Morris Simon

A vena cava filter using thermal shape memory alloy. Experimental aspects.

Surgical ligation of the vena cava in the treatment of pulmonary embolism is already being superseded by devices introduced via a peripheral vein. A new metal alloy (nitinol) with unique memory characteristics forms the basis of an experimental device which promises even greater safety, simplicity and speed of introduction. It is inserted as a straight thin wire via the small bore catheter used for angiographic diagnosis. Upon reaching the lumen of the inferior vena cava and sensing body temperature, it reverts to its preset complex filter shape and locks into place permanently. It will trap further thromboemboli from the pelvis or lower limbs.

An Angiographic Severity Index for Pulmonary Embolism

This report has discussed the use of an angiographic severity index for pulmonary embolism in the analysis of pulmonary angiograms from 160 patients admitted to the Urokinase-Pulmonary Embolism Trial. Angiographic studies done before and after treatment with urokinase or heparin were analyzed independently by three radiologists who had no knowledge of treatment assignment. A subjective evaluation and a subsequent objective recording of abnormalities were made. The computation of a severity index was based on a numerical grading system for definite abnormalities specific for pulmonary embolism (intraluminal filling defects and vascular obstructions).The procedure for computing the severity index was simple enough that recorded abnormalities were coded and punched by a statistical clerk and analyzed by computer. Correlations between subjective evaluations and objective severity indices were high. There was excellent agreement among the three radiologists for both subjective and objective methods. Highly significant treatment differences were detected.The angiographic severity index might help to classify patients, predict prognosis, plan clinical studies, and assess treatment effects.

Local intravascular effects of the nitinol wire blood clot filter.

To determine the biocompatibility and thrombogenicity of nitinol blood clot filters, we inserted 27 nitinol wire devices into the venae cavae of 16 dogs and one sheep and studied the results angiographically and at autopsy after periods of one week to four years. Filter shape, location in the vena cava, wire cleaning procedure and wire surface finish were varied. All 18 cleaned nitinol wire filters remained patent by venogram, although some showed small venographic filling defects caused by adherent organized thrombi. Filters in larger veins tended to have less thrombus. Surface polishing and filter shape had no observable effect on thrombogenicity. Histologic study revealed patchy chronic inflammation at the surface of uncleaned filters but only benign fibrous tissue reaction for the cleaned filters. Neointimal tissue overgrowth was observed where nitinol wire contacted the wall of the vena cava. Two filters implanted for four years had no appreciable weight loss caused by corrosion. Platelet adhesion and plasma coagulation effects of nitinol wire were tested in vitro in human blood and found to be similar to those of stainless steel, which is used in comparable devices. These encouraging results suggest that nitinol may be a promising material for human intravascular prosthetic applications.

The pulmonary veins in mitral stenosis

Summary Engorgement of the upper lobe veins and narrowing of lower lobe veins are demonstrated in patients with mitral stenosis. Grading of engorgement of the upper lobe veins is discussed, and its h˦modynamic significance is investigated. The radiological observations are explained by a new hypothesis.

Gross Gastric Metaplasia of Ileum After Regional Enteritis

Summary A case of severe gastric metaplasia of the small bowel is reported. The patient had a long history of recurrent regional enteritis requiring repeated resections of the diseased ileum. Severe metaplasia resulting in gross morphologic abnormalities was present in the last resected bowel, not associated with active regional enteritis. The characteristic radiologic features are readily recognizable and diagnosable. The gastric nature of the metaplasia is indicated by the presence of fundic as well as the pyloric gastric cells. The sequence of events in this case supports the concept of the acquired nature of the metaplasia and also suggests that in its gross form it may be symptomatic.

The Pulmonary Vessels in Incipient Left Ventricular Decompensation

Dilatation of the pulmonary vessels of the upper zones and constriction of the vessels of the lower zones characterizes left ventricular decompensation. These changes may precede the onset of clinical symptoms providing a useful warning sign of impending danger. A hypothesis is suggested to account for the non-uniform vessel pattern. An exception is noted in patients with severe emphysema or bronchitis in whom generalized dilatation may occur.

Duodenal Compression by the Mesenteric Root in Acute Pancreatitis and Inflammatory Conditions of the Bowel

One of the unfortunate consequences of mans assumption of the erect posture is a sharp decrease in the angle formed between the aorta and the root of the mesentery, the latter containing the superior mesenteric artery. The third part of the duodenum crosses the aorta just beneath the origin of the superior mesenteric artery, thus tending to become wedged in this angle. This constitutes a precarious anatomical situation. Obstruction of the duodenum due to compression by the mesenteric root as a chronic intermittent condition is a well recognized syndrome (1–3). Similar compression of the duodenum as an acute transient phenomenon, secondary to local and more remote inflammation, appears either not to have been described or, in many cases, to have been erroneously attributed to duodenal atony. The selected cases to be reported here illustrate the varied clinical causes of duodenal compression, on the one hand, and the possibility of a unifying concept of mechanism, on the other. Appreciation of this concept...

Advances in Radiologic Reporting with Computerized Language Information Processing (CLIP)

Computerized Language Information Processing (CLIP) is a system of radiologic reporting in which the user interacts with a computer keyboard and cathode-ray tube terminal to generate coded reports. The hierarchical medical classification on which the code is based permits rapid on-line compilation of reports of any degree of complexity. The system provides organized sets of pre-assembled statements that are rapidly accessed and modified for each examination. Although the reports are printed in English, they are held in the computer as a succinct code that is eminently suited for permanent storage and rapid retrieval.

Paddle-wheel multislice helical CT display of pulmonary vessels and other lung structures

The authors have now instituted the paddle-wheel method of CT reconstruction imaging of the lungs as a routine supplement to the standard axial multislice helical CT pulmonary angiography images for pulmonary embolism, and are exploring its role in other diseases. This unique way of viewing lung structures adds a new dimension to pulmonary imaging. Large-scale comparison studies of the traditional and the proposed paddle-wheel CT display method are necessary to quantitate their relative clinical effectiveness in the evaluation of the pulmonary vasculature, airways, and lungs.

Computerized Radiology Reporting Using Coded Language

A logical and comprehensive classification code has been built into a computerized system to permit the direct generation of radiologic reports. The report appears instantly on the television screen and, upon approval, is typed out both in the patients area and radiology department, bypassing the traditional transcription and delivery process. No secretary or mail clerk is needed. Since preceded input is used, data retrieval will be highly efficient and accurate. Computer operating costs will be competitive with conventional manual reporting. The CLIP (Coded Language Information Processing) system is presently undergoing clinical trial.