Relationship between portal venous flow and liver regeneration in patients after living donor right-lobe liver transplantation

Abstract

The purpose of this study is to evaluate the relationship between portal venous (PV) velocity and degree of liver regeneration in humans after living donor liver transplantation (LDLT). Between July 1997 and September 2002, a total of 15 adult-to-adult LDLTs with right-lobe grafts were performed, and 13 of these patients were enrolled in this study. Postoperative PV dynamics differed according to the primary liver disease; therefore, patients were divided into two groups: a fulminant hepatic failure (FHF) group (n ‫؍‬ 4) and a liver cirrhosis (LC) group (n ‫؍‬ 9). Right-lobe donors (n ‫؍‬ 13; D group) were used as controls. Doppler ultrasound was used to measured changes in PV velocity preoperatively; postoperative days (PODs) 1, 3, 7, 14, and 28; and 3 months after LDLT. To assess hepatic regeneration, the increase in liver volume ratio (postoperative liver volume to standard liver volume [SLV]) was measured. PV velocity after LDLT in the LC group increased sharply until POD 7, whereas those in the FHF and D groups were constant. In the first 3 months after LDLT, mean PV velocity was greater in the LC group than the other groups, reflecting the persistent hyperdynamic state in chronic end-stage liver disease. Liver regeneration also was more rapid in the LC group than the FHF and D groups and reached 100% as early as 2 weeks posttransplantation, whereas both the FHF and D livers reached approximately 80% of SLV at 3 months. PV velocity POD 7 correlated significantly with regeneration of the partial-liver allograft at 1 month (r ‫؍‬ 0.84; P ‫؍‬ .0091). In conclusion, the PV persistent hyperdynamic state in the LC group could directly trigger early liver regeneration in partial-liver allografts after LDLT. (Liver Transpl 2003;9:547-551.) D espite recent advances in molecular biology and cell physiology, the precise mechanism of liver regeneration after partial hepatectomy remains to be elucidated. Initiation of liver regeneration by increased shear stress in the portal venous (PV) wall, i.e., the shear-stress theory, has been shown in rats. 1-3 PV hypertension after partial liver resection in rats induces the expression and upregulation of many regeneration-related genes in the liver, followed by DNA synthesis and mitosis. 4 However, few attempts have been made to determine whether such a theory is applicable to liver regeneration in humans.Because of the shortage of brain-dead donors, partial-liver transplantation from living related donors has gained popularity worldwide. 5 In contrast to wholeliver transplantation, a partial-liver allograft regenerates to adjust to the recipient's environment. 6 Thus, partialliver transplantation provides a unique opportunity to investigate the unresolved mechanism of liver regeneration and determine the liver volume required to sustain life in humans. [7][8][9] Because a persistent PV hyperdynamic state after orthotopic liver transplantation has been reported in patients with liver cirrhosis, we hypothesized that this should affect a partial-liver allograft more than a wholel...

Systemic hemodynamics in advanced cirrhosis: Concerns during perioperative period of liver transplantation

“…Vascular alterations do not easily disappear despite restorations of PH and liver function in recipients with LC, and PVF impacts liver regeneration after LT [43] . Stability of characteristic systemic hyperdynamics is indispensable for adequate PVF and successful LT [1,2] .…”

“…Selection of a graft with an GRWR of ≥ 0.8 and establishment of a target PVP of ≤ 15 mmHg during LDLT are considered keys for successful LDLT [40] . Optimal PVF is required for successful LDLT [2,43] . Ligation of collaterals and shunts often require an advanced surgical technique because these vessels are always abnormal [41,42] .…”

“…ICG kinetics reflect the functional hepatocytes (cell volume) and effective PVF (clearance) [31,[49][50][51][52] , and PVF is a major determinant of kICG in the normal liver [32,34,49,51,53] . The PVF has a large influence on liver regeneration after LT [32,43] , and reversible damage to hepatocytes begins immediately after graft recirculation [32,38,39,43] . Some researchers have focused on ICG kinetics as a liver function test after LT [31,32] , and kICG values can predict clinical outcomes in the early postoperative period after LDLT by closely reflecting the influence of systemic dynamics on the splanchnic circulation [32] .…”

Small‐for‐Size Syndrome After Partial Liver Transplantation: Definition, Mechanisms of Disease and Clinical Implications

“…Small grafts have a higher portal resistance, leading to higher portal pressure in patients (27). In this setting of partial transplantation, recipient hemodynamics are also important, as cirrhotic recipients demonstrate higher portal flow than noncirrhotics (16).…”

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“…8 Eguchu and associates studied 13 LDLT patients and found elevated mean PV velocities during the first 3 months after transplant, with higher velocities in the cirrhotic group than in the noncirrhotic group. 13 In their study on 14 consecutive donor-recipient pairs, Gondolesi and associates found that the PV velocity/flow dramatically increased 1 hour after reperfusion (94.7 ± 28.4 cm/s; P = .004), with return to baseline 3 months after transplant (58.8 ±37.8 cm/s; P = .01). 14 Furthermore, Sugimoto and colleagues studied 10 donor-recipient pairs for 2 weeks after transplant and reported a marked elevation of PV velocity in recipients on the first day after transplant (106.3 ± 45.2 cm/s).…”