Reinterventions in Patients with Claudication and Chronic Limb Threatening Ischemia

Insulin Requirement and Infrainguinal Bypass Outcomes in Patients with Peripheral Arterial Disease

BACKGROUND

Diabetes mellitus (DM) is a major risk factor for peripheral artery disease. The association of DM with major adverse limb events (MALE) after lower extremity revascularization remains controversial, as patients with diabetes are typically analyzed as a single, homogenous group. Using a large national database, this study examines the impact of insulin use and glycemic control on the outcomes following infrainguinal bypass. The hypothesis is that prevalent insulin therapy and elevated hemoglobin A1c (HbA1c) are associated with an increased risk of MALEs after infrainguinal bypass in patients with DM and could therefore be used for risk stratification.

METHODS

The Vascular Quality Initiative database files for infrainguinal bypass (2007-2021) were retrospectively reviewed. Patients with DM undergoing bypass for peripheral artery disease were included. Patients on dialysis or with prior kidney transplantation were excluded. The characteristics and outcomes of patients with insulin-requiring diabetes mellitus (IRDM) were compared to those of patients not requiring insulin (noninsulin-requiring diabetes mellitus [NIRDM]) prior to the bypass procedure.

RESULTS

A total of 9,686 patients with DM (56% IRDM) underwent bypass. Patients with IRDM were significantly younger than patients with NIRDM, more likely to be female (P < 0.01), African American (P < 0.01), and Hispanic (P = 0.031), and more likely to have comorbidities and be categorized into American Society of Anesthesiologist classes IV-V. They were more likely to be treated for chronic limb-threatening ischemia (P < 0.001). Patients with IRDM had significantly higher perioperative complications with no difference in perioperative mortality between the 2 groups. Beyond the perioperative period, with a mean follow-up of 427 days, patients with IRDM had significantly lower crude rates of primary patency and higher crude rates of major amputation, MALE, and mortality compared to patients with NIRDM. Regression analyses demonstrated that insulin requirement, but not HbA1c, was independently associated with a higher risk of MALE (hazard ratio = 1.17 [1.06-1.29]) and mortality (hazard ratio = 1.28 [1.16-1.43]).

CONCLUSIONS

Insulin requirement, but not HbA1c, is significantly associated with MALEs and survival after infrainguinal bypass in the Vascular Quality Initiative. Stratification of patients with DM based on their prevalent insulin use prior to infrainguinal bypass surgery could improve the prediction of outcomes of peripheral arterial bypass surgery in patients with diabetes.

Long-term limb salvage and functional outcomes for patients undergoing partial calcanectomy

INTRODUCTION

Partial calcanectomy (PC) can be performed to treat chronic heel ulcers in patients with calcaneal osteomyelitis. Patients undergoing PC often have multiple comorbidities, limited mobility, and face high risk of major limb amputation. This study examined the extent of vascular diagnostic testing and interventions as well as long-term outcomes in patients undergoing PC.

METHODS

A retrospective analysis was performed on patients who underwent PC for non-healing calcaneal ulcer over a ten-year period. Demographics, comorbidities, vascular testing, and procedural data were recorded. Additional subgroup analysis was performed according to presence or absence of peripheral arterial disease (PAD). Primary outcomes were major limb amputation (above or below the knee) and mortality. Secondary outcomes included successful wound healing, time to complete wound healing, re-interventions, and change in ambulatory status.

RESULTS

A total of 157 patients underwent partial calcanectomies on 162 limbs. 78.3% of patients had diabetes mellitus and 47.8% were diagnosed with PAD. Ankle brachial index with pulse volume recording (ABI/PVR) was performed for 46.5% (73/157) of patients, arterial duplex in 44.6% (70/157), and 19.7% (31/157) had a computed tomography angiogram. Lower extremity revascularization was performed in 28.4% of limbs (46/162). Independent ambulatory status was reported in 40.1% prior to PC and decreased to 17.9% by the time of last recorded follow-up (p < .00001). Long-term amputation-free survival was significantly higher in patients without PAD at 7 years (78.4% vs 57.1%, p = .02). Multivariate logistic regression analysis demonstrated that PAD and end-stage renal disease (ESRD) increased the odds of major limb amputation (OR 3.5 and 2.8, respectively), whereas ESRD and adjuvant podiatric procedures were associated with increased mortality (OR 4.8 and 4.8, respectively).

CONCLUSION

Non-invasive vascular testing should be obtained in all patients undergoing PC, in order to stratify risk of amputation and identify candidates for revascularization. Over the long-term, patients undergoing PC face significant risk of prolonged wound healing, decline in ambulatory status, and major limb amputation.

Perioperative complications of minor and major reinterventions for peripheral arterial disease

INTRODUCTION

Patients with peripheral arterial disease (PAD) frequently require reinterventions after lower-extremity revascularization (LER) to maintain perfusion. Current Society for Vascular Surgery guidelines define reinterventions as major or minor based on the magnitude of the procedure. While prior studies have compared primary LER procedures of different magnitudes, similar studies for reinterventions have not been performed. The objective of this study is to compare perioperative outcomes associated with major and minor reinterventions.

METHODS

Patients undergoing LER for PAD at a tertiary care center from 2013 to 2017 were included. A retrospective review of electronic medical records was performed, and reinterventions were categorized as major or minor based on the procedure magnitude. Minor reinterventions included endovascular procedures and open revision with patch angioplasty, while major reinterventions were characterized by open surgical or endovascular LER with catheter-directed thrombolysis (CDT). Perioperative outcomes following LER were captured and compared for major and minor reinterventions. An additional subgroup analysis was performed comparing outcomes associated with major reinterventions stratified into open major surgical reinterventions and CDT.

RESULTS

This study included 713 patients over a mean follow-up of 2.5 years. A total of 291 patients underwent 696 ipsilateral reinterventions (range = 1-12 reinterventions). Most reinterventions were minor (72.1%, N = 502) and 27.9% (N = 194) were major. Patients receiving reinterventions had an average age of 67.2 ± 11.5 and most were white (73.5%) males (60.1%) initially treated for claudication (58.2%) and CLTI (41.8%). There was significantly higher post-operative bleeding (9.8% vs 3.4%, p = .001), arterial thrombosis (3.1% vs 1.0%, p = .047), and acute renal failure (6.2% vs 2.4%, p = .014) after major reinterventions than minor. Additionally, major reinterventions had significantly higher return to the OR (17.0% vs 11.3%, p = .046) and longer hospital stays (7.5 vs 4.3 days, p = <.0001). Overall, major reinterventions were associated with significantly increased perioperative morbidity (37.6% vs 19.7%, p ≤ .001) with no difference in perioperative mortality. In the subgroup analysis, open reinterventions resulted in significantly longer hospital stays (8.6 days vs 5.5 days, p ≤ .001) and more wound infections than CDT (11.0% vs 0%, p = .017). However, there was no other significant difference in morbidity or mortality following treatment with open surgical reinterventions or CDT.

CONCLUSIONS

In this study, major reinterventions after LER were associated with greater perioperative morbidity than minor reinterventions, with no difference in mortality. Major reinterventions performed via open surgery and CDT had similar morbidity and mortality.

Advancements in Omics and Breakthrough Gene Therapies: A Glimpse into the Future of Peripheral Artery Disease

Peripheral artery disease (PAD), a highly prevalent global disease, associates with significant morbidity and mortality in affected patients. Despite progress in endovascular and open revascularization techniques for advanced PAD, these interventions grapple with elevated rates of arterial restenosis and vein graft failure attributed to intimal hyperplasia (IH). Novel multiomics technologies, coupled with sophisticated analyses tools recently powered by advances in artificial intelligence, have enabled the study of atherosclerosis and IH with unprecedented single-cell and spatial precision. Numerous studies have pinpointed gene hubs regulating pivotal atherogenic and atheroprotective signaling pathways as potential therapeutic candidates. Leveraging advancements in viral and nonviral gene therapy (GT) platforms, gene editing technologies, and cutting-edge biomaterial reservoirs for delivery uniquely positions us to develop safe, efficient, and targeted GTs for PAD-related diseases. Gene therapies appear particularly fitting for ex vivo genetic engineering of IH-resistant vein grafts. This manuscript highlights currently available state-of-the-art multiomics approaches, explores promising GT-based candidates, and details GT delivery modalities employed by our laboratory and others to thwart mid-term vein graft failure caused by IH, as well as other PAD-related conditions. The potential clinical translation of these targeted GTs holds the promise to revolutionize PAD treatment, thereby enhancing patients' quality of life and life expectancy.

Peripheral Artery Disease: Underappreciated Impact and Residual Cardiovascular Risk Despite Revascularization

This Commentary highlights the under-recognized prevalence and heavy burden of peripheral artery disease (PAD) and its important role as a harbinger of complications of atherosclerotic cardiovascular disease. Although increasing in prevalence globally, PAD is being further accelerated with diabetes, and patients with advanced PAD are at high risk for chronic limb-threatening ischemia. The need for (repeated) revascularization and amputation places a heavy social burden on patients and family, and a heavy financial burden on the health care system, exceeding the cost of coronary artery and cerebrovascular diseases. Clinical trial research in PAD will be enhanced by widely agreed-upon definitions of major adverse cardiovascular events and major adverse limb events. Antithrombotic and lipid-lowering therapies are recommended but underutilized, while the optimal peri-interventional antithrombotic regimen is still under debate. Additional antiinflammatory treatment is currently an unaddressed strategy in the management of patients with PAD, and there is a strong case for the evaluation of widely available antiinflammatory agents such as colchicine.

Differences in Long-Term Outcomes in End-Stage Kidney Disease Patients with Chronic Limb-Threatening Ischemia

BACKGROUND

End-stage kidney disease (ESKD) is a risk factor for peripheral arterial disease and major adverse limb events following infra-inguinal bypass. Despite comprising an important patient population, ESKD patients are rarely analyzed as a subgroup and are underrepresented in vascular surgery guidelines. This study aims to compare the long-term outcomes of patients with and without ESKD undergoing endovascular peripheral vascular intervention (PVI) for chronic limb-threatening ischemia (CLTI).

METHODS

CLTI patients with and without ESKD from 2007-2020 were identified in the Vascular Quality Initiative PVI dataset. Patients with prior bilateral interventions were excluded. Patients undergoing femoral-popliteal and tibial interventions were included. Mortality, reintervention, amputation, and occlusion rates at 21 months following intervention were examined. Statistical analyses were completed with the t-test, chi-square, and Kaplan-Meier curves.

RESULTS

The ESKD cohort was younger (66.4 ± 11.8 vs. 71.6 ± 12.1 years, P < 0.001) with higher rates of diabetes (82.2 vs. 60.9%, P < 0.001) the non-ESKD cohort. Long-term follow-up was available for 58.4% (N = 2,128 procedures) of ESKD patients and 60.8% (N = 13,075 procedures) of non-ESKD patients. At 21 months, ESKD patients had a higher mortality (41.7 vs. 17.4%, P < 0.001) and a higher amputation rate (22.3 vs. 7.1%, P < 0.001); however, they had a lower reintervention rate (13.2 vs. 24.6%, P < 0.001).

CONCLUSIONS

CLTI patients with ESKD have worse long-term outcomes at 2 years following PVI than non-ESKD patients. Mortality and amputation are higher with ESKD, while the reintervention rate is lower. Development of guidelines within the ESKD population has the potential to improve limb salvage.

Eligibility of Patients with Chronic Limb Threatening Ischemia for Deep Venous Arterialization

OBJECTIVES

Percutaneous deep venous arterialization (pDVA) has emerged as a new modality for limb salvage in patients with chronic limb threatening ischemia (CLTI) and no standard option for revascularization. The proportion of patients facing major amputation that are eligible for this technology remains unknown. This study aims to provide a real-life estimate of patient eligibility for pDVA to reduce major amputations.

METHODS

Electronic medical records of 100 consecutive patients with peripheral arterial disease (PAD) who underwent major amputation of 106 limbs were reviewed. Angiograms performed ≤6 months before amputation were assessed by two vascular surgeons. Disease severity was categorized using the Global Limb Anatomic Staging System and patients were classified as ideal, possible, or not candidates for pDVA. Ideal candidates had ≥1 patent tibial artery, no target in the foot, and no proximal disease. Possible candidates had ≥1 patent tibial artery with PAD, no target in the foot, and proximal disease amenable to endovascular therapy. Patients were not eligible if there was no patent tibial artery, extensive PAD, or an arterial target in the foot for bypass.

RESULTS

Of 106 limbs reviewed, 35 (33%) did not undergo angiography ≤6 months before amputation because of infection (n=14), advanced tissue loss (n=10), failed revascularizations (n=8), advanced limb ischemia (n=2), and refusing revascularization (n=1). Thus, 69 lower extremity angiograms (2 incomplete excluded) in 68 patients were analyzed. 15 patients with 16 limbs (23.2%) were identified as candidates for pDVA (ideal=7, possible=9). There were no differences in demographics between the two groups, but candidates for pDVA were less likely to have hyperlipidemia and congestive heart failure than those who were not candidates. pDVA candidates underwent significantly fewer interventions prior to major amputation compared to patients who were not candidates (1.50 ± 0.73 vs 2.61 ± 2.57, p=0.007). Angiographically, patients who were pDVA candidates had significantly higher Inframalleolar GLASS grades (1.81 ± 0.40 vs 0.86 ± 0.41, p<0.0001) but lower Femoropopliteal Glass grades (0.73 ± 1.10 vs 2.43 ± 1.71, p<0.0001) than patients who were not candidates. There was no significant difference in GLASS stage between these two groups (p=0.368). After mean follow-up of 48 months, there was no difference in mortality between both groups (40% vs 32.1%, p=0.567).

CONCLUSION

Among patients considered for revascularization, 23.2% had favorable angiography and 14.7% could have benefited for pDVA as a new therapeutic modality for limb salvage. 33% of major amputations were performed for clinically-deemed unsalvageable CLTI.