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N Akamatsu

Publications and source records attributed to N Akamatsu.

At least 19 recordsLinked to original sources
PubMed2006

Hemophagocytic syndrome after adult-to-adult living donor liver transplantation.

Hemophagocytic syndrome is a fatal complication after liver transplantation that is rarely reported. Among 260 adult patients who underwent living donor liver transplantation at our hospital, three cases (1%) were complicated with hemophagocytic syndrome. Intensive investigation revealed Aspergillus, cytomegalovirus, and hepatitis C virus as the most likely causative organisms in each patient. Despite the immediate initiation of anti-infectious treatment and supportive care, all patients died. When pancytopenia with possible underlying infectious disease is observed in liver transplant recipients, hemophagocytic syndrome should be suspected and bone marrow biopsy considered. The prognosis of hemophagocytic syndrome remains poor and further investigations are required to establish effective therapeutic options.

Adult↗
PubMed2006

Renal impairment after living donor liver transplantation.

BACKGROUND: There are few reports of postoperative renal impairment after living donor liver transplantation (LDLT). METHODS: We reviewed 246 LDLT recipients to examine the effects of postoperative renal impairment on the results of LDLT. RESULTS: The incidence of renal impairment and the requirements for postoperative renal replacement therapy were 29% and 9%, respectively. Intraoperative blood loss (P<.0001) and preoperative serum creatinine (P=.0002) were significant independent risk factors for the development of early renal dysfunction. Patients who required renal replacement therapy had a lower survival rate (P=.01). CONCLUSIONS: We identified the risk factors for postoperative renal impairment, providing useful metrics to establish a treatment strategy for high risk liver transplant patients.

Adult↗
PubMed2006

Impact of celiac axis stenosis on living donor hepatectomy.

BACKGROUND: Celiac axis stenosis was once cited as a reason for exclusion from living donor liver transplantation. Donor hepatectomy, however, leaves the pancreaticoduodenal artery arcade untouched, and theoretically, celiac axis stenosis has no impact on otherwise possible donors. METHODS: Among 350 consecutive adult living donors of liver transplantation at Tokyo University Hospital, we experienced 11 (3%) donors with celiac axis stenosis or occlusion due to the median arcuate ligament. RESULTS: Harvesting of the right liver was the most common procedure (n = 8), followed by harvesting of segments II and III (n = 2), and left liver (n = 1). The postoperative course was uneventful in all of the donors. CONCLUSIONS: Our results indicate that donor hepatectomy can be safely performed in the presence of significant celiac artery stenosis.

Adult↗
PubMed2005

Relation between the middle hepatic vein drainage area volume and alanine aminotransferease after left liver harvesting.

Complete outflow is impossible to maintain on both sides in donors undergoing hemiliver graft harvesting, because the middle hepatic vein (MHV) can be preserved on only one side. The area in which outflow veins are disrupted becomes congested and does not sufficiently regenerate. The relation between changes in alanine aminotransferase (ALT) and the congestive area volume of the congestive area is unknown. The 64 subjects presented herein were living donors who provided the left liver with the caudate lobe and MHV trunk. The midpoint between the tributaries of the MHV and the right hepatic vein was determined preoperatively using computed tomography. The midpoint between the tributaries of the MHV and right hepatic vein and the borderline between the right and left liver were used to predict the MHV drainage area volume. ALT was measured in donors on postoperative days 1, 3, 5, 7, 10, and 14. The patients were divided into three groups according to the ratio of calculated MHV drainage area volume in the remnant right liver: less than 15% (n = 21, group A); greater than 15% and less than 20% (n = 18, group B); greater than 20% (n = 25, group C). There were significant differences in the ALT levels between groups (P = .004). MHV drainage area volume, calculated using the present method, was associated with high ALT levels after left liver harvesting with the MHV. The present study suggests that persistently high ALT levels are associated with the volume of the interrupted MHV drainage area.

Alanine Transaminase↗
PubMed2005

Long-term survival and causes of late graft loss after adult-to-adult living donor liver transplantation.

The vast amount of experience with deceased donor liver transplantation allows for the evaluation of the causes underlying late graft loss and the adoption of strategies for its prevention. In contrast, the long-term results or causes of late graft loss after adult-to-adult living donor liver transplantation have not been fully examined. Thus, we analyzed 176 adult recipients who survived at least 1 year after living donor liver transplantation. The median follow-up period was 33 months. Of the 176 recipients, eight died and three others underwent retransplantation. The most common cause of graft loss in our series was cholangitis (n = 4), which might be due partly to technical problems. The 3-year and 5-year patient survival rates of the subjects were 95% and 90%, respectively. Long-term survival after living donor liver transplantation was satisfactory in our series. Further improvement of surgical techniques for biliary reconstruction may reduce late graft loss.

Adult↗
PubMed2005

Proviral status of HTLV-1 integrated into the host genomic DNA of adult T-cell leukemia cells.

Human T-cell leukemia virus type-1 (HTLV-1) is the etiological agent of adult T-cell leukemia (ATL), and leukemic cells always carry the proviral genome monoclonally integrated into their host genomes at the same sequence site, designated as the monoclonal integration. Using Southern blot hybridization (SBH) and sequenced tagged site polymerase chain reaction assays, we examined the proviral status in 558 clinical specimens from 350 patients who are suspected to have ATL. A total of 321 specimens (57.5%) from 241 patients showed positive results for the monoclonal integration according to SBH, using EcoR1 and Pst1. The 241 patients consisted of 136 patients (56.4%) with the complete provirus (C-type), 62 patients (25.7%) with a defective provirus (D-type), and 43 patients (17.8%) with multibands (M-type). The incidence of the D- and M-types were in the order of smoldering, chronic, and acute subtypes of ATL, suggesting that such an aberrant proviral status is generated on the way to multistep carcinogenesis and is subsequently clinically important for the malignant behavior of the disease. Moreover, our data showed that the partial deletion of the proviral genome is initiated first at the site of the gag region and spreads into the sites of the pol and env regions, whereas the long terminal repeats and pX regions are almost always conserved. These results suggest that analysis of the proviral status provides useful diagnostic and virologic-oncological information about ATL and HTLV-1 pathology, especially the important role of pX gene in tumorigenesis.

Adult↗
PubMed2005

Cryptococcosis after living donor liver transplantation: report of three cases.

Cryptococcosis is the third most common invasive fungal infection in solid organ transplantation, which usually occurs more than 6 months after the primary operation. In our series of 180 consecutive adult living-donor liver transplantation recipients, three (1.5%) had cryptococcosis and one of these patients died. The serum cryptococcal antigen examination was positive in all three patients who suffered from cryptococcosis. The serum cryptococcal antigen test might contribute to the early detection and treatment of cryptococcosis.

Aged↗
PubMed2004

Prediction of hepatic artery thrombosis by protocol Doppler ultrasonography in pediatric living donor liver transplantation.

Hepatic arterial thrombosis (HAT) after liver transplantation is a life-threatening event. Previous reports have suggested that the resistive index (RI) of the hepatic artery predicts HAT. Doppler ultrasonography (US) to measure RI, however, is not routinely performed. The subjects were 70 pediatric patients who underwent living donor liver transplantation (LDLT). Protocol Doppler US was performed once or twice a day for 2 weeks postoperatively and 692 records were examined. Changes in RI values were examined separately in patients with and without HAT complications. The incidence of HAT was 10% (seven of 70). HAT was diagnosed an average of 6.2 days after LDLT. In patients without HAT complications ( n = 63), average RI levels at 14 days after LDLT were 0.71 +/- 0.1 (records, n = 625). In patients with HAT complications, RI decreased gradually within 2 days before the onset of HAT. RI values of less than 0.6 predicted HAT within 2 days before onset, with 83% sensitivity and 85% specificity. RI during the first 2 weeks after LDLT is a sensitive predictor for HAT. Thrombectomy and reanastomosis should be considered when RI values are less than 0.6 in Doppler US.

Adolescent↗
PubMed2004

Living donor liver transplantation for end-stage hepatitis C.

Living donor liver transplantation is important for patients with end-stage viral hepatitis because of the shortage of organs from deceased donors. However, preliminary results indicate that living liver donation might be disadvantageous for hepatitis C virus-positive patients. Twenty-seven patients who underwent living donor liver transplantation for hepatitis C virus cirrhosis preemptively received antiviral therapy using interferon-alpha2b and ribavirin, which was started an average of 32 days after the operation and continued for at least 6 months thereafter. The serum hepatitis C virus RNA became negative in the 8 of 16 patients with more than 1 year follow-up. The cumulative 3-year patient survival was 85%, which was comparable to that of hepatitis C virus negative patients (n = 93; 90%). Preemptive antiviral therapy after transplantation may be necessary for satisfactory results after living donor liver transplantation.

Adult↗
PubMed2004

Classification of portal vein anatomy for partial liver transplantation.

The anatomy of the portal vein is usually classified as 3 to 5 patterns and simple compared with the anatomy of the hepatic artery. The variety of portal vein anatomy was examined in 287 living donors for liver transplantation. More than 90% of donors showed a normal bifurcation type; 6% showed the trifurcation type. Only 3% displayed a separate origin of the right paramedian and the right lateral branches. There was no anomalous pattern that had not been reported previously. In our series, we conclude that it is rare for 2 or more stumps of portal vein to appear in partial liver transplantation. The frequency is much less if the left liver or the right lateral liver graft is used for adult-to-adult living donor liver transplantation.

Functional Laterality↗
PubMed2004

Simultaneous hepatic artery and portal vein thrombosis after living donor liver transplantation.

Simultaneous hepatic artery and portal vein thrombosis rarely occurs after liver transplantation. The etiology is unknown. Of 213 patients (72 children and 141 adults) that underwent living donor liver transplantation (LDLT) from January 1996 to March 2003, 4 (2%) developed simultaneous thrombosis at 3 hours to 7 days (median, 4 days) after the operation. Emergent thrombectomy was performed in three patients; the remaining patient was registered in the Japan organ transplant network. All of the patients died due to hepatic failure (range, 18 hours to 6 days after the diagnosis; median, 2 days). Portal vein, hepatic artery, and hepatic vein velocity in the liver graft were measured every 12 hours by Doppler ultrasonography for 2 weeks after liver transplantation. These parameters were stable until just before the simultaneous thrombosis. These findings indicate that protocol Doppler ultrasonography can diagnose, but not predict, this fatal complication.

Adolescent↗
PubMed2004

Conversion to cyclosporine provides valuable rescue therapy for living donor adult liver transplant patients intolerant to tacrolimus: A single-center experience at the University of Tokyo.

Tacrolimus-based immunosuppression is currently accepted as mainstream therapy in many transplant centers worldwide due to its potent immunosuppressive activity compared to cyclosporine. A tacrolimus-based regimen has been successfully used for our living donor liver transplantation (LDLT) recipients. Adverse effects such as neurotoxicity, nephrotoxicity, and new-onset diabetes mellitus, however, have limited its clinical application. In deceased donor liver transplantation, cyclosporine rescue therapy is valuable for such complications, but few reports have described a strategy for conversion in LDLT. Herein, we present our experience of conversion from tacrolimus to cyclosporine therapy in adult LDLT recipients. Among 203 recipients, 37 patients (18%) required conversion, primarily for neurotoxicity (41%), diabetes mellitus (16%), hematopoietic disorder (16%), and gastrointestinal intolerance (11%). Primary adverse events resolved within 2 months after conversion in 35/37 (94%) of the patients. For LDLT recipients unable to maintain effective immunosuppression with tacrolimus, conversion to cyclosporine is an effective option.

Adult↗
PubMed2003

Duct-to-duct biliary reconstruction for living donor liver transplantation: experience of 92 cases.

Bile duct-to duct reconstruction is now performed in living donor liver transplantation (LDLT) for adult patients. To confirm the feasibility, the results after the reconstruction were retrospectively analyzed. The subjects were 92 adult patients who underwent LDLT at the University of Tokyo Hospital. During the observation period (median 546 days), biliary complications were observed in 28 cases (30%). The complications included bile juice leakage in 11, stenosis at the anastomotic site in 9, and tube trouble in 8. Of these, 20 patients required surgical revision. The results suggest that duct-to-duct reconstruction provides satisfactory results, although long-term observation will be necessary.

Bile Ducts↗
PubMed2003

Left liver grafts for patients with MELD score of less than 15.

Left liver grafts are now seldom used for adult recipients of living donor liver transplantations because the left liver is believed to be insufficient to meet patient metabolic demands. At the University of Tokyo Hospital, left liver grafts have been limited to patients with fulminant hepatic failure or chronic hepatic failure with a model for end-stage liver disease (MELD) score of less than 15. Since 2000 25 adult patients received left liver grafts. The mean graft weight to standard liver volume ratio was 44%. The rates of acute rejection, vascular, and biliary complications were 24%, 0%, and 25%, respectively. All patients survived the operation and are doing well with a mean follow-up of 17 months. The present results suggest that left liver grafts provide acceptable results among patients satisfying our criteria.

Adult↗
PubMed2001

Decreased susceptibility to pentylenetetrazol-induced seizures after low-frequency transcranial magnetic stimulation in rats.

We studied the effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) on seizure susceptibility in rats. rTMS of 1000 pulses at 0.5 Hz led to a prolonged latency for seizure development after an intraperitoneal injection of pentylenetetrazol. The rTMS effectively prevented the development of status epilepticus of pentylenetetrazol-induced convulsions. These findings indicate that low-frequency rTMS affects the neural excitability, in the direction of anticonvulsive, and therefore, suggest the possibility of therapeutic use of rTMS in epilepsy.

Animals↗
PubMed2001

Acquired storage-pool disorders occurring late after allogeneic bone marrow transplantation: partial activation of platelets in asymptomatic patients.

Bone marrow transplantation (BMT) may be complicated by coagulation abnormalities. The present study evaluated whether platelets might be activated in patients who had undergone BMT without significant coagulopathy. The patients selected had received allogeneic BMTs a median of 39 months before the study (range, 11-124 months) and had not received cyclosporine, FK506 (tacrolimus), or other medication affecting cyclo-oxygenase for at least 3 months prior to the collection of blood samples. Furthermore, patients had platelet counts greater than 100 x 10(9) cells/L and normal serum creatinine levels. Twenty-five healthy volunteers acted as controls. Platelet aggregation studies and a mepacrine assay of platelets showed abnormal aggregation and decreased staining in some patients. The platelet storage-pool adenosine 5'-triphosphate (ATP) level in 15 patients after BMT was 0.45+/-0.24 micromol per 10(11) platelets, whereas the level in 18 controls was 1.03+/-0.36 micromol per 10(11) platelets (P = .00078). The total ATP levels of platelets in patients and controls were 4.33+/-1.14 and 5.63+/-1.51 micromol per 10(11) platelets, respectively (P = .016). With the exception of 1 patient, plasma levels of thrombomodulin and von Willebrand factor were all within the normal range. The average plasma level of 11-dehydrothromboxane B2 was significantly increased in 15 patients after BMT compared with controls, 20.6+/-8.2 and 10.3+/-1.2 pg/mL, respectively (P = .0004). These findings suggest a long-term process of platelet activation in patients after BMT and, following the cessation of cyclosporine, development of acquired storage-pool disorder of platelets.

Adenosine Triphosphate↗