Portal vein embolization before major hepatectomy

The role of EUS in diagnosis and treatment of liver disorders

Background and aim  Transabdominal ultrasound (US), computed tomographic scanning (CT) and magnetic resonance imaging (MRI) are established diagnostic tools for liver diseases. Percutaneous transhepatic cholangiography is used to perform hepatic interventional procedures including biopsy, biliary drainage procedures, and radiofrequency ablation. Despite their widespread use, these techniques have limitations. Endoscopic ultrasound (EUS), a tool that has proven useful for evaluating the mediastinum, esophagus, stomach, pancreas, and biliary tract, has an expanding role in the field of hepatology complementing the traditional investigational modalities. This review aimed to assess the current scientific evidence regarding diagnostic and therapeutic applications of EUS for hepatic diseases.

Liver Functional Volumetry by Tc-99m Mebrofenin Hepatobiliary Scintigraphy before Major Liver Resection: A Game Changer

Future remnant liver function (FRL-F) estimation is important before major liver resection to avoid posthepatectomy liver failure (PHLF). Conventionally, it is estimated by global dynamic liver function tests which assume homogeneous liver function and unable to calculate regional function. Computed tomography is another method to estimate FRL volume but assumes that volume is equivalent to function. Hence, a global and regional non-invasive liver function test is desirable. Studies were identified by MEDLINE, PubMed, and Google Scholar for articles from January 1990 to December 2017 using the following keywords “Mebrofenin, hepatobiliary scintigraphy (HBS), FRL-F, PHLF, portal vein embolization (PVE).” HBS with technetium-99 m galactosyl human serum albumin (Tc-99m GSA) and Tc-99m Mebrofenin is a known test for functional liver assessment. Restricted availability of Tc-99m GSA only in Japan is a main drawback for its global acceptance. However, Tc-99m Mebrofenin is routinely available to the rest of the world. A unique protocol for FRL-F estimation by Tc-99m Mebrofenin is described in detail in this review. Tc-99m Mebrofenin HBS has shown a strong correlation to 15 min indocyanine green clearance. HBS has been reported better in predicting the risk of PHLF with a 2.69%/min/m² cutoff of FRL-F. Tc-99m Mebrofenin HBS has been found better in stratification of PVE before major liver surgery as well. We concluded, Tc-99m Mebrofenin HBS was unique in calculating global and regional liver function and takes nonuniformity and underlying pathology in the account. Moreover, a single cutoff might fit in all for PHLF risk assessment and PVE stratification.

Effects of liver cirrhosis on portal vein embolization prior to right hepatectomy in patients with primary liver cancer

Preoperative portal vein embolization (PVE) induces compensatory hyperplasia of the future liver remnants (FLR), thus increasing resectability in the non-cirrhotic patients with primary liver cancer (PLC). However, it is unclear if it is similar in patients with liver cirrhosis. Therefore, the present study investigated the PVE value prior to liver resection in patients with PLC, and the liver cirrhotic effects on the compensatory hypertrophy of FLRs following PVE. In the present study, 21 patients with PLC who successfully underwent hepatic resection subsequent to PVE, were retrospectively examined. The patients were divided into a non-cirrhosis group and a cirrhosis group according to the absence or presence of cirrhosis, respectively. The FLR volume between the two groups of patients was compared. There was a significant difference in the FLR volume for all patients prior to, and 4–6 weeks following, PVE (P<0.001). PVE induced significant compensatory hypertrophy in the FLRs whether in the non-cirrhosis group (P=0.002) or cirrhosis group (P<0.001). However, no significant difference was identified between the two groups with respect to FLR volume enlargement 4–6 weeks following PVE (P=0.373). In conclusion, PVE prior to hepatectomy may promote FLR compensatory hypertrophy and an increase in the resectability of PLC tumors. No significant effects of liver cirrhosis were identified on liver lobe hyperplasia following PVE.

Does portal vein embolization prior to liver resection influence the oncological outcomes - A propensity score matched comparison

INTRODUCTION

There is an ongoing controversy surrounding portal vein embolization (PVE) regarding the short-term safety of PVE and long-term oncological benefit. This study aims to compare survival outcomes of patients subjected to major liver resection for colorectal liver metastases (CRLM) with or without PVE.

METHODS

All consecutive patients who underwent major liver resection for CRLM in four high volume liver centres between January 2000 and December 2015 were included. Major liver resection was defined as resection of at least three Couinaud liver segments. To reduce selection bias, propensity score matching was performed for PVE and non-PVE patients with overall and disease-free survival as primary endpoints. For matching, all patients who underwent PVE followed by a major liver resection were selected. Patients were matched to patients who had undergone major liver resection without PVE.

RESULTS

Of 745 patients undergoing major liver resection for CRLM, 53 patients (7%) underwent PVE before liver resection. In the overall cohorts, PVE patients had inferior DFS and a trend towards inferior OS. A total of 46 PVE patients were matched to 46 non-PVE patients to create comparable cohorts and between these two matched cohorts no differences in DFS (3-year DFS 16% vs 9%, p = 0.776) or OS (5-year OS 14% vs 14%, p = 0.866) were found.

CONCLUSIONS

This retrospective, matched analysis does not suggest a negative impact of PVE on long-term outcomes after liver resection in patients with CRLM.

The role of bile salts in liver regeneration

A growing body of evidence has demonstrated that bile salts are important for liver regeneration following partial hepatectomy. The relative bile salt overload after partial liver resection causes activation of bile salt receptors in non-parenchymal (viz. the plasma membrane receptor TGR5) and parenchymal (viz. the intracellular receptor FXR) cells in the liver, thus, providing signals to the regenerative process. Impaired bile salt signaling in mice with genetic deficiency of Tgr5 or Fxr results in delayed liver regeneration after partial hepatectomy, and is accompanied by mortality in case of Fxr knock-out mice. Conversely, compensatory liver re-growth in hepatectomized mice can be stimulated by feeding of bile salts or alisol B 23-acetate, a natural triterpenoid agonist of Fxr. A large number of animal studies underscore the importance of strict maintenance of bile salt homeostasis for proper progression of liver regeneration. Both ileal and hepatic Fxr play a key role in regulation of bile salt homeostasis and, thus, preventing hepatotoxicity caused by excessive levels of bile salts. They further contribute to liver regeneration by induction of mitogenic factors. Agents that target bile salt receptors hold promise as drugs to stimulate liver regeneration in selected patients.

Preoperative portal vein embolization in liver cancer: indications, techniques and outcomes

Postoperative liver failure is a severe complication of major hepatectomies, in particular in patients with a chronic underlying liver disease. Portal vein embolization (PVE) is an approach that is gaining increasing acceptance in the preoperative treatment of selected patients prior to major hepatic resection. Induction of selective hypertrophy of the non-diseased portion of the liver with PVE in patients with either primary or secondary hepatobiliary, malignancy with small estimated future liver remnants (FLR) may result in fewer complications and shorter hospital stays following resection. Additionally, PVE performed in patients initially considered unsuitable for resection due to lack of sufficient remaining normal parenchyma may add to the pool of candidates for surgical treatment. A thorough knowledge of hepatic segmentation and portal venous anatomy is essential before performing PVE. In addition, the indications and contraindications for PVE, the methods for assessing hepatic lobar hypertrophy, the means of determining optimal timing of resection, and the possible complications of PVE need to be fully understood before undertaking the procedure. Technique may vary among operators, but cyanoacrylate glue seems to be the best embolic agent with the highest expected rate of liver regeneration for PVE. The procedure is usually indicated when the remnant liver accounts for less than 25-40% of the total liver volume. Compensatory hypertrophy of the non-embolized segments is maximal during the first 2 weeks and persists, although to a lesser extent during approximately 6 weeks. Liver resection is performed 2 to 6 weeks after embolization. The goal of this article is to discuss the rationale, indications, techniques and outcomes of PVE before major hepatectomy.

Laparoscopic first step approach in the two stage hepatectomy

Resection is the gold standard therapeutic option for patients with colorectal liver metastases. However, only 20-30% of patients are resectable. In patients with a concomitant future liver remnant (FLR) less than 25-30%, a single stage resection is not feasible. The aim of this study is to evaluate the feasibility and the rates of morbidity and mortality of the laparoscopic approach in the first-step of two stage hepatectomy. From 2004 to March 2014, 73 patients underwent a two stage hepatectomy: of these, four underwent a totally laparoscopic first step [wedge left liver resection and right portal vein ligation (PVL)]. All the patients were male. Median age was 55 years. One patient underwent an atypical wedge resection of segment II-III and a laparoscopic PVL (LPVL), one patient had a first wedge resection of segment II and LPVL, and two patients underwent a wedge resection of segment III and LPVL. First step surgical mean time was 189 (range, 160-244) min, mean blood loss was 22 (range, 0-50) cc. No transfusion was required in this series. The results of our study demonstrate that the first step of hepatic resection and PVL is feasible with a laparoscopic approach in patients with bilobar liver metastases.

Endoscopic stenting in bile duct cancer increases liver volume

BACKGROUND

Objective evaluation tools for assessing the effectiveness of stenting in palliative treatment of malignant biliary obstruction are not satisfactory. Effects of biliary stenting on liver volume change have never been studied.

OBJECTIVE

We aimed to use volumetry to analyze liver volume changes after endoscopic stenting in bile duct cancer according to the location and number of stents.

DESIGN

Retrospective review.

SETTING

University hospital.

PATIENTS

Patients with a diagnosis of hilar or distal bile duct cancer and who underwent biliary metal stenting.

INTERVENTIONS

ERCP with self-expandable metal stent placement.

MAIN OUTCOME MEASUREMENTS

Liver volume change after biliary stenting and its comparison according to the location (hilar vs distal common bile duct) and number (hilar bilateral vs hilar unilateral).

RESULTS

There were 60 patients; 31 were treated for hilar bile duct cancer (13 for bilateral stent and 18 for unilateral stent) and 29 for distal bile duct cancer. Overall mean follow-up duration was 11.7 ± 4.9 weeks. Liver volume increased 17.4 ± 24.1%. The rate of liver growth was rapid during the early period from 4 to 8 weeks. Stenting in hilar bile duct cancer tended to increase liver volume more than distal biliary stents (22.5% vs 11.9%, P = .091). In hilar bile duct cancer, unilateral and bilateral stents showed similar liver volume increases (20.1% and 25.8%, respectively; P = .512).

LIMITATIONS

Single center, retrospective.

CONCLUSIONS

Biliary stenting markedly increased liver volume in both hilar and distal bile duct cancer. Our data suggest that liver volume assessment could be a useful tool for evaluating stent efficacy.

Bile salts predict liver regeneration in rabbit model of portal vein embolization

BACKGROUND

Portal vein embolization (PVE) is employed to increase future remnant liver (FRL) volume through induction of hepatocellular regeneration in the nonembolized liver lobe. The regenerative response is commonly determined by CT volumetry after PVE. The aim of the study was to examine plasma bile salts and triglycerides in the prediction of the regenerative response following PVE.

METHODS

PVE of the cranial liver lobe was performed in 15 rabbits, divided into three groups: NaCl (control), gelatin sponge (short-term occlusion), and polyvinyl alcohol particles with coils (PVAc, long-term occlusion). In all rabbits CT volumetry and blood sampling were performed prior to PVE and on days 3 and 7. Plasma bile salts and triglycerides were correlated with volume increase of the nonembolized liver lobe.

RESULTS

After 3 and 7 d, respectively, FRL volume was increased in both embolized groups, with the largest hypertrophy response observed in the PVAc group. Plasma bile salt levels were increased after PVE, especially in the PVAc group at day 3 (P < 0.01 compared to gelatin sponge). Plasma bile salts at day 3 predicted FRL volume increase at day 7 showing a positive correlation of 0.811 (P < 0.001). Levels of triglycerides were not significantly altered in either of the PVE procedures.

CONCLUSIONS

Plasma bile salt levels early after PVE strongly correlated with the regenerative response in a rabbit model of PVE, showing more pronounced elevation with larger volume increase of the nonembolized lobe. Therefore, plasma bile salts, but not triglycerides, can be used in the prediction of the regenerative response after PVE.

Preoperative portal vein embolization (PVE) for patients with hepatocellular carcinoma can improve resectability and may improve disease-free survival

BACKGROUND

The aim of this study is to identify the efficacy of portal vein embolization (PVE) before right hepatectomy in patients with hepatocellular carcinoma (HCC) with regard to hepatic function, surgical stress, and survival benefit.

METHODS

Fifty-five patients with HCC underwent right hepatectomy between 1999 and 2009. Preoperative PVE was performed in 19 patients (PVE group) and was not applied in 36 patients (non-PVE group). Changes in liver function and volume were investigated in PVE group. Short and long clinical outcomes after the surgeries were compared between the two groups.

RESULTS

The percentage of future liver remnant (%FLR) before PVE was significantly lower (37.8%) in PVE group than in non-PVE group (58.1%) but increased remarkably after PVE (from 37.8% to 55.0%, P < 0.0001). Cumulative disease-free survival and overall survival rates in PVE group were significantly superior to those in non-PVE group (P = 0.010 and 0.049, respectively). Although surgical stress estimated by E-PASS scores and CRP value was not different between the groups, the postoperative value of PT on postoperative day 3 in PVE group was significantly better than in non-PVE group.

CONCLUSIONS

Preoperative PVE improves resectability and may improve disease-free survival for patients with HCC requiring right hepatectomy.

Risk factors for liver failure and mortality after hepatectomy associated with portal vein resection

OBJECTIVE

To report the postoperative outcome of hepatectomy associated with portal vein resection (PVR) and to identify risk factors of clinical value for predicting postoperative liver failure and mortality.

SUMMARY BACKGROUND DATA

Resection of the portal vein during hepatectomy allows an increase in the number of patients who may benefit from a potentially curative operation that is, however, technically difficult and may increase postoperative morbidity and mortality. Few data are available about risk factors for liver failure and mortality after such extensive operations.

METHODS

Between July 1996 and July 2008, a total of 1348 patients were operated on for liver disease in our institution. Among them, 55 patients underwent liver resection associated with PVR. Medical records of these patients were prospectively collected and retrospectively analyzed.

RESULTS

Overall mortality for this selected group of patients was 7.2%. Irreversible liver failure was the main cause of death. Overall morbidity was 58.1%. A total of 94% of the patients (n = 52) underwent a major (≥ 3 segments) or an extended > 4 segments) right or left hepatectomy. Univariate analysis showed that male gender (P = 0.004), extended liver resection (P = 0.028), and, particularly, extended right hepatectomy (P = 0.015) were significantly associated with an increased risk of postoperative liver failure. Male gender was the single independent risk factor for liver failure. Moreover, the presence of liver steatosis (P = 0.014), an extended right hepatectomy procedure (P = 0.047), and postoperative liver failure (P = 0.046) were significantly associated with an increased rate of postoperative mortality.

CONCLUSION

The present study confirmed that major or extended hepatic resection with PVR can be performed with acceptable overall morbidity and mortality rates. Preoperative selection of the patients should take in consideration the gender and the extent of hepatic resection to avoid irreversible postoperative liver failure. Extended right hepatectomy with PVR should be carefully considered in patients with liver steatosis due to the high risk of postoperative mortality.

Role of laparoscopic right portal vein ligation in planning staged or major liver resection

BACKGROUND AND AIMS

Right portal vein ligation (PVL) has its recognized role in inducing hypertrophy of future liver remnant (FLR) prior to major liver resection. The aim of this study was to evaluate the safety, feasibility, and effectiveness of laparoscopic right PVL and to explore its applications.

METHODS

Laparoscopic right PVL was employed either during staging laparoscopy when a right hepatic trisectionectomy was indicated, leaving a small (<25%) FLR (indication 1), or during a laparoscopic left hepatic lobectomy (left lateral sectionectomy) when a second-stage right hemihepatectomy was to follow (indication 2). A follow up cross-sectional liver imaging was performed 4-6 weeks later with liver volumetry to confirm hypertrophy of the FLR before proceeding to major hepatectomy.

RESULTS

Six patients (female, 5), 74-83 years old, underwent a laparoscopic right PVL, of whom 4 patients fulfilled indication 1 while 2 patients fulfilled indication 2. The median operating time for indication 1 was 60 minutes. There were no intra- or postoperative complications, and all procedures were completed laparoscopically. Repeat imaging of the liver demonstrated a median (range) hypertrophy of FLR of 24.5% (range, 20.7-33.1%). The right liver experienced atrophy.

CONCLUSIONS

In the hands of the experienced laparoscopic hepatobiliary surgeon, laparoscopic right PVL is feasible and safe, and induces adequate regeneration of the FLR. Laparoscopic right PVL has its applications at the time of staging laparoscopy in patients requiring a right hepatic trisectionectomy in the presence of a small FLR and as part of a staged liver resection in patients with bilobar liver disease that spares segments 1 and 4.

Trans-ileocecal portal vein embolization as a preoperative treatment for right trisegmentectomy with caudate lobectomy

BACKGROUND AND OBJECTIVES

The indication of preoperative portal vein embolization (PVE) has been expanded to hepatocellular carcinoma, cholangiocellular carcinoma (CCC), hepatic metastasis, and gallbladder (GB) cancer as well as hilar cholangiocarcinoma (hCC). However, biliary cancers sometimes cause peritoneal dissemination.

PATIENTS AND METHODS

We performed our preoperative trans-ileocecal-vein PVE (TIPE) method on 14 (3 GB cancer, 1 CCC, and 10 hCC), whose estimated residual liver volume was <30%.

RESULTS

Out of 14 patients, peritoneal dissemination was encountered in two patients with GB cancer and one with hCC (21.4%) during our procedure. The estimated residual liver volume was 37.4 +/- 2.7% at 14 days after PVE in patients without predisposing cholangitis, while those in patients with cholangitis was 29.3 +/- 1.3% (P = 0.0002). No major complication due to the procedure was encountered in this series.

CONCLUSIONS

PTPE could be the first choice for patients with hCC, hepatocellular carcinoma, and hepatic metastases. Although the TIPE proposed here has some potential disadvantages, we would recommend it especially for patients with GB cancer because of its high potential to cause cancerous peritonitis. When a patient had predisposing cholangitis, radical operation should be scheduled on >21 days after PVE rather than on 14 days.

Preoperative Portal Vein Embolization and Surgical Resection in Patients with Hepatocellular Carcinoma and Small Future Liver Remnant Volume: Comparison with Transarterial Chemoembolization

BACKGROUND

Preoperative portal vein embolization (PVE) increases the future liver remnant (FLR) volume, thus enabling surgical resection in patients with small FLR volume. It is unclear, however, if this approach can enhance survival in patients with hepatocellular carcinoma (HCC). We therefore compared the outcomes of preoperative PVE and surgical resection with transarterial chemoembolization (TACE).

METHODS

Changes in FLR volumes were analyzed in 32 HCC patients who underwent preoperative PVE and surgical resection. Long-term outcomes were compared with 64 TACE-treated patients matched for gender, Child-Turcotte-Pugh class, tumor size and number, serum alpha-fetoprotein levels, and UICC stage.

RESULTS

In the PVE group, the baseline ratio of FLR/total estimated liver volumes (TELV) was 27.6 +/- 7.2%. Following PVE, FLR volume increased 34% (336.5 vs 449.4 mL, P < .001) and the ratio of FLR/TELV increased from 27.6 +/- 7.2 to 36.9 +/- 8.1% (P < .001). There was no mortality associated with PVE or surgical resection. The 5-year survival rate was significantly higher in the PVE group than in the TACE group (71.9% vs 45.6%, P = .03). Multivariate analysis showed that treatment modality was an independent predictive factor for survival (odds ratio 2.05, 95% confidence interval 1.01-4.16, P = .046).

CONCLUSIONS

Preoperative PVE enables surgical resection in HCC patients with small FLR volume and improves patient survival compared with TACE.

[Management of hilar cholangiocarcinoma]

Hilar cholangiocarcinoma is a rare disease departing from the biliary convergence. It is primarily revealed by the onset of retention jaundice. Only 20%-30% of patients can undergo resection at diagnosis. The only chance for survival for these patients is R0 resection, which requires hepatectomy associated with resection of the common bile duct and pedicle lymph node removal, whatever the classification of the cholangiocarcinoma. No adjuvant treatment has been shown to be effective to date. Palliative treatment is most often based on implanting a biliary stent. Dynamic phototherapy may be beneficial in these situations. Improvements in survival for selected N0 hilar cholangiocarcinoma may be obtained with neoadjuvant treatment with radiochemotherapy followed by liver transplantation.

Liver regeneration: mechanisms, mysteries and more

BACKGROUND

Liver regeneration remains a fascinating topic, still partly clouded to many as to the exact cellular and molecular mechanisms that bring about this phenomenon. It is an area, therefore, of active research today. This review looks at the recent published reports that have led to a greater understanding of this process.

METHODS

A database search was carried out on Medline search using the terms liver regeneration with no linguistic limitations from 1966 to 2006.

RESULTS

There are two randomized controlled trials on the topic and most data and information have come from experimental studies in animals.

CONCLUSION

Liver regeneration is a complex, tightly controlled process involving many inflammatory cells growth factors and hormones. More information about it is awaited in studies on humans.

Enucleation of centrally located giant hepatic hemangioma: report of two cases

Two centrally located giant hepatic hemangiomas were referred with severe pain, one of which had a protruding abdominal mass was listed for transplantation at another center. Tumors were 35 and 30 cm at their longest diameter. One was centrally located involving the hilum and segments VI/VII and II/III were partially spared. Volumetric analysis and imaging suggested enucleation is feasible if the left lateral segment and the right posterior sector are left intact. Operation was straightforward except few breaks in enucleation technique in an effort to secure the venous drainage of the remnant liver. She had an uneventful recovery except a biliary fistula through the operatively severed left hepatic duct, which was repaired over a stent. This was managed by lateral segmentectomy and resection of the fistula after the enlargement of the right posterior sector was confirmed volumetrically. The other tumor-involved segments II, III, IV, V, and VIII and the hilum were totally hemangiomatic. Enucleation and postoperative recovery was uneventful. The era of liver transplantation enhanced our knowledge about complex liver surgery and these cases are good examples about the feasibility of enucleation even in extremely complicated liver hemangiomas saving both the patients and a donor liver.

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Interventional procedures involving portal vein circulation: a review

Rapid development of diagnostic radiological methods during recent decades has been followed by development of new interventional procedures involving portal circulation. The majority of these interventions were developed for treatment of patients with symptoms secondary to portal hypertension (PH). Interventions involving portal vein circulation have an established position in the treatment of PH and other diseases, and further development of these methods can be expected.

Portal vein embolization induces compensatory hypertrophy of remnant liver

AIM: To evaluate the effectiveness and safety of different portal vein branch embolization agents in inducing compensatory hypertrophy of the remnant liver and to offer a theoretic basis for clinical portal vein branch embolization.

METHODS: Forty-one adult dogs were included in the experiment and divided into four groups. Five dogs served as a control group, 12 as a gelfoam group, 12 as a coil-gelfoam group and 12 as an absolute ethanol group. Left portal vein embolization was performed in each group. The results from the embolization in each group using different embolic agents were compared. The safety of portal vein embolization (PVE) was evaluated by liver function test, computed tomography (CT) and digital subtraction angiography (DSA) of liver and portal veins. Statistical test of variance was performed to analyze the results.

RESULTS: Gelfoam used for PVE was inefficient in recanalization of portal vein branch 4 wk after the procedure. The liver volume in groups of coil-gelfoam and absolute ethanol increased 25.1% and 33.18%, respectively. There was no evidence of recanalization of embolized portal vein, hepatic dysfunction, and portal hypertension in coil-gelfoam group and absolute ethanol group.

CONCOUSION: Portal vein branch embolization using absolute ethanol and coil-gelfoam could induce atrophy of the embolized lobes and compensatory hypertrophy of the remnant liver. Gelfoam is an inefficient agent.