Henning C. Fiegel

Development of hepatic tissue engineering

Liver transplantation is still the only treatment for end-staged liver diseases in children. However, donor organ shortage and immunosuppression are major limitations. Thus, approaches of hepatocyte transplantation are under investigation. Using cells might permit mass expansion, cryopreservation, and the ex vivo genetic modification of cells. For the development of cell-transplantation techniques, the use of three-dimensional scaffolds as carrier was shown to be advantageous. Polymeric matrices permit the formation of a neo-tissue and stimulation by the modification of the matrix surface. Another important issue is to define the right cell type for transplantation. Adult hepatocytes have a limited growth and differentiation potential. In contrast, fetal liver cells (FLC) possess an enormous growth and a bipotential differentiation potential. Thus, these cells may be very attractive as a cell resource for developing cell-based liver replacement. A third major issue in this approach is the neo-vascularization. Therefore, the transplantation in a recently developed model using a microsurgically created arterioveno-venous (AV) loop as a central vessel for the neo-tissue was used for transplantation of FLC in a fibrin-matrix. Initial results indicated that the transplantation of FLC using the AV-loop transplantation model may be promising for the development of highly vascularized in vivo tissue-engineered liver support systems.

Tunneled central venous catheters in children with malignant and chronic diseases: A comparison of open vs. percutaneous implantation

PURPOSE Tunneled central venous catheters (tCVCs) are routinely used for long-term venous access in children with cancer and chronic diseases. They may be inserted by surgical venous cut-down or percutaneously. The aim of this study was to compare the operative times and intraoperative complications of both techniques. METHODS This study compared group A (surgical venous cut-down, years 2002-2006) with group B (percutaneous, years 2008-2012). Patient characteristics, operative times, and intraoperative complications were obtained from surgical reports. (IRB review and approval, number 6/15). Both Hickman/Broviac and Portacath catheters were included. RESULTS 343 patients in group A and 321 patients in group B were studied. Ages at implantation and underlying diagnoses were similar. Operative time was significantly shorter in group B. Only 60% of primarily dissected veins were suitable for surgical implantation, whereas successful vessel puncture was possible in 96% (87% on the first attempt, 9% on the second). Bleeding occurred in 2% of patients in group A, and pneumothorax occurred in 1.8% of patients in group B. Early catheter dislodgement was similar in both groups. CONCLUSION Percutaneous tCVC implantation is safe, less invasive, and faster than surgical implantation. Both techniques are feasible, and complication rates are low. LEVEL OF EVIDENCE Level III.

Embryology of the testicular descent.

Numerous researchers studied the morphology of the testicular descent, including the possible function of the gubernaculum. However, a clear illustration of this process is still missing. The aim of this paper was to illustrate the embryology of the testicular descent in the rat by scanning electron microscopy. In a first phase of the intra-abdominal testicular descent, the testis moves actively from the lower pole of the kidney towards the bladder neck. In a second inguinal phase the testis enters groin and moves in the developing processus vaginalis peritonei caused by the disappearance of the bulb of the gubernaculums testis.

The testicular descent in the rat: a scanning electron microscopic study

PurposeNumerous researchers studied the morphology of testicular descent including the possible function of gubernaculum. However, a clear illustration of this process is still missing. The aim of this study was to illustrate testicular descent using scanning electron microscopy (SEM) in a rat model.MethodsThe abdomen of rat fetuses between gestational day (E) 15 and E 22 and newborns at postnatal day (D) 0 and D 1.5 was opened by microsurgery. Standard preparation for SEM was carried out. The position of the testis and gubernaculum testis was documented.ResultsThe gubernaculum was obvious in male rat embryos at E 17.5. In a first phase (E 16–E 21) the testis moved from cranio-lateral and dorsal to caudo-medial and ventral, while clear signs of an active role of the gubernaculum were missing. In a second phase (E 22–D 1.5) the processus vaginalis peritonei (PVP) developed, while the conus of the gubernaculum disappeared, after which, the testis moved out of the abdominal cavity and entered the PVP.ConclusionIn our study, we could not specify the role of gubernaculum for testicular descent. However, our data showed that the testis lay intraperitoneal throughout the descensus testis.

Adenomyoma of the small intestine a rare pathological lead point for intussusception in an infant

IntroductionIntussusception is a typical abdominal emergency in early childhood.Case descriptionWe report a case of an infant in the typically affected age group with an intussusception triggered by a rare benign intramural intestinal adenomyoma as a pathological lead point. The infant had the typical symptoms of a recurrent idiopathic ileocolic intussusception.Discussion and evaluationIdiopathic intussusception is frequent in the infant age group. Contrary to that, reports on pathological lead points for intussusceptions are sparse in the toddler age.ConclusionsThat case illustrates that even in intussusceptions in the typically affected age group, it is important to be aware of pathological lead points, especially if the intussusceptions are recurrent.

Systematic review shows that pathological lead points are important and frequent in intussusception and are not limited to infants

Intussusception is the most clinically relevant cause of bowel obstruction in infancy and can be idiopathic or occur as a result of pathological lead points. The incidence of these pathological lead points varies from 0.3 to 20%, and they can be mucosal, intramural or extrinsic structures. A systematic literature review was performed from 1998 to 2016 to evaluate the incidence and types of pathological lead points in paediatric intussusception, and this identified 31 epidemiological and retrospective case cohort studies, reviews and case reports.