Determination of implantation time of hydatid cyst protoscolexes in the abdominal cavity following perforation in rats

Dissertation:

To receive a specialized doctorate degree in the field of general surgery

Problem

Hydatid cyst disease is one of the common diseases of humans and animals that is caused by Echinococcus granulosis. (1) This disease is more common in areas where there are more animals such as sheep and dogs, such as Iran, Turkey, Mediterranean countries and the Middle East, South America, New Zealand, and Australia (2). Its highest incidence is in Uruguay, 32 cases per 100,000 cases per year in Argentina, 21 cases per 100,000 cases per year (3). Iran is also one of the most important foci of hydatid cysts (4). Its incidence rate in 1991 in Iran was 67 per 100,000 people, and the highest cases were reported in Khorasan-Isfahan and Fars, respectively, 106-51-36 people. cases have been reported in 100,000 cases (5). In the natural cycle, dogs are the main hosts and sheep - camels and goats are the intermediate hosts (6). This disease is a tissue infection caused by the larval stage of the parasite Echinococcus granulosis (7). At least 7 of the 9 genotypes of this parasite cause disease in humans, and in Iran, most human cases occur from the sheep chain. Liver cysts (70%) and lung cysts (20%) are the most common location of the disease (8). Most patients with liver hydatid cyst do not have any symptoms and may be discovered by chance during a scan or may be identified only by the size of the liver. Large cysts may become painful, but hydatid cyst symptoms are usually the result of various complications that may occur. A hydatid cyst may rupture into the bile ducts and lead to cholangitis, or it may rupture into the peritoneal cavity in cases where it is placed under the liver capsule and lead to anaphylactic shock, and in some cases, it may become infected and the symptoms of liver abscess are obvious symptoms. Surgery is the main treatment and the only way to completely eliminate cysts, but it may have dangerous side effects such as death or recurrence of the cyst after surgery (9). Since experimental studies and numerous objective observations have shown that it is possible to directly implant pronovascolexis of this parasite following pressure, trauma or cyst rupture during surgery (10 and 11), investigating the duration of time required for reimplantation of the parasite (implantation) can complete human knowledge regarding the developmental stages of this parasite and may be effective as a fundamental research in advancing the control and treatment of this disease. Let's evaluate the re-implantation of protoscolexes after cyst rupture

1-2 General

1-2-1 Hydatid cyst

Hydatid cyst disease is a common parasitic disease of humans and animals. The cause of this disease is a small, wide banded worm called Echinococcus granulosus from the family of cestodes, which is 3-5 mm long and can hardly be seen with the eye. The main hosts of these worms are dogs and the worm lives in the small intestine of infected dogs. The body of these worms has three bands and in the last band, there are thousands of contaminating eggs that are released after this band is broken. Infected canines spread the eggs of these worms in fields, pastures and vegetables through their feces, causing environmental pollution. If these eggs are eaten by a random intermediate host such as a cow, sheep, goat, camel or human along with fodder and raw vegetables, the embryo that is in these eggs is released in the intestine and penetrates the mucous tissue of the intestine and reaches the liver, lung, brain, kidney, bones and other tissues through blood circulation, where it forms bags the size of a small and sometimes large ball. These bags have white and hard walls and there is a colorless liquid inside. These bags are called hydatid cysts (30). style="direction: rtl;">The most common location of hydatid cyst is in the liver (70%) and lung (20-30%).. If the cyst is punctured (for example, during surgery), the fluid containing the baby worm (protoscolex) is sprayed around under pressure, and each of these babies can create a cyst again by direct implantation or through other parts of the body. Hydatid cyst is common in Iran, like many countries in the Middle East, and this disease is endemic in most places. This parasite that causes hydatid cyst is also known as Teania Echinococus. This parasite was discovered in 1695 by Hartman. Its cases have been seen all over the world, and it is mostly seen in countries where cattle and sheep breeding is popular, and a connection between humans and sheep is seen in this parasite. (23) It is 6-3 mm and is made up of three parts:

Head: It has four fangs and a rostellum with two thorn-like fangs can also be seen. The second matured Windsumi contains Gravid.

Life cycle = The worm spends its lifetime in two hosts

. 1- Definitive host: which consists of dogs, wolves, foxes and jackals, which live in the thin intestines of these animals, and a large amount of eggs are released by the excrement of these animals. The dog is one of the main definitive hosts of this parasite. 2- Intermediate hosts include sheep, pigs, horses, goats, and humans. The larval stage of the parasite has passed in these hosts and causes the formation of hydatid cysts. Sheep is one of the main intermediate hosts of this parasite. But if the symptoms of the disease become symptomatic, it depends on the location of the cyst in the body (pressure on the organs). For example, in the liver, it manifests as indigestion, pain and palpation of a lump in the RUQ. Other manifestations are obstruction of the bile ducts, jaundice and secondary infection. In the lungs, symptoms of respiratory system involvement such as cough, shortness of breath, sputum, hemoptysis, chest pain and fever. If the cyst grows in the spleen, it does not show any symptoms, but it may rupture due to a small impact or an accident, which leads to shock and immediate death of the patient. If a cyst grows in the brain, symptoms similar to a brain tumor are seen. A liver cyst may remain asymptomatic for 10-20 years or more, until the size of the cyst is easily palpable, or it causes the ventricles to rupture or the symptoms arise. Its symptoms include pain in the right upper quadrant of the heart, vomiting, and the production of complex obstructive cysts. With secondary bacterial cholangitis, cirrhosis and portal vein hypertension are seen. style="direction: rtl;">Treatment of this disease is possible with surgical removal of cysts or drugs such as metronidazole and albendazole. Praziquantil is prescribed in the amount of 120-210mg/kg.w for 5-6 days. Prevention or prevention: Prevention of canine infection by continuing to use anti-worm drugs by dogs in endemic areas. Washing hands before eating food and refraining from contact with dogs and internal organs of animals such as sheep. Avoiding consumption of internal organs that do not have a seal of health approval.