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Pelvic magnetic resonance imaging in the evaluation of uterine torsion
PELVIC MAGNETIC RESONANCE IMAGING IN THE EVALUATION OF UTERINE TORSION
Wanda K. Nicholson, MD, Carol C. Coulson, MD, M. Cathleen McCoy, MD, and Richard C. Semelka, MD Background: Uterine torsion is defined as the rotation of
more than 45° around the long axis of the uterus. An uncommon but potentially fatal event, uterine torsion is rarely diagnosed until the time of surgery. With magnetic resonance imaging (MRI), however, an accurate diagnosis of uterine torsion may now be made preoperatively. Case: We describe a patient with uterine torsion in whom the correct diagnosis was made prenatally with the use of MRI, by the demonstration of an X-shaped configuration of the upper vagina. Conclusion: Distinctive features suggestive of uterine tor• sion were demonstrated by MRI and enabled an accurate preoperative diagnosis. To our knowledge, this is the first reported case of uterine torsion diagnosed on MRI. (Obstet GynecoI1995;85:888-90)
Uterine torsion, defined as a rotation of more than 45° around the long axis of the uterus, has been described in the obstetrics literature for over 30 years. 1 The clinical challenge of uterine torsion lies in its elusive diagnosis. Although a potentially catastrophic event for mother and fetus, uterine torsion diagnosis is often not possible until the time of surgery. Review of the literature suggests that the difficulty in diagnosis is because of a lack of symptoms specific to the condition. 2- 4 Most women present with generalized complaints of abdom• inal pain, vaginal bleeding, and gastrointestinal or urinary discomfort. 3-7 The differential diagnosis includes appendicitis, pla• cental abruption, and abdominal pregnancy, all of which lead to surgical intervention and the intraopera• tive diagnosis of torsion. Because of the high soft tissue contrast and excellent anatomical depiction provided with magnetic resonance imaging (MRJ), the diagnosis of uterine torsion can be made prenatally. We present a case of uterine torsion initially referred with the diag• nosis of abdominal pregnancy. With the use of pelvic MR!, uterine torsion was accurately diagnosed before the time of laparotomy.
From the Departments of Obstetrics and Gynecology and Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
888
0029-7844/95/$9.50
ssm 0029-7844(94)00283-1
Case Report A 32-year old white primigravida with a spontaneously COn• ceived gestation presented to her local physician for a sched• uled visit at 40 weeks and 3 days. Her pregnancy had been uncomplicated. She denied vaginal bleeding, uterine contrac_ tions, or abdominal pain, and reported normal fetal move• ment. At this visit, a cervical examination was performed to evaluate the patient for labor induction. Despite multiple painstaking attempts by several examiners, no cervix could be palpated. Previous examinations had been normal, inclUding a first-trimester Papanicolaou smear and pelvic examination. Further investigation at another hospital included an MRI examination, which was initially interpreted as suspicious for an abdominal pregnancy. In order to demonstrate whether this was a true abdominal pregnancy, the local physicians chose oxytocin augmentation, thinking that evidence of COn• tractions would negate the diagnosis of abdominal pregnan_ cy.a No uterine contractions were noted, and the patient Was transferred to our institution for further evaluation. Examination on arrival was limited by maternal discomfort; however, the fetal vertex could be palpated bulging into the cul-de-sac. After epidural anesthesia, a repeat vaginal exami_ nation was remarkable for a palpable cervix, which Was mildly effaced and which deviated far anteriorly and to the right. No presenting part was palpable through the cervix. An ultrasound examination appeared to confirm an intrauterine gestation with a normal-appearing fundal placenta. A non• stress test was reactive without uterine contractions. Reinterpretation of the Original MRI revealed an effaCed cervix, 2 em dilated and angled to the right by apprOXimately 90°. The fetus was intrauterine in a vertex presentation. The wall of the upper and mid-vagina, which appears as a low_ signal-intensity linear structure, was oriented in an X-shaped configuration (Figure 1, top panel), whereas more inferiorly at the level of the low vagina, the normal H-shaped cOnfigura_ tion was present (Figure 1, bottom panel). Schematic repre• sentation of the changes in appearance of the vagina, second_ ary to torsion, are shown in Figure 2. The vertical bars of the H represent the two lateral walls of the vagina, whereas the horizontal bar represents the anterior and posterior walls. With uterine torsion, the upper lateral vaginal walls are twisted relative to bony landmarks and the lower lateral walls which are fixed at the introitus. The left lateral vaginal wali apex is twisted to the right side of the pelvis and vice versa forming the X-shaped configuration. These specific MRI find~ ings helped to establish the diagnosis of uterine torsion before the laparotomy. Because of the possibility of uterine rupture with labor induction, the patient underwent an elective cesarean deliv• ery. The peritoneum was opened, and the uterus was noted to be dextrorotated 120°. The left adnexa and broad ligament were rotated anteriorly. The uterus was levorotated to an anatomically normal position. A low transverse incision was created, and a 3380-g female neonate was delivered from the footling breech presentation. Apgar scores were 9 and 9 at 1 and 5 minutes, respectively. Further examination revealed a bicornuate uterus with a left rudimentary horn. The dominant
Obstetrics & Gynecology
Figure 1. Magnetic resonance im• aging of the vagina (v), urethra (u), and anal canal (a) (transverse sec• tion). Top panel: Distorted anatomy in uterine torsion (X-shaped config• uration). Bottom panel: Normal ana• tomic position at the level of the inferior vagina (H-shaped configu• ration). The lower vagina is fixed at the introitus so the normal H• shaped configuration is maintained.
cavity was explored, and no connection could be demon• strated between the horns. Both adnexa appeared nonnal, and both kidneys were palpated. The patient and her newborn did well postoperatively and were discharged on postoperative day 4.
Discussion Uterine torsion is a rare phenomenon, the diagnosis of which has been delayed until the time of surgery.3-6.9
VOL. 85, NO.5, PART 2, MAY 1995
This delay in diagnosis can lead to inadvertent incisions into the broad ligament at the time of cesarean delivery or uterine rupture into the cul-de-sac when attempting vaginal delivery.2.3.7 In this patient, the diagnosis of torsion was not considered initially, and an attempt at oxytocin induction might have been fatal. Jensen3 reported a total of 19 maternal deaths from complications of uterine torsion, although most oc• curred in more advanced cases, with torsion of greater than 180°. Most cases of uterine torsion are associated
Nicholson et al
MRI in Uterine Torsion
889
AIgflt lalefa/ WI
Anlenor!Post.r\o( Wall
1 Righi Let.ta1 Wall
Lett lateral Will
Normal anatomic position "H"slgn
Figure 1. Schl'mallc representattoa of uI,'nne 1",""lOn at the level of the upP"r vaKina
____
Torsion of 120·
with congenital or acquired uterine defonnities. Myo• matous uteri are the most common abnonnalities over• all in cases of uterine torsion; however, bicornuate uteri are identified in most cases attributed to congenital uterine anomalies,2-4,6-8,tO Severe pelvic adhesions and adnexal masses are other common findings. On MRI, high soft-tissue contrast resolution pennits an accurate evaluation of pelvic organs. The nonnal vagina is well shown on MRI as an H-shaped struc• ture. lt Recognition that the upper and mid-vagina had assumed an X-shaped configuration on MRI led to the correct preoperative diagnosis. We present this case as an example in which pelvic MRI, obtained to evaluate a suspected abdominal pregnancy, was instrumental in making the early diagnosis of uterine torsion leading to the appropriate surgical management of the patient.
References
"X" sign following torsion
6. Nesbitt REL, Comer GW. Tor.uon of the human pregnant utenaa. Obstet Gynecol Surv 1956;11:311-32. 7. Jensen }G. Pathologic lor.iion 01 the pregnanl uterus. Acta ~
Gynecol Scand 1990;69:431-2. 8. Cordero DR, Adra A, Yasln S. O'Sullivan MJ. Intraligamentuy pregnancy. Obstet Gynecol SUN I994;4'1:2lJt>-'1. 9. Nie15en TF. Torsion of the pregnant hUmdn uterus without sYIhp• toms. Am J Obstet Gynecol 19111.l4l.83H-'1. 10. Caughey AF, Higuera IG, MONjei' R. Torsion of the t\Onftal pregnant uterus. Obstet Gynecol 1%.';;21'0344-5. 11. Hricak H, Chang YCF, Thurner S. VaRina: Evaluation with MIt imaging. Part I. Normal anatomy and conRemtal anomalies. Radi• ology 1988;169:169-74.
Address reprint requests to: M. GlthlfflJ McCoy, MD
University
of North Glro/i"" School of Ml'dici,,1'
Department of Obstttrics ""d Gy"I'CllIt':{y Division of MiJtmuJl-Fttal Medicinl'
ClMt 7570, 214 MAcNider Buildi"X
1. Graber EA. Surgery of the uterus in pregnancy. In: Barber HRK, Graber EA, eds. Surgical disease in pregnancy. Philadelphia: we
Chapel Hill, NC 27599-7570
Saunders, 1974:387-8.
2. Ban I, Bergman B. A case of torsion of the pregnant uterus. Acta Obstel Gynecol Scand 1984;63:373-4. 3. Jensen JG. Uterine torsion in pregnancy. Acta Obstet Gynecol Scand 1992;71:260-5. 4. Ulslein MK. Torsion of the human pregnant uterus. Acta Obstet Gynecol Scand 1969;48:267-71. 5. Crona N, Bachrach I. Pathologic torsion of the pregnant uterus. Acta Obstet Gynecol Scand 1984;63:375-6.
890 Nicholson et al
MRl in Uterine Torsion
Received April 25, 1994. R£crivnl in rt'Uiw fcmn funt 27, /994. Acupted funt 28, 1994.
e
COpyright 1995 by The Amencan C"UCKe "I Obstetricians ~ Gynecologists.
Obstl'trlCs £:, GY'I«'OIoo
Wanda K. Nicholson, MD, Carol C. Coulson, MD, M. Cathleen McCoy, MD, and Richard C. Semelka, MD Background: Uterine torsion is defined as the rotation of
more than 45° around the long axis of the uterus. An uncommon but potentially fatal event, uterine torsion is rarely diagnosed until the time of surgery. With magnetic resonance imaging (MRI), however, an accurate diagnosis of uterine torsion may now be made preoperatively. Case: We describe a patient with uterine torsion in whom the correct diagnosis was made prenatally with the use of MRI, by the demonstration of an X-shaped configuration of the upper vagina. Conclusion: Distinctive features suggestive of uterine tor• sion were demonstrated by MRI and enabled an accurate preoperative diagnosis. To our knowledge, this is the first reported case of uterine torsion diagnosed on MRI. (Obstet GynecoI1995;85:888-90)
Uterine torsion, defined as a rotation of more than 45° around the long axis of the uterus, has been described in the obstetrics literature for over 30 years. 1 The clinical challenge of uterine torsion lies in its elusive diagnosis. Although a potentially catastrophic event for mother and fetus, uterine torsion diagnosis is often not possible until the time of surgery. Review of the literature suggests that the difficulty in diagnosis is because of a lack of symptoms specific to the condition. 2- 4 Most women present with generalized complaints of abdom• inal pain, vaginal bleeding, and gastrointestinal or urinary discomfort. 3-7 The differential diagnosis includes appendicitis, pla• cental abruption, and abdominal pregnancy, all of which lead to surgical intervention and the intraopera• tive diagnosis of torsion. Because of the high soft tissue contrast and excellent anatomical depiction provided with magnetic resonance imaging (MRJ), the diagnosis of uterine torsion can be made prenatally. We present a case of uterine torsion initially referred with the diag• nosis of abdominal pregnancy. With the use of pelvic MR!, uterine torsion was accurately diagnosed before the time of laparotomy.
From the Departments of Obstetrics and Gynecology and Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
888
0029-7844/95/$9.50
ssm 0029-7844(94)00283-1
Case Report A 32-year old white primigravida with a spontaneously COn• ceived gestation presented to her local physician for a sched• uled visit at 40 weeks and 3 days. Her pregnancy had been uncomplicated. She denied vaginal bleeding, uterine contrac_ tions, or abdominal pain, and reported normal fetal move• ment. At this visit, a cervical examination was performed to evaluate the patient for labor induction. Despite multiple painstaking attempts by several examiners, no cervix could be palpated. Previous examinations had been normal, inclUding a first-trimester Papanicolaou smear and pelvic examination. Further investigation at another hospital included an MRI examination, which was initially interpreted as suspicious for an abdominal pregnancy. In order to demonstrate whether this was a true abdominal pregnancy, the local physicians chose oxytocin augmentation, thinking that evidence of COn• tractions would negate the diagnosis of abdominal pregnan_ cy.a No uterine contractions were noted, and the patient Was transferred to our institution for further evaluation. Examination on arrival was limited by maternal discomfort; however, the fetal vertex could be palpated bulging into the cul-de-sac. After epidural anesthesia, a repeat vaginal exami_ nation was remarkable for a palpable cervix, which Was mildly effaced and which deviated far anteriorly and to the right. No presenting part was palpable through the cervix. An ultrasound examination appeared to confirm an intrauterine gestation with a normal-appearing fundal placenta. A non• stress test was reactive without uterine contractions. Reinterpretation of the Original MRI revealed an effaCed cervix, 2 em dilated and angled to the right by apprOXimately 90°. The fetus was intrauterine in a vertex presentation. The wall of the upper and mid-vagina, which appears as a low_ signal-intensity linear structure, was oriented in an X-shaped configuration (Figure 1, top panel), whereas more inferiorly at the level of the low vagina, the normal H-shaped cOnfigura_ tion was present (Figure 1, bottom panel). Schematic repre• sentation of the changes in appearance of the vagina, second_ ary to torsion, are shown in Figure 2. The vertical bars of the H represent the two lateral walls of the vagina, whereas the horizontal bar represents the anterior and posterior walls. With uterine torsion, the upper lateral vaginal walls are twisted relative to bony landmarks and the lower lateral walls which are fixed at the introitus. The left lateral vaginal wali apex is twisted to the right side of the pelvis and vice versa forming the X-shaped configuration. These specific MRI find~ ings helped to establish the diagnosis of uterine torsion before the laparotomy. Because of the possibility of uterine rupture with labor induction, the patient underwent an elective cesarean deliv• ery. The peritoneum was opened, and the uterus was noted to be dextrorotated 120°. The left adnexa and broad ligament were rotated anteriorly. The uterus was levorotated to an anatomically normal position. A low transverse incision was created, and a 3380-g female neonate was delivered from the footling breech presentation. Apgar scores were 9 and 9 at 1 and 5 minutes, respectively. Further examination revealed a bicornuate uterus with a left rudimentary horn. The dominant
Obstetrics & Gynecology
Figure 1. Magnetic resonance im• aging of the vagina (v), urethra (u), and anal canal (a) (transverse sec• tion). Top panel: Distorted anatomy in uterine torsion (X-shaped config• uration). Bottom panel: Normal ana• tomic position at the level of the inferior vagina (H-shaped configu• ration). The lower vagina is fixed at the introitus so the normal H• shaped configuration is maintained.
cavity was explored, and no connection could be demon• strated between the horns. Both adnexa appeared nonnal, and both kidneys were palpated. The patient and her newborn did well postoperatively and were discharged on postoperative day 4.
Discussion Uterine torsion is a rare phenomenon, the diagnosis of which has been delayed until the time of surgery.3-6.9
VOL. 85, NO.5, PART 2, MAY 1995
This delay in diagnosis can lead to inadvertent incisions into the broad ligament at the time of cesarean delivery or uterine rupture into the cul-de-sac when attempting vaginal delivery.2.3.7 In this patient, the diagnosis of torsion was not considered initially, and an attempt at oxytocin induction might have been fatal. Jensen3 reported a total of 19 maternal deaths from complications of uterine torsion, although most oc• curred in more advanced cases, with torsion of greater than 180°. Most cases of uterine torsion are associated
Nicholson et al
MRI in Uterine Torsion
889
AIgflt lalefa/ WI
Anlenor!Post.r\o( Wall
1 Righi Let.ta1 Wall
Lett lateral Will
Normal anatomic position "H"slgn
Figure 1. Schl'mallc representattoa of uI,'nne 1",""lOn at the level of the upP"r vaKina
____
Torsion of 120·
with congenital or acquired uterine defonnities. Myo• matous uteri are the most common abnonnalities over• all in cases of uterine torsion; however, bicornuate uteri are identified in most cases attributed to congenital uterine anomalies,2-4,6-8,tO Severe pelvic adhesions and adnexal masses are other common findings. On MRI, high soft-tissue contrast resolution pennits an accurate evaluation of pelvic organs. The nonnal vagina is well shown on MRI as an H-shaped struc• ture. lt Recognition that the upper and mid-vagina had assumed an X-shaped configuration on MRI led to the correct preoperative diagnosis. We present this case as an example in which pelvic MRI, obtained to evaluate a suspected abdominal pregnancy, was instrumental in making the early diagnosis of uterine torsion leading to the appropriate surgical management of the patient.
References
"X" sign following torsion
6. Nesbitt REL, Comer GW. Tor.uon of the human pregnant utenaa. Obstet Gynecol Surv 1956;11:311-32. 7. Jensen }G. Pathologic lor.iion 01 the pregnanl uterus. Acta ~
Gynecol Scand 1990;69:431-2. 8. Cordero DR, Adra A, Yasln S. O'Sullivan MJ. Intraligamentuy pregnancy. Obstet Gynecol SUN I994;4'1:2lJt>-'1. 9. Nie15en TF. Torsion of the pregnant hUmdn uterus without sYIhp• toms. Am J Obstet Gynecol 19111.l4l.83H-'1. 10. Caughey AF, Higuera IG, MONjei' R. Torsion of the t\Onftal pregnant uterus. Obstet Gynecol 1%.';;21'0344-5. 11. Hricak H, Chang YCF, Thurner S. VaRina: Evaluation with MIt imaging. Part I. Normal anatomy and conRemtal anomalies. Radi• ology 1988;169:169-74.
Address reprint requests to: M. GlthlfflJ McCoy, MD
University
of North Glro/i"" School of Ml'dici,,1'
Department of Obstttrics ""d Gy"I'CllIt':{y Division of MiJtmuJl-Fttal Medicinl'
ClMt 7570, 214 MAcNider Buildi"X
1. Graber EA. Surgery of the uterus in pregnancy. In: Barber HRK, Graber EA, eds. Surgical disease in pregnancy. Philadelphia: we
Chapel Hill, NC 27599-7570
Saunders, 1974:387-8.
2. Ban I, Bergman B. A case of torsion of the pregnant uterus. Acta Obstel Gynecol Scand 1984;63:373-4. 3. Jensen JG. Uterine torsion in pregnancy. Acta Obstet Gynecol Scand 1992;71:260-5. 4. Ulslein MK. Torsion of the human pregnant uterus. Acta Obstet Gynecol Scand 1969;48:267-71. 5. Crona N, Bachrach I. Pathologic torsion of the pregnant uterus. Acta Obstet Gynecol Scand 1984;63:375-6.
890 Nicholson et al
MRl in Uterine Torsion
Received April 25, 1994. R£crivnl in rt'Uiw fcmn funt 27, /994. Acupted funt 28, 1994.
e
COpyright 1995 by The Amencan C"UCKe "I Obstetricians ~ Gynecologists.
Obstl'trlCs £:, GY'I«'OIoo