Focusing on Amputation Prevention in a Challenging PAD Anatomical Subset

Abstract

Nationwide limb salvage programs can potentially save the U.S. healthcare system up to 38.5 billion dollars. Low revascularization volume hospitals have been associated with higher lower extremity amputation indices, and there is therefore a need for experienced operators ready to tackle the challenging anatomical subsets that are considered in many cases nonrevascularizable via an endovascular approach. One challenging anatomical subset is the “flush” proximal superficial femoral artery (SFA) occlusion. Pedal access techniques have improved the success of intervening in these types of occlusions, as these caps can be approached retrograde. We present a technique to approach this particular anatomical subset by gaining direct needle access retrograde into the proximal SFA occlusion using extravascular ultrasound with the goal of both increasing the probability of success and shortening procedural time.

VASCULAR DISEASE MANAGEMENT 2019;16(5):E63-E68

Key words: PAD, amputation prevention, critical limb ischemia, hyperbaric oxygen therapy

The medical community has implemented limb preservation programs in response to the already significant economic burden of minor and major amputation. Palli and colleagues concluded that nationwide limb salvage programs can potentially save the U.S. healthcare system up to $38.5 billion.¹ Various models of interdisciplinary cooperation exist, and each exemplifies the titanic collaboration efforts needed to decrease the incidence of amputation. In a recent study, higher lower extremity amputation indices were associated with low revascularization volume hospitals.² Thus, amputation likely represents the most severe manifestation of critical limb ischemia (CLI), and proper revascularization is likely the most appropriate way to bring adequate perfusion to the affected limb.³ In an extensive 22-year prospective study, Boyko and colleagues noted the intricate relationship between macrovascular disease and the protagonist role of poor perfusion on the road to amputation.⁴

Case Presentation

An 82-year-old Hispanic woman was initially referred by her primary care doctor to the Hyperbaric & Wound Care Center at Mercy Hospital in Miami, Florida. She presented with a progressively worsening non-healing painful ulcer for the prior 7 months that now exhibited purulent discharge. Her past medical history included peripheral arterial disease (PAD), chronic obstructive pulmonary disease, hypertension, and 1 pack per day tobacco use for most of her life, though she had quit smoking 4 years ago. The woman described bilateral lower extremity claudication symptoms that had occurred during the prior 3 years upon walking less than a half block. 

Her laboratory results revealed anemia and an elevated erythrocyte sedimentation rate. On physical examination, she appeared underweight and older than her stated age. There was a full thickness ulceration of the left plantar first metatarsal with necrotic base and positive probe to bone (Figure 1). The peri-wound was dusky in appearance with atrophic changes consistent with chronic disease. The temperature was warm to cool from tibial tuberosity to digits with delayed capillary filling time. Pedal pulses were non-palpable. Lower extremity arterial Doppler revealed extensive left lower extremity PAD with monophasic wave forms in the infrapopliteal vessels with occlusive disease. An MRI of the left foot showed no evidence of osteomyelitis with ulceration of the plantar aspect of the foot superficial to the proximal phalanx of the first toe, as well as nonspecific minimal marrow within the lateral sesamoid without circumscribed collection, suggesting an abscess and subcutaneous edema. In view of her clinical presentation, lower extremity angiography was recommended. This revealed:

• Aneurysmal infrarenal aorta with moderate atherosclerotic disease;

• Left common and external iliac arteries with 30%-40% stenosis;

• Left common femoral artery (CFA) with 40%-50% calcified stenosis;

• Left superficial femoral artery (SFA) with "flush" 100% occlusion at the proximal segment extending distally into the popliteal artery (Figures 2A and 2B);

• Left popliteal artery with 100% occlusion proximally with reconstitution at the mid segment via profound artery collaterals (Figure 2B);

• Left anterior tibial with 100% occlusion and reconstitution at the ankle (Figure 2C);

• Left posterior tibial (PT) diffuse was the single vessel runoff to the foot 95%-99% segmental stenosis (Figure 2C);

• Left peroneal artery had mild diffuse disease and collateralized the anterior tibial (Figure 2C);

Endovascular Technique 

A 5 French (Fr) 11 cm sheath that was initially placed in the right CFA was exchanged over a wire for a 7 × 45 cm sheath that was advanced “up and over” and placed antegrade at the ipsilateral left CFA. Brief unsuccessful attempts were made with .018-inch and .014-inch wires to cross the SFA given the calcific proximal “flush” occlusion, with wires favoring the open profunda artery (Figure 2A). Using extravascular ultrasound visualization, a micropuncture needle tip (Cook Medical) was advanced retrograde directly into the proximal left SFA 100% occlusion, and a .014-inch wire was advanced through a needle into the occlusion and across the proximal cap into the left

CFA (Figures 3, 4, and 5A). 

Initially, a 12 g CTO wire (Cook Medical) was eventually successfully crossed with a Hydro ST wire (Cook Medical). This wire was advanced into the antegrade sheath and retrieved through the contralateral hemostasis valve (Figure 6). The micropuncture needle was removed (Figure 7). A CXI .018-inch microcatheter (Cook Medical) was advanced over this wire through the antegrade sheath and, using ultrasound visualization, the catheter was advanced into the proximal left SFA just proximal to the wire exiting the vessel out to the skin (Figures 5B and 8). The wire was removed and manual pressure applied at the ipsilateral retrograde needle/wire entry point for one minute with excellent hemostasis. A therapeutic dose of heparin was given, and we proceeded to intervene through the SFA in standard fashion via the contralateral sheath (Figure 5C). We attempted to advance .018-inch and .014-inch wires antegrade through the SFA, but angiographically the wire appeared to progress to the extraluminal space at the mid portion. We therefore gained retrograde left ankle PT access using ultrasound guidance, and a 5 Fr pedal sheath (Cook Medical) was inserted. The 0.014-inch Hydro ST wire was advanced retrograde through the pedal sheath using 0.014-inch CXI catheter support across the left popliteal artery reconstitution site and through the distal and mid segments of the SFA, appearing angiographically to stay

intraluminal, but unable to reenter the left CFA. 

Knowing our initial retrograde left proximal SFA needle/wire access was intraluminal, we advanced a 3 mm × 40 mm balloon over the antegrade wire into the left CFA/proximal SFA junction and inflated this to nominal pressure to create a new more “reentry-ready” proximal cap (Figures 9A and 10). During antegrade balloon deflation, the retrograde Hydro ST wire was advanced and able to reenter the left CFA (Figures 9B and 11). This wire was inserted into the antegrade sheath (Figure 9C). Through microcatheter exchange, we advanced a Grand Slam wire (Asahi Intecc) antegrade with the tip left in the left popliteal artery rather than the PT to avoid being occlusive at the single runoff vessel. It also allowed us to reduce the risk of causing slow flow and “trashed foot” during intervention, including during atherectomy. 

To avoid embolization with this poor distal runoff, the Jetstream device (Boston Scientific) was used to perform aspiration during atherectomy of the entire SFA into the popliteal artery. Post balloon angioplasty was initially performed with a 3 mm × 220 mm balloon throughout the SFA. The wire was

exchanged for a ViperWire (Cardiovascular Systems Inc) and advanced into the left PT, and orbital atherectomy was performed with a 1.25 mm Solid Crown throughout the posterior tibial artery. Post balloon angioplasty was performed with a 2.5 mm × 220 mm balloon to nominal pressures with excellent results (Figures 12A-B). The wire was exchanged for a.035-inch Glidewire (Terumo) and post balloon angioplasty of the SFA was performed with a 4 mm Lutonix drug-coated balloon (BD PV) to nominal pressures with excellent results (Figures 12C-D). Throughout both Jetstream and orbital atherectomy we allowed “bleed out” through the pedal sheath to enable any possible distal embolization to exit the body. There was no evidence of distal embolization, despite initial poor runoff.  

The Challenge of Proximal SFA Flush Occlusions

Proximal caps can be a challenge in general. When the proximal cap is truly “flush” at the CFA bifurcation, CFA vessel size and the patent profunda artery make it very difficult to direct the wire and/or the support catheters that allow for adequate weight to penetrate that cap, particularly convex and/or significantly calcified caps. Additionally, there is always skepticism that the interventionist might be overly aggressive at the CFA/profunda artery, given the risk of perforation, dissection, and acute closure of the single vessel to the leg. These complications preferably should be treated surgically. 

Pedal access techniques have improved the success of intervening in these types of SFA occlusions, as these caps can be approached retrogradely.⁵ Despite this improvement, the pedal approach does not guarantee that a retrograde wire can be maintained intraluminally, or even if luminal, that the CFA can be reentered. Approaching the proximal SFA occlusion directly under extravascular ultrasound guidance retrograde with a micropuncture needle (Figures 3, 4, and 5A) allows for the visualization of the needle tip well enough to ensure that the wire is intraluminal and also provides great support to advance both 0.014-inch and 0.018-inch wires, both hydrophilic tip and heavy gram wires, with excellent control. The wire can then be advanced into the previously placed antegrade sheath, and a microcatheter can be advanced antegrade past the proximal cap and worked via the standard access (Figures 5B-C). 

Wiring retrograde into the sheath (Figure 6) may be a challenge, but we have used 5-mm snares to retrieve the wire through the antegrade sheath with minimal effort. Multiple cases performed in this manner have taken less than 5 minutes. In this case herein, we gained pedal access via the antegrade approach, but were unable to maintain intraluminal position. We were unable to re-enter the CFA retrograde via the pedal wire for which that initial direct needle access technique helped us to know the antegrade wire was intraluminal at the proximal cap. We could comfortably perform balloon angioplasty across the ostial SFA occlusion/cap (Figure 9A), creating a new reentry cap/point in the SFA (Figure 9B). 

In other cases, we have been able to work through the SFA without needing pedal access. This technique may be restricted to patients who are not of large body habitus, which limits both adequate visualization of the vessel and on occasion, the reach of the micropuncture needle. Particularly in short SFA occlusions or in patients with severe infrapopliteal artery disease where pedal access may not be an option, this approach is an alternative that can be performed easily and quickly, as well as ensure "flush" SFA occlusion proximal cap intraluminal access. This approach can serve as an adjunct in cases in which crossing the proximal cap antegrade or retrograde via pedal access is difficult, and it can also shorten the interventional time.

Conclusions

We continue to search for endovascular techniques to approach certain traditionally challenging anatomical subsets that technology has not yet been able to tackle in the setting of advanced PAD and CLI. Our patient had a deep wound that had developed within the prior 7 months and had healed within 4 weeks. Immediately after the endovascular procedure, we witnessed markedly improved perfusion (Figure 13). After the revascularization, our patient underwent 4 hyperbaric oxygen therapy (HBOT) sessions in combination with non-cytotoxic agent cleansing and application of Opticell AG (Medline) as the primary wound dressing. After 6 weeks of local management, the wound was fully epithelialized (Figure 14). Our patient benefited from a team-focused limb salvage and endovascular approach to achieving optimal care. The team approach was in place for early wound care and revascularization,  as well as for post revascularization care (including HBOT), wound care, and follow-up. This approach helped to ensure medical adherence. 

Disclosure: Drs Hernandez, Montoya, and Fuentes have no disclosures to report.

Manuscript submitted on April 11, 2019; accepted on April 18, 2019.

Address for correspondence: Enrique Hernandez, MD, Hyperbaric & Wound Care Center at Mercy Hospital, Miami, Florida. Email: enriquehernandezmd@gmail.com

REFERENCES

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2. Jindeel A, Gessert C, Johnson BP.  Variations and trends in lower extremity amputation rates in Los Angeles County Hospitals 2000-2010. Int J Low Extrem Wounds. 2016;15(3):232-240. 

3. Peacock JM, Keo HH, Duval S, et al. The incidence and health economic burden of ischemic amputation in Minnesota, 2005-2008. Prev Chronic Dis. 2011;8(6):A141.

4. Boyko EJ, Seelig AD, Ahroni JH. Limb- and person-level risk factors for lower-limb amputation in the prospective Seattle diabetic foot study. Diabetes Care. 2018;41(4):891-898.

5. Mustapha JA, Saab F, McGoff  T, et al. Tibio-pedal arterial minimally invasive retrograde revascularization in patients with advanced peripheral vascular disease: the TAMI technique, original case series. Catheter Cardiovasc. Interv. 2014;83(6):987-994.