The clinical significance of x-ray pelvimetry

believe that cases which have been treated since these with a IargPr initial dosage, up to 5400 milligram hours,. are ~:oing to show bettrr results but they are still too reeent for an~' valnablr conclusions to be drawn. SUMMARY

'rhe proportion between the three cdl types in squamous cancrr of the cE'rvix is about the same in the rl ifferent cl iniral stageR of tllf• disease. r:l'he order of malignancy of the different cell types progressing from least to most is spinal, adenocarcinoma, transitional, and fat :-;pindlP. The type of cell does not indicate whether operation or ra(1ium is the better treatment for any type. The cases having more stroma than cancer tissue respond more favorably to either kind of treatment than wht>re the C'onditions are reversed. HEI!'ERENCE::i

(1) Urol. and Cutan . .Rev., St ..Louis, 1924, XHii, 447. (:;) .Johns Hop. Hosp. Bull., 1923, x.xxiv, 141. (3) Jour. Am. Med. ASSJJ., 192-1-, lxxxiii, 1060. ( ±) AM. JOrR. 0BST. AND GYNEC., 1925, ix, 6H. (5) Ibir1., }!)~±, 1·ii, 6l:l. (6) Ibid., lf)2G, ix, fiOR. (7) Ibirl., 1925, ix, 621. (S) Ibid., 19:}.>, x, 140. ( fl) Ibid., l!l~G, ix, 1121. ]9il COMMONWEALTH AVENUE.

(For

d-is<~ISRion

sre r1age 607.!

THE CLINICAL SIGNI.B'ICA:t\CB UP X-HAY PEI;VDIETRY"' HERBEHT 'rHoMs, M.D., F.A.C.S., NEw HAvE~, CoNx. (From the Woman's Cl·inie, Yale Unive1·sity Sc.lwol of Mfd·icine)

BY

D

URING the past five years, I have been interested in the determination, by means of the x-ray, of the lengths of the diameter>! of the pelvic inlet. The principles of the method which I have used were first described in a communication which was published in 1922. 1 Since that date, the technic has been simplified and improved, anrl in the present paper, I shall describe the proeE·dure which i:s 11ow employed. r:l'he problems of this method of roentgen-ray pelvimetry are twofold. First, the position which must be maintained by t.he patient, in order to make the superior strait parallel with the sensitive plate; and secondly, the determination of the degree of divergence from the vertical which the x-rays undergo in their passage from the tube through the superior strait to the sensitive plate. A graphic representation of these problems is shown in Fig. 1, where T represents the tube or target, and PBS the superior strait, and SP the sensitive plate. *Read, by invitation, a.t the Fifty-first Annual Meeting of th•· ,\nwrican n;-n•·colog!cal Society, Stockbridge, Mass., May 20, 21 and 22, 1926.

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THE AMERICA.::\ JOUH:::-
It is apparent, on viewing this diagram, that in order that the distortion thus produced may be equal in all directions, the tube must be centered over the superior strait and the plane of the ~uperior strait must be parallel to the sensitive plate beneath. These conditions are fulfilled when the patient is placed in the semirecumbent position, with the back arched, in the manner shown in Fig. 2. In order to determine the level of the superior strait, it is necessary to identify two points on the external surface of the body. These are located, one on the anterior surface of the symphysis, JT

1\

\

r·

Fig. 1.-Showing direction of rays from target ( T) through superior strait ( SP) to sensitive plate. In order to have equal divergence the superior strait must be parallel to the sensitive plate ( S' P').

one em. below the superior border, and posteriorly at the depression just below the spine of the fourth lumbar vertebra. An imaginary line connecting these two points traverses the anteroposterior diameter of the superior strait. It is essential, therefore, that these points shall be of equal distance from the plane upon which the patient sits. The plane of the superior strait can be made parallel to the sensitive plate by employing the device shown in Fig. 3. With the horizontal arm placed on the upper anterior surface of the symphysis, the height is read from the vertical arm and an equal distance measured pos-

THOMS:

CLINICAL SIGNIFICANCE OF X-RAY PELVIMETRY

:)45

teriorly by means of calipers, as shown. The patient having been placed in this position, the tube is placed 36 inches above the plate, over a point 5 em. posterior to the upper border of the symphysis

Fig. 2.-Patient in se mirecumbent position with back arched. In thiR position the pla ne of the pelvic inlet Is made horizonta l aml pamlkl to the sensitive plate beneath.

pubis. If the tube is centered in this manner, and the pelvis made horizontal, we have found that a moderate variation does not materially affect the end-result. Thus, the tube may vary 2 to 4 em. away

Fig. 3.-Showing method of making superior ffltrait horizontal and parallel to sensitive plate beneath (see text).

from a point above the center of the superior strait, or the pelvis itself may vary 1 or 1.5 em. from the absolute horizontal, without affecting the reading much more than a millimeter. This leeway makes the method one of practical application, because of personal

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variations which are bound to occur, in placing and maintaining th e correct position. 'l'he second problem is the determination of the exact amount of divergence or spreading away from the vertical which the rays undergo in their passage from the tube to the plate. The character of the problem will be made clear by the study of Fig. 4. It is evident that in diagram A, in which the superior strait is represented as being 13 em. above the plate, this divergence will not be as great as in diagram B, in which the superior .strait is r epresented as being 18 em. above the plate. It is also evident that the degree of distortion for different levels may be readily plotted upon a large piece of paper,

Fig. 4.-Diagrams explaining principle of this meth od of x -ra y pelvimetry. Dive rgence of r ays through the s uperior strait with the tube a t 36 " dis t a nce is measured and calibrated on lea d strips (see text).

with the use of a '1' square and pencil. We determine, therefore, for all time, this divergence for planes from 11 to 22 em. above the plate. The degree of divergence for each level is indicated by a series of notches upon a fiat lead strip, and we then possess lllead strips notched as shown for the different levels described. It is apparent .that these notches represent "corrected centimeters "-that is, each space between the notches represents a centimeter in the plane to be measured. The lead strip · is placed upon the edge of the plate just before exposure. For example, if the patient's superior strait rests 16 em. above the plate, number 16 strip is used. The amount of ray divergence at 36-inch tube distance is not as great as one might suppose; for instance, at a 19 em. level, it is approximately as in the ratio of 10 :12.5. That is, 10 em. at the superior strait becomes 12.5 em. on the plate.

THOMS:

CLINICAL SWNIFICANCE OF X-RAY PELVD!ETRY

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The x-ray technic is as follows: Duplitized supcrspeed :films, a double screen with Bucky diaphragm, and a medium focus Coolidge tube arc used. The distance of the target plate is 36 inches. A point spark gap distance of 7 inches--which is equivalent to approximately 65 kilovolts-is employed. The amount of current is 20 milliamperes, and by using an ammeter in filament circuit, this voltage can readily be obtained without passing the current througb the tube. A medium focus Coolidge tube will run easily up to approximately twenty secm1ds at this setting without greatly overheating. There is no apparent reason why with a heavy patient the tube may not be allowed to cool for tetl or fifteen seconds, the patient holding the arched position, with possibly a second setting of the Bucky diaphragm. The time of exposure is as follows: 'l'IME

16 seconds 20 seconds ------------- 30 seconds

Thin Medium Heavy _

10 seconds 14 seconds 17 seconil.~

As compared with other methods of r·oentgen·ray pelvimetry, the procedure which I have described is of unmmal simplicity. Inderdure oceupies scarcely more time than does the taking of an ordinary roentgenogram. It is not necessary to emphasize its value in obstetrieal practice. \Vhile the usual method of internal pelvimetry foeu:;;es attention almo~t entirely upon the measurement of the antrroposterior diameter of the superior strait, it is possible, by employing the procedure in (111e~tion, to determinf~ not only the length of this diameter, but also to measure the length~ of the transverse and oblique diametm·s with remarkable accuracy. The practical value of such additional information is well illustrated in the accompanying pelvigram, in this case, that of a primiparou:-> patient, the external diameters of whose pelvis were a;;; follows: spines 22; crests 24.5; trochanters 29.2G; external conjugate 16.75 em. She was of short stature and weighed 94 pounds. We have repeatedly proved that in many individuals of this type, particularly those with a slight build, the capacity of the p,e1vis is surprisingly large, despite the fact that the length:-; of the external diameters are far below normal. An examination of the pelvigram brings out tbis discrepancy-for in spite of the shortened external diameters, th(• anteroposterior diameter of the superior measure!; 10.75 en1., and tlw transverse diameter 12.25 em. At this point, I wish to refer to the taking of roentgenograms with the patient in the lateral position, an accessor~' measure which has been of great usefulness during the past year. 1'his procedure, while not specifically employed as a means of pelvimetry, is of value in depicting the relationship of the fetal head to the superior strait, and is of importance in those cases in which an abnormality in the sacrum is suspected. The technic of the method is :;;imple. With the patient

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THE AMERICA~ JOURNAL OF OBSTETRIC'S AND GYNECOLOGY

in the lateral position, the tube is centered over the crest of the ilium 36 inches above the plate, at a point midway between the symphysis and the depression underneath the fourth lumbar vertebra, and a suitable exposure made. The anterior and posterior surfaces of the sacrum in their lateral aspect are well shown and an outline of the fetal head, with its relationship to the superior strait, is readily distinguishable. When it is remembered that the unengaged head of the fetus usually rests with the occipitofrontal diameter parallel to the transverse diameter of the inlet, it is apparent that an estimation of the length of the biparietal diameter can also be made (see Fig. 6). In the use, therefore, of the two methods above described, we feel that we pos'sess substantial additions to our usual pelvimetric pro-

Fig. 5.-Pelvigram showing outline of superior strait. Scale at side of film in "corrected centimeter s." By m eans of ca lipers a ny dia meter of this pla ne m a y be measured readily.

cedures. Their application is much more difficult to describe than to perform. It is unusual for us, in performing both technics, to occupy more than ten minutes with each patient. Their clinical application is obvious. It is our custom to take pictures of the inlet in all patients in whom the external measurements point to pelvic abnormality. Where the influence of rickets is suspected, we have found at times that the only definite means of diagnosis depends upon the roentgenographic study of the sacrum. The routine use of this procedure in abnormal pelves I feel certain is going to point out a greater incidence of rachitic deformities than we have hitherto supposed, particularly in the milder grades. In patients in whom the fetal head fails

THOMS:

CLINICAL SIGNIFICANCE OF X-RAY PELVIMETRY

;)4~1

to become fixed at the superior strait at term, we can readily determine whether the nonengagement is the result of bony disproportion or is due to some other factor. In a recent patient, in whom the fetal head was floating at term, a lateral picture showed the presenting part high above the superior strait, in spite of the fact that a space 2-3 em. in width was present between the posterior parietal bone and the promontory of the sacrum. Although measurements of the diameter,; of the inlet showed the pelvis to be of adequate dimensions for a moderate sized fetus, manual pressure from above failed to force the occiput into the superior strait. It was evident that some other than

Fig. 6.-Lateral roentgenogram at term. Showln" relationship of presenting part to superior strait where disproportion was suspected been nse of nondescent. ~'I" disproportion present, sacrum shows normal concaYity of anterior surface.

bony disproportion on the part of the mother wa:;; present. Becauf;e the previous labor had been terminated by cesarean section, it seemed wise, under the circumstances, to effect delivery in a similar fashion. Following the removal of the fetus, the placental site was found low down on the posterior wall of the uterus, and it appears that the undescent of the fetal head in this patient depended upon interferenee offered by an unusually low implantation of that organ. SUJ\1MARY

1. A method of x-ray pelvimetry has been presented by means ot which the dimensions of the superior strait can be measured with re.

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TilE AMERICA:\ ,JOUR~AL OF OB~TE'I'RIC~ A::-<0 GY:-JE('QI,OGY

markable accuracy. 'l'he method is applicable in any stage of pregnancy and does not require elaborate apparatus. 2. A technic has been described which makes it possible to obtain lateral views of the pelvis showing the contour of the sacrum and the relation of the presenting part to the superior strait. Attention is drawn to the value of such information in the diagnosis of the less severe grades of rachitic pelvic deformity. 3. The importance of the two methods as aids in the study of contractions of the pelvis is emphasized. In conclusion, I wish to acknowledge my indebtedness to Dr. C. R. Scott and Mr. E. F. Furbush, of the Department of Roentgenology of the New Haven Hospital. '!'heir help in working out the technic of taking the pictures has been invaluable. 129

WHIT~EY

( Fo1' disoussion see page 599. ).

AVE!WE,

TRIAL LABOR IN THE TREATMENT OF 477 CASES OF' CONTRACTED PEINES* CoNDUCTED UNDER ONE PLAN OF' 'l'REA'l'MEN'r DURING THE LAST FouR YEARs

By

HAROLD BAILEY,

M.D.,

NEw

YoRK, N.Y.

0

BSTETRICS is, for the most part, in the hands of the general practitioner, and as perfect surgical technic is not readily acquired by the occasional operator, the existing high maternal death rate is without doubt related to his errors. These have become more pronounced in the last few years, for conservatism has been abandoned and ·we are in an era of operative obstetrics. This is due to the attitude of the leaders in the medical centers. Because of the high infant mortality, the time honored resources of induction, high forceps, version and craniotomy are frowned upon in the manag.ement of labor in contracted pelves. When clif;proportion is present or the pelvic measurement:-; are below normal, it i;; impossible to judge whether or not a spontaneou~ tleliver;· ean OC'('HJ', awl if in a test of labor the head fails to engage, the accoucheur has now but one procedure at his command. He must do a cesarean section or send the patient to a hospital where, frequently, a man unversed in obstetrical mechanism opens the uterus forthwith. 'l'he incidence of cesarean section has increased until in certain clinics it is as high a:> 7.1 per cent.l The question to be considered is whether the adoption of cesarean section has resulted in an increased saving of life of mother and child. In New York State (outside of New York City) one out of

•Read at the Fifty-first Annual Meeting of the American Gynecological Society, Stockbridge, Mass., May 20, 21 ann 22, 1926.