Treatment of chronic ventilatory failure using a diaphragmatic pacemaker.

We present our series of patients with chronic ventilatory failure treated with electrophrenic respiration: 13 males and nine females with a mean age of 12 +/- 11.5 years. The etiology was, 13 tetraplegia, five sequelae of surgical treatment of intracranial lesions, and four central alveolar hypoventilation. The mean duration of the conditioning period were 3-4 months. Eighteen patients (81.8%) achieved permanent, diaphragmatically-paced breathing with bilateral stimulation and in four (18.2%) patients, pacing was only during sleep. Five patients died (22.7%): two during the hospital stay and three at home; two deaths had unknown cause and three were due respectively to, lack of at-home care, recurrence of an epidermoid tumor, and sequelae of accidental disconnection of the mechanical ventilation before beginning the conditioning period. Two cases were considered failures: One patient had transitory neurapraxia lasting 80 days, and the other had an ischemic spinal cord syndrome with progressive deterioration of the left-side response to stimulation. One patient had right phrenic nerve entrapment by scar tissue and four suffered infections. The follow-up periods since pacemaker implantation are currently: 1, 11 years; 4, 10 years, and 17, less than 5 years. The results of our experience demonstrate that complete stable ventilation can be achieved using diaphragmatic pacing and that it improves the prognosis and life quality of patients with severe chronic respiratory failure.

IgG and IgM autoantiidiotype antibodies against antibody to HBsAg in chronic hepatitis B.

Antibody directed against HBsAg carries idiotypic determinants that may induce an autoantiidiotype antibody response. We describe a solid-phase radioimmunoassay which allows specific detection of either IgG or IgM antibody to antibody directed against HBsAg. Among 138 chronic hepatitis B virus carriers, IgG autoantiidiotype was detected in 98 (71%) and IgM autoantiidiotype in 10 (80%). The autoantiidiotype reaction was blocked with antibody directed against HBsAg after removal of immune complexes by polyethylene glycol precipitation. The prevalence and levels of both classes of autoantiidiotype antibodies were highest in patients with hepatitis B virus DNA or HBeAg in serum. During follow-up, patients who lost hepatitis B virus DNA and HBeAg from serum had lower titers of autoantiidiotype and were less likely to have autoantiidiotype than patients who persisted in having hepatitis B virus DNA and HBeAg in serum. Thus, the presence and titer of autoantiidiotype correlated with serologic evidence of active viral replication in chronic hepatitis B. These findings suggest that the antibody directed against HBsAg response may play a role in modulating viral replication in chronic hepatitis B.

Assessment of hepatitis B virus DNA levels in chronic HBsAg carriers with or without hepatitis delta virus superinfection.

In order to document the incidence of hepatitis delta virus (HDV) replication markers and their relationship to HBV replication, 91 HBsAg chronic carriers were studied. Of these, 51 were anti-HD-positive (19 HBeAg-positive and 32 anti-HBe-positive). Liver HDAg was found in 75% of anti-HD-positive patients. Of the 19 patients who had anti-HD and HBeAg, 13 were HBV-DNA-positive. None of the anti-HBe patients were HBV-DNA-positive. No differences with respect to HBV-DNA concentration were observed between anti-HD-positive and -negative patients. Liver HDAg was detected with similar frequency in patients who were HBeAg- and HBV-DNA-positive (63.6%) and in those who were anti-HBe-positive (78.5%), with no statistically significant difference. HBcAg and HDAg were simultaneously detected in 36% of the anti-HD cases. Patients with anti-HD and HBV-DNA had the highest levels of transaminases (SGPT). Our results suggest that in certain patients HDV and HBV replication coexists without mutual inhibition.

Salmonella infections of the abdominal aorta cured with prolonged antibiotic treatment.

Three cases of endovascular infection of atherosclerotic aneurysm of the abdominal aorta due to Salmonella spp. are described. 'Breakthrough' or relapsing bacteraemia were major clues for diagnosis in each case. They were treated with a prolonged course of bactericidal antibiotics before surgery. Resection with an interposed graft was performed in all cases and antibiotic treatment continued. Two of our patients have survived for more than two years and the other for 18 months without evidence of relapse. Thus, it would appear possible at times to treat successfully mycotic aneurysm of the abdominal aorta with antimicrobial agents plus resection of the aneurysm followed by in situ bypass grafting. Extra-anatomical grafts should be kept for infections due to antimicrobial-resistant organisms or when periaortic infection is widespread.