Albert Cy Chan

Modulation of graft vascular inflow guided by flowmetry and manometry in liver transplantation

BACKGROUNDnSurvival of the partial graft after living donor liver transplantation owes much to its tremendous regenerative ability. With excellent venous outflow capacity, a graft within a wide range of graft-to-standard-liver-volume ratios can cope with portal hypertension that is common in liver transplant recipients. However, when the ratio range is exceeded, modulation of graft vascular inflow becomes necessary for graft survival. The interplay between graft-to-standard-liver-volume ratio and portal pressure, in the presence of portosystemic shunt or otherwise, requires individualized modulation of graft portal and arterial inflows. Boosting of portal inflow by shunt ligation can be guided by transonic flowmetry, whereas muting of portal inflow by splenic artery ligation can be monitored by portal electronic manometry.nnnMETHODnWe describe four cases to illustrate the above.nnnRESULTSnOne patient had hepatic artery thrombosis resulting from splenic artery steal syndrome which was the sequela of small-for-size syndrome. Emergency splenic artery ligation and re-anastomosis of the hepatic artery successfully muted the portal inflow and boosted the hepatic arterial inflow. Another patient with portal vein thrombosis underwent thrombendvenectomy. Portal inflow was boosted with ligation of portosystemic shunt, which is often present in these patients with portal hypertension. The coexistence of splenic aneurysm and splenorenal shunt required ligation of both in the third patient. The fourth patient, with portal pressure and flow monitoring, avoided ligation of a coronary vein which became a main portal inflow after portal thrombendvenectomy.nnnCONCLUSIONnManagement of graft inflow modulation guided selectively by transonic flowmetry or portal manometry was described.

Rapid measurement of indocyanine green retention by pulse spectrophotometry: A validation study in 70 patients with Child-Pugh A cirrhosis before hepatectomy for hepatocellular carcinoma

BACKGROUNDnThe indocyanine green (ICG) retention test is the most popular liver function test for selecting patients for major hepatectomy. Traditionally, it is done using spectrophotometry with serial blood sampling. The newly-developed pulse spectrophotometry is a faster alternative, but its accuracy on Child-Pugh A cirrhotic patients undergoing hepatectomy for hepatocellular carcinoma has not been well documented. This study aimed to assess the accuracy of the LiMON(®), one of the pulse spectrophotometry systems, in measuring preoperative ICG retention in these patients and to devise an easy formula for conversion of the results so that they can be compared with classical literature records where ICG retention was measured by the traditional method.nnnMETHODSnWe measured the liver function of 70 Child-Pugh A cirrhotic patients before hepatectomy for hepatocellular carcinoma from September 2008 to January 2009. ICG retention at 15 minutes measured by traditional spectrophotometry (ICGR15) was compared with ICG retention at 15 minutes measured by the LiMON (ICGR15(L)).nnnRESULTSnThe median ICGR15 was 14.7% (5.6%-32%) and the median ICGR15(L) was 10.4% (1.2%-28%). The mean difference between them was -4.3606. There was a strong correlation between ICGR15 and ICGR15(L) (correlation coefficient, 0.844; 95% confidence interval, 0.762-0.899). The following formula was devised: ICGR15=1.16XICGR15(L)+2.73.nnnCONCLUSIONSnThe LiMON provides a fast and repeatable way to measure ICG retention at 15 minutes, but with constant underestimation of the real value. Therefore, when comparing results obtained by traditional spectrophotometry and the LiMON, adjustment of results from the latter is necessary, and this can be done with a simple mathematical calculation using the above formula.

Survival outcomes of right-lobe living donor liver transplantation for patients with high Model for End-stage Liver Disease scores.

BACKGROUNDnControversy exists over whether living donor liver transplantation (LDLT) should be offered to patients with high Model for End-stage Liver Disease (MELD) scores. This study tried to determine whether a high MELD score would result in inferior outcomes of right-lobe LDLT.nnnMETHODSnAmong 411 consecutive patients who received right-lobe LDLT at our center, 143 were included in this study. The patients were divided into two groups according to their MELD scores: a high-score group (MELD score ≥25; n=75) and a low-score group (MELD score <25; n=68). Their demographic data and perioperative conditions were compared. Univariable and multivariable analyses were performed to identify risk factors affecting patient survival.nnnRESULTSnIn the high-score group, more patients required preoperative intensive care unit admission (49.3% vs 2.9%; P<0.001), mechanical ventilation (21.3% vs 0%; P<0.001), or hemodialysis (13.3% vs 0%; P=0.005); the waiting time before LDLT was shorter (4 vs 66 days; P<0.001); more blood was transfused during operation (7 vs 2 units; P<0.001); patients stayed longer in the intensive care unit (6 vs 3 days; P<0.001) and hospital (21 vs 15 days; P=0.015) after transplantation; more patients developed early postoperative complications (69.3% vs 50.0%; P=0.018); and values of postoperative peak blood parameters were higher. However, the two groups had comparable hospital mortality. Graft survival and patient overall survival at one year (94.7% vs 95.6%; 95.9% vs 96.9%), three years (91.9% vs 92.6%; 93.2% vs 95.3%), and five years (90.2% vs 90.2%; 93.2% vs 95.3%) were also similar between the groups.nnnCONCLUSIONSnAlthough the high-score group had significantly more early postoperative complications, the two groups had comparable hospital mortality and similar satisfactory rates of graft survival and patient overall survival. Therefore, a high MELD score should not be a contraindication to right-lobe LDLT if donor risk and recipient benefit are taken into full account.

Acute pancreatitis induced by transarterial chemoembolization: a single-center experience of over 1500 cases

BACKGROUNDnAcute pancreatitis is a relatively rare but potentially lethal complication after transarterial chemotherapy. This study aimed to review the complications such as acute pancreatitis after transarterial chemotherapy with or without embolization for hepatocellular carcinoma.nnnMETHODSnA total of 1632 patients with hepatocellular carcinoma who had undergone transarterial chemoembolization from January 2000 to February 2014 in a single-center were reviewed retrospectively. We investigated the potential complications of transarterial chemoembolization, such as acute pancreatitis and acute pancreatitis-related complications.nnnRESULTSnOf the 1632 patients with hepatocellular carcinoma who had undergone 5434 transarterial chemoembolizations, 1328 were male and 304 female. The median age of these patients was 61 years. Most (79.6%) of the patients suffered from HBV-related hepatocellular carcinoma. The median tumor size was 5.2 cm. Of the 1632 patients, 145 patients underwent transarterial chemoembolization with doxorubicin eluting bead, making up a total of 538 episodes. The remaining patients underwent transarterial chemoembolization with cisplatin. Seven (0.4%) patients suffered from acute pancreatitis post-chemoembolization. Six patients had chemoembolization with doxorubicin and one had chemoembolization with cisplatin. Patients who received doxorubicin eluting bead had a higher risk of acute pancreatitis [6/145 (4.1%) vs 1/1487 (0.1%), P<0.0001]. Two patients had anatomical arterial variations. Four patients developed acute pancreatitis-related complications including necrotizing pancreatitis (n=3) and pseudocyst formation (n=1). All of the 4 patients resolved after the use of antibiotics and other conservative treatment. Three patients had further transarterial chemoembolization without any complication.nnnCONCLUSIONSnAcute pancreatitis after transarterial chemoembolization could result in serious complications, especially after treatment with doxorubicin eluting bead. Continuation of current treatment with transarterial chemoembolization after acute pancreatitis is feasible providing the initial attack is completely resolved.

Radiological prognosticators of hepatocellular carcinoma treated by hepatectomy.

BACKGROUNDnHepatectomy is the main curative treatment for hepatocellular carcinoma (HCC), but postoperative long-term survival is poor. Preoperative radiological features of HCC displayed by computed tomography or magnetic resonance imaging could serve as additional prognostic factors. This study aimed to identify preoperative radiological features of HCC that may be of prognostic significance in hepatectomy.nnnMETHODSnNinety-two patients who underwent hepatectomy for HCC were included in this study. Preoperative radiological features including tumor number, size, location (peripheral, middle, central), portal vein invasion, hepatic vein invasion, and presence of pseudo-capsule were analyzed in relation to survival.nnnRESULTSnWith a median follow-up period of 41.7 months, the 1-, 3- and 5-year overall survival rates were 85%, 65% and 58%, respectively. Univariate analysis showed that portal vein invasion and absence of pseudo-capsule were significant prognostic factors for overall survival, while all the examined radiological features were prognostic factors for disease-free survival. Multivariate analysis for overall survival found no significant factor. On multivariate analysis for disease-free survival, patients who had tumors with portal vein invasion had poorer survival with a hazard ratio of 2.26 (95% CI, 1.05-4.91; P=0.038) and patients with single nodular HCC or pseudo-capsulated HCC had better survival with a hazard ratio of 0.50 (95% CI, 0.27-0.94; P=0.032) and 0.38 (95% CI, 0.14-0.99; P=0.048), respectively.nnnCONCLUSIONSnDemonstrable pseudo-capsule of HCC and solitary HCC on imaging and absence of portal vein invasion are features associated with better disease-free survival after hepatectomy. These features may guide treatment planning for HCC.

Outcomes of side-to-side conversion hepaticojejunostomy for biliary anastomotic stricture after right-liver living donor liver transplantation

BACKGROUNDnConversion hepaticojejunostomy is considered the salvage intervention for biliary anastomotic stricture, a common complication of right-liver living donor liver transplantation with duct-to-duct anastomosis, after failed endoscopic treatment. The aim of this study is to compare the outcomes of side-to-side hepaticojejunostomy with those of end-to-side hepaticojejunostomy.nnnMETHODSnProspectively collected data of 402 adult patients who had undergone right-liver living donor liver transplantation with duct-to-duct anastomosis were reviewed. Diagnosis of biliary anastomotic stricture was made based on clinical, biochemical, histological and radiological results. Endoscopic treatment was the first-line treatment of biliary anastomotic stricture.nnnRESULTSnInterventional radiological or endoscopic treatment failed to correct the biliary anastomotic stricture in 13 patients, so they underwent conversion hepaticojejunostomy. Ten of them received end-to-side hepaticojejunostomy and three received side-to-side hepaticojejunostomy. In the end-to-side group, two patients sustained hepatic artery injury requiring repeated microvascular anastomosis, two developed re-stenosis requiring further percutaneous transhepatic biliary drainage and balloon dilatation, and two required revision hepaticojejunostomy. In the side-to-side group, one patient developed re-stenosis requiring further endoscopic retrograde cholangiography and balloon dilatation. No re-operation was needed in this group. Otherwise, outcomes in the two groups were similar in terms of liver function and graft survival.nnnCONCLUSIONSnDespite the similar outcomes, side-to-side hepaticojejunostomy may be a better option for bile duct reconstruction after failed interventional radiological or endoscopic treatment because it can decrease the chance of hepatic artery injury and allows future endoscopic treatment if re-stricture develops. However, more large-scale studies are warranted to validate the results.

Common Peroneal Nerve Palsy after Liver Transplantation

Common peroneal nerve (CPN) palsy is a well-recognized complication after pelvic surgery and gynecological procedure when a lithotomy position is frequently adopted. This postoperative morbidity is both physically and psychologically disturbing to the patient. However, its occurrence after orthotropic liver transplantation is exceedingly rare and is seldom reported [1,2]. We therefore reviewed our experience of CPN palsy after liver transplantation.

The impact of family history of hepatocellular carcinoma on its patients' survival.

BACKGROUNDnFamily history of hepatocellular carcinoma (HCC) has been identified as a risk factor for the development of the disease. The aim of this study is to evaluate the impact of such a history on HCC patients survival.nnnMETHODSnData of all HCC patients (n=4532) managed at our center from 1989 to 2008 were prospectively collected. The patients were quizzed on their various characteristics including family HCC history.nnnRESULTSnTotally 475 (10.48%) patients had a family history of HCC. They presented the disease at a significantly earlier age (median 53 vs 59 years, P<0.0001) and at an earlier stage (the United Network for Organ Sharing staging system). They had significantly better liver function in terms of Child-Pugh classification and serum albumin and bilirubin levels. Significantly more of them presented the disease without symptoms (44.0% vs 29.4%, P<0.0001). They also had significantly better overall survival under these specifications: patients in the whole study cohort, patients who had minor hepatectomy, patients with stage I disease, patients with stage II disease, and patients with stage III disease.nnnCONCLUSIONSnContrary to what is generally believed, we found in this study cohort that patients with a family history of HCC had better overall survival than those without such a history. We believe this was in part due to earlier diagnosis of the disease and better liver function in this group of patients. However, the effects of genetic factors on the risk of HCC cannot be overlooked and are yet to be identified.

Retrohepatic vena cava deroofing in living donor liver transplantation for caudate hepatocellular carcinoma

The removal of tumor together with the native liver in living donor liver transplantation for hepatocellular carcinoma is challenged by a very close resection margin if the tumor abuts the inferior vena cava. This is in contrast to typical deceased donor liver transplantation where the entire retrohepatic inferior vena cava is included in total hepatectomy. Here we report a case of deroofing the retrohepatic vena cava in living donor liver transplantation for caudate hepatocellular carcinoma. In order to ensure clear resection margins, the anterior portion of the inferior vena cava was included. The right liver graft was inset into a Dacron vascular graft on the back table and the composite graft was then implanted to the recipient inferior vena cava. Using this technique, we observed the no-touch technique in tumor removal, hence minimizing the chance of positive resection margin as well as the chance of shedding of tumor cells during manipulation in operation.

Hepatitis B vaccination in patients receiving oral antiviral therapy without hepatitis B immune globulin after liver transplantation

Our study aimed to determine if a double-dose pre-S containing hepatitis B virus (HBV) vaccination (Sci-B-Vac) could elicit an adequate and sustainable immune response in HBV patients who developed spontaneous hepatitis B surface antibody (anti-HBs) response after liver transplant.nnnPATIENTS AND METHODSnAll patients who received transplants for HBV-related disease for >1 year with normal graft function and hepatitis B surface antigen seronegativity were evaluated. They received a 40-μg HBV vaccine if they were responders in our previous vaccine trial, if anti-HBs was positive for >1 year after liver transplant (LT), or if a peak anti-HBs at any time point after LT was >100 mIU/mL. Primary endpoint was the development of anti-HBsxa0≥ 10 mIU/mL from previous negative value or a 1-log increase from baseline.nnnRESULTSnA total of 86 patients were recruited; 5 were responders from a previous trial; 45 patients had detectable anti-HBs >1 year after LT, and 36 patients had an anti-HBs >100xa0mIU/mL. All (5/5, 100%) previous responders responded to booster vaccination. For the remaining 81 patients, 10 of 81 (12.3%) responded.nnnCONCLUSIONnAll previous responders responded to booster vaccination, implying durability and memory of HBV immune response, which is an important prerequisite for definitive host immunity for HBV. In patients who had spontaneous anti-HBs production after LT, a single vaccination can induce response in 12.3% of patients.