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Controlled Environment Treatment is a new approach to wound management--for the first time it provides the surgeon with the means of controlling and optimizing the wound environment for the duration of the healing period. Equipment is commercially available and the technique is now being applied internationally; the technique has been established for the treatment of limbs--application to the trunk requires further investigation and development. Spin-offs have already occurred, one being the control of certain types of lymphoedema by the patient in their own home; the other concerns the application of plaster of Paris to produce casts having significantly superior physiological characteristics using minimal manipulative skills. The former is known as Pressure Environment Treatment, the latter is known as Controlled Pressure Casting; equipment is commercially available internationally.
The controlled environment vitrification system (CEVS) permits cryofixation of hydrated biological and colloidal dispersions and aggregates from a temperature- and saturation-controlled environment. Otherwise, specimens prepared in an uncontrolled laboratory atmosphere are subject to evaporation and heat transfer, which may introduce artifacts caused by concentration, pH, ionic strength, and temperature changes. Moreover, it is difficult to fix and examine the microstructure of systems at temperatures other than ambient (e.g., biological systems at in vivo conditions and colloidal systems above room temperature). A system has been developed that ensures that a liquid or partially liquid specimen is maintained in its original state while it is being prepared before vitrification and, once prepared, is vitrified with little alteration of its microstructure. A controlled environment is provided within a chamber where temperature and chemical activity of volatile components can be controlled while the specimen is being prepared. The specimen grid is mounted on a plunger, and a synchronous shutter is opened almost simultaneously with the release of the plunger, so that the specimen is propelled abruptly through the shutter opening into a cryogenic bath. We describe the system and its use and illustrate the value of the technique with TEM micrographs of surfactant microstructures in which specimen preparation artifacts were avoided. We also discuss applications to other instruments like SEM, to other techniques like freeze-fracture, and to novel "on the grid" experiments that make it possible to freeze successive instants of dynamic processes such as membrane fusion, chemical reactions, and phase transitions.
A controlled environment unit has been compared with plaster dressings in the management of the below knee stump in 60 patients undergoing amputation for advanced vascular disease. The main criteria were stump healing and the speed of rehabilitation. There were 30 patients in each group. Three patients died within 10 days of operation. Primary healing was obtained in 65 per cent, secondary healing in 22 per cent and revision to above knee was required in 13 per cent. There were no statistically significant differences between the two groups. Neither did they differ in the times taken to reach the various stages of rehabilitation from bed exercises to independent walking with final prosthesis. While the controlled environment unit was as effective as the plaster dressing it tended to impede the patients' early mobility and to hinder nursing care. In particular it is not recommended for patients who may be confused or restless in the early postoperative period.
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This paper demonstrates a new approach to postsurgical and post-traumatic wound management in the lower limbs. Our own results of 20 below-knee amputations are documented. A less detailed report is then given of experience with an additional 20 amputees: this second group includes experience not only here at Seattle but at five other centers in the United States. The same method for wound management and for control of edema was employed in all cases. The method, Controlled Environment Treatment (CET), uses filtered air as a dressing medium, with a control console to maintain the pressure, constant or varying, according to a preset program. Temperature and humidity are also controllable, as is gas composition. The limb, together with its controlled environment, is contained with a pliable, transparent, treatment bag, which permits inspection and palpation of the wound site without disturbing the bacteriologically sterile air within the chamber. A special seal reduces air leakage yet avoids constriction of the limb. This CET system was originally developed by the Department of Health and Social Security, Biomechanical Research and Development Unit, Roehampton, England. Subsequent developments are also noted of an improved Mark II CET Unit and of simpler, related, management systems for conditions not requiring sterile environments.
A case of surgically-treated elephantiasis of a lower limb is reported in which preoperative controlled environment therapy (CET) proved to be an effective, rapid method of reducing the oedema.
Two thin film culture systems, the controlled environment steady state system (SS) and the rocker tube configuration of that system (RT), were used to identify some of the conditions that appear to maintain morphologic and functional characteristics of cells of human bone marrow explants in vitro. The systems configuration assured continual gassing, control and easy monitoring of the cultures. Cytocentrifuge preparations of media of specimens cultured in RT disclosed, though in decreasing numbers, various hematopoietic cells for periods exceeding one month. Hematopoietic cells shed from specimens cultured in the SS system were retained in the culture tubes; cells of the myelocytic series predominated for the first two weeks while an increasing number of monocytes and macrophages appeared in the media of of older cultures. Histologic examination of cultured explants disclosed preservation of the marrow architecture and the persistence of hematopoietic cells. Specimens cultured in RT tubes tended to be less cellular than similar cultures placed in dialysis bags or as cultured in the SS system. Immunoglobulins (Ig) were released into the culture media at a constant rate throughout the period of culture. Specimens that were cultured at a controlled pH of 7.4 released 2 to more than 4 times as much Ig as similar specimens maintained at a pH level of 7.1. There were no definitive differences in Ig levels in the cultures maintained at comparable pH levels and overlaid with various CO2 concentrations, i.e. 2%, 5%, 10% similarly, no differences in Ig levels were found in specimens cultured in media containing fetal bovine sera as opposed to horse sera.
This paper describes a new approach to early postsurgical wound management of the patient with a below-knee amputation. The method involves using the Controlled Environment Treatment (CET) machine, which wasdeveloped in England. A brief explanation of the components of the machine and its capabilities are listed. Ambient pressure, temperature, sterility, and humidity are easily controllable; advantages and disadvantages of this device over immediate post-operative plaster and conventional dressings as they relate both to wound environment and to physical therapy are mentioned. The early postsurgical therapy program used at Prosthetics Research Study is outlined.
Bone marrow biopsy specimens from patients with myeloma were cultured in either 1 of 2 thin-film culture systems, a controlled environment steady state system or a rocker tube configuration of the system, for periods up to 42 days. Both functional and morphological characteristics of the myeloma cells were well-maintained in these systems. Cytocentrifuge preparations of the culture media disclosed hematopoietic cells that included from 5% to almost 100% plasma cells. Histological examination of the cultured specimens disclosed infiltration of the marrow with myeloma cells. Myeloma proteins were released at a steady rate throughout the period of culture after the 1st 4 days. Bone-resorbing activity was demonstrated in the culture media in 7 of 9 myeloma culture media and was well maintained, particularly during the 1st week of culture. This activity was associated with severe osteolytic lesions in the donor patient and marked infiltration of the cultured specimen by myeloma cells. The potential use of these organ culture systems for the further definitive identification of the factor responsible for bone destruction in myeloma is discussed.
Control of the environment is a cost-effective method of limiting allergic reactions in susceptible people. For physicians working with allergic patients, this approach involves guiding the patient and family in ridding their home and surroundings of allergens and irritants. Dr. Klein discusses the environmental-control protocol, particularly in regard to dust mites, mold, pollen, and pets.