From: Bill Hall (bill.hall@hotkey.net.au)
Date: Mon 09 Jun 2003 - 04:05:28 GMT
Scott Chase said with his sarcasm mode on:
> Yeah I could see how fortunate it has been that barbaric practices like
> bleeding, especially using leeches in this practice, have ceased being a
> part of the modern medical repertoire. I'd hate to think that a doctor in
> our enlightened times would succumb to the "meme" of attaching a leech to
a
> patient, especially after the patient's finger has been surgically
> reattached and restored circulation becomes a necessity [sarcasm mode off]
>
Interestingly enough, this is the *exact* situation where the use of
medicinal leeches has been scientifically proven to be of genuine medical
use. e.g., see the first Google hit on [anticoagulation leech]
(http://www.google.com.au/search?q=leech+anticoagulation).
Journal of Rehabilitation Research and Development
Vol. 39 No. 4 July/August 2002
Pages 497-504
Development of a mechanical device to replace medicinal leech (Hirudo
medicinalis) for treatment of venous congestion
----------------------------------------------------------------------------
---- Michael L. Conforti, DVM, MS; Nadine P. Connor, PhD; Dennis M. Heisey, PhD; Ray Vanderby, PhD; David Kunz, PhD; Gregory K. Hartig, MD Department of Research, William S. Middleton VA Hospital, Madison, WI; Department of Surgery, University of Wisconsin Medical School, Madison, WI Abstract: Medicinal leeches are used to treat venous congestion, a complication of reconstructive surgery. Despite substantial drawbacks of leeching, little progress has been made to develop a device that would replace the leech for this purpose. The goal of this study was to develop and test mechanical prototypes for the treatment of venous congestion. We tested four prototypes (1, 2, 3a, and 3b) using congested fasciocutaneous flaps in swine. Blood removed by each prototype was measured for up to 4 hours. On average, the four prototypes removed 609%, 644%, 853%, and 811% more blood, respectively, from congested flaps versus a leech. Prototypes 3a and 3b, which allowed for innovative subcutaneous chemical (3a and 3b) and mechanical (3b) anticoagulation at the bleeding wound, sustained high levels of blood removal for up to 4 hours. Thus, a mechanical device can potentially replace the use of leeches for treating venous congestion. Key words: Hirudo medicinalis, mechanical device, medicinal leech, reconstruction, replantation, venous congestion. Introduction INTRODUCTION Reconstructive surgical procedures, such as free flaps, pedicle flaps, and replantation of amputated tissues, often include an anastomosis between either surgically ligated or traumatically severed blood vessels. Venous congestion is a serious complication of these types of procedures and occurs when the venous outflow from a tissue is reduced relative to arterial input. Kinking or impingement on the veins and/or thrombus formation within the veins can cause this reduction [1-4]. If venous congestion is not corrected (either surgically or via some other means), the developed stasis within the vasculature of the tissue will cause the replanted region to necrose. Although medicinal leeches (Hirudo medicinalis) have been a part of medical practice for thousands of years, not until the advent of reconstructive microsurgery in the 1960s did bloodletting by the leech have a legitimate medical purpose. Specifically, medicinal leeches are placed upon the congested tissue to facilitate removal of excess blood until microvenous circulation can be effectively reestablished approximately 4 to 10 days after surgery [5-11]. Unfortunately, leeches only remove small quantities of blood from the congested tissue and cannot be relied upon to effectively decongest large regions of tissue. In addition, the use of leeches is suboptimal because of other drawbacks [12]. These drawbacks are substantial and include negative patient and family perception, unreliability of leech attachment (i.e., the leeches may not attach to, or may migrate from, the impaired tissue and may feed on healthy adjacent skin), excessive cost because of constant staff monitoring, and the possibility of infection [13-16]. There have been several attempts in the last 10 years to develop a mechanical and/or chemical leech that would replace the medicinal leech [17-20]. Although these attempts showed some success, a clinically applicable product has not been developed to date, which would replace the use of medicinal leeches for the successful treatment of venous congestion. ------------ Here is another meme, "Before turning on sarcasm mode, check your facts!" Bill Hall Documentation Systems Analyst Honorary Research Fellow Strategy and Development Knowledge Management Lab Tenix Defence School of Information Management & Systems Williamstown, Vic. 3016 Monash University Phone: 03 9244 4820 Caulfield East, Vic. 3145 Email: bill.hall@tenix.com Phone: 03 9903 1883 URL: http://www.tenix.com Email: william.hall@infotech.monash.edu.au URL: http://www.sims.monash.edu.au/research/km/ =============================================================== This was distributed via the memetics list associated with the Journal of Memetics - Evolutionary Models of Information Transmission For information about the journal and the list (e.g. unsubscribing) see: http://www.cpm.mmu.ac.uk/jom-emit
This archive was generated by hypermail 2.1.5 : Mon 09 Jun 2003 - 03:53:00 GMT