ObjectiveTo evaluate the survival and function of hepatocytes (HCs) on a novel three-dimensional (3D) synthetic biodegradable polymer scaffold with an intrinsic network of interconnected channels under continuous flow conditions. Summary Background DataThe authors' laboratory has investigated HC transplantation using 3D biodegradable polymers as scaffolding as an alternative approach to treatment of end-stage liver disease. Previous studies have demonstrated survival of HCs transplanted on polymer discs in peripheral tissue sites and partial correction of single enzyme liver defects. One of the major limitations has been the insufficient survival of an adequate mass of transplanted cells; this is thought to be caused by inadequate oxygen diffusion. MethodsHCs and nonparenchymal liver cells from Lewis rats were seeded onto 3D biodegradable polymer scaffolds. Microporous 3D polymers were created using 3D printing on copolymers of polylactide-coglycolide. The cell/polymer constructs were placed in static culture or continuous flow conditions. The devices were retrieved after 2 days and examined by scanning electron microscopy and histology. Culture medium was analyzed for albumin by enzyme-linked immunosorbent assay (ELISA). Differences in culture parameters including pH, PCO2, P02, glucose, lactate, and HCO3 were examined. ResultsScanning electron microscopy revealed successful attachment of HCs on the 3D poymer in both static and flow conditions. Histology demonstrated viable HCs in both conditions. EUSA demonstrated a significantly higher mean concentration of albumin in flow conditions than in static conditions. Cufture parameter analysis revealed a significantly higher P02 and glucose level, and a more physiologic pH in flow conditions than in static conditions. ConclusionsHCs cocultured with nonparenchymal cells can attach to and survive on the 3D polymer scaffolds in both static and flow conditions in the size and configuration used in this study. Flow conditions may provide a more conducive environment for HC metabolism and albumin synthesis than static conditions. The authors hypothesize that flow through directed channels will be necessary for the transfer of large masses of cells when implantation studies are initiated.Each year 26,000 people die of end-stage liver disease in the United States, with an estimated annual cost of $9

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Our laboratory has investigated hepatocyte transplantation using biodegradable polymer matrices as an alternative treatment to end-stage liver disease. One of the major limitations has been the insufficient survival of an adequate mass of transplanted cells. This study investigates a novel method of dynamic seeding and culture of hepatocytes in a flow perfusion system. In experiment I, hepatocytes were flow-seeded onto PGA scaffolds and cultured in a flow perfusion system for 24 h. Overall metabolic activity and distribution of cells were assessed by their ability to reduce MTT. DNA quantification was used to determine the number of cells attached. Culture medium was analyzed for albumin content. In Experiment II, hepatocyte/polymer constructs were cultured in a perfusion system for 2 and 7 days. The constructs were examined by SEM and histology. Culture medium was analyzed for albumin. In experiment I, an average of 4.4 X 10(6) cells attached to the scaffolds by DNA quantification. Cells maintained a high metabolic activity and secreted albumin at a rate of 13 pg/cell/day. In experiment II, SEM demonstrated successful attachment of hepatocytes on the scaffolds after 2 and 7 days. Cells appeared healthy on histology and maintained a high rate of albumin secretion through day 7. Hepatocytes can be dynamically seeded onto biodegradable polymers and survive with a high rate of albumin synthesis in the flow perfusion culture system.

Although the laparoscopic approach to the treatment of complex biliary disease is possible, it is technically challenging. In an attempt to overcome these difficulties, the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, California) was used to facilitate the minimally invasive treatment of a type I choledochal cyst in a 5-year-old, 22 kg, girl. Complete resection of the choledochal cyst and a Roux-en-Y hepaticojejunostomy were performed using the robotic surgical system. Total robotic setup time (preparation, port placement, docking) was 40 minutes. Total procedure time was 440 minutes. Total robotic operative time was 390 minutes. No intraoperative complications or technical problems were encountered. At 6-month follow-up, the child is doing well with no episodes of cholangitis. Robot-assisted laparoscopic type I choledochal cyst resection appears safe and feasible. The three-dimensional visualization and wristed instrumentation greatly aids in the dissection of the cyst and in the biliary reconstruction.

Background Minimally invasive surgical techniques, specifically the thoracoscopic approach, have been applied to congenital diaphragmatic hernia (CDH) with varying outcomes from selected centers. The aim of our study was to examine the rate of successful completion and compare outcomes between open and thoracoscopic approaches in CDH repair. Methods We performed a retrospective analysis of infants with CDH repair (From February 2004 to January 2008). Patients were divided into thoracoscopic and open groups, based on operative approach. We analyzed demographic, clinical, and hospitalization characteristics to compare the completion rate and outcomes in these two groups. Results Analysis of 31 infants with CDH (14 thorascocopic and 17 open) demonstrated no differences in sex (P = 0.132), age (P = 0.807), birthweight (P = 0.256), weight at operation (P = 0.647), pulmonary hypertension (P = 0.067), preoperative intensive care unit (ICU) days (P = 0.673), ventilator days (P = 0.944), or use of a patch (P = 0.999) between the groups. Seventy-nine percent of thoracoscopic operative approaches were completed successfully. There was a significant difference between the open and thoracoscopic groups with respect to estimated gestational age (39 versus 36.5 weeks; P = 0.006) and operating room time (70 versus 145 minutes; P = 0.004). The total (P = 0.662), ICU (P = 0.889), and postoperative (P = 0.619) length of stay and days on ventilator (P = 0.705), as well as days until initial enteral feeds (P = 0.092), were not significantly different between groups. There were no deaths and no evidence of recurrence, with a mean follow-up of 346 days. Conclusions In our early experience, the thoracoscopic approach for congenital diaphragmatic hernia repair was completed in 80% of our patient population with minimal exclusion criteria. Further study, with larger sample sizes, is needed to ascertain differences in outcomes, such as length of stay and initiation of enteral feeding.

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