DILATA'fiON O.F' THE CERVIX lJ'l'BlU BY MB.::'..NS
S1'ATISTICAL REVIEW
L.
STONE,
(From the ObstetrioaZ Department
:M.D.,
John.~
BAWIMORE, 1\ID.
Hopkins Hospital and Dni1Jersity)
HE best means of artificially dilating the cervix of the pregnant T uterus has never been established on a perfectly satisfactory basis. As a consequence, the operation is performed in many different ways, and the various alternatives have aroused exhaustive discussions. It has been inevitable that such variations of procedure should exist, because (1) the operation is indicated in a variety of pathologic conditions, each one demanding individual study; and (2) interference may be imperative at any period of gestation, when there are commonly great variations in the recognized principles of treatment. In the induction of abortion, the Champetier de Ribes balloon or the Voorhees bag must compete primarily with curettage, digital or instrumental, preceded or not by a preliminary mechanical dilatation or softening of the cervix by tamponade. Although instrumental curettage of the early pregnant uternfl can be vigorously deprecated from the outset because of (a) liability to trauma, (b) destruction of any accumulated cellular resistance against infection, and (c) the uncertainty of completely removing all the tissue; yet digital curettage is satisfactory and safe, and it is often indicated, whatevet· method of cervical dilatation has been employed. At the same time. it should always be remembered that forcible dilatation of the cervical canal, instrumentally or by the fingers, carries the same risks and disadvantages that it doer; later in pregnancy. The pack may spare the cervix from trauma, but it i~,; uncertain in action, particularly in the time element. Moreover, since it promptl~· becomes saturated with secretions from the surrounding tissues, it ac.ts exactly as a lamp wick in carrying infectious material upward into the uterine cavity. Although the removal of the cervical pack will frequently be followed by the product of conception, ,vet, so often is secondary interference necessary for the complete emptying of the uterus, that this method of dilating the cervical canal cannot be looked upon as a procedure of choice . . In the occasional instance, when in the presence of a rigid, unyielding cervix:, a rapid evacuation of the uterus is indicated, vaginal hysterotomy is clearly indicated; but the disadvantages of a prolonged convalescence and of a permanent scar in the lower uterine segment are not to be regarded lightly. :u.-1
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315
Simple rupture of the membranes or the application of a bougie must be mentioned, but their status is best considered later, in view of their more frequent employment at or near term. In the induction of abortion, we have employed the hydrostatic bag with relatively gratifying results, particularly when the pregnancy has progressed beyond the third month. The operative aspect of the case is confined in most instances to one sitting, and often the introduction of the bag can be effected without anesthesia. Once properly placed, dilatation of the canal almost always follows, and usually with reasonable promptness; and, in view of the complete effacement of the cervix, spontaneous completion of the abortion is the rule. After the period of viability of the fetus has been reached, the indications for artificial dilatation of the cervix broaden perceptibly, and the bag finds favor in several groups of cases: (a) Inductipn of labor may be necessary for beginning disproportion, whether referable to pelvic contraction or postmaturity of the child. (b) Constitutional diseases often warrant the induction of labor, particularly toxemias of the nephritic type, intractable urinary infections, and occasionally eclampsia. These two groups may be classified in a neutral zone where urgency is not usually essential, and in which it is preferable to make a trial with castor oil and quinine, the Watson method, or the application of a bougie. Whereas these latter methods frequently fail to accomplish the desired result, the bag used as a terminal procedure rarely fails to bring about sufficient dilatation of the cervix to permit prompt termination of the pregnancy. In contrast to these types of eases, there is the more tragic variety, which urgently demands a relative acceleration of the first stage: (a) The occasional instance of cervical dystocia or uterine inertia, where the dilatation is excessively, and often unexplainedly, retarded. (b) The "hemorrhage" group, including all the placenta previa cases, as well as certain degrees of premature separation of the placenta. In these instances the hydrostatic bag finds its greatest usefulness, and in our judgment, is often the only rational procedure. In regard to the other alternatives: I. Simple rupture of the membranes is nseful in cases of hydramnios, but carries the following objections: (a) Loss of the physiologic hydrostatic dilator, (b) The opening of an avenue of infection by the transamniotic route, and (c) An uncertainty of action. II. While the bougie, when successful, should be regarded as the :ruQst conservative and ideal means of inducing normal labor, it act::s
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with a striking lack of specificity, and is useful only when the operator can afford to wait or is prepared for failure. III. The cervical pack and larninaria tent carry the same objections, in addition to their insidious potentialities as regards infection. IV. Manual dilatation of the cervix-accouchement force-has practically fallen into disrepute, except in the rare instances in which a soft and almost fully dilated cervix requires only a few turns of the hand to effect its complete effacement. In such circumstances, the rewards of the moment more than compensate for the inevitable trauma and exposure to infection, or when a more temporizing program seems unfair to an exhausted patient. V. Similarly, Duhrssen 's multiple incisions, or even vaginal hysterotomy, are doubtless justified in rare instances; while the BraxtonHicks version may likewise be preferred or even necessitated by the pressure of circumstances. In brief, we find that the hydrostatic bag is applicable- to the greatest number of case types; that it serves well in complications of pregnancy after the fourth month; that it most accurately simulates the physiologic mechanics, and that the maternal and fetal welfare are best insured through its employment. 'l'he bag, hov1rever, in common with most of its competitors, possesses the following inherent disadvantages: (a) Its introduction often forces the presenting part out of the pelvis, and thus converts a potentially spontaneous into an operative labor, frequently necessitating version after the expulsion of the bag. (b) It tends to cause premature rupture of the membranes, with its associated liabilities. (c) The patient requires reasonably close supervision, since, when the membranes are already ruptured, the cord is liable to prolapse following the expulsion of the bag. (d) 'l'he risk of leakage from or of a collapse of the bag is a definite handicap. In order to appraise the true value of the hydrostatic bag, the clinical material of this department has been reviewed from its opening in 1899 up to May 1, 1925. During this. period, 14,822 cases have been discharged from the house service, and the bag has been employed 178 times-the incidence being 1.2 per cent, or once in every 83.3 patients. To obtain ideal statistics it would be necessary to divide the cases into groups, and compare the results in each with those of similar cases treated under the same conditions by other means. This, however, would render the case groups so small that conclusions would hardly be justified. Employing the arbitrary limits of 2500 grams and above for ma-
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turity, 1500 to 2500 grams for prematurity, and below 1500 grams for abortion, the cases may be grouped as follows: Term 92 Premature 50 Abortion 36
This confirms, in brief, our generalization that the bag is applicable to problems arising in all periods of pregnancy, except in the first three months. The indications for the operation fall into four distinct groups: (a) Pathologic aspects of the mechanics of labor; (b) Hemorrhage; (c) Toxemias, and (d) Simple inductions. Whereas several cases present multiple problems, the outstanding one is selected for comparative figures, and secondary considerations are included separately, as follows: C€rvical dystocia Uterine inertia Transverse presentation Missed labor Ruptured uterus
21 16
(b)
Premature separation of placenta Placenta previa centralia Placenta previa partialis Placenta previa marginalis
15 8 21 31
(c)
Preeclamptic toxemia Eclampsia Nephritic toxemia
9 19
(d)
Induction of labor Induction of abortion
15 7
(a)
4
2 1
9
44
75
37 22 178
.Added factors affecting the decision to treat patients in this manner are as follows : Premature rupture of the membranes 34 Failure of bougie 26 Intrapartum infection 25 Prolonged labor 19 Prolapsed cord 8 6 Failure of oil and quinine 5 Failure of "pituitary" induction Cardiac disease 4 Shock 2 Chorea, contraction ring, diabetes, hy· dramnios, pyelitis--each 1
In this series, considerations of the bony pelvis are of relatively slight importance in indicating the use of the bag; for we reject on principle the induction of premature labor on account of contracted pelvis. It might be added that, in this series, the incidence of pelvic
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contraction, contrasted with correspondingly low incidence of pelvic dystocia, serve:> to show that it should be regarded merely as an accidental complication. TABLE
I
TYPE OF PELVIS
OOOURRENCE
DYSTOCIA
contracted Ge11en\lly contracted funnel Gel1er1tlly contracted rach. :funnel Flat, simple Flat, rachitic Funnel, simple
II
0
...
.:>
0 1 11
49
Table I shows that, while 27.5 per cent of the 178 patients presented contracted pelves, yet only in 6.2 per cent 'vere signs of pelvic dystocia apparent. Analyses of the clinical course in each instance of dilatation with the bag are here appended. For greater clarity of interpretation the cases are rlivided into (a) Term, (b) Premature, and (c) Abortion. ABORTION
TERM
I.
1. 2. 3. 4. IL 5. 6. III. 7. 8. 9. 10. 11. 12. IV. 13. 14. 15. 16. 17.
(92) (36) (50) Average time of expulsion 7 h. 38m. 6 h. 18m. 8 h. 49 m. Spontaneous delivery 32 25 22 2[) Version 15 9 ., Braxton-Hicks version 1 " Bag failures 13 5 8 () .; Manual dilatation (following failure of bag) 9 Forceps 10 0 " }.j Breeeh extraction 4 1 0 Craniotomy 9 2 Cervical repair 5 1 0 Manual removal of placenta 5 1 7 R Ts.mponade of uterus 0 0 Prolapsed cord 11 0 0 Contraction ring 0 1 0 Third degree laceration :l 0 0 Vaginal hysterotomy 0 0 1 Subsequent hysterectomy 0 1 1
..
The accompanying chart shows the percentage frequency of the mor.e important features, and the figures warrant the following comments: (a) The likelihood of spontaneous delivery following the expulsion of the bag, varies inversely with the size and development of the fetus. (b) Version is the operation most frequently employed to effect final delivery, and its incidence is practically the same at all periods of pregnancy. (c) Manual dilatation of the cervix, as an adjunct, is most frequently necessitated in early pregnancy, doubtless due to the relative insufficiency of the uterine musculature in expelling the bag.
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319
(d) The incidence of minor operative interference is not appreci· ably increased. (e) The small number of primary cervical repairs suggests that the maternal soft tissues are not unduly traumatized by the procedure. (f) The average time of expulsion is within limits of reasonable promptness on the one hand, and of conservative expectancy on the · other, as compared with the results of accouchement force. A consideration of the effect upon the cervix is next presented, and although the factor of multiparity and previous local trauma confuses the picture, it appears, at least, that the conditions compare favorably with those found subsequent to spontaneous delivery.
Chart I.
No tear Slight bilateral Slight stellate Moderate bilateral Moderate stellate Deep bilateral Deep stellate Not recorded
28 29 31 18 21 17 4
30 178
The puerperium in our patients shows the following morbidity figures: PUERPERAL INFECTiON
Culture not taken Saprophytes Mixed culture Str.eptoooccus <.,"'ulture negative B. coli Gonoooccus Peritonitis
17 11 7 4 4 3
2 3
Phlebitis Septicemia Pyelitis Mastitis Pneumonia Bronchitis Measles Operative reaction
1 1
3
1 1
1 1 2
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In other words, a Gross morlJidity of Maternal deaths attributable to infPetiotl Maternal mortality (infection)
1.7%
The total maternal mortality for the series is 10, or 5.62 per cent, wit.h the causes of death distributed as follO\\'S: 1. 2. 3. 4.
Hemorrhage Infootion Shock Toxemia
3
....,
,,2 10
Of these cases, five were admitted in extremis from outside sources, so that the corrected mortality, which we consider fairly attributable to the treatment, rather than to the underlying pathology, is 5, or 2.81 per cent. When it is recalled that the gross maternal mortality for all types of cases runs about 0.8 per cent per annum, and that the cases under discussion often represent the most serious surgical risks, we are inclined to look upon this figure as reasonably small. Brief summaries of the fatal cases are appended: NoTE: Cases eliminated in corrected mortality are Nos. IV, VI, VII, VIII, and X. I. Para vi. Nephritic toxemia without convulsions. Prc~,Dature rupture of membranes. Eight em. bag. Bag ruptured after three hours. Transverse pre6entation. Manual dilatation of cervix. V~>rsion. Postpartum hemorrhage 1200 e.c. Uterine atony. Child alive, normal. Weight 2030 grams. Patient died. of shock. (12058) II. Para v. Nephritic toxemia without convulsions. .Attempted in·duction of labor by 8 em. bag. In.effootual. Secondary development of premature separation of the placenta, with concealed and external hemorrhage. Cesarean section with hysterectomy. Died first day (hemorrhage). Child, stillborn. Weight 1470 grams. (J1626) III. Para m. Intrapartum infection. Premature rupture of membranes, twenty hours standing. Ten em. bag, expelled in seven hours. Spontaneous delivery. Child stillborn, cord pressure ( 1). Weight 3400 grams. Puerperium febrile. Uterine culture, saprophytes. Placenta, inflammation amnion and chorion. Died; puerperal infection with thrombophlebitis. (11543) IV. Para iii. Placenta previa marginalis. Excessh·e hemorrhage. prior to admission. Ten em. bag, expelled in two hours. Immediate version. Child stillborn, excessive size. Weight 4500 grams. Died, hemorrhage. ( H.302) V. Para i. Pr.entature rupture of membranes. Prolonged labor. Intrapartum infection. Ten em. bag, removed at 7 em. cervical dilatation (fetal asphyxia). Manual dilatation of cervix. Version. Craniotomy on after-coming head. Weight il940 grams. Pelvis normal. Puerperium febrile. Pt>ritonitis. Septicemia. (B. coli). Dioo. (11199) VI. Para i. Eclampsia. Died undelivered. Bag in situ two hourR. Child died in utero. Development, eight months. (8797) VII. Para iii. Referred from midwife. Tentative diagnosis, placenta previa. Ten em. bag applied, and removed in four hours. (Impending ahock). Reexe.mina· tion showed ruptured uterus. Version and extracthm throngh rent in uterus. Tamp·
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DILATATION OF THE CERVIX UTERI
!made. Child stillborn, macerated. Weight 4610 grams. Patient died ninth day, peritonitis. (2810) VIII. Para i. Referred from outside physician. Intractable vomiting. Possible intestinal obstruction. Induction by bag. Bag collapsed in ten hours. Manual dilatation of cervix. Version. Child stillborn. Weight 3330 grams. Patient died first day. Shock, intestinal obstruction, phlebitis. Patient, a morphine habituee. (1499) IX. Para i. Eclampsia. Bag collapsed in six hours. Manual dilatation of wrvix. Version. Manual removal of placenta. Stillborn abortion. Patient ·died on the e'eventh day. Septicemia and pyemia. (576) X. Para iii. Placenta previa centralis. Patient in extr<'mis on admission. Three hemorrhages at home. Bag expelled in three hours. Immediate version. Child stillhorn. Weight 3025 grams. Patient died (hemorrhage). ( 13838)
'fable II gives the data concerning the fetal mortality: TABLE
2. 3. 4. II. 5. 6. III. 7. 8. 9. 10. IV. 11. 12. 13. v. 14,
Placenta previa partialis Placenta previa marginalia Premature separation plac-enta Eclampsia Nephritic toxemia Prolapsed cord Compressed cord Birth injury Hydroc-ephalus Inevitable abortion Missed labor Syphilis Fetal death during labor (cause unknown) 15. Maternal death in labor group Percentage deaths in each group Macerated mortality
II
4 9 2 5 3 7 2 6
8 4 3 2 5 0 0 0 0 0 2 1
2
0 2 3
4 0 53 57.6% 9
3
5
8
2 7 0 0 0 0 8 0 0
2 1 60% 10
''macerated' '
0 0 34 94.4:% 11
=
It is conceivable that such a net mortality could be fmther reduced by the eliminatio1;1 of fetal deaths quite obviously unrelated to the treatment under discussion, but solely eliminating the instances of macerated infants where death clearly occurred prior to the onset of labor, the figures justify the following observations: (a) The physiologic inverse proportion between fetal mortality risk and the degree of maturity is everywhere evident. This is here demonstrable in lesions peculiar to all periods of pregnancy, such as chronic nephritis. (b) However, the increased number of lesions characteristic of a mature pregnancy (placenta previa, syphilitic deaths, birth injuries) increases the relative mortality for the term cases.
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THE AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY
(c) The survival of two u abortions" merely indicates that the weights were at or about 1500 grams, falling virtually in the premature group. '!'ABLE
2. 3. 4. 5. 6. 7.
III
Placenta previa partialis Placenta previa marginalis Premature separation of placenta , Nephritic toxemia (incl. preeclamptic)! Eclampsia Total remaining cases-inductions accidents of labor
12
7
7
66.6 50. 71.4 38.1 100.
56
32
57.2
18
26 7 21
13
5 8
It then follows that: (a) The extremes of success from the fetal standpoint fall within the toxemic group, with the best results in the nephritic class, and the poorest among the eclamptics. (b) The hemorrhagic lesions show an average fetal mortality of about 75 per cent, varying, in the cases of placenta previa, with the extent of the lesion. (c) The fetal mortality figures for the other complications of labor are comparable to the degrees of surgical risk which these cases ordinarily involve. In 1906, Dr. Williams reported to the American Gynecological Society the results of accouchement force among the first 5000 cases admitted to this clinic. Because that period probably represents the era in which that operation attained its highest degree of technical perfection, and since that time the clinical problems have been attacked under the same general supervision, a few comparative statistics might rightly be presented. Whereas the 1906 series included only 15 instances of balloon dilatation, accouchement force was employed 83 times. It was then found quite conclusively that manual dilatation by the Harris method could be unreservedly advised only under the following special conditions: (a) When the cervical canal was obliterated and the external os partially dilated and easily dilatable; (b) when it was executed with great care by an experienced operator; and (c) when placenta previa could be definitely ruled out. These limitations still hold after twenty added years of experience. A detailed analogy between these two series of cases is impossible, because of the frequent employment of accouchement force in eclampsia in past years-a procedure long since abandoned in this clinic. At the same time, it can be stated that eighty-three cases of accouchement force terminated in thirteen deaths (15.7 per cent), of which four were attributable to the operation (4.82 per cent), practical1y each group of indications offering at least one instance of
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uterine rupture, complete or otherwise. Graphic comparison with the more conservative treatment under discussion is as follows: CORRECTED MORTALITY
UNOORRECTED MORTALITY
Accouchement forc6 Balloon
4.82o/o 2.81 o/o
15.70% 5.62%
The effect upon the cervix in the cases dilated manually is compared with the results of hydrostatic dilatation in Table IV: TABLE
NO TEAR
Accouchement foroo Balloon
SLIGHT
38 (45.8%) 12 (14.5%)
IV MODERATE
--
DEEP
PRIMARY REPAIR
19 (22.9%) 14 (16.8%)
28 (17.2%) 60 (38.9%) 39 (25.5%) 21 (13.8%)
6 ( 4.6%)
Interpretations of corrected mortality, as well as the extent of cervical lesions, are variable with the individual, and in a series of cases extending over so long a period, the opinions of many observers are included. For this reason, the figures may be misleading in certain instances; but the present statistical study would seem to indicate that, although the ideal mechanism for artificial cervical dilatation has not been found, the conservative policy of later years has materially improved the results obtained.