Onset of vertical bonds in new GaN multilayers: beyond van der Waals solids.

A suspended single layer of GaN in a honeycomb structure is stable in a planar geometry. By stacking these GaN layers one can construct bilayers or multilayers, even new three-dimensional (3D) periodic structures. In this study, we clarified how the planar layers are buckled with the onset of vertical Ga-N bonds. Among the four stable phases of bilayer GaN, only one of them maintains the planar geometry, which is bound by weak van der Waals interactions. For the remaining three phases, the layers are buckled with the onset of weak vertical bonds, and attain total energies slightly lower than that of the planar geometry. Structural phase changes, as well as direct-indirect band transitions take place under strain and electrostatic charging. The vertical bonds become shorter in multilayers, and eventually attain the bulk value. Among the stable phases of 3D periodic GaN, only one with a graphite-like structure behaves as a layered, van der Waals solid; whereby others are 3D uniform crystals beyond the van der Waals solid.

Management of high-grade renal injury in children.

INTRODUCTION: The management of severe renal trauma is disputable. Herein, we present diagnosis and treatment of patients with high-grade renal injury (grades IV and V). MATERIALS AND METHODS: The records of 31 patients with severe renal trauma who were treated between 2009 and 2014 were analyzed retrospectively. All patients' CT results were evaluated by two radiologists and assigned grades of IV or V in accordance with the American Association for the Surgery of Trauma Organ Injury Severity Scale. All hemodynamically stable renal trauma patients were treated conservatively. Patients with renal traumas of grade IV and V were evaluated statistically via the SPSS 15.0 software program. Chi-square and Mann-Whitney U tests were used to evaluate the categorical data. RESULTS: Thirteen (42 %) of 31 patients had grade IV, and 18 (58 %) had grade V renal traumas. Twenty-seven (87 %) of the patients had suffered blunt trauma, and four (13 %) had sustained penetrating injuries. Additional organ injuries were seen in 16 patients (52 %), and 15 (48 %) had no concurrent injuries. Twenty-five patients (89 %) were monitored conservatively, three (10 %) underwent surgery, and three patients with grade V renal trauma and additional organ injuries died. There was no statistically significant difference between the grade IV and grade V groups, except in hemoglobin values and the affected kidney (P = 0.07 and P = 0.02, respectively). CONCLUSIONS: Computerized tomography can help to grade renal injury and assess additional organ injuries quickly. Most children with high-grade renal injury can be managed conservatively. However, conservative management of renal traumas relies on a multidisciplinary approach. Additionally, surgical intervention is generally required in the face of hemodynamic instability or other concurrent organ injuries.

Gastrointestinal tract duplications in children.

AIM: Gastrointestinal tract duplications (GTD) are rare congenital abnormalities that can occur anywhere along the gastrointestinal tract. These anomalies may present as a single, multiple, or a vague pathologies. Diagnosing and treating these diseases may be difficult in some patients. We aimed to present 32 patients who were followed and treated in our clinic. PATIENTS AND METHODS: This study included the patients between 2000 and 2013. Evaluations included clinical presentations, diagnostic strategies and algorithms, surgical procedures and associated anomalies, and presence of ectopic tissue, complications, and prognosis. RESULTS: Common clinical presentations included vomiting (n=8; 25%), palpable abdominal mass (n=4; 13%). Twenty-eight patients (2 of them antenatally) were diagnosed preoperatively while four of them were diagnosed at surgery. Ileal duplications constituted the most common type (34%) while the least common ones were located in appendix, thoracoabdomen and rectum. One of our patients was present with a gastric duplication which was closely interconnected to a tubular duplication of esophagus, which had never been encountered in the literature before. CONCLUSIONS: It is crucial to note that duplications are likely to occur in various types and numbers and also may accompany other anomalies. Computed Tomography (CT) remains the method of choice since Magnetic Resonance (MR) is likely to cause the use of sedation and analgesia at very young ages and it may also be relatively costly despite being more sensitive in soft tissues. Mucosal stripping is an ideal method for the patients requiring restricted surgery. The antenatal asymptomatic cases can be operated after their 6th months of age.

Social factors associated with pulmonary hydatid cyst in Aegean, Turkey.

BACKGROUND: Pulmonary hydatid cysts are caused by larval forms of the tapeworm Echinococcus granulosus. Hydatid disease, which is endemic in Turkey, is an important health problem in agricultural and stockbreeding areas where there are insufficient environmental health and preventive medicine services. Previous studies on this topic reported that hydatid disease was frequently associated with stockbreeding in rural areas. OBJECTIVES: In this retrospective clinical study, it is aimed to evaluate the social factors associated with pulmonary hydatid cyst in the Aegean region of Turkey. METHODS: Seventy-one pulmonary hydatid cyst cases reported between 1998 and 2010 in four hospitals in the Aegean region for which data were available on social and lifestyle factors were reviewed. RESULTS: In contrast to expectations, we found that pulmonary hydatid disease in the Aegean region was associated with city rather than rural life and with occupations other than stockbreeding. CONCLUSION: The findings are attributed to the presence of uncontrolled dogs in the city and urban environmental pollution. The offices of the public administration have a responsibility to inform citizens about the control of street animals, environmental health, and food hygiene.

Primer hydatid cyst of thymus: report of a case.

Cystic lesions in the mediastinum constitute one-fourth of all mediastinal masses and are usually identified incidentally. However, hydatid cysts very rarely present in the mediastinum. A 13-year-old male patient was admitted to our hospital because of chest pain and cough. A chest roentgenogram and computed tomography examination found a homogeneous cystic lesion with a size of 7.5 x 7 cm in the anterior mediastinum. Thymectomy was performed following a left thoracotomy in order to complete the pericystectomy. The histological diagnosis was hydatid cyst. No recurrence was observed during 1 year of follow-up.

Intrathoracic migration of ventriculoperitoneal shunt: a case report.

INTRODUCTION: Intrathoracic migration of ventriculoperitoneal shunt can be transdiaphragmatic or supradiaphragmatic. This complication causes important respiratory symptoms. CASE PRESENTATION: A 7 year-old Caucasian female, hospitalized with the prediagnosis of pneumonia, was determined to have ventriculoperitoneal shunt migration at left hemithorax. A left thoracotomy was performed and the shunt was successfully removed transdiaphragmatically. CONCLUSION: The patients with intrathoracic migration of ventriculoperitoneal shunt must be treated surgically as soon as possible. Transdiaphragmatic surgical approach would be more suitable from the point of surgical easiness.

Bax, bcl-2 and c-kit expression in non-small-cell lung cancer and their effects on prognosis.

In non-small-cell lung cancer (NSCLC), stage of the disease is still the most important prognostic factor. Other than stage, many biological markers and many other prognostic factors are studied to define their effects on prognosis of lung cancer. In this study, we aimed to evaluate the expressions of Bax and bcl-2 genes which are important in apoptosis and c-kit, which is a tyrosine kinase transmembrane receptor, as well as searched their response to treatment modalities and effects on survival. Sixty-nine NSCLC cases' pathological samples were stained with specific Bax, bcl-2 and c-kit dyes by immunohistochemical (IHC) methods. IHC evaluation was done by the semichantitative method according to the distribution and intensity of the staining. Twelve of 69 cases (17.4%) were stage I, 28 (40.5%) were stage II, 17 were (24.6%) stage IIIA, nine cases were (13.1%) stage IIIB and three cases (4.4%) were stage IV patients. Their histological subtypes were as follows: of 69 cases, 36 (52.2%) were squamous cell carcinoma, 28 (40.6%) were adenocarcinoma, five (7.2%) were adenosquamous cell carcinoma (two patients) and large-cell carcinoma (three patients). The positive immunostaining rates for Bax and bcl-2 in whole group, squamous cell carcinoma and adenocarcinoma groups were 40.6%/36.2%, 55.6/69.4% and 25.0/0.0%, respectively. The positive immune staining rates for c-kit in whole group, squamous cell carcinoma and adenocarcinoma groups were 7.2, 5.6 and 7.1%, respectively. We didn't find any correlation with Bax, bcl-2 and c-kit expressions and clinicopathological parameters such as age, tumour size, lymph node involvement, smoking, stage of the disease, response to radiotherapy and chemotherapy. Results are interpreted according to survival; bax and bcl-2 expressions were not so effective both in whole group and histologically subgrouped patients. C-kit expression was also found not related with survival in whole group whereas found as a bad prognostic factor in patients with squamous cell carcinoma. These findings could indicate that the expression of apoptotic pathway markers and c-kit may have a role in the prognosis of early stage NSCLC, especially with squamous cell carcinoma subtype.

Prognostic factors in limited-stage small cell lung cancer of patients treated with combined modality approach.

PURPOSE: To evaluate the combined modality treatment results of patients with limited-stage small cell lung cancer (SCLC), who were treated and followed by the DELCSG. PATIENTS AND METHODS: Sixty-three patients with limited-stage SCLC diagnosed between April 1991 and December 2002 were included. All patients were treated with combined chemotherapy and thoracic radiotherapy. Median age was 59 years (range 36-84), and all patients were male except 4. Surgery was performed for diagnosis in 3 patients. Four cycles of chemotherapy (median) were administered, composed of cisplatin-etoposide (CE) (26 patients), cyclophosphamide-vincristine-adriamycin (CAV) (10 patients) or alternated CE and CAV (18 patients). Nine patients received various chemotherapy regimes other than CE and/or CAV. A total dose of 5000 cGy with 180-200 cGy daily fractions was given to the primary tumor and mediastinum, excluding the spinal cord after 4500 cGy. Prophylactic cranial irradiation (PCI) was performed in 13 (20%) patients. Overall survival (OS) and progression-free survival (PFS) were calculated, beginning from the date of diagnosis and the end of radiotherapy, respectively. Kaplan-Meier method was used for obtaining survival rates. Log-rank test and Cox proportional hazards model were used for univariate and multivariate analyses, respectively. RESULTS: Median follow-up time was 17 months (range 3-131). Median PFS and OS were 12 (range 1-131) and 17 (range 3-131) months, respectively. Two-years PFS and OS rates were 27 % and 38 %, respectively. During follow-up, 27 (43%) patients developed brain metastasis; among them only 3 had received PCI. Univariate analysis showed that addition of PCI significantly improved PFS (p=0.025) and advanced age was a favorable prognostic factor for OS (p=0.039). In the multivariate analysis, advanced age (p=0.034) and addition of PCI (p=0.004) were independent factors increasing PFS, however no significant prognostic factor influencing OS was found. CONCLUSION: Our treatment results are in accordance with the relevant literature. It is also concluded that PCI should be given to all patients with complete response to chemotherapy. However, analysis of prognostic factors should be cautiously evaluated because of small number and heterogeneous distribution of patients in subgroups. Prospective studies are necessary for better determination of prognostic factors.

Primary hydatid disease of the chest wall: a case report.

Primary hydatid disease of the chest wall is extremely rare. We report a case of a primary chest wall hydatid cyst in a 72-year old woman who had not been operated on before for hydatid disease. Chest wall hydatid disease should be considered in the differential diagnosis of chest wall mass.

Surgical treatment of pulmonary hydatid cysts in children: report of 66 cases.

AIM OF THE STUDY: Hydatid disease is a parasitic infestation which is endemic in many sheep and cattle raising areas and is still an important health problem in the world. The aim of our study was to present our surgical experience and strategy in the management of pulmonary hydatid disease. METHODS: Sixty-six patients with 83 pulmonary hydatid cysts underwent surgical treatment in our institution between January 1990 and March 2003. We used double-lumen endotracheal tubes in children older than 12 years who were operated on for hydatic cyst in the last 8 years. RESULTS: There were 38 boys and 28 girls with a mean age of 9.6 +/- 7 years (range 5-15 years). Of the 83 cysts, 61 were intact and 22 were ruptured cysts. Isolated pulmonary hydatid cyst was seen in 61 patients (92.4 %), while 5 patients (7.6 %) had combined pulmonary and hepatic cysts. Lateral thoracotomy was performed in 54 patients (82 %), thoracophrenotomy in 5, bilateral thoracotomy in 4, and median sternotomy in 3 patients. Cystotomy and capitonnage was performed in 58 cysts, cystotomy alone in 21, and resection techniques were used in 4. There were 8 postoperative complications in 7 patients. The most common complication was atelectasis. CONCLUSIONS: Surgery is the treatment of choice for most patients with pulmonary hydatid cysts. The usage of double-lumen tubes may decrease intra- and postoperative complications. Thoracophrenotomy can be chosen as the surgical procedure in the management of hepatic and pulmonary hydatid cysts.

Non-operative management of isolated solid organ injuries due to blunt abdominal trauma in children: a fifteen-year experience.

The purpose of this study was to evaluate essential prerequisites for a selective non-operative approach in children with solid organ injuries due to blunt abdominal trauma, and to determine the predictive value of two different trauma scoring systems: the Injury Severity Score (ISS) and the Paediatric Trauma Score (PTS). A retrospective review of children who were admitted with blunt abdominal solid organ injuries to a paediatric trauma centre between January 1986 and September 2001 was performed. Hepatic, splenic, and renal injuries were graded, based on the American Association for the Surgery of Trauma (AAST) Organ Injury Scale (ranged from grade I to IV). The patients were treated non-operatively or operatively and the two groups were compared for variables such as age, blood transfusion, ISS, PTS, length of hospitalisation, morbidity and mortality rate. Two hundred and five patients (147 boys and 58 girls) entered in this study. Median age was 7 years (1 - 15 yrs). The most common cause of trauma was falls (50%). Abdominal organ injuries were present in all patients with the spleen as the most commonly injured organ (111 patients). Fifty-one patients (32%) had additional extra-abdominal organ injuries. Thirty-five (17%) patients were treated operatively, while 170 (83%) were treated non-operatively. Post-traumatic complications developed in 10 patients treated operatively versus 4 patients treated non-operatively. Four patients died due to multiple organ failure (2 non-operative, 2 operative). When compared to the non-operative group, higher transfusion requirements (p < 0.05), a higher ISS (p < 0.01), lower PTS values (p = 0.0001), a longer hospitalisation period (p = 0.0001), and a higher complication rate (p < 0.05) were observed in the operative group. In addition, the non-operative treatment approach was more common in the last five years compared to the previous ten years (p = 0.002). In conclusion, the appropriate non-operative management of injured children reduces the risks of blood transfusion and decreases the length of hospital stay compared with a surgical approach. The use of physiological parameters and radiological findings may be sufficient criteria for observing haemodynamically stable patients with isolated abdominal organ injuries, and thus intensive care unit costs may be avoided. In addition, a careful and close follow-up is essential in injured patients with a low PTS or high ISS.

Management of anorectal injuries in children: an eighteen-year experience.

Anorectal injuries (ARI) are rare in childhood and yet occur due to sexual abuse and firearm injuries in developed countries. The labeling of ARI remains controversial in spite of a number of divergent reports over the past decade. We evaluated the surgical indications for primary repair of ARI without stoma, and also the potential risk factors affecting morbidity and mortality in children with ARI. Between 1983 and 2001, 41 children were diagnosed as ARI in our institution due to blunt or penetrating trauma. There were 17 male and 24 female patients. Causes of anorectal injury were blunt injuries in the majority of cases (56 %). Vagina and extremity fractures were the organs most frequently associated with ARI. There was isolated ARI in 49 % of cases. Intraperitoneal organ injury was found in 3 patients (7 %). The distribution of injury location according to the classification of ARI in our children was as follows: 10 % in G I, 32 % in G II, 51 % in G III, and 10 % in G V. Primary repair without colostomy was performed in 51 % of cases. Primary repair and diversion of faecal stream by loop colostomy was required in 20 (49 %) patients. Postoperative septic complications occurred in 29 % of cases. Some potential risk factors such as trauma mechanism and associated organ injury were not significantly correlated to postoperative septic complications, while other risk factors such as mode of treatment, time of operative intervention and contamination were significantly related to postoperative septic complications (p < 0.05). The sensitivity of trauma scoring systems for the estimation of postoperative complication occurrence was significant for ISS (p < 0.05) and ARI score (p < 0.05). The relative risk of developing a postoperative septic complication was higher than 2 for patients with ARI grade III, ISS > 15, primary repair + colostomy group, and time of operative intervention > 8 hours. A child in the colostomy + primary repair group died on the first postoperative day from rapidly progressing septicaemia and multiple organ failure (2.4 %). The management of ARI can be carried out by primary repair procedure without colostomy in the majority of cases if the needed selectivity is established.

Epidemiology and control of nosocomial infections in paediatric surgery.

The purpose of this study was to determine the epidemiology and control of hospital-acquired infections (HAI) in paediatric surgery. We reviewed 2844 hospitalized children in a paediatric surgical clinic between January 1997 and December 2000. The diagnosis of HAI was made based on criteria proposed by Centers for Disease Control and Prevention (CDC). The incidence, type of micro-organisms and infections, age, sex, risk factors, and the economic aspects were recorded. The mortality, duration of hospitalization and economic aspects of patients were compared with 78 control patients matured for age, sex and primary illness and free of HAI. There were 78 children with HAI, the overall incidence was 2.74% (4.99% in 1997, 3.89% in 1998, 1.33% in 1999, 1.44% in 2000). The most frequent infections were surgical wound (28 patients) and urinary tract (25 patients). The most frequent risk factors were urethral catheterization (10.26%), trauma (9.25%), and parenteral nutrition (8.70%). Mean hospitalization was 16 days (range 4-28 days) in patients with infection compared with nine days (range 2-22 days) in control group. Eight patients died in the infection group, while two died in the control group. HAI caused a significant increase in mortality, prolonged hospitalization and increased costs (P < 0.05, P < 0.001, P < 0.001, respectively).

Three-year clinical evaluation of a resin modified glass-ionomer cement and a composite resin in non-carious class V lesions.

The purpose of this study was a 3-year clinical evaluation of a resin modified glass-ionomer and a composite resin restorative material in non-carious class V lesions. In 24 patients 98 non-carious class V lesions were restored with either a resin modified glass-ionomer (Vitremer), or a composite resin restoration (Z100). The restorations were clinically evaluated after 6, 12, 24 and 36 months with the US Public Health Service criteria. At 3 years, 88 teeth of 21 patients were evaluated. All restorations were rated clinically acceptable for colour match, marginal discoloration, marginal adaptation and anatomical form. Restoration retention of both groups was high without any statistically significant difference. However, Vitremer restorations showed a lower incidence of Alfa scores for colour match and marginal discoloration than Z100 restorations (P < 0.05).

Esophageal, tracheal and pulmonary parenchymal alterations in experimental esophageal atresia and tracheoesophageal fistula. A histological and morphometric study.

Pulmonary complications are among the most important causes of morbidity and mortality in neonates with esophageal atresia and tracheofistula. We aimed to investigate the possible causes of respiratory complications encountered in esophageal atresia (EA) and tracheoesophageal fistula (TEF) in an experimental model. Sprague-Dawley fetal rats treated with adriamycin were used for the experiment. Time mated pregnant rats were given 1.75 mg/kg of adriamicyn intraperitoneally on days 6-9 of gestation. The fetuses were sacrificed on day 21, weighed, and dissected under the surgical microscope. The animals were divided into four groups: (1) control group; (2) saline-injected group; (3) adriamycin-induced EA group, and (4) adriamycin administered but without development of EA. The lungs, esophagus, and trachea were excised and underwent histological examination. The mucosa of distal esophagus was thickened (p < 0.05); the submucosa was thinner (p < 0.05); and the muscular layer was thickened (p < 0.05) in fetuses with EA and TEF. In adriamycin-treated rats, in which EA and TEF developed, tracheal cartilage was loosened and formed into a D or C shape. The cartilage was fragmented into several segments on transverse sections in most fetuses. Alveolar septa were thin in lungs of fetus with EA and TEF (p < 0.05), without any fibrosis or evidence of parenchymal abnormality microscopically. Our findings suggest that respiratory complications may contribute to structural lesions in the trachea and particularly in the distal esophagus but not in the pulmonary parenchyma itself.

Fluoride release and uptake characteristics of aesthetic restorative materials.

The aims of this study were firstly to investigate the fluoride-releasing characteristics of two composite resins (Tetric and Valux Plus), two polyacid-modified resin composites (Compoglass and Dyract), and conventional glass-ionomer cement (Ceramfil beta). The second aim was to assess the fluoride uptake and subsequent release from the same range of materials. Fifteen discs (6 mm diameter and 1.5 mm height) were prepared for each material. Each disc was immersed in 4 ML of deionized water within a plastic vial. The release of fluoride was measured daily at 1, 2, 3, 4, 5, 15, 30 and 60 days. After daily fluoride release was measured for 60 days, samples were refluoridated in 1000-ppm sodium fluoride (NaF) solutions (pH 6.6) for 10 min and fluoride release was measured daily for a total of 5 days. The release of fluoride from aesthetic restorative materials was measured by using specific fluoride electrode and an ionanalyser. Results were statistically analysed by two-way repeated measure ANOVA and Duncan's multiple range test. The results revealed that all fluoride-containing materials (Ceramfil beta, Compoglass, Dyract, Tetric) released fluoride initially and the release was greatest at the first day. At any time during the test period Ceramfil beta released the most and Valux Plus did not release any detectable fluoride (P < 0.01). Sample exposures to 1000 ppm NaF solution increased the 24-h fluoride release from all fluoride-containing materials. This difference lasted only 24-48 h after exposure. Ceramfil beta had a tendency to recharge not seen with the other materials (P < 0.05).

Long-term followup of prenatally detected severe bilateral newborn hydronephrosis initially managed nonoperatively.

PURPOSE: We determine the outcome of severe bilateral primary ureteropelvic junction type hydronephrosis detected prenatally and managed postnatally with an initially nonoperative protocol. MATERIALS AND METHODS: A total of 19 newborns (38 kidneys) with prenatally diagnosed primary grade 3 to 4 bilateral hydronephrosis were followed nonoperatively for a mean of 54 months (range 14 to 187). If urinary obstruction with evidence of renal deterioration (decreased differential function and/or progressive hydronephrosis) occurred pyeloplasty was performed. RESULTS: Pyeloplasty was required in 13 kidneys (35%) in 9 patients (bilateral 4, unilateral 5). Age at pyeloplasty ranged from 2 to 22 months (mean 6.5) in 12 patients and 64 months in 1. The remaining 25 kidneys were followed nonoperatively (bilateral 20, unilateral 5). At last followup the Society for Fetal Urology grade of hydronephrosis in kidneys followed nonoperatively was 0 to 2 in 21 and 3 in 4, compared to 0 to 2 in 9 and Society for Fetal Urology 3 in 4 kidneys treated with pyeloplasty. Mean followup required for the most severely hydronephrotic kidney to achieve maximum ultrasound improvement was 10 months (range 3 to 34) for kidneys followed nonoperatively and 14 months (4-31) for kidneys after pyeloplasty. Differential renal function was measured in each kidney pair and compared using the difference in percent function between the 2 kidneys. In the nonoperative group mean initial difference in percent function was 8% (range 6% to 20%) and mean final difference was 5% (2% to 8%). In the pyeloplasty group mean initial difference in percent function was 16% (range 8% to 30%) and mean final difference was 7% (2% to 16%). With close followup and prompt pyeloplasty renal function improved to greater than pre-deterioration levels in all kidneys. CONCLUSIONS: These data represent the natural history of severe bilateral newborn hydronephrosis. Renal dilatation and function improve with time in most kidneys. Close followup is required in the first 2 years of life to identify the subgroup (35%) of children with obstruction that requires prompt surgery. Such an approach prevented permanent loss of renal function. Nonoperative management with close followup during the first 2 years appears to be a safe and recommended approach for neonates with primary bilateral ureteropelvic junction type hydronephrosis.

Blunt renal trauma in children with previously undiagnosed pre-existing renal lesions and guidelines for effective initial management of kidney injury.

OBJECTIVES: To record pre-existing renal lesions (PERL) found incidentally during evaluation for blunt renal trauma in children, determine their importance, suggest guidelines for the effective initial management of children with significant renal trauma and to evaluate the role of temporary percutaneous nephrostomy tube drainage (TPND) in these patients. PATIENTS AND METHODS: We reviewed 338 children who were hospitalized with blunt abdominal trauma between 1992 and 2000. Thirty-one patients had significant renal injury, 17 before 1997 (reviewed retrospectively) and the others reviewed and followed prospectively. RESULTS: Eleven of the 31 children had a PERL, which had been undiagnosed before the injury. The mean (range) follow-up was 52 (15-104) months. There were 22 boys and nine girls (mean age 9.1 years, range 2-13). The mean age was lower in patients with a PERL than in children with isolated renal injury. The most common cause of blunt renal injuries was a fall (45%) followed by motor vehicle accidents. Renal stones were present in five children, pelvi-ureteric junction obstruction in four, megaureter in one and a renal cyst in one. The mean injury severity scores were 12 in the children with a PERL and 14 in patients without. TPND was used in seven (22%) children; four were associated with a PERL. The mean grade of injury score for the kidney was higher in patients with a PERL and in children who underwent TPND than in patients who previously had a normal kidney and in children who did not undergo TPND. Early surgical intervention was required in three children; all were associated with a PERL. Of the 13 children who underwent surgery 11 had previous disease. CONCLUSIONS: The frequency of PERL is high (36%) in children with blunt renal trauma. PERL can predispose minor trauma to cause kidney injury even with no evidence of hydronephrosis. When a minor trauma results in renal injury, it is important to seek a PERL. In selected patients, TPND may decrease the length of hospital stay and improve the outcome of the injured kidney, thereby decreasing the need for further surgery in those with isolated renal injury; however, it appears not to decrease the need for later operations in children with a PERL.