Lower Extremity Arterial Bypass with Arm Vein Conduits and Literature Review

Omniflow® II biosynthetic graft offers acceptable early and mid-term outcomes in redo surgery in patients with critical limb-threatening ischemia with no available autologous vein material

BACKGROUND

In this study, the early and mid-term outcomes of Omniflow® II (LeMaitre Vascular, Inc., Burlington, MA, USA) biosynthetic graft in redo surgery in patients with critical limb-threatening ischemia (CLTI) with no available autologous vein material were investigated with the aim to compare the outcomes obtained in "de novo" surgery versus redo surgery.

METHODS

From January 2018 until December 2022, data of CLTI patients from 18 centers in Italy with no autologous vein material underwent infrainguinal bypass with Omniflow® II biosynthetic graft were collected. Thirty-day outcome measures including intraoperative technical success, major morbidity, mortality, and graft patency were assessed and compared. At two-year follow-up, estimated outcomes of survival, primary patency, primary assisted patency, secondary patency, freedom from reintervention, and amputation-free survival were analyzed using Kaplan-Meier curves and compared between groups using the log-rank test.

RESULTS

In the study period 119 CLTI patients had an infrainguinal bypass with Omniflow® II biosynthetic graft. Seventy-seven patients (64.7%) underwent bypass as "de novo" treatment (group de novo), whilst in the remaining 42 patients (35.3%) the procedure was performed as redo surgery due to occlusion and/or infection of a previous bypass graft (group redo). Two groups were homogeneous in terms of demographic, clinical, and morphological data. In group redo explantation of an infected prosthetic graft was needed in 4 cases (9.5%). Intraoperative technical success was achieved in all cases in both groups. At 30 days, the overall patency rate did not differ between the two groups (69/77, 89.6%, group de novo vs. 35/42, 83.3%, group redo; P=0.24), whilst in group redo limb loss was higher with a statistically significant different 30-day major amputation rate between the two groups (11.9% group redo vs. 1.3% group de novo; P<0.001). Overall median duration of follow-up was eight months (IQR 6-13). At two-year follow-up there were no differences between the two groups in terms of survival (67.7% group de novo vs. 55.8% group redo, P=0.53), primary patency (34.4% group de novo vs. 26.8% group redo, P=0.25), primary assisted patency (43.6% group de novo vs. 28.8% group redo, P=0.12), freedom from reintervention (64.1% group de novo vs. 68.8% group redo, P=0.98), and amputation-free survival (67.8% group de novo vs. 60% group redo, P=0.12). Secondary patency was significantly higher in group de novo (53.7% vs. 32.3%, P=0.05). During the follow-up, the overall rates of graft infection and aneurysmal degeneration were 3.4%, and 0.8%, respectively.

CONCLUSIONS

Nevertheless, poorer early outcomes in terms of limb salvage, Omniflow® II biosynthetic graft offers acceptable ywo-year outcomes in redo surgery in CLTI patients with no available autologous vein material. Further studies with larger population sizes are needed to validate these outcomes.

Limb salvage after aneurysmal degeneration of a cryopreserved vein allograft: Searching the autologous veins of the arm is worth the effort

CLINICAL DATA

We hereby report a case of limb salvage involving a 64-year-old man who was hospitalized with ischemic foot ulcers for two months. Endarterectomy with patching and stenting of the left iliofemoral artery failed. A composite bypass of two segments of the endarterectomized superficial femoral artery and a cryopreserved saphenous vein graft was implanted one week later. On day 4 postoperatively, an infection (Staphylococcus epidermidis and Pseudomonas aeruginosa) was treated empirically with antibiotics. Four months later, the femoro-tibial bypass thrombosed and the patency was restored by thrombolysis. The aneurysmal cryopreserved vein was excised. Iterative complications followed and final success was attained after implantation of autologous cephalic and basilic veins. Four years later, this femoro-tibial is still patent.

PATHOLOGICAL ANALYSES

After a gross observation, the explant was dissected and the most significant sections were processed for histology, followed by analyses in scanning electron microscopy, light microscopy and transmission electron microscopy.

RESULTS

The explanted specimen showed a smooth flow surface proximally but a severe distortion distally, with an accumulation of poorly organized mural thrombi. The wall of the arterialized vein was accompanied with an important inflammatory reaction. The degradation of the collagen structure was evidenced in TEM. The fibrils of collagen were still individualized but were fragmented and did not display parallelly. The regular banding was preserved. The presence of Pseudomonas aeruginosa was shown inside the wall of the homologous vein.

COMMENTS

In case of sepsis, the most aggressive antibiotic treatments cannot fully eliminate the bacteremic colonizations within the wall of an alternative conduit. The cephalic and basilic autologous veins are proved to be preferable in absence of the autologous saphenous vein. The amputation was prevented and four years later the bypass is still patent. This is an outstanding result based upon the comorbidities of the patient. The most aggressive harvesting shall be recommended. This patient represented a considerable challenge and the clinical result is highly gratifying: the search for the autologous cephalic and basilic veins proved to be worth the effort.

Effects of endovascular first strategy on spliced vein bypass outcomes

OBJECTIVE

Aggressive endovascular interventions for patients without adequate full-length venous conduit have gained popularity. The purpose of this study is to evaluate the outcomes of spliced vein bypass (SVB) as primary treatment versus treatment after failed endovascular intervention (endovascular SVB [ESVB]) for infrainguinal revascularization.

METHODS

A retrospective analysis of a single vascular group's database of all SVBs was queried for demographics, indications, intraoperative details, and outcomes. Exclusion criteria included acute ischemia, aneurysm, dual outflow, bypass revisions, and patients lost to immediate follow-up. SPSS software was used for statistical analysis.

RESULTS

Two hundred thirty-five infrainguinal SVBs were performed between January 2011 and March 2017. There were 182 SVB (77%) and 53 ESVB (23%) with a mean follow-up of 488 days (range, 1-2140). Demographics between the SVB and ESVB groups were similar in all categories recorded: diabetes, hypertension, coronary artery disease, current smoker, chronic obstructive pulmonary disease, hyperlipidemia, and renal disease (P = .29). Indications for bypass were not statistically significant between SVB and ESVB (P = .48). The study included Rutherford class 3 (14 vs 2), class 4 (51 vs 20), class 5 (67 vs 18), and class 6 (50 vs 13). Inflow was grouped into iliac (2.6%), femoral (88%), and popliteal (9.8%). Outflow arteries were grouped into below knee popliteal (14.9%) and infrapopliteal (85.1%). Inflow and outflow arteries, as well as number of spliced pieces per bypass were not different between groups. Major amputation rates were not different between SVB and ESVB for the entire study period. There was no statistical difference with patency outcomes based on Kaplan-Meier survival analysis (P = .84).

CONCLUSIONS

An aggressive endovascular first strategy for treatment of patients without adequate autogenous conduit seems to offer benefit without negatively affecting future bypass options. SVB patency and major amputation rates in this series were not affected by a prior endovascular treatment.

Creation of an Arterialized Cephalic Vein as Autologous Bypass for Below-Knee Reconstruction in Critical Limb Ischemia

Two cases of below-knee bypasses using an arterialized cephalic vein (CV) are presented. Both patients had critical ischemia, but no greater or lesser saphenous veins (LSVs) were usable. According to ultrasound, the CVs were thin but regularly positioned. Four weeks after wrist fistula was created, ultrasound showed adequate maturation, and the bypass operations were performed. Both patients had uneventful courses and were discharged after a few days with patent bypasses since then (35 and 18 months). As this report shows, creation of a fistula can be a useful option to gain autologous bypass material in case of critical limb ischemia.