A case of severe hemorrhagic shock caused by traumatic avulsion of uterine fibroid.

Case presentation: A 40-year-old woman was injured in a motor vehicle accident. Physician-staffed helicopter emergency medical service (HEMS) was dispatched, and after the HEMS physician performed thoracostomy and tracheal intubation to relieve the tension pneumothorax and hemorrhagic shock, her carotid artery became unpalpable. The physician then decided to perform prehospital resuscitative thoracotomy. Immediately after arriving at the hospital, an emergency laparotomy was performed. Intraoperative findings showed that a huge uterine fibroid had been avulsed from the uterine wall, and we performed temporary hemostasis by extraction of the avulsed tumor and application of packing to the pelvic cavity. She was transferred to a rehabilitation hospital 42 days after the operation. Conclusion: The injury mechanism in this case was considered a "submarine effect." This was an extremely rare case in which the acute care surgeon and a gynecologist collaboratively employed a damage control strategy to deal with impending cardiac arrest.

Emergent surgery for cardiac herniation coexisting with complex blunt cardiac injury: A case report.

A 38-year-old man was pressed on his trunk by a heavy object weighing about 100 kg. The patient was in shock status on arrival to the hospital. Circular collapse progressed rapidly during contrast computed tomography (CT) scanning. CT images revealed exacerbation of the right lateral deviation of the heart that was earlier seen on X-ray imaging. Considering cardiac herniation based on CT findings, we immediately performed resuscitative thoracotomy and clamshell thoracotomy at the emergency department. Intraoperative findings showed a pericardial defect, and the heart had deviated to the right thoracic cavity. Immediate repositioning revealed a marked improvement in circulation. Full-thickness cardiac injury was observed in the anterior wall of the left ventricle; no active bleeding was observed. We performed temporary thoracic wall closure after cardiorraphy for damage control. After admission to the intensive care unit, he presented with respiratory failure associated with pulmonary contusion. Therefore, veno-venous extracorporeal membrane oxygenation (V-V ECMO) was used from the 2nd to the 5th hospital day. After confirming no intra-thoracic events on the 6th hospital day, chest wall closure was performed. The patient subsequently developed heart failure and mitral regurgitation associated with papillary muscle rupture. On the 62nd hospital day, he underwent mitral annuloplasty at the cardiovascular surgery division; After rehabilitation till 152nd hospital day, he was discharged without any neurological abnormality. This was an extremely rare case with concomitant full-thickness myocardial injury, intracardiac injury, and cardiac herniation. Rapid resuscitative thoracotomy and damage control including V-V ECMO yielded good results. Retrospectively, cardiac herniation should have been suspected earlier basis this observation. Our report highlights that cardiac herniation should be considered in case of cardiac shadow aberrations in cases of blunt chest trauma, familiarity with condition and its characteristic imaging findings are critical for the doctor overseeing initial trauma treatment.

Diagnostic accuracy of diffusion-weighted whole-body imaging with background body signal suppression/T2-weighted image fusion for the detection of abdominal solid cancer.

Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) images show significant contrast for cancer tissues against non-cancerous tissues. Fusion of a DWIBS and a T2-weighted image (DWIBS/T2) can be used to obtain functional, as well as anatomic, information. In the present study, the performance of DWIBS/T2 in the diagnosis of abdominal solid cancer was evaluated. The records of 14 patients were retrospectively analyzed [5 patients with hepatocellular carcinoma (HCC), 4 with metastatic liver cancer, 3 with pancreatic cancer, 1 with renal cellular carcinoma and 1 with malignant lymphoma of the para-aortic lymph node]. T1WI and T2WI scans did not detect pancreatic cancer in certain cases, whereas DWIs and DWIBS/T2 clearly demonstrated pancreatic cancer in all cases. In addition, metastatic liver cancer and HCC were successfully detected with abdominal US and CECT; however, US did not detect pancreatic cancer in 1 case, while CECT and DWIBS/T2 detected pancreatic cancer in all cases. In conclusion, the diagnostic performance of DWIBS/T2 was the same as that of abdominal US and CECT in detecting primary and metastatic liver cancer. DWIBS/T2 enabled the diagnosis of pancreatic cancer in cases where it was not detected with US, T1WI or T2WI.

Diffusion-weighted whole-body imaging with background body signal suppression/T2 image fusion and positron emission tomography/computed tomography of upper gastrointestinal cancers.

PURPOSE: Diffusion-weighted whole-body imaging with background body signal suppression/T2 image fusion (DWIBS/T2) strongly contrasts cancerous tissue against background healthy tissues. Positron emission tomography/computed tomography (PET/CT) applies the uptake of 18-fluorodeoxyglucose in the diagnosis of cancer. Our aim was to compare DWIBS/T2 and PET/CT in patients with upper gastrointestinal cancers. METHODS: Patient records, including imaging results from July 2012 to March 2015, were analyzed retrospectively. Four men (age, 72.5 ± 5.3 years) and ten women (age, 71.6 ± 4.0 years) were enrolled in this study. The numbers of patients with esophageal cancer, gastric cancer, gastrointestinal stromal tumor, and duodenal cancer were one, eight, three, and two, respectively. RESULTS: Six out of eight patients with gastric cancer had positive results on both DWIBS/T2 and PET/CT. The diameter and depth of invasion of gastric cancer was larger in patients with positive DWIBS/T2 and PET/CT findings than those with negative findings. These results suggested that patients with gastric cancer with larger pixel numbers might tend to show positive results with DWIBS/T2. CONCLUSIONS: DWIBS/T2 and PET/CT have similar sensitivity for the diagnosis of upper gastrointestinal cancer. The diameter and depth of invasion affected the detectability of gastric cancer.

Thoracoscopic hepatectomy for malignant liver tumor.

BACKGROUND: Anatomical position of the liver poses a difficulty in approaching the lesions using a laparoscopic approach. METHODS: The patient was a 79-year-old man with a surgical history of laparoscopic sigmoidectomy for colon cancer and posterior segmentectomy of the liver for metastatic liver tumor. On admission, he presented with another liver tumor (diameter, 1.5 cm) in the dome of segment VIII. Because of the high possibility of severe adhesion around the liver and difficulty of approaching the lesion from the abdomen, we selected the transthoracic approach rather than the abdominal approach; the patient consented to this procedure. The patient was placed in the left-lateral position under general anesthesia with single-lung ventilation. We placed three trocars into the right thoracic space. The intrathoracic space was observed using a flexible-tip rigid scope (Olympus, Tokyo, Japan). The tumor was detected by inserting a flexible laparoscopic ultrasound probe (Hitachi Aloka, Ltd., Tokyo, Japan) through the diaphragm; the diaphragm was dissected immediately above the tumor using a harmonic scalpel (Ethicon Endo-Surgery, Inc., Cornelia, GA). The liver surface was precoagulated using a low-voltage monopolar coagulator with a ball-shaped tip (Amco Inc., Tokyo, Japan) with the electrosurgical unit VIO300D (Erbe Elektromedizin, Tuebingen, Germany). The parenchyma was first sealed using BiClamp LAP forceps (Erbe Elektromedizin) and divided using the harmonic scalpel. The specimen was extracted using a retrieval bag. After complete hemostasis was achieved, the diaphragm was closed by continuous suturing. RESULTS: The operation lasted for 310 min and estimated blood loss was 10 mL. The patient was discharged on postoperative day 4. CONCLUSIONS: Although the duration of TH was long because of the narrow thoracic cavity space, TH was performed without any problems. As a rule, we should select TH for lesions located in the dorsal segment VII/VIII, with severe adhesion around the liver.

Adult with primary hyperoxaluria type 1 regrets not receiving preemptive liver transplantation during childhood: report of a case.

A 32-year-old male was suspected to have primary hyperoxaluria type 1 (PH1) and eventually underwent liver transplantation (LT). He was diagnosed with nephrolithiasis at 9 years of age. Right heminephrectomy was performed for a staghorn calculus. He underwent urethrotomy for urinary retention at 12 years of age. Percutaneous nephrolithotomy was performed for nephrolithiasis when he was 16 years of age. He underwent frequent extracorporeal shock wave lithotripsy for recurrent nephrolithiasis from 18 to 24 years of age. PH1 was suspected at 32 years of age, and pharmacological therapy was also initiated. He developed renal failure at 36 years of age, which was treated with intensive hemodialysis. A definitive diagnosis of PH1 was made based on a liver needle biopsy 1 month later. He received a living-donor LT at 38 years of age, and a living-donor kidney transplant from the same donor 8 months later. Though he made a good recovery, an early diagnosis and preemptive LT are important for PH1 patients.

Newly designed bioabsorbable substitute for the treatment of diaphragmatic defects.

PURPOSE: Earlier studies have investigated the suitability of various materials and autologous grafts for the repair of diaphragmatic defects. Our group investigated the feasibility of using an artificial diaphragm (AD) to repair wide diaphragmatic defects. METHODS: Twelve pigs were laparotomized and, in each pig, a defect was fashioned by resecting a round 8-cm diameter hole in the left diaphragm. Next, the defect was repaired by implanting an AD. The animals were relaparotomized 8 or 24 weeks after implantation for gross, histological and radiological observation of the implanted sites. RESULTS: All recipient animals survived until killing for evaluation. Chest X-ray examinations showed no differences between the preoperative diaphragms and the grafted diaphragms at 8 and 24 weeks after implantation. At 8 weeks after implantation, the implanted sites exhibited fibrous adhesions to the liver and lungs without deformities or penetrations. Parts of the surface tissue at the graft sites had a varnished appearance similar to those of the native diaphragm. Histology performed at 8 weeks detected no trace of the ADs in the graft sites; however, numerous inflammatory cells and profuse fibrous connective tissue were observed. At 24 weeks after implantation, no differences were found in the thorax between the areas with the grafts and the unaffected areas. Histology of the graft sites in the thorax confirmed growth of mesothelial cells similar to that observed in the native diaphragm. CONCLUSIONS: Artificial diaphragms can be a novel substitute for diaphragmatic repair.

An extrahepatic bile duct grafting using a bioabsorbable polymer tube.

BACKGROUND: Thus far, no ideal substitutions have been developed for completely replacing the extrahepatic bile duct (EHBD). METHODS: We used a bioabsorbable polymer tube (BAPT) for the complete reconstruction of an EHBD in pigs. A 2-cm-long EHBD was resected from the duodenal side, and a 4-cm-long BAPT graft was implanted at that site. The animals were re-laparotomized at 1 or 4 months after the grafting; subsequently, gross, histological, and blood chemical studies were performed. RESULTS: At 1 month after grafting, tubular structure was observed in all resected specimens, and the lumen of the graft site had remnants of degraded BAPT. Gross examination at 4 months after grafting revealed that the BAPT had been completely absorbed, and the graft site was indistinguishable from the native extrahepatic bile duct. The lengths of the graft region at 4 months were 70% of the replaced BAPT. Simultaneously performed histological examination revealed the growth of a neo-bile duct at the graft site, with an epithelium identical to that of the native bile duct. CONCLUSION: The BAPT graft implanted in this study completely replaced the EHBD defect. Hence, BAPT has the potential for application as a novel treatment modality for hepatobiliary diseases.

Single-port laparoscopic hepatectomy: technique, safety, and feasibility in a clinical case series.

BACKGROUND: The recent use of single-port-access surgery in cholecystectomy and other abdominal surgeries has confirmed its safety and validity as a treatment option. However, few reports have described the use of complete single-port access surgeries in hepatectomy for neoplasms. METHODS: The authors performed single-port laparoscopic hepatectomy (SLH) for eight patients (5 patients with hepatocellular carcinoma, 1 patient with metastatic liver tumor, 1 patient with endocrine liver tumor, and 1 patient with hemangioma). Furthermore, in terms of Child-Pugh classification, five patients were in category A, two in category B, and one in category C. The patients were eligible for SLH if they had solitary tumors measuring 3 cm or smaller on the caudal surface of the liver. The lesion was approached through a 20-mm supraumbilical incision using a single-port access device. RESULTS: No patient experienced intraoperative complications that required additional port access and conversion to laparotomy. The operative time was 148 min (range, 141-235 min). The postoperative course of the patients was uneventful, and they were discharged an average of 6.2 days (range, 3-11 days) after the operation. Approximately 2 weeks after discharge, the patients experienced no wound pain or liver dysfunction. CONCLUSION: The SLH technique is a safe and feasible procedure for a specific group of candidates, including patients with high-grade liver dysfunction.

Regeneration of extrahepatic bile ducts by tissue engineering with a bioabsorbable polymer.

With the widespread adoption of laparoscopic cholecystectomy and living-donor liver transplantation in recent years, complications involving the biliary system, stenosis in particular, are increasing. Various invasive and non-invasive techniques are now available for the treatment of biliary stenosis, but all are compromised by a high risk of recurrence and other problems. As a potential solution, our group has developed a bioabsorbable polymer (BAP) tube for implantation as a bypass graft. In the study reported here, we implanted this BAP tube and confirmed bile duct regeneration at the graft site after the tube had been degraded and absorbed into the body. We briefly describe our findings on extrahepatic biliary tissue regeneration, focusing on the possibility of its clinical application. This artificial bile duct may promote the development of novel treatments for biliary disease.

Liver resection using a soft-coagulation system without the Pringle maneuver.

BACKGROUND/AIMS: The Pringle maneuver is generally performed to reduce the amount of blood loss during hepatic resection. We have developed a method to sufficiently control blood loss during hepatectomy without applying the Pringle maneuver. This study was performed to determine the safety and operative blood loss in hepatectomy performed by this new method. METHODOLOGY: We performed 102 hepatic resections without the Pringle maneuver. We retrospectively compared the short-term operative outcome between these 102 cases and another 75 hepatic resections performed with the Pringle maneuver. The resections without the Pringle maneuver were performed using a soft-coagulation system. RESULTS: The median length of the surgery using the soft-coagulation system without the Pringle maneuver was 135 minutes, significantly shorter than the surgical time required for resection with the Pringle maneuver 297 minutes (p<0.001). The median volume of operative blood loss was significantly lower in the non-Pringle-maneuver group (200cc vs. 704cc; p<0.001). Regarding postoperative liver function, AST, ALT, T-Bil and PT, levels were all significantly improved in the non-Pringle-maneuver group (p<0.01). CONCLUSIONS: Our data suggest that hepatic resection using a soft-coagulation system without the Pringle maneuver is extremely safe and effective in controlling bleeding.

Duct-to-mucosa pancreatojejunostomy for small main pancreatic duct by the parachute technique after pancreatoduodenectomy.

A duct-to-mucosa pancreatojejunostomy is technically difficult to perform for a small main pancreatic duct after pancreatoduodenectomy. Our group applied the parachute technique to reconstruct and attach a small pancreatic duct to the jejunal mucosa. This method makes it very easy to position stitches on the posterior row of the anastomosis. It also allows a complete view of every stitch, both inside and outside the pancreatic duct and jejunal wall. Sixteen patients underwent pancreatoduodenectomy followed by duct-to-mucosa pancreatojejunostomy by the parachute technique. Pancreatic fistulae developed in 3 of the patients, but none of the fistulae were severe. The median postoperative hospital stay was 14.5 days, and there were no postoperative deaths during that time. In conclusion, pancreatojejunostomy by the parachute technique is a simple method with a very low risk of pancreatic fistula formation and a considerably shortened postoperative hospital stay. The method is also useful for reconstruction with pancreatojejunostomy after pancreatoduodenectomy.

Preoperative 18[F]-fluorodeoxyglucose positron emission tomography/computed tomography predicts early recurrence after pancreatic cancer resection.

BACKGROUND: An important step in deciding the treatment strategy for pancreatic cancer is to preoperatively predict the possibility of early recurrence. We reviewed whether 18[F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) before pancreatic cancer resection could predict tumor recurrence in the early postoperative period. METHODS: FDG-PET/CT was performed preoperatively on 56 patients with pancreatic cancer. The maximum standardized uptake (SUV(max)) values obtained by FDG-PET/CT were compared between two groups: patients with and without recurrence within the first 6 postoperative months. SUV(max) analyses were also performed to determine whether age, sex, CA 19-9 values, the operative method, and portal vein resection were also predictive of recurrence within less than 6 months after tumor resection. RESULTS: The median SUV(max) values of the recurrence group and no-recurrence group were 7.9 and 4.2, respectively (P = 0.0042). The SUV(max) was the only risk factor for recurrence in the first 6 postoperative months identified by multivariate analysis (P = 0.0062). CONCLUSIONS: Preoperative SUV(max) was higher in the recurrence group during the early postoperative period, and a high SUV(max) was a risk factor for early postoperative recurrence. Based on these results, we conclude that FDG-PET/CT is predictive of the recurrence of pancreatic cancer in the early postoperative period.

Development of a novel reflux-free bilioenteric anastomosis procedure by using a bioabsorbable polymer tube.

BACKGROUND: Bilioenteric anastomosis allows reflux of bowel fluid into bile ducts, resulting in reflux cholangitis. We sought to develop a reflux-free procedure of bilioenteric anastomosis endowed using an artificial bile duct (ABD). METHODS: The study was performed in four groups of pigs. In Group A, end-to-side choledochoduodenostomy using the interposed ABD with its distal end wrapped by the duodenal seromuscular layer was performed. In Group B, conventional end-to-side choledochoduodenostomy using the ABD was performed. In Group C, conventional end-to-side choledochoduodenostomy was performed. In Group D, sham operation was performed. In each groups, 12 weeks later, animals were evaluated. RESULTS: Bile amylase levels were significantly lower in Group A (36.9 +/- 21.7 U/L) compared with Group B (469 +/- 140.9 U/L). No significant differences were observed in bile amylase levels between Groups A and D or between Groups B and C. On histology, the neo-bile duct in Group A was covered with the duodenal muscular layer at the orifice into the intestinal tract. CONCLUSION: This study suggests that the ABD is useful in the regeneration of extrahepatic bile ducts and that to bury the ABD in the duodenum can be a preventive measure against reflux of bowel fluid to bile ducts.

A novel treatment for bile duct injury with a tissue-engineered bioabsorbable polymer patch.

BACKGROUND: With the recent widespread use of laparoscopic cholecystectomy and living-donor liver transplantation, complications involving the biliary system, and stenosis in particular, are encountered frequently. Although various invasive and noninvasive techniques are now available for the treatment of biliary stenosis, recurrence and other problems limit their value and utility. Our group sought to investigate whether a bioabsorbable polymer (BAP) patch could serve as a novel treatment for biliary stenosis. METHODS: In anesthetized hybrid pigs (n = 12), a spindle-shaped portion of the lower common bile duct wall was excised, and a BAP patch was implanted at the excision site. The animals underwent repeat laparotomy at 5 weeks (n = 6) and at 4 months (n = 6) after implantation to recover the graft sites for gross and histologic studies. Blood chemistry was analyzed from samples taken during the patch implantation and recovery. RESULTS: All of the recipient pigs survived until killing. All gained weight and showed no evidence of jaundice. The BAP-patched duct remained patent without obstruction at 5 weeks postimplantation. Blood chemistry did not reveal any increases in hepatobiliary enzyme activities. Histology showed accessory glandular structures in the neo-bile duct. At 4 months, the graft site was indistinguishable from the native duct. Intra-operative cholangiography revealed dilation of the patched site, but no dilatation of the intrahepatic bile ducts. Blood chemistry values were within normal ranges. Histology at the site of the patch confirmed the growth of a cuboidal columnar epithelium similar to that of the native duct. CONCLUSION: The bile duct was dilated only focally at the site of implantation. This newly designed substitute has potential for application as a novel treatment for biliary injury and stenosis.

Transport-mediated angiogenesis in 3D epithelial coculture.

Increasing interest has focused on capturing the complexity of tissues and organs in vitro as models of human pathophysiological processes. In particular, a need exists for a model that can investigate the interactions in three dimensions (3D) between epithelial tissues and a microvascular network since vascularization is vital for reconstructing functional tissues in vitro. Here, we implement a microfluidic platform to analyze angiogenesis in 3D cultures of rat primary hepatocytes and rat/human microvascular endothelial cells (rMVECs/hMVECs). Liver and vascular cells were cultured on each sidewall of a collagen gel scaffold between two microfluidic channels under static or flow conditions. Morphogenesis of 3D hepatocyte cultures was found to depend on diffusion and convection across the nascent tissue. Furthermore, rMVECs formed 3D capillary-like structures that extended across an intervening gel to the hepatocyte tissues in hepatocyte-rMVEC coculture while they formed 2D sheet-like structures in rMVEC monoculture. In addition, diffusion of fluorescent dextran across the gel scaffold was analyzed, demonstrating that secreted proteins from the hepatocytes and MVECs can be exchanged across the gel scaffold by diffusional transport. The experimental approach described here is useful more generally for investigating microvascular networks within 3D engineered tissues with multiple cell types in vitro.

Extended left hepatic lobectomy for hepatic hilar bile duct cancer: a novel surgical procedure in which the right hepatic duct is transected before the hepatoduodenal ligament is skeletonized.

As a general principle, the procedure of isolating a cancer region from surrounding tissues (skeletonization) is not taken until the last stage of a cancer operation. This principle is often disregarded in surgery for cancers of the hepatic hilar duct, however, as it may be mandatory to skeletonize the region before resecting the liver. Our group invented 'extended left hepatic lobectomy', a new surgical procedure for hepatic hilar bile duct cancer, in which we isolate the liver and transect the right hepatic duct before skeletonizing the cancer region in the hepatoduodenal ligament.

Regeneration of the inferior vena cava with a bioabsorbable polymer implant: a histological study.

BACKGROUND: Cell implantation into ischemic regions has recently been introduced as a novel strategy for therapeutic angiogenesis. Little is known, however, about the process of blood vessel regeneration, particularly that of the inferior vena cava (IVC). The indicators of normal angiogenesis are also unestablished. PURPOSE: To investigate the process of regeneration of the IVC from a histological viewpoint and to speculate on how the new formation and regeneration of the blood vessels proceed. MATERIALS AND METHODS: Our previous studies showed that a bioabsorbable polymer patch implanted into the IVC formed vessels resembling the native IVC (J Gastrointest Surg 2005;9:789). Using this model system, we investigated the histology and time course of IVC regeneration in the graft site. A 3 x 2 portion of infrahepatic IVC was substituted by a bioabsorbable polymer patch of the same size in hybrid pigs. The patched area was excised for histology at 2 weeks and 3, 6, and 12 months after implantation (n = 3, each). RESULTS: By 2 weeks, the patched area had developed vascular endothelial cells of the same type seen in native veins. The polymer implant was still detectable at 2 weeks but histologically absorbed at 3 months. Smooth muscle was barely formed at 2 weeks, but the ratio of smooth muscle to subendothelial connective tissue gradually increased as time advanced to 3, 6, and 12 months. Even at the last observation at 12 months, however, the amount of smooth muscle formed made up no more than one-half of the native IVC. The case with the elastic fibers accounted for about 90% of the total number of native fibers at 12 months. On gross examination, the patched area resembled the native IVC at 3 months after implantation. CONCLUSION: These results demonstrated that the subendothelial tissue regenerated gradually, requiring more than 1 year to resemble native tissue, whereas the vascular endothelium regenerated in the early phase after injury. Our findings make it possible to establish criteria by which to evaluate venous regeneration.

Hepatocyte dynamics in a three-dimensional rotating bioreactor.

BACKGROUND AND AIMS: The use of an artificial liver system with extracorporeal circulation or a three-dimensional bioreactor perfused with liquid culture medium inevitably exposes hepatocytes to fluid mechanical stress (MS). The expression of liver-specific hepatocyte functions seems to be modulated by the magnitude of MS. Nonetheless, few studies have focused on the direct effects of MS on hepatocytes. We subjected hepatocytes to MS using an MS loading device and investigated the effects on the cytoskeleton and hepatocyte dynamics inside three-dimensional scaffolds by monitoring the changes in actin fiber, one of the components of the cytoskeleton. We also assessed the influence of MS on specific hepatocyte functions. METHODS: We subjected hepatocytes to MS by a rotating radial flow bioreactor (RRFB) and examined the effects by comparing the MS-loaded culture cells with cells cultured under stationary conditions without MS loading. The hepatocytes (1 x 10(6)/cm(3)) were seeded on gauze without collagen coating and examined to determine morphological changes after 60 h incubation. Actin filaments in samples from the MS-loaded hepatocyte culture were stained by fluorescein isothiocyanate-labeled phalloidin. RESULTS: Hepatocyte aggregation was observed in the MS-loaded culture, but not in the unloaded stationary culture. Better albumin products were observed in the MS-loaded group than in the stationary culture group at all measurement points. Actin filaments extended toward the scaffold after the start of MS loading incubation and polymerized around the hepatocytes. The hepatocyte aggregation eventually advanced to the formation of spheroids. CONCLUSION: These results suggest that MS-induced polymerization of actin filaments stimulate hepatocyte aggregation and thereby improve hepatocyte-specific function.