Formation of venous collaterals and regeneration in the donor remnant liver: volumetric analysis and three-dimensional visualization

Ad Integrum Functional and Volumetric Recovery in Right Lobe Living Donors: Is It Really Complete 1 Year After Donor Hepatectomy?

The partial liver's ability to regenerate both as a graft and remnant justifies right lobe (RL) living donor liver transplantation. We studied (using biochemical and radiological parameters) the rate, extent of, and predictors of functional and volumetric recovery of the remnant left liver (RLL) during the first year in 91 consecutive RL donors. Recovery of normal liver function (prothrombin time [PT] ≥70% of normal and total bilirubin [TB] ≤20 µmol/L), liver volumetric recovery, and percentage RLL growth were analyzed. Normal liver function was regained by postoperative day's 7, 30, and 365 in 52%, 86%, and 96% donors, respectively. Similarly, mean liver volumetric recovery was 64%, 71%, and 85%; whereas the percentage liver growth was 85%, 105%, and 146%, respectively. Preoperative PT value (p = 0.01), RLL/total liver volume (TLV) ratio (p = 0.03), middle hepatic vein harvesting (p = 0.02), and postoperative peak TB (p < 0.01) were predictors of early functional recovery, whereas donor age (p = 0.03), RLL/TLV ratio (p = 0.004), and TLV/ body weight ratio (p = 0.02) predicted early volumetric recuperation. One-year post-RL donor hepatectomy, though functional recovery occurs in almost all (96%), donors had incomplete restoration (85%) of preoperative total liver volume. Modifiable predictors of regeneration could help in better and safer donor selection, while continuing to ensure successful recipient outcomes.

Risk of venous congestion in live donors of extended right liver graft

AIM: To investigate middle hepatic vein (MHV) management in adult living donor liver transplantation and safer remnant volumes (RV).

METHODS: There were 59 grafts with and 12 grafts without MHV (including 4 with MHV-5/8 reconstructions). All donors underwent our five-step protocol evaluation containing a preoperative protocol liver biopsy Congestive vs non-congestive RV, remnant-volume-body-weight ratios (RVBWR) and postoperative outcomes were evaluated in 71 right graft living donors. Dominant vs non-dominant MHV anatomy in total liver volume (d-MHV/TLV vs nd-MHV/TLV) was constellated with large/small congestion volumes (CV-index). Small for size (SFS) and non-SFS remnant considerations were based on standard cut-off- RVBWR and RV/TLV. Non-congestive RVBWR was based on non-congestive RV.

RESULTS: MHV and non-MHV remnants showed no significant differences in RV, RV/TLV, RVBWR, total bilirubin, or INR. SFS-remnants with RV/TLV < 30% and non-SFS-remnants with RV/TLV ≥ 30% showed no significant differences either. RV and RVBWR for non-MHV (n = 59) and MHV-containing (n = 12) remnants were 550 ± 95 mL and 0.79 ± 0.1 mL vs 568 ± 97 mL and 0.79 ± 0.13, respectively (P = 0.423 and P = 0.919. Mean left RV/TLV was 35.8% ± 3.9%. Non-MHV (n = 59) and MHV-containing (n = 12) remnants (34.1% ± 3% vs 36% ± 4% respectively, P = 0.148. Eight SFS-remnants with RVBWR < 0.65 had a significantly smaller RV/TLV than 63 non-SFS-remnants with RVBWR ≥ 0.65 [SFS: RV/TLV 32.4% (range: 28%-35.7%) vs non-SFS: RV/TLV 36.2% (range: 26.1%-45.5%), P < 0.009. Six SFS-remnants with RV/TLV < 30% had significantly smaller RVBWR than 65 non-SFS-remnants with RV/TLV ≥ 30% (0.65 (range: 0.6-0.7) vs 0.8 (range: 0.6-1.27), P < 0.01. Two (2.8%) donors developed reversible liver failure. RVBWR and RV/TLV were concordant in 25%-33% of SFS and in 92%-94% of non-SFS remnants. MHV management options including complete MHV vs MHV-4A selective retention were necessary in n = 12 vs n = 2 remnants based on particularly risky congestive and non-congestive volume constellations.

CONCLUSION: MHV procurement should consider individual remnant congestive- and non-congestive volume components and anatomy characteristics, RVBWR-RV/TLV constellation enables the identification of marginally small remnants.

How do transplant surgeons accomplish optimal portal venous flow during living-donor liver transplantation? Noninvasive measurement of indocyanine green elimination rate

BACKGROUND

Balancing donor safety and graft volume is difficult. We previously reported that intentional modulation of portal venous pressure (PVP) during living-donor liver transplantation (LDLT) is crucial to overcoming problems with small-for-size grafts; however, detailed studies of portal venous flow (PVF) and a reliable parameter are still required.

PATIENTS AND METHODS

The elimination rate (k) of indocyanine green (ICG) was measured in 49 adult LDLT recipients. PVP was controlled during LDLT, with a target of <20 mm Hg. ICG reflects hepatocyte volume and effective PVF. The kICG value is divided by the graft weight to calculate PVF. Recipients were divided into 2 groups: those with severe and/or fatal complications within 1 month after LDLT and those without.

RESULTS

Survival rates and postoperative profiles were significantly different between the 2 groups. Univariate analysis showed significant differences in ABO blood group, final PVP, final kICG, and the final kICG/graft weight value; however, multivariate analysis showed that only the kICG/graft weight value was significant. The cutoff level for the final kICG/graft weight value for predicting successful LDLT was 3.1175 × 10(-4)/g.

CONCLUSION

Accurate evaluation and monitoring of optimal PVF during LDLT should overcome the use of small-for-size grafts and improve donor safety and recipient outcomes.

How transplant surgeons can overcome the inevitable insufficiency of allograft size during adult living-donor liver transplantation: strategy for donor safety with a smaller-size graft and excellent recipient results

Small-for-size grafts are an issue in liver transplantation. Portal venous pressure (PVP) was monitored and intentionally controlled during living-donor liver transplantation (LDLT) in 155 adult recipients. The indocyanine green elimination rate (kICG) was simultaneously measured in 16 recipients and divided by the graft weight (g) to reflect portal venous flow (PVF). The target PVP was <20 mmHg. Patients were divided by the final PVP (mmHg): Group A, PVP < 12; Group B, 12 ≤ PVP < 15; Group C, 15 ≤ PVP < 20; and Group D, PVP ≥ 20. With intentional PVP control, we performed splenectomy and collateral ligation in 80 cases, splenectomy in 39 cases, and splenectomy, collateral ligation, and additional creation in five cases. Thirty-one cases received no modulation. Groups A and B showed good LDLT results, while Groups C and D did not. Final PVP was the most important factor for the LDLT results, and the PVP cutoffs for good outcomes and clinical courses were both 15.5 mmHg. The respective kICG/graft weight cutoffs were 3.5580 × 10(-4) /g and 4.0015 × 10(-4) /g. Intentional PVP modulation at <15 mmHg is a sure surgical strategy for small-for-size grafts, to establish greater donor safety with good LDLT results. The kICG/graft weight value may have potential as a parameter for optimal PVF and a predictor for LDLT results.

The "carving" liver partitioning technique for graft hepatectomy in live donor liver transplantation: a single-center experience

BACKGROUND

In adult live donor liver transplantation, postoperative venous congestion of graft and remnant livers can lead to life-threatening complications. The purpose of this study was to evaluate the safety and benefits of our 3-dimensional, computed tomographic, computer-assisted donor hepatectomy using the "carving" partitioning technique.

METHODS

Eighty-three consecutive adult live donor liver transplantations were performed based on data obtained from individualized preoperative 3-dimensional, computed tomographic reconstructions and virtual graft hepatectomies.

RESULTS

There were 71 right and 12 left grafts. Small grafts (graft volume body weight ratio, <1.0) were used in 20 cases. We observed no clinically important differences in postoperative function between right and left grafts. Four recipients developed lethal small-for-size syndrome. Reversible small-for-size syndrome was observed in a right graft recipient and in 2 right graft donors.

CONCLUSION

Preoperative 3-dimensional, computed tomographic, computer-assisted planning using virtual liver partitioning allowed for: (1) an individualized carving technique based on specific donor anatomic characteristics, (2) donor safety based on individualized patterns of venous outflow, and (3) optimized drainage of the medial area of the graft based on the preferential inclusion of the middle hepatic vein.