Predictive Value of Hepatic Venous Pressure Gradient for Graft Hemodynamics in Living Donor Liver Transplantation

Outcomes of living donor liver transplant recipients receiving grafts with the graft-to-recipient weight ratio less than 0.6%: A matched pair analysis

We sometimes experience living donor liver transplantation (LDLT) involving very small grafts with graft-to-recipient weight ratio (GRWR) < 0.6% when the actual graft size is smaller than predicted. The outcomes in this situation have not been fully investigated. The present study aimed to determine the graft outcomes of LDLT with GRWR < 0.6%. We retrospectively reviewed 280 cases of adult LDLT performed at our institution between January 2000 and March 2021. In our institution, the lower limit for graft volume/standard liver volume ratio was 30%. The patients were divided into 2 groups according to the cutoff value of 0.6% for actual GRWR. Graft survival and surgical outcomes, including small-for-size syndrome (SFSS), were compared between the groups using propensity score matching analysis. Risk factors associated with SFSS in recipients with GRWR < 0.6% were also evaluated. Fifty-nine patients received grafts with GRWR < 0.6%. After propensity score matching, similar graft survival rates were observed for GRWR < 0.6% (n = 53) and GRWR ≥ 0.6% (n = 53) ( p = 0.98). However, patients with GRWR < 0.6% had a significantly worse 3-month graft survival rate (86.8% vs. 98.1%, p = 0.03) and higher incidence of SFSS ( p < 0.001) than patients with GRWR ≥0.6%. On multivariate analysis, Model for End-Stage Liver Disease score and donor age were associated with SFSS in patients with GRWR < 0.6%. The same factors were also associated with graft survival. In conclusion, although similar overall graft survival rates were observed for LDLT with GRWR < 0.6% and GRWR ≥ 0.6%, GRWR < 0.6% was associated with an increased risk of SFSS. Appropriate donor and recipient selection is important for successful LDLT with very small grafts.

Development of a Direct Non-Puncture Device for Measuring Portal Venous Pressure during Liver Transplantation-A Swine Model

Portal hypertension-related complications pose a significant risk for liver failure post-transplantation. Thus, accurate monitoring of intraoperative portal venous pressure (PVP) is crucial. However, current PVP monitoring techniques requiring direct percutaneous puncture carry the risk of graft damage. In this study, we present an innovative non-puncture PVP monitoring device (PVPMD) using a 3D-printed prototype. PVPMD design is inspired by the sphygmomanometer principle, and strategically encompasses the portal vein and enables precise PVP measurement through blood flow ultrasonography after temporary occlusion. By a series of mini-pig experiments, the prototype PVPMD demonstrated a strong correlation with invasive catheter measurements in the main trunk of the portal vein (rs = 0.923, p = 0.000). There was a significant repeatability and reproducibility between the prototype PVPMD- and invasive catheter-measured PVP. This indicates that the PVPMD holds immense potential for direct application in liver transplantation and surgery. Moreover, it has the potential to replace catheter-based central venous pressure (CVP) measurements, thereby mitigating catheter-related complications during many surgeries. In conclusion, our innovative device represents a significant advancement in PVP monitoring during liver transplantation, with comprehensive validation from principle exploration to successful animal experiments. We anticipate that this groundbreaking PVPMD will attract the attention of researchers and clinicians, propelling the noninvasive measurement of PVP or other venous/arterial pressures into a new era of clinical practice.

Biliary complications following split liver transplantation in adult recipients: a matched pair analysis on single-center experience

The utilization of split liver grafts can increase access to liver transplantation (LT) for adult patients, particularly when liver grafts are shared between 2 adult recipients. However, it is yet to be determined whether split liver transplantation (SLT) increases the risk of biliary complications (BCs) compared with whole liver transplantation (WLT) in adult recipients. This retrospective study enrolled 1441 adult patients who underwent deceased donor LT at a single-site between January 2004 and June 2018. Of those, 73 patients underwent SLTs. Graft type for SLT includes 27 right trisegment grafts, 16 left lobes, and 30 right lobes. A propensity score matching analysis selected 97 WLTs and 60 SLTs. Biliary leakage was more frequently seen in SLTs (13.3% vs. 0%; p <0.001), whereas the frequency of biliary anastomotic stricture was comparable between SLTs and WLTs (11.7% vs. 9.3%; p=0.63). Graft and patient survival rates of patients undergoing SLTs were comparable to those undergoing WLTs (p=0.42 and 0.57, respectively). In the analysis of the entire SLT cohort, BCs were seen in 15 patients (20.5%) including biliary leakage in 11 patients (15.1%) and biliary anastomotic stricture in 8 patients (11.0%) [both in 4 patients (5.5%)]. The survival rates of recipients who developed BCs were significantly inferior to those without BCs (p <0.01). By multivariate analysis, the split grafts without common bile duct increased the risk of BCs. In conclusion, SLT increases the risk of biliary leakage compared with WLT. Biliary leakage can still lead to fatal infection and thus should be managed appropriately in SLT.

Living Donor Liver Transplantation With Augmented Venous Outflow and Splenectomy: A Promised Land for Small Left Lobe Grafts

OBJECTIVE

Living donor liver transplantation (LDLT) using small grafts, especially left lobe grafts (H1234-MHV) (LLG), continues to be a challenge due to small-for-size syndrome (SFSS). We herein demonstrate that with surgical modifications, outcomes with small grafts can be improved.

METHODS

Between 2012 and 2020, we performed 130 adult LDLT using 61 (47%) LLG (H1234-MHV) in a single Enterprise. The median graft-to-recipient weight ratio was 0.84%, with graft-to-recipient weight ratio <0.7% accounting for 22%. Splenectomy was performed in 72 (56%) patients for inflow modulation before (n=50) or after (n=22) graft reperfusion. In LLG-LDLT, venous outflow was achieved using all three recipient hepatic veins. In right lobe graft (H5678) (RLG)-LDLT, the augmented graft right hepatic vein was anastomosed to the recipient's cava with a large cavotomy. Outcome measures include SFSS, early allograft dysfunction (EAD), and survival.

RESULTS

Graft survival rates at 1, 3, and 5 years were 94%, 90%, and 83%, respectively, with no differences between LLG (H1234-MHV) and RLG (H5678). Splenectomy significantly reduced portal flow without increasing the complication rate. Despite the aggressive use of small grafts, SFSS and EAD developed in only 1 (0.8%) and 18 (13.8%) patients, respectively. Multivariable logistic regression revealed model for end-stage liver disease score and LLG (H1234-MHV) as independent risk factors for EAD and splenectomy as a protective factor (odds ratio: 0.09; P =0.03). For LLG (H1234-MHV)-LDLT, patients who underwent prereperfusion splenectomy tended to have better 1-year graft survival than those receiving postreperfusion splenectomy.

CONCLUSIONS

LLG (H1234-MHV) are feasible in adult LDLT with excellent outcomes comparable to RLG (H5678). Venous outflow augmentation and splenectomy help lower the threshold of using small-for-size grafts without compromising graft survival.

Clinical Impact of Spontaneous Portosystemic Shunts in Liver Transplantation: A Comprehensive Assessment Through Total Shunt Area Measurement

BACKGROUND

The impact of spontaneous portosystemic shunts (SPSSs) on natural history of cirrhotic patients was recently evaluated through the measurement of total shunt area (TSA), a novel tool that allows a comprehensive assessment of SPSSs extension, identifying a direct correlation of higher TSA with lower patient survival. The role of SPSSs in liver transplant (LT) is still debated: we sought to investigate the clinical impact of TSA on the development of early allograft dysfunction (EAD), acute kidney injury (AKI), postoperative complications, and graft and patient survival following LT.

METHODS

Preoperative imaging of 346 cirrhotic patients undergoing primary LT between 2015 and 2020 were retrospectively revised, recording the size and anatomy of each SPSS to calculate TSA. The impact of TSA and selected patient and donor characteristics on the development of EAD, AKI, and clinically relevant complications was evaluated through univariate and multivariate logistic regression, whereas their effect on graft and patient survival was investigated through Cox regression analysis.

RESULTS

A TSA exceeding 78.54 mm 2 resulted as an independent risk factor for the development of EAD (odds ratio [OR]: 2.327; P = 0.003), grade 3 AKI (OR: 2.093; P = 0.041), and clinically relevant complications (OR: 1.962; P = 0.015). Moreover, higher TSA was significantly related to early graft and patient survivals, emerging as an independent risk factor for 12-mo graft loss (hazard ratio: 3.877; P = 0.007) and patient death (hazard ratio: 2.682; P = 0.018).

CONCLUSIONS

Higher TSA emerged as a significant risk factor for worse postoperative outcomes following LT, supporting the need for careful hemodynamic assessment and management of patients presenting multiple/larger shunts.

Three-dimensional modeling in complex liver surgery and liver transplantation

Liver resection and transplantation are the most effective therapies for many hepatobiliary tumors and diseases. However, these surgical procedures are challenging due to the anatomic complexity and many anatomical variations of the vascular and biliary structures. Three-dimensional (3D) printing models can clearly locate and describe blood vessels, bile ducts and tumors, calculate both liver and residual liver volumes, and finally predict the functional status of the liver after resection surgery. The 3D printing models may be particularly helpful in the preoperative evaluation and surgical planning of especially complex liver resection and transplantation, allowing to possibly increase resectability rates and reduce postoperative complications. With the continuous developments of imaging techniques, such models are expected to become widely applied in clinical practice.

Endoscopic therapy + β-blocker vs. covered transjugular intrahepatic portosystemic shunt for prevention of variceal rebleeding in cirrhotic patients with hepatic venous pressure gradient ≥16 mmHg

BACKGROUND AND OBJECTIVE

Currently, monitoring hepatic venous pressure gradient (HVPG) have been proved to be the best predictor for the risk of variceal bleeding. We performed the study to evaluate the effect of endoscopic therapy + β-blocker vs. covered transjugular intrahepatic portosystemic shunt (TIPS) for the prevention of variceal rebleeding in cirrhotic patients with HVPG ≥16 mmHg.

METHODS

Consecutive cirrhotic patients with HVPG ≥16 mmHg treated with endoscopic therapy + β-blocker or covered TIPS for variceal bleeding were retrospectively gathered between April 2013 and December 2018. The variceal rebleeding rate, survival, and incidence of overt hepatic encephalopathy (OHE) were compared.

RESULTS

A total of 83 patients were analyzed, of which 46 received endoscopic therapy + β-blocker and 37 covered TIPS. During a median follow-up of 12.0 months, the rebleeding rate (32.6 vs. 10.8%, P = 0.017) and rate of OHE (2.2 vs. 27.0%, P = 0.001) showed significant differences between the two groups, while liver transplantation-free survival (93.5 vs. 94.6%, P = 0.801) was similar. Preoperative and postoperative Child-Turcotte-Pugh scores were similar in either group. In addition, no significant differences of rebleeding rate (25.0 vs. 21.3%, P = 0.484) and survival (97.2 vs. 91.5%, P = 0.282) were observed between patients with 16 mmHg ≤ HVPG < 20 mmHg and HVPG ≥ 20 mmHg.

CONCLUSION

Covered TIPS was more effective than endoscopic therapy + β-blocker in preventing rebleeding in patients with HVPG ≥16 mmHg but did not improve survival. TIPS also induce more OHE.

Does graft hemodynamics affect the risk of hepatocellular carcinoma recurrence after liver transplantation?

Although experimental studies have reported that hepatic ischemia-reperfusion injury promotes tumor growth and metastases, the impact of graft hemodynamics on the recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) is unclear. To investigate the association between graft hemodynamics and HCC recurrence after LT, we conducted a retrospective analysis of 279 patients who underwent LT for HCC. Graft hemodynamics including portal vein flow (PVF), hepatic artery flow (HAF), and total hepatic flow (THF) was analyzed as a predictor of HCC recurrence, using competing risk regression analyses. The cutoff values of PVF, HAF, and THF were set at the lower quartile of distribution. A cumulative recurrence curve demonstrated that low THF (<1511 mL/min, P = .005) was significantly associated with increased recurrence, whereas neither low PVF (<1230 mL/min, P = .150) nor low HAF (<164 mL/min, P = .110) was significant. On multivariate analysis, outside Milan criteria (sub-hazard ratio [SHR] = 3.742; P < .001), microvascular invasion (SHR = 3.698; P < .001), and low THF (SHR = 2.359; P = .010) were independently associated with increased HCC recurrence. In conclusion, our findings suggest that graft hemodynamics may play an important role in HCC recurrence after LT.