LEECH THERAPY

LEECH THERAPY

The European medicinal leech ( Hirudo medicinalis ) is an inver - tebrate annelid; its saliva contains hirudin (an anticoagulant), hyaluronidase (which facilitates anticoagulant penetration into - the wound) and histamine (to maintain vasodilatation). The primary indication for leec h therapy is to improve drainage from flaps that are venously congested, i.e. those that are dusky - blue with a brisk capillary refill and a rapid, dark pinprick. Such congestion may result from a particular vein being too small or not present or a venous anastomosis not being technically possible (e.g. a distal digital replant where an artery is reconstructed but not the vein). Leeches are not normally - used in cases of suspected venous obstruction of a free flap as immediate surgical exploration is required; likewise they - are of no benefit in an arterially compromised flap as, again, immediate surgical exploration is mandated. As leeching is used for venous (as opposed to arterial) insu ffi ciency , a typical course of treatment may last for up to 2 /uni00A0 weeks – until new vein formation occurs at the margins of the flap ( Figure 47.29 ). The anticoagulant e ff ect persists once the leech has detached from the patient, with bleeding occur - - ring for some hours; each leech will imbibe up to 5 /uni00A0 mL of blood and up to 150 /uni00A0 mL of blood may be lost in the subse - quent ooze; thus, all patients must have their haemoglobin level monitored r egularly and blood transfusion may be necessary . Leeches contain Aeromonas hydrophila , so patients require pro phylactic antibiotics (typically a quinolone) until wound closure is complete.

Figure 47.29 Leeching used for a venously congested replanted right external ear.

LEECH THERAPY

The European medicinal leech ( Hirudo medicinalis ) is an inver - tebrate annelid; its saliva contains hirudin (an anticoagulant), hyaluronidase (which facilitates anticoagulant penetration into - the wound) and histamine (to maintain vasodilatation). The primary indication for leec h therapy is to improve drainage from flaps that are venously congested, i.e. those that are dusky - blue with a brisk capillary refill and a rapid, dark pinprick. Such congestion may result from a particular vein being too small or not present or a venous anastomosis not being technically possible (e.g. a distal digital replant where an artery is reconstructed but not the vein). Leeches are not normally - used in cases of suspected venous obstruction of a free flap as immediate surgical exploration is required; likewise they - are of no benefit in an arterially compromised flap as, again, immediate surgical exploration is mandated. As leeching is used for venous (as opposed to arterial) insu ffi ciency , a typical course of treatment may last for up to 2 /uni00A0 weeks – until new vein formation occurs at the margins of the flap ( Figure 47.29 ). The anticoagulant e ff ect persists once the leech has detached from the patient, with bleeding occur - - ring for some hours; each leech will imbibe up to 5 /uni00A0 mL of blood and up to 150 /uni00A0 mL of blood may be lost in the subse - quent ooze; thus, all patients must have their haemoglobin level monitored r egularly and blood transfusion may be necessary . Leeches contain Aeromonas hydrophila , so patients require pro phylactic antibiotics (typically a quinolone) until wound closure is complete.

Figure 47.29 Leeching used for a venously congested replanted right external ear.

LEECH THERAPY

The European medicinal leech ( Hirudo medicinalis ) is an inver - tebrate annelid; its saliva contains hirudin (an anticoagulant), hyaluronidase (which facilitates anticoagulant penetration into - the wound) and histamine (to maintain vasodilatation). The primary indication for leec h therapy is to improve drainage from flaps that are venously congested, i.e. those that are dusky - blue with a brisk capillary refill and a rapid, dark pinprick. Such congestion may result from a particular vein being too small or not present or a venous anastomosis not being technically possible (e.g. a distal digital replant where an artery is reconstructed but not the vein). Leeches are not normally - used in cases of suspected venous obstruction of a free flap as immediate surgical exploration is required; likewise they - are of no benefit in an arterially compromised flap as, again, immediate surgical exploration is mandated. As leeching is used for venous (as opposed to arterial) insu ffi ciency , a typical course of treatment may last for up to 2 /uni00A0 weeks – until new vein formation occurs at the margins of the flap ( Figure 47.29 ). The anticoagulant e ff ect persists once the leech has detached from the patient, with bleeding occur - - ring for some hours; each leech will imbibe up to 5 /uni00A0 mL of blood and up to 150 /uni00A0 mL of blood may be lost in the subse - quent ooze; thus, all patients must have their haemoglobin level monitored r egularly and blood transfusion may be necessary . Leeches contain Aeromonas hydrophila , so patients require pro phylactic antibiotics (typically a quinolone) until wound closure is complete.

Figure 47.29 Leeching used for a venously congested replanted right external ear.