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a high-protein, low-salt diet; he was treated with spironolactone,both alone and in combination with mersalyl, chlorothiazide,hydrochlorothiazide, and bendrofluazide and chlorthalidone;the addition of mannitol and albumin infusions still failed toprovoke a diuresis. su 8824 (’Metopirone) was used withprednisolone (in the manner suggested by Shaldon and

McLaren 8) but without success.Nine months after insertion of the Holter Valve, he has hardly

any ascites; his weight is steady at 68-69 kg., his girth is 46 in.,and he is able to do light work. His plasma albumin (formerly1-4 g. per 100 ml.) is now 42 g. per 100 ml., and liver functionis improved. There is no ankle or sacral oedema, and there hasbeen no portal-systemic encephalopathy. He has been kepton a maintenance dose of chlorthalidone alone, 400 mg. threetimes weekly.

This use of the Holter valve would not be suitable forall types of ascites. In malignant cases, for example, freecells might block the valve millipore, and would certainlybe widely disseminated in the circulation. A sample of theascitic fluid should be obtained beforehand by asepticparacentesis; it is important that the protein content ofthis fluid should be low, that it should not clot on standingfor at least 24 hours, and that it should be bacteriologicallysterile. At operation, more fluid may be withdrawn toreduce the strain on the wound; but all the fluid must notbe removed at this time, for the valve must have fluidperfusing it from the start, in case it becomes occluded byfilm and detritus, or by omental tags sealing off the poresof the peritoneal catheter. Should any valve become

3. Shaldon, S., McLaren, J. R. Lancet, 1960, ii, 1330.

occluded, it would be a simple matter to replace it byanother on the same side of the body.Few patients with ascites and obvious hepatic failure

will be fit for treatment by major elective surgery. Several

operations have been suggested in the past decade:Vesicocoelomic drainage 4 (where the peritoneal cavity and

bladder are connected by a length of tubing) has the dis-

advantage that large amounts of protein may be lost in theurine, and the method fails if the tube kinks and stops drainingproperly.

Ileal entectropy 6 (where an ileal loop is opened out withinthe peritoneal cavity to allow absorption of fluid) usually defeatsits own purpose, because the mucosal surface secretes mucus,and local infection ensues.

Almost all patients respond to the most modern of thediuretic agents. Nevertheless, our method of inserting theHolter valve may find a use; we found that, in a patientwith advanced liver disease, this operation was followedby a great improvement in the liver function and generalclinical condition. If others find the same, the techniquecould be used both to treat the ascites, and also to preparea proportion of patients for the construction of a porto-caval shunt later.The expenses were defrayed by the Moray Fund of the University

of Edinburgh.A. N. SMITH

M.D. Glasg., F.R.C.S.E.Senior Lecturer

Department of Clinical Surgery,University of Edinburgh

4. Mulvaney, D. ibid. 1955, ii, 748.5. Neumann, C. G., Braunwald, N. S., Hinton, J. W. Surg. Forum, 1955,

6, 374.

New Inventions

A SIMPLE INSTRUMENT FOR RAPID,CONTINUOUS DETERMINATION OF

OPERATIVE BLOOD-LOSS

To measure operative blood-loss accurately and con-

tinuously is difficult. Several methods are based on differentprinciples, such as swab weighing, repeated volume determina-tion, and weighing the patient. We describe here an instrumentbased upon extraction-dilution analysis of oxyhxmoglobin.Any machine which measures blood-loss by such a technique

must satisfy the criteria of:Complete mechanical extraction of blood.Accuracy and sensitivity to an arbitrary standard-say, 10 ml. of

blood.A small error gain over a wide operating range-i.e., a large diluting

volume for a relatively small amount of blood. Useful figures are a50 litre bath for a 500 ml. loss, giving a dilution error not greaterthan 1 %. ·

An additional criterion is that the haematocrit should remain

Fig. I-Block diagram of instrument.a=50-litre tank, bauxiliary pump, c=now through cell,

<= light source, e = photocell; and f = meter.

Fig. 2-A typical calibration and blood-loss determination.The patient was a man of 52 (Hb 92 %) undergoing subtotal gastrec-

tomy for carcinoma of stomach. Deflection given by a 1 % dilution ofthe patient’s blood =6. Meter reading of 1-25= 100 ml.&mdash;i.e., bloodloss is 100 ml.

constant throughout the operation; this has not been fullyinvestigated, but changes greater than 5 % are uncommon.

THE NEW INSTRUMENT

The instrument (fig. 1) is a domestic washing-machine(General Electric Co.) with a 50-litre tank, modified byincluding a small electric pump, which circulates the dilutingfluid at 11 litres per min. through the flow-cell of a specialcolorimeter (Evans Electroselenium). To this tank, whichcontains 0-04% ammonium hydroxide, are added all swabs,gauzes, linens, and drapes, as well as blood aspirated from theoperation site; and on agitation an oxyhaemoglobin solution isproduced which is continuously circulated through the light-path of the colorimeter.The colorimeter gives a linear response at 650A to 10 ml.

increments of blood from 0 to 500 ml., and it can discriminate10 ml. increments.

Repeated recovery investigations, by adding to the tank-fluid known volumes of blood either in liquid form or assoaked gauzes, yield a 100% recovery from gauzes, and showthat the machine has an overall accuracy of 3%.

673

In use, calibration points corresponding to 250 ml. and500 ml. of the patient’s own blood are established with a

reference cell. An individual graph is then drawn (fig. 2) byextrapolation from these points, and the scale deflection can beread continuously. Swabs and the suction fluid from a trapbottle, excluding liquid seen to contain little or no blood, arethen added as they become available; the swabs are finally putthrough the spin-drier to avoid change in volume of the bathcontents.

We do not regard the machine in its present form as suitablefor routine use, but it may interest those for whom accurateassessment of blood-loss is important. Suitably modified it

could form the basis of an everyday piece of theatre equipment.We are grateful to the board of management of the Aberdeen

General Hospitals for a grant from endowments to develop this

instrument, and to Evans Electroselenium Ltd., for developing thecolorimeter.

C. F. ROEM.B. Aberd.

A. J. S. GARDINERM.B. Aberd.

H. A. F. DUDLEYCH.M Edin., F.R.C.S.E.

Department of Surgery,University of Aberdeen

A MODIFIED SILVERMAN BIOPSY NEEDLEFOR USE IN CHILDREN

NEEDLE biopsy of the liver has for many years been a

diagnostic procedure in adults, with an estimated mortality-rateof between 0-12 and 0-3%. 2 In children it has mostly beenused for research, and only recently have its practical poten-tialities been exploited.3-6 Probably the most popular liver-biopsy instruments are (1) the Vim-Silverman needle andits modifications, in which tissue is grasped by the prongs ofa split inner needle, and (2) the modified Gillman apparatus, 8whose action depends on a combination of cutting and suction.It was with the former needle that Kark and Muehrcke 9 10

devised their safe and efficient technique of percutaneous renalbiopsy, which has since been applied in children." 12During the past three years I have gained experience of

these techniques in children, and I have been able to obtain

adequate specimens with the least possible risk to the patients,especially infants. The Gillman instrument proved too largeand difficult to control in babies, and it is unsuitable for renalbiopsy in the prone position. After initial trials, I thereforeabandoned it in favour of the Vim-Silverman needle.

Certain defects in the standard pattern soon became evident.It was difficult to control the depth of insertion of the outer cannula,

which should be far enough to cover the tips of the inner needle, butno further. Over-penetration is of minor importance in adults, butit increases the risk of trauma in infants.The actual time spent in taking the biopsy was lengthened because

of the necessity to rotate the inner needle through a complete circlein order to twist off the specimen at its attachment.The depth of insertion of the inner needle could not be adjusted.

A penetration of 2-5 cm. beyond the tip of the outer cannula producesgood specimens with safety in older children, but it adds to tht. risksof the procedure in babies.Being top-heavy because of its steel mounts, the instrument was

difficult to control while identifying the organs by their respiratorymovements, particularly in renal biopsies in small children.The standard mount of the inner needle could not be grasped

conveniently for the dual purpose of thrusting it sharply into theorgan and fixing it between thumb and finger while the outer cannulawas advanced.

1. Terry, R. Brit. med. J. 1952, i, 1102.2. Sherlock, S. Diseases of the Liver and Biliary System; p. 64. Oxford,

1958.3. Bruton, O. C., Metzger, J. F., Sprinz, H. Pediatrics, 1955, 16, 836.4. Kaye, R., Wagner, B. H., Koop, C. E., Hope, J. W. A.M.A.J. Dis.

Child. 1957, 94, 417.5. Kaye, R., Koop, C. E., Wagner, B. M., Picou, D., Yakovac, W.C. ibid.

1959, 98, 699.6. Hong, R., Schubert, W. K. ibid. 1960, 100, 42.7. Silverman, I. Amer. J. Surg. 1938, 40, 671.8. Terry, R. Brit. med. J. 1949, i, 657.9. Kark, R. M., Muehrcke, R. C. Lancet, 1954, i, 1047.10. Kark, R. M., Muehrcke, R. C. Pirani, C. L. J., Urol. 1955, 74, 267.11. Gal&aacute;n, E., Mas&oacute;, C. Pediatrics, 1957, 20, 610.12. Vernier, R. L., Farquhar, M. G., Brunson, J. G., Good, R. A. A.M.A.J.

Dis. Child. 1958, 96, 306.

These faults have been overcome by the simple modificationsdescribed below (see figure).

THE MODIFICATIONS

An adjustable stop is mounted on the outer cannula, A,and secured by a thumb screw, so that the cannula can beconfidently plunged to the calculated depth. When the needleis used for adults, the stop can if necessary be removed to allowinsertion of the whole length (8-5 cm.) of the shaft.The need to rotate the inner needle is abolished by incorporat-

ing Franklin’s modification,9 in which the pointed tip of eachhollowed prong is filled with silver solder. When the prongsare closed by advancing the outer cannula, the specimen isdivided at its attachment and retained in the channel formedbetween the prongs, while the whole instrument is removed.In fashioning the tips of the inner needle, a bevel angle of 20&deg;to the long axis of each prong is critical. Preliminary necropsystudies showed that longer bevels provide insufficient openingthrust during insertion, often with the result that no specimenwas obtained, while shorter ones give ragged specimens of poordiagnostic value. Perfect sharpness is also important if goodspecimens are to be obtained.The depth of insertion of the inner needle can be adjusted

through a range of 1-5-25 cm. by means of a runner, mountedon a thread, B, at the base of the needle.To reduce the weight of the instrument, the mounts, runner,

and stop are made of aluminium alloy; this slightly increasesthe cost, and its surface becomes dull after repeated sterilisation.

Finally, the shape of the inner-needle mount, c, has beenmodified so that it can be comfortably grasped between thethumb and middle finger, and thrust by the index finger restingon its top, without a change of position.

For sterilisation, the cannula, stillette, and inner needle areinserted separately into three lengths of glass tubing to protecttheir points, and they are then packed in a large ’Pyrex’boiling-tube which is plugged with cotton-wool, sealed, andautoclaved. The points of the inner needle are readily bluntedby rough handling, but with care they need little attentionbeyond occasional hand-sharpening.

PERSONAL EXPERIENCE

I have now used this needle in infants and children for

fifty-five liver biopsies, without failure, and for eighty renalbiopsies, with nine failures, though only the first three wereattributable to minor faults in the needle prototype, and thesehave since been corrected. Specimens up to 30 mm. long havebeen obtained without distortion, and some recent renal biopsieshave contained more than a hundred glomeruli. (Details ofthese will be published.) Most of the earlier liver biopsies ininfants with obstructive jaundice were performed experiment-ally just before laparotomy, which provided the opportunity toobserve that the capsular punctures were small, and thatbleeding was very slight.The instrument was manufactured by Messrs. Down Bros. and

Mayer & Phelps Ltd., Church Path, Mitcham, Surrey. I should liketo thank Mr. Maurice Down for technical advice.

R. H. R. WHITEM.A., M.B. Cantab., M.R.C.P., D.C.H.

Senior Registrar,Hospital for Sick Children,

Great Ormond Street,London W.C.1

Department of Paediatricsand Child Health,

Mulago Hospital Medical School,Kampala, Uganda