A substantial body of evidence supports the use of extracorporeal shock wave therapy (ESWT) for fracture non-unions in human medicine. However, the success rate (i.e., radiographic union at six months after ESWT) is only approximately 75%. Detailed knowledge regarding the underlying mechanisms that induce bio-calcification after ESWT is limited. The aim of the present study was to analyse the biological response within mineralized tissue of a new invertebrate model organism, the zebra mussel Dreissena polymorpha, after exposure with extracorporeal shock waves (ESWs). Mussels were exposed to ESWs with positive energy density of 0.4 mJ/mm² or were sham exposed. Detection of newly calcified tissue was performed by concomitantly exposing the mussels to fluorescent markers. Two weeks later, the fluorescence signal intensity of the valves was measured. Mussels exposed to ESWs showed a statistically significantly higher mean fluorescence signal intensity within the shell zone than mussels that were sham exposed. Additional acoustic measurements revealed that the increased mean fluorescence signal intensity within the shell of those mussels that were exposed to ESWs was independent of the size and position of the focal point of the ESWs. These data demonstrate that induction of bio-calcification after ESWT may not be restricted to the region of direct energy transfer of ESWs into calcified tissue. The results of the present study are of relevance for better understanding of the molecular and cellular mechanisms that induce formation of new mineralized tissue after ESWT. Specifically, bio-calcification following ESWT may extend beyond the direct area of treatment.

Radical surgical resection of metastases is an important prognostic factor for survival of patients suffering from solid pediatric tumors. The aim of this study is to evaluate the efficacy of median sternotomy as treatment option for the resection of multiple bilateral lung metastases in children with different tumor entities. Furthermore, the sensitivity of preoperative imaging (CT) was assessed by intraoperative findings.

Between 2002 and 2007, thirteen children (4x sarcoma, 4x nephroblastoma, 5x hepatoblastoma) underwent median sternotomy for resection of bilateral lung metastases after R0 – resection of the primary tumor. In 6/13 cases, the sternotomy was combined with the primary tumor resection.

Median patients at the first operation age was 5 years (range: 11 months – 17 years). The median total number of resected metastases per operation was 9 and ranged from 0 to 65. In 13/16 operations, the intraoperative number of metastases did not agree with the preoperative radiological work-up. Median hospital stay was 14 days (range from 9 to 36 days). 10/13 children are alive after a median follow–up of 13 months (range from 6 to 66 months).

Median sternotomy is an adequate treatment modality for the resection of bilateral pulmonary metastases as a one stage procedure. The combination of primary tumor resection with sternotomy should be considered as treatment option. Complete resection of metastases of solid pediatric tumors should be aimed for in order to increase the survival of these patients.