Tracheal resection and reconstruction.

PURPOSE: To review the literature on tracheal and carinal resection and reconstruction, and to report the general approach to these patients, as well as the general guidelines for the safe administration of anesthesia. The airway management is extensively reviewed. SOURCE: Articles obtained from a Medline search (1960 to October 1997; keywords: tracheal surgery, carinal surgery, airway management). Textbook literature including the bibliographies were also consulted. PRINCIPAL FINDINGS: Benign or malignant tracheal and carinal pathology causing obstruction can be managed in several ways but resection and reconstruction are the treatment of choice for most patients with tracheal stenosis or tumour. Surgery of the trachea is a special endeavour where the airway is shared by the surgeon and the anesthesiologist. The principal anesthetic consideration is ventilation and oxygenation in the face of an open airway. Ventilation can be managed in different ways, including manual oxygen jet ventilation, high frequency jet ventilation, distal tracheal intubation, spontaneous ventilation, and cardiopulmonary bypass. CONCLUSION: The management of anesthesia for tracheal surgery presents many challenges to the anesthesiologist. Knowledge of the various techniques for airway management is crucial. Meticulous planning and communication between the anesthesia and surgical teams are mandatory for the safe and successful outcome of surgery for patients undergoing this procedure.

Transfer of mlt mutations into polyomavirus intronless genomes by intramolecular recombination in bacteria.

We describe a modification of the procedure of Weber and Weissmann [Nucl. Acids Res. 11 (1983) 5661-5669] for the formation of hybrid genes by in vivo recombination to introduce two separate mutations into the same gene. The mutants of interest are inserted as head-to-tail tandems in a bacterial plasmid in such a way that the 5'-proximal mutation is located upstream from the mutant with the more distal mutation. Propagation of the plasmid in a rec+ strain of Escherichia coli allows recombination between homologous sequences in the insert. DNA with the size expected for the recombinant plasmid is isolated by agarose gel electrophoresis, cloned in a recA strain, and characterized by restriction endonuclease mapping. Using this procedure, we have transferred the deletion from polyomavirus mutant dl-8 into other mutant genomes lacking the intervening sequences for either middle T or large T.