Signet ring cell component, not the Lauren subtype, predicts poor survival: an analysis of 198 cases of gastric cancer.

AIM: Prognostic differences between major histologic gastric cancer groups, intestinal and diffuse are uncertain, since cellular components in each of them possibly have different behaviors. MATERIALS & METHODS: We reviewed 198 gastric cancer patients charts diagnosed from January 2003 to December 2015 in a tertiary hospital. Multivariate Cox proportional survival models were used to evaluate the impact of histologic groups on overall survival. RESULTS: About a third had the signet-ring cell carcinoma (SRCC). In a comparison of the different histologic subtypes, SRCC had the worst prognosis of all. The median durations of survival for patients with stage III and stage IV were 19.7 and 7.7 months, respectively. CONCLUSION: Signet-ring cell component seem to have a relevant role in defining prognosis for gastric cancer.

Evaluation of the clinical and inflammatory responses in exclusively NOTES transvaginal cholecystectomy versus laparoscopic routes: an experimental study in swine.

BACKGROUND: The aim of this study was to evaluate the clinical and inflammatory responses to surgical trauma caused by the natural orifice transluminal endoscopic surgery (NOTES) transvaginal endoscopic procedure compared with those of the laparoscopic route. METHODS: Twenty-one female swine were divided into three groups of seven animals and subjected to cholecystectomy using laparoscopic, laparotomic, and exclusively NOTES transvaginal routes. A group of five animals served as a control. The animals were monitored during surgery to evaluate anesthetic/surgical time and the presence of complications, which were evaluated after surgery with respect to roaming time, feeding, and the presence of clinical occurrence Measurements of TNF-α, IL-1ß, IL-6, CRP, IFN-γ were obtained before and after surgery, on the second and seventh postoperative days, and when the animals were killed and necropsied. RESULTS: All procedures were successfully completed as proposed in each group. Perioperative complications consisted of only gallbladder perforation and hepatic bleeding. The anesthetic/surgical time was longer in the NOTES vaginal group (p < 0.001). The postanesthetic recovery time, roaming, nutrition, and clinical evolution were similar in all groups. IL-1ß and IL-6 were undetectable in all groups. Levels of TNF-α, CRP, and IFN-γ were similar among the groups. However, the evolution of the inflammatory process, measured as the difference between the peak dose and the basal dose of IFN-γ, was lower in the NOTES group than in the laparotomy group. In the necropsy findings, only adhesions were found, with no difference among the groups. CONCLUSIONS: The entirely NOTES transvaginal cholecystectomy was feasible and safe. The surgical time was greater for the NOTES vaginal route. The inflammatory response was similar among the groups based on the levels of CRP and IFN-γ. However, the evolution of the inflammatory process seems to have been shorter in the vaginal NOTES group than in the laparotomy group as demonstrated by the difference between the peak and basal doses of IFN-γ.

Castleman's disease mimetizing pancreatic tumor.

CONTEXT: Angiofollicular lymph node hyperplasia or Castleman's disease is a rare clinical condition. Knowledge about etiology and physiopathology; and treatment management as well are yet to be defined. Unicentric presentation of this disease affecting single lymph nodes in the mediastinum seems to be the most common presentation. Castleman's disease localized in the pancreas topographic area that mimics a pancreatic neoplasm is an even more uncommon event, with available published data of less than 15 cases until now. CASE REPORT: We present a 64-year-old male patient with a six-month past history of asthenia, adynamia, and lack of general clinical conditions. Imaging studies showed a nodular hypoechoic mass in the pancreatic head. Enucleation of the lesion was performed. Histopathological study revealed unicentric form of Castleman's Disease. CONCLUSIONS: Castleman's disease mimetizing pancreatic tumor is uncommon and it also curses with a difficult preoperative diagnosis. Surgery seems to be the best therapeutic alternative for this disease.

Is it possible to adopt the same oncological approach in urgent surgery for colon cancer?

BACKGROUND: Locoregional complications may occur in up to 30% of patients with colon cancer. As they are frequent events in the natural history of this disease, there should be a concern in offering an oncologically adequate surgical treatment to these patients. AIM: To compare the oncological radicality of surgery for colon cancer between urgent and elective cases. METHODS: One-hundred and eighty-nine consecutive patients with non-metastatic colon adenocarcinoma were studied over two years in a single institution, who underwent surgical resection as the first therapeutic approach, with 123 elective and 66 urgent cases. The assessment of oncological radicality was performed by analyzing the extension of the longitudinal margins of resection, the number of resected lymph nodes, and the percentage of surgeries with 12 or more resected lymph nodes. Other clinicopathological variables were compared between the two groups in terms of sex, age, tumor location, type of urgency, surgical access, staging, compromised lymph nodes rate, differentiation grade, angiolymphatic and perineural invasion, and early mortality. RESULTS: There was no difference between the elective and urgency group concerning the longitudinal margin of resection (average of 6.1 in elective vs 7.3 cm in urgency, P = 0.144), number of resected lymph nodes (average of 17.7 in elective vs 16.6 in urgency, P = 0.355) and percentage of surgeries with 12 or more resected lymph nodes (75.6% in elective vs 77.3% in urgency, P = 0.798). It was observed that the percentage of patients aged 80 and over was higher in the urgency group (13.0% in elective vs 25.8% in urgency, P = 0.028), and the early mortality was 4.9% in elective vs 15.2% in urgency (P = 0.016, OR: 3.48, 95%CI: 1.21-10.06). Tumor location (P = 0.004), surgery performed (P = 0.016) and surgical access (P < 0.001) were also different between the two groups. There was no difference in other clinicopathological variables studied. CONCLUSION: Oncological radicality of colon cancer surgery may be achieved in both emergency and elective procedures.

Sleeve Gastrectomy in Septuagenarians: a Case-Control Study.

PURPOSE: There are few studies published referring to bariatric surgery in patients older than 70 years. The aim of this study is to evaluate whether there are benefits to performing sleeve gastrectomy (SG) in patients over 70 years of age and to compare the results with a younger control group. MATERIALS AND METHODS: Data were retrospectively collected from a Private Clinic's electronic medical records of patients undergoing SG between June 2017 and September 2020. Inclusion criteria were patients older than 70 years [septuagenarian group (SpG)] who met all institutional protocols. Patients in the control group (CG) were selected with a 1:1 ratio and under 60 years of age, according to body mass index and comorbidities. The primary endpoint of the study was to evaluate the morbidity and mortality during the 30-day postoperative period and percentage of total weight loss (%TWL), and improvement of comorbidities after 1 year of follow-up. RESULTS: Fifty patients were included in the study. Both groups were similar regarding gender, weight, BMI, and presence of DM. The 30-day morbidity and mortality were similar between the groups. The patients in the SpG had 26.9% of %TWL and the CG, 28% (p = 0.32). The remission rate of DM (50% vs. 85% p = 0.01) and SAH (30% vs. 64% p = 0.04) was lower for septuagenarian patients. CONCLUSION: The sleeve gastrectomy surgery performed in patients over 70 years of age is safe. The early results suggest similar benefits regarding weight loss and improvement of comorbidities to those having SG before age 60.

Analysis of the Immunohistochemical Expression of Ghrelin in the Gastric Mucosa and Correlation with Weight Loss After Sleeve Gastrectomy.

INTRODUCTION: Sleeve gastrectomy is one of the main techniques used to treat severe obesity. The study of the immunohistochemical expression of ghrelin in the gastric mucosa has already been related to weight loss and can be a promising method to predict the surgical outcome. PURPOSE: To analyze the immunohistochemical expression of ghrelin in the gastric mucosa and its correlation with weight loss, comorbidities, and inflammatory changes after sleeve gastrectomy. METHODS: Thirty-five patients submitted to sleeve gastrectomy were evaluated, 29 of whom were female (82.9%), with a mean age of 35.2 years and an average body mass index of 38.1 kg/m2. Endoscopic samples of the mucosa were collected, whose ghrelin expression was evaluated in a semi-quantitative way through the stained antibody area. These data were correlated with weight loss at 3, 6, and 12 months and with the control of comorbidities, and inflammatory alterations. RESULTS: The average total weight loss (TWL%) was 17.7, 26.4, and 32.1%, respectively, at 3, 6, and 12 months. A negative correlation was found between the immunohistochemical expression of ghrelin in the endoscopic biopsy of the fundus and weight loss at 3 (s = - 0.536; p = 0.001) and 6 months (s = - 0.339; p = 0.047). CONCLUSION: The immunohistochemical expression of ghrelin in the mucosa of the gastric fundus was negatively correlated with early weight loss after sleeve gastrectomy.

Clinical Course, Genetic, and Immunohistochemical Characterization of Solid Pseudopapillary Tumor of the Pancreas (Frantz Tumors) in a Brazilian Cohort.

Frantz tumors or solid pseudopapillary pancreatic neoplasm (SPN) are rare exocrine neoplasms that carry a favorable prognosis; they represent up to 3% of all tumors located in the region of the pancreas and have specific age and gender predispositions. In recent years, the rising curve of diagnosis is entitled to the evolution and access of diagnostic imaging. In this paper, we have retrospectively reviewed and described the clinical course of 40 patients with SPN from three institutions in Brazil, who had their diagnosis between 2005 and 2020, and analyzed the clinicopathological, genetic, and surgical aspects of these individuals. In accordance with the literature, most patients were women, 60% with unspecified symptoms at diagnosis, with tumors mainly located in the body and tail of the pancreas, of whom 70% underwent a distal pancreatectomy with sparing splenectomy as a standard procedure, and none of the cases have experienced recurrence to date. Surgery still remains the mainstay of treatment given the low metastatic potential, but more conservative approaches as observed in this cohort are evolving to become the standard of care. Herein, we present an in-depth analysis of cases focusing on the latest literature and report some of the smallest tumor cases in the literature. To our knowledge, this is the first report evaluating germline genetic testing and presenting a case of detected Li-Fraumeni syndrome.

New trends in diffusion-weighted magnetic resonance imaging as a tool in differentiation of serous cystadenoma and mucinous cystic tumor: a prospective study.

BACKGROUND/AIMS: Pancreatic cystic lesions are increasingly being recognized. Magnetic resonance imaging (MRI) is the method that brings the greatest amount of information about the morphologic features of pancreatic cystic lesions. To establish if diffusion-weighted MRI (DW-MRI) can be used as a tool to differentiate mucinous from nonmucinous lesions. METHODS: Fifty-six patients with pancreatic cystic lesions (benign, n = 46; malignant, n = 10) were prospectively evaluated with DW-MRI in order to differentiate mucinous from nonmucinous lesions. Final diagnosis was obtained by follow-up (n = 31), surgery (n = 16) or endoscopic ultrasound-guided fine needle aspiration (n = 9). Serous cystadenoma was identified in 32 (57%) patients. RESULTS: The threshold value established for the differentiation of mucinous from nonmucinous lesions was 2,230.06 s/mm(2) for ADC of 700. DWI-MRI behavior between mucinous and nonmucinous groups revealed sensitivity, specificity, positive predictive value, negative predictive value and accuracy to be 80, 98, 92, 93 and 93%, respectively (p < 0.01, power of sample = 1.0). In the comparison of the diffusion behavior between mucinous (n = 13) and serous (n = 32) lesions, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 100, 97, 92, 100 and 98%, respectively (p < 0.01, power of sample = 1.0). The results of endoscopic ultrasound-guided fine needle aspiration were similar to those of DW-MRI. CONCLUSIONS: DW-MRI can be included as part of the array of tools to differentiate mucinous from nonmucinous lesions and can help in the management of pancreatic cystic lesions. and IAP.

Abdominal drain amylase on the first day after pancreatectomy: a predictive factor for pancreatic fistula.

OBJECTIVE: To analyze abdominal drain on the first postoperative day and evaluate its predictive nature for the diagnosis of Pancreatic Fistula exclusion, seeking to establish a cutoff point from which lower values demonstrate safety in excluding the possibility of this complication. METHODS: From August 2017 to June 2020, data from 48 patients undergoing pancreatic resection were collected and analyzed from a prospective cohort. The patients were divided into two groups, one group consisting of patients who did not develop PF (Group A), and the other composed of patients who developed PF (Group B). The receiver operation characteristic curve was constructed, and cutoff points were evaluated by calculating sensitivity and specificity. RESULTS: Group A brought 30 patients together (62.5%) and Group B brought 18 patients together (37.5%). The 444 U/L value was the most satisfactory cutoff point for the receiver operation characteristic curve (CI 0.690-0.941), with a sensitivity of 94.4% and a specificity of 60%, thus being able to select 18 of 30 patients who did not succumb to PF. CONCLUSIONS: Abdominal drain on the first postoperative day can be used as a predictive factor in the diagnosis of PF exclusion (CI 0.690-0.941), with the value of 444 U/L being the best performance cutoff point.

von Hippel-Lindau Syndrome: Genetic Study of Case With a Rare Pathogenic Variant With Optic Nerve Hemangioblastoma, a Rare Phenotypic Expression.

von Hippel-Lindau syndrome (VHLS) is a rare, autosomal dominant genetic disease with high penetrance and variable phenotypic expression caused by variants in the VHL gene. VHLS is associated with the presence of vascular tumors, often hemangioblastoma of the central nervous system, retina, or spinal cord and, less frequently, pancreatic cystic neoplasm, pancreatic neuroendocrine tumor, clear cell carcinoma of the kidney, endolymphatic sac tumor, pheochromocytoma, and paraganglioma. The authors report a case of a patient with VHLS with a rare pathogenic variant in the VHL gene and with an optic nerve hemangioblastoma, a rare phenotypic expression. Case report: A 49-year-old woman was diagnosed with cystic neoplasm of the pancreas, renal cell carcinoma of the right kidney, and hemangioblastoma of the left optic nerve. The patient's family history revealed siblings with VHLS manifestations. The index case was her mother who died at age 63 of clear cell renal carcinoma. The information was obtained by consulting the patient's medical register and by interviews with the patient and her relatives. The presence of left optic nerve hemangioblastoma was suggested by CT scan of the skull and orbit. The sequencing of the VHL gene was performed in the peripheral blood by the polymerase chain reaction (PCR) technique, and the duplication and deletion research was performed using the multiplex ligation-dependent probe amplification (MPLA) technique. The presence of a rare pathogenic variant c.263G> A (p.Trp88Ter) was observed in heterozygosity in the VHL gene that determined a premature stop codon. CT scan of the skull and orbits suggested the presence of HB in the optic nerve of the left eye. The results of the CT scan of the skull and orbits show thickening with tortuosity of the left optic nerve, with a small area of nodular enhancement. The right optic nerve had a conserved aspect. Conclusion: This is the fourth case described of this rare pathogenic variant of the VHL gene, according to the Human Gene Mutation Database and VHLdb database records and with an optic nerve hemangioblastoma of the optic nerve, a very rare phenotypic expression of the VHLS.

Laparoscopic evaluation of abdominal adhesions with different prosthetic meshes in rabbits.

BACKGROUND: The use of prosthetic materials to reinforce the abdominal wall is associated with a low index of recurrence; however, intraperitoneal placement of a foreign body may lead to adhesions. The present investigation was designed to determine adhesion formation with commercially available meshes implanted laparoscopically in rabbits. METHODS: Three different meshes were implanted laparoscopically in 24 rabbits: polypropylene (mesh A), polypropylene and sodium hyaluronate-carboxymethylcellulose (mesh B), and polypropylene and expanded polytetrafluoroethylene (mesh C). Sites of implantation for each mesh (the left lower quadrant, right lower quadrant, and lower midline) were randomly determined so that every rabbit had all 3 meshes implanted. All animals underwent diagnostic laparoscopy after 28 days to grade adhesions and histological analysis of inflammation. RESULTS: Adhesions were noticed in 46 of the 72 meshes implanted (64%). The number of adhesions was higher for mesh C (87.5%) compared with meshes A (62.5%) and B (41.6%). The severity of adhesions was also higher for mesh C (grade I in 14, II in 6, and III in 1) compared with mesh A (grade I in 10, II in 4, and III in 1 case) and B (all of them grade II). Histological inflammatory reaction was classified as mild in 23 cases of mesh A, 15 of mesh B, and 23 of mesh C. A moderate reaction was found in 1 case of mesh A, 4 cases of mesh B, and 1 case of mesh C. Severe reaction was induced in 5 cases of mesh B. Mesh B induced a higher inflammatory reaction compared with the other meshes. CONCLUSIONS: All meshes induced adhesions of different grades. Mesh B had fewer adhesions and more intense inflammation them did the others.

Prospective ultrasonographic study of blood flow and testicular volume in patients submitted to surgical repair of inguinal hernia without using prosthesis.

PURPOSE: To evaluate the behavior of arterial circulation and testicular volume in patients submitted to conventional inguinal hernia repair without the use of a synthetic prosthesis to reinforce the posterior wall. METHODS: A prospective observational clinical trial was performed on 26 male patients with unilateral inguinal hernia types I and II by the Nyhus classification, who underwent surgical correction using the modified Bassini technique. Bilateral Doppler ultrasonography was performed preoperatively, at the third and at the sixth postoperative month. The studied variables were: systolic peak velocity (SPV), diastolic peak velocity (DPV), resistance index (RI), pulsatility index (PI) and testicular volume. RESULTS: There were no statistically significant changes over time in the variables studied on the operated side: SPV (p = 0.916), DPV (p = 0.304), RI (p = 0.879), PI (p = 0.475), and testicular volume (p = 0.100). The variables on the control side also did not change statistically until the sixth postoperative month: SPV (p = 0.784), DPV (p = 0.446), RI (p = 0.672), PI (p = 0.607), and testicular volume (p = 0.413). CONCLUSION: Surgical correction of the inguinal hernia without the use of a prosthesis does not cause alterations in vascularization and testicular volume in the first six months postoperatively.

Laparoscopic enucleation of pancreatic insulinomas.

Insulinomas are rare endocrine pancreatic tumors whose incidence has been increasing in recent years owing to early detection by clinical and radiologic, such as remote neural monitoring, computed tomography (CT), and ultrasound (US) findings. The classical treatment consists of open surgical resection, which is associated with relative morbidity and mortality rates. The aim of this paper was to present 5 patients who were diagnosed with pancreatic insulinomas that were treated by laparoscopic resection. Five (5) patients, ranging from 14 to 45 years and presenting with classical Whipple Triad, had lesions ranging from 1.5 to 2.5 cm by CT (body and tail of the pancreas), which were subsequently diagnosed as insulinomas. An ecoendoscopy showed no combined lesions. They were treated by a laparoscopic resection. Glicemic levels were controlled during surgery with an expected glucose rise. All patients had an uneventfull recovery. The mean length of follow-up is 14 months. The laparoscopic resection of pancreatic insulinomas is a reliable procedure for superficial lesions in the body and tail of the pancreas.

Prospective study on the effects of a polypropylene prosthesis on testicular volume and arterial flow in patients undergoing surgical correction for inguinal hernia.

PURPOSE: To evaluate testicular volume and arterial flow in patients undergoing surgical correction for inguinal hernia, with polypropylene prosthesis. METHODS: This was an observational prospective clinical study on 39 male patients with unilateral inguinal hernia of types III A and III B according to the Nyhus classification who underwent surgical correction with implantation of a polypropylene prosthesis by means of the Lichtenstein technique. The patients were evaluated using Doppler ultrasound before the operation and selectively at the third and sixth months after the operation. The variables studied were testicular volume, systolic and diastolic velocity, resistance index and pulsatility index. RESULTS: No statistically significant alterations in the variables studied were observed over the course of time: testicular volume (p= 0.197); systolic velocity (p= 0.257); diastolic velocity (p= 0.554); resistance index (p= 0.998); and pulsatility index (p= 0.582). CONCLUSION: No alteration in testicular volume and arterial flow over a six-month period was observed among patients who underwent surgical correction for inguinal hernia using a polypropylene prosthesis.

Randomized trial of total fundoplication and fundal mobilization with or without division of short gastric vessels: a short-term clinical evaluation.

PURPOSE: Evaluate short results after fundoplication procedure, concerning the division of short gastric vessels. METHODS: A prospective randomization of 90 patients with indication for hiatoplasty and total fundoplication with fundus mobilization was performed. They were divided into two groups: no SGV division (group A, n= 46) and with SGV division (Group B, n=44), although in both groups the gastric fundus was mobilized to perform a floppy valve. Early outcome with clinical follow up (1 year) was observed. RESULTS: Both groups were similar regarding preoperative parameters and severity of gastroesophageal reflux disease (GERD). No difference in morbidity was observed during hospital stay. Nevertheless, the median operating time was 80,2 minutes in group A and 94,1 minutes (p=0,021) in Group B. Transitory dysphagia during the first year was significantly lower in group B (46,6% versus 23,2%, p=0,012). However, in 12 months clinical outcome was similar in both groups (clinical symptoms of GERD, persistent dysphagia and reoperations). CONCLUSION: There was no improvement in routine division of SGV in total fundoplication procedure when the gastric fundus was mobilized.

Experimental model of severe acute pancreatitis in rabbits.

PURPOSE: To develop an experimental model of severe acute pancreatitis in rabbits through a pancreatic ductal injection of sodium taurocholate. METHODS: Twenty-four albino rabbits of the New Zealand lineage were distributed into four groups of six animals (A, B, C and S). The rabbits of three experimental groups (A, B and C) were submitted to a laparatomy and received a pancreatic ductal injection of 1 ml/kg sodium taurocholate 5%. Also, they were submitted to further laparatomies after 4h, 8h and 12h, respectively. The control group (S) was subdivided into two groups of three animals: in subgroup S1 only the pancreatic duct catheterization was performed whereas in subgroup S2 the pancreatic duct catheterization as well as an injection of 1 ml/kg physiologic solution 0.9% were carried out. After 12 hours, the rabbits were evaluated. In the re-intervention, blood was collected to determine the amylasemia and a pancreatectomy was carried out to investigate interstitial infiltration, steatonecrosis and necrosis of the organ, using an optical microscope. RESULTS: There was an elevation of amylase in all groups thus proving the existence of acute pancreatitis. The size of the interlobular septum increased progressively with a greater variation between group S1 (0.13) and group C (0. 53) (p=0.035). While all the animals in group A exhibited focal cellular necrosis, it was more intense in the rabbits of group B and culminated with a high proportion of severe pancreatic necrosis in group C animals. The difference in the intensity of cellular necrosis showed statistic significance (p=0.001). CONCLUSION: The proposed experimental model demonstrated its reproducibility and effectiveness in producing severe acute pancreatitis in rabbits.

Use of fibrinogen and thrombin sponge in pediatric split liver transplantation.

PURPOSE:: To analyze the use of this sponge in pediatric patients undergoing split-liver transplantation. METHODS:: Retrospective study, including 35 pediatric patients undergoing split-liver transplantation, divided into two groups according to the use of the sponge: 18 patients in Group A (no sponge) and 17 in Group B (with sponge). RESULTS:: The characteristics of recipients and donors were similar. We observed greater number of reoperation due to bleeding in the wound area in Group A (10 patients - 55.5%) than in Group B (3 patients - 17.6%); p = 0.035. The median volume of red blood cells transfused in Group A was significantly higher (73.4 ± 102.38 mL/kg) than that in Group B (35.1 ± 41.67 mL/kg); p = 0.048. Regarding bile leak there was no statistical difference. CONCLUSION:: The use of the human fibrinogen and thrombin sponge, required lower volume of red blood cell transfusion and presented lower reoperation rates due to bleeding in the wound area.

Liver retransplantation: a model for determining long-term survival.

BACKGROUND: Because of the worse results from retransplantation in relation to the initial liver transplantation, there is a need to refine the indication for retransplantation, such that fair distribution of this benefit is obtained. METHODS: This was a study of 139 patients who underwent liver retransplantation. Thirty variables were studied: 18 relating to the recipient and 12 to the donor. All the independent variables were initially compared with the length of survival using univariate analyses. Variables presenting significance were compared with the dependent variable of length of survival, to determine which factors were related to longer survival among patients, when evaluated together. RESULTS: A multivariate model for determining long-term survival among patients with retransplants was built up using the following variables: recipient's age, creatinine, urgency of retransplantation and early failure of the first graft. Through this multivariate model it was possible to determine a score that was categorized according to tertile distributions (below the 33rd percentile, score <24; 33rd to 66th percentile, 24 < or = score < or = 32; above the 66th percentile, score > 32). One-year, 3-year, and 5-year patient survival rates following retransplantation were respectively 85%, 82%, and 77% for scores <24; 69%, 66%, and 61% for scores between 24 and 32; and 21%, 19%, and 16% for scores >32 (P < 0.0001). CONCLUSION: The variables of recipient's age, creatinine, urgency of retransplantation, and early failure of the initial transplantation were factors that were independently related to the long-term survival of patients with liver retransplants.

Evaluating the best time to intervene acute liver failure in rat models induced by d-galactosamine.

PURPOSE:: To describe an animal model for acute liver failure by intraperitoneal d-galactosamine injections in rats and to define when is the best time to intervene through King's College and Clichy´s criteria evaluation. METHODS:: Sixty-one Wistar female rats were distributed into three groups: group 1 (11 rats received 1.4 g/kg of d-galactosamine intraperitoneally and were observed until they died); group 2 (44 rats received a dose of 1.4 g/kg of d-galactosamine and blood and histological samples were collected for analysis at 12 , 24, 48 , 72 and 120 hours after the injection); and the control group as well (6 rats) . RESULTS:: Twelve hours after applying d-galactosamine, AST/ALT, bilirubin, factor V, PT and INR were already altered. The peak was reached at 48 hours. INR > 6.5 was found 12 hours after the injection and factor V < 30% after 24 hours. All the laboratory variables presented statistical differences, except urea (p = 0.758). There were statistical differences among all the histological variables analyzed. CONCLUSION:: King's College and Clichy´s criteria were fulfilled 12 hours after the d-galactosamine injection and this time may represent the best time to intervene in this acute liver failure animal model.