Another patient (man, 67 years old) visited our hospital with chest tightness after activity for 1 day on September 10, 2019. This patient had a history of left lower limb trauma 2 months ago without history of hypertension, diabetes mellitus, and smoking. We did some laboratory tests and examinations for this patient immediately after admission to the hospital. Whole blood count analysis revealed a white blood cell count of 7.0 x 109/l (reference range 3.5-9.5 x 109/l), haemoglobin level of 138 g/l (reference range 115-150 g/l), hematocrit level of 39.1% (reference range 40-50%), and a platelet count of 103 x 109/l (reference range 125-350 x 109/l). The results of NT-proBNP and creatine were 5305 pg/ml (reference range 0-1800 pg/ml) and 76.1 mumol/l (reference range 20-98 mumol/l), respectively. The level of troponin was normal. Further examination showed that autoantibodies were normal. The blood pressure was 110/70 mmHg, with 107 heartbeats per minute when admitted to the hospital. An old thrombus was found in the left lower extremity venous ultrasound examination. And pulmonary artery computed tomography angiography (CTA) showed bilateral pulmonary embolism (Figures 3(a) and 3(b)). Electrocardiogram showed SIQIIITIII sign, and echocardiogram showed larger right ventricular transverse diameter (46 mm), decreased left ventricular end diastolic anteroposterior diameter (34 mm), and higher pulmonary artery pressure (44 mmHg). According to the clinical manifestations, CTA, NT-proBNP, and echocardiogram, this patient was diagnosed with submassive pulmonary embolism. Pulmonary angiography was done on September 10, 2019, and the result confirmed pulmonary embolism. In addition, percutaneous mechanical pulmonary thrombectomy was done using the Angiojet system (Figure 4). The injection pattern by urokinase (urokinase 25 wiu + sodium chloride injection 50 ml) was used. And the main left pulmonary artery was treated by the Angiojet system for 20 s, and the main right pulmonary artery was treated by the Angiojet system for 20 s. Thrombus aspiration was performed in both pulmonary arteries using a catheter by 50 ml syringe, and a massive thrombus was extracted (Figures 5(a) and 5(b)). And we placed the catheter in the inferior vena cava. Intravascular thrombolysis by urokinase (100 wiu/day, 1 day) was done after being back in the ward. And low molecular weight heparin was used in hospitalization, and rivaroxaban was used after discharge. In addition, whole blood count analysis revealed a white blood cell count of 6.6 x 109/l (reference range 3.5-9.5 x 109/l), haemoglobin level of 134 g/l (reference range 115-150 g/l), hematocrit level of 37.8% (reference range 40-50%), and a platelet count of 74 x 109/l (reference range 125-350 x 109/l) on September 11. And the level of platelet count was 125 x 109/l (reference range 125-350 x 109/l) on September 12. The results of NT-proBNP and creatine were 1391 pg/ml (reference range 0-1800 pg/ml) and 54.1 mumol/l (reference range 20-98 mumol/l) on September 12 and 22, respectively. And echocardiogram showed decreased right ventricular transverse diameter (29 mm), normal left ventricular end diastolic anteroposterior diameter (51 mm), and normal pulmonary artery pressure (26 mmHg) on September 26. The clinical characteristics of these two patients are shown in Table 1.
In addition, pulmonary artery computed tomography angiography showed pulmonary embolism disappearance in the second patient after 3 months (Figure 6).
The patient was supine, and the conventional bilateral inguinal region skin was disinfected by sterile drapes. 1% lidocaine anesthesia was done in the right femoral vein puncture point, the right femoral vein puncture, implanted with a 5 f sheath pipe. By going through the sheath pipe, the pigtail catheter was placed at the level of L5 by an ultrasmooth guide wire. The patency of inferior vena cava and bilateral renal vein open position were confirmed by angiography. The tail catheter and sheath tube were removed, and the ultrasmooth guide wire was retained. The special long sheath for the filter was replaced using an ultrasmooth guide wire, and the inferior vena cava filter (DENALI) was implanted in the lower segment of the renal vein and the vertical segment of the inferior vena cava. The long sheath of the filter was replaced by a soft sheath tube with a hard guide wire, and the sheath tube was placed near the heart position of the inferior vena cava. Guided by the sheath tube and ultrasmooth guide wire, the pigtail catheter was placed in the main pulmonary artery, and pulmonary angiography was performed to confirm pulmonary embolism. The stiff guide wire through the pigtail catheter at the main left pulmonary artery was placed, the pigtail catheter was removed, and the sheath catheter was placed through the guide wire at the main pulmonary artery. The Angiojet system was placed in the main pulmonary artery through the sheath tube, and the injection device was used for thrombolysis treatment. And then, the Angiojet system was removed, and the catheter was placed into the main pulmonary artery through a sheath tube, with a 50 ml syringe at the end of the catheter for thrombus aspiration. Finally, the pigtail catheter was placed through the sheath at the main pulmonary artery for reexamination. The sheath was withdrawn to the inferior vena cava L5 level under the support from the thread. And we placed the catheter in the inferior vena cava. Intravascular thrombolysis by urokinase (100 wiu/day, 1 day) was done after being back in the ward. After 24 hours, the catheter and sheath tube were pulled out, and local pressure was applied for 10 minutes. Then, the bandages were bandaged. The bandage was removed, and the patient could move out of bed after 24 hours.