Doppler ultrasonographic evaluation of hepatic circulation in patients following Kasai's operation for biliary atresia

Liver and systemic hemodynamics in children with cirrhosis: Impact on the surgical management in pediatric living donor liver transplantation

Cirrhosis in adults is associated with modifications of systemic and liver hemodynamics, whereas little is known about the pediatric population. The aim of this work was to investigate whether alterations of hepatic and systemic hemodynamics were correlated with cirrhosis severity in children. The impact of hemodynamic findings on surgical management in pediatric living donor liver transplantation (LT) was evaluated. Liver and systemic hemodynamics were studied prospectively in 52 children (median age, 1 year; 33 with biliary atresia [BA]). The hemodynamics of native liver were studied preoperatively by Doppler ultrasound and intraoperatively using invasive flowmetry. Portosystemic gradient was invasively measured. Systemic hemodynamics were studied preoperatively by Doppler transthoracic echocardiography and intraoperatively by using transpulmonary thermodilution. Hemodynamic parameters were correlated with Pediatric End-Stage Liver Disease (PELD) score and the histological degree of fibrosis (collagen proportionate area [CPA]). Cirrhosis was associated with a 60% reduction of pretransplant total liver flow (n = 46; median, 36 mL/minute/100 g of liver) compared with noncirrhotic livers (n = 6; median, 86 mL/minute/100 g; P = 0.002). Total blood flow into the native liver was negatively correlated with PELD (P < 0.001) and liver CPA (P = 0.005). Median portosystemic gradient was 14.5 mm Hg in children with cirrhosis and positively correlated with PELD (P < 0.001). Portal vein (PV) hypoplasia was observed mainly in children with BA (P = 0.02). Systemic hemodynamics were not altered in our children with cirrhosis. Twenty-one children met the intraoperative criteria for PV reconstruction using a portoplasty technique during the LT procedure and had a smaller PV diameter at pretransplant Doppler ultrasound (median = 3.4 mm; P < 0.001). Cirrhosis in children appears also as a hemodynamic disease of the liver, correlated with cirrhosis severity. Surgical technique for PV reconstruction during LT was adapted accordingly. Liver Transplantation 23 1440-1450 2017 AASLD.

Impact of pre-transplant liver hemodynamics and portal reconstruction techniques on post-transplant portal vein complications in pediatric liver transplantation: a retrospective analysis in 197 recipients

BACKGROUND AND OBJECTIVE

Portal vein (PV) complications are the most frequent vascular complications in pediatric liver transplant (LT). We hypothesized that pre-LT liver hemodynamic parameters and PV reconstruction technique could predict the risk of PV complications post-LT.

METHODS

Three hundred seventy-three children had a primary LT. A detailed ultrasound study of the pre-LT native liver hemodynamics was available in 198 cases, with details of PV anastomosis available for 197 of these: end-to-end anastomosis (n = 146, 74%), interposition vein graft technique (n = 28, 14%), or portoplasty (latero-lateral anastomosis of vein graft and recipient PV) (n = 23, 12%).

RESULTS

Overall 5-year patient survival rate was 90%. Among the 198 patients with pre-LT hemodynamic data, 79 (40%) had PV hypoplasia (diameter ≤4 mm), 64 (32%) had a pathological portal flow (nonhepatopetal flow), and 47 (24%) had an arterial resistance index (ARI) ≥1. Abnormal hemodynamics were mostly observed in biliary atresia (BA). Among these 3 parameters, only ARI ≥1 was significantly correlated with a higher rate of PV complications post-LT (P = 0.041). PV complication-free survival at 5 years were 91% for end-to-end anastomosis, 91% for portoplasty, and 62% for interposition vein graft technique (P = 0.002). At multivariate analysis, the use of an interposition vein graft was the only factor to be significantly associated with a higher rate of PV complications post-LT (P = 0.003).

CONCLUSIONS

PV hypoplasia with liver hemodynamic disturbances was mainly observed in BA. Hepatic ARI ≥1 might be a good predictor of PV complications post-LT. Latero-lateral portoplasty seemed to provide the best results when end-to-end anastomosis is not feasible.

Direct measurement of hepatic blood flow during living donor liver transplantation in children

BACKGROUND

The changes in liver blood flow associated with living donor liver transplantation (LDLT) in children have not yet been studied. The aim of the present study was to investigate changes in hepatic hemodynamics before and after pediatric partial liver transplantation.

METHODS

In 7 pediatric recipients with congenital cholestasis and native liver Child-Pugh classes B and C, portal vein flow (PVF) and hepatic arterial flow (HAF) were measured using an ultrasonic transit time flow meter before removal of the native liver and after transplantation and compared with donor left PVF and donor left HAF.

RESULTS

The mean portal contribution to total hepatic blood flow was markedly decreased in the recipient native liver compared with that in the donor (69% +/- 15% vs 32% +/- 15%; P = .0003) and after reperfusion changed to almost the same ratio as that in the donor liver (73% +/- 18%; P < .0001).

CONCLUSION

The extreme imbalance between PVF and HAF that is common in implanted partial liver in adult LDLT recipients was not observed in pediatric LDLT. After transplantation of an appropriately sized liver graft, the portal contribution to total liver blood flow normalized to the value for normal liver.

Biliary atresia. A surgical perspective

The combination of portoenterostomy with subsequent liver transplantation is the treatment of choice for patients with biliary atresia. It is important, however, to attempt to keep the patient's own organ by continuing efforts to achieve the best possible results with portoenterostomy. Additional basic research, perhaps concerning on the role of cytokines and apoptosis in the control of biliary atresia, may provide insight into possible new medical strategies for treating patients with biliary atresia. For example, in addition to portoenterostomy, control of apoptosis at various cellular levels and of bile duct cell proliferation and maturation by manipulation of the growth factors and cytokines may become part of future treatment modalities. Another direction of research should be the control of fibrogenesis, which might be accomplished by blocking TGF-beta 1 and platelet-derived growth factor and by HGF gene therapy. The author's current strategy for surgical treatment for patients with biliary atresia include (1) early diagnosis, including prenatal diagnosis and broader use of mass screening programs, (2) hepatic portoenterostomy, without stoma formation; (3) close postoperative care, especially for prevention of postoperative cholangitis; (4) revision of portoenterostomy only in selected cases; (5) early liver transplantation in patients with absolutely failed portoenterostomy; (6) avoidance of laparotomy for the treatment of esophageal varices and hypersplenism; (7) consideration of exploratory laparotomy or primary liver transplantation for patients with advanced liver disease at the time of referral. The development of new treatment modalities based on the understanding of the pathogenesis of the disease, and especially on the biology of intrahepatic bile ducts and hepatic fibrosis, is essential.

Prediction of survival in extrahepatic biliary atresia by hepatic duplex sonography

BACKGROUND

The clinical course of biliary atresia patients is extremely variable. To optimize conservative treatment and correctly schedule liver transplantation, noninvasive investigations that are predictive of individual survival and that can be performed regularly are needed. In this study, the prognostic value of Doppler sonography was investigated in these patients.

METHODS

Thirty biliary atresia patients (age range, 1 month to 15.2 years; mean, 4.0 years) and 38 control subjects underwent standardized Doppler sonography of liver and spleen. Biochemical tests of liver function and of fibrogenesis were performed in parallel. Individual clinical outcome was registered 1 and 2 years later.

RESULTS

In control subjects, maximum portal flow velocity (Vmax) was more than 16 cm/sec, and the hepatic vein flow pattern was triphasic. Among children with biliary atresia, those with diminished portal Vmax, a flattened hepatic vein flow curve, or a hepatic artery resistance index of 0.8 or more had significantly lower indices of hepatic protein synthesis (albumin, cholinesterase), higher bilirubin levels, and higher concentrations of markers of connective tissue turnover (procollagen peptides, laminin P1) than did those with normal Doppler sonography measurements. The rate of survival without transplantation during the following 2 years was significantly lower in children with abnormal Doppler findings. From portal and hepatic vein flow measurements, patient survival 2 years later could be predicted with an accuracy of 93%.

CONCLUSIONS

In children with extrahepatic biliary atresia, Doppler sonography of the hepatic blood flow is a noninvasive indicator of disease severity. Moreover, it allows a highly accurate prediction of patient survival for the following 2 years.