ABSTRACT
Transvenous pacemaker lead extraction has become a commonly performed procedure that is associated with a small but significant risk. We report two cases where lead extraction was complicated by arteriovenous fistulae between branches of the aortic arch and the left brachiocephalic vein. Presenting signs and symptoms included severe chest or back pain, persistent or copious bleeding from the venous puncture site, unexplained hypotension or anemia, superior vena cava syndrome, and signs of central venous hypertension or acute heart failure. One patient whose injury was not recognized immediately and who did not undergo repair died rapidly, whereas the other patient who was diagnosed quickly underwent successful repair. Immediate diagnosis with arteriography and rapid intervention with surgery or percutaneous techniques are indicated and may prevent mortality.
Subject(s)
Aorta, Thoracic , Arteriovenous Fistula/surgery , Blood Vessel Prosthesis Implantation , Brachiocephalic Veins , Pacemaker, Artificial , Aged , Angiography , Aorta, Thoracic/surgery , Aortography , Arteriovenous Fistula/diagnosis , Arteriovenous Fistula/etiology , Brachiocephalic Veins/surgery , Female , Follow-Up Studies , Humans , Middle Aged , Polytetrafluoroethylene , Time FactorsABSTRACT
We have developed a rapid and highly sensitive nonradioactive method for the detection of a mutant codon 12 human c-K-ras allele in the presence of as many as 10(4) copies of the wild type codon 12 allele. This sensitivity is achieved by selective polymerase chain reaction (PCR) amplification of mutant K-ras gene sequences employing a two stage procedure. The first stage entails the amplification of both K-ras mutant and wild type codon 12 sequences, followed by a selective restriction enzyme digestion of only wild type sequences. The second stage involves a subsequent amplification of undigested amplified fragments, enriched in mutant codon 12 sequences. These products are subject to restriction length polymorphism analysis for the detection of point mutations at codon 12. This technique is rapid, nonradioactive, and eliminates the need for either oligonucleotide hybridization or DNA sequencing. Variations of this selective amplification procedure may prove promising for the detection of specific point mutations in heterogenous cell populations.
