An Update on Endovascular Therapy of the Lower Extremities

Physician impact on use of fluoroscopy during endovascular procedures to improve radiation safety

OBJECTIVE

To determine whether differences exist in fluoroscopy time and radiation exposure during lower extremity endovascular procedures performed by fellowship trained vascular surgeons vs general surgeons, to minimize radiation exposure to operating room staff.

METHODS

A retrospective review of all lower extremity endovascular procedures was performed from August 1, 2014, to January 29, 2016. The procedures were performed by the surgical department's four surgeons with endovascular privileges: two vascular surgeons and two general surgeons. Only procedures involving lower extremity arterial angiograms with balloon angioplasty, stenting, or atherectomy were included. The operative records were reviewed for each case. The total fluoroscopy time and total radiation dose for each procedure were recorded. Procedures were grouped according to the number of endovascular interventions as one to two interventions, three to four interventions, and five or more interventions performed. Statistical analysis was performed with a P value of less than .05 considered significant.

RESULTS

About 271 lower extremity endovascular procedures were performed during the study period by 4 surgeons. The average age of the patient population was 70 years. The total number of procedures performed over the study period were 112, 45, 91, and 25 for surgeons 1 through 4, respectively. On average, 3.24 interventions were performed during each procedure. Vascular surgeons were found to have shorter fluoroscopy time for procedures involving one to two (7.8 vs 30.1; P < .01), three to four (9.3 vs 34.2; P < .01), and five or more (11.5 vs 51.9; P < .01) interventions. Vascular surgeons were also found to have less radiation exposure compared with general surgeons in procedures with one to two (1.69 vs 3.53; P = .001) and five or more (2.3 vs 5.4; P = .003) interventions. There was no significant difference in radiation exposure between vascular and general surgeons for procedures with three to four interventions (5.86 vs 5.59; P = .95).

CONCLUSIONS

In this small series at our institution, lower extremity endovascular procedures performed by specialty trained vascular surgeons were associated with both decreased operative fluoroscopy time and decreased radiation exposure when compared with general surgeons.

First-in-man experience of self-expanding nitinol stents combined with drug-coated balloon in the treatment of femoropopliteal occlusive disease

Purpose

The present study aimed to determine the safety and efficacy of a drug-coated balloon inflated within a thin-strut self-expanding bare-metal stent in patients with severe and complex femoropopliteal occlusive disease.

Methods

This prospective study used the Pulsar-self-expanding stent and Passeo-18 Lux drug-coated balloon in patients with severe and complex femoropopliteal occlusive disease. The primary endpoint was the 12-month primary patency, and the secondary endpoints included 24-month primary patency, assisted primary patency, secondary patency, and clinically associated target lesion revascularisation.

Results

The study included 44 patients (51 limbs). The mean age of the patients was 67.6 ± 10.2 years, with 73% men. Chronic limb severity was classified as Rutherford Category III in 41% of the patients, stage IV in 31%, and stage V in 27%. Lesions were predominantly Trans-Atlantic Inter-Society Consensus (TASC 2007) D (51%) and C (45%), with 32 (63%) chronic total occlusions. Procedural success was obtained in all cases. The mean lesion length was 200 ± 74.55 mm (95% CI = 167.09–208.01) with a mean number of stents per limb used of 1.57 ± 0.70 (95% CI = 1.37–1.76). Distal embolisation occurred in two patients. The primary patency rates at the 12- and 24-month follow-up were 94% (95% CI = 82.9–98.1) and 88% (95% CI = 75.7–94.5), respectively. The assisted primary was 94% (95% CI = 82.9–98.1) and secondary patency was 96% (95% CI = 85.2–99.0) at 24-month follow-up. The cumulative stent fracture rate at the 24-month follow-up was 10%. Freedom from clinically driven target lesion revascularisation was 94% (95% CI = 83–98%) at 12-month follow-up and 88% (95% CI = 76–94%) at 24-month follow-up, with two patients requiring a bypass graft.

Conclusion

Our novel approach involving the combination of a thin-strut bare-metal stent and a drug-coated balloon may be safe and effective, with sustainable and promising clinical outcomes up to 24 months after treatment.

Application of rotational atherectomy for a calcified superficial femoral artery lesion

A 78-year-old man on dialysis with a history of femoro-popliteal bypass grafting of his right superficial femoral artery was presented with a recurrence of intermittent claudication. Angiography revealed new heavily calcified stenosis located distal to the anastomosis of the graft. A guide wire was crossed the lesion, however, a balloon catheter could not pass. Rotational atherectomy with Rotablator enabled the balloon to cross the lesion with full dilatation. Due to residual stenosis and dissection, a stent was implanted. Final angiogram showed no residual stenosis with TIMI 3 flow. The patient remained free of symptoms during the 1-year follow-up.

Surgeon education decreases radiation dose in complex endovascular procedures and improves patient safety

OBJECTIVE

Complex endovascular procedures such as fenestrated endovascular aneurysm repair (FEVAR) are associated with higher radiation doses compared with other fluoroscopically guided interventions (FGIs). The purpose of this study was to determine whether surgeon education on radiation dose control can lead to lower reference air kerma (RAK) and peak skin dose (PSD) levels in high-dose procedures.

METHODS

Radiation dose and operating factors were recorded for FGI performed in a hybrid room over a 16-month period. Cases exceeding 6 Gy RAK were investigated according to institutional policy. Information obtained from these investigations led to surgeon education focused on reducing patient dose. Points addressed included increasing table height, utilizing collimation and angulation, decreasing magnification modes, and maintaining minimal patient-to-detector distance. Procedural RAK doses and operating factors were compared 8 months pre- (group A) and 8 months post- (group B) educational intervention using analysis of variance with Tukey pairwise comparisons and t-tests. PSD distributions were calculated using custom software employing input data from fluoroscopic machine logs.

RESULTS

Of 447 procedures performed, 300 FGIs had sufficient data to be included in the analysis (54% lower extremity, 11% thoracic endovascular aneurysm repair, 10% cerebral, 8% FEVAR, 7% endovascular aneurysm repair, 5% visceral, and 5% embolization). Twenty-one cases were investigated for exceeding 6 Gy RAK. FEVAR comprised 70% of the investigated cases and had a significantly higher median RAK dose compared with all other FGIs (P < .0001). There was no difference in body mass index between groups A and B; however, increasing body mass index was an indicator for increased RAK. PSD calculations were performed for the 122 procedures that focused on the thorax and abdomen (group A, 80 patients; group B, 42 patients). Surgeon education most strongly affected table height, with an average table height elevation of 10 cm per case after education (P < .0001). The dose index (PSD/RAK ratio) was used to track changes in operating practices, and it decreased from 1.14 to 0.79 after education (P < .0001). These changes resulted in an estimated 16% reduction in PSD. There was a trend toward a decrease in patient to detector distance, and the use of collimation increased from 25% to 40% (P < .001) for all cases; however, these did not result in a decrease in PSD. The number of cases that exceeded 6 Gy RAK did not change after education; however, the proportion of non-FEVAR cases that exceeded 6 Gy decreased from 40% to 20%.

CONCLUSIONS

Surgeon education on the appropriate use of technical factors during FGIs improved operating practice, reduced patient radiation dose, and decreased the number of non-FEVAR cases that exceeded 6 Gy. It is essential that vascular surgeons be educated in best operating practices to lower PSD; nonetheless, FEVAR remains a high-dose procedure.

Is the length of follow-up evaluation in published reports on the treatment of infrainguinal occlusive disease decreasing?

BACKGROUND

There is increasing pressure for the rapid development and implementation of new techniques and procedures. This study examined whether or not there has been a trend toward increasingly short follow-up times for studies evaluating the treatment of lower-extremity occlusive disease.

METHODS

A search was performed of PubMed using the term "femoropopliteal occlusive disease" from 1976 to 2006. Reports describing the open and/or endovascular treatment of femoropopliteal occlusive disease were classified according to the number of patients, method of treatment, and follow-up time.

RESULTS

A total of 103 of the 435 reports met the inclusion criteria. Average follow-up times from 1976 to 1986 were a mean of 43.3 months and a median of 38.8 months, from 1986 to 1996 were a mean of 32.4 months and a median of 16.9 months, from 1996 to 2006 were a mean of 22.6 months and a median of 16.5 months.

CONCLUSIONS

The number of reports on femoropopliteal occlusive disease treatment has increased. The length of follow-up period was 2- to 3-fold longer for reports on open procedures compared with those on endovascular procedures. Whether length of follow-up evaluation and reporting intervals should be standardized warrants further investigation.

Four-year randomized prospective comparison of percutaneous ePTFE/nitinol self-expanding stent graft versus prosthetic femoral-popliteal bypass in the treatment of superficial femoral artery occlusive disease

BACKGROUND

This is a randomized prospective study comparing the treatment of superficial femoral artery occlusive disease percutaneously with an expanded polytetrafluoroethylene (ePTFE)/nitinol self-expanding stent graft (stent graft) versus surgical femoral to above-knee popliteal artery bypass with synthetic graft material.

METHODS

One hundred limbs in 86 patients with superficial femoral artery occlusive disease were evaluated from March 2004 to May 2005. Patient symptoms included both claudication and limb threatening ischemia with or without tissue loss. Trans-Atlantic InterSociety Consensus (TASC II) A (n = 18), B (n = 56), C (n = 11), and D (n = 15) lesions were included. Patients were randomized prospectively into one of two treatment groups; a percutaneous treatment group (group A; n = 50) with angioplasty and placement of one or more stent grafts, or a surgical treatment group (group B; n = 50) with a femoral to above-knee popliteal artery bypass using synthetic conduit (Dacron or ePTFE). Patients were followed for 48 months. Follow-up evaluation included clinical assessment, physical examination, ankle-brachial indices, and color flow duplex sonography at 3, 6, 9, 12, 18, 24, 36, and 48 months.

RESULTS

Mean total lesion length of the treated arterial segment in the stent graft group was 25.6 cm (SD = 15 cm). The stent graft group demonstrated a primary patency of 72%, 63%, 63%, and 59% with a secondary patency of 83%, 74%, 74%, and 74% at 12, 24, 36, and 48 months, respectively. The surgical femoral-popliteal group demonstrated a primary patency of 76%, 63%, 63%, and 58% with a secondary patency of 86%, 76%, 76%, and 71% at 12, 24, 36, and 48 months, respectively. No statistical difference was found between the two groups with respect to primary (P = .807) or secondary (P = .891) patency.

CONCLUSION

Management of superficial femoral artery occlusive disease with percutaneous stent grafts exhibits similar primary patency at 4-year (48 month) follow up when compared with conventional femoral-popliteal artery bypass grafting with synthetic conduit. This treatment method may offer an alternative to treatment of the superficial femoral artery segment for revascularization when prosthetic bypass is being considered or when autologous conduit is unavailable.

Balloon angioplasty compared with stenting for treatment of femoropopliteal occlusive disease: a meta-analysis

BACKGROUND

The goal of this study was to review the currently available literature and to compare the short and long-term results of primary stenting and angioplasty of femoropopliteal occlusive disease by performing a meta-analysis review.

METHODS

A systematic review of the literature that was published between September 2000 and January 2007 was performed. All studies that reported data on the long-term results after balloon dilatation or stent implantation were included if at least one-year primary patency or restenosis rate was presented; the study follow-up was at least 1 year and the number of subjects at the start of study was at least 20 patients. Three investigators independently extracted the data. The Pooled survival curves were then constructed for graft patency according to a random-effects protocol for meta-analysis.

RESULTS

Twenty-four articles were initially identified but only seven were selected and included in this meta-analysis: seven were RCTs publications and one was a retrospective study comparing the outcome of angioplasty and stenting of the femoropopliteal segment. In our meta-analysis, there were a total of 934 patients with 452 patients who underwent balloon angioplasty (273 patients were male) and 482 patients who underwent stenting (297 patients were male). Primary patency at 1-year and postoperative ABI post intervention was used to evaluate the pooled odds ratio (OR) of all studies. The pooled OR of all studies estimate for the 12-month patency rates was 0.989 (95% confidence interval [CI], 0.623 to 1.570, P = .962) showing no difference in outcome between the two groups (SE 0.269% to 1.025%). The pooled OR estimate for the postoperative ABI was 0.869 (95% CI, 0.557 to 1.357, P = .561) showing a slight advantage in favor of the angioplasty group but the P value was not statistically significant (SE 0.282% to 1.326%). The 1-year primary patency rates following balloon angioplasty ranged from 45% to 84.2% and at 2 years it varied from 25% to 77.2%. In the stent implantation group, the 1-year primary patency rates varied from 63% to 90%, and 2-year primary patency ranged from 46% to 87%. Heterogeneity was seen among studies, and publication bias could not be excluded.

CONCLUSIONS

The results of our meta-analysis suggest that stent placement in the femoropopliteal occlusive disease does not increase the patency rate when compared with angioplasty alone at 1 year. This conclusion should be viewed in the light of study-design considerations and all limitations in this meta-analysis that may have an impact of the outcome of stenting and angioplasty after a 1-year follow-up.

Ionizing radiation absorption of vascular surgeons during endovascular procedures

OBJECTIVE

Endovascular procedures have become an integral part of a vascular surgeon's practice. The exposure of surgeons to ionizing radiation and other safety issues have not been well studied. We investigated the radiation exposure of a team of vascular surgeons in an active endovascular unit and compared yearly dosages absorbed by various body parts among different surgeons. Patients' radiation exposure was also assessed.

METHODS

The radiation absorption of a team of vascular surgeons was prospectively monitored in a 12-month period. During each endovascular procedure, the effective body, eye, and hand radiation doses of all participating surgeons were measured by mini-thermoluminescent dosimeters (TLD) attached at the chest level under a lead apron, at the forehead at eye level, and at the hand. The type of procedure, fluoroscopy machine, fluoroscopy time, and personal and operating theatre radiation protection devices used in each procedure were also recorded. One TLD was attached to the patient's body near the operative site to measure the patient's dose. The yearly effective body, eye, and hand dose were compared with the safety limits of radiation for occupational exposure recommended by the International Commission on Radiation Protection (ICRP). The radiation absorption of various body parts per minute of fluoroscopy was compared among different surgeons.

RESULTS

A total of 149 consecutive endovascular procedures were performed, including 30 endovascular aortic repairs (EVAR), 58 arteriograms with and without embolization (AGM), and 61 percutaneous transluminal angioplasty and stent (PTA/S) procedures. The cumulative fluoroscopy time was 1132 minutes. The median yearly effective body, eye, and hand dose for the surgeons were 0.20 mSv (range, 0.13 to 0.27 mSv), 0.19 mSv (range, 0.10 to 0.33 mSv) and 0.99 mSv (0.29 to 1.84 mSv) respectively, which were well below the safety limits of the ICRP. The mean body, eye, and hand dose of the chief surgeon per procedure were highest for EVAR. A significant discrepancy was observed for the average hand dose per minute of fluoroscopy among different surgeons. The mean radiation absorption of patients who underwent EVAR, AGM, and PTA/S was 12.7 mSv, 13.6 mSv, and 3.4 mSv, respectively.

CONCLUSION

With current radiation protection practice, the radiation absorbed by vascular surgeons with a high endovascular workload did not exceed the safety limits recommended by ICRP. Variations in practice, however, can result in significant discrepancy of radiation absorption between surgeons.

Plaque excision with the Silverhawk catheter: Early results in patients with claudication or critical limb ischemia

OBJECTIVE

This study was conducted to detail the early experience after infrainguinal atherectomy using the Silverhawk plaque excision catheter for the treatment of symptomatic peripheral vascular disease.

METHODS

A prospective database was established in August 2004 in which data for operations, outcomes, and follow-up were recorded for patients undergoing percutaneous plaque excision for peripheral arterial occlusive disease. Society for Vascular Surgery (SVS) ischemia scores and femoropopliteal TransAtlantic Inter-Society Consensus (TASC) criteria were assigned. A follow-up protocol included duplex ultrasound surveillance at 1, 3, and 6 months and then yearly thereafter. Standard statistical analyses were performed.

RESULTS

During a 17-month period, 66 limbs of 60 patients (37 men [61.7%]) underwent 70 plaque excisions (four repeat procedures). Indications included tissue loss based on SVS ischemia at grades 5 and 6 (25/70), rest pain at grade 4 (22/70), and claudication at grades 2 to 3 (23/70). The mean lesion length was 8.8 +/- 0.7 cm. The technical success rate was 87.1% (61/70). Adjunctive treatment was required in 17 procedures (24.3%), consisting of 14 balloon angioplasties and three stents. Femoropopliteal TASC criteria included 5 TASC A lesions, 14 TASC B lesions, 32 TASC C lesions, and 19 TASC D lesions. Although 17 plaque excisions included a tibial vessel, no patient underwent isolated tibial atherectomy. The mean increase in ankle-brachial index was 0.27 +/- 0.04 and in toe pressure, 20.3 +/- 6.9 mm Hg. Mean duplex ultrasound follow-up was 5.2 months (range, 1 to 17 months). One-year primary, primary assisted, and secondary patency was 61.7%, 64.1%, and 76.4%, respectively. Restenosis or occlusion developed in 12 patients (16.7%) and was detected at a mean of 2.8 +/- 0.7 months. Restenosis or occlusion was significantly more common (P < .05) in patients with TASC C and D lesions compared with patients with TASC A and B lesions. Six (8.3%) of 12 patients underwent reintervention on the basis of duplex ultrasound surveillance results. Four (33.3%) of 12 patients experienced reocclusion during the same hospitalization, and amputation and open revascularization were required in two patients each.

CONCLUSIONS

Percutaneous plaque excision is a viable treatment option for lower extremity revascularization. Outcomes are related to ischemia and lesion severity. Patency and limb salvage rates are equivalent to other endovascular modalities.

Self-expanding nitinol stents for treatment of infragenicular arteries following unsuccessful balloon angioplasty

The feasibility of self-expanding nitinol stents for treatment of infragenicular arteries following unsuccessful balloon angioplasty was assessed. Options for lower limb percutaneous revascularization are limited, especially for complex vessel obstruction. Depending on the lesion and the experience of the interventionalist, the failure rate of balloon angioplasty (PTA) ranges between 10 and 40%. Until recently, no self-expanding stent for the use in the infragenicular arteries was available. This is the first report of the results for 18 consecutive patients who received 4F sheath compatible self-expanding nitinol stents following unsuccessful PTA or early restenosis. Twenty-four stents were implanted in 21 lesions for various indications residual stenosis >50% due to heavy calcification, flow-limiting dissection, occluding thrombus resistant to thrombolyis, thrombaspiration, and PTA, and early restenosis after previous PTA. Stent implantation was feasible in all cases. No complications occurred. After the stent implantation, all primarily unsuccessful interventions could be transformed into successful procedures with no residual stenosis >30% in any case. After 6 +/- 2 months, two of the 18 patients died, and 14 of the 16 remaining patients improved clinically. At follow-up, the patency could be assessed in 14 stented arteries. Three stents were occluded, one stent showed some neointimal hyperplasia (50-70% restenosis), the remaining ten stents showed no restenosis (0-30%). The use of self-expanding nitinol stents in tibioperoneal and popliteal arteries is a safe and feasible option for the treatment of unsuccessful PTA. The 6-months patency is high.

Bypass versus angioplasty in severe ischaemia of the leg (BASIL): multicentre, randomised controlled trial

BACKGROUND

The treatment of rest pain, ulceration, and gangrene of the leg (severe limb ischaemia) remains controversial. We instigated the BASIL trial to compare the outcome of bypass surgery and balloon angioplasty in such patients.

METHODS

We randomly assigned 452 patients, who presented to 27 UK hospitals with severe limb ischaemia due to infra-inguinal disease, to receive a surgery-first (n=228) or an angioplasty-first (n=224) strategy. The primary endpoint was amputation (of trial leg) free survival. Analysis was by intention to treat. The BASIL trial is registered with the National Research Register (NRR) and as an International Standard Randomised Controlled Trial, number ISRCTN45398889.

FINDINGS

The trial ran for 5.5 years, and follow-up finished when patients reached an endpoint (amputation of trial leg above the ankle or death). Seven individuals were lost to follow-up after randomisation (three assigned angioplasty, two surgery); of these, three were lost (one angioplasty, two surgery) during the first year of follow-up. 195 (86%) of 228 patients assigned to bypass surgery and 216 (96%) of 224 to balloon angioplasty underwent an attempt at their allocated intervention at a median (IQR) of 6 (3-16) and 6 (2-20) days after randomisation, respectively. At the end of follow-up, 248 (55%) patients were alive without amputation (of trial leg), 38 (8%) alive with amputation, 36 (8%) dead after amputation, and 130 (29%) dead without amputation. After 6 months, the two strategies did not differ significantly in amputation-free survival (48 vs 60 patients; unadjusted hazard ratio 1.07, 95% CI 0.72-1.6; adjusted hazard ratio 0.73, 0.49-1.07). We saw no difference in health-related quality of life between the two strategies, but for the first year the hospital costs associated with a surgery-first strategy were about one third higher than those with an angioplasty-first strategy.

INTERPRETATION

In patients presenting with severe limb ischaemia due to infra-inguinal disease and who are suitable for surgery and angioplasty, a bypass-surgery-first and a balloon-angioplasty-first strategy are associated with broadly similar outcomes in terms of amputation-free survival, and in the short-term, surgery is more expensive than angioplasty.

Treatment for diabetic foot ulcers

People with diabetes develop foot ulcers because of neuropathy (sensory, motor, and autonomic deficits), ischaemia, or both. The initiating injury may be from acute mechanical or thermal trauma or from repetitively or continuously applied mechanical stress. Patients with clinically significant limb ischaemia should be assessed by a vascular surgeon to determine the need for angioplasty, stenting, or femorodistal bypass. When infection complicates a foot ulcer, the combination can be limb or life-threatening. Infection is defined clinically, but wound cultures reveal the causative pathogens. Tissue specimens are strongly preferred to wound swabs for wound cultures. Antimicrobial therapy should be guided by culture results, and should aim to cure the infection, not to heal the wound. Alleviation of the mechanical load on ulcers (off-loading) should always be a part of treatment. Neuropathic ulcers typically heal in 6 weeks with total contact casting, because it effectively relieves pressure at the ulcer site and enforces patient compliance. The success of other approaches to off-loading similarly depends on the patients' adherence to the effectiveness of pressure relief. Surgery to heal ulcers and prevent recurrence can include tenotomy, tendon lengthening, reconstruction, or removal of bony prominences. However, these procedures may result in secondary ulceration and other complications. Ulcer recurrence rates are high, but appropriate education for patients, the provision of posthealing footwear, and regular foot care can reduce rates of re-ulceration.