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The use of the vacuum extractor in a Nigerian hospital
ht. J. Gynaecol Obstet., 1982,20: 29-33 International Federation of Gynaecology & Obstetrics
THE USE OF THE VACUUM EXTRACTOR IN A NIGERIAN HOSPITAL
E.E. OKPERE and A.I. ITABOR Department of Obstetricsand Gynaecology, Universityof Benin Teaching Hospital, Benin City, Nigeria (Received January 26th, 1981) (Accepted April 2nd, 1981)
Abstract Okpere EE, Itabor AI(Dept of Obstetrics and Gynaecology, University of Benin Teaching Hospital, Benin City, Nigeria). The use of the vacuum extractor in a Nigerian hospital. Int J Gynaecol Obstet 20: 29-33, 1982 The use of the vacuum extractor over a j-year period is reviewed. The instrument was used on 319 occasions, with a 2.8% failure rate and a 25 per thousand corrected perinatal mortality. The maternal morbidity attributable to the use of the instrument was low. The main indications for use were to expedite labor either in the first or second stage because of maternal or fetal distress, and in the rotation and subsequent delivery of the malpositioned vertex. It was found to be particularly useful for the platypellic pelvis with an android tendency, a type rather common in Nigerian parturients.
Key words: Vacuum extractor; Maternal morbidity; Maternal stress; Fetal stress; Malpositioned vertex; Platypellic pelvis with android tendency; Antenatal course; Ventouse Introduction It was perhaps Hildanus [9] who first employed the vacuum principle in surgery when he treated depressed fractures of the skull in infants with a leather sucker. Half a century later came the first suggestion of the use of a cupping glass to assist delivery when OOZ-7292/82/0000-0000/$02.75 0 1982 International Federation of Gynaecology & Obstetrics
James Yonge [ 161 tried unsuccessfully to deliver a baby with a cupping glass fixed to the scalp with an air pump. The modem era of vacuum: extraction operative delivery began with the introduction in 1954 of Malmstrom’s mushroomshaped cup whose inside circumference was wider than that presenting to the fetal scalp, thereby holding within the cup a “chignon” of edematous scalp tissue upon which traction forces could act without easily dislodging the instrument. This instrument became so popular in Scandinavia, the Eastern European countries and Russia that Ghosh and Raad [7] reported that the instrument had progressively replaced the forceps in their unit. In the United States, however, its use was not widespread largely because of reports like those of Aguero and Alvarez [ 11 of Venezuela that called attention to cases of severe fetal scalp lesions occurring in vacuum extraction deliveries. The use of the vacuum extraction in the African setting was highly recommended by Hassim and Lucas [ 8 3, who indicated that the main advantages of the vacuum over the forceps are even more significant in the contracted African pelvis when the obstetrician is faced with the alternatives of a difficult manual rotation or application of Kielland’s forceps. Since the establishment of the University of Benin Teaching Hospital in 1973, the vacuum extraction has been used there extensively. The forceps is now reserved almost exclusively for the delivery of preInt J Gynaecd Obstet 20
30
Okpere and Itabor
mature babies and the aftercoming head. Such wide use of the instrument stimulated a review of vacuum deliveries in the Department of Obstetrics, University of Benin Teaching Hospital, between July 1, 1975, and June 30, 1980. Our results are discussed v&a-vis similar studies in other centers. Materials and methods The maternity records of all patients who delivered during that period were examined. The case notes of all patients and babies who had a vacuum extraction were studied in detail. Areas of interest in the study included the antenatal course; labor and mode of delivery; operative and postoperative complications; perinatal morbidity and mortality; and maternal morbidity and mortality. Results During this period, 13,376 patients delivered at the University of Benin Teaching Hospital. The ventouse was used on 319 occasions (2.4%). There were nine failures (2.8%). Of the failed extractions, five were delivered by forceps and four by cesarean Table I.
Indications for vacuum extraction in 3 19 cases,
Indication Positional problem Occipito-posterior and occipito-lateral Fetal distress Hypertensive disorders in pregnancy Pre-eclampsia (30) Eclampsia (1) Hypertension (2 1) Poor maternal effort Cervical dystocia Uterine inertia Abruptio placentae Placenta praevia 1 degree Intrauterine deaths/fresh still births Sickle cell disease Cord prolapse Pulmonary tuberculosis (previous lobactomy) Cardiac disease Delayed second twin
Int J Gynaecol Obstet 20
No.
114 80 51
31 10 10 4 1 10 2 2 1 1 2
Tabb II. Vacuum extraction in the first stage of labor for 110 cases. Cervical dilatation (cm)
No.
%
6 I 8 9
2 24 54 30
1.8 21.8 49.1 21.3
sections. Among the 3 19 mothers, 137 (43%) were primiparas and 182 (57%) were multiparas. Fifty-four or 16.9% of the sample were grand multiparas (>para 5). General anesthesia was found necessary in only five cases. In 2 10 cases, pudendal block was used and local infilteration was adequate in 52 cases. No anesthetic was used in 57 cases. The indications for use of the ventouse in this series are shown in Table I. In 110 cases (340/o), the instrument was applied during the first stage of labor (Table II). Most applications before full cervical dilatation were for Table III.
Fetal results.
Morbidity
No.
Scalp abrasion Jaundice (serum bilirubin, 7.10 mg/lOO ml)
13
4
3 (all had exchange blood transfusion) 3 (all transfused) 70 (see Table IV)
1.9
Anemia Asphyxia Hypoglycemia Cephalohematoma Subaponeurotic hemorrhage Hemorrhagic disease Total Mortality Intrauterine deaths (No fetal tones before onset of vacuum extraction) Fresh stillbirths Neonatal deaths Total
.1
2 2 1 95
6
2 6 14
%
1.9 21.9 0.3 0.6 0.6 0.3 29.8%
Vacuum extraction Table VI. series.
Oneminute
Apgar score for 3 19 deliveries in our
Score
Description
No.
0
Stillbirths Severe asphyxia Moderate asphyxia Good
8 20 50 241
1-3 4-5 26
fetal distress and/or maternal distress. There was no maternal mortality. Three patients had cervical tears, and six had vaginal wall lacerations that were easily repaired. There was 14 cases of puerperal pyrexia; six were a result of urinary tract infections and eight were from genital sepsis. Episiotomies were performed in 160 cases. Eighteen patients (5.6%) had primary postpartum hemorrhage; eight of them required blood transfusion. There were two cases of retained placenta. The fetal results are shown in Tables III and IV. Abrasions of the skin about the rim of application site occurred in 13 cases. These healed readily without visible scar or alopecia. There were two cases of cephalohematoma and two cases of subaponeurotic hemorrhages. There were 14 perinatal deaths (including six intrauterine deaths). The corrected perinatal mortality was, therefore, 25 per thousand (8 of 319). Discussion Our results show that acceptable fetal results may be obtained by the judicious use of the vacuum extractor. Several factors make a forceps delivery a hazardous procedure in the African obstetric environment. These include the lack of proper obstetric training; the high number of unbooked patients presenting after a prolonged labor at home with resultant obliteration of the fetal land marks; and the not uncommon pelvis with an android tendency found in Africans [ 81. The vacuum extractor is, therefore, ideal for the African setting and, given the same level of competence, it should bring consistently
31
better maternal and fetal results than forceps delivery. In this series, the vacuum was applied 114 times (37.7%) for position problems, either occipito-posterior or occipito-lateral. It was successful in all cases. Hassim and Lucas [ 81 had two failures using the vacuum as a rotator in 37 cases. Contrary to Malmstrom [ 121, active rotation is accepted as unnecessary. The head should be allowed to chose its own what Evelbauer [ 61 course, undergoing a movement that termed “autorotation”, would be prevented if forceps were used. Occasionally, rotation does not take place and the head is born “face to pubis”. This occurred 15 times in our series. One may assume that the pelvis in such a situation is probably suited to an occipito-posterior delivery. The usual protection to the perinium aided by a generous episiotomy would, therefore, be mandatory. An outstanding advantage of the ventouse is its use in the first stage of labor. In this series, the vacuum extractor was applied 109 times in the first stage. In all but one case (subsequently delivered by cesarean section), the babies were delivered vaginally ; a success rate of 99%. The maximum time of application was 25 min. There was one case of cervical laceration measuring 2 cm. Bleeding was minimal, and it was easily repaired. Lillie [ 111 also found trauma to the cervix to be minimal. Chukwudebelu [ 51, working at Enugu (an environment similar to Benin), in a series of 500 vacuum extractions applied the cup 104 times (20.8%) in the first stage of labor with a success rate of 96%. He emphasized the importance of proper technique if failures are to be minimized. Controlled and steady traction during and between contractions (with short periods of relaxation) should be maintained until the cervix becomes fully dilated. Thereafter, traction should be synchronous with uterine contractions. Fetal distress is no contraindication to the use of the vacuum extractor. In well selected cases, delivery by a vacuum extractor would Int J Gynaecol Obstet 20
32
Okpere and Itabor
be consistently quicker than an emergency cesarean section with its associated maternal morbidity and mortality risks. The effects of negative pressure on the skull of an already compromised fetus is difficult to assess, as is the theory that the resultant vagal stimulation might worsen an already present bradycardia. In this series, the vacuum was used on 80 occasions because of fetal distress either in the first or second stages of labor with generally good results. There was, however, a stillbirth who had loops of cord coiled tightly round its neck. Presumably, fetal asphyxia here worsened with descent of the head and tightening of the umbilical noose. Proper selection of cases for vacuum extraction, especially for fetal distress in the first stage, is therefore important. The head must be deeply engaged, and the cervix, which must be at least 7 cm dilated, should be thin and well applied to the presenting part. With experience one can always gauge the amount of negative pressure required; the establishment of a chignon is not always imperative. Some edematous scalp lesions seem unavoidable if any suction extraction instrument is used. The objective must be to minimize serious hemorrhagic scalp lesions. Abrassive and ecchymotic lesions can be reduced by keeping negative suction to a maximum of 0.7/kg cm*, shortening the time of cup application to a maximum of 20 min and avoiding “pull offs” of the suction cup. Personal bias comes in, in a comparative study of our soft-injury cases with other series. As emphasized by Plauche [ 151, most scalp lesions labelled cephalohematoma are really subcutaneous ecchymosis that are more diffuse, not always sharply limited by sutures and are reabsorbed much more readily than He described classic cephalohematoma. cephalohematoma as the result of rupture of a dipioic or emissary vein. They, therefore, accumulate and are confined beneath the periosteum of a single cranial bone by tight periosteal attachments. Subaponeurotic hemorrhages, on the In t J Gynaecol Obstet 20
other hand, occur when the emissary veins are ruptured beneath the gales aponeurotics; it may, therefore, dissect across the cranial vault, elevating a portion or all of the scalp. It may thus be massive and life-threatening, as in one case in our series that required a blood transfusion. Compared to other series, our 0.6% incidence of cephalohematoma is quite low. In an extensive literature review of 8 108 cases, Plauche [ 151 found a mean incidence of 6%. The 0.6% incidence of subaponeurotic hemorrhages compares favorably with Lange [ 10 1 and Malmstrom and Jansson [ 131, who found an incidence of 0.32% and 0.38%, respectively. Other fatal complications attributable to the use of the vacuum extractor (intracranial bleeding and coagulopathies) were fortunately not found in this series. Our corrected perinatal mortality figure of 2.5% compares favorably with Chukwudebelu [S] and Okoisor and Coker [ 141, who reported 4.8% and 2.8%, respectively, but is higher than the 0.7% reported by Chalmers [3] and the 0.5% reported by Chalmers and Prakash 141. The vacuum extractor should be available in all peripheral hospitals in Africa. Basic training in its use, even by midwives, can give acceptable results. The risks to baby and mother can be easily minimized by adhering strictly to the basic procedure. We advise that if more than one fifth of the head is palpable per abdomen, a more senior medical personnel should be called in. Our results at Benin are a sequalae of good supervision in the use of this instrument. Uncommonly, we have failed either as a result of instrument fault or poor patient selection, we have learned by our mistakes in these instances. References 1 Aguero 0, Alvarez H: Fetal injury due to vacuum extiaction. Obstet Gynecol19: 212,1962. 2 Brat T: Indications for and results of the use of the
Vacuum extraction
3 4
5 6 7 8
9 10
ventous ostetricale (a ten year study). J Obstet Gynaecol Br Commonw 72: 883,196s. Chalmers JA: The vacuum extractor in difficult delivery. J Obstet Gynaecol Br Commonw 72: 889,196s. Chalmers JA, Prakash A: Vacuum extraction initiated during the first stage of labour. J Obstet Gynaecol Br Commonw 78: 554,197l. Chukwudebelu WO: Vacuum extraction before full cervical dilatation. Int Surg 63: 89,1978. Evelbauer K: Experience with the use of the vacuum extractor. Geburtshilfe Frauenheilkd 16: 223, 1956. Ghosn G, Raad J: Le vacuum extractor dans la partique obstetricalle. Rev Fr Gynaecol.54: 4, 1964. Has& AM, Lucas C: The place of the ‘Ventouse’ in developing Africa. J Obstet Gynaecol Br Commonw 73: 787,1966. Hildamus: Guildhehni Fabricii Hildani. Opera, Frankfurtam-Main, 1632. Lenge P: The vacuum extractor, values in relation to forceps and range of implications. Acta Obstet Gynecol Stand [Suppl] 43: 57, 1964.
33
11 Lillie EW: The use of the vacuum extractor in labour. Jr J Med Sci 439: 309,1962. 12 Malmstrijm T: The vacuum extractor - an obstetrical instrument. Elander Boktrycteri A.B., Gothenburg, 1957. 13 Malmstrom, T, Jansson J: Use of the vacuum extractor. Clin Obstet Gynecol8: 893,196s. 14 Okoisor AT, Coker 00: Five-year review of cases delivered by the vacuum extractor in Lagos University Teaching Hospital. Niger Med J 8: 2,1978. 15 Plauche WC: Fetal cranial injuries related to delivery with the mahnstrom vacuum extractor. Obstet Gynecol 53: 750,1979. 16 Yonge J: Philos Trans R Sot Lond (Biol) 25: 2387,1706.
Address for reprints: E.E. Okpere Dept of Obstetrics and Gynaecology University of Benin Teaching Hospital Benin City, Nigeria
Int J Gynaecol Obstet 20
THE USE OF THE VACUUM EXTRACTOR IN A NIGERIAN HOSPITAL
E.E. OKPERE and A.I. ITABOR Department of Obstetricsand Gynaecology, Universityof Benin Teaching Hospital, Benin City, Nigeria (Received January 26th, 1981) (Accepted April 2nd, 1981)
Abstract Okpere EE, Itabor AI(Dept of Obstetrics and Gynaecology, University of Benin Teaching Hospital, Benin City, Nigeria). The use of the vacuum extractor in a Nigerian hospital. Int J Gynaecol Obstet 20: 29-33, 1982 The use of the vacuum extractor over a j-year period is reviewed. The instrument was used on 319 occasions, with a 2.8% failure rate and a 25 per thousand corrected perinatal mortality. The maternal morbidity attributable to the use of the instrument was low. The main indications for use were to expedite labor either in the first or second stage because of maternal or fetal distress, and in the rotation and subsequent delivery of the malpositioned vertex. It was found to be particularly useful for the platypellic pelvis with an android tendency, a type rather common in Nigerian parturients.
Key words: Vacuum extractor; Maternal morbidity; Maternal stress; Fetal stress; Malpositioned vertex; Platypellic pelvis with android tendency; Antenatal course; Ventouse Introduction It was perhaps Hildanus [9] who first employed the vacuum principle in surgery when he treated depressed fractures of the skull in infants with a leather sucker. Half a century later came the first suggestion of the use of a cupping glass to assist delivery when OOZ-7292/82/0000-0000/$02.75 0 1982 International Federation of Gynaecology & Obstetrics
James Yonge [ 161 tried unsuccessfully to deliver a baby with a cupping glass fixed to the scalp with an air pump. The modem era of vacuum: extraction operative delivery began with the introduction in 1954 of Malmstrom’s mushroomshaped cup whose inside circumference was wider than that presenting to the fetal scalp, thereby holding within the cup a “chignon” of edematous scalp tissue upon which traction forces could act without easily dislodging the instrument. This instrument became so popular in Scandinavia, the Eastern European countries and Russia that Ghosh and Raad [7] reported that the instrument had progressively replaced the forceps in their unit. In the United States, however, its use was not widespread largely because of reports like those of Aguero and Alvarez [ 11 of Venezuela that called attention to cases of severe fetal scalp lesions occurring in vacuum extraction deliveries. The use of the vacuum extraction in the African setting was highly recommended by Hassim and Lucas [ 8 3, who indicated that the main advantages of the vacuum over the forceps are even more significant in the contracted African pelvis when the obstetrician is faced with the alternatives of a difficult manual rotation or application of Kielland’s forceps. Since the establishment of the University of Benin Teaching Hospital in 1973, the vacuum extraction has been used there extensively. The forceps is now reserved almost exclusively for the delivery of preInt J Gynaecd Obstet 20
30
Okpere and Itabor
mature babies and the aftercoming head. Such wide use of the instrument stimulated a review of vacuum deliveries in the Department of Obstetrics, University of Benin Teaching Hospital, between July 1, 1975, and June 30, 1980. Our results are discussed v&a-vis similar studies in other centers. Materials and methods The maternity records of all patients who delivered during that period were examined. The case notes of all patients and babies who had a vacuum extraction were studied in detail. Areas of interest in the study included the antenatal course; labor and mode of delivery; operative and postoperative complications; perinatal morbidity and mortality; and maternal morbidity and mortality. Results During this period, 13,376 patients delivered at the University of Benin Teaching Hospital. The ventouse was used on 319 occasions (2.4%). There were nine failures (2.8%). Of the failed extractions, five were delivered by forceps and four by cesarean Table I.
Indications for vacuum extraction in 3 19 cases,
Indication Positional problem Occipito-posterior and occipito-lateral Fetal distress Hypertensive disorders in pregnancy Pre-eclampsia (30) Eclampsia (1) Hypertension (2 1) Poor maternal effort Cervical dystocia Uterine inertia Abruptio placentae Placenta praevia 1 degree Intrauterine deaths/fresh still births Sickle cell disease Cord prolapse Pulmonary tuberculosis (previous lobactomy) Cardiac disease Delayed second twin
Int J Gynaecol Obstet 20
No.
114 80 51
31 10 10 4 1 10 2 2 1 1 2
Tabb II. Vacuum extraction in the first stage of labor for 110 cases. Cervical dilatation (cm)
No.
%
6 I 8 9
2 24 54 30
1.8 21.8 49.1 21.3
sections. Among the 3 19 mothers, 137 (43%) were primiparas and 182 (57%) were multiparas. Fifty-four or 16.9% of the sample were grand multiparas (>para 5). General anesthesia was found necessary in only five cases. In 2 10 cases, pudendal block was used and local infilteration was adequate in 52 cases. No anesthetic was used in 57 cases. The indications for use of the ventouse in this series are shown in Table I. In 110 cases (340/o), the instrument was applied during the first stage of labor (Table II). Most applications before full cervical dilatation were for Table III.
Fetal results.
Morbidity
No.
Scalp abrasion Jaundice (serum bilirubin, 7.10 mg/lOO ml)
13
4
3 (all had exchange blood transfusion) 3 (all transfused) 70 (see Table IV)
1.9
Anemia Asphyxia Hypoglycemia Cephalohematoma Subaponeurotic hemorrhage Hemorrhagic disease Total Mortality Intrauterine deaths (No fetal tones before onset of vacuum extraction) Fresh stillbirths Neonatal deaths Total
.1
2 2 1 95
6
2 6 14
%
1.9 21.9 0.3 0.6 0.6 0.3 29.8%
Vacuum extraction Table VI. series.
Oneminute
Apgar score for 3 19 deliveries in our
Score
Description
No.
0
Stillbirths Severe asphyxia Moderate asphyxia Good
8 20 50 241
1-3 4-5 26
fetal distress and/or maternal distress. There was no maternal mortality. Three patients had cervical tears, and six had vaginal wall lacerations that were easily repaired. There was 14 cases of puerperal pyrexia; six were a result of urinary tract infections and eight were from genital sepsis. Episiotomies were performed in 160 cases. Eighteen patients (5.6%) had primary postpartum hemorrhage; eight of them required blood transfusion. There were two cases of retained placenta. The fetal results are shown in Tables III and IV. Abrasions of the skin about the rim of application site occurred in 13 cases. These healed readily without visible scar or alopecia. There were two cases of cephalohematoma and two cases of subaponeurotic hemorrhages. There were 14 perinatal deaths (including six intrauterine deaths). The corrected perinatal mortality was, therefore, 25 per thousand (8 of 319). Discussion Our results show that acceptable fetal results may be obtained by the judicious use of the vacuum extractor. Several factors make a forceps delivery a hazardous procedure in the African obstetric environment. These include the lack of proper obstetric training; the high number of unbooked patients presenting after a prolonged labor at home with resultant obliteration of the fetal land marks; and the not uncommon pelvis with an android tendency found in Africans [ 81. The vacuum extractor is, therefore, ideal for the African setting and, given the same level of competence, it should bring consistently
31
better maternal and fetal results than forceps delivery. In this series, the vacuum was applied 114 times (37.7%) for position problems, either occipito-posterior or occipito-lateral. It was successful in all cases. Hassim and Lucas [ 81 had two failures using the vacuum as a rotator in 37 cases. Contrary to Malmstrom [ 121, active rotation is accepted as unnecessary. The head should be allowed to chose its own what Evelbauer [ 61 course, undergoing a movement that termed “autorotation”, would be prevented if forceps were used. Occasionally, rotation does not take place and the head is born “face to pubis”. This occurred 15 times in our series. One may assume that the pelvis in such a situation is probably suited to an occipito-posterior delivery. The usual protection to the perinium aided by a generous episiotomy would, therefore, be mandatory. An outstanding advantage of the ventouse is its use in the first stage of labor. In this series, the vacuum extractor was applied 109 times in the first stage. In all but one case (subsequently delivered by cesarean section), the babies were delivered vaginally ; a success rate of 99%. The maximum time of application was 25 min. There was one case of cervical laceration measuring 2 cm. Bleeding was minimal, and it was easily repaired. Lillie [ 111 also found trauma to the cervix to be minimal. Chukwudebelu [ 51, working at Enugu (an environment similar to Benin), in a series of 500 vacuum extractions applied the cup 104 times (20.8%) in the first stage of labor with a success rate of 96%. He emphasized the importance of proper technique if failures are to be minimized. Controlled and steady traction during and between contractions (with short periods of relaxation) should be maintained until the cervix becomes fully dilated. Thereafter, traction should be synchronous with uterine contractions. Fetal distress is no contraindication to the use of the vacuum extractor. In well selected cases, delivery by a vacuum extractor would Int J Gynaecol Obstet 20
32
Okpere and Itabor
be consistently quicker than an emergency cesarean section with its associated maternal morbidity and mortality risks. The effects of negative pressure on the skull of an already compromised fetus is difficult to assess, as is the theory that the resultant vagal stimulation might worsen an already present bradycardia. In this series, the vacuum was used on 80 occasions because of fetal distress either in the first or second stages of labor with generally good results. There was, however, a stillbirth who had loops of cord coiled tightly round its neck. Presumably, fetal asphyxia here worsened with descent of the head and tightening of the umbilical noose. Proper selection of cases for vacuum extraction, especially for fetal distress in the first stage, is therefore important. The head must be deeply engaged, and the cervix, which must be at least 7 cm dilated, should be thin and well applied to the presenting part. With experience one can always gauge the amount of negative pressure required; the establishment of a chignon is not always imperative. Some edematous scalp lesions seem unavoidable if any suction extraction instrument is used. The objective must be to minimize serious hemorrhagic scalp lesions. Abrassive and ecchymotic lesions can be reduced by keeping negative suction to a maximum of 0.7/kg cm*, shortening the time of cup application to a maximum of 20 min and avoiding “pull offs” of the suction cup. Personal bias comes in, in a comparative study of our soft-injury cases with other series. As emphasized by Plauche [ 151, most scalp lesions labelled cephalohematoma are really subcutaneous ecchymosis that are more diffuse, not always sharply limited by sutures and are reabsorbed much more readily than He described classic cephalohematoma. cephalohematoma as the result of rupture of a dipioic or emissary vein. They, therefore, accumulate and are confined beneath the periosteum of a single cranial bone by tight periosteal attachments. Subaponeurotic hemorrhages, on the In t J Gynaecol Obstet 20
other hand, occur when the emissary veins are ruptured beneath the gales aponeurotics; it may, therefore, dissect across the cranial vault, elevating a portion or all of the scalp. It may thus be massive and life-threatening, as in one case in our series that required a blood transfusion. Compared to other series, our 0.6% incidence of cephalohematoma is quite low. In an extensive literature review of 8 108 cases, Plauche [ 151 found a mean incidence of 6%. The 0.6% incidence of subaponeurotic hemorrhages compares favorably with Lange [ 10 1 and Malmstrom and Jansson [ 131, who found an incidence of 0.32% and 0.38%, respectively. Other fatal complications attributable to the use of the vacuum extractor (intracranial bleeding and coagulopathies) were fortunately not found in this series. Our corrected perinatal mortality figure of 2.5% compares favorably with Chukwudebelu [S] and Okoisor and Coker [ 141, who reported 4.8% and 2.8%, respectively, but is higher than the 0.7% reported by Chalmers [3] and the 0.5% reported by Chalmers and Prakash 141. The vacuum extractor should be available in all peripheral hospitals in Africa. Basic training in its use, even by midwives, can give acceptable results. The risks to baby and mother can be easily minimized by adhering strictly to the basic procedure. We advise that if more than one fifth of the head is palpable per abdomen, a more senior medical personnel should be called in. Our results at Benin are a sequalae of good supervision in the use of this instrument. Uncommonly, we have failed either as a result of instrument fault or poor patient selection, we have learned by our mistakes in these instances. References 1 Aguero 0, Alvarez H: Fetal injury due to vacuum extiaction. Obstet Gynecol19: 212,1962. 2 Brat T: Indications for and results of the use of the
Vacuum extraction
3 4
5 6 7 8
9 10
ventous ostetricale (a ten year study). J Obstet Gynaecol Br Commonw 72: 883,196s. Chalmers JA: The vacuum extractor in difficult delivery. J Obstet Gynaecol Br Commonw 72: 889,196s. Chalmers JA, Prakash A: Vacuum extraction initiated during the first stage of labour. J Obstet Gynaecol Br Commonw 78: 554,197l. Chukwudebelu WO: Vacuum extraction before full cervical dilatation. Int Surg 63: 89,1978. Evelbauer K: Experience with the use of the vacuum extractor. Geburtshilfe Frauenheilkd 16: 223, 1956. Ghosn G, Raad J: Le vacuum extractor dans la partique obstetricalle. Rev Fr Gynaecol.54: 4, 1964. Has& AM, Lucas C: The place of the ‘Ventouse’ in developing Africa. J Obstet Gynaecol Br Commonw 73: 787,1966. Hildamus: Guildhehni Fabricii Hildani. Opera, Frankfurtam-Main, 1632. Lenge P: The vacuum extractor, values in relation to forceps and range of implications. Acta Obstet Gynecol Stand [Suppl] 43: 57, 1964.
33
11 Lillie EW: The use of the vacuum extractor in labour. Jr J Med Sci 439: 309,1962. 12 Malmstrijm T: The vacuum extractor - an obstetrical instrument. Elander Boktrycteri A.B., Gothenburg, 1957. 13 Malmstrom, T, Jansson J: Use of the vacuum extractor. Clin Obstet Gynecol8: 893,196s. 14 Okoisor AT, Coker 00: Five-year review of cases delivered by the vacuum extractor in Lagos University Teaching Hospital. Niger Med J 8: 2,1978. 15 Plauche WC: Fetal cranial injuries related to delivery with the mahnstrom vacuum extractor. Obstet Gynecol 53: 750,1979. 16 Yonge J: Philos Trans R Sot Lond (Biol) 25: 2387,1706.
Address for reprints: E.E. Okpere Dept of Obstetrics and Gynaecology University of Benin Teaching Hospital Benin City, Nigeria
Int J Gynaecol Obstet 20