Collateral circulation between angiosomes in the feet of diabetic patients

Perioperative Risk Factors for Early Major Amputation Following First-Time Diabetic Forefoot Amputation

BACKGROUND

Despite a meticulous multidisciplinary team approach, limb salvage remains uncertain even after the initial forefoot amputation in patients with end-stage diabetes. Which of many factors strongly influence the early failure of the limb salvage strategy remains unknown. This study aimed to analyze perioperative independent risk factors for major amputation within 1 year following first-time diabetic forefoot amputation.

METHODS

Perioperative variables of 808 diabetic forefoot amputations performed in a tertiary referral center specialized for organ transplantation and end-stage diabetes were analyzed. Major amputations were performed in 104 patients (12.9%) throughout follow-up, and 77 (74%) of 104 patients had their major amputation within 1 year. Cox proportional hazards were examined to assess the risk factors for major amputation performed within 1 year.

RESULTS

In univariate analysis, 18 possible risk factors significantly differed between patients with and without early major amputation. In stepwise multivariable analysis, chronic renal failure (CRF), peritoneal dialysis, and bilateral initial amputation were strong risk factors for early major amputation, with hazard ratios of 2.973 (95% CI 1.805-4.896, P < .0001), 2.558 (95% CI 1.113-5.881, P = .027), and 2.515 (95% CI 1.318-4.798, P = .005), respectively.

CONCLUSION

Regardless of kidney transplantation (KT) status, CRF strongly predicts >20% chance of major amputation within 1 year after the first diabetic forefoot amputation.

Optimizing Lower Extremity Local Flap Reconstruction in Peripheral Vascular Disease

BACKGROUND

Local flaps remain a valuable reconstructive tool as a means for limb salvage for patients with advanced arterial disease. Our single-center, retrospective cohort study aims to compare the outcomes of different patterns of blood flow affected by vascular disease to pedicles in local flap reconstruction of the foot and ankle.

METHODS

A retrospective review of 92 patients and 103 flaps was performed. On angiograms, pattern of blood flow to the flap pedicle was determined to be direct inline flow (DF) or indirect flow (IF). Patterns of IF were either by arterial-arterial connections (AC) or unnamed randomized collaterals (RC). Primary outcomes were immediate flap success and limb salvage. Comparative analyses were performed using the χ2 and Fisher tests for categorical variables.

RESULTS

Among all flaps, 73.8% (n = 76/103) had DF and 26.2% (n = 27/103) had IF. Both groups experienced similar rates of immediate flap success (DF = 97.3% vs IF = 92.6%, P = 0.281) and limb salvage (DF = 75.% vs IF = 66.7%, P = 0.403). However, the rate of contralateral amputation was significantly higher in the IF group (26.9% vs 5.3%, P = 0.006). When comparing the 3 distinct patterns of blood flow (DF vs AC vs RC), pedicled flaps were more commonly supplied by DF and AC, while random pattern flaps were more commonly supplied by RC (P = 0.042).

CONCLUSIONS

Alternative routes of revascularization can maintain local flap viability and achieve similar rates of limb salvage but risks contralateral amputation. We found that pedicled and local muscle flaps require inline blood flow or blood supply by ACs. Meanwhile, random pattern flap can be supported by random collaterals.

Implications of Single-Vessel Runoff on Long-Term Outcomes of Free Tissue Transfer for Lower Extremity Reconstruction

BACKGROUND

 Patients with complex lower extremity (LE) wounds and single-vessel LE runoff (1-VRO) are often considered for amputation. While more challenging, free tissue transfer (FTT) is a means for limb salvage. This study aims to demonstrate the feasibility of limb salvage with FTT in patients with 1-VRO.

METHODS

 Patients undergoing FTT by a single surgeon between 2011 and 2021 were retrospectively reviewed. Data collected included demographics, wound characteristics, vascular status, and operative details. Patients were divided into cohorts based on 1- versus 3-VRO of tibial vessel inflow. Outcomes of interest included postoperative complications such as flap necrosis, flap success, limb salvage, and ambulatory status.

RESULTS

 A total of 188 patients underwent FTT to LE, with 25 patients (13.3%) having 1-VRO. Patients with 1-VRO had a comparable prevalence of diabetes (56.0% vs. 50.0%, p = 0.569) and end-stage renal disease (8.0% vs. 3.7%, p = 0.319). Osteomyelitis was more common in the 1-VRO group (80.0% vs. 60.1%, p = 0.056). FTT donor sites and flap composition were similar between cohorts. At mean follow-up of 21.2 months (interquartile range 24.5:5.6, 30.1 months), limb salvage rates were similar between cohorts (84.0% vs. 91.4%, p = 0.241), with no significant differences in ambulatory status or mortality. Higher complication rates occurred in the 1-VRO cohort (48.0% vs. 21.5%, p = 0.004), of which partial flap necrosis was more prevalent in the 1-VRO group (8.0% vs. 1.2%, p = 0.029). There was no difference in flap success rates between groups (p = 0.805). More postflap angiograms were performed in the 1-VRO group (32.0% vs. 9.2%, p = 0.001), but there was no difference in need for repeat percutaneous endovascular intervention between groups.

CONCLUSION

 This study demonstrates that FTT reconstruction to the LE remains a reliable reconstruction option for limb salvage in patients with single-vessel supply to the LE. Reliance on advanced perioperative management and patient optimization is effective at reducing negative outcomes.

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.

[Evaluation of revascularization efficiency using near-infrared oximetry in patients with diabetic foot syndrome]

OBJECTIVE

To evaluate prognostic significance of tissue oximetry in healing of trophic defects in patients with diabetic foot syndrome (DFS) after endovascular revascularization.

MATERIAL AND METHODS

In 42 patients with DFS, tissue oximetry was performed in angiosome projection with the FORE-SIGHT MC-2000 (CASMED) device before and the next day after revascularization of lower limb arteries. The 1st group included 30 patients with wound healing throughout 3 months, the 2nd group included 12 patients with amputation or no healing of trophic defects.

RESULTS

Direct revascularization was more common in the 1st group (p=0.001). On the day after intervention, oxygen saturation (StO2) increased in all angiosomes in both groups (p<0.05). StO2 increment differed significantly between groups in all angiosomes except for point I (p<0.05). According to ROC analysis, StO2 increment by 4.5% in absolute values and 7.9% in percentage leads to trophic defect healing within 3 months (sensitivity and specificity were 76.7% and 66.7% for absolute values, 80% and 58.3% for percentage, respectively).

CONCLUSION

Evaluation of StO2 in target angiosome may be valuable to predict trophic defect healing after endovascular surgery.