Efficacy of Leeching in Frostbite

A6

Unani Medicine, University of Kashmir, India

drarsheediqbal@gmail.com recurrence rate.

Keywords: Frostbite; Leeching; Hirudotherapy

Introduction

Frostbite is well documented in the military and in countries with extreme temperatures for centuries. The earliest documented evidence of frostbite may be a 5,000- year-old pre-Columbian mummy discovered in the Andes [1]. The first report of mass cold injuries was by Baron Larrey, Surgeon-in-Chief to Napoleon's Army throughout the invasion of Russia during the winter of 1812–1813 [2]. More recent descriptions of cold injury have centered around military campaigns, from Xenophon’s writings of 210 BC [3] to Dr. James Thatcher’s reports during the American Revolution [4] and cases from the Korean and Falklands wars. Baron Dominique Larrey, Napoleon’s military surgeon, gave the first description of the pathophysiology of frostbite during the infamous 1812 retreat from Moscow [5]. He wrote: “The natural heat is absorbed and a discharge of caloric takes place, the pores close and the capillary vessels fall into a state of contraction; the fluids are condensed and flow more slowly.” Larrey introduced the concept of friction massage with ice or snow and was the first to describe the similarities to burns. The extreme effects of cold on ground troops were again seen during the world wars of the 20th century. Many of these injuries were sustained at non-freezing temperatures and, although similar to frostbite, were caused by prolonged immersion in cold water (1.6°C– 4.4°C). This led to the term “trench foot” [3, 6] or “immersion foot”[7]. Cold injury, however, was not limited to ground troops. High-altitude frostbite, first described in 1943, was recognized from the treatment of aviators during World War II. In fact, heavy bomber crews sustained more injuries from frostbite than from all other causes combined [7].

Pathophysiology

Two distinct mechanisms are apparently responsible for tissue injury: (1) cellular death occurring at the time of exposure to the cold, and (2) deterioration and necrosis attributable to progressive dermal ischemia [8, 9, 10]. Freezing of tissue leads initially to the formation of extracellular ice crystals. These crystals directly damage the cell membrane and change the osmotic gradient across it, resulting in intracellular dehydration [11]. The intracellular electrolyte concentration increases dramatically and initiating cell death. As the temperature of the tissue continues to fall, intracellular ice forms. These ice crystals expand, causing the mechanical destruction of cells [12].

Material and Methods

Leech was applied to 40 patients of clinically diagnosed frostbite. The patients with frostbite in feet were only selected for study. The study was done in coldest months of the year at RRIUM, Srinagar from November to February. All the base line investigations including electrolytes were done before the study. The patients were given six sittings of leech therapy every after one week to both the feet. The part to which the leech was applied was hygienically prepared. Six leeches were applied on each foot for a period of at least 40 minutes or till they terminate of their own. The wounds were allowed to bleed at least for one hour and then an antiseptic dressing was applied and was kept for 12 hours. The patients were continuously monitored for any type of allergic reaction or infection. After completing the six sittings of leech therapy the patients were fallowed up for complete one year.

Clinical Manifestations

Frostbite has been categorized into four degrees. In first-degree frostbite, there is a numb central white plaque with surrounding erythema. Second degree injury causes blister formation surrounded by erythema and oedema. These blisters fill with clear or milky fluid in the first twenty four hours. Third degree injury is characterized by haemorrhagic blisters that result in a hard black eschar two weeks later. Fourth degree injury produces complete necrosis and tissue loss. In the long term, cold sensitivity, sensory loss, and hyperhidrosis may persist in the affected part for years [13]. Less commonly, growth plate disturbances [14, 15], osteoarthritis [16], chronic pain [14], and heterotopic calcification have also been reported [17].

Radiological Assessment of Tissue Injury

Several radiologic techniques have been applied to this problem in an attempt to provide an accurate early assessment of tissue viability. These include plain radiographs, venous radioisotope scanning (131I, 133Xe, and 99Tc), angiography, and digital plethysmography for assessment of tissue perfusion. Plain radiographs may be helpful in the assessment of frostbitten extremities. Early radiographic manifestations include soft tissue swelling and loss of tissue, especially at the tips of the digits, osteoporosis and periosteitis may occur at a slightly later stage [17]. In the early stages, arteriography demonstrates marked slowing of blood flow in sizeable branches. As rewarming occurs, arterial flow improves but residual occlusions are often noted [18]. Angiography has been used in the diagnosis and treatment of cold injury, although arteriograms obtained soon after injury do not sufficiently clarify levels of viability [6]. Laser Doppler flowmetry appears to offer accurate assessment of vasomotor status [19], Technetium scintigraphy has become the standard imaging study used within the first few days after injury [20, 21, 22]. Use of this technique has been suggested to assess tissue viability in an effort to allow earlier debridement of soft tissue and coverage of ischemic bony structures [23, 24]. Some authors are now advocating magnetic resonance imaging and magnetic resonance angiography as superior techniques. These techniques, by allowing direct visualization of occluded vessels and imaging of the surrounding tissues and by showing a more clear-cut line of demarcation of ischemic soft tissue, may make earlier surgical intervention possible.

Discussion

Leeching help in removing the toxins from the blood by improving the deranged humours and enhancing the blood perfusion infusing healthy bioactive enzymes in to the body and thus modulating the body to heal itself. The Hirudotherapy (Leeching) help to maintain vascular patency and improve their health there by regulate the blood circulation by way of peptides and proteins of leech salivary secretion. Hirudotherapy transmits enzymes like hyaluronidase that enhance the viscosity of the interstitial fluid. It has acetylcholine and histamine like substances as well as carboxypeptidase A inhibitors which can increase flow by dilating constricted vessels. Calin is an important bioactive substance that inhibits the coagulation and another component named as destabilase dissolve fibrin clots and as well as inhibits the formation of thrombus. The leeches have some important enzymes that removes infected blood and releases some therapeutic components that help in resolving the inflammation reducing the pain and healing the wounds. These bioactive substances thus help in healing frostbite wounds and to resolves the associated inflammatory conditions.

Conclusion

Deep frostbite is a serious condition that is associated with significant morbidity, and it is becoming more frequent in young active individuals who put themselves at risk like prolonged hiking and snow skating. Timely pre-hospital and definitive hospital management are important to minimize final tissue loss and maximize functionality of the affected limb. Surgeons should not rush for early amputation. We have outlined a series of management frameworks, which we hope will enable surgeons who rarely see this condition to have a greater understanding of frostbite and its management. Either intravenous iloprost or thrombolysis with rTPA should be considered in all patients who present within 24 hours of sustaining an appropriately severe injury and if the facility is capable of appropriate administration and monitoring. Both treatments should be started as soon as it is practical to gain maximal benefit. There is some evidence iloprost can be used beyond the 24 hour window and it is the treatment of choice where there are contraindications to thrombolysis. Bone scanning is helpful to ascertain deep tissue injury and response to therapy. If iloprost is an available option, then iloprost is the preferred option based upon its simplicity of administration, safety and efficacy. Prevention with education, behaviour modification and appropriate use of suitable equipment is important to reduce frostbite incidence. The saliva of Medicinal leech contains a powerful anticoagulant, a vasodilator, a spreading factor, enzymes and an anesthetic. The anticoagulant prevents blood from clotting. The vasodilator opens up blood vessels helping to increase blood flow. An anesthetic is pumped into bite from minute ducts between its teeth. This makes a leech bite painless. The spreading factor moves all chemical quickly into tissue farthest from the bite, liquefying any hardening blood and in this way these bioactive substances help in healing frostbite wounds and to resolve the associated inflammatory conditions.

Acknowledgement

Authors duly acknowledge the Assistant Director In Charge and Hospital staff of Regional Research Institute of Unani Medicine, University of Kashmir, Srinagar.