Striving for perfection: evaluation of the right lobe live liver donor

Incidence of death and potentially life-threatening near-miss events in living donor hepatic lobectomy: a world-wide survey

The incidence of morbidity and mortality after living donor liver transplantation (LDLT) is not well understood because reporting is not standardized and relies on single-center reports. Aborted hepatectomies (AHs) and potentially life-threatening near-miss events (during which a donor's life may be in danger but after which there are no long-term sequelae) are rarely reported. We conducted a worldwide survey of programs performing LDLT to determine the incidence of these events. A survey instrument was sent to 148 programs performing LDLT. The programs were asked to provide donor demographics, case volumes, and information about graft types, operative morbidity and mortality, near-miss events, and AHs. Seventy-one programs (48%), which performed donor hepatectomy 11,553 times and represented 21 countries, completed the survey. The average donor morbidity rate was 24%, with 5 donors (0.04%) requiring transplantation. The donor mortality rate was 0.2% (23/11,553), with the majority of deaths occurring within 60 days, and all but 4 deaths were related to the donation surgery. The incidences of near-miss events and AH were 1.1% and 1.2%, respectively. Program experience did not affect the incidence of donor morbidity or mortality, but near-miss events and AH were more likely in low-volume programs (≤50 LDLT procedures). In conclusion, it appears that independently of program experience, there is a consistent donor mortality rate of 0.2% associated with LDLT donor procedures, yet increased experience is associated with lower rates of AH and near-miss events. Potentially life-threatening near-miss events and AH are underappreciated complications that must be discussed as part of the informed consent process with any potential living liver donor.

Variability of standard liver volume estimation versus software-assisted total liver volume measurement

The estimation of the standard liver volume (SLV) is an important component of the evaluation of potential living liver donors and the surgical planning for resection for tumors. At least 16 different formulas for estimating SLV have been published in the worldwide literature. More recently, several proprietary software-assisted image postprocessing (SAIP) programs have been developed to provide accurate volume measurements based on the actual anatomy of a specific patient. Using SAIP, we measured SLV in 375 healthy potential liver donors and compared the results to SLV values that were estimated with the previously published formulas and each donor's demographic and anthropomorphic data. The percentage errors of the 16 SLV formulas versus SAIP varied by more than 59% (from -21.6% to +37.7%). One formula was not statistically different from SAIP with respect to the percentage error (-1.2%), and another formula was not statistically different with respect to the absolute liver volume (18 mL). More than 75% of the estimated SLV values produced by these 2 formulas had percentage errors within ±15%, and the formulas provided good predictions within acceptable agreement (±15%) on scatter plots. Because of the wide variability, care must be taken when a formula is being chosen for estimating SLV, but the 2 aforementioned formulas provided the most accurate results with our patient demographics.

Accurate estimation of living donor right hemi-liver volume from portal vein diameter measurement and standard liver volume calculation

Lee et al. recently published a method for estimating right hemi-liver volume (RHLV) by using bedside ultrasound measurement of right (R) and left (L) portal vein (PV) diameters and Urata's standard liver volume (SLV) formula where RHLV = SLV×[R(2) /(R(2) +L(2) )]. We calculated RHLV by substituting SLV from 15 different published formulas in the worldwide literature. We also modified Lee's method using right anterior (RA) and posterior (RP) where RHLV = SLV×[(RA(2) +RP(2) )/(RA(2) +RP(2) +L(2) )] for donors with unusual PV branching. We compared the calculated RHLV with RHLV estimated with software-assisted CT (SACT) volumetry and actual graft weight after right-lobe donation in 200 right-lobe donors. This study confirmed that accurate estimates of RHLV can be achieved by SACT volumetry or by the simple method of Lee but using the SLV of only 3 of the 15 published formulas (Lin or Vauthey using body weight or body surface area) rather than Urata's. Our modification of the Lee's formula using RA and RP, PV diameters was also accurate and not different from Lee's formula. These simplified formulas may be used for donor screening for graft size adequacy before expensive evaluation proceeds.