Hepatic lobar atrophy following obstruction of the ipsilateral portal vein from hilar cholangiocarcinoma

Liver volumetry and liver-regenerative interventions: history, rationale, and emerging tools

BACKGROUND

Postoperative hepatic insufficiency (PHI) is the most feared complication after hepatectomy. Volume of the future liver remnant (FLR) is one objectively measurable indicator to identify patients at risk of PHI. In this review, we summarized the development and rationale for the use of liver volumetry and liver-regenerative interventions and highlighted emerging tools that could yield new advancements in liver volumetry.

METHODS

A review of MEDLINE/PubMed, Embase, and Cochrane Library databases was conducted to identify literature related to liver volumetry. The references of relevant articles were reviewed to identify additional publications.

RESULTS

Liver volumetry based on radiologic imaging was developed in the 1980s to identify patients at risk of PHI and later used in the 1990s to evaluate grafts for living donor living transplantation. The field evolved in the 2000s by the introduction of standardized FLR based on the hepatic metabolic demands and in the 2010s by the introduction of the degree of hypertrophy and kinetic growth rate as measures of the FLR regenerative and functional capacity. Several liver-regenerative interventions, most notably portal vein embolization, are used to increase resectability and reduce the risk of PHI. In parallel with the increase in automation and machine assistance to physicians, many semi- and fully automated tools are being developed to facilitate liver volumetry.

CONCLUSION

Liver volumetry is the most reliable tool to detect patients at risk of PHI. Advances in imaging analysis technologies, newly developed functional measures, and liver-regenerative interventions have been improving our ability to perform safe hepatectomy.

Contemporary Surgical Management of Colorectal Liver Metastases

Colorectal cancer is the third most common cancer in the United States and the second most common cause of cancer-related death. Approximately 20-30% of patients will develop hepatic metastasis in the form of synchronous or metachronous disease. The treatment of colorectal liver metastasis (CRLM) has evolved into a multidisciplinary approach, with chemotherapy and a variety of locoregional treatments, such as ablation and portal vein embolization, playing a crucial role. However, resection remains a core tenet of management, serving as the gold standard for a curative-intent therapy. As such, the input of a dedicated hepatobiliary surgeon is paramount for appropriate patient selection and choice of surgical approach, as significant advances in the field have made management decisions extremely nuanced and complex. We herein aim to review the contemporary surgical management of colorectal liver metastasis with respect to both perioperative and operative considerations.

Comparing iodized oil with polyvinyl alcohol for portal vein embolization in promoting liver remnant increase before partial hepatectomy

BACKGROUND

To compare the efficacy and safety of iodized oil versus polyvinyl alcohol (PVA) particles in portal vein embolization (PVE) before partial hepatectomy.

METHODS

From October 2016 to December 2021, 86 patients who planned to undergo hepatectomy after PVE were enrolled, including 61 patients post-PVE with PVA particles + coils and 25 patients post-PVE with iodized oil + coils. All patients underwent CT examination before and 2-3 weeks after PVE to evaluate the future liver remnant (FLR). The intercohort comparison included the degree of liver volume growth, changes in laboratory data, and adverse events.

RESULTS

There was no significant difference in the resection rate between the iodized oil group and the PVA particle group (68 % vs. 70 %, p = 0.822). In terms of the degree of hypertrophy (9.52 % ± 13.47 vs. 4.03 % ± 10.55, p = 0.047) and kinetic growth rate (4.07 % ± 5.4 vs. 1.55 % ± 4.63, p = 0.032), the iodized oil group was superior to the PVA group. The PVE operation time in the PVA particle group was shorter than that in the iodized oil group (121. 72 min ± 34.45 vs. 156. 2 min ± 71.58, p = 0.029). There was no significant difference in the degree of hypertrophy between the high bilirubin group and the control group (5.32 % ± 9.21 vs. 6.1 % ± 14.79, p = 0.764). Only 1 patient had a major complication.

CONCLUSIONS

Compared with PVA particles, iodized oil PVE can significantly increase liver volume and the degree of hypertrophy without any significant difference in safety.

Pushing the Limits of Surgical Resection in Colorectal Liver Metastasis: How Far Can We Go?

Colorectal cancer is the third most common cancer worldwide, and up to 50% of all patients diagnosed will develop metastatic disease. Management of colorectal liver metastases (CRLM) has been constantly improving, aided by newer and more effective chemotherapy agents and the use of multidisciplinary teams. However, the only curative treatment remains surgical resection of the CRLM. Although survival for surgically resected patients has shown modest improvement, this is mostly because of the fact that what is constantly evolving is the indication for resection. Surgeons are constantly pushing the limits of what is considered resectable or not, thus enhancing and enlarging the pool of patients who can be potentially benefited and even cured with aggressive surgical procedures. There are a variety of procedures that have been developed, which range from procedures to stimulate hepatic growth, such as portal vein embolization, two-staged hepatectomy, or the association of both, to technically challenging procedures such as simultaneous approaches for synchronous metastasis, ex-vivo or in-situ perfusion with total vascular exclusion, or even liver transplant. This article reviewed the major breakthroughs in liver surgery for CRLM, showing how much has changed and what has been achieved in the field of CRLM.

Increased Prevalence of Left Lobe Atrophy in Long-standing Extrahepatic Portal Vein Obstruction

OBJECTIVES

The aim of this study was to describe long-term changes in standard blood tests and ultrasound (US) findings in pediatric patients with Extrahepatic Portal Vein Obstruction (EHPVO) who have not undergone Meso-Rex Bypass (MRB) surgery.

METHODS

US, laboratory, and endoscopic data of 77 patients were analyzed and compared at 2 different points in time: at initial workup and at most recent follow-up. Differences were assessed using McNemar and Wilcoxon tests, while correlations were evaluated using generalized estimating equations.

RESULTS

Upper gastrointestinal bleeding was the most frequent initial manifestation of EHPVO, in 45.4% of subjects. The mean age at diagnosis was 4.3 years. Seventy-four percentage had a previous history of umbilical catheterization and/or neonatal sepsis. Over time, there was a significant increase in the prevalence of leukopenia, thrombocytopenia, and, interestingly, of left lobe atrophy (LLA), even though the number of esophageal varices and the need for endoscopic interventions reduced. A significant correlation was found between history of umbilical catheterization and LLA, splenomegaly and LLA, and gallbladder wall thickening and LLA. Overall, the number of patients with cholelithiasis at initial workup was low (and therefore, not analyzed with inferential statistics); however, we observed a relative increase over time.

CONCLUSIONS

In this cohort of patients with EHPVO followed over more than 8 years without treatment with MRB, we report the novel finding of a significant increase in the prevalence of LLA over time. LLA correlated with past medical history of umbilical catheterization, and findings of splenomegaly and gallbladder wall thickening. We propose that that LLA should be further explored as a marker of portal hypertension, particularly in the context of a history of umbilical catheterization.

Reporting standards for primary sclerosing cholangitis using MRI and MR cholangiopancreatography: guidelines from MR Working Group of the International Primary Sclerosing Cholangitis Study Group

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disorder affecting the bile ducts and is characterized by biliary strictures, progressive liver parenchymal fibrosis, and an increased risk of hepatobiliary malignancies primarily cholangiocarcinoma (CCA). PSC may lead to portal hypertension, liver decompensation, and liver failure with the need for liver transplantation. Magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) are considered the imaging standard for diagnosis and follow-up in patients with PSC. Currently, there are no universally accepted reporting standards and definitions for MRI/MRCP features. Controversies exist about the definition of a high-grade stricture and there is no widely agreed approach to their management. The members of the MRI working group of the International Primary Sclerosing Cholangitis Study Group (IPSCSG) sought to define terminologies and reporting standards for describing MRI/MRCP features that would be applied to diagnosis and surveillance of disease progression, and potentially for evaluating treatment response in clinical trials. In this extensive review, the technique of MRI/MRCP and assessment of image quality for the evaluation of PSC is briefly described. The definitions and terminologies for severity and length of strictures, duct wall thickening and hyperenhancement, and liver parenchyma signal intensity changes are outlined. As CCA is an important complication of PSC, standardized reporting criteria for CCA developing in PSC are summarized. Finally, the guidelines for reporting important changes in follow-up MRI/MRCP studies are provided. KEY POINTS: • Primary sclerosing cholangitis is a chronic inflammatory disorder affecting the bile ducts, causing biliary strictures and liver fibrosis and an increased risk of cholangiocarcinoma. • This consensus document provides definitions and suggested reporting standards for MRI and MRCP features of primary sclerosing cholangitis, which will allow for a standardized approach to diagnosis, assessment of disease severity, follow-up, and detection of complications. • Standardized definitions and reporting of MRI/MRCP features of PSC will facilitate comparison between studies, promote longitudinal assessment during management, reduce inter-reader variability, and enhance the quality of care and communication between health care providers.

Ipsilateral access portal venous embolization (PVE) for preoperative hypertrophy exhibits low complication rates in Clavien-Dindo and CIRSE scales

Background

Portal venous embolization (PVE) is a minimal invasive preoperative strategy that aims to increase future liver remnant (FLR) in order to facilitate extended hemihepatectomy. We analyzed our data retrospectively regarding complications and degree of hypertrophy (DH).

Methods: 88 patients received PVE either by particles / coils (n = 77) or by glue / oil (n = 11), supported by 7 right hepatic vein embolizations (HVE) by coils or occluders. All complications were categorized by the Clavien- Dindo (CD) and the CIRSE classification.

Results

In 88 patients (median age 68 years) there was one intervention with a biliary leak and subsequent drainage (complication grade 3 CD, CIRSE 3), two with prolonged hospital stay (grade 2 CD, grade 3 CIRSE) and 13 complications grade 1 CD, but no complications of grade 4 or higher neither in Clavien- Dindo nor in CIRSE classification. The median relative increase in FLR was 47% (SD 35%). The mean pre-intervention standardized FLR rose from 23% (SD 10%) to a post-intervention standardized FLR of 32% (SD 12%). The degree of hypertrophy (DH) was 9,3% (SD 5,2%) and the kinetic growth rate (KGR) per week was 2,06 (SD 1,84).

Conclusion

PVE and, if necessary, additional sequential HVE were safe procedures with a low rate of complications and facilitated sufficient preoperative hypertrophy of the future liver remnant.

Successful Resection and Vascular Ligation of a Large Hepatic Artery Aneurysm - A Case Report and Literature Review

The occurrence of hepatic artery aneurysms is rare and might be incidentally diagnosed, as the patient remains asymptomatic for a long period of time. However, due to the fact that these lesions are associated with a high risk of developing life threatening complications, such as intraperitoneal rupture, it has been stated that all cases should be submitted to treatment by endovascular or surgical approach. We present the case of a 68-year-old patient, who presented with recurrent upper digestive tract bleedings and was diagnosed with a large aneurysm of the common and the proper hepatic artery, and the gastroduodenal artery. The preoperative angiography revealed an anatomic variation consisting of the common hepatic artery originating from the celiac trunk, and the left hepatic artery originating from the left gastric artery. A percutaneous right portal vein embolization was performed in order to induce hypertrophy of the left lobe and prepare the patient for a right hepatectomy and aneurysmal resection. However, at the time of surgery, after performing the aneurysmal resection and arterial ligation, the vascular supply of the entire liver was efficiently provided by the left hepatic artery and its collaterals. Concluding, hepatic resection was no longer necessary.

Small intestinal obstruction due to the metastasis of intrahepatic cholangiocarcinoma: A case report

RATIONALE

The small intestine (SI) does not commonly harbor cancer but is occasionally involved by metastatic cancer from other organs. To manage SI cancer appropriately, surveillance for primary origin outside the SI is essential.

PATIENT CONCERNS

This study presents a 54-year-old Thai man diagnosed with SI obstruction which required laparoscopy- assisted partial ileal resection.

DIAGNOSES

On the basis of the expression pattern of cytokeratins (CKs) and mucins (MUCs) in the resected SI adenocarcinoma, we suspected this was metastasized from the pancreatobiliary tract. Imaging studies revealed a hepatic segmental atrophy with an occlusion of the posterior segmental blanch of the portal vein without any contrast-enhanced lesions in the liver. Pathology of the liver biopsy revealed intrahepatic cholangiocarcinoma (ICC) with the same expression pattern of CKs and MUCs as the SI adenocarcinoma.

INTERVENTIONS

Systemic chemotherapy (gemcitabine and cisplatin) was initiated.

OUTCOMES

Despite of the chemotherapy for 20 months, he died of ICC.

LESSONS

This is the first case of SI obstruction caused by the metastasis of ICC. We demonstrate that immunohistochemical staining of CKs and MUCs discriminate between primary and metastatic SI cancer and predict its primary origin outside the SI. This case also suggests that a hepatic segmental atrophy with portal vein occlusion would be an atypical but important finding to diagnose ICC.

Palliative Percutaneous Biliary Interventions in Malignant High Bile Duct Obstruction

The optimal palliative intervention for malignant biliary obstruction is internal drainage by placement of a metallic stent. For patients with hilar biliary obstruction or low bile duct obstruction in whom endoscopy is not feasible, a percutaneous transhepatic approach in interventional radiology is preferred. This article reviews the rationale for this approach, periprocedural management, and techniques to optimize stent patency.

Hepatic segmental atrophy and nodular elastosis: imaging features

PURPOSE

To evaluate the imaging features of hepatic segmental atrophy and nodular elastosis.

MATERIALS AND METHODS

In this Institutional review board (IRB)-approved, HIPAA-compliant study, we reviewed imaging features in six cases of histologically confirmed hepatic segmental atrophy (HSA) and nodular elastosis (NE). Retrospective review of ultrasound (US) in 2 patients, computed tomography (CT) in 5 patients, magnetic resonance imaging (MRI) in 4 patients, and positron emission tomography (PET) in 2 patients was performed. Location, size, and attenuation/density/signal intensity of these lesions were evaluated. Clinical presentation and coexistent conditions were also recorded.

RESULTS

All six patients were females. Mean age of presentation was 58.3 years (range 37-80). A single HSA and NE lesion in each patient was found. The mean size of the lesion was 18 mm (range: 3 mm to 36 mm). Most lesions were detected incidentally (5/6). On contrast-enhanced single-phase (portal venous) CT, most lesions were hypodense (4/5) and one lesion was hyperdense to fatty liver parenchyma. On MRI, the lesions were iso- to hyperintense on T2-weighted images, T1 hypointense, and hyperintense on diffusion-weighted images (DWI). Three lesions were hypointense on arterial, portal venous, and delayed phases. One lesion occurring in fatty liver appeared hyperintense on all three phases. Gd-EOB-DTPA-enhanced images were available in 2 patients and lesions were hypointense on the 20-min hepatobiliary phase. On PET, two lesions were isometabolic to the background hepatic parenchyma. On ultrasound, one lesion appeared hypoechoic and another lesion isoechoic to hepatic parenchyma.

CONCLUSIONS

Hepatic segmental atrophy and nodular elastosis is an uncommon benign lesion and can simulate metastases due to variable imaging features. Lack of FDG uptake on PET/CT may be a clue to the benign nature of the lesion and may suggest the possibility of HSA and NE.

MRI rare finding: Absence of the left liver lobe

We report a rare case of left liver lobe absence in an 80-year-old male patient discovered during an MRI scan. The main imaging features of this condition are briefly reviewed, together with its pathogenesis and the most common associations and differential diagnoses.

A systematic review and meta-analysis of feasibility, safety and efficacy of associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) versus two-stage hepatectomy (TSH)

This meta-analysis aimed to review the regeneration rate of future liver remnant (FLR) and perioperative outcomes after associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) and two-stage hepatectomy (TSH). A web search was performed in "MEDLINE", "EMBASE", and "SCIENCE DIRECT" databases using both subject headings (MeSH) and truncated word to identify all the articles published that related to this topic. Pooled risk ratios were calculated for categorical variables and mean differences for continuous variables using the fixed-effects and random-effects models for meta-analysis. Three studies involved 282 patients, of whom 234 were in the TSH group and 48 in the ALPPS group. Morbidity was experienced in 56.3% patients in the ALPPS group and 36.1% in the TSH group. There was a statistical difference (RR = 1.08; Z = 3.24; 95% CI, p = 0.001). Second surgeries were performed successfully in 79.1% patients in the portal vein embolization (PVE) group and 100% in the ALPPS group. There was a statistical difference (Z = 2.48; 95% CI, p = 0.01). The mean regeneration rate of FLR in the ALPPS group was 56.4% compared with 52.8% in the TSH group. There was no statistical difference (95% CI, p = 0.34). So from the outcome of this meta-analysis, TSH had a similar remnant liver regeneration ability compared to ALPPS while the morbidity and mortality rates were relatively low. Cancer progression while waiting for the staged liver resection after portal vein embolization was a drawback for TSH.

Short Communications

Congenital agenesis of the right lobe of the liver is a rare anomaly. In a case report the diagnosis was made by computed tomography. A retro- or suprahepatic location of the gallbladder and compensatory hypertrophy of the left liver lobe and/or caudate lobe may give support to the diagnosis. Before diagnosing congenital agenesis of the lobe, lobar atrophy due to cirrhosis, cholangiocarcinoma or any other predisposing conditions should be eliminated.

A comparison of portal vein embolization with poly(2-hydroxyethylmethacrylate) and a histoacryl/lipiodol mixture in patients scheduled for extended right hepatectomy

To determine whether PHEMA [poly(2-hydroxyethylmethacrylate)] is suitable for portal vein embolization in patients scheduled to right hepatectomy and whether it is as effective as the currently used agent (a histoacryl/lipiodol mixture). Two groups of nine patients each scheduled for extended right hepatectomy for primary or secondary hepatic tumor, had right portal vein embolization in an effort to induce future liver remnant (FLR) hypertrophy. One group had embolization with PHEMA, the other one with the histoacryl/lipiodol mixture. In all patients, embolization was performed using the right retrograde transhepatic access. Embolization was technically successful in all 18 patients, with no complication related to the embolization agent. Eight patients of either group developed FLR hypertrophy allowing extended right hepatectomy. Likewise, one patient in each group had recanalization of a portal vein branch. Histology showed that both embolization agents reach the periphery of portal vein branches, with PHEMA penetrating somewhat deeper into the periphery. PHEMA has been shown to be an agent suitable for embolization in the portal venous system comparable with existing embolization agent (histoacryl/lipiodol mixture).

Percutaneous unilateral biliary metallic stent placement in patients with malignant obstruction of the biliary hila and contralateral portal vein steno-occlusion

Objective

To investigate the outcomes of percutaneous unilateral metallic stent placement in patients with a malignant obstruction of the biliary hila and a contralateral portal vein steno-occlusion.

Materials and Methods

Sixty patients with a malignant hilar obstruction and unilobar portal vein steno-occlusion caused by tumor invasion or preoperative portal vein embolization were enrolled in this retrospective study from October 2010 to October 2013. All patients were treated with percutaneous placement of a biliary metallic stent, including expanded polytetrafluoroethylene (ePTFE)-covered stents in 27 patients and uncovered stents in 33 patients.

Results

A total of 70 stents were successfully placed in 60 patients. Procedural-related minor complications, including self-limiting hemobilia (n = 2) and cholangitis (n = 4) occurred in six (10%) patients. Acute cholecystitis occurred in two patients. Successful internal drainage was achieved in 54 (90%) of the 60 patients. According to a Kaplan-Meier analysis, median survival time was 210 days (95% confidence interval [CI], 135-284 days), and median stent patency time was 133 days (95% CI, 94-171 days). No significant difference in stent patency was observed between covered and uncovered stents (p = 0.646). Stent dysfunction occurred in 16 (29.6%) of 54 patients after a mean of 159 days (range, 65-321 days).

Conclusion

Unilateral placement of ePTFE-covered and uncovered stents in the hepatic lobe with a patent portal vein is a safe and effective method for palliative treatment of patients with a contralateral portal vein steno-occlusion caused by an advanced hilar malignancy or portal vein embolization. No significant difference in stent patency was detected between covered and uncovered metallic stents.

Safety and efficacy of portal vein embolization before planned major or extended hepatectomy: an institutional experience of 358 patients

INTRODUCTION

Portal 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.

METHODS

Records of 358 consecutive patients who underwent PVE before intended major hepatectomy at our institution from 1995 through 2012 were retrospectively reviewed.

RESULTS

One 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.

CONCLUSIONS

PVE can be safely performed with minimal morbidity. Most patients can proceed to extended hepatectomy, which is associated with a minimal mortality rate.

Analysis of the efficacy of portal vein embolization for patients with extensive liver malignancy and very low future liver remnant volume, including a comparison with the associating liver partition with portal vein ligation for staged hepatectomy approach

BACKGROUND

The primary reported indication for the associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) technique is in patients with very low future liver remnant volumes. Given the elevated incidence of major morbidity (40%) and liver-related mortality (12%) with ALPPS, we sought to determine the safety and efficacy of percutaneous portal vein embolization (PVE) in a similar patient population.

STUDY DESIGN

Tumor resectability and morbidity and mortality rates were reviewed for 144 consecutive liver tumor patients with future liver remnant to body weight ratios (LR/BW) less than 0.5%. All patients were referred for preoperative percutaneous right plus segment IV PVE using embolic microspheres, with planned reassessment of the LR/BW 30 days after PVE. Post-PVE outcomes were compared with reported outcomes for ALPPS.

RESULTS

Percutaneous PVE was successfully performed in 141 of the 144 study patients (97.9%). Adequate regeneration was observed in 139 patients (98.5%) with median post-PVE LR/BW rising from 0.33% to 0.52% (p < 0.0001), representing a per-patient median regeneration rate of 62% (range 0.3% to 379%). In total, 104 patients underwent extended right hepatectomy (n = 102) or right hepatectomy (n = 2). The remaining 40 patients (27.8%) were not resectable due to short-interval disease progression (27 patients, 18.5%), insufficient liver regeneration (5 patients, 3.5%), and medical comorbidities (8 patients, 5.6%). After resection, the following outcomes were observed: major morbidity: 33.0% (34 of 104), liver insufficiency: 12.5% (13 of 104), and 90-day liver-related mortality: 5.8% (6 of 104). These oncologic and technical results compare favorably with those of ALPPS.

CONCLUSIONS

Based on its ability to select oncologically resectable patients and superior safety and efficacy profiles, percutaneous right + segment IV PVE and interval surgery remains the standard of care for patients with very low future liver remnant volumes.

Analysis of the efficacy of portal vein embolization for patients with extensive liver malignancy and very low future liver remnant volume, including a comparison with the associating liver partition with portal vein ligation for staged hepatectomy approach

BACKGROUND

The primary reported indication for the associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) technique is in patients with very low future liver remnant volumes. Given the elevated incidence of major morbidity (40%) and liver-related mortality (12%) with ALPPS, we sought to determine the safety and efficacy of percutaneous portal vein embolization (PVE) in a similar patient population.

STUDY DESIGN

Tumor resectability and morbidity and mortality rates were reviewed for 144 consecutive liver tumor patients with future liver remnant to body weight ratios (LR/BW) less than 0.5%. All patients were referred for preoperative percutaneous right plus segment IV PVE using embolic microspheres, with planned reassessment of the LR/BW 30 days after PVE. Post-PVE outcomes were compared with reported outcomes for ALPPS.

RESULTS

Percutaneous PVE was successfully performed in 141 of the 144 study patients (97.9%). Adequate regeneration was observed in 139 patients (98.5%) with median post-PVE LR/BW rising from 0.33% to 0.52% (p < 0.0001), representing a per-patient median regeneration rate of 62% (range 0.3% to 379%). In total, 104 patients underwent extended right hepatectomy (n = 102) or right hepatectomy (n = 2). The remaining 40 patients (27.8%) were not resectable due to short-interval disease progression (27 patients, 18.5%), insufficient liver regeneration (5 patients, 3.5%), and medical comorbidities (8 patients, 5.6%). After resection, the following outcomes were observed: major morbidity: 33.0% (34 of 104), liver insufficiency: 12.5% (13 of 104), and 90-day liver-related mortality: 5.8% (6 of 104). These oncologic and technical results compare favorably with those of ALPPS.

CONCLUSIONS

Based on its ability to select oncologically resectable patients and superior safety and efficacy profiles, percutaneous right + segment IV PVE and interval surgery remains the standard of care for patients with very low future liver remnant volumes.

Analysis of the efficacy of portal vein embolization for patients with extensive liver malignancy and very low future liver remnant volume, including a comparison with the associating liver partition with portal vein ligation for staged hepatectomy approach

BACKGROUND

The primary reported indication for the associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) technique is in patients with very low future liver remnant volumes. Given the elevated incidence of major morbidity (40%) and liver-related mortality (12%) with ALPPS, we sought to determine the safety and efficacy of percutaneous portal vein embolization (PVE) in a similar patient population.

STUDY DESIGN

Tumor resectability and morbidity and mortality rates were reviewed for 144 consecutive liver tumor patients with future liver remnant to body weight ratios (LR/BW) less than 0.5%. All patients were referred for preoperative percutaneous right plus segment IV PVE using embolic microspheres, with planned reassessment of the LR/BW 30 days after PVE. Post-PVE outcomes were compared with reported outcomes for ALPPS.

RESULTS

Percutaneous PVE was successfully performed in 141 of the 144 study patients (97.9%). Adequate regeneration was observed in 139 patients (98.5%) with median post-PVE LR/BW rising from 0.33% to 0.52% (p < 0.0001), representing a per-patient median regeneration rate of 62% (range 0.3% to 379%). In total, 104 patients underwent extended right hepatectomy (n = 102) or right hepatectomy (n = 2). The remaining 40 patients (27.8%) were not resectable due to short-interval disease progression (27 patients, 18.5%), insufficient liver regeneration (5 patients, 3.5%), and medical comorbidities (8 patients, 5.6%). After resection, the following outcomes were observed: major morbidity: 33.0% (34 of 104), liver insufficiency: 12.5% (13 of 104), and 90-day liver-related mortality: 5.8% (6 of 104). These oncologic and technical results compare favorably with those of ALPPS.

CONCLUSIONS

Based on its ability to select oncologically resectable patients and superior safety and efficacy profiles, percutaneous right + segment IV PVE and interval surgery remains the standard of care for patients with very low future liver remnant volumes.

Percutaneous unilateral placement of biliary covered metallic stent in patients with malignant hilar biliary obstruction and contralateral portal vein occlusion

BACKGROUND

Unilateral biliary metallic stent placement in the lobe with patent portal vein seemed to be a safe and effective palliative treatment of patients with contralateral portal vein occlusion caused by advanced hilar malignancy, obviating bilateral stent placement in these patients, because the hepatic lobe with portal vein occlusion ceases to produce bile due to interruption of enterohepatic circulation.

PURPOSE

To investigate the safety and efficacy of percutaneous unilateral expanded polytetrafluoroethylene (ePTFE)-covered stent placement in malignant hilar biliary obstruction with contralateral portal vein occlusion.

MATERIAL AND METHODS

From February 2008 to March 2011, 24 consecutive patients with malignant hilar biliary obstruction and unilobar portal vein occlusion were enrolled in this prospective study. All patients were treated by percutaneous placement of ePTFE-covered stents.

RESULTS

Stent deployment was technically successful in all patients. Two (8%) patients experienced minor self-limiting hemobilia. No major complication was noted. Successful internal drainage was achieved in 22 (91.6%) patients. Mean serum bilirubin level, which was 12.5 mg/dl ± 8.4 before drainage, decreased significantly to 2.7 mg/dl ± 3.4, 1 month after stent placement (P < 0.001). Median survival was 191 days (95% CI, 94-288 days) and cumulative stent patency rates at 1, 3, 6, 9, and 12 months were 100%, 95%, 95%, 95%, and 71%, respectively. Two (8%) patients presented with stent occlusion due to sludge incrustation. Aside from two patients who had died within 30 days after stent placement, the other 22 patients demonstrated slight decrease in diameter of undrained lobe and did not experience cholangitis nor jaundice.

CONCLUSION

Unilateral placement of ePTFE-covered stent in the lobe with patent portal vein seems to be a safe and effective method for palliative treatment of patients with contralateral portal vein occlusion. In addition, ePTFE-covered stent placement can prevent tumor ingrowth without functional occlusion of segmental bile ducts.

Short-term effects of combined hepatic vein embolization and portal vein embolization for the induction of liver regeneration in a rabbit model

PURPOSE

Alternative methods to optimize the hypertrophy response after portal vein embolization (PVE) are desired. This study assessed the effect of hepatic vein embolization (HVE) in addition to PVE on liver hypertrophy response in a standardized rabbit model.

MATERIALS AND METHODS

Thirty rabbits were allocated to groups according to intervention: PVE alone, HVE alone, and a combination of HVE and PVE. The liver regeneration response of the nonembolized, caudal liver was assessed by computed tomographic volumetry, liver-to-body weight index, and the amount of proliferating hepatocytes.

RESULTS

The caudal liver volume (CLV) increased significantly more in the PVE and combined PVE/HVE group than in the HVE group at 3 and 7 days after the procedure (P < .01). There were no significant differences in CLV increase or degree of hypertrophy between the PVE and combined embolization groups. The caudal liver-to-body weight index was significantly higher in the PVE and combined embolization groups than in the HVE group on day 7 (P < .01). The index was also significantly higher in the combined PVE/HVE group compared with the PVE group (P = .008). The caudal liver tissue of the PVE and combined groups contained a significantly higher number of proliferating hepatocytes compared with the HVE group on day 7 (P < .01).

CONCLUSIONS

Although histologic and additional regenerative changes are seen, HVE in addition to PVE has no additional short-term effect on hypertrophy response. The combination of HVE and PVE may therefore have little use in a clinical setting.

Liver regeneration after portal vein embolization using absorbable and permanent embolization materials in a rabbit model

OBJECTIVE

To compare the safety and hypertrophy response after portal vein embolization (PVE) using 2 absorbable and 3 permanent embolization materials.

BACKGROUND

Portal vein embolization is used to increase future remnant liver volume preoperatively. Application of temporary, absorbable embolization materials could be advantageous in some situations, provided sufficient hypertrophy is achieved from the nonembolized lobe.

METHODS

Six groups of rabbits (n = 5) underwent PVE of 80% of the total liver volume using saline (sham), gelatin sponge, fibrin glue, polyvinyl alcohol particles with coils, n-butyl cyanoacrylate, or polidocanol. The rabbits were killed after 7 days. Portography, computed tomographic volumetry, Doppler ultrasonography, laboratory liver function and damage parameters (nonembolized) liver-to-body weight ratio, immunohistochemistry, and cytokine and growth factor tissue levels were assessed to examine the differences in the liver regeneration response.

RESULTS

Polidocanol was discontinued because of toxic reactions in 3 rabbits. Gelatin sponge was the only material that was absorbed after 7 days and resulted in less hypertrophy of the nonembolized lobe than the other 3 materials. There were no significant differences in hypertrophy response between the other 3 embolization groups. Volumetric data obtained from computed tomography were supported by liver-to-body weight ratio and the amount of proliferating hepatocytes. The volume gain of the nonembolized lobe was proportional to the volume loss of the embolized liver lobes. The number of Kupffer cells in the embolized liver lobe was significantly higher in the fibrin glue, polyvinyl alcohol particles with coils, and n-butyl cyanoacrylate groups than in the sham and gelatin sponge groups. However, the levels of interleukin-6, tumor necrosis factor-α, hepatocyte growth factor, and transforming growth factor-β1 were significantly lower.

CONCLUSIONS

Temporary occlusion using gelatin sponge for PVE resulted in significantly less hypertrophy response than the use of permanent embolization materials. Except for polidocanol, none of the embolization materials exhibited evident hepatotoxicity.

Percutaneous biliary metallic stent placement in patients with unilobar portal vein occlusion caused by advanced hilar malignancy: outcome of unilateral versus bilateral stenting

OBJECTIVE

The purpose of this study was to investigate the outcome of biliary metallic stent placement in patients with contralateral portal vein occlusion caused by advanced hilar malignancy and to compare the outcomes of unilateral and bilateral stent placement.

MATERIALS AND METHODS

From January 2007 to December 2009, 41 patients with unilobar portal vein occlusion due to advanced hilar malignancy were enrolled in this retrospective study. All patients were treated with percutaneous placement of biliary metallic stents: unilateral stent placement in 23 patients, bilateral stent placement in 18 patients.

RESULTS

There were no significant differences in technical success (p > 0.999), successful drainage (p > 0.999), early cholangitis (p = 0.734), stent occlusion (p = 0.713), stent patency (p = 0.653), or patient survival (p = 0.493) between the two groups. In the patients who underwent unilateral stent placement, a slight decrease in diameter (mean diameter, 7.2 ± 3 mm before drainage, 6.2 ± 3 mm after stent placement) (p = 0.058) was observed in the intrahepatic bile duct of the undrained lobe with portal vein occlusion. Four of the patients who underwent unilateral stent placement had stent malfunctions, but the other 19 patients did not experience cholangitis or jaundice before death or the end of the study.

CONCLUSION

Unilateral biliary metallic stent placement in the lobe with a patent portal vein seems to be a safe and effective palliative treatment of patients with contralateral portal vein occlusion caused by advanced hilar malignancy, obviating bilateral stent placement in these patients.

Lobar and segmental liver atrophy associated with hilar cholangiocarcinoma and the impact of hilar biliary anatomical variants: a pictorial essay

The radiological features of lobar and segmental liver atrophy and compensatory hypertrophy associated with biliary obstruction are important to recognise for diagnostic and therapeutic reasons. Atrophied lobes/segments reduce in volume and usually contain crowded dilated bile ducts extending close to the liver surface. There is often a “step” in the liver contour between the atrophied and non-atrophied parts. Hypertrophied right lobe or segments enlarge and show a prominently convex or “bulbous” visceral surface. The atrophied liver parenchyma may show lower attenuation on pre-contrast computed tomography (CT) and CT intravenous cholangiography (CT-IVC) and lower signal intensity on T1-weighted magnetic resonance imaging (MRI). Hilar biliary anatomical variants can have an impact on the patterns of lobar/segmental atrophy, as the cause of obstruction (e.g. cholangiocarcinoma) often commences in one branch, leading to atrophy in that drainage region before progressing to complete biliary obstruction and jaundice. Such variants are common and can result in unusual but explainable patterns of atrophy and hypertrophy. Examples of changes seen with and without hilar variants are presented that illustrate the radiological features of atrophy/hypertrophy.

Volumetric analysis of the liver after right portal vein embolization: mid-term follow-up based on embolization score

AIM

To evaluate liver volume alterations and liver function after right portal vein embolization (PVE) during mid-term follow-up based on embolization score.

MATERIALS AND METHODS

Computed tomography (CT) images and liver function profiles were obtained before PVE, and at short-term (7-45 days), and mid-term follow-up (106-380 days) after PVE in all 30 patients. The patients were divided into group A (PVE score >or=3, n=20) and group B (PVE score <3, n=10). High score indicates more complete embolization.

RESULTS

Left liver volume (LLV) and percentage future liver remnant (%FLR) increased significantly between pre-PVE and short-term follow-up and between short-term and mid-term follow-up in group A. Increase in FLR volume was significantly higher at the mid-term follow-up than at the short-term follow-up in group A. The ratio of embolized to total liver volume (RETLV) on short-term follow-up was significantly higher in group A than in group B. Aspartate transaminase (AST) and alanine transaminase (ALT) were elevated on short-term follow-up, whereas at mid-term follow-up in group A, they had significantly returned to the baselines.

CONCLUSION

PVE resulted in continued compensatory hypertrophy of the unembolized liver during the 6-month follow-up. Compensatory hypertrophy in the unembolized liver was proportional to the ratio of embolization and to the embolized liver volume.

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.

Biliary intraductal papillary-mucinous neoplasm manifesting only as dilatation of the hepatic lobar or segmental bile ducts: imaging features in six patients

OBJECTIVE

The purpose of this study was to evaluate the imaging features of intrahepatic biliary intraductal papillary-mucinous neoplasm manifesting only as dilatation of the lobar or segmental bile ducts without a visible mass to determine whether this type of cholangiocarcinoma can be recognized on the basis of distinct imaging features.

CONCLUSION

Intrahepatic biliary intraductal papillary-mucinous neoplasm can spread along the mucosa without forming a mass and can produce a large amount of mucin. Severe dilatation of the lobar or segmental intrahepatic bile ducts with crowding and severe atrophy of the hepatic parenchyma are helpful imaging findings.

Chemotherapy and its effect on liver hypertrophy: implications for portal vein embolization and resection

Liver resection remains the gold standard treatment for colorectal liver metastases (CRLM). The improvement of the efficacy of chemotherapy has resulted in an increase of CRLM candidates for curative resection, including a significant proposition of patients initially deemed unresectable. The safety of liver resection has increased by taking advantage of regenerative capacities of the liver with preoperative portal vein embolization (PVE) and two-stage strategies. However, chemotherapy regimens including new drugs such as oxaliplatin and irinotecan may induce pathologic changes of the nontumorous liver parenchyma that could increase the risk of liver resection, and the impact of chemotherapy on the nontumorous liver parenchyma may limit tolerance of these resections. Preoperative portal obstruction, including PVE, which aimed to hypertrophy the future remnant liver, can be adversely affected by this chemotherapy. The aim of this article is to describe the impact of chemotherapy on nontumorous liver parenchyma and to evaluate the impact of chemotherapy on the regenerative capacities of the liver, especially after PVE.

Right portal vein ligation is as efficient as portal vein embolization to induce hypertrophy of the left liver remnant

BACKGROUND

Aim of this retrospective study was to compare induction of left liver hypertrophy after right portal vein ligation (PVL) and right portal vein embolization (PVE) before right hepatectomy for liver metastases.

MATERIALS AND METHODS

Between 1998 and 2005, 18 patients underwent a PVE, whereas 17 patients underwent a PVL during a first stage laparotomy.

RESULTS

There was no complication related to PVE or PVL. After a similar interval time (7 +/- 3 vs 8 +/- 3 weeks), the increase of the left liver volume was similar between the two groups (35 +/- 38 vs 38 +/- 26%). After PVE and PVL, right hepatectomy was performed in 12 and 14 patients, respectively. Technical difficulties during the right hepatectomy were similar according to duration of procedure (6.4 +/- 1 vs 6.7 +/- 1 h, p = 0.7) and transfusion rates (33 vs 28%, p = 0.7). Mortality was nil in both groups, and morbidity rates were respectively 58% for the PVE group and 36% for the PVL group (p = 0.6).

CONCLUSION

Right PVL and PVE result in a comparable hypertrophy of the left liver. During the first laparotomy of a two-step liver resection, PVL can be efficiently and safely performed.

Percutaneous ipsilateral portal vein embolization using a modified four-lumen balloon catheter with fibrin glue: initial clinical experience

PURPOSE

The purpose of the present study was to show the feasibility and safety of ipsilateral portal vein embolization (PVE) using an improved four-lumen balloon catheter with fibrin glue.

MATERIALS AND METHODS

To improve the ipsilateral PVE with fibrin glue, we modified a commercially available four-lumen balloon catheter to create a catheter comprising one lumen with a catheter tip for a guidewire, one lumen for an occlusion balloon, and two lumens, each with a side-hole just proximal to the balloon. Eight patients had hepatobiliary disease (three with bile duct carcinoma, two with gallbladder carcinoma, one with hepatocellular carcinoma, one with Caroli disease, and one with metastatic carcinoma).

RESULTS

All embolization procedures were technically successful. After embolization, the volume of the future remnant liver increased a mean of 131%. There was no inadvertent embolization of portal vein branches and no major procedure-related complications.

CONCLUSION

Our method is potentially easier and safer than the traditional ipsilateral method with fibrin glue using a three-lumen balloon catheter because the fourth lumen makes possible the use of a guidewire to access the targeted portal vein and measurement of any portal vein pressure elevation following PVE via the fourth lumen.

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.

The effects of pentoxifylline on liver regeneration after portal vein ligation in rats

AIM

To determine the effects of pentoxifylline, a methyl xanthine derivative on hepatic cell production of uninterferred lobe after portal vein branch ligation.

METHODS

Sixty-six rats were randomly allocated into 9 groups with 8 rats in PVL groups and 6 rats in sham operation groups. The portal branches of the median and the lateral liver lobes, corresponding to approximately 70% of the liver volume were ligated in the PVL groups. The control group received 0.9% NaCl solution. The rats in the treatment groups received pentoxifylline at the dose of 50 mg/kg/dy. After 1, 2, 4 days of portal vein ligation in both PVL and PVNL lobes the levels of adenine nucleotides were determined and flowcytometric analysis of cell cycles were performed.

RESULTS

On the first day of portal branch ligation energy charge was significantly lower, in pentoxifylline treated group comparing to pentoxifylline untreated group, both in PVL and PVNL lobes (P<0.05). Proliferative indexes were 0.38 and 0.29 in pentoxifylline treated and pentoxifylline untreated PVNL lobes respectively (P<0.05).

CONCLUSION

Pentoxifylline treatment resulted in an increase of percentage of calls entering mitosis phase on the first day after PVL, somehow accelerating the regeneration process.

Improving outcome in patients undergoing liver surgery

Liver surgery is associated with many factors, which may affect outcome. Preoperative assessment of patient's general condition, resectability, and liver reserve are paramount for success. The Child-Pugh score and other scoring systems only partially enables to assess the risk associated with liver surgery. The presence of portal hypertension per se is a major risk factor for hepatectomy. Intraoperatively, any attempts should be made to minimize blood loss. Low central venous pressure and inflow occlusion best prevent bleeding. Ischemic preconditioning and intermittent clamping are routinely applied in many centers to protect against long periods of ischemia, although the mechanisms of protection remain unclear. In this review we describe recent advances in activated pathways associated with protection against ischemia. Postoperatively, the best factor impacting on outcome probably resides in experienced medical care particularly in the intensive care setting. Currently, no drug or gene therapy approaches has reached the clinic. The future relies on new insight into mechanisms of ischemia-reperfusion injury.

Portal vein ligation and partial hepatectomy differentially influence growth of intrahepatic metastasis and liver regeneration in mice

BACKGROUND/AIMS

Since modern treatment of liver metastases includes serial hepatectomies and portal vein obstruction, we investigated the effects of portal vein ligation (PVL) and partial hepatectomy (PH) on tumor growth.

METHODS

The effects of 70% PH and PVL on liver and lung metastases were evaluated in mice. Tumor growth and liver regeneration were assessed by morphometry and immunohistochemistry for PCNA and BrdU. The effect of growth factors of liver regeneration on CT-26 cells was tested in vitro, and TGF-beta secretion of CT-26 cells was measured by ELISA. RNA synthesis of TGF-beta and activin A was measured by RT-PCR.

RESULTS

Liver regeneration after PH and PVL was similar in tumor-free mice. Intrahepatic tumor growth was lower after PH than after PVL (p=0.016). Extrahepatic tumor growth was not different. In contrast to PVL, liver regeneration was delayed after PH in metastatic livers (p=0.001). Tested growth factors of liver regeneration stimulated CT-26 cells in vitro, and CT-26 secreted significant amounts of TGF-beta in vitro and in vivo.

CONCLUSIONS

Although similar in tumor-free mice, liver regeneration significantly differed between PVL and PH in metastatic livers. In addition, PH and PVL differently affected intrahepatic tumor growth.

Hepatic atrophy-hypertrophy complex due to Echinococcus granulosus

Obstruction of a major hepatic vein, or major portal vein, or biliary tree branch causes atrophy of the related hepatic region, and frequently, hypertrophy in the remaining liver-the atrophy-hypertrophy complex (AHC). Whether hydatid cysts can cause AHC is controversial. The records of 370 patients who underwent surgery for hepatic hydatid disease between August 1993 and July 2002 were evaluated retrospectively. Excluding six patients with previous interventions on the liver, AHC had been recorded in the operative notes of 16 patients (4.4%); for all patients, a cyst located in the right hemiliver had caused atrophy of the right hemiliver and compensatory hypertrophy of the left hemiliver. The computed tomography images of seven patients were suitable for volumetric analysis. The median (range) right and left hemiliver volumes were 334 (0-686) ml and 1084 (663-1339) ml, respectively. The median (range) cyst volume was 392 (70-1363) ml. AHC due to Echinococcus granulosus was confirmed by objective volumetric analysis. The presence of AHC should alert the surgeon to two implications. First, pericystectomy may be hazardous due to association with major vascular and biliary structures. Second, in patients with AHC, the hepatoduodenal ligament rotates around its axis; this should be considered to avoid vascular injury if a common bile duct exploration is to be performed.

Diagnostic value of measuring liver volume for detecting occult hepatic metastases from colorectal or gastric cancer

Some studies have shown reduced portal blood flow in patients with occult hepatic metastases, which may lead to decreased liver volume. A retrospective study was conducted in patients undergoing curative resection for colorectal (n = 63) or gastric (n = 52) cancer. The ratio of the preoperative computed tomography (CT)-estimated liver volume to the standard liver volume (CV/SV ratio) was calculated. The mean +/- SD CT-estimated liver volume was 858 +/-109 in 14 patients who subsequently developed hepatic metastases and 1173 +/- 230 ml in 101 patients without metastases (p < 0.0001). The CV/SV ratio was smaller in patients with metachronous hepatic metastases than in those without (0.78 +/- 0.08 vs. 1.02 + 0.13; p < 0.0001). The results suggest that the liver with occult metastases decreases in size before metastases develop that are detectable using conventional imaging techniques. The CV/SV ratio may be of value in detecting occult hepatic metastases from colorectal and gastric cancer.

Portal Vein Embolization with N-Butyl Cyanoacrylate before Partial Hepatectomy in Patients with Hepatocellular Carcinoma and Underlying Cirrhosis or Advanced Fibrosis

PURPOSE

To describe the safety, complications, and liver regeneration associated with the left liver after embolization of the right portal vein (PV) in patients with hepatocellular carcinoma (HCC) developed in the setting of advanced liver fibrosis and cirrhosis.

MATERIALS AND METHODS

Forty patients (31 men, nine women; mean age, 62 years) with HCC underwent PV embolization over a 4-year period. Embolization was performed from a left PV percutaneous access with use of n-butyl cyanoacrylate (NBCA) mixed with iodized oil. Computed tomography (CT) volumetry was performed before and 1 month after PV embolization to measure the left lobe volume as well as the functional liver ratio defined by the ratio between the left lobe and the total liver volume minus tumoral volume. PV pressure and liver enzyme levels were compared before and 1 month after the procedure and complications were registered. Factors potentially affecting regeneration (age, sex, diabetes, chemoembolization, functional liver ratio before PV embolization, and Knodell histologic score) were evaluated by one-way and stepwise regression analysis.

RESULTS

PV embolization could be achieved successfully in all cases. Two patients had partial PV thrombosis on the 1-month follow-up CT and two patients developed transient ascites after PV embolization. The left lobe volume increase was 41% +/- 32% after PV embolization and the functional liver ratio increased from 28% +/- 10% to 36% +/- 10% (P < .0001). Hypertrophy of the left lobe was greater in patients with a low functional liver ratio before PV embolization and those with an F3 fibrosis score. Other factors had no influence on left lobe regeneration.

CONCLUSION

PV embolization with use of NBCA is feasible in patients with advanced fibrosis and cirrhosis. Hypertrophy of the left lobe of the liver after PV embolization has a statistically significant correlation with lower functional liver ratio and lower degrees of fibrosis.

Portal vein embolization in preparation for major hepatic resection: evolution of a new standard of care

Portal vein (PV) embolization (PVE) is gaining acceptance in the preoperative management of patients selected for major hepatic resection. PVE redirects portal blood flow to the intended liver remnant to induce hypertrophy of the nondiseased portion of the liver and thereby reduce complications and shorten hospital stays after resection. This article reviews the rationale and existing literature on PVE, including the mechanisms of liver regeneration, the pathophysiology of PVE, the imaging techniques used to measure liver volumes and estimate functional hepatic reserve, and the technical aspects of PVE, including approaches and embolic agents used. In addition, the indications and contraindications for performing PVE in patients with and without chronic liver disease and the multidisciplinary approach required for the treatment of these complex cases are emphasized.