MARIA MERCES SANTOS
Projetos de Pesquisa
Unidades Organizacionais
Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina
LIM/30 - Laboratório de Investigação em Cirurgia Pediát, Hospital das Clínicas, Faculdade de Medicina
LIM/30 - Laboratório de Investigação em Cirurgia Pediát, Hospital das Clínicas, Faculdade de Medicina
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- 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, UenisBackground/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.
- 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, UenisAcute 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
- 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, UenisBackground: 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.
- 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, UenisIRI 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.
- 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, UenisPurpose: 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.
- 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, UenisBackground/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.
- Congenital chylous ascites: A report of a case treated with hemostatic cellulose and fibrin glue(2013) MOREIRA, Daniel de Albuquerque Rangel; SANTOS, Maria Merces; TANNURI, Ana Cristina Aoun; TANNURI, UenisWe report a case of an infant with recurrent chylous ascites who was unresponsive to conventional medical treatment. An exploratory laparotomy revealed no macroscopically visible sites of lymph leakage that could be ligated. Lymph exudation was noted in areas near the subhepatic recess and in the lesser sac surrounding the pancreas, which was not amenable to suture. The treatment consisted of the placement of a hemostatic mesh composed of oxidized cellulose (Surgicel (R)) on these areas, with a thin layer of fibrinogen/thrombin glue over the mesh (Tissucol (R)). The cellulose mesh allowed for greater adhesion of the fibrin glue to the diseased tissues. The patient had no recurrence of ascites and is currently 20 months old, with good weight-height gain, and free of ascites.
- Current management of biliary atresia based on 35 years of experience at a single center(2018) ANDRADE, Wagner de Castro; SILVA, Marcos Marques; TANNURI, Ana Cristina Aoun; SANTOS, Maria Merces; GIBELLI, Nelson Elias Mendes; TANNURI, UenisOBJECTIVE: The prognosis of patients with biliary atresia undergoing Kasai portoenterostomy is related to the timing of the diagnosis and the indication for the procedure. The purpose of the present study is to present a practical flowchart based on 257 children who underwent Kasai portoenterostomy. METHODS: We conducted a retrospective cohort study of patients who underwent Kasai portoenterostomy between 1981 and 2016. RESULTS: During the first period (1981 to 2009), 230 infants were treated, and the median age at the time of surgery was 84 days; jaundice was resolved in 77 patients (33.5%). During the second period, from 2010 to 2016, a new diagnostic approach was adopted to shorten the wait time for portoenterostomy; an ultrasonography examination suggestive of the disease was followed by primary surgical exploration of the biliary tract without complementary examination or liver biopsy. Once the diagnosis of biliary atresia was confirmed, a portoenterostomy was performed during the same surgery. During this period, 27 infants underwent operations; the median age at the time of surgery was 66 days (p <0.001), and jaundice was resolved in 15 patients (55.6% - p=0.021), with a survival rate of the native liver of 66.7%. CONCLUSION: Primary surgical exploration of the biliary tract without previous biopsy was effective at improving the prognostic indicators of patients with biliary atresia undergoing Kasai portoenterostomy.