Skin Perfusion Pressure Values Research Articles

Abstract 18185: A Multicenter Prospective Trial of Therapeutic Angiogenesis Using Bone Marrow-Derived Mononuclear for Patients With Critical Limb-Threatening Ischemia Caused by Thromboangiitis Obliterans

Background: Thromboangiitis obliterans (TAO) can develop critical limb-threatening ischemia (CLTI). Despite conventional treatments, such as smoking cessation or revascularization, young patients require limb amputation. Therapeutic angiogenesis using bone marrow-derived mononuclear cell (BM-MNC) implantation has demonstrated long-term efficacy and safety in patients with CLTI, particularly those with TAO. To expand BM-MNC implantation in clinical practice, further evidence is required in CLTI patients with TAO. We aimed to determine the efficacy of BM-MNC implantation in a prospective trial. Methods: This multicenter, prospective, interventional trial was performed under an advanced medical care program. We enrolled 22 patients with CLTI and skin perfusion pressure (SPP) <30 mmHg; they underwent BM-MNC implantation within 28 days (Figure.1). The follow-up period was 180 days, and the primary endpoint was an improvement in the SPP value in the affected target limb 180 days after the implantation. One patient dropped out from the follow-up. Results: The mean age was 47.6 years (male: 90.5%, Fontaine classification IV: 57.1%). The SPP value significantly improved on day 180 (p<0.001) (Figure. 2). The secondary endpoints, i.e., numerical rating scale scores and transcutaneous oxygen pressure values significantly improved within day 180. The 3-year major amputation-free and overall survival probability in the safety analysis set were 95.5% and 89.5%, respectively (Figure. 3). No severe adverse events occurred. Conclusions: We believe that the BM-MNC implantation will likely become a feasible and safe therapy for CLTI patients caused by TAO.

The fluctuation of skin perfusion pressure in hemodialysis patients treated with LDL apheresis therapy: A comparison of LDL adsorption and double filtration plasmapheresis.

There have been a number of reports suggesting that LDL apheresis, including LDL adsorption and double filtration plasmapheresis (DFPP), can be applied for the treatment of lower extremity peripheral arterial disease (PAD) in hemodialysis patients, whereas there is no definitive recommendation for the use of LDL apheresis. The change of skin perfusion pressure (SPP) during LDL apheresis was measured in every single treatment to determine the effect of LDL adsorption and DFPP on improving blood flow in lower extremity PAD hemodialysis patients. Eleven hemodialysis patients treated with more than two series of LDL apheresis were involved in the study. "One series" included 10 treatments of LDL apheresis according to the Japanese health care insurance system. In total, 320 treatments (32 series) of LDL apheresis were performed utilizing either LDL adsorption or DFPP treatment in 11 patients. The SPP values pre- and post-apheresis were recorded in 315 treatments (228 LDL adsorption and 87 DFPP). The SPP was significantly improved after both LDL adsorption (P < .001) and DFPP (P=.002) treatment. The median change of SPP was significantly larger in the LDL adsorption group (12.6 mm Hg, range: -48.5, 77.0 mm Hg) than in the DFPP group (6.7 mm Hg, range: -42.0, 72.5 mm Hg) (P=.003). The LDL adsorption consistently offered a significant increase in the SPP, whereas DFPP treatment seemed to have modest effects on the improvement of SPP compared to the LDL adsorption. These data indicate that LDL adsorption should be considered the primary LDL apheresis therapy for lower extremity PAD in hemodialysis patients to achieve improvement of blood flow.

Utility of Superb Microvascular Imaging in the Assessment of Foot Perfusion in Patients with Critical Limb Ischemia.

(1) Background: Although the ankle-brachial index (ABI) and skin perfusion pressure (SPP) are commonly used to evaluate the peripheral circulation in critical limb ischemia (CLI), they often cannot be performed on sore areas. We investigated the utility of superb microvascular imaging (SMI) for assessing foot perfusion in CLI patients. (2) Methods: We measured the SMI-based vascular index (SMI-VI) at six sites in the foot before and after endovascular treatment (EVT) in 50 patients with CLI who underwent EVT of the superficial femoral artery and compared the results with SPP values and the ABI. (3) Results: SMI visualized foot perfusion in all subjects in accordance with the angiosome, including the toe areas, while the ABI was unmeasurable in three patients on hemodialysis and SPP failed in four patients. SMI-VI values were significantly lower in the CLI group than in controls, and the plantar SMI-VI had the highest diagnostic performance for CLI (sensitivity 88.6%, specificity 95.6%). After EVT, the increase in the SMI-VI was positively correlated with the increase in SPP but not that in the ABI, implying that the SMI-VI reflects foot microcirculation. (4) Conclusions: SMI enables the visualization and quantification of foot microcirculation based on the angiosome. SMI has high utility as a tool for assessing foot perfusion in CLI.

Clinical utility of skin perfusion pressure measurement in diabetic foot wounds: An observational study.

The degree of blood vessel stenosis significantly influences diabetic foot treatment. This study aimed to investigate the association between computed tomography angiography (CTA) stenosis and skin perfusion pressure (SPP), which are noninvasive vascular assessments used to evaluate diabetic foot wounds. Forty patients who reported diabetic foot wounds between November 2016 and December 2017 were included in the study. SPPand CTA were performed to evaluate the blood flow, and the rate of decrease in wound size was measured for the wounds corresponding to Meggitt-Wagner grade 1 at the first evaluation and 4-week intervals. The P value of the association between the degree of CTA stenosis and the SPP value was 0.915, and the P value of the association between CTA stenosis and decreasing rate of wound size was .235. There was no statistically significant association between SPP and the decreasing rate of wound size according to the degree of CTA stenosis. The association between SPP value and the decreasing rate of wound size was statistically significant (P < .05). The decreasing rate in diabetic foot wound size was significantly associated with SPP but not with CTA stenosis.

Relationship between fluctuations in skin perfusion pressure values and wound healing in patients with chronic limb-threatening ischemia undergoing hemodialysis.

Background : Patients with chronic limb-threatening ischemia are often on hemodialysis. It is unclear which skin perfusion pressure (SPP) values, i.e., those measured immediately after hemodialysis on a hemodialysis day or those measured on a non-hemodialysis day, reflect the actual wound healing course in chronic limb-threatening ischemia. Methods : Eighteen patients undergoing hemodialysis (49 measurements) who were treated for leg ulcers due to critical limb ischemia were included in the study. The SPP values were divided into two groups : those measured immediately after hemodialysis (HD day group) and those measured on non-hemodialysis days (non-HD day group). The wound healing outcomes were investigated. The cutoff SPP value for predicting wound healing was set to ≥ 35 mmHg. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of SPP in each group were measured. The relationship between SPP and blood pressure was analyzed by regression analysis. Results : Significant differences were observed in the positive predictive value (HD day : 100%, non-HD day : 50% ; P = 0.002), The correlation coefficient was 0.698 in the HD day group and 0.292 in the non-HD day group. Diastolic blood pressure had a significant effect on SPP (P = 0.039). Conclusions : The measurements are best taken immediately after hemodialysis for more accuracy. J. Med. Invest. 69 : 294-298, August, 2022.

Effectiveness of Lower-Extremity Electrical Stimulation to Improve Skin Perfusion.

Although numerous studies suggest the benefit of electrical stimulation (E-Stim) therapy to accelerate wound healing, the underlying mechanism of action is still debated. In this pilot study, we examined the potential effectiveness of lower-extremity E-Stim therapy to improve tissue perfusion in patients with diabetic foot ulcers. Thirty-eight patients with diabetic foot ulcers underwent 60 min of active E-Stim therapy on acupuncture points above the level of the ankle joint using a bioelectric stimulation technology platform. Perfusion changes in response to E-Stim were assessed by measuring skin perfusion pressure (SPP) at baseline and during 30 and 60 min of therapy; retention was assessed 10 min after therapy. Tissue oxygen saturation (SatO2) was measured using a noninvasive near-infrared camera. Skin perfusion pressure increased in response to E-Stim therapy (P = .02), with maximum improvement observed at 60 min (11%; P = .007) compared with baseline; SPP reduced 10 min after therapy but remained higher than baseline (9%; P = .1). Magnitude of improvement at 60 min was negatively correlated with baseline SPP values (r = -0.45; P = .01), suggesting that those with lower perfusion could benefit more from E-Stim therapy. Similar trends were observed for SatO2, with statistically significant improvement for a subsample (n = 16) with moderate-to-severe peripheral artery disease. This study provides early results on the feasibility and effectiveness of E-Stim therapy to improve skin perfusion and SatO2. The magnitude of benefit is higher in those with poorer skin perfusion. Also, the effects of E-Stim could be washed out after stopping therapy, and regular daily application might be required for effective benefit in wound healing.

Skin perfusion pressure for predicting access-related hand ischemia following arteriovenous fistula surgery based on the brachial artery.

Access-related hand ischemia (ARHI) is a major complication of arteriovenous fistula (AVF). This study aimed to assess the predictive efficacy of skin perfusion pressure (SPP) measurement for ARHI by examining the relationship between SPP and ARHI development and progression after AVF surgery. Twenty-five patients (16 men and 9 women) who underwent AVF surgery based on the brachial artery between January 2018 and December 2018 were included. The pre- and postoperative SPP values were measured on the day of surgery. ARHI occurrence and severity were measured within 3 days and at 6 months after surgery. Receiver operating characteristic curve analysis was used to evaluate the prediction model of ARHI, and the cutoff points for the calculated coefficients were determined. There was a significant correlation between the occurrence of immediate ARHI and the SPP gradient (p = 0.024). An SPP gradient value >50 mmHg had sensitivity and specificity values of 53.85% and 91.67%, respectively, in predicting the occurrence of immediate ARHI. A postoperative SPP <48 mmHg was significantly correlated with the occurrence of 6-month ARHI (p = 0.005), with sensitivity and specificity values of 71.43% and 83.33%, respectively. The SPP gradient and postoperative SPP values may be effective clinical predictors of ARHI occurring immediately and 6 months after surgery, respectively, with high specificity. These findings could allow clinicians to diagnose and begin early interventions to help prevent ischemic tissue damage in hemodialysis patients following AVF surgery.

Low plantar skin perfusion pressure predicts long-term atherosclerotic vascular events and mortality in maintenance haemodialysis patients

Background and aimsEnd-stage renal disease is associated with an increased risk of atherosclerotic vascular disease (AVD). We investigated whether low plantar skin perfusion pressure (SPP), a useful indicator of peripheral arterial disease (PAD), predicts systemic AVD events and mortality in outpatients undergoing maintenance haemodialysis (HD). MethodsA total of 206 HD patients were enrolled and followed for 5 years. They were divided into 3 groups according to measured SPP: group 1 (G1), SPP >70 mmHg (n = 123); G2, SPP 50–70 mmHg (n = 61); and G3, SPP <50 mmHg (n = 22). ResultsDuring the follow-up period (median, 4.2 years), 56 AVD events (27.2%) and 68 deaths (33.0%) occurred. In G1, G2, and G3, the event-free survival rates were 74%, 55% and 19%, respectively, for AVD events (p < 0.01) and 73%, 54% and 26%, respectively, for mortality (p < 0.01). A Cox multivariate analysis showed that lower SPP was an independent predictor for AVD events [hazard ratio (HR) 3.12, 95% confidence interval (CI) 1.45–6.77, p < 0.01 for G3 vs. G1] and mortality (HR 3.06, 95% CI 1.57–5.98, p < 0.01 for G3 vs. G1). Furthermore, the addition of the SPP value to a model with established risk factors improved the predictability of increasing the net reclassification improvement (NRI; 0.463, p < 0.01) and integrated discrimination improvement (IDI; 0.039, p < 0.01) for AVD events. Similar results were obtained for mortality. ConclusionsLow plantar SPP can stratify risk and improve the predictability of both systemic AVD events and mortality in the maintenance HD population.

Utility of skin perfusion pressure values with the Society for Vascular Surgery Wound, Ischemia, and foot Infection classification system

ObjectiveThe addition of skin perfusion pressure (SPP) might enhance the predictive value of the Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) classification system. The purpose of the present study was to evaluate the SPP for each WIfI classification stage among patients with foot wounds by cross-referencing the results of prospectively monitored limb outcomes and to derive the SPP criteria that could be combined with other measurements to grade ischemia for the WIfI classification. MethodsFrom July 2015 to June 2017, patients with foot wounds that met the WIfI classification criteria were prospectively enrolled. We assessed the limbs using the WIfI ischemia grade without measuring the transcutaneous oxygen pressure but measured the SPP. After monitoring for 1 year, the predictability of the WIfI stages was analyzed according to whether the limbs had not healed (unchanged or worsened wounds, minor or major amputation, all-cause death) or had healed (improved or healed wounds) by comparing stages 1 and 2 with stages 3 and 4. We also statistically analyzed the SPP values that could be the boundary values between each ischemia grade and reevaluated the predictability of the WIfI stages with the boundary SPP values. ResultsWe enrolled a total of 91 limbs for 76 patients (mean age, 70.5 ± 12.0 years). The mean SPP values stratified by ischemia grade 0 to 3 were 52.1, 41.1, 27.1, and 18.8 mm Hg, respectively (an SPP of <30 mm Hg indicates severe ischemia). After monitoring for 1 year, 19 of 48 limbs in stage 1 and 2 and 35 of 43 in stage 3 and 4 were in the nonhealed group and 29 limbs in stage 1 and 2 and 8 limbs in stage 3 and 4 were in the healed group. The SPP boundary values between each ischemia (I) grade were calculated as 45 mm Hg for I-0/I-1, 35 for I-1/I-2, and 25 for I-2/I-3. When jointly using the boundary SPP values, the ischemia grade changed for 23 limbs, altering the distribution of the WIfI stages and limb outcomes: 11 of 38 limbs in stage 1 and 2 and 43 of 53 in stage 3 and 4 were transferred to the nonhealed group. The sensitivity, efficiency, and negative predictive value of WIfI staging improved when staging with SPP: from 65% to 80%, 70% to 77%, and 60% to 71%, respectively. ConclusionsThe SPP boundary values that could be used with ischemia grade in the WIfI classification were identified as 45, 35, and 25 mm Hg. The addition of SPP could improve the accuracy of the evaluation.

Clinical Effects of Planned Endovascular Therapy for Critical Limb Ischemia Patients with Tissue Loss.

Aim: The aim of this study was to investigate the clinical effect of planned endovascular therapy (EVT) for critical limb ischemia (CLI) patients with tissue loss. Although several rounds of EVT for CLI patients are required for complete wound healing, time required for complete wound healing depends on the wound severity. We hypothesized that planned EVT might reduce the time to wound healing.Methods: A total of 89 limbs of 76 CLI patients with tissue loss, who had undergone more than at least two EVTs were included in this study. From January 2013 through December 2015 (Conventional-EVT-group, 52 limbs), indication of target lesion revascularization (TLR) was decided based on decreased skin perfusion pressure (SPP) values or delayed wound healing. From January 2016 through October 2016 (Planned-EVT-group, 37 limbs), TLR were done every two months regardless of the SPP values until complete wound healing was obtained. Time to wound healing and complete wound healing rates were compared between the two groups.Results: No significant differences existed in baseline patients and lesion characteristics between the two groups. There was no significant difference in total EVT numbers between the two groups (2.0; interquartile range, 2.0–3.0 versus 2.0; interquartile range, 2.0–3.0; P = 0.9). Although complete wound healing rate was similar in both groups (71.2% versus 73.0%, p = 1.0), time to wound healing was significantly shorter (95 days versus 143 days, p = 0.025) in the Planned-EVT-group than in the Conventional-EVT-group.Conclusions: Planned-EVT is a useful strategy to shorten the time to wound healing for CLI patients with tissue loss.

High prevalence of peripheral arterial disease (PAD) in incident hemodialysis patients: screening by ankle-brachial index (ABI) and skin perfusion pressure (SPP) measurement

BackgroundPeripheral arterial disease (PAD) has much impact on mortality in hemodialysis (HD) patients. Ankle-brachial index (ABI) and skin perfusion pressure (SPP) are useful tools to detect PAD in HD patients. However, the prevalence of PAD in incident HD patients by ABI and SPP measurement has not been fully elucidated.MethodsWe examined both ABI and SPP in 185 consecutive patients with end-stage renal failure at the initiation of HD therapy. PAD was diagnosed by previous history, clinical symptoms, histories of endovascular peripheral intervention, bypass surgery, amputation due to PAD, and values of ABI and SPP. Cut-off value of ABI and SPP for diagnosing PAD was set at < 0.9 and < 50 mmHg, respectively.ResultsThe percentage of limbs with ABI < 0.9 and SPP value < 50 mmHg among total limbs were 10.8 and 21.1%, respectively. Among 185 patients in incident HD patients, 45 patients were diagnosed as having PAD. ABI and SPP positively correlated (r = 0.311, p = 0.006). However, discrepancy between ABI and SPP values (normal or high ABI with low SPP, or low ABI with normal SPP) was also found. Among 45 incident HD patients with PAD, only 14 patients (31.1%) showed low ABI and low SPP values.ConclusionMeasurement of both ABI and SPP might be necessary to improve the diagnostic accuracy of PAD. Prevalence of PAD in incident HD patients was proved to be very high.

Skin perfusion pressure as an indicator of tissue perfusion in valvular heart surgery: Preliminary results from a prospective, observational study.

Hemodynamic management aims to provide adequate tissue perfusion, which is often altered during cardiac surgery with cardiopulmonary bypass (CPB). We evaluated whether skin perfusion pressure (SPP) can be used for monitoring of adequacy of tissue perfusion in patients undergoing valvular heart surgery. Seventy-two patients undergoing valve replacement were enrolled. SPP and serum lactate level were assessed after anaesthesia induction (baseline), during CPB, after CPB-off, end of surgery, arrival at intensive care unit, and postoperative 6 h. Lactate was further measured until postoperative 48 h. Association of SPP with lactate and 30-day morbidity comprising myocardial infarction, acute kidney injury, stroke, prolonged intubation, sternal infection, reoperation, and mortality was assessed. Among the lactate levels, postoperative 6 h peak value was most closely linked to composite of 30-day morbidity. The SPP value during CPB and its % change from the baseline value were significantly associated with the postoperative 6 h peak lactate (r = -0.26, P = 0.030 and r = 0.47, P = 0.001, respectively). Optimal cut-off of % decrease in SPP during CPB from baseline value for the postoperative 6 h hyperlactatemia was 48% (area under curve, 0.808; 95% confidence interval (CI), 0.652–0.963; P = 0.001). Decrease in SPP >48% during CPB from baseline value was associated with a 12.8-fold increased risk of composite endpoint of 30-day morbidity (95% CI, 1.48–111.42; P = 0.021) on multivariate logistic regression. Large decrease in SPP during CPB predicts postoperative 6 h hyperlactatemia and 30-day morbidity, which implicates a promising role of SPP monitoring in the achievement of optimal perfusion during CPB.

Evaluation of skin perfusion pressure to assess refractory foot ulcers.

The number of patients with foot gangrene caused by critical ischaemia and severe infection is increasing significantly in developed countries. The measurement of perilesional skin blood flow by skin perfusion pressure (SPP) is useful to select the appropriate treatment of gangrenous lesions, in that it is not affected by calcifications of blood vessels. However, the prognosis of a foot ulcer may also be affected by the level of blood sugar and infections. This study aimed to validate the use of SPP in cases of foot gangrene and ulcers in patients with and without diabetes mellitus (DM) and infection. Clinical symptoms, ankle-brachial pressure index (ABPI) and SPP were assessed to evaluate the condition of each foot ulcer. Every foot ulcer was treated as independent, even if a participant had multiple ulcers. All ulcers for which we measured SPP were subject to the analysis. All ulcers were purely ischaemic in nature and were exclusively located on the foot or toes. Data were collected from 117 foot ulcers on 91 toes and feet from 65 patients. Almost all SPP values in healed cases were > 27 mmHg. There were three patients whose ulcers failed to heal by conservative treatments were complicated with severe infection. However, no effect of DM on the relationship between SPP values and prognosis was observed. Logistic regression analysis of all ulcers except for the 5 cases complicated with infection revealed that those with 30 mmHg or lower SPP values are likely to heal by conservative treatment with 23% or lower probability, whereas any ulcer with more than 50 mmHg SPP value and without severe infection may heal without the need for further operations with 80% or higher probability. The combination of SPP and careful evaluation of infection may be a good parameter to decide the appropriate treatment for ischaemic skin ulcers, regardless of the complication of DM.

Skin Perfusion Pressure and Wound Closure Time in Lower Extremity Wounds

IntroductionPeripheral Arterial Disease (PAD) affects approximately 8 million patients in the United States. We investigate the relationship of Skin Perfusion Pressure (SPP) and wound closure time in lower extremity wounds. MethodsWe conducted a retrospective study of 1125 lower extremity wounds in 998 patients between June 2006 and October 2014 in our wound clinic. We analyzed the relationship between SPPand wound closure time. SPP was measured using a Laser Doppler instrument. ResultsPatients with SPP values over 30 mmHg had shorter wound closure times, while patients with SPP values below 30 mmHg had a significantly longer wound closure time. Diabetic patients took longer to achieve wound closure compared to non-diabetics. No significant relationship was observed between SPP and wound closure time in relation to age or gender. ConclusionSPP is a useful tool in estimating time to wound closure and assessing the necessity of vascular interventions in lower extremity wounds.

Skin perfusion pressure predicts mortality in hemodialysis patients: long term follow-up

Peripheral artery disease (PAD) is not only a serious complication but also a risk factor to predict prognosis in the patients with hemodialysis (HD). Ankle-brachial blood pressure index (ABI) has been widely used for detection of PAD. Skin perfusion pressure (SPP) was used for early detection of PAD by measurement of microcirculation of subcutaneous tissue. We studied the effectiveness of ABI and SPP to predict prognosis of HD patients. Both SPP and ABI were measured in 45 HD outpatients in Nagahara Hospital. The patients were followed with a mean observational period of 44.4 months to evaluate the association of ABI or SPP value with any-cause mortality. The median ABI and SPP values in all patients were 1.15 and 70.0 mmHg, respectively, and the patients were classified into two groups with the median value used as the cutoff points. In Kaplan-Meier analysis, the lower SPP group showed significantly worse survival curve than the higher SPP group while there were no differences between ABI groups. Cox proportional hazards model demonstrated SPP values are independent and significant risk factors for mortality. These results suggest evaluation of PAD by SPP measurement is useful to predict prognosis of HD patients.

Predictive value of skin perfusion pressure after endovascular therapy for wound healing in critical limb ischemia.

To determine the predictive value of skin perfusion pressure (SPP) for wound healing after endovascular therapy (EVT). Between May 2004 and March 2011, 113 consecutive patients (84 men; mean age 71.5±12.5 years) with CLI (123 limbs) underwent successful balloon angioplasty ± stenting (flow from >1 vessel to the foot without bypass) and were physically able to undergo SPP measurement before and within 48 hours after EVT. The status of wound healing was recorded over a mean follow-up of 17.4±12.4 months. The wound healing rate was 78.9% (97 limbs of 89 patients). SPP values after EVT were significantly higher in these patients than in the 24 patients (26 limbs) without wound healing (44.2±15.6 mmHg vs. 27.5±10.4 mmHg, p<0.001). Receiver operating characteristics analysis of SPP after EVT to predict wound healing had an area under the curve of 0.81 (95% CI 0.723 to 0.899, p<0.001). The optimal cutoff for predicting wound healing was 30 mmHg, with a sensitivity of 81.4% and a specificity of 69.2%. Binary logistic regression analysis demonstrated SPP after EVT to be an independent predictor of wound healing (p<0.001). The probability of wound healing with SPP values >30 mmHg, 40 mmHg, and 50 mmHg were 69.8%, 86.3%, and 94.5%, respectively. SPP after EVT is an independent predictor of wound healing in patients with CLI. In our study, an SPP value of 30 mmHg was shown to be the best cutoff for prediction of wound healing after EVT.

Comparison of characteristics and healing course of diabetic foot ulcers by etiological classification: Neuropathic, ischemic, and neuro-ischemic type

AimsTo identify differences in the characteristics of patients with diabetic foot ulcers (DFUs) according to their etiological classification and to compare their healing time. MethodsOver a 4.5-year period, 73 patients with DFUs were recruited. DFUs were etiologically classified as being of neuropathic, ischemic, or neuro-ischemic origin. Descriptive analyses were performed to characterize study subjects, foot-related factors, and healing outcome and time. Duration of healing was assessed using the Kaplan–Meier method. Healing time among the three types was compared using the log rank test. ResultsThe number of patients manifesting neuropathic, ischemic, and neuro-ischemic ulcers was 30, 20, and 14, respectively. Differences were identified for age, diabetes duration, body mass index, hypertension, and estimated glomerular filtration rate. Patients with neuro-ischemic ulcers had better ankle–brachial index, skin perfusion pressure (SPP), and transcutaneous oxygen pressure values compared to those with ischemic ulcers. The average time in which 50% of patients had healed wounds was 70, 113, and 233days for neuropathic, neuro-ischemic, and ischemic ulcers, respectively. Main factors associated with healing were age and SPP values. ConclusionsBased on the etiological ulcer type, DFU healing course and several patient factors differed. Failure to consider the differences in DFU etiology may have led to heterogeneity of results in previous studies on DFUs.

Blood circulation in the fingers is aggravated after creating a vascular access for dialysis: assessment using skin perfusion pressure

Internal vascular shunts for haemodialysis can cause different complications. One of the most serious complications is steal syndrome, which can result in disturbed peripheral circulation causing finger necrosis and lead to amputation. Thus, prevention of these complications is important. Measurement of skin perfusion pressure (SPP) has been used in various clinical settings, including wound-healing management, and its usefulness has been increasingly unveiled. The present study was undertaken to evaluate changes in haemodynamics after internal shunt creation by measuring SPP of the thumb and the little finger before and after surgery in five patients undergoing shunt surgery using the radial artery and the cephalic vein. The study revealed average changes of −22.8 mmHg in thumb SPP. The change in the thumb was statistically significant (p < 0.05). If the effect of surgery and the threshold for wound healing are taken into account, the present results indicate the necessity to pay extra attention to fingers with extremely low preoperative SPP values. For the prevention of serious disturbances of peripheral circulation (e.g. steal syndrome), routine preoperative SPP measurement seems effective for screening of high-risk patients.

Assessment of the Characteristics and Detectability of Skin Perfusion Pressure Measured Using a Thermostatic Heating Probe

To assess the characteristics of skin perfusion pressure (SPP) measured using a thermostatic heating probe and whether a thermostatic heating probe improves SPP detection. We studied 8 feet of healthy young subjects and 31 feet of elderly patients suspected to have severe limb ischemia. We measured SPP at the dorsum and plantar aspects of each foot using a plain laser Doppler probe and a thermostatic heating probe heated at 44°C. Results were expressed as median. Comparisons were analyzed using a non-parametric test. In the healthy subjects, the SPP values at both the dorsum and the plantar aspect were not significantly different after heating. The thermostatic heating probe did not improve the SPP detection rates. In the patients with ischemic limb, the SPP values at both the dorsum and the plantar aspect significantly increased after heating (p <0.001 for both). The SPP detection rate at the dorsum remained at 96.8%; however, it was improved from 87.1% to 100% at the plantar aspect after heating. The thermostatic heating probe was shown to be useful for improving the detectability of SPP in the ischemic limbs. An SPP increase after heating may be considered as a parameter of limb ischemia.

Effects of the Ankle-brachial Blood Pressure Index and Skin Perfusion Pressure on Mortality in Hemodialysis Patients

Clinically, the ankle-brachial blood pressure index (ABI) and skin perfusion pressure (SPP) are used to screen for subclinical peripheral artery disease. However, the association between the SPP and mortality in hemodialysis patients has not been previously reported. We investigated these factors and compared the ABI and SPP in patients receiving hemodialysis. A total of 102 patients receiving maintenance hemodialysis were enrolled in this study. The ABI was determined using an ABI-form (Colin, Japan). The SPP was measured using a SensiLase(TM) PAD3000 (Kaneka, Osaka, Japan). The mean follow-up period was 3.2 ± 1.4 years. A multivariate Cox analysis identified a low ABI (p=0.019) and a low SPP (p=0.047) as being independent predictors of mortality. A receiver operating characteristic (ROC) analysis of the ABI revealed a cutoff point of 1.1 and an area under the curve (AUC) of 0.79, with a sensitivity of 90% and a specificity of 62%. A ROC analysis of the SPP revealed a cutoff point of 54.0 mmHg and an AUC of 0.71, with a sensitivity of 55% and a specificity of 84%. Both low ABI and SPP values were found to be independent risk factors for mortality among hemodialysis patients. The cutoff point for ABI as a predictor of mortality was 1.1, while that for SPP was 54.0 mmHg.