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Dive into the research topics where Taiichi Wakiya is active.

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Featured researches published by Taiichi Wakiya.


Transplant International | 2011

Double-balloon enteroscopy for bilioenteric anastomotic stricture after pediatric living donor liver transplantation.

Yukihiro Sanada; Koichi Mizuta; Tomonori Yano; Wataru Hatanaka; Noriki Okada; Taiichi Wakiya; Minoru Umehara; Satoshi Egami; Taizen Urahashi; Shuji Hishikawa; Takehito Fujiwara; Yasunaru Sakuma; Masanobu Hyodo; Hironori Yamamoto; Yoshikazu Yasuda; Hideo Kawarasaki

Bilioenteric anastomotic stricture after liver transplantation is still frequent and early detection and treatment is important. We established the management using double‐balloon enteroscopy (DBE) and evaluated the intractability for bilioenteric anastomotic stricture after pediatric living donor liver transplantation (LDLT). We underwent DBE at Jichi Medical University from May 2003 to July 2009 for 25 patients who developed bilioenteric anastomotic stricture after pediatric LDLT. The patients were divided into two types according to the degree of dilatation of the anastomotic sites before and after interventional radiology (IVR) using DBE. Type I is an anastomotic site macroscopically dilated to five times or more, and Type II is an anastomotic site dilated to less than five times. The rate of DBE reaching the bilioenteric anastomotic sites was 68.0% (17/25), and the success rate of IVR was 88.2% (15/17). There were three cases of Type I and 12 cases of Type II. Type II had a significantly longer cold ischemic time and higher recurrence rate than Type I (P = 0.005 and P = 0.006). In conclusion, DBE is a less invasive and safe treatment method that is capable of reaching the bilioenteric anastomotic site after pediatric LDLT and enables IVR to be performed on strictures, and its treatment outcomes are improving. Type II and long cold ischemic time are risk factors for intractable bilioenteric anastomotic stricture.


American Journal of Transplantation | 2010

Living Donor Liver Transplantation for Neonates Using Segment 2 Monosubsegment Graft

Koichi Mizuta; Yoshikazu Yasuda; Satoshi Egami; Yukihiro Sanada; Taiichi Wakiya; Taizen Urahashi; Minoru Umehara; Shuji Hishikawa; Makoto Hayashida; Masanobu Hyodo; Yasunaru Sakuma; Takehito Fujiwara; Kentaro Ushijima; Koichi Sakamoto; Hideo Kawarasaki

The prognosis of liver transplantation for neonates with fulminant hepatic failure (FHF) continues to be extremely poor, especially in patients whose body weight is less than 3 kg. To address this problem, we have developed a safe living donor liver transplantation (LDLT) modality for neonates. We performed LDLTs with segment 2 monosubsegment (S2) grafts for three neonatal FHF. The recipient age and body weight at LDLT were 13–27 days, 2.59–2.84 kg, respectively. S2 or reduced S2 grafts (93–98 g) obtained from their fathers were implanted using temporary portacaval shunt. The recipient portal vein was reconstructed at a more distal site, such as the umbilical portion, to have the graft liver move freely during hepatic artery (HA) reconstruction. The recipient operation time and bleeding were 11 h 58 min–15 h 27 min and 200–395 mL, respectively. The graft‐to‐recipient weight ratio was 3.3–3.8% and primary abdominal wall closure was possible in all cases. Although hepatic artery thrombosis occurred in one case, all cases survived with normal growth. Emergency LDLT with S2 grafts weighing less than 100 g can save neonates with FHF whose body weight is less than 3 kg. This LDLT modality using S2 grafts could become a new option for neonates and very small infants requiring LT.


Transplantation Proceedings | 2010

Living-Donor Liver Transplantation in 126 Patients with Biliary Atresia: Single-Center Experience

Koichi Mizuta; Yukihiro Sanada; Taiichi Wakiya; Taizen Urahashi; Minoru Umehara; Satoshi Egami; Shuji Hishikawa; Noriki Okada; Youichi Kawano; T. Saito; Makoto Hayashida; S. Takahashi; H Yoshino; A. Shimizu; Y. Takatsuka; T. Kitamura; Y. Kita; T. Uno; Y. Yoshida; Masanobu Hyodo; Yasunaru Sakuma; Takehito Fujiwara; Kentaro Ushijima; K. Sugimoto; Masami Ohmori; S. Ohtomo; Koichi Sakamoto; Manabu Nakata; Tomonori Yano; Hironori Yamamoto

OBJECTIVES To describe our experience with 126 consecutive living-donor liver transplantation (LDLT) procedures performed because of biliary atresia and to evaluate the optimal timing of the operation. PATIENTS AND METHODS Between May 2001 and January 2010,126 patients with biliary atresia underwent 130 LDLT procedures. Mean (SD) patient age was 3.3 (4.2) years, and body weight was 13.8 (10.7) kg. Donors included 64 fathers, 63 mothers, and 3 other individuals. The left lateral segment was the most commonly used graft (75%). Patients were divided into 3 groups according to body weight: group 1, less than 8 kg (n = 40); group 2,8 to 20 kg (n = 63); and group 3, more than 20 kg (n = 23). Medical records were reviewed retrospectively. Follow up was 4.5 (2.7) years. RESULTS All group 3 donors underwent left lobectomy, and all group 1 donors underwent left lateral segmentectomy. No donors required a second operation or died. Comparison of the 3 groups demonstrated that recipient Pediatric End-Stage Liver Disease score in group 1 was highest, operative blood loss in group 2 was lowest (78 mL/kg), and operative time in group 3 was longest (1201 minutes). Hepatic artery complications occurred more frequently in group 1 (17.9%), and biliary stenosis (43.5%) and gastrointestinal perforation (8.7%) occurred more frequently in group 3. The overall patient survival rates at 1, 5, and 9 years was 98%, 97%, and 97%, respectively. Five-year patient survival rate in groups 1,2, and 3 were 92.5%, 100%, and 95.7%, respectively. Gastrointestinal perforation (n = 2) was the primary cause of death. CONCLUSIONS Living-donor liver transplantation is an effective treatment of biliary atresia, with good long-term outcome. It seems that the most suitable time to perform LDLT to treat biliary atresia is when the patient weighs 8 to 20 kg.


Transplantation Proceedings | 2009

Living Donor Liver Transplantation for Congenital Absence of the Portal Vein

Yukihiro Sanada; Koichi Mizuta; Youichi Kawano; Satoshi Egami; Makoto Hayashida; Taiichi Wakiya; M. Mori; Shuji Hishikawa; K. Morishima; Takehito Fujiwara; Yasunaru Sakuma; Masanobu Hyodo; Yoshikazu Yasuda; Eiji Kobayashi; Hideo Kawarasaki

The congenital absence of the portal vein (CAPV) is a rare venous malformation in which mesenteric venous blood drains directly into the systemic circulation. Liver transplantation (OLT) may be indicated for patients with symptomatic CAPV refractory to medical treatment, especially due to hyperammonemia, portosystemic encephalopathy, hepatopulmonary syndrome, or hepatic tumors. Because portal hypertension and collateral circulation do not occur with CAPV, significant splanchnic congestion may occur when the portocaval shunt is totally clamped during portal vein (PV) reconstruction in OLT. This phenomenon results in severe bowel edema and hemodynamic instability, which negatively impact the patients condition and postoperative recovery. We have successfully reconstructed the PV in living donor liver transplantation (LDLT) using a venous interposition graft, which was anastomosed end-to-side to the portocaval shunt by a partial side-clamp, using a patent round ligament of the liver, which was anastomosed end-to-end to the graft PV with preservation of both the portal and caval blood flows. Owing to the differences in anatomy among patients, at LDLT for CAPV liver transplant surgeons should seek to preserve both portal and caval blood flows.


World Journal of Gastroenterology | 2014

Protocol liver biopsy is the only examination that can detect mid-term graft fibrosis after pediatric liver transplantation

Yukihiro Sanada; Koshi Matsumoto; Taizen Urahashi; Yoshiyuki Ihara; Taiichi Wakiya; Noriki Okada; Naoya Yamada; Yuta Hirata; Koichi Mizuta

AIM To assessed the clinical significance of protocol liver biopsy (PLB) in pediatric liver transplantation (LT). METHODS Between July 2008 and August 2012, 89 and 55 PLBs were performed in pediatric patients at two and five years after LT, respectively. We assessed the histopathological findings using the Metavir scoring system, including activity (A) and fibrosis (F), and we identified factors associated with scores of ≥ A1 and ≥ F1. Our results clarified the timing and effectiveness of PLB. RESULTS The incidences of scores of ≥ A1 and ≥ F1 were 24.7% and 24.7%, respectively, at two years after LT and 42.3% and 34.5%, respectively, at five years. Independent risk factors in a multivariate analysis of a score of ≥ A1 at two years included ≥ 2 h of cold ischemic time, no acute cellular rejection and an alanine amino transaminase (ALT) level of ≥ 20 IU/L (P = 0.028, P = 0.033 and P = 0.012, respectively); however, no risk factors were identified for a score of ≥ F1. Furthermore, no independent risk factors associated with scores of ≥ A1 and ≥ F1 at five years were identified using multivariate analysis. A ROC curve analysis of ALT at two years for a score of ≥ A1 demonstrated the recommended cutoff value for diagnosing ≥ A1 histology to be 20 IU/L. The incidence of scores of ≥ A2 or ≥ F2 at two years after LT was 3.4% (three cases), and all patients had an absolute score of ≥ A2. In contrast to that observed for PLBs at five years after LT, the incidence of scores of ≥ A2 or ≥ F2 was 20.0% (11 cases), and all patients had an absolute score of ≥ F2. In all cases, the dose of immunosuppressants was increased after the PLB, and all ten patients who underwent a follow-up liver biopsy improved to scores of ≤ A1 or F1. CONCLUSION PLB at two years after LT is an unnecessary examination, because the serum ALT level reflects portal inflammation. In addition, immunosuppressive therapy should be modulated to maintain the ALT concentration at a level less than 20 IU/L. PLB at five years is an excellent examination for the detection of early reversible graft fibrosis because no serum markers reflect this finding.


Surgery | 2012

The role of operative intervention in management of congenital extrahepatic portosystemic shunt

Yukihiro Sanada; Taizen Urahashi; Yoshiyuki Ihara; Taiichi Wakiya; Noriki Okada; Naoya Yamada; Satoshi Egami; Shuji Hishikawa; Youichi Kawano; Kentaro Ushijima; Shinya Otomo; Koichi Sakamoto; Manabu Nakata; Yoshikazu Yasuda; Koichi Mizuta

BACKGROUND AND AIMS Congenital extrahepatic portosystemic shunt (CEPS) is a rare venous malformation in which mesenteric venous blood drains directly into the systemic circulation. It is still a matter of debate whether conservative or operative strategies should be used to treat symptomatic CEPS. The aim of this study was to evaluate the role of operative intervention in the management of CEPS. METHODS Between June 2004 and August 2010, 6 consecutive patients with symptomatic CEPS were treated in our department. There were 3 male and 3 female patients, with a median age of 3.5 years (range, 1-8). Their demographic, clinical, and laboratory data were analyzed. All patients were scheduled to undergo shunt ligation or liver transplantation (LT). RESULTS Living donor LT was carried out in 4 patients, and shunt ligation in 2. After a median follow-up of 25 months, all the patients are alive currently with marked relief of symptoms. CONCLUSION Shunt ligation or LT for symptomatic CEPS is potentially curative.


Transplant International | 2014

Maternal grafts protect daughter recipients from acute cellular rejection after pediatric living donor liver transplantation for biliary atresia

Yukihiro Sanada; Youichi Kawano; Atsushi Miki; Junko Aida; Kenichi Nakamura; Naotaka Shimomura; Naoshi Ishikawa; Tomio Arai; Yuta Hirata; Naoya Yamada; Noriki Okada; Taiichi Wakiya; Yoshiyuki Ihara; Taizen Urahashi; Yoshikazu Yasuda; Kaiyo Takubo; Koichi Mizuta

Some studies have found that gender mismatch between donors and recipients are related to poor graft prognosis after liver transplantation. However, few studies have investigated the impact of gender mismatch on acute cellular rejection (ACR) in pediatric living donor liver transplantation (LDLT). This retrospective study investigated the clinical significance of these factors in ACR after pediatric LDLT. Between November 2001 and February 2012, 114 LDLTs were performed for recipients with biliary atresia (BA) using parental grafts. We performed univariate and multivariate analyses to identify the factors associated with ACR. The donor–recipient classifications included mother donor to daughter recipient (MD; n = 43), mother to son (n = 18), father to daughter (FD; n = 33), and father to son (n = 20) groups. The overall incidence rate of ACR in the recipients was 36.8%. Multivariate analysis showed that gender mismatch alone was an independent risk factor for ACR (P = 0.012). The FD group had a higher incidence of ACR than the MD group (P = 0.002). In LDLT, paternal grafts with gender mismatch were associated with a higher increased incidence of ACR than maternal grafts with gender match. Our findings support the possibility that maternal antigens may have an important clinical impact on graft tolerance in LDLT for patients with BA.


Pediatric Transplantation | 2015

The impact of rituximab in ABO‐incompatible pediatric living donor liver transplantation: The experience of a single center

Noriki Okada; Yukihiro Sanada; Yuta Hirata; Naoya Yamada; Taiichi Wakiya; Yoshiyuki Ihara; Taizen Urahashi; Atsushi Miki; Yuji Kaneda; Hideki Sasanuma; Takehito Fujiwara; Yasunaru Sakuma; Atsushi Shimizu; Masanobu Hyodo; Yoshikazu Yasuda; Koichi Mizuta

Previous studies have demonstrated the safety of ABO‐incompatible pediatric LDLT using preoperative plasmapheresis and rituximab; however, no reports have described the timing and dosage of rituximab administration for pediatric LDLT. This study aimed to describe a safe and effective dosage and timing of rituximab for patients undergoing pediatric ABO‐incompatible LDLT based on the experience of our single center. A total of 192 LDLTs in 187 patients were examined. These cases included 29 ABO‐incompatible LDLTs in 28 patients. Rituximab was used beginning in January 2004 in recipients older than two yr of age (first period: 375 mg/m2 in two cases; second period: 50 mg/m2 in two cases; and 200 mg/m2 in eight cases). Two patients who received 375 mg/m2 rituximab died of Pneumocystis carinii pneumonia and hemophagocytic syndrome. One patient who received 50 mg/m2 rituximab required retransplantation as a consequence of antibody‐mediated complications. All eight patients administered 200 mg/m2 survived, and the mean CD20+ lymphocyte count was 0.1% at the time of LDLT. In the preoperative management of patients undergoing pediatric ABO‐incompatible LDLT, the administration of 200 mg/m2 rituximab three wk prior to LDLT was safe and effective.


Experimental and clinical transplantation : official journal of the Middle East Society for Organ Transplantation | 2013

Effect of repeat Kasai hepatic portoenterostomy on pediatric live-donor liver graft for biliary atresia.

Taizen Urahashi; Yoshiyuki Ihara; Yukihiro Sanada; Taiichi Wakiya; Naoya Yamada; Noriki Okada; Koichi Mizuta

OBJECTIVES Treatment for patients with biliary atresia is a Kasai hepatic portoenterostomy; however, the efficacy of repeat Kasai hepatic portoenterostomy is unclear. This study sought to examine the effect of a prior Kasai hepatic portoenterostomy, especially a repeat Kasai hepatic portoenterostomy, on the outcomes of living-donor liver transplant. MATERIALS AND METHODS One hundred twenty-six of 170 children that underwent a living-donor liver transplant between May 2001, and March 2010, received a living-donor liver transplant for biliary atresia. These patients were divided into 2 groups according to the number of previous portoenterostomies: 1 (group A, n=100) or 2 or more Kasai hepatic portoenterostomies (group B, n=26). Portoenterostomy was performed twice in 24 patients in group B, 3 times in 1, and 4 times in 1. Preoperative, operative factors, mortality, morbidity, and survival rates were examined and compared between groups. RESULTS The surgical factors such as operative time, blood loss per weight, cold ischemia time, and weight of the native liver were significantly greater in group B than they were in group A. The patient survival rates were comparable in the 2 groups (94.5% in group A and 93.3% in group B), and the difference was not statistically significant. No statistically significant difference was observed between the groups with regard to vascular complications, biliary complications, and other factors including postoperative variables. Bowel perforation requiring surgical repair was more frequent in group B than it was in group A. CONCLUSIONS Repeat Kasai hepatic portoenterostomy might have a negative effect on patients who undergo living-donor liver transplant for biliary atresia patients with potential lethal complications such as bowel perforation. More biliary atresia patients could have a liver transplant, with improved survival and better life expectancy, if they have inadequate biliary drainage after the initial Kasai hepatic portoenterostomy.


Transplantation proceedings | 2012

Veno-occlusive disease/sinusoidal obstruction syndrome associated with potential antibody-mediated rejection after pediatric living donor liver transplantation: a case report.

Naoya Yamada; Taizen Urahashi; Yoshiyuki Ihara; Yukihiro Sanada; Taiichi Wakiya; Noriki Okada; Koichi Mizuta

A 9-month-old girl with biliary atresia underwent successful living donor liver transplantation from her 42-year-old ABO blood-type incompatible mother. The postoperative course was uneventful until postoperative day (POD) 13 when the recipient displayed an increased volume of drained ascites and decreased her platelet count showing low-velocity portal venous inflow without hepatic venous outflow obstruction. We suspected potential veno-occlusive disease/sinusoidal obstruction syndrome (vod/sos) due to an acute cellular rejection (ACR) episode and performed a liver biopsy (LB). We diagnosed severe episode (Rejection Activity Index Score; P3V3B1 = 7) and started steroid pulse therapy. We performed a second LB on POD 27 because the patient showed weight gain and tender hepatomegaly, diagnosing moderate ACR (P1V3B1 = 5). We started a second course of steroid pulse therapy, but the patients clinical findings did not improve. On POD 43, her third LB finding showed P1V1B1 with improved processes from ACR, but still displaying severe congestion and fibrotic obliteration of small hepatic veins. We suspected that her immunologic responses were associated with antibody-mediated rejection (AMR) because her anti-HLA class I and class II antibodies were positive by flow panel-reactive antibody method and donor-specific antigen class II and C4d staining were also positive. We added mycophenolate mofetil and administered high-dose intravenous immunoglobulin to control the AMR, and anticoagulant therapy for the VOD/SOS. Her clinical findings and graft venous abnormalities finally improved; she was eventually discharged without sequelae on POD 72.

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Koichi Mizuta

Jichi Medical University

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Noriki Okada

Jichi Medical University

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Naoya Yamada

Jichi Medical University

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Satoshi Egami

Jichi Medical University

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