Extra-abdominal pneumodissection after laparoscopic antireflux surgery.

The presence of pneumoperitoneum during laparoscopic antireflux surgery can lead to the dissection of carbon dioxide into the mediastinum, retroperitoneum, subcutaneous tissues, and neck (pneumodissection). The purpose of this study is to describe the incidence, extent, duration and pathways of pneumodissection during laparoscopic antireflux surgery. Twenty patients who underwent laparoscopic antireflux surgery from August 1998 through May 1999 were studied. Physical examination and chest radiographs were performed in the recovery room and each day postoperatively. Noncontrast computerized tomography (CT) of the neck, chest, and upper abdomen was also performed on postoperative day one. Subcutaneous emphysema and radiologic evidence of pneumodissection occurred commonly and typically resolved within 4 days postoperatively. The incidence of pneumomediastinum (85%) seen on CT scan was similar to that of pneumodissection into the neck (80%). The most common pathway of dissection of gas was through the anterior mediastinum and into the neck through the carotid space. Other findings on CT scan revealed pneumoperitoneum in 70 per cent, pneumoretroperitoneum in 10 per cent, and pneumothorax in 0 per cent. The dissection of gas into the mediastinum, neck, and subcutaneous tissues is very common after laparoscopic antireflux surgery. Subcutaneous emphysema on physical examination and radiographic pneumodissection typically resolves within 3 to 4 days. After this time one should consider the presence of any substantial amount of gas as a potential complication related to the procedure.

The role of spiral volumetric computed tomography in the diagnosis of pulmonary embolism.

To evaluate the evidence for the use of spiral volumetric computed tomography (SVCT) in the diagnosis of acute pulmonary embolism (PE), the 11 English-language studies published through July 1998 that compared SVCT with a reference standard for PE were systematically reviewed. Among the reviewed studies, methodological problems were common. Only 5 of these studies fulfilled 5 of 11 basic standards addressing important issues in diagnostic test research. The reported sensitivities of SVCT compared with pulmonary angiography varied widely (64%-93%), which was likely the result of differences in study populations. Spiral volumetric computed tomography may be relatively sensitive and specific for diagnosing central pulmonary artery PEs, but it is insensitive for diagnosing subsegmental clots. Spiral volumetric computed tomography may have a role as a "rule-in" test for large central emboli, but additional research is required to establish its place in clinical practice.

Regulation of the Immune Response by Eicosanoids: Pharmacology and Clinical Effects of Prostaglandin E in Aspirin-Sensitive Syndromes.

Immunomodulatory effects of prostaglandin E(2) (PGE(2)) have been documented both in vitro and in vivo. Our previous studies have examined the effects of intravenously administered PGE(2) in mast-cell-mediated diseases, including aspirin-sensitive asthma and systemic mast-cell-activation syndrome. The basis for investigations of these particular diseases has been the hypothesis that the inhibition of cyclooxygenase removes one of its products, PGE(2), that provides a critical restraint on the activation of the mast cell. Based on the beneficial effects of PGE(2) found in these studies, we have extended our investigations to an evaluation of misoprostol, the orally available analog of PGE(1). Our preliminary studies with this drug are consistent with an inhibition of mast cell activation by misoprostol, an effect observed at doses higher than currently recommended for gastric protection. The findings from these initial trials have led to the development of ex vivo whole-blood assays that assess the pharmacodynamics of misoprostol's immunomodulatory actions, which support the concept of employing higher doses to obtain sustained systemic effects. To extend these results, we have undertaken double-blinded, placebo-controlled clinical investigations to examine the effects of the higher doses of misoprostol (300--600 &mgr;g QID) given chronically in aspirin-sensitive asthma and systemic mast cell activation. Although still ongoing, our studies have confirmed by a variety of clinical evaluations that the higher doses of misoprostol can be tolerated by many patients and appear to be safe. Based on our findings and those of others, further investigation of the therapeutic usefulness of this drug or other PGE analogs in allergic and immunologic diseases appears warranted.