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ficance as an isolated lymphatic metastasis, but if it ismassive and associated with loose clots, emboli are almostcertain to have passed to the liver. Patients with one tothree lymphatic metastases often survive 5 years, butthis 5th anniversary is rarely reached by patients withfour or five. The position of lymphatic metastases is ofeven greater importance than the number. A survey ofthe extent of local and lymphatic spread in a large seriesof cases treated by a combined operation has shown thatabout half of these might have stood as good a chance ofcure if a perineal excision had been done instead. In theother half the combined operation probably gave a betterchance.

After surgical treatment most recurrences are manifestwithin 3 years, and it is very rare for a patient who haspassed the 5th anniversary of his operation to die ofrectal cancer. Judged on 5-year survival, it seems thatthe surgical treatment given to these patients curedabout half. After removal of the rectum for cancer,patients who survive 5 years now have as good anexpectation of life as a control non-cancer populationstill possessing a rectum. More than 80% of A cases(growth limited to rectum) are cured by operation, andmore than 60% of B cases (spread to perirectal fat butno glandular metastases) ; but unfortunately at presentless than half the patients are operated on at thesestages, and once lymphatic spread has commenced (Ccases) the prospects of surgical cure rapidly decline. Thedisease is commoner in men than in women, but at thetime of treatment it is generally more advanced in women*than in men. After operation the survival curves followa similar course for 3-4 years, after which there aremore female survivors than male. For cases withoutlymphatic metastases the survival-rate is practically thesame irrespective of the type of operation, but for thosewith lymphatic metastases the results of the combinedoperation (including abdomino-perineal, perineo-ab-dominal, and synchronous combined) show an improve-ment of 13% on the perineal. Recent improvements insurgical technique may bring this credit balance up to15% or 20%.In the period covered by this review, said Dr. Dukes,

the treatment of rectal cancer by rectal surgeons reacheda level never before attained ; but the results of surgicaltreatment generally throughout the country might befurther improved. One obvious way is for the specialhospitals to provide more facilities for postgraduatestudy and the sharing. of experience. The other is tomake it better known that in its early stages rectal cancercan be completely cured, and that even in more advancedcases surgical treatment is often satisfactory. The chiefneed of the day is earlier diagnosis and the best means ofensuring this is to awaken more interest in the diseaseand more confidence in the possibility of cure.

MEDICAL SOCIETY OF LONDONAT a meeting on Nov. 8, with Prof. G. GREY TURNER,

the president, in the chair, Prof. H. J. SEDDON spoke onSurgery of the Nerve Gap

The power of the central end of a severed nerve to putout axons, he said, remains unimpaired for a very longtime. When the ends of a severed nerve are broughttogether regeneration depends not only on this powerbut on the formation of a conducting bridge of Schwanncells which grow for the most part from the peripheralstump. Nerve-fibres cannot attain ’ maturity unlessthey find their way into the Schwann tubes of theperipheral stump. The proliferative activity of theSchwann cells reaches a maximum at the twenty-fifthday and then declines fairly rapidly, though there isstill some power of growth after a year. The out-growing axons may encounter other troubles ; theSchwann columns in the peripheral stump shrink pro-gressively, so that many fibres may remain unmyelinated,and incapable of proper functioning. Degenerativechanges in motor and sensory end-organs are largelyreversible in the early stages but long delay is harmful,especially to motor endings. He believes that primarysuture is less satisfactory than early secondary suture,and therefore inadvisable ; but every effort should bemade to get the injured limb into such a condition thatthe nerve can be repaired within a few months or weeksof injury.

In end-to-end suture the surgeon must, he said,mobilise the nerve before performing any kind ofresection. The central and peripheral stumps must befreed as far as is anatomically possible ; most of thecollateral nutrient vessels have to be divided, but thelongitudinal supply is so good that this is rarely harmful.The gain from freeing the central and peripheral stumpsis only about 3 cm., but is essential for what follows.Flexing of a neighbouring joint usually allows so muchapproximation of stumps that considerable gaps can beclosed. One stump may be tethered down by branches,but every branch is bound to the main trunk only byepineurium and perineurium for several centimetresabove the point at which it appears to leave it, and it ispossible to gain considerable mobility by stripping thebranches back to their real point of origin. This isdone with a very sharp-pointed knife, and must stopinstantly the moment the point of fusion of the branchwith the main trunk is reached. If stripping does notgive the necessary mobility the surgeon must decidewhether he is justified in sacrificing one or more branches.He has to balance what he will lose against what he willgain, but the distal parts supplied by a main trunk areon the whole more important than the proximal parts.Thus sacrifice of the branch to the brachioradialis in alesion of the radial nerve just above the elbow is alwaysjustifiable if it allows good apposition of the cut ends.Transposition of the ulnar nerve gives a useful increasein length. Very large gaps have sometimes beenclosed by suturing the nerve with a joint in a positionof extreme flexion.

In the early days of this work, Prof. Seddon said,he and (the lamented) Highet had tried to outdoeach other in the closure of large gaps by this method,and Highet had won by closing a gap of 17 cm. inthe external popliteal ; but when they came to surveyresults they found that the nerves had not regenerated.Thus the biological limit to success is stricter than theanatomical one. Postoperative stretching, in - thesecases, produced a traction lesion of far greater extentand severity than that for which resection and.suturewere originally performed. This point is more importantin the lower than in the upper limb, for the patientmust be able to extend his knee fully if he is to walkproperly ; postoperative stretching is therefore maximal.In the upper limb, at the elbow, some compromise ispossible, and postoperative stretching can be cut shortat 30°-45° of flexion-a position of useful function inthe upper limb. Bulb-suture is sometimes used whenthe nerve ends are too far apart for resection and sutureafter full mobilisation. The ends are overlapped with-out resection and stitched together firmly, and post-operative stretching is begun immediately and usuallycompleted in three weeks. He had used the method in5 cases, with 1 success and 2 failures ; in 2 cases it wasstill too early to expect recovery. Bone shortening, hesaid, has been condemned as unjustifiable by JocelynSwan, but in cases of ununited fracture of the humeruswith division of the radial nerve it is permissible. Theproblem presented by the nerve gap is serious. In theOxford series there were 200 sutures, and 61 cases inwhich no form of direct repair was possible. Of the 61,only 27 had been dealt with by extraordinary surgicalmeasures. There were 5 bulb sutures, 2 bone shorten-ings with nerve suture, 16 autografts and 4 homografts.In many of the 200 sutures the gaps that had to beclosed were considerable and it is now certain that theprospect of recovery was spoiled by excessive post-operative stretching. Hence, about a third of all casesof nerve division require treatment by some means otherthan direct end-to-end suture.

Speaking of grafting, he said that since it is necessaryto close a gap in a nerve by providing a scaffold ofSchwann cells, all forms of treated graft are useless.The histological findings when such a graft has beenused are no different from those seen when the axonshave tried to bridge a large gap for .which no kind ofrepair has been attempted. In rabbits, short auto-grafts of small diameter have been as successful as theresults of primary suture. In man digital and facialnerve autografts have given good results. All graftsshrink, and should therefore be on the long side, or theypull away at one point of union. In 6 cases of digitalgrafting he had had 3 failures because resection of the

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peripheral stumps had been inadequate. Cable graftshave a limited application because no patient has enoughcutaneous nerves to spare to make up a really longthick cable. He had used it in 6 cases with one goodand one poor recovery and 2 failures ; in the remaining 2it was still too soon to expect return of function. In apatient with two serious nerve lesions, one of which isbeyond hope of repair, it is sometimes possible to usean autograft from the irreparable trunk to bridge alarge gap in the other. Heterografting is useless.Small homografts have been successful in rabbits, but inman he had had no success in 4 cases. The bodytreated the grafts as foreign material.. Medawar hasshown, he said, that skin homografts, after growingvigorously for a few weeks, melt away and disappear ;and a second set of homografts, transplanted from thesame donor while this reaction is at its height, dis-appears immediately. This evidence of the develop-ment of specific antibodies to the graft probably appliesalso to nerve tissue-which, like skin, is epiblastic. Inthe rabbit fibres can probably cross a small homograftbefore the antibodies develop and disrupt the graft.But in man the development of immunity probablywins the race against the growing axons, and destroysthe- graft before they can bridge the gap.To sum up : end-to-end suture is still the best form

of repair for a divided nerve ; mobilisation to bringtogether widely separated stumps has a biologicallimit which is stricter than the anatomical one ; theideal bridge is some sort of graft and autografts workperfectly experimentally and after a little more workmay prove extremely useful in man ; homografts arenot promising ; and heterografts and all preservedgrafts are useless.

DISCUSSION

In the discussion which followed Major-General D. 0.MONRO asked whether nerves should be sutured bysurgeons working near the front line, in the occasionalcase where the wound was a clean cut and likelyto heal by first intention. He said that he had beenunimpressed with results of nerve-grafting in Russia.-Brigadier W. R. BRISTOW considered that no cases

ought to be treated at any hospital in front of the base,and that nearly all cases of nerve injury should be senthome. Under service conditions there are neitherfacilities nor time for this intricate kind of surgery.The most that the front-line surgeon should do is toanchor together the ends of a divided nerve, whichprobably makes the task of the surgeon carrying outsecondary repair somewhat easier.-Sir JAMBS WALTONrecalled that eight years ago, in Paris, he had seen nervegaps bridged with preserved spinal cord taken from therabbit ; it was claimed -that functional recovery occurredas early as three weeks ; but he had felt sceptical.The CHAIRMAN asked whether there was any special

merit, as Ballance had claimed, in predegenerate auto-grafts. He thought Prof. Seddon a little impatientin condemning as hopeless the failures after resectionand suture for large gaps. In some cases of suturerecovery hes been seen as late as ten years after operativerepair, and it may well be that rates of regeneration re-garded as normal are inapplicable in complicated cases.-Prof. SEDDON replied that late recovery might perhapsoccur, not because the regeneration in the nerve itselfwas slow, but because of very slow improvement at theperiphery, especially in muscles. Predegenerate graftswere superior to fresh grafts in only one respect : theywere easier to handle.

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Reviews of Books

Cirugia PlasticaLELio ZENO, professor of surgery in the Rosario MedicalFaculty. (El Ateneo, Buenos Aires. Pp. 337).WHEN a surgeon employs a scientific approach to a

book on surgical technique he is compelled first to out-line his personal medical beliefs before proceeding todetailed descriptions of procedure. In his firm adher-ence to the Hippocratic tradition and to its modernscientific version, especially the physiological schoolof Claude Bernard, Dr. Zeno belongs to that generationwhich is trying to raise surgery from a purely manualart to -a science, or at least to give mere " art " a second-ary place and to insist on the prime importance ofscientific principles. He brings out these points clearlyin his book. The first section is devoted to a descrip-tion of wounds, burns, infections, scars and grafts, anddeals with the use of inert. substances in plastic recon-struction.. He gives almost colloquially the results ofhis personal experience, at the same time discussingand analysing many surgical problems ; the lesion andits treatment are always placed together. In the treat-ment of burns, he recommends the use of plaster-of-paris and puts forward his claim to have originated theuse of plaster for this condition. In skin grafting heis a follower of Gillies ; he also describes bone and othergrafts. The second section deals with the surgicaltechnique of the various regions of the body ; it is wellillustrated with photographs of cases and is probablythe best part of the book. The third section is byDr. E. Pizarro Crespo, the psychiatrist. He discussesthe psychological and social aspects of injury, mutilationand reconstruction. Taken as a whole, this book is oneof the best contributions to the surgery of repair whichhas come from this notable surgical school of theArgentine.Modern Treatment Year Book 1943

Editor : CECIL P. G. WAKELEY, DSOLOND, FRCS. (Baillierefor Medical Pre88 and Circular. Pp. 260. 12s. 6d.) c

WHERE year books are concerned, the general practi-tioner seems to be as nebulous a person as is the " intelli-gent layman " to the writer of popular scientific works.The term " modern," too, is apt to be used in a sensewhich even Einstein might have some difficulty indenning... It is doubtful whether many GPs will be