Safety and Feasibility of Laparoscopic Liver Resection with the Clamp-Crush Method Using the BiSect.

BACKGROUND: Various energy devices are available for resection of the liver parenchyma during laparoscopic liver resection (LLR). We have historically performed liver resections using the Cavitron Ultrasonic Surgical Aspirator (CUSA). More recently, we have used new bipolar forceps (BiSect; Erbe Elektromedizin GmbH, Tübingen, Germany) to perform clamp-crush dissection with good results. The BiSect is a reusable bipolar forceps with a laparoscopic dissecting forceps tip and both an incision mode and coagulation mode. We evaluated the perioperative clinical course of patients who underwent LLR using the clamp-crush method with the BiSect compared with the CUSA. METHODS: This single-center case control study involved patients with liver metastasis from colorectal cancer who underwent LLR using either the BiSect or CUSA at our hospital from January 2019 to December 2022. We performed the LLR using CUSA from January 2019 to early October 2020. After introduction of the BiSect in late October 2020, we used BiSect for the LLR. Before surgery, the three-dimensional liver was constructed based on computed tomography images, and a preoperative simulation was performed. We evaluated the results of LLR using the BiSect versus the CUSA and assessed the short-term results of LLR. RESULTS: During the study period, we performed partial liver resection using the BiSect in 26 patients and the CUSA in 16 patients. In the BiSect group, the median bleeding volume was 55 mL, the median operation time was 227 minutes, and the median postoperative length of hospital stay was 9 days. In the CUSA group, the median bleeding volume was 87 mL, the median operation time was 305 minutes, and the median postoperative length of hospital stay was 10 days. There were no statistically significant differences in the clinical course including bile leakage, bile duct stenosis, and post operative hospital stay between the two groups. CONCLUSIONS: Compared with LLR using the CUSA, the clamp-crush method using the BiSect in LLR is a safe and useful liver transection technique. Further study should be conducted to clarify whether BiSect is safe and useful in LLR for patients with other tumor types and patients who undergo other procedures.

Causes and Management of Endoscopic Retrograde Cholangiopancreatography-Related Perforation: A Retrospective Study.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is essential for diagnosing and treating biliopancreatic disease. Because ERCP-related perforation can result in death, therapeutic decisions are important. The aim of this study was to determine the cause of ERCP-related perforation and suggest appropriate management. METHODS: Between January 1999 and August 2022, 7,896 ERCPs were performed in our hospital. We experienced 15 cases (0.18%) of ERCP-related perforation and conducted a retrospective review. RESULTS: Of the 15 patients, 6 were female and 9 were male, and the mean age was 77.1 years. According to Stapfer's classification, the 15 cases of ERCP-related perforation comprised 3 type I (duodenum), 3 type II (periampullary), 9 type III (distal bile duct or pancreatic duct), and no type IV cases. Fourteen of 15 (92.6%) were diagnosed during ERCP. The main cause of perforation was scope-induced damage, endoscopic sphincterotomy, and instrumentation penetration in type I, II, and III cases, respectively. Four patients with severe abdominal pain and extraluminal fluid collection underwent emergency surgery for repair and drainage. One type III patient with distal bile duct cancer underwent pancreaticoduodenectomy on day 6. Three type III patients with only retroperitoneal gas on computed tomography (CT) performed immediately after ERCP had no symptoms and needed no additional treatment. Seven of the 15 patents were treated by endoscopic nasobiliary drainage (n=5) or CT-guided drainage (n=2). There were no deaths, and all patients were discharged after treatment. CONCLUSIONS: Early diagnosis and appropriate treatment are important in managing ERCP-related perforation.

Evaluation of positive ductal margins of biliary tract cancer in intraoperative histological examination.

At present the only method available to confirm microscopic infiltration of cancer into ductal margins during surgery, is intraoperative histological examination. In the present study, the status of the surgical margins and postoperative course were evaluated to determine any correlation between remnant carcinoma and postoperative survival. All consecutive patients who underwent resection for biliary tract cancer between January 2004 and May 2012 were identified from a database. Positive margin cases were divided into two groups, invasive carcinoma and carcinoma in situ (CIS). Immunohistochemical staining targeting Ki67 and p53 for positive margins was performed. Cases of major vessel invasion were significantly increased in the positive group compared with the negative group. The recurrence rate was significantly lower in the CIS group compared with the invasive group. The survival rate was significantly increased in the CIS group compared with the invasive group. The expression levels of p53 and Ki67 were significantly increased in the invasive group compared with the CIS group. No statistical correlations were observed between the expression of p53 or Ki67 and the survival or recurrence of disease. In the positive group, resected margin status was the principal factor associated with recurrence-free survival according to Cox-regression analysis. In conclusion, the status of the resected margins in the positive group was the most important factor for postoperative survival and recurrence in cholangiocarcinoma, not immunohistochemical staining targeting Ki67 and p53.

An opportunity in difficulty: Japan-Korea-Taiwan expert Delphi consensus on surgical difficulty during laparoscopic cholecystectomy.

BACKGROUND: We previously identified 25 intraoperative findings during laparoscopic cholecystectomy (LC) as potential indicators of surgical difficulty per nominal group technique. This study aimed to build a consensus among expert LC surgeons on the impact of each item on surgical difficulty. METHODS: Surgeons from Japan, Korea, and Taiwan (n = 554) participated in a Delphi process and graded the 25 items on a seven-stage scale (range, 0-6). Consensus was defined as (1) the interquartile range (IQR) of overall responses ≤2 and (2) ≥66% of the responses concentrated within a median ± 1 after stratification by workplace and LC experience level. RESULTS: Response rates for the first and the second-round Delphi were 92.6% and 90.3%, respectively. Final consensus was reached for all the 25 items. 'Diffuse scarring in the Calot's triangle area' in the 'Factors related to inflammation of the gallbladder' category had the strongest impact on surgical difficulty (median, 5; IQR, 1). Surgeons agreed that the surgical difficulty increases as more fibrotic change and scarring develop. The median point for each item was set as the difficulty score. CONCLUSIONS: A Delphi consensus was reached among expert LC surgeons on the impact of intraoperative findings on surgical difficulty.

Subsequent biliary cancer originating from remnant intrapancreatic bile ducts after cyst excision: a literature review.

PURPOSE: There are sporadic reports of cancers developing in the remnant intrapancreatic bile duct tissues of patients with a history of primary choledochal cyst excision. The objective of this review is to study the clinical course of patients who develop subsequent biliary cancer originating from the remnant intrapancreatic bile ducts after cyst excision. METHODS: We describe a total of 17 cases (male:female 5:11; mean age 39.5 years), including the present case, from a review of the medical literature. RESULTS: Type I, type Iva, and unknown-type choledochal cysts according to the Todani classification were reported in nine, five, and three cases, respectively. The mean time to the development of subsequent cancer was 13.6 years. With the exception of one case, all of the cases (seven/eight cases) had elevated levels of serum CEA and/or CA19-9. Computed tomography was useful for detecting tumors (9/10 cases). Despite aggressive treatment, the cumulative survival rate after treatment was approximately 40 % at 1 year, with a mean survival duration of 12 months. CONCLUSION: Cancer may develop up to 10 years after choledochal cyst excision, indicating the need for life-long follow-up in this patient population.

Successful treatment of limy bile syndrome extending to the common bile duct by laparoscopic cholecystectomy and common bile duct exploration: A case report and literature review.

Limy bile syndrome extending to the common bile duct (CBD) is a rare condition that lacks a standardized treatment. Laparoscopic cholecystectomy with laparoscopic choledocholithotomy by CBD exploration is preferred because it preserves the function of the sphincter of the Vater's papilla and allows treatment of both lesions. A 37-year-old man who was receiving entecavir for chronic hepatitis B developed right upper quadrant pain. Abdominal ultrasonography revealed a calcified shadow in the gallbladder and CBD. Abdominal imaging revealed a liquid-like material identified by a calcified shadow in two phases separated by a fluid-fluid level. Abdominal and 3-D drip infusion cholangiography CT showed stones in the gallbladder and CBD with limy bile. The patient underwent laparoscopic cholecystectomy and choledocholithotomy. Intraoperatively, white-yellow-colored bile and stones were drained from the CBD. A C-tube was placed. Postoperatively, remnant stones and radiopaque materials were absent. The stones comprised of >95% calcium carbonate.

The "right" way is not always popular: comparison of surgeons' perceptions during laparoscopic cholecystectomy for acute cholecystitis among experts from Japan, Korea and Taiwan.

BACKGROUND: Generally, surgeons' perceptions of surgical safety are based on experience and institutional policy. Our recent pilot survey demonstrated that the acceptable duration of surgery and criteria for open conversion during laparoscopic cholecystectomy (LC) vary among workplaces. METHODS: A web-based survey was distributed to 554 expert LC surgeons in Japan, Korea, and Taiwan. The questionnaire covered LC experience, safety measures and recognition of landmarks, decision-making regarding conversion to open/partial cholecystectomy and the implications of this decision. Overall responses were compared among nations, and then stratified by LC experience level (lifetime cases 200-499, 500-999, and ≥1,000). RESULTS: The response rate was 92.6% (513/554); 67 surgeons with ≤199 LCs were excluded, and responses from 446 surgeons were analyzed. We observed significant differences among nations on almost all questions. Differences that remained after stratification by LC experience were on questions related to acceptable duration of surgery, adoption rates of intraoperative cholangiography, the "critical view of safety" technique, identification of Rouvière's sulcus, recognition of the SS-Inner layer theory, and intraoperative judgment to abandon conventional LC. CONCLUSIONS: Even among experts, surgeons' perceptions during LC are workplace-dependent. A novel grading system of surgical difficulty and standardized LC procedures are paramount to generate high-level evidence.

Interventional Treatment of Severe Portal Vein Thrombosis after Living-Donor Liver Transplantation.

Portal vein thrombosis (PVT) is a rare complication of liver transplantation which can lead to graft failure and patient death. Treatment can be difficult, especially in cases of PVT from the intrahepatic portal vein to the proximal jejunal veins. A 55-year-old woman had undergone living-donor liver transplantation with splenectomy for end-stage liver cirrhosis due to hepatitis C with hepatocellular carcinoma. Ten months after transplantation, massive ascites and slight abdominal pain developed, and computed tomography revealed a PVT between the intrahepatic portal vein and the superior mesenteric vein. Repeated interventional radiology procedures were used in combination with thrombolysis, thrombectomy, and metallic stent replacement to obtain favorable portal flow to the graft. Five years after being treated, the patient is well, with favorable portal flow having been confirmed. In conclusion, repeated and assiduous interventional radiological treatment combined with thrombolytic therapy, thrombectomy, and metallic stent replacement could be important for severe PVT.

Cecal Volvulus Following Elective Laparoscopic Cholecystectomy: A Case Report.

Cecal volvulus is characterized by torsion of the cecum around its own mesentery. However, cecal volvulus rarely develops soon after elective laparoscopic cholecystectomy. We report on a case of cecal volvulus that developed in a 54-year-old women 1 day after elective laparoscopic cholecystectomy and was successfully treated via colonoscopic decompression. The symptoms gradually improved in conjunction with recovery from postoperative ileus. Whether the incidence of volvulus has increased with the use of laparoscopic procedures, including laparoscopic cholecystectomy, has yet to be determined. Considering the current trend toward minimally invasive surgery, cecal volvulus should be considered in patients who have postoperative abdominal pain and distention.

Evaluation of Postoperative Pain Control and Quality of Recovery in Patients Using Intravenous Patient-Controlled Analgesia with Fentanyl: A Prospective Randomized Study.

AIM: Opioids are increasingly used to control postoperative pain via intravenous patient-controlled analgesia, with several advantages. The present study evaluated the effects of intravenous patient-controlled analgesia with different doses of fentanyl on postoperative pain and on the quality of physical/emotional recovery from surgery and anesthesia. METHODS: We retrospectively reviewed data from 288 patients, and evaluated whether intravenous patient-controlled analgesia with fentanyl correlated with the degree of postoperative pain. We then prospectively studied 47 patients who underwent elective laparoscopic cholecystectomy. The patients were randomized into 2 groups (15 or 30 µg/mL of fentanyl), and postoperative pain control was compared using a visual analog scale score. Furthermore, the Japanese 40-item quality of recovery (QoR-40J) score (global and dimensional) and Hospital Anxiety and Depression Scale (HADS) were used to assess the quality of recovery from surgery and anesthesia. RESULTS: Of 288 patients, 20% complained of intolerable pain and 18% experienced postoperative nausea and vomiting. In the prospective study, the visual analog scale pain score was lower in the Fentanyl 30 group than in the Fentanyl 15 group (p<0.05) on postoperative day 1. Dimensional QoR-40J pain subscales correlated with both the emotional state subscales (postoperative day 1, p<0.05; day 2, p<0.05) and global QoR-40 scores on both postoperative days (day 1, p<0.05; day 2, p<0.05). CONCLUSION: The postoperative pain as well as the physical and emotional quality of recovery in the patients who underwent laparoscopic cholecystectomy could be alleviated by sufficient doses of opioids.

What are the appropriate indicators of surgical difficulty during laparoscopic cholecystectomy? Results from a Japan-Korea-Taiwan multinational survey.

BACKGROUND: Serious complications continue to occur in laparoscopic cholecystectomy (LC). The commonly used indicators of surgical difficulty such as the duration of surgery are insufficient because they are surgeon and institution dependent. We aimed to identify appropriate indicators of surgical difficulty during LC. METHODS: A total of 26 Japanese expert LC surgeons discussed using the nominal group technique (NGT) to generate a list of intraoperative findings that contribute to surgical difficulty. Thereafter, a survey was circulated to 61 experts in Japan, Korea, and Taiwan. The questionnaire addressed LC experience, surgical strategy, and perceptions of 30 intraoperative findings listed by the NGT. RESULTS: The response rate of the survey was 100%. There was a statistically significant difference among nations regarding the duration of surgery and adoption rate of safety measures and recognition of landmarks. The criteria for conversion to an open or subtotal cholecystectomy were at the discretion of each surgeon. In contrast, perceptions of the impact of 30 intraoperative findings on surgical difficulty (categorized by factors related to inflammation and additional findings of the gallbladder and other intra-abdominal factors) were consistent among surgeons. CONCLUSIONS: Intraoperative findings are objective and considered to be appropriate indicators of surgical difficulty during LC.

Invention of Two Instruments Fitted with SECUREA™ Useful for Laparoscopic Liver Resection.

Laparoscopic liver resection (LLR) became common in Japan when advanced techniques and instruments for the procedure became available and the national medical insurance began covering partial resection and lateral segmentectomy. A successful LLR requires a gentle and powerful hold on the specimens, a steady operating field, and fast and rapid compression of the bleeding point to achieve hemostasis. In this paper we describe two instruments developed in our department by attaching the SECUREA™ endoscopic surgical spacer to the forceps and suction tube used for LLR. The instruments are useful and practical for any type of LLR, even in the hands of less experienced surgeons.

Modified laparoscopic biliary enteric anastomosis procedure using handmade double-armed needles.

INTRODUCTION: Laparoscopic biliary enteric anastomosis (BEA) offers several advantages, including good visualization, which helps to overcome the compromised visual field resulting from the biliary tract being located on the right anterior side of the body at some distance from the surgical opening. Laparoscopic BEA, however, requires skillful manipulation of the forceps over a limited range to achieve optimal outcomes. Here we describe a modified and reorganized BEA technique that increases the simplicity and feasibility of the procedure. MATERIALS AND SURGICAL TECHNIQUES: After biliary tract surgery for benign diseases such as laparoscopic choledocholithotomy, handmade double-sided needles were used for BEA in 20 patients. First, one of the needles was placed at the right edge of the bile duct wall from the outside to the inside, while the other arm of the needle entered the right edge of the intestine from the outside to the inside. Next, continuous sutures were placed on the posterior wall with the needle that was placed on the intestine. Then, continuous sutures were placed on the anterior wall with a second needle. Finally, both threads were laparoscopically tied. DISCUSSION: This relatively simple and feasible method has demonstrated excellent results and will be beneficial in the clinical setting.

Clinical outcomes for 14 consecutive patients with solid pseudopapillary neoplasms who underwent laparoscopic distal pancreatectomy.

INTRODUCTION: The postoperative results of laparoscopic distal pancreatectomy for solid pseudopapillary neoplasm of the pancreas (SPN), including the effects of spleen-preserving resection, are still to be elucidated. METHODS: Of the 139 patients who underwent laparoscopic pancreatectomy for non-cancerous tumors, 14 consecutive patients (average age, 29.6 years; 1 man, 13 women) with solitary SPN who underwent laparoscopic distal pancreatectomy between March 2004 and June 2015 were enrolled. The tumors had a mean diameter of 4.8 cm. Laparoscopic spleen-preserving distal pancreatectomy was performed in eight patients (spleen-preserving group), including two cases involving pancreatic tail preservation, and laparoscopic spleno-distal pancreatectomy was performed in six patients (standard resection group). RESULTS: The median operating time was 317 min, and the median blood loss was 50 mL. Postoperatively, grade B pancreatic fistulas appeared in two patients (14.3%) but resolved with conservative treatment. No patients had postoperative complications, other than pancreatic fistulas, or required reoperation. The median postoperative hospital stay was 11 days, and the postoperative mortality was zero.None of the patients had positive surgical margins or lymph nodes with metastasis. The median follow-up period did not significantly differ between the two groups (20 vs 39 months, P = 0.1368). All of the patients are alive and free from recurrent tumors without major late-phase complications. CONCLUSION: Laparoscopic distal pancreatectomy might be a suitable treatment for patients with SPN. A spleen-preserving operation is preferable for younger patients with SPN, and this study demonstrated the non-inferiority of the procedure compared to spleno-distal pancreatectomy.

Study on laparoscopic spleen preserving distal pancreatectomy procedures comparing splenic vessel preservation and non-preservation.

BACKGROUND: The purpose of this study is to investigate whether two types of laparoscopic spleen-preserving distal pancreatectomy (Lap-SPDP) techniques are being implemented safely. The study compares the clinical outcomes from laparoscopic Warshaw operation (Lap-W) with those from laparoscopic splenic vessels preserving SPDP (Lap-SPDP-VP) and considers the role of those operations. METHODS: On August 2013, the Warshaw technique was introduced to our institution and 17 patients with a lesion in the distal pancreas who underwent Lap-SPDP by December 2015 were enrolled. Six patients who underwent a Lap-W and 11 patients who underwent a Lap-SPDP-VP were investigated retrospectively. RESULTS: In the Lap-W and Lap-SPDP-VP patients, the sizes of the tumors were 46.5±31.2 and 25.7±14.9 mm [Probability (P) value =0.0913)]; the operative times were 287 min (range, 225-369 min) and 280 min (range, 200-496 min); the blood loss was 95 mL (range, 50-200 mL) and 60 mL (range, 0-650 mL); the length of the postoperative hospital stay was 12 days (range, 8-43 days) and 11 days (range, 7-28 days); median follow-up was 19 months (range, 13-28 months) and 23 months (range, 6-28 months), respectively. There was no case of symptomatic spleen infarction in either group. However, partial infarctions of the spleen without symptoms were observed by computed tomography in three out of six cases (50%) in the Lap-W. No patient required reoperation and the postoperative mortality was zero in both groups. All patients were alive and recurrence-free at the end of the follow-up period. Collateral veins around the spleen developed in 83.3% (five out of six patients) in the Lap-W and developed in 12.5% (one out of eight patients) in the Lap-SPDP-VP. A significant difference was observed between groups (P=0.0256). Gastric varices developed in 33.3% (two out of six patients) in the Lap-W. However, no case of rupture of varices, or other late phase complications was observed in either group. CONCLUSIONS: Both the Lap-W and Lap-SPDP-VP were found to be safe and effective, and in cases in which the detachment work of the splenic vessels from the tumor or the pancreatic parenchyma is difficult, performing Lap-W, rather than Lap-SPDP-VP, is considered appropriate. While Lap-SPDP is recommended for patients with benign or low grade malignant diseases, long-term follow-up to monitor hemodynamic changes in splenogastric circulation is considered needed.

Dysregulated miRNA in progression of hepatocellular carcinoma: A systematic review.

Hepatocellular carcinoma (HCC) is the fifth most frequent cancer and the third cause of cancer-related mortality worldwide. The primary risk factor for HCC is liver cirrhosis secondary to persistent infection with hepatitis B virus or hepatitis C virus. Although a number of cellular phenomena and molecular events have been reported to facilitate tumor initiation, progression and metastasis, the exact etiology of HCC has not yet been fully uncovered. miRNA, a class of non-coding RNA, negatively regulate post-transcriptional processes that participate in crucial biological processes, including development, differentiation, apoptosis and proliferation. In the liver, specific miRNA can be negative regulators of gene expression. Recent studies have uncovered the contribution of miRNA to cancer pathogenesis as they can function as oncogenes or tumor suppressor genes. In addition, other studies have demonstrated their potential value in the clinical management of patients with HCC as some miRNA may be used as prognostic or diagnostic markers. In this review, we summarize the current knowledge about the roles of miRNA in the carcinogenesis and progression of HCC.

Intraperitoneal Migration of a Mesh Plug from a Hernioplasty Forming a Colocutaneous Fistula with the Cecum: Report of a Case.

Tension-free hernia repair with a mesh plug causes relatively low postoperative pain and allows an earlier return to work, as well as a low recurrence rate. Occasionally, however, hernioplasty can result in complications including mesh migration and invasion of intra-abdominal organs. This report describes the case of a 57-year-old man who had undergone a right inguinal hernioplasty 13 years previously. Recovery was uneventful until he experienced inflammation of the groin, and required open drainage three times for a refractory abscess in his right groin. Additional colonoscopy and x-ray examinations with contrast medium clearly demonstrated a mesh plug that had migrated and penetrated the cecum, forming a colocutaneous fistula. The mesh was successfully removed under general anesthesia, and the inflammation in the groin resolved.

Laparoscopic skill improvement after virtual reality simulator training in medical students as assessed by augmented reality simulator.

INTRODUCTION: Definitive assessment of laparoscopic skill improvement after virtual reality simulator training is best obtained during an actual operation. However, this is impossible in medical students. Therefore, we developed an alternative assessment technique using an augmented reality simulator. METHODS: Nineteen medical students completed a 6-week training program using a virtual reality simulator (LapSim). The pretest and post-test were performed using an object-positioning module and cholecystectomy on an augmented reality simulator(ProMIS). The mean performance measures between pre- and post-training on the LapSim were compared with a paired t-test. RESULTS: In the object-positioning module, the execution time of the task (P < 0.001), left and right instrument path length (P = 0.001), and left and right instrument economy of movement (P < 0.001) were significantly shorter after than before the LapSim training. With respect to improvement in laparoscopic cholecystectomy using a gallbladder model, the execution time to identify, clip, and cut the cystic duct and cystic artery as well as the execution time to dissect the gallbladder away from the liver bed were both significantly shorter after than before the LapSim training (P = 0.01). CONCLUSIONS: Our training curriculum using a virtual reality simulator improved the operative skills of medical students as objectively evaluated by assessment using an augmented reality simulator instead of an actual operation. We hope that these findings help to establish an effective training program for medical students.

Clinical outcomes of 15 consecutive patients who underwent laparoscopic insulinoma resection: The usefulness of monitoring intraoperative blood insulin during laparoscopic pancreatectomy.

BACKGROUND: Insulinoma is a very serious functional tumor. Surgeons should confirm complete resection of insulinomas before completing the operation, even in laparoscopic surgery. METHODS: Between August 2007 and September 2014, 15 consecutive patients with biochemical evidence of an insulinoma underwent laparoscopic pancreatectomy. Intraoperatively, a peripheral arterial blood sample was taken, and insulin was measured by quick insulin assay. Insulin levels were determined before anesthesia induction, every 30 min thereafter, and every 30 min for at least 1 h after tumor resection to confirm insulin levels did not increase before surgery was completed. RESULTS: All 15 patients (3 men and 12 women, average age 57.2 years) successfully underwent laparoscopic resection. One patient had two tumors, and the remaining 14 patients had one tumor each (three in the head, five in the body, and eight in the tail of the pancreas). Preoperative localization and regionalization studies identified the tumor correctly through CT (12/15 [80.0%]), MRI (9/12 [75.0%]), angiography (11/13 [84.6%]), endoscopic ultrasonography (7/10 [70.0%]), and selective arterial calcium injection (14/14 [100%]). Intraoperative ultrasonography detected 13 of 15 tumors (86.7%), and intraoperative blood insulin monitoring confirmed the complete resection of 16 of 16 tumors (100%). All patients were discharged with normal insulin levels and have been followed up for 3-88 months. There has been no recurrence of symptoms in any patients and none has died. CONCLUSION: Complete removal of an insulinoma can be reliably predicted by intraoperative blood insulin monitoring even in laparoscopic pancreatectomies.

Host cellular microRNA involvement in the control of hepatitis B virus gene expression and replication.

A large number of studies have demonstrated that the synergistic collaboration of a number of microRNAs (miRNAs), their growth factors and their downstream agents is required for the initiation and completion of pathogenesis in the liver. miRNAs are thought to exert a profound effect on almost every aspect of liver biology and pathology. Accumulating evidence indicates that several miRNAs are involved in the hepatitis B virus (HBV) life cycle and infectivity, in addition to HBV-associated liver diseases including fibrosis, cirrhosis and hepatocellular carcinoma (HCC). In turn, HBV can modulate the expression of several cellular miRNAs, thus promoting a favorable environment for its replication and survival. In this review, we focused on the involvement of host cellular miRNAs that are directly and indirectly associated with HBV RNA or HBV associated transcription factors. Exploring different facets of the interactions among miRNA, HBV and HCV infections, and the carcinogenesis and progress of HCC, could facilitate the development of novel and effective treatment approaches for liver disease.