An investigation into perioperative outcome following gastrointestinal resection in England

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Title: An investigation into perioperative outcome following gastrointestinal resection in England
Authors: Mamidanna, Ravikrishna
Item Type: Thesis or dissertation
Abstract: This thesis represents research from Hospital Episode Statistics data and provides an insight into gastrointestinal resectional surgery in England. It examines national outcomes following major colorectal resection, oesophagectomy and gastrectomy. Having established these outcomes, I ventured to investigate the commonly used mortality measures in the literature. I also studied the timing and causes of deaths following colorectal resection in English NHS Trust hospital. I was able to demonstrate that a significant number of adverse outcomes occur beyond the initial hospital stay. I evaluated the role of two key factors - minimally invasive surgery and surgeon volume in trying to mitigate these adverse outcomes. I found that national outcome following elective or planned colorectal resection are comparable with other published cancer registry reports in England. For upper gastrointestinal resection for cancer, however, outcome are significantly worse than those from Far East, but superior to studies from the States. I derived 'medical morbidity' by studying secondary codes for medical complications. Surgical complications were quantified by using surrogates such as unplanned re-operation and re-intervention following the initial procedure. I undertook a review of the literature for published outcomes following planned colorectal resection in the elderly. This demonstrated heterogeneity in studies with regards to sample size and type of study. The most commonly used measure of post-operative risk was in-hospital or 30-day mortality. In the elderly population, we demonstrated high mortality up to one year following emergency colorectal resection. To understand this excess mortality that is not taken into account by short term metrics, we studied the causes of deaths in these patients. Significant deaths occur in the young and elderly due to cardiac causes, up to one year following major colorectal resection. This calls for further research to define a new intermediate term metric that accurately quantifies the mortality risk. The uptake of minimally invasive gastrointestinal resection in England has been promising. During the study period there has been a steady rise in number of resections undertaken laparoscopically. In colorectal surgery, laparoscopic resection has been associated with shorter length of stay, reduced morbidity and mortality. Outcome following minimally invasive oesophagectomy and gastrectomy have shown this technique to be safe and potentially beneficial in reducing pulmonary complications and length of stay. However further research is needed into this. Oesophagectomy, gastrectomy and pancreatectomy for cancer have all demonstrated a positive volume-outcome relationship. With increasing surgeon caseload, risk of 30-day mortality is lower. These structure and process measures may be utilised by policy makers to improve outcome following gastrointestinal resection in England.
Content Version: Open Access
Issue Date: Sep-2014
Date Awarded: Jun-2015
URI: http://hdl.handle.net/10044/1/25622
DOI: https://doi.org/10.25560/25622
Supervisor: Faiz, Omar
Hanna, George
Aylin, Paul
Department: Department of Surgery & Cancer
Publisher: Imperial College London
Qualification Level: Doctoral
Qualification Name: Doctor of Philosophy (PhD)
Appears in Collections:Medicine PhD theses



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