• Transcutaneous oxygen tension P tc o 2 is directly related to skin oxygen delivery. Regional transcutaneous oximetry (RTO) compares peripheral and truncal (P tc O 2 )3 yielding a regional perfusion index indicative of local limb perfusion. The relative diagnostic values of RTO, Doppler ankle-brachial pressure ratio (ABR), pulse volume recording (PVR), and toe pulse reappearance time (PRT/2) were studied in 64 limbs of patients with diabetes. These limbs were clinically classifiable into claudication, rest pain, and gangrene groups. Regional transcutaneous oximetry had a higher diagnostic accuracy than ABR (χ 2 = 27.47, P 2 = 7.54, P 2 =10.99, P ( Arch Surg 1984;119:690-694)

https://jamanetwork.com/HttpHandlers/ArticlePdfHandler.ashx?journal=SURG&articleId=590396&pdfFileName=archsurg_119_6_009.pdf

Superiority of Transcutaneous Oximetry in Noninvasive Vascular Diagnosis in Patients With Diabetes

https://www.tandfonline.com/doi/pdf/10.3109/17453678509154156

Skin perfusion pressure measured by radioisotope washout for predicting wound healing in lower limb amputation for arterial occlusive disease.

https://www.jvascsurg.org/article/0741-5214(85)90005-9/pdf

Skin perfusion pressure in the prediction of healing in diabetic patients with ulcers or gangrene of the foot

Noninvasive diagnostic techniques in peripheral vascular disease.

Regional transcutaneous oximetry is a new, noninvasive diagnostic technique for the investigation of peripheral vascular disease (PVD) that uses differences in limb and trunk transcutaneous PO 2 to assess the adequacy of local perfusion. The application of such measurements would be of great importance in diabetes, in which limb ischemia is commonly difficult to assess. A group of diabetic subjects with symptomatic PVD was studied with regional oximetry, Doppler-assisted blood pressure measurements, and arteriography. Doppler studies correlated poorly to symptom grade and angiographie data, while oximetry clearly demonstrated limb hypoxia under the functional conditions appropriate to the patients’ clinical symptomatology. The superiority of oximetry to Doppler studies was highly significant (X 2 = 12.64, P Because of its dependence on the adequacy of local oxygenation, transcutaneous oximetry is a powerful tool for investigation of the pathophysiology of PVD and will, in the future, have wide-ranging applications to the diagnosis and therapy of PVD.

Assessment of Perfusion in the Diabetic Foot by Regional Transcutaneous Oximetry

Using intraarterial injections of Tc99m and In113m labeled albumin microspheres we are able to generate, employing a rectilinear scanner, comparative peripheral perfusion scans at rest and with the vasculature under stress.We have chosen what appears to be the most reliable means of producing significant vasodilatation, that being reactive hyperemia, as the stress. The perfusion scans obtained, when compared, demonstrate the dynamic changes which occur in peripheral perfusion when stressed. Although, at this time, our clinical experience is limited, we are encouraged by our initial findings and believe that the procedure may prove to be both diagnostically and prognostically significant in the evaluation of peripheral vascular disease.

Effect of reactive hyperemia on the distribution of radioactive microspheres in patients with peripheral vascular disease

Relative regional perfusion of the microcirculation of the extremities is demonstrated by scanning after an intra-arterial injection of Tc99m labeled human serum albumin microspheres. The injections were most conveniently made just prior to peripheral angiography. Perfusion patterns ranged from those proportional to muscle masses to those proportional to skin surface. The former was seen in normals, while the latter was seen in patients with generalized vascular disease. Regions of increased radioactivity were observed in patients with focal disease such as Paget’s disease of bone or dermatitis.Three basic scan patterns are described in which the radioactivity is distributed: (1) proportional to muscle masses; (2) asymmetrically with relative decreases in one or more muscle masses; (3) diffusely diminished in the muscles or proportional to skin surface. Two supplemental patterns include regions of localized increased radioactivity to (4) hyperemia of soft tissue lesions and (5) diseased osseous structures.

The distribution of radioactive microspheres after intra arterial injection in the legs of patients with peripheral vascular disease

Thromboemboli were localized in dogs by intravenous injection of 131I-streptokinase. Thrombi tagged with 99mTc microspheres were released into the bloodstream. The dots were localized with a 99mTc scan, after which the dogs were given 131I-streptokinase and rescanned for 131I radioactivity. In the locations previously shown by the 99mTc scan.

Scanning of Thromboemboli with 131I-Streptokinase1

Forty patients with an ischemic ulcer of the lower extremity had peripheral vascular perfusion studies, performed with intra-arterial injections of aggregated technetium Tc 99m serum albumin microspheres (15μ to 30μ in diameter), in an attempt to develop an objective prognostic criterion for healing. The association between ulcer healing and the presence or absence of diabetes mellitus, palpable peripheral pulses, and patent trifurcation vessels on the arteriogram was reviewed and no association was noted. When, however, there was a relative hyperemia of the ulcer bed in comparison to the adjacent tissue of at least 3.5:1, as determined by counting the amount of radioactivity per unit area, 86% of patients went on to heal their ulcers. In those without this degree of hyperemia, only 11% were healed with conservative nonsurgical management. The results have shown that relative hyperemia of the ulcer bed is a clinically useful prognostic indicator in the patient with ischemic ulcer disease.

Perfusion of ischemic ulcers of the extremity: a prognostic indicator of healing.

Peripheral vascular perfusion scan during rest and reactive hyperemia does not necessarily offer the same information as the arteriogram or the clinical assessment of the peripheral pulses. The information obtained from the peripheral vascular perfusion scan offers potentially clinically useful information regarding the physiologic significance of various arterial lesions to the surgeon in selection of his therapeutic approach. The peripheral vascular perfusion scan uniquely and under varied physiologic conditions permits assessment of the effect of arterial disease on the distribution of perfusion within the extremity. The peripheral vascular perfusion scan is not in competition with, but is complementary to, arteriography and clinical assessment of the patient with peripheral vascular disease.

Michael E. Siegel

Papers

Effect of reactive hyperemia on the distribution of radioactive microspheres in patients with peripheral vascular disease

The distribution of radioactive microspheres after intra arterial injection in the legs of patients with peripheral vascular disease

Scanning of Thromboemboli with 131I-Streptokinase1

Perfusion of ischemic ulcers of the extremity: a prognostic indicator of healing.

Peripheral vascular perfusion scanning. Correlation with the arteriogram and clinical assessment in the patient with peripheral vascular disease.