Biomedical subjects
Publications and source records attributed to Y Robert.
The authors report a case of orbital granulocytic sarcoma complicating a case of acute myeloblastic leukaemia, which was investigated by CT and MRI. CT revealed a moderately contrast-enhanced orbital mass. The MR signal intensity was identical to that of grey matter on T1-weighted sequences and identical to that of white matter on T2-weighted sequences.
The high spatial resolution of computed tomography allows visualisation of the fine structures of the facial skeleton and gives precise information about the anatomy of the nasal cavity, the paranasal sinuses and their relations with adjacent structures. A detailed knowledge of the normal anatomy, particularly of the nasal cavity and ethmoid, is very useful to provide to the surgeon with a precise pre operative surgical map, before transnasal endoscopic ethmoidectomy or management of paranasal sinuses tumors.
Hopeless glaucoma cases fluctuate between excessive pressures and phthisis. Due to the underlying disease (neovascularization in the chamber angle, chronic inflammation, dysgenesis, aphakia) the customary surgical pressure-lowering operations often fail and medication is also useless. As a "last-ditch" measure, there remains only destruction of the ciliary body. In the Zurich eye department, noninvasive cyclophotocoagulation has been performed since 1987. The present paper reports on the first cases with long-term follow-up.
A radiological technique, using a new CT software program for the evaluation of alveolar process height and width is presented. Our experience with this technique is described.
A mucocele is rarely observed after esophageal exclusion for corrosive burns. It may represent a contra-indication to esophageal conservation in case of a total gastric resection for necrosis and perforation of the stomach. To evaluate this risk, 15 patients, operated between January 1970 and december 1988, were reviewed: they underwent total gastric resection with esophageal exclusion, followed by a secondary colon transplant between the cervical esophagus and the duodenum. A plain chest film was performed for 13 patients and a CT scan for 11 patients. Mean follow-up was 5.7 years (2 months - 17 years). Four patients died, one of them after resection of a compressive esophageal mucocele. Six mucoceles were detected on 13 chest films and 7 were described on 11 CT scans. On the whole, 8 mucoceles were diagnosed on 15 patients; one of them was complicated by tracheal compression. The formation of a secondary esophageal mucocele is a late sign of incomplete destruction of the esophageal wall. It is a frequent complication of esophageal exclusion performed after total gastrectomy for corrosive burns of the stomach. It must be detected on a chest film which shows the largest dilatations or on a CT scan, which is a better investigation. When the diameter of the mucocele is equal of superior to 50 mm, it can be compressive and must be treated by resection of internal diversion.
A 65-year-old hypertensive and atheromatous presented with "unilateral superior vena cava syndrome". Venography and computed tomography scan with hemodynamic studies demonstrated an intermittent compression of the left innominate vein by the supra-aortic trunks, mainly due to the left subclavian artery, during expiration. The late development of symptoms might be due to arterial atheroma coupled with a narrow superior mediastinum. The case described here is a thoracic equivalent of Cockett's syndrome and so can be called "innominate vein compression syndrome".
In order to assess the value of tomodensitometric classification of squamous cell carcinomas of the upper esophagus, which has been recently advocated, we compared the CT-measured diameters and the extent of intraparietal invasion in 101 tumors. According to selected criteria (superficial -T1- tumors: not apparent or less than 10 mm; tumors infiltrating incompletely the muscularis -T2- ; mass less than 10 to less than 20 mm in diameter; tumors extending beyond the muscularis -T3, T4- : diameter greater than or equal to 30 mm), 84/101 tumors were correctly assessed. The positive predictive value for T2 tumors was 73% in the 10 to less than 20 mm diameter range, and 71% for T3 and T4 tumors in the 20 to less than 30 diameter range. Starting from 30 mm, this value was 96% for T3 and T4 tumors. At the close of this study, it appeared that the classification criteria proposed did not have to be modified. CT-scanning is worth using jointly with ultrasonographic endoscopy (more performing when analysing small tumors) for pre-treatment classification of carcinomas of the upper esophagus, owing to the fact that the extent of wall infiltration is one of the elements which need be taken into account when planning therapy: direct surgery or, possibly, combined preoperative radio- and chemotherapy.
Explore the source record for details and available documents.
The degree of retinal nerve fiber loss within the papillomacular bundle in optic neuropathies was evaluated from red-free fundus photographs. Visual evoked potentials were obtained from pattern reversal with variable check sizes. A semiquantitative scale was used for the estimation of nerve fiber loss and amplitude reduction of the visual evoked potentials. A significant correlation was found between both. However, a few patients showed rather well-preserved visual evoked potentials with an atrophic nerve fiber layer. Possibly a small number of invisible remaining fibers are able to sustain nearly normal visual evoked potentials. On the other hand, some patients had abnormal visual evoked potentials in the presence of a normal nerve fiber layer. We conclude that evaluation of the nerve fiber layer of the papillomacular bundle without functional testing of the optic nerve is not sufficient to predict degree of foveal integrity.
The author explains the difficulties of a topographical quantification of papillary changes. On the one hand this is due to the unprecise definition of the papilla's boundaries, on the other hand these boundaries might themselves fluctuate. Afterwards a description of the dynamic provoked circulatory response follows. This is an examination which tests the change of redness of the rim when the intraocular pressure is artificially risen. Two properties of the vascular system of the papilla are checked with it. When looking at the 'latency time', the time which elapses between beginning of the provocation and beginning of pallor increase, the vascular resistance is controlled. When measuring a decrease of pallor while increasing the intraocular pressure autoregulation of the papillary capillaries are tested. The dynamic provoked circulatory response is the only clinically available test of the papilla's vascular system.
The ability of glaucomatous eyes to adjust to a sudden increase in intraocular pressure was investigated in nine certain glaucoma cases and in ten normal subjects. The "dynamic provoked circulatory response" (DPCR) was determined by continuously measuring the brightness of the papilla before (baseline), during, and after an abrupt artificial elevation in intraocular pressure. Following the onset of intraocular pressure elevation, the period during which the baseline brightness of the papilla persisted (latency time) was significantly (P less than 0.001) shorter in glaucomatous eyes (0.64 +/- 0.25 s) than in normal eyes (2.39 +/- 0.68 s). This led to the suggestion that the extent to which an eye can adjust to abruptly higher intraocular pressure is measurably reduced in glaucoma. That this effect can be quantified indicates a potentially useful method for detection and follow-up of glaucoma.
On the basis of a number of examples the authors describe specific glaucomas which have often reached their final stages by the time the patients are referred to the clinic. They include sub-acute and chronic angle-closure glaucoma, pseudoexfoliation syndrome, and pigmentary glaucoma. An unpleasant feature of these glaucomas is that, somehow or other, treatment comes too late: complete cupping of the optic disk when the ophthalmologist is first consulted, increased intraocular pressure in exfoliation syndrome detected too late, or a tardy decision to perform an iridotomy or a fistulizing operation. The following are some important points: gonioscopy should be performed not only at the initial examination but also at subsequent ones; subacute and chronic pupillary or angle-closure glaucomas are progressive diseases for which the sensible therapy is not miotics but laser iridotomy; because papillary changes usually precede visual field changes (automated perimetry notwithstanding), particular attention must be paid to the former. This can only be accomplished with exact documentation. Therefore, glaucoma follow-up means pressure measurement and gonioscopy and examination of the optic disk and visual field. In conclusion, aids for decision-making and a follow-up schedule are presented.
A mucocele is rarely observed after esophageal exclusion for corrosive burns. It may represent a contra-indication to esophageal conservation in case of a total gastric resection for necrosis and perforation of the stomach. To evaluate this risk, 15 patients, operated between January 1970 and December 1988, were reviewed: they underwent total gastric resection with esophageal exclusion, followed by a secondary colon transplant between the cervical esophagus and the duodenum. A plain chest film was performed for 13 patients and a CT scan for 11 patients. Mean follow-up was 5.7 years (2 months - 17 years). Four patients died, one of them after resection of a compressive esophageal mucocele. Six mucoceles were detected on 13 chest films and 7 were described on 11 CT scans. On the whole, 8 mucoceles were diagnosed on 15 patients; one of them was complicated by tracheal compression. The formation of a secondary esophageal mucocele is a late sign of incomplete destruction of the esophageal wall. It is a frequent complication of esophageal exclusion performed after total gastrectomy for corrosive burns of the stomach. It must be detected on a chest film which shows the largest dilatations or on a CT scan, which is a better investigation. When the diameter of the mucocele is equal of superior to 50 mm, it can be compressive and must be treated by resection of internal diversion.
Contrast sensitivity (CS) and differential light sensitivity (LUE) tend to deteriorate with increasing severity of the neuropathy. However, the correlation between the two psychophysical functions is low for the total number of optic neuropathies as well as for groups with different visual acuities. This fact is mainly explained by the range of scatter in LUE values. Moreover, visual acuity is much better correlated with CS than with LUE. CS and LUE represent different visual functions that may be processed by separate neural structures.
Halothane lowers the peripheral vascular resistance and blocks autoregulation in the cerebral vessels. Proceeding from the assumption that the papillary vessels behave in like manner, the authors examined increases in papillary pallor under artificial IOP elevation in anesthetized patients with and without Halothane, using the photopapillometer. This provocation test was conducted in 14 patients, first on one eye under normal (N2O/O2) anesthesia, then on the fellow eye after steady state had been attained with subsequently administered Halothane. By quantifying ocular circulatory conditions, the demonstration of the lowering of peripheral vascular resistance in the papillary vessels under Halothane was convincing; the blockage of autoregulation was less obvious. To explain these results the authors suggest that the two effects are gradual and mutually influential.
Hydroxy-propyl-methyl-cellulose (HPMC) was injected into the anterior chambers or vitreous bodies of rabbit eyes in order to test local and systemic tolerance. In doing so the typical intraoperative complication of capsule rupture, which, in anterior segment surgery in man, allows HPMC to enter the vitreous body, was simulated. Neither clinically, nor in laboratory workup, nor histopathologically could any difference be shown between the local and systemic reactions of HPMC and those of DRSS. The data obtained in the study admit the conclusion that HPMC can be used in surgery of the anterior segment without any risk of adverse reactions.
Starting from the structural analogy between bromo-ergocryptine (Parlodel) and dihydroergocryptine caffeine (Vasobral), as well as with dihydroergotoxine (Hydergine), the authors decided to test the efficacy of the last two products in inhibiting post-partum physiological milk secretion. Twelve patients will be treated with either one of the two products, with a clinical and biological efficacy (serum prolactin level assay) which is comparable to that found in the literature regarding Parlodel. This study confirm the results obtained in a study of the inhibition of hyper-prolactinemia of other origin, by the same authors.