574
Methods and Devices
routine carried out.3 Unless the perineum is tight, thus angling the proximal end of the instrument, the adhesion is so firm that both hands of the operator are free for
sampling. SUCTION AMNIOSCOPE R. H. C. BENTALL St. Bartholomew’s
Hospital
Medical
College,
London E.C.1
AT present fetal blood is sampled by the Saling method1 modified in the United Kingdom by Morris and Beard.23 The sample is collected through a vaginal endoscope in a heparinised glass tube. The endoscope is passed through the partially dilated cervix and is held by pressure of the operator’s hand against the fetal head. This procedure has disadvantages, particularly for the inexperienced operator: (a) movement of the fetal head; (b) the field of vision may be obscured and the sample contaminated by liquor; (c) one hand of the operator is continuously employed in holding the instrument against the fetal head. The suction endoscope was devised in order to secure adhesion of the instrument to the fetal head, thus producing, not only firm fixation to the fetal site, but also a field free from contamination by liquor. The Instrument The instrument consists of an endoscope to which has been added a suction collar around the distal end (figs. 1 and 2). From this the suction tube arises and is connected to a vacuum extractor. Fig. 3 shows how at the distal end the suction collar surrounds the endoscope; the space thus formed between the endoscope and the outer suction edge is known as the suction annulus. To achieve a good suction
Clinical Experience Clinical experience with this instrument is encouraging. It handles with ease; a blood-sample is readily obtained, and readings are consistent. The results will be reported later. I thank Prof. C. J. Dewhurst for his interest and for allowing clinical evaluation of this instrument in his department; Mr. P. J. Paterson for his help in the early stages and Dr. R. Beard for continuing the clinical studies; Miss A. M. Dickins for her encouragement; and Mr. C. Lordon and Mr. G. Williams for their help. Inquiries should be addressed to the National Research Development Corporation, 66 Victoria Street, London S.W.I. REFERENCES 1. 2. 3.
Saling, E. Arch. Gynäk. 1962, 197, 108. Beard, R. W., Morris, E. D. J. Obstet. Gynœc., Br. Commonw. 1965, 72, 496. Morris, E. D. Proc. R. Soc. Med. 1968, 61, 487.
CYTOLOGICAL METHOD FOR ASSESSING TOPOGRAPHY OF NEOPLASTIC CHANGE IN ENDOCERVICAL CANAL D. M. D. EVANS St. David’s Hospital,
Group Laboratory,
Cardiff
IN planning the management of a patient with a positive cervical smear the gynxcologist is hampered by inadequate information concerning the extent of the lesion. As a first step towards overcoming this difficulty a method has been devised for assessing the topography of neoplastic cells on the ectocervix. It consists essentially in applying a plastic membrane to the ectocervix on which the surface cells adhere.! The surface pattern of the neoplastic lesion is then indicated by the distribution of neoplastic cells on the membrane, demonstrated microscopicallv.2 I describe here a further development of this approach designed to determine the extent of a carcinomain-situ in the endocervical canal. THE DEVICE
Fig. 2-Longitudinal aspect of the suction amnioscope.
fit to the fetal head the outer rim extends 0-5 mm. beyond the end of the endoscope.
Technique The suction endoscope is passed vaginam. Once the fetal head is felt with the end of the instrument, suction can be gradually applied up to 12-14 lb. per sq. in., and firm adhesion is obtained even in the presence of prolific fetal hair. After this, the fetal site is dried with a swab and the normal sampling
The membrane, consisting of a cylinder of ’Nuclepore’ filter (G.E.C.), approximately 3 cm. in length and 0-2 cm. in diameter, is applied to the endocervical surface by means of the Tenovus probe. This is essentially a thin rod, on the surface of which the membrane is attached, with a retractable cover to protect it during its introduction and removal. The probe is constructed of stainless steel (fig. 1). It has an outer tube to one end of which a flat disc is attached, acting as a shoulder against the ectocervix when the probe is introduced. Movement of the retractable inner tube, which acts as the membrane cover, is controlled by the sliding handle, seen in fig. 1. Almost at the end of the central rod there is a 3 cm. portion with a narrow diameter (slightly less than 0-2 cm.) round which the membrane is applied (fig. 2). The membrane is attached to the probe by means of double-sided scotch tape.
per
Fig. 3-Enlarged view of suction annulus.
THE METHOD
The patient is placed in the dorsal position and the cervix exposed by means of a speculum. provided that the patient is not menstruating or pregnant, the probe with its membrane protected by the sliding tube is introduced into the endocervix until the metal shoulder is flush
Fig. IEndocervical
probe.
575 with the ectocervix (fig. 3). The retractable cover is then withdrawn so that the surface of the membrane
Reviews
into contact with the endocervical canal (fig. 4). Gentle pressure of the metal shoulder against the ectocervix encourages close apposition of the membrane to the endocervical surface. The sliding tube is then returned so that the membrane is again protected as in fig. 3. The probe is withdrawn from the patient, the membrane is exposed by retracting Fig. 2-Attachment of transthe guard, and the cells parent membrane to endoare fixed by spraying the cervical probe. membrane with an aerosol cvtolosical fixative. The membrane is conveniently transported to the laboratory on the probe, in a polyethylene bag. Removal of the membrane from the probe requires considerable care. By means of a pair of forceps with ends specially ground to provide a flat gripping surface, the membrane is gently unpeeled and a small notch is cut in
of Books
comes
Fig. 3-Diagram of probe inserted into endocervical canal with membrane covered by sliding tube.
Fig. 4-Sliding tube retracted to uncover membrane, bringing it into apposition with the endocervical epithelium.
the vaginal end of the membrane to facilitate orientation. To avoid excessive handling, it is placed in a tissue-processing basket and stained on a cytology staining machine, using the standard Papanicolaou procedure for staining and clearing. The membrane is then mounted as for a tissue section and examined under the microscope, the position of each group of abnormal cells being marked by an ink dot on the coverslip. The pattern of ink dots over the impression area indicates the distribution of carcinoma cells in the endocervical canal. The results of correlating the endocervical membrane cytological topography with the histological localisation of in-situ carcinoma in the subsequent biopsy specimen appear very encouraging, and will be described in a more detailed report. I thank Mr. D. Griffiths for making the Tenovus applicator; Mrs. J. McCormack, Miss G. Shelley, and Mr. P. Ponsford for expert technical assistance; Mr. G. Haddock for the illustrations ; Dr. Jane Jones for invaluable clinical cooperation; and Tenovus for their support in this project. REFERENCES
1. 2.
Evans, D. Evans, D. Jones, J.
M. D. Lancet, 1967, ii, 972. M. D., McCormack, J., Sanerkin, N. G., Acta cytol. 1969, 13, 119.
Ponsford, P.,
Paediatric
Endocrinology
DOUGLAS HUBBLE, C.B.E., M.D., F.R.C.P., lately professor of pxdiatrics and child health and director of the Institute of Child Health, University of Birmingham. Oxford: Blackwell Scientific Publications. 1969. Pp. 492. Editor:
f,7 lOs.
THIS is the long-awaited British text on pxdiatric endocrinology, and the editor has stimulated his contributors (all but one from the U.K.) to provide a very complete pictureoftheendocrinologyof childhood which we have in the late 1960s. Professor Hubble himself deals with the endocrine control of growth and skeletal maturation in a first chapter which sets the tone for his co-authors. He later contributes the chapter on puberty; this section makes excellent reading, the few pages on delayed puberty being a masterpiece of succinct and lucid writing. The nonendocrinologist may be daunted by the apparent complexity of parts of Prof. Zvi Laron’s work on the hypothalamus and hypophysis, but patience will be repaid by the excellent clinical descriptions and illustrations towards the end of the chapter. One picture is said to be worth many words, and readers will be struck by the photographs of a boy with cerebral gigantism. These two simple clinical photographs reveal all the salient physical signs; they should be compulsory study for clinical photographers. The thyroid is thoroughly covered by Prof. James Hutchison. Not everyone would agree, however, with the bald statement that " radioisotopic techniques are never required merely to establish a diagnosis of hypothyroidism " ; there are some difficult cases of suspected cretinism in young infants in which the other diagnostic criteria are equivocal and the answer is only clearly (and safely) obtained by the use of radioiodine-uptake tests. Dr. Malcolm Macgregor contributes a useful and commendably uncluttered section on the parathyroids. X-rays of diseased bones are not easy to reproduce, and changes illustrated are difficult to make out, but this is a minor point of criticism. Dr. D. Methven Cathro’s monumentally detailed treatise on the adrenal cortex and medulla (142 pages including 19 pages of references) would have benefited from a little editorial discipline. However, it may be that those with a particular adrenal problem or with time on their hands will be well rewarded by a study of this chapter. Dr. M. A. Ferguson-Smith and Mr. Henry Roberts deal with the gonads and intersex in relatively short, informative, and well-illustrated chapters. Diabetes mellitus is clearly described by Dr. June Lloyd and Prof. Otto Wolff: modern thought on this disorder is well set out. The advice on diet is refreshingly practical: dare one hope that paediatrics is at last to be rid of the wearisome weighing of food portions, line diets, and the like ? The final chapter is a rather compressed account of the hypoglycxniic syndromes by Dr. Brian Bower. The everyday paediatrician may well find this section the most rewarding reading, and a subject of such importance deserves more than 12 pages. Neonatal hypoglyctmia is well dealt with, and is as up to the minute as is possible in a chapter where the most recent references are to 1967 publications. The production is first class and the text seems singularly free from literals. The bibliography is massive but, in some sections at least, important papers have not been mentioned; but this should not greatly detract from the value of the bibliography as a source of endocrinological references. The index seems to contain no serious deficiency. This book should provide an indispensable reference work for all clinical paediatricians, laboratory staff investigating endo-