Correlation Between Splenectomy and Portal Vein Complications in Living Donor Liver Transplantation

Longitudinal ultrasound imaging and network modeling in rats reveal sex-dependent suppression of liver regeneration after resection in alcoholic liver disease

Liver resection is an important surgical technique in the treatment of cancers and transplantation. We used ultrasound imaging to study the dynamics of liver regeneration following two-thirds partial hepatectomy (PHx) in male and female rats fed via Lieber-deCarli liquid diet protocol of ethanol or isocaloric control or chow for 5–7 weeks. Ethanol-fed male rats did not recover liver volume to the pre-surgery levels over the course of 2 weeks after surgery. By contrast, ethanol-fed female rats as well as controls of both sexes showed normal volume recovery. Contrary to expectations, transient increases in both portal and hepatic artery blood flow rates were seen in most animals, with ethanol-fed males showing higher peak portal flow than any other experimental group. A computational model of liver regeneration was used to evaluate the contribution of physiological stimuli and estimate the animal-specific parameter intervals. The results implicate lower metabolic load, over a wide range of cell death sensitivity, in matching the model simulations to experimental data of ethanol-fed male rats. However, in the ethanol-fed female rats and controls of both sexes, metabolic load was higher and in combination with cell death sensitivity matched the observed volume recovery dynamics. We conclude that adaptation to chronic ethanol intake has a sex-dependent impact on liver volume recovery following liver resection, likely mediated by differences in the physiological stimuli or cell death responses that govern the regeneration process. Immunohistochemical analysis of pre- and post-resection liver tissue validated the results of computational modeling by associating lack of sensitivity to cell death with lower rates of cell death in ethanol-fed male rats. Our results illustrate the potential for non-invasive ultrasound imaging to assess liver volume recovery towards supporting development of clinically relevant computational models of liver regeneration.

Does modification of portal pressure and flow enhance recovery of the recipient after living donor liver transplantation? A systematic review of literature and expert panel recommendations

BACKGROUND

Portal inflow modulation (PIM) aimed at reducing portal hyperperfusion is commonly used in living donor liver transplantation (LDLT) to reduce the risk of small-for-size syndrome (SFSS). Many different techniques, both pharmacological and surgical have been used for this purpose. There is, however, little consensus on the best method of PIM, its exact role in preventing SFSS and on early post-LDLT recovery.

OBJECTIVES

To identify whether modifications of portal pressures and flows enhance recovery after LDLT and to provide international expert panel recommendations.

DATA SOURCES

Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central.

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel.

PROSPERO ID

CRD42021260997.

RESULTS

Five hundred and ninety four articles were identified through databases' search. Of the 24 included for a final review by the working group (WG), there were five randomized control trials, four prospective studies and 15 retrospective series. Six outcome measures which were likely to influence early recovery after LDLT, especially in small-for-size grafts (SFSG) were shortlisted. These included acute kidney injury, SFSS, morbidity including sepsis, length of ICU and hospital stay, morbidity of the PIM technique and overall mortality. The WG noted that PIM in this subset of LDLT recipients had a beneficial effect on all the outcomes measures.

CONCLUSIONS

Considering all decision domains, the panel recommends pre- and intraoperative actual graft weight validation, portal pressure/flow measurements, and a comprehensive donor evaluation for the determination of potentially small-for-size/ small-for-flow grafts as mandatory. (Quality of Evidence: Moderate | Grade of Recommendation: Strong) Pharmacological PIM helps improve early renal function in LDLT recipients. (Quality of Evidence: High | Grade of Recommendation: Strong) In selected patients with SFSG, PIM helps reduce SFSS/EAD and sepsis. (Quality of Evidence: Moderate | Grade of Recommendation: Strong) PIM in the form of splenectomy has increased morbidity compared to splenic artery ligation (SAL). (Quality of Evidence: Low | Grade of Recommendation: Strong) In LDLT recipients with SFSG, PIM may help reduce morbidity/mortality. (Quality of Evidence: Low | Grade of Recommendation: Strong) In LDLT recipients with SFSG, modification of portal pressures and flows enhances recovery after LDLT. (Quality of Evidence: Moderate | Grade of Recommendation: Strong).

Risks of Living Donor Liver Transplantation Using Small-For-Size Grafts

BACKGROUND

In living donor liver transplantation (LDLT), a graft-to-recipient weight ratio (GRWR) of under 0.8 is recognized as the critical graft size. Our aim was to compare the survival rates of recipients with small-for-size grafts (SFSG: GRWR <0.8), normal-sized grafts (NSG), and large-for-size grafts (LFSG: GRWR ≥ 3.5) and to investigate the mortality risk with SFSG.

METHODS

Between 1991 and April 2019, we performed 188 LDLT surgeries. Recently, we added splenectomy when portal vein pressure is high (>17 mm Hg) to interrupt the splenic bloodstream. We divided all LDLT cases retrospectively into 3 groups: an SFSG group (n = 22), NSG group (n = 154), and LFSG group (n = 12). We investigated the survival rates in these groups. Furthermore, we divided the SFSG group into 2 subgroups: an SFSG with splenectomy (SFSG+S) group (n = 7) and an SFSG without splenectomy group. We investigated the occurrence rates of lethal complications such as portal vein thrombosis, hepatic artery thrombosis, and hepatic vein thrombosis.

RESULTS

The 5-year survival rate in the SFSG group was significantly lower (52.8%) than in the other groups (NSG: 84.5%; LFSG: 83.3%), but that of the SFSG+S group was similar (80.0%) to that of other groups. There was no difference in the occurrence of postoperative complications such as portal vein thrombosis, hepatic artery thrombosis, or hepatic vein thrombosis between the SFSG+S group and other groups.

CONCLUSIONS

Graft survival of LDLT using SFSG+S was as good as that of normal-sized grafts. Reducing portal vein pressure was important for SFSG.