Is low-intensity anticoagulant therapy possible with an open pivot valve?: analysis of its development.

In 1976, the authors became the codevelopers of the first successful bileaflet heart valve which has become the standard in valvular surgery. However, there still remains a significant rate of thromboembolism and thrombosis which can be attributed to the inherent design of cavities in the pivot area. These cavities contribute to stagnant areas that lead to thrombus formation. The literature indicates that this rate is approximately 2% to 2.5% per patient year. To maintain these thromboembolism rates, certain levels of warfarin have had to be used leading to a significant rate of bleeding complications. We present the theory and development of the new generation of heart valves without cavities and with an open semisphere pivot area. Results of 912 years of clinical studies of almost 50,000 valves, as well as additional features that have been incorporated to improve hemodynamics and quality of life for the patient, are discussed. The clinical results of the European Community Certification and U.S. Food and Drug Administration premarket application (PMA) studies also are given. The differences in the pivot area suggest that a reduction in thromboembolism is possible at anticoagulant levels as low as 1.5 international normalization ratio (INR) resulting in virtually no bleeding complications. Midterm clinical results are encouraging, and studies are being conducted presently to eliminate totally anticoagulants in certain patients.

Localized transscleral staphylococcal abscess simulating a neoplasm.

A 47-year-old woman with a history of breast cancer developed a focal epibulbar mass in the right eye. The initial diagnosis was nodular episcleritis, but the lesion failed to respond to local and systemic corticosteroids. The rule out an epibulbar metastatic carcinoma an excisional biopsy was performed, which demonstrate a localized staphylococcal abscess that had locally eroded the sclera and exposed the underlying uveal tract. Covering the defect with a scleral patch graft and promptly instituting oral amoxicillin/clavulanic acid and topical cefazolin treatment resulted in an uncomplicated recovery. Infectious scleral abscess in an uncommon entity and the differential diagnosis includes nodular episcleritis and epibulbar metastatic tumor.

Latex versus iodinated contrast media anaphylaxis in the cardiac cath lab.

A 65-year-old man had bypass surgery 10 years previously with pulmonary artery catheter monitoring. Shortness of breath and mitral regurgitation necessitated repeat left and right heart catheterization using a pulmonary artery catheter. Before any iodinated contrast media exposure, the pulmonary artery catheter was inserted and within 2 min the patient developed anaphylaxis associated ventricular fibrillation. It was discovered that the pulmonary artery catheter used in the cath lab had a latex balloon and that the patient had been exposed to latex 10 years ago. Latex induced anaphylaxis is rarely considered in the differential diagnosis of patients with hypersensitivity reactions in the cath lab, intensive care unit, and operating room. The principal reason for failure to recognize the latex balloon as a potential allergen is that most health professionals are not aware that almost all pulmonary artery catheters contain a latex balloon. The risk of an allergic response to latex is 0.8% for the general population. Others at high risk include those who have had multiple surgical procedures and interventions with repeated latex exposure. Five to 10% of all U.S. health professionals and those performing household duties wearing latex gloves have an allergic response to latex. Latex hypersensitivity is an IgE dependent reaction, while iodinating contrast medium reaction is an IgE independent reaction. If latex hypersensitivity is suggested by pre-procedural history or if the patient falls into a high-risk group, pre-procedural skin testing and/or latex IgE radioallergosorbent (RAST) should be performed.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the unwanted optical images produced by 6 mm and 7 mm intraocular lenses.

Unwanted optical images are noticed by a surprisingly large number of patients following cataract extraction with implantation of posterior chamber intraocular lenses (IOLs). These images are caused by the positioning holes, lens edge, or laser ridge. We studied 550 eyes in which one of seven different IOLs was inserted. The IOLs varied in optic diameter, the presence or absence of positioning holes or a laser ridge, the use of partial depth holes or placement of positioning holes in tabs outside the optical zone. We determined that unwanted optical images could practically be eliminated by using a 7 mm optic without positioning holes. This study also demonstrated that partial depth holes offer no advantage over full thickness holes for reducing unwanted optical images and that positioning holes, even on a 7 mm optic, produce a significant number of complaints.

Laser angioplasty of totally occluded coronary arteries and vein grafts: preliminary report on a current trial.

CLINICAL PERSPECTIVE: Among the various laser angioplasty systems and atherectomy devices currently in clinical trials, the Lastac system appears to be particularly suitable for treating totally occluded coronary arteries and vein grafts. Preliminary results of a clinical trial in more than 35 patients show a recanalization rate of 92% and no complications attributable to the laser. Restenosis has occurred in five cases; in three of these, the arteries were reopened with laser or conventional angioplasty.

Blepharochalasis.

Blepharochalasis is an uncommon disorder distinguished by recurrent episodes of eyelid oedema in young patients. A hypertrophic form, manifested as fat herniation, and an atrophic form, manifested as fat atrophy, have been described. Ptosis with excellent levator function, laxity of the lateral canthal structures with rounding of the lateral canthal angle, nasal fat pad atrophy, and redundant eyelid skin develop after many episodes of eyelid swelling. Fine wrinkling, atrophy, and telangiectasias characterise the excess eyelid skin. We describe four cases of this syndrome in which external levator aponeurosis tuck, blepharoplasty, lateral canthoplasty, and dermis fat grafts were used to correct atrophic blepharochalasis after the syndrome had run its course.

In-vivo NMR spectroscopy of the fetal lung in guinea-pigs.

We have been successful in achieving phosphorus NMR in-vivo spectra of the fetal lung in an animal model. We used pregnant guinea-pigs with a gestational age of 45 to 65 days. The spectra were recorded on a Bruker tomograph (BMT 24/30) with a field strength of 2.35 T. The spectra showed a typical pattern. After recording the animals were sacrificed and the lungs were prepared for electron microscopic examinations. In the spectra peaks were found which appeared to be phosphorylcholine and phosphatidylcholine. For one peak it could be observed that the relative signal intensity increased with increasing gestational age as well as with increasing lung maturity. This could not be observed for other peaks. So the lecithin of the surfactant in the tissue of the fetal lung appears to be directly accessible through phosphorus in-vivo NMR spectroscopy. The peaks found appear already before the lamellar bodies are present in the pneumocytes type II.

Brain stem anesthesia after retrobulbar block.

Presented is a series of eight patients in whom neurologic sequelae developed after retrobulbar anesthesia. All patients demonstrated blockade of one or more cranial nerves and six progressed to apnea, requiring intubation and mechanical ventilation. Neurologic findings included amaurosis in the contralateral eye (5 patients), nonreactive pupil in the contralateral eye (6 patients), ductional defects (2 patients), and dysphagia (4 patients). In all cases, these findings resolved in 2 to 12 hours. In patients who progressed to apnea, spontaneous respiration resumed within 30 to 60 minutes. These findings are particularly significant in light of recent decisions to reduce anesthesia coverage for cataract surgery in some regions.

Contralateral amaurosis after retrobulbar injection.

Contralateral amaurosis after retrobulbar injection of local anesthetic agents occurred in two patients, a 64-year-old woman and a 57-year-old man. The amaurosis resulted from migration of the anesthetic agents to the optic chiasm and contralateral optic nerve via the subarachnoid space. In both cases visual acuity returned to preoperative levels within 90 minutes. A modified technique in which patients look straight ahead or slightly downward and outward during retrobulbar injection, as opposed to the traditional upward and inward positioning of the globe, avoids inadvertent piercing of the sheaths of the optic nerve and injection of substances into the subarachnoid space.

A model of experimental isolation perfusion using cis-platinum.

An animal model has been devised to investigate effects of hyperthermia and chemotherapeutic agents on normal and neoplastic tissue. This model uses the rabbit as the experimental animal and will permit the passage of the transplantable VX-2 carcinoma. The technique described parallels clinical isolation-perfusion and utilizes cis-platinum as the chemotherapeutic agent. This model has proven to be reliable and consistent in achieving tissue temperature at therapeutic ranges and has documented the safety of using cis-platinum in this mode of therapy.

Thymoma diagnosed by transthoracic fine needle aspiration.

The cytologic diagnosis of a thymoma by transthoracic fine needle aspiration is described. A 64-year-old female was found toi have a left hilar mass following an episode of hemoptysis. Fine needle aspiration of the lesion demonstrated an intimate admixture of two cell types: epithelial and lymphoid. On the basis of the biphasic cytomorphology, the diagnosis of thymoma was suggested; this was confirmed by light and electron microscopic examination of tissue obtained at thoracotomy. Because of the paucity of cytologic descriptions of thymoma in the literature, pertinent morphologic features are emphasized, differential diagnostic possibilities are discussed, and the value of ultrastructural studies is confirmed.

Evaluation of unusual QRS complexes produced by pacemaker stimuli--with special reference to the vectorcardiographic and echocardiographic findings.

Fifty-seven patients with electronic pacemakers were studied from electrocardiograms (ECGs), vectorcardiograms (VCGs), and echocardiograms. Thirty-nine patients with transvenous right ventricular (RV) pacemakers showed a left bundle branch block (LBBB) pattern and nine patients with transvenous RV pacemakers showed a right bundle branch block (RBBB) pattern. There was no evidence of perforation of the right ventricle or malposition of the catheter electrode. Eight patients with left ventricular (LV) pacemakers showed a RBBB pattern and one showed a LBBB pattern. The maximal QRS vector of a RBBB pattern induced by RV pacing was directed leftwards and anteriorly, whereas that of a RBBB pattern induced by LV pacing was oriented rightwards and posteriorly. A rapid posterior motion of the left side of the interventricular septum (IVS) during the early systole, and/or anterior or flat motion of the IVS during the ejection period were almost exclusively limited to cases with RV pacing, regardless of the ECG wave form. There was one exceptional case in LV pacing, which showed a LBBB pattern with the same septal motion as that in RV pacing. However, the maximal QRS vector in this case was directed inferiorly, which is in sharp contrast to that in the RV pacing which was directed superiorly. Based on the hypothesis that the ECG wave form by LV pacing might be equivalent to that in a case of perforated right ventricle, the following conclusions can be drawn from the present study. (1) A RBBB pattern in RV pacing could be differentiated from perforation of the right ventricle. The following findings may support uncomplicated RV pacing: (a) the left and anterior orientation of the maximal QRS vector, and (b) a rapid initial posterior septal motion during the early systole and/or a paradoxical anterior septal motion during the ejection period. (2) A LBBB pattern with inferior orientation of the maximal QRS vector would suggest perforation of the right ventricle.

Studies of acute myocardial infarction with intermittent bundle branch and hemiblock.

Two cases of transient hemiblock occurring during the course of acute myocardial infarction are reported. The transient manifestation permits the accurate evaluation of the diagnostic features of the hemiblocks as modified by acute infarction. One case reflects the development of left bundle branch block due to bilateral post-divisional block which inter alia permits the study of left bundle branch block in the presence of acute myocardial infarction.

Reappearance of anterior QRS forces after coronary bypass surgery. An electrovectorcardiographic study.

This report describes the reappearance of anterior QRS electrical forces in six patients after direct coronary arterial bypass surgery. Each patient had severe coronary artery disease including a segmental stenosis of the left anterior descending artery. Revascularization was performed by direct anastomosis of the left mammary artery to the left anterior descending coronary artery and saphenous vein bypass of other stenotic coronary arteries. Preoperative electrocardiograms and vectorcardiograms showed patterns of anterior wall myocardial infarction with absent or diminutive anterior QRS forces. In each case, postoperative studies demonstrated the regeneration of anterior QRS forces within 10 days of operation. Although these patients represent a small percent of those with a preoperative pattern of infarction who undergo coronary revascularization, the findings demonstrate that electrically silent areas of myocardium may be altered and are not always synonymous with myocardial cell death. Chronic myocardial ischemia may in certain instances produce electrocardiographic and vectorcardiographic patterns of myocardial infarction that may be reversible upon reestablishment of perfusion to ischemic areas.