Parameters Associated with Changes in Liver Volume in Patients Undergoing Portal Vein Embolization

Artificial Intelligence-Driven Patient Selection for Preoperative Portal Vein Embolization for Patients with Colorectal Cancer Liver Metastases

PURPOSE

To develop a machine learning algorithm to improve hepatic resection selection for patients with metastatic colorectal cancer (CRC) by predicting post-portal vein embolization (PVE) outcomes.

MATERIALS AND METHODS

This multicenter retrospective study (2000-2020) included 200 consecutive patients with CRC liver metastases planned for PVE before surgery. Data on radiomic features and laboratory values were collected. Patient-specific eigenvalues for each liver shape were calculated using a statistical shape model approach. After semiautomatic segmentation and review by a board-certified radiologist, the data were split 70%/30% for training and testing. Three machine learning algorithms predicting the total liver volume (TLV) after PVE, sufficient future liver remnant (FLR%), and kinetic growth rate (KGR%) were trained, with performance assessed using accuracy, sensitivity, specificity, area under the curve (AUC), or root mean squared error. Significance between the internal and external test sets was assessed by the Student t-test. One institution was kept separate as an external testing set.

RESULTS

A total of 114 (76 men; mean age, 56 years [SD± 12]) and 37 (19 men; mean age, 50 years ± [SD± 11]) patients met the inclusion criteria for the internal validation and external validation, respectively. Prediction accuracy and AUC for sufficient FLR% or liver growth potential (KGR%> 0%) were high in the internal testing set-85.81% (SD ± 1.01) and 0.91 (SD ± 0.01) or 87.44% (SD ± 0.10) and 0.66 (SD ± 0.03), respectively. Similar results occurred in the external testing set-79.66% (SD ± 0.60) and 0.88 (SD ± 0.00) or 72.06% (SD ± 0.30) and 0.69 (SD ± 0.01), respectively. TLV prediction showed discrepancy rates of 12.56% (SD ±4.20%; P = .86) internally and 13.57% (SD ± 3.76%; P = .91) externally.

CONCLUSIONS

Machine learning-based models incorporating radiomics and laboratory test results may help predict the FLR%, KGR%, and TLV as metrics for successful PVE.

Assessment of Segmentary Hypertrophy of Future Remnant Liver after Liver Venous Deprivation: A Single-Center Study

Background: Liver venous deprivation (LVD) is a recent radiological technique that has shown promising results on Future Remnant Liver (FRL) hypertrophy. The aim of this retrospective study is to compare the segmentary hypertrophy of the FRL after LVD and after portal vein embolization (PVE). Methods: Patients undergoing PVE or LVD between April 2015 and April 2020 were included. The segmentary volumes (seg 4, seg2+3 and seg1) were assessed before and after the radiological procedure. Results: Forty-four patients were included: 26 undergoing PVE, 10 LVD and 8 eLVD. Volume gain of both segment 1 and segments 2+3 was significantly higher after LVD and eLVD than after PVE (segment 1: 27.33 ± 35.37 after PVE vs. 38.73% ± 13.47 after LVD and 79.13% ± 41.23 after eLVD, p = 0.0080; segments 2+3: 40.73% ± 40.53 after PVE vs. 45.02% ± 21.53 after LVD and 85.49% ± 45.51 after eLVD, p = 0.0137), while this was not true for segment 4. FRL hypertrophy was confirmed to be higher after LVD and eLVD than after PVE (33.53% ± 21.22 vs. 68.63% ± 42.03 vs. 28.11% ± 28.33, respectively, p = 0.0280). Conclusions: LVD and eLVD may induce greater hypertrophy of segment 1 and segments 2+3 when compared to PVE.

The Guidelines for Percutaneous Transhepatic Portal Vein Embolization: English Version

Preoperative portal vein embolization is a beneficial option to reduce the risk of postoperative liver failure by promoting the growth of the future liver remnant. In particular, a percutaneous transhepatic procedure (percutaneous transhepatic portal vein embolization) has been developed as a less-invasive approach. Although percutaneous transhepatic portal vein embolization is widely recognized as a safe procedure, various complications, including rare but fatal adverse events, have been reported. Currently, there are no prospective clinical trials regarding percutaneous transhepatic portal vein embolization procedures and no standard guidelines for the PTPE procedure in Japan. As a result, various methods and various embolic materials are used in each hospital according to each physician's policy. The purpose of these guidelines is to propose appropriate techniques at present and to identify issues that should be addressed in the future for safer and more reliable percutaneous transhepatic portal vein embolization techniques.

Relationship of Immunonutritional factor with Changes in Liver Volume after Portal Vein Embolization

Background

To identify predictors of changes in hepatic volumes after portal vein embolization, we examined the relationship with preoperative nutritional and immunological parameters.

Patients and Methods

Ninety-three patients who underwent portal vein embolization were included. The control group comprised 13 patients who underwent right hepatectomy without portal vein embolization. Computed tomographic volumetric parameter was measured for changes in embolized and nonembolized liver. Correlation with various candidates of immunonutritional parameters was examined.

Results

Difference in increased liver ratio was 9.1%. C-reactive protein levels significantly increased after portal vein embolization (P < .01), whereas albumin and total cholesterol levels significantly decreased, respectively (P < .01). The C-reactive protein/albumin ratio, prognostic nutritional index, Controlling Nutritional Status score, and modified Glasgow Prognostic Score were significantly different, respectively (P < .01). Prothrombin activity and total cholesterol level significantly correlated with the increased change in nonembolized liver (P < .05). The C-reactive protein and C-reactive protein/albumin ratio after portal vein embolization negatively correlated with hypertrophic ratio (P < .05). By comparing posthepatectomy outcomes between 64 patients undergoing portal vein embolization and 13 who did not, the prevalence of severe complications and mortality in the portal vein embolization group was not different from that in the non–portal vein embolization group. Liver activity at 15 minutes > 0.92 and increased liver volume ≥ 10% tended to correlate with lower prevalence of severe complications. Only increased intraoperative blood loss ≥ 1,500 mL was significantly associated with morbidity and mortality (P < .05).

Conclusion

Contrary to our hypothesis, immunonutritional parameters, except C-reactive protein and C-reactive protein/albumin ratio, did not reflect hypertrophy after portal vein embolization. Although it is difficult to predict the hypertrophic degree, the strategy of scheduled hepatectomy should be switched in case of impaired inflammatory status after portal vein embolization.

Safety and outcomes of pre-operative portal vein embolization using N-butyl cyanoacrylate (Glue) in hepatobiliary malignancies: A single center retrospective analysis

Aims and Objectives:

To evaluate the outcome of preoperative portal vein embolization (PVE) using N-butyl cyanoacrylate (NBCA) for change in future liver remnant (FLR) volume, biochemical changes, and procedure-related complications. The factors affecting FLR hypertrophy and the rate of resection was also evaluated for this cohort.

Materials and Methods:

From 2012 to 2017, PVE utilizing NBCA mixed with lipiodol (1:4) was performed using percutaneous approach in 28 patients with hepatobiliary malignancies with low FLR. All patients underwent volumetric computed tomography (CT) assessment before and at 3–5 weeks after PVE and total liver volume (TLV), FLR volume, and FLR/TLV ratio, changes in portal vein diameter and factors affecting FLR were evaluated. Complications and the resectability rate were recorded and analyzed.

Result:

PVE was successful in all 28 patients. The mean FLR increased by 52% ± 32% after PVE (P < 0.0001). The FLR/TLV ratio was increased by 14.2% ± 2.8% (P < 0.001). Two major complications were encountered without any impact on surgery. There was no significant change seen in liver function test and complete blood counts after PVE. Eighteen patients (64.28%) underwent hepatic resection without any liver failure, and only three patients developed major complication after surgery. Remaining ten patients did not undergo surgery because of extrahepatic metastasis detected either on follow-up imaging or staging laparotomy. Patients with diabetes showed a lower rate of hypertrophy (P < 0.05).

Conclusion:

Preoperative PVE with NBCA is safe and effective for increasing FLR volume in patients of all age group and even in patients with an underlying liver parenchymal disease with hepatobiliary malignancy. Lesser hypertrophy was noted in patients with diabetes. A reasonable resectability was achieved despite having a high rejection in gall bladder cancer subgroup due to rapid disease progression.

Evaluation of liver regeneration and post-hepatectomy liver failure after hemihepatectomy in patients with hepatocellular carcinoma

Aim: To explore clinical factors associated with extent of liver regeneration after hemihepatectomy to treat hepatocellular carcinoma (HCC).Methods: Future liver remnant volume (as a percentage of functional liver volume, %FLRV) and remnant liver volume were measured preoperatively and at 1, 5, 9, and 13 weeks postoperatively.Results: After hepatectomy, 1 of 125 patients (0.8%) died within 3 months, 13 (10.4%) experienced liver failure, and 99 (79.2%) experienced complications. %FLRV was able to predict liver failure with an area under the receiver operating characteristic curve of 0.900, and a cut-off value of 42.7% showed sensitivity of 85.7% and specificity of 88.6%. Postoperative median growth ratio was 21.3% at 1 week, 30.9% at 5 weeks, 34.6% at 9 weeks, and 37.1% at 13 weeks. Multivariate analysis identified three predictors associated with liver regeneration: FLRV < 601 cm3, %FLRV, and liver cirrhosis. At postoperative weeks (POWs) 1 and 5, liver function indicators were significantly better among patients showing high extent of regeneration than among those showing low extent, but these differences disappeared by POW 9.Conclusions: FLRV, %FLRV, and liver cirrhosis strongly influence extent of liver regeneration after hepatectomy. %FLRV values below 42.7% are associated with greater risk of post-hepatectomy liver failure.

Future Liver Remnant (FLR) Increase in Patients with Colorectal Liver Metastases Is Highest the First Week After Portal Vein Occlusion : FLR Increase in Patients with CRLM Is Highest the First Week After PVO

BACKGROUND

Portal vein occlusion (PVO) is an established method to increase the volume of the future liver remnant (FLR). The main reasons for not proceeding to radical hepatectomy are lack of volume increase and tumor progression due to a wait-time interval of up to 8 weeks. The hypothesis was that the increase in FLR volume is not linear and is largest during the first weeks.

METHODS

Patients with colorectal liver metastases (CRLM) and standardized future liver remnant (sFLR) < 30% treated with PVO were prospectively included. All patients had at least one CT evaluation before radical hepatectomy.

RESULTS

Forty-eight patients were included. During the first week after PVO, the kinetic growth rate (KGR) was 5.4 (± 4), compared to 1.5 (± 2) between the first and second CT (p < 0.05). For patients reaching adequate FLR and therefore treated with radical hepatectomy, the KGR was 7 (± 4) the first week, compared to 4.3 (± 2) for patients who failed to reach a sufficient volume (p = 0.4). During the interval between the first and second CT, the KGR was 2.2 (± 2), respectively (± 0.1) (p = 0.017).

DISCUSSION

The increase in liver volume after PVO is largest during the first week. As KGR decreases over time, it is important to shorten the interval between PVO and the first volume evaluation; this may aid in decision-making and reduce unnecessary waiting time.

Safe Resection of Renal Cell Carcinoma with Liver Invasion Using Liver Hanging Technique Supported by Preoperative Portal Vein Embolization

In cases of RCC with liver involvement, partial hepatectomy is known to provide a better chance of survival for patients. For this reason, complete resection with clear surgical margin is thought to be necessary to achieve favorable outcome. Anterior liver hanging maneuver was extremely useful during hemihepatectomy in this rare type of RCC. A 63-year-old male was diagnosed with a large right renal cell carcinoma. The tumor measured 10 cm in diameter with tumor thrombus toward the inferior vena cava (IVC). In addition, we observed direct infiltration to the liver. We attempted a preoperative portal vein embolization (PVE) to preserve residual liver volume and function after right lobectomy. After PVE the resected volume decreased from 921 cm³ (71%) to 599 cm³ (53.4%). During the procedure, a nasogastric tube was placed in the retrohepatic space for liver hanging maneuver according to the original Belghiti's maneuver after dissection of the renal artery and vein. After hepatic parenchymal transection exposing vena cava, the right hepatic veins were safely transected using vascular stapler; right nephrectomy and hemihepatectomy were performed. The patient recovered without postoperative hepatic or urinary complications and has remained free of local recurrence and any de novo metastasis for 18 months.

Portal vein ligation versus portal vein embolization for induction of hypertrophy of the future liver remnant: A systematic review and meta-analysis

An important risk of major hepatic resection is postoperative liver failure, which is directly related to insufficient future liver remnant (FLR). Portal vein embolization (PVE) and portal vein ligation (PVL) can minimize this risk by inducing hypertrophy of the FLR. The aim of this systematic review and meta-analysis was to compare the efficacy and safety of PVE and PVL for FLR hypertrophy. A systematic search was conducted on the17^th of January 2017. The methodological quality of the studies was assessed using the Oxford Critical Appraisal Skills Program for cohort studies. The primary endpoint was the relative rate of hypertrophy of the FLR. Number of cancelled hepatic resection and postoperative morbidity and mortality were secondary endpoints. For meta-analysis, the pooled hypertrophy rate was calculated for each intervention. The literature search identified 21 eligible studies with 1953 PVE and 123 PVL patients. All studies were included in the meta-analysis. No significant differences were found regarding the rate of FLR hypertrophy (PVE 43.2%, PVL 38.5%, p = 0.39). The number of cancelled hepatic resections due to inadequate hypertrophy was significantly lower after PVL (p = 0.002). No differences were found in post-intervention mortality and morbidity. This meta-analysis demonstrated no significant differences in safety and rate of FLR hypertrophy between PVE and PVL. PVE should be considered as the preferred strategy, since it is a minimally invasive procedure. However, during a two-stage procedure, PVL can be performed with expected comparable outcome as PVE.

Remnant growth rate after portal vein embolization is a good early predictor of post-hepatectomy liver failure

BACKGROUND

After portal vein embolization (PVE), the future liver remnant (FLR) hypertrophies for several weeks. An early marker that predicts a low risk of post-hepatectomy liver failure can reduce the delay to surgery.

STUDY DESIGN

Liver volumes of 153 patients who underwent a major hepatectomy (>3 segments) after PVE for primary or secondary liver malignancy between September 1999 and November 2012 were retrospectively evaluated with computerized volumetry. Pre- and post-PVE FLR volume and functional liver volume were measured. Degree of hypertrophy (DH = post-FLR/post-functional liver volume - pre-FLR/pre-functional liver volume) and growth rate (GR = DH/weeks since PVE) were calculated. Postoperative complications and liver failure were correlated with DH, measured GR, and estimated GR derived from a formula based on body surface area.

RESULTS

Eligible patients underwent 93 right hepatectomies, 51 extended right hepatectomies, 4 left hepatectomies, and 5 extended left hepatectomies. Major complications occurred in 44 patients (28.7%) and liver failure in 6 patients (3.9%). Nonparametric regression showed that post-embolization FLR percent correlated poorly with liver failure. Receiver operating characteristic curves showed that DH and GR were good predictors of liver failure (area under the curve [AUC] = 0.80; p = 0.011 and AUC = 0.79; p = 0.015) and modest predictors of major complications (AUC = 0.66; p = 0.002 and AUC = 0.61; p = 0.032). No patient with GR >2.66% per week had liver failure develop. The predictive value of measured GR was superior to estimated GR for liver failure (AUC = 0.79 vs 0.58; p = 0.046).

CONCLUSIONS

Both DH and GR after PVE are strong predictors of post-hepatectomy liver failure. Growth rate might be a better guide for the optimum timing of liver resection than static volumetric measurements. Measured volumetrics correlated with outcomes better than estimated volumetrics.

Left-liver hypertrophy after therapeutic right-liver radioembolization is substantial but less than after portal vein embolization

In patients with liver malignancies potentially amenable to curative extended right hepatectomy but insufficient size of the future liver remnant (FLR), portal vein embolization (PVE) of the tumor-bearing liver is used to induce contralateral liver hypertrophy but leaves the tumor untreated. Radioembolization (RE) treats the tumor in the embolized lobe along with contralateral hypertrophy induction. We performed a matched-pair analysis to compare the capacity for hypertrophy induction of these two modalities. Patients with right-hepatic secondary liver malignancies with no or negligible left-hepatic tumor involvement who were treated by right-lobar PVE (n = 141) or RE (n = 35) at two centers were matched for criteria known to influence liver regeneration following PVE: 1) baseline FLR/Total liver volume ratio (<25 versus ≥ 25%); 2) prior platinum-containing systemic chemotherapy; 3) embolization of segments 5-8 versus 4-8; and 4) baseline platelet count (<200 versus ≥ 200 Gpt/L).The primary endpoint was relative change in FLR volume from baseline to follow-up. Twenty-six matched pairs were identified. FLR volume increase from baseline to follow-up (median 33 [24-56] days after PVE or 46 [27-79] days after RE) was significant in both groups but PVE produced significantly more FLR hypertrophy than RE (61.5 versus 29%, P < 0.001). Time between treatment and follow-up was not correlated with the degree of contralateral hypertrophy achieved in both groups. Although group differences in patient history and treatment setting were present and some bias cannot be excluded, this was minimized by the matched-pair design, as remaining group differences after matching were found to have no significant influence on contralateral hypertrophy development.

CONCLUSION

PVE induces significantly more contralateral hypertrophy than RE with therapeutic (nonlobectomy) doses. However, contralateral hypertrophy induced by RE is substantial and RE minimizes the risk of tumor progression in the treated lobe, possibly making it a suitable modality for selected patients.

Percentage of future liver remnant volume before portal vein embolization influences the degree of liver regeneration after hepatectomy

BACKGROUND

Clinical determinants of liver regeneration induced by portal vein embolization (PVE) and hepatectomy remain unclear. The aims of this study were to investigate how liver regeneration occurs after PVE followed by hepatectomy and to determine which factors strongly promote liver regeneration.

METHODS

Thirty-six patients who underwent both preoperative PVE and major hepatectomy were enrolled in this study. Percentage of future liver remnant volume before PVE (%FLR-pre) was compared with the remnant liver volume after PVE (%FLR-post-PVE) and on postoperative day 7 after hepatic resection (%FLR-post-HR). Clinical indicators contributing to liver regeneration induced by both PVE and hepatectomy were examined by logistic regression analysis.

RESULTS

PVE and hepatectomy caused a two-step regeneration. FLR-pre, FLR-post-PVE, and FLR-post-HR were 448, 579, and 761 cm(3), respectively. The %FLR-pre was significantly associated with liver regeneration induced by both PVE and hepatectomy (r = 0.63, p < 0.0001). Multiple regression analysis showed that only %FLR-pre was independently correlated with posthepatectomy liver regeneration (p = 0.027, odds ratio = 13.8).

CONCLUSION

After PVE and the subsequent hepatectomy, liver regeneration was accomplished in a two-step manner. Liver regeneration was strongly influenced by the %FLR-pre.

Prediction of indocyanine green retention rate at 15 minutes by correlated liver function parameters before hepatectomy

BACKGROUND

Indocyanine green retention rate at 15 min (ICGR15) is a useful marker of liver function in deciding on the extent of hepatectomy. To determine ICGR15 regardless of liver condition, we sought to establish a formula for converted ICGR15 based on conventional blood tests and technetium-99 m galactosyl human serum albumin ((99m)Tc-GSA) scintigraphy.

MATERIALS AND METHODS

We measured liver function parameters, including ICGR15, in 307 patients, including 265 liver cancer patients without biliary obstruction (no obstruction group) and 42 with biliary obstruction (obstruction group).

RESULTS

In the no obstruction group, multiple regression analysis identified blood pool clearance ratio (HH15), liver uptake ratio (LHL15) calculated by heart and liver activity between 3 and 15 min after injection of (99m)Tc-GSA, and serum hyaluronic acid as significant correlates (P < 0.05). The calculated converted ICGR15 was then equal to 0.02∗HA + 0.276∗(HH15∗100)-0.501∗(LHL15∗100) + 41.41. The mean difference between actual and converted ICGR15 was significantly lower in the obstruction than in the no obstruction group (P = 0.031). A significantly larger proportion of patients of the obstruction group had lower converted ICGR15 than those of the no obstruction group (P = 0.045).

CONCLUSION

The converted ICGR15 is useful for evaluating hepatic function in patients with biliary obstruction who plan to undergo major hepatectomy.

Relationship of hepatic functional parameters with changes of functional liver volume using technetium-99m galactosyl serum albumin scintigraphy in patients undergoing preoperative portal vein embolization: a follow-up report

BACKGROUND

To identify predictors of changes in functional hepatic volumes after portal vein embolization (PVE) before hepatectomy, we examined the relationship between hepatic functional parameters and changes in functional volume of the embolized and non-embolized liver based on a previous volumetric analysis.

MATERIAL AND METHODS

Subjects were 24 patients who underwent PVE, which was performed through the trans-ileocolic vein (n = 4) or by percutaneous transhepatic puncture (n = 20). The RI liver volume parameter was measured by liver scintigraphy with technetium-(99m) galactosyl human serum albumin ((99m)Tc-GSA). Computed tomography (CT) volume parameter was also measured.

RESULTS

Significant atrophy of the embolized liver and hypertrophy of the non-embolized liver (change of 72 ± 108 cm(3) and 111 ± 91 cm(3), respectively) (change of 7.8%) was observed after PVE. The change in these RI volume parameters (change of 173 ± 175 cm(3) and 145 ± 137 cm(3) , respectively) (16.5%) was significantly greater than CT volume parameters (P < 0.01). CT vol and RI vol in the embolized and non-embolized liver were well correlated (r = 0.75 and 0.69, respectively). However, the correlation between CT and RI volume parameters in the embolized and non-embolized liver after PVE was very weak (r = 0.17 and 0.03, respectively). Only alkaline phosphatase level correlated negatively with atrophic CT volume parameter of the embolized liver (r = -0.455, P < 0.05). When compared with CT volume parameter, more parameters were significantly correlated with changes of RI volume parameter in the embolized liver: pre-PVE pressure; ICGR15; and serum levels of hyaluronate, total bilirubin, albumin, and alkaline phosphatase. Only platelet count was significantly correlated with hypertrophy of the non-embolized liver.

CONCLUSION

RI volume parameter might more accurately reflect functional changes in the embolized liver and non-embolized liver than CT volume parameter. Correlated parameters might allow us to predict the functional effect of PVE.

Predictive factors for hypertrophy of the future remnant liver after selective portal vein embolization

BACKGROUND

To analyze predictive factors of hypertrophy of the nonembolized future remnant liver (FRL) after transhepatic preoperative portal vein embolization (PVE) of the liver to be resected.

MATERIALS AND METHODS

Age, gender, indocyanin green clearance test, chemotherapy before PVE, type of chemotherapy, operators, extent of PVE, radiofrequency ablation (RFA) associated with PVE, time delay between PVE and surgery, and platelet count were retrospectively evaluated as predictive factors for hypertrophy of FRL in 107 patients with malignant disease in noncirrhotic liver. PVE targeted the right liver lobe [n = 70] or the right liver lobe and segment IV [n = 37] when FRL/total liver volume ratio was below 25% in healthy liver or 40% in altered liver.

RESULTS

After PVE, FRL volume significantly increased by 69%, from 344 +/- 156 cm(3) to 543 +/- 192 cm(3) (P < .0001). The degree of hypertrophy was negatively correlated with FRL volume (correlation coefficient = -0.55, P < .0001) and FRL/TFL ratio (correlation coefficient = -0.52, P < .0001) before PVE. Patients, who have undergone chemotherapy with platin agents prior to PVE, demonstrated lower hypertrophy (P = .048).

CONCLUSION

Hypertrophy after PVE is inversely correlated to initial FRL volume. Hypertrophy of the liver might be influenced by the systemic chemotherapeutic received before PVE.

Increase in the serum bile acid level predicts the effective hypertrophy of the nonembolized hepatic lobe after right portal vein embolization

BACKGROUND

The purpose of the present study was to investigate the clinical association between serum bile acid level changes and liver hypertrophy in portal vein embolization (PVE).

METHODS

In 31 patients, the serum total bile acid level was prospectively measured before and 1, 3, 5, 7, and 14 days after right PVE. Computed tomographic volumetry was performed before and 25.0 +/- 3.6 days after PVE.

RESULTS

Portal vein embolization induced the liver hypertrophy with a median increase in the left lobe volume (ILV) of 165 cm(3) and a median percentage ILV (%ILV) of 29%. Compared with the pretreatment level, the serum bile acid levels significantly increased on day 3 and day 14 after PVE (p = 0.017 and p = 0.003, respectively). In patients with greater hypertrophy after PVE (ILV > 165 cm(3) and %ILV > 30%), the increases in the bile acid level on day 3 were larger than that in those with lesser hypertrophy (p = 0.008 and p = 0.002, respectively). The increase on day 3 positively correlated with the ILV and %ILV (p = 0.003 and p = 0.004, respectively). The serum bile acid levels on day 3, 5, and 7 after PVE increased in patients with %ILV > 30% but not in those with %ILV < or = 30%.

CONCLUSIONS

Portal vein embolization increases the serum bile acid level in patients with effective liver hypertrophy in the nonembolized lobe. The increase on day 3 is a useful predictor of effective hypertrophy of the nonembolized lobe. Thus, bile acid signaling may be important for liver regeneration post-PVE.

Usefulness of measuring hepatic functional volume using Technetium-99m galactosyl serum albumin scintigraphy in bile duct carcinoma: report of two cases

We report the usefulness of measuring functional liver volume in two patients undergoing hepatectomy. Case 1 involved a 47-year-old man with hepatitis B virus infection. The indocyanine green test retention rate at 15 min (ICGR15) was 14%. Liver uptake ratio (LHL15) by technetium-99 m galactosyl human serum albumin ((99m)Tc-GSA) liver scintigraphy was 0.91. The patient displayed hilar bile duct carcinoma necessitating right hepatectomy. After preoperative portal vein embolization (PVE), future remnant liver volume became 54% and functional volume by (99m)Tc-GSA became 79%. Although the permitted resected liver volume was lower than the liver volume, scheduled hepatectomy was performed following the results of functional liver volume. Case 2 involved a 75-year-old man with diabetes. ICGR15 was 27.4% and LHL15 was 0.87. The patient displayed bile duct carcinoma located in the upper bile duct with biliary obstruction in the right lateral sector. The right hepatectomy was scheduled. After PVE, future remnant volume became 68% and functional volume became 88%. Although ICGR15 was worse as 31%, planned hepatectomy was performed due to the results of functional volume. In the liver with biliary obstruction or portal embolization, functional liver volume is decreased more than morphological volume. Measurement of functional volume provides useful information for deciding operative indication.