Surgical radical resection remains superior to other treatments in terms of survival and quality of life for patients with hilar cholangiocarcinoma. Combined hemihepatectomy and caudate lobectomy are now the standard radical procedure (Bismuth type II and above), and in order to achieve multiple negative margins, some patients often require combined vascular resection reconstruction and/or more extensive hepatic resection. The larger the volume of liver resection, the greater the risk that the patient will develop postoperative liver failure due to insufficient residual liver volume. Portal vein embolization (PVE), as a means to overcome this problem, has been used in Japan, Europe and the United States for metastatic hepatocellular carcinoma, hepatocellular carcinoma and biliary tract tumors since 1984 when Makuuchi et al. reported its first application for hilar cholangiocarcinoma. Numerous retrospective clinical studies have demonstrated that PVE can induce preoperative enlargement of the non-embolized liver lobes and help protect patients from postoperative liver failure by increasing the functional reserve of the liver. In recent years, controversies and advances coexist regarding the indications for PVE selection, portal vein access, types of embolization materials, complications, and methods of future liver remnant (FLR) function evaluation, and there is still a lack of multicenter randomized controlled studies of PVE. As a special indication for PVE, the selection indications and procedures for hilar cholangiocarcinoma should not be fully equivalent to hepatocellular carcinoma or colorectal cancer liver metastasis, because most patients with hilar cholangiocarcinoma have biliary obstruction, some have concomitant cholangitis, and a few have combined cirrhosis and diabetes mellitus. In Asia, the main indications for PVE are biliary tract tumors, among which hilar cholangiocarcinoma is the most common, especially in Japan. The study of preoperative PVE for hepatoportal cholangiocarcinoma is actively carried out in China. This paper discusses the experience of PVE in 40 cases of hilar cholangiocarcinoma as of the end of 2010 in the author’s (unit: Department of Biliary I, Shanghai Oriental Hepatobiliary Surgery Hospital). Influencing factors of liver volume change after PVE CT liver volume measurement method CT is the most commonly used and reliable method to evaluate volume change before and after PVE. Usually the scan interval is 2-10 mm, and the scan is enhanced by intravenous injection of contrast, which is sufficient to evaluate the volume of each liver segment. Currently, multi-row CT with 3-D maximum intensity projection technique is mostly used to provide a more accurate volume analysis for each liver segment. The metrics used to study the volume changes of liver lobes are mostly expressed as the absolute value of volume gain/atrophy after PVE (cm3), the rate of non-embolic lobes (or FLR) gain (%), and the proportion of non-embolic lobes to the whole liver (%). Although 3D-CT volumetry appears to be more accurate than conventional 2D-CT, it may still yield an error rate of approximately 10%. For future marginal candidates with a small residual liver (25%-35% whole liver volume), this error may be substantial. The author experiences that CT volume determination, either by direct area measurement or by software calculation, is based on the anatomical basis of lobar segmentation of the liver and requires the operator performing the measurement to be familiar with normal and variant portal vein and hepatic vein alignment, which should be determined in cases of complex vascular alignment with joint study by radiologists and surgeons. Timing of CT liver volume measurement The timing of cardiac liver volume remeasurement in Europe and the United States is mostly after 4 weeks of PVE, and most patients have liver metastases from colon cancer (long FLR hyperplasia, no acute or chronic liver impairment). Jaeck et al. reported 145 cases of PVE, in which the FLR increased from 472 ± 20 cm3 to 197 ± 12 cm3 4 to 8 weeks after PVE, with an FLR hyperplasia rate of 48 ± 32 (4 to 150)%. Their PVE to hepatectomy interval was longer (2.2±0.1 months). In Japan, most of the PVE liver volume retesting reported were within 3 weeks after PVE, and most of the cases were biliary tract tumors (intrahepatic cholangiocarcinoma, hilar cholangiocarcinoma, gallbladder cancer, etc.), and the FLR augmentation rate was lower than those reported in Europe and the United States, but the PVE to surgery interval was shorter. 240 cases of PVE (total hepatic biliary drainage was used for biliary obstruction before PVE) reported by Nagino et al. had non-embolization at an average of 2 weeks after PVE The liver lobe increased from 361±119 cm3 to approximately 99 cm3, with an augmentation rate of 33±24 (0-122) %. The general timing of CT volume retesting is at or after 2 weeks of PVE, and the choice of the timing of retesting needs to be determined by the patient’s FLR volume and functional compensatory hyperplasia, the rate of tumor progression, and other factors. Biliary obstruction and cholangitis in patients with hilar cholangiocarcinoma Reports from Japan generally suggest that the proliferation rate of non-embolic liver lobes in patients with hilar cholangiocarcinoma is about 20%. In general, PVE induces compensatory hyperplasia of the non-embolic lobes within 14 days and without serious complications. However, in patients with obstructive jaundice or cholangitis, the extent of hyperplasia is severely compromised and biliary obstruction of one hepatic segment impairs not only the cellular function of the obstructing lobe, but also the non-obstructing lobe. Longer time intervals between embolization and surgery may be required to induce FLR volume proliferation to a sufficient size. In addition, patients with combined intrahepatic cholangitis have worse complication rates and mortality after major hepatectomy (resection of 3 or more liver segments) than those without combined cholangitis. There is now a consensus to aggressively drain inflamed bile ducts prior to PVE for combined cholangitis. Whether total biliary drainage (TBD) or selective biliary drainage (SBD), which drains only the FLR, should be performed in patients with hilar cholangiocarcinoma without cholangitis remains controversial. PVE can be performed only when the patient’s serum TB drops below 2-5 mg/dl (34-86µmol/L. Makuuchi et al. first reported 15 cases of PVE after SBD with a higher rate of augmentation with drainage of non-embolic liver lobes only than with bilateral drainage. The mechanism of this phenomenon needs further study. Based on the author’s current experience with 40 cases, SBD was used in 32 cases prior to PVE, achieving effective volume augmentation of the nonembolic liver lobes. TBD may be the only option before PVE when unilateral drainage serum bilirubin levels remain high alone. Several studies have reported that internal biliary drainage provides a better environment for liver regeneration than external drainage, and that internal drainage also helps to maintain intestinal integrity, which may maintain normal intestinal immune function and allow patients to better tolerate the severe effects of an enlarged hepatectomy. If external drainage is performed, the drained bile should be returned to the infusion whenever possible. Other Factors Affecting the Ability of the Liver to Regenerate To the extent that it can be tolerated, the degree of liver regeneration is proportional to the degree of damage it endures. Clearly the same extent of hepatectomy induces more liver regeneration than PVE. The same right-sided PVE before right hepatectomy may produce a stronger proliferative effect in patients with marginal FLR volume ratio than in non-marginal patients. The author’s previous study of 16 PVE cases (on the basis of SBD) showed that the volume of the non-embolic liver lobe increased by 66 ± 36 cm3 (P<0.01) from 892 ± 278 cm3 before PVE on retest CT 2 weeks after PVE, and the rate of liver proliferation was 5.1 ± 2.7 cm3/d. The proliferation results were slightly lower than those reported abroad, which may be mainly due to the relatively large volume of the non-embolic liver lobe (48.5 ±12.6%). In addition, hepatitis cirrhosis, diabetes, chronic alcoholism, severe fatty liver and malnutrition, advanced age, and males were also considered to be factors limiting liver proliferation. Indications for PVE selection for future residual liver volume There are still no clear indications for PVE for future residual liver volume. Ladurner, Hemming et al. performed PVE in patients with an estimated residual liver volume of ≤25% of total liver volume, and they limited PVE to patients with an expected small residual liver, which is usually considered to be intolerant to resection. Other study groups had PVE indications of <30% or <40% estimated future residual liver. Because PVE significantly improves postoperative complication morbidity and mortality, should we limit PVE to marginal patients? If the administration of PVE results in zero mortality and minimal complication rates, we could extend the indication to patients who are ready to undergo extended hepatectomy. In fact, some centers have included right hemihepatectomy as an indication for PVE, possibly with an FLR volume ratio >40%, and Elias et al. suggested that the lower limit of the volume ratio, which is an indication for PVE selection, should be increased if the patient has undergone multiple courses of chemotherapy. It has even been suggested that PVE should be performed prior to major hepatectomy in patients with hepatic fibrosis, although patients with hilar cholangiocarcinoma usually have a normal hepatic base and most hepatic impairment is reversible if biliary obstruction is properly drained. However, it should be noted that the degree of functional impairment of the FLR due to obstructive jaundice can vary widely, and jaundice due to long-term biliary obstruction combined with biliary tract infection is often mixed, usually with varying degrees of digestive dysfunction and malnutrition. Especially in patients of advanced age, combined with cirrhosis and diabetes mellitus, strict volume ratio indications may place critical patients who have been denied PVE at risk of postoperative liver failure. In our experience, preoperative PVE selection criteria for hilar cholangiocarcinoma: no cirrhosis and jaundice/bile duct dilatation to PVE < 8 weeks and future residual/whole liver < 50%; with cirrhosis or finding jaundice/bile duct dilatation ≥ 8 weeks and future residual/whole liver < 60%. On the other hand, of course, it is particularly important to evaluate patients with hilar cholangiocarcinoma before PVE for the presence of acute and chronic liver impairment and other factors limiting liver regeneration. Since the aim of PVE is to spare patients as much as possible the risk of liver failure after major hepatectomy, there is no need to set a <40% limit for patients with acute or chronic liver impairment in FLR and it should be relaxed appropriately. the indications for the selection of FLR volume ratio for PVE should be changed, at least not simply by volume percentage delineation. The ultimate trend in preoperative PVE selection must be: a rational PVE and hepatic resection strategy, accurate FLR functional status assessment, individualized FLR proliferation potential assessment, grouping and application with other methods of promoting FLR regeneration, and there should be room for the possibility of intraoperative or postoperative FLR being struck twice. Embolization materials Gelatin sponges, fibrin glue, iodinated oil, cyanoacrylate and anhydrous ethanol, with or without embolization steel rings, have been used as classical embolization materials. No randomized controlled studies comparing the efficiency of these embolic materials have been performed so far. A report comparing gelatin sponges with anhydrous ethanol showed that gelatin sponges were ineffective in regenerating non-embolic lobes due to the high incidence of portal vein branch recanalization. in the 240 cases of PVE reported by Nagino, the embolic material used was initially fibrin glue, which was subsequently changed to a combination of ethanol and embolic steel rings. Although the recanalization rate was slightly higher with fibrin glue than with ethanol plus coils (8.3% vs 5.1%), there was no significant difference in the rate of non-embolic lobe augmentation or embolic lobe atrophy between the two. The reason for changing the embolic material was that the health insurance system considered fibrin glue too costly. Anhydrous ethanol readily perfuses to the level of the sinusoidal space and damages the endothelial cells of the sinusoidal space, and its perfusion causes more severe liver tissue damage than other embolic materials. Ethanol is able to drain into the terminal branch hepatic veins and subsequently into the body circulation. Further studies to elucidate the side effects of ethanol perfusion are necessary to determine the appropriate dose of ethanol to use. Several new embolic materials have been developed in recent years, such as: a mixture of N-butyl cyanoacrylate (NBCA) and iodinated oil, polyethylene glycol (PVA) pellets (non-spherical pellets, 355 to 1000 microns). Clinically proven to be useful. Recently, small spherical embolic particles (triacrylate-based microspheres, 100 to 700 microns) have become commercially available. One report showed that the degree of embolic hyperplasia was significantly greater with small spherical embolic particles than with large non-spherical particles (PVA). The benefit of these microspheres is that there is a wider range of particle sizes selected according to the size of the portal vein branch to be embolized. It is possible to use smaller particles to occlude the distal branches and larger particles to end branches to occlude the proximal branches. Histological results show that tripropylene-based microspheres can cause more distal embolization than polyethylene glycol in resected livers. Small microspheres can not only block portal blood flow but also reduce arterial blood flow by blocking arteriovenous traffic branches in the hepatic microcirculation. Our PVE is currently performed by simple steel coil embolization of the 1st to 2nd level branches of the portal vein, which is a permanent embolization of the proximal side without significant complications and is very well tolerated by patients, with significant fever (>38.5°C) being uncommon. After completion of embolization, portal venography confirmed that the embolized branch reached complete embolization, and CT volumetrics confirmed the ability to effectively induce volume increase in the non-embolized liver lobes, with clear intraoperative hyperplastic atrophy borders observed. Ultimately, the choice of embolic material serves the desired embolic goal – to efficiently induce non-embolic lobe hyperplasia and to be better tolerated by the patient. the initial clinical implementation of PVE was inspired by the phenomenon of lobe hyperplasia and atrophy following invasion of a portal vein branch on one side of a tumor patient, and by animal studies in which portal vein branch ligation simulated ischemia-induced promotion of liver regeneration. Clinical studies still sometimes report that portal vein branch ligation is effective in inducing liver regeneration; portal vein ligation is also routinely used as a standard control method in PVE animal studies. In fact, it remains controversial which is more effective: portal vein embolization or portal vein ligation. The debate over the ideal mode of embolization is inevitable. It is generally accepted that permanent embolization is preferable to transient embolization and that distal embolization of portal branches is preferable to proximal embolization. However, Lainas et al. reported that transient (reversible) embolization using gelatin sponges also induced effective liver regeneration; Furrer et al. concluded that the foreign body reaction caused by the distal embolization material impaired liver regeneration by sequestering macrophages. Is embolization of segment IV branches of the portal vein necessary? Portal cholangiocarcinoma frequently presents with invasion of the intrahepatic bile ducts, and sometimes, extensive hepatic resection (e.g., right trilobar resection) is required. Portal vein embolization is clearly necessary because the expected future residual liver volume in these patients is extremely small. The controversy of whether to embolize the left inner lobe (segment IV) branch at the time of right trilobar resection remains. Since segments II, III, and IV branches of the portal vein usually originate in the umbilicus of the portal vein, the undesired segment IV proliferation is bound to occur after embolization of the right branch alone, and adequate proliferation of segments II and III is inevitably compromised. From an operational point of view, embolization of segment IV branches is relatively difficult. Embolization of this branch is favored in some centers where IV branch embolization can be performed proficiently.Nimura et al. reported right trilobar PVE using an ipsilateral pathway approach and concluded that right trilobar portal vein embolization is more useful than standard right branch embolization for preparing for right trilobar resection and can increase surgical safety in patients with hilar cholangiocarcinoma.Madoff, Vauthey et al. also reported IV segment embolization. In contrast to these reports, Capussotti et al. reported that embolization expanding to segment IV should not be routinely used because similar segment II and III volume growth can be achieved simply by right PVE. The answer is unclear, as these studies included very small samples and again randomized controlled studies are lacking. What about inadequate FLR augmentation after PVE? A common reason why patients after PVE end up inoperable is inadequate FLR proliferation and tumor progression. adequate volume increase in the non-embolic lobes after PVE is not always achieved. If the increase is too small, hepatic resection should be abandoned, even in these patients where there are no factors suggesting that liver regeneration has been compromised. The mechanism of response to PVE in such patients with impaired liver regeneration is not known. What strategy should we choose as the next step in the management of these patients? As a result of the hepatic artery buffering response, there is a significant increase in hepatic artery flow in the embolized lobe, and the increased flow helps the embolized lobe to maintain its volume. Therefore, arterial embolization of the embolized hepatic lobe may be a way to further improve the effect of PVE. In patients with inadequate volume growth after PVE, some authors have reported the usefulness of performing sequential ipsilateral portal vein plus hepatic artery embolization. However, this essentially implies “in situ hepatectomy” of the embolization lobe and carries a high risk of developing liver abscess. Therefore, the indication for such invasive double embolization should be strictly chosen and one should always be prepared to manage the subsequent liver abscess by an interventional approach. Selective anhydrous ethanol ablation of intrahepatic bile ducts induces atrophy of the injected lobe and hyperplasia of the non-injected lobe. An experimental study in rats showed that 70% of the total liver weight of lobes injected with selective anhydrous ethanol decreased in weight to less than 50% of the total liver weight after 14 days of treatment. In contrast, the weight of non-injected lobes rose to 1.6 times the original weight. The injected ethanol soaked through the Glisson sheath and destroyed the hepatocytes without damaging the portal vein and hepatic artery. If the embolized lobe bile ducts are completely separated from the rest of the bile duct branches by the tumor, there is no risk of damaging the FLR bile ducts and this approach (e.g. selective intrahepatic bile duct anhydrous ethanol ablation) may be another option to achieve further volume increase. This in turn suggests to us that in patients with hilar cholangiocarcinoma, why not use SBD before PVE to keep the embolized liver lobe always jaundiced when inadequate FLR proliferation after PVE can be remedied by bile duct ablation? Extrahepatic hematopoietic stem cells are known to be involved in liver proliferation after hepatectomy, and CD133+ stem cells have been used to support myocardial tissue and organ regeneration. am Esch et al. recently reported the infusion of autologous CD133+ bone marrow cells into the liver via the portal vein in parallel with PVE. After PVE was completed, CD133+ cells were selectively applied to non-embolized hepatic portal branches. Although this preliminary study involved fewer patients, the data provided may be promising. In the post-PVE + bone marrow stem cell application group, the average daily volume increase in the non-embolic lobes was higher than in the PVE alone group. This approach may be a future countermeasure for patients with inadequate volume increases from PVE alone. Future evaluation of residual liver function The hilar bile duct, due to the specific site of tumor origin, dictates that most tumors require combined hemi/greater hepatic resection to achieve radical cure; the usually small tumor size results in the majority of resected lobes being functional liver parenchyma; and the preoperative combination of obstructive jaundice in most cases results in varying degrees of impairment of FLR function. Not only that, FLR function may still suffer intraoperative ischemic damage from combined hilar vascular resection and reconstruction, and postoperatively, it may be hit twice by complications such as liver abscess and liver trauma infection, etc. If the preoperative basis of diseases affecting liver regeneration such as cirrhosis and diabetes is also present, then the residual liver lobe function may be difficult or even impossible to compensate, and the chance of liver insufficiency or even failure will be greatly increased. Therefore, it is important to adequately and accurately assess FLR function before and after PVE in the perioperative (especially preoperative) period when major hepatectomy is planned for hilar cholangiocarcinoma. Although CT volumetry is a reliable measure of FLR volume compensation, it should be understood that the order of liver regeneration in PVE, as in major hepatectomy, is one in which functional compensation takes precedence over volume compensation, and the former is more sensitive. Due to the wide variety of methods used to assess liver function and reserve function, the methods used vary in different clinical centers. Classical practical indicators include TB, transaminases, PT, Pre-Alb, etc. Most serological indicators reflect whole liver function and are inconvenient to estimate FLR function. Of course, for patients with hilar cholangiocarcinoma with bilateral biliary obstruction performing SBD including FLR, TB can reflect the function of the biliary drainage liver lobe. Some current estimates of pre-PVE FLR function are achieved by multiplying the ratio of FLR to whole liver volume by indicators of drug hepatic metabolism tests (especially clearance). Indocyanine green clearance rate (ICGK) The indication for hepatic resection after PVE should not be determined simply by the volume of the future residual liver. It is generally accepted that 65% hepatic resection is safe for patients with normal liver function. In patients with chronic liver disease, hepatic resection should be limited to less than 50-60%. Indocyanine green 15-minute retention rate (ICGR15) or clearance rate (ICGK) may be the most useful method to assess future residual liver function and determine the extent of hepatic resection. kubota et al. suggested that PVE should be used in patients with ICGR15 in the range of 10-20%. Another report showed that ICGR15 less than 16% after PVE was a beneficial prognostic factor for complications after major hepatectomy. the results of Nimura et al. showed that patients with ICGK <0.05 for FLR had significantly higher postoperative mortality than those with >0.05. This may be a simple and reliable method to assess FLR function. Galactose human serum albumin scintigraphy 99 mTc diethylenetriaminepentaacetic acid galactose human serum albumin (99mTc-GSA) liver-powered single-photon emission tomography to assess residual liver function prior to hepatectomy is another useful method. 99mTc-GSA scintigraphy causes specific binding to different hepatocytes and serves as an indicator of liver function. The non-embolized lobes not only showed increased volume but also 99mTc-GSA uptake at week 1 after PVE. Postoperative liver failure occurred more frequently in patients with significantly lower 99mTc-GSA uptake. kubo et al. reported an average increase in the non-embolic lobes of patients of approximately 30%, although the average volume increase was less than 10% of the whole liver. In contrast, patients with embolic lobes decreased by an average of approximately 20%. similar results were reported by Nishiguchi et al. in patients with bile duct cancer (37% increase in non-embolic lobes; 23% decrease in embolic lobes). These results suggest that functional compensation of the FLR precedes volume increase. Interestingly, Uesaka et al. observed similar results by comparing embolic lobe and non-embolic lobe biliary ICG excretion using a PTBD catheter separated on both sides. after PVE, biliary ICG excretion in the non-embolic lobe as a percentage of whole liver excretion increased by an average of 20.1% , while at the same time the non-embolic lobe volume as a percentage of whole liver volume increased by only 8.3%. Therefore, FLR function should not be assessed simply by its volume. Contribution of PVE to improved outcomes after major hepatectomy Does PVE contribute to improved postoperative outcomes? As mentioned above, there are no randomized controlled clinical studies of the effectiveness of PVE and this question remains controversial. However, many reports have shown a benefit of PVE on outcomes after major hepatectomy. After Nimura et al. reported implementation of PVE, the incidence of liver failure after major hepatectomy decreased from 33.3% to 23.8%. Meanwhile, the mortality rate after major hepatectomy for biliary tract tumors (including gallbladder and bile duct cancers) decreased from 21.9% to 9.5%. After 2001, the mortality rate was only 1.6%. In our preoperative PVE study performed in 16 cases of hilar cholangiocarcinoma, TB decreased from 83.7±40.7 μmol/L before PVE to 53.5±31.2 μmol/L 2 weeks after PVE (P<0.01), suggesting a significant compensatory liver function. Thirteen patients in this group eventually underwent right or superhemispheric hepatectomy after steel-ring PVE, and nearly 33.3% (11/33) of the non-PVE hepatectomy group (n=33) had right or superhemispheric hepatectomy as the type of surgery during the same period. Although there was no statistical difference in operative mortality (0 vs 9.1%, P>0.05), or complication rate (69.2% vs 63.6%, P>0.05) between the two groups, all of the PVE group underwent more extensive hepatectomy and did not have an increased risk of postoperative liver insufficiency or postoperative complications. While it would be unethical to conduct a randomized controlled study of the effectiveness of PVE because of its clear benefits and the potentially devastating risk of a too-small remaining future residual liver, an RCT of different embolization patterns and materials for PVE is feasible. From the evidence of retrospective clinical studies, there was no perioperative mortality and no statistical difference in the rate of perioperative complications between the groups receiving and not receiving PVE. These results suggest that at least PVE is not a harmful method. It should be recognized that without PVE preparation, some marginal candidates for hepatectomy will be excluded from surgical treatment and probably surgery is the only chance to reach radical cure. Nevertheless, we should not ignore the side effects of PVE, which may also reduce the number of patients who are candidates for preparation for surgery. Risks of PVE In general, PVE is considered to be a safe approach. Mild side effects exist, such as mild abdominal pain, hypothermia, nausea and vomiting. AST, ALT and TB levels may also be elevated after PVE, but the elevation is mild and usually the enzymatic elevation does not exceed three times the pre-PVE baseline, with values falling back to preoperative levels within 1 week. Transient hepatic insufficiency after PVE has been reported, with 3.2% (6/188) of de Baere’s reports showing transient liver failure, mostly in patients with cirrhosis (5/6), who recovered well and had unaffected Child classification. Acute liver failure death after PVE has not been reported. There were no statistical differences in TB, enzymatic parameters and PT between patients before and 3 d after our steel coil PVE (n=16), suggesting that this method has little effect on total liver function. Platelet counts were lower (P<0.01) 3 d after PVE than before embolization, suggesting platelet depletion, possibly related to peri-steel coil thrombosis. Although reports showing serious side effects of PVE are uncommon, we must be aware of the risks associated with the PVE approach. The incidence of complications (requiring special management or leading to prolonged hospitalization) due to PVE varies. de Baere et al. retrospectively evaluated adverse events after PVE in 188 patients with cases including bile duct cancer, hepatocellular carcinoma, and colorectal cancer liver metastases. The complication rate was 12.8% (24/188) using NBCA mixed with iodinated oil as the primary embolic agent. Complications included future residual liver perfusion portal vein branch thrombosis, embolic migration, abdominal bleeding, biliary bleeding, subperitoneal hematoma, and liver failure. In addition, in approximately 10% of patients, hepatic resection was cancelled due to tumor progression, inadequate non-embolic liver augmentation, and complete portal vein thrombosis.Kodama et al. also analyzed post-PVE complications with a complication rate of 14.9% (7/47), including pneumothorax, subperitoneal hematoma, arterial injury, pseudoaneurysm, biliary bleeding, and non-embolic portal vein branch thrombosis, although no patients died. Complications reported by Nimura et al. included a case of portal and mesenteric vein embolism after extended PVE in a patient with combined S protein deficiency. Acute embolization of a major vessel in this patient may have triggered a coagulation cascade effect. Although routine assessment of hypercoagulable status is not practical, it should at least be done in these high-risk groups of patients. They concluded that to minimize non-embolic liver lobe injury, the portal vein embolization pathway should be performed from the same side as much as possible. Our preliminary 16 PVE complication rate of 18.7% (3/16) was a biliary leak at the puncture site and a small amount of steel ring displacement. Patients who developed PVE bile leak underwent percutaneous peritoneal peritoneal drainage successfully; two cases of PVE coil displacement and one case of one coil displacement to the main branch of S4, which was not affected by preoperative S4 main branch blood flow, and CT confirmed embolization of the main branch of S4 at 1.2 months after PVE (0.5 months after hepatectomy), but was accompanied by compensatory thickening of other small branches, and no extension of other branches was detected at follow-up until 14.3 months after PVE embolization. In the other case, 2 coils were displaced to the S3 branch, and the S3 branch remained patent until 12.5 months after PVE (11.7 months after hepatectomy). These two patients recovered after surgery. All 16 PVE cases did not show recanalization of the embolized target vein and no local necrotic liquefaction of the liver. PVE-responsive release of circulating growth factors may accelerate tumor progression. In patients with highly progressive tumors, this may accelerate the progression of the clinical stage of the tumor, rendering the patient inoperable. Certainly adequate assessment of tumor staging and resectability prior to PVE should be given adequate attention. the misuse of PVE may significantly prolong preoperative preparation time and provide the opportunity for tumor staging expansion, again without achieving the goal of radical resection. For patients with hepatoportal cholangiocarcinoma, the realization of a safe, reliable, efficient and effective PVE approach remains a joint effort of our colleagues.