CLINICAL AND MORPHOLOGICAL EVIDENCE OF THE EFFECTIVENESS OF HYDROGEN PEROXIDE (PERHYDROL) APPLICATION FOR THE RECURRENCE PREVENTION AFTER HYDATID CYSTECTOMY FOR HEPATIC ECHINOCOCCOSIS

Objective: Experimental and histological justification of the use of perhydrol to treat the residual cavity (RC) and recurrence prevention after hydatid cystectomy for hepatic echinococcosis (HE) Methods: The results of surgical treatment of 85 patients with HE were evaluated between 2010 and 2019. In all patients after hydatid cystectomy, RCs were treated with 33% perhydrol. The scolicidal activity of 33% perhydrol was tested in vitro when the latter acted on protoscoleces obtained during the operation. In addition, a histological examination of the fibrous capsule (FC) was performed before and after RC treatment with a perhydrol solution. Results: Following exposure to perhydrol, the protoscolices lost their characteristic round or oval shape with the translucence of the parenchymatous tissue and the disappearance of the calcareous corpuscles. Following 1-minute exposure to a perhydrol solution, scolex swelling was observed, followed by a decrease in size due to the "boiling" of the released gas bubbles, as a result of perhydrol decomposition to oxygen and water with release of heat. Following 1.5-minutes of exposure to perhydrol solution, significant destructive changes were observed: delamination and tegument integrity loss, free hooklets, protoscolices dissolution, which indicated the parasite's death. On RC histological tissue preparations, stratification and destruction of FC were noted. In the long-term follow-up period for operated patients, there were no cases of HE recurrence. Conclusion: In vitro studies have shown that the treatment of protoscoleces with perhydrol solution leads to destruction followed by dissolution of the germinal layer. The perhydrol penetration into the FC walls resulting in its stratification and destruction contributes to the disease recurrence prevention. Keywords: Hepatic echinococcosis, hydatid cyst disease (HCD), fibrous capsule, residual cavity, recurrence, scolex, morphological study.residual cavity, recurrence, scolex, morphological study.