Spontaneous Rupture of Subserous Uterine Vein in a 35-Weeks Pregnant Woman Who Presented with Massive Hemoperitoneum

Introduction

Hemoperitoneum is defined as the collection of blood in the peritoneal cavity with no traumatic or iatrogenic cause. ¹ Although hemoperitoneum is rare; it is a life-threatening complication. The source of the hemorrhage can be visceral (hepatic, splenic, renal, adrenal), gynecologic, obstetric, or vascular. ¹ Rupture of an ectopic pregnancy or ovarian cyst are considered the most common gynecologic causes of hemoperitoneum in pregnancy. ² The main obstetric causes are ruptured uterus and morbidly adherent placenta.^3,4

In some instances, hemoperitoneum in pregnancy could result from ruptured uterine vessels. ⁵ Sudden rise in venous pressure is a major risk factor in vessel rupture. Spontaneous rupture of uterine veins is very uncommon, occurring in ∼1/10000 births. ⁶ It commonly occurs in the broad ligament (78.3%), followed by the back of the uterus (18.3%). ⁶

The nonspecific clinical presentation of the condition usually leads to delayed or missed diagnosis that carries a poor prognosis for the mother and her fetus. The peritoneal cavity is highly distensible and can simply hold up to 5 L of blood. Thus, massive hemoperitoneum could induce profound hypovolemic shock that may lead to death. ⁷

Herein, this article reports a case of spontaneous hemoperitoneum in a 35-week pregnant woman due to rupture of a subserous uterine vein that was managed successfully, saving both the mother and her infant.

Case

A 32-year-old female patient—gravida 7, para 4 + 2, with 3 living males and 1 female— was 34 weeks' pregnant, based on an early ultrasound (US). She was referred to the authors' tertiary health care center as a case of placenta previa with a high possibility of placental invasion. She had a history of previous 4 cesarean sections, with the last one occurring 3 years prior to her current pregnancy. US and Doppler tests at the authors' center confirmed a diagnosis of placenta previa centralis, but there was no evidence of myometrial invasion. Cardiotocography showed a reassuring trace with no uterine contractions.

The patient was admitted to the inpatient unit for preparation of crossmatched blood and close observation until termination of her pregnancy by elective cesarean section at the gestational age of 36 weeks, after receiving a course of betamethasone to ensure lung maturity. The patient's hemoglobin (Hb) level at admission was 10.1 g/dL. Her blood group was B, and her Rhesus factor was positive.

Five days later, this patient developed acute abdominal pain and had sudden fainting in her inpatient room. She was transferred rapidly to the emergency unit and an urgent ultrasound revealed marked intraperitoneal fluid collection. However, the fetus was still alive. A general examination showed that the patient was pale, her pulse was 130 beats per minute (bpm), and her blood pressure (BP) was 80/50 mm Hg. An abdominal examination revealed generalized tenderness and rebounding in her lower abdomen.

The patient was counseled regarding the high possibility of a ruptured uterus, and informed consent for abdominal exploration with the possible need for hysterectomy was obtained from her and her spouse. The patient was initially resuscitated by intravenous (IV) fluids and a crossmatched blood transfusion, followed by rapid transfer to the operative room. In view of the high index of suspicion for a ruptured uterus, an urgent exploratory laparotomy though a midline incision was performed under general anesthesia.

On entry to the peritoneal cavity, marked intraperitoneal blood collection with blood clots were found. Rapid suction of ∼2 L of blood was performed. Surprisingly, inspection of the uterine scar revealed no evidence of a ruptured uterus or placental invasion to the lower segment. Additionally, the broad ligaments were intact with no bleeding from the varicose veins. Only dilated congested veins were observed below the visceral peritoneal covering of the lower segment, with generalized oozing from the peritoneum and no definite bleeding point. The surgeons suspected that the bleeding originated from one of the subperitoneal uterine veins being ruptured.

Lower uterine segment transverse incision was performed for delivery of the fetus, followed by delivery of the single living male fetus weighing 2700 g, with an Apgar score 6/10 at 1 minute and an Apgar score of 9/10 at 5 minutes. The placenta was separated completely from the lower segment with no missed parts. Bilateral uterine artery ligation was done to control the placental-bed oozing until complete hemostasis was achieved. Closure of the cesarean incision was performed in two layers.

There was a surgical consultation to explore the peritoneal cavity for other sources of spontaneous hemoperitoneum. A general surgeon evaluated the spleen, liver, and mesentery, and confirmed that there were no other sources of bleeding. The patient's vital signs started to improve; her pulse became 100 bpm and her BP was 100/60 mm Hg.

The patient received 3 units of packed red blood cells and 4 units of fresh frozen plasma. The operative time was 140 minutes, and the patient's estimated intraoperative blood loss was 2800 cc. The abdomen was closed with a peritoneal drain in situ. A urethral Foley's catheter was fixed and 2 g of IV third-generation cephalosporin was given. The patient had a smooth recovery from her anesthesia and was then transferred to the postoperative care room. She passed flatus 12 hours after surgery.

Results

This patient's postoperative Hb level was 10.4 g/dL. Her postoperative course was uneventful and she was discharged on the sixth day, in good condition, with her infant.

Discussion

Spontaneous hemoperitoneum during pregnancy is associated with high maternal and fetal mortality. The high blood flow in the uterine vessels could cause fatal consequences if the diagnosis was missed or intervention was delayed. ⁷ Thanks to the advances in resuscitative and anesthesia techniques, the mortality rate has sharply declined for this condition.

In the third trimester of pregnancy, abdominal pain and/or intraperitoneal hemorrhage can be attributed mainly to placental abruption, uterine rupture, placenta increta, a twisted ovarian cyst, or degeneration of uterine fibroid. ¹ In some reported cases, rare causes of hemoperitoneum were noticed, such as spontaneous rupture of uterine vessels,^7,8 rupture of uterine-surface varicose veins, ⁹ spontaneous rupture of a previously unknown scarred uterus, ¹⁰ rupture of a uterine rudimentary horn, ¹¹ or idiopathic causes. ¹²

Rupture of subserous uterine veins can be explained by the dilation of uterine veins in late pregnancy in addition to their “tortuous” nature, absence of valves, increasing physiologic demands of pregnancy, and any sudden rise in the venous pressure leading to spontaneous rupture. ⁷ Whether or not uterine contractions have an effect on the rupture of these vessels or not is still unclear. It is hypothesized that myometrial activity can lead to increased pressure in the dilated uterine vessels due to the physiologically increased pressure in the iliac and inferior vena cava areas caused by hormonal and anatomical changes. ¹³

Sudden onset of abdominal pain and hypovolemic shock signs in late pregnancy indicate a surgical emergency due to intraperitoneal bleeding. In the current case, the possibility of ruptured uterus was high, due to presence of four uterine scars from the patient's previous cesarean deliveries. However, a preoperative US revealed a living fetus in utero. The second possibility was erosion of the uterine wall by an invading low placenta in despite of the Doppler evaluation that revealed no evidence of abnormal vascularity in the lower-segment myometrium. Therefore, diagnosis of a cause for the hemoperitoneum was difficult to make before surgery.

When an acute abdomen is diagnosed, hemoperitoneum should be considered in the differential diagnosis during any pregnancy trimester. ¹⁴ Additionally, nonspecific symptoms and signs, such as vomiting and anemia, are signals of hemoperitoneum that should be kept in mind. Regarding management, the only possibility of improving the prognosis is to explore the abdomen urgently and deal with the anatomical cause of the hemoperitoneum. Uterine arteries' embolization could have a complementary role if no identifiable cause of bleeding is present. ¹⁵ This is considered a treatment option for controlling and preventing pregnancy-related hemorrhage, which has been established to be safe and effective.

Conclusions

Sudden onset of abdominal pain and signs of hypovolemic shock with no external bleeding can indicate intraperitoneal hemorrhage. If hemoperitoneum is suspected, immediate abdominal exploration should be considered even if the preoperative US findings are normal. Early surgical intervention can save the lives of the mother and her infant.