Indications for a "Surgery-First" Approach for the Treatment of Lower Extremity Arterial Disease

BACKGROUND

In recent years, there has been a tendency toward an "endovascular-first" approach for the treatment for femoropopliteal arterial disease. The purpose of this study is to determine if there are patients that are better served with an initial femoropopliteal bypass (FPB) rather than an endovascular attempt at revascularization.

METHODS

A retrospective analysis of all patients undergoing FPB between June 2006 - December 2014 was performed. Our primary endpoint was primary graft patency, defined as patent using ultrasound or angiography without secondary intervention. Patients with <1-year follow-up were excluded. Univariate analysis of factors significant for 5-year patency was performed using χ2 tests for binary variables. A binary logistic regression analysis incorporating all factors identified as significant by univariate analysis was used to identify independent risk factors for 5-year patency. Event-free graft survival was evaluated using Kaplan-Meier models.

RESULTS

We identified 241 patients undergoing FPB on 272 limbs. FPB indication was disabling claudication in 95 limbs, chronic limb-threatening ischemia (CLTI) in 148, and popliteal aneurysm in 29. In total, 134 FPB were saphenous vein grafts (SVG), 126 were prosthetic grafts, 8 were arm vein grafts, and 4 were cadaveric/xenografts. There were 97 bypasses with primary patency at 5 or more years of follow-up. Grafts patent at 5 years by Kaplan-Meier analysis were more likely to have been performed for claudication or popliteal aneurysm (63% 5-year patency) as compared with CLTI (38%, P < 0.001). Statistically significant predictors (using log rank test) of patency over time were use of SVG (P = 0.015), surgical indication of claudication or popliteal aneurysm (P < 0.001), Caucasian race (P = 0.019) and no history of COPD (P = 0.026). Multivariable regression analysis confirmed these 4 factors as significant independent predictors of 5-year patency. Of note, there was no statistical correlation between FPB configuration (above or below knee anastomosis, in-situ versus reversed saphenous vein) and 5-year patency. There were 40 FPBs in Caucasian patients without a history of COPD receiving SVG for claudication or popliteal aneurysm that had a 92% estimated 5-year patency by Kaplan-Meier survival analysis.

CONCLUSIONS

Long-term primary patency that was substantial enough to consider open surgery as a first intervention was demonstrated in Caucasian patients without COPD, having good quality saphenous vein, and who underwent FPB for claudication or popliteal artery aneurysm.

Outcomes of Femoropopliteal Bypass for Lifestyle-Limiting Claudication in the Endovascular Era

INTRODUCTION

Outcomes after femoropopliteal bypass for intermittent claudication (IC) remain unclear in the endovascular era.

METHODS

A multi-institutional database was retrospectively queried for all femoropopliteal bypass procedures performed between 1995 and 2020. Demographics, operative details, and outcomes were documented. A statistical analysis included Kaplan-Meier curves and Cox proportional hazards ratios (HR).

RESULTS

A total of 282 patients underwent femoropopliteal bypass surgery for IC. Median age was 68 y (interquartile range, 61-73 y). Bypass conduits included great saphenous vein (GSV) (48.2%), prosthetic grafts (48.9%), and non-GSV autogenous grafts (2.8%). Distal bypass target was above-knee in 62.1% and below-knee in 37.9% of patients. The most common postoperative complications were wound infections (14.2%) followed by unplanned 30-d hospital readmissions (12.4%). Mortality rates were low at 0.4% (30 d) and 3.2% (1 y). Five-year primary patency rates trended highest for claudicants undergoing above-knee bypass with GSV conduit (log-rank P = 0.065). Five-year amputation-free survival rates were highest using GSV conduit regardless of distal bypass target (log-rank P = 0.017). On a multivariable analysis, age (HR 1.02 [1.00-1.04], P = 0.023) and active smoking (HR 1.48 [1.06-2.06], P = 0.021) were identified as risk factors for diminished primary graft patency. Risk factors for amputation-free survival included age (HR 1.03 [1.01-1.05], P < 0.001) and GSV conduit type (HR 0.65 [0.46-0.90], P = 0.011).

CONCLUSIONS

Femoropopliteal bypass among claudicants is associated with high rates of wound infection and hospital readmission. Active smoking portends worse outcomes in this population. These data may inform clinical decision-making regarding surgical intervention for claudication in the endovascular era.

Impact of Anticoagulation/Antiplatelet Therapy on Femoropopliteal Bypass Graft Outcomes

INTRODUCTION

Anticoagulant and antiplatelet (AC/AP) medications have been reported to improve bypass graft patency, however, the optimal AC/AP strategy remains unclear in the heterogenous peripheral artery disease population.

METHODS

A multi-institutional retrospective review utilizing the Research Patient Data Registry (RPDR) database from 1995-2020 was performed for all patients who underwent femoropopliteal bypass procedures. Electronic medical records were used to obtain demographic information, comorbidities, smoking status, operative details (bypass target), postoperative AC/AP medications, postoperative complications, and long-term outcomes were reviewed for the cohort. Cox proportional hazards model was used to determine independent risk factors for major adverse limb events (MALE) following bypass. MALE was defined as reintervention for patency or major amputation of index limb (above- or below-knee amputation).

RESULTS

A total of 1421 patients underwent femoropopliteal bypass between 1995-2020 throughout five institutions included in this study. Complete data was available for 1292/1421 (90.9%) patients. Indications for bypass included intermittent claudication (21.4%), rest pain (30.3%), tissue loss (33.5%), and non-atherosclerotic disease (14.8%). Distal bypass targets comprised above-knee (38.6%) and below-knee (61.4%) popliteal arteries. Patients were divided into six groups based on postoperative AC/AP use including none (n=57, 4.4%), mono-antiplatelet therapy (MAPT) (n=587, 45.4%), dual antiplatelet therapy (DAPT) (n=214, 16.6%), AC alone (n=73, 5.7%), AC+MAPT (n=319, 24.7%), and AC+DAPT (n=42, 3.3%). Postoperative bleeding complications were low for both hematoma (3.7%) and pseudoaneurysm (0.7%). There was no difference in bleeding complications across AC/AP groups (hematoma p=0.61, pseudoaneurysm p=0.31). After adjusting for patient factors, below-knee bypass target (HR 1.25 [1.04-1.52], p=0.019) and bypass for tissue loss (HR 1.40 [1.04-1.88], p=0.028) were independent predictors for MALE. Great saphenous vein conduit trended towards protection for MALE, compared with prosthetic grafts (HR 0.84 [0.70-1.01], p=0.06). No AC/AP regimen was associated with of MALE, even stratifying by above-knee and below-knee bypass cohorts. Median follow-up period was two years.

CONCLUSIONS

Among patients undergoing femoropopliteal bypass grafting, no combination of anticoagulation or antiplatelet medications was associated with improved graft patency, however, a below-knee target and tissue loss were associated with adverse limb events. Anticoagulation and antiplatelet regimen may be individualized post-bypass with regard to other concomitant medical comorbidities.

The aging venous system: from varicosities to vascular cognitive impairment

Aging-induced pathological alterations of the circulatory system play a critical role in morbidity and mortality of older adults. While the importance of cellular and molecular mechanisms of arterial aging for increased cardiovascular risk in older adults is increasingly appreciated, aging processes of veins are much less studied and understood than those of arteries. In this review, age-related cellular and morphological alterations in the venous system are presented. Similarities and dissimilarities between arterial and venous aging are highlighted, and shared molecular mechanisms of arterial and venous aging are considered. The pathogenesis of venous diseases affecting older adults, including varicose veins, chronic venous insufficiency, and deep vein thrombosis, is discussed, and the potential contribution of venous pathologies to the onset of vascular cognitive impairment and neurodegenerative diseases is emphasized. It is our hope that a greater appreciation of the cellular and molecular processes of vascular aging will stimulate further investigation into strategies aimed at preventing or retarding age-related venous pathologies.

Age-related Notch-4 quiescence is associated with altered wall remodeling during vein graft adaptation

BACKGROUND

The link of aging to specific mechanisms of vascular biology is not well understood. We have previously shown that aging is associated with increased vein graft wall thickness and that this process involves the VEGF-Delta/Notch-ephrin/Eph cascade. Therefore, we examined whether Dll-4 or Notch-4 are differentially expressed, according to age, during vein graft adaptation.

MATERIALS AND METHODS

Vein grafts were performed in 6-mo and 24-mo Fischer 344 rats. Gene expression was analyzed by quantitative real-time PCR, and the distribution of Dll-4 and Notch-4 was observed by immunofluorescence.

RESULTS

The expression of Dll-4 and Notch-4 was reduced in vein grafts performed in aged rats compared with the expression in young adult rats. Both Dll-4 and Notch-4 were distributed in vein graft endothelium as well as the outer adventitia, with reduced amounts in the outer adventitia of aged vein grafts. Aged veins had reduced eNOS membrane targeting and colocalization with caveolin-1 as well as reduced eNOS protein expression in comparison to young adult veins. In an exchange model between young and aged animals, heterogeneous vein grafts (Yo(Ag) and Ag(Yo)) showed significantly thicker neointima compared with young (Yo(Yo)) controls, and had Notch-4-positive cells, but not Dll-4-positive cells, diminished in the adventitia. Vein grafts that were air-denuded of endothelium did not show any adaptation to the arterial environment and also lacked both Dll-4 and Notch-4 expression at 3 wk.

CONCLUSIONS

During vein graft adaptation to the arterial environment, both Dll-4 and Notch-4 expression are down-regulated in an aged, but not a young, background. Loss of Notch-4 is associated with loss of attenuation of neointima. The delta-Notch signaling pathway may be active during vein graft adaptation.

Basic data related to surgical infrainguinal revascularization procedures: a twenty year update

In 1990, Dalman and Taylor published a compilation of reported data that were identified by them as related to infrainguinal revascularization procedures in peripheral vascular surgery during the decade of the 1980s. The intervening 20 years has seen revolutionary advances in the field of peripheral vascular surgery, especially in the adoption of endovascular techniques, and an explosion of data related to emerging technologies in the field of infrainguinal revascularization. The tables in this manuscript reflect the evolution of our surgical knowledge during the turn of the 21st century. The superior patency of autologous saphenous vein in all positions is reaffirmed.

Limb ischemia after iliac ligation in aged mice stimulates angiogenesis without arteriogenesis

OBJECTIVE

Older patients are thought to tolerate acute ischemia more poorly than younger patients. Since aging may depress both angiogenesis and arteriogenesis, we determined the effects of age on both angiogenesis and arteriogenesis in a model of severe acute limb ischemia.

METHODS

Young adult (3-months-old) and aged (18-months-old) C57BL/6 mice underwent right common iliac artery and vein ligation and transection. Data were collected on days 0, 7, and 14. Perfusion was measured with a laser Doppler scan and compared to the contralateral limb. Functional deficits were evaluated with the Tarlov scale. Capillary density and endothelial progenitor cell (EPC) number were determined by direct counting lectin-positive/alpha-actin-negative cells and VEGFR2/CXCR4 dually-positive cells, respectively; angiography was performed to directly assess arteriogenesis.

RESULTS

Young adult and aged mice had a similar degree of decreased perfusion after iliac ligation (young, n = 15: 20.4 +/- 1.9%, vs aged, n = 20: 19.6 +/- 1.3%; P = .72, analysis of variance [ANOVA]); however, young mice recovered faster and to a greater degree than aged mice (day 7, 35 +/- 6% vs 17 +/- 4%, P = .046; day 14, 60 +/- 5% vs 27 +/- 7%, P = .0014). Aged mice had worse functional recovery by day 14 compared to young mice (2.3 +/- 0.3 vs 4.3 +/- 0.4; P = .0021). Aged mice had increased capillary density (day 7, 12.9 +/- 4.4 vs 2.8 +/- 0.3 capillaries/hpf; P = .02) and increased number of EPC incorporated into the ischemic muscle (day 7, 8.1 +/- 0.9 vs 2.5 +/- 1.9 cells; P = .007) compared to young mice, but diminished numbers of collateral vessels to the ischemic limb (1 vs 9; P = .01), as seen on angiography.

CONCLUSION

After severe hind limb ischemia, aged animals become ischemic to a similar degree as young animals, but aged animals have significantly impaired arteriogenesis and functional recovery compared to younger animals. These results suggest that strategies to stimulate arteriogenesis may complement those that increase angiogenesis, and may result in improved relief of ischemia.

Endovascular placement of an extraluminal femoropopliteal bypass graft in human cadavers

PURPOSE

A method to create an extraluminal femoropopliteal bypass graft using endovascular techniques was evaluated in situ on cadaver extremities in an attempt to develop a minimally invasive alternative technique for the management of infrainguinal occlusive arterial disease.

METHODS

The endovascular placement of an extraluminal femoropopliteal bypass graft was undertaken in 5 cadaver legs. Following percutaneous access to the popliteal artery (PA) or common femoral artery (CFA), a Rosch-Uchida needle was used to perforate the vascular wall, followed by the creation of an extraluminal tract using a looped wire and catheter. Once the desired level was reached the needle was again used to perforate the vascular wall of the proximal superficial femoral artery (SFA) or PA depending on the access used. Self-expanding expanded polytetrafluoroethylene (ePTFE) stent-grafts were then deployed to establish the extraluminal femoropopliteal bypass connecting the two arterial puncture sites. Following dilatation of the stent-graft, angiography was performed to assess the endoprostheses and to look for contrast leaks.

RESULTS

Technical success was achieved in all 5 legs. Procedure time varied from 15 to 30 min. The angiographic studies performed immediately after completion of the bypass procedure showed patency of the grafts with no evidence of kinking or leakage in any of the cases.

CONCLUSION

This study has proved that the endovascular placement of an extraluminal femoropopliteal bypass graft in human cadaver legs using endovascular techniques under fluoroscopic control is technically feasible.

Diabetes and the outcome of infrainguinal bypass for critical limb ischaemia

AIM

To examine the influence of diabetes mellitus (DM) on the outcome of infrainguinal bypass operations performed for critical foot ischaemia in Chinese patients.

METHODS

A prospective audit of 265 consecutive infrainguinal bypass operations.

RESULTS

Diabetic patients suffered more frequently from ischaemic heart disease (48% vs 25%, P=0.001) and tissue loss (90% vs 79%, P=0.01) at presentation. Cigarette smoking was more prevalent in the non-diabetic (NDM) group (72% vs 51%, P=0.001). Arterial segments distal to the common femoral artery were more often used as inflow to bypass graft in DM patients (36% vs 22%, P=0.02). Operative mortality (seven DM vs one NDM, P=0.19). Early graft failure (7% in DM group vs 10% in NDM group, P=0.24), wound infection rate (24% in DM group vs 17% in NDM group, P=0.21), early limb loss (9% in DM group vs 6% in NDM group, P=0.66) were comparable. However, hospital mortality was higher in DM patients (8% vs 1%, P=0.04). DM patients more frequently required further surgical debridement postoperatively (20% vs 9%, P=0.04). Long-term, patient survival was inferior in the DM group (43% NDM vs 33% DM at 5 years, P=0.03). Primary graft patency (46% DM vs 34% NDM at 4 years P=0.19), secondary graft patency (57% DM vs 47% NDM at 4 years P=0.14) and limb salvage rate (78% vs 81% at 5 years, P=0.79) were comparable.

CONCLUSION

Diabetes mellitus adversely affects hospital mortality and long-term survival. Graft patency and limb salvage are not compromised by the presence of DM.

Infrainguinal bypass graft patency and limb salvage rates in critical limb ischemia: influence of the mode of presentation

Rest pain, ulceration, and gangrene are often considered together in studies describing outcomes in patients with critical limb ischemia. A retrospective analysis of prospectively collected data of 152 infrainguinal bypass grafts performed on 128 patients with chronic critical limb ischemia over a 6-year period was carried out. Grafts were classified according to the mode of presentation and were followed up by regular clinical and duplex examinations. Mean follow-up period was 29 months (range 12 to 60 months). Patients' demographics, risk factors, and graft characteristics were not statistically different between the groups. The 5-year cumulative primary patency rates were 33%, 52%, and 51% for gangrene, ulceration, and rest pain, respectively (p = 0.04). The 5-year cumulative primary assisted patency rates were 46%, 70%, and 72% for gangrene, ulceration, and rest pain, respectively (p = 0.01). The 5-year cumulative secondary patency rates were 48%, 76%, and 75% for gangrene, ulceration, and rest pain, respectively (p = 0.003). The 5-year cumulative limb salvage rates were 59%, 87%, and 83%, for gangrene, ulceration, and rest pain, respectively (p = 0.01). Gangrene is a distinct subcategory of critical limb ischemia with a worse prognosis than ulceration and rest pain and should be classified as such when reporting results of infrainguinal bypass grafts.

The influence of gender difference on the outcomes of infrainguinal bypass for critical limb ischaemia in Chinese patients

PURPOSE

to investigate the influence of gender difference on the outcomes of infrainguinal bypass operations performed in Chinese patients with critical limb ischaemia.

METHODS

we prospectively studied the results of 191 consecutive infrainguinal bypass operations (98 men, 93 women) for critical lower limb ischaemia in Chinese patients.

RESULTS

the women were older than men (median 75 vs 70 years, p=0.001) and cigarette smoking was commoner in men (83% vs 37% p<0.001). The calibre of run-off arteries at the level of distal anastomosis was smaller in women (median 2.5 mm vs 2.0 mm, p=0.03). The 30-day mortality was 3% (five men vs one woman, p=0.09) and early graft failure occurred in 19 patients (12 women vs seven men, p=0.28). At 3 months limb loss occurred in 16 (10 women vs six men, p=0.35) patients. Survival (38% vs 60% at 4 years, p=0.12) was similar in men and women. However, women suffered from poorer primary (33% vs 49% at 3 years, p=0.03) secondary graft patency rates (35% vs 64% at 3 years, p=0.02) than men. Limb survival rate in two groups (75% vs 85% at 4 years, p=0.18) was comparable.

CONCLUSION

following infrainguinal bypass for critical limb ischaemia, early results were similar in both gender groups. In the long-term, women patients suffered from significantly higher graft failure rate. However, their long-term survival and limb salvage rate remained comparable to those of men.