A Comparative Review of the Outcome Following MVD and PBC in Patients with Trigeminal Neuralgia.

BACKGROUND: This study aims to systematically review the treatment outcomes of percutaneous balloon compression (PBC) and microvascular decompression (MVD) in patients with trigeminal neuralgia. METHODS: A systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline was performed using PubMed, Embase, and Cochrane Central Registry of Controlled Trials databases. Only those articles with more than 5 years' follow-up length were included in this investigation. To uniformly assess the postoperative outcome, we defined pain relief as totally pain free, while the postoperative hospitalization and last follow-up period were defined as early and long term, respectively. The facial numbness was quantified with Barrow Neurological Institute Pain Intensity Score (BNI). RESULTS: After database searching and screening, 7,797 cases were finally included according to the criteria. The early pain relief rates were 94.1% (1,551/1,649) and 89.9% (4,962/5,482) following PBC and MVD (odds ratio [OR] = 0.603; p < 0.05), while the long-term rates were 58.1% (921/1,566) and 74.9% (4,549/6,074; OR = 2.089; p < 0.05), respectively. Although a significant higher facial numbness occurred in the PBC group in the early stage, it was mostly diminished 5 years later compared with the MVD group. At long-term follow-up, hypoacusis and facial palsy occurred more often in the MVD group (p < 0.05). CONCLUSIONS: Both MVD and PBC provide a satisfactory outcome for the patients in the long term. As a simple, safe, and reliable technique, PBC should be considered as a viable alternative.

Genome-wide copy number variation study in anorectal malformations.

Anorectal malformations (ARMs, congenital obstruction of the anal opening) are among the most common birth defects requiring surgical treatment (2-5/10 000 live-births) and carry significant chronic morbidity. ARMs present either as isolated or as part of the phenotypic spectrum of some chromosomal abnormalities or monogenic syndromes. The etiology is unknown. To assess the genetic contribution to ARMs, we investigated single-nucleotide polymorphisms and copy number variations (CNVs) at genome-wide scale. A total of 363 Han Chinese sporadic ARM patients and 4006 Han Chinese controls were included. Overall, we detected a 1.3-fold significant excess of rare CNVs in patients. Stratification of patients by presence/absence of other congenital anomalies showed that while syndromic ARM patients carried significantly longer rare duplications than controls (P = 0.049), non-syndromic patients were enriched with both rare deletions and duplications when compared with controls (P = 0.00031). Twelve chromosomal aberrations and 114 rare CNVs were observed in patients but not in 868 controls nor 11 943 healthy individuals from the Database of Genomic Variants. Importantly, these aberrations were observed in isolated ARM patients. Gene-based analysis revealed 79 genes interfered by CNVs in patients only. In particular, we identified a de novo DKK4 duplication. DKK4 is a member of the WNT signaling pathway which is involved in the development of the anorectal region. In mice, Wnt disruption results in ARMs. Our data suggest a role for rare CNVs not only in syndromic but also in isolated ARM patients and provide a list of plausible candidate genes for the disorder.

Perioperative and late outcomes of laparoscopic fundoplication for neurologically impaired children with gastro-esophageal reflux disease.

BACKGROUND: Persistent gastro-esophageal reflux (GER) due to various pathological factors often results in overt clinical symptoms and signs, which is termed as gastro-esophageal reflux disease (GERD). Affected children usually present with failure to thrive, recurrent pneumonia or apnea. Many neurologically impaired children have symptoms related to GERD. Although laparoscopic fundoplication has been established to be an effective treatment modality for children with GERD, data on its role and long-term efficacy for neurologically impaired patients remain sparse. The aim of this study was to review the results of such patients who underwent laparoscopic fundoplication. METHODS: A retrospective review was performed from 1998 to 2009. All children with neurological impairment who had laparoscopic fundoplication were included. RESULTS: Fifty-nine GERD patients (male = 32, female = 27; mean age 6 years) were identified. All subjects showed symptoms of frequent emesis; 32 of them had history of hematemesis (54.2%); 54 had feeding difficulty; 35 (59.3%) had associated respiratory symptoms, including recurrent pneumonia. Gastrostomy was performed concurrently in 39 cases. There was no conversion to open procedure nor was there intra-operative complications and operative mortality. Emesis or hematemesis was controlled adequately in all. However, respiratory symptoms were not controlled in 10 patients (16.9%), and five of them required further respiratory assistance including nasal airway tube and tracheostomy. Clinical recurrence of GERD was not observed in any subject. Twelve patients died during follow-up (range from 3 months to 9 years) due to severe respiratory complications, cardiac arrest, and brain tumor. CONCLUSIONS: Laparoscopic fundoplication is an excellent procedure for controlling clinically significant symptoms in neurological impaired patients with GERD. Further studies are required to assess the improvement of the quality of life in such patients.

Genome-wide copy number analysis uncovers a new HSCR gene: NRG3.

Hirschsprung disease (HSCR) is a congenital disorder characterized by aganglionosis of the distal intestine. To assess the contribution of copy number variants (CNVs) to HSCR, we analysed the data generated from our previous genome-wide association study on HSCR patients, whereby we identified NRG1 as a new HSCR susceptibility locus. Analysis of 129 Chinese patients and 331 ethnically matched controls showed that HSCR patients have a greater burden of rare CNVs (p = 1.50 × 10(-5)), particularly for those encompassing genes (p = 5.00 × 10(-6)). Our study identified 246 rare-genic CNVs exclusive to patients. Among those, we detected a NRG3 deletion (p = 1.64 × 10(-3)). Subsequent follow-up (96 additional patients and 220 controls) on NRG3 revealed 9 deletions (combined p = 3.36 × 10(-5)) and 2 de novo duplications among patients and two deletions among controls. Importantly, NRG3 is a paralog of NRG1. Stratification of patients by presence/absence of HSCR-associated syndromes showed that while syndromic-HSCR patients carried significantly longer CNVs than the non-syndromic or controls (p = 1.50 × 10(-5)), non-syndromic patients were enriched in CNV number when compared to controls (p = 4.00 × 10(-6)) or the syndromic counterpart. Our results suggest a role for NRG3 in HSCR etiology and provide insights into the relative contribution of structural variants in both syndromic and non-syndromic HSCR. This would be the first genome-wide catalog of copy number variants identified in HSCR.

Mutations in the NRG1 gene are associated with Hirschsprung disease.

Hirschsprung disease (HSCR, congenital colon aganglionosis) is a relatively common complex genetic condition caused by abnormal development of the enteric nervous system (ENS). Through a recent genome-wide association study conducted on Chinese HSCR patients, we identified a new HSCR contributing locus, neuregulin 1 (NRG1; 8p12), a gene known to be involved in the development of the ENS. As genes in which disease-associated common variants are found are to be considered as candidates for the search of deleterious rare variants (RVs) in the coding sequences, we sequenced the NRG1 exons of 358 sporadic HSCR patients and 333 controls. We identified a total of 13 different heterozygous RVs including 8 non-synonymous (A28G, E134K, V266L, H347Y, P356L, V486M, A511T, P608A) and 3 synonymous amino acid substitutions (P24P, T169T, L483L), a frameshift (E239fsX10), and a c.503-4insT insertion. Functional analysis of the most conserved non-synonymous substitutions, H347Y and P356L, showed uneven intracellular distribution and aberrant expression of the mutant proteins. Except for T169T and V486M, all variants were exclusive to HSCR patients. Overall, there was a statistically significant over-representation of NRG1 RVs in HSCR patients (p = 0.008). We show here that not only common, but also rare variants of the NRG1 gene contribute to HSCR. This strengthens the role of NRG1.

RET mutational spectrum in Hirschsprung disease: evaluation of 601 Chinese patients.

Rare (RVs) and common variants of the RET gene contribute to Hirschsprung disease (HSCR; congenital aganglionosis). While RET common variants are strongly associated with the commonest manifestation of the disease (males; short-segment aganglionosis; sporadic), rare coding sequence (CDS) variants are more frequently found in the lesser common and more severe forms of the disease (females; long/total colonic aganglionosis; familial).Here we present the screening for RVs in the RET CDS and intron/exon boundaries of 601 Chinese HSCR patients, the largest number of patients ever reported. We identified 61 different heterozygous RVs (50 novel) distributed among 100 patients (16.64%). Those include 14 silent, 29 missense, 5 nonsense, 4 frame-shifts, and one in-frame amino-acid deletion in the CDS, two splice-site deletions, 4 nucleotide substitutions and a 22-bp deletion in the intron/exon boundaries and 1 single-nucleotide substitution in the 5' untranslated region. Exonic variants were mainly clustered in RET the extracellular domain. RET RVs were more frequent among patients with the most severe phenotype (24% vs. 15% in short-HSCR). Phasing RVs with the RET HSCR-associated haplotype suggests that RVs do not underlie the undisputable association of RET common variants with HSCR. None of the variants were found in 250 Chinese controls.

Fine mapping of the NRG1 Hirschsprung's disease locus.

The primary pathology of Hirschsprung's disease (HSCR, colon aganglionosis) is the absence of ganglia in variable lengths of the hindgut, resulting in functional obstruction. HSCR is attributed to a failure of migration of the enteric ganglion precursors along the developing gut. RET is a key regulator of the development of the enteric nervous system (ENS) and the major HSCR-causing gene. Yet the reduced penetrance of RET DNA HSCR-associated variants together with the phenotypic variability suggest the involvement of additional genes in the disease. Through a genome-wide association study, we uncovered a ∼350 kb HSCR-associated region encompassing part of the neuregulin-1 gene (NRG1). To identify the causal NRG1 variants contributing to HSCR, we genotyped 243 SNPs variants on 343 ethnic Chinese HSCR patients and 359 controls. Genotype analysis coupled with imputation narrowed down the HSCR-associated region to 21 kb, with four of the most associated SNPs (rs10088313, rs10094655, rs4624987, and rs3884552) mapping to the NRG1 promoter. We investigated whether there was correlation between the genotype at the rs10088313 locus and the amount of NRG1 expressed in human gut tissues (40 patients and 21 controls) and found differences in expression as a function of genotype. We also found significant differences in NRG1 expression levels between diseased and control individuals bearing the same rs10088313 risk genotype. This indicates that the effects of NRG1 common variants are likely to depend on other alleles or epigenetic factors present in the patients and would account for the variability in the genetic predisposition to HSCR.

Genome-wide association study identifies a susceptibility locus for biliary atresia on 10q24.2.

Biliary atresia (BA) is characterized by the progressive fibrosclerosing obliteration of the extrahepatic biliary system during the first few weeks of life. Despite early diagnosis and prompt surgical intervention, the disease progresses to cirrhosis in many patients. The current theory for the pathogenesis of BA proposes that during the perinatal period, a still unknown exogenous factor meets the innate immune system of a genetically predisposed individual and induces an uncontrollable and potentially self-limiting immune response, which becomes manifest in liver fibrosis and atresia of the extrahepatic bile ducts. Genetic factors that could account for the disease, let alone for its high incidence in Chinese, are to be investigated. To identify BA susceptibility loci, we carried out a genome-wide association study (GWAS) using the Affymetrix 5.0 and 500 K marker sets. We genotyped nearly 500 000 single-nucleotide polymorphisms (SNPs) in 200 Chinese BA patients and 481 ethnically matched control subjects. The 10 most BA-associated SNPs from the GWAS were genotyped in an independent set of 124 BA and 90 control subjects. The strongest overall association was found for rs17095355 on 10q24, downstream XPNPEP1, a gene involved in the metabolism of inflammatory mediators. Allelic chi-square test P-value for the meta-analysis of the GWAS and replication results was 6.94 x 10(-9). The identification of putative BA susceptibility loci not only opens new fields of investigation into the mechanisms underlying BA but may also provide new clues for the development of preventive and curative strategies.

Laparoscopic correction of biliary duct stenosis in choledochal cyst.

BACKGROUND/PURPOSES: Laparoscopy has been widely accepted as a technique for the excision of choledochal cyst, but there has been little experience using it as a therapeutic modality for hepatic duct stenosis. The aim of this study is to present our experiences in laparoscopic excision of biliary stenosis and Roux-en-Y reconstruction for patients with choledochal cysts. METHODS: Eight patients, 3 boys and 5 girls (ranged from 6 months to 12 years; median age, 3.6 years), with hepatic duct stenosis underwent laparoscopic excision of the cyst and ductoplasty, with a Roux-en-Y hepaticoenterostomy between July 2001 and January 2005. Seven of the 8 patients had common hepatic duct stenosis with intrahepatic duct dilatation, and 1 had right hepatic duct stenosis with proximal dilatation. Four ports were inserted for instruments of 3- and 5-mm sizes. Each patient underwent a laparoscopic cholangiography. The gallbladder and dilated bile ducts were completely excised. The strictures of the hepatic ducts were treated by ductoplasty. The cut end of the duct was widened by incising along the anterior wall of the hepatic duct after excision of the narrow segment. By using intraoperative bile duct endoscopy, the optimal level of resection of the common hepatic duct was determined safely without endangering the orifices of the hepatic ducts or leaving any redundant duct, and the stone debris in the bile duct was identified and washed out. The Roux-en-Y jejunal loop was fashioned extracorporeally by exteriorizing the jejunum through the umbilical incision (1.0-1.5 cm) and passed up retrocolically followed by an end-to-side hepaticojejunostomy. RESULTS: The median duration of the operation was 4.3 hours (3.8-5.6 hours). Intraoperative bleeding was minimal, with no patients requiring blood transfusion. In 7 of the 8 cases, postoperative hospital stay ranged from 4 to 6 days; the other case had bile leak, which was cured by draining for 26 days without surgical intervention. All the patients had been followed up for 6 to 51 months. They stayed asymptomatic and well with no delayed complication. CONCLUSIONS: Laparoscopically assisted hepatic ductoplasty is effective and safe for children with choledochal cyst. Bile duct endoscopy proved to be a valuable instrument in showing detailed variations of the biliary system and allowed a safe hepatic hilum exploration and accurate placed hepaticojejunal anastomosis.