Experimental comparison of abdominal drainage systems.

BACKGROUND: In an experimental study the performance of different closed abdominal drainage systems was tested. METHODS: A vacuum bottle designed for Redon Drainage, a flexible plastic bulb designed for Jackson-Pratt drains and a V.A.C.® Negative Pressure Wound Therapy System were used. In a porcine cadaveric study mimicking the abdominal cavity the intrinsic pressure (IP) at one and three minutes (T0, T3) and the amount of evacuated fluid were measured. RESULTS: The Redon and Jackson drainage displayed a rapid decline to IP values of almost zero comparing T0 and T3. Only the V.A.C.® system was able to preserve constant values of negative IP values measured at both time points. Only the V.A.C.® system was able to remove almost the whole amount of inserted fluid. CONCLUSIONS: In an experimental setting the V.A.C.® system was superior to the other two tested systems in delivering constant negative IP and the amount of evacuated fluid.

Oxidized LDL Is Strictly Limited to Hyperthyroidism Irrespective of Fat Feeding in Female Sprague Dawley Rats.

Metabolic dysfunctions might play a crucial role in the pathophysiology of thyroid dysfunctions. This study aimed to investigate the impact of a controlled diet (normal versus high fat feeding) on hypothyroid and hyperthyroid Sprague Dawley rats. Female Sprague Dawley rats (n = 66) were grouped into normal diet (n = 30) and high-fat diet (n = 36) groups and subdivided into controls, hypothyroid and hyperthyroid groups, induced through propylthiouracil or triiodothyronine (T3) treatment, respectively. After 12 weeks of treatment metabolic parameters, such as oxidized LDL (oxLDL), malondialdehyde (MDA), 4-hydroxynonenal (HNE), the lipid profile, body weight and food intake parameters were analyzed. Successfully induced thyroid dysfunctions were shown by T3 levels, both under normal and high fat diet. Thyroid dysfunctions were accompanied by changes in calorie intake and body weight as well as in the lipid profile. In detail, hypothyroid rats showed significantly decreased oxLDL levels, whereas hyperthyroid rats showed significantly increased oxLDL levels. These effects were seen under high fat diet and were less pronounced with normal feeding. Taken together, we showed for the first time in female SD rats that only hyper-, but not hypothyroidism, is associated with high atherogenic oxidized LDL irrespective of normal or high-fat diet in Sprague Dawley rats.

Seamless vascularized large-diameter tubular collagen scaffolds reinforced with polymer knittings for esophageal regenerative medicine.

A clinical demand exists for alternatives to repair the esophagus in case of congenital defects, cancer, or trauma. A seamless biocompatible off-the-shelf large-diameter tubular scaffold, which is accessible for vascularization, could set the stage for regenerative medicine of the esophagus. The use of seamless scaffolds eliminates the error-prone tubularization step, which is necessary when emanating from flat scaffolds. In this study, we developed and characterized three different types of seamless tubular scaffolds, and evaluated in vivo tissue compatibility, including vascularization by omental wrapping. Scaffolds (luminal Ø âˆ¼ 1.5 cm) were constructed using freezing, lyophilizing, and cross-linking techniques and included (1) single-layered porous collagen scaffold, (2) dual-layered (porous+dense) collagen scaffold, and (3) hybrid scaffold (collagen+incorporated polycaprolacton knitting). The latter had an ultimate tensile strength comparable to a porcine esophagus. To induce rapid vascularization, scaffolds were implanted in the omentum of sheep using a wrapping technique. After 6 weeks of biocompatibility, vascularization, calcification, and hypoxia were evaluated using immunohistochemistry. Scaffolds were biocompatible, and cellular influx and ingrowth of blood vessels were observed throughout the whole scaffold. No calcification was observed, and slight hypoxic conditions were detected only in the direct vicinity of the polymer knitting. It is concluded that seamless large-diameter tubular collagen-based scaffolds can be constructed and vascularized in vivo. Such scaffolds provide novel tools for esophageal reconstruction.

Decellularized ovine esophageal mucosa for esophageal tissue engineering.

BACKGROUND: The success of a tissue engineered construct is greatly influenced by the choice of scaffold material. Decellularized esophageal matrix is a promising material for esophageal tissue engineering. The aim of this study was to develop a decellularized ovine esophageal mucosa and to investigate the effect of decellularization on the appearance of the resulting tissue. METHODS: Ovine esophagi were decellularized by combination of agitation, enzymatic digestion and treatment with 1 and 5% sodium dodecyl sulphate (SDS). Efficiency of decellularization was assessed by histological examination and DNA quantification. Finally, the effect of decellularization on tissue morphology was investigated by scanning electron microscopy. RESULTS: Decellularization resulted in a highly efficient removal of cells and DNA content. Electron microscopic investigation revealed a denuded, rough, undulating surface with preserved papillary structures. Individual papillae had a length of approximately 55 µm and were present at a density of 1332 µm/mm(2). Closer examination revealed a tightly packed sponge-like appearance with pores in the region of 300 nm. Numerous, intact collagen fibres were also visible. CONCLUSION: Ovine esophagus can be successfully decellularized through treatment with SDS. The resulting decellularized mucosal surface possesses a rough, 2D surface with a well preserved extracellular matrix. Such a material may be of advantage in tissue engineering of the esophagus. Characterisation of the papillary layer gives important insight into the suitability of decellularized esophageal mucosa for use in esophageal reconstruction and also provides morphological information which may help in the design of synthetic, biomimetic materials.

Effects of sodium hydroxide exposure on esophageal epithelial cells in an in vitro ovine model: implications for esophagus tissue engineering.

BACKGROUND: Esophagus tissue engineering holds promises for esophageal replacement after severe caustic injuries. The aim of this study was to determine whether viable esophageal epithelial cells could be isolated from an esophagus exposed to varying concentrations of alkali with regard to number, viability, and morphology during in vitro culture. METHODS: Ovine esophagi were exposed to phosphate-buffered saline 2.5%, 15%, or 25% sodium hydroxide (NaOH). The effect of NaOH concentrations on epithelial damage was assessed histologically. Esophageal epithelial cells were then isolated, and cell count and viability were investigated. Finally, cell number, viability, and morphology of esophageal epithelial cells were determined for 24 days of in vitro culture. RESULTS: Histologic analysis showed a progressive destruction of the epithelium proportional to increasing NaOH concentrations. Esophagi treated with phosphate-buffered saline and 2.5% NaOH showed significantly higher viable cell counts after isolation and culture in comparison with those treated with 15% to 5% NaOH. CONCLUSION: The evidence presented in this study indicates that epithelial biopsies from an esophagus exposed to low concentrations (2.5%) of NaOH will still yield large numbers of viable cells suitable for tissue engineering applications. In cases of exposure to higher concentrations (15%-25%), alternative cell sources for epithelial regeneration, such as stem cells, will be necessary for tissue engineering applications.

Evaluation of fractures in children and adolescents in a Level I Trauma Center in Austria.

BACKGROUND: Injury represents a major concern for children and adolescents worldwide. It is estimated that 10% to 25% of all pediatric injuries will result in fractures. This study aimed to analyze the epidemiology, gender distribution, age, and circumstances of fractures in childhood in a Level I Trauma Center in Austria. METHODS: Children managed with fractures between December 2004 and October 2006 were prospectively evaluated. Patients were divided into four age groups: infants (<1 year), preschool children (1-6 years), school-aged children (6-14 years), and adolescents (>14 years). RESULTS: The study included 3,339 patients younger than 19 years, who presented with 3,421 fractures. There was a male predominance (61.3%, n = 2,096). Girls (38.7%, n = 1,325) had a lower mean age at presentation of 8.2 years (boys, 9.8 years). An increase in the incidences of fractures was observed until a peak of 11 years in girls and 12 years in boys. A majority of fractures occurred in sports facilities (34.7%), followed by those at home (17.6%) and outdoors (16.7%). The most frequent mechanisms were falls on level surface (41.9%), falls from a height <3 m (23.2%), and involuntary contact with persons or objects (18.2%). The most common fractures were those of the distal radius (15.3%), followed by those of the finger (14%) and distal forearm fractures (8%). CONCLUSION: As the Department of Pediatric Surgery in Graz serves as the referral center at least for nearly all major pediatric fractures in the Austrian state of Styria, mechanisms and patterns of major fractures in this study can serve as the basis for state-wide pediatric injury prevention efforts. These prevention strategies should not aim to reduce the level of exposure but should increase the risk awareness and encourage children and their parents to use necessary precautions.

Esophagus tissue engineering: in situ generation of rudimentary tubular vascularized esophageal conduit using the ovine model.

PURPOSE: Esophagus replacement using the present surgical techniques is associated with significant morbidity. Tissue engineering of the esophagus may provide the solution for esophageal loss. In our attempts to engineer the esophagus, this study aimed to investigate the feasibility of generating vascularized in situ esophageal conduits using the ovine model. METHODS: Esophageal biopsies were obtained from lambs, and ovine esophageal epithelial cells (OEEC) were proliferated. The OEEC were seeded on to bovine collagen sheets preseeded with fibroblasts. After 2 weeks of maintaining the constructs in vitro, the constructs were tubularized on stents to create a tube resembling the esophagus and implanted into the omentum for in situ tissue engineering. The edges of the omentum were sutured using nonabsorbable suture material. The implanted constructs were retrieved after 8 and 12 weeks. RESULTS: The omental wrap provided vascular growth within and around the constructs as they were integrated along the outer surface area of the scaffold. After removal of the stents, the engineered conduit revealed a structure similar to the esophagus. Histologic investigations demonstrated esophageal epithelium organization into patches on the luminal side and vascular ingrowths on the conduit's outer perimeter. CONCLUSION: Our study demonstrated the seeding of OEEC on collagen scaffolds and formation of a rudimentary conduit resembling esophageal morphology after in situ omental implantation. Vascular coverage and ingrowth in the periphery of the construct could also be demonstrated. These findings hold future promise for the engineering of the esophagus with improved microarchitecture.

Culture of ovine esophageal epithelial cells and in vitro esophagus tissue engineering.

BACKGROUND: Esophagus replacement presents major surgical challenges both in the pediatric and in adult patients since the various surgical techniques presently employed are associated with complications and high morbidity. AIM: The aim of this study was to establish protocols for isolation and culture of ovine esophageal epithelial cells (OEEC) and to investigate their viability on collagen scaffolds for in vitro tissue engineering. METHODS: OEEC were sourced from adult Austrian mountain sheep. Briefly, the esophagus was dissected, treated with dispase to separate the epithelial layer, and further subjected to a modified explants technique to isolate OEEC. The OEEC were cultured in vitro and seeded on to unidirectional two-dimensional and three-dimensional collagen scaffolds. RESULTS: Successful protocol was established for OEEC isolation and culture. OEEC exhibited organization and differentiation after 7 days in culture, which was complete after 18 days with the formation of a single layer sheet of differentiated cells exhibiting morphology of mature esophageal epithelium. OEEC seeded on two-dimensional collagen scaffolds demonstrated viability up to 6 weeks of in vitro culture with single layer epithelium formation after 3 weeks confirmed using pan-Cytokeratin markers. OEEC on three-dimensional scaffolds were viable for 6 weeks but did not form an epithelium sheet. CONCLUSION: Protocols for OEEC isolation were developed and established from adult ovine esophageal tissue. The generation of sheets of esophageal epithelium in culture and the viability of OEEC on collagen scaffolds for 6 weeks in vitro was observed. The prerequisite for esophagus tissue engineering, which is the ability to form epithelium when seeded on collagen scaffolds, was demonstrated.

Fluorescence-activated cell sorting of PCK-26 antigen-positive cells enables selection of ovine esophageal epithelial cells with improved viability on scaffolds for esophagus tissue engineering.

OBJECTIVE: For esophagus tissue engineering, isolation and proliferation of esophageal epithelial cells (EEC) is a pre-requisite for scaffold seeding to create constructs. The aim of this study was to sort EEC expressing cytokeratin markers and their proliferative subpopulations; also, to investigate the viability of differentiated EEC subpopulations on collagen scaffolds. METHODS: Ovine esophageal epithelial cells (OEECs) from sheep esophagus were analyzed using flow cytometry for pan cytokeratin (PCK-26) and proliferation cell nuclear antigen (PCNA). Using fluorescent-activated cell sorting, OEEC were separated and analyzed for PCNA expression. The OEEC subpopulations were seeded on collagen scaffolds for a week in vitro culture. RESULTS: Proliferation cell nuclear antigen was expressed in >45% of OEEC isolated. In flow cytometry, 30% OEEC were PCK-26 positive which exhibited a high-proliferative capacity of 80%. PCK-26-negative OECC exhibited a low-proliferative capability of 13%. Scanning electron microscopy demonstrated organized attachment and uniform scaffold coverage in PCK-26-positive cells. CONCLUSION: Ovine esophageal epithelial cells can be divided into PCK-26-positive and negative subpopulations. PCK-26-positive OEEC constitute one-third of the isolated cells with high-proliferative capability. Seeding of PCK-26-positive OEEC on collagen scaffolds leads to uniform distribution of cells in vitro. In esophagus, tissue engineering PCK-26-positive OEEC subpopulation is important for optimal construct generation.

Esophagus tissue engineering: in vitro generation of esophageal epithelial cell sheets and viability on scaffold.

PURPOSE: Management of long gap esophageal atresia poses challenges. The surgical techniques for esophageal replacement are associated with complications and high morbidity. The aim of this study was to develop protocols to obtain single layer sheets of esophageal epithelial cells (EECs) and to investigate their survival on collagen scaffolds. METHODS: Esophageal epithelial cells were sourced from adult Sprague-Dawley rats. Briefly, the esophagus was treated with dispase to separate the epithelial layer and further trypsined to obtained EEC. The esophageal epithelial cells were cultured in vitro and seeded on to new generation of 3-dimensional collagen scaffolds. RESULTS: Esophageal epithelial cells organized after 48 hours in culture and formed clusters after 72 to 96 hours. Organization of the EEC was completed after 7 days in culture and characteristic sheets of EEC with the histologic morphology of mature esophageal epithelium were obtained after 14 days of culture. Immunohistochemistry demonstrated pure EEC culture using cytokeratin (CK-14) markers. The esophageal epithelial cells transferred on to collagen polymers demonstrated excellent viability after 8 weeks of in vitro culture. CONCLUSION: Successful protocols for EEC isolation and proliferation have been established. The engineering of sheets of EEC and the viability of EEC on collagen scaffolds for 8 weeks in vitro, which are prerequisites for esophagus tissue engineering, was demonstrated.

Analysis of 347 kindergarten-related injuries.

While it has been shown that non-parental child care is associated with a reduced risk for unintentional injuries, a considerable number of accidents in kindergartens do result in severe injuries. We have collected data on the behavioral and environmental aspects of accidents that occurred in kindergartens in Austria with the aim of determining possible prevention measures. Included in the study were all kindergarten-related injuries (347) from among 21,582 pediatric trauma cases treated in a 22-month period in Graz, Austria. Kindergarten-related injuries that were treated during the same period at six participating hospitals located throughout Austria were used for comparison. A questionnaire was completed at first attendance, and additional information was achieved by interviews with the parents and kindergarten teachers. Only the 347 kindergarten accidents that occurred in Graz were analyzed in detail. Half of the injuries occurred in an outdoor environment (outside), even though most of the time was spent indoors. Boys were more frequently involved in accidents than girls (male:female=3:2). We identified seasonal and circadian differences, with most children being injured during the first 2 months of attendance (September and October), during the first 3 days of the week (Monday to Wednesday) and in the hour before and after lunch, respectively. Of the 347 accidents analyzed, 24% resulted in serious injury, and injuries occurring outdoors were more severe than those occurring indoors. Most parents felt that the accidents were unpreventable (47%), while 18% stated that improved supervision may have prevented the accident. Kindergarten accidents in Austria still result in a significant number of severe injuries. Kindergarten injuries were related to gender, season, time of day and location. Our results indicate the necessity of a continuous child safety training program that involves the participation of all teachers in day-care functions.

Pin tract infection with external fixation of pediatric fractures.

BACKGROUND: This study aimed to evaluate the incidence and severity of pin tract infections in a series of pediatric trauma patients. METHODS: All pediatric trauma patients with external fixation who were treated at our institution between 1998 and 2003 were included. The charts of 30 children (20 males; 10 females; mean age, 13.2 years; range, 7-19 years) with 37 episodes of external fixation were reviewed. The average duration of external fixation was 17.5 weeks (range, 1-94 weeks). Pin tract infections were graded using the Dahl classification. Bacterial cultures were obtained in case of drainage from the pin site. RESULTS: In 18 (48%) of 37 external fixations, no signs of infection occurred during the treatment period. In the remaining 19 (52%) external fixations, 35 episodes of infection were documented. Most infections were mild or moderate, whereas only 3 (9%) severe deep infections were noted (grade 5). Six (17%) infections healed with local application of rifamycin, whereas 27 (77%) of 35 infections were successfully treated with systemic antibiotics (cefuroxime, clindamycin). The remaining 2 infections (6%) required removal of a pin. CONCLUSIONS: Pin tract infection occurred in half of the patients who were treated with external fixations. Most of the pin site infections in the present series were mild and could be managed by local or systemic application of antibiotics. The occurrence of pin tract infections did not require a change of the method of stabilization.

School accidents in Austria.

The aim of this study was to obtain information about the mechanisms and types of injuries in school in Austria. Children between 0 and 18 years of age presenting with injuries at the trauma outpatient in the Department of Pediatric Surgery in Graz and six participating hospitals in Austria were evaluated over a 2-year prospective survey. A total of 28,983 pediatric trauma cases were registered. Personal data, site of the accident, circumstances and mechanisms of accident and the related diagnosis were evaluated. At the Department of Pediatric Surgery in Graz 21,582 questionnaires were completed, out of which 2,148 children had school accidents (10%). The remaining 7,401 questionnaires from peripheral hospitals included 890 school accidents (12%). The male/female ratio was 3:2. In general, sport injuries were a predominant cause of severe trauma (42% severe injuries), compared with other activities in and outside of the school building (26% severe injuries). Injuries during ball-sports contributed to 44% of severe injuries. The upper extremity was most frequently injured (34%), followed by lower extremity (32%), head and neck area (26%) and injuries to thorax and abdomen (8%). Half of all school related injuries occur in children between 10 and 13 years of age. There are typical gender related mechanisms of accident: Boys get frequently injured during soccer, violence, and collisions in and outside of the school building and during craft work. Girls have the highest risk of injuries at ball sports other than soccer.

Management of acute scrotum in children--the impact of Doppler ultrasound.

BACKGROUND: Investigation of the value of scrotal Doppler ultrasound (DUS) in the diagnosis of acute scrotum and its impact on the treatment strategy was undertaken. METHOD: Seventy-nine children (mean age, 9.2 years) with acute scrotum were prospectively studied. The protocol included history, clinical examination, scrotal DUS, and standard laboratory analysis. Depending on scrotal DUS findings, the children were treated either nonoperatively (normal or increased testicular blood flow) or surgically (reduced or absent testicular blood flow). A follow-up investigation 6 weeks after discharge included a scrotal DUS. RESULTS: In 66 children (84%), the result of DUS determined the management; 26 children with hyperperfusion (epididymitis and orchitis), 18 children with appendix testis torsion (ATT), and 9 children with normal perfusion (edema and hematoma) were treated nonoperatively. The follow-up examination revealed no testicular atrophy and confirmed the primary diagnosis. Ten children without testicular perfusion and suspected torsion and 3 children with orchitis and pyocele were surgically explored, and again, the initial DUS diagnosis was verified. In the remaining 13 patients (16%), the result of the ultrasound examination was unclear. Of these, 6 children were noncompliant and refused to undergo ultrasonography. Another 4 children were explored because of persistence of symptoms. In 3 additional patients, a testicular tumor was suspected. All these 13 children underwent surgical exploration, revealing inflammation (epididymitis) in 6 children and acute ATT in 4 children, whereas the suspected tumor emerged as postacute ATT in 3 boys. CONCLUSION: In 84% of children with acute scrotal pain, the DUS was able to differentiate between surgical emergencies and other etiologies. In 16% of our pediatric patients, the DUS remained unclear, thereby necessitating surgical exploration.

Analysis of dog bites in children who are younger than 17 years.

OBJECTIVES: This study focuses on the pattern of incidence, mechanisms, and circumstances of accident and injury in a series of pediatric patients who sustained dog bites. METHODS: In our retrospective survey, the medical charts of all children who were younger than 17 years and sought medical attention after a dog bite between 1994 and 2003 were reviewed. To obtain the total number of each dog breed in the administrative district, we analyzed 5873 files from the community dog registers. For establishment of a risk index, the representation of a dog breed among the total canine population was divided by the frequency of dog bites from this breed. RESULTS: A total of 341 children (mean age: 5.9 years) were identified. The annual incidence of dog bites was 0.5 per 1000 children between 0 and 16 years of age. Incidence was highest in 1-year-old patients and decreased with increasing age. The relative risk for a dog attack by a German shepherd or a Doberman was approximately 5 times higher than that of a Labrador/retriever or cross-breed. The vast majority (82%) of the dogs were familiar to the children. Most (322; 94%) of the children had injuries to 1 body region; in the remaining 19 (6%) children, up to 3 body regions were injured. Of 357 injuries, the face, head, and neck region was the leading site affected (50%). Inpatient treatment was required in 93 (27%) patients. CONCLUSIONS: Dog bites in children are frequent and influenced by the breed-related behavior of dogs, dog owners, children, and parents. Therefore, prevention strategies should focus on public education and training of dogs and their owners. Children who are younger than 10 years represent the high-risk group for dog attacks.

Williams-Beuren syndrome associated with caudal regression syndrome and coagulopathy--a case report.

Williams-Beuren syndrome is a genetic disorder caused by a heterozygous deletion at 7q11.23. The present report describes a female patient with Williams-Beuren syndrome combined with caudal regression syndrome and two forms of coagulopathy. Besides the typical developmental abnormalities such as mental and growth retardation, a distinctive facial appearance, and cardiovascular anomalies, our patient showed fusion of fourth and fifth lumbar vertebra and a sacrococcygeal agenesis. Blood coagulation tests revealed a deficiency of coagulation factor XI and XII. Magnetic resonance imaging angiography showed multiple vascular stenoses mainly in the abdominal aorta and its major branches as a consequence of the insufficient elastin gene. Previous reports identified a deletion of HLXB9 as a possible genetic cause of the caudal regression syndrome, which could not be identified in the present case. This unusual combination of the above-mentioned genetic disorders has not been published so far.

The use of a hand-held metal detector for localisation of ingested metallic foreign bodies - a critical investigation.

UNLABELLED: Ingested metallic foreign bodies (MFBs) are usually diagnosed by taking X-ray films of the neck, chest and/or abdomen. This study evaluates the use of a hand-held metal detector (HHMD) for the diagnosis and localisation of MFBs. In a prospective study, 53 consecutive paediatric patients with history of a swallowed MFB were examined with X-rays and HHMD. In 47 children, the MFB could be verified radiologically. Coins were most frequently swallowed. The HHMD could detect and locate all coins but only 47% of other MFBs. There were no false-positive results. A HHMD is an effective tool for screening the location of suspected ingested coins. This method is easy, inexpensive and free of radiation. Very small MFBs cannot be reliably detected. CONCLUSION: If an innocuous metallic foreign body is clearly identified with a hand-held metal detector in the stomach or lower gastrointestinal tract of an asymptomatic child, additional radiological confirmation is not required.