Methane gas in breath test is associated with non-alcoholic fatty liver disease.

Although the associations between a patient's body mass index (BMI) and metabolic diseases, as well as their breath test results, have been studied, the relationship between breath hydrogen/methane levels and metabolic diseases needs to be further clarified. We aimed to investigate how the composition of exhaled breath gases relates to metabolic disorders, such as diabetes mellitus, dyslipidemia, hypertension, and nonalcoholic fatty liver disease (NAFLD), and their key risk factors. An analysis was performed using the medical records, including the lactulose breath test (LBT) data of patients who visited the Ajou University Medical Center, Suwon, Republic of Korea, between January 2016 and December 2021. The patients were grouped according to four different criteria for LBT hydrogen and methane levels. Of 441 patients, 325 (72.1%) had positive results for methane only (hydrogen < 20 parts per million [ppm] and methane ⩾ 3 ppm). BMIs and NAFLD prevalence were higher in patients with only methane positivity than in patients with hydrogen and methane positivity (hydrogen ⩾ 20 ppm and methane ⩾ 3 ppm). According to a multivariate analysis, the odds ratio of only methane positivity was 2.002 (95% confidence interval [CI]: 1.244-3.221,P= 0.004) for NAFLD. Our results demonstrate that breath methane positivity is related to NAFLD and suggest that increased methane gas on the breath tests has the potential to be an easily measurable biomarker for NAFLD diagnosis.

Anterior segment congestion of a right liver lobe graft in living-donor liver transplantation and strategy to prevent congestion.

BACKGROUND/PURPOSE: A left lobe graft from a small donor will not usually fulfill the metabolic demands of a larger recipient in adult-to-adult living-donor liver transplantation (LDLT). One solution to this problem is to use a right lobe graft. However, the necessity of middle hepatic vein (MHV) outflow drainage from the anterior segment (AS) of a right lobe graft has not yet been clearly described in the literature. From July 1997 to February 1998, five right lobe grafts without MHV outflow drainage were implanted in five adult recipients. The graft weights ranged from 650 to 1000 g, and their volumes ranged from 48% to 83% of the ideal liver mass of the recipients. Two grafts showed severe congestion of the AS immediately after reperfusion, followed by prolonged massive ascites and severe liver dysfunction in each patient postoperatively. Eventually, one patient died of sepsis, on posttransplant day 20, demonstrating progressive hepatic dysfunction. METHODS: Subsequently, since March 1998, 176 of 208 adult recipients who received a right lobe graft, while demonstrating sizable (greater than 5-mm diameter) MHV tributaries underwent reconstruction of MHV outflow drainage, using the recipient's own autogenous or cryopreserved cadaveric interposition vein grafts. RESULTS: In 170 of the 176 recipients, AS congestion was not demonstrated on enhanced liver computerized tomography (CT) or Doppler ultrasonography (USG) postoperatively, and the patency rate of interposition vein grafts was 96.6% on day 30 posttransplant. CONCLUSIONS: A right lobe graft without MHV outflow drainage might result in severe congestion of the AS, which could lead to the patient's death in an extreme situation. Preservation of MHV outflow drainage in a right lobe graft is possible by two harvesting methods: an extended right lobe (ERL)graft, in which the MHV trunk is included in the graft, and a modified right lobe (MRL) graft, in which venous tributaries of the MHV are reconstructed via interposition vein grafts into the recipient's hepatic venous system. From the viewpoint of donor safety, the ERL graft increases the donor's risk more than the MRL graft, because the remaining left liver lobe of the donor does not possess an MHV. Here, we introduce our experiences of MRL grafts in adult-to-adult LDLTs.

Approach to anatomic variations of the graft portal vein in right lobe living-donor liver transplantation.

Right lobe living-donor liver transplantation (LDLT) is often not attempted in donors with anomalous portal venous branching (APVB). The authors describe their experience with portal vein (PV) reconstruction in 17 cases of APVB in right lobe LDLT. From July 1997 to December 2001, 214 right liver LDLT were performed at the Asan Medical Center. Seventeen of the donors had APVB and successfully underwent right lobectomy. The APVB were type II (trifurcation) in nine cases, type III (independent posterior segmental branching from main PV trunk) in seven, and unclassified in one. All 17 donors and recipients are alive, with good liver function. In type II APVB, the donor PV branches were obtained with separate openings that were joined as a common orifice at the back table in two, with a discoid-patch single opening in four, and with one common opening in three. In type III APVB, the donor PV were divided with two openings in four and with a discoid-patch single opening in three. The discoid-patch defect in the remnant PV was repaired with a vein patchplasty in two donors and resected with end-to-end anastomosis in five. However, one donor developed portal vein thrombosis (PVT) that was managed successfully by re-exploration and insertion of a metallic vascular stent. Of the four type III APVB obtained with two separate PV openings, the first two liver grafts were each reconstructed as double PV anastomoses. One of them required re-exploration because of PVT. In the two succeeding cases, a Y-graft interposition technique using a cryopreserved cadaveric iliac vein or the recipient's own portal confluence was successfully applied. To minimize the risk of PVT in donors with APVB, discoid-patch excision followed by repair with vein patchplasty or segmental resection should be avoided. Individual division of the PV branches creating two separate openings instead is recommended. To decrease the recipient's risk of PVT, interposition Y-graft venous reconstruction at the back table is superior to double PV anastomoses.

Safety of anti-hepatitis B core antibody-positive donors for living-donor liver transplantation.

Serologic evidence of resolved hepatitis B virus (HBV) infection (HBV surface antigen negative, anti-HBV core antibody [HBc] positive) in a liver donor can be regarded as an occult infection with episomal HBV in the liver. The purpose of this study was to evaluate the safety of anti-HBc-positive living donors. Between March 2001 and January 2002, 127 donors underwent hepatectomy for living-donor liver transplantation at Asan Medical Center. They were classified as members of an anti-HBc-positive group (n=50) or an anti-HBc-negative group (n=77). The two groups were subdivided into right lobectomy (n=86) and left lobectomy (n=34) groups to compare operative risk. Perioperative clinical profiles were compared by anti-HBc status and extent of donor hepatectomy. There were no statistical differences of preoperative liver function and liver steatosis between the anti-HBc-positive and anti-HBc-negative groups. Operation time and blood loss did not show any differences between the hepatectomy-matched anti-HBc-positive and anti-HBc-negative groups. Postoperative recovery of liver function, incidence of complication, and regeneration rate of the remnant liver after right lobectomy also did not show significant differences. The anti-HBc-positive group did not exhibit any adverse preoperative, intraoperative, or postoperative outcomes compared with the anti-HBc-negative group. This indicates that anti-HBc-positive donors can be assessed to have the same degree of risk for donor operation as anti-HBc-negative donors.