A Comparison of Femorocrural Bypasses Performed with Modified Heparin-Bonded Expanded Polytetrafluorethylene Grafts and Those with Great Saphenous Vein Grafts to Treat Critical Limb Ischemia

Systematic literature review comparing clinical utility of heparin-bonded expanded polytetrafluoroethylene graft with autologous saphenous vein graft for the management of below-the-knee peripheral arterial disease

BACKGROUND

This systematic literature review compares the clinical outcomes of heparin-bonded expanded polytetrafluoroethylene with autologous saphenous vein in the management of patients undergoing below-the-knee bypass to treat peripheral arterial disease.

METHODS

An electronic literature search was conducted in MEDLINE and Embase to identify comparative studies in patients who underwent below-the-knee surgical bypass. Studies were screened at abstract and full text review using predefined inclusion criteria by two independent reviewers and critically appraised for risk of bias. Meta-analyses were conducted using Review Manager 5 software (Nordic Cochrane Centre).

RESULTS

Eight retrospective cohort studies were identified. Meta-analysis of primary patency demonstrated no significant difference between heparin-bonded expanded polytetrafluoroethylene and autologous saphenous vein grafts after 1 (odds ratio: 0.91, 95% confidence interval: [0.52-1.59]; P = .74), 2 (1.12 [0.60-2.10]; P = .77), 3 (0.62 [0.26-1.48]; P = .28), and 4 years (0.70 [0.36-1.39]; P = .31). Similarly, for secondary patency, no significant difference was detected at 1 (0.62 [0.33-1.15]; P = .13), 2 (0.83 [0.32-2.13]; P = .69), 3 (0.60 [0.27-1.32]; P = .20), and 4 years (0.66 [0.32-1.36]; P = .26). There was no significant difference between autologous veins and heparin-bonded expanded polytetrafluoroethylene for limb salvage and mortality at all time points. A sensitivity analysis to compare outflow vessels was conducted in only tibial bypass and identified no differences. All analyses were considered at high-risk bias because of heterogeneity in study populations and attrition in follow-up.

CONCLUSIONS

This meta-analysis demonstrates similar outcomes between autologous saphenous vein and heparin-bonded expanded polytetrafluoroethylene for patency, limb salvage, and mortality through 4 years. The use of heparin-bonded expanded polytetrafluoroethylene synthetic grafts is a satisfactory option to prevent amputation, particularly when autologous saphenous vein grafts are not available. Controlled clinical studies are needed to further inform future decision-making and economic modeling related to the choice of conduit for below-the-knee graft construction.

Heparin-Bonded Expanded Polytetrafluoroethylene Is a Solution for Infrapopliteal Revascularization in the Absence of an Adequate Autologous Vein Graft

BACKGROUND

To analyze the outcomes of heparin-bonded expanded polytetrafluoroethylene (HePTFE) graft as an alternative conduit in infrapopliteal revascularization of chronic limb-threatening ischemia (CLTI) in the absence of an autologous vein conduit.

METHODS

A single-center retrospective analysis of patients with CLTI submitted to infrapopliteal bypasses with autologous vein graft (VEIN group) or HePTFE graft (HePTFE group) was implemented. Primary end points were freedom from CLTI at 12 months and recurrence of CLTI at 3 years. Secondary end points included freedom from major amputation, amputation-free survival (AFS), survival, and primary (PP) and secondary patency (SP) rates at 3 years of follow-up.

RESULTS

A total of 348 limbs submitted to infrapopliteal bypasses, 214 with venous graft and 134 with HePTFE graft, were followed-up for a median of 25 months. Most patients of the HePTFE group were male (69%), with a median age of 76 years (interquartile range [IQR] 15). Fifty-nine percent of the limbs of the HePTFE group had Wound grade ≥2, being 46% of them infected. Eighty-eight percent were GLASS stage III. Freedom from CLTI was not significantly different between HePTFE and VEIN groups (75% vs. 84%, adjusted hazard ratio [aHR] 0.88, confidence interval [CI] 0.66-1.18, P = 0.401). Recurrence of CLTI was higher in the HePTFE group (42% vs.18% at 3 years; aHR 2.82, CI 1.59-5.00, P < 0.001). The VEIN group achieved higher rates of freedom from major amputation (87% vs.69% at 3 years; aHR 2.21, CI 1.31-3.75, P = 0.003) and AFS (59% vs. 37% at 3 years; aHR 1.39, CI 1.02-1.88, P = 0.036), but no significance in survival (aHR 1.10, CI 0.72-1.66, P = 0.667). Patency rates were inferior in the HePTFE group, with 2-year PP and SP rates of 52% vs. 74%, and 76% vs. 90%, respectively (PP: aHR 1.70, CI 1.11-2.59, P = 0.014; SP: aHR 2.51, CI 1.42-4.42, P = 0.001).

CONCLUSIONS

Infrapopliteal bypass with autologous vein graft is the gold standard to treat CLTI limbs. HePTFE graft should be regarded as an alternative for complex infrapopliteal revascularization when lacking an autologous vein conduct.

Endovascular aneurysm repair with mesenteric artery bypass for abdominal aortic aneurysm with occlusion of celiac and superior mesenteric arteries

A 67-year-old male patient required surgical management of an abdominal aortic aneurysm. Contrast-enhanced computed tomography showed a saccular infrarenal abdominal aortic aneurysm and occlusion of the origins of the celiac artery, superior mesenteric artery, and inferior mesenteric artery. Aortography revealed large amounts of blood flow from capillaries around the abdominal aorta to the inferior mesenteric artery and retrograde blood flow to a meandering mesenteric artery through the superior rectal artery. Considering the risk of bowel ischemia, we performed endovascular aneurysm repair with mesenteric artery bypass. The operation was successful, and his postoperative course was uneventful. This procedure could be useful and less invasive.

Outcomes of Omniflow® II prosthesis used for revascularization in the femoral tract both in infected and non-infected setting

BACKGROUND

Evidence regarding the outcomes of Omniflow® II prosthesis in peripheral arterial revascularization at different anatomical sites and for different indications is scarce. Therefore, the aim of this study was to evaluate the outcomes of the Omniflow® II used at various positions within the femoral tract both in infected and non-infected setting.

METHODS

Patients who underwent reconstructive lower leg vascular surgery with implantation of an Omniflow® II from 2014 until 2021 at five medical centers were retrospectively included (N.=142). Patients were subdivided into the following categories: femoro-femoral crossover (N.=19), femoral interposition (N.=18), femoro-popliteal (above-the-knee [N.=25; AK] or below-the-knee [N.=47; BK]), and femoro-crural bypass grafts (N.=33). Primary outcome was primary patency and secondary outcomes included primary assisted patency, secondary patency, major amputation, vascular graft infection, and mortality. Outcomes were compared according to different subgroups and the surgical setting (infected versus non-infected).

RESULTS

The median follow-up was 35.0 (17.5-54.3) months. Three years primary patency of 58% was observed for femoro-femoral crossover bypass, 75% for femoral interposition graft, 44% for femoro-popliteal above-the-knee bypass, 42% for femoro-popliteal below-the-knee bypass, and 27% in the femoro-crural position (P=0.006). Freedom from major amputation at three years were 84% for femoro-femoral crossover bypass, 88% for femoral interposition bypass, 90% for femoro-popliteal AK bypass, 83% for femoro-popliteal BK bypass, and 50% for femoro-crural bypass (P<0.001).

CONCLUSIONS

This study demonstrates the safety and feasibility of the use of Omniflow® II for femoro-femoral crossover-, femoral interposition-, and femoro-popliteal (AK and BK) bypass. Omniflow® II seems to be less suitable for femoro-crural bypass with a significantly lower patency compared to other positions.

Evaluation of Arterial and Venous Allografts in Subinguinal Bypasses

BACKGROUND

Autologous saphenous vein is the preferred conduit for below-the-knee bypasses in patients with critical limb-threatening ischemia. Alternative graft must be considered for patients without (autologous saphenous vein). The aim of this article is to evaluate the mid-term performance of arterial allograft (AA) and venous allograft (VA) used as alternative conduits.

METHODS

This retrospective study included patients with critical limb-threatening ischemia, with or without a history of homolateral femoropopliteal bypass, and no autologous veins were available who underwent infrainguinal arterial reconstructions using VA or AA from 2008 to 2018. Patients undergoing revision operations for infected bypasses were excluded. Primary patency (PP), primary assisted patency, secondary patency, major amputation, and death from any cause were the endpoints. For each event, a set of analyses were performed.

RESULTS

Overall, 111 patients (63 VAs and 48 AAs) were included, with 108 having below-the-knee bypass. The median follow-up time was 27.8 months (15.6-37.4). The difference in PP between the 2 allograft types was significant (P = 0.049), with 65.9% (43.7-81.0), 44.1% (24.2-62.3), and 44.1% (24.2-62.3) in the AA group, respectively, at 6, 12, and 18 months, whereas 55.6% (40.0-68.6), 46.0% (30.6-60.2), and 33.2% (18.2-49.0) in the VA group. The choice of an AA over a VA was an independent factor associated with patency (for PP: hazard ratio [HR] = 0.43 [0.24-0.75], P = 0.003); primary assisted patency: HR = 0.52 (0.30-0.89], P = 0.018; and secondary patency: HR = 0.49 (0.27-0.88), P = 0.016. The allograft type did not affect either the incidence of major amputation or death from any cause (respectively, HR = 1.20 [0.49-2.93], and 0.88 [0.37-2.14]).

CONCLUSIONS

The nature of the allograft appears to influence the patency of infrainguinal reconstruction, but not the course of the disease. Performant alternative grafts answering infectious issues are needed.

Saphenous vein dilation as an alternative to prosthetic femoral–distal bypass revascularization

A 63-year-old man with a history of bipolar and schizoaffective disorder was admitted to the psychiatry unit. His comorbidities included active smoking, hypertension, diabetes, hyperlipidemia, coronary artery disease after coronary artery bypass grafting, and peripheral arterial disease. During the admission, the patient began to complain of right foot pain at rest. Angiography revealed occlusion of a previously placed right superficial femoral artery and popliteal stents, severe common femoral and distal popliteal stenosis with only a patent posterior tibial (PT) artery runoff. Serial venoplasty was performed and revealed an inadequately sized, ipsilateral great saphenous vein, followed by a delayed femoral–PT in situ saphenous vein bypass. Angiography at 32 months demonstrated a patent femoral–PT great saphenous vein bypass.

Comparison of Cryopreserved Arterial Allografts Versus Heparin-bonded Vascular Grafts in Infragenicular Bypass for Chronic Limb Threatening Ischemia

BACKGROUND

The purpose of this study was to compare cryopreserved arterial allograft (CAA) to heparin-bonded prosthesis (HBP) in infragenicular bypasses for patients with chronic limb-threatening ischemia (CLTI).

METHODS

This retrospective study took place in 2 university hospitals and included 41 consecutive patients treated for CLTI. In the absence of a suitable saphenous vein, an infragenicular bypass was performed using either CAA (24 cases) or HBP (17 cases). Kaplan-Meyer analysis compared primary and secondary patency and amputation-free survival rates. Binomial logistic regression analyzed risk factors for major amputation and thrombosis.

RESULTS

The mean followup was 18.5 months (±14.3) in the CAA group, 17.6 (±6.1) in the HBP group. In the CAA group, primary and secondary patency rates at 12 months were 52% (±10.6) and 61% (±10.3), compared to 88% (±7.8) and 94% (±5.7) in the HBP group, respectively. The difference in patency rates was not statistically different (P = 0.27 and P = 0.28, respectively). The statistically significant factors of graft thrombosis were, a stage 4 from the WIfI classification (Wound Ischemia foot Infection) with a 6 times higher risk (P = 0.04), and a distal anastomosis on a leg artery with a 9 times higher risk of thrombosis (P = 0.03). Amputation-free survival rates at 18 months were similar between the groups (CCA: 75% (±9) versus HBP: 94% (±6), P = 0.11). Patients classified as WIfI stage 4 had 13 times higher odds to undergo major amputation than patients with WIfI stage 2 or 3 (95% CI, 1.16-160.93; P = 0.04). The intervention was longer in the CCA group of 74 min (278 min ± 86) compared to the HBP group (203 min ± 69). This difference was statistically significant (95% CI, 17.86-132.98), t(35) = 2.671, P = 0.01.

CONCLUSIONS

CCA is not superior to HBP in infragenicular bypasses for CLTI, and may not be worth the extra cost and the longer operative duration.

Comparison of Endovascular Versus Bypass Surgery in Femoropopliteal TASC II D Lesions: A Single-Center Study

BACKGROUND

In patients with severe occlusive disease (Trans-Atlantic Inter-Society Consensus II D [TASC II D]) of the femoropopliteal segment, the advantages of endovascular versus bypass revascularization still remain debated. Most reports available in literature comparing percutaneous transluminal angioplasty (PTA) ± bare metal stent (BMS) versus synthetic bypass analyze patients with heterogeneous anatomical lesions creating possible bias when results of different treatments are matched. In this study, we compared early and midterm outcomes of PTA ± BMS versus heparin-bonded expanded polytetrafluoroethylene graft (Propaten-Gore) + Linton patch in patient affected by symptomatic femoropopliteal TASC II-D lesions.

METHODS

Eighty limbs with symptomatic severe occlusive disease (TASC II D) of the femoropopliteal segment observed from January 2013 to January 2017 were included in this retrospective study. Indication to treatment was severe claudication in 17 limbs (21.2%) and critical limb ischemia (CLI) in 63 (78.8%). 36.2% of limbs presented at least 2 distal patent vessels, and 63.8% had only 1 patent vessel. Of these limbs, 40 were treated by means of PTA ± BMS (group A), and 40 were treated by means of femoropopliteal bypass with Propaten-Gore graft + Linton patch (group B). Patients were followed with a clinical assessment and duplex at 1, 6, and 12 months after procedure and then annually. A closer follow-up was performed in case of any complication. Patency, reintervention rate, and limb salvage were compared in the 2 groups.

RESULTS

The mean length of arterial occlusion was 22.1 cm (range, 8-37) in group A versus 25.2 cm (range, 9-41) in group B, P = ns. A slight difference in mean procedural time was observed (83.5 min of group A versus 114 min of group B, minutes, P = 0.02). Mean follow-up was 26.7 months (range, 3-46). Primary patency at 6, 12, and 24 months of group A versus group B was 76.9% vs. 97.5% (P = 0.007), 65.7% vs. 89.1% (P = 0.05), and 52.6% vs. 78.1% (P = 0.005), respectively. Assisted primary patency was 76.9% vs. 97.5% (P = 0.007), 68.5% vs. 91.8% (P = 0.02), and 57.8% vs. 87.5% (P = 0.001), respectively. Secondary patency was 94.8% vs. 97.5% (P = ns), 85.7% vs. 97.2% (P = ns), 73.6% vs. 93.7% (P = 0.004), respectively. Rate of reintervention at 24 months was 45% in group A vs. 20% in group B (P = 0.03). Limb salvage rate at 24 months was 90% for group A vs. 92.5% for group B (P = ns). Univariate analysis showed CLI and poor runoff to be independent risk factors for significant restenosis/occlusion of target artery and reintervention.

CONCLUSIONS

In patients with severe femoropopliteal occlusive disease (TASC II D), the surgical revascularization by means of Propaten-Gore bypass + Linton patch can be considered safe and effective. Early and midterm results of this approach seem to be superior to PTA ± BMS in terms of restenosis/occlusion and reintervention rates. Larger cohort and longer term results are mandatory to better define this advantage.

Results of peripheral bypass surgery in patients with critical limb ischemia (CRITISCH registry)

Aim

On the basis of the CRITISCH registry outcomes in patients with critical limb ischemia (CLI) undergoing lower extremity bypass surgery were analyzed according to the site of distal anastomosis and type of bypass material.

Patients and methods

A total of 284 patients with lower extremity bypasses consisting of 75 patients with bypasses above the knee (group 1), 80 with bypasses below the knee (group 2) and 129 crural or pedal bypasses (group 3) were included in the study. Altogether, 159 autologous saphenous vein grafts and 125 synthetic grafts were used.

Results

There were no perioperative complications in 191 out of the 284 patients (67.3 %) and 236 of the 284 patients (83.1 %) had open bypasses at hospital discharge. An uneventful postoperative course was observed in 76 % of the patients in group 1, 62.5 % in group 2 and 65.1 % in group 3. Amputation-free survival was 86 % at 1 year in group 1, 65 % in group 2 and 69 % in group 3. For bypasses above the knee synthetic grafts were at least not inferior to vein grafts (amputation-free survival at 1 year: prosthetic bypasses 92 % and saphenous vein grafts 71 %, p = 0.147), whereas in the crural/pedal bypass group vein grafts showed better amputation-free survival at 1 year (76 %) compared with synthetic bypasses (56 %, p = 0.105). Patients with a PREVENT III (PIII) CLI risk score ≤3 exhibited better amputation-free survival at 1 year (78 %) compared to patients with a PIII CLI risk score of 4–7 (69 %, p = 0.053). The same applied to patients with Rutherford class 4 vs. Rutherford class 6 CLI.

Conclusion

In patients with CLI and above-knee bypasses, vein grafts confer no benefits compared with synthetic grafts for at least 1 year follow-up; however, in the case of more distal anastomoses vein grafts should be preferred.