Regeneration of a transplanted liver after right hepatic lobectomy

Long term outcomes of hepatic resection following orthotopic liver transplant

BACKGROUND

Liver resection is sometimes used as a graft saving procedure following orthotopic liver transplantation.

METHODS

In this single centre retrospective cohort study, 12 adult patients underwent resection over a 20 year period, including recipients of split livers and second grafts.

RESULTS

Indications for resection were vascular (portal vein obstruction and hepatic artery thrombus), biliary (ischaemic cholangiopathy, chronic biliary obstruction, biliary-vascular fistula and biloma) and recurrence of disease (primary sclerosing cholangitis [PSC] and hepatocellular carcinoma [HCC]). There was no perioperative mortality. Median follow up was 89 months. At the completion of the study 40% of patients had functioning grafts. One third required retransplantation with a median 1 year 6 months post resection. Three patients were deceased (recurrent HCC n = 1, PSC n = 1 and unspecified causes n = 1). Total graft survival was 91.7% at 1 year, 73.3% at 5 years and 64.2% at 10 years.

CONCLUSIONS

Liver resection following liver transplant in select patients may salvage the graft or delay the need for retransplantation.

Outcomes of Liver Resections after Liver Transplantation at a High-Volume Hepatobiliary Center

Although more than one million liver transplantations have been carried out worldwide, the literature on liver resections in transplanted livers is scarce. We herein report a total number of fourteen patients, who underwent liver resection after liver transplantation (LT) between September 2004 and 2017. Hepatocellular carcinomas and biliary tree pathologies were the predominant indications for liver resection (n = 5 each); other indications were abscesses (n = 2), post-transplant lymphoproliferative disease (n = 1) and one benign tumor. Liver resection was performed at a median of 120 months (interquartile range (IQR): 56.5-199.25) after LT with a preoperative Model for End-Stage Liver Disease (MELD) score of 11 (IQR: 6.75-21). Severe complications greater than Clavien-Dindo Grade III occurred in 5 out of 14 patients (36%). We compared liver resection patients, who had a treatment option of retransplantation (ReLT), with actual ReLTs (excluding early graft failure or rejection, n = 44). Bearing in mind that late ReLT was carried out at a median of 117 months after first transplantation and a median of MELD of 32 (IQR: 17.5-37); three-year survival following liver resection after LT was similar to late ReLT (50.0% vs. 59.1%; p = 0.733). Compared to ReLT, liver resection after LT is a rare surgical procedure with significantly shorter hospital (mean 25, IQR: 8.75-49; p = 0.034) and ICU stays (mean 2, IQR: 1-8; p < 0.001), acceptable complications and survival rates.

[Computerized liver volume for evaluation and following liver regeneration after partial hepatectomy in swines]

OBJECTIVES

To analyze the hepatic volume by computerized tomography using a semiautomatic computerized program of acquisition and processing digitalized images, to follow the hepatic regeneration in swine after partial hepatectomy.

METHODS

Twelve female young Landrace swine were separated in three groups according to the observation time between hepatectomy and sacrifice: G5 (5 days), G10 (10 days) and G15 (15 days). All animals were submitted to partial hepatectomy of the right lobe and followed until sacrifice, when regenerated liver was ressected. The surgical piece and the regenerated liver were weighted and submitted to tomographic volume evaluation by the software HEPATO, taking place acquisition and analysis of the tomography images in a semiautomatic way. Statistical analysis used the non-parametric Kruskal-Wallis and Wilcoxon tests.

RESULTS

Medium weigh of regenerated liver was G5=434,5 g, G10=449,25g and G15=486,5 g (p=0,592). The regeneration index obtained using liver weight was 83,58% (G5), 94,95% (G10) and 101,63% (G15) (p=0,197). Medium volume of regenerated liver was G5=403,58 cm(2), G10=450,88 cm(2) and G15=458,93 cm(2) (p=0,941). Liver regeneration index obtained using liver volume was 74,25% (G5), 88% (G10) and 100% (G15) (p=0,326). Liver regeneration index was not different when assessed using liver weigh or liver volume.

CONCLUSION

The liver volumetric evaluation by computerized tomography using a computerized semiautomatic program of digitalized images acquisition and processing is a trustworthy method for evaluation and following the liver regeneration in swine after partial hepatectomy.

Hepatic resection in liver transplant recipients: single center experience and review of the literature

Biliary complications such as ischemic (type) biliary lesions frequently develop following liver transplantation, requiring costly medical and endoscopic treatment. If conservative approaches fail, re-transplantation is most often an inevitable sequel. Because of an increasing donor organ shortage and unfavorable outcomes in hepatic re-transplantation, efforts to prolong graft survival become of particular interest. From a series of 1685 liver transplants, we herein report on three patients who underwent partial hepatic graft resection for (ischemic type) biliary lesions. In all cases, left hepatectomy (Couinaud's segments II, III and IV) was performed without Pringle maneuver or mobilization of the right liver. All patients fully recovered postoperatively, but biliary leakage required surgical revision twice in one patient. At last follow-up, two patients presented alive and well. The other patient with persistent hepatic artery thrombosis (HAT), however, demonstrated progression of disease in the right liver remnant and required re-transplantation 13 months after hepatic graft resection. Including our own patients, review of the literature identified 24 adult patients who underwent hepatic graft resection. In conclusion, partial graft hepatectomy can be considered a safe and beneficial procedure in selected liver transplant recipients with anatomical limited biliary injury, thereby, preserving scarce donor organs.

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

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.

The economic impact of preservation time in cadaveric liver transplantation

There has been considerable recent debate concerning the reconfiguration of the cadaveric liver allocation system with the intent to allocate livers to more severely ill patients over greater distances. We sought to assess the economic implications of longer preservation times in cadaveric liver transplantation that may be seen in a restructured allocation system. A total of 683 patients with nonfulminant liver disease, aged 16 years or older, receiving a cadaveric donor liver as their only transplant, were drawn from a prospective cohort of patients who received transplants between January 1991 and July 1994 at the University of California, San Francisco, the Mayo Clinic, Rochester, Minnesota, or the University of Nebraska, Omaha. The primary outcome measure was standardized hospitalization resource utilization from the day of transplantation through discharge. Secondary outcome measures included 2-year patient survival, and 2-year retransplantation rates. Results indicated that each 1-h increase in preservation time was associated with a 1.4% increase in standardized hospital resource utilization (p = 0.014). The effects on 2-year patient survival and retransplantation rates were not measurably affected by an increase in preservation time. We conclude that policies that increase preservation time may be expected to increase the cost of liver transplantation.

Right hepatic lobectomy as a liver graft-saving procedure

Retransplantation is common after liver transplantation (LT). However, in the present era of organ shortages, every attempt to save the liver graft should be performed before considering retransplantation. We report our experience with right hepatic lobectomy (RHL) for liver graft salvage. In a retrospective series of 180 adult LTs, 4 patients underwent RHL (Couinaud's segments V, VI, VII, VIII) in the post-LT period. In all cases, the procedure was performed without Pringle's maneuver or mobilization of the left liver lobe to preserve its vascularization. Three liver graft recipients developed intrahepatic biliary strictures, mainly localized to the right lobe of the graft, and RHL was performed 14, 75, and 78 months after LT. These patients were alive at last follow-up without further episodes of cholangitis or retransplantation (mean follow-up, 38 months). The fourth patient developed early post-LT right liver necrosis with a functioning hepatic artery and underwent right lobectomy 48 hours after LT. He later developed cholangitis secondary to late hepatic artery thrombosis, requiring retransplantation after 18 months. We conclude that RHL can be considered a graft-saving option in selected liver transplant recipients with localized biliary strictures, with excellent patient and graft survival.

Changes in liver regenerative factors in a case of living-related liver transplantation

Liver regeneration in a patient with fulminant hepatic failure (FHF) who underwent living-related partial liver transplantation (LRLT) was investigated regarding hepatic growth factors. The patient was a 16-yr-old Japanese male who developed severe subacute FHF. LRLT was performed using an extended left lobe of the ABO matched patient's mother. In the recipient, the pre-transplant levels of both plasma hepatocyte growth factor (HGF) and transforming growth factor (TGF)-beta were extremely high and rapidly decreased following the liver replacement. The liver volume evaluated using a CAT scan increased 195% after 2 wk in graft liver and 110% after 2 wk in the hepatectomized donor. The explanted liver (FHF liver), the liver from donor (normal liver), and the graft liver [the 3rd post-transplant day (POD 3)] were all investigated immunohistochemically. FHF liver: No liver regeneration was observed [proliferative cell nuclear antigen (PCNA) labeling index (L.I.): 0%]. In the liver, both HGF in the hepatocytes and c-met on the membrane of the hepatocytes were positive. TGF-beta was positive in the hepatocytes and no apoptosis was detected by the TUNEL method. Donor liver (POD 0): Few PCNA stained hepatocytes were detected. No HGF was detected but c-met was clearly detected on the cell membrane of the hepatocytes. Neither TGF-beta nor apoptosis was detected. Graft liver (POD 3): The PCNA L.I. was conspicuous at 40%. HGF was positive in non-parenchymal cells and c-met was positive in the cytoplasm of the hepatocytes. TGF-beta was negative while apoptosis was positive in the zone 3 hepatocytes. In conclusion, these findings suggested that the liver of the patient with FHF did not respond to liver regenerative stimulus, in part, through involvement of inhibitor TGF-beta. On POD 3, the transplanted graft was in a vigorous regenerative status in comparison to that in the hepatectomized donor. The HGF/c-met system is thought to be involved in the mechanism of regeneration. Intrahepatic apoptosis was detected in the graft on the 3rd post-transplant day probably due to transient ischemia in the liver, which was not related to the Fas/Fas-ligand system.