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the creation of a special prisons health authority,responsible to the DHSS. A forensic psychiatry servicecould be developed within such a structure, and itwould be easier to organise professional training,research, and cooperation with the related academicinterests. A special authority might ease the transfer ofsome difficult-to-place mentally abnormal offendersfrom the prison system to an NHS bed. Above all, itwould free prison medical officers from their perceivedethical dilemma, whereby the pull of association withprison management conflicts with their duty to those intheir care. The weaknesses in nursing training andqualification could be more readily overcome; andpharmaceutical control would be provided, like allother support services, from the NHS administrationcovering the area in which the prison lay.There are several counter arguments. The statutory

one is that the Home Secretary would have to retainoverall responsibility for management of the prisonsystem, and, if the PMS was part of the NHS, awkwarddivisions in management and operational policy couldarise. The allocation of resources to such a PMS mightwell suffer if (as is likely) it held a low place in thepriority order for DHSS support. Prison care or

dialysis units? There is little comfort for the PMS insuch questions. Again, would the DHSS, Ministers oradministrators, be willing to accept responsibility forthe PMS? The likelihood is that they would not,particularly in view of the known attitude of the HomeOffice. There are clear advantages in an increase infunctional cooperation between an individual prisonand its surrounding NHS structure, although this

rapport is already well developed, as the number ofconsultations and NHS admissions show (p 789). Muchscope for progress certainly exists in the training of newprison medical officers and in the provision of NHSforensic psychiatry training posts, which would makebetter use of the abundance of opportunities for clinicalexperience in prisons. Moreover, as Smith’ observedafter his telling survey of prison health care in Britain,"the prison authorities should adopt a much morepositive attitude towards research". Collaborationwith academic centres must expand. The view thatprison medical officers should, wherever possible,undertake sessions in NHS establishments is wellworth further exploration and experiment.

It will no doubt occur to the committee to examinemore closely the analogue of the Defence MedicalServices. There the pressure of security also applies;and the particular environmental and professionalfactors require special training and organisation. No-one seriously suggests that the DHSS should take overthe medical function from the Ministry of Defence.The RAMC needs nurse-qualified soldiers; and it alsorequires and trains medical assistants. The needsof the PMS for mobility of staff, to cover outlyingestablishments and to fill vacancies quickly, are

similar. Such a comparison could lead to recommend-

1 Smith R. Prison health care. Based on articles published in the British Medical JournalLondon. British Medical Association, 1984.

ations which encourage the Home Office to emulate thestructure and training programmes of the DefenceMedical Services-as far as the analogy holds.The main discussion, however, should centre not so

much on the probably sterile argument about whoprovides the medical and nursing care but rather onhow best to raise and maintain the quality of the servicesupplied. Here, there is much to be said for involvingthe interested Colleges and Faculties, such as the RoyalCollege of General Practitioners, the Royal College ofPsychiatrists, the Faculties of Community Medicineand of Occupational Medicine, and the Royal Collegeof Nursing. Ideally, all should unite to prescribedesirable standards in training, attainment, and

experience in the prison medical and allied staff. Adifficulty may lie in providing an independent forumfor such collaboration.The committee has earlier voiced concern over the

need to provide support outside hospital for thosepatients who will be discharged from the large mentalhospitals scheduled for closure in the near future. Whatproportion of these patients will find their way,inappropriately, into the prison system, which is likelyin many places to be the only asylum left open to themby an apparently indifferent community. Will theprison system have the means-in institutions andstaff-to cope? Already there are multiplying signs ofthis deplorable flow of institutionalised individualsinto the prison system.On balance, the desirable route lies in the brisker

forms of evolutionary change, some of which arealready under way. The recruitment of medical officersis now fortified in numbers and in improvedexperience and qualification. New qualification targetsfor nurses are in process of achievement; and new ideasfor integration of the nursing services are under

development. Communications with the media, theDHSS, and the NHS are improving. The SelectCommittee will serve a supremely valuable function infocusing public and political attention on the pressingneed for improvement in the PMS. If its forthcomingreport can accelerate beneficial change by heighteningthe priority given to betterment of the PMS, then thecommittee’s guidance can go far to remove a long-standing cause for public and professional concern.

Which Heart Valve Prosthesis?

REPLACEMENT of cardiac valves has now been

possible for 25 years, and in the UK valve replacementis undertaken in almost 5000 patients every year.’ IThere have been many designs but none is anywherenear perfect, so, while valve replacement may relievesymptoms and reduce the risk caused by haemo-dynamic abnormality, it introduces a new set ofhazards for the patient. These hazards include suddenmechanical failure, resulting in embolisation or

1 English TAH, Bailey AR, Dark JF, Williams WG The UK cardiac surgical registerBr Med J 1984; 289: 1166-70.

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obstruction of part of the mechanism; deterioration ofthe valve, necessitating reoperation; thrombo-

embolism ; and the risk of bleeding due to anti-

coagulants. The history of valve substitutes has beensummarised by Black et a1.2 Of the mechanical valves,the ball-and-cage pattern (eg, the Starr-Edwards valve),first reported in 1960, the tilting disc type (Bjork-Shiley), and the bi-leaflet pattern (St Jude) are

representative. Homograft (allograft) aortic

replacement was pioneered by Donald Ross in 1962and the very low incidence of thromboembolic

complications encouraged the development of tissuevalves. The development of glutaraldehyde-fixed pigvalves provided the opportunity for commercial

production of the Hancock and Carpentier-Edwardsvalves. Another important type of bioprosthesis isfashioned from animal tissue (eg, the Ionescu-Shileymade from calf pericardium). Plentiful follow-updata are available but attempts to draw conclusionsare bedevilled by the difficulties of comparingretrospective studies against a background of change.No worthwhile randomised trials have been done.Valves which fail have been abandoned, those which dowell have been modified (not always for the better);some surgeons choose one valve for the young andactive, another for the old or frail; and any attempt tocompare contemporary data with early experience isconfounded by the many factors other than valvedesign that have improved the duration and quality ofsurvival after cardiac surgery. 3The Starr valve remains the standard by which

others may be judged and, in the most durable design,which has been available for 20 years (a ’Silastic’ ball inan uncovered frame), primary valve failure is virtuallyunknown.4 The same cannot be said of disc valves,5while the choice of a tissue valve includes acceptance ofthe inevitability of time-related tissue failure. The

proportion of valves still functioning in large series ofporcine valves is given as 96-98% at five years,6-B 85%at eight years,9 71-86% at ten years,"-’" and 5807o at 13years," with aortic prostheses tending to be better thanthose in the mitral position. Pericardial valves look atleast as durable at eight years.’2 While some of these

2 Black MM, Drury PJ, Tindale WB Twenty five years of heart valve substitutes. areview J Roy Soc Med 1983, 76: 667-80.

3 Macmanus Q, Grunkemeier GL, Lambert LE, Teply JF, Harlan BJ, Starr A. Year ofoperation as a risk factor in the late results of valve replacement. J Thorac CardriovascSurg 1980, 80: 834-41.

4 Miller DC, Oyer PE, Mitchell RC, Stinson EB, Jamieson SW, Shumway NEPerformance characteristics of the Starr-Edwards Model 1260 aortic valve

prosthesis beyond ten years. J Thorac Cardiovasc Surg 1984; 88: 193-207.5 Khalil Y, Sethia B, Quin RO, Bain WH. Disc and strut embolism after minor strut

fracture in a Bjork-Shiley mitral valve prosthesis. Thorax 1985; 40: 158-59.6 Magilligan DJ, Lewis JW, Tilley B, Peterson E. The porcine bioprosthetic valve.

Twelve years later. J Thorac Cardiovasc Surg 1985; 89: 499-507.7 Janusz MT, Jamieson WRE, Allen P, et al Experience with the Carpentier-Edwards

porcine valve prosthesis in 700 patients. Ann Thorac Surg 1982; 34: 625-338. Jamieson WRE, Pelletier C, Janusz MT, Chaitman BR, Tyers FO, Miyagishima RT. 5

year evaluation of the Carpentier Edwards porcine bioprosthesis. J ThoracCardiovasc Surg 1984, 88: 324-33

9 Gallo I, Ruiz B, Duran CMG. Five- to eight-year follow-up of patients with theHancock bioprosthesis J Thorac Cardiovasc Surg 1983; 86: 897-902.

10 Cohn LH, Allred EN, DiSesa VJ, Sawtelle K, Shemin RJ, Collins JJ. Early and late riskof aortic valve replacement a 12 year concomitant comparison of porcinebioprosthetic and tilting disc prosthetic aortic valves J Thorac Cardiovasc Surg1984, 88: 695-705

failures are due to leaflet tearing and are sudden anddevastating,’3 more often they are due to stiffening andcalcification, happen slowly, and permit reoperation.Earlier degeneration and calcification is a particularproblem in children,14,15 and remains so up to about theage of 35.6 Below that age only 55% are free fromdegeneration at ten years, while 80% are satisfactory at10 years if patients less than 35 are excluded from theanalysis.6

.

Since its inception with closed mitral valvotomy,valve surgery has entailed a proportion of reoperations,which is more or less accepted by cardiologists andsurgeons-less acceptable is the irretrievable damage ofstroke in-a a patient beginning to enjoy a much improvedlevel of physical activity. The thromboembolism rate is3-4-4-6 per 100 patient-years for the ball-and-cagevalves,’6-’8 and by 15 years 40% of patients have hadone or more episode of thromboembolism, many ofwhich are transient. Since anticoagulation is

mandatory, there is a risk of haemorrhage (3-4% peryear), which may result in death or permanentneurological sequelae. With porcine valves, there is nouniformity in anticoagulant usage, even within series,but in general it is likely to be confined to the first fewweeks after surgery, to be used in mitral rather thanaortic replacement, and then perhaps restricted topatients in atrial fibrillation or with a large left atrium.There is also potential variability in the reporting ofevents. Nevertheless, data in large series of porcinevalves6-’,",10 are remarkably consistent. For mitralvalve replacement the rate of thromboembolic events is1 4-2 1 per 100 patient-years with embolus-free ratesat 3, 5, 8, 10, and 13 years of 96, 89, 88, 84, and 79%.Aortic valve cases fare better, with a rate of 0 94-1’ 1per 100 patient-years and the proportion who areembolus-free falls from 96% to 88% between 3 and 10

years.While figures for valve performance may be difficult

to compare there is one universal endpoint, the death ofthe patient. For Starr valves there are now large serieswith up to twenty years of follow-up4,16-ls reporting

1 1. Galluci V, Bortolotti U, Milano A, Valfre C, Mazzucco AM, Thiene G. Isolated mitralvalve replacement with the Hancock bioprosthesis: a 13-year appraisal. Ann ThoracSurg 1984; 38: 571-78.

12 Ionescu MI, Tandon AP, Chidambaram M, Yakirevich VS, Silverton NP. Durabilityof the pericardial valve. Eur Heart J 1984; 5 (suppl D): 101-06

13 Pomar JL, Bosch X, Chaitman BR, Pelletier C, Grondin CM. Late tears in leaflets ofporcine bioprostheses in adults Ann Thorac Surg 1984; 37: 78-83

14. Walker WE, Duncan JM, Frazier OH, Livesay JJ, Ott DA, Reul GJ, Cooley DA. Earlyexperience with the Ionescu-Shiley pericardial xenograft valve. Acceleratedcalcifiction in children. J Thorac Cardiovasc Surg 1983, 86: 570-75

15 Fiddler GJ, Gerlis LM, Walker DR, Scott O, Williams GJ Calcification of

glutaraldehyde-preserved porcine and bovine xenografts in young children AnnThorac Surg 1983; 35: 257-61

16. Teply JF, Grunkemeier GL, Sutherland HD’A, Lambert LE, Johnson VA, Starr A.The ultimate prognosis after valve replacement: an assessment at twenty years. AnnThorac Surg 1981; 32: 111-19

17. Fuster V, Pumphrey CW, McGoon MD, Chesebro JH, Pluth JR, McGoon DCSystemic thromboembolism in mitral and aortic Starr-Edwards prostheses- a 10-19year follow-up. Circulation 1982; 66 (suppl I): 157-61

18. Sala A, Schoevardts J-C, Jaumin P, Ponlot R, Chalant C-H. Review of 387 isolatedmitral valve replacements by the model 6120 Starr-Edwards prosthesis. J ThoracCardiovasc Surg 1982; 84: 744-50.

19 Forfar JC. A 7-year analysis of haemorrhage in patients on long-term anticoagulantcontrol. Br Heart J 1979, 42: 128-32

20. Pelletier C, Chaitman BR, Baillot R, Guiteras P, Bonan R, Dydra I. Clinical and

haemodynamic results with the Carpentier-Edwards porcine bioprosthesis. AnnThorac Surg 1982, 34: 612-24.

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actuarial survival of 78% at five years and 72% at ten

years for mitral valve replacement with respectivefigures of 71% and 52% for aortic valve

replacement.16,17 Results for tissue valves may seembetter at five years, with survival of about 850/o for

single valve replacement,7,20 but the comparison is

unfair, because the zero is set fifteen years later.

Twelve-year figures for porcine valves6 more closelyresemble Starr valve data, five and ten year figures formitral valves being 80% and 69% and for aortic valves7807o and 57%.The variety of materials and designs available

indicates that there is no ideal valve. The choice ofvalve is not easy, and published retrospective data,collected, analysed, and interpreted in different ways,can justify almost any valve policy. Few clearstatements can be made. In children and young peopletissue valves are likely to fail sooner than they would inolder people. If life-long anticoagulation is

unacceptable or unrealistic, a tissue valve should beused. Beyond that it is a trade-off between the provendurability of the best-tried mechanical valves withanticoagulation for life and the safer and perhaps betterquality of life with a tissue valve, free from regulartablets, blood tests, and the risk of bleeding but withthe prospect of a further valve replacement in ten tofifteen years. Most cardiac surgeons try to choose thebest valve for individual patients, often - taking intoaccount age, life style, and attitudes to surgery andmedicines. This careful selection will make publishedseries just as hard to interpret a decade from now asthey are today.

PATHOLOGY OF BREAST CANCERS IN LONG-TERMSURVIVORS

AN important investigation into the clinical and

pathological features of long-term survivors with breastcancer has been published from Edinburgh.’ The patients,all treated by simple mastectomy and irradiation, weredivided into two groups. Long-term survivors (119 out of 626individuals alive at 16-20 years after surgery) were comparedwith 200 consecutive patients, treated in the same mannerduring the same period, who died within 10 years. In contrastto the short-term survivors, the long-term survivors had agreater incidence of non-invasive caricers (7 [5’ 90/0] versusnone), more microinvasive cancers (7 [5’ 90/0] versus 2

[1. 00/0]), and a striking excess of "special" morphologicaltypes of invasive carcinomas (72 [60.50/0] versus 32 [16%]).The incidence of invasive carcinomas of no specificmorphological type (carcinomas not otherwise specified,NOS) was correspondingly lower-33 (27-7%) versus 166(83%)-among the long-term survivors, but they included alarger proportion of better differentiated grade I and grade IIlesions. Tumours from long-term survivors generally showedmore elastosis, and less necrosis and invasion of local

lymphatics and blood vessels. Fibrosis was similar in the twogroups. Differences in the clinical features were less clear cut.

1. Dixon JM, Page DL, Anderson TJ, et al. Long-term survivors after breast cancer Br JSurg 1985, 72: 445-48

Age, menopausal status, and parity were comparable, but asignificant excess of earlier stage tumours was found amongthe long-term survivors. Histological and clinical featureswere reanalysed in 101 pairs of long-term and short-termsurvivors matched for age, menopausal status, parity, tumoursize and location, and clinical lymph-node status. All thehistological differences were shown to be independent of theclinical features.The principal finding to emerge from this work is the

excess of special morphological types of tumour among thelong-term survivors. The 72 invasive cancers encountered inthe Edinburgh survey were classified as follows: cribriform(16), variants of lobular (13), tubular (10), classical medullary(9), variants of tubular (8), classical lobular (6), invasive

papillary (6), mucoid (2), and variants of medullary (2). Asimilar correlation between special tumour morphology andlong-term survival has been previously described in reportsfrom New York2 and Chicago.3 In the Chicago series, 97patients who lived 25 years after radical mastectomy showed aclear preponderance of special tumour types compared with amatched series of short-term survivors living for a mean of3’8 years after surgery ( 19% versus 2%). The authorscomment that "While the presence of a tubular, medullary orcolloid carcinoma does not guarantee 25 years’ survival, itmakes it more likely".The Edinburgh findings on special types of tumour raise

some general issues.4-6 The tumours in question are

uncommon and sometimes extremely rare. Descriptivecriteria and terminology vary in some instances. Individualtumours may show both mixed and transitional appearancesunder the microscope which can make classification difficultor impossible. Thorough tissue sampling and expert reviewof pathological material are essential. Survival patterns areinevitably based on small numbers of patients. The tumoursin the Edinburgh survey exemplify the dilemmas. The classiclobular infiltrating carcinoma, for example, is usually easy todiagnose, composed of small regular cells with distinctive"indian-file" and "targetoid" growth patterns.4-6,9 But

increasing numbers of variant infiltrating lobular carcinomashave now been described and their identification issometimes extremely difficult:6- 10 "several criteria have to beconsidered in combination and ... no single pattern can beregarded as diagnostic". Precise tissue diagnosis is far fromacademic in such circumstances, in view of the associationbetween morphology and survival. Tubular carcinomas arevery well differentiated lesions, sometimes confused withsclerosing adenosis, which constitute about 5% of invasivebreast cancers.4-6,II "Pure" tubular carcinomas infrequentlymetastasise to axillary lymph nodes and carry a goodprognosis. Some of them contain a minor cribriform

2. Adair F, Berg J, Joubert L, Robbins GF Long-term follow-up of breast cancer patients.the 30-year report. Cancer 1974; 33: 1145-50.

3. Dawson PJ, Ferguson DJ, Karrison T. The pathologic findings of breast cancer inpatients surviving 25 years after radical mastectomy Cancer 1982; 50: 2131-38.

4. McDivitt RW, Stewart FW, Berg JW. Tumors ofthe breast. Atlas of tumor pathology,second series, fascicle 2. Washington, DC: Armed Forces Institute of Pathology,1968.

5. Fisher ER, Gregorio RM, Fisher B, Redmond C, Vellios F, Sommers SC, andcooperating investigators. The pathology of invasive breast cancer. A syllabusderived from findings of the national surgical adjuvant breast project (protocol no.4) Cancer 1975, 36: 1-85.

6. Azzopardi JG. Problems in breast pathology. Philadelphia: W. B. Saunders, 1979.7. Fechner RE. Histologic variants of infiltrating lobular carcinoma of the breast. Hum

Pathol 1975; 6: 373-78.8 Fisher ER, Gregorio RM, Redmond C, Fisher B. Tubulolobular invasive breast

cancer a variant of lobular invasive cancer. Hum Pathol 1977; 8: 679-83.9. Martinez V, Azzopardi JG. Invasive lobular carcinoma of the breast: incidence and

variants Histopathology 1979; 3: 467-88.10. Dixon JM, Anderson TJ, Page DL, Lee D, Duffy SW. Infiltrating lobular carcinoma of

the breast Histopathology 1982; 6: 149-61