- Email: [email protected]
Clinician-performed ultrasound diagnosis of ruptured interstitial pregnancy
American Journal of Emergency Medicine (2009) 27, 1170.e1–1170.e2
www.elsevier.com/locate/ajem
Case Report Clinician-performed ultrasound diagnosis of ruptured interstitial pregnancy
Abstract An interstitial pregnancy is a rare type of ectopic pregnancy located within the proximal portion of the fallopian tube in the muscular wall of the uterus. They are more likely to result in significant or fatal hemorrhage because of the increased vascularity. Diagnosis of interstitial pregnancy is challenging but critical to facilitate prompt and appropriate intervention. Ultrasound performed by an emergency physician is commonly used to assess early pregnancy, but little has been published in the emergency medicine literature regarding its use in assessing for presence of interstitial pregnancy. We describe a case of a ruptured interstitial pregnancy diagnosed by emergency ultrasonography in the emergency department and review the literature regarding the sonographic findings of interstitial pregnancies. A 41-year-old, gravida 5 para 4 woman presented by ambulance as tachycardic, hypotensive, and diaphoretic and with chief a complaint of abdominal pain. Through limited English, family indicated that the patient was 13 weeks pregnant. She had no prenatal care and experienced back pain and “gaslike” abdominal pain for 1 week before arrival, which became acutely severe, without associated vaginal bleeding. She appeared somewhat lethargic and uncomfortable and complained of abdominal pain, preferring to lie on her left side. Her peripheral pulses were absent and her femoral pulse was thready at a rate of 98 beats/min. Initial blood pressure was unobtainable. Her skin was pale and diaphoretic, and abdominal examination was significant for diffuse tenderness. Rectal examination was hemeoccult negative and there was no vaginal bleeding. Results of a limited emergency ultrasound (EUS), performed by the attending emergency physician, demonstrated an eccentrically located pregnancy at approximately 14 weeks and without fetal cardiac activity (Fig. 1). Also noted was a large amount of free intraperitoneal fluid (Fig. 2). She was intubated and transfused with uncrossmatched blood. Both obstetrics and general surgery were consulted emergently. Minutes later, a repeat EUS by the attending emergency physician suggested an empty uterus (Fig. 3), suggesting a diagnosis of ruptured cornual or interstitial 0735-6757/$ – see front matter © 2009 Elsevier Inc. All rights reserved.
pregnancy. The patient underwent emergent laparotomy by obstetrics. Operative findings included approximately 2 L of blood in the peritoneum. The left cornual area of the uterus was ruptured and the fetus was free floating in the peritoneum with an intact amniotic sac. The fallopian tubes and ovaries were normal. The left cornual defect was closed. The patient's postoperative course was complicated by pneumonia, but she was discharged to home on postoperative day 7. Pathology judged the fetus to be 13 to 14 weeks based on skeletal parameters. An interstitial pregnancy is one in which implantation has occurred in the proximal portion of the fallopian tube within the muscular wall of the uterus, but with the main portion of the gestational sac located outside of the uterine cavity. They are thought to account for 2% to 4% of ectopic pregnancies [1,2]. We could find only 2 case reports of ectopic interstitial pregnancy in the emergency medicine literature [3,4]. Risk factors include a history of previous ectopic pregnancy, prior salpingectomy, in vitro fertilization, uterine anomalies, and pelvic inflammatory disease [1,3,5]. The mortality rate of interstitial pregnancies is more than twice that of other types of ectopic pregnancies owing to the increased risk of significant hemorrhage from rupture of an ectopic pregnancy near the uterine artery [2]. Classic teaching states that interstitial pregnancies rupture later than other types of ectopic pregnancies because of the more distensible myometrium. More recently, this notion has been challenged as relatively early rupture of interstitial pregnancies were noted [1]. Interstitial
Fig. 1 Transabdominal sagittal image of the uterus confirming the presence of an early pregnancy. Biparietal diameter measurement (linear distance between “+" symbols) suggests a gestational age of approximately 14 weeks.
1170.e2
Fig. 2 Image of the right upper quadrant indicating free fluid (arrow) in the hepatorenal space.
pregnancy and cornual pregnancy are often used interchangeably in the literature. A cornual pregnancy, by contrast, is a pregnancy located in the superolateral aspect of the uterus or in 1 horn of a bicornuate uterus [5,6]. Bedside ultrasound has become an increasingly popular and useful tool for the emergency physician. With limited training in ultrasonography, physicians can make prompt diagnosis of complications of early pregnancy. However, the diagnosis of an interstitial pregnancy can be difficult. Timor-Tritsch et al [4] proposed sonographic criteria for the diagnosis of an interstitial pregnancy: (1) an empty uterine cavity, (2) a chorionic sac seen separately and more than 1 cm from the most lateral edge of the uterine cavity, and (3) myometrial mantle thinning to less than 5 mm representing the insertion of the fallopian tube to the uterus. The sensitivity of these criteria is roughly 40%, with specificity ranging from 62% to 93%. All these criteria were demonstrated in our EUS evaluation (Fig. 3). If there is no demonstrable gestational sac, the sensitivity decreases significantly to approximately 25% to 33% [2]. The interstitial line (representing the endometrial canal or the interstitial portion of the fallopian tube) has been offered as a more sensitive (80%) and specific (98%) criterion for sonographic diagnosis of interstitial pregnancy [2]. However, it has not been prospectively validated. Increased vascularity in the cornual region on Doppler examination is another sonographic sign suggestive of interstitial pregnancy [7]. Differentiating an eccentric intrauterine pregnancy from an interstitial location by ultrasonography is difficult because both have some degree of eccentric location of the gestational sac and thinning of the myometrial mantle. This case illustrates the use of EUS in the diagnosis of interstitial pregnancy in the emergency department. To our knowledge, this is the first case of an interstitial pregnancy diagnosed preoperatively by an emergency physician using EUS. We believe that given the rapidly expanding interest and skill in emergency ultrasonography, physicians will need to consider interstitial ectopic pregnancy among the differential of complications of early pregnancy. Using the criteria we have outlined, physicians should feel more confident in making this rare diagnosis.
Case Report
Fig. 3 Midline sagittal image of the pelvis demonstrating an empty uterus (small arrows) and eccentrically located gestational sac with fetus (large arrow).
David Duong MD, MS Department of Emergency Medicine University of California San Francisco San Francisco General Hospital San Francisco, CA 94110, USA William E. Baker MD Department of Emergency Medicine Boston University, Boston, MA 02118, USA E-mail address: [email protected] Adeyinka Adedipe MD RDMS Department of Medicine Division of Emergency Medicine University of Washington Seattle, WA 98155, USA doi:10.1016/j.ajem.2009.01.002
References [1] Tulandi T, Al-Jaroudi D. Interstitial pregnancy: results generated from the Society of Reproductive Surgeons Registry. Obstet Gynecol 2004; 103:47-50. [2] Ackerman TE, Levi CS, Dashefsky SM, Holt SC, Lindsay DJ. Interstitial line: sonographic finding in interstitial (cornual) ectopic pregnancy. Radiology 1993;189:83-7. [3] Chan LY, Fok WY, Yuen PM. Pitfalls in diagnosis of interstitial pregnancy. Acta Obstet Gynecol Scand 2003;82:867-70. [4] Timor-Tritsch IE, Monteagudo A, Matera C, Veit CR. Sonographic evolution of cornual pregnancies treated without surgery. Obstet Gynecol 1992;79:1044-9. [5] Akrivis C, Varras M, Kyparos J, Demou A, Stefanaki S, Antoniou N. Early ultrasonographic diagnosis of unruptured interstitial pregnancy: a case report and review of the literature. Clin Exp Obstet Gynecol 2003; 30:60-4. [6] Malinowski A, Bates SK. Semantics and pitfalls in the diagnosis of cornual/interstitial pregnancy. Fertil Steril 2006;86:1764.e11-4. [7] Hamada S, Naka O, Moride N, Higuchi K, Takahashi H. Ultrasonography and magnetic resonance imaging findings in a patient with an unruptured interstitial pregnancy. Eur J Obstet Gynecol Reprod Biol 1997;73:197-201.
www.elsevier.com/locate/ajem
Case Report Clinician-performed ultrasound diagnosis of ruptured interstitial pregnancy
Abstract An interstitial pregnancy is a rare type of ectopic pregnancy located within the proximal portion of the fallopian tube in the muscular wall of the uterus. They are more likely to result in significant or fatal hemorrhage because of the increased vascularity. Diagnosis of interstitial pregnancy is challenging but critical to facilitate prompt and appropriate intervention. Ultrasound performed by an emergency physician is commonly used to assess early pregnancy, but little has been published in the emergency medicine literature regarding its use in assessing for presence of interstitial pregnancy. We describe a case of a ruptured interstitial pregnancy diagnosed by emergency ultrasonography in the emergency department and review the literature regarding the sonographic findings of interstitial pregnancies. A 41-year-old, gravida 5 para 4 woman presented by ambulance as tachycardic, hypotensive, and diaphoretic and with chief a complaint of abdominal pain. Through limited English, family indicated that the patient was 13 weeks pregnant. She had no prenatal care and experienced back pain and “gaslike” abdominal pain for 1 week before arrival, which became acutely severe, without associated vaginal bleeding. She appeared somewhat lethargic and uncomfortable and complained of abdominal pain, preferring to lie on her left side. Her peripheral pulses were absent and her femoral pulse was thready at a rate of 98 beats/min. Initial blood pressure was unobtainable. Her skin was pale and diaphoretic, and abdominal examination was significant for diffuse tenderness. Rectal examination was hemeoccult negative and there was no vaginal bleeding. Results of a limited emergency ultrasound (EUS), performed by the attending emergency physician, demonstrated an eccentrically located pregnancy at approximately 14 weeks and without fetal cardiac activity (Fig. 1). Also noted was a large amount of free intraperitoneal fluid (Fig. 2). She was intubated and transfused with uncrossmatched blood. Both obstetrics and general surgery were consulted emergently. Minutes later, a repeat EUS by the attending emergency physician suggested an empty uterus (Fig. 3), suggesting a diagnosis of ruptured cornual or interstitial 0735-6757/$ – see front matter © 2009 Elsevier Inc. All rights reserved.
pregnancy. The patient underwent emergent laparotomy by obstetrics. Operative findings included approximately 2 L of blood in the peritoneum. The left cornual area of the uterus was ruptured and the fetus was free floating in the peritoneum with an intact amniotic sac. The fallopian tubes and ovaries were normal. The left cornual defect was closed. The patient's postoperative course was complicated by pneumonia, but she was discharged to home on postoperative day 7. Pathology judged the fetus to be 13 to 14 weeks based on skeletal parameters. An interstitial pregnancy is one in which implantation has occurred in the proximal portion of the fallopian tube within the muscular wall of the uterus, but with the main portion of the gestational sac located outside of the uterine cavity. They are thought to account for 2% to 4% of ectopic pregnancies [1,2]. We could find only 2 case reports of ectopic interstitial pregnancy in the emergency medicine literature [3,4]. Risk factors include a history of previous ectopic pregnancy, prior salpingectomy, in vitro fertilization, uterine anomalies, and pelvic inflammatory disease [1,3,5]. The mortality rate of interstitial pregnancies is more than twice that of other types of ectopic pregnancies owing to the increased risk of significant hemorrhage from rupture of an ectopic pregnancy near the uterine artery [2]. Classic teaching states that interstitial pregnancies rupture later than other types of ectopic pregnancies because of the more distensible myometrium. More recently, this notion has been challenged as relatively early rupture of interstitial pregnancies were noted [1]. Interstitial
Fig. 1 Transabdominal sagittal image of the uterus confirming the presence of an early pregnancy. Biparietal diameter measurement (linear distance between “+" symbols) suggests a gestational age of approximately 14 weeks.
1170.e2
Fig. 2 Image of the right upper quadrant indicating free fluid (arrow) in the hepatorenal space.
pregnancy and cornual pregnancy are often used interchangeably in the literature. A cornual pregnancy, by contrast, is a pregnancy located in the superolateral aspect of the uterus or in 1 horn of a bicornuate uterus [5,6]. Bedside ultrasound has become an increasingly popular and useful tool for the emergency physician. With limited training in ultrasonography, physicians can make prompt diagnosis of complications of early pregnancy. However, the diagnosis of an interstitial pregnancy can be difficult. Timor-Tritsch et al [4] proposed sonographic criteria for the diagnosis of an interstitial pregnancy: (1) an empty uterine cavity, (2) a chorionic sac seen separately and more than 1 cm from the most lateral edge of the uterine cavity, and (3) myometrial mantle thinning to less than 5 mm representing the insertion of the fallopian tube to the uterus. The sensitivity of these criteria is roughly 40%, with specificity ranging from 62% to 93%. All these criteria were demonstrated in our EUS evaluation (Fig. 3). If there is no demonstrable gestational sac, the sensitivity decreases significantly to approximately 25% to 33% [2]. The interstitial line (representing the endometrial canal or the interstitial portion of the fallopian tube) has been offered as a more sensitive (80%) and specific (98%) criterion for sonographic diagnosis of interstitial pregnancy [2]. However, it has not been prospectively validated. Increased vascularity in the cornual region on Doppler examination is another sonographic sign suggestive of interstitial pregnancy [7]. Differentiating an eccentric intrauterine pregnancy from an interstitial location by ultrasonography is difficult because both have some degree of eccentric location of the gestational sac and thinning of the myometrial mantle. This case illustrates the use of EUS in the diagnosis of interstitial pregnancy in the emergency department. To our knowledge, this is the first case of an interstitial pregnancy diagnosed preoperatively by an emergency physician using EUS. We believe that given the rapidly expanding interest and skill in emergency ultrasonography, physicians will need to consider interstitial ectopic pregnancy among the differential of complications of early pregnancy. Using the criteria we have outlined, physicians should feel more confident in making this rare diagnosis.
Case Report
Fig. 3 Midline sagittal image of the pelvis demonstrating an empty uterus (small arrows) and eccentrically located gestational sac with fetus (large arrow).
David Duong MD, MS Department of Emergency Medicine University of California San Francisco San Francisco General Hospital San Francisco, CA 94110, USA William E. Baker MD Department of Emergency Medicine Boston University, Boston, MA 02118, USA E-mail address: [email protected] Adeyinka Adedipe MD RDMS Department of Medicine Division of Emergency Medicine University of Washington Seattle, WA 98155, USA doi:10.1016/j.ajem.2009.01.002
References [1] Tulandi T, Al-Jaroudi D. Interstitial pregnancy: results generated from the Society of Reproductive Surgeons Registry. Obstet Gynecol 2004; 103:47-50. [2] Ackerman TE, Levi CS, Dashefsky SM, Holt SC, Lindsay DJ. Interstitial line: sonographic finding in interstitial (cornual) ectopic pregnancy. Radiology 1993;189:83-7. [3] Chan LY, Fok WY, Yuen PM. Pitfalls in diagnosis of interstitial pregnancy. Acta Obstet Gynecol Scand 2003;82:867-70. [4] Timor-Tritsch IE, Monteagudo A, Matera C, Veit CR. Sonographic evolution of cornual pregnancies treated without surgery. Obstet Gynecol 1992;79:1044-9. [5] Akrivis C, Varras M, Kyparos J, Demou A, Stefanaki S, Antoniou N. Early ultrasonographic diagnosis of unruptured interstitial pregnancy: a case report and review of the literature. Clin Exp Obstet Gynecol 2003; 30:60-4. [6] Malinowski A, Bates SK. Semantics and pitfalls in the diagnosis of cornual/interstitial pregnancy. Fertil Steril 2006;86:1764.e11-4. [7] Hamada S, Naka O, Moride N, Higuchi K, Takahashi H. Ultrasonography and magnetic resonance imaging findings in a patient with an unruptured interstitial pregnancy. Eur J Obstet Gynecol Reprod Biol 1997;73:197-201.