Sonic hedgehog signaling controls gut epithelium homeostasis following intestinal ischemia-reperfusion in a rat.

PURPOSE: One of the major regulators of gastrointestinal tract development is the hedgehog signaling pathway. The purpose of this study was to evaluate the role of sonic hedgehog (SHh) signaling 24 and 48 h following intestinal ischemia-reperfusion (IR) in a rat. MATERIALS AND METHODS: Male rats were divided into four experimental groups: (1) Sham-24 h rats underwent laparotomy and were sacrificed after 24 h, (2) Sham-48h rats underwent laparotomy and were sacrificed after 48 h, (3) IR-24h rats underwent occlusion of both superior mesenteric artery and portal vein for 20 min followed by 24 h of reperfusion, and (4) IR-48 h rats underwent ischemia for 20 min followed by 48 h of reperfusion. Intestinal structural changes, enterocyte proliferation and enterocyte apoptosis were determined by immunohistochemistry 24 and 48 h following IR. SHh-related genes and protein expression were determined using real-time PCR, Western blot and immunohistochemistry. RESULTS: IR-24 rats demonstrated a significant decrease in Shh, Ihh, GIL and Ptch2 mRNA in jejunum and ileum compared to Sham-24 animals that was accompanied by a significant decrease in the number of SHH-positive cells (Immunohistochemistry) in jejunum (2.5-fold decrease) and ileum (37%). After 48 h, IR rats demonstrated a significant increase in Dhh, Ihh, Gil and PTCH2 mRNA in jejunum as well as in Dhh, Ihh, SMO, GIL, PTCH2 mRNA in ileum compared to IR-24 animals that was coincided with increased number of SHH-positive cells in jejunum (2.6-fold increase) and ileum (1.4-fold increase). CONCLUSIONS: 24 h following intestinal IR, inhibited cell turnover was associated with inhibited SHh signaling pathway. Signs of intestinal recovery appeared 48 h after IR and were correlated with increase in SHh signaling pathway activity.

Activated Notch signaling cascade is correlated with stem cell differentiation toward absorptive progenitors after massive small bowel resection in a rat.

Notch signaling is thought to act to drive cell versification in the lining of the small intestine. The purpose of the present study was to evaluate the role of the Notch signaling pathway in stem cell differentiation in the late stages of intestinal adaptation after massive small bowel resection in a rat. Male Sprague-Dawley rats were randomly assigned to one of two experimental groups of eight rats each: Sham rats underwent bowel transection and reanastomosis, while SBS rats underwent 75% small bowel resection. Rats were euthanized on day 14 Illumina's Digital Gene Expression (DGE) analysis was used to determine Notch signaling gene expression profiling. Notch-related gene and protein expression was determined using real-time PCR, Western blot analysis, and immunohistochemistry. From seven investigated Notch-related (by DGE analysis) genes, six genes were upregulated in SBS vs. control animals with a relative change in gene expression level of 20% or more. A significant upregulation of Notch signaling-related genes in resected animals was accompanied by a significant increase in Notch-1 protein levels (Western blot analysis) and a significant increase in the number of Notch1 and Hes1 (target gene)-positive cells (immunohistochemistry) compared with sham animals. Evaluation of cell differentiation has shown a strong increase in total number of absorptive cells (unchanged secretory cells) compared with control rats. In conclusion, 2 wk after bowel resection in rats, stimulated Notch signaling directs the crypt cell population toward absorptive progenitors.NEW & NOTEWORTHY This study provides novel insight into the mechanisms of cell proliferation following massive small bowel resection. We show that 2 wk after bowel resection in rats, enhanced stem cell activity was associated with stimulated Notch signaling pathway. We demonstrate that activated Notch signaling cascade directs the crypt cell population toward absorptive progenitors.

Redo pullthrough for Hirschsprung disease.

Pullthrough procedures for Hirschsprung diseases typically have favorable results. However, some children experience long-term postoperative complications comprising stooling disorders, such as intermittent enterocolitis, severe stool retention, intestinal obstruction, as well as incontinence. Reoperative Hirschsprung Disease surgery is complex. This begins with the workup after the initial presentation following primary pullthrough, continues with the definitive surgical correction with redo pullthrough, and ends with long-term follow-up of individuals. The decision tree can be varied with each patient. The operating pediatric surgeon must be able to utilize different operations and treatment options available. While lesser procedures may provide relief in a select population, those with residual aganglionosis or transition zone pathology or mechanical problems will likely require a redo pullthrough. Thus, the diagnostic workup, treatment plan, and definitive surgical care should be coordinated, and executed by an experienced, specialized team at a pediatric referral center.

Does Staphylococcus aureus nasal carriage require eradication prior to elective ambulatory surgery in children?

PURPOSE: Rates of community-associated Staphylococcus aureus, and particularly of methicillin-resistant Staphylococcus aureus (MRSA) in children, have increased in recent years. We investigated rates of nasal colonization of S. aureus, and a possible correlation between nasal carriage and wound infection. METHODS: A prospective study of children scheduled for elective day-care surgical procedures between January 2008 and December 2012 at one medical center. Nasal swabs were taken before surgery, and follow-up was performed 1-2 weeks following surgery. RESULTS: Of 1,127 children (median age 2 years, 70.6% males), positive nasal swabs were detected in 228 (20.2%). Rates of S. aureus nasal carriage were lowest for ages 6 months to 2 years and highest for ages 4-11 years. Child's sex did not associate with the risk for positive nasal swabs. Positive nasal swabs for MRSA were detected in five boys (0.62% of the population). Five children (0.44%) had wound infection. None of them was a nasal carrier. CONCLUSIONS: No correlation was observed between positive nasal swabs and wound infection in children who were candidates for elective ambulatory operations. This suggests that evaluation of S. aureus nasal carriage and eradication may not be necessary in this population.

Effect of ozone on intestinal recovery following intestinal ischemia-reperfusion injury in a rat.

BACKGROUND: Growing evidence suggests that ozone (O3) protects the host against pathological conditions mediated by reactive oxygen species by increasing the activity of antioxidant enzymes. The purpose of the present study was to examine the effect of O3 on intestinal recovery and enterocyte turnover after intestinal ischemia-reperfusion (IR) injury in rats. METHODS: Male Sprague-Dawley rats were divided into four experimental groups: (1) sham rats underwent laparotomy; (2) sham-O3 rats underwent laparotomy and were treated with an ozone/oxygen mixture intraperitoneally and intraluminally (50 %/50 %); (3) IR rats underwent occlusion of both superior mesenteric artery and portal vein for 20 min followed by 48 h of reperfusion, and (4) IR-O3 rats underwent IR and were treated with an ozone/oxygen mixture similar to group 2. Intestinal structural changes, Park's injury score, enterocyte proliferation and enterocyte apoptosis were determined 48 h following IR. Western blot was used to determine ERK and Bax protein levels. A non-parametric Kruskal-Wallis ANOVA test was used for statistical analysis with p < 0.05 considered statistically significant. RESULTS: Treatment of IR rats with O3 resulted in a significant increase in mucosal weight in jejunum (70 %) and ileum (32 %), mucosal DNA (twofold increase) and protein (35 %) in ileum, villus height and crypt depth in jejunum (61 and 16 %, correspondingly) and ileum (31 and 43 %, correspondingly) compared to IR animals. IR-O3 rats also had a significantly lower intestinal injury score as well as a lower apoptotic index in jejunum and ileum compared and IR animals. A significant increase in cell proliferation rates in IR-O3 animals was accompanied by increased levels of p-ERK protein. CONCLUSIONS: Treatment with ozone prevents intestinal mucosal damage, stimulates cell proliferation and inhibits programmed cell death following intestinal IR in a rat.

The diagnosis of fetal esophageal atresia and its implications on perinatal outcome.

The current diagnostic accuracy and perinatal outcome of fetuses with esophageal atresia (EA) continues to be debated. In this review, we report on our experience at a tertiary care fetal center with the prenatal ultrasound diagnosis of EA. Enrollment criteria included a small/absent stomach bubble with a normal or elevated amniotic fluid index between 2005 and 2013. Perinatal outcomes were analyzed and compared to postnatally diagnosed EA cases. Of the 22 fetuses evaluated, polyhydramnios occurred in 73%. Three (14%) died in utero or shortly after birth, but none had EA. In the presence of an absent/small stomach and polyhydramnios, the positive predictive value for EA was 67%. In fetal EA cases confirmed postnatally (group 1, n = 11), there were no differences in gestational age, birthweight, or mortality when compared to postnatally diagnosed infants (group 2, n = 59). Group 1 was associated with long-gap EA, need for esophageal replacement, and increased hospital length of stay. When taken in context with the current literature, we conclude that ultrasound findings suggestive of EA continue to be associated with a relatively high rate of false positives. However, among postnatally confirmed cases, there is an increased risk for long-gap EA and prolonged hospitalization.

Wnt/ß-catenin signaling cascade down-regulation following massive small bowel resection in a rat.

BACKGROUND: Growing evidence suggests that the Wnt/ß-catenin signaling cascade is implicated in the control of stem cell activity, cell proliferation, lineage commitment, and cell survival during normal development and tissue regeneration of the gastrointestinal epithelium. The roles of this signaling cascade in stimulation of cell proliferation after massive small bowel resection are unknown. The purpose of this study was to evaluate the role of Wnt/ß-catenin signaling during late stages of intestinal adaptation in a rat model of short bowel syndrome (SBS). METHODS: Male rats were divided into two groups: sham rats underwent bowel transection and SBS rats underwent a 75 % bowel resection. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined 2 weeks after operation. Illumina's digital gene expression analysis was used to determine Wnt/ß-catenin signaling gene expression profiling. Twelve Wnt/ß-catenin-related genes and ß-catenin protein expression were determined using real-time PCR, western blotting and immunohistochemistry. RESULTS: From the total number of 20,000 probes, 20 genes related to Wnt/ß-catenin signaling were investigated. From these genes, seven genes were found to be up-regulated and eight genes to be down-regulated in SBS vs. sham animals with a relative change in gene expression level of 20 % or more. From 12 genes determined by real-time PCR, nine genes were down-regulated in SBS rats compared to control animals including target gene c-Myc. SBS rats also showed a significant decrease in ß-catenin protein compared to control animals. CONCLUSION: Two weeks following massive bowel resection in rats, Wnt/ß-catenin signaling pathway is inhibited. In addition, it appears that cell differentiation rather than proliferation is most important in the late stages of intestinal adaptation.

Reversal of severe methotrexate-induced intestinal damage using enteral n-3 fatty acids.

Growing evidence suggests that n-3 PUFA and their specific lipid mediators can reduce the activity of inflammatory processes. In the present study, we evaluated the effects of oral n-3 PUFA supplementation on intestinal structural changes, enterocyte proliferation and apoptosis during methotrexate (MTX)-induced intestinal damage in the rat. A total of thirty-two male rats were divided into four experimental groups: control (CONTR) rats; CONTR-n-3 PUFA rats treated with oral administration of n-3 PUFA at a dose of 300 µg/kg once per d 72 h before and 72 h following vehicle injection; MTX rats treated with a single dose of MTX; MTX-n-3 PUFA rats treated with oral n-3 PUFA following the injection of MTX. Intestinal mucosal damage, mucosal structural changes, enterocyte proliferation and enterocyte apoptosis determined 72 h following MTX injection. Real-time PCR was used to determine B-cell lymphoma 2 (Bcl2)-associated X protein (Bax) and Bcl2 mRNA expression. Western blotting was used to determine phosphorylated extracellular signal-related kinase, ß-catenin, Bax and Bcl2 protein levels. MTX-n-3 PUFA rats demonstrated a greater jejunal and ileal bowel weight, greater ileal mucosal weight, greater ileal mucosal DNA and protein levels, greater villus height in the jejunum and ileum and crypt depth in the ileum, compared with MTX animals. A significant decrease in enterocyte apoptosis in the ileum of MTX-n-3 PUFA rats (v. MTX) was accompanied by decreased Bax mRNA and protein expression and increased Bcl2 mRNA levels. Thus, the treatment with oral n-3 PUFA prevented mucosal injury and improved intestinal recovery following MTX-injury in rats.

Redo esophageal surgery: the diagnosis and management of recurrent tracheoesophageal fistula.

This article presents a 30-year review of 38 recurrent tracheoesophageal fistulas. The initial 26 cases were presented in 2009 at the annual meeting of the British Association of Pediatric Surgeons and the European Association of Pediatric Surgeons Joint Conference and published in the Journal of Pediatric Surgery (Bruchet al. J Pediatr Surg 45:337-340, 2010). In the initial cohort of 26 patients, 18 had a leak after their primary operation and 22 had respiratory symptoms leading to the discovery of the recurrent fistula. The diagnosis was made by a contrast study in 24. The repairs entailed replacing a catheter through the fistula, separating the trachea and esophagus completely using sharp dissection and placing vascularized tissue, either pleura or pericardium between the suture lines. Postoperative complications included seven anastomotic leaks, four strictures and three recurrent fistulas. Long-term follow-up (median of 84 months) showed that 21 took all of their nutrition by mouth, three were tube fed and two required a combination of both. Of the 23 patients with growth chart data, 16 fell into the first quartile of the growth chart, whereas none fell between the 75th and 100th percentile. In conclusion, this initial series of 26 patients along with the updated additional series of 12 patients is the largest series thus far reported in the literature. All 38 patients represent the characteristics of recurrent tracheoesophageal fistulas, including techniques to make the diagnosis and to provide a secure closure of the fistula, and the long-term outcomes of these patients.

Hirschsprung-associated enterocolitis: pathogenesis, treatment and prevention.

Hirschsprung-associated enterocolitis (HAEC) is a common and sometimes life-threatening complication of Hirschsprung disease (HD). Presenting either before or after definitive surgery for HD, HAEC may manifest clinically as abdominal distension and explosive diarrhea, along with emesis, fever, lethargy, and even shock. The pathogenesis of HAEC, the subject of ongoing research, likely involves a complex interplay between a dysfunctional enteric nervous system, abnormal mucin production, insufficient immunoglobulin secretion, and unbalanced intestinal microflora. Early recognition of HAEC and preventative practices, such as rectal washouts following a pull-through, can lead to improved outcomes. Treatment strategies for acute HAEC include timely resuscitation, colonic decompression, and antibiotics. Recurrent or persistent HAEC requires evaluation for mechanical obstruction or residual aganglionosis, and may require surgical treatment with posterior myotomy/myectomy or redo pull-through. This chapter describes the incidence, pathogenesis, treatment, and preventative strategies in management of HAEC.

Dietary supplementation with vitamin D stimulates intestinal epithelial cell turnover after massive small bowel resection in rats.

PURPOSE: While the endocrine action of the active metabolite 1,25-dihydroxyvitamin D (VtD) has been well characterized in relation to the maintenance of plasma calcium and phosphate homeostasis through regulation of intestinal absorption, recent research has focused on its autocrine and/or paracrine activities. Such activities have been best characterized in intestine, where VtD regulates cell differentiation and maturation. The purpose of this study was to evaluate the effect of VtD on enterocyte turnover in a rat model of short bowel syndrome (SBS). METHODS: Male rats were divided into four groups: sham rats underwent bowel transection, sham-VtD rats underwent bowel transection and were treated oral VtD, SBS rats underwent a 75 % bowel resection, and SBS-VtD rats underwent bowel resection and were treated with VtD. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined at sacrifice. Illumina's digital gene expression (DGE) analysis was used to determine VtD pathway-related gene expression profiling. VtD receptor (VDR) and its promoter, Bax and Bcl-2 mRNA expression were determined using real-time PCR. Western blotting was used to determine p-ERK, Bax and ß-catenin protein levels. RESULTS: From the total of 20,000 probes, 11 genes related to VtD signaling were investigated. Of these genes, five were found to be up-regulated in SBS versus sham animals with a relative change in gene expression level of 20 %, five remained unchanged, and one was down-regulated. VtD treatment in sham and SBS rats resulted in significant up-regulation of the VDR gene and its promoter's expression. SBS-VtD rats demonstrated a significant increase in all intestinal mucosal parameters compared to SBS animals. A significant increase in cell proliferation in SBS-VtD rats was accompanied by increased ß-catenin protein levels. A significant decrease in cell apoptosis in this group was correlated with lower Bax/Bcl-2 mRNA and protein levels. CONCLUSION: In a rat model of SBS, dietary supplementation with VtD stimulates enterocyte turnover, which correlates with up-regulated VtD receptor expression in the remaining small intestine.

Methotrexate induces germ cell apoptosis and impairs spermatogenesis in a rat.

PURPOSE: The primary toxic effects of methotrexate (MTX) are myelosuppression and/or intestinal mucositis. The objective of the present study is to investigate the effect of MTX on germ cell apoptosis and spermatogenesis in a rat. METHODS: Male Sprague-Dawley rats were divided into three experimental groups: control rats treated with vehicle; MTX-2 rats treated with one dose (20 µg/kg) of MTX given IP and killed on the second day; and MTX rats treated with IP MTX (20 µg/kg) and killed on day 4. Johnsen's criteria and the number of germinal cell layers in the testes were used to categorize the spermatogenesis. TUNEL assay was used to determine germ cell apoptosis. Western blotting was used to determine Bax and Bcl-2 protein levels. Statistical analysis was performed using the non-parametric Kruskal-Wallis ANOVA test, with p less than 0.05 considered statistically significant. RESULTS: On day 2, MTX-treated animals demonstrated minimal changes in the histological parameters of spermatogenesis, but germ cell apoptosis increased significantly (threefold increase, p = 0.002) compared to control rats. On day 4, MTX-treated rats demonstrated a trend toward a decrease in germ cell apoptosis, compared to day 2, and showed histological signs of impaired spermatogenesis (decreased number of germ cell layers and Johnsen's criteria). A significant increase in cell apoptosis in MTX-treated rats was correlated with higher Bax/Bcl-2 protein levels. CONCLUSIONS: MTX induced germ cell apoptosis and impaired spermatogenesis in rat testes.

PDGF-α stimulates intestinal epithelial cell turnover after massive small bowel resection in a rat.

Numerous cytokines have been shown to affect epithelial cell differentiation and proliferation through epithelial-mesenchymal interaction. Growing evidence suggests that platelet-derived growth factor (PDGF) signaling is an important mediator of these interactions. The purpose of this study was to evaluate the effect of PDGF-α on enterocyte turnover in a rat model of short bowel syndrome (SBS). Male rats were divided into four groups: Sham rats underwent bowel transection, Sham-PDGF-α rats underwent bowel transection and were treated with PDGF-α, SBS rats underwent a 75% bowel resection, and SBS-PDGF-α rats underwent bowel resection and were treated with PDGF-α. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined at euthanasia. Illumina's Digital Gene Expression analysis was used to determine PDGF-related gene expression profiling. PDGF-α and PDGF-α receptor (PDGFR-α) expression was determined by real-time PCR. Western blotting was used to determine p-ERK, Akt1/2/3, bax, and bcl-2 protein levels. SBS rats demonstrated a significant increase in PDGF-α and PDGFR-α expression in jejunum and ileum compared with sham animals. SBS-PDGF-α rats demonstrated a significant increase in bowel and mucosal weight, villus height, and crypt depth in jejunum and ileum compared with SBS animals. PDGF-α receptor expression in crypts increased in SBS rats (vs. sham) and was accompanied by an increased cell proliferation following PDGF-α administration. A significant decrease in cell apoptosis in this group was correlated with lower bax protein levels. In conclusion, in a rat model of SBS, PDGF-α stimulates enterocyte turnover, which is correlated with upregulated PDGF-α receptor expression in the remaining small intestine.

Dietary L-arginine supplementation reduces Methotrexate-induced intestinal mucosal injury in rat.

BACKGROUND: Arginine (ARG) and nitric oxide maintain the mucosal integrity of the intestine in various intestinal disorders. In the present study, we evaluated the effects of oral ARG supplementation on intestinal structural changes, enterocyte proliferation and apoptosis following methotrexate (MTX)-induced intestinal damage in a rat. METHODS: Male rats were divided into four experimental groups: Control rats, CONTR-ARG rats, were treated with oral ARG given in drinking water 72 hours before and 72 hours following vehicle injection, MTX rats were treated with a single dose of methotrexate, and MTX-ARG rats were treated with oral ARG following injection of MTX. Intestinal mucosal damage, mucosal structural changes, enterocyte proliferation and enterocyte apoptosis were determined 72 hours following MTX injection. RT-PCR was used to determine bax and bcl-2 mRNA expression. RESULTS: MTX-ARG rats demonstrated greater jejunal and ileal bowel weight, greater ileal mucosal weight, greater ileal mucosal DNA and protein levels, greater villus height in jejunum and ileum and crypt depth in ileum, compared to MTX animals. A significant decrease in enterocyte apoptosis in the ileum of MTX-ARG rats (vs MTX) was accompanied by decreased bax mRNA and protein expression and increased bcl-2 protein levels. CONCLUSIONS: Treatment with oral ARG prevents mucosal injury and improves intestinal recovery following MTX- injury in the rat.

TGF-ß affects enterocyte turnover in correlation with TGF-ß receptor expression after massive small bowel resection.

OBJECTIVES: In the present study, we evaluated the effect of transforming growth factor-beta 2 (TGF-ß2)-enriched diet on enterocyte turnover and correlated it with TGF-ß2 receptor expression along the villus-crypt axis in a rat model of short bowel syndrome (SBS). METHODS: CaCo-2 cells were incubated with increasing concentrations of TGF-ß2. Alamar Blue reduction test was used for investigation of cell viability and evaluation of cell apoptosis was assessed by flow cytometry. Male rats were divided into 4 groups: Sham rats underwent bowel transection, Sham TGF-ß rats were treated with diet enriched with TGF-ß2, SBS rats underwent a 75% bowel resection, and SBS TGF-ß rats were fed a diet enriched with TGF-ß2 after bowel resection. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined at sacrifice. TGF-ß2r expression in villus tips, lateral villi and crypts was assessed by immunohistochemistry. The effect of TGF-ß2 on enterocyte turnover for each compartment was evaluated in correlation with TGF-ß2r expression. RESULTS: Incubation of CaCo-2 cells with TGF-ß2 resulted in a significant decrease in cell viability and increased cell apoptosis. TGF-ß2r expression in crypts increased in SBS rats (vs sham) and was accompanied by decreased cell proliferation and increased cell apoptosis following TGF-ß2 administration. A significant decrease in TGF-ß2r expression at villous tips in SBS rats was accompanied by a decreased cell apoptosis in this compartment following exposure to TGF-ß2-enriched diet. CONCLUSIONS: In a rat model of SBS, the inhibiting effect of TGF-ß2 on enterocyte turnover correlates with TGF-ß2 receptor expression along the villus-crypt axis.

Oral insulin stimulates intestinal epithelial cell turnover following massive small bowel resection in a rat and a cell culture model.

PURPOSE: We have recently reported that oral insulin (OI) stimulates intestinal adaptation after bowel resection and that OI enhances enterocyte turnover in correlation with insulin receptor expression along the villus-crypt axis. The purpose of the present study was to evaluate the effect of OI on intestinal epithelial cell proliferation and apoptosis in a rat model of short bowel syndrome (SBS) and in a cell culture model. METHODS: Caco-2 cells were incubated with increasing concentrations of insulin. Cell proliferation and apoptosis were determined by FACS cytometry. Cell viability was investigated using the Alamar Blue technique. Male rats were divided into three groups: Sham rats underwent bowel transection, SBS rats underwent a 75% bowel resection, and SBS-OI rats underwent bowel resection and were treated with OI given in drinking water (1 U/ml) from the third postoperative day. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined on day 15. Real time PCR was used to determine the level of bax and bcl-2 mRNA and western blotting was used to determine bax, bcl-2, p-ERK and AKT protein levels. Statistical analysis was performed using the one-way ANOVA test, with P < 0.05 considered statistically significant. RESULTS: Treatment of Caco-2 cells with insulin resulted in a significant increase in cell proliferation (twofold increase after 24 h and 37% increase after 48 h) and cell viability (in a dose-dependent manner), but did not change cell apoptosis. In a rat model of SBS, treatment with OI resulted in a significant increase in all parameters of intestinal adaptation. Elevated cell proliferation rate in insulin treated rats was accompanied by elevated AKT and p-ERK protein levels. Decreased cell apoptosis in SBS-INS rats corresponded with a decreased bax/bcl-2 ratio. CONCLUSIONS: Oral insulin stimulates intestinal epithelial cell turnover after massive small bowel resection in a rat model of SBS and a cell culture model.

The 100 most-cited articles in Pediatric Surgery International.

PURPOSE: Citation analysis within specific journals and subject areas has become a popular method to assess the impact of a journal, article or author. To date, only a few evaluations of citation reports have been published in the field of pediatric surgery. Twenty-six years after its inception, Pediatric Surgery International (PSI) is a firmly established journal in pediatric surgery. The aim of this study was to identify, analyze and categorize the characteristics of the 100 most-cited articles published in PSI since its founding in 1986. METHODS: The Web of Knowledge(SM), hosted by the Institute for Scientific Information, was searched with the all-database function for the 100 most-cited articles in PSI published from 1986 to the present. Each article was reviewed and the following parameters were recorded: number of citations, type of article, topic, year of publication, country of origin, institution and authorship. RESULTS: Between 1986 and 2012, 4,907 articles were published in PSI and 3,608 (73.53 %) of these were cited at least once. The 100 most-cited articles received a total of 3,309 citations with a mean of 33.09 (range 24-81). These articles were published between 1987 and 2007, with 73 articles published after 1997. Leading countries were USA (n = 15), Australia (n = 12), UK (n = 9) and Ireland (n = 9). Articles were categorized as followed: 92 original articles, 5 reviews and 3 case reports. 84 articles derived from clinical research and 16 derived from basic science. The most prolific authors were from 7 different institutions and published 37 articles, which received 1,213 (36.66 %) citations. CONCLUSION: The 100 most-cited articles published in PSI were predominately original articles from English-speaking countries dealing with clinical topics. This analysis may be of value to the editorial board and authors by providing some insights into what types of manuscripts appear to be of interest to the reading audience of PSI.

Technical considerations in children undergoing laparoscopic ileal-J-pouch anorectal anastomosis for ulcerative colitis.

BACKGROUND: Sub-total colectomy and restorative proctocolectomy with j-pouch ileo-anorectal anastomosis is the treatment of choice in children with ulcerative colitis uncontrolled with medical therapy. OBJECTIVE: To present some technical considerations about children undergoing laparoscopic ileal-J-pouch anorectal anastomosis. SETTINGS AND PATIENTS: All patients with ulcerative colitis undergoing laparoscopic ileal-J-pouch anorectal anastomosis were evaluated from January 2006 to February 2011. INTERVENTION: The new technical innovations herein are (1) total laparoscopic approach, (2) a very short 3-cm J-pouch ileal reservoir created outside the stoma incision, (3) preservation of the entire anal canal and the Knight-Griffen double stapled anastomosis, less than 3 cm from the dentate line, (4) use of a Multiple Instrument Access Port system in the stoma skin incision to reduce the number of port site incisions and (5) proctectomy performed using only an electrosurgical vessels sealing device thus avoiding clips to close rectal pedicle. RESULTS: Seventeen laparoscopic ileo J-pouch low rectal anastomosis were performed by the same surgical staff. Three complications occurred postoperatively: one bowel obstruction, one ileostomy prolapse, and one anastomotic stricture. Satisfactory functional results were achieved in all, there was no significant perineal excoriation and quality of life was excellent. CONCLUSIONS: A Multiport Instrument Access Port placed in the stoma site allowed the use of more instruments through a single incision. The very short ileo J-pouch low rectal anastomosis has been shown to be a safe, feasible, and effective reconstructive procedure.