Application of a new system for classifying root canal morphology in undergraduate teaching and clinical practice: a national survey in Malaysia.

AIM: To evaluate and compare the feedback of final year undergraduate dental students in eight Malaysian dental schools on the application of a new system for classifying root canal morphology in teaching and clinical practice. METHODS: One PowerPoint presentation describing two classification systems for root canal morphology (Oral Surgery Oral Medicine Oral Pathology, 1974 38, 456 and its supplemental configurations, International Endodontic Journal 2017, 50, 761) was delivered to final year undergraduate dental students in eight dental schools in Malaysia by two presenters (each presented to four schools). To examine students' feedback on the utility of each system, printed questionnaires consisting of six questions (five multiple choice questions and one open-ended question) were distributed and collected after the lecture. The questionnaire was designed to compare the classification systems in terms of accuracy, practicability, understanding of root canal morphology and recommendation for use in pre-clinical and clinical courses. The exact test was used for statistical analysis, with the level of significance set at 0.05 (P = 0.05). RESULTS: A total of 382 (out of 447) students participated giving a response rate of 86%. More than 90% of students reported that the new system was more accurate and more practical compared with the Vertucci system (P < 0.001). Overall, 97% of students reported the new system helped their understanding of root and canal morphology compared with the Vertucci classification (P < 0.001). Over 97% of students recommended the use of the new system in teaching, pre-clinical courses and clinical practice (P < 0.001). Except for two schools, no significant difference was detected between the responses of students for all questions at the different schools (P > 0.05). The students' responses for all questions were almost similar for both presenters (P > 0.05). CONCLUSIONS: The new system of International Endodontic Journal 2017, 50, 761 for classifying root and canal morphology was favoured by final year undergraduate dental students in Malaysia. The new system has the potential to be included in the undergraduate endodontic curriculum for teaching courses related to root and canal morphology.

Living related donor liver transplantation in children.

OBJECTIVE: The objective of this study was to report our experience with pediatric orthotopic liver transplantation (OLT) with living related donors. METHODS: We performed a retrospective chart analysis of 121 living related donor liver transplantations (LRDLT) from June 1998 to June 2010. RESULTS: Indications were biliary atresia (BA; n = 81), primary sclerosing cholangitis (n = 5), α-1 antitrypsin deficiency (n = 4); cholestasis (n = 9), fulminant hepatic failure (n = 8), autoimmune hepatitis (n = 2), Alagille syndrome (n = 4), hepatoblastoma (n = 3), tyrosinemia (n = 2), and congenital hepatic fibrosis (n = 3). The age of the recipients ranged from 7-174 months (median, 22) and the weights ranged from 6-58 kg (median, 10). Forty-nine children (40.5%) weighed ≤10 kg. The grafts included the left lateral segment (n = 108), the left lobe (n = 12), and the right lobe (n = 1). The donors included 71 mothers, 45 fathers, 2 uncles, 1 grandmother, 1 grandfather, and 1 sister with a median age of 29 years (range, 16-53 ys) and a median weight of 68 kg (range, 47-106). Sixteen patients (12.9%) required retransplantation, most commonly due to hepatic artery thrombosis (HAT; n = 13; 10.7%). The other complications were biliary stenosis (n = 25; 20.6%), portal vein thrombosis (PVT; n = 11; 9.1%), portal vein stenosis (n = 5; 4.1%), hepatic vein stenosis (n = 6; 4.9%), and lymphoproliferative disorders (n = 8; 6.6%). The ultimate survival rate of recipients was 90.3% after 1 year and 75.8% after 3 years. Causes of early death within 1 month were HAT (n = 6), PVT (n = 2), severe graft dysfunction (n = 1), sepsis (n = 1), and intraoperative death in children with acute liver failure (n = 2). Causes of late deaths included lymphoproliferative disease (n = 3), chronic rejection (n = 2), biliary complications (n = 3), and recurrent disease (n = 3; hepatoblastoma and primary sclerosing cholangitis). CONCLUSIONS: Despite the heightened possibility of complications (mainly vascular), LRDLT represented a good alternative to transplantation from cadaveric donors in pediatric populations. It was associated with a high survival ratio.

Orthotopic liver transplantation in biliary atresia: a single-center experience.

INTRODUCTION: Biliary atresia (BA) is the leading indication for orthotopic liver transplantation (OLT) among children. However, there are technical difficulties, including the limited dimensions of anatomical structures, hypoplasia and/or thrombosis of the portal vein and previous portoenterostomy procedures. OBJECTIVE: The objective of this study was to present our experience of 239 children with BA who underwent OLT between September 1989 and June 2010 compared with OLT performed for other causes. METHODS: We performed a retrospective analysis of patient charts and analysis of complications and survival. RESULTS: BA was the most common indication for OLT (207/409; 50.6%). The median age of subjects was 26 months (range, 7-192). Their median weight was 11 kg (range, 5-63) with 110 children (53.1%) weighing ≤10 kg. We performed 126 transplantations from cadaveric donors (60.8%) and 81 from living-related donors (LRD) (39.2%). Retransplantation was required for 31 recipients (14.9%), primarily due to hepatic artery thrombosis (HAT; 64.5%). Other complications included the following: portal vein thrombosis (PVT; 13.0%), biliary stenosis and/or fistula (22.2%), bowel perforation (7.0%), and posttransplantation lymphoproliferative disorder (PTLD; 5.3%). Among the cases of OLT for other causes, the median age of recipients was 81 months (range, 11-17 years), which was higher than that for children with BA. Retransplantation was required in 3.5% of these patients (P < .05), mostly due to HAT. The incidences of PVT, bowel perforation, and PTLD were significantly lower (P < .05). There was no significant difference between biliary complications in the 2 groups. The overall survival rates at 1 versus 5 years were 79.7% versus 68.1% for BA, and 81.2% versus 75.7% for other causes, respectively. CONCLUSIONS: Children who undergo OLT for BA are younger than those engrafted for other causes, displaying a higher risk of complications and retransplantations.

Rex shunt for acute portal vein thrombosis after pediatric liver transplantation in children with biliary atresia.

BACKGROUND/PURPOSE: Posttransplantation portal vein thrombosis (PVT) can have severe health consequences, and portal hypertension and other consequences of the long-term privation of portal inflow to the graft may be hazardous, especially in young children. The Rex shunt has been used successfully to treat PVT patients since 1998. In 2007, we started to perform this surgery in patients with idiopathic PVT and late posttransplantation PVT. Herein we have reported our experience with this technique in acute posttransplantation PVT. METHODS: Three patients of ages 12, 15, and 18 months underwent cadaveric (n = 1) or living donor (n = 2) orthotopic liver transplantation (OLT). All patients had biliary atresia with portal vein hypoplasia; they developed acute PVT on the first postoperative day. They underwent a mesenteric-portal surgical shunt (Rex shunt) using a left internal jugular vein autograft (n = 2) or cadaveric iliac vein graft (n = 1) on the first postoperative day. RESULTS: The 8-month follow-up has confirmed shunt patency by postoperative Doppler ultrasound. There have been no biliary complications to date. CONCLUSIONS: The mesenteric-portal shunt (Rex shunt) using an autograft of the left internal jugular or a cadaveric vein graft should be considered for children with acute PVT after OLT. These children usually have small portal veins; reanastomosis is often unsuccessful. In addition, this technique has the advantage to avoid manipulation of the hepatic hilum and biliary anastomosis. Although this study was based on a limited experience, we concluded that this technique is feasible, with great benefits to and low risks for these patients.

Multiple clinical presentations of lymphoproliferative disorders in pediatric liver transplant recipients: a single-center experience.

Posttransplantation lymphoproliferative disorder (PTLD) is a serious complication following solid organ transplantation that has been linked to Epstein-Barr virus (EBV) infection. The aim of this article was to describe a single-center experience with the multiplicity of clinical presentations of PTLD. Among 350 liver transplantations performed in 303 children, 13 survivor children displayed a histological diagnosis of PTLD (13/242 survivors; 5.4%). The age at diagnosis ranged from 12 to 258 months (median, 47), and the time from transplantation ranged from 1 to 84 months (median, 13). Ten of these children (76.9%) were EBV-naïve prior to transplantation. Fever was present in all cases. The clinical signs at presentation were anemia (92.3%), diarrhea and vomiting (69.2%), recurrent upper airway infections (38.4%), Waldeyer ring lymphoid tissue hypertrophy (23.0%), abdominal mass lesions (30.7%), massive cervical and mediastinal adenopathy (15.3%), or gastrointestinal and respiratory symptoms (30.7%). One child developed fulminant hepatic allograft failure secondary to graft involvement by PTLD. Polymorphic PTLD was diagnosed in 6 patients; 7 had the diagnosis of lymphoma. Treatment consisted of stopping immunosuppression as well as starting intravenous gancyclovir and anti-CD20 monoclonal antibody therapy. The mortality rate was 53.8%. The clinical presentation of PTLD varied from fever of unknown origin to fulminant hepatic failure. The other symptoms that may be linked to the diagnosis of PTLD are pancytopenia, tonsil and adenoid hypertrophy, cervical or mediastinal lymph node enlargement, as well as abdominal masses. Despite numerous advances, the optimal treatment approach for PTLD is not completely known and the mortality rate is still high.

Sirolimus in pediatric liver transplantation: a single-center experience.

BACKGROUND AND AIMS: Liver transplantation (OLT) in children has seen significant improvements in recent years. Long-term immunosuppressive strategies have focused on avoiding the risks of long-term immunosuppression, particularly nephrotoxicity, de novo malignancy and late infections. Since its introduction in renal transplantation in 1999, sirolimus (SRL) has been used by an increasing number of liver transplant centers. The aim of this study was to review the experience using SRL in pediatric liver transplant recipients at a single center. METHODS: Between 1989 and 2006, 318 children underwent OLT including 13 who were converted to SRL therapy because of tacrolimus-related side effects. The indications were posttransplant lymphoproliferative disease (PTLD; n = 11), nephrotoxicity (n = 1), and de novo autoimmune hepatitis (n = 1). One patient with PTLD previously concurrently displayed chronic rejection. SRL dosages ranged between 0.4 and 5 mg/d. The median duration of follow-up was 18 months. RESULTS: PTLD recurred in 1 patient. There were no episodes of acute rejection. One child developed hyperlipidemia that resolved with diet and medication. CONCLUSIONS: Conversion from tacrolimus to SRL in selected pediatric liver transplant recipients is safe. Children with PTLD may benefit from immunosuppression with SRL after liver transplantation.

"Rex shunt" for the treatment of portal vein thrombosis after pediatric liver transplantation: a case report.

BACKGROUND AND PURPOSE: Late portal vein thrombosis (PVT) can be extremely well tolerated, although portal hypertension and other consequences of the long-term deprivation of portal inflow to the graft may be hazardous, especially in young children. Recently, the "Rex shunt" has been used successfully to treat these patients. We now report the initial experience with this novel technique. METHODS: A 3-year-old girl with PVT at 7 months after whole organ cadaveric liver transplant displayed portal hypertension with an episode of gastrointestinal bleeding, requiring a mesenteric-portal surgical shunt ("Rex shunt") using a left internal jugular vein autograft. RESULTS: Upon current follow-up of 6 months, postoperative Doppler ultrasound confirmed shunt patency. Endoscopic status was significantly improved after surgery with resolution of portal hypertension. There was no recurrence of bleeding. CONCLUSIONS: The mesenteric-portal shunt ("Rex shunt"), using a left internal jugular vein autograft, should be considered for children with late PVT after liver transplantation. Although this is an initial experience, we may conclude that this technique is feasible, with great potential benefits and low risks for these patients.

Pediatric liver transplantation: fourteen years of experience at the children institute in São Paulo, Brazil.

This study reports the 14-year experience of a single center on 206 liver transplantations from living and cadaveric donors performed in 179 pediatric patients. Biliary atresia (57.2%) and fulminant hepatitis (9.8%) were the most frequent indications. The mean age of the recipients was 3 years, 7 months (9 months to 18 years) and mean weight was 14 kg (7 to 57 kg). The allografts were distributed as 82 (39.8%) whole cadaveric, 76 (36.9%) reduced-size cadaveric, 46 (22.3%) living donor liver transplants, and 2 (0.9%) ex situ split livers. The waiting periods were 25 days for living donors and 2.5 years for cadaveric donors (P <.001). Twenty-seven children were retransplanted with hepatic artery thrombosis the most frequent indication. The postoperative complications were: primary nonfunction (12.2%), biliary stenosis (28.8%), hepatic artery thrombosis (12.2%), portal vein stenosis (4.9%), hepatic vein stenosis (6.9%), and lymphoproliferative disorder (5.9%). The diagnosis of biliary stenosis was obtained by liver biopsy and transhepatic cholangiography and treated by balloon dilatation, although four children (3.9%) required a redo hepaticojejunostomy. The venous stenoses were percutaneously dilated with five-children (4.9%) requiring venous stents. The incidence of hepatic vein stenosis was 15.6% among living donor and 2.5% in cadaveric liver transplantation (P <.05). The overall 5-year patient and graft survivals were 70.2% and 65.1%. Liver transplantation provides excellent long-term survival. The use of grafts from living donors decreases the waiting periods but increases the incidence of hepatic vein stenosis.

Basiliximab-chimeric anti-IL2-R monoclonal antibody in pediatric liver transplantation: comparative study.

Basiliximab is a monoclonal antibody that binds to the alpha subunit (CD(25)) of the interleukin-2 receptor of activated T lymphocytes. The advantage of basiliximab in organ transplantation is the reduce possibility to calcineurin inhibitor dosages to avoid nephrotoxicity. Basiliximab has significantly reduced the incidence of acute rejection (AR) in renal transplant recipients; however, the results are uncertain in liver transplantation (LT). The objective of this investigation was to assess the effect of basiliximab to prevent AR in the first 6 months after pediatric LT. From March 2000 to October 2001, 32 recipients of a primary orthotopic cadaveric or living donor LT were given basiliximab by intravenous bolus injection on the day of transplantation (day 0) and on day 4. Four children who received one dose were excluded from the study. The rate and the intensity of AR episodes, the incidence of chronic rejection, serum creatinine level, incidence of infections, adverse side effects, and daily oral dosage of cyclosporine (Neoral) to maintain the target blood level of 850 to 1000 mg/dL at C2, 2 hours after the administration, were analyzed in the remaining 28 recipients. Results were compared to those obtained from a matched historical group (n = 28) of similar age, weight, and hepatic diseases distribution. None of the analyzed parameters was statistically significant (P >.05) except for the daily oral dose of cyclosporine (7 to 13 mg/kg/dose, P <.05). In our series, the addition of basiliximab to the immunosuppressive therapy did not reduce the incidence of AR in pediatric LT.

Surgically produced congenital diaphragmatic hernia in fetal rabbits.

Animal models of congenital diaphragmatic hernia (CDH) still are indispensable for the evolution of knowledge related to this disease and to fetal surgery in general. The lamb has provided the most reliable experimental design thus far. Considering the possible advantages of using rabbits (rather than lambs) namely lower costs, no need of special veterinary facilities, smaller body size, year-round availability, higher number of fetuses per pregnancy, and shorter gestational period, a successful model of CDH was developed in fetal rabbits. Sixteen pregnant New Zealand rabbits underwent hysterotomy and fetal operation. Group 1 (6 does) underwent surgery on gestational day 20 and group 2 (10 does) on gestational day 24 or 25. The normal full gestation time is 31 to 33 days. In group 1, the CDH was created by transabdominal puncture and dilatation of the fetal diaphragm. In group 2, the CDH was created through open thoracotomy, either left or right. The fetuses were delivered by cesarean section on gestational day 30. The overall fetal survival rate was 0 for group 1 and 70% for group 2. All operated fetuses in group 2 that were born alive had CDH. The histological morphometric examinations (radial alveolar count after sustained lung expansion) of the normal and operated fetuses in group 2 showed pulmonary hypoplasia in all the lungs on the same side as the CDH (statistical analysis was performed using the Neuman-Keuls test and analysis of variance; the significance level was set at .05).(ABSTRACT TRUNCATED AT 250 WORDS)

[Liver transplantation in children: initial experience of the Instituto da Criança of the Hospital das Clínicas of Universidade de São Paulo]. / Transplante de fígado em criança: experiência inicial do Instituto da Criança do Hospital das Clínicas da Universidade de São Paulo.

The initial experience at the Instituto da Criança do Hospital das Clínicas--School of Medicine of São Paulo University with liver transplantation in children is presented. A staff experienced in the management of children, including pediatric surgeons, hepatologists, critical care specialists, anesthesiologists, and other has been joined to draw therapeutic protocols. Afterward, more than 100 experimental liver transplant were performed in animals of medium size (dogs and pigs). From September, 1989 to July 1991, 12 liver transplants were performed on 9 children (3 retransplants) ranging in age from 2.5 to 17 years, being 5 boys and 4 girls. The donors had been selected according to the ABO blood group and body weight. Just once a blood A+ recipient received a liver from a blood O+ donor. The regular postoperative immunosuppression consisted of triple therapy with cyclosporin, prednisone and azathioprine. The postoperative stay in the Intensive Care Unit ranged from 3 to 24 days, according to the necessity of ventilatory support. These was no intraoperative mortality, arterial or venous thromboses, or early biliary complications. The overall survival is 78% (7/9). Primary non-function of the graft was the cause of death in two of our children. Although the number of cases is still small our results are comparable to those of the best liver transplant centers in the world.

Is there a role for pericytic cells in the vascular bed of infantile hemangioendothelioma of the liver?

Electron microscopic examination of an infantile hemangioendothelioma (IHE) type I of the liver, appearing in a five month old child, showed a high density of pericytes in the walls of the neoplastic vessels. These vessels, in part of the IHE patients, establish an important arteriovenous shunt leading to high output, congestive cardiac failure. It is unclear whether functions ascribed to pericytes, such as participation in microvascular contractility or as suppressors of endothelial cell proliferation are involved in two noteworthy aspects of the present case. The child exhibited no congestive heart failure and the multiple nodular lesions underwent spontaneous regression.