Biomedical subjects

K Yanaga

Publications and source records attributed to K Yanaga.

At least 91 records · Page 5Linked to original sources

PubMed1994

Strategies for reducing blood transfusions in hepatic resection.

A comparison of 60 blood transfused and 71 nonblood transfused hepatic resection patients was done to evaluate strategies for reducing blood transfusions during hepatic surgery. There were no significant differences between the two groups with regard to preoperative laboratory data, except for prothrombin time and hematocrit value. The mean operative blood loss was 1990 ml and 760 ml in the blood transfused and nonblood transfused groups, respectively. A multivariate analysis suggested that the patient's body weight, preoperative prothrombin time, and operative blood loss independently predicted the need for intraoperative blood transfusion. Major postoperative complications developed more frequently in the blood transfused group than in the nonblood transfused group (31.7 vs. 11.3%, p < 0.005). These results suggest that the difference in operative blood loss between the two groups was related to the prolonged prothrombin time and a susceptibility for blood transfusion was found to exist particularly in patients with a lower hematocrit value as well as a lower body weight. Thus, the improvement of these preoperative laboratory data combined with avoiding the use of the hematocrit value as a determining factor for intraoperative transfusion could correspond to a reduction in operative blood loss, while curtailing the demands on blood bank facilities, and lowering the risk of postoperative complications.

Adult↗

PubMed1994

Characteristics of hepatocellular carcinoma originating in the caudate lobe.

Nine patients with hepatocellular carcinoma originating in the caudate lobe who underwent hepatic resection were studied. The caudate lobe was divided into three parts, according to the criteria of Kumon, including the Spiegel lobe, the paracaval portion and the caudate process. The tumors were located in the Spiegel lobe in four, the paracaval portion in four and the caudate process in one. Surgical procedures consisted of right hepatic lobectomy in one, central bisegmentectomy in one and caudate lobectomy in seven. The mean surgical time was 379 +/- 129 min; the mean estimated blood loss was 2,994 +/- 2,303 ml. The above-mentioned surgical risks were more clearly recognized in the paracaval portion than in the Spiegel lobe. In addition, most patients experienced significant post-operative complications. Six of eight patients with 6 mo or longer follow-up had recurrences, and two of six patients died. The characteristics of hepatocellular carcinoma in the caudate lobe were as follows: (a) a higher surgical risk, and more definite risk in the paracaval portion; and (b) a higher rate of early recurrence. A left lobectomy for the Spiegel lobe, a right or left trisegmentectomy for the paracaval portion and a right lobectomy for the caudate process would be ideal from the point of view of the portal supply of the caudate lobe. However, in cirrhotic patients either a caudate lobectomy or partial resection might be preferable because longer survival can be expected.

Aged↗

PubMed1994

Isolated hepatic caudate lobectomy.

BACKGROUND: Isolated caudate lobectomy is a challenging surgical procedure for which safe and reliable techniques have yet to be developed. METHODS: Isolated caudate lobectomy was performed by initial inflow control of the caudate lobe, full mobilization of the liver from the inferior vena cava by dividing all short hepatic veins, and parenchymal division dorsal to the major hepatic veins with a clockwise rotation of the liver while the liver was selectively devascularized by Pringle's maneuver and occlusion of the confluence of the major hepatic veins flush with the inferior vena cava. RESULTS: Two patients with cirrhosis underwent this procedure successfully without intraoperative hemodynamic instability or postoperative liver dysfunction. CONCLUSIONS: This technique allows safe and truly selective excision of the caudate lobe without the need for occlusion of the inferior vena cava or venovenous bypass.

Carcinoma, Hepatocellular↗

PubMed1993

Development of antitissue factor antibodies in patients after liver surgery.

After liver surgery, two patients developed unexplainable prolonged prothrombin times (PT) that were not associated with bleeding tendency. The substitution of rabbit thromboplastin for either human or monkey thromboplastin in performing PT tests resulted in a normal clotting time. Tissue factor (TF) procoagulant activity assays and an immunoblotting analysis showed that these patients had developed IgG lambda-type immediate anticoagulants directed against both rabbit and bovine TF that did not crossreact with human or monkey TF. In a chromogenic assay, the patient IgG caused a decrease in both the Km and the Vmax of the factor X activation by rabbit TF-factor VIIa complex. The lack of reactivity of the patient IgG with human TF presumably explained why there was no clinical bleeding. Both patients had been treated earlier with a topical hemostatic agent prepared from bovine corium, microfibrillar collagen hemostat, while undergoing previous surgery. In an immunoblotting analysis, the patient IgG stained a 42-Kd band in the Triton extract of the collagen preparation under either reducing or nonreducing conditions. The Triton extract of the collagen preparation blocked the binding of the patient IgG to bovine TF. Thus, it is suggested that the iatrogenic immunization by intraoperative exposure of bovine TF retained in the collagen preparation may be responsible for the development of anti-TF antibodies in these patients. The anti-TF antibodies resulted in a clinical error in the evaluation of coagulation status after the use of rabbit thromboplastin.

Animals↗

PubMed1993

Effect of diabetes mellitus on hepatic resection.

We evaluated the effect of diabetes mellitus on mortality and morbidity after elective hepatic resections. Of 209 patients who underwent hepatic resections between April 1985 and July 1990, 49 (23.4%) were diabetic. Postoperative morbidity was more common among diabetics than among nondiabetics (75.5% vs 51.3%), mainly due to hepatic decompensation (55.1% vs 36.3%) and intraperitoneal sepsis (18.4% vs 6.3%). However, their incidence of hospital death (2% vs 2.5%), mean +/- SD postoperative hospital stay (36.1 +/- 20.2 days vs 29.4 +/- 28.2 days), and long-term survival were comparable with those of nondiabetics. Diabetics with and without complications were similar in preoperative or postoperative insulin requirement, duration of diabetes, and preoperative fasting glucose. Nevertheless, all eight patients with 24-hour urinary glucose excretion above 1 g developed complications. We conclude that diabetics are at a high risk of morbidity, but not of mortality after elective hepatic resection.

Adolescent↗

PubMed1993

Open and closed suction drainage after hepatic resection.

A retrospective study was conducted to compare open conduit drains with closed suction drains, with regard to the occurrence of intraperitoneal septic complications after hepatectomy (IPSCH). The subjects comprised 50 consecutive Japanese patients who underwent hepatic resection followed by the insertion of a closed suction drain and the control group comprised 50 patients in whom a simple conduit drain had been placed following liver surgery. There were no significant differences between the two groups in sex, age, underlying liver disease, or the type of hepatectomy performed; nor was there a significant difference in the incidence of IPSCH, the simple conduit drain group versus the closed suction drain group being (10% versus 8%, respectively). However, bile leakage was highly related to IPSCH, the incidence being 60% and 100% in the simple conduit drain and closed suction drain groups, respectively. Thus, to prevent IPSCH, the treatment of bile leakage is a much more important factor than the type of drain used.

Aged↗

PubMed1993

Prediction of hepatic graft viability before reperfusion: an analysis of effluent from porcine allografts.

Rapid and reliable assessment of hepatic graft viability is important for successful orthotopic liver transplantation (OLTx). OLTx was performed in 11 pairs of pigs via a venovenous bypass. Six of these grafts were transplanted immediately (group A), while the other five were preserved in University of Wisconsin (UW) solution for 24 h and then transplanted (group B). All grafts were flushed with 300 ml of chilled (4 degrees C) Ringer's lactate solution before reperfusion of the graft, when 20 ml of effluent from the graft was collected and the concentrations of ammonia, lactic acid, GOT, and LDH were measured. Four of the six pigs in group A survived longer than 3 days, while the other two pigs died of causes other than graft dysfunction. All five pigs in group B died either of hemoperitoneum or hemodynamic instability due to liver failure. The histology of postperfusion biopsies in group A showed minimal pathological changes, while the grafts in group B revealed moderate to severe ischemic injuries. Ammonia and lactic acid in the effluent of group B were significantly higher than those of group A (1511 +/- 216 vs 417 +/- 333 micrograms/dl and 114.1 +/- 12.2 vs 91.4 +/- 12.2 mg/dl, respectively; P < 0.05 in both cases). Before reperfusion, the rate of total adenine nucleotides in all of the substances in the graft, which were measured using high performance liquid chromatography (HPLC), inversely correlated with the ammonia levels in the effluent. We conclude that an analysis of the effluent, (i.e. the levels of ammonia and lactic acid), flushed from a hepatic graft before reperfusion could serve as a predictor of hepatic graft viability.

Adenine Nucleotides↗

PubMed1993

Alternate hemihepatic vascular control technique for hepatic resection.

This report describes a simple and improved inflow control technique for resection of a hepatic tumor that lies across the right and left hepatic lobes. With alternate hemihepatic inflow control by en masse occlusion of Glisson's sheath of each hemipedicle at the bifurcation, hepatic resection across the two hepatic lobes is completed. Compared with Pringle's maneuver, this technique eliminates splanchnic congestion and reduces warm ischemia of the remnant liver, while maintaining a comparable hemostatic effect.

Humans↗

PubMed1993

Graft replacement of pararenal inferior vena cava for leiomyosarcoma with the use of venous bypass.

Total replacement of the inferior vena cava across the renal vein confluence was successfully performed under venovenous bypass in a patient with primary leiomyosarcoma of the inferior vena cava. Concomitant resection of metastases by right nephrectomy, partial hepatectomy, and cholecystectomy allowed recurrence-free survival for the past 20 months. To the best of our knowledge, this is the first report of successful replacement of the inferior vena cava for a primary tumor.

Female↗

PubMed1993

Extracorporeal hepatic resection for previously unresectable neoplasms.

BACKGROUND: Some hepatic tumors are judged inoperable solely for anatomic reasons, such as the proximity of the tumor with the major vasculature. This is because of high mortality and morbidity rates, as well as a compromised surgical margin. METHODS: We successfully performed extracorporeal hepatic resections in two patients who were judged to have inoperable tumors by conventional means. RESULTS: Both patients had an uneventful postoperative course, and although one patient had intrahepatic recurrence 6 months after operation, the other patient shows no recurrence 10 months later. CONCLUSIONS: Advances in techniques for liver transplantation and organ preservation now allow resection of anatomically unresectable hepatic tumors that were deemed inoperable in the past.

Extracorporeal Circulation↗

PubMed1992

Interference with cyclophosphamide-induced skin allograft tolerance by cyclosporin A.

In a murine strain combination identical in H-2 Ag but disparate in minor histocompatibility (H) Ag consisting of C3H/He (C3H; H-2k, Mls-1b) mice as recipients and AKR/J (AKR; H-2k, Mls-1a) mice as donors, a permanent skin allograft tolerance can be achieved by the cyclophosphamide (CP)-induced tolerance system that consists of i.v. injection of donor spleen cells (day -2) and i.p. injection of CP 2 days later (day 0). Such permanent take of allografts in CP-induced tolerant mice was interfered with by intramuscular injection of cyclosporin A (CsA) from day -5 to day -1 and their grafts were rejected by 21 days after grafting. Mls-1a-reactive CD4+V beta 6+ T cells in the periphery, as the indicator to follow the kinetics of donor-reactive T cells, increased on day 0 and day 3 in the C3H mice treated with AKR spleen cells alone, whereas they disappeared rapidly from day 0 to day 3 in CP-induced tolerant mice. When CsA capable of interfering with IL-2 production and T cell proliferation was administered before CP treatment in CP-induced tolerance system, the number of CD4+V beta 6+ T cells in periphery did not increase on day 0 and 3, but increased on day 7 in contrast to the decreased number of those in CP-induced tolerant mice. On day 7, MLR against donor cells was decreased in CP-induced tolerant mice, but maintained in CsA-interfered tolerant mice. These result may indicate that the destruction of donor-Ag-stimulated, proliferating T cells by CP is interfered with by CsA, probably because CsA inhibits the proliferation of donor-reactive T cells at the time of CP treatment. Furthermore, these results also implicate that the protocol for immunosuppression with CsA and antimetabolites has to be designed carefully in clinical transplantation.

Animals↗

PubMed1992

Ischemic injury in liver transplantation: difference in injury sites between warm and cold ischemia in rats.

Using liver allografts with warm or cold ischemia, we evaluated functional and morphological alterations in hepatocytes, sinusoidal endothelial cells and Kupffer cells in a rat transplantation model. All recipients of allografts with either 4 hr of cold or 30 min of warm ischemia lived more than 22 days and were judged viable. On the other hand, all recipients of grafts with 6 hr of cold or 60 min of warm ischemia died within 2 days and were therefore judged to be nonviable. With these viable and nonviable allograft models, hepatocyte function was evaluated by the bile output and serum glutamic-oxaloacetic transaminase, serum glutamic-pyruvic transaminase and serum lactate dehydrogenase levels; endothelial cell function was judged by the serum hyaluronic acid level, and Kupffer cell function was measured by an intravenous colloidal carbon clearance test. Hepatocyte injury was the prominent feature in warm ischemic grafts, especially in the nonviable ones. On the other hand, serum hyaluronic acid values were significantly higher in the nonviable cold ischemic group, compared with the viable counterpart, suggesting that the functional depression of endothelial cells was predominant in cold, nonviable livers. Histological examinations coincided with the above findings. The phagocytic activity of Kupffer cells was depressed by warm or cold ischemia, whereas the number of Kupffer cells was reduced in the warm ischemia group. We conclude that in liver allografts the main site of injury in warm ischemia is the hepatocytes and suggest that cold ischemia is associated with endothelial cell damage.

Animals↗

PubMed1992

Biliary tract reconstruction in liver transplantation.

Biliary tract complications are often referred to as the "Achilles' heel" of liver transplantation and various techniques have been developed to overcome them. The two major methods of bile duct reconstruction currently in use consist of either (1) choledochocholedochostomy over a T-tube or, when duct-to-duct approximation is not feasible, choledochojejunostomy over an internal stent, or (2) interposition of the donor gallbladder as a conduit between the donor bile duct and either the recipient bile duct or a jejunal loop. Although these standardizations of biliary tract reconstruction have resulted in a reduction of biliary complications after liver transplantation, further advancement in the elucidation of ampullary obstruction and viability of the donor bile duct is needed.

Animals↗

PubMed1992

Pretransplant assessment of human liver grafts by plasma lecithin: cholesterol acyltransferase (LCAT) activity in multiple organ donors.

In spite of the improved outcome of orthotopic liver transplantation (OLTx), primary graft nonfunction remains one of the life-threatening problems following OLTx. The purpose of this study was to evaluate plasma lecithin: cholesterol acyltransferase (LCAT) activity in multiple organ donors as a predictor of liver allograft viability prior to OLTx. Thirty-nine donors were studied during a 5-month period between April and August 1988. Allograft hepatectomy was performed using a rapid technique or its minor modification with hilar dissections, and the allografts were stored cold (4 degrees C) in University of Wisconsin (UW) solution. Early post-transplant allograft function was classified as good, fair, or poor, according to the highest SGOT, SGPT, and prothrombin time within 5 days following OLTx. Procurement records were reviewed to identify donor data, which included conventional liver function tests, duration of hospital stay, history of cardiac arrest, and graft ischemic time. Blood samples from the donors were drawn immediately prior to aortic crossclamp, and from these plasma LCAT activity was determined. Plasma LCAT activity of all donors was significantly lower than that of healthy controls (12.4 +/- 8.0 vs 39.2 +/- 13.3 micrograms/ml per hour, P less than 0.01). LCAT activity (16.4 +/- 8.3 micrograms/ml per hour) in donors of grafts with good function was significantly higher than that in those with fair (8.6 +/- 4.5 micrograms/ml per hour, P less than 0.01) or poor (7.3 +/- 2.4 micrograms/ml per hour, P less than 0.01) function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

Simplified hilar division in controlled right hepatectomy.

Right hepatectomy with preliminary vascular control at the hepatic hilus could be performed not by the method of dividing the structures in the hepatoduodenal ligament separately but instead by simultaneously employing both the hemihepatic vascular control method and the ultrasonic dissector. When applying the tape around the first portal pedicle, the anterior and posterior portal pedicles are easily exposed by using the ultrasonic dissector and, thereafter, ligated and cut; by utilizing this simplified hilar division, hemostasis of the right hepatic lobe can be achieved.

Hepatectomy↗

PubMed1991

Improved method of porcine renal allografting for transplantation research.

This study presents a refined, reproducible, and clinically appropriate animal model of renal transplantation. A pair of kidneys are harvested from a donor pig and preserved in Euro-Collins' solution (4 degrees C). After a set period of preservation, the allografts are transplanted to two recipient pigs. The abdomen is entered through a midline incision. The right common iliac artery and vein are dissected and bilateral native nephrectomy is performed. Each allograft is then randomly assigned and transplanted to the recipients. Three minutes before unclamping, 100 mg of furosemide and 10 g of mannitol are given IV. Immediately after reperfusion, urine output is measured for 1 h. The allograft is biopsied and ureteroneocystostomy is created. Cystostomy is then placed using a 16F Foley catheter. The bladder neck is ligated to secure complete diversion of urine, and the abdomen is closed in layers. This kidney transplant model allows an absolutely paired study of the kidney allograft function from the same donor and also collection of pure urine at any time postoperatively, obviating the need for metabolic cages or sedation for urinary collection. This model and its unique modifications allow various transplant studies, including organ preservation, immunosuppressive protocol, and the prevention of reperfusion injury from oxygen free radicals.

Animals↗

PubMed1991

Ultrasonographic anatomy of veins draining the left lobe of the liver. Feasibility of live related transplantation.

The anatomic variations of the left hepatic vein (LHV) in 182 patients with normal liver functions were analyzed using ultrasonography in order to clarify the feasibility of live related hepatic transplantation (LRHT). LHV was demonstrated in 151 patients (83%). Based on the location of the confluence of the middle hepatic vein (MHV) and LHV and the ramifications of the left medial vein (LMV) and the left superior vein (LSV), the livers were classified into 3 types: a) intrahepatic confluence (42/151 livers, 27.8%); b) extrahepatic confluence (69/151 livers, 45.7%); c) separate insertion (40/151 livers, 26.5%); and 23 subtypes. The length of the common trunk and the intrahepatic common trunk of MHV and LHV and the distance from LMV or LSV to the confluence of MHV and LHV were measured. Overall, the control of LHV in situ for LRHT appeared easy in 34/151 patients (22.5%), while in 44/151 patients (29.1%), the length of free LHV and the common trunk was less than optimal for procurement of a left hepatic lobe graft with complete venous outflow and sufficient extraparenchymal length of LHV.

Adult↗

PubMed1991

[Clinical study of patients with hepatic disease at a city hospital in Japan--consideration on indications for liver transplantation].

One-hundred and ninety-one patients with liver diseases who were admitted to National Fukuoka Central hospital during a 3 years period between January 1, 1984 and December 31, 1986 were studied to assess the indications for liver transplantation with the use of a criteria by Dr. Van Thiel et al. The patients were divided into 2 groups; I--indication and II--no indication. Then group I was divided into 3 groups; A--no contraindication, B--relative-contraindication and C--contraindication. Of the 131 patients, group A and B which had the indication of liver transplantation without contraindication were 17%. Deaths by April 30, 1990 were as follows; I 62% (A 36%, B 86%, C 100%) and II 12%. Ten out of 13 deaths in Group I were all due to hepatic failure, while only 3 out of 8 deaths in Group II were due to hepatic failure. Of the other 60 patients with malignancy, 57 were hepatocellular carcinomas, and the other 3 were 2 metastatic hepatic cancers and cholangioma. Among the patients with hepatocellular carcinoma, 24 out of 46 died of cancer, while the other 19 patients died of hepatic failure. The criteria of the indication of liver transplantation seems acceptable for the evaluation of Japanese patients with non-malignant hepatic diseases. As to patients with hepatocellular carcinoma, a new and separate criteria is in need to evaluate them for liver transplantation.

Female↗