Extended Liver Resection Research Articles

Surgical approaches to hepatic hydatidosis ranging from partial cystectomy to liver transplantation.

Backgrounds/AimsA wide range of surgical approaches has been described for hepatic hydatidosis aiming primarily at the reduction of disease recurrence and minimization of postoperative morbidity.MethodsA database analysis of patients with liver hydatidosis who underwent different surgical procedures between March 2010 and May 2016 was performed.ResultsA total of 21 patients with cystic echinococcosis (CE) and four cases of alveolar echinococcosis (AED) were detected. Nine patients manifested recurrent disease at presentation. Among CE cases, 5 underwent partial cystectomy (2 laparoscopic and 3 open), 9 cysto-pericystectomy (7 open and 2 robotic) and 7 hepatectomies (1 central, 4 right, 1 left and 1 right trisectionectomy). Living donor liver transplantation was performed in 3 patients with AED and the fourth patient underwent right trisectionectomy with en bloc resection of hepatic flexure and right diaphragm. Seven developed Clavien grade II and three grade III complications. The mean follow-up of CE was 34.19±19.75 months. One patient of laparoscopic partial cystectomy developed disease recurrence at 14 months. No recurrence was detected at a mean follow-up of 34±4.58 months following LDLT and at 24 months following multivisceral resection for AED.ConclusionsThe whole spectrum of tailored surgical approaches ranging from minimally invasive to open and extended liver resections represents safe, effective and recurrence-free treatment of hepatic hydatidosis.

Predictors of post-hepatectomy liver failure in patients undergoing extensive liver resections for hepatocellular carcinoma.

Backgrounds/AimsTo determine the prevalence of post-hepatectomy liver failure/insufficiency (PHLF/I) in patients undergoing extensive hepatic resections for hepatocellular carcinoma (HCC) and to assess the predictive value of preoperative factors for post-hepatectomy liver failure or insufficiency (PHLF/I).MethodsA retrospective review of patients who underwent liver resections for HCC between 2001 and 2013 was conducted. Preoperative parameters were assessed and analyzed for their predictive value of PHLF/I. Definitions used included the 50–50, International Study Group of Liver Surgery (ISGLS) and Memorial Sloan Kettering Cancer Centre (MSKCC) criteria.ResultsAmong the 848 patients who underwent liver resections for HCC between 2001 and 2013, 157 underwent right hepatectomy (RH) and extended right hepatectomy (ERH). The prevalence of PHLF/I was 7%, 41% and 28% based on the 50–50, ISGLS and MSKCC criteria, respectively. There were no significant differences in PHLF/I between RH and ERH. Model for End-Stage Liver Disease (MELD) score and bilirubin were the strongest independent predictors of PHLF/I based on the 50–50 and ISGLS/MSKCC criteria, respectively. Predictive models were developed for each of the criteria with multiple logistic regression.ConclusionsMELD score, bilirubin, alpha-fetoprotein and platelet count showed significant predictive value for PHLF/I (all p<0.05). A composite score based on these factors serves as guideline for physicians to better select patients undergoing extensive resections to minimize PHLF.

Central hepatectomy: A valuable option to avoid posthepatectomy liver insufficiency in patients requiring extensive liver resection.

Central hepatectomy: A valuable option to avoid posthepatectomy liver insufficiency in patients requiring extensive liver resection.

Impact of liver volume and liver function on posthepatectomy liver failure after portal vein embolization- A multivariable cohort analysis.

BackgroundLiver failure remains a life-threatening complication after liver resection, and is difficult to predict preoperatively. This retrospective cohort study evaluated different preoperative factors in regard to their impact on posthepatectomy liver failure (PHLF) after extended liver resection and previous portal vein embolization (PVE).MethodsPatient characteristics, liver function and liver volumes of patients undergoing PVE and subsequent liver resection were analyzed. Liver function was determined by the LiMAx test (enzymatic capacity of cytochrome P450 1A2). Factors associated with the primary end point PHLF (according to ISGLS definition) were identified through multivariable analysis. Secondary end points were 30-day mortality and morbidity.Results95 patients received PVE, of which 64 patients underwent major liver resection. PHLF occurred in 7 patients (11%). Calculated postoperative liver function was significantly lower in patients with PHLF than in patients without PHLF (67 vs. 109 μg/kg/h; p = 0.01). Other factors associated with PHLF by univariable analysis were age, future liver remnant, MELD score, ASA score, renal insufficiency and heart insufficiency. By multivariable analysis, future liver remnant was the only factor significantly associated with PHLF (p = 0.03). Mortality and morbidity rates were 4.7% and 29.7% respectively.ConclusionFuture liver remnant is the only preoperative factor with a significant impact on PHLF. Assessment of preoperative liver function may additionally help identify patients at risk for PHLF.

Computational Modeling in Liver Surgery.

The need for extended liver resection is increasing due to the growing incidence of liver tumors in aging societies. Individualized surgical planning is the key for identifying the optimal resection strategy and to minimize the risk of postoperative liver failure and tumor recurrence. Current computational tools provide virtual planning of liver resection by taking into account the spatial relationship between the tumor and the hepatic vascular trees, as well as the size of the future liver remnant. However, size and function of the liver are not necessarily equivalent. Hence, determining the future liver volume might misestimate the future liver function, especially in cases of hepatic comorbidities such as hepatic steatosis. A systems medicine approach could be applied, including biological, medical, and surgical aspects, by integrating all available anatomical and functional information of the individual patient. Such an approach holds promise for better prediction of postoperative liver function and hence improved risk assessment. This review provides an overview of mathematical models related to the liver and its function and explores their potential relevance for computational liver surgery. We first summarize key facts of hepatic anatomy, physiology, and pathology relevant for hepatic surgery, followed by a description of the computational tools currently used in liver surgical planning. Then we present selected state-of-the-art computational liver models potentially useful to support liver surgery. Finally, we discuss the main challenges that will need to be addressed when developing advanced computational planning tools in the context of liver surgery.

FIRST RUSSIAN EXPERIENCE OF USING THE INTEGRATED SYSTEM OF LASER THERMOABLATION THERAPY IN THE TREATMENT OF METASTATIC LIVER CANCER

Extensive liver resections are the main method of treatment of patients with primary and metastatic liver cancer, which allows the noticeable prolongation of life. In patients with a reduced functional reserve of the liver or a missing volume of the remaining liver parenchyma, these interventions become impossible because of the increased risk of postresectional acute hepatic insufficiency. One of the most modern and promising ways to overcome this obstacle is the use of minimally invasive methods of tumor destruction. This article presents two observations of the clinical application of the laser ablator “Echolaser X4”: open laser ablation of the metastatic focus with subsequent atypical liver resection and percutaneous laser ablation of the metastasis of the neuroendocrine tumor into the liver. The presented experience testifies to the justification of using laser destruction of metastatic malignant liver tumors and demonstrates the possibilities of laser thermoablation therapy in patients who can not perform radical surgical treatment.

MANAGEMENT OF SEVERE PERIOPERATIVE BLEEDING IN PATIENTS DURING EXTENSIVE LIVER RESECTIONS FOR COLORECTAL METASTASES

Aim of the study. To estimate an influence of the Cavitron ultrasonic surgical aspirator (CUSA) on intraoperative blood loss. Material and methods. An analysis of 185 cases of extensive liver resections in patients for colorectal liver metastases has been performed. All patients were assigned to CUSA group (n = 56) or clamp crashing group (n = 129). Patients from the first group received regional FOLFOX6 or FOLFOX6 + bevacizumab chemotherapy. Preoperative chemotherapy did not performed for second group of patients. Results. Liver transection with CUSA did not lead to the decline in intraoperative blood loss (p = 0.35). Conclusion. Median intraoperative blood loss was 1065 and 1180 ml respectively. Method for liver transection did not lead to the decline in intraoperative blood loss (p = 0.35). Intraoperative blood loss increases from standard to extensive liver resection (p = 0.0007). Resection of contralateral blood lobe metastases did not lead to statistically significant increase in blood loss as compared with standard mode of the operation (p = 0.005).

Impaired liver regeneration after hepatectomy and bleeding is associated with a shift from hepatocyte proliferation to hypertrophy.

Extensive liver resections are common, and bleeding is frequent in these operations. Impaired regeneration after partial hepatectomy (PHx) may contribute to liver failure. We thus assessed the impact of acute bleeding on the liver regeneration progress after PHx and explored possible contributing molecular mechanisms. In rats, the regeneration progress was delayed and attenuated with PHx and bleeding and was not restored with colloid resuscitation. Livers restored their initial volume by postoperative day (POD) 2 after PHx through hepatocyte proliferation vs. POD 4 in the PHx and bleeding group, primarily by hepatocyte hypertrophy. With bleeding, hepatocyte proliferation was hindered in two mechanisms: by inhibiting cells from starting proliferation and by causing hindrance in G1/S progression. Liver hypoxia was prominent, with significant prolonged up-regulation of hypoxia-inducible factors (HIF) and HIF-targeted genes only in the PHx and bleeding group. Gene expression profiling revealed alterations in numerous genes that belong to critical pathways, including cell cycle, DNA replication, PI3K-Akt, purine, and pyrimidine metabolism. Because liver surgery is frequently performed in patients with a predamaged liver, an improper regenerative process after PHx and bleeding might lead to decompensation. The results hint at specific pathways to target in order to improve liver regeneration during PHx and bleeding.—Matot, I., Nachmansson, N., Duev, O., Schulz, S., Schroeder-Stein, K., Frede, S., Abramovitch, R. Impaired liver regeneration after hepatectomy and bleeding is associated with a shift from hepatocyte proliferation to hypertrophy.

POST-TEXT III and IV Hepatoblastoma: Extended Hepatic Resection Avoids Liver Transplantation in Selected Cases.

To analyze the outcome of hepatoblastoma (HB) patients presenting with post treatment extent of disease (POST-TEXT) stages III and IV after neoadjuvant chemotherapy. Primary liver transplantation has been advocated as surgical treatment for children with HB involving 3 or 4 sectors at diagnosis. However, in some cases, tumors seem resectable after chemotherapy through aggressive use of nontransplant surgical procedures. Data of 27 HB patients were reviewed, undergoing extended liver resection for POST-TEXT III or IV tumors after chemotherapy between 1992 and 2015. Median follow-up was 58 months (range 9-188). Median age at surgery was 18.2 months (interquartile range 10.8-32.5). Staging of the children after chemotherapy revealed POST-TEXT III in 21 and POST-TEXT IV in 6 cases. In 2 children, the hepatic resection was performed under cardiopulmonary bypass because of extended vena cava thrombosis; in 2 patients, a simultaneous sternotomy was performed for resection of bilateral lung metastases. The 5-year overall survival rate was 80.7%. Aggressive surgical resection is a successful approach in some patients with POST-TEXT III and IV HB who otherwise would be candidates for liver transplantation. These children should undergo central review and should be surgically managed at centers of excellence for pediatric liver surgery. Despite challenging surgical procedures and complex clinical courses, the patients benefit from avoidance of morbidities of organ transplant. However, preparation of backup liver transplantation should be considered in selected cases.

Modified hanging manoeuvre facilitates inferior vena cava resection and reconstruction during extended right hepatectomy: A technical case report.

Liver resections are safe when performed by specialized hepatobiliary teams. However, complex liver resections are accompanied by significant perioperative risk and they may require modifications of the conventional surgical techniques. We herein report the case of a 54-year-old male patient who underwent an extended right liver resection with en bloc resection and reconstruction of the inferior vena cava. For this complex resection, a modification of the standard operative technique was required. A modified hanging manoeuvre was performed using two 19Fr nasogastric tubes outside the traditional avascular plane to facilitate resection. This modification of the hanging manoeuvre was proven to be feasible and safe, and it is recommended for inclusion in the armamentarium of hepatobiliary surgeons when complex resections are required.

Modulation of hepatic perfusion did not improve recovery from hepatic outflow obstruction

BackgroundFocal hepatic venous outflow obstruction frequently occurs after extended liver resection and leads to a portal hypertension, arterial hypoperfusion and parenchymal necrosis.In this study, we investigated the pharmacological modulation of liver perfusion and hepatic damage in a surgical model of hepatic outflow obstruction after extended liver resection by administration of 5 different drugs in comparison to an operative intervention, splenectomy.MethodsMale inbred Lewis rats (Lew/Crl) were subjected to right median hepatic vein ligation + 70% partial hepatectomy. Treatment consisted of a splenectomy or the application of saline, carvedilol or isosorbide-5-mononitrate (ISMN) (5 mg · kg−1 respectively 7,2 mg · kg−1 per gavage 12 h−1). The splenectomy was performed during operation. The effect of the treatments on hepatic hemodynamics were measured in non-operated animals, immediately after operation (n = 4/group) and 24 h after operation (n = 5/group). Assessment of hepatic damage (liver enzymes, histology) and liver cell proliferation (BrdU-immunohistochemistry) was performed 24 h after operation. Furthermore sildenafil (10 μg · kg−1 i.p. 12h−1), terlipressin (0.05 mg · kg−1 i.v. 12 h−1) and octreotide (10 μg · kg−1 s.c. 12 h−1) were investigated regarding their effect on hepatic hemodynamics and hepatic damage 24 h after operation (n = 4/group).ResultsCarvedilol and ISMN significantly decreased the portal pressure in normal non-operated rats from 11,1 ± 1,1 mmHg (normal rats) to 8,4 ± 0,3 mmHg (carvedilol) respectively 7,4 ± 1,8 mmHg (ISMN). ISMN substantially reduced surgery-induced portal hypertension from 15,4 ± 4,4 mmHg to 9,6 ± 2,3 mmHg. Only splenectomy reduced the portal flow immediately after operation by approximately 25%. No treatment had an immediate effect on the hepatic arterial perfusion. In all treatment groups, portal flow increased by approximately 3-fold within 24 h after operation, whereas hepatic arterial flow decreased substantially. Neither treatment reduced hepatic damage as assessed 24 h after operation. The distribution of proliferating cells appeared very similar in all drug treated groups and the splenectomy group.ConclusionTransient relative reduction of portal pressure did not result in a reduction of hepatic damage. This might be explained by the development of portal hyperperfusion which was accompanied by arterial hypoperfusion.

Mesenchymal stem cells correct haemodynamic dysfunction associated with liver injury after extended resection in a pig model

In patients, acute kidney injury (AKI) is often due to haemodynamic impairment associated with hepatic decompensation following extended liver surgery. Mesenchymal stem cells (MSCs) supported tissue protection in a variety of acute and chronic diseases, and might hence ameliorate AKI induced by extended liver resection. Here, 70% liver resection was performed in male pigs. MSCs were infused through a central venous catheter and haemodynamic parameters as well as markers of acute kidney damage were monitored under intensive care conditions for 24 h post-surgery. Cytokine profiles were established to anticipate the MSCs’ potential mode of action. After extended liver resection, hyperdynamic circulation, associated with hyponatraemia, hyperkalaemia, an increase in serum aldosterone and low urine production developed. These signs of hepatorenal dysfunction and haemodynamic impairment were corrected by MSC treatment. MSCs elevated PDGF levels in the serum, possibly contributing to circulatory homeostasis. Another 14 cytokines were increased in the kidney, most of which are known to support tissue regeneration. In conclusion, MSCs supported kidney and liver function after extended liver resection. They probably acted through paracrine mechanisms improving haemodynamics and tissue homeostasis. They might thus provide a promising strategy to prevent acute kidney injury in the context of post-surgery acute liver failure.

Laparoscopic Parenchymal-Sparing Liver Resections Using the Intrahepatic Glissonian Approach

One of the main criticisms of laparoscopic liver resection is that it is difficult, or not possible, to perform liver-sparing resections. Our aim was to present short videos where the intrahepatic Glissonian approach was used to perform anatomical liver segmental resections, instead of a larger operation, to avoid unnecessary sacrifice of the liver parenchyma. We selected six types of anatomical liver resections to exemplify the use of the intrahepatic Glissonian approach to perform segment-oriented liver resections. These types of hepatectomies were used as an alternative to right or left hepatectomy, or as an alternative to extended liver resections. The intrahepatic Glissonian approach was feasible in all cases. The use of anatomical landmarks previously described was essential to reach and control the Glissonian pedicles. Among the liver-sparing resections, we were able to perform right anterior (S5+S8) and posterior (S6+S7) sectionectomies, resection of segments 2, 3, and 4, and mesohepatectomy (S4+S5+S8). No patient presented postoperative liver failure. Laparoscopic liver-sparing resections are feasible and may be a good alternative to hemihepatectomies or extended liver resections. The use of the intrahepatic Glissonian approach can be useful.

Benefit of an implanted solid barrier for the feasibility of a sequence of three different hepato-biliary operations in a small animal model

Current liver surgery includes complex multi-stage procedures such as portal vein ligation (PVL) followed by extended liver resection, especially in patients with Klatskin tumours. The risk for severe adhesions increases with every procedure. Finally, this complex sequence could fail because of malignant adhesions. Therefore, we proved the hypothesis of reducing malignant adhesions and increasing feasibility of a sequence with three hepato-biliary operations by implantation of a solid barrier. We operated in male rats (n=40). Our sequence included as 1st operation bile duct ligation mimicking Klatskin III° or IV°, the 2nd operation was a selective portal vein ligation (sPVL) and 3rd procedure was a 70% liver resection. The mechanical barrier (part of a sterile glove) was implanted at the end of the first operation between the upper (median lobe+left lateral lobe [ML+LLL]) and lower (right lobe+caudate lobe [RL+CL]) rat liver lobes. We assessed the degree of adhesions and the feasibility of the 2nd and 3rd operation by using an established adhesion score (Zühlke) and a feasibility score. The severity of the adhesions and the pro-inflammatory cellular response were further evaluated by morphometry of thickness (HE) of the adhesion layer and quantification of infiltrating neutrophils (ASDCL) in the adhesion layer on the liver surface. The planned liver resection as the third procedure was only feasible when a mechanical barrier was placed. Extent of cholestasis or time interval between the operations had no significant impact on adhesions score or feasibility of the whole sequence. A sequence of three hepato-biliary operations in a small animal model (rat) is feasible. It should be considered to implant a mechanical barrier in a sequence of more than two surgical interventions in an experimental model in order to assure the feasibility of the final operation.

Extended liver resection in a central biliary cystadenoma

Objective: Biliary cystoadenomas are rare, less than 5% of non-parasitic liver cysts and often confused with other more common cystic disease. Its premalignant potential indicates the need for a complete surgical resection. Video presentation of a central cystadenoma with bilateral vascular relations. Methods: 61 year old female with a cystic tumor involving segments 3,4b,5,7 and 8; diagnosed 5 years ago and followed up by ultrasound with slow growth. CT: multilocular cyst that compress bilaterally elements of hepatic hilum. MRI: 13 cm centrally located tumor extending cephalic from the liver caudate lobe to the dome, hypointense in T1, hyperintense in T2; in contact with pancreatic head and bilateral hepatic highland displacement. Results: Right extended hepatectomy was performed with good postoperative evolution. Discharge at 5th day. Pathology: mucinous cystic neoplasm of the liver with low-grade dysplasia, negative margins. Conclusion: Complete resection is the best treatment for biliary cystadenoma in order to avoid recurrence and malignant transformation. According to the anatomical location, the parenchymal characteristics and the liver remnant the best approach for a complete resection needs to the considered. Partial resections must be avoided.

Predicting the trajectory of post-hepatectomy liver dysfunction (PHLD)

Objective: PHLD is an expected outcome with more extensive liver resections, and it remains a major cause of morbidity. Early recognition of severe cases may be beneficial. The International Study Group of Liver Surgery (ISGLS) consensus criteria for post-hepatectomy liver failure serve to identify individuals with significant liver dysfunction. However, because the diagnostic criteria comprise liver dysfunction persisting more than 4 days after hepatectomy, the ISGLS definition is of limited use to a clinician. Our objective was to identify factors that inform the clinician whether PHLD is likely to be accompanied by an adverse clinical course. Methods: Liver resections between 2006 and 2014 were retrospectively reviewed. Patients with bilirubin ≥40 μmol/L and/or prothrombin time ≥1.5 at any time after surgery were identified. Factors associated with severe complications, ICU admission and death were identified. Results: During the study period, 1010 liver resections were performed and 110 patients (10.9%) had PHLD. Of those, 76 (69%) met the ISGLS criteria for liver failure. Clavien-Dindo complication grades ≥4 (ICU admission or mortality) occurred in 25 patients (22.7%). Factors associated with those adverse outcomes included patient age (P=0.015), duration of surgery (P=0.030), estimated blood loss (P=0.010), and the need for intraoperative blood transfusions (P < 0.001). The extent of liver resection and presence of cirrhosis did not predict clinical trajectory. Conclusion: Intraoperative events leading to prolonged surgery and excessive blood loss had the greatest influence on the clinical trajectory of PHLD.

RESULTS OF ADEMETHIONIN ADMINISTRATION AFTER EXTENSIVE LIVER RESECTIONS

Aim. To study adamethionin effect on liver failure course after extensive liver resection. Material and Methods . 538 patients after extensive liver resection were included into study. Adamethionin has been used in the main group (326 patients) postoperatively while in the control group (212 patients) hepatoprotective therapy was absent. Incidence and severity of liver failure as well as postoperative complications were analyzed. Results. Total incidence of post-resection liver failure was 23% (18.7% and 30.2% in the main and control groups respectively, p &lt; 0.05). Mild complications were predominant in the main group while moderate and severe events were observed in the control groups. Post-resection liver failure by “50–50 criteria” was revealed in 27 patients of the control group (12.7%) vs. 13 patients of the main group (4.0%) (p &lt; 0.05). There was significant decrease of ALT and AST activity in the main group compared with the control group postoperatively. Overall incidence of postoperative complications was 18.9% and 17.2% in control and main groups respectively. The incidence of biliary complications was 7.5% and 6.4% in both groups respectively (p &gt; 0.05). Postoperative hospital-stay was 15 (12–28) days in the control group and 11 (9–19) days in the main group (p &lt; 0.05). Conclusion. Liver failure is possible after extensive liver resections (over three segments). Ademetionin contributes to restoration of liver structure and function, reduces the incidence of liver failure and hospital-stay, provides faster recovery of residual liver parenchyma.

Establishing a Porcine Model of Small for Size Syndrome following Liver Resection.

Background Small for size syndrome (SFSS) is responsible for a high proportion of mortalities and morbidities following extended liver resection. Aim The aim of this study was to establish a porcine model of SFSS. Methods Twenty-four Landrace pigs underwent liver resection with a remnant liver volume of 50% (group A, n = 8), 25% (group B, n = 8), and 15% (group C, n = 8). After resection, the animals were followed up for 8 days and clinical, laboratory, and histopathological outcomes were evaluated. Results The survival rate was significantly lower in group C compared with the other groups (p < 0.001). The international normalized ratio, bilirubin, aspartate transaminase, alanine transaminase, and alkaline phosphatase levels increased shortly after surgery in groups B and C, but no change was observed in group A (p < 0.05 for all analyses). The histopathological findings in group A were mainly mild mitoses, in group B severe mitoses and hepatocyte ballooning, moderate congestion, and hemorrhage, along with mild necrosis, and in group C extended tissue damage with severe necrosis, hemorrhage, and congestion. Conclusions Combination of clinical, laboratory, and histopathological evaluations is needed to confirm the diagnosis of SFSS. 75% liver resection in porcine model results in SFSS. 85% liver resection causes irreversible liver failure.

Hyperplasia vs hypertrophy in tissue regeneration after extensive liver resection.

AIMTo address to what extent hypertrophy and hyperplasia contribute to liver mass restoration after major tissue loss.METHODSThe ability of the liver to regenerate is remarkable on both clinical and biological grounds. Basic mechanisms underlying this process have been intensively investigated. However, it is still debated to what extent hypertrophy and hyperplasia contribute to liver mass restoration after major tissue loss. We addressed this issue using a genetically tagged system. We were able to follow the fate of single transplanted hepatocytes during the regenerative response elicited by 2/3 partial surgical hepatectomy (PH) in rats. Clusters of transplanted cells were 3D reconstructed and their size distribution was evaluated over time after PH.RESULTSLiver size and liver DNA content were largely recovered 10 d post-PH, as expected (e.g., total DNA/liver/100 g b.w. was 6.37 ± 0.21 before PH and returned to 6.10 ± 0.36 10 d after PH). Data indicated that about 2/3 of the original residual hepatocytes entered S-phase in response to PH. Analysis of cluster size distribution at 24, 48, 96 h and 10 d after PH revealed that about half of the remnant hepatocytes completed at least 2 cell cycles. Average size of hepatocytes increased at 24 h (248.50 μm2 ± 7.82 μm2, P = 0.0015), but returned to control values throughout the regenerative process (up to 10 d post-PH, 197.9 μm2 ± 6.44 μm2, P = 0.11). A sizeable fraction of the remnant hepatocyte population does not participate actively in tissue mass restoration.CONCLUSIONHyperplasia stands as the major mechanism contributing to liver mass restoration after PH, with hypertrophy playing a transient role in the process.

ABOUT THE LIVER FUNCTIONAL RESERVE

Aim. Combined evaluation of liver functional and volumetric reserves prior to advanced liver resections. Material and Methods. The study included 24 patients who underwent extended liver resections for the period 2013– 2016. Clinical and laboratory data, indocyanine green (ICG) clearance, CT volumetry, static polypositional hepatoscintigraphy were assessed in all cases. Results. Individual tests showed sufficient functional reserve of FLR in all patients. However in 7 (29.2%) cases advanced resections were refused in favor of less liver volume removal, two-stage surgery or portal vein embolization to increase remnant liver volume. The reasons for refusal were compiled simulation of extended resection using PET combined with scintigraphy and comprehensive analysis of all factors affecting postoperative liver failure. Conclusion. Comprehensive assessment of functional and volumetric reserve prevents postoperative liver failure. At present time transition from evaluation of total liver parenchyma reserves to isolated assessment of FLR reserve is the most actual problem.