Popliteal Retrograde Approach is Effective and Safe for Superficial Femoral Artery Chronic Total Occlusion

Abstract

Objective: Endovascular treatment (EVT) using a popliteal approach is effective for superficial femoral artery (SFA) chronic total occlusion (CTO); however, its effectiveness, safety, and consequent complications are unclear.

Materials and Methods: We studied 324 consecutive EVTs (in 187 patients) performed at three centers between April 2008 and March 2013, and selected all EVTs that included SFA CTO regions. A total of 91 EVTs (in 65 patients) were included and divided into two groups; “with popliteal approach” (WPA) and “without popliteal approach” (WOPA).

Results: Despite higher rates of hypertension (WPA, 88.9% vs. WOPA, 69.1%; p = 0.04) and CTO length >200 mm (55.6% vs. 28.3%, respectively; p <0.01), the primary success rate was better in the WPA group (97.2% vs. 78.2%, respectively; p <0.01); however, both total complication rate and major complication rate were not significantly different.

We compared popliteal puncture using a sheath and using a microcatheter alone. There were no significant differences between sheath and microcatheter use in terms of primary success rates (95.5% vs. 100%, respectively; p = 0.61) and puncture site complications (22.7% vs. 14.2%, respectively; p = 0.53).

Conclusion: A popliteal approach improved the primary success rate of EVT for SFA CTO.

Introduction

Chronic total occlusion (CTO) of the superficial femoral artery (SFA) is a femoropopliteal disease characterized by long, diffuse occlusions and/or long total occlusions, and it commonly requires endovascular treatment (EVT).¹⁾ The primary success rate of EVT for SFA CTO has improved from 75% in 2001²⁾ to 81%–94% in 2014.³⁾ EVTs for SFA are generally managed by the antegrade approach, which uses a contralateral retrograde puncture or ipsilateral antegrade puncture of the common femoral artery. Alternatively, the popliteal approach is less frequently utilized. The popliteal approach, first reported by Tonnesen et al.⁴⁾ and initially performed with patients in a prone position,⁵⁾ has been associated with complications such as dissections, arterial ruptures, arteriovenous fistula, pseudoaneurysms, bleeding, and hematomas,^6,7) making it less popular than the antegrade approach.⁸⁾ Furthermore, to avoid changing a patient’s position, popliteal puncture with patients lying in the supine position has been reported.⁹⁾ In addition, the use of lower-diameter puncture instruments, such as 3 Fr sheaths or microcatheters, instead of the conventional 4–6 Fr sheaths, has been attempted.^10,11) With the use of these modifying techniques, the aim is to reduce complications and the nuisance of popliteal puncture, and it has since gained popularity.

This study investigates the effectiveness and safety of the popliteal retrograde approach for SFA CTO. We compared EVT with the popliteal approach and EVT without popliteal approach in terms of primary success rates and puncture site complications. Another purpose of this study was to clarify the type of complications occurring during EVT with and without the popliteal approach. Furthermore, we analyzed the details of each complication. Moreover, we evaluated whether using a microcatheter without a sheath decreases puncture site complications.

Materials and Methods

Study design

We retrospectively studied consecutive EVTs in three centers between April 2008 and March 2013, and selected all EVTs in which SFA CTO lesions were included. We included only de novo lesions and excluded acute total occlusions. We included the cases where EVTs were simultaneously performed for other lesions, such as the iliac artery or below the knee arteries, besides the SFA. The study population was divided into two groups: “with popliteal approach’’ (WPA) and “without popliteal approach’’ (WOPA); the primary success and complication rates in both groups were compared. In addition, we compared primary success and complication rates between the two techniques within popliteal punctures: using a sheath and using a microcatheter alone.

This study was approved by the institutional ethical review board of each center. According to the Ethical Guidelines for Epidemiological Research, we published the relevant details of this study maintaining patient confidentiality, and thus the requirement for informed consent was waived.

EVT procedures

We performed EVTs for patients who had peripheral arterial disease (PAD) and had claudication or more severe symptoms after medical and physical therapies. We prescribed one or two of three defined anti-platelet therapies (aspirin, ticlopidine, and clopidogrel). Adding cilostazol and/or sarpogrelate was (not forced) recommended. We required each patient to quit smoking and to exercise for more than 30 min on a daily basis. We performed EVT although patients had symptoms 2 months after starting these therapies. Furthermore, we performed EVT earlier if patients had more severe conditions than claudication.

All three centers were responsible for deciding whether to elect EVT or bypass surgery; however, when patients’ conditions of PAD were more severe than Rutherford stage 6, surgery was elected. The technique of EVTs, including use of popliteal puncture or not, depended on the interventionist in each of the centers; routine procedures were employed. In this retrospective study, we did not set criteria for determining whether we performed a retrograde approach or not. However, we performed a retrograde approach in cases where the lesion had severe calcification and/or the CTO length was relatively long. In three cases of the WPA group, the popliteal approach was performed after the antegrade approach was unsuccessful; there was no rule when including the popliteal approach, but in these three cases, the physician included the popliteal artery when they could not control antegrade guidewires. In all other cases of the WPA group, the popliteal approach was decided in advance. When we performed the popliteal approach in the prone position, we first punctured the popliteal artery with ultrasonography guidance. After puncture and retrograde insertion of either the sheath or a microcatheter, the patients were changed to a supine position. The common femoral artery was then punctured in an antegrade or retrograde manner, using either a 4.5 Fr or 6 Fr sheath, or a sheathless catheter. For certain EVTs, patients were placed in a supine position at the start, and the common femoral artery was punctured first. When we performed popliteal puncture, the desired limb was lifted, then a puncture was made in the popliteal area using a needle inserted upward to form an angle of 45°–60° with skin surface under ultrasonography or angiography guidance. We used a 20 or 22 G needle for popliteal punctures. After these punctures, we administered 5000–8000 U heparin by bolus injection and used 0.014 or 0.018 inch wires for intraluminal intervention. We manipulated guidewires through CTOs under the guidance of ultrasound and angiography. The following techniques were commonly used for hemostasis. Upon insertion of the sheath into the popliteal artery, we inflated a 4–6 mm diameter balloon at 2–4 atm at the puncture site; it acted as a tamponade and spontaneously applied manual compression at the popliteal puncture site. For procedures in which a sheath was not used, we applied compression on the popliteal artery for hemostasis.

Study population

We retrospectively studied 324 consecutive EVTs that were performed in 187 patients. Of these, 91 consecutive EVTs for SFA CTO (in 65 patients; 24 were female, age 44–99 years) were included; there were 36 EVTs performed using the popliteal approach (WPA group), and 55 EVTs performed without the popliteal approach (WOPA group). In the WPA group, a sheath was used in 22 EVTs (4 Fr sheath in 14 patients, 4.5 Fr sheath in two patients, and 6 Fr sheath in one patient), whereas a microcatheter alone was used in 14 EVTs.

Definitions and endpoints

We categorized the length of CTO into five sections: <50 mm, 50–100 mm, 100–150 mm, 150–200 mm, and >200 mm. Patients were designated as having chronic heart failure (CHF) if they were hospitalized because of symptoms of CHF, or if their serum B-type natriuretic peptide (BNP) level was >200 pg/ml before EVT. Patients who had a low-density lipoprotein cholesterol level of >140 mg/dl, glycated hemoglobin (HbA1c) level of >6.5%, and home systolic blood pressure of >140 mm Hg before EVT, or those who were being treated with corresponding medications before or during EVT, were designated as having hyperlipidemia (HL), diabetes mellitus (DM), and hypertension (HT). Ischemic heart diseases were defined if there was a positive history of ischemic heart disease episodes, including angina pectoris and myocardial infarction. Cerebrovascular diseases (CVD) were defined if the patient had history of transient cerebral ischemia and cerebral infarction. Safety of puncture was assessed by the occurrence of major and minor complications. Bleeding and hematomas were defined as major complications if a transfusion or surgical treatment was required and minor complications if transfusion or surgical treatments were not required. Pain lasting ≥2 days was defined as a major complication, whereas pain lasting >2 days was defined as a minor complication. We evaluated whether complications would increase with the addition of the popliteal approach, and if common femoral artery puncture was inevitable in our strategies. We then counted the total number of complications due to puncture. Although a complication occurred because of a common femoral puncture, we counted it as a complication for the WPA group. Primary success was defined as the recovery of good blood flow evaluated by angiography after EVT.

Statistical analysis

Continuous data were analyzed for normal distribution with the Kolmogorov–Smirnov test. Continuous data that were normally distributed were presented as mean ± standard deviation and compared using Student’s t-test. Discrete data were presented as median (interquartile range), and were compared using Wilcoxon signed-rank test. Categorical variables were summarized as frequencies (number). The chi-square test was used to compare categorical variables that were sufficient in number, whereas Fisher’s exact test was used for categories with fewer values. The estimation of cumulative re-stenosis rates was performed using the Kaplan–Meier method, and events were compared using the log-rank test. All p values were two-sided, and a p value <0.05 was considered statistically significant. Statistical analysis was performed using the statistical software JMP 9 developed by SAS institute (Cary, North Carolina, USA).

Results

Flow diagram of procedure and baseline characteristics

The flow diagram of this study is shown in Fig. 1. All attempted popliteal punctures were successfully completed; EVT was successful in 35 of 36 EVTs in the WPA group, and in 43 of 55 EVTs in the WOPA group. The mean age of participants was 70 years. According to baseline characteristics (Table 1), the mean BMI was 22 kg/m². Half of the patients had intermittent claudication, and around 30% had CLI in both groups. In general, the popliteal approach was used in patients who had greater CTO (p <0.01). The proportion of patients with CTO <50 mm was 0% (n = 0) in the WPA group, and 15.1% (n = 8) in the WOPA group. The proportion of EVTs with CTO >200 mm was significantly higher in the WPA group (55.6%, n = 20) than in the WOPA group (28.3%, n = 15). Approximately 15% of patients were on hemodialysis and insulin therapy. Stroke was higher in the WPA group, although this was not statistically significant. The rate of hypertension was significantly higher in the WPA group (WPA, 88.9% vs. WOPA, 69.1%; p = 0.04). Medical therapy was similar in both groups. Statins and ACE-Is/ARBs were prescribed in 50% of the patients, whereas cilostazol was prescribed for >60% of patients. Aspirin was used by 70%–80% of the patients and ticlopidine by 20%. Regarding EVT strategy, there was no significant difference between the two groups; a non-significant greater tendency of stent use existed in the WPA group.

Fig. 1.

Flow diagram of the methodology. EVT: endovascular treatment; SFA: superficial femoral artery; CTO: chronic total occlusion

Complication rates due to puncture and primary success rates

Figure 2 shows the total number of complications (WPA, 13.9% vs. WOPA, 23.6%; p = 0.29) and the number of major complications (WPA 2.8 vs. WOPA, 5.5; p = 0.48) because of puncture were similar in the WOPA and WPA groups. However, the primary success rate was significantly higher in the WPA group than in the WOPA group (97.2% vs. 78.2%, respectively; p <0.01). Although the procedure and fluoroscopy time were longer in WPA, there were no significant differences (Table 1).

Fig. 2.

Comparison of complications and primary success rates between endovascular therapies, with and without popliteal approach (n = 91). Each data are presented as the percentage and compared using Fisher’s exact test.

We showed details of each complication in Table 2. Overall, a total of three complications (two minor bleeds and one major bleed) occurred purely at the popliteal puncture site. Four major complications were observed in our study (one in the WPA group and three in the WOPA group), and retroperitoneal hematoma was the only complication that required interventional hemostasis. This complication occurred because of wire perforation at the common iliac artery. We inflated an 8 mm diameter balloon at the perforation point so that it acted as a tamponade, and gained hemostasis without implanting a covered stent. The other complications were ameliorated using only manual compression. We had no occlusions that resulted in a fatal problem or major amputation.

Microcatheter vs. sheath for popliteal puncture

The primary success rates were similarly high in both strategies (sheath, 95.5% vs. microcatheter alone, 100%; p = 0.61). In the sheath group, one case had bleeding that required transfusion (major complication) and four cases had minor hematoma. In the microcatheter group, no major complications were observed, and two minor complications were observed: one case had a minor hematoma and another case had pain lasting a day because of puncture site oppression. There was no statistically significant difference in either group in terms of major and minor complications (Table 3).

Discussion

Our study shows that the popliteal approach during EVT for SFA CTO was effective and safe in terms of primary procedure success. Moreover, the technique of popliteal puncture was not very difficult, as demonstrated by successful popliteal puncture attempts in all EVTs. There were some complications because of the popliteal approach, but most of them were not severe. Only one primary procedure failure occurred in the WPA group because we delivered an inflated balloon along a guidewire that was in a side branch of the SFA. This failure could have been prevented by carefully checking the guidewire position by routine or intravascular ultrasonography. We attempted to perform intraluminal intervention in all cases. However, the effectiveness of using a 1.5 mm J-tip hydrophilic guidewire¹²⁾ and sub-intimal intervention¹³⁾ to shorten procedure time has been reported. However, when we performed unidirectional sub-intimal intervention, if the guidewire did not re-enter the intraluminal lumen of the artery at the distal end of CTO, we could broaden the length to treat; placement of stents in the common femoral artery and popliteal arteries should be avoided.¹⁴⁾ We believe that a bidirectional approach is particularly important in Japan where a re-entry device is not available for sub-intimal intervention.

The effectiveness of the popliteal retrograde approach was previously confirmed for percutaneous coronary intervention (PCI).¹⁵⁾ During PCI, collateral vessels are used for the retrograde approach; during EVT, we could use collateral or puncture directly. For both direct puncture and collateral approaches, high success rates were reported.^16–18) The collateral approach has the advantage of omitting another puncture, but there are some drawbacks. It is difficult to control and push the retrograde guidewire and microcatheter via collateral, and if the collateral is damaged, which is the only feeder for the distal artery, the patient’s leg condition could become more severe. The drawbacks of direct puncture are complications because of puncture and the nuisance of the puncture. However, as we mentioned in this paper, the major complications because of popliteal puncture are few. Moreover, popliteal puncture in the supine position was useful because we could add a popliteal puncture (though we had to puncture after heparinization) whenever we required to use the retrograde approach. Therefore, we normally used the direct puncture method rather than the collateral approach. Primary success and complication rates did not show any significant difference whether using a sheath or a microcatheter during popliteal puncture. However a certain number of complications were observed in the sheath group. Because primary success rates showed no differences, the use of a microcatheter alone may be better because of easy hemostasis. We found that the best method of EVT for SFA CTO is to start EVT with the antegrade approach and immediately add the retrograde approach from the popliteal artery, or start EVT with a premeditated bidirectional approach.

According to the latest studies, including ours, the primary success rate of EVT for SFA CTO was substantially high and is no longer a major issue. However, mortality and re-stenosis rates in patients who have PAD are reported to be high despite undergoing EVT.¹⁹⁾ Our study revealed low prescription rates of statins and ACEIs/ARBs. Clinicians should consider increasing the utility of these medicines instead of depending on the success of EVT alone.²⁰⁾

There were certain limitations to our study. This was a retrospective observational study and was performed in only three centers; hence, the population size was small and there was a potential for bias. The choice of medications, intention for treatment, indications for EVT, and strategy of EVT including the use of ultrasound guidance or not were limitations. We had a low rate of cilostazol prescription because of hesitation in including it for patients who were already treated with anticoagulant or dual antiplatelet therapy. We did not have a proper specialized exercise therapy center. Our poor non-invasive therapies could affect our results. We included the cases in which not only SFA CTO but also another occluded lesion existed, and the occlusion length was different between the two groups. These variables could have influenced primary success and re-stenosis rates. Finally, our results could be affected by physicians’ subjective judgment and strategy to some extent.

Our study showed in detail on consequent complications so that this study can give some information especially about complications when managing popliteal approach.

Conclusion

The popliteal approach during EVT for SFA CTO was remarkably effective in terms of primary success. The incidence of major complications because of the popliteal approach was low and most of them were not severe.

Disclosure of Conflict of Interest

All authors declare that they have no conflicts of interest.