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Featured researches published by H. Kokai.


Surgery Today | 2006

Management of major portosystemic shunting in small-for-size adult living-related donor liver transplantation with a left-sided graft liver

Yoshinobu Sato; Satoshi Yamamoto; Toshiyuki Takeishi; Kenichiro Hirano; Takashi Kobayashi; Takashi Kato; Y. Hara; Takaoki Watanabe; H. Kokai; Katsuyoshi Hatakeyama

PurposeWe investigated the mechanisms of small-for-size graft syndrome by time-lag ligation, a novel approach to treating major portosystemic shunts in small-for-size adult living-related donor liver transplantation (LRDLT) using left-sided graft liver.MethodsFive patients with end-stage liver failure and major splenorenal shunting underwent LRDLT using left lobe grafts. The average graft volume to recipient body weight (GV/RBW) ratio was 0.68 ± 0.14. Two patients underwent time-lag ligation of their splenorenal (SR) shunts on postoperative days (PODs) 8 and 14, respectively. The shunts of the other three patients were untreated.ResultsThe portal pressures in the first patient who underwent time-lag ligation rose above 300 mmH2O and remained there for 2 weeks. Thus, we ligated the SR shunt in the second patient on POD 14, resulting in an increase from 177 mmH2O to 258 mmH2O, but it decreased again thereafter. In the other three patients, the SR shunt was not ligated because portal blood flow volumes remained sufficient. Total bilirubin levels in the first time-lag ligation patient rose to 16 mg/dl, paralleling the rise in portal pressures. Although they increased after ligation in the second patient, they did not exceed 10 mg/dl.ConclusionsWe recommend time-lag ligation if portal venous blood flow decreases in the early post-transplant period, but not until at least 2 weeks after transplantation. If the portal venous blood flow does not decrease, early postoperative ligation is unnecessary. If there are no major portosystemic shunts, making a portosystemic shunt might decompress excessive portal hypertension. With donor safety priority in LRDLT, novel approaches must be developed to enable the use of smaller donor grafts. We describe a potential means of using left lobe grafts in adult LRDLT.


Transplantation Proceedings | 2012

Magnetic Compression Anastomosis for Bile Duct Stenosis After Donor Left Hepatectomy: A Case Report

H. Oya; Yoshinobu Sato; E. Yamanouchi; Satoshi Yamamoto; Y. Hara; H. Kokai; T. Sakamoto; Kohei Miura; K. Shioji; Yutaka Aoyagi; K. Hatakeyama

Magnetic compression anastomosis (MCA) provides a minimally invasive treatment creating a nonsurgical, sutureless enteric anastomosis in conjunction with an interventional radiologic technique by using 2 high-power magnets. Recently, the MCA technique has been applied to bile duct strictures after living donor liver transplantation or major hepatectomy. Herein we described use of MCA for bile duct stenosis 5 months after donor left hepatectomy in a 24-year-old man who presented with a stricture at the porta hepatis and intrahepatic bile duct dilatation. Unsuccessful transpapillary biliary drainage and balloon dilatation through a percutaneous transhepatic biliary drainage (PTBD) route led to the MCA. A 4-mm-diameter cylindrical samarium-cobalt (Sm-Co) daughter magnet with a long nylon wire was placed at the superior site of the obstruction through the PTBD route. A 5-mm-diameter Sm-Co parent magnet with an attached nylon handle was endoscopically inserted into the common bile duct and placed at the inferior site of obstruction. The 2 magnets were attracted, sandwiching the stricture and establishing a reanastomosis. In conclusion, the MCA technique was a unique procedure for choledochocholedochostomy in a patient with bile duct stenosis after donor hepatectomy.


Transplantation | 2010

Method for spontaneous constriction and closure of portocaval shunt using a ligamentum teres hepatis in small-for-size graft liver transplantation.

Yoshinobu Sato; H. Oya; Satoshi Yamamoto; T. Kobayashi; Y. Hara; H. Kokai; Katsuyoshi Hatakeyama

Background. We have developed a new portocaval (PC) shunt creation technique for use in small-for-size (SFS) graft liver transplantations. PC shunts are already used to avoid SFS graft syndrome in cases of adult-to-adult living donor liver transplantation (LDLT), but the current method of creating these shunts is subject to two problems: reportal hypertension and liver dysfunction after premature ligation of the PC shunt; and graft atrophy and liver dysfunction because of the loss of portal venous flow late in the recovery period after LDLT. Methods. Our new technique avoids these two problems simultaneously by using the interposed obliterated ligamentum teres hepatis (LTH) to create the PC shunt, then obstructing the PC shunt after regeneration of the liver graft. Results. We have used this technique in four cases. In all cases, portal venous pressures after shunting were lower than those before shunting, and PC shunts with lower portal pressure were obstructed faster than that with higher portal pressure. Conclusion. Our results suggest that the LTH can function as a shape memory graft to reduce portal venous flow after regeneration of the graft liver. Using the LTH to create a PC shunt might help to prevent both SFS graft syndrome early in the recovery period after LDLT and loss of portal venous flow late in the recovery period.


Transplantation Proceedings | 2008

Successful Super-Small-for-Size Graft Liver Transplantation by Decompression of Portal Hypertension via Splenectomy and Construction of a Mesocaval Shunt: A Case Report

H. Kokai; Y. Sato; Satoshi Yamamoto; H. Oya; H. Nakatsuka; Takehiro Watanabe; Kazuyasu Takizawa; Katsuyoshi Hatakeyama

We performed a successful super-small-for-size graft liver transplantation by decompressing portal hypertension via splenectomy and a mesocaval shunt. A 46-year-old woman with Child-Pugh class C liver cirrhosis associated with Wilsons disease underwent a living donor liver transplantation (LDLT). The donor had an anomalous portal vein, hepatic vein, and bile duct, so we had to use the right lateral segment for the graft. Preoperative computed tomographic (CT) volumetry showed the volume of this area to be 433 mL; graft-to-recipient weight ratio (GRWR) was 0.72; and graft-to-standard liver volume (GV/SLV) was 39.0%. However, the real volume of the resected right lateral segment was 281 g; GRWR was 0.47; and GV/SLV was 25.3%--a super-small-for-size graft. After implantation, congestion of the small graft was severe due to excessive portal hypertension. Therefore, we tried decompressing the portal vein. First, we performed splenectomy which reduced the portal pressure which remained excessive. Second, a mesocaval shunt was constructed decreasing the portal pressure from 38 to 30 cm H2O. Additionally, we initiated continuous portal injection of prostaglandin E1. The postoperative course was not smooth, but the general status slowly recovered. Over 25 cm H2O of portal hypertension was observed until postoperative day 21 when it improved. At last, the recipient was discharged on postoperative day 156. Accurate preoperative CT volumetry is important to obtain sufficient graft volume. Our case may be one of the smallest-for-size grafts that was successfully transplanted. Management of excessive portal hypertension is important for LDLT, especially using a small-for-size graft. Splenectomy and construction of a mesocaval shunt may be useful strategies to decompress the portal vein.


Transplantation Proceedings | 2009

Feasibility of Auxiliary Partial Living Donor Liver Transplantation for Fulminant Hepatic Failure as an Aid for Small-for-Size Graft : Single Center Experience

Takashi Kobayashi; Y. Sato; Satoshi Yamamoto; H. Oya; Y. Hara; Takehiro Watanabe; H. Kokai; Katsuyoshi Hatakeyama

Auxiliary partial orthotopic liver transplantation (APOLT) or heterotopic auxiliary partial liver transplantation (HAPLT) was initially indicated for potentially reversible fulminant hepatic failure (FHF). We started auxiliary partial living donor liver transplantation (LDLT) for FHF in February 2002. Since then, 5 FHF patients (3 females and 2 males) underwent auxiliary partial LDLT: 3 cases of APOLT and 2 cases of HAPLT. All of them received a small-for-size graft: graft-to-recipient weight ratio (GRWR) < or = 1.0%. The etiologies of FHF were hepatitis B virus (HBV) in 1, Wilsons disease in 1, and unknown origin in 3 cases. Three were the acute type and 2 the subacute type of FHF. Median age was 45 years (range, 14-54 years). Blood type was identical in all cases. A left lobe graft was used in 4 instances and a right lobe graft in 1 case. Median GRWR was 0.74 (range, 0.42-0.85). Median follow-up was 42 months (range, 3 days to 70 months). Three of 5 patients (60%) were alive (at 42, 67, and 70 months) and 1 was free of immunosuppression after sufficient recovery of the native liver. Two cases succumbed: 1 at postoperative day 3 because of cytomegalovirus pneumonia and 1 at 10 months after APOLT because of sepsis. Complications were seen in all 5 patients: Relaparotomy for hemostasis in 3, decompression surgery of the abdominal cavity in 1, rehepaticojejunostomy in 1, and biliary strictures in 2 cases. Auxiliary partial LDLT may be a choice as an aid for a small-for-size graft in FHF.


Transplantation Proceedings | 2009

Long-Term Follow-up Study of Biliary Reconstructions and Complications After Adult Living Donor Liver Transplantation: Feasibility of Duct-to-Duct Reconstruction With a T-Tube Stent

Takashi Kobayashi; Y. Sato; Satoshi Yamamoto; H. Oya; Y. Hara; Takehiro Watanabe; H. Kokai; Katsuyoshi Hatakeyama

The aim of this study was to analyze the feasibility of duct-to-duct biliary reconstruction (hepaticohepaticostomy) with a T-tube stent (HH-T) after adult living donor liver transplantation (LDLT) based on long-term follow-up. We retrospectively evaluated 63 primary adult LDLTs who had survived >1 month from March 1999 to January 2008. We compared the incidence of bile leaks and biliary strictures (BS) in 3 groups of patients: Roux-en-Y hepaticojejunostomy (HJ; n = 18); duct-to-duct hepaticohepaticostomy with external stents except a T-tube (HH; n = 26); and HH-T (n = 19). Median follow-up was longer among the HJ (63 months) than the other groups (32 months in HH and 25 months in HH-T; P = .04). Bile leaks developed in 8 of the HJ cases (44%); 9 of the HH cases (33%); and 1 of the HH-T cases (5%; P = .02). All cases with bile leaks (n = 18) were treated using continuous drainage, 15 of them (83%) successfully. BS developed in 4 HJ cases (22%); 12 HH cases (46%), and 4 HH-T cases (21%; P = .12). Intervention for BS (n = 20) was successful in 10 cases (50%) via an endoscopic approach and 6 cases (30%) via a percutaneous transhepatic approach. Operative management for BS was required in 4 cases (20%). Biliary reconstruction using HH-T may be effective to prevent bile leaks after LDLT. However, HH-T may not decrease the incidence of BS after adult LDLT.


Surgery Today | 2013

Catheter-directed continuous thrombolysis following aspiration thrombectomy via the ileocolic route for acute portal venous thrombosis: report of two cases

Kohei Miura; Yoshinobu Sato; H. Nakatsuka; Satoshi Yamamoto; H. Oya; Y. Hara; H. Kokai; Katsuyoshi Hatakeyama

Although acute portal venous thrombosis (PVT) is a potentially life-threatening complication that occurs after hepatobiliary surgery with portal vein (PV) reconstruction or splenectomy, no effective or universal treatments have yet been established. Transjugular or transhepatic catheter-directed thrombolysis has recently been reported to be effective for treating acute PVT. However, the efficiency of this treatment for complete PV occlusion might be limited because a poor portal venous flow prevents thrombolytic agents from reaching and dissolving thrombi. Moreover, the use of the transjugular or transhepatic route might not be suitable in patients who have undergone major hepatectomy or in those with ascites due to an increased risk of residual liver injury or intra-abdominal bleeding following puncture to the residual liver. We herein describe the cases of two patients with almost total PV occlusion caused by massive thrombi that formed after hepatobiliary surgery, who were successfully treated with catheter-directed continuous thrombolysis following aspiration thrombectomy via the ileocolic route. This treatment should be considered beneficial for treating selected patients such as the two patients described herein.


Transplantation Proceedings | 2009

De Novo Autoimmune Hepatitis After Living Donor Liver Transplantation in a 25-Day-Old Newborn Baby: A Case Report

H. Oya; Y. Sato; Satoshi Yamamoto; Takashi Kobayashi; Takehiro Watanabe; H. Kokai; Katsuyoshi Hatakeyama

De novo autoimmune hepatitis (AIH) has been described recently as a new type of graft dysfunction in pediatric patients receiving liver transplantation. Herein we have reported the case of a boy, diagnosed as neonatal hemochromatosis, who received a reduced left lateral graft 25 days after birth. Pretransplantation autoantibodies and serological tests were negative. The postoperative course was smooth. No episode of vascular or biliary complication or acute cellular rejection was observed. The maintenance immunosuppressant was tacrolimus only. Liver dysfunction occurred 13 months after living donor liver transplantation. Liver biopsies showed no acute cellular rejection, but severe apoptosis and regeneration of liver cells at the centrolobular area. At that time, various autoantibodies including anti-nuclear, anti-double-stranded DNA, and anti-smooth muscle antibodies were positive. In addition, serum immunoglobulin G (IgG) was elevated. Based on these findings, he was diagnosed as de novo AIH. The treatment consisted of reducing the tacrolimus dose and reintroduction of steroids. After 12 months of treatment, liver dysfunction improved, serum autoantibodies became negative, and serum IgG level normalized. Currently his immunosuppressive therapy consists of low-dose tacrolimus and prednisolone. In conclusion, the present case demonstrated that de novo AIH can appear in living donor liver transplant patients despite appropriate immunosuppression. Reducing the tacrolimus dose and reintroduction of prednisolone sustained the graft and prevented retransplantation.


Surgery Today | 2013

Successful laparoscopic division of a patent ductus venosus: report of a case

Y. Hara; Yoshinobu Sato; Satoshi Yamamoto; H. Oya; Masato Igarashi; Satoshi Abe; H. Kokai; Kohei Miura; Takeshi Suda; Minoru Nomoto; Yutaka Aoyagi; Katsuyoshi Hatakeyama

Patent ductus venosus (PDV) is a rare condition of a congenital portosystemic shunt from the umbilical vein to the inferior vena cava. This report presents the case of an adult patient with PDV, who was successfully treated with laparoscopic shunt division. A 69-year-old male was referred with hepatic encephalopathy. Contrast-enhanced CT revealed a large connection between the left portal vein and the inferior vena cava, which was diagnosed as PDV. The safety of a shunt disconnection was confirmed using a temporary balloon occlusion test for the shunt, and the shunt division was performed laparoscopically. The shunt was carefully separated from the liver parenchyma with relative ease, and then divided using a vascular stapler. Portal flow was markedly increased after the operation, and the liver function of the patient improved over the 3-month period after surgery. Although careful interventional evaluation for portal flow is absolutely imperative prior to surgery, a minimally invasive laparoscopic approach can be safely used for treating PDV.


Transplantation Proceedings | 2010

Auxiliary partial orthotopic living donor liver transplantation for fulminant hepatic failure with flat electroencephalogram: a case report.

Takashi Kobayashi; Y. Sato; Satoshi Yamamoto; Toshiyuki Takeishi; H. Oya; N. Hideki; H. Kokai; Isao Kurosaki; Katsuyoshi Hatakeyama

A 54-year-old woman with hepatic encephalopathy grade IV (coma) and flat electroencephalogram (EEG) due to fulminant liver failure (FHF) due to hepatitis B virus infection was admitted to our hospital on May 24, 2002. We performed a living donor auxiliary partial orthotopic liver transplantation (APOLT) emergently on the day of admission. The donor was the patients son, whose ABO blood group was identical. The immunosuppressant regimen consisted of tacrolimus and low-dose steroids. The left lobe (260 g) of the recipient, which was removed using a Pringle maneuver, was reconstructed with a left lobe (417 g) graft from the donor, which was orthotopically positioned as an auxiliary support. The patient remained in a coma for the first 5 days but on day 6 her eyes opened and followed objects. Finally, she recovered an almost normal appearance. Abdominal compartment syndrome, bile leak, and a mild rejection episode occurred during the postoperative course; all were treated successfully. The patient was discharged on the postoperative day 142. Computed tomography (CT) scan and biopsy were used to follow the changes in the graft and the native liver. On postoperative day 520, a CT scan showed a remarkable improvement in native liver size (493 cm3). Immunosuppression was tapered off and stopped on the postoperative day 635 to surrender the grafted liver. The graft liver biopsy specimen showed severe chronic rejection. The present status of the patient, who is now more than 7 years after transplantation, is an absence of neurological findings with normal liver function.

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