Ultrasound-Guided Urokinase in the Remedy of Spontaneous Vaginal Hematoma After Vaginal Delivery: A Case Report

Introduction

Vaginal hematoma is a common complication in natural childbirth that causes postpartum hemorrhage, which can be life-threatening.¹ Hematomas are most commonly treating using incision and sutures, while uterine arterial embolization is used to treat complicated hematomas.² When the hematoma is deep, it needs to be surgically removed under anesthesia. Furthermore, the inaccessible location makes exposing and suturing the hematoma difficult and increases the risk of secondary injury and operation failure.³ The success of the neurosurgical application of urokinase in the treatment of craniocerebral hematoma has led obstetricians to consider it for treating pelvic hematomas. While a literature review has examined hematomas associated with childbirth,⁴ the present report is the first to describe the use of urokinase injection for treating vaginal hematoma under ultrasound guidance.

Case Presentation

A 32-year-old multipara at 41 weeks of pregnancy was admitted to our hospital. Childbirth commenced naturally, and the patient delivered a baby weighing 3150 g. She sustained a first-degree perineal laceration but no vaginal laceration. A rectal examination 2 hours after delivery revealed no hematomas, and the patient reported no anal swelling. On the first postpartum day, routine pelvic floor ultrasound examination revealed a slightly hypoechoic mass near the posterior wall of the vagina, which was about 8.32 × 5.41 cm in size by abdominal ultrasonography (Figure 1A) and 8.92 × 5.71 cm in size by vaginal ultrasonography (Figure 1B). It was diagnosed as a vaginal hematoma.

Figure 1 Grayscale ultrasound image showing a cystic solid mass with clear boundaries in the posterior vaginal wall by abdominal ultrasonography (2020.05.23, (A)) and vaginal ultrasonography (2020.05.23, (B)).

Because the hematoma was large and located deep in the vaginal wall, exposing and surgically removing it was difficult. At 2 days postpartum, the vital signs were stable, and we speculated that the patient had no active bleeding. However, her hemoglobin level dropped to 79 g/L, so she received a transfusion of 1.5 u red blood cells and 200 mL fresh frozen plasma. After discussion and comprehensive evaluation, we performed conservative treatment. If the hematoma increased in size, it may compress the rectum and bladder, resulting in urination difficulties and anal distension. Thus, promoting hematoma absorption is critical.

After considering the previous success of using urokinase to promote the absorption of hematoma in neurosurgery,⁵ as well as the patient’s risk for infection and the long absorption time of the hematoma, urokinase was injected into the hematoma under ultrasound on the fourth day postpartum.

The hematoma was examined again before the operation, and its size was about 7.62 × 6.79 cm (Figure 2). Under the guidance of real-time ultrasound, a puncture needle was inserted into the lesion, and a small amount of pooled blood was obtained, which further confirmed our diagnosis of vaginal hematoma. Then, 100,000 units of urokinase with 50 mL normal saline were repeatedly infused into the hematoma, with 20 mL of urokinase retained.

Figure 2 Grayscale ultrasound image showing a well-defined mass in the posterior vaginal wall (2020.05.25).

After 8 days, the patient received the second treatment. The hematoma was measured again, and its size was about 7.06 × 6.77 cm (Figure 3). This time, we withdrew 135 mL of pooled blood. Then, urokinase was infused into the hematoma, with 20 mL retained.

Figure 3 Vaginal ultrasound image showing a dark liquid area (2020.06.03).

After 7 days, the patient received a third urokinase treatment. The size of hematoma had shrunk to 6.61 × 5.27 cm (Figure 4). As performed previously, 180 mL of pooled blood was aspirated, and 20 mL urokinase was retained in the hematoma.

Figure 4 Vaginal ultrasound showing a dark, liquid area (2020.06.10).

Five days after the third treatment, we performed another ultrasound examination. The length of the hematoma had shrunk significantly to 4.09 cm (Figure 5). Thus, we stopped the treatment and allowed the hematoma to be absorbed. On examination at 42 days postpartum, the hematoma had dramatically disappeared (Figure 6).

Figure 5 Grayscale ultrasound image showing the length of a mass (2020.06.15).

Figure 6 Normal vaginal ultrasound image indicating the disappearance of the mass (2020.07.03).

Discussion and Conclusion

The vulva and vagina are rich in blood vessels with soft subcutaneous tissues, making these areas prone to hematoma formation owing to the rupture of subcutaneous blood vessels.⁶ With increasing age, the elasticity of the birth canal tissue decreases and the brittleness of blood vessels increases.⁷ This increases the likelihood of birth canal scarring and poor ductility of the vaginal wall, which further increasing the risk of bleeding and subsequent hematoma formation. However, not all women develop anal swelling. Consequently, an ultrasound examination of the postpartum pelvic floor after vaginal delivery is necessary. Doctors should monitor hemoglobin levels or perform a digital rectal test the following day. The present case demonstrates the necessity of these interventions.

Studies have shown that arterial embolization using interventional embolization technology for preventive or therapeutic embolization, such as by interventional angiography, is effective in treating vaginal hematoma.⁸ However, complications can develop, such as excessive embolism, false embolism, and vascular injury.

Urokinase is a type of plasminogen activator with a thrombolytic effect. Thus, it can promote the degradation and transformation of fibrin and massive hematomas.⁹ It has been used in neurosurgery for treating intracranial hematomas with a remarkable curative effect. Based on these successes, we used urokinase in the present case to dissolve the vaginal hematoma and successfully promote hematoma absorption. Performed under ultrasound guidance, urokinase treatment features few side effects, low risk, fast recovery, and accurate treatment. However, this treatment is not a standard procedure for vaginal hematomas. Rather, it is an option when the hematoma is discovered late and is difficult to cut and suture in a patient with normal blood pressure and heart rate. While complications, such as fever, infection, and bleeding, are commonly reported with urokinase treatment of intracranial hematomas,¹⁰ we did not observe such complications in the present case. However, more cases are needed to draw further conclusions.

Urokinase injection presents a new minimally invasive method for treating vaginal hematomas contraindicated for incision and suture. The treatment facilitates the hematoma absorption, reduces the risk of the hematoma affecting rectal and bladder function, and reduces the risk of infection. This study is the first successful report on the treatment of a vaginal hematoma by urokinase injection.