Use of PLGA 90:10 scaffolds enriched with in vitro-differentiated neural cells for repairing rat sciatic nerve defects.

Poly(lactic-co-glycolic acid) (PLGA) nerve tube guides, made of a novel proportion (90:10) of the two polymers, poly(L-lactide): poly(glycolide) and covered with a neural cell line differentiated in vitro, were tested in vivo for promoting nerve regeneration across a 10-mm gap of the rat sciatic nerve. Before in vivo testing, the PLGA 90:10 tubes were tested in vitro for water uptake and mass loss and compared with collagen sheets. The water uptake of the PLGA tubes was lower, and the mass loss was more rapid and higher than those of the collagen sheets when immersed in phosphate-buffered saline (PBS) solution. The pH values of immersing PBS did not change after soaking the collagen sheets and showed to be around 7.4. On the other hand, the pH values of PBS after soaking PLGA tubes decreased gradually during 10 days reaching values around 3.5. For the in vivo testing, 22 Sasco Sprague adult rats were divided into four groups--group 1: gap not reconstructed; group 2: gap reconstructed using an autologous nerve graft; group 3: gap reconstructed with PLGA 90:10 tube guides; group 4: gap reconstructed with PLGA 90:10 tube guides covered with neural cells differentiated in vitro. Motor and sensory functional recovery was evaluated throughout a healing period of 20 weeks using sciatic functional index, static sciatic index, extensor postural thrust, withdrawal reflex latency, and ankle kinematics. Stereological analysis was carried out on regenerated nerve fibers. Both motor and sensory functions improved significantly in the three experimental nerve repair groups, although the rate and extent of recovery was significantly higher in the group where the gap was reconstructed using the autologous graft. The presence of neural cells covering the inside of the PLGA tube guides did not make any difference in the functional recovery. By contrast, morphometric analysis showed that the introduction of N1E-115 cells inside PLGA 90:10 tube guides led to a significant lower number and size of regenerated nerve fibers, suggesting thus that this approach is not adequate for promoting peripheral nerve repair. Further studies are warranted to assess the role of other cellular systems as a foreseeable therapeutic strategy in peripheral nerve regeneration.

Pediatric surgeons and gastroesophageal reflux.

BACKGROUND/AIMS: Better antacid medications and the introduction of laparoscopy destabilize the indications for fundoplication. This study aims at raising a discussion among pediatric surgeons on these indications, modalities, and the results of this operation. MATERIALS AND METHODS: A total of 252 refluxing children operated between 1992 and 2006 were divided into groups according to predominant symptoms (93 digestive, 47 respiratory, and 68 neurologic) or to comorbidities (27 esophageal atresia, 10 diaphragmatic hernia, 5 abdominal wall defects, and 2 caustic stricture), and the indications, complications, mortality, and long-term results were reviewed. Features of open (n = 135) and laparoscopic (n = 117) approaches were compared, and long-term integrity of the wrap was analyzed using the Kaplan-Meier method. RESULTS: Digestive, respiratory, and neurologic patients had more often laparoscopic plications, whereas all others rather had an open approach. The rate of complications was 22%, and they were more frequent in children operated by laparotomy (P < .05). Median follow up was 51.3 months (range, 6-160). Overall wrap integrity was maintained in 89% of the children, and the proportions for digestive, respiratory, and neurologic groups were 95%, 95%, and 87%, respectively. For esophageal atresia, congenital diaphragmatic hernia, abdominal wall defects, and caustic stricture, they were 72%, 77%, 100%, and 0%, respectively. The functional results were fully satisfactory in 83% of patients. There were 17 deaths (6.7%), but only 3 in the first postoperative month and only 1 related to the operation (0.4%). CONCLUSIONS: Fundoplication is a powerful method of reflux control. It is indicated after failure of medical treatment in gastroesophageal reflux disease and in symptomatic refluxers with some particular comorbidities. Surgery should be offered only after diagnosis has been firmly established, and the indications must remain identical for open and laparoscopic procedures. High technical standards and rigorous report of the results are required for keeping a relevant place of pediatric surgery in the treatment of this disease.

Teratomas of the neck and mediastinum in children.

This retrospective study reviews a series of teratomas of the neck and mediastinum aiming at defining the features of these particular locations. We recorded prenatal diagnosis, perinatal management, clinical and radiologic features, pathology, surgical strategies and results in cervical and mediastinal teratomas treated over the last 10 years. During this period we treated 66 children with teratoma of which 11 (6 male and 5 female) had cervicomediastinal locations. Five babies had cervical teratomas extended into the anterior mediastinum in two cases. Prenatal diagnosis was made in three (two with polyhydramnios). Four babies were born by C-section and only one had a successful EXIT procedure. The diagnosis was confirmed by imaging and increased AFP. Surgical treatment involved total tumor removal and in one case subsequent removal of lymph node metastases. All children survived except one in whom airway could not be cleared at birth. Two children bear mild hypothyroidism. During the same period six patients aged 0-17 years were treated for mediastinal teratoma. Only one was prenatally diagnosed and only two had some dyspnea. Removal was performed either by median sternotomy, thoracotomy, or thoracoscopy. They all survive and are free of disease. Teratomas of the neck may cause fetal disease and unmanageable neonatal airway obstruction. Prenatal diagnosis and planned multidisciplinary management are mandatory at birth. In contrast, only some mediastinal tumors cause respiratory embarrassment. Although benign, these tumors are sometimes immature and may metastasize to regional lymph nodes. Total surgical removal is curative. Thyroid insufficiency may be present at birth in cervical teratomas and may be aggravated by surgery.