Kky Wong

COG5-CDG with a Mild Neurohepatic Presentation

The conserved oligomeric Golgi (COG) complex is an eight subunit protein involved in the retrograde transport of Golgi components. It affects the localization of several Golgi glycosyltransferases and hence is involved in N- and O-glycosylation. Genetic defects in this complex belong to the rapidly expanding family of congenital disorders of glycosylation (CDG). Patients have been reported with defects of subunit 1 (CDG1-CDG), subunit 4 (CDG4-CDG), subunit 5 (CDG5-CDG), subunit 6 (CDG6-CDG), subunit 7 (CDG7-CDG), and subunit 8 (CDG8-CDG). This paper is on the second reported patient with COG5-CDG. She showed a mild neurohepatic disease with central as well as peripheral neurological involvement while in the first reported patient (with a different mutation) only mild central neurological involvement was reported.

Performing Kasai Portoenterostomy Beyond 60 Days of Life Is Not Necessarily Associated With a Worse Outcome

The introduction of Kasai portoenterostomy has dramatically improved the management and survival of children with biliary atresia. The success rate of this operation worldwide varies with different centers. In this respect, many authors have studied the correlation of a successful outcome with various factors, such as the experience and workload of the surgical center, the use of postoperative steroids, the underlying biliary anatomy, as well as the age of patients at the time of the operation. Indeed, the age of 60 days has been used by clinicians as a critical time beyond which the rate of success of the Kasai operation markedly reduces. Despite this worldwide adoption, clear evidence supporting this critical operative time is still lacking. We undertook a review of our experience in the management of children with biliary atresia and focused specifically on the issue of the timing of operation. We showed that performing the Kasai operation beyond the age of 60 days was not associated with a worse outcome and that a high percentage of patients could still achieve good bile flow with normal bilirubin postoperatively. Thus, we believe that until the age of 100 days, the age of the patients does not play a significant role in determining the success of the Kasai operation.

Stage specific requirement of platelet-derived growth factor receptor-α in embryonic development

Background Platelet-derived growth factor receptor alpha (PDGFRα) is a cell-surface receptor tyrosine kinase for platelet-derived growth factors. Correct timing and level of Pdgfra expression is crucial for embryo development, and deletion of Pdgfra caused developmental defects of multiple endoderm and mesoderm derived structures, resulting in a complex phenotypes including orofacial cleft, spina bifida, rib deformities, and omphalocele in mice. However, it is not clear if deletion of Pdgfra at different embryonic stages differentially affects these structures. Purpose To address the temporal requirement of Pdgfra in embryonic development. Methods We have deleted the Pdgfra in Pdgfra-expressing tissues at different embryonic stages in mice, examined and quantified the developmental anomalies. Results Current study showed that (i) conditional deletion of Pdgfra at different embryonic days (between E7.5 and E10.5) resulted in orofacial cleft, spina bifida, rib cage deformities, and omphalocele, and (ii) the day of Pdgfra deletion influenced the combinations, incidence and severities of these anomalies. Deletion of Pdgfra caused apoptosis of Pdgfra-expressing tissues, and developmental defects of their derivatives. Conclusion Orofacial cleft, spina bifida and omphalocele are among the commonest skeletal and abdominal wall defects of newborns, but their genetic etiologies are largely unknown. The remarkable resemblance of our conditional Pdgfra knockout embryos to theses human congenital anomalies, suggesting that dysregulated PDGFRA expression could cause these anomalies in human. Future work should aim at defining (a) the regulatory elements for the expression of the human PDGFRA during embryonic development, and (b) if mutations / sequence variations of these regulatory elements cause these anomalies.

Pneumatosis intestinalis presenting as pneumoperitoneum in a teenage girl with pyloric stenosis.

A 16-year-old girl presented with free gas under the diaphragm after endoscopic balloon dilation for pyloric stenosis. There was no perforation site identified on laparotomy. However, there was massive pneumatosis intestinalis involving the entire small bowel.

Clinical Research and Evidence Based Pediatric Surgery

Evidence-based medicine (EBM) is the process of acquiring the best available research evidence and applying this evidence to inform the best practice in a defined problem in clinical practice. The widespread popularization of the concept of EBM since its first introduction more than three decades ago has resulted in a paradigm shift in biomedicine from a largely experienceand opinion-based practice toward one based increasingly on objective scientific evidence. Properly designed and implemented clinical research represents the best way to provide high-quality scientific evidence for informing the practice of EBM. Among different study designs, prospective randomized controlled trial (RCT) is regarded as the gold standard of clinical research and gives the highest level of evidence (Class I evidence). For specialties that are progressing faster in the practice of EBM, the rapid accumulation of research finding also highlights the importance of critical appraisal skill for assessing the quality of available evidence. In many surgical settings including pediatric surgery, however, important barriers that may hinder the proper design and implementation of RCTs are still common. A better understanding of the concept of clinical research and EBM would thus serve to equip researchers in these settings to produce better scientific evidence and for practitioners to incorporate the best available evidence into their clinical practice.

Long-term Results and Quality of Life Assessment in Biliary Atresia Patients

Objectives: To review long-term transplant-free survival and quality of life (QOL) of patients with biliary atresia (BA). Methods: A retrospective study reviewing all patients with Kasai operation between January 1, 1980 and December 31, 2015 was performed to evaluate the transplant-free survival. Subgroup analysis of patients older than 20 years was carried out to assess the QOL using the Short Form-36 Health Survey and incidences of disease-related complications. Comparison between patients with native and transplanted liver was performed using two-tailed independent samples t-test (P value < 0.05, significant). Results: The 20-year Kaplan-Meier transplant-free survival of the 141 patients in our study was 51%. The subgroup analysis of long-term survivors revealed a trend of increased prevalence of complications like esophageal varices, portal hypertension, and recurrent admissions in the patient groups with raised serum bilirubin (SB). Thirty-one patients were successfully contacted for QOL assessment, 26 (16 with native liver and 10 with transplanted liver) responded (76.5%). BA patients who were documented to have active complications have a significantly lower vitality score (50.7 vs 57.5, P = 0.015). There was no statistically significant difference in the scores between the transplanted group and the disease-free control group. However, the native liver group achieved a lower score in both the general health section (42.9 vs 49.6, P = 0.029) and the overall physical component (49.6 vs 54.4, P = 0.037). Conclusions: A significant proportion of our patients survive with their native liver for more than 20 years. These long-term survivors may suffer from complications that impair their QOL. They require continuous life-long care.

Acute appendicitis presenting as pneumoperitoneum in a teenage boy undergoing chemotherapy

Chemotherapy of paediatric haematological malignancies can induce infectious complications of the gastrointestinal tract, with predilection of the ileocaecal region. Common causes of right lower abdominal pain in the febrile patient with neutropaenia include acute appendicitis, typhlitis, ileus and intussusception. In this case report, we describe a teenage boy with acute appendicitis presenting with pneumoperitoneum during his course of chemotherapy. The incidence, aetiology, diagnosis, investigations and management of this uncommon presentation in a common disease are discussed. The controversial topic of the management of acute appendicitis in a febrile patient with neutropaenia is also reviewed and discussed.

Single-port laparoscoic varicocelectomy induces minmal post-operative stress response in children

During laparoscopic orchidopexy (LO) closing the peritoneum over the area of the deep inguinal ring (DIR) is a routine step of the procedure for many authors. However, we do LO with a modification of not closing the DIR. We postulated that this step is not necessary. We report our experience and focus on this technique. Material and Methods: This is a retrospective chart review, including hospital charts and office records, for patients who underwent laparoscopy for impalpable testes between May 2004 and May 2010. A-84 IPEG 2011—POSTER ABSTRACTS