Kinetic Growth Rate after Portal Vein Embolization Predicts Posthepatectomy Outcomes: Toward Zero Liver-Related Mortality in Patients with Colorectal Liver Metastases and Small Future Liver Remnant

Abstract

Background Standardized future liver remnant (sFLR) volume and degree of hypertrophy after portal vein embolization (PVE) have been recognized as significant predictors of surgical outcomes after major liver resection. However, regeneration rate of the FLR after PVE varies among individuals and its clinical significance is unknown. Study Design Degree of hypertrophy at initial volume assessment divided by number of weeks elapsed after PVE was defined as the kinetic growth rate (KGR). In 107 consecutive patients who underwent liver resection for colorectal liver metastases with a sFLR volume of greater than 20%, the ability of the KGR to predict overall and liver-specific postoperative morbidity and mortality was compared with sFLR volume and degree of hypertrophy. Results Using receiver operating characteristic analysis, the best cut-off values for sFLR volume, degree of hypertrophy, and KGR for predicting postoperative hepatic insufficiency were estimated as, respectively, 29.6%, 7.5%, and 2.0% per week. Among these, KGR was the most accurate predictor (area under the curve, 0.830 [0.736-0.923]; asymptotic significance, 0.002). KGR of less than 2% per week vs. ≥2% per week correlate with rates of hepatic insufficiency (21.6% vs. 0%, p = 0.0001) and liver-related 90-day mortality (8.1% vs. 0%, P=0.04). The predictive value of KGR was not influenced by sFLR volume or the timing of initial volume assessment when evaluated within 8 weeks after PVE. Conclusions KGR is a better predictor of postoperative morbidity and mortality after liver resection for small FLR than conventional measured volume parameters (sFLR volume and degree of hypertrophy).

Identification of cofactors influencing hypertrophy of the future liver remnant after portal vein embolization—the effect of collaterals on embolized liver volume

“…It has been hypothesized that the rate and overall ability for hypertrophy in response to PVE is an indicator of FLR function that is associated with the avoidance of post-operative liver insufficiency. 6,28 Recent data support this hypothesis with the use of non-parametric regression and showed that post embolization, no patient with a growth rate .2.66% per week developed liver failure. 29 In patients with chronic liver disease, some investigators have adopted algorithms incorporating functional tests, such as the indocyanine green retention rate, which has been proposed as an adjunct to the volumetric measurements.…”

“…3 However, an extended right hepatectomy (ERH) leaves a residual liver volume of ,20% of the total liver volume (TLV) in .75% of all cases; 4,5 this poses a risk in itself, as patients with a small future liver remnant (FLR) volume are likely to experience post-operative liver insufficiency. Therefore, as resection safety is dependent on the volume and function of the FLR, 6 appropriate pre-operative procedures are warranted to enlarge the (left) FLR.…”

“…If collaterals are detected in these early controls paired with a slow increase in FLR, e.g. measured by the kinetic growth rate, 6 additional measures to improve hypertrophy should be discussed. Therefore, the finding of collaterals and low hypertrophy may in future lead to decisions such as: if a control CT of sufficient quality does not demonstrate collaterals, the effect of added ALLPS may be small.…”

Portal Vein Embolization: Tailoring, Optimizing, and Quantifying an Invaluable Procedure in Hepatic Surgery

“…Shindoh et al reported that a kinetic growth rate C2% per week was associated with no liver failure-related deaths in a series of 103 patients with colorectal liver metastases. 11 The kinetic growth rate has become an invaluable functional tool to assess the FLR. A kinetic growth rate C2% per week predicts a favorable outcome even in patients sustaining complications, and appears to protect patients with infectious complications from progressing from hepatic dysfunction to liver failure.…”

Postoperative Complications and Oncologic Outcomes after Resection of Colorectal Liver Metastases: The Importance of Staying on Track

“…During a median 4-5 weeks between PVE and hepatectomy, surgeons study both the degree of hypertrophy (DH, needs to be [5 %) and the kinetic growth rate (DH divided by time in weeks), a promising tool that may help us reach the goals of minimal hepatic insufficiency and 0 % liver-related mortality. 12 Patients with a kinetic growth rate of \2 % may be spared a complex hepatectomy that would have left an insufficient FLR for safe recovery. It also is important to point out that not all PVEs are equal.…”