Impact of Infrapopliteal Revascularisation Establishing In Line Flow to the Wound in Patients with Chronic Limb Threatening Ischaemia.

OBJECTIVE: This study aimed to determine the impact of infrapopliteal (IP) revascularisation establishing in line flow to the wound (IFW) on wound healing in chronic limb threatening ischaemia (CLTI), using a core laboratory assessment for wounds and in line flow. METHODS: The Wound directed Angiosome RevasculaRIsation apprOach to patients with cRitical limb iSchaemia (WARRIORS) multicentre observational study enrolled patients with CLTI with tissue loss undergoing IP revascularisation in Japan, with scheduled two year follow up. The primary outcome measure was complete wound healing, defined as achievement of complete epithelialisation of all wounds without major amputation. IP revascularisation establishing IFW was defined as revascularisation after which a tibiopedal artery that actually fed an injured pedal unit was patent. The incidence of wound healing was compared between the IFW and non-IFW groups using inverse probability of treatment weighting based on the propensity score. RESULTS: A total of 440 patients with CLTI (median age, 75 years; male, 64.1%; diabetes mellitus, 72.0%; dialysis, 57.7%) with tissue loss (Wound, Ischaemia, and foot Infection stage 4, 66.4%) who underwent IP revascularisation (endovascular procedure, n = 304; bypass grafting, n = 136) between October 2017 and June 2020 were registered. During a median follow up of 23.6 months, 51.1% achieved wound healing. Successful IP revascularisation with IFW was achieved in 68.2%. After analysis, the IFW group had a higher rate of wound healing than the non-IFW group (34.5 vs. 16.1 per 100 person years; p = .030). The association between IFW and wound healing was not statistically different between patients undergoing bypass grafting and those undergoing an endovascular procedure (p for interaction = .38). There was no statistically significant interaction effect between IFW and direct revascularisation for wound healing (p for interaction = .51). CONCLUSION: IP revascularisation establishing IFW was statistically significantly associated with a higher wound healing rate in patients with CLTI.

The anatomy of the superficial inferior epigastric artery: Cautious optimism and rightful reluctance for the championing of a minimally morbid abdominal flap.

The superficial inferior epigastric artery (SIEA) flap has gained interest due to its potential as an abdominal breast reconstruction flap that incurs minimal donor site morbidity. Historical descriptions of its anatomy however paint the artery as small in calibre, with a restrictive angiosome and a high agenesis rate. This review examines the most contemporary anatomical data of the SIEA across clinical, cadaver and radiological modalities and balances the promise of encouraging anatomical data against the clinical practicalities of consistently and safely raising an SIEA flap.

Application of flow-through flaps for replantation after traumatic limb amputation according to the angiosome concept.

OBJECTIVE: This study was performed to explore the treatment of the injury caused by traumatic limb amputation. METHODS: From October 2002 to October 2021, 30 cases were enrolled in the present study. The reasons for injury were as follows: 8 cases with single hydraulic column crush injury, 12 cases with gear and wire rope stranding, 6 cases with belt avulsion injury, and 4 cases with carbon block smash injury. The present study application of a free or small saphenous vein bypass to reconstruct the injured artery and vein according to the concept of the angiosome model. The defective vessels were bridged with the axial vessels of a flow-through flap, such as a medial calf flap or anterolateral femoral flap, to construct an additional blood supply and drainage vein for the severed limb. The clinical data of 30 cases with traumatic limb amputation of the lower leg and ankle were retrospectively analyzed. RESULTS: In all 30 cases of traumatic limb amputation, the replantation via the adoption of a flow-through flap was successful, and 85.6% of the patients remained in good postoperative condition. There were no symptoms of ischemia in the marginal segment after blood supply reconstruction of the transected limb by axial vascular bridging within the flap. CONCLUSION: Via the adoption of microsurgical techniques, the blood supply to the transected limb can be reconstructed by bridging the defective vessels with the adoption of the axial vessels of the flow-through flap is a feasible and advanced treatment option.

Prediction of pedicled flap survival preoperatively by operating indocyanine green angiography at 1,450 nm wavelength: an animal model study.

Background: Predicting flap viability benefits patients by reducing complications and guides flap design by reducing donor areas. Due to varying anatomy, obtaining individual vascular information preoperatively is fundamental for designing safe flaps. Although indocyanine green angiography (ICGA) is a conventional tool in intraoperative assessment and postoperative monitoring, it is rare in preoperative prediction. Methods: ICGA was performed on 20 male BALB/c mice under five wavelengths (900/1,000/1,100, /1,250/1,450 nm) to assess vascular resolution after ICG perfusion. A "mirrored-L" flap model with three angiosomes was established on another 20 male BALB/c mice, randomly divided into two equal groups. In Group A, a midline between angiosomes II and III was used as a border. In Group B, the points of the minimized choke vessel caliber marked according to the ICG signal at 1,450 nm wavelength (ICG1450) were connected. Necrotic area calculations, pathohistological testing, and statistical analysis were performed. Results: The vascular structure was clearly observed at 1,450 nm wavelength, while the 900 to 1,100 nm failed to depict vessel morphology. Necrosis was beyond the borderline in 60% of Group A. Conversely, 100% of Group B had necrosis distal to the borderline. The number of choke vessels between angiosomes II and III was positively correlated with the necrotic area (%). The pathohistological findings supported the gross observation and analysis. Conclusion: ICG1450 can delineate the vessel structure in vivo and predict the viability of pedicled skin flaps using the choke vessel as the border between angiosomes.

Distal Bypass Improves Skin Perfusion Pressure at the Whole Foot Regardless of Angiosomes in Patients with Chronic Limb-Threatening Ischemia.

Objectives: Distal bypass surgery's effect on tissue blood pressure beyond a focal angiosome remains debated. This study assessed tissue blood pressure in both direct revascularized angiosome (DRA) and indirect revascularized angiosome (IRA) after bypass surgery, utilizing repeated skin perfusion pressure (SPP) measurements. Methods: Twenty-nine limbs in 27 chronic limb-threatening ischemia (CLTI) patients (22 males and five females, age: 70.2 ± 9.3 years) who received distal bypass surgery were enrolled. SPP measurements were conducted for the DRA and IRA at 10 time intervals, encompassing both preoperative and postoperative periods of every 3-5 days until 30 days. Results: In total, 486 SPP measurements were collected from 58 measurement sites, and the transition of the SPP at the DRA was 35.4-62.5-59.5-70.2-58.2-62.2-63.1-63.6-63.8-73.4 mmHg and IRA was 29.4-53.4-53.7-58.8-51.3-63.1-47.9-62.1-57.6-61.0 mmHg. No significant differences were observed between SPP at the DRA and IRA. Fifteen wounds on the DRA (63%) and five on the IRA (100%) healed. Conclusion: Distal bypass improves SPP in both direct and IRAs of CLTI patients. These data indicated distal bypass improves tissue blood flow at entire foot regardless of angiosomes.

Perfusion increase in foot angiosomes: Comparison between direct and indirect revascularization of crural arteries.

BACKGROUND AND AIMS: In retrospective studies, wound healing and leg salvage have been better if revascularization is targeted to the crural artery supplying arterial flow to the wound angiosome. No data exist on how revascularization changes the blood flow in foot angiosomes. The aim of this study was to evaluate the change in perfusion after infrapopliteal artery revascularization in all foot angiosomes and to compare directly revascularized (DR) angiosomes to the indirectly revascularized (IR) angiosomes. METHODS: In this prospective study, foot perfusion was measured with indocyanine green fluorescence imaging (ICG-FI) before and after either surgical or endovascular below-knee revascularization. According to angiograms, we divided the foot angiosomes into DR and IR angiosomes. Furthermore, in a subanalysis, the IR angiosomes were graded as IR_Coll+ angiosomes if there were strong collaterals arising from the artery which was revascularized, and as IR_Coll- angiosomes if strong collaterals were not seen. RESULTS: A total of 72 feet (28 bypass, 44 endovascular revascularizations) and 282 angiosomes were analyzed. Surgical and endovascular revascularization increased perfusion significantly in both DR and IR angiosomes. After bypass surgery, the increase in DR angiosomes was 55 U and 53 U in IR angiosomes; there were no significant difference in the perfusion increase between IR and DR angiosomes. After endovascular revascularization, perfusion increased significantly more, 40 U, in DR angiosomes compared to 26 U in IR angiosomes (p < 0.05). In the subanalysis of IR angiosomes, perfusion increased significantly after surgical bypass regardless of whether strong collaterals were present or not. After endovascular revascularization, however, a significant perfusion increase was noted in the IR_Coll+ but not in the IR_Coll- subgroup. CONCLUSION: Open revascularization increased perfusion equally in DR and IR angiosomes, whereas endovascular revascularization increased perfusion significantly more in DR than in IR angiosomes. Strong collateral network may help increase perfusion in IR angiosomes.

Validation of MRI assessment of foot perfusion for improving treatment of patients with peripheral artery disease.

INTRODUCTION: Information on tissue perfusion in the foot is important when treating patients with chronic limb-threatening ischemia. This study aims to test the reliability of different magnetic resonance sequences when measuring perfusion in the foot. METHODS: Sixteen healthy volunteers had their right foot scanned in a test/retest study with six different magnetic resonance sequences (BOLD, multi-echo gradient echo (mGRE), 2D and 3D pCASL, PASL FAIR, and DWI with intravoxel incoherent motion (IVIM) with quantitative measurements of perfusion. For five sequences, cuff-induced ischemia followed by a hyperactive response was measured. Images of the feet were segmented into angiosomes and perfusion data were extracted from the five angiosomes. RESULTS: BOLD, PASL FAIR, mGRE, and DWI with IVIM had low mean differences between the first and second scans, while the results of 2D and 3D pCASL had the highest differences. Based on a paired t-test, BOLD, and FAIR were able to distinguish between perfusion and no perfusion in all angiosomes with p-values below 0.01. This was not the case with 2D and 3D pCASL with p-values above 0.05 in all angiosomes. The mGRE could not distinguish between perfusion and no perfusion in the lateral side of the foot. CONCLUSION: BOLD, mGRE, pASL FAIR, and DWI with IVIM seem to give more robust results compared to 2D and 3D pCASL. Further studies on patients with peripheral artery disease should explore if the sequences can have clinical relevance when assessing tissue ischemia and results of revascularization. IMPLICATIONS FOR PRACTICE: This study provides knowledge that could be used to improve the diagnosis of patient with chronic limb-threatening ischemia to explore tissue perfusion.

Challenging the angiosome concept: Delineating peripheral arterial disease patterns in diabetic foot ulcers.

OBJECTIVES: The angiosome concept has significantly impacted diabetic foot ulcer management by highlighting the vascular anatomy's role in wound healing. However, its clinical applicability and validity remain debated due to complexities in foot blood supply and ulcer location determination. METHODS: A cross-sectional study was conducted on 84 individuals with diabetic foot ulcers undergoing lower limb angiography. Demographics, ulcer characteristics, and angiographic data were collected and analyzed using descriptive statistics and relevant tests. RESULTS: Digital subtraction angiography assessed 89 limbs with diabetic foot ulcers; males comprised 54.8%, primarily type 2 diabetes (96.4%), averaging 64.36 ± 10.09 years. Of 129 angiosomes, angiosome 2 (40.3%) had the highest ulcer incidence. Posterior tibial artery (PTA) involvement was predominant (72.9%), while external iliac artery (EIA) and profunda femoris artery (PFA) were least affected (2.4% each). Posterior tibial artery showed 46.5% complete occlusion. Angiosome 2 correlated notably with anterior tibial artery (ATA), peroneal artery (CPA), and PTA, but categorizing angiosomes by supply patterns showed no significant artery correlation (p > .05). CONCLUSIONS: The research indicates inconsistent support for below-the-knee artery involvement correlating with foot ulcer locations in angiosomes. While aiding vascular comprehension, the angiosome concept may not fully elucidate lower limb vascular complexities and ulcer genesis. Factors like collateral circulation should be noticed to understanding ulcer localization and severity, extending beyond angiosomal arterial supply.

Oxygen Saturation Increase in Ischemic Wound Tissues after Direct and Indirect Revascularization.

BACKGROUND: The primary approach for treating ischemic wounds is restoring oxygen supply to the ischemic region. While direct angiosomal revascularization is often associated with better post-operative wound healing and limb salvage, its superiority over non-angiosomal revascularization remains controversial. This study aimed to compare intraoperative tissue oxygen saturation changes in ischemic zones following either direct or indirect revascularization in below-the-knee arteries. METHODS: This prospective observational study included patients undergoing direct and indirect below-the-knee endovascular revascularizations. Assignment to the groups was not randomized. Near-infrared spectroscopy was used to monitor rSO2 changes near the ischemic wounds intraoperatively. The changes were compared between the groups. RESULTS: 15 patients (50%) underwent direct angiosomal revascularization, while an equal number of patients underwent indirect revascularization. Overall, a statistically significant increase in regional oxygen saturation was observed after revascularization (p = 0.001). No statistically significant difference was found between the direct and indirect revascularization groups (p = 0.619). CONCLUSIONS: This study revealed a minor difference in the oxygen saturation increase between the angiosomal and non-angiosomal revascularization groups. Such a finding indicates that the clinical significance of angiosomal revascularization is negligible and might be concealed by confounding factors, such as the vessel diameter and outflow impact on the restenosis rate.

Angiosome-Targeted Infrapopliteal Angioplasty: Impact on Clinical Outcomes-An Observational Study.

Background: Revascularization based on the angiosome concept (AC) is a controversial subject because there is currently no clear evidence of its efficacy, due to the heterogeneity of patients (multiple and diverse risk factors and comorbidities, multiple variations in the affected angiosomes). Choke vessels change the paradigm of the AC, and the presence or absence of the plantar arch directly affects the course of targeted revascularization. The aim of this study was to evaluate the effect of revascularization based on the AC in diabetic patients with chronic limb-threatening ischemia (CLTI). Methods: This retrospective analysis included 51 patients (40 men, 11 women), with a mean age of 69 years (66-72) and a total of 51 limbs, who presented with Rutherford 5-6 CLTI, before and after having undergone a drug-coated balloon angioplasty (8 patients) or plain balloon angioplasty (43). Between November 2018 and November 2019, all patients underwent below-the-knee balloon angioplasties and were followed up for an average of 12 months. The alteration of microcirculation was compared between directly and indirectly revascularized angiosomes. The study assessed clinical findings and patient outcomes, with follow-up investigations, comparing wound healing rates between the different revascularization methods. Patient records and periprocedural leg digital subtraction angiographies (DSA) were analyzed. Differences in outcomes after direct revascularization and indirect percutaneous transluminal angioplasty (PTa) were examined using Cox proportional hazards analysis, with the following endpoints: ulcer healing, limb salvage, and also amputation-free survival. Results: Direct blood flow to the angiosome supplying the ulcer area was achieved in 38 legs, in contrast to 13 legs with indirect revascularization. Among the cases, there were 39 lesions in the anterior tibial artery (ATA), 42 lesions in the posterior tibial artery (PTA), and 8 lesions in the peroneal artery (PA). According to a Cox proportional hazards analysis, having fewer than three (<3) affected angiosomes (HR 0.49, 95% CI 0.19-1.25, p = 0.136) was associated with improved wound healing. Conversely, wound healing outcomes were least favorable after indirect angioplasty (p = 0.206). When adjusting the Cox proportional hazard analysis for the number of affected angiosomes, it was found that direct drug-coated angioplasty resulted in the most favorable wound healing (p = 0.091). At the 1-year follow-up, the major amputation rate was 17.7%, and, according to a Cox proportional hazards analysis, atrial fibrillation (HR 0.85, 95% CI 0.42-1.69, p = 0.637), hemodialysis (HR 1.26, 95% CI 0.39-4.04, p = 0.699), and number of affected angiosomes > 3 (HR 0.94, 95% CI 0.63-1.39, p = 0.748) were significantly associated with poor leg salvage. Additionally, direct endovascular revascularization was associated with a lower rate of major amputation compared to indirect angioplasty (HR 1.09, 95% CI 0.34-3.50, p = 0.884). Conclusions: Observing the angiosomes concept in decision-making appears to result in improved rates of arterial ulcer healing and leg salvage, particularly in targeted drug-coated balloon angioplasty for diabetic critical limb ischemia, where multiple angiosomes are typically affected.

Successful Revascularization, Angiosome Concept, and Multivessel Revascularization: Effects on Wound Healing: An Asian Perspective.

Endovascular treatment for revascularization in patients with chronic limb-threatening ischemia (CLTI), which is commonly found in patients with diabetes mellitus demonstrates a variable result of vessel patency, wound healing rate, and limb salvage rate. The angiosome concept has been adopted to determine the best target arterial path (TAP) for revascularization for wound healing in CLTI patients. Recent publications demonstrated the benefit of angiosome-targeted revascularization to guide the endovascular treatment in patients CLTI. The best TAP under angiosome concept by direct revascularization with at least 2 of 3 below-the-knee arteries runoff to restore in-line pulsatile blood flow to the ischemic tissue shows the best patency and high rate of wound healing. However, the clinical evidence and application of the angiosome concept in daily practice are difficult and not well established. The vascular territories, collateral vessel, wound area, and locations which associated with angiosome are varied. This article review aims to summarize the concept of angiosome-targeted revascularization and multivessel revascularization for application to the real-world practice under the evidence-based data.

Success of transmetatarsal amputation for limb salvage in patients with peripheral artery disease.

Limb salvage is a difficult path for patients to travel as there is no guarantee of the outcome, often the major factor is perfusion. For patients who underwent transmetatarsal amputation (TMA), success rate is crucial as the next option is most likely a major amputation. We performed a 10 years (2010-2020) retrospective review of patients that underwent a TMA and had an angiogram or computed tomography angiography (CTA) perioperatively at the Dallas VA Medical Center. Failure after TMA was defined as a patient requiring a proximal amputation within 1 year. There were 125 TMAs performed between 2010 and 2020 at the institution. Forty-four (35.2%) patients had an angiogram/CTA peri-operative and met the inclusion criteria. Seventeen subjects (38.6%) had a higher level of amputation. Of the 17 failures, 2 (11.8%) patients had no patent vessel runoff to the foot, 9 (52.9%) had one vessel, 4 (23.5%) had two vessels, and 2 (11.8%) had three vessels runoff. One vessel runoff to the foot yielded a high rate of poor outcomes (56.3%) defined as a higher level of amputation. Two or more vessels runoff to the foot had over 75% success of limb salvage with a TMA.

Angiosome Oriented or Least Diseased Vessel, Which Is the Optimal Target Arterial Path for Endovascular Revascularisation in Patients With Diabetic Foot Ulcers?

OBJECTIVE: The aims were to determine whether, when treating diabetic foot ulcers (1), selecting an angiosome directed (AD) vessel as the target arterial path (TAP) when candidate vessels have comparably severe disease impacts outcomes and (2) whether a more severely affected AD vessel or a less severely affected non-angiosome directed (NAD) vessel should be chosen. METHODS: This was a retrospective observational study. Patients with diabetic foot ulcers who had undergone endovascular revascularisation in the institution between January 2016 and May 2020 and had been followed up for two years were included. Eligible patients were identified retrospectively and relevant data were collected from the institution's electronic medical records. The severity of the lesions was classified using the Global Limb Anatomic Staging System (GLASS). Outcomes between various subgroups were compared according to the severity of the lesions to determine the optimal TAP choice in each case. RESULTS: The study cohort comprised 215 patients (216 limbs). The affected limbs were classified as follows: 93 (43.1%) as GLASS 1 - 2 AD; 27 (12.5%) as GLASS 1 - 2 NAD, 62 (28.7%) as GLASS 3 AD, and 34 (15.7%) as GLASS 3 NAD groups. In the GLASS 1 - 2 group, rates of ulcer healing, survival, and amputation free survival were higher and time to healing shorter in the AD than NAD group. In the GLASS 3 group, there were no significant differences between the AD and NAD groups for any studied outcome measures, including ulcer healing and overall survival. Using a more severely diseased AD as the TAP did not achieve significantly better outcomes than using a less severely affected NAD vessel. CONCLUSION: Selecting the AD vessel may achieve better outcomes when two candidate TAPs belong to GLASS 1 - 2, whereas selecting the least diseased vessel as the TAP regardless of AD or NAD status may be preferable in other situations.

An angiosome-centred approach for TcpO2 electrode positioning.

Background: The latest guidelines propose a TcpO2 value of 30 mmHg to help to confirm the diagnosis of chronic limb threatening ischemia. However, placement of electrodes is not standardised. The relevance of an "angiosome-centred" approach for TcpO2 electrode positioning has never been evaluated. We therefore retrospectively analysed our TcpO2 results to study the impact of electrode placement on the different angiosomes of the foot. Patients and methods: Patients consulting the vascular medicine department laboratory for suspicion of CLTI using TcpO2 electrodes placement on the different angiosome arteries of the foot (first inter metatarsal space, lateral edge of the foot and plantar side of the foot) were included. As the mean intra-individual variation is reported to be 8 mmHg, a variation of mean TcpO2 for the 3 locations ≤8 mmHg was considered to be not clinically significant. Results: Thirty-four patients (34 ischemic legs) were analysed. The mean TcpO2 was higher at the lateral edge of the foot (55 mmHg) and plantar side of the foot (65 mmHg) than at the first intermetatarsal space (48 mmHg). There was no clinically significant variation of mean TcpO2 according to anterior/posterior tibial artery patency and fibular artery patency. This was present when stratifying on the number of patent arteries. Conclusions: The present study suggests that multi-electrode TcpO2 is not useful to assess tissue oxygenation in the different angiosomes of the foot to guide surgical decision; first intermetatarsal electrode alone would be preferred. TcpO2 seems rather to evaluate overall tissue oxygenation of the foot. Electrode location on the plantar side of the foot may overestimate results and lead to misinterpretation.

Presence of a patent pedal arch is the primary predictor of transmetatarsal amputation healing and limb salvage.

OBJECTIVE: Transmetatarsal amputation (TMA) is a durable and important functional limb salvage option. We have presented our results in identifying the angiographic predictors of TMA healing using single-institution retrospective data. METHODS: Consecutive patients within our institution who had undergone TMA and lower extremity arteriography from 2012 to 2020 were included. Patients whose TMA had healed were compared with those whose TMA had not healed. Using pre- and perioperative patient factors, in addition to the Global Limb Anatomic Staging System (GLASS) and evaluation of the tibial runoff vessels, multivariate analysis was used to define the predictors of TMA healing at 30 days and 1 year. For those patients who had undergone an intervention after TMA, including repeat interventions, the postintervention GLASS stage was calculated. All patients were followed up by the vascular surgeon using standard ultrasound surveillance and clinical examinations. Once the predictors had been identified, an analysis was performed to correlate the 30-day and 1-year limb salvage rates. RESULTS: A total of 89 patients had met the inclusion criteria for the study period. No difference was found in the GLASS femoropopliteal or infrapopliteal stages for those with a healed TMA and those without. After multivariate regression analysis, the presence of a patent pedal arch vs a nonintact arch had a 5.5 greater odds of TMA healing at 30 days but not at 1 year. Additionally, the presence of a patent arch was strongly associated with limb salvage at both 30 days (86% vs 49%; P < .01) and 1 year (79% vs 49%; P < .01). CONCLUSIONS: In the present series of patients who had undergone TMA and arteriography, with appropriate GLASS staging, we found patency of the pedal arch was a significant predictor of healing and limb salvage. The GLASS femoropopliteal and infrapopliteal stages did not predict for TMA healing.

Angiosome-directed endovascular intervention and infrapopliteal disease: Intraoperative evaluation of distal hemodynamic changes and foot blood volume of lower extremity.

Objectives: To evaluate foot blood volume and hemodynamics and explore whether quantitative techniques can guide revascularization. Materials and methods: A prospective single-center cohort study included thirty-three patients with infrapopliteal artery occlusion who underwent percutaneous transluminal angioplasty (PTA) between November 2016 and May 2020. The time-to-peak (TTP) from color-coded quantitative digital subtraction angiography (CCQ-DSA) and parenchymal blood volume (PBV) were used to evaluate the blood volume and hemodynamic changes in different regions of the foot before and after the operation. Results: After the intervention procedure, the overall blood volume significantly increased from 25.15 ± 21.1 ml/1,000 ml to 72.33 ± 29.3 ml/1,000 ml (p < 0.001, with an average increase of 47.18 ml/1,000 ml. The overall TTP decrease rate, postoperative blood flow time significantly faster than those preoperatively, from 22.93 ± 7.83 to 14.85 ± 5.9 s (p < 0.001, with an average decrease of 8.08 s). Direct revascularization (DR) resulted in significant blood volume improvement than compared with indirect revascularization (IR) [188% (28, 320) vs.51% (10, 110), p = 0.029]. Patients with DR had a significantly faster blood flow time than those with IR [80% (12, 180) vs. 26% (5, 80), p = 0.032]. The ankle-brachial index (ABI) of the affected extremity also showed an significant change from 0.49 ± 0.3 to 0.63 ± 0.24 (p < 0.001) after the intervention. The relative values of ΔTTP and ΔABI showed a weak correlation (r = -0.330). Conclusions: The quantitative measurement results based on PBV and CCQ-DSA techniques showed that the overall blood volume increased significantly and that the foot distal hemodynamics were significantly improved after endovascular treatment. DR in the ischemic area could r improve foot perfusion.

Bridging a Century-Old Problem: The Pathophysiology and Molecular Mechanisms of HA Filler-Induced Vascular Occlusion (FIVO)-Implications for Therapeutic Interventions.

Biocompatible hyaluronic acid (HA, hyaluronan) gel implants have altered the therapeutic landscape of surgery and medicine, fostering an array of innovative products that include viscosurgical aids, synovial supplements, and drug-eluting nanomaterials. However, it is perhaps the explosive growth in the cosmetic applications of injectable dermal fillers that has captured the brightest spotlight, emerging as the dominant modality in plastic surgery and aesthetic medicine. The popularity surge with which injectable HA fillers have risen to in vogue status has also brought a concomitant increase in the incidence of once-rare iatrogenic vaso-occlusive injuries ranging from disfiguring facial skin necrosis to disabling neuro-ophthalmological sequelae. As our understanding of the pathophysiology of these injuries has evolved, supplemented by more than a century of astute observations, the formulation of novel therapeutic and preventative strategies has permitted the amelioration of this burdensome complication. In this special issue article, we review the relevant mechanisms underlying HA filler-induced vascular occlusion (FIVO), with particular emphasis on the rheo-mechanical aspects of vascular blockade; the thromboembolic potential of HA mixtures; and the tissue-specific ischemic susceptibility of microvascular networks, which leads to underperfusion, hypoxia, and ultimate injury. In addition, recent therapeutic advances and novel considerations on the prevention and management of muco-cutaneous and neuro-ophthalmological complications are examined.

An animal experiment study on the application of indocyanine green angiography in the harvest of multi-angiosome perforator flap.

Background: This study sought to explore the application value of indocyanine green angiography (ICGA) in the harvest of multi-angiosome perforator flap and the effect of low molecular weight heparin (LMWH) on the survival of postoperative flap. Methods: Twenty-four SD male rats were selected to construct a three-angiosome perforator flap model with the unilateral iliolumbar artery perforator. They were randomly divided into two groups: the control group was injected with indocyanine green (ICG) into the femoral vein during the operation, and the fluorescence signal was collected and quantitatively analyzed using Real-Time Image Guided System to determine the intraoperative fluorescence imaging length. The experimental group was injected subcutaneously with LMWH (400 U/kg) after 0.5 h postoperatively, and the control group was injected with the same amount of normal saline. The injection was repeated at the same time each day from 0 to 7 days postoperatively. After the flap was sutured in situ, ICGA was performed at 0, 1, 3, 5, and 7 days postoperatively to observe the vascular structure of the two groups of flaps. The flap survival length of the control group was counted at 7 days postoperatively, and the correlation between the intraoperative fluorescence imaging length and the survival length at 7 days postoperatively was calculated. The proportion of distal necrosis of the flaps between the two groups was compared at 7 days postoperatively. Results: The average length of intraoperative fluorescence imaging in the control group was 6.29±0.50 cm, and the survival length of the flap at 7 days postoperatively was 8.24±0.52 cm. The actual survival length was higher than the intraoperative fluorescence imaging length, with a ratio of 1.31±0.08. The difference was statistically significant (P<0.05). At 7 days postoperatively, the flap necrosis ratio of experimental group and control group were 10.92%±1.30% and 19.11%±1.19%, and the flap necrosis ratio of experimental group was lower than that of control group (P<0.001). Conclusions: ICGA can locate the position of perforator, and can be used to predict and observe the length of distal survival of multi-angiosome perforator flap postoperatively. LMWH can promote the distal survival of flap and reduce flap necrosis.

Grades of Below-the-Ankle Arterial Occlusive Disease following the Angiosome Perfusion: A New Morphological Assessment and Correlations with the Inframalleolar GVG Stratification in CLTI Patients.

PURPOSE: To assess a specific classification of the foot atherosclerotic disease concerning the angiosomal source arteries, the connected foot arches and attached collaterals for Rutherford 5, CLTI patients. To compare eventual analogies of this novel grading system with previously reported GLASS/GVG inframalleolar patterns of occlusive disease (P0-P2). MATERIALS AND METHODS: A series of 336 ischemic feet (221 diabetics) were selected and retrospectively analyzed. For each angiographic pattern of inframalleolar atherosclerotic disease, 4 severity classes of targeted angiosomal artery path (TAAP), associating 4 other classes concerning linked foot arches (LFA) and collaterals occlusive disease were described. By associating the 4 TAAP with the 4 others parallel LFA and collaterals classes, 4 novel anatomical "Grades" (A-D) of occlusive disease were described. Limb salvage was studied between groups of diabetic and non-diabetic patients. RESULTS: Using a primary endovascular approach, limb preservation comparison of grade A/B proved without significance for diabetics (P = 0.032) and non-diabetics (P = 0.226). Comparison in diabetics and/or non-diabetics between A/C (P = 0.045 and 0.046), A/D (P = 0.027 and 0.030,B/C (P = 0.009 and 0.038), and B/D (P = 0.006 and P = 0.042), as well as C/D groups (P = 0.048 and P = 0.034) proved ponderous. Parallel analysis of similar grades (A/A, B/B, etc.) with, or without diabetes appeared without significance (P > 0.05). Further comparison between grades A+B (assigned as P0/GVG), versus C (P1), and D (P2), proved significant (P < 0.0001). CONCLUSION: The present grading system proposes a useful correlation between the severity of foot angiosomal arteries, arches, and collaterals disease and limb salvage, confirming the clinical significance of P0-P2 GVG severity score. This analysis also points the limits of EVT to be probably avoided in grade D patients.

The impact of an angiosome-targeted revascularization on healing rate, limb salvage and survival in critical limb threatening ischemia.

OBJECTIVE: According to the angiosome concept ulcer healing and limb salvage should be superior if direct arterial flow to the source vessel of an affected angiosome is established compared to indirect flow where the angiosome is perfused by means of collaterals. The objective of this study was to evaluate the impact of direct versus indirect revascularization (DR/IR) in endovascular versus bypass surgery on ulcer healing, limb salvage and mortality. MATERIALS AND METHODS: A retrospective analysis of both endovascular and bypass distal (below the knee) lower limb revascularizations for chronic limb-threatening ischemia (CLTI) between 1993 and 2014 was performed. RESULTS: The study population consisted of 126 endovascular and 198 bypass procedures. DR and IR were achieved in 57.4% and 42.6% limbs respectively. DR was not superior to IR regarding all three major endpoints when endovascular and bypass procedures were analyzed separately. Endovascular and bypass procedures resulted in comparable healing rates. All patients who did not achieve wound healing (HR 7.49; 95% CI 4.25-13.20, p = .0001) or needed to be treated with a bypass (HR 1.79; 95% CI 1.05-3.05, p = .034) were at an increased risk for major amputation. Increased mortality rate was noted after endovascular procedures (HR 1.45; 95% CI 1.04-2.00, p = .026). CONCLUSION: This retrospective study with comparable results for DR and IR did not support the angiosome concept. Achieving wound healing remains critical in patients with CLTI to reduce major amputation rates. Overall the implications of the angiosome concept seem to be limited due to its feasibility in patients with CLTI.