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Biomedical subjects

S Uemoto

Publications and source records attributed to S Uemoto.

At least 55 records · Page 3Linked to original sources
PubMed1999

Auxiliary partial orthotopic living donor liver transplantation as an aid for small-for-size grafts in larger recipients.

BACKGROUND: In countries where living donors are the only source of liver grafts, restrictions on graft size are a serious obstacle for the expansion of indications for adult recipients. To overcome this problem, auxiliary partial orthotopic liver transplants (APOLT*) was performed on the basis of the concept that the residual native liver would support the graft function until the graft had grown enough to function by itself. METHODS: APOLT as an aid for small-for-size (SFS) grafts was reviewed retrospectively to evaluate its feasibility. Between April 1995 and March 1998, 20 recipients underwent APOLT, which was indicated because of a SFS graft in 15 of them. The indication was based on the estimated graft/recipient's body weight ratio (GRWR). If the ratio was <0.8%, APOLT was performed. The other 5 patients had a graft with a GRWR >0.8% and underwent APOLT on the basis of the residual native liver supporting the graft function temporarily, 4 for supplementation of the defective enzyme in metabolic liver diseases and one for leaving the potential of the regeneration of the native liver in fulminant hepatic failure. The recipients who underwent APOLT because of a SFS graft were categorized as the SFS group, and the others were the second group. RESULTS: In the SFS group, the age of the recipients ranged from 13 to 48 (median 23). The original indications of this group were fulminant hepatic failure in 2 recipients, acute deterioration of chronic liver diseases in 3, Wilson's disease in 2, biliary atresia in 4, primary biliary cirrhosis in 3, and primary sclerosing cholangitis (PSC) in one. The actual GRWR ranged from 0.45 to 0.72 (median 0.55). The graft was implanted after resection of the left lateral segment of the native liver. Except in the first two patients, the portal vein to the residual native liver was completely transected so that all of the portal blood drained into the graft liver. This procedure was successful in 9 patients. The cause of death in the other 6 was mainly infection. The mortality rate among the recipients with signs of advanced liver failure, such as massive ascites or hepatic coma, was higher, even though APOLT was used to support the SFS graft. In the second group, in the other five recipients who underwent APOLT for other indications, one recipient with fulminant hepatic failure died of sepsis caused by the dehiscence of bilio-enteric anastomosis. CONCLUSIONS: APOLT as an aid for a SFS graft is technically viable. This procedure can thus expand the indication of living donor liver transplants for adult recipients when the native liver retains some functional capability to support the grafted liver during the immediate postoperative period.

Adolescent↗
PubMed1999

Long-term outcome of living related liver transplantation for patients with intrapulmonary shunting and strategy for complications.

BACKGROUND: In 320 living related liver transplantation performed between June 1990 and September 1997, there were 21 living related liver transplantation for patients with intrapulmonary shunting, manifested by digital clubbing, cyanosis, and dyspnea. We report the long-term outcome for more 6 months and our strategy to overcome complications in these recipients. PATIENTS: A total of 21 patients (age range 2-33 years, 19 children and 2 adults, 6 males and 15 females) were classified into three grades according to shunt ratio calculated by TcMAA pulmonary scintigraphy; 5 in mild group (shunt ratio: less than 20%), 6 in moderated group (20%-40%), and 10 in severe group (more than 40%). The original underlying liver disease was biliary atresia in all patients. RESULTS: Spearmen's correlation coefficient rank test revealed that shunt ratio correlated significantly with PaO2 in room air (P=0.0001), PaO2 in 100% oxygen (P=0.0004), hematocrit (P=0.0276), and period of dyspnea before transplantation (P=0.023). COMPLICATIONS: Wound infection occurred in 80, 66, and 80%, and bile leakage in 20, 0, 40% in mild, moderate, and severe group, respectively. Patients who had portal vein thrombosis, and intracranial complication were classified as severe group and the incidence was 20 and 20%, respectively. The patient actuarial one year survival was 80, 66.7, and 48%, in mild, moderate, and severe group, respectively, although there was no significant difference. All patients who survived improved hepatopulmonary syndrome and the length of period required for the resolution was significantly correlated to the preoperative shunt ratio (P=0.023). COMMENTS: Patients with severe shunting are susceptible to wound infection and bile leak. The trend of higher incidence of portal thrombosis and intracranial complications in the severe group was closely related high hematocrit. Secure surgical technique to reduce bile leak and delayed primary wound closure to reduce wound infection were found to be effective. Anticoagulant therapy by infusing heparin through the portal vein followed by coumadin could prevent fatal portal vein thrombosis without counter risk of fatal cerebral hemorrhage.

Adolescent↗
PubMed1999

Postoperative flow cytometry crossmatch in living donor liver transplantation: clinical significance of humoral immunity in acute rejection.

BACKGROUND: The role of humoral immunity in acute rejection in solid organ transplantation remains controversial, although it is known that the presence of antidonor antibodies may precipitate graft rejection. We investigated the clinical relevance of antidonor humoral immunity for living donor liver transplantation (LDLT) by means of flow cytometry crossmatch (FCXM). METHODS: T cell FCXM using fresh donor peripheral lymphocytes was performed before and up to 1 month after LDLT in 58 patients. Ten patients received ABO-incompatible grafts. IgM and IgG antidonor antibodies were analyzed in relation to clinical acute rejection as defined by liver function tests with or without histological evidence. RESULTS: Pretransplantation FCXM was positive for five patients (8.6%), resulting in two cases of positive posttransplantation FCXM and two rejection episodes. Twelve patients (20.7%) showed positive posttransplantation FCXM. The incidence of acute rejection within 1 month was 100% in FCXM-positive patients and 17.4% in FCXM-negative patients (P<0.001). Thirteen (76.5%) of 17 rejection episodes in ABO-compatible cases were associated with concomitant antidonor IgM antibody. IgG antibody was also identified in six of these episodes. Antidonor antibodies disappeared after rejection treatments in all cases, but with some delay in clinical improvement. On the other hand, no antidonor antibodies were detected in any of the four rejection episodes in ABO-incompatible cases. CONCLUSIONS: Early acute rejection in LDLT is significantly associated with antidonor T cell antibody formation in ABO-compatible cases. This suggests a definite role for donor-specific humoral immunity in acute rejection. Rejection episodes without antidonor antibodies may suggest graft injury by pure cellular immunity, or possibly the presence of humoral immunity triggered by antigens not present on donor T cells.

ABO Blood-Group System↗
PubMed1999

Idiopathic thrombocytopenic purpura after a living-related liver transplantation.

BACKGROUND: Idiopathic thrombocytopenic purpura (ITP) is a rare complication after liver transplantation. We describe three cases of ITP in pediatric patients after a living-related liver transplantation (LRLT). METHODS: Of 266 patients who underwent an LRLT between June 1990 and June 1996, severe thrombocytopenia developed in three pediatric patients after transplantation, and ITP was also diagnosed. The original disease was biliary atresia in all cases, and the patients were given a partial liver graft from a living-related mother and subsequently treated with tacrolimus and low-dose steroids as an immunosuppressive regimen. RESULTS: The duration until the onset of ITP after transplantation in the three cases was 1 day, 3 months, and 13 months, respectively. The platelet-associated IgG levels increased in all cases. A preceding viral infection was suspected in two of the three cases. All patients were treated with intravenous gamma globulin with a transient recovery of thrombocytopenia in two cases and a sustained recovery in another. CONCLUSIONS: Transplant clinicians need to be aware of the possibility of ITP complication because a sudden onset of severe thrombocytopenia can occur even in patients who are apparently doing well after undergoing an LRLT.

Biliary Atresia↗
PubMed1999

Impact of graft size mismatching on graft prognosis in liver transplantation from living donors.

BACKGROUND: Although living donor liver transplantation for small pediatric patients is increasingly accepted, its expansion to older/larger patients is still in question because of the lack of sufficient information on the impact of graft size mismatching. METHODS: A total of 276 cases of living donor liver transplantation, excluding ABO-incompatible, auxiliary, or secondary transplants, were reviewed from graft size matching. Forty-three cases were highly urgent cases receiving intensive care preoperatively. Cases were categorized into five groups by graft-to-recipient weight ratio (GRWR): extra-small-for-size (XS; GRWR<0.8%, 17 elective and 4 urgent cases), small (S; 0.8< or =GRWR< 1.0%, 21 and 7), medium (M; 1.0< or =GRWR<3.0%, 119 and 19), large (L; 3.0< or =GRWR<5.0%, 67 and 10), and extra-large (XL; GRWR> or =5.0%, 9 and 3). RESULTS: Smaller-for-size grafts were associated not only with larger and older recipients, but also with rather older donors. Posttransplant bilirubin clearance was delayed and aspartate aminotransferase corrected by relative graft size was higher in XS and S. Posttransplant hemorrhage and intestinal perforation were more frequent in XS and S, and vascular complications and acute rejection were more frequent in larger-for-size grafts. Consequently, graft survival in XS (cumulative 58% and actuarial 42% at 1 year) and S (76% and 74%) was significantly lower compared with that in M (93% and 92%) in elective cases. Graft survival in L (83% and 82%) and XL (75% and 71%) did not reach statistical significance. CONCLUSIONS: The use of small-for-size grafts (less than 1% of recipient body weight) leads to lower graft survival, probably through enhanced parenchymal cell injury and reduced metabolic and synthetic capacity. Although large-for-size grafts are associated with some anatomical and immunological disadvantages, the negative impact is less pronounced.

Actuarial Analysis↗
PubMed1999

Native hepatectomy after auxiliary partial orthotopic liver transplantation.

In countries where a living donor is the only source of the graft, the limited size of the graft is of serious concern when considering extending the procedure to adult recipients. In order to overcome this problem, auxiliary partial orthotopic liver transplantation (APOLT) was applied to the concept that the residual native liver would support the graft function until the graft expanded enough to work by itself. We herein report on a 20-year-old woman with primary sclerosing cholangitis (PSC), who received a small-size liver graft by APOLT. Computed tomography and scintigraphy showed that the graft had regenerated sufficiently 1 month after the operation. The diseased residual native liver is potentially carcinogenetic. Therefore, second-stage native hepatectomy was done 35 days after the first operation. Histopathologic examination of the resected native liver revealed biliary cirrhosis with PSC but no evidence of cholangiocarcinoma. Second-stage native hepatectomy after APOLT seems to be a curative treatment for chronic end-stage liver disease with graft size mismatch that may be as good as orthotopic liver transplantation.

Adolescent↗
PubMed1999

Severe late acute allograft rejection in a child after living-related auxiliary partial orthotopic liver transplantation for ornithine transcarbamylase deficiency.

Auxiliary liver transplantation (ALT) is known to correct liver-based metabolic disorders. However, it remains unclear whether the presence of a native liver influences the long-term prognosis of ALT for metabolic diseases. We reported on a 4-yr-old girl who had undergone living-related auxiliary partial orthotopic liver transplantation (APOLT) for ornithine transcarbamylase deficiency and experienced severe late acute rejection 18 months after liver transplantation, during weaning of immunosuppressive agents. Results of histological analysis of the graft indicated very severe acute rejection (rejection activity index, 9/9), and computed tomography revealed graft liver atrophy. These observations suggest the possibility that severe rejection might occur in APOLT, especially during weaning of immunosuppression.

Acute Disease↗
PubMed1999

Living related liver transplantation from heterozygote genetic carriers to children with Wilson's disease.

We reviewed the outcome of children undergoing living related liver transplantation (LRLT) for Wilson's disease (WD), and specifically addressed the potential risk associated with the use of donors who were heterozygous for the Wilson genetic defect. LRLTs were carried out in 11 children with WD, nine of whom presented with fulminant hepatic failure and two with end-stage hepatic insufficiency. The age of the patients ranged from 6 to 16 yr. Eight patients had hepatic encephalopathy and were plasmapheresed preoperatively. The donors (all parents: six fathers and five mothers) were all one-haplotype matched with their respective recipients, and were all therefore heterozygote carriers of the WD genetic defect. The serum ceruloplasmin levels were within normal limits in all donors (mean: 20.0 +/- 2.85 mg/dL). All recipients but one had low serum ceruloplasmin levels with a mean value of 11.6 +/- 7.36 mg/dL before transplantation. The serum ceruloplasmin levels had increased to an average of 21.0 +/- 3.76 mg/dL after LRLT at the latest evaluation, which ranged between 7 and 75 months after transplantation. A marked reduction in urinary copper excretion was observed in all recipients after transplantation. Of eight recipients presenting preoperatively with Kayser-Fleischer (K-F) rings, this abnormality resolved completely after LRLT in five patients and partially in three. All recipients are alive and remain well, and none have developed signs of recurrent WD after a mean follow-up period of 31 months (range 7-75 months). In conclusion, LRLT is an excellent choice for effective treatment of WD, and grafts chosen from heterozygote carriers of the condition do not appear to confer any risk of recurrence in the recipients.

Adolescent↗
PubMed1999

Intrapulmonary shunting in biliary atresia before and after living-related liver transplantation.

BACKGROUND: Intrapulmonary shunting (IPS) is frequently observed and causes hypoxaemia in liver cirrhosis. This study investigated the prevalence, predictors of reversibility and the effect of living-related liver transplantation (LRLT) on IPS using contrast echocardiography in patients with end-stage biliary atresia. METHODS: Fifty consecutive patients with biliary atresia were examined for IPS using contrast echocardiography before and after LRLT until IPS disappeared. The severity of IPS was classified into five grades according to the extent of contrast in the left ventricle (0, none; 1, trivial; 2, apparent; 3, complete but less than in right ventricle; 4, as dense as in right ventricle). RESULTS: Thirty-two patients (grade 1, n = 15; grade 2, n = 7; grade 3, n = 4; grade 4, n = 6) had IPS before LRLT. Forty-four patients have survived for 9-26 months after LRLT. Among patients with grade 3 or 4 IPS (n = 8), there was a significant correlation between age at LRLT and the duration of IPS persistence after LRLT (P = 0.044). CONCLUSION: IPS takes longer to disappear in older children than in younger ones, but always disappears eventually. LRLT is an effective treatment for biliary atresia with IPS. Presented to the 31st annual meeting of the Pacific Association of Pediatric Surgeons, Maui, Hawaii, June 1998

Adolescent↗
PubMed1999

Portal blood flow and liver regeneration in auxiliary partial orthotopic liver transplantation in a canine model.

Functional competition has been shown to lead to a detrimental outcome in auxiliary liver transplantation. We evaluated the interaction in auxiliary partial orthotopic liver transplantation between the native liver and the graft in terms of portal flow and regeneration. The need for diversion of the portal flow to the graft was also assessed. Reduced-size liver grafts were transplanted orthotopically after partial hepatectomy in beagles. There were two groups: the preserved group, where portal inflow to the native liver was preserved, and the ligated group, where it was interrupted. Portal flow was measured serially and liver regeneration was evaluated on postoperative day 5. Functional competition was not observed in the preserved group. On the other hand, ligation of the native liver portal vein had no obviously detrimental effects on the remnant native liver. This leads to the conclusion that the portal vein to the native liver can be safely ligated to prevent functional competition.

Animals↗
PubMed1999

[Weaning of immunosuppression in living-related liver transplantation].

In our experience of living donor liver transplantation (LDLT), some recipients could be successfully weaned from any immunosuppressant in case of various situations like severe infectious complications, posttransplant lymphoproliferative disorder, and noncompliance. Based on such unexpected experiences, we started the intentional weaning of immunosupressants after LDLT. The patients were selected among the recipients who had been followed up longer than two years with stable normal graft function, and without any rejection episodes in the latest one year. So far, 26 cases were enrolled into this program, and 6 cases could be intentionally weaned from any immunosuppressants. Four recipients unfortunately had a rejection episode during the weaning. Immunosuppressants were again returned to the pre-weaning level in these recipients, and the rejection could be treated without any persistent dysfunction of the graft. Clear discrimination of the recipients who will be or will not be able to be weaned from immunosuppression is still impossible. Mixed lymphocyte reaction showed tendency of low response to the donor, but the result is not stationary in all recipients. Identification of suitable parameters to promise the possibility of weaning is a big problem to be solved in the future.

Graft Rejection↗
PubMed1999

Innovative techniques for and results of portal vein reconstruction in living-related liver transplantation.

BACKGROUND: Portal vein reconstruction is a crucial factor affecting the outcome of a successful living-related liver transplantation. We describe here our experience with portal vein reconstruction in 314 cases of living-related liver transplantation with use of novel surgical modalities to enable the transplant surgeons to deal with any size mismatch between the donor's and recipient's portal veins. METHODS: Portal vein reconstruction was classified into 2 major groups, anastomosis without and with a vein graft. When there was no stenosis of the recipient portal vein and the diameter was the same, the portal trunk was used for anastomosis. When the diameter mismatch was minimal, branch patch anastomosis was feasible. When the recipient portal vein was significantly stenotic and the portal vein of the graft was long enough, we removed the stenotic trunk and constructed an anastomosis between the graft portal vein and the confluence of the recipient portal vein. When the graft portal vein was short, a vein graft was interposed. The vein patch technique was preferable when the diameter of the graft vein was not large enough for the interposition technique. RESULTS: Anastomosis without vein graft included trunk anastomosis (n = 156), branch patch anastomosis (n = 39), and confluence anastomosis (n = 22). Anastomosis with vein graft used the interposition technique (n = 77) and vein patch technique (n = 27). The origin of the grafts was mostly from the maternal left ovarian vein (70%) or the paternal inferior mesenteric vein (27%). Complications related to portal vein reconstruction occurred in 16 (5%) patients: portal vein thrombosis in 8, stenosis in 7, and fatal rupture in 1 patient. The incidence of complications was similar for all techniques except for confluence anastomosis. CONCLUSION: Our innovative techniques should be helpful for overcoming diameter or length mismatches in portal vein reconstruction in pediatric liver transplantation.

Adolescent↗
PubMed1998

Selective portal blood flow diversion in auxiliary partial orthotopic liver transplantation to induce regeneration of the graft.

Experience with auxiliary partial orthotopic liver transplantation (APOLT) is still very limited and many questions remain to be solved. In this article, we present the case of a 5-year-old girl with ornithine transcarbamylase deficiency who initially did well after APOLT. During a severe rejection episode 16 months after transplantation, she developed encephalopathy and hyperammonemia. Despite a good clinical and histopathological response to antirejection therapy, the graft had become smaller and the native liver had undergone compensatory hypertrophy. After we surgically ligated the right portal branch, the graft recovered and the patient was able to stop her medication 1 month after surgery. We have estimated that the minimum volume of normal liver required to correct the metabolic defect in ornithine transcarbamylase deficiency is 8 cm3/kg. The ligation of the right portal branch was a safe and effective method of inducing a gradual and progressive involution of the hypertrophic native liver and regeneration of the atrophic graft.

Atrophy↗
PubMed1998

Auxiliary partial orthotopic liver transplantation from living donors: significance of portal blood flow.

BACKGROUND: Auxiliary liver transplantation has several advantages over standard orthotopic liver transplantation. However, functional competition has been reported even in auxiliary partial orthotopic liver transplantation (APOLT). We evaluated herein the interaction in APOLT between the native liver and the graft in terms of portal blood flow and regeneration. The need for diversion of the portal blood flow to the graft was also assessed. METHODS: A total of 15 patients received APOLT from living donors. Portal blood flow to the native liver was preserved in 6 patients, and the portal vein to the native liver was preemptively transected at the time of transplantation in 9 patients. RESULTS: Of the patients with preservation of the portal blood flow to the native liver, two showed inadequate graft portal blood flow just after operation, and in the other three patients the graft portal blood flow decreased or the graft atrophied after deterioration of the graft function. In the patients with preemptive transection of the portal vein to the native liver, optimal graft portal blood flow was obtained, and the native liver, supplied only by arterial inflow, supported a small-for-size graft until the graft regenerated. The damage to the native liver was minimal. CONCLUSIONS: Functional competition may occur in APOLT with preservation of the portal blood flow to the native liver, whereas preemptive transection of the native liver portal vein is a safe procedure and effectively prevents the portal steal phenomenon.

Adolescent↗
PubMed1998

Living-related liver transplantation and neurological outcome in children with fulminant hepatic failure.

BACKGROUND: Fulminant hepatic failure (FHF) in children is associated with high mortality under medical management. Living-related liver transplantation (LRLT) is an accepted measure to treat the children with end-stage liver disease. Reversibility of hepatic encephalopathy is crucial for the quality of life among the survivors after transplantation. METHODS: A retrospective review was made of the records of children undergoing LRLT at this hospital between May 1992 and November 1996. RESULTS: Eleven children with FHF underwent emergency LRLT. The mean age was 5 years (range, 2 months to 15 years). The indication for transplantation was persistent or worsening hepatic encephalopathy and severe coagulopathy, despite repeated plasma exchanges or exchange transfusions. The cause of FHF was non-A, non-B hepatitis in seven children, hepatitis B in two children, herpes simplex virus hepatitis in one child, and fulminant Wilson's disease with intravascular hemolysis in one child. The grade of hepatic encephalopathy was II in four children, III in two, and IV in five. The actuarial survival rate was 73% after a mean follow-up of 28 months (range, 13-67 months). Short-term neurological morbidity was present in two children with grade IV encephalopathy who also showed brain edema on cranial computed tomography. Eight survivors exhibited no long-term neurological deficit; the mean intelligence or developmental quotient was 97 (range, 86-110) at the end of the follow-up period. CONCLUSIONS: LRLT is an effective option for the treatment of FHF in children. The long-term neurological status is satisfactory among survivors.

Brain Edema↗
PubMed1998

Transmission of hepatitis B virus from hepatitis B core antibody-positive donors in living related liver transplants.

BACKGROUND: In order to clarify the risk of hepatitis B virus (HBV) transmission from hepatitis B core antibody-positive (HBcAb(+)) donors and to evolve a new strategy to counter such a risk, we undertook a retrospective (1990-1995) and prospective (1995-1996) analysis of our experience with living related liver transplantation involving HBcAb(+) donors. METHODS: Between June 15, 1990, and June 30, 1995, HBcAb(+) individuals were not excluded as donor candidates at our institutions. For 171 liver transplants, 16 donors were HBcAb(+). Between July 1, 1995, and June 30, 1996, HBcAb(+) individuals were generally excluded as donor candidates; however, three recipients were given liver grafts from HBcAb(+) donors because other donor candidates presented even higher risks. In the latter period, recipients with transplants from HBcAb(+) donors underwent prophylactic passive immunization with hyperimmune hepatitis B immunoglobulin (HBIG). The serum of 10 HBcAb(+) donors was examined by nested polymerase chain reaction for the presence of HBV-DNA, but it was not detected in any of them. However, the same examination of the liver tissue of five such donors yielded positive results in all cases. RESULTS: In the first 5-year period, out of 16 recipients with HBcAb(+) donors, 15 became hepatitis B surface antigen-positive after transplant. The three recipients with HBcAb(+) donors during the second 1-year period, who were treated by prophylactic passive immunization with HBIG, remained hepatitis B surface antigen-negative and negative for serum HBV-DNA after transplant. CONCLUSIONS: HBV exists in the liver of healthy HBcAb(+) individuals, but not in the blood. Therefore, HBV is thought to be transmitted to recipients by liver grafts from the HBcAb(+) donors at a significantly high rate. The prevention of viral activation and clinical disease development by means of passive immunization with HBIG seems promising, although the follow-up period in our study may be too short for any definitive conclusions.

DNA, Viral↗
PubMed1998

Fulminant hepatic failure secondary to herpes simplex virus infection in a neonate: A case report of successful treatment with liver transplantation and perioperative acyclovir.

Neonatal disseminated herpes simplex virus (HSV) infection, including fulminant hepatic failure (FHF), is lethal, and the patients rarely have a chance for liver transplantation because of the rapid development of the disease. We describe of a case of FHF secondary to HSV infection in a neonate successfully treated by aggressive intensive care followed by liver transplantation.

Acyclovir↗