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Projetos de Pesquisa
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Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina
LIM/30 - Laboratório de Investigação em Cirurgia Pediát, Hospital das Clínicas, Faculdade de Medicina

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Agora exibindo 1 - 10 de 18
  • article 6 Citação(ões) na Scopus
    Living donor liver transplantation in children: Should the adult donor be operated on by an adult or pediatric surgeon? Experience of a single pediatric center
    (2014) ANDRADE, Wagner de Castro; VELHOTE, Manoel Carlos Prieto; AYOUB, Ali Ahman; SILVA, Marcos Marques; GIBELLI, Nelson Elias M.; TANNURI, Ana Cristina A.; SANTOS, Maria Merces; PINHO-APEZZATO, Maria Lucia; BARROS, Fabio de; MOREIRA, Daniel Rangel; MIYATANI, Helena T.; PEREIRA, Raimundo Renato; TANNURI, Uenis
    Background/Purpose: Living donor liver transplantation has become a cornerstone for the treatment of children with end-stage hepatic dysfunction, especially within populations or countries with low rates of organ utilization from deceased donors. The objective is to report our experience with 185 living donors operated on by a team pediatric surgeons in a tertiary center for pediatric liver transplantation. Methods: Retrospective analysis of medical records of donors of hepatic grafts for transplant undergoing surgery between June 1998 and March 2013. Results: Over the last 14 years, 185 liver transplants were performed in pediatric recipients of grafts from living donors. Among the donors, 166 left lateral segments (89.7%), 18 left lobes without the caudate lobe (9.7%) and 1 right lobe (0.5%) were harvested. The donor age ranged from 16 to 53 years, and the weight ranged from 47 to 106 kg. In 10 donors, an additional graft of the donor inferior mesenteric vein was harvested to substitute for a hypoplastic recipient portal vein. The transfusion of blood products was required in 15 donors (8.1%). The mean hospital stay was 5 days. No deaths occurred, but complications were identified in 23 patients (12.4%): 9 patients experienced abdominal pain and severe gastrointestinal symptoms and 3 patients required reoperations. Eight donors presented with minor bile leaks that were treated conservatively, and 3 patients developed extra-peritoneal infections (1 wound collection, 1 phlebitis and 1 pneumonia). Eight grafts (4.3%) showed primary dysfunction resulting in recipient death (3 cases of fulminant hepatitis, 1 patient with metabolic disease, 1 patient with Alagille syndrome and 3 cases of biliary atresia in infants under 1 year old). There was no relation between donor complications and primary graft dysfunction (P = 0.6). Conclusions: Living donor transplantation is safe for the donor and presents a low morbidity. The donor surgery may be performed by a team of trained pediatric surgeons.
  • article 23 Citação(ões) na Scopus
    Pediatric acute liver failure in Brazil: Is living donor liver transplantation the best choice for treatment?
    (2016) TANNURI, Ana Cristina Aoun; PORTA, Gilda; MIURA, Irene Kazue; SANTOS, Maria Merces; MOREIRA, Daniel de Albuquerque Rangel; REZENDE, Nathassia Mancebo Avila de; MIYATANI, Helena Thie; TANNURI, Uenis
    Acute liver failure (ALF) in children is a life-threatening condition that often leads to urgent liver transplantation (LT). The aim of the present investigation was to describe the experience in Brazil in treating pediatric ALF, with an emphasis on the role of living donor liver transplantation (LDLT) in treating this condition. All children with ALF who fulfilled the criteria for an urgent LT were admitted to the intensive care unit. Patients were divided into 2 groups based on the moment of admission: before and after June 2007, when the LDLT program for ALF was started. Statistical analyses were performed to identify prognostic factors of patients with ALF. For the study, 115 children with ALF were admitted. All patients had some degree of encephalopathy. Among the patients, 26% of them required intracranial pressure monitoring (IPM), 12.8% of the patients required hemodialysis, and 79 patients underwent transplantation (50 deceased donors and 29 living donors) corresponding to 12.4% of all pediatric LTs. Only 9 children recovered without LT. The need for IPM and nonperformance of LT were related to a higher mortality. The mortality rate of patients who underwent LT was significantly lower than that of children with ALF who did not undergo a LT (48.1% versus 75%; P = 0.02). The incidences of primary nonfunction and mortality were statistically higher among deceased donor liver transplantations than LDLTs. Finally, it was verified that the overall survival rate of transplanted patients was increased after the introduction of LDLT (P = 0.02). In conclusion, ALF in children continues to be a severe and devastating condition, and a LT should be performed promptly. The introduction of LDLT could increase the survival rate of patients in Brazil. Liver Transplantation 22 1006-1013 2016 AASLD
  • article 18 Citação(ões) na Scopus
    Is hematoxylin-eosin staining in rectal mucosal and submucosal biopsies still useful for the diagnosis of Hirschsprung disease?
    (2017) SERAFINI, Suellen; SANTOS, Maria Merces; TANNURI, Ana Cristina Aoun; ZERBINI, Maria Claudia Nogueira; COELHO, Maria Cecilia de Mendonca; GONCALVES, Josiane de Oliveira; TANNURI, Uenis
    Background: Hematoxylin-eosin (HE) staining of a full-thickness rectal wall fragment is classically used for the diagnosis of Hirschsprung disease (HD). However, this technique requires large fragments for a better diagnosis. Additionally, the histochemical and immunohistochemical methods of staining small fragments of rectal mucosal and submucosal biopsies are not available in all centers. Therefore, the possibility of diagnosing HD through HE staining in these biopsies could be a valuable alternative for centers that do not have more specific techniques. The objectives of the current investigation were to evaluate the concordance of the results obtained by HE staining and the calretinin method with acetylcholinesterase (AChE) activity in fragments of mucosa and submucosa in the diagnosis of HD. Methods: For this study, 50 cases from our laboratory were selected. The tissue material was embedded in paraffin. Sixty levels of each fragment were utilized for HE, and the other 3 levels were used for calretinin. These slides were analyzed under the microscope, photographed and classified as either positive for HD when no ganglion cells were found with nerve trunks present or as negative when ganglion cells were found. The results from reading the slides were compared with those of AChE. Results: Of the 50 cases evaluated by the HE technique, only 5 contradicted the diagnosis based on AChE, with a Kappa value of 0.800 and an accuracy of 90%. In the comparison between calretinin and AChE, 8 cases were discordant, with a Kappa value of 0.676 and an accuracy of 84%. Conclusions: The concordance of results from AChE and HE methods was satisfactory, allowing for the potential use of the HE method for fragments of mucosa and submucosa as a valid alternative in the diagnosis of HD. The immunohistochemical technique of calretinin did not show good agreement with the AChE activity in our study.
  • article 10 Citação(ões) na Scopus
    The role of interleukin-6, endothelins, and apoptotic genes in small bowel transplantation, in a swine model of ischemia and reperfusion injury
    (2011) PINHO-APEZZATO, Maria Lucia de; MAKSOUD-FILHO, Joao Gilberto; VALINETTI, Emilia Aparecida; SANTOS, Maria Merces; TANNURI, Ana Cristina Aoun; MELLO, Evandro Sobroza; SILVA, Luiz Fernando; COELHO, Maria Cecilia de Mendonca; GIBELLI, Nelson Elias Mendes; ROCHA, Rafael Malagoli; NONOGAKI, Suely; GUIMARAES, Raimundo Renato Nunes; TANNURI, Uenis
    IRI is closely related to sepsis in ITx setting. Complete understanding of the mechanisms involved in IRI development may improve outcomes. Ortothopic ITx without immunosuppression was performed in order to characterize IRI-associated mucosal damage. Twenty pigs underwent ITx. Two groups were assigned to different CI times: G1: 90 min and, G2: 180 min. Euro-Collins was used as preservation solution. Jejunal fragments were collected at donor laparotomy, 30 min, and 3 days after reperfusion. IRI assessment involved: histopathologic analysis, quantification of MPO-positive cells through immunohistochemical studies, quantification of epithelial apoptotic cells using TUNEL staining, and quantification of IL-6, ET-1, Bak, and Bcl-XL genes expression by RT-PCR. Neutrophilic infiltration increased in a similar fashion in both groups, but lasted longer in G2. Apoptosis detected by TUNEL staining increased and anti-apoptotic gene Bcl-XL expression decreased significantly in G1, 3 days after surgery. Endothelin-1 and IL-6 genes expression increased 30 min after the procedure and returned to baseline 3 days after surgery. In conclusion, IL-6 and ET-1 are involved precociously in the development of intestinal IRI. Apoptosis was more frequently detected in G1 grafts by TUNEL-staining and by RT-PCR.
  • article 37 Citação(ões) na Scopus
    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), alpha-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.
  • article 15 Citação(ões) na Scopus
    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.
  • article 0 Citação(ões) na Scopus
    Microsurgical arterial anastomosis in young and adult rats: an evolutive and comparative study
    (2022) SANTOS, Maria Merces; TANNURI, Ana Cristina Aoun; LACERDA, Adriana Vasconcelos; GONCALVES, Josiane de Oliveira; RICARDI, Luiz Roberto Schlaich; TANNURI, Uenis
    Purpose: To evaluate the caliber of an arterial micro-anastomosis in the young growing animal using a continuous suture technique. Additionally, late morphological changes and blood flows distal to the anastomosis were evaluated. Methods: Seventy-four Wistar rats were submitted to laparotomy to access the aorta for blood flow measurement. The aorta was sectioned using microsurgery technique and an end-to-end anastomosis with continuous suture. After a period of six months to one year, the anastomosis was checked. Results: Regarding the size of the aortas, comparing the pre- and postoperative values, there was an increase of 13.33% in adult animals and 25% in young animals, without any difference in the blood flows. Conclusion: The arteries of young rats show signs of growth at the site of the anastomosis performed with continuous suture.
  • article 16 Citação(ões) na Scopus
    A new simplified technique of arterial reconstruction in pediatric living-donor liver transplantation: A comparison with the classical technique
    (2014) TANNURI, Ana Cristina Aoun; MONTEIRO, Roberta Figueiredo; SANTOS, Maria Merces; MIYATANI, Helena Thie; TANNURI, Uenis
    Background/Aim: Hepatic artery anastomosis (HAA) is the most important aspect of living donor liver transplantation (LDLT), and it is currently performed by a specialized microsurgeon using micro surgical techniques, with interrupted sutures and the aid of an operative microscope. To simplify the procedure, we studied a new, simpler technique performed by pediatric transplant surgeons with continuous sutures and the same 3.5x magnification loupe used during other transplant procedures. The aim of this study was to compare these two hepatic artery reconstruction techniques in two pediatric LDLT series. Methods: This study was initiated in January 2010 and finished in June 2013. In the first period, the arterial reconstruction was performed with an operating microscope and the classical technique of 9-0 separate sutures. In the second period, the arterial reconstruction was performed using a simpler technique, with surgical loupe and continuous 8-0 Prolene sutures. The incidences and outcomes of complications within the two periods were analyzed and compared. Results: A total of 82 LDLTs were performed, 38 in the first period and 44 in the second period. There were no differences between the periods, except for the arterial ischemia time, which was lower in the second period. Conclusion: Hepatic artery anastomosis can be safely performed with low complication rates by a pediatric transplant surgeon using continuous sutures with a 3.5x magnifying loupe. This technique is simpler, less time consuming and simplifies the complex pediatric LDLT procedure.
  • article 15 Citação(ões) na Scopus
    Which is the best technique for hepatic venous reconstruction in pediatric living-donor liver transplantation? Experience from a single center
    (2011) TANNURI, Uenis; SANTOS, Maria M.; TANNURI, Ana Cristina A.; GIBELLI, Nelson E.; MOREIRA, Airton; CARNEVALE, Francisco C.; AYOUB, Ali A.; MAKSOUD-FILHO, Joao G.; ANDRADE, Wagner C.; VELHOTE, Manoel C. P.; SILVA, Marcos M.; PINHO-APEZZATO, Maria L.; MIYATANI, Helena T.; GUIMARAES, Raimundo R. N.
    Background/purpose: The introduction of the piggyback technique for reconstruction of the liver outflow in reduced-size liver transplants for pediatric patients has increased the incidence of hepatic venous outflow block (HVOB). Here, we proposed a new technique for hepatic venous reconstruction in pediatric living-donor liver transplantation. Methods: Three techniques were used: direct anastomosis of the orifice of the donor hepatic veins and the orifice of the recipient hepatic veins (group 1); triangular anastomosis after creating a wide triangular orifice in the recipient inferior vena cava at the confluence of all the hepatic veins (group 2); and a new technique, which is a wide longitudinal anastomosis performed at the anterior wall of the inferior vena cava (group 3). Results: In groups 1 and 2, the incidences of HVOB were 27.7% and 5.7%, respectively. In group 3, no patient presented HVOB (P = .001). No difference was noted between groups 2 and 3. Conclusions: Hepatic venous reconstruction in pediatric living-donor liver transplantation must be preferentially performed by using a wide longitudinal incision at the anterior wall of the recipient inferior vena cava. As an alternative technique, triangulation of the recipient inferior vena cava, including the orifices of the 3 hepatic veins, may be used.
  • article 16 Citação(ões) na Scopus
    Technique advance to avoid hepatic venous outflow obstruction in pediatric living-donor liver transplantation
    (2015) TANNURI, Uenis; TANNURI, Ana Cristina A.; SANTOS, Maria M.; MIYATANI, Helena T.
    HVOO represents a serious critical complication of pediatric living-donor liver transplantation because open surgical repair is virtually impossible. Currently, despite several technical innovations and the introduction of triangulated anastomosis for hepatic vein reconstruction, the reported incidence of HVOO is still considerable. The aim of this study was to propose a new technique for hepatic venous reconstruction that avoids the original orifice of the recipient hepatic veins. Instead, anastomosis is performed in a newly created wide longitudinal orifice in the anterior wall of the recipient inferior vena cava. A total of 210 living related-donor liver transplantations were performed using two methods for reconstruction of the hepatic vein. Group 1 included 69 patients subjected to direct anastomosis of the orifice of the graft hepatic vein and a wide orifice created in the recipient inferior vena cava by the confluence of the orifices of the right, left, and middle hepatic veins. Group 2 included 141 patients in whom the original orifices of the recipient hepatic veins were closed, the inferior vena cava was widely opened, and a long longitudinal anastomosis was performed using two lines of continuous sutures. Diagnosis of HVOO was suspected based on clinical findings and ultrasound studies and then confirmed by liver biopsy and interventional radiology examinations. Among the 69 recipients in group 1, 16 patients died due to graft problems during the postoperative period and eight of the survivors (15.1%) presented with HVOO. In group 2 (141 patients), 21 patients died, and there were no cases of HVOO. A comparison of the incidence of HVOO between groups revealed a significant difference (p=0.01). Hepatic venous reconstruction during pediatric living-donor liver transplantation should be performed using a wide longitudinal incision in the anterior wall of the recipient inferior vena cava because this technique eliminated anastomosis complications.