Successful Treatment of Massive Pulmonary Embolism in Pregnancy with Catheter-Directed Embolectomy.

A 37-year-old, gravida 1 para 1, presented to our emergency department (ED) with a 1-day onset of a syncopal episode after suffering from dyspnea and chest pain. At the time of presentation, the patient confirmed chest pains, palpitations, and dyspnea. She denied fever, chills, nausea, vomiting, abdominal pain, and leg swelling. Her past medical history was notable for hyperlipidemia, bipolar disorder, morbid obesity, chronic microcytic anemia, and endometriosis. Surgical history included a previous uncomplicated cesarean section. Medications included venlafaxine, ziprasidone, and trazodone. Family and social history were unremarkable. Emergency medical services reported on arrival that the patient's oxygen saturation was 70% on room air and her initial blood pressure (BP) reading was 80/60 mm Hg. She received 100 mL of intravenous fluid (IVF) on her way to the hospital. On presentation in the ED, the patient was afebrile, tachycardic at 120 beats per minute, tachypneic at 31 breaths per minute, BP of 94/73 mm Hg that improved to 122/72 mm Hg after IVF resuscitation, and oxygen saturation of 88% on nonrebreather mask. Physical exam was notable for a diaphoretic woman with obesity in acute respiratory distress. She was placed on bilevel positive airway pressure with her oxygen saturation improving to 100%. A computed tomography angiogram ( Fig. 1 ) was significant for an occlusive bilateral PE beginning at the first bifurcation of the bilateral pulmonary arteries extending to all lobes of the lung, associated significant right heart strain, and a possible intrauterine pregnancy. Therapeutic anticoagulation with unfractionated heparin drip was started and the patient was admitted to the critical care medicine service for further evaluation and monitoring. At this time, laboratory workup incidentally showed beta-human chorionic gonadotropin at 34,003 mIU/mL (normal < 5 mIU/mL) and severe lactic acidosis of 6.9 mmol/L (normal 0.5–2.2 mmol/L). The patient was taken emergently for catheter-directed embolectomy by entrapment ( Fig. 2 ). Computed tomography angiography of the chest. ( A and B ) Frontal view showing massive bilateral pulmonary embolism. ( C and D ) Possible intrauterine pregnancy (yellow circle). Selective right and left pulmonary artery angiography . ( A ) Preintervention impaired perfusion to the right lower lobe. ( B ) Postintervention improvement in perfusion to the right lower lobe. ( C ) Preintervention impaired perfusion to the left lower lobe. ( D ) Postintervention improvement in perfusion to the left lower. Initial survey of the pulmonary vasculature showed significant clot burden in the bilateral main pulmonary arteries, bilateral lower lobes, and the right upper lobe. Her thrombus was aspirated without complication ( Fig. 3 ). Image of the gross specimen removed after catheter-directed embolectomy by entrapment. Postprocedure, the patient's condition improved immediately with heartrate decreasing from 135 to 99 bpm and her oxygen requirements decreasing to 2L/min nasal cannula. The patient underwent hypercoagulable workup that was negative. She continued anticoagulation with heparin drip. A pelvic ultrasound confirmed a viable intrauterine pregnancy estimated at 10 weeks gestation. She was discharged on hospital day 4 with therapeutic low-molecular weight heparin (LMWH) and instructions for close follow-up with maternal–fetal medicine and hematology. The patient did not have any further coagulation issues throughout her pregnancy and remained compliant on her LMWH. She underwent uncomplicated repeat cesarean section and had a female infant weighing 7 lb and 5.8 oz at 38 weeks gestation.

Our patient met the criteria of a massive PE due to her initial BP of 80/60 requiring IVF resuscitation and her associated syncopal episode. 3 Her hemodynamic instability necessitated the consideration of thrombolysis. There is limited data on the efficacy and safety of thrombolysis in pregnancy. Pregnancy is considered a relative contraindication for thrombolysis due to concerns about potential harm to the mother or fetus. 4 However, limited alternative options warrant its consideration, particularly in the setting of a hemodynamically unstable patient. Guidelines specifying the suggested treatment of acute PE with life-threatening hemodynamic instability in pregnancy are detailed below ( Table 1 ): The most common thrombolytic treatment for PE in pregnancy is catheter-directed thrombolysis, a technique involving the delivery of fibrinolytic drugs through a catheter embedded within a thrombus. 12 Several cases report on the safety and efficacy of pharmacologic thrombolysis to treat massive DVT and PE in pregnancy, but this is considered only when the patient's life or limbs are at risk by many prominent medical professional societies. 7 8 9 10 11 There are also several adverse events associated with pharmacologic thrombolysis in pregnancy, such as major bleeding, uterine or placental hemorrhages, and traumatic hematomas. 13 Tissue plasminogen activator has also been shown to take several hours before appreciable clinical improvement, whereas a patient who underwent percutaneous catheter-directed embolectomy such as ours showed rapid improvement afterward. 14 Surgical thrombectomies during pregnancy have been associated with major bleeding episodes (7/35; 95% confidence interval [CI]: 8–37) and fetal death (2/10; 95% CI: 3–56). 12 Percutaneous mechanical thrombectomy notably has a reported maternal survival rate of 100% (7/7' 95% CI: 59–100). 12 This may be due to the technique utilizing a less invasive and targeted approach to remove the patient's clot, thus bypassing the risks of maternal or fetal hemorrhage through surgical injury or movement of fibrinolytic medication into the systemic circulation. There have been several reported cases of using catheter-directed embolectomy as the first-line option to treat severe PE in pregnancy prior to delivery. 6 12 14 15 16 17 18 In two cases, the patients developed complications such as acute kidney injury, spontaneous abortion, and maternal decompensation requiring further treatment with surgical embolectomy. 16 18 In one case, the patient underwent an emergent cesarean section prior to the thrombectomy. 6 Two cases utilized rheolytic thrombectomy where high-pressured jet streams disrupt the thrombus that is aspirated into the catheter. 12 18 19 Our review of literature also yielded two similar cases of catheter-directed embolectomy by entrapment in a peripartum patient: one published by Yarusi et al and one presented by Nemani et al at a meeting. 19 However, the patient in both cases had to be placed emergently on venoarterial extracorporeal membrane oxygenation (VA-ECMO) due to cardiac arrest, which we were able to avoid with our patient. 14 This discrepancy could be due to our patient presenting during the first trimester of her pregnancy and her initial hemodynamic instability leading to a rapid decision to treat with catheter-directed embolectomy. The other two patients were initially hemodynamically stable despite their PE and had spontaneous vaginal deliveries soon after their admissions. 14 However, both patients had cardiac arrests postpartum, necessitating VA-ECMO and later catheter-directed embolectomy. 14 Both patients recovered soon after the procedure and were discharged home on therapeutic LMWH, similar to our patient. 14 The successful outcomes of these three cases indicate there is potential for catheter-directed embolectomy to be considered as a first-line treatment for hemodynamically unstable peripartum and postpartum patients with acute PE. Complications associated with catheter-directed embolectomy include clot dislocation, damage to the heart or vasculature, acute kidney injury, and pulmonary artery dissection. 20 Despite these risks, catheter-directed embolectomy can be considered as an initial treatment option in pregnancy where thrombolytics and surgical thrombectomy place significant risk and complications for both the mother and fetus because it can avoid potentially introducing fibrinolytic medications to the systemic circulation and injury or infection related to surgery. Further discussions and research should attempt to create evidence-based guidelines, involving the input of specialists in obstetrics, cardiology, and critical care medicine. However, this case introduces the possibility of adding catheter-directed embolectomy to the treatment algorithm of massive PE in pregnancy.