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 RevasculaRIzation 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, Ischemia, 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 incidence of wound healing than the non-IFW group (34.5 vs. 16.1 per 100 person years; p = .030). The association of IFW with 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).
CONCLUSIONS: IP revascularisation establishing IFW was statistically significantly associated with a higher wound healing rate in patients with CLTI.

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.

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.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.

BACKGROUND: 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.
CONCLUSIONS: 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.
CONCLUSIONS: This study provides knowledge that could be used to improve the diagnosis of patient with chronic limb-threatening ischemia to explore tissue perfusion.

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.

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.

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.

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.
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.
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).
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.