but the workload involved is unknown. AIM: To study prospectively the workload of a proactive, multidisciplinary PEG advice team over a 2-year period. METHODS: Separate documentation from main case notes of each episode of the team's contact with PEG or potential PEG patients, including assessment, advice and therapy given, from the time of its establishment, for four consecutive 6-monthly periods. RESULTS: During the audit, 89 patients were referred to the team for consideration of PEG insertion and PEGs were placed in 74. Eighty-nine additional patients were referred for follow up having had a PEG placed elsewhere. During the four audit periods the rate of new PEG insertions increased by 53%, the rate of PEG replacements by 315%, and the number of patients under the team increased from 16 to 70, an increase of 337%. Numbers of inpatient and outpatient consultations, and visits to other institutions by members of the team increased commensurately. CONCLUSIONS: The rapidly increasing workload of the team suggests it is playing a valued role but there are significant resource implications.

Enteral Nutrition↗

PubMed2000

The tissue effect of argon plasma coagulation on esophageal and gastric mucosa.

BACKGROUND: Argon plasma coagulation is a diathermy-based non-contact therapeutic endoscopic modality that may have a lower risk of perforation than other tissue ablation techniques. METHODS: Its effect was studied on three fresh esophageal and three fresh gastric resection specimens using power settings from 40 to 99 Watts at 90 degrees, with 1 mm separation using pulse durations of 1 and 3 seconds. A scoring system for depth of tissue damage was created and samples were analyzed blindly by a gastrointestinal histopathologist. RESULTS: There was significantly greater damage to gastric tissue using a 3-second (compared with 1-second) pulse (p = 0.003) and marginally significantly greater damage to esophageal tissue using the 3-second pulse (p = 0.053). Tissue damage was related to power setting for gastric (p = 0.031) but not for esophageal tissue (p = 0. 065). Only 1 of 42 esophageal samples and 2 of 42 gastric samples examined showed damage extending into the muscularis propria. CONCLUSIONS: Deep tissue damage that could lead to perforation was rare with argon plasma coagulation. The depth of gastric mucosal damage increased with increased pulse duration and increasing power settings, and, although the depth of esophageal mucosal damage was marginally related to pulse duration, it was not related to the power setting. (Gastrointest Endosc 2000;52:342-5).

Adenocarcinoma↗

PubMed1997

A prospective evaluation of cytology from biliary strictures.

BACKGROUND: Bile duct strictures may be benign or malignant. A definite diagnosis is desirable to advise patients of their prognosis and to identify any amenable to curative surgery. AIMS: To compare different methods of cytology sampling from biliary strictures and evaluate the use of cytology in this context. PATIENTS AND METHODS: In a prospective study 54 patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) had cytology samples obtained as follows: (1) biliary stricture brushings, (2) from the screw thread of a "Soehendra stent retriever" inserted through the stricture, (3) from the proximal end of a blocked biliary stent, and (4) cellular material spun down from a 20 ml specimen of bile. Examination of slides and rinsings was performed by an expert cytologist who graded them for the adequacy of the sample and for evidence of malignancy. RESULTS: Prolonged follow up disclosed malignancy in 52 of the 54 cases, the other two being chronic pancreatitis. Bile samples provided adequate cytology samples in 44%, the Soehendra stent retriever in 70%, retrieved stents in 84%, and cytology brush sampling in 96%. Overall, 28 malignancies were detected by cytology, including 14 of 28 pancreatic carcinomas and 12 of 16 cholangiocarcinomas. Twenty two of the malignancies were detected by brush sampling and the other methods added a total of another six cases. CONCLUSIONS: Cytology sampling is best done by brushing the biliary stricture. Cytology sampling can confirm the diagnosis in 75% of cholangiocarcinomas and 50% of pancreatic carcinomas. The techniques involved are simple to perform and should be routine clinical practice whenever potentially malignant biliary strictures are encountered at ERCP.

Adult↗

PubMed1997

Percutaneous endoscopic gastroenterostomy and jejunal extension for gastric stasis in pancreatic carcinoma.

Gastric stasis in pancreatic cancer without mechanical obstruction is distressing and difficult to manage. We describe two patients who were treated by percutaneous endoscopic gastroenterostomy (PEG) combined with a jejunal extension. Both patients had pancreatic cancer and gastric stasis, with recurrent vomiting and no evidence of distal duodenal obstruction. They were unresponsive to high-dose prokinetic agents. In both cases a Bower-PEG feeding tube with jejunal extension was inserted endoscopically, with clinical improvement. The technique has the advantages of permitting enteral feeding and allowing aspiration of upper gastrointestinal secretions between feeds, which produces symptomatic relief from nausea and vomiting. This manoeuvre can produce effective palliation, perhaps following the patient to be managed at home during the terminal phase of their illness.

Aged↗

PubMed1996

Combination of laser treatment and intraluminal radiotherapy for malignant dysphagia.

BACKGROUND: Laser treatment for malignant dysphagia is limited by recurrent intraluminal tumour requiring repeated treatment at four to eight week intervals. AIMS: To reduce the need for follow up treatment and to improve survival, patients successfully palliated by laser were treated with intraluminal radiotherapy. PATIENTS: 32 patients with inoperable oesophageal carcinoma (18 adeno and 14 squamous cell carcinoma). METHODS: The patients were initially palliated by a median of three laser treatments. They were then treated with intraluminal radiotherapy, receiving 10-15 Gy at 1 cm from the source as a single treatment with the Selectron system. Patients with squamous cell carcinoma also received external radiotherapy (30 to 50 Gy). RESULTS: After the radiotherapy nine patients survived a median of 22 (range 4-40) weeks without requiring any further endoscopic treatment. The remaining patients survived a median of 40 (range 4-102) weeks and required a median of three follow up endoscopic treatments over that time. Eleven patients developed fibrous strictures with no intraluminal tumour and were treated by dilatation. Twelve patients required dilatation and repeat laser therapy for a combination of fibrous stricture and recurrent intraluminal tumour. Six patients eventually required Atkinson tubes. CONCLUSIONS: The combination of laser treatment with intraluminal radiotherapy provides good palliation and may reduce the need for repeated endoscopic treatment. Fibrous stricture formation is a common complication.

Adenocarcinoma↗

PubMed1992

Limitations of laser treatment for malignant dysphagia.

Of 86 patients with inoperable malignant dysphagia, 68 (79 per cent) underwent successful palliation by endoscopic laser therapy, of whom 24 remained well palliated until the time of death. In 18 patients laser treatment was unsuccessful and nine of these underwent intubation, eight successfully. After successful laser therapy, dysphagia recurred in 44 patients a mean of 7.8 weeks later. Of these, 31 received palliation until death by dilatation with or without laser therapy, and 13 required intubation. The overall laser-related complication rate was 12 per cent with a mortality rate of 4 per cent. The intubation-related mortality rate was 9 per cent.

Adenocarcinoma↗

PubMed1990

Randomized comparison of Nd YAG laser, heater probe, and no endoscopic therapy for bleeding peptic ulcers.

Of 550 patients admitted with acute upper gastrointestinal hemorrhage, 143 with peptic ulcers containing stigmata of recent hemorrhage accessible to endoscopic therapy were included in a randomized comparison of neodymium yttrium aluminum garnet laser, heater probe, and no endoscopic therapy. The rebleeding rate in laser-treated patients (20%) was significantly less than in controls (42%; p less than 0.05), but in heater probe-treated patients (28%) it was not significantly different from either of the other two groups. The mortality rate in the laser group (2%) was not significantly different from either the heater probe (10%) or the control (9%) group. This trial has confirmed the efficacy of the Nd YAG laser but not that of the heater probe in the prevention of rebleeding from recently bleeding peptic ulcers.

Duodenal Ulcer↗

PubMed1989

Low power interstitial Nd YAG laser photocoagulation: studies in a transplantable fibrosarcoma.

The effects of interstitial delivery of low power (1.2-2 W), long exposure (600-1200 s) Nd YAG laser light on a transplantable fibrosarcoma in rats have been studied. Three cohorts of ten animals were treated either by 1.2 W for 600 s, 1.2 W for 1200 s or 2 W for 600 s to each tumour nodule. An additional untreated cohort served as controls and a further cohort was treated by radical surgical resection. A partial response as evidenced by ulceration was seen in all laser-treated tumours. In the cohort treated by 2 W for 600 s there was complete loss of palpable tumour, and in five out of the ten animals there was no evidence of local recurrence following a prolonged period of observation. Three of these eventually died from metastatic disease and two were cured. There was a significant prolongation of survival in this cohort compared with the controls (median 70 days versus 30 days, P less than 0.05), but not in any of the other cohorts. Histological assessment of tumours 2 days after laser treatment showed a central area of degeneration with shrunken and densely staining nuclei and disorganized cytoplasm, the boundary between the degenerate zone and surrounding viable tumour being well defined. The technique might be used to induce necrosis of intrahepatic and other solid organ tumours.

Animals↗

PubMed1988

Low power interstitial Nd YAG laser photocoagulation in normal and neoplastic rat colon.

The effects of low power (1-2 Watts), long exposure (30-400 seconds), interstitial Nd YAG laser therapy on dimethylhydrazine induced rat colonic neoplasms and normal rat colon have been studied. After a single exposure with appropriate laser parameters, dimethylhydrazine induced rat colonic neoplasms underwent coagulative necrosis, sloughed off over a four day period, and left an ulcer which healed within 28 days. Inadequate laser energy resulted in incomplete tumour necrosis whilst excessive laser power or energy increased the likelihood of perforation. Treatment of normal colon with 1 Watt for 30 seconds or longer resulted in coagulative damage which healed by granulation. Mean colonic bursting pressures were significantly decreased one hour after treatment with 1 Watt for 75 or 100 seconds compared with untreated colon (p less than 0.05 and p less than 0.001 respectively) but not in colon treated with 1 Watt for 30 or 50 seconds. In animals treated with 1 Watt for 100 seconds mean bursting pressures were significantly lower than untreated animals when the animals were killed two, four, and seven days after lasering (p less than 0.001 in each case) but not in animals killed at 11, 17, or 21 days. The technique may be of value in the treatment of some inoperable colorectal cancers and sessile polyps in man.

Animals↗

PubMed1988

Which peptic ulcer patients bleed?

In order to identify factors associated with peptic ulcers which present with bleeding rather than with pain, we have prospectively evaluated patient and endoscopic features in 139 consecutive patients presenting with acute bleeding and 74 presenting with pain found to have peptic ulceration at endoscopy. Patients with bleeding were more likely to have taken non-steroidal anti-inflammatory drugs within the preceding four weeks (58% v 18%, p less than 0.001). They were older (66 v 51 years, p less than 0.001), more likely to have had a previous ulcer complication (21% v 1%, p less than 0.001), and to have an ulcer diameter greater than 20 mm (27% v 6%, p less than 0.05). The presence of one or more of these features in a patient who develops a peptic ulcer appears to be associated with a greater likelihood of presentation with a gastrointestinal haemorrhage.

Adult↗

PubMed1987

Biological effects of intrahepatic neodymium:yttrium-aluminum-garnet laser photocoagulation in rats.

The effects of low-power neodymium:yttrium-aluminum-garnet laser light delivered intrahepatically in normal rats have been studied. Power settings of 0.5-2.0 W and exposures of 50-2400 s produced well-defined, highly reproducible necrotic lesions of up to 16 mm in diameter. The diameter of the necrotic lesions depended upon both the power setting and total energy delivered. Histologic examination showed coagulative necrosis that healed by granulation with a small residual fibrous nodule by 60 days. Microthermocouples embedded within the liver indicated temperatures of up to 100 degrees C close to the fiber tip for the higher power settings, and temperatures at the periphery of the necrotic zones were consistent with tissue damage by a purely thermal effect. Radiologic examination of photocoagulated lobes of liver in which arterial tree had been filled with a radiopaque polymer demonstrated loss of all small and some large vessels in the treated area. The technique could be used to induce necrosis of intrahepatic and other tumors.

Aluminum↗

PubMed1987

Endoscopic laser palliation for advanced malignant dysphagia.

Palliative treatment of malignant dysphagia aims to optimise swallowing for the maximum time possible with the minimum of general distress to these seriously ill patients. Thirty four patients considered unsuitable for surgery because of advanced malignancy, other major pathology or in whom previous surgery had been unsuccessful were treated endoscopically with the Nd YAG laser. Significant improvement was achieved in 29 (85%). On a scale of 0-4 (0 = normal swallowing; 4 = dysphagia for all fluids), mean improvement was 1.7, with 25 patients (74%) able to swallow most, or all solids after treatment. With increasing experience, the average number of treatment sessions required for each patient became less; initial time in hospital became comparable to that needed for intubation. Failures were caused by inappropriate patient selection (3), or laser related perforation (2). The mean survival in the whole group was 19 weeks (range 2-44). Eighteen patients needed further treatment for recurrent dysphagia, a mean of six weeks (range 2-15) after initial therapy. Ten of these responded, but eight eventually required insertion of a prosthetic tube. The duration of good palliation was very variable after initial laser therapy.

Aged↗

PubMed1987

Effect of ethanol challenge on serum glycoproteins in alcoholic and non-alcoholic liver disease.

The effects of acute ethanol challenge on serum glycoprotein concentrations in man were studied. Serum levels of haptoglobin, alpha-2-macroglobulin and pre-albumin were measured fasting and 6 hr after oral ethanol 0.75 g/kg body weight in 8 healthy controls, 13 patients with alcoholic liver disease and 13 with non-alcoholic-related liver damage, both patient groups being further subdivided into those with and without cirrhosis. Basal levels of haptoglobin were significantly higher in non-cirrhotic alcoholics than controls and pre-albumin levels were lower in non-alcohol-related cirrhotic liver disease. In response to ethanol challenge, no consistent change was observed in any group, nor was there any significant difference between groups. There was, however, a significant correlation (r = 0.53, P less than 0.005) between the percentage changes in haptoglobin and alpha-2-macroglobulin. In 16 subjects (2 controls, 8 alcoholics and 6 non-alcoholics) blood levels of ethanol and acetaldehyde were measured serially: there was no relationship between the peak or mean concentration and the glycoprotein response. This study does not substantiate other reports which claimed to be able to predict the severity and reversibility of alcoholic liver disease on the basis of the serum glycoprotein response to ethanol: ethanol challenge with measurement of serum glycoproteins cannot substitute for proper histological assessment.

Acetaldehyde↗

PubMed1986

Endoscopic treatment of inoperable colorectal cancers with the Nd YAG laser.

Seventeen patients with cancers of the rectum or distal sigmoid and considered inoperable because of old age, severe concomitant disease or advanced stage of malignancy, were treated endoscopically with the Nd YAG laser. Symptoms included rectal bleeding, obstruction, diarrhoea and incontinence. Significant improvement was achieved in 15 (88 per cent) and there were no complications. The procedure was carried out with simple bowel preparation and minimal sedation and, for otherwise fit individuals, the mean total hospital stay was 6.8 days, with day case therapy sometimes possible. Three patients required further therapy for recurrent symptoms 6-8 weeks after treatment. Fourteen patients died 1-39 weeks after therapy (mean survival 15 weeks). Three are alive and free of bowel symptoms after 39-54 weeks. This technique is the only non-surgical therapy that can be used safely for lesions above the peritoneal reflection and provides palliation at least as good as electrocoagulation, cryotherapy and radiotherapy with minimal upset to these seriously ill patients.

Adenocarcinoma↗

PubMed1986

Erythrocyte aldehyde dehydrogenase activity in alcoholic subjects and its value as a marker for hepatic aldehyde dehydrogenase in subjects with and without liver disease.

Erythrocyte aldehyde dehydrogenase activity was assayed in actively drinking alcoholics, patients with alcoholic liver disease who claimed to be abstaining, patients with non-alcoholic liver disorders and normal controls. Hepatic cytosolic aldehyde dehydrogenase was also assayed in the majority of the subjects. Actively drinking alcoholics had significantly lower erythrocyte aldehyde dehydrogenase activity than controls (P less than 0.01) but abstaining alcoholic liver disease and non-alcoholic liver disorder subjects did not. There was a significant correlation between erythrocyte and hepatic cytosolic aldehyde dehydrogenase activity in the control group (r = 0.94, P less than 0.05) but not in the other study groups.

Adolescent↗

PubMed1986

Impaired acetaldehyde metabolism in patients with non-alcoholic liver disorders.

In order to determine the specificity of abnormalities of alcohol metabolism in patients with alcoholic liver disease, blood acetaldehyde concentrations after oral ethanol challenge and the activities of alcohol metabolising enzymes in liver biopsy samples have been determined in patients with alcoholic liver disease and a wide variety of non-alcoholic liver disorders. Significant decreases in hepatic cytosolic aldehyde dehydrogenase activity were associated with significant increases in acetaldehyde concentrations after ethanol in both patient groups compared with control subjects. There was a significant correlation between hepatic cytosolic aldehyde dehydrogenase and mean blood acetaldehyde concentration 30-180 min after ethanol ingestion (y = 17.4-0.45x; r = -0.56; p less than 0.01) confirming the importance of this enzyme in controlling blood acetaldehyde concentrations. These findings suggest that disturbances in alcohol metabolism in patients with alcoholic liver disease are the consequence of liver damage rather than a specific abnormality predisposing to alcohol induced liver injury.

Acetaldehyde↗

PubMed1986

Plasmapheresis in acute liver failure.

A series of 9 patients with acute hepatic failure and Grade IV hepatic coma received daily plasmapheresis until they recovered or death ensued. Of the nine, seven (77%) showed an improvement in coma grade and five (55%) survived to leave hospital. Plasmapheresis significantly decreased serum bilirubin, aspartate aminotransferase and plasma ammonia concentrations. Survival following plasmapheresis appeared substantially better than in a non randomized group of similar patients not plasmapheresed. The simplicity of the procedure, biochemical improvements observed and apparent efficacy, suggest that further evaluation of the technique as a means of providing temporary hepatic support is indicated.

Hepatic Encephalopathy↗

PubMed1985

Endoscopic laser treatment of vascular anomalies of the upper gastrointestinal tract.

Vascular anomalies of the gastrointestinal tract are an important source of both acute and chronic blood loss. They present difficult management problems as they are often multiple, involving more than one part of the gastrointestinal tract, and may give rise to bleeds of increasing frequency and severity over a period of many years. We present the results of endoscopic argon and Nd YAG laser treatment of 18 patients with documented recurrent, severe haemorrhage from vascular lesions of the upper gastrointestinal tract with follow up of up to five years. Four patients with hereditary haemorrhagic telangiectasia, five with single angiodysplasias and three with multiple angiodysplasias have had their transfusion requirements reduced to minimal levels after one or more courses of laser treatment. Two of these have required no blood for over two years despite previous total requirements of 52 and 129 units of blood. Four patients were submitted to surgery (two in whom the laser failed to control haemorrhage and two who did not have immediate access to laser therapy at the time of severe bleed). Two of these, however, bled again soon afterwards. Two patients are still undergoing courses of laser therapy although have already shown reductions in transfusion requirements. Both lasers were effective. The Nd YAG laser appears to produce better long term results as its greater penetration makes it possible to ablate the main areas of vascular ectasia in the submucosa, although it does have a slightly higher risk of causing haemorrhage in the first few days after treatment.

Adult↗