Cerebral infarction by paradoxical gas embolism detected after laparoscopic partial hepatectomy with an insufflation management system: a case report.

BACKGROUND: Laparoscopic surgery has reduced surgical morbidity and postoperative duration of hospital stay. Gas embolism is commonly known as a risk factor for all laparoscopic procedures. We report a case of severe cerebral infarction presumably caused by paradoxical CO2 embolism in laparoscopic partial hepatectomy with an insufflation management system. CASE PRESENTATION: A male in his 60 s was diagnosed with recurrence of liver metastasis in the right hepatic lobe after laparoscopic lower anterior resection for rectal cancer. We performed laparoscopic partial hepatectomy with an AirSeal® under 10 mmHg of intra-abdominal pressure. During the surgery, the patient's end-tidal CO2 and percutaneous oxygen saturation dropped from approximately 40-20 mmHg and 100-90%, respectively, while the heart rate increased from 60 to 120 beats/min; his blood pressure remained stable. Postoperatively, the patient developed right hemiplegia and aphasia. Brain magnetic resonance imaging showed cerebral infarction in the broad area of the left cerebral cortex. Thereafter, transesophageal echocardiography revealed a patent foramen ovale, suggesting cerebral infarction due to paradoxical gas embolism. CONCLUSIONS: A patent foramen ovale is found in approximately 15-20% of healthy individuals. While gas embolism is a rare complication of laparoscopic surgery, cerebral infarction must be considered a possible complication even if the intra-abdominal pressure is constant under 10 mmHg with an insufflation management system.

Preferable Transplant Site for Hepatocyte Transplantation in a Rat Model.

Intraportal injection is regarded as the current standard procedure of hepatocyte transplantation (HTx). In islet transplantation, which shares many aspects with HTx, recent studies have clarified that instant blood-mediated inflammatory reaction (IBMIR), characterized by strong innate immune responses, can cause poor engraftment, so other transplant sites to avoid such a reaction have been established. Although IBMIR was reported to occur in HTx, few reports have evaluated alternative transplant sites for HTx. In this study, we sought to determine the optimum transplant site for HTx. Rat hepatocytes (1.0 × 107) were transplanted at the 9 transplant sites (intraportal (IPO), intrasplenic (IS), liver parenchyma, subcutaneous, intraperitoneal, renal subcapsular, muscle, inguinal subcutaneous white adipose tissue, and omentum) of analbuminemic rats. The serum albumin levels, immunohistochemical staining (albumin, TUNEL, and BrdU), and in vivo imaging of the grafts were evaluated. The serum albumin levels of the IPO group were significantly higher than those of the other groups (p < .0001). The BrdU-positive hepatocyte ratio of liver in the IS group (0.9% ± 0.2%) was comparable to that of the IPO group (0.9% ± 0.3%) and tended to be higher than that of the spleen in the IS group (0.5% ± 0.1%, p = .16). Considering the in vivo imaging evaluation and the influence of splenectomy, the graft function in the IS group may be almost entirely achieved by hepatocytes that have migrated to the liver. The present study clearly showed that the intraportal injection procedure is more efficient than other procedures for performing HTx.

Chronic Active Antibody-Mediated Rejection With Donor-Specific Anti-HLA-DP Antibodies Following Living Donor Kidney Transplantation: A Case Report.

Posttransplant donor-specific anti-HLA antibodies (DSA) cause chronic antibody-mediated rejection. Anti-DR and anti-DQ DSAs have especially been shown to be associated with negative graft function. In contrast, the prevalence and significance of anti-DP DSA have not been well established and remain unclear. We report a case of living donor kidney transplantation. The level of serum creatinine gradually became elevated because of chronic active antibody-mediated rejection, which was considered to be caused by anti-DP DSA. In this report, we indicate the significance of pretransplant screening for HLA-DP in donors to evaluate more comprehensively the donor specificity of posttransplant HLA antibodies.

A Simple and Useful Predictive Assay for Evaluating the Quality of Isolated Hepatocytes for Hepatocyte Transplantation.

No optimal assay for assessing isolated hepatocytes before hepatocyte transplantation (HTx) has been established, therefore reliable and rapid assays are warranted. Isolated rat hepatocytes were dipped in a water bath (necrosis model), and were also cultured with Okadaic acid (apoptosis model) or vehicle, followed by cellular assessment including trypan blue exclusion (TBE) viability, ADP /ATP ratio, plating efficiency (PE), DNA quantity and ammonia elimination. Hepatocytes were transplanted into the liver of analbuminemic rats, subsequently engraftment was assessed by serum albumin and the histology of transplanted grafts. In the necrosis model, the ADP/ATP ratio was strongly and negatively correlated with the TBE (R2 = 0.559, P < 0.001). In the apoptosis model, the ADP/ATP ratio assay, PE, DNA quantification and an ammonia elimination test clearly distinguished the groups (P < 0.001, respectively). The ADP/ATP ratio, PE and DNA quantity were well-correlated and the ammonia elimination was slightly correlated with the transplant outcome. TBE could not distinguish the groups and was not correlated with the outcome. The ADP/ATP ratio assay predicted the transplant outcome. PE and DNA quantification may improve the accuracy of the retrospective (evaluations require several days) quality assessment of hepatocytes. The ADP/ATP ratio assay, alone or with a short-term metabolic assay could improve the efficiency of HTx.

The Optimization of Short-Term Hepatocyte Preservation Before Transplantation.

BACKGROUND: No optimal methods for short-term hepatocyte preservation have been established. We have recently developed a prominent oxygen-permeable bag (Tohoku Device [TD]) for pancreatic islet culture and transplantation. In this study, we investigated whether TD is also effective for hepatocyte preservation and tried to optimize other conditions. METHODS: Hepatocytes were preserved in the following conditions, and their outcomes were observed. First, the effectiveness of TD was investigated. Second, hepatocyte medium (HM) and organ preservation solutions with or without fetal bovine serum (FBS) were compared. Third, as supplementations, FBS and human serum albumin (HSA) were compared. Fourth, low, room and high temperature were compared. And finally, hepatocytes preserved in various conditions were transplanted into the subrenal capsule space of nonalbumin rats and engrafted areas were assessed. RESULTS: The survival rate of hepatocytes preserved in TD tended to be higher and their viability and function were maintained significantly greater than those of non-TD group. Irrespective of FBS supplementation, the survival rate of HM group was significantly higher than those of organ preservation solution group while viabilities and plating efficiency were similar among them. Although survival rates of groups without FBS were extremely low, results of HSA supplemented group were not inferior to FBS supplemented group. Hepatocytes preserved at high temperature had the worst results. The engrafted area of TD group tended to be higher than those of other groups. CONCLUSIONS: TD is effective for short-term hepatocyte preservation. HSA is a useful substitute for FBS, and preserving in HM at low temperature is recommended.

Hepatectomy for Colorectal Cancer Liver Metastases in the Era of Modern Preoperative Chemotherapy: Evaluation of Postoperative Complications.

BACKGROUND: Recently, an increasing number of patients with liver metastases from colorectal cancer have received chemotherapy before hepatectomy. However, the effect of chemotherapy on postoperative short-term outcome is not well defined. METHODS: We retrospectively investigated the postoperative complications of 439 patients who underwent hepatectomy for colorectal liver metastases in our division from 2005 to 2014. Patients were classified into two groups according to the presence (Cx; 84 patients) or absence (NCx; 355 patients) of preoperative chemotherapy. Univariate and multivariate analyses were conducted to determine the predictive factors for postoperative complications. RESULTS: There was neither mortality nor liver failure after surgery. There was no significant difference in the frequency of postoperative complications between Groups Cx and NCx [29 vs 26 % for all complications; both 6 % for bile leakage that required therapeutic intervention; and 2 vs 3 % for Clavien-Dindo (CD) Grade ≥ IIIa, respectively]. In Group Cx, morbidity rates were similar among patients with different chemotherapy regimens. Chemotherapy-related factors (administration of bevacizumab, oxaliplatin or irinotecan, duration of chemotherapy >150 days, and timing of hepatectomy) were not significantly associated with clinically relevant bile leakage and CD ≥ IIIa in multivariate analysis. CONCLUSION: Even after combination chemotherapy including targeted therapy, hepatectomy for colorectal liver metastases can be performed safely without increasing morbidity or mortality, if the patients fulfill the conventional criteria for surgery.