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Artificial organs and cardiopulmonary support systems
256
REVIEWS
There are references, usually to current medical literature, at the end of each chapter (with one exception, the one on nursing care), but the lists are of unequal length and value. The inevitable overlap between chapters has been well handled and cross-referencing is good. The book can be thoroughly recommended to all those concerned with the care of the very ill child; they will find this a highly practical guide within the area delineated by the authors. GERALDGRAHAM
ARTIFICIAL
ORGANS
AND
CARDIOPULMONARY
SUPPORT
SYSTEMS
Edited by Felix T. Rapaport and John P. Merrill. pp. 183, Grune & Stratton, New York, 1971. This book is compiled of 23 papers and a summary by Dr Merrill (one of the editors) of a symposium covering the two main areas indicated in the title. It represents a progress report on the current state of the art in the United States. Since, with the possible exception of home dialysis, much of the new and experimental surgery in this area is being carried out in the United States, and the Transplantation Society is an American organization, it is reasonable to regard this symposium as representative of the views of the international avant-garde. In remarking on the general high standard of the symposium, one is impressed by the vigorous, active and multifarious progress in the transplant field. Belding Scribner reviews the relative values of the renal dialysis and kidney transplantation in the treatment of renal failure. There is an overwhelming cost advantage in home dialysis relative to hospital treatment. Kidney transplants are obviously going to have more future, if the immunosuppression problem can be solved and tissue matching improved. As far as the donor is concerned, there are ethical objections to moving the donor, and the use of the perfused cadaver organ avoids these, and must become the method of choice. Scribner points out that the efficiency of dialysis has been found to be independent of the blood flow (‘the square metre hypothesis’), so that perfusions as slow as IOO ml/min can be used. Constantine Hampers reviews the complications of prolonged artificial kidney treatment. There is a pronounced uraemia; the patients often have an intractable anaemia, with haematocrits of 15-25%, indicating that there is bone-marrow suppression. Other complications are hypertension, the ‘restless leg syndrome’, osteodystrophy, hypercalcaemia and pruritus. Present-day mortality is only 5% per annum. She discusses the symptomatic treatment of these complications. Pierre Galletti discusses the potential role of artificial lungs, as being, first, oxygenation in organ preservation; secondly, temporary support for lung cripples awaiting transplanation; thirdly-in the future, long-term artificial lungs. Converse Pierce and colleagues have developed membrane oxygenators, and in venovenous and venoarterial perfusions, have shown better oxygenation and carbon dioxide exchange in dogs. Philip Drinker finds dogs susceptible to septicaemia, shock and fibrinolysis, and uses lambs for his experiments. He describes the ‘heparin tightrope’-in which sufficient heparin must be given to prevent clotting in the machine but not enough to cause haemorrhage in the patient.
REWEWS 257 &nald fill and his colleaguea ask the question, ‘for how long, safely and efficiently, can a patient suffering from severe respiratory insufficiency be supported by a membrane oxygenator?’ The treated ten patients, six with venovenous and four with venoarterial perfusions; five of them improved, one survived. They conclude that the patients have a good chance of survival if the lung parenchyma is not substantially destroyed. Michael de Bakey pinpoints unresolved problems in artificial heart total implants. No-one has yet devised an adequate implantable power system; clotting is still a major embarrassment in the pumps; cardiac output in the artificial pumps is still inadequate; air embolisms occur, and the pumps are not yet reliable mechanically. W. J. Kolff has trouble with coagulation in the intima of his polyurethane hearts, and pulmonary complications occur with their use. However, their cardiac output is improving. A. Kantrowitz and colleagues, and Austen and colleagues, have been testing balloon pumping in the aorta. They use a catheter-mounted polyurethane chamber inflated by helium. Both groups had 75% of their patients coming out of cardiogenic shock, much more often if they were treated within 30 h. The use of balloons is indicated also in open heart surgery where cardiopulmonary bypass circulation has stopped. It causes a rise in peak diastolic pressure, cardiac output and urine secretion. One of its disadvantages is that a substantial proportion of patients become dependent upon it. Arnold Lande describes the use of a small disposable membrane oxygenator, which can take flows of 15oo-3000 ml/mm. H. S. Soroff and ,colleagues give their preliminary results on dogs and nine normal subjects of counter-pulsation, in which a pulsatile g-suit is applied to the lower half of the body. The technique is at present being used in a widespread clinical test in nine hospitals in the Boston area. William McDermott and John Norman temporarily prolonged the lives of ten patients in liver failure by using perfused pig liver, and found that glucose uptake is the most sensitive index of liver function. B. Eisenman and T. Soyer have been experimenting in dogs with prostheses consisting of liver slices and cell suspensions, so far with only limited success. D. M. Hume and colleagues prefer baboon to pig livers for perfusion. They review comprehensively the following methods of support in liver failure: exchange transfusion, plasmapheresis, liver perfusion, administration of heterologous XC, liver X-P and L-dopa. They conclude that exchange transfusion and plasmapheresis are the methods of choice, and extracorporeal heterologous perfusion with baboon liver is useful in hepatic coma, if it can be managed. Basil Pruitt and Paul Silverstein review the materials which have been used to resurface denuded skin areas; they include frozen skin, freeze-dried skin, embryo tissue, collagen and several artificial materials, like Aeroplast, cellophan, silicone and vinyl polymers, which they have been testing histologically. Maurice Slapak and Hendon Lehr both conclude that freezing is the best way to date to preserve tissue. Kenneth Sell and Jeffrey Benjamin have invented a new technology-xenobanking. Apparently, if monkey kidneys before transplantation are perfused by an intermediate host, they survive much longer. In this review some of the more exciting and original advances at present being made have been selected for mention. This book illustrates their breadth and imagination-an imagination which has fired their research organizations to support them
258
REVIEWS
fully. The symposium should illustrate to non-Americans that it is the imagination and the courage to pursue what on first sight seem to be outlandish ideas, which have put the United States in the forefront of experimental surgery. ARTIFICIAL ORGANS AND CARDIOPULMONARY SUPPORT SYSTEE~S can be recommended for anyone who wishes to know the current state of the art, and where to find relevant and recent references to many important advances.
REVIEWS
There are references, usually to current medical literature, at the end of each chapter (with one exception, the one on nursing care), but the lists are of unequal length and value. The inevitable overlap between chapters has been well handled and cross-referencing is good. The book can be thoroughly recommended to all those concerned with the care of the very ill child; they will find this a highly practical guide within the area delineated by the authors. GERALDGRAHAM
ARTIFICIAL
ORGANS
AND
CARDIOPULMONARY
SUPPORT
SYSTEMS
Edited by Felix T. Rapaport and John P. Merrill. pp. 183, Grune & Stratton, New York, 1971. This book is compiled of 23 papers and a summary by Dr Merrill (one of the editors) of a symposium covering the two main areas indicated in the title. It represents a progress report on the current state of the art in the United States. Since, with the possible exception of home dialysis, much of the new and experimental surgery in this area is being carried out in the United States, and the Transplantation Society is an American organization, it is reasonable to regard this symposium as representative of the views of the international avant-garde. In remarking on the general high standard of the symposium, one is impressed by the vigorous, active and multifarious progress in the transplant field. Belding Scribner reviews the relative values of the renal dialysis and kidney transplantation in the treatment of renal failure. There is an overwhelming cost advantage in home dialysis relative to hospital treatment. Kidney transplants are obviously going to have more future, if the immunosuppression problem can be solved and tissue matching improved. As far as the donor is concerned, there are ethical objections to moving the donor, and the use of the perfused cadaver organ avoids these, and must become the method of choice. Scribner points out that the efficiency of dialysis has been found to be independent of the blood flow (‘the square metre hypothesis’), so that perfusions as slow as IOO ml/min can be used. Constantine Hampers reviews the complications of prolonged artificial kidney treatment. There is a pronounced uraemia; the patients often have an intractable anaemia, with haematocrits of 15-25%, indicating that there is bone-marrow suppression. Other complications are hypertension, the ‘restless leg syndrome’, osteodystrophy, hypercalcaemia and pruritus. Present-day mortality is only 5% per annum. She discusses the symptomatic treatment of these complications. Pierre Galletti discusses the potential role of artificial lungs, as being, first, oxygenation in organ preservation; secondly, temporary support for lung cripples awaiting transplanation; thirdly-in the future, long-term artificial lungs. Converse Pierce and colleagues have developed membrane oxygenators, and in venovenous and venoarterial perfusions, have shown better oxygenation and carbon dioxide exchange in dogs. Philip Drinker finds dogs susceptible to septicaemia, shock and fibrinolysis, and uses lambs for his experiments. He describes the ‘heparin tightrope’-in which sufficient heparin must be given to prevent clotting in the machine but not enough to cause haemorrhage in the patient.
REWEWS 257 &nald fill and his colleaguea ask the question, ‘for how long, safely and efficiently, can a patient suffering from severe respiratory insufficiency be supported by a membrane oxygenator?’ The treated ten patients, six with venovenous and four with venoarterial perfusions; five of them improved, one survived. They conclude that the patients have a good chance of survival if the lung parenchyma is not substantially destroyed. Michael de Bakey pinpoints unresolved problems in artificial heart total implants. No-one has yet devised an adequate implantable power system; clotting is still a major embarrassment in the pumps; cardiac output in the artificial pumps is still inadequate; air embolisms occur, and the pumps are not yet reliable mechanically. W. J. Kolff has trouble with coagulation in the intima of his polyurethane hearts, and pulmonary complications occur with their use. However, their cardiac output is improving. A. Kantrowitz and colleagues, and Austen and colleagues, have been testing balloon pumping in the aorta. They use a catheter-mounted polyurethane chamber inflated by helium. Both groups had 75% of their patients coming out of cardiogenic shock, much more often if they were treated within 30 h. The use of balloons is indicated also in open heart surgery where cardiopulmonary bypass circulation has stopped. It causes a rise in peak diastolic pressure, cardiac output and urine secretion. One of its disadvantages is that a substantial proportion of patients become dependent upon it. Arnold Lande describes the use of a small disposable membrane oxygenator, which can take flows of 15oo-3000 ml/mm. H. S. Soroff and ,colleagues give their preliminary results on dogs and nine normal subjects of counter-pulsation, in which a pulsatile g-suit is applied to the lower half of the body. The technique is at present being used in a widespread clinical test in nine hospitals in the Boston area. William McDermott and John Norman temporarily prolonged the lives of ten patients in liver failure by using perfused pig liver, and found that glucose uptake is the most sensitive index of liver function. B. Eisenman and T. Soyer have been experimenting in dogs with prostheses consisting of liver slices and cell suspensions, so far with only limited success. D. M. Hume and colleagues prefer baboon to pig livers for perfusion. They review comprehensively the following methods of support in liver failure: exchange transfusion, plasmapheresis, liver perfusion, administration of heterologous XC, liver X-P and L-dopa. They conclude that exchange transfusion and plasmapheresis are the methods of choice, and extracorporeal heterologous perfusion with baboon liver is useful in hepatic coma, if it can be managed. Basil Pruitt and Paul Silverstein review the materials which have been used to resurface denuded skin areas; they include frozen skin, freeze-dried skin, embryo tissue, collagen and several artificial materials, like Aeroplast, cellophan, silicone and vinyl polymers, which they have been testing histologically. Maurice Slapak and Hendon Lehr both conclude that freezing is the best way to date to preserve tissue. Kenneth Sell and Jeffrey Benjamin have invented a new technology-xenobanking. Apparently, if monkey kidneys before transplantation are perfused by an intermediate host, they survive much longer. In this review some of the more exciting and original advances at present being made have been selected for mention. This book illustrates their breadth and imagination-an imagination which has fired their research organizations to support them
258
REVIEWS
fully. The symposium should illustrate to non-Americans that it is the imagination and the courage to pursue what on first sight seem to be outlandish ideas, which have put the United States in the forefront of experimental surgery. ARTIFICIAL ORGANS AND CARDIOPULMONARY SUPPORT SYSTEE~S can be recommended for anyone who wishes to know the current state of the art, and where to find relevant and recent references to many important advances.