Surgical treatment of liver echinococcosis and alveococcosis.

Parasitic liver zoonoses are endemic to some regions of Russia as well as to Mediterranean countries, Australia, New Zealand, South America, and the Indian subcontinent. However, the available data on the surgical treatment of patients with parasitic liver diseases are often contradictory, and such treatments remain a difficult task today. The effectiveness of surgical treatment was analyzed in 628 patients with echinococcosis and 58 patients with liver alveococcosis managed at the Republican Clinical Hospital during 1998-2018. The most commonly performed surgery for echinococcosis was closed echinococcectomy of different types, which was applied in 428 patients. Surgical outcomes were evaluated according to the type of surgery. Although there were no differences in outcomes in the immediate postoperative period, long-term postoperative outcomes differed with the type of surgery, compelling us to reconsider the surgical methods employed, with a preference for implementing cystectomy with omentoplasty of the residual cavity of the liver. In fact, the best outcomes in terms of recurrence and complications were obtained with minimal but adequate procedures, namely actual echinococcectomy without the resection of the residual cavity or liver. Thus procedures with low-traumatic access should be performed in cases with specific indications, such as the presence of easily accessible and well-visualized parasitic cysts.

[Hepatic Parasitosis: Atypical presentation] / Parasitosis Hepática: Presentación atípica.

Benign solid liver tumors are composed by a heterogeneous group of lesions. Hepatic parasitosis is an infrequent etiological cause of benign solid liver tumors. Objective. To present the case of a patient with benign solid liver tumors treated with right portal vein embolization and, later, with hepatectomy. Clinical case. 60-year-old, male patient diagnosed with multiple solid liver tumors, due to a generalized case of jaundice. The decision to perform surgery was made on the basis of the clinical symptoms and the impossibility of discarding malignancy through complementary tests. Before surgery, hepatic volumetry and right portal vein embolization were done to increase future hepatic remnant. Right hepatectomy and hepatic resection of segment IVa were performed. The patient evolved positively from jaundice and the anatomopathological results showed a lesion related to hepatic parasitosis. Conclusion. In the presence of a solid liver tumor, it is necessary to rule out the malignant etiology of the lesion. If this is not possible, or if the patient continues with the symptomatology, surgical resection is prescribed, taking into account the volume of the hepatic gland and future hepatic remnant.

Los tumores hepáticos sólidos benignos están formados por un grupo heterogéneo de lesiones. Las parasitosis hepáticas conforman una causa etiológica poco frecuente de tumores hepáticos sólidos benignos. Objetivo. Reportar el caso de un paciente con tumores hepáticos solidos benignos tratado con embolización portal derecha y posteriormente hepatectomía. Caso clínico. Paciente de 60 años, sexo masculino, al cual se le diagnostican múltiples tumores hepáticos sólidos, debido a cuadro de ictericia generalizada. Debido al cuadro sintomático, y al no poder descartar malignidad con las pruebas complementarias, se decide realizar cirugía. Previamente se realiza volumetría de la glándula hepática y embolización portal derecha para aumentar el remanente hepático futuro. Se realiza hepatectomía derecha y segmentectomía hepática IVa. Evoluciona con mejoría del cuadro ictérico y el resultado anatomopatológico informa lesión vinculable a parasitosis hepática. Conclusión. Ante la presencia de un tumor hepático sólido, es necesario descartar etiología maligna de la lesión. Si no es posible descartar esto, o si el paciente persiste con sintomatología, la resección quirúrgica está indicada, teniendo en cuenta el volumen de la glándula hepática y del remanente hepático futuro.

Hepatic Paragonimiasis Mimicking Hepatocellular Carcinoma.

Paragonimiasis is a parasitic lung infection caused by lung flukes of the genus Paragonimus. Ectopic infection may occur but rarely involves the liver. Here, we report a case of hepatic paragonimiasis in a Chinese man who was initially suspected to have hepatocellular carcinoma. He had been previously diagnosed with chronic hepatitis B. No specific symptoms or abnormal blood test results were observed, except for a significant rise in serum alfa-fetoprotein. Magnetic resonance imaging revealed a 12-cm mass with inhomogeneous signal intensity at the left lobe of the liver. Laparoscopic left hemihepatectomy was performed. He was finally diagnosed as hepatic paragonimiasis upon pathological examination and antibody serology. The postoperative course was uneventful. He received a standard course of praziquantel and recovered well. Our case is unique in its tumor-like characteristic and protrudes the difficulty of differential diagnosis with both benignant and malignant hepatic diseases by imaging studies or non-specific symptoms. Hepatic paragonimiasis is unusual; however, it should be considered in the differential diagnosis of liver malignancy by clinicians.

Feasibility of laparoscopic major hepatectomy for hepatic paragonimiasis: two case reports.

BACKGROUND: Though accumulated evidence proved that laparoscopic major hepatectomy was technically feasible, it remains a challenging procedure and is limited to highly specialized centers. Paragonimiasis is one of the most important food-borne parasitic zoonoses caused by the trematode of the genus Paragonimus. Although hepatic paragonimiasis is rare, the previous studies had investigated hepatic paragonimiasis from different perspectives. However, the safety and feasibility of laparoscopic major hepatectomy for hepatic paragonimiasis have not yet been reported in the literature. METHODS: We here present 2 cases of hepatic paragonimiasis at the deep parts of the liver with treatment by laparoscopic major hepatectomy. One case is a 32-year-old male patient who was admitted to the hospital due to upper abdominal discomfort without fever for 1 month. The clinical imaging revealed that there was a lesion about 5.9 × 3.7 cm in the boundary of right anterior lobe and right posterior lobe of the liver with rim enhancement and tract-like nonenhanced areas. The other one is a 62-year-old female patient who was referred to the hospital for 1 month of right upper abdominal pain and fever. The ultrasonography showed that there was a huge hypoechoic mass (about 10.8 × 6.3 cm) in middle lobe of the liver with tract-like nonenhanced areas. Both patients were from an endemic area of paragonimiasis and the proportion of eosinophil in the second case was increased. RESULTS: The preoperative diagnosis of the first case was ambiguous and the hepatic paragonimiasis was considered for the second case. The first case underwent laparoscopic extended right posterior lobe hepatectomy and the other case underwent laparoscopic extended left hemihepatectomy. Both operations went very well and the operation times for the 2 cases were 275 minutes and 310 minutes, respectively. The 2 patients' postoperative recovery was smooth without major postoperative complications (such as, bleeding, bile leakage, and liver failure). Moreover, the 2 patients were discharged on the 6th day and 7th day after surgery, respectively. The postoperative histopathological examination manifested hepatic paragonimiasis in both patients. CONCLUSION: This study suggests that the laparoscopic approach may be safe and technically feasible for hepatic paragonimiasis.

Feasibility study of high intensity focused ultrasound (HIFU) for the treatment of hydatid cysts of the liver.

This study evaluates the feasibility of using high intensity focused ultrasound (HIFU) for the treatment of hydatid cysts of the liver. HIFU ablation was carried out in 62 patients with echinococcosis of the liver. The mean age of patients was 40.76±14.84 (range: 17-72 years). The effectiveness of the treatment was monitored in real-time by changes in the gray-scale, and by morphological studies, computed tomography, magnetic resonance imaging, and ultrasound. Criteria for evaluating the effectiveness of treatment in real time were outlines. Cytomorphological picture of destructive changes of parasitic elements was presented as well. Loss of embryonic elements of the parasite was observed at the subcellular level after HIFU-ablation and underlines the effectiveness of HIFU.

F-18 FDG hypermetabolism in mass-forming focal pancreatitis and old hepatic schistosomiasis with granulomatous inflammation misdiagnosed by PET/CT imaging.

PURPOSE: We report the case of a 59-year-old male patient who presented with space-occupying lesions in the pancreas and liver suggestive of metastatic pancreatic cancer. MATERIALS AND METHODS: Whole-body F-18 fluorodeoxyglucose (FDG) PET/CT imaging and enhanced CT imaging of the lesions were performed in addition to abdominal ultrasound, ERCP, and MRCP. Tumor markers, including CA199 and AFP, were also evaluated. RESULTS: PET/CT imaging showed a soft tissue mass with indistinct boundaries in the head of the pancreas with a maximum SUV of 4.39. A less dense shadow was also found in the left lobe of the liver with an indistinct boundary and a maximum SUV of 4.13. Enhanced CT revealed an enhancing mass in the head of the pancreas on arterial phase imaging as well as a mildly enhancing focus in the left lobe of the liver. The patient was diagnosed with a space-occupying lesion of the uncinate process of the pancreas suggestive of pancreatic cancer with metastasis to the liver. However, serum tumor markers were normal. Postoperative pathology was consistent with chronic pancreatitis and old hepatic schistosomiasis associated with granulomatous inflammation of the liver. CONCLUSION: This case of mass-forming pancreatitis and granulomatous inflammation in old hepatic schistosomiasis mimicked metastatic pancreatic cancer on PET/CT. Such false positive lesions have not been reported before, and further exploration and investigation are needed.

Splenectomy and gastric vein ligature in hepatosplenic schistosomiais: effects upon esophageal variceal pressure and endoscopic risk factors of esophageal variceal bleeding.

BACKGROUND: A significant number of patients with schistosomiasis develop the hepatosplenic form, with portal hypertension, in which bleeding caused by rupture of esophagogastric varices emerged as the leading cause of morbidity and mortality. AIM: To investigate the effects of splenectomy and ligature of the left gastric vein on risk factors for bleeding of esophagogastric varices in patients with schistosomiasis mansoni, hepatosplenic form, with a history of upper gastrointestinal bleeding. METHODS: The main risk factors of bleeding from esophagogastric varices were studied in 34 patients. The following parameters were investigated: 1) esophageal variceal pressure, measured by the endoscopic pneumatic balloon technique; 2) size, fundamental color, extension and red signs of esophageal varices, gastric varices and gastropathy of portal hypertension. The evaluations were performed in the preoperative period, immediate postoperative period (between the sixth and eighth postoperative days) and the sixth month of follow-up. RESULTS: The variceal pressure has fallen from 22.3+/-2.6 mmHg before surgery to 16.0+/-3.0 mmHg in the immediate postoperative period (p<0.001), reaching 13.3+/- 2.6 mmHg in the sixth month of follow-up. A significant reduction of the frequency of the parameters associated with a greater risk of hemorrhage was observed between the preoperative period and six-month follow-up, when the proportion of large esophageal varices (p<0.05), varices extending to the upper esophagus (p<0.05), bluish varices (p<0.01), varices with red signs (p<0.01) and gastropathy (p<0.05) decreased. CONCLUSION: In patients with hepatosplenic schistosomiasis with a previous history of variceal hemorrhage, splenectomy and gastric vein ligation was effective in reducing the main hemorrhagic risk factors until the sixth month of follow-up, indicating a good way to control the bleeding episodes.

Esplenectomia e ligadura da veia gástrica esquerda na esquistossomose mansônica: efeitos sobre pressão das varizes do esôfago e indicadores endoscópicos de risco de sangramento por varizes esofagogástricas / Splenectomy and gastric vein ligature in hepatosplenic schistosomiais: effects upon esophageal variceal pressure and endoscopic risk factors of esophageal variceal bleeding

RACIONAL: Expressivo contingente de pacientes esquistossomóticos com a forma hepatoesplênica e hipertensão portal apresentam hemorragia causada pela ruptura de varizes esofagogástricas, principal causa de alta morbidade e mortalidade da doença. OBJETIVO: Investigar os efeitos da esplenectomia e ligadura da veia gástrica esquerda sobre fatores de risco de sangramento por varizes esofagogástricas em portadores de esquistossomose mansônica, forma hepatoesplênica, com antecedente de hemorragia digestiva alta. MÉTODO: Estudaram-se, de forma prospectiva, 34 pacientes, com idade entre 1 e 74 anos (média 44,14), sendo 18 (53%) mulheres. Analisaram-se: 1) pressão das varizes do esôfago, aferida pela técnica endoscópica do balão pneumático; 2) tamanho, local, cor e sinais de cor vermelha nas varizes do esôfago; 3) varizes gástricas e gastropatia da hipertensão portal. Realizaram-se avaliações no pré-operatório, no pós-operatório imediato e no sexto mês após a ligadura da veia gástrica esquerda. RESULTADOS: A pressão das varizes do esôfago diminuiu de 22,3+/-2,6 mmHg, antes da operação, para 16,0+/-3,0 mmHg no pós-operatório imediato (p<0,001), caindo para 13,3+/-2,6 mmHg no pós-operatório do sexto mês (p<0,001). A proporção de varizes de grosso calibre, varizes no esôfago superior, varizes de cor azul, varizes com sinais de cor vermelha e de gastropatia da hipertensão portal decresceu de forma significante apenas no sexto mês de pós-operatório. CONCLUSÃO: A ligadura da veia gástrica esquerda, em esquistossomóticos hepatoesplênicos, com antecedente de hemorragia digestiva alta, revelou-se eficaz em diminuir alguns dos principais fatores de risco de hemorragia por varizes esofagogástricas, indicando boa perspectiva no controle definitivo do sangramento.

BACKGROUND: A significant number of patients with schistosomiasis develop the hepatosplenic form, with portal hypertension, in which bleeding caused by rupture of esophagogastric varices emerged as the leading cause of morbidity and mortality. AIM: To investigate the effects of splenectomy and ligature of the left gastric vein on risk factors for bleeding of esophagogastric varices in patients with schistosomiasis mansoni, hepatosplenic form, with a history of upper gastrointestinal bleeding. METHODS: The main risk factors of bleeding from esophagogastric varices were studied in 34 patients. The following parameters were investigated: 1) esophageal variceal pressure, measured by the endoscopic pneumatic balloon technique; 2) size, fundamental color, extension and red signs of esophageal varices, gastric varices and gastropathy of portal hypertension. The evaluations were performed in the preoperative period, immediate postoperative period (between the sixth and eighth postoperative days) and the sixth month of follow-up. RESULTS: The variceal pressure has fallen from 22.3+/-2.6 mmHg before surgery to 16.0+/-3.0 mmHg in the immediate postoperative period (p<0.001), reaching 13.3+/- 2.6 mmHg in the sixth month of follow-up. A significant reduction of the frequency of the parameters associated with a greater risk of hemorrhage was observed between the preoperative period and six-month follow-up, when the proportion of large esophageal varices (p<0.05), varices extending to the upper esophagus (p<0.05), bluish varices (p<0.01), varices with red signs (p<0.01) and gastropathy (p<0.05) decreased. CONCLUSION: In patients with hepatosplenic schistosomiasis with a previous history of variceal hemorrhage, splenectomy and gastric vein ligation was effective in reducing the main hemorrhagic risk factors until the sixth month of follow-up, indicating a good way to control the bleeding episodes.

Human pentastomiasis caused by Armillifer moniliformis in Malaysian Borneo.

We report a case of visceral pentastomiasis caused by Armillifer moniliformis in a 70-year-old aboriginal farmer from rural Malaysian Borneo. The patient complained of upper abdominal pain, jaundice, and loss of weight. Radiological investigations and subsequent histopathological examination revealed an adenocarcinoma of the pancreas with an adjacent liver nodule containing a nymph of A. moniliformis. This report constitutes the first documented human pentastomid infection in the whole of Malaysia after nearly 40 years, and it is the third description from Malaysian Borneo. Cases of human and animal pentastomiasis in Malaysia are discussed.

Severe hepatosplenic schistosomiasis: clinicopathologic study of 102 cases undergoing splenectomy.

We present the preoperative findings of 102 patients who underwent successful splenectomy for advanced schistosomiasis japonica. All patients were symptomatic for schistosomiasis and had splenomegaly greater than or equal to II according to the Hackett criteria. Before surgery, all patients underwent clinical examination including full blood count; fibrinogen and serum protein levels; liver function tests; and serology for hepatitis B, C, and D. Ultrasound examination of the liver and spleen and liver histology for evidence of pathology were also undertaken. Ninety patients had a treatment history for schistosomiasis. Fifty-six patients were seropositive for hepatitis B virus antibody, and 6 patients were seropositive for hepatitis C virus antibody. Immunohistochemical testing of the liver samples confirmed that 45 patients were positive for hepatitis B virus surface antigen, thereby indicating active infection. A total of 66.7% of patients had fibrosis stages II to III by ultrasound; and 76.5% of patients had portal vein inner diameter greater than 12 mm, indicating portal vein hypertension. A total of 83.2% of patients showed various stages of esophageal varicosis via x-ray, and 81.4% had fibrotic stages III to IV by liver biopsy. Coinfection with hepatitis B virus accelerated the development of liver fibrosis. There was moderate concordance between the fibrosis assessed by ultrasonography and histopathology, indicating that ultrasound underestimates the true pathology. Combined assessment is needed to improve the diagnosis of clinical hepatic fibrosis.

Evaluation of the cytokines IL-10 and IL-13 as mediators in the progression of Symmers fibrosis in patients with hepatosplenic schistosomiasis mansoni.

OBJECTIVE: To investigate the serum levels of IL-10 and IL-13 in patients with hepatosplenic schistosomiasis mansoni (HSM), evaluating the role of these cytokines in the development of hepatic fibrosis. METHODS: The study was prospective and analytical, developed at the Department of Surgery, Federal University of Pernambuco, Keizo Asami Laboratory of Immunology. We studied three groups: Group I - 25 patients with hepatosplenic schistosomiasis mansoni who were not submitted to surgery; Group II - 30 individuals who underwent splenectomy and ligature of left gastric vein; Group III - 33 subjects without hepatosplenic schistosomiasis mansoni or any other disease or condition that could compromise the hepatic functional reserve. Serum concentrations of IL-10 and IL-13 were obtained through ELISA. Considering their non-parametric nature, all concentrations were analyzed by Kruskal-Wallis test, with p<0.05 used to reject the null hypothesis. RESULTS: The mean concentrations of IL-10 in ng/mL in serum were GI: 50.0 ± 59.0; GII: 38.0 ± 270; GIII: 38.0 ± 20.0. Concentrations of IL-13 in ng/mL in the serum of patients were respectively: 41.0 ± 93.0 in GI, 16.0 ± 17.0 in GII and 18.0 ± 34.0 in GIII. There was no significant difference between the mean concentrations of IL-10 and IL-13 between the study groups (p> 0.05). CONCLUSION: The mean serum concentrations of IL-10 and IL-13 were similar in all three groups, indicating that possibly the presence of these cytokines in serum is not associated with different degrees of Symmers fibrosis in patients with hepatosplenic schistosomiasis mansoni.

Avaliação das citocinas IL-10 e IL-13 como mediadores na progressão da fibrose de Symmers em portadores de esquistossomose mansônica na forma hepatoesplênica / Evaluation of the cytokines IL-10 and IL-13 as mediators in the progression of symmers fibrosis in patients with hepatosplenic schistosomiasis mansoni

OBJETIVO: Investigar os níveis de IL-10 e IL-13 no soro de portadores da esquistossomose mansônica na forma hepatoesplênica (EHE), avaliando o papel destas citocinas no desenvolvimento da fibrose hepática. MÉTODOS: O estudo foi prospectivo e analítico, desenvolvido no Departamento de Cirurgia da Universidade Federal de Pernambuco, Laboratório de Imunologia Keizo Asami. Foram estudados três grupos: Grupo I - 25 portadores de esquistossomose mansônica na forma hepatoesplênica e não submetidos a tratamento cirúrgico; Grupo II - 30 submetidos à esplenectomia e ligadura da veia gástrica esquerda; Grupo III - 33 indivíduos sem esquistossomose mansônica na forma hepatoesplênica ou qualquer outra doença ou agravo que comprometesse a reserva funcional hepática. As concentrações séricas de IL-10 e IL-13 foram obtidas pelo método ELISA. Considerando-se a natureza não paramétrica, todas as concentrações foram analisadas pelo teste de Kruskal-Wallis. p<0,05 foi usado para rejeição da hipótese de nulidade. RESULTADOS: As médias das concentrações de IL-10, em ng/mL, no soro foram: GI 50,0 ± 59,0; GII 38,0 ± 270; GIII 38,0 ± 20,0. As concentrações de IL-13, em ng/mL, no soro dos pacientes foram respectivamente: GI 41,0 ± 93,0; GII 16,0 ± 17,0; GIII 18,0 ± 34,0. Não se observou diferença significante entre as médias das concentrações de IL-10 e IL-13 entre os grupos de estudo (p>0,05). CONCLUSÃO: As médias das concentrações séricas de IL-10 e IL-13 foram similares nos três grupos estudados, indicando que, possivelmente, estas citocinas no soro não estejam associadas aos diferentes graus de fibrose de Symmers nos pacientes.

OBJECTIVE: To investigate the serum levels of IL-10 and IL-13 in patients with hepatosplenic schistosomiasis mansoni (HSM), evaluating the role of these cytokines in the development of hepatic fibrosis. METHODS: The study was prospective and analytical, developed at the Department of Surgery, Federal University of Pernambuco, Keizo Asami Laboratory of Immunology. We studied three groups: Group I - 25 patients with hepatosplenic schistosomiasis mansoni who were not submitted to surgery; Group II - 30 individuals who underwent splenectomy and ligature of left gastric vein; Group III - 33 subjects without hepatosplenic schistosomiasis mansoni or any other disease or condition that could compromise the hepatic functional reserve. Serum concentrations of IL-10 and IL-13 were obtained through ELISA. Considering their non-parametric nature, all concentrations were analyzed by Kruskal-Wallis test, with p<0.05 used to reject the null hypothesis. RESULTS: The mean concentrations of IL-10 in ng/mL in serum were GI: 50.0 ± 59.0; GII: 38.0 ± 270; GIII: 38.0 ± 20.0. Concentrations of IL-13 in ng/mL in the serum of patients were respectively: 41.0 ± 93.0 in GI, 16.0 ± 17.0 in GII and 18.0 ± 34.0 in GIII. There was no significant difference between the mean concentrations of IL-10 and IL-13 between the study groups (p> 0.05). CONCLUSION: The mean serum concentrations of IL-10 and IL-13 were similar in all three groups, indicating that possibly the presence of these cytokines in serum is not associated with different degrees of Symmers fibrosis in patients with hepatosplenic schistosomiasis mansoni.

Ascariasis in the hepatobiliary system: laparoscopic management.

BACKGROUND: Ascariasis is an endemic disease in developing countries. The parasite can invade the hepatobiliary tree and cause symptoms. Medical therapy can be ineffective in these patients and intervention techniques required. STUDY DESIGN: A retrospective review of patient charts between February 1992 and February 2007 in the Hospital Latinoamericano, Cuenca, Ecuador, was performed to identify patients having surgical or endoscopic treatment for hepatobiliary ascariasis. Patient demographics, treatment algorithms, and outcomes are described and analyzed. RESULTS: There were 13 cases of hepatobiliary infestation by ascaris treated through endoscopy or operation. All patients presented with colicky abdominal pain in the right upper quadrant. Hepatic and biliary ultrasonography identified parasites in 12 patients. In the other patient, a hepatic abscess containing ascaris was found incidentally during cholecystectomy. There were 11 patients with ascariasis in the common bile duct, 1 in whom the cystic duct was occluded, causing acute cholecystitis. In 12 patients, conservative management was attempted and was unsuccessful. Endoscopic extraction was successful in four of these patients. Six patients underwent laparoscopic cholecystectomy, common bile duct exploration with parasite extraction, and T-tube placement. Parasite extraction through common bile duct exploration followed by primary closure was performed in one patient. Cholecystotomy and parasite extraction followed by cholecystectomy were performed in one patient. The final patient had cholecystectomy and parasite extraction from a liver abscess without earlier medical therapy. CONCLUSIONS: Ascariasis in the hepatobiliary system should be considered in the differential diagnosis of upper abdominal pain for patients in populations at risk. When an operation is indicated, it can be accomplished by endoscopic or laparoscopic approach.

Role of partial hepatectomy on Capillaria hepatica-induced hepatic fibrosis in rats

It is known that hepatic fibrosis may regress following partial hepatectomy, since the hepatic parenchyma regenerates very rapidly, but not the excess of fibrous tissue. The present study evaluated this hypothesis by observing the behavior of systematized septal fibrosis induced by either 30 or 90-day-old Capillaria hepatica infection, in rats subjected to partial hepatectomy. The results revealed that the morphology of the fibrosis was unaffected, but its relative quantity within the microscope field appeared significantly decreased, as a consequence of the increased liver tissue mass following regeneration.

Sabe-se que a fibrose hepática pode sofrer uma redução em seqüência uma hepatectomia parcial, uma vez que o parênquima hepático se regenera muito rápido, mas não o excesso de tecido fibroso. O presente trabalho avalia esta hipótese ao observar como se comporta a fibrose septal sistematizada induzida pela Capillaria hepática no rato, após infecção de 30 ou 90 dias de duração, em animais submetidos à hepatectomia parcial. Os resultados revelaram que a fibrose em si mesma não foi afetada na sua morfologia, mas a sua quantidade relativa apareceu diminuída significativamente no campo microscópico como conseqüência do aumento da massa de tecido hepático pós-regeneração.