Demographics and preoperative comorbidities
Between January 2003 and December 2017, 44 IAO patients visited Peking Union Medical College Hospital. 16 patients received EVT, 28 patients received aortofemoral bypass. The mean age(61.9y for the EVT group, 56.7 for the bypass group) and male proportion(93.8% for the EVT group, 96.4% for the bypass group) of the two groups were similar(P>.050 each). Cardiovascular risk factors, including hypertension, diabetes mellitus, coronary artery disease hyperlipidemia, smoking, and homocysteinemia were equally prevalent between the two groups(P>.050 each). As for other comorbidities,1 patient had renal insufficiency, and 10 patients had cerebral infarction in total, both of them were equally common between the two groups(P>.050 each)(Table 1).
Preoperative Rutherford classification and physical examination
Most patients had severe claudication. According to the Rutherford classification, 11.4% of patients(n =5) were class II, 61.4%(n =27) were class III, 18.2%(n =8) were class IV, 6.8%(n =3) were class V. Preoperative physical examination showed that most patients had diminished arterial pulse and a significant decrease in ABI(left side: total 0.24,EVT 0.18, bypass 0.33; right side: total 0.29, EVT 0.34, bypass 0.26)(Table 2). The two groups were matched in Rutherford classification(P>.050) and ABI (left side, p = 0.084; right side, p = 0.42)(Table 2)
Perioperative period
Revascularization was all achieved in the aortofemoral bypass group(100%, n=37). In the EVT group, there were 2 cases of technical failure, and the technical success rate was 87.5% (14/16). One case was that the guidewire could not pass through the occluded segment to establish a working route. Considering the patient's advanced age, the surgeon did not perform further treatment. The other case was that the patient underwent catheter-directed thrombolysis before EVT, and then acute renal infarction occurred(Cr 146mmol/L). The patient was discharged with conservative treatment. However, due to the small sample size, there was no statistical difference in the technical success rate between the three groups (P>0.05). The 2 severe complications in the EVT group were acute kidney failure and retroperitoneal hematoma, respectively; the 7 severe complications of the aortofemoral bypass group were severe atrial fibrillation, severe pneumonia, infection of the graft, anaphylactic shock due to anesthesia, severe acute coronary syndrome, acute anterior myocardial infarction combined with pneumonia, massive pleural effusion with postoperative intestinal obstruction, respectively. The proportion of serious complications in EVT the group was less than that of the bypass group (12.5%(2/16) in the EVT group, 25%(7/28) in the aortofemoral bypass group), but there was no statistical difference due to the small sample size(Table 3.). A representative example of the EVT procedure was shown in figure 1. The duration of hospital stays was 4 days for the EVT group, 11 days for the bypass group(Table 3.). There was a significant difference in hospital stay between the EVT group and the bypass groups (P<0.05).
Follow-up
40 out of 44 patients had an effective follow-up after surgery. The median follow-up period was 50.9 months. 31 out of the 40 patients' symptoms disappeared after the operation and reached an asymptomatic state (Table 3). The 1-year, 3-year, and 5-year cumulative symptom-free survival rates were 85.7%, 85.7% and 85.7% in the EVT group, 100%, 94.1% and 80.7% in the aortofemoral bypass group. There was no significant difference in symptom-free survival rate between the two groups according to the log-rank test(P=0.92)(figure 1). The evaluation of primary and secondary patency was not conducted because a majority of asymptomatic patients had not performed any imaging examinations after surgery.