Molecular genetic microbiological and clinical analysis of Hirudo species (leeches) : implications for use in surgical practice

Abstract

The aims of this thesis are to investigate the historical journey of the use of leeches in medicine (Chapter 2) and to review the mechanisms of action relevant to the reconstructive surgeon (Chapter 3). With a specific focus on infective complications following leech therapy, we will investigate the culturable and unculturable microbiota of Hirudo orientalis using contemporary molecular genetic techniques and accurately measure antibiotic sensitivities (see figure 2) (Chapter 4), present a 5 year follow up study of the use of antibiotics in the UK and suggest an appropriate antibiotic prophylactic regimen (Chapter 5 and 6). In Chapter 7, the largest individual series of patients post reconstructive surgery treated with leeches to date will be outlined (n=35 over a 4 year period). The previous largest clinical series can be seen in table 2. A comprehensive systemative review of the use of leeches in surgical practice (277 clinical cases) will be presented, with special consideration to the indications, outcomes and complications of associated with such therapy. (Chapter 8) In chapter 9, we present and analyse mechanical and chemical alternatives to leech therapy. A summary of the thesis and potential implications of differences between the FDA approved, and other leech species are discussed in Chapter 10. Chapter 11 incorporates several appendices including a protocol for leech use and details on how to order leeches worldwide. In this thesis we will answer the following questions: What species of medicinal leech are available for clinical use, and which are we using currently? (Chapter 1); How long have we used leeches throughout history and for what indications? (Chapter 2); What is the mechanism of action of medicinal leeches relevant to the surgeon? (Chapter 3); What is the extent of use of medicinal leeches in reconstructive surgery?(Chapter 5); What do we know about the microbiota of the leech and what is the potential to cause infective complications? (Chapter 4); Does infection affect salvage rates? (Chapter 7 & 8); How should we be preventing and treating these infections? (Chapters 4,6,7); Are we currently using appropriate antibiotic prophylaxis or treatment?(Chapter 5,6); What indications are leeches most commonly used for? (Chapter 7,8); Is there a viable alternative at present to leech use? (Chapter 9); Does it matter which species of medicinal leech we are using? (Chapter 10).