Outcome of infra-inguinal bypass grafts using vein conduit with less than 3 millimeters diameter in critical leg ischemia

Correlations between ultrasound, tomographic, and intraoperative measurements of the great saphenous vein used as an arterial graft

Background

The great saphenous vein is the major superficial vein of the lower limb, and also the most often used as arterial graft material for lower limb revascularization. Prior knowledge of the quality of the vein can guide choice of therapeutic strategy, avoiding surgery that is doomed to failure. Discrepancies between intraoperative findings of the quality of the great saphenous vein and imaging tests are also frequently observed.

Objectives

To evaluate the diameter of the great saphenous vein using two imaging methods (Duplex Ultrasound and Computed Tomography) and the gold-standard (intraoperative direct measurement of the vein), comparing the results.

Methods

Prospective, observational study of data obtained during routine medical procedures performed by the Vascular Surgery team.

Results

41 patients were evaluated, with a 12-month follow-up. 27 (65.85%) were male and mean age was 65.37 years. 19 (46.34%) patients had femoropopliteal grafts and 22 (53.66%) had distal grafts. Preoperative saphenous vein internal diameters measured with the patient supine were on average 16.4% smaller on CT and 33.8% smaller on US than the external diameters measured after intraoperative hydrostatic dilatation. There were no statistical differences in measurements when sex, weight, and height were considered.

Conclusions

Saphenous vein diameters were underestimated by preoperative US and CT scans when compared to intraoperative measurements. Thus, in patients undergoing graft planning for revascularization, the choice of conduit should take this data into consideration, so that use of the saphenous vein is not ruled out unnecessarily during planning.

Chronic Limb-Threatening Ischemia and the Need for Revascularization

BACKGROUND

Patients presenting with critical limb-threatening ischemia (CLTI) have been increasing in number over the years. They represent a high-risk population, especially in terms of major amputation and mortality. Despite multiple guidelines concerning their management, it continues to be challenging. Decision-making between surgical and endovascular procedures should be well established, but there is still a lack of consensus concerning the best treatment strategy. The aim of this manuscript is to offer an overview of the contemporary management of CLTI patients, with a focus on the concept that evidence-based revascularization (EBR) could help surgeons to provide more appropriate treatment, avoiding improper procedures, as well as too-high-risk ones.

METHODS

We performed a search on MEDLINE, Embase, and Scopus from 1 January 1995 to 31 December 2022 and reviewed Global and ESVS Guidelines. A total of 150 articles were screened, but only those of high quality were considered and included in a narrative synthesis.

RESULTS

Global Vascular Guidelines have improved and standardized the way to classify and manage CLTI patients with evidence-based revascularization (EBR). Nevertheless, considering that not all patients are suitable for revascularization, a key strategy could be to stratify unfit patients by considering both clinical and non-clinical risk factors, in accordance with the concept of individual residual risk for every patient. The recent BEST-CLI trial established the superiority of autologous vein bypass graft over endovascular therapy for the revascularization of CLTI patients. However, no-option CLTI patients still represent a critical issue.

CONCLUSIONS

The surgeon's experience and skillfulness are the cornerstones of treatment and of a multidisciplinary approach. The recent BEST-CLI trial established that open surgical peripheral vascular surgery could guarantee better outcomes than the less invasive endovascular approach.

Ilio-Deep Femoral Bypass – an Alternative Treatment Strategy to Critical Limb Ischemia (CLI)

Background: Critical limb ischemia is considered the most severe form of peripheral artery disease. High morbidity and mortality rates are associated with this pathology due to poor economic management of complications. Case summary: A 68-year-old female patient underwent a routine Doppler ultrasound which revealed the obstruction of both the common and superficial right femoral arteries, as well as the right deep femoral artery. In this case, an iliofemoral bypass was performed using the right deep femoral artery as the outflow artery. Conclusion: Revascularization of the deep femoral artery has a reasonable chance of preserving the ischemic lower limb whenever the common and superficial femoral arteries suffer major atherosclerotic blockages.

Saphenous vein size as a surrogate marker for mortality of patients with chronic limb-threatening ischemia undergoing endovascular therapy

BACKGROUND

The size of the autologous vein graft is an important determinant of prognosis in patients with chronic limb-threatening ischemia (CLTI) undergoing bypass surgery. However, it is unclear whether reconstruction using a small vein graft would directly affect prognosis, or a subgroup having small veins would be subject to a poor prognosis. If the latter is true, having small veins would work as a marker for a poor prognosis even in patients with CLTI undergoing endovascular therapy (EVT). Therefore, we investigated the association between the size of saphenous veins and prognosis in patients with CLTI undergoing EVT.

METHODS

This study included 209 consecutive patients with CLTI who primarily underwent EVT between January 2017 and December 2018. The diameter of the saphenous vein was measured at three locations (saphenous-femoral junction, knee, and ankle joint) per limb before EVT by ultrasonography. A small saphenous vein was defined as the mean diameter <3.0 mm.

RESULTS

All-cause mortality rate was significantly higher in patients with a small saphenous vein than in those with non-small one (46.3% versus 10.7% at 2 years, p<0.001). The multivariate Cox regression analysis revealed that a small saphenous vein was independently associated with an increased risk of all-cause mortality.

CONCLUSIONS

Having a small saphenous vein was an independent marker for all-cause mortality in patients with CLTI undergoing EVT.

Role of Bypass with Preoperatively Diagnosed Small Caliber Veins in Chronic Limb-Threatening Ischemia

BACKGROUND

In chronic limb-threatening ischemia (CLTI), although recent studies suggested that limbs classified as a higher Wound, Ischemia, foot Infection (WIfI) stage would benefit more from bypass surgery than endovascular therapy (EVT), graft unavailability is a major limitation for bypass. However, such graft unavailability is not clearly defined. This study aimed to assess whether bypass with veins judged as small by preoperative ultrasound is acceptable to achieve wound healing.

METHODS

Ninety-five limbs classified as WIfI stage 3/4 that underwent infrainguinal bypass with veins were enrolled and divided into two groups based on the preoperative inner diameter of veins. Those with a diameter <2.5 mm were classified as small caliber grafts (SMGs, n=28) and those with a diameter ≥2.5 mm as sufficient caliber grafts (SUGs, n=67), and wound-related outcomes were evaluated. Wound healing rate (WHR) was analyzed in all cohort, and wound recurrence-free rate (WRF) and wound recurrence-free amputation-free survival rate (WRAFS) were calculated for limbs that achieved wound healing. A propensity score matched analysis was also performed to minimize the background difference, and 21 matched pairs were included for the analysis.

RESULTS

Although the primary patency rate was significantly worse in SMGs (1-year patency, Crude model: 82.1% in SUGs and 51.0% in SMGs, P=0.0003; matched model: 77.7% in SUGs and 41.6% in SMGs, P = 0.005), the secondary patency rate was maintained in the equivalent level (1-year patency, Crude model: 81.8% in SUGs and 83.1% in SMGs, P=0.26; matched model: 77.7% in SUGs and 78.4% in SMGs, P = 0.24). One-year WHR was equivalent between the groups in both crude and matched models (Crude model: 87.0% in SUGs and 83.8% in SMGs, P=0.13; matched model: 66.3% in SUGs and 61.4% in SMGs, P = 0.65). One-year WRF and WRAFS were also equivalent (Crude model: WRF, 95.9% in SUGs and 100% in SMGs, P = 0.71; WRAFS, 87.2% in SUGs and 88.0% in SMGs, P = 0.78. Matched model: WRF, 100% in SUGs and 100% in SMGs, P = 0.85; WRAFS, 92.9% in SUGs and 78.6% in SMGs, P = 0.38).

CONCLUSIONS

Although bypass with small caliber veins showed an inferior primary patency rate, WHR and WRF were equally good if grafts are maintained patent. Bypass with small caliber vein grafts would be an important option to achieve wound healing.

Examination of race and infrainguinal bypass conduit use in the Society for Vascular Surgery Vascular Quality Initiative

BACKGROUND

Vein conduit is known to have better patency than prosthetic for infrainguinal bypass. Here we explore if racial disparities exist in infrainguinal bypass vein conduit use amid preoperative patient and systemic factors.

METHODS

Retrospective Society for Vascular Surgery Vascular Quality Initiative data for 23,959 infrainguinal bypasses between 2003 and 2017 for occlusive disease were analyzed. For homogeneity, only infrainguinal bypasses originating from the common femoral artery were included. Demographics of patients receiving vein vs prosthetic were compared and logistic regression analyses were performed with race and preoperative factors to evaluate for predictors of vein conduit use.

RESULTS

Adjusted regression models demonstrated black patients were 76% as likely (p < .001) and Hispanic patients 79% as likely (p = .003) to have vein conduit compared to white patients. Factors positively correlating with vein use included vein mapping, more distal bypass target, tissue loss or acute ischemia bypass indications, commercial insurance, and weight. Factors against vein use included advanced age, female gender, ASA class 4, urgent procedure, preoperative mobility limitation, prior CABG or leg bypass, prior smoking, preoperative anticoagulation, and a bypass performed in the Southern US or before 2012. While black and Hispanic patients were less likely to receive vein, they were vein mapped at similar or higher rates than other groups.

CONCLUSION

Racial disparities exist in conduit use for infrainguinal bypass, with black and Hispanic patients less likely to receive vein bypasses. However, the contribution of race to conduit selection is small in adjusted and unadjusted models. Overall, pre-operative variables in the Vascular Quality Initiative poorly predicted vein conduit use for infrainguinal bypass.

Distal bypasses in patients with diabetes and infrapopliteal disease: technical considerations to achieve success

The combination of diabetes and peripheral arterial disease (PAD) is challenging in many ways. The characteristic and complex distal distribution of PAD often encountered in patients with diabetes means that bypass surgery in this context is technically challenging. In addition, many of these patients have a burden of serious comorbidities that must be optimized and managed concurrently. While the authors acknowledge that "achieving success" in distal bypass relies on much more than technical expertise, there are some technical aspects that should be considered when planning surgery on these patients. This article outlines some important issues in the treatment pathway of a patient with diabetes and PAD requiring distal bypass surgery--from selection and optimization of the patient (in the context of a multidisciplinary team) and preoperative workup, to the operative strategy planning, technical tips, and nonoperative adjuncts. These considerations, as well as sound knowledge of the underlying disease process, confounding medical factors and awareness of the difficulty in predicting treatment outcomes, should help maximize the chances of success.

Bypass surgery for lower extremity limb salvage: vein bypass

Bypass surgery for limb salvage in cases of chronic limb ischemia is a well-established treatment modality. Use of an autogenous vein provides the best conduit for infrainguinal arterial bypass procedures, particularly for bypass to the infrapopliteal arteries. In this article, we discuss infrainguinal vein bypass surgery including indications, perioperative care, and long-term follow up. We also discuss the outcomes of the procedure with regard to patient survival and limb salvage. The autogenous vein continues to be the best available conduit with the highest patency rate and the best treatment option. Compared to all other revascularization options for infrainguinal disease, the vein bypass has the best limb salvage and long-term survival in patients appropriately selected for the procedure.

A cost-effectiveness analysis of infrainguinal bypass in the absence of great saphenous vein conduit

BACKGROUND

Good-quality great saphenous vein (GSV) is the preferred conduit for infrainguinal surgical revascularizations, but it is not available in all patients. We sought to identify the alternative conduit that would maximize cost-effectiveness in the context of infrapopliteal bypass for critical limb ischemia and nonhealing foot wounds.

METHODS

A Markov model was used to create a detailed simulation of 10-year outcomes in a hypothetical Edifoligide for the Prevention of Infrainguinal Vein Graft Failure (PREVENT) III-type patient cohort undergoing infrainguinal bypass for nonhealing foot wounds. The following management options were evaluated: (1) conservative therapy (local wound care, amputation as needed); (2) primary amputation; (3) bypass with autologous alternative vein (AAV), including arm or lesser saphenous vein; (4) bypass with GSV <3 mm in diameter; (5) bypass with polytetrafluoroethylene (PTFE); (6) cryopreserved venous allograft; and (7) cryopreserved arterial allograft. Estimates of 10-year total costs were incorporated into the model. Cost-effectiveness was measured in terms of incremental United States dollars per additional year of ambulation.

RESULTS

Bypass with AAV had the highest effectiveness as measured in median years of ambulation. After primary amputation, bypass with PTFE had the lowest total costs. With incremental cost-effectiveness ratios of $5325 and $21,228, bypass with PTFE or AAV appeared to be cost-effective alternatives to conservative therapy for nonhealing ischemic wounds. Primary amputation, GSV <3 mm, and allograft options were dominated (ie, more costly and less effective). Primary amputation was weakly dominated.

CONCLUSIONS

Bypass with PTFE or AAV appears to be a cost-effective option for the management of critical limb ischemia and nonhealing foot wounds when good-quality GSV is not available.

Outcome of Lower Limb Distal Bypass in Afro-Caribbean Populations

There is little data on outcome following lower limb bypass surgery in ethnic minorities in the United Kingdom. We looked at the results of distal bypass surgery in Afro-Caribbeans (AFCs) and compared it to caucasians (CAs). Patients undergoing distal bypass between 2004 and 2009 were analyzed. Life table analyses and log rank were used to compare graft patency and amputation-free survival. A total of 86 CA and 39 AFC patients, with a median age of 78 years and 73 years, respectively (P = .01), underwent bypass. There were more women in AFC groups (41.1%) compared to CA group (19.2%, P = .01). Tissue loss as indication for surgery was more in AFC than in CA group (92.3% vs73.9%, P = .03). Primary, primary-assisted and secondary patency rates, and amputation-free survival at 12 months for AFCs compared to CAs (51.3 vs 44.6; 85.2 vs 80.9; 91.2 vs 84.4; and 84.9 vs 75.1). Graft patency after lower limb distal revascularization in AFCs is comparable to CAs.