Outcomes of a bypass-first strategy in chronic limb-threatening ischemia based on the Global Vascular Guidelines

Learning curve in tibial and pedal bypass with autologous vein graft

OBJECTIVES

The 2019 Global Vascular Guidelines recommended open bypass for patients at average risk with greater limb severity and anatomical complexity. However, the outcomes of tibial and pedal bypass (TPB) are inferior to those of above-the-knee surgical revascularization. This may be due to the technical difficulty and need for development of skills to perform TPB. However, there is a limited knowledge on the learning curve in TPB. Thus, the aim of the study is to assess this learning curve in a single-center retrospective analysis.

METHODS

Cases treated with TPB with an autologous vein conduit in patients with chronic limb-threatening ischemia (CLTI) at a Japanese single center from 2009 to 2022 were analyzed retrospectively. The primary endpoint was the learning curve for TPB.

RESULTS

The study included 449 TPB procedures conducted by a single main surgeon in patients with CLTI (median age, 75 years; 309 males; diabetes mellitus, 73%; end stage renal failure with hemodialysis, 44%). The operative time decreased significantly as the number of cases accumulated (p < .001). Using the cumulative sum (CUSUM) operative time, the learning curve was estimated to be phase 1 (initial learning curve) for 134 cases (1-134); phase 2 (competent period) for 179 cases (135-313); and phase 3 (mastery and challenging period) for 136 cases (314-449). The mean follow-up period was 34 ± 31 months. The 1- and 3-year limb salvage rates of 97% and 96% in phase 3 were significantly higher than those in phases 1 and 2 (p < .001, p = .029). Major adverse limb events (MALE) occurred in 117 (26%) patients, and the 1- and 3-year MALE rates of 10% and 17% in phase 3 were significantly lower than those in phases 1 and 2 (p < .001, p = .009).

CONCLUSIONS

In the study, vascular surgeon required a learning curve of 134 TPB cases to Overcoming the learning curve for bypass was associated with improvement of medium-term outcomes for limb salvage and freedom from MALE.

Effect of gait speed on clinical outcomes after crural and pedal bypass in patients with chronic limb-threatening ischemia

OBJECTIVES

Many factors affect long-term outcomes after open bypass in patients with chronic limb-threatening ischemia (CLTI). Ambulatory status has been suggested to be associated with clinical outcomes, but there is limited knowledge on the effect of gait speed on outcomes. The purpose of this study is to evaluate the effect of gait speed assessed in a 6-min walk test (6MWT) on outcomes after crural and pedal bypass in patients with CLTI.

METHODS

A retrospective analysis was performed in patients with CLTI who underwent a 6MWT at 1 month after crural and pedal bypass at a single center from 2014 to 2021. Comparisons were made between those with high gait speed (HG group, 6-min walk distance (6MWD) > 288 m) and those with low gait speed (LG group, 6MWD ≤288 m). The primary endpoint was survival, and the secondary endpoints were graft patency, limb salvage, wound healing, major adverse cardiovascular events (MACEs), and hospital outcomes.

RESULTS

Of 104 patients with CLTI who underwent a 6MWT after crural and pedal bypass, 46 (44%) and 58 (56%) were placed in the HG and LG groups, respectively. The LG group was older (p < .001), had more female subjects (p = .006), and had a higher prevalence of cerebrovascular disease (p = .042) and tissue loss (p = .007). The median follow-up was 36 (22-57) months. The HG group had significantly higher 3-year primary patency (65% vs 42%, p = .013), 3-year secondary patency (87% vs 66%, p = .018), 3-year overall survival (89% vs 58%, p < .001), and 3-year freedom from MACE (79% vs 67%, p = .039). The 3-year limb salvage and 12-month wound healing rates did not differ between the groups.

CONCLUSIONS

Gait speed in patients with CLTI after crural and pedal bypass was associated with survival, freedom from MACE, and graft patency but not with limb salvage and wound healing. A detailed study of walking ability in these patients may be needed in the future.

Adherence to vascular care guidelines for emergency revascularization of chronic limb-threatening ischemia

Objective

In 2022, the National Health Service Commissioning for Quality and Innovation (CQUIN) indicator for vascular surgery, with its pay-for-performance incentive for timely (5-day) revascularization of chronic limb-threatening ischemia (CLTI), was introduced. We sought to assess its effects in terms of (1) changes in the care pathway process measures relating to timing and patient outcomes; and (2) adherence to the Peripheral Arterial Disease Quality Improvement Framework (PAD-QIF) guidelines for patients admitted with CLTI.

Methods

A retrospective before-and-after cohort study was performed from January to June 2022 of nonelective admissions for CLTI who underwent revascularization (open, endovascular, or hybrid) at Cambridge University Hospitals National Health Service Foundation Trust, a regional vascular "hub." The diagnostic and treatment pathway timing-related process measures recommended in the PAD-QIF were compared between two 3-month cohorts-before vs after introduction of the CQUIN.

Results

For the two cohorts (before vs after CQUIN), 17 of 223 and 17 of 219 total admissions met the inclusion criteria, respectively. After introduction of financial incentives, the percentage of patients meeting the 5-day targets for revascularization increased from 41.2% to 58.8% (P = .049). Improvements were also realized in the attainment of PAD-QIF targets for a referral-to-admission time of ≤2 days (from 82.4% to 88.8%; P = .525) and admission-to-specialist-review time of ≤14 hours (from 58.8% to 76.5%; P = .139). An increase also occurred in the percentage of patients receiving imaging studies within 2 days of referral (from 58.8% to 70.6%; P = .324). The reasons for delay included operating list pressures and unsuitability for intervention (eg, active COVID-19 [coronavirus disease 2019] infection). No statistically significant changes to patient outcomes were observed between the two cohorts in terms of complications (pre-CQUIN, 23.5%; post-CQUIN, 41.2%; P = .086), length of stay (pre-QUIN, 12.0 ± 12.0 days; post-QUIN, 15.0 ± 21.0 days; P = .178), and in-hospital mortality (pre-QUIN, 0%; post-QUIN, 5.9%). Other PAD-QIF targets relating to delivery of care were poorly documented for both cohorts. These included documented staging of limb threat severity with the WIfI (wound, ischemia, foot infection) score (2.9% of patients; target >80%), documented shared decision-making (47.1%; target >80%), documented issuance of written information to patient (5.9%; target 100%), and geriatric assessment (6.3%; target >80%).

Conclusions

The pay-for-performance incentive CQUIN indicators appear to have raised the profile for the need for early revascularization to treat CLTI, engaging senior hospital management, and reducing the time to revascularization in our cohort. Further data collection is required to detect any resultant changes in patient outcomes. Documentation of guideline targets for delivery of care was often poor and should be improved.

Treatment Outcomes between Bypass Surgery and Endovascular Therapy in Patients with Chronic Limb-Threatening Ischemia classified as Bypass-preferred category based on Global Vascular Guidelines

OBJECTIVE

To examine outcomes between bypass surgery and endovascular therapy (EVT) in patients with chronic limb-threatening ischemia (CLTI), classified as bypass-preferred according to the Global Vascular Guidelines (GVG).

METHODS

We retrospectively analyzed the multi-center data of patients who underwent infrainguinal revascularization for CLTI with Wound, Ischemia, and foot Infection (WIfI) Stage 3-4 and Global Limb Anatomical Staging System (GLASS) Stage III, which is classified as bypass-preferred category by the GVG between 2015 and 2020. The endpoints were limb salvage and wound healing.

RESULTS

We analyzed 301 patients and 339 limbs following 156 bypass surgery and 183 EVT. The 2-year limb salvage rates were 92.2% in the bypass surgery group and 76.3% in the EVT group, respectively (P < .01). The 1-year wound healing rates were 86.7% in the bypass surgery group and 67.8% in the EVT group (P < .01). Multivariate analysis shows decreased serum albumin level (P < .01), increased wound grade (P = .04), and EVT (P < .01) were risk factors for major amputation. Decreased serum albumin level (P < .01), increased wound grade (P < .01), GLASS infrapopliteal grade (P = .02), and inframalleolar (IM) P grade (P = .01), and EVT (P < .01) were risk factors for impaired wound healing. Subgroup analysis of limb salvage in patients after EVT, decreased serum albumin level (P < .01), increased wound grade (P = .03), increased IM P grade (P = .04), congestive heart failure (P < .01) were risk factors for major amputation. According to scoring by existence of these risk factors, 2-year limb salvage rates following EVT were 83.0% and 42.8% for the total score of 0-2 and of 3-4, respectively (P < .01).

CONCLUSIONS

Bypass surgery provides better limb salvage and wound healing in patients with WIfI Stage 3-4 and GLASS Stage III, which is classified as bypass-preferred category by the GVG. In patients after EVT, serum albumin level, wound grade, IM P grade, and congestive heart failure were related to major amputation. Although bypass surgery may be considered as initial revascularization procedure in patients classified as bypass-preferred category, in case that EVT has to be selected, relatively acceptable outcomes can be expected in patients with less these risk factors.