Prediction of limb salvage after therapeutic angiogenesis by autologous bone marrow cell implantation in patients with critical limb ischemia

[Phenomenon of unstable tcpO2 level in transcutaneous oximetry in patients with diabetes mellitus]

The back of the foot is a standard region for measuring transcutaneous oxygen tension (tcpO2) with a reliably determined threshold of ischaemia, but such measurement reflects blood supply of only a portion of angiosomes of the foot. Determining the reference values of tcpO2 in other regions of the lower extremity is of current importance. However, measuring the tcpO2 level on the plantar surface and in some other regions not uncommonly reveal a phenomenon of its steady decrease instead of formation of a plateau. The purpose of the present study was to analyse the frequency of the phenomenon of a steady decrease in ptcO2 level while performing transcutaneous oximetry in various zones of the lower extremity. We retrospectively analysed the results of a total of 160 measurements of tcpO2 in 35 patients with diabetes mellitus. The patients' mean age amounted to 68 (47-87) years, with the duration of diabetes mellitus averaging 14 (1-24) years. The male-to-female ratio was 60:40. Seventy-seven percent of patients had foot ulcers/wounds, 34% of patients had a history of previously endured revascularization. The examination was carried out in the dorsal, plantar, medial plantar regions of the foot, on the medial surface of the crus and in the subclavian region, using the TCM 400 monitoring device (Radiometer, Denmark). The measurements were performed by an experienced operator in strict accordance with the manufacturer's recommendations. We evaluated the average value of tcpO2 between the 15th and 19th minutes of measurement and the peculiarities of the tpcO2 curve (plateau/increase/decrease of the value) within this time interval. The mean tcpO2 value in the medial plantar region was significantly higher than that on the back of the foot: 34 (3-70) versus 22 (1-59) mm Hg, p=0.003. A portion of measurements demonstrated a steady decrease in the tpcO2 during the measurement up to the 40th minute. Complying with the stable plateau phase criteria we had developed were 92% of measurements in the subclavian region, 100% - in the middle third of the crus, 76% - on the back of the foot, 77% - in the medial plantar region and 43% - on the plantar surface of the foot. CONCLUSIONS: 1) the revealed phenomenon of a steady decrease of tcpO2 in some patients needs to be taken into consideration in clinical practice and deserves further study; 2) the nature of this phenomenon is unclear, with a possible effect of skin creams on the results of the measurements; 3) it is advisable to include into the functions of the devices for transcutaneous oximetry an algorithm for confirmation of the true phase of the plateau and calculation of the mean tcpO2 value for a chosen period; 4) despite the need for measurement of tcpO2 in the 'alternative zones' it is necessary to thoroughly study the reliability of the data in these zones and to determine the normal values of the parameter separately for each of them.

A novel Tc-99m and fluorescence labeled peptide as a multimodal imaging agent for targeting angiogenesis in a murine hindlimb ischemia model

The serine-aspartic acid-valine (SDV) peptide binds specifically to integrin αvβ3. We developed a Tc-99m and TAMRA labeled peptide, Tc-99m SDV-ECG-K-TAMRA for multimodal imaging of angiogenesis. Tc-99m SDV-ECG-K-TAMRA was prepared in high yield (>96%) and showed low cytotoxicity. Tc-99m tetrofosmin images 1 week after operation, revealed significantly decreased perfusion of the ischemic hindlimb, and the perfusion recovered gradually for 4 weeks. In contrast, Tc-99m SDV-ECG-K-TAMRA uptake was maximal 1 week after the operation (ischemic-to-non-ischemic uptake ratio =5.03±1.01) and decreased gradually. The ischemic-to-non-ischemic ratio of Tc-99m SDV-ECG-K-TAMRA and Tc-99m tetrofosmin was strongly negatively correlated (r =-0.94). A postmortem analysis revealed increased angiogenesis markers and uptake of Tc-99m SDV-ECG-K-TAMRA by ischemic tissue. Our in vivo and in vitro studies revealed substantial uptake of Tc-99m SDV-ECG-K-TAMRA by ischemic tissue. Tc-99m SDV-ECG-K-TAMRA could be a good candidate dual-modality imaging agent to assess angiogenesis.

Imaging Angiogenesis Using 99mTc-Macroaggregated Albumin Scintigraphy in Patients with Peripheral Artery Disease

One problem of vascular angiogenesis therapy is the lack of reliable methods for evaluating blood flow in the microcirculation. We aimed to assess whether (99m)Tc-macroaggregated albumin perfusion scintigraphy ((99m)Tc-MAA) predicts quantitated blood flow after therapeutic angiogenesis in patients with peripheral artery disease.

METHODS

Forty-six patients with peripheral artery disease were treated with bone marrow mononuclear cell implantation (BMCI). Before and 4 wk after BMCI, blood flow was evaluated via transcutaneous oxygen tension (TcPO2), ankle-brachial index, intravenous (99m)Tc-tetrofosmin perfusion scintigraphy ((99m)Tc-TF), and intraaortic (99m)Tc-MAA.

RESULTS

Four weeks after BMCI, TcPO2 improved significantly (20.4 ± 14.4 to 36.0 ± 20.0 mm Hg, P < 0.01), but ankle-brachial index did not (0.65 ± 0.30 to 0.76 ± 0.24, P = 0.07). Improvement in (99m)Tc-TF count (0.60 ± 0.23 to 0.77 ± 0.29 count ratio/pixel, P < 0.01) and (99m)Tc-MAA count (5.21 ± 3.56 to 10.33 ± 7.18 count ratio/pixel, P = 0.02) was observed in the foot region but not the lower limb region, using both methods. When these data were normalized by subtracting the pixel count of the untreated side, the improvements in (99m)Tc-TF count (-0.04 ± 0.26 to 0.08 ± 0.32 count ratio/pixel, P = 0.04) and (99m)Tc-MAA count (1.49 ± 3.64 to 5.59 ± 4.84 count ratio/pixel, P = 0.03) in the foot remained significant. (99m)Tc-MAA indicated that the newly developed arteries were approximately 25 μm in diameter.

CONCLUSION

BMCI induced angiogenesis in the foot, which was detected using (99m)Tc-TF and (99m)Tc-MAA. (99m)Tc-MAA is a useful method to quantitate blood flow, estimate vascular size, and evaluate flow distribution after therapeutic angiogenesis.

Therapeutic vascular angiogenesis for intractable macroangiopathy-related digital ulcer in patients with systemic sclerosis: a pilot study

OBJECTIVE

SSc causes intractable ischaemic ulcers. To avoid major amputation, we examined the safety and efficacy of therapeutic vascular angiogenesis for digital ulcers due to SSc.

METHODS

A single-centre, open-label pilot study was conducted in patients with an ischaemic digital ulcer [n = 40, mean age 65 years (s.d. 8), Rutherford class III-5 or III-6) due to lcSSc (n = 11) or arteriosclerosis obliterans (ASO; n = 29). Bone marrow mononuclear cells (0.4-5.1 × 10(10) cells in total) were administered into the ischaemic limbs. We evaluated short-term safety and efficacy by means of a pain scale, (99m)Tc-tetrofosmin scintigraphy and transcutaneous oxygen tension (TcPO2) before and 4 weeks after treatment. Also, the 2-year outcome was compared.

RESULTS

There was a case of amputation in each group within 4 weeks after therapy. The pain scale significantly decreased in both groups [lcSSc 93 mm (s.d. 9) to 11 (s.d. 16), P < 0.01; ASO 77 mm (s.d. 22) to 16 (s.d. 13), P < 0.01] and TcPO2 significantly improved [lcSSc 9.0 mmHg (s.d. 9) to 35 (s.d. 14), P < 0.01; ASO 18 mmHg (s.d. 10) to 29 (s.d. 21), P < 0.05). At the 2-year follow-up, the limb amputation rate was 9.1% in lcSSc and 20.7% in ASO (P = 0.36), while the recurrence rate was 18.2% in lcSSc and 17.2% in ASO (P = 0.95). All-cause mortality was 27.3% in lcSSc and 17.2% in ASO (P = 0.65).

CONCLUSION

In patients with lcSSc, bone marrow mononuclear cell implantation provides clinical benefit and is safe, without major adverse reactions, and may become an effective strategy.

TRIAL REGISTRATION

UMIN-CTR, http://www.umin.ac.jp/ctr/index-j.htm, no. UMIN000004112.

Diabetes-related lower extremities amputations in saudi arabia: the magnitude of the problem

BACKGROUND

Data on diabetes-related lower extremities amputations in the Kingdom of Saudi Arabia (KSA) and perhaps in all of Middle East and North African (MENA) countries are limited, in view of the absence of national registries.

METHODS

This review aims to challenge media figures by review of data in the local database of the author, available published data, as well as by analysis of recent annual reports of the Saudi Ministry of Health to estimate the magnitude of the problem. Different methods of analysis are used based on the number of beds, operations and admissions in KSA to generate approximate figures of the annual expected numbers of amputations in KSA and MENA countries. The 2010 International Diabetes Federation IDF comparative prevalence rate of 16.8% was used to standardize the analysis methods.

RESULTS

Findings of 2 previous studies and 3 analytical methods led me to the prediction that about 325 amputations are likely to occur annually in Jeddah compared to 741 in Riyadh and 3970 in KSA. When we applied the results of KSA to those of MENA countries, 44208 amputations were predicted annually.

CONCLUSION

Half a million diabetes-related amputations of the lower extremities are likely to occur in KSA and MENA countries over the coming decade. National registries are urgently needed.