Esophagectomy for failed endoscopic therapy in patients with high-grade dysplasia or intramucosal carcinoma.

Endoscopic therapy (ablation +/- endoscopic resection) for high-grade dysplasia and/or intramucosal carcinoma (IMC) of the esophagus has demonstrated promising results. However, there is a concern that a curable, local disease may progress to systemic disease with repeated endotherapy. We performed a retrospective review of patients who underwent esophagectomy after endotherapy at three tertiary care esophageal centers from 2006 to 2012. Our objective was to document the clinical and pathologic outcomes of patients who undergo esophagectomy after failed endotherapy. Fifteen patients underwent esophagectomy after a mean of 13 months and 4.1 sessions of endotherapy for progression of disease (53%), failure to clear disease (33%), or recurrence (13%). Initially, all had Barrett's, 73% had ≥3-cm segments, 93% had a nodule or ulcer, and 91% had multifocal disease upon presentation. High-grade dysplasia was present at index endoscopy in 80% and IMC in 33%, and some patients had both. Final pathology at esophagectomy was T0 (13%), T1a (60%), T1b (20%), and T2 (7%). Positive lymph nodes were found in 20%: one patient was T2N1 and two were T1bN1. Patients with T1b, T2, or N1 disease had more IMC on index endoscopy (75% vs. 18%) and more endotherapy sessions (median 6.5 vs. 3). There have been no recurrences a mean of 20 months after esophagectomy. Clinical outcomes were comparable to other series, but submucosal invasion (27%) and node-positive disease (20%) were encountered in some patients who initially presented with a locally curable disease and eventually required esophagectomy after failed endotherapy. An initial pathology of IMC or failure to clear disease after three treatments should raise concern for loco-regional progression and prompt earlier consideration of esophagectomy.

Immunomodulatory effects of mixed hematopoietic chimerism: immune tolerance in canine model of lung transplantation.

Long-term survival after lung transplantation is limited by acute and chronic graft rejection. Induction of immune tolerance by first establishing mixed hematopoietic chimerism (MC) is a promising strategy to improve outcomes. In a preclinical canine model, stable MC was established in recipients after reduced-intensity conditioning and hematopoietic cell transplantation from a DLA-identical donor. Delayed lung transplantation was performed from the stem cell donor without pharmacological immunosuppression. Lung graft survival without loss of function was prolonged in chimeric (n = 5) vs. nonchimeric (n = 7) recipients (p < or = 0.05, Fisher's test). There were histological changes consistent with low-grade rejection in 3/5 of the lung grafts in chimeric recipients at > or =1 year. Chimeric recipients after lung transplantation had a normal immune response to a T-dependent antigen. Compared to normal dogs, there were significant increases of CD4+INFgamma+, CD4+IL-4+ and CD8+ INFgamma+ T-cell subsets in the blood (p < 0.0001 for each of the three T-cell subsets). Markers for regulatory T-cell subsets including foxP3, IL10 and TGFbeta were also increased in CD3+ T cells from the blood and peripheral tissues of chimeric recipients after lung transplantation. Establishing MC is immunomodulatory and observed changes were consistent with activation of both the effector and regulatory immune response.

Optimizing a canine survival model of orthotopic lung transplantation.

INTRODUCTION: While acute models of orthotopic lung transplantation have been described in dogs, the technical considerations of developing a survival model in this species have not been elaborated. Herein, we describe optimization of a canine survival model of orthotopic lung transplantation. METHODS: Protocols of orthotopic left lung transplantation and single lung ventilation were established in acute experiments (n=9). Four dogs, serving as controls, received autologous, orthotopic lung transplants. Allogeneic transplants were performed in 16 DLA-identical and 16 DLA-mismatched unrelated recipient dogs. Selective right lung ventilation was utilized in all animals. A Malecot tube was left in the pleural space connected to a Heimlich valve for up to 24 hours. To date, animals have been followed up to 24 months by chest radiography, pulmonary function tests, bronchoscopy with lavage, and open biopsies. RESULTS: Long-term survival was achieved in 34/36 animals. Two recipients died intraoperatively secondary to cardiac arrest. All animals were extubated on the operating table, and in all cases the chest tube was removed within 24 hours. Major complications included thrombosis of the pulmonary artery and subcritical stenosis of bronchial anastamosis. One recipient underwent successful treatment of a small bowel intussusception. CONCLUSIONS: We report our experience in developing a survival canine model of orthotopic single lung transplantation. While short-term survival following canine lung transplantation is achievable, we report particular considerations that facilitate animal comfort, early extubation, and lung reexpansion in the immediate postoperative period, further optimizing use of this species for experimental modeling of long-term complications after lung transplantation.