Cool Excimer Laser-Assisted Angioplasty vs Tibial Balloon Angioplasty in Management of Infragenicular Tibial Arterial Occlusion in Critical Lower Limb Ischemia TASC D

Abstract

Endovascular revascularization (EVAR) is the current gold standard and first line of therapy for critical limb ischemia (CLI). However, despite the advances of EVAR, there is still concern about its capability for treating complex tibial lesions. This study aims to compare outcomes with cool excimer laser-assisted angioplasty (CELA) vs tibial balloon angioplasty (TBA) in patients with CLI TASC D. The primary endpoints are sustained clinical improvement and amputation-free survival (AFS). Secondary endpoints are binary restenosis, target lesion revascularization (TLR), target extremity revascularization (TER), all-cause survival, and survival free from major adverse events (MAE).

VASCULAR DISEASE MANAGEMENT 2011;8(11):E187–E197

Introduction

Endovascular specialists are often confronted with the escalating incidence of complex co-moribund critical lower limb patients. The growing epidemic of peripheral vascular disease (PVD) is occurring in tandem with the diabetes epidemic and both are developing in the context of an aging population. As a result, critical limb ischemia (CLI) patients are getting older and sicker, and their disease is more complex with a higher incidence of small distal arterial tibial disease.

Initial pessimism about TBA has been dispelled and recent reports have indicated favorable results¹ from conventional TBA especially for older comorbid patients. The key to sustained clinical success is to reduce the rate of immediate failures.

Recently, laser-assisted angioplasty has emerged as a technique that provides enhanced outcome. This success is a product of the relationship between high deliberate practice volume (DPV) and clinical excellence.^2,3 High volumes of procedures and a history of troubleshooting have led to the refinement of laser techniques, thus maximizing the chances of primary technical success. The fact that the successful application of laser has been largely confined to high DPV centers underscores the second statement from the European consensus on CLI, which was published over two decades ago.⁴ More recent publications such as the ACC/AHA⁵ and TASC-II⁶ guidelines have reiterated this view and have shown that tibial techniques have not been well disseminated and for acceptable outcomes they should still only be performed in high DPV centers.

Patients with end-stage CLI exist on borrowed time and amputation is inevitable if no aggressive management is instigated. Amputation and the resultant restricted mobility and unavoidable morbidity expedites death, so the quality of life can be improved by limb salvage if performed in a cost-effective manner. However, a successful tibial bypass carries a morbidity and mortality of up to 86% so limb salvage needs to be achieved by minimally invasive means.⁷

Cool Excimer Laser-Assisted Angioplasty (CELA)

Protracted encroachment of the cool laser catheter will result in the absorption of laser light by tissue and this leads to the production of photo-acoustic, photochemical, and photomechanical energy. This is absorbed by the non-aqueous components of the atherosclerotic plaque and disrupts the molecular bond at cellular level. However the rapid conversion of water-to-water vapor produces an explosive increase in volume and generates stress waves that propagate away from the tissues. The unique properties of photochemical ablation and favorable interaction with thrombus make the cool excimer laser a valuable tool to treat diffuse thrombotic calcified long occlusions in medium to small arteries. It rapidly removes the target thrombus, vaporizes pro-coagulant reactants, avoids a systemic lytic state, facilitates adjunctive balloon angioplasty and stenting as well as augmenting tissue plasminogen activator activity and suppressing platelet aggregation kinetics.^8,9 In essence, CELA enhances immediate technical success by initially debulking the lesion, thereby reducing the amount of tissue that will be compressed against the arterial wall during balloon inflation. Theoretically this ameliorates the arterial wall disruption, which has been well documented with TBA and results in a relatively smooth lumen, which is larger than the laser probe.

Aim of Study
The aim of “Six L” is to compare the outcome of CELA vs TBA in occlusive tibial lesions in patients with CLI TASC II D. The Null hypothesis is that CELA affords no benefit over TBA at 4 years post treatment of occlusive, TASC II D tibial lesions.

More intuitive primary endpoints of sustained clinical improvement and AFS were chosen. Secondary endpoints were binary restenosis rate (defined as duplex peak systolic velocity ratio of more than 2.4 at the target lesion), target lesion revascularization, target extremity revascularization, survival free from MAE, Q-TWIST and cost per quality-adjusted life years (QALY). This prioritization of outcomes acknowledges that the promotion of quality of life and minimal invasiveness are far more important than the outdated and erroneous endpoints of “clinical patency” or “hemodynamic patency.”

Patients and Methods
From June 2005-Dec 2008, 1406 patients were referred with PVD, 472 with CLI. Of the 115 patients presenting with CLI and tibial artery disease with TASC II D lesions, 56 patients were deemed eligible for inclusion in this study. All of these patients presented as emergencies and were allocated to the next available treatment list. Overall, the 56 patients underwent 65 endovascular revascularizations: 35 using TBA and 30 using CELA. In the spirit of minimal-invasiveness without compromising clinical excellence, the sole preoperative imaging tool was duplex ultrasound.¹⁰ In any patient in whom preoperative duplex was inconclusive, mainly due to calcification, we relied on on-table angiogram rather than resorting to MRA or CTA. This contributed to a reduction in contrast load and enhanced cost-effectiveness. All patients ineligible for tibial angioplasty were treated on an ArtAssist program (ACI Medical).¹¹

This study compared the 4-year outcomes following CELA with TBA in TASC D occlusions. The patients had access to the laser option if they were treated in the first 3 days of the week as another institute shares the laser machine.

Treated patients were high-risk: 75% were diabetic and one quarter of all patients had chronic renal insufficiency (Table 1). All patients had CLI Rutherford Category 4, 5, or 6 with rest pain, tissue loss, and/or gangrene (Table 2). There was no significant difference between the groups regarding lesion length, inflow, or run-off. Eighty-five percent of all patients had only one named diseased tibial artery and 60% had no duplex proof of a patent vessel beyond the ankle (Table 3).

All patients were given optimal medical therapy in the form of 80 mg of atorvastatin for one week, which was then reduced to 40mg; 300mg of aspirin; 5mg of atenolol and/or 5mg of amlodipine; and 75mg clopidogrel in the immediate postoperative period. Atorvastatin was only given to patients with normal liver function who could tolerate the high dose. Patients who couldn’t tolerate atorvastatin were shifted to simvastatin or rosuvastatin. Patients with elevated liver function were not commenced on a statin at all. Fasting serum homocysteine levels were checked in all patients and those with elevated levels above 13μmol/L were aggressively managed with folate therapy,¹² commenced on a sequential compression biomechanical device therapy program (ArtAssist), and reassessed after 3 weeks. Blood sugars were rigorously controlled and a consultant diabetologist’s input was readily sought to keep HbA1C levels below 6%.¹³ All patients with elevated NT-proBNP (level >250 pg/mL)^14,15 were cancelled and any patients with myocardial infarction in the preceding 3 months were excluded from the study.¹⁶

All procedures were performed under loco-regional anesthesia on an intention to treat basis. Loco-regional anesthesia had a number of advantages, in the form of accurate digital imaging by elimination of any artifacts due to limb movements on DSA, reduced arterial spasm, and concomitant ulcer debridement or trans-metatarsal amputation.

Technique of Tibial Angioplasty
The contralateral approach was used in 35% of cases. Intraoperatively 4000 units of intravenous heparin were administered after cannulation of the site of entry. The main goal was to maximize the runoff and establish a continuous inline flow beyond the ankle. The anterior or posterior tibial arteries were the preferred targets. Total occlusions were crossed with a 0.014 inch (Submarine, Invatec) or a 0.018 inch V18 guidewire (Boston Scientific) supported with a Quick-Cross catheter (Spectranetics). Long Amphirion Deep balloons (Invatec), 2.5mm or 3.5mm in diameter, and 80 to 220 mm in length, were used. If necessary, a cross was made from the posterior tibial artery to the dorsalis pedis in order to take advantage of recanalization of the foot arch and thereby enhance the outflow and heal deep foot ulcers (Figure 1). In cases where the wire might have extruded through a recent open transmetatarsal amputation to the exterior, this was seen as advantageous and rendered the exchange of catheters, balloons, and stents easier to handle (Figure 2). The subintimal approach was used in 6 of the TBA cases. A total of 13 stents were deployed in 11 of the TBA cases and femoropopliteal angioplasty with/without stenting was performed as an adjuvant procedure in 27 of the TBA cases (Table 4).

Technique of Cool Excimer Laser-Assisted Angioplasty
The laser catheter was advanced slowly at a rate of 0.5mm/sec, with multiple passes, to maximally ablate the target tissue and to prevent dilatation rather than vaporizing the plaque. Saline infusion was used in combination with the slow rate of advancement to minimize the risk of perforation, acute thrombosis, major dissection, and spasm. A total of 15 stents were deployed in 13 of the CELA cases and the following proximal adjuvant procedures were performed: femoropopliteal angioplasty with/without stenting, femoropopliteal vein graft angioplasty, and femoropopliteal synthetic graft angioplasty (Table 4).

Follow-up
Follow-up was performed in the immediate postoperative period, at 6 weeks postoperatively, at 6-month intervals for the first 2 years, and yearly thereafter. The follow-up protocol consisted of interval history (new symptoms) and examination, assessment of wound and/or ulcer sites, measurement of ABIs, and duplex scanning of the entire length of the target lesion. Peak systolic velocities and the velocity ratios were calculated across all identified lesions. A PSV ratio >2.4 together with a drop in ABI of >0.15, in the presence of deterioration in clinical status, was taken as an indication for re-intervention.^{17, 18}

Clinical Improvement

• Perioperative morbidity and mortality rates were compared between groups for the period of hospitalization for the primary procedure.
• Amputation free survival: Kaplan-Meier analysis was used to calculate long-term survival and the cumulative endpoint of AFS and the curves for CELA and TBA were compared by log rank analysis. Only amputations above the level of the mid-forefoot were counted as major amputations. Minor amputations were considered to be of little handicap and often the best that could be achieved in patients who presented with gangrene of the digits.
• Sustained clinical improvement was defined as a persistent upward shift of at least 2 Rutherford categories and/or hemodynamic improvement (ABI >0.15) without the need for repeated TLR in surviving patients. Relief of rest pain, which is essentially a purely subjective phenomenon, was defined for the purposes of this study as complete relief of pain without the use of any analgesics. Only patients with flat surface or transdermal ulcers were admitted to the trial and ischemic cracks between the toes or on the heel were not used as measurable endpoints. Total ulcer healing was taken as the primary endpoint, rather than merely a tendency to healing or reduction in ulcer size.

Procedural Outcome

A distinction was made between clinical success, which applied to the whole limb and binary restenosis, applying to the revascularized segment only.

• Endovascular technical success was defined as successful access and opening of the occluded segment with less than 30% diameter residual stenosis after revascularization.
• Binary restenosis rate was assessed by duplex ultrasound and was defined as a peak velocity ratio of <2.4 at the target lesion and was calculated using Kaplan Meier Survival curves.
• Freedom from repeated TLR was defined as a cumulative endovascular or surgical target lesion redo-procedure in surviving patients with preserved limbs and was calculated using Kaplan Meier survival analysis.
• Freedom from repeated TER was defined as a cumulative analysis of endovascular or surgical target extremity redo-procedure in surviving patients with preserved limb and was calculated using Kaplan-Meier survival analysis.

Hemodynamic outcome

• Immediate hemodynamic improvement: ABI improvement of 0.15;
• Sustained hemodynamic improvement: Cumulative ABI improvement of 0.15 without the need for repeated TLR in surviving patients.

Statistical Analyses

Continuous data are presented as means ± standard deviation; categorical data are given as counts (percentages). Data were analyzed on an intention-to-treat basis. Categorical variables were compared with the chi-square or Fisher exact test where appropriate; continuous variables were examined using a Student t test or Mann-Whitney U test as appropriate. Kaplan-Meier life-table analysis was used to estimate AFS. Kaplan-Meier analysis was also used to compare the rates for sustained clinical improvement, freedom from TLR, freedom from TER, and freedom from binary restenosis.

A Cox proportional-hazards survival regression model was used to predict the influence of the following covariates on AFS: sustained clinical improvement, freedom from binary restenosis, freedom from TLR, and freedom from TER survival curves such as cardiac disease, smoking, renal insufficiency, hypertension, diabetes mellitus, elevated HbA1c (>6.0%), hyperlipidemia, hyperhomocysteinemia (>13.9 μmol/L) and hyperfibrinogenemia (>3.6 g/L). Data from these hazards models were reported as the risk ratio (RR) and 95% CI. P <0.05 was considered significant. Data were analyzed using PASW statistics (Version 17, SPSS Inc.).

Quality of Life Assessment

A special Quality-Adjusted Life Year (QALY) endpoint, which incorporates both length and quality of life, was used to evaluate treatments. TWiST¹⁹ was useful for solving the dilemma of treatment selection if sustained clinical improvement and/or AFS differences were statistically significant but overall survival differences were not, since it deals with the fact that extensions to disease-free time may be at the expense of treatment toxicity (Appendix).

Q-Time spent without symptoms of disease or toxicity from treatment (Q-TWiST)
The Q-TWiST endpoint was used as a natural extension of the quality-of-life oriented endpoint TWiST. Q-TWiST is an adaptation of the concept of QALYs and the methodology was extended so that periods spent with toxicity or relapses were included in the analysis but weighted to represent their quality value relative to TWiST. Thus, overall survival was scaled downwards by arbitrarily giving survival during treatment or symptoms a reduced value.

Utility values for both CELA and TBA were based on values previously derived using a Markov decision analysis model.²⁰

Due to the risk of informative censoring and biased Kaplan–Meier estimates of the survival function, we performed partitioned survival analysis.¹⁹ Overall survival was partitioned into the time spent in each health state (i.e., time spent without symptoms or toxicity from treatment was separated from time spent with toxicity of treatment and time spent with secondary intervention). The mean duration in each state for each group was combined as a weighted sum according to the Q-TWiST model. Weighting the time spent in each health state at the group level, rather that at the individual level, avoided the need to weight censored survival times and thus overcame the problem of informative censoring.

The upper time limit for the analysis, 48 months, was based on the follow-up time of the study cohort and was so chosen to reduce censoring.

A sensitivity analysis was performed in accordance with the methods described by Gelber et al¹⁹ as part of the of Q-TWiST model; Q-TWiST values were compared for both treatment methods across a full range of utility values from 0 to 1, where 0 indicated no impact of subsequent treatments and 1 denoted maximum impact.

Cost
The total costs per procedure, inclusive of follow-up, were calculated in order to estimate the cost per QALY gained and the incremental cost-effectiveness ratio (ICER) of a CELA program relative to the standard TBA program.

Results

Clinical Outcome — Morbidity and Mortality
There was no 30-day mortality in either group and no significant difference in 30-day morbidity between treatment groups (Table 5). Length of hospital stay was similar for both groups (p=0.309).

Time to a MAE (11 vs 9 months, p=0.005) was significantly longer in CELA patients and at 4 years freedom from a MAE was still significantly more likely with CELA. (70% vs 51.4%, p=0.02, HR= 0.37, [95% CI, 0.16 – 0.86]) (Figure 3).

Amputation
Four-year limb salvage rates (93% vs 89%, p=0.482) were improved with CELA. At 4 years, AFS was also improved with CELA (93.3%) compared to TBA (88.5%) but this was not statistically significant (p=0.475, HR=0.56, [95% CI, 0.11-2.78]) (Figure 4).

Sustained Clinical Improvement
Immediate clinical improvement was significantly enhanced in the CELA group with 80% improvement to Rutherford category 3 or less compared to 66% of TBA (p=0.048), with hemodynamic success in 90% of CELA vs 71% of TBA (p=0.041) (Table 7).

Sustained clinical improvement lasted on average 14 months with CELA vs 11 months with TBA (=0.310). Cumulative sustained clinical improvement rates were enhanced with CELA at 48 months (CELA 73.3% vs TBA 65.7%, p=0.310), although this did not quite reach statistical significance. (p=0.409, HR=0.67, [95% CI. 0.27-1.72]) (Figure 5, Table 8).
 

Procedural Outcome

Technical Success
Technical success was 80% using CELA and 74% in the TBA group (p=0.278) (Table 6). Of the 6 failures in the CELA group, one underwent a planter bypass and 5 were commenced on the sequential compression biomechanical device therapy (ArtAssist program). Two of those treated with ArtAssist went on to have a major amputation. One case of compartment leg syndrome was observed in a young patient with Buerger’s disease post-CELA. This required fasciotomy and closure through the shoelaces technique. Technical outcome was independent of type of procedure, stent placement, multilevel interventions, and any adjunctive maneuvers.

Binary Restenosis
Average time to binary restenosis was significantly superior with CELA (12 vs 10 months, p=0.044). At 4 years, freedom from binary restenosis was also improved with CELA (76.6%) when compared to TBA (54.2%), but was not statistically significant. (p=0.0699, HR=0.45, [95% CI, 0.19-1.07]) (Figure 6).

Repeated TLR
Mean time to TLR was significantly superior with CELA (12 vs 9 months, p=0.002). Freedom from TLR in surviving patients with preserved limbs was significantly more likely 4 years post–intervention in the CELA group (93.3%) than in the TBA group (65.7%), p=0.0053, HR=0.219, [95% CI, 0.0752-0.637] (Figure 7). When assessing TLR, we took into account the edge phenomena, where intimal hyperplasia is induced at stent edges of target lesions.

Repeated TER

Mean time to TER was increased with CELA vs TBA (11 vs 10 months, p=0.252) and at 4 years, freedom from TER remained improved with CELA (80% vs. 90%, p=0.256, HR= 0.49, [95% CI, 0.14-1.69]) (Figure 8).

When TLR was subtracted from TER to determine the influence of de novo lesions that arose outside the original target lesion on TER, it gave a more realistic estimate of the rate of revascularization performed due to progression of arteriosclerosis, rather than due to restenosis of the target lesion. This was statistically significant in favor of CELA at 4 years (p=0.005, HR= 0.13, [95% CI, 0.03 – 0.55]) (Figure 9).

Cox Proportional Hazards Ratio
Cox-proportional Hazards ratio analysis did not reveal any factor which had an influence on outcomes at 4 years (Table 9).

Quality of Life Analysis
Time with toxicity of treatment and progression of disease was shorter in CELA patients. Time spent without symptoms of disease or toxicity of treatment (TWiST) was longer in CELA patients at 8.7 months and shorter for TBA at 5.94 months (p=0.071). The Q-TWiST was improved in CELA patients at 9.7 months and TBA was 7.4 months (p=0.078) (Table 10).

Prospective clinical prelude showed that ostial lesions with poor distal run-off have a reduced prospect of distal embolization. Furthermore, CELA ameliorated PTA, if used primarily in instances where the wire can cross but not the balloon. Initially compromised endeavors at crural PTA can be treated successfully with redo-PTA without spoiling subsequent attempts at bypass grafting.

Cost Analysis
In-patient hospital expenses and the costs accumulated during follow-up are shown in Table 11. Mean total cost and cost per QALY were substantially reduced with CELA compared to TBA, with ICER of €2,073.19 per QALY gained in favor of CELA.

Discussion

Endovascular techniques as the primary route of intervention for critically ischemic lower limbs with complex tibial lesions have been the gold standard for almost half a decade. Despite the paucity of published clinical data, the minimally invasive endovascular tibial therapies are a natural choice. Contemporary clinical practice superseded best clinical evidence and demonstrated increasingly favorable outcomes with tibial endovascular technologies, which do not compromise subsequent bypass surgery outcomes.¹ The unprecedented escalation in our elderly population with worsening comorbid status and growing incidence of diabetes gave rise to an enormous cohort of CLI patients with diminished life expectancy. In this population, durability of the procedure is not the primary concern.⁶ Rather, the main objectives of treatment are sustained clinical improvement, such that the maximum number of these patients can have the best quality of life attainable with minimal invasiveness and minimal cost. Once a procedure is easily reproducible with the least amount of morbidity and cost, re-intervention should not be a contraindication.

Although the rates of technical success and durability of complex tibial angioplasty are not as favorable as with bypass surgery, the sustained clinical benefit is more than acceptable because limb salvage rates are equivalent to bypass surgery.¹ Technical success rates of over 80% and limb salvage rates of 90% have been welcomed with rapture, despite secondary patency rates of only of 46% at 3 years, and have encouraged many to persevere with tibial endovascular techniques in the quest to find an ultimate solution for the complex tibial fiasco.^21–23 Such outcomes emphasize the need for more contemporary treatment endpoints than patency.¹⁸ Our technical success rate of 80% for CELA and 74% for TBA mirrors the finding of Vraux et al²⁴ who had 18% technical failures, although our limb salvage rates (CELA vs TBA, 93% vs 89%, p=0.482) at 4 years are more sustained than their limb salvage rate at of 87% at 2 years.

The successful clinical application of contemporary laser technology has been documented with publications from the LACI registry.^3,8,25-27 The LACI publications demonstrated excellent limb salvage rates of 70–95% in a patient population with a high percentage of diabetes, poor distal runoff, and diffuse multilevel disease. The LACI registry proved that the severity, location, and the length of the occlusive lesion do not compromise the technical success or limb salvage rate. The authors concluded that pretreatment with cool laser excimer facilitated guidewire placement in chronic total occlusion, removed the thrombus burden, and provided luminal gain, simplifying the vascular milieu and decreasing the possibility of balloon-induced distal embolization and dissection.

The LACI registry reiterates the point that excellent limb salvage rates are achievable despite less than optimal long-term patency. Patency was initially used to objectively gauge bypass procedural outcomes, but as our population ages and sickens, functional endpoints such as sustained clinical improvement, quality of life, and AFS are more pertinent. Technical refinements are substantially improving endovascular outcomes and techniques such as subintimal angioplasty and laser-assisted angioplasty. These techniques facilitate successful treatment of multilevel long occlusions and justify the use of endovascular therapy as a first line treatment for the most severe classification of disease morphology (e.g., occlusive TASC II D lesions). Vraux et al²⁴ showed that despite a high 46% rate of occlusions at 2 years’ post-intervention, only one third of those with occlusions, had recurrence of their symptoms. Thus, despite lower long-term patency than bypass surgery, tibial angioplasty is indicated in CLI where temporary improvement of vascularization is sufficient to achieve healing of the ulcer or amputation site. Once it is healed, the oxygen demand of the extremity drops. Furthermore, neither early nor late occlusion precludes subsequent conventional surgery. Vraux’s findings emulate our contemporary tactics for such patients at the closing stages of their life.

Despite successful employment of SIA even in more proximal TASC D lesions,²⁸ the patterns of severe tibial disease in the setting of CLI precludes conventional SIA in the majority of TASC II D cases. The reason for this is that TASC D is a multi-level vessel disease, especially in diabetic patients with long highly calcified plaques, which are extremely difficult to cross with guidewires. However, the initial concerns with LASER angioplasty techniques and fine-tuning of the procedure have led to dramatic improvements in technical success and subsequent limb salvage. In multi-level disease the use of concomitant proximal SIA for long occlusive lesions in the femoropopliteal segment in combination with CELA for TASC II D crural vessels has shown phenomenally enhanced outcomes, enhanced our treatment aggressiveness, and expanded our indications for endovascular intervention. Because the majority of these patients, especially those with diabetes, have substantial infection in the limb, endovascular techniques are the preferred option because they permit multi-level revascularization with no subsequent issue of concomitant surgical wound infection.

Utilizing the laser catheter along the whole length of the tibial artery has avoided geographical miss and circumvented tissue recoil. In both the CELA and the TBA group we used long balloons to further reduce the risk of such technical shortfalls.²⁹

Pharmacological manipulation of CLI patients with a high-dose statin, potent antiplatelets, cardio-selective beta-blockers, and agents to ameliorate the effect of hyperhomocysteinemia, together with the exclusion of patients with elevated ProBNP added to enhanced outcome.³⁰

DeRubertis et al³¹ reported that CLI in the presence of diabetes is an independent risk factor for limb loss. All patients in this study presented with advanced CLI in a limb-threatening situation. However, we did not find that diabetes was an independent risk factor for limb loss. We also did not find that chronic renal failure increased the risk of a negative outcome (p>0.05). Therefore, these patient characteristics should not be considered contraindications to endovascular therapy.

Our results in this trial³² underscore the favorable clinical outcomes that are possible with cool excimer laser-assisted angioplasty (Spectranetics) in management of infragenicular tibial arterial occlusion in CLI and contradict the results of Steinkamp et al,³³ who found that only one third of their patients had a successful intervention. However Steinkamp et al limited their number of re-interventions to 3 times after which primary amputation was offered. None of our patients required more than 3 interventions. Only 3 bypasses were done in our series; we had to proceed to distal bypass in one case in the CELA group and 2 cases in the TBA. None of these patients required more distal bypass than previously anticipated and overall this did not hinder our TER rates.

This study is the first to report Q-TWiST for CELA and TBA. Times with toxicity of treatment and progression of disease were shorter in CELA patients. Time of TWiST was longer in CELA patients. The Q-TWiST was improved in CELA patients compared to TBA, with an ICER of €2,073.19 per QALY gained in favor of CELA.

The meta-analysis done by Romiti et al¹ introduced a bias in favor of crural PTA compared with distal bypass surgery, which depicts our current protocol. Haider et al³⁴ asserted that a bypass first crural strategy is not prudent, which contradicts contemporary literature results.

We found that ostial tibial lesions with poor distal run off vessels are better managed with laser with reduced prospect of distal embolization. Laser supplements PTA in instances where the wire can traverse the occlusion but the balloon cannot.

At our university vascular center, in conjunction with other major vascular centers, we have had a paradigm shift towards endovascular CLI management as the primary modality tool. If this is unsuccessful we maintain our goal of minimal invasiveness and offer the ArtAssist program.¹¹ We reserve bypass surgery as a last option before major amputation in patients no longer suitable for endovascular therapy who cannot endure the ArtAssist.

This pivotal observational analogy congregating proportional analysis over 48 months is not randomized and this is one of its foremost shortcomings. However, this study has proven that CELA is feasible and has broadened our scope and elucidated a missed opportunity in complex tibial lesions presenting on an emergency basis.

Conclusion

Failed endeavors at crural PTA can be treated successfully with redo crural PTA without spoiling subsequent attempts at bypass grafting. The ease of use of CELA leads to a standpoint that it is an ethical imperative to treat CLI patients using aggressive procedures in order to further the QALY. Both CELA and TBA have surpassed traditional revascularization techniques with better functional outcomes than any bypass surgery reported in the literature. They impart recuperated anatomical, clinical, and technical success rates in complex tibial vessel lesions. CELA in particular has enhanced immediate clinical improvement, reduced binary restenosis, TLR rates, cost-effectiveness with superior Q-TWiST and QALY, and offers an outstanding survival rate free from MAE at 4 years.

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From the Western Vascular Institute, University College Hospital Galway, Galway, Ireland.
Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.
Manuscript submitted March 31, 2011, provisional acceptance given June 2, 2011, final version accepted August 11, 2011.
Address for correspondence: Sherif Sultan, MD, Western Vascular Institute, University College Hospital Galway, Newcastle Road, Galway, Ireland, E-mail: mrsherif.sultan@gmail.com