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This issue of Annals, and the next, feature selected papers presented at a conference entitled ,, Vascular Surgery : The 30-Year Reunion ,, held in May, 1984 at Meadowbrook Hall in Rochester, Michigan.

The 30-year reunion brought together pioneers in vascular surgery from America and Europe. Its purpose was to honor their contributions and to address philosophical questions regarding their disco- veries. Dialogue also touched on the growth of vascular surgery, our recognition as a surgical specialty and our future.

In addition to the pioneers, leading personafities unofficially representing modem vascular surgery, biological research, philosophy of science and the higher councils of surgery in the USA participated in the reunion.

The splendid Meadowbrook Hall, its tudor design modeled after Hampton Court in England, provided an ideal setting for informal exchange and smafl group discussion. Along with the faculty listed below, 70 vascular surgeons participated as guests during the proceedings.

FACULTY

John Bergan Ramon Berguer (Program Chairman) Allan Callow Michael DeBakey James DeWeese Charles Dubost H.H.G. Eastcott Joel Feldman

William Fry Edouard Kieffer Peter Medawar Robert Petersdorf John Pfeifer (Chairman, Committee on Local Arrangements) Charles Rob Emerick Szitagyi Alexander Walt

Vascular Surgery �9 What Was and What Will Be

Ramon Berguer, MD, PhD, Detroit, Michigan

From the Division of Vascular Surgery, Department of Surgery, Wayne State University, Detroit, Michigan.

Presented at ~ Vascular Surgery : The Thirty Year Reu- nion ~ Meadow Brook Hal!, Rochester, Michigan 3,lay 25- 26, 1984.

Reprint requests : R. Berguer, MD, PhD, Section of Vas- cular Surgery, Harper Hospital, 3990 John R., Detroit, Michigan 48201.

About thirty years ago vascular surgery was born. Although the historical roots of operating on arter- ies can be traced further back, our specialty, in pratical terms, was born in the mid-fifties. The pio- n.eering work of Carrell and Guthrie at the begin- nlng of our century had little impact then because it had to wait for us to better understand the patho- logy of atherosclerosis as well as the discovery of heparin and arteriography.

ANNALS OF 226 V A S C U L A R S U R G E R Y VASCULAR SURGERY

Since its birth, the growth of our specialty has fol- lowed - - like the growth of most things - - a sigmoid curve. So do crystals, grass, sociological ideas, and even fashion. A new development usually appears as a discontinuity within an apparently stable system. This new entity grows for a while in advantageous competition with other elements but eventually its rapid growth is control led by competi t ion with neighboring entities which slows it down until the new element finds a place within the larger struc- ture. The addition of new technologies has modifi- ed the shape of the curve as have other sociolog- ical and political factors. My impression is that we are now entering a plateau phase. Fur ther growth will depend on our ability to develop new technology and to apply new scientific concepts.

Very few anatomical areas lie where we have not ventured. The vessels of the brain are handled by neurosurgeons : those of the heart by cardiac sur- geons, and microvascular repairs of the hands are done by plastic surgeons. We have improved the lives of our patients by operations that prevent strokes, amputations, and ruptured aneurysms. The sur- vival of our patients today is mostly determined by the condition of their coronary arteries. On the other hand, the willingness of society to continue to underwrite these expensive vessel repairs is waver- ing. A few vascular surgeons have started to ana- lyze the operations we do in terms of their cost-ben- efit ratios. This would have sounded crass, even impious, fifteen years ago. Today, it is a relevant question.

For having been born in the mid-fifties, the offi- cial baptism of our specialty has taken a long time. Its sanction by the higher councils of surgery arrived so to speak only as we reached adulthood. During the debates that led to our recognition, the concept of a surgical subspecialty was often represented in a rigid manner : a domain with fixed but often dispu- ted boundaries . These boundaries are generally those of an organ system or a specific anatomic re- gion.

I view the field of a specialty as a territory tempo- rarily occupied by a group of surgeons whose special skills and knowledge give them an edge in dealing with the specific set of problems encountered in it. To the caricature of the myopic specialist, comforta- bly limited to a small field and often ignorant of others, I would substitute the image of an individual who has chosen to concentrate his general know- ledge on a set of related problems and thus advance solutions to them.

The boundaries of a specialty should be, and really are, temporary and reflect the capacity of a group to advance the solution to a problem. For ins- tance, the treatment of head and neck cancer used to be the business of general surgeons. It then be- came a common operation for ENT surgeons who

combined primary organ extirpation with regional dissection. Today the presence of plastic and recon- structive surgeons in head and neck cancer is more a reflection of their expertise in reconstructing the battlefield left after a wide resection than the result of any superior understanding on their part of the pa- thology of tumors or of the anatomy of the neck. Neurosurgeons have gradually abandoned carotid surgery to vascular surgeons since they have limited expertise in handling the various neck and chest ar- teries involved in extracranial reconstructions. For similar reasons, many modern cardiothoracic sur- geons cannot lay a strong claim to esophageal opera- tions. And, given our meager enthusiasm for venous or lymphatic problems, we have little right to claim them as our turf.

if it is to claim a territory or system, a surgical specialty must maintain the lead in investigating it and in treating its diseases. A surgical specialist who advances the understanding and the treatment of the system in which he works generates surgical know- ledge from which other groups benefit. A number of contributions from vascular surgeons have done so. For example : microvascular surgery is now a pow- erful tool for many susbspecialties. Ultrasound and Doppler technology are available for general medi- cal use. Many techniques and materials in renal transplantation and dialysis have derived from vas- cular surgical work. Saphenous vein bypass grafting was put to test in the legs 15 years before it was used in the heart by thoracic surgeons, and in the brain by neurosurgeons. Such cross-fertil ization is the rule ; its consequence is progress in surgery.

It is up to us to maintain the lead in our field and thus our surgical relevance. Are we doing our job ? Let us glance over educational programs, societies. research and surgical advances and see what changes may be needed to maintain our claims as a specialty for the years to come.

SOCIETIES

The main vascular surgical organizations in the US are the North American Chapter of the Interna- tional Society for Cardiovascular Surgery (ISCVS), the Society for Vascular Surgery (SVS) and the re- gional societies. There is a formal and traditional difference between the ISCVS and SVS, and there are advantages in having two professional societies each serving a different purpose. However, our practice of having both societies meet together and share similar programs blurs their identity and partly negates the advantages of their different roles.

In our yearly meetings we have formal paper pre- sentations, from basic research to case reviews, tech- nical exhibits, special lectures, breakfast review pro- grams and other activities, each fulfilling a specific need. I think making a single affair of these different efforts weakens their impact.

VOLUME 1 No 2 - 1986 V A S C U L A R S U R G E R Y 227

We need to have a yearly meeting to review and discuss knowledge, to enjoy fellowship and to make policy in our standards of practice. The ISCVS can and should host such a meeting alone. Because of its wide membership, it should also involve itself with matters of general policy and politics.

But, there is also a need for a smaller elitist so- ciety, concerned not so much with delivering pro- grams of instruction, review, and progress, as with being a forum to explore the leading edge of re- search and education and provide a testing ground for hypotheses or new procedures not yet in the realm of daily practice. To be agile and participa- tory, such a society must have a small membership and admit only individuals with special surgical and scientific skills. The American Surgical Society or the Society of University Surgeons could serve as a role model. The Society for Vascular Surgery had for a time this type of membership and purpose. The SVS, protected by restrictive and singular criteria for admission and active participation, could easily fulfill the role of the leading, research-or iented group, probing and advancing the field of vascular surgery.

I have had the opportunity of organizing two in- terdisciplinary conferences whose purpose was to compare notes about two somewhat obscure areas : the vertebral arterial system and the pathology of the orbital vessels. I was struck by the amazing amount of valuable information not shared between specialties and by the conceptual differences in the understanding of diseases between specialties. Some promising hypotheses were generated by the clarifi- cation and debate of these problems. In contrast most courses and seminars in vascular surgery tend to deal with the usual list of disease entities, gen- erally discussed by an authority within the field who, more often than not, will reiterate accepted know- ledge. The discussion from a monochromatic au- dience is often limited to traditional and sometimes Byzantine dilemmas such as to shunt or not to shunt or the advantage of one prosthesis over the other,

Meetings for review and update of knowledge such as the latter are needed but they do not gene- rally advance our field. Much stands to be gained by comparing and debating concepts with other discipli- nes. We need to learn from neurologists the dif- ference between a sensory seizure and a transient is- chemic attack. We need to show the inside of an ul- cerated atheroma to those who think antiplatelet agents are sensible treatment for all kinds of tran- sient ischemic attacks. We should agree one day on what constitutes the largely' invisible and mythical ,< small vessel disease ,,. Neurologists may pay more attention to the concept of sleeping - - and thus arousable - - brain cells since cessation of function, even for a long while, is not synonymous with cessa- tion of life.

Since surgery is an applied discipline I believe the solution to most of our problems is likely to derive

from contributions from other , more basic disci- plines. If our work is discussed only within our spe- cialty and within the set of axioms that we have evolved, we will see involution rather than evolu- tion. We should increase our effort to integrate scientists and clinicians of different lineage in those scientific meetings where research or controversial issues are the subject.

E D U C A T I O N

I submit too that the education of a vascular sur- geon may need some readjustment . First of all I want to make a plea for our rapprochement to the neurological sciences. In our field, the introduction of carotid surgery by Rob, Eastcott, and DeBakey, was a landmark nearly as crucial as the aortocoro- nary bypass operation for thoracic surgery in the United States. It is also the vascular operation that has raised the most criticism, some of which, no doubt, is justified.

In our beginning years our work was dominated by operations on the aorta and on the arteries of the legs. During those years we had few medical coun- terparts in our specialty, so we developed our own diagnostic skills and studied much of the physiology of the system in health and in disease. We were truly a medicosurgical specialty. Later on, the repair of arteries supplying complex organs such as the kidney and the brain required new and complex knowledge of their physiology. The diagnosis of the malfunction of these organs and the downstream consequences of our operations far more difficult to understand. In these areas we do have medical counterparts with whom we should work.

We have poor communication with neurologists and at the same time are a bit ignorant on matters neurologic. It is no less true that many neurologists have a poor understanding of arterial pathology and brain flow. But, since we intrude in their territory, we must learn their science. In fact, our special need for neurological knowledge, beyond that which is expected of a general physician, is not restricted to cerebrovascular disease but is essential to the un- derstanding of thoracic outlet syndromes and of the various sensorimotor dysfunctions of the arms and legs secondary to neuropathies, trauma, ischemia and ruptured aneurysms.

Our training programs for vascular surgeons do not generally fulfill this need. We do not have for- mal exposure to the neurosciences, during the gener- al surgical education. The short, one-year fellowship m vascular surgery', provides only marginal contact with these disciplines. We teach our trainees how to read angiograms but very few gain enough know- ledge to interpret properly intracranial views or CT scans. To be sure, we cannot pretend the compe-

ANNALS OF 228 V A S C U L A R S U R G E R Y VASCULAR SURGERY

tence of a neuroradiologist in these matters, but such expert advice is not always available in smaller hospitals where carotid operations are performed.

Another area in which the vascular surgeon often feels uncomfortable is the chest. I submit that only a few need to gain expertise in doing thoracoabdomi- nal aneurysms but everyone should be taught how to handle the branches of the aortic arch. It is an essen- tial skill for anyone treating cerebrovascular disease.

Let us look also at the surgeons that we recruit into our educational programs. Szilagyi warned us a few years ago that we are graduating too many vas- cular surgeons. Some of these excesses will be tem- pered by the new requirements for training and cer- tification of vascular surgeons. In addition to ques- tioning whether we train too many vascular sur- geons, let us consider if we should not require some added qualifications of the surgeons that we do re- cruit and educate.

Vascular surgeons are relatively scarce in leading academic positions. An obvious reason is that we are a new specialty. Another may be that the recog-, nition of our specialty in academic departments has been slow. However, if we are to advance vascular surgery we need to place in academic departments a core of well-trained operating surgeons with exper- tise in those areas on which we depend to advance, among the most important today �9 eng!neering, coag- ulation, the neurosciences, and mlcrosurgery. I propose that those of you with academic training programs in vascular surgery encourage expertise in one of these fields prior to accepting a fellow for vascular surgical training. Such a policy may give us, in a few years, a crop of academic surgeons capable of engaging in multidisciplinary inquiries of the sort we need to maintain surgical relevance.

The current twelve months of fellowship training is too brief a period to acquire the thorough compe- tency that one associates with subspecialty educa- tion. An obvious solution is to lengthen the fellow- ship to two years. However, if we add this to the proposed special knowledge in one of the basic disci- plines, it adds up to a mimmum of three years follo- wing a general surgical residency, and that is a a bit long.

Some of the clinical exposure to neurosciences and vascular surgery could be integrated into the ge- neral surgical training program. The basic general surgery program could be modified so that one of the five years - - preferably six months in the fourth year and six months in the fifth y e a r - would be concentrated in neurology and vascular surgery. Such an arrangement implies a subspecialty choice during the first half of the general surgical residency, as is the case with other subspecialties, but would not necessarily disenfranchise the individual from taking the American Board of Surgery examination.

RES EA RCH AND D E V E L O P M E N T

Endothelial Seeding

In the design of artificial organs for long-term im- plantation, the blood-prosthesis interface is a crucial problem. Thrombosis is the rule whenever blood cir- culates outside the protective coating of endothe- lium. It is likely to occur at the point where the im- plant is hooked-up to its arterial and venous supply and at the exchange membrane or the pump that mimics the function of the organ.

Seeding the inside of arterial and venous prosthe- ses and membranes with host-derived endothelium is an elegant solution to the unwanted deposition of thrombus at the blood-prosthesis interface because the endothelial lining so achieved retains the anti- thrombotic and filtration properties of native endo- thelium.

I do not know if the delicate techniques of endo- thelial culture and seeding will ever be part of rou- tine vascular operations, but it strikes me that this line of research has also given us the key to the de- velopment of artificial hybrid organs. And I see us in the coming years contributing to the development of these organs and implanting them into major ves- sels.

Microsurgery

Repairing vessels smaller-than three mm diameter is perhaps at the frontier of our general technical competence. To be sure, we can do even smaller anastomoses, b u t our success is far inferior to what we achieve in larger vessels. Part of the prob- lem must be lack of proper microsurgical techni- que, at least in those cases where only autogenous material is used and no prosthetic tube can be blamed. Neurologic and plastic surgeons achieve re- markable success in anastomoses of vessels of one millimeter using the operating microscope. Many of their patients are not in the young age group with healthy arteries. It can be said that a low peripheral resistance and subsequent high flow rate help the neurosurgeon achieve the excellent patency rates re- por ted in microsurgical anastomoses within the brain, but this surely does not explain the compa- rable success obta ined by plastic surgeons in finger reimplantat ion and free flaps. Technique, then, must take some credit. And yet very few among us have expertise and use microsurgical techniques routinely.

We may not have explored sufficiently the role of small-caliber vein grafts for small vessel reconstruc- tion. With few exceptions, veins other than the sa- phenous have not faired well in arterial reconstruc- tion and as a consequence they have been all but abandoned. Their small size or thin walls may have been a disadvantage there, but the could be a desir-

VOLUME 1 No 2 - 1986 VASCULAR SURGERY 229

able attr ibute when extending a bypass procedure into the palm of the hand or into the proximal foot.

Small caliber prostheses

We need a small caliber synthetic prosthesis that will work well in the under-4 mm diameter vessel. Just as subcompact cars cannot be a scaled-down re- duction of full-sized models, we may need to go back to the drawing board to satisfy the special re- quirements of miniaturization. Size carries qualita- tive as well as quanti tat ive differences. Af te r all a nearly impervious~ thick and stiff prosthesis will do well in the thoracic aorta, but would not stand much of a chance as a popliteal artery replacement.

C O N C L U S I O N

Our relevance in the world of surgery cannot be predicated on our ability to do a dozen different vascular operat ions, even if we do them bet ter than other groups of surgeons. We have to maintain lea- dership in the understanding and t rea tment of vas- cular diseases. For this we need to acquire more refined technical skills, to expand our basic knowledge and the educat ion of our trainees, to seek a greater interdisciplinary part icipation in our investigations and to develop s t ronger academic programs and presence.

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