Enlarging vascular stents after pediatric liver transplantation.

BACKGROUND: Endovascular intervention with stent placement to treat portal vein (PV) and hepatic vein (HV) stenosis after pediatric liver transplantation (LT) is still controversial in small children owing to the potential risk of functional stenosis after growth. The aim of this study is to evaluate the safety and efficacy of stent placement in this population. METHODS: Between 2004 and 2016, 6 children (all <3 years) received HV (n = 2) and PV (n = 4) stents placement among 46 pediatric LT patients at our institution. The clinical outcome and patency rate were followed. Morphologic changes of stents were assessed from plain films by a new index: the stent diameter ratio (SDR). RESULTS: The median age of the patients at LT was 8.9 months. The patency rate was 100% without functional stenosis during a median follow-up period of 65.5 months. The "stent growth" phenomenon was demonstrated by SDR with significant resolution of hourglass deformity 2 years after stent placement (p for trend <.001). CONCLUSION: Vascular stent placement is a safe and effective method for the management of PV and HV stenosis following pediatric LT because these stents will enlarge as children grow. TYPE OF STUDY: Case Series with no Comparison Group LEVEL OF EVIDENCE: Level IV.

Surgical outcomes of total colonic aganglionosis in children: a 26-year experience in a single institute.

BACKGROUND: There is a lack of consensus regarding the treatment of total colonic aganglionosis (TCA) with respect to perioperative morbidity, mortality, complications, and functional outcomes. The aim of this study was to review the results of surgical TCA treatment over a 26-year period and characterize the outcomes. METHODS: We retrospectively reviewed the clinical characteristics, surgical courses, and outcomes of TCA patients who underwent definitive pull-through operations from 1986 to 2012. Follow-up data were collected by chart reviews and telephone interviews using a standardized questionnaire. RESULTS: We identified nine infants with TCA (8.6%) from among 105 infants with Hirschsprung's disease treated during the 26-year period. Neither sex predominated (male/female ratio = 4:5). All infants underwent laparotomies and simultaneous enterostomies. All patients eventually underwent modified Duhamel pull-through procedures at a mean age of 179 days (range, 47-352 days). Two infants died of complications after surgery including heart failure and sepsis. The remaining infants recovered smoothly with antilaxative medications, and all but one was weaned off these medications. Although the surviving patients did not catch up on growth, they and their families were satisfied with the surgical results. CONCLUSION: Infants with TCA had satisfactory outcomes after the modified Duhamel pull-through operation. Based on our experience, we suggest that the pull-through operation could be performed earlier, even when there are loose stools from the enterostomy.

A newly designed total implantable venous access device in rats for research with high efficiency and low cost.

BACKGROUND: In this study, we introduced a newly designed totally implantable device for long-term vascular access in rats and compared its efficacy, related complications, and cost-effectiveness with conventional exteriorized jugular vein catheters. METHODS: Forty adult male Sprague-Dawley rats, weighing 250-300 g, were equally divided into two groups (I and II) and all underwent jugular vein catheterization surgery. The totally implanted device was used in group I and conventional exteriorized catheters were used in group II. The functionality of each catheter was checked every 3 d and evaluation included vascular accessibility, patency, and infection. The weight of the animal and microbial culture from the wound and tube were also monitored. We analyzed the cause of vascular access failure and complications, both mechanical and infectious, and compared related variables. RESULTS: The proportions of 9-d patency and 30-d patency in group I were 90% (18/20) and 75% (15/20), respectively, and in group II 80% (16/20) and 35% (7/20), respectively. There was a statistically significant difference in 30-d patency. The rats in group II were more liable to involve vascular access failure because of catheter dislodgment and had a higher infection rate (P = 0.001). Daily body weight gain was also greater in group I than in group II (2.46 ± 0.59 g/d versus 1.84 ± 0.96 g/d; P = 0.02). CONCLUSIONS: This newly designed and totally implanted device substantially increases the success rate of long-term venous access compared with conventional methods. It reinforces the merits of the subcutaneous port and a tethered swivel system and overall has better performance and reliability. Furthermore, given its low cost and the high level of effectiveness offered, this technology could be a powerful tool to be used in future translational medicine research, especially in cases of long-term intravascular administration.

Amelioration of paraquat-induced pulmonary injury by mesenchymal stem cells.

Acute paraquat (PQ) poisoning induces redox cycle and leads to fatal injury of lung. Clinical management is supportive in nature due to lack of effective antidote, and the mortality is very high. Mesenchymal stem cells (MSCs) process the properties of immunomodulation, anti-inflammatory, and antifibrotic effects and oxidative stress resistance. MSC transplantation may theoretically serve as an antidote in PQ intoxication. In this study, we examined the potential therapeutic effects of MSCs in PQ-induced lung injury. The degree of PQ toxicity in the rat type II pneumocyte cell line, L2, and MSCs was evaluated by examining cell viability, ultrastructural changes, and gene expression. L2 cells treated with 0.5 mM PQ were cocultured in the absence or presence of MSCs. For the in vivo study, adult male SD rats were administered an intraperitoneal injection of PQ (24 mg/kg body weight) and were divided into three groups: group I, control; group II, cyclophosphamide and methylprednisolone; group III, MSC transplantation 6 h after PQ exposure. MSCs were relatively resistant to PQ toxicity. Coculture with MSCs significantly inhibited PQ accumulation in L2 cells and upregulated the expression of antioxidative heme oxygenase 1 and metallothionein 1a genes, reversed epithelial-to-mesenchymal transition, and increased the viability of PQ-exposed L2 cells. Treatment with MSCs resulted in a significant reduction in severity of liver and renal function deterioration, alleviated lung injury, and prolonged the life span of rats. Altogether, our results suggest that MSCs possess antidote-like effect through multifactorial protection mechanism. The results of this preclinical study demonstrate that transplantation of MSCs may be a promising therapy and should be further validated clinically.

Augmentation cystoplasty and simultaneous ureteral reimplantation reduce high-grade vesicoureteral reflux in children with neurogenic bladder.

BACKGROUND: To compare the incidence of residual high-grade vesicoureteral reflux (HVUR) (≥Grade III) in neurogenic bladder patients receiving augmentation cystoplasty alone or with simultaneous ureteral reimplantation. Furthermore, we also tried to find the risk factors of residual VUR and febrile urinary tract infection. METHODS: Between 1999 and 2009, urinary bladder augmentation was performed in 21 children with neurogenic bladder. Seventeen of these patients had VUR on preoperative voiding cystourethrography, of whom 11 patients (14 ureters) received augmentation alone (Group A) and 6 patients (8 ureters) received simultaneously ureteral reimplantation (Group B). Univariate logistic regression analysis and Fisher exact test were used for statistical analysis. RESULTS: Six patients (8 ureters) had residual HVURs in Group A, but none in Group B. The incidences of residual HVUR were 57.14% and 0%, respectively. Seven patients had febrile UTIs after operation, 6 of them had residual HVURs. In risk factor analysis, postoperative follow-up duration less than 12 months and lack of anti-reflux operation were significant risk factors for residual HVUR; the residual HVUR was the significant risk factor for febrile urinary tract infection. CONCLUSION: Simultaneous ureteral reimplantation reduces postop HVUR significantly. We recommend augmentation and simultaneous ureteral reimplantation in children with HVUR and neurogenic bladder if technically feasible.

Using vote cards to encourage active participation and to improve critical appraisal skills in evidence-based medicine journal clubs.

RATIONALE, AIMS AND OBJECTIVES: Evidence-based medicine (EBM) journal clubs are used by health care practitioners to critique and remain updated on relevant health literature. Vote cards, in three different colours (green/yellow/red), allow participants to express their opinions (agree/doubt/reject) on the quality and possibility of clinical application regarding the article being reviewed. Our aim is to assess the efficacy of using vote cards in EBM journal clubs. METHODS: Evidence-based medicine journal club is held on a weekly basis in the Department of Surgery in Taipei Medical University Hospital, Taiwan. The participants of EBM journal clubs include medical students, resident doctors and primary care faculty members. After the presentation, participants use their vote cards to critically appraise the literature and decide if the rationales could be applied in their own practice. After a 12-week period, we evaluated the effectiveness of the vote cards based on survey findings of the participants. RESULTS: The majority of 66 respondents agreed that vote cards can improve the overall quality of EBM journal clubs, may encourage active participation and improve critical appraisal skills. They also rated the vote cards more favourably than traditional hand voting and agree that vote cards should be used in future EBM journal clubs. CONCLUSION: We suggest the regular and routine use of vote cards in EBM journal clubs.

Successful redo pull-through for Hirschsprung's disease in a Haddad syndrome patient.

Haddad syndrome is characterized by congenital central hypoventilation syndrome (Ondine's curse) associated with segmental distal gut aganglionosis (Hirschsprung's disease). The prognosis of Haddad syndrome is very poor, and survival is often less than 2 years. Treatment of Hirschsprung's disease is usually influenced by the association with Ondine's curse. We report the case of a girl with Haddad syndrome who underwent redo pull-through with Duhamel's method because of persistent obstruction after primary transanal pull-through surgery. After 7 years of follow-up, the patient is alive and does not suffer from recurrent partial intestinal obstruction. She performs her daily activities with the support of a portable ventilator. Thus, aggressive surgical treatment for Hirschsprung's disease could have good outcome in terms of long-term survival in Haddad syndrome patients.

Isolation and characterization of human muscle-derived cells.

OBJECTIVES: To isolate and characterize human muscle-derived cells (MDCs) for future management applications on lower urinary tract symptoms, including stress urinary incontinence and bladder reconstitution. The development of muscle stem cells for transplantation or gene transfer in patients with muscle disorders has become more attractive and challenging recently. METHODS: Human MDCs were isolated from the skeletal muscles of the limbs. The muscle tissues were minced, digested at 37 degrees C by 0.2% collagenase, trypsinized, filtered, and cultured in F12 medium with 15% fetal bovine serum at 37 degrees C. Human MDCs were then isolated using a modified preplate technique. After isolation, the MDCs were characterized by immunohistochemistry, flow cytometry, and indirect immunofluorescence. RESULTS: The growth doubling time of the MDCs was approximately 24 hours. Immunohistochemistry study was performed with the stem cell markers CD34, CD117, vascular cell adhesion molecule, and vascular endothelial growth factor receptor 2, and the relative stem cell position was identified. Positive immunofluorescence outcomes were found with the stem cell markers, myoblast markers CXCR4, CD56, desmin, and a fibroblast marker AB-1. Flow cytometry analysis identified markers CD34 and CD56 in the isolated MDCs, with a percentage of 5.12% and 10.34%, respectively. CONCLUSIONS: The isolation and characterization of human MDCs was successfully achieved. Human MDCs might have the potential to be a novel tool for the management of stress urinary incontinence and bladder reconstitution.

Analysis of the RET gene in subjects with sporadic Hirschsprung's disease.

BACKGROUND: Hirschsprung's disease (HSCR), or aganglionic megacolon, is a hereditable disease of the enteric nervous system. It is an embryonic developmental disorder characterized by the absence of ganglion cells in the lower enteric plexus. Gut motility is compromised in HSCR, with consequent risk of intestinal obstruction. METHODS: We sequenced the RET gene and characterized the clinical manifestations in 15 unrelated Chinese patients (9 males, 6 females; age range, 2-21 years) with sporadic HSCR. Genomic DNA extraction, PCR and DNA sequence analysis were performed according to standard procedures. RESULTS: We identified heterozygous RET gene mutations in 2 patients. The mutations included a missense mutation in exon 2 (CGC --> CAC) resulting in a substitution of arginine by histidine at codon 67 (patient 1), and a missense mutation in exon 3 (TAC --> AAC) resulting in a substitution of tyrosine by asparagine at codon 146 (patient 2). The pathological findings disclosed short-segment HSCR in patient 1 and long-segment HSCR in patient 2, respectively. CONCLUSION: We identified RET gene mutations in 2 of 15 patients with HSCR in Taiwan. The Y146N mutation we identified was novel.

Prepubertal testicular germ cell tumors: 25-year experience in Taipei Veterans General Hospital.

BACKGROUND: Due to the rarity of testicular tumors in the prepubertal population, adequate information about their biological course is difficult to document well in a single institution. The purpose of this study was to focus on prepubertal males in an attempt to evaluate clinical features and optimal management among various testicular germ cell tumors with long-term follow-up. METHODS: We retrospectively reviewed the records of children younger than 12 years of age with primary testicular germ cell tumors between February 1981 and December 2005 at Taipei Veterans General Hospital. Thirty-four children were diagnosed with adequate clinical and pathologic data. The stage of the disease was determined according to the staging system used by the Children's Oncology Group. Mean follow-up time was 139 months (range, 2-283 months). RESULTS: All of the 34 prepubertal patients were diagnosed initially with a painless scrotal mass. The mean age of the patients at diagnosis ranged from 6 months to 84 months (mean, 20.5 months). All patients underwent radical orchiectomy as an initial treatment. Twenty-nine (85.3%) patients had yolk sac tumors, and 5 (14.7%) had mature teratomas. Of the 29 patients with yolk sac tumor, 26 (89.7%) were diagnosed as stage I, 1 (3.4%) as stage III, and 2 (7.0%) as stage IV. Five (19.2%) of the 26 stage I yolk sac tumors progressed to metastasis after radical orchiectomy, and all of these 5 patients later received chemotherapy. One patient initially with stage III yolk sac tumor and 2 patients with stage IV yolk sac tumor were also treated with chemotherapy. Eventually, 1 patient with stage IV yolk sac tumor died due to tumor progression; the remaining 28 patients with yolk sac tumor all survived without tumor relapse after appropriate treatment. In the 5 patients with teratomas, there was no tumor relapse after radical orchiectomy with a mean follow-up time of 139.1 months. The 5-year survival rates for yolk sac tumor and teratomas were 96.5% and 100%, respectively. CONCLUSION: The most common prepubertal malignant testicular tumor is yolk sac tumor, and the most common benign testicular tumor is teratoma. Children with testicular germ cell tumors have excellent long-term survival rates after appropriate treatment.

Severe necrotizing fasciitis of the abdominal wall secondary to colon perforation in a child.

We discuss the successful saving of an 18-month-old boy with necrotizing fasciitis of the abdominal wall secondary to colon perforation and peritonitis. The patient underwent emergency surgery with exploratory laparotomy, repeated procedures of debridement, and reconstructive abdominal wall surgery with skin graft. He recovered 6 months after admission. We also address the issue of the closure of large abdominal wall defect and the importance of alimentation in this patient group. We discuss the need to recognize necrotizing fasciitis as a potential complication of intra-abdominal disease, as once necrotizing fasciitis occurs, mortality is more likely. We conclude that recognition and aggressive surgical debridement is mandatory.

Totally implantable venous access ports via the external jugular vein: safety and effectiveness for young pediatric patients.

BACKGROUND AND AIMS: Various venous approaches are possible during implanting a totally venous access port. The veins, which are commonly used in pediatric patients are internal and external jugular veins. Comparison of different venous approaches has been discussed in a few reports only. The present study reviews the complication rate, operation time of implanting the port via different veins in children. PATIENTS AND METHODS: From January 2003 to December 2005, 94 venous access ports were implanted in 88 consecutive patients in the Pediatric Surgical section of the Taipei Veterans General Hospital. The patients were classified according to the vein used. Group A (n=45), the external jugular vein access group; and group B (n=43), the internal jugular vein access group. RESULTS: The operation time in group A and B were 38.4+/-11.1 and 57.6+/-20.3 min, respectively. The mean operation time of group A was significantly shorter than that of group B (P<0.001). The overall complication rates in group A and B were 8.5%, and 19.1%, respectively. These differences, however, were not significant (P>0.05). CONCLUSIONS: The external jugular vein approach has a shorter operation time and a lower complication rate than the internal jugular vein approach. This approach may be a method of choice in selected pediatric patients.

Renal cell carcinoma in children and young adults.

Renal cell carcinoma (RCC) is a relatively uncommon tumor in childhood. Its biologic behavior and prognostic factors have rarely been documented. We report treatment and survival of 4 children (aged 8, 9, 11, and 14 years) who had RCC, along with a review of the literature to analyze the frequency of major symptoms, clinical stage, and prognostic factors based on 130 published cases of RCC in individuals younger than 20 years of age. Two of our cases had renal tumors detected by ultrasound screening, and all 4 cases were followed for a considerable length of time and were alive and free of disease after treatment. An analysis of these 130 published cases of pediatric RCC showed tumor staging and cell type to be the factors that affected patient survival. Tumors composed of granular cells or mixed cells, or at advanced stages, had a poor prognosis. Age, sex, tumor size, symptom duration, and cellular pattern were not related to patient prognosis. Children older than 10 years of age, who have an abdominal mass, flank pain, and/or hematuria should alert clinicians to consider the possibility of RCC. The importance of early diagnosis of renal tumors, using ultrasound as a tool of screening, is emphasized, since surgical treatment leads to a favorable prognosis only in the early stage of RCC.

Surgical treatment of chylothorax caused by cardiothoracic surgery in children.

Four pediatric cases of chylothorax after cardiothoracic surgery, which were managed surgically, are reviewed retrospectively. All patients underwent right thoracotomy and mass ligation of the right thoracic duct without detecting the true site of leakage. Although 1 patient died from heart failure the day after operation, the other 3 recovered quickly without sequelae. Based on our limited experience, we suggest that right thoracotomy with mass ligation of the right thoracic duct can successfully cure chylothorax on either side, particularly if identification of the site of leakage is considered too risky because of severe adhesion from previous cardiothoracic surgery.

Experience with removing Palmaz stents with a rigid bronchoscope.

BACKGROUND: The Palmaz stent can relieve congenital malacia or stenosis of airway, but reports on the indications and results of stent removal are rare. The authors report their experience in removing Palmaz stents and discuss the indications for removal. METHODS: Thirteen stents in 12 patients were removed by a rigid bronchoscope for various reasons. The indications were expected recovery (n = 5), severe granulations and expected recovery (n = 2), stent collapse (n = 2), and stent migration and/or fracture (n = 4). RESULTS: The course after removal was smooth in 9 patients and complicated in 3. The indications for stent removal in these 3 complicated cases were all expected recovery. One of the 3 complicated cases needed emergent cardiopulmonary bypass and tracheostomy for a collapsed stent that occluded airway, 1 failed for intractable bleeding, and 1 failed for intense vagal reflex causing cardiac arrest. At 6 months of follow-up, satisfactory results were seen in all but one case that needed further procedures for an iatrogenic tracheoesophageal fistula. CONCLUSIONS: Most Palmaz stents can be removed smoothly with a rigid bronchoscope; however, lethal complications can happen. The authors suggest that indications for stent removal should be intractable airway symptoms caused by the stent rather than expected recovery. Muscle relaxants should be avoided during anesthesia to maintain spontaneous breathing, and cardiopulmonary bypass should be on standby.

Hepatoblastoma and hepatocellular carcinoma in children.

BACKGROUND: After nation-wide hepatitis B vaccination in Taiwan, the authors reviewed retrospectively their experience to investigate how the histopathology type of pediatric malignant hepatic tumors changed and whether the survival rate was improved with current surgical technique and adjuvant chemotherapy. METHODS: Cases of hepatoblastoma and hepatocellular carcinoma were retrospectively analyzed and divided into 2 groups by time of diagnosis. Group I was those who received treatments during 1978 to 1990. Group II was those treated during 1991 to 2001. RESULTS: There were 20 cases of hepatoblastoma and 15 cases of hepatocellular carcinoma. Male predominance was noted in both groups (male:female, 12:8 and 9:6, respectively). The patients with hepatoblastoma were younger than those with hepatocellular carcinoma (mean/range, 9/2-36 months and 10/0.7-15 years, respectively). Cases of hepatocellular carcinoma were all hepatitis B carriers. The ratio of hepatoblastoma:hepatocellular carcinoma increased from 11:12 in group I to 9:3 in group II. Three-year survival rate of hepatoblastoma was zero in group I and 55% (5/9) in group II. Three-year survival rate of hepatocellular carcinoma was zero in both groups. Operative mortality was 9% (2/23) in group I and zero in group II. CONCLUSIONS: Since the institution of national program of universal hepatitis B vaccination, the incidence of hepatocellular carcinoma in children have declined in Taiwan. The improved survival of hepatoblastoma resulted from better surgical technique and chemotherapy.