Tracheoplasty with cartilage-engineered esophagus environments.

PURPOSE: Our objective was to investigate the feasibility of engineering cartilage on the esophagus layer and outside the esophagus. Moreover, we investigated the feasibility of tracheoplasty with cartilage engineered on the esophagus in rabbits. METHODS: Chondrocytes were isolated from auricular cartilages. 1. Engineered cartilage formation by histological findings on/into the esophageal layer was compared with that of injectable scaffold and preformed scaffold with chondrocytes. 2. Chondrocytes adhered to gelatin+vicryl mesh™ and b-FGF, were implanted on the outer esophageal surface. Four weeks after seeding, we found that cartilage was implanted in the midposterior portion of the cervical trachea (n=5), and it was retrieved 8weeks after seeding. RESULTS: 1. A gelatin sponge incorporating ß-TCP with vicryl mesh™ showed the best performance for fabricating engineered cartilage on the outer side of the esophagus. 2. Two of 5 rabbits died due to obstructed esophagus. Cartilage engineered outside the esophagus by a composite scaffold as the main material in the gelatin sponge, maintained the airway structure for up to 1month after implantation. Tracheal epithelial regeneration occurred in the internal lumen of this engineered cartilage. CONCLUSION: Tracheoplasty with cartilage engineered outside the esophagus may be useful for reconstructing airways.

Optimal amount of basic fibroblast growth factor in gelatin sponges incorporating ß-tricalcium phosphate with chondrocytes.

BACKGROUND: A gelatin sponge with slowly releasing basic fibroblast growth factor (b-FGF) enhances chondrogenesis. This study investigated the optimal amount of b-FGF in gelatin sponges to fabricate engineered cartilage. MATERIALS AND METHODS: b-FGF (0, 10, 100, 500, 1000, and 2000 µg/cm(3))-impregnated gelatin sponges incorporating ß-tricalcium phosphate (ß-TCP) were produced. Chondrocytes were isolated from the auricular cartilage of C57B6J mice and expanded. The expanded auricular chondrocytes (10×10(6) cells/cm(3)) were seeded onto the gelatin sponges, which served as scaffolds. The construct assembly was implanted in the subcutaneous space of mice through a syngeneic fashion. Thereafter, constructs were retrieved at 2, 4, or 6 weeks. RESULTS: (1) Morphology: The size of implanted constructs was larger than the size of the scaffold with 500, 1000, and 2000 µg/cm(3) b-FGF-impregnated gelatin sponges incorporating ß-TCP at 4 and 6 weeks after implantation. (2) The weight of the constructs increased roughly proportional to the increase in volume of the b-FGF-impregnated scaffold at 2, 4, and 6 weeks after implantation, except in the 2000 µg/cm(3) b-FGF-impregnated constructs group. (3) Histological examination: Extracellular matrix in the center of the constructs was observed in gelatin sponges impregnated with more than 100 µg/cm(3) b-FGF at 4 weeks after implantation. The areas of cells with an abundant extracellular matrix were positive for cartilage-specific marker type 2 collagen in the constructs. (4) Protein assay: Glycosaminoglycan and collagen type 2 expression were significantly increased at 4 and 6 weeks on implantation of gelatin sponges impregnated with more than 100 µg/cm(3) b-FGF. At 6 weeks after implantation, the ratio of type 2 collagen to type 1 collagen in constructs impregnated with 100 µg/cm(3) or more b-FGF was higher than that in mice auricular cartilage. CONCLUSION: Gelatin sponges impregnated with more than 100 µg/cm(3) b-FGF incorporating ß-TCP with chondrocytes (10×10(6) cells/cm(3)) can fabricate engineered cartilage at 4 weeks after implantation.

The junction between hyaline cartilage and engineered cartilage in rabbits.

OBJECTIVES/HYPOTHESIS: Tracheoplasty using costal cartilage grafts to enlarge the tracheal lumen was performed to treat congenital tracheal stenosis. Fibrotic granulomatous tissue was observed at the edge of grafted costal cartilage. We investigated the junction between the native hyaline cartilage and the engineered cartilage plates that were generated by auricular chondrocytes for fabricating the airway. STUDY DESIGN: Controlled, prospecive study. METHODS: In group 1, costal cartilage from New Zealand white rabbits was collected and implanted into a space created in the cervical trachea. In group 2, chondrocytes from auricular cartilages were seeded on absorbable scaffolds. These constructs were implanted in the subcutaneous space. Engineered cartilage plates were then implanted into the trachea after 3 weeks of implantation of the constructs. The grafts in group 1 and 2 were retrieved after 4 weeks. RESULTS: In group 1, histological studies of the junction between the native hyaline cartilage and the implanted costal cartilage demonstrated chondrogenic tissue in four anastomoses sides out of the 10 examined. In group 2, the junction between the native trachea and the engineered cartilage showed neocartilage tissue in nine anastomoses sides out of 10. CONCLUSIONS: Engineered cartilage may be beneficial for engineered airways, based on the findings of the junction between the native and engineered grafts.

Slow release of basic fibroblast growth factor (b-FGF) promotes growth of tracheal cartilage.

PURPOSE: Tracheomalacia is a major cause of morbidity in conditions such as oesophageal atresia. However, symptoms usually improve with age. A more rapid growth of tracheal cartilage can be induced by basic-Fibroblast Growth Factor (b-FGF). This study aimed to investigate whether slow-release b-FGF could act as a novel treatment for tracheomalacia. METHODS: Biodegradable gelatin hydrogel sheets incorporating 0.5, 5, or 50 µg/20 µl of b-FGF solution were inserted between the cervical trachea and esophagus of rats. No intervention was performed in rats in a control group. All animals were sacrificed 4 weeks later, and the luminal area of the cervical trachea and the thickness of the cartilage were measured. RESULTS: The mean luminal areas in the control group and in the b-FGF groups were 3.1, 3.2, 3.8, and 2.6mm(2), respectively, and showed a peak area at 5 µg of b-FGF. A significant difference was seen only between the control group and the b-FGF 5 µg group (p<0.05). The mean thickness of the tracheal cartilage was 0.12, 0.13, 0.19, and 0.32 mm in the control and the b-FGF groups, respectively, and showed a dose-dependent increase, which was statistically significant between the b-FGF 5 µg or 50 µg groups and the control group (p<0.01). CONCLUSION: This study showed that slow-release b-FGF enlarges the tracheal lumen and thickens the cartilage in a dose-dependent fashion.

Visceral coverage with absorbable mesh followed by split-thickness skin graft in the treatment of ruptured giant omphalocele.

We report a case of ruptured giant omphalocele in whom herniated organs were successfully covered by an absorbable mesh and a subsequent skin graft. A 2,200 g male baby was born at 35 weeks of gestation. An abdominal wall abnormality was detected by prenatal ultrasound at 21 weeks of gestation. At birth, the entire liver, stomach, and small and large bowel had herniated from the defect of the abdominal wall. The thorax and abdomen were highly underdeveloped, and attempts to reduce the organs into the abdomen were unsuccessful due to the extremely small abdominal cavity and associated pulmonary hypoplasia. To protect the herniated organs and prevent abdominal infections, the organs were covered by a polyglycan mesh and subsequently a meshed split-thickness skin graft. Ten weeks later, it was confirmed that the organs were completely covered by epithelialized tissue. However, the patient suffered from frequent respiratory infections and finally died of respiratory insufficiency. Based on the experience of the patient, we conclude that coverage of the herniated organs with an absorbable mesh and a skin graft is a recommendable treatment in ruptured giant omphalocele.

Splenic autotransplantation for a congested and enlarged wandering spleen with torsion: report of a case.

In children with diseases of the spleen, every effort should be made to preserve the organ, to prevent severe infections postsplenectomy. We report the case of a 7-year-old girl with torsion of a wandering spleen who we treated by autotransplantation of splenic tissues following splenectomy, when fixation of the enlarged spleen seemed impossible. Spleen scintigraphy showed uptake in the regenerating splenic tissues 9 months after surgery, and evidence of an increase in the size of the tissues 23 months after surgery. Howell-Jolly bodies had disappeared by 16 months after surgery. These findings suggested that the transplanted splenic tissues were resuming splenic functions. Based on our experience with this case, we conclude that autotransplantation after splenectomy is a treatment option for wandering spleen with torsion when fixation seems difficult because of splenic congestion and enlargement.

Efficacy of granulocyte apheresis in pediatric patients with ulcerative colitis: a pilot study.

OBJECTIVES: Granulocyte apheresis (GCAP), involving the removal of granulocytes from the blood, may improve clinical symptoms and facilitate a reduction in the dose of steroids in adult patients with ulcerative colitis. As a preliminary trial, GCAP was used to taper the dose of steroids in 4 pediatric patients with ulcerative colitis. METHODS: Three males and 1 female ranging from 11 to 17 years old were treated with GCAP once per week for 5 consecutive weeks/course. The ages of patients at clinical onset ranged from 8 to 12 years and the length of time from the clinical onset to GCAP treatment ranged from 28 to 58 months (median, 38.5 months). RESULTS: In 2 patients, symptoms and signs indicating disease activity improved after 2 courses of GCAP. Laboratory data and endoscopic findings also improved after treatment and the clinical efficacy was judged to be excellent in these patients. In 1 patient, GCAP improved laboratory and endoscopic hallmarks, but bloody stools persisted. Finally, the treatment was ineffective in the fourth patient who eventually underwent surgery. CONCLUSIONS: GCAP is effective in improving clinical symptoms and may play an important role in converting steroid therapy to other treatments in children with steroid-refractory or steroid-dependent ulcerative colitis.

Clinical characteristics and surgical treatment of perianal and perineal rhabdomyosarcoma: analysis of Japanese patients and comparison with IRSG reports.

Rhabdomyosarcomas of the perianal and perineal regions are uncommon. This study was performed to clarify the clinical characteristics and guidelines of surgical treatment of patients with perianal and perineal rhabdomyosarcomas younger than 20 years of age. Twenty-nine patients, 26 patients identified in the Japanese literature and three of our own, were analyzed and the results were compared with the data reported from the Intergroup Rhabdomyosarcoma Study Group (IRSG). Female predominance and a twin-peak age distribution in infancy and adolescence were characteristic findings of the Japanese patients that were not observed in the IRSG studies. The demographic differences between the two groups were attributed to the differences in demographics of patients younger than 10 years of age. Of the 29 patients, 17 were categorized into clinical groups III/IV and 21 patients into stages 3/4. Alveolar histology was diagnosed in 18 patients. In patients more than 10 years of age, the female predominance was more prominent and the incidences of advanced clinical groups/stages and alveolar histology were significantly higher than those in patients younger than 10 years of age. Inguinal lymph nodes were always involved in patients with lymph node metastases and three patients developed metastases to the breast. Information regarding the survival time was available for 18 patients and the 5-year overall survival was 20%. Two patients with a group I/stage 2 tumor and one with a group II/stage 3 tumor survived for more than 2 years with no evidence of the disease. In these patients, the tumors were excised by primary surgery or primary reexcision and they were not accompanied by lymph node metastasis. Based on these data, complete tumor resection prior to chemotherapy should be pursued and the inguinal lymph nodes should be at least sampled because nodal involvement is closely associated with the patient's prognosis.

Secretion and expression of epithelial markers supports the biliary origin of solitary nonparasitic cyst of the liver in infancy.

Solitary nonparasitic cyst of the liver (SNPCL) is rare in children. Although there are several hypotheses regarding the pathogenesis, the true origin of SNPCL remains unknown. The authors present an infant with a huge SNPCL in whom the epithelial markers, CA19-9, DU-PAN-2, and SPan-1, were elevated in the serum and cystic fluid. The presence of CA19-9 and DU-PAN-2 was shown by immunohistochemistry in the cystic epithelia. These indicate that the classical idea of biliary origin of SNPCL is supported.