Peptic ulcer haemorrhage with particular reference to neodymium YAG laser photocoagulation

MacLeod, Ian Alexander (1983) Peptic ulcer haemorrhage with particular reference to neodymium YAG laser photocoagulation. MD thesis, University of Glasgow.

Abstract

This thesis is concerned with a series of personal studies on acute upper gastrointestinal haemorrhage carried out over a period of several years in two different hospitals. The first part presents the results of two policies of diagnosis and management of patients admitted to the Western Infirmary, Glasgow. The initial group of patients were admitted to individual units and barium meal examination was the main diagnostic procedure; the second group were admitted to a single medical unit, early endoscopy was used for diagnosis and a haematemesis team was available. From comparison of the results in those two groups, it was concluded that early endoscopy was an accurate means of identifying the site and cause of bleeding but that this knowledge was not associated with improvement in outcome. Despite improvements in medical care, there was no evidence that this reduced mortality and blood loss remained the main cause of death. Emergency surgery had an appreciable mortality and it was concluded that there was a need to have a non-operative technique to treat or prevent further haemorrhage. The second part of the thesis is concerned with an investigation into the application of the neodymium YAG laser to endoscopic therapy in Glasgow Royal Infirmary. Preliminary animal studies were performed to assess the safety and efficacy of the neodymium YAG laser using prototype equipment. The effects of the radiation on the rabbit stomach were assessed by varying the different parameters of radiation and observing the resultant tissue changes by macroscopic and histological assessment. It was concluded that the tissue effects were predictable and within the range of radiation likely to be used for photocoagulation, the risk of visceral perforation was minimal. A further study was performed to see if the extension of tissue necrosis could be reduced by a prostaglandin analogue or a H2 receptor antagonist but the results were inconclusive. The ability of the neodymium YAG laser to arrest haemorrhage was assessed in an acute dog model with the splenic artery brought up to a hole in the stomach wall. Arterial haemorrhage was produced by fenestrating the vessel and within the limitations of the study the active bleeding could be arrested by laser photocoagulation. A pilot study of laser photocoagulation was then performed on a group of patients, many of whom were poor surgical risks. The purpose of this pilot study was to improve the laser and ancillary equipment and assess whether it was worthwhile proceeding to a controlled trial. It was concluded that within the limits of an uncontrolled assessment, the laser could reduce further haemorrhage but that objective assessment would be required to provide the answer. A prospective controlled trial was performed to assess the efficacy of the neodymium YAG laser in patients bleeding from peptic ulcers and single vessels. Entry criteria consisted of clinical features (shock, blood transfusion, haemoglobin concentration <10g.dl-1 ) that conveyed an increased risk of further haemorrhage and endoscopic appearances (gastric or duodenal ulcer with either an artery or spot in the floor or a single vessel). Of 657 patients admitted with acute non variceal haemorrhage, 184 were bleeding from peptic ulcers and single vessels; 130 of them were ineligible for study inclusion and all of them settled. Fifty four patients were eligible but 9 were excluded. Forty five patients were included in the study, 2 5 of whom were bleeding from ulcers with spots and irrespective of therapy, they all settled. Of the 20 who were bleeding from arteries, all 8 who were allocated to the control group underwent emergency surgery and 2 died. Four of the 12 patients who were allocated to receive laser therapy did not receive it and did as badly as the controls. Of the 8 who received laser therapy, only one required emergency surgery. It was concluded that neodymium YAG photocoagulation could reduce the need for emergency surgery but within the experience of the study, it was not applicable in those who had brisk arterial haemorrhage or who had ulcers in positions that were inaccessible to the laser beam. In general, it was concluded that by identifying those patients who had bled from arteries, it was possible to identify those who require emergency surgery. Furthermore if early semi elective surgery or laser photocoagulation was performed on these patients before further haemorrhage had occurred, then the mortality might be reduced in those bleeding from peptic ulcers. With this information available, there would be no need to provide special care for all patients admitted with acute upper gastrointestinal haemorrhage because the high risk group could be identified.

• Item Type: Thesis (MD)
• Qualification Level: Doctoral
• Additional Information: Adviser: D C Carter
• Keywords: Medicine
• Date of Award: 1983
• Depositing User: Enlighten Team
• Unique ID: glathesis:1983-72661
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 11 Jun 2019 11:06
• Last Modified: 11 Jun 2019 11:06
• URI: https://theses.gla.ac.uk/id/eprint/72661