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The strong association between gastroesophageal reflux disease (GERD) and the development and progression of pulmonary diseases has been suggested, and GERD has been focused on as a potential cause and thus a target for prevention and/or therapy. Because GERD is curable, the proper diagnosis and management of underlying GERD would theoretically improve the outcomes. This article reviews the existing literature and discusses the strategy to manage GERD in patients with end-stage pulmonary diseases before and after lung transplantation., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Gastroesophageal reflux disease (GERD) is common in patients with end-stage lung disease (ESLD). GERD may cause obliterative bronchiolitis after lung transplantation (LTx), represented by a decline in forced expiratory volume in 1 second (FEV(1))., Objectives: To identify the patterns of reflux in patients with ESLD and to determine whether antireflux surgery (ARS) positively impacts lung function., Design: Retrospective review of prospectively collected data., Setting: Tertiary care university hospital., Patients: Forty-three patients with ESLD and documented GERD (pre-LTx, 19; post-LTx, 24)., Interventions: Antireflux surgery., Main Outcome Measures: Reflux patterns including laryngopharyngeal reflux as measured by esophageal impedance, and FEV(1), and episodes of pneumonia and acute rejection before and after ARS., Results: Before ARS, 19 of 43 patients (44%) were minimally symptomatic or asymptomatic. Laryngopharyngeal reflux events, which occurred primarily in the upright position, were common in post-LTx (56%) and pre-LTx (31%) patients. At 1 year after ARS, FEV(1) significantly improved in 91% of the post-LTx patients (P < .01) and 85% of the pre-LTx patients (P = .02). Of patients with pre-ARS declining FEV(1), 92% of post-LTx and 88% of pre-LTx patients had a reversal of this trend. Episodes of pneumonia and acute rejection were significantly reduced in post-LTx patients (P = .03) or stablilized in pre-LTx patients (P = .09)., Conclusions: There should be a low threshold for performing objective esophageal testing including esophageal impedance because GERD may be occult and ARS may improve or prolong allograft and native lung function.

Beginning with the widespread introduction of laparoscopic cholecystectomy in late 1989, minimally invasive surgical technique has been refined in conjunction with the development of advanced instrumentation and have subsequently been applied to increasingly complicated disease processes. Esophageal surgeons have increasingly incorporated minimally invasive surgery into their practice since the first laparoscopic fundoplication was described by Dallemagne et al. in 1991. Esophagectomy is associated with significant morbidity and mortality even in highly experienced centers. Many esophageal surgeons have had a great deal of interest in minimally invasive esophagectomy (MIE), which has the potential advantages of being a less traumatic procedure with a resultant improvement in postoperative convalescence and fewer wound and cardiopulmonary complications compared to the open approaches. Throughout the 1990s, as confidence with laparoscopic surgery of the esophagogastric junction grew, MIE was initially attempted with hybrid operations combining traditional open surgery with minimally invasive approaches. Subsequently, a totally laparoscopic transhiatal approach was described; however, this approach was perceived to be very challenging and has not gained widespread acceptance. Approaches used at present depend on cancer stage, cancer location, body habitus, and pulmonary function. For localized cancer (T1N0) or HGD, we prefer laparoscopic inversion esophagectomy (retrograde or antigrade). This approach may also be used for patients at high risk for thoracotomy. For locally advanced cancer in the middle third of the esophagus or for proximal third esophageal cancer, we prefer 3-field MIE (abdomen, and chest with neck anastomosis). For locally advanced cancer in the distal esophagus, especially in patients with a short thick neck, we prefer thoracoscopic-laparoscopic (2-field) esophagectomy (TLE).

Background: The functional lumen imaging probe (FLIP) uses impedance planimetry to measure the geometry of a distensible organ. The purpose of this study was to evaluate FLIP as a method to determine structural changes at the gastroesophageal junction (GEJ) following transoral incisionless fundoplication (TIF) and compare these findings with the accepted methods of esophageal testing., Methods: Two different approaches (TIF1.0 and 2.0) using the EsophyX™ device were performed in six and five animals, respectively. Three dogs underwent a sham procedure. FLIP measurements were performed pre- and post-procedure and at 2-week follow-up. Upper endoscopy, manometry, and 48-h pH testing were also performed at each time point. FLIP was performed in ten patients before and 3 months after TIF., Results: Following TIF procedures, there was a significant decrease in cross-sectional area (CSA) of GEJ compared to baseline; however, the CSA of both groups returned to baseline at 2-week follow-up. The FLIP results were supported with pH testing and correlated highly with both measures of GEJ structural integrity (LES and cardia circumference). Following TIF in humans, there was a decrease in GEJ distensibility compared to baseline that persisted to the 3-month evaluation., Conclusion: FLIP is able to measure and display changes in tissue distensibility at the GEJ, and results correlate with established methods of testing. FLIP may represent a single testing modality by which to diagnose GERD and evaluate the outcome after antireflux surgery.

As a result of injury caused by chronic gastroesophageal reflux, Barrett's esophagus with high-grade dysplasia and esophageal adenocarcinoma are rapidly increasing problems in the United States. The current standard of care involves esophagectomy, a procedure associated with a high morbidity, a negative impact on long term quality of life, and a mortality rate of 1-6 percent. An entirely endoscopic technique for circumferential, long segment en bloc removal of the mucosa and submucosa with subsequent placement of a biologic scaffold material that promotes a constructive remodeling response and minimizes stricture is described herein. The results of this approach are reported for five patients with 4-24-month follow-up. Restoration of normal mature, K4+/K14+, squamous epithelium, and return to a normal diet without significant dysphagia is reported for all patients. Two of five patients show a small focus of recurrent Barrett's esophagus at the gastroesophageal junction, but the entire length and circumference of the reconstituted esophageal mucosa remains free of disease. This experience provides evidence that a regenerative medicine approach may, for the first time, enable aggressive endoscopic resection of early stage neoplasia without the need for esophagectomy and its associated complications.

Objectives: Endoscopic local procedures are increasingly applied in patients with superficial esophageal cancer as an alternative to radical oncologic resection. The objective of this article is to determine the risk of nodal metastases in submucosal (sm) esophageal cancer, comparing the two predominating histologic tumor types, squamous cell cancer (SCC) and adenocarcinoma (ADC)., Methods: A query of PubMed, MEDLINE, Embase and Cochrane Library (1980-2009) using predetermined search terms revealed 675 abstracts, of which 485 full-text articles were reviewed. A total of 105 articles met the selection criteria. A review of article references and consultation with experts revealed additional articles for inclusion. Studies that enrolled patients with submucosal esophageal cancer and provided adequate extractable data were included., Results: The pooled outcomes of 7645 patients with esophageal cancer involving the sm level of infiltration were included in the analysis. Overall, the percentage of lymph node metastasis in submucosal cancer was 37%. Lymph node (N), lymphatic (L) and vascular (V) invasion in sm1 esophageal cancers was 27, 46 and 22%, respectively. Within sm2 lesions, N, L and V invasion were involved in 38, 63 and 38% of patients, respectively. Finally, N, L and V involvement in patients with sm3 lesions was 54, 69 and 47%, respectively. The rates of lymph node metastasis for sm1 and sm2 were higher in SCC compared with ADC, whereas the lymph node metastasis for sm3 was comparable, with >50% involvement in both histologic subtypes. SCC revealed an overall more aggressive behavior compared with ADC (N+: 45 vs 26%; L+: 57 vs 37%; V+: 40 vs 18%)., Discussion: While endoscopic therapy may be adequate in selected patients with 'low-risk' sm1 ADC, submucosal SCC necessitates esophageal resection and systematic lymphadenectomy because of its aggressive nature and tendency for early metastasis.

Background & Aims: Hepatocyte transplantation is a potential therapeutic approach for liver disease. However, most patients with chronic hepatic damage have cirrhosis and fibrosis, which limit the potential for cell-based therapy of the liver. The development of an ectopic liver as an additional site of hepatic function represents a new approach for patients with end-stage liver disease. We investigated the development and function of liver tissue in lymph nodes in mice with liver failure., Methods: Hepatocytes were isolated from 8- to 12-week-old mice and transplanted by intraperitoneal injection into 8- to 12-week-old fumarylacetoacetate hydrolase mice (Fah(-/-)), a model of the human liver disease tyrosinemia type I. Survival was monitored and the locations and functions of the engrafted liver cells were determined., Results: Lymph nodes of Fah(-/-) mice were colonized by transplanted hepatocytes; Fah(+) hepatocytes were detected adjacent to the CD45(+) lymphoid cells of the lymphatic system. Ten weeks after transplantation, these mice had substantial improvements in serum levels of transaminases, bilirubin, and amino acids. Homeostatic expansion of donor hepatocytes in lymph nodes rescued the mice from lethal hepatic failure., Conclusions: Functional ectopic liver tissue in lymph nodes rescues mice from lethal hepatic disease; lymph nodes therefore might be used as sites for hepatocyte transplantation., (Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background: Transoral incisionless fundoplication (TIF) using the EsophyX™ system has been introduced as a possible alternative for the treatment of gastroesophageal reflux disease (GERD). The efficacy of this procedure in our centers was evaluated., Methods: Patients were selected for treatment if they had typical GERD symptoms, failed management with proton pump inhibitors (PPIs), a positive esophageal pH test with symptom correlation, and no hiatus hernia larger than 2 cm., Results: Nineteen patients (11 men, 8 women) underwent the TIF procedure between April 2008 and July 2009. Mean age was 48.2 years and body mass index was 24.6. The major complication rate was 3/19, including esophageal perforation, hemorrhage requiring transfusion, and permanent numbness of tongue. At mean 10.8 months follow-up, 5/19 had completely discontinued PPIs, and 3/19 had decreased their PPI dose. However, 10/19 had been converted to laparoscopic fundoplication for recurrent reflux symptoms and an endoscopically confirmed failed valve. Nine of 17 were dissatisfied with the outcome, and eight were satisfied. Thirteen of 19 (68%) were considered to have been unsuccessful., Conclusion: At short-term follow-up, the TIF procedure is associated with an excessive early symptomatic failure rate, and a high surgical re-intervention rate. This procedure should not be performed outside of a clinical trial.

Introduction: Limitations of endoscopic therapies for Barrett's esophagus and superficial cancer include a compromised histological assessment, the need for surveillance, subsequent procedures, and stricture formation. Circumferential en bloc resection of the mucosa-submucosa complex followed by deployment of a biologic scaffold onto the remaining muscularis propria may address these concerns. The objective of this study was to determine technical feasibility of transoral resection of the esophageal lining., Materials and Methods: Transoral endoscopic inner layer esophagectomy was performed in ten swine. Endpoints included procedure duration, hemorrhage, number of perforations, and adequacy of resection length and depth., Results: Procedures were successfully completed in all animals without perioperative mortality. Procedure times averaged 179 min (range 125-320). No perforations were found, and a mean of 1.7 (0-4) interventions for hemorrhage was required. Complete longitudinal resection was achieved in nine of ten animals. Resection depth included all mucosal layers in 100% of tissue sections, the submucosal layers, SM1 in 100%, and SM2 in 96%. A portion of SM3 was adherent to the muscularis propria in 70%., Conclusion: Transoral endoscopic resection of the inner esophageal layers was feasible and reproducible. This technique may facilitate a single-step definitive treatment and staging tool for early neoplastic lesions, obviating the need for esophagectomy.

Human cancers have been found to include transformed stem cells that may drive cancer progression to metastasis. Here, we report that metastatic colon cancer contains clonally derived tumor cells with all of the critical properties expected of stem cells, including self-renewal and the ability to differentiate into mature colon cells. Additionally, when injected into mice, these cells initiated tumors that closely resemble human cancer. Karyotype analyses of parental and clonally derived tumor cells expressed many consistent (clonal) along with unique chromosomal aberrations, suggesting the presence of chromosomal instability in the cancer stem cells. Thus, this new model for cancer origin and metastatic progression includes features of both the hierarchical model for cancerous stem cells and the stochastic model, driven by the observation of chromosomal instability.

We previously reported that the in vitro maturation of CD49f(+)Thy1(-)CD45(-) (CD49f positive) fetal hepatic progenitor cells (HPCs) is supported by Thy1-positive mesenchymal cells derived from the fetal liver. These mesenchymal cell preparations contain two populations, one of a cuboidal shape and the other spindle shaped in morphology. In this study, we determined that the mucin-type transmembrane glycoprotein gp38 could distinguish cuboidal cells from spindle cells by immunocytochemistry. RT-PCR analysis revealed differences between isolated CD49f(+/-)Thy1(+)gp38(+)CD45(-) (gp38 positive) cells and CD49f(+/-)Thy1(+)gp38(-)CD45(-) (gp38 negative) cells, whereas both cells expressed mesenchymal cell markers. The coculture with gp38-positive cells promoted the maturation of CD49f-positive HPCs, which was estimated by positivity for periodic acid-Schiff (PAS) staining, whereas the coculture with gp38-negative cells maintained CD49f-positive HPCs negative for PAS staining. The expression of mature hepatocyte markers, such as tyrosine aminotransferase, tryptophan-2,3-dioxygenase, and glucose-6-phosphatase, were upregulated on HPCs by coculture with gp38-positive cells. Furthermore, transmission electron microscopy revealed the acquisition of mature hepatocyte features by HPCs cocultured with gp38-positive cells. This effect on maturation of HPCs was inhibited by the addition of conditioned medium derived from gp38-negative cells. By contrast, the upregulation of bromodeoxyuridine incorporation by HPCs demonstrated the proliferative effect of coculture with gp38-negative cells. In conclusion, these results suggest that in vitro maturation of HPCs promoted by gp38-positive cells may be opposed by an inhibitory effect of gp38-negative cells, which likely maintain the immature, proliferative state of HPCs.

It is difficult to induce the maturation of embryonic stem (ES) cells into hepatocytes in vitro. We previously reported that Thy1-positive mesenchymal cells derived from the mouse fetal liver promote the maturation of hepatic progenitor cells. Here, we isolated alpha-fetoprotein (AFP)-producing cells from mouse ES cells for subsequent differentiation into hepatocytes in vitro by coculture with Thy1-positive cells. ES cells expressing green fluorescent protein (GFP) under the control of an AFP promoter were cultured under serum- and feeder layer-free culture conditions. The proportion of GFP-positive cells plateaued at 41.6 +/- 12.2% (means +/- SD) by day 7. GFP-positive cells, isolated by flow cytometry, were cultured in the presence or absence of Thy1-positive cells as a feeder layer. Isolated GFP-positive cells were stained for AFP, Foxa2, and albumin. The expression of mRNAs encoding tyrosine amino transferase, tryptophan 2,3-dioxygenase, and glucose-6-phosphatase were only detected following coculture with Thy1-positive cells. Following coculture with Thy1-positive cells, the isolated cells produced and stored glycogen. Ammonia clearance activity was also enhanced following coculture. Electron microscopic analysis indicated that the cocultured cells exhibited the morphologic features of mature hepatocytes. In conclusion, coculture with Thy1-positive cells in vitro induced the maturation of AFP-producing cells isolated from ES cell cultures into hepatocytes.

Previously, we reported a system to enrich mouse fetal hepatic progenitor cells (HPCs) by forming cell aggregates. In this study, we sorted two cell populations, CD49f(+)Thy1(-)CD45(-) cells (CD49f-positive cells) and CD49f(+/-)Thy1(+)CD45(-) cells (Thy1-positive cells), from the cell aggregates using a flow cytometer. CD49f-positive cells stained positive for endodermal specific markers such as alpha-fetoprotein (AFP), albumin (ALB), and cytokeratin 19 (CK19), and are thus thought to be HPCs. However, Thy1-positive cells were a morphologically heterogeneous population; reverse-transcription polymerase chain reaction (RT-PCR) and immunocytochemical analyses revealed the expression of mesenchymal cell markers such as alpha-smooth muscle actin, desmin, and vimentin, but not of AFP, ALB, or CK19. Therefore, Thy1-positive cells were thought to be of a mesenchymal lineage. When these two cell populations were co-cultured, the CD49f-positive colonies matured morphologically and stored a significant amount of glycogen. Furthermore, real-time RT-PCR demonstrated an increased expression of tyrosine amino transferase and tryptophan oxygenase mRNA, and transmission electron microscopy confirmed that co-cultured cells produced mature hepatocytes. However, when CD49f-positive cells were cultured alone or when the two populations were cultured separately, the CD49f-positive cells did not mature. These results indicate that CD49f-positive cells are primitive hepatic endodermal cells with the capacity to differentiate into hepatocytes, and that Thy1-positive cells promote the maturation of CD49f-positive cells by direct cell-to-cell contact. In conclusion, we were able to isolate CD49f-positive primitive hepatic endodermal cells and Thy1-positive mesenchymal cells and to demonstrate the requirement of cell-to-cell contact between these cell types for the maturation of the hepatic precursors.

Background/aims: Recently, several cells found within the liver have been reported to derive from bone marrow (BM). This study sought to examine the commitment of BM cells to hepatic stellate cell (HSC) lineage in mouse liver., Methods: We transplanted BM cells from green fluorescent protein (GFP) transgenic mice into age-matched C57BL/J mice. Hepatic nonparenchymal cells were isolated from the livers of BM-transplanted mice using density gradient centrifugation with Nycodenz. The expression of lineage markers by the isolated cells was evaluated by RT-PCR and immunostaining. We then examined the histology of liver tissues obtained from BM-transplanted mice with and without carbon tetrachloride-induced injury., Results: GFP-expressing cells with intracytoplasmic lipid droplets comprised 33.4 +/- 2.3% of the cells isolated by density gradient centrifugation. These cells expressed the HSC lineage markers, such as desmin and glial fibrillary acidic protein (GFAP), by both RT-PCR and immunostaining. During a 7-day culture, GFP-positive cells began to express alpha-smooth muscle actin, a marker of activated HSC. In the liver of BM-transplanted mice, GFP-positive nonparenchymal cells expressed GFAP and extended their process around hepatocytes. Upon liver injury, these cells also co-expressed desmin and alpha-smooth muscle actin., Conclusions: Nonparenchymal cells, derived from transplanted BM, acquired HSC characteristics in both quiescent and activated states.