A retrospective study of hydatid cysts in patients undergoing liver and lung surgery in Tehran, Iran.

Hydatid cyst, caused by larval stages of Echinococcus granulosus, is a zoonotic parasitic disease with public health importance. The disease is cosmopolitan and endemic in Iran. We conducted a retrospective study of the records of Milad Hospital, Tehran, Iran to establish the proportion of lung and liver surgical procedures that were performed for removal of hydatid cyst and to investigate the demography of the population undergoing lung and liver hydatid cyst surgery in this hospital. A retrospective cross-sectional study was conducted of records of 682 patients who underwent liver (n = 404) or lung (n = 278) surgery from April 2009 to March 2013. In 404 liver surgeries, 111 (27.5%) diagnoses of hydatid cyst were verified. Liver hydatid infection demonstrated a significant age-related difference (p < 0.05). Cysts were found in 64 of 217 females (29.5%) and 47 of 187 males (25.1%). While in both sexes, more cysts were found in liver, the liver/lung ratio in females was significantly higher than in males (p < 0.001). Hydatid cyst was verified in 59 (21.2%) of 278 lung surgeries: 27 of 105 females (25.7%) and 32 of 173 males (18.5%). There was a significant relationship between sex and organ site (p < 0.001) with the proportion of hydatid cysts in males occurring in lung higher than seen in females. In the five investigated years, approximately 25% of liver and lung surgeries conducted at Milad Hospital were related to hydatidosis. Increasing public awareness of principles of avoiding infection could reduce the risk of nearly a quarter of liver and lung surgeries and costs associated with the treatment of hydatid cysts.