European Journal of Obstetrics & Gynecology and Reproductiue Biology, 47 (1992) 164-166
164
0 1992 Elsevier Science Publishers
B.V.
All rights reserved 0028-2243/92/$05.00
ELJROBS 01396
Ultrasound diagnosis of interstitial pregnancy C.N. de Boer a, P.W.J. van Dongen a, W.N.P. Willemsen a and C.W.D.A. Klapwijk b aDepartment of Obstetrics and Gynaecology, Universi@ Hospital Nijmegen, Nijmegen, The Netherlands b Department of Obstetrics and Gynaecology, Hospital ‘Gelderse Vallei’, Wageningen, The Netherlands
Accepted for publication 5 June 1992 Summary
A case of interstitial pregnancy is reported. The diagnosis was made by ultrasound examination in an asymptomatic patient at risk for ectopic pregnancy following cornual anastomosis. Characteristic sonographic signs are discussed, with a review of the literature. Interstitial pregnancy; Ultrasound diagnosis; Cornual resection; Tuba1 reimplantation; Ectopic pregnancy
Introduction
Interstitial pregnancy is by definition located in the intramural part of the fallopian tube, i.e., the part of the tube that traverses the uterine wall. It is the least frequent variety of tubal gestation, with an incidence estimated to comprise 2-4% of all ectopic pregnancies [l]. Greater distensibility of the myometrium tends to allow a gestation at this site to advance further before a rupture occurs than at a more lateral tubal location. When rupture occurs, the more advanced gestation and greater vascularity of the comual area usually cause more profuse haemorrhage and greater danger to maternal life in comparison with other tubal pregnancies. Widespread use of ultrasound in modern obstetric care may modify the clinical picture of this condition by early diagnosis before severe complications arise, as illustrated by the following case. Case
report
The patient is a 29-year-old, gravida 2 para 0, with a longstanding history of infertility. In 1971, at age 13,
Correspondence to: Dr. P.W.J. van Dongen, Department of Obstetrics and Gynaecology, University Hospital Nijmegen, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
she underwent an appendectomy for acute appendicitis, followed by a second laparotomy for generalized peritonitis. After failing to conceive for several years, bilateral hydrosalpinges were diagnosed at age 26. Reconstructive surgery was carried out, consisting of extensive pelvic adhesiolysis, partial omentectomy, bilateral salpingostomy and reimplantation of the left tube. Subsequent hysterosalpingography showed patency of both tubes. A year later the first pregnancy ended in curettage for missed abortion. In 1987 the second pregnancy occurred. Ultrasound examination at 10 weeks’ gestation revealed a gestational sac located in the left comual area containing a live embryo with a crown-rump length of 24 mm, corresponding to 9 gestational weeks. A myometrial layer of 10 mm separated the sac from the thickened endometrium, whereas the covering myometrium measured only 3 mm in thickness (Fig. 1). Diagnostic laparoscopy showed a protuberance of the uterus at the left cornu from which the slender left tube and the round ligament originated, confirming the diagnosis of interstitial pregnancy at the site of the cornual anastomosis. Although the patient was asymptomatic, continuation of this pregnancy was likely to result in rupture of the cornual area, with possibly disastrous consequences for the uterus and future fertility. Elective resection of the affected part was decided upon. At laparotomy the cornual swelling was incised, exposing the sac with embryo. A simple resection of the affected area includ-
165
\\
myometrium ,
\
foetus
chorionic
vi//i
Fig. 1. Oblique ultrasound scan of uteiws with uterine cavity and gestational sac.
ing the left fallopian tube was performed. The uterus was closed in three layers. Subsequently, some filmy adhesions involving the right ovary and tube were severed, resulting in satisfactory ovum pick-up. Postoperative recovery was uneventful. Histology was compatible with the clinical diagnosis; there were no congenital defects; the crown-rump length measured 25 mm, Carnegie Stage 22. Right tubal patency was demonstrated at later hysterosalpingography. The third (spontaneous) pregnancy ended in 1991 with the birth of a healthy boy, by elective caesarean section at 38 weeks. Discussion The most important etiologic factors for interstitial pregnancy are, as for other tubal pregnancies, a history of pelvic inflammatory disease and previous tubal surgery. Three to twenty percent of pregnancies following tubal surgery will be ectopic [2]. After cornual anastomosis this rate is even higher: ll-40% [3]. Cornual resection when performing salpingectomy for tubal pregnancy or for other reasons was advocated in the past as prophylaxis against interstitial pregnancy. This is no longer recommended because it certainly does not always prevent its occurrence and may weaken the myometrium, predisposing to rupture in a subsequent pregnancy and placenta accreta [4,5]. Interstitial pregnancy is a dangerous form of ectopic gestation. Rupture may occur into the peritoneal cav-
ity, into the uterine cavity or into the myometrium depending on the exact implantation site. It leads to rapid and profuse haemorrhage with mortality rates of 2-7%, compared with less than 1% for other tubal pregnancies [ 1,6]. Signs and symptoms are non-specific, resembling those of other tubal pregnancies, though the gestation at the time of rupture tends to be more advanced. At pelvic examination a broad-based palpable mass may be found extending outward from the uterine angle (Baart de la Faille’s sign), or the fundus is displaced to the contralateral side with rotation of the uterus and elevation of the affected cornu (RugeSimon syndrome), but these signs are .by no means constant [7]. In the past, diagnosis was usually made at laparotomy. With the advent of ultrasonography and its routine use in early pregnancy interstitial pregnancy can be detected with accuracy before serious complicaTABLE I Sonographic signs of interstitial
pregnancy
0 empty uterine cavity. l eccentrically placed or very lateral gestational sac. l thin or incomplete myometrial mantle covering the gestational sac. l demonstration of myometrium between sac and uterine cavity. l no gestational sac visible above the level of the internal OS in the longitudinal plane of the uterus.
166 TABLE
2 Lavy G, Diamond MP, DeCherney AH. Ectopic preg-
II
Differential diagnosis of interstitial pregnancy l leiomyomatous uterus distorting normal anatomy. 0 sacculation of the uterus. l more lateral tubal pregnancy. l pregnancy in a rudimentary horn (cornual pregnancy
l l
proper). pregnancy in a septate or otherwise malformed uterus. Piskacek’s sign (temporary asymmetry of the fundus in a normal intra-uterine pregnancy before the 12th week of gestation).
3 4
5
6 7
tions arise. Several
authors
have reported
characteris-
signs, summarized in Table I [8-14). In our case all these signs were present. Differential diagnostic considerations are listed in Table II. An interstitial pregnancy seldom proceeds into the third trimester. Until 1988 no fetal survival was documented, but two casts resulting in live, full term infants have since been reported [15,16]. Cornual resection or, in case of rupture, repair of the laceration would be the treatment of choice. Severe damage or uncontrollable haemorrhage may necessitate hysterectomy. In selected cases conservative surgical management with preservation of tubal patency on the affected side may be feasible [17]. In subsequent prcgnancies there is danger of overt or occult rupture of the previously repaired cornual arca [18]. tic sonographic
Conclusion Routine ultrasonography in early pregnancy may produce signs pointing to a diagnosis of interstitial pregnancy before a possibly catastrophic rupture occurs. Patients with a history of cornual surgcty arc especially at risk. It is likely that early diagnosis will contribute to a better prognosis. References
8
9
10
11
12
13
14
15
16
17
1 Durfee RB. Obstetric complications of pregnancy. In: Pernoll ML, Benson RC, eds. Current Obstetric and Gynecologic Diagnosis and Treatment. Nonvalk, Connecticut/Los Altos, California: Appleton & Lange, 1987;255-278.
18
nancy: its relationship to tubal reconstructive surgery. Fertil Steril 1987;47:543-556. Lavy G, Diamond MP, DeCherney AH. Pregnancy following tubocornual anastomosis. Fertil Steril 1986;46:21-25. Miihlen K, Shortle B. Comual resection as prophylaxis against interstitial pregnancy: is it necessary or dangerous? A review of the literature. Eur J Obstet Gynecol Reprod Biol 1984;17:155-163. Kalchman GG, Meltzer RM. Interstitial pregnancy following homolateral salpingectomy. Am J Obstet Gynecol 1966%1139-l 143. Felmus LB, Pedowitz P. Interstitial pregnancy. A survey of 45 cases. Am J Obstet Gynecol 1953;66:1271-1279. Skulj V, Bunarevic A, Bacic G et al. Interstitial pregnancy. Review of 24 cases. Am J Obstet Gynecol 1964$8:5%-600. Chandra P, Koenigsberg M, Romney SL et al. Unruptured interstitial pregnancy: diagnosis and treatment. Obstet Gynecol 1978;52:612-615. Graham M, Cooperberg PL. Ultrasound diagnosis of interstitial pregnancy: findings and pitfalls. J Clin Ultrasound 1979;7:433-437. Smith HJ, Hanken H, Brundelet PJ. Ultrasound diagnosis of interstitial pregnancy. Acta Obstet Gynecol Stand 1981;60:413-416. Maher PJ, Grimwade JC. Cornual pregnancy - Diagnosis before rupture. A report of 2 cases. Aust NZ J Obstet Gynecol 1982;2:172-174. Auslender R, Arodi J, Pascal B et al. Interstitial pregnancy: Early diagnosis by ultrasonography. Am J Obstet Gynecol 1983;146:717-718. Toady DJ, Snyder JR, Goldstein SR et al. Ultrasound diagnosis of interstitial pregnancy. NY State J Med 1985;5:655-656. Weissman A, Fishman A, Gal D. Interstitial pregnancy: a diagnostic challenge. Int J Gynecol Obstet 1989;29:373375. Rosenxweig BA, Rotmensch S, Ressetar A. Term interstitial pregnancy resulting in a live infant. Obstet Gynecol 1988;72:491-493. Bond AL, Grifo JA, Chevernak FA et al. Term interstitial pregnancy with uterine torsion: sonographic, pathologic and clinical findings. Obstet Gynecol 1989;73:857-859. Confino E, Gleicher N. Conservative management of interstitial pregnancy. Fertil Steril 1989;52:60&603. Malfetano, JH: Occult rupture of uterus following ruptured interstitial pregnancy, Am J Obstet Gynecol 70:1361, 1955.
164
0 1992 Elsevier Science Publishers
B.V.
All rights reserved 0028-2243/92/$05.00
ELJROBS 01396
Ultrasound diagnosis of interstitial pregnancy C.N. de Boer a, P.W.J. van Dongen a, W.N.P. Willemsen a and C.W.D.A. Klapwijk b aDepartment of Obstetrics and Gynaecology, Universi@ Hospital Nijmegen, Nijmegen, The Netherlands b Department of Obstetrics and Gynaecology, Hospital ‘Gelderse Vallei’, Wageningen, The Netherlands
Accepted for publication 5 June 1992 Summary
A case of interstitial pregnancy is reported. The diagnosis was made by ultrasound examination in an asymptomatic patient at risk for ectopic pregnancy following cornual anastomosis. Characteristic sonographic signs are discussed, with a review of the literature. Interstitial pregnancy; Ultrasound diagnosis; Cornual resection; Tuba1 reimplantation; Ectopic pregnancy
Introduction
Interstitial pregnancy is by definition located in the intramural part of the fallopian tube, i.e., the part of the tube that traverses the uterine wall. It is the least frequent variety of tubal gestation, with an incidence estimated to comprise 2-4% of all ectopic pregnancies [l]. Greater distensibility of the myometrium tends to allow a gestation at this site to advance further before a rupture occurs than at a more lateral tubal location. When rupture occurs, the more advanced gestation and greater vascularity of the comual area usually cause more profuse haemorrhage and greater danger to maternal life in comparison with other tubal pregnancies. Widespread use of ultrasound in modern obstetric care may modify the clinical picture of this condition by early diagnosis before severe complications arise, as illustrated by the following case. Case
report
The patient is a 29-year-old, gravida 2 para 0, with a longstanding history of infertility. In 1971, at age 13,
Correspondence to: Dr. P.W.J. van Dongen, Department of Obstetrics and Gynaecology, University Hospital Nijmegen, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
she underwent an appendectomy for acute appendicitis, followed by a second laparotomy for generalized peritonitis. After failing to conceive for several years, bilateral hydrosalpinges were diagnosed at age 26. Reconstructive surgery was carried out, consisting of extensive pelvic adhesiolysis, partial omentectomy, bilateral salpingostomy and reimplantation of the left tube. Subsequent hysterosalpingography showed patency of both tubes. A year later the first pregnancy ended in curettage for missed abortion. In 1987 the second pregnancy occurred. Ultrasound examination at 10 weeks’ gestation revealed a gestational sac located in the left comual area containing a live embryo with a crown-rump length of 24 mm, corresponding to 9 gestational weeks. A myometrial layer of 10 mm separated the sac from the thickened endometrium, whereas the covering myometrium measured only 3 mm in thickness (Fig. 1). Diagnostic laparoscopy showed a protuberance of the uterus at the left cornu from which the slender left tube and the round ligament originated, confirming the diagnosis of interstitial pregnancy at the site of the cornual anastomosis. Although the patient was asymptomatic, continuation of this pregnancy was likely to result in rupture of the cornual area, with possibly disastrous consequences for the uterus and future fertility. Elective resection of the affected part was decided upon. At laparotomy the cornual swelling was incised, exposing the sac with embryo. A simple resection of the affected area includ-
165
\\
myometrium ,
\
foetus
chorionic
vi//i
Fig. 1. Oblique ultrasound scan of uteiws with uterine cavity and gestational sac.
ing the left fallopian tube was performed. The uterus was closed in three layers. Subsequently, some filmy adhesions involving the right ovary and tube were severed, resulting in satisfactory ovum pick-up. Postoperative recovery was uneventful. Histology was compatible with the clinical diagnosis; there were no congenital defects; the crown-rump length measured 25 mm, Carnegie Stage 22. Right tubal patency was demonstrated at later hysterosalpingography. The third (spontaneous) pregnancy ended in 1991 with the birth of a healthy boy, by elective caesarean section at 38 weeks. Discussion The most important etiologic factors for interstitial pregnancy are, as for other tubal pregnancies, a history of pelvic inflammatory disease and previous tubal surgery. Three to twenty percent of pregnancies following tubal surgery will be ectopic [2]. After cornual anastomosis this rate is even higher: ll-40% [3]. Cornual resection when performing salpingectomy for tubal pregnancy or for other reasons was advocated in the past as prophylaxis against interstitial pregnancy. This is no longer recommended because it certainly does not always prevent its occurrence and may weaken the myometrium, predisposing to rupture in a subsequent pregnancy and placenta accreta [4,5]. Interstitial pregnancy is a dangerous form of ectopic gestation. Rupture may occur into the peritoneal cav-
ity, into the uterine cavity or into the myometrium depending on the exact implantation site. It leads to rapid and profuse haemorrhage with mortality rates of 2-7%, compared with less than 1% for other tubal pregnancies [ 1,6]. Signs and symptoms are non-specific, resembling those of other tubal pregnancies, though the gestation at the time of rupture tends to be more advanced. At pelvic examination a broad-based palpable mass may be found extending outward from the uterine angle (Baart de la Faille’s sign), or the fundus is displaced to the contralateral side with rotation of the uterus and elevation of the affected cornu (RugeSimon syndrome), but these signs are .by no means constant [7]. In the past, diagnosis was usually made at laparotomy. With the advent of ultrasonography and its routine use in early pregnancy interstitial pregnancy can be detected with accuracy before serious complicaTABLE I Sonographic signs of interstitial
pregnancy
0 empty uterine cavity. l eccentrically placed or very lateral gestational sac. l thin or incomplete myometrial mantle covering the gestational sac. l demonstration of myometrium between sac and uterine cavity. l no gestational sac visible above the level of the internal OS in the longitudinal plane of the uterus.
166 TABLE
2 Lavy G, Diamond MP, DeCherney AH. Ectopic preg-
II
Differential diagnosis of interstitial pregnancy l leiomyomatous uterus distorting normal anatomy. 0 sacculation of the uterus. l more lateral tubal pregnancy. l pregnancy in a rudimentary horn (cornual pregnancy
l l
proper). pregnancy in a septate or otherwise malformed uterus. Piskacek’s sign (temporary asymmetry of the fundus in a normal intra-uterine pregnancy before the 12th week of gestation).
3 4
5
6 7
tions arise. Several
authors
have reported
characteris-
signs, summarized in Table I [8-14). In our case all these signs were present. Differential diagnostic considerations are listed in Table II. An interstitial pregnancy seldom proceeds into the third trimester. Until 1988 no fetal survival was documented, but two casts resulting in live, full term infants have since been reported [15,16]. Cornual resection or, in case of rupture, repair of the laceration would be the treatment of choice. Severe damage or uncontrollable haemorrhage may necessitate hysterectomy. In selected cases conservative surgical management with preservation of tubal patency on the affected side may be feasible [17]. In subsequent prcgnancies there is danger of overt or occult rupture of the previously repaired cornual arca [18]. tic sonographic
Conclusion Routine ultrasonography in early pregnancy may produce signs pointing to a diagnosis of interstitial pregnancy before a possibly catastrophic rupture occurs. Patients with a history of cornual surgcty arc especially at risk. It is likely that early diagnosis will contribute to a better prognosis. References
8
9
10
11
12
13
14
15
16
17
1 Durfee RB. Obstetric complications of pregnancy. In: Pernoll ML, Benson RC, eds. Current Obstetric and Gynecologic Diagnosis and Treatment. Nonvalk, Connecticut/Los Altos, California: Appleton & Lange, 1987;255-278.
18
nancy: its relationship to tubal reconstructive surgery. Fertil Steril 1987;47:543-556. Lavy G, Diamond MP, DeCherney AH. Pregnancy following tubocornual anastomosis. Fertil Steril 1986;46:21-25. Miihlen K, Shortle B. Comual resection as prophylaxis against interstitial pregnancy: is it necessary or dangerous? A review of the literature. Eur J Obstet Gynecol Reprod Biol 1984;17:155-163. Kalchman GG, Meltzer RM. Interstitial pregnancy following homolateral salpingectomy. Am J Obstet Gynecol 1966%1139-l 143. Felmus LB, Pedowitz P. Interstitial pregnancy. A survey of 45 cases. Am J Obstet Gynecol 1953;66:1271-1279. Skulj V, Bunarevic A, Bacic G et al. Interstitial pregnancy. Review of 24 cases. Am J Obstet Gynecol 1964$8:5%-600. Chandra P, Koenigsberg M, Romney SL et al. Unruptured interstitial pregnancy: diagnosis and treatment. Obstet Gynecol 1978;52:612-615. Graham M, Cooperberg PL. Ultrasound diagnosis of interstitial pregnancy: findings and pitfalls. J Clin Ultrasound 1979;7:433-437. Smith HJ, Hanken H, Brundelet PJ. Ultrasound diagnosis of interstitial pregnancy. Acta Obstet Gynecol Stand 1981;60:413-416. Maher PJ, Grimwade JC. Cornual pregnancy - Diagnosis before rupture. A report of 2 cases. Aust NZ J Obstet Gynecol 1982;2:172-174. Auslender R, Arodi J, Pascal B et al. Interstitial pregnancy: Early diagnosis by ultrasonography. Am J Obstet Gynecol 1983;146:717-718. Toady DJ, Snyder JR, Goldstein SR et al. Ultrasound diagnosis of interstitial pregnancy. NY State J Med 1985;5:655-656. Weissman A, Fishman A, Gal D. Interstitial pregnancy: a diagnostic challenge. Int J Gynecol Obstet 1989;29:373375. Rosenxweig BA, Rotmensch S, Ressetar A. Term interstitial pregnancy resulting in a live infant. Obstet Gynecol 1988;72:491-493. Bond AL, Grifo JA, Chevernak FA et al. Term interstitial pregnancy with uterine torsion: sonographic, pathologic and clinical findings. Obstet Gynecol 1989;73:857-859. Confino E, Gleicher N. Conservative management of interstitial pregnancy. Fertil Steril 1989;52:60&603. Malfetano, JH: Occult rupture of uterus following ruptured interstitial pregnancy, Am J Obstet Gynecol 70:1361, 1955.
