Re: never wanting to grow up

From: Bill Hall (
Date: Mon 09 Jun 2003 - 04:05:28 GMT

  • Next message: Scott Chase: "Re: never wanting to grow up"

    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
    > 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]

    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.
    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
    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:       Phone: 03 9903 1883
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