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Cardiovascular physiology
B O O K REVIEWS John M. Porter, ~ ,
Book Review Section Editor
Biostatistics and epidemiology: A
primer for health
professionals SylVia Wassertheil-Smolter, New Springer-Verlag, 119 pages, $25.
York,
1990,
For the vascular surgical investigator, a sound knowledge of statistics is fundamental to the analysis of data and the design of clinical trials. Even for those not involved in research, critical interpretation of the literature requires some familiarity with statistical methods. Although there is no dearth of texts on biostatistics, many are rather esoteric and are quickly put aside by all but the most committed medical students and physicians. Designed as a primer for health care professionals and aimed at diverse groups with varying experience, this short book endeavors to distill statistical principles into a manageable form and succeeds in at least touching on most areas of concern to the vascular snrgeon. According to the preface the author's intent was to be "nonthreatening to those who have limited or no background in mathematics." To a large extent this goal has been achieved, but "no background" is overstating the facts a little, because the reader must be familiar with simple algebraic notation and manipulations, even to the point of understanding exponentials. The serious student may lament the lack of formula derivations, but the average reader will probably be just as happy to accept the concepts on faith. The book is clearly written in a pleasing, almost conversational style; but because of its brevity, virtually every sentence contains important information. Because each topic is packaged so tightly, one almost feels as if he were reading lecture notes replete with "must know" material. The book begins with a basic review of the scientific method, during which the null hypothesis and the concept of type I and II errors are introduced. The second section is a very cursory review of probability. Statistics in general, epidemiology, and clinical trials are dealt with in the major part of the book. In addition to basic descriptive statistics and common tests of significance, Z scores, the Bonferroni procedure, analysis of variance, linear regression and correlation, sensitivity and specificity, receiver operating characteristic curves, odds ratios, and estimation of sample size are considered. Examples of how to do simple statistical calculations (standard deviation, t test, chi-square, etc.) are included in the text and appendix. For those tests requiring complicated calculations, such as Fisher's exact test and logistic regression, the reader is referred to more advanced books (but, unfortunately, not told which one to go to) or simply instructed to use a computer program. An annotated list of recommended texts is appended. There are, as one might predict in a volume o f this size, some notable omissions. Inexplicably, nonparametric m e t h o d s - w h i c h are often required in vascular surgical research when data are not normally distributed-are not 330
mentioned. In fact, asymmetric frequency distributions are not alluded to anywhere in the book. Although KaplanMeier survival curves are considered, there is no mention of the actuarial form of life-table analysis or of log-rank tests to evaluate differences between survival curves. Missing also is any discussion of Bayes' theorem or the binomial distribution, One sentence deals With the Cox proportional hazards model, and no reference is provided. In the interest of brevity, all topics are dealt with in a few pages'or paragraphs, Enough information is given, however, to tell how to interpret test results, which test to use, and what pitfalls to avoid; but discussion of more subtle statistical fallacies is limited. Although illustrations are satisfactory and convey the message, a few of the probability curves were evidently drawn by hand, lack symmetry, and do not accurately adhere to the mathematic formulas. Column headings of two tables in the appendix are mislabelec~~ which might cause some temporary confusion. Overall the author has done a credible job in compressing a great deal of material in a short space. Although this book will not substitute for a more standard text, it may prove useful as an introduction to statistics for the neophyte and as a review for those with a limited background in the discipline. David S. Sumner, AID Southern Illinois University St. John's Hospital Springfield, Ill.
Cardiovascular physiology Robert M. Berne, Matthew N. Levy, St. Louis, 1992, Mosby-Year Book, Inc., 298 pages, $26.95. The first edition of Cardiovascular Physiology by Berne and Levy was published in 1967, and with the release of the sixth edition, this textbook has now been in print for a quarter of a century. It is a mark of longevity, both for the book and its authors, that the latest edition is dedicated to the authors' grandchildren. Because it has been written a ~ revised primarily for medical students, the form and content of this book will be familiar to many readers of the JOURNAL OF VASCULAR SURGERY who have attended medical school during the past 25 years. I found a dusty, well-underlined copy of the second edition, published in 1972, on my own bookshelf. As stated in the authors' preface, general physiologic concepts and simplified models are stressed over exhaustive detail throughout the book. There are few specific references to the literature in the text, although selected journal articles and books are fisted at the end of each chapter. In spite of this approach the depth of coverage is entirely sufficient for clinicians without specialized training in physiology. The overall emphasis on cardiac physiology is evident from the observation that five of the 12 chapters
JOURNAL OF VASCULARSURGERY Volume 18, Number 2
concern the heart. These include discussions on the electrical activity of the heart, the myocardinm and cardiac valves, the various factors that regulate cardiac function, and the coronary circulation. Most vascular surgeons should find r_he chapter on hemodynamics particularly valuable. The relationships between velocity, pressure, and flow are clearl,y presented, as are the concepts of viscosity, shear stresS, ~md resistance. The chapter on the arterial system begins with a consideration of arterial elasticity and concludes with a relatively long discussion on the determinants Ofblo0d pressure. A separate chapter on control of the peripheral circulation prOvideS additional information on the diverse mechanisms that regulate blood pressure and blood flow. The anatomy and function of the microcirculation and lymphatics are succinctly covered in a single chapter, These chapters on the general aspects of arterial physiology are: complemented by a chapter on special areas of the circulation, including the cutaneous, cerebral, pulmonary, splanchnic, and renal circulations. The text concludes with a discussion of how the various central and peripheral factors interact to control the circulation in response to exercise and hemorrhage. The major strength of this book is its concise presentation of many complex topics in physiology, and the overall clarity of the text reflects the many revisions that preceded this sixth edition. Although the authors attempt to simplify many physiologic concepts, the coverage is not superficial. Mathematic methods, including elementary calculus~ are liberally used to illustrate physiologic relationships. The text is accompanied by numerous well-designed figures, and each chapter contains distinct subheadings and a summary that make it easy to locate material on any desired topic. Although certain aspects of venous physiology are menti,oned in several chapters, coverage of the venous system is relatively meager. Adding a brief chapter on venous physiology would enhance the appeal of the book to readers interested in peripheral vascular disease. This minor criticism aside, Cardfovascular Pbysiolody provides an excellent review of the important topics in the field at a very reasonable cost. The paperback format of the sixth edition is a departure from the hard cover of some previous editions, but this change certainly does not detract c?om the textbook's overall quality. This book can be recommended for vascular surgeons and other medical specialists who l~eela need to review this basic material. For those who haw: been educated by previous editions, the book provides a valuable review with a touch of nostalgia. R. Eugene Zierler~ MD University of Washington School of ~4edicine Seattle, Wash.
Current practice of interventional radiology Saadoon Kadir, Philadelphia, 1991, B.C. Decker, 779 pages, $155. From tentative beginnings as an outgrowth of diagnostic angiography, the medical specialty of interventional radiology has had phenomenal growth over the past 10 to
Book reviews 331
15 years. Interventional radiologic techniques now play a role in the management of a wide variety of clinical problems, nowhere more evident than in the treatment of vascular diseases. Dr. Kadir has assembled the contributions of 149 authors into a comprehensive text of interventional radiology, with chapters on vascular procedures slightly outnumbering all others. Following an introductory secnon on General Principles and Topics, the book is organized anatomically with chapters on vascular and nonvascular interventions for specific disease processes in each body regron. The short, well-edited chapters are written by experienced practitioners and organized into a brief discussion of the clinical entity followed by paragraphs on indications and patient selection. The technical aspects of the interventional techniques are described with sufficient detail to be of use to experienced practitioners, but the authors presume the reader has a general knowledge of angiographie techniques. Results, complications, and comparisons with alternative therapies are presented as appropriate. Each chapter ends with a short list of pertinent suggested readings. The chapters on angioplasty and thrombolysis in vessels of the abdomen, pelvis, and lower extremities are particularly well done and will be of interest to vascular surgeons. Slight variations in technique presented from chapter to chapter reflect the "art" and rapid technical evolution of the discipline. Expected results, complication rates, and comparisons of efficacy of different techniques, including balloon angioplasty, percutaneous athereetomy, and laser recanalization, are clearly presented. The focus is on the practical application of current technology, but the potential (and hyperbole) associated with some of the experimental technologies is critically examined. There is an excellent discussion of the uses of adjunctive angioplasty and thrombolysis in vascular graft anastomotic strictures and occlusions. Also of potential interest to vascular surgeons is the section on the Head and Neck, which includes descriptions of state-of-the-art neurologic interventions, including brachiocephalic and intracranial angioplasty. Caval filters, evaluation and angioplasty of portacaval shunts, and transcatheter treatment of the Budd-Chiari syndrome are well covered in the Abdominal section. The book lacks a discussion of the transjugular intrahepatic portosystemic shunt procedure, which has been recently clinically introduced, but I detected no other significant omissions. Although I found the organ system-and body regionoriented chapters well organized, readable, and clinically pertinent, the summarizing chapters in the General Principles and Topics section were disappointing. The chapters on noninvasive methods for acquisition of physiologic data in peripheral vascular diseases and vascular ultrasonography are brief and too superficial to be of interest or use to the practicing or in-training surgeon, The chapters on newer and experimental techniques, including laser angioplasty, intravascnlar ultrasonography, angioscopy, mechanical atherectomy, and intravascular stents, introduce these
Book Review Section Editor
Biostatistics and epidemiology: A
primer for health
professionals SylVia Wassertheil-Smolter, New Springer-Verlag, 119 pages, $25.
York,
1990,
For the vascular surgical investigator, a sound knowledge of statistics is fundamental to the analysis of data and the design of clinical trials. Even for those not involved in research, critical interpretation of the literature requires some familiarity with statistical methods. Although there is no dearth of texts on biostatistics, many are rather esoteric and are quickly put aside by all but the most committed medical students and physicians. Designed as a primer for health care professionals and aimed at diverse groups with varying experience, this short book endeavors to distill statistical principles into a manageable form and succeeds in at least touching on most areas of concern to the vascular snrgeon. According to the preface the author's intent was to be "nonthreatening to those who have limited or no background in mathematics." To a large extent this goal has been achieved, but "no background" is overstating the facts a little, because the reader must be familiar with simple algebraic notation and manipulations, even to the point of understanding exponentials. The serious student may lament the lack of formula derivations, but the average reader will probably be just as happy to accept the concepts on faith. The book is clearly written in a pleasing, almost conversational style; but because of its brevity, virtually every sentence contains important information. Because each topic is packaged so tightly, one almost feels as if he were reading lecture notes replete with "must know" material. The book begins with a basic review of the scientific method, during which the null hypothesis and the concept of type I and II errors are introduced. The second section is a very cursory review of probability. Statistics in general, epidemiology, and clinical trials are dealt with in the major part of the book. In addition to basic descriptive statistics and common tests of significance, Z scores, the Bonferroni procedure, analysis of variance, linear regression and correlation, sensitivity and specificity, receiver operating characteristic curves, odds ratios, and estimation of sample size are considered. Examples of how to do simple statistical calculations (standard deviation, t test, chi-square, etc.) are included in the text and appendix. For those tests requiring complicated calculations, such as Fisher's exact test and logistic regression, the reader is referred to more advanced books (but, unfortunately, not told which one to go to) or simply instructed to use a computer program. An annotated list of recommended texts is appended. There are, as one might predict in a volume o f this size, some notable omissions. Inexplicably, nonparametric m e t h o d s - w h i c h are often required in vascular surgical research when data are not normally distributed-are not 330
mentioned. In fact, asymmetric frequency distributions are not alluded to anywhere in the book. Although KaplanMeier survival curves are considered, there is no mention of the actuarial form of life-table analysis or of log-rank tests to evaluate differences between survival curves. Missing also is any discussion of Bayes' theorem or the binomial distribution, One sentence deals With the Cox proportional hazards model, and no reference is provided. In the interest of brevity, all topics are dealt with in a few pages'or paragraphs, Enough information is given, however, to tell how to interpret test results, which test to use, and what pitfalls to avoid; but discussion of more subtle statistical fallacies is limited. Although illustrations are satisfactory and convey the message, a few of the probability curves were evidently drawn by hand, lack symmetry, and do not accurately adhere to the mathematic formulas. Column headings of two tables in the appendix are mislabelec~~ which might cause some temporary confusion. Overall the author has done a credible job in compressing a great deal of material in a short space. Although this book will not substitute for a more standard text, it may prove useful as an introduction to statistics for the neophyte and as a review for those with a limited background in the discipline. David S. Sumner, AID Southern Illinois University St. John's Hospital Springfield, Ill.
Cardiovascular physiology Robert M. Berne, Matthew N. Levy, St. Louis, 1992, Mosby-Year Book, Inc., 298 pages, $26.95. The first edition of Cardiovascular Physiology by Berne and Levy was published in 1967, and with the release of the sixth edition, this textbook has now been in print for a quarter of a century. It is a mark of longevity, both for the book and its authors, that the latest edition is dedicated to the authors' grandchildren. Because it has been written a ~ revised primarily for medical students, the form and content of this book will be familiar to many readers of the JOURNAL OF VASCULAR SURGERY who have attended medical school during the past 25 years. I found a dusty, well-underlined copy of the second edition, published in 1972, on my own bookshelf. As stated in the authors' preface, general physiologic concepts and simplified models are stressed over exhaustive detail throughout the book. There are few specific references to the literature in the text, although selected journal articles and books are fisted at the end of each chapter. In spite of this approach the depth of coverage is entirely sufficient for clinicians without specialized training in physiology. The overall emphasis on cardiac physiology is evident from the observation that five of the 12 chapters
JOURNAL OF VASCULARSURGERY Volume 18, Number 2
concern the heart. These include discussions on the electrical activity of the heart, the myocardinm and cardiac valves, the various factors that regulate cardiac function, and the coronary circulation. Most vascular surgeons should find r_he chapter on hemodynamics particularly valuable. The relationships between velocity, pressure, and flow are clearl,y presented, as are the concepts of viscosity, shear stresS, ~md resistance. The chapter on the arterial system begins with a consideration of arterial elasticity and concludes with a relatively long discussion on the determinants Ofblo0d pressure. A separate chapter on control of the peripheral circulation prOvideS additional information on the diverse mechanisms that regulate blood pressure and blood flow. The anatomy and function of the microcirculation and lymphatics are succinctly covered in a single chapter, These chapters on the general aspects of arterial physiology are: complemented by a chapter on special areas of the circulation, including the cutaneous, cerebral, pulmonary, splanchnic, and renal circulations. The text concludes with a discussion of how the various central and peripheral factors interact to control the circulation in response to exercise and hemorrhage. The major strength of this book is its concise presentation of many complex topics in physiology, and the overall clarity of the text reflects the many revisions that preceded this sixth edition. Although the authors attempt to simplify many physiologic concepts, the coverage is not superficial. Mathematic methods, including elementary calculus~ are liberally used to illustrate physiologic relationships. The text is accompanied by numerous well-designed figures, and each chapter contains distinct subheadings and a summary that make it easy to locate material on any desired topic. Although certain aspects of venous physiology are menti,oned in several chapters, coverage of the venous system is relatively meager. Adding a brief chapter on venous physiology would enhance the appeal of the book to readers interested in peripheral vascular disease. This minor criticism aside, Cardfovascular Pbysiolody provides an excellent review of the important topics in the field at a very reasonable cost. The paperback format of the sixth edition is a departure from the hard cover of some previous editions, but this change certainly does not detract c?om the textbook's overall quality. This book can be recommended for vascular surgeons and other medical specialists who l~eela need to review this basic material. For those who haw: been educated by previous editions, the book provides a valuable review with a touch of nostalgia. R. Eugene Zierler~ MD University of Washington School of ~4edicine Seattle, Wash.
Current practice of interventional radiology Saadoon Kadir, Philadelphia, 1991, B.C. Decker, 779 pages, $155. From tentative beginnings as an outgrowth of diagnostic angiography, the medical specialty of interventional radiology has had phenomenal growth over the past 10 to
Book reviews 331
15 years. Interventional radiologic techniques now play a role in the management of a wide variety of clinical problems, nowhere more evident than in the treatment of vascular diseases. Dr. Kadir has assembled the contributions of 149 authors into a comprehensive text of interventional radiology, with chapters on vascular procedures slightly outnumbering all others. Following an introductory secnon on General Principles and Topics, the book is organized anatomically with chapters on vascular and nonvascular interventions for specific disease processes in each body regron. The short, well-edited chapters are written by experienced practitioners and organized into a brief discussion of the clinical entity followed by paragraphs on indications and patient selection. The technical aspects of the interventional techniques are described with sufficient detail to be of use to experienced practitioners, but the authors presume the reader has a general knowledge of angiographie techniques. Results, complications, and comparisons with alternative therapies are presented as appropriate. Each chapter ends with a short list of pertinent suggested readings. The chapters on angioplasty and thrombolysis in vessels of the abdomen, pelvis, and lower extremities are particularly well done and will be of interest to vascular surgeons. Slight variations in technique presented from chapter to chapter reflect the "art" and rapid technical evolution of the discipline. Expected results, complication rates, and comparisons of efficacy of different techniques, including balloon angioplasty, percutaneous athereetomy, and laser recanalization, are clearly presented. The focus is on the practical application of current technology, but the potential (and hyperbole) associated with some of the experimental technologies is critically examined. There is an excellent discussion of the uses of adjunctive angioplasty and thrombolysis in vascular graft anastomotic strictures and occlusions. Also of potential interest to vascular surgeons is the section on the Head and Neck, which includes descriptions of state-of-the-art neurologic interventions, including brachiocephalic and intracranial angioplasty. Caval filters, evaluation and angioplasty of portacaval shunts, and transcatheter treatment of the Budd-Chiari syndrome are well covered in the Abdominal section. The book lacks a discussion of the transjugular intrahepatic portosystemic shunt procedure, which has been recently clinically introduced, but I detected no other significant omissions. Although I found the organ system-and body regionoriented chapters well organized, readable, and clinically pertinent, the summarizing chapters in the General Principles and Topics section were disappointing. The chapters on noninvasive methods for acquisition of physiologic data in peripheral vascular diseases and vascular ultrasonography are brief and too superficial to be of interest or use to the practicing or in-training surgeon, The chapters on newer and experimental techniques, including laser angioplasty, intravascnlar ultrasonography, angioscopy, mechanical atherectomy, and intravascular stents, introduce these