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.

Usefulness of Preoperative Controlling Nutritional Status in Predicting Prolonged Hospitalization and Incidence of Postoperative Delirium for Elderly Hepatectomy with Hepatocellular Carcinoma.

The number of elderly patients with hepatocellular carcinoma (HCC) has been increasing, but it remains unclear whether hepatectomy can be performed using the same criteria as in younger patients. Furthermore, the appropriate preoperative evaluation for hepatectomy in elderly patients is not yet clearly defined. Here, we investigated the applicability of preoperative assessment using the Controlling Nutritional Status (CONUT) score to help improve hepatectomy outcomes in elderly patients with HCC. This was a single-center retrospective analysis, and the study population comprised 64 consecutive patients who underwent hepatectomy for HCC between January 2012 and August 2016. We compared the preoperative assessment and perioperative outcomes between elderly (≥ 75 years old) and younger (< 75 years old) patients. A total of 61 patients were reviewed. Poor preoperative CONUT score was associated with a longer postoperative hospital stay in elderly patients undergoing hepatectomy for HCC. In addition, although elderly patients had similar perioperative outcomes to younger patients, the incidence of delirium was significantly higher, and univariate analysis confirmed that old age is a risk factor for delirium among the preoperative factors. Hepatectomy for HCC in the elderly can be safely performed with appropriate preoperative nutritional assessment using CONUT score and prevention of postoperative delirium. Preoperative nutritional assessment using the CONUT score was useful in predicting prolonged hospitalization for elderly hepatectomy with HCC.

Cytoprotective Effects of Mesenchymal Stem Cells During Liver Transplantation From Donors After Cardiac Death in Swine.

BACKGROUND: Liver transplantation from donors after cardiac death (DCDs) can increase the pool of available organs. Recently, mesenchymal stem cells (MSCs) have been used to treat various diseases. Some studies have reported that MSCs improve the outcome of liver transplantation from DCDs in mice. The aim of this study was to evaluate the cytoprotective effects and safety of MSC transplantation on liver grafts from DCDs in swine. METHODS: For the MSCs, we used swine adipose-derived stem cells (ADSCs). Landrace swine were divided into 3 groups (n = 5) as follows: 1. the heart-beating (HB) group, from which liver grafts were retrieved and transplanted; 2. the DCD group, from which liver grafts were retrieved 10 minutes after apnea-induced cardiac arrest and transplanted; and 3. the ADSC group, from which liver grafts were retrieved as with the DCD group, transplanted, and then infused with 1.0 × 107 ADSCs 2 hours after reperfusion. RESULTS: In the HB group, all 5 recipients survived for >7 days, whereas all 5 recipients in the DCD group died within 24 hours after transplantation. In the ADSC group, 3 recipients survived for >7 days, whereas 2 recipients died within 4 days after transplantation. The survival rate was significantly higher in the ADSC group than in the DCD group. CONCLUSIONS: MSCs could protect the function of liver grafts from warm ischemia-reperfusion injury and improve the viability of DCD liver grafts.

Risks of Living Donor Liver Transplantation Using Small-For-Size Grafts.

BACKGROUND: In living donor liver transplantation (LDLT), a graft-to-recipient weight ratio (GRWR) of under 0.8 is recognized as the critical graft size. Our aim was to compare the survival rates of recipients with small-for-size grafts (SFSG: GRWR <0.8), normal-sized grafts (NSG), and large-for-size grafts (LFSG: GRWR ≥ 3.5) and to investigate the mortality risk with SFSG. METHODS: Between 1991 and April 2019, we performed 188 LDLT surgeries. Recently, we added splenectomy when portal vein pressure is high (>17 mm Hg) to interrupt the splenic bloodstream. We divided all LDLT cases retrospectively into 3 groups: an SFSG group (n = 22), NSG group (n = 154), and LFSG group (n = 12). We investigated the survival rates in these groups. Furthermore, we divided the SFSG group into 2 subgroups: an SFSG with splenectomy (SFSG+S) group (n = 7) and an SFSG without splenectomy group. We investigated the occurrence rates of lethal complications such as portal vein thrombosis, hepatic artery thrombosis, and hepatic vein thrombosis. RESULTS: The 5-year survival rate in the SFSG group was significantly lower (52.8%) than in the other groups (NSG: 84.5%; LFSG: 83.3%), but that of the SFSG+S group was similar (80.0%) to that of other groups. There was no difference in the occurrence of postoperative complications such as portal vein thrombosis, hepatic artery thrombosis, or hepatic vein thrombosis between the SFSG+S group and other groups. CONCLUSIONS: Graft survival of LDLT using SFSG+S was as good as that of normal-sized grafts. Reducing portal vein pressure was important for SFSG.

Effects of Short-Term Normothermic and Subnormothermic Perfusion After Cold Preservation on Liver Transplantation From Donors After Cardiac Death.

BACKGROUND: Liver transplantation from donors after cardiac death (DCD) could increase the pool of organs. We previously reported that oxygenated subnormothermic (20°C-25°C) ex vivo liver perfusion (SELP) improved the graft viability in rats. This study aimed to compare the effectiveness of SELP and normothermic (37°C) ex vivo liver perfusion (NELP) after cold storage (CS) in DCD liver grafts. METHODS: Male Wistar rats were used, and grafts were retrieved 30 minutes after cardiac arrest. We performed oxygenated NELP and SELP with a Krebs-Henseleit buffer for different time points and durations: Group 0, donation performed from heart-beating donors (control); Group 1 (DCD group), donation performed from DCD donors with no treatments; Group 2, NELP performed before CS (30 minutes); Group 3, NELP performed after CS (30 minutes); Group 4, SELP performed after CS (30 minutes); Group 5, SELP performed after CS (60 minutes); and Group 6, SELP performed after CS (90 minutes). After 15 minutes of incubation at room temperature, the grafts were reperfused under normothermic conditions for 60 minutes as a model of liver transplantation. RESULTS: No significant differences in body and liver weight were observed between all groups. In the SELP after CS groups, even 30 minutes of perfusion improved bile production, tumor necrosis factor-α, and interleukin-1ß significantly compared with the DCD group (P < .05), comparable with NELP groups. CONCLUSION: SELP rescued DCD livers from ischemia-reperfusion injury the same as the normothermic perfusion before or after CS groups. SELP after CS is more convenient than normothermic perfusion; hence, this technique may increase the organ pool.

The Effects of Short-term Subnormothermic Perfusion After Cold Preservation on Liver Grafts From Donors After Circulatory Death: An Ex Vivo Rat Model.

BACKGROUND: We previously reported that short oxygenated warm perfusion before cold storage (CS) had improved the graft viability of rat livers from donors after circulatory death (DCD). In this study, we investigated the effectiveness of short-term oxygenated subnormothermic perfusion for different durations after CS in a rat DCD model. METHODS: We used an isolated perfused rat liver system. In study 1: the grafts were retrieved from Wistar rats 30 minutes after cardiac arrest (thoracotomy), preserved in CS for 6 hours, and perfused with oxygenated subnormothermic (20-25°C) Krebs-Henseleit buffer for different durations (0, 15, 30, 60, and 90 minutes groups; n = 5 in each). In study 2: in addition to subnormothermic ex vivo liver perfusion (SELP), after 15-minute incubation at room temperature, the grafts were reperfused under normothermic condition for 60 minutes as a model of liver transplantation (0, 30, 60, and 90 minutes groups; n = 5 in each). RESULTS: In study 1, portal flow, bile production and tissue adenosine triphosphate increased with perfusion duration. In study 2, SELP significantly improved portal flow volume (P <0.05), and bile production (P <0.05), decreased liver enzymes (P <0.05) and cytokines (P <0.0001), and increased tissue adenosine triphosphate (P <0.01). Histological examinations showed that additional SELP ameliorated tissue deterioration, preserved the parenchymal structure, and decreased apoptosis (P <0.01). Furthermore, scanning electron microscopy revealed that additional SELP alleviated sinusoidal endothelial cells and hepatic microvasculature. CONCLUSIONS: Even 30 minutes of SELP after CS rescued DCD livers from ischemia-reperfusion injury, which may help the viability of the grafts.

Arterial and biliary complications after living donor liver transplantation: a single-center retrospective study and literature review.

AIM: The mortality of patients on the waiting list for deceased donor liver transplantation (DDLT) is high, especially in countries where donation rates are low. Thus, living donor liver transplantation (LDLT) is an attractive option. However, compared with DDLT, LDLT is associated with increased rates of arterial and biliary complications. We examined the rates of complications and risk factors following LDLT. METHODS: We retrospectively investigated and compared the rates of complications of DDLT and LDLT in our institute. We also performed univariate and multivariate analyses to identify the independent risk factors for these complications. The complications and specific disadvantages of LDLT were reviewed and discussed. RESULTS: The incidence rate of arterial complications in LDLT was 6.0%, compared with 3.2% (13/441) in DDLT. A multivariate analysis identified low body weight (P = 0.032) as the only independent risk factor for hepatic artery thrombosis. The rate of all biliary complications in LDLT was 17.3%, compared with 18.7% in DDLT. The risk factors for biliary stricture identified by the multivariate analysis were recurrent cholangitis and the number of bile ducts. The durations of hospital stay and overall survival rates were similar between the two groups. CONCLUSION: Given the shortage of deceased donor organs, we believe that LDLT is acceptable in an attempt to meet demand.

The extra-anatomical jump graft reconstruction of the right hepatic artery after resection of a biliary tract malignancy with a common hepatic artery aneurysm: a case report.

Performing resection of a biliary tract malignancy with a hepatic artery aneurysm is very challenging. Resection of the extrahepatic bile duct and extra-anatomical reconstruction can be successfully performed using free radial artery autografts from the aorta to the right hepatic artery. Hepatic artery thrombosis can be prevented with intimal preservation.

Hypercobalaminemia induced by an energy drink after total gastrectomy: a case report.

We encountered a case of hypercobalaminemia induced by oral intake of an energy drink after total gastrectomy. The patient was referred to our hospital due to findings suspicious for gastric cancer on screening. A 20 mm type 0-IIc lesion was detected in the gastric subcardia on esophagogastroduodenoscopy. Total gastrectomy followed by Roux-en-Y reconstruction was performed. He was discharged without complications. His basal serum vitamin B12 level was initially maintained with monthly intramuscular injections of vitamin B12. After 9 months, his serum vitamin B12 level suddenly increased up to 36-fold higher than the normal range and persisted there for one year without vitamin B12 injections. The patient ultimately reported consuming half a bottle of an energy drink each day during this time period. This case demonstrates the risk of unexpected hypervitaminemia resulting from self-administration of nutritional supplements.

A novel regulatory role of gp49B on dendritic cells in T-cell priming.

Dendritic cells (DC) play pivotal roles in the induction and regulation of both innate and acquired immunity. DC express several cell-surface immune inhibitory receptors. However, little is known about their potential immunoregulatory functions in the context of T-cell activation. Here we report that murine gp49B, a member of the immunoglobulin superfamily, harboring immunoreceptor tyrosine-based inhibitory motifs, is expressed on DC and downregulates cellular activity to prevent the excessive activation of T cells in vitro and in vivo. Bone marrow-derived DC (BMDC) from newly generated gp49B-deficient (gp49B(-/-)) mice induced enhanced proliferation and IL-2 release of antigen-specific CD4(+) and CD8(+) T cells compared with BMDC from wild-type mice, in a cell-cell contact manner. The enhanced proliferation by gp49B(-/-) BMDC was also observed in allogeneic CD4(+) and CD8(+) T cells. Moreover, the transfer of allogeneic BALB/c splenocytes into C57BL/6 gp49B(-/-) mice induced severe acute graft-versus-host disease with an augmented upregulation of CD86 on CD11c(+) splenic gp49B(-/-) DC, while transfer of C57BL/6 gp49B(-/-) splenocytes into BALB/c mice did not, suggesting the exacerbation of the disease was due, at least in part, to augmented activation of recipient gp49B(-/-) DC. These findings demonstrate a novel regulatory role of gp49B in the function of DC.