Background: Cryptorchidism represents the most common endocrine disease in boys, with infertility frequently observed in unilateral as well as bilateral forms. In this study, we examined the role of Ad (dark) spermatogonia for fertility in cryptorchid boys. The hypothesis to be proven was that boys lacking Ad spermatogonia will develop infertility despite a successful orchidopexy at an early age. Methods: To estimate total sperm count, one of the most predictive parameters of male fertility, we analyzed the ejaculatein 218 cryptorchid men and correlated it with the developmental stage of their germ cells at the time of successful surgery. Results: Abnormal sperm concentration (<40 × 10⁶/ejaculate) was found in half of the patients under the study. 47.5% of unilateral and 78% of bilateral cryptorchid males had their sperm concentration in the infertility range according to the WHO standards. If transformation into Ad spermatogonia had occured, age-related differences in the fertility outcome was observed. The younger the unilateral cryptorchid boys were at surgery, the higher their sperm count. Age-related difference was not found in the group of cryptorchid men having had no A dark spermatogonia at time of surgery, indicating that in this group a successful orchidopexy is insufficient to prevent infertility development and, in particular, the development of azoospermia. Conclusion: The presence of Ad spermatogonia at surgery is an excellent prognostic parameter for future fertility. Cryptorchid boys lacking these cells will develop infertility despite successful orchidopexy at an early age.

Congenital abdominal wall defects are impressive and dramatic malformations. Common surgical therapy for omphalocele and gastroschisis is to place the herniated viscera back into the abdomen and to close the fascia. Small defects can be closed directly by surgical treatment. In large defects, resorbable and non-resorbable artificial materials are necessary to close the fascia. The aim of this study is to find out whether new biocompatible materials might be suitable for the treatment of such abdominal wall defects. A median laparotomy was performed in young Wistar rats with a body weight of 75-100 g. Then a full thickness defect was created by excising a 1.5 x 2.5 cm segment including fascia, muscles and peritoneum. These defects were then closed by implantation of a PTFE mesh (Dual-Mesh, n = 6), a PPP mesh (Prolene, n = 6) or a new biocompatible mesh (NBM; Lyoplant, n = 6). Each rat was examined daily after treatment. Bodyweight was determined and the possible development of a hernia was monitored. After 6 weeks, the abdomen was opened again. Adhesions to the intestine were measured and the abdominal wall was removed for histological and tensiometric examination. (1) Compared to the untreated controls, all animals showed physiologic growth and normal bodyweight curve. (2) Only in one rat (Prolene) did an abdominal hernia develop. (3) In contrast to PTFE and PPP mesh, NBM showed only minimal adhesion to the intestine. (4) Tensiometry revealed high stability for non-resorbable materials. However, the characteristics of NBM were very similar to untreated abdominal wall. Our initial results indicate that biocompatible materials can also be used for the therapy of congenital abdominal wall defects.

A xenogeneic extracellular matrix, such as Lyoplant, may induce an immune response which is predominantly TH2-like and comparable with a remodelling reaction rather than rejection.

The IONM of both RLN and EBSLN in adult surgery could be used successfully in paediatric surgery. In this study a clear and positive identification of both nerves was possible in all patients. Therefore the IONM of the RLN and EBSLN could develop into a successful and easy method for the prevention of intraoperative nerve damage during thyroid surgery in childhood and young adolescence. Assuming that a constant IONM signal represents a normal vocal cord, our evaluation showed that there is a small percentage of false negative and positive results.

62 cryptorchid boys aged 2–6 years were selected at random either for surgical or for hormonal LH-RH treatment. As all biopsies from boys operated show typical histological and ultrastructural signs of cryptorchidism, it can be concluded that only true cryptorchid patients are included in our study. LH-RH treatment was successful in 16 (55%) of 31 boys. Median 30-min response values to LH-RH test of LH were initially normal in all boys. Those treated successfully remain normal after treatment whereas unsuccessfully treated patients have significantly lower LH 30-min response values at the end of the 4 weeks of LH-RH treatment. FSH response was not statistically different before or after treatment. This might indicate that a normal LH response is necessary for testicular descent. In the 15 boys operated after 4 weeks of unsuccessful LH-RH treatment, testes biopsies show recruitment of the Leydig cell precursors and development of juvenile Leydig cells with an increase in their content of lipoid droplets and smooth endoplasmic reticulum. No adverse effect on the number of spermatogonia could be observed after 4 weeks of LH-RH treatment.