Standardized Future Liver Remnant Research Articles

Safety and Efficacy of Portal Vein Embolization Before Planned Major or Extended Hepatectomy: An Institutional Experience of 358 Patients

IntroductionPortal vein embolization (PVE) stimulates hypertrophy of the future liver remnant (FLR) and may improve the safety of extended hepatectomy. The efficacy of PVE was evaluated. MethodsRecords of 358 consecutive patients who underwent PVE before intended major hepatectomy at our institution from 1995 through 2012 were retrospectively reviewed. ResultsOne hundred twelve patients (31.3 %) had right PVE alone; 235 (65.6 %) had right PVE plus segment IV embolization. The first-session PVE completion rate was 97.8 %. The PVE complication rate was 3.9 %. The median pre-PVE and post-PVE standardized FLRs were 19.5 % (interquartile range, 15.0–25.9) and 29.7 % (interquartile range, 22.5–38.2), respectively. Two hundred forty patients (67.0 %) underwent potentially curative resection. Sixty-two patients (25.8 %) had major post-hepatectomy complications; rates of postoperative hepatic insufficiency and 90-day liver-related mortality were 8.3 and 3.8 %, respectively. The proportion of patients with colorectal liver metastasis increased from 38.6 % before 2005 to 78.2 % in 2010–2012. Despite increased use of preoperative chemotherapy, postoperative hepatic insufficiency and 90-day liver-related mortality rates dropped from 10.6 and 4.1 %, respectively, before 2010 to 2.9 and 2.9 %, respectively, in 2010–2012. ConclusionsPVE can be safely performed with minimal morbidity. Most patients can proceed to extended hepatectomy, which is associated with a minimal mortality rate.

Salvage parenchymal liver transection for patients with insufficient volume increase after portal vein occlusion – An extension of the ALPPS approach

Portal vein ligation (PVL) or embolization (PVE) are standard approaches to induce liver hypertrophy of the future liver remnant (FLR) prior to hepatectomy in primarily non-resectable liver tumors. However, this approach fails in about one third of patients. Recently, the new "ALPPS" approach has been described that combines PVL with parenchymal transection to induce rapid liver hypertrophy. This series explores whether isolated parenchymal transection boosts liver hypertrophy in scenarios of failed PVL/PVE. A multicenter database with 170 patients undergoing portal vein manipulation to increase the size of the FLR was screened for patients undergoing isolated parenchymal transection as a salvage procedure. Three patients who underwent PVL/PVE with subsequent insufficient volume gain and subsequently underwent parenchymal liver transection as a salvage procedure were identified. Patient characteristics, volume increase, postoperative complications and outcomes were analyzed. The first patient underwent liver transection 16 weeks after failed PVL with a standardized FLR (sFLR) of 30%, which increased to 47% in 7 days. The second patient showed a sFLR of 25% 28 weeks after PVL and subsequent PVE of segment IV, which increased to 41% in 7 days after transection. The third patient underwent liver partition 8 weeks after PVE with a sFLR of 19%, which increased to 37% in six days. All patients underwent a R0 resection. Failed PVE or PVL appears to represent a good indication for the isolated parenchymal liver transection according to the newly developed ALPPS approach.

Optimal Future Liver Remnant in Patients Treated with Extensive Preoperative Chemotherapy for Colorectal Liver Metastases

Patients with colorectal liver metastases (CLM) are increasingly treated with preoperative chemotherapy. Chemotherapy associated liver injury is associated with postoperative hepatic insufficiency (PHI) and mortality. The adequate minimum future liver remnant (FLR) volume in patients treated with extensive chemotherapy remains unknown. All patients with standardized FLR>20%, who underwent extended right hepatectomy for CLM from 1993-2011, were divided into three cohorts by chemotherapy duration: no chemotherapy (NC, n=30), short duration (SD, ≤12weeks, n=78), long duration (LD, >12weeks, n=86). PHI and mortality were compared by using uni-/multivariate analyses. Optimal FLR for LD chemotherapy was determined using a minimum p-value approach. A total of 194 patients met inclusion criteria. LD chemotherapy was significantly associated with PHI (NC+SD 3.7 vs. LD 16.3%, p=0.006). Ninety-day mortality rates were 0% in NC, 1.3% in SD, and 2.3% in LD patients, respectively (p=0.95). In patients with FLR>30%, PHI occurred in only two patients (both LD, 2/20, 10%), but all patients with FLR>30% survived. The best cutoff of FLR for preventing PHI after chemotherapy >12weeks was estimated as >30%. Both LD chemotherapy (odds ratio [OR] 5.4, p=0.004) and FLR≤30% (OR 6.3, p=0.019) were independent predictors of PHI. Preoperative chemotherapy >12weeks increases the risk of PHI after extended right hepatectomy. In patients treated with long-duration chemotherapy, FLR>30% reduces the rate of PHI and may provide enough functional reserve for clinical rescue if PHI develops.

What Is a Safe Future Liver Remnant Size in Patients Undergoing Major Hepatectomy for Colorectal Liver Metastases and Treated by Intensive Preoperative Chemotherapy?

A multidisciplinary approach involving preoperative chemotherapy has become common practice in patients with colorectal liver metastases (CLM). The definition of a safe future liver remnant (FLR) volume based on preoperative clinical data in these patients is lacking. Our aim was to identify predictors of postoperative morbidities in patients undergoing major hepatectomy after intensive preoperative chemotherapy for CLM. Between January 2000 and August 2010, a total of 101 consecutive patients with CLM underwent major hepatectomy after preoperative chemotherapy (≥6 cycles of oxaliplatin or irinotecan regimen with or without targeted therapies). The FLR ratio was calculated by two formulas: actual FLR (aFLR) ratio, and standardized FLR (sFLR) ratio. Predictors of postoperative overall morbidity, sepsis, and liver failure were identified by univariate and multivariate analyses. Fifty-eight patients (57.4%) had 95 postoperative complications. Sepsis and postoperative liver failure occurred in 23 (22.8%) and 16 patients (15.8%), respectively. On univariate analysis, small aFLR ratio was significantly associated with all complications, and sFLR ratio was associated with sepsis and liver failure. In receiver-operating characteristic analysis, the cutoff of aFLR ratio in predicting overall morbidity, sepsis, and liver failure was 44.8, 43.1, and 37.7%, respectively, and that of sFLR ratio in predicting sepsis and liver failure was 43.6 and 48.5%, respectively. On multivariate analysis, these aFLR and sFLR ratio cutoffs were independent predictors of all complications and of sepsis and liver failure, respectively. This study provides a cutoff FLR ratio for safe postoperative outcome after major hepatectomy in CLM patients receiving six or more cycles of preoperative chemotherapy.

Portal vein embolization: rationale, outcomes, controversies and future directions

Portal vein embolization (PVE) is now considered the standard of care to improve safety for patients undergoing extensive hepatectomy with an anticipated small future liver remnant (FLR). PVE is used to induce contralateral liver hypertrophy in preparation for major liver resection. Optimal patient selection is essential to maximize the clinical benefits of PVE. Computed tomography volumetry is used to calculate a standardized FLR and determine the need for preoperative PVE. Percutaneous PVE can be performed via the transhepatic ipsilateral or contralateral approaches, depending on operator preference. Several different embolic agents are available to the interventional radiologist, all with similar effectiveness in inducing hypertrophy. When an extended hepatectomy is planned, right PVE should include segment 4, in order to maximize FLR hypertrophy. Multiple studies have demonstrated the beneficial outcomes of PVE in both patients with healthy livers and with underlying liver diseases. Novel improvements to PVE should expand its scope to patients who were previously not candidates for the procedure.