Partial esophagectomy with single layer closure for treatment of esophageal sarcomas in 6 dogs

OBJECTIVE: To report partial esophagectomy (PE) as a treatment for esophageal sarcoma in dogs. STUDY DESIGN: Retrospective study (2000-2002). ANIMALS: Six dogs with caudal thoracic esophageal tumors. METHODS: Medical records of 6 dogs that had surgical removal of esophageal tumors were reviewed. Signalment, medical history, physical examination results, complete blood count, surgical procedure, tumor classification, postoperative treatment, and complications were retrieved. RESULTS: Esophageal masses were approached by thoracotomy and esophagotomy on the side opposite the mass, removed with 1 cm margins by full thickness excision, and the defects closed with a single layer of interrupted sutures. All dogs recovered rapidly without major complications. Tumors were fibrosarcoma (3 dogs), undifferentiated sarcoma (1), and osteosarcoma (2). Five dogs were administered doxorubicin chemotherapy after surgery. Good quality of life was observed postoperatively in 5 dogs until deterioration necessitated euthanasia; survival ranged from 2-16 months. The remaining dog was alive, 20 months after surgery. CONCLUSIONS: Partial esophagectomy and closure using 1 suture layer, was an effective, simple, and safe technique for removal of sarcomas of the distal thoracic esophagus. CLINICAL RELEVANCE: Removal of esophageal masses by partial esophagectomy can be used reliably as a method of esophageal surgery.     

Clonal variation in crown structure, absorbed photosynthetically active radiation and growth of loblolly pine and slash pine

Crown structure, absorbed photosynthetically active radiation (APAR) and growth were analyzed in 300 replicated loblolly (Pinus taeda L.) and slash pine (Pinus elliottii Engelm. var. elliotti) clones to: (1) quantify genetic variation in crown structural traits, growth and APAR at the species, family and clonal levels; and (2) estimate within-family genetic and environmental influences on measured variables. Species and family-within-species differences were found in some growth traits, crown size, leaf area, APAR and branch angle. Loblolly pine developed larger crowns, exposed more leaf area with an acute angle, and intercepted more radiation than slash pine. Significant differences among clones within-family were found for stem volume and crown architecture. Loblolly pine and slash pine within-family, individual-tree broad-sense heritabilities ranged from 0.00 to 0.41 for growth and crown structural traits and most were between 0.10 and 0.25 when estimated from a combined analysis across families. Genetic correlations of crown size, leaf area and APAR with volume increment generally ranged from 0.60 to 0.75. This knowledge of the genetic interactions among growth and crown structural traits improves our understanding of how crown morphology affects light interception and stand development, and ultimately how these attributes can be incorporated in the selection of families or clones for the development of new crop tree ideotypes.