Faculty Bibliography

BACKGROUND: The association of vaginal atresia (or Mayer-Rokitansky-Kuster-Hauser Syndrome) with imperforate anus is rare and can present significant diagnostic and therapeutic challenges. This study describes clinical characteristics, surgical treatment and outcomes in this group of complex children. METHODS: Records of 20 patients were retrospectively analyzed from two pediatric surgical centers. RESULTS: Five patients were excluded from the long-term analysis due to inadequate information, leaving long-term follow-up in 15 patients. Mean follow-up was 10years (range 1-31.1years). The diagnosis of vaginal atresia was made pre-operatively in 12 out of 15 patients, and in three patients it was identified during the anoplasty. The anorectal malformations were rectoperineal (N=2), rectovestibular (N=6), recto-bladder neck (N=1) and imperforate anus without fistula (N=6). Satisfactory surgical repair was performed in 13 patients, while one continues to stool through a low perineal fistula awaiting definitive surgery and another underwent a colostomy and mucous fistula. Delayed vaginal reconstruction was due to a failure to identify the problem prior to anoplasty (N=3). Long-term results demonstrated that anorectal continence was much worse than initially appreciated, and many had associated urinary incontinence. Overall stooling score was far lower than in a separate group of children with imperforate anus without vaginal atresia (Levitt and Pena, 2007). CONCLUSIONS: Vaginal atresia with imperforate anus is a rare and an extensive pre-operative workup of females with imperforate anus must include assessment of vagina patency. Vaginal reconstruction and anorectal continuity can be performed in a variety of approaches, but long-term continence is often not optimal. We propose a pathway for management of this difficult genito-anorectal disorder.

BACKGROUND: The positive effects of ozone therapy have been described in many gastrointestinal disorders. The mechanisms of this positive effect of ozone therapy are poorly understood. The purpose of the present study was to investigate whether the use of ozone may potentiate the gut intestinal mucosal homeostasis in a rat model. METHODS: Adult rats weighing 250-280 g were randomly assigned to one of three experimental groups of 8 rats each: 1) Control rats were given 2 mL of water by gavage and intraperitoneally (IP) for 5 days; 2) O3-PO rats were treated with 2 mL of ozone/oxygen mixture by gavage and 2 mL of water IP for 5 days; 3) O3-IP rats were treated with 2 mL of water by gavage and 2 mL of ozone/oxygen mixture IP for 5 days. Rats were sacrificed on day 6. Bowel and mucosal weight, mucosal DNA and protein, villus height and crypt depth, and cell proliferation and apoptosis were evaluated following sacrifice. RESULTS: The group of O3-IP rats demonstrated a greater jejunal and ileal villus height and crypt depth, a greater enterocyte proliferation index in jejunum, and lower enterocyte apoptosis in ileum compared to control animals. Oral administration of the ozone/oxygen mixture resulted in a less significant effect on cell turnover. CONCLUSIONS: Treatment with an ozone/oxygen mixture stimulates intestinal cell turnover in a rat model. Intraperitoneal administration of ozone resulted in a more significant intestinal trophic effect than oral administration.

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.

INTRODUCTION: This study presents our surgical experience for redo-pullthrough (RedoPT) for Hirschsprung disease (HD). It reviews the patient's clinical outcomes and assesses stooling patterns after RedoPT. METHODS: A retrospective review of our institution's RedoPTs as well as one author's overseas cases was performed. Stooling scores were tabulated using an established survey tool and compared to primary PT matched patients. RESULTS: Between 1974 and 2012, 46 individuals (52% males) underwent RedoPT, representing 3 percent of all HD pullthroughs. Median age at primary PT and RedoPT was 1year (range 1week-18years) and 3.5years (range 8weeks-41years), respectively. Indications for RedoPT were predominately for aganglionosis/transition zone pathology (71%); followed by stricture or an obstructing Duhamel pouch (19%), tight cuff (8%) and a twisted PT (4%). None were performed for an isolated clinical diagnosis of repeated bouts of enterocolitis. RedoPT surgical approach depended upon the initial pullthrough technique and any previous complications. Stooling scores were significantly (P<0.05) worse in the RedoPT patients compared to the historically-matched group of children undergoing a primary PT for HD (5.5+/-1.2 vs. 12.2+/-1.4, primary PT versus RedoPT, respectively). When breaking down this total score into individual parameters, stooling pattern scores (1.0+/-0.2 vs. 4.1+/-0.4, P=0.001) and enterocolitis scores (2.0+/-0.4 vs. 4.2+/-0.4, P=0.001) were statistically worse in the RedoPT group. Patients in both groups had similar overall continence rates. CONCLUSION: Appropriately selected children undergoing a RedoPT can achieve good results, with comparable continence rates to those undergoing a primary PT.

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.

BACKGROUND: Growing evidence suggests that the Wnt/beta-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/beta-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/beta-catenin signaling gene expression profiling. Twelve Wnt/beta-catenin-related genes and beta-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/beta-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 beta-catenin protein compared to control animals. CONCLUSION: Two weeks following massive bowel resection in rats, Wnt/beta-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.

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.

Toll-like receptor 4 (TLR-4) is crucial in maintaining intestinal epithelial homeostasis, participates in a vigorous signaling process and heightens inflammatory cytokine output. The objective of this study was to determine the effects of glutamine (GLN) on TLR-4 signaling in intestinal mucosa during methotrexate (MTX)-induced mucositis in a rat. Male Sprague-Dawley rats were randomly assigned to one of four experimental groups of 8 rats each: 1) control rats; 2)CONTR-GLN animals were treated with oral glutamine given in drinking water (2%) 48 hours before and 72 hours following vehicle injection; 3) MTX-rats were treated with a single IP injection of MTX (20 mg/kg); and 4) MTX-GLN rats were pre-treated with oral glutamine similar to group B, 48 hours before and 72 hours after MTX injection. Intestinal mucosal damage, mucosal structural changes, enterocyte proliferation and enterocyte apoptosis were determined 72 hours following MTX injection. The expression of TLR-4, MyD88 and TRAF6 in the intestinal mucosa was determined using real time PCR, Western blot and immunohistochemistry. MTX-GLN rats demonstrated a greater jejunal and ileal mucosal weight and mucosal DNA, greater villus height in ileum and crypt depth and index of proliferation in jejunum and ileum, compared to MTX animals. The expression of TLR-4 and MyD88 mRNA and protein in the mucosa was significantly lower in MTX rats versus controls animals. The administration of GLN increased significantly the expression of TLR-4 and MyD88 (vs the MTX group). In conclusion, treatment with glutamine was associated with up-regulation of TLR-4 and MyD88 expression and a concomitant decrease in intestinal mucosal injury caused by MTX-induced mucositis in a rat.

BACKGROUND/AIMS: Intestinal mucositis is a common side-effect in patients who receive aggressive chemotherapy. The Wnt signaling pathway is critical for establishing and maintaining the proliferative compartment of the intestine. In the present study, we tested whether Wnt/beta-catenin signaling is involved in methotrexate (MTX)-induced intestinal damage in a rat model. METHODS: Non-pretreated and pretreated with MTX Caco-2 cells were evaluated for cell proliferation and apoptosis using FACS analysis. Adult rats were divided into three experimental groups: Control rats; MTX-2 animals were treated with a single dose of MTX given IP and were sacrificed on day 2, and MTX-4 rats were treated with MTX similar to group B and were sacrificed on day 4. Intestinal mucosal damage, mucosal structural changes, enterocyte proliferation, and enterocyte apoptosis were measured at sacrifice. Real Time PCR and Western blot was used to determine the level of Wnt/beta-catenin related genes and protein expression. RESULTS: In the vitro experiment, treatment with MTX resulted in marked decrease in early cell proliferation rates following by a 17-fold increase in late cell proliferation rates compared to early proliferation. Treatment with MTX resulted in a significant increase in early and late apoptosis compared to Caco-2 untreated cells. In the vivo experiment, MTX-2 and MTX-4 rats demonstrated intestinal mucosal hypoplasia. MTX-2 rats demonstrated a significant decrease in FRZ-2, Wnt 3A Wnt 5A, beta-catenin, c-myc mRNA expression and a significant decrease in beta-catenin and Akt protein levels compared to control animals. Four days following MTX administration, rats demonstrated a trend toward a restoration of Wnt/beta-catenin signaling especially in ileum. CONCLUSIONS: Wnt/beta-catenin signaling is involved in enterocyte turnover during MTX-induced intestinal mucositis in a rat.

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.