Influence of surgical correction of inguinal hernia and hydrocele on testicular blood flow in children

Inguinal hernia and hydrocele affect the blood circulation of the testicle. Surgical trauma may change testicular blood flow. Objective. To study changes in blood flow parameters in children with pathology of the processus vaginalis, requiring surgical correction, using the analysis of ultrasound data. Materials and methods. We observed 87 boys from 3 to 17 years old, operated for congenital inguinal hernia and hydrocele. As a control group we examined 34 boys without pathology of the reproductive system. Patients held Doppler ultrasound the day before surgery, at 1 and 7 days after. Peak systolic flow velocity, end-diastolic flow velocity and resistance index were studied. Results. The resistance index on the affected side was higher compared with the control group before operation (p<0,05). The values of peak systolic and end diastolic blood flow velocities were lower than in the comparison group (p<0,05). Resistance index increased compared with preoperative period 1 day after surgery (p<0,05). Values of flow velocity parameters decreased to 4-9 % compared to values before the operation. The resistance index decreased (p<0,05) to near baseline figures a week after the operation. Peak systolic and end-diastolic flow velocity raised to 15-21 % compared to the preoperative period. However, the intensity of the blood flow in the affected testicle remained lower than in the control group (p<0,05). Conclusions. The blood flow of affected testicle in children with inguinal hernia and hydrocele is initially decreased. Early postoperative period is characterized by intensification of testicular parenchyma’s ischemia. Postoperative blood flow in the affected testicle is improved a week after surgery, but the lack of blood supply to the testicle is retained

Singularities of bi-Hamiltonian systems

We study the relationship between singularities of bi-Hamiltonian systems and algebraic properties of compatible Poisson brackets. As the main tool, we introduce the notion of linearization of a Poisson pencil. From the algebraic viewpoint, a linearized Poisson pencil can be understood as a Lie algebra with a fixed 2-cocycle. In terms of such linearizations, we give a criterion for non-degeneracy of singular points of bi-Hamiltonian systems and describe their types