Ali Sarikaya

The Fate of Intramuscularly Injected Fat Autografts: An Experimental Study in Rabbits

An experimental study was designed to assess the viability and revascularization of intramuscularly injected fat autografts. For the study, 18 rabbits were divided into two groups. In the first group, fat was injected intramuscularly (12 rabbits). Autologous fat was obtained from the inguinal area and subsequently injected into the thigh muscle. In the second group, physiologic saline was injected intramuscularly to determine the effects of cannulation and pressure on muscle tissue (6 rabbits). Fat autografts were performed on the right side of the animal, and the left side was used as the control. Scintigraphic imaging and histopathologic examination of the limbs were performed after injection of adipose tissue on days 15, 30, 45, 60, 90, and 120. On the technetium-99m (99mTc) hexamethylpropylene amine oxime scintigraphy, whereas similar activity distribution was observed between the left and right thigh on days 15, 30, and 45, there was increased uptake at the right thigh on days 60, 90, and 120. This increased uptake indicates that there is viable fat tissue in this region. Histopathologic evaluation showed that microcysts resulting from degeneration of some adipocytes and inflammatory changes on day 15 additionally increased vascularity and fibrosis in some animals on day 30, as well as fibrosis, microcysties, and focal calcification areas in adipose tissue on day 45 and later. It was observed that adipose tissue survived in more than 50% of the graft area in all the animals. These findings show that fat autografts can survive in muscle tissue with less than 50% fibrotic change.

Review of monitoring free muscle flap transfers in reconstructive surgery : role of 99mTc sestamibi scintigraphy

BackgroundFree tissue transfer is a method of moving any tissue from a donor area of the body to a recipient site and re-attaching the arteries and veins to the blood vessels at the recipient site by microvascular surgery. Improved microsurgical techniques have resulted in a high percentage of successful free tissue transfers. Post-operative monitoring of tissue viability can detect early problems in free tissue transfer which may allow early intervention and salvage. Although many flap monitoring methods have been described, there is still no consensus on which of these techniques will become the standard accepted method for monitoring free muscle flaps. ObjectiveIn present study, we investigated the use of 99mTc sestamibi scintigraphy in determining free muscle flap viability and complications, and also in directing treatment. MethodsThirteen patients were examined prospectively during the post-operative period after free tissue transfer for foot defects. The cause of the defect was diabetic foot ulcer in 10 patients, dermatofibrosarcoma in one patient, squamous cell carcinoma in one patient and gunshot wound in one patient. Foot defect covering was carried out with a free latissimus dorsi muscle flap and skin graft (n=12) and a free gracilis muscle flap (n=1). All patients were examined with a monitoring system that consisted of visual inspection, hand-held Doppler ultrasonography and scintigraphic examinations. Scintigraphic imaging of all cases was performed routinely within the first 48 h post-operatively, and also on days 10 and 91 in two patients. ResultsThere were four flap failures during the study. One of these patients had viable findings upon visual inspection and no evidence of vascular compromise on Doppler at the first examination. In the other patient, visual inspection of the flap showed that it was ischaemic in one region, but there was no vascular compromise on Doppler examination. Scintigraphic images of each of these patients showed a partial hypoperfused area in the flap region. Later, these two flaps showed positive clinical indications of hypoperfusion (colour of muscle and appearance of skin graft) and Doppler abnormalities. The remaining two patients had non-viable scintigraphic images as well as positive clinical indicators of hypoperfusion and evidence of vascular compromise on Doppler. Nine patients each had a viable flap. In these patients, all three examination tools demonstrated that the flaps were totally viable and there were no vascular complications. ConclusionAccording to the results of this study, 99mTc sestamibi scintigraphy appears to be a feasible and promising method in the evaluation of free muscle flap viability and complications. On the other hand, to demonstrate any impact on management or patient outcome, further evaluation of 99mTc sestamibi imaging, including comparative studies with different established methods in a larger patient population, is highly recommended.

Effects of gender and age on the quantitative parameters of [99mTc]pertechnetate salivary gland scintigraphy in normal subjects.

AimTo assess the effect of gender and age on [99mTc]pertechnetate salivary gland scintigraphy (SGS) in healthy subjects. MethodsThe study population consisted of 93 normal subjects (46 women, 47 men; age range 20–59 years). The subjects were categorized into eight (four female and four male) subgroups according to age decades. Dynamic SGS was performed after intravenous injection of 370 MBq [99mTc]pertechnetate. Anterior salivary gland images were acquired for 30 min. On the basis of the time–activity curves, three functional parameters were calculated for the parotid and submandibular salivary glands: (1) the first minute uptake ratio, (2) the maximum uptake ratio, and (3) the maximum secretion percentage. ResultsFor women, all parotid and submandibular functional parameters had a peak in the fourth decade group. The comparison of four age groups in the female subjects showed significant differences, except for the third versus the fifth decades, at least for one parameter. The number of significant differences was highest in the comparison between the second versus the fourth decades. Among men, the highest values for all parotid and submandibular parameters were in the second decade, except for the first minute uptake ratio in the submandibular gland. The number of parameters that were significantly different among the four age groups in men was lower than in women. The first minute uptake ratio of the submandibular gland had the most significant differences among the groups of male subjects. ConclusionAge and gender differences have a significant effect on salivary gland functions which is more apparent in women than in men.

Assessment of tissue viability after frostbite injury by technetium-99m-sestamibi scintigraphy in an experimental rabbit model

Abstract. Frostbite causes injury to the tissue by direct ice-crystal formation at the cellular level with cellular dehydration and microvascular occlusion. Muscle that initially appears viable on reperfusion may subsequently become necrotic because of microcirculatory collapse. Since muscle is a sensitive tissue in frostbite injury, we used technetium-99m-sestamibi limb scintigraphy to assess tissue viability in an experimental rabbit model. Twelve rabbits were used for this investigation. The right hind limb of the rabbits was immersed to the ankle joint in a container filled with 90% ethanol at –25°C for 10 min. Frostbitten limbs were allowed to thaw in air at room temperature. Imaging and pathological examination of the affected limbs were performed 2 h, 24 h, 48 h and 72 h after freezing. In 2-h images, initial hypoperfusion was seen that corresponded to circulatory collapse. In 24-h images, there was hyperperfusion (so-called period of temporary reperfusion), corresponding to circulatory restoration. In 48-h images, a second hypoperfusion corresponded to viable but ischaemic tissue. In 72-h images, there was non-perfusion of the limb that correlated with the pathologically determined diagnosis of necrosis. All scintigraphic patterns correlated with pathological findings. We suggest that these scintigraphic patterns in soft tissue may be helpful in distinguishing between frank infarction and reversible ischemia and therefore may be useful in selecting early therapeutic or surgical interventions to salvage bone and soft tissue. Further studies are needed to show the usefulness of 99mTc sestamibi scintigraphy in clinical frostbite cases.

Technetium-99m sestamibi limb scintigraphy in post-traumatic reflex sympathetic dystrophy: preliminary results.

Abstract. Reflex sympathetic dystrophy (RSD) has widely variable clinical manifestations. Its pathogenesis remains partially unexplained. RSD is commonly divided into three stages; these stages are not always clearly separable, but staging remains important for correct treatment. Since the disease involves soft tissue alterations as well as bone changes, we decided to investigate whether technetium-99m sestamibi limb imaging can be used to evaluate the soft tissue appearance. Fifteen patients (seven females and eight males; age range 12–68 years) with clinically significant post-fracture RSD were evaluated with both three-phase bone scan (TPBS) and 99mTc-sestamibi limb scintigraphy. Although, in general, patients with similar duration of disease, clinical stage and TPBS activity tended to have similar patterns of sestamibi uptake, discordant uptake patterns were observed in some patients with clinical stage 1. Thus, of 12 patients with stage I disease, eight had increased 99mTc-sestamibi activity in the distal part of the affected limb, while three had normal activity and one had decreased activity. All three patients with stage II disease showed normal 99mTc-sestamibi uptake. Although most of the patients with increased 99mTc-sestamibi uptake had increased activity on all three phases of the bone scan, there were discordant results between the scan patterns in other patients. On the basis of these findings, we suggest that 99mTc-sestamibi imaging may contribute to the differentiation between clinical stages and may permit evaluation of the disease course and selection of appropriate therapy. 99mTc-sestamibi imaging is not, however, a primary diagnostic procedure for RSD.

The relationship between 99Tcm-sestamibi uptake and ultrastructural cell types of thyroid tumours

Although several hypotheses have been suggested regarding the accumulation of 99Tcm-sestamibi in tumours, the exact uptake mechanism is still a matter of discussion. We investigated ultrastructural cell type of thyroid tumours by electron microscopy (EM) and compared them with uptake of 99Tcm-sestamibi. Thyroid scintigraphy with 99Tcm-sestamibi was performed on 25 patients who displayed a cold nodule on previous pertechnetate scintigraphy. Tumour-to-thyroid (T/N) uptake ratio was measured semiquantitatively. Surgery was performed in all patients and cytological evaluations were done by EM. Histopathology revealed six papillary carcinomas, 16 follicular adenomas and three Hurthle cell tumours. Thyroid cells were classified as A and B cells using EM. The cytoplasm of an A cell has the normal amount of mitochondria, whereas cytoplasm of a B cell (mitochondria-rich oxyphilic cell) contains abundant mitochondria. The median T/N ratio on the early scan for an A-cell tumour was 1.21 (range, 0.74-3.2), late T/N ratio was 1.25 (range, 0.72-3.85). The T/N ratio for the B-cell tumours was 1.42 (range, 0.6-3.6) on the early scan and 1.18 (range, 0.64-5.58) on the late scan. There was no statistically significant difference between T/N ratios of A- and B-cell tumour groups. A significant difference was also not seen between early and late T/N ratios. According to our findings, 99Tcm-sestamibi accumulates in thyroid tumours with both A and B cells, therefore these results suggest that the mitochondrial content of tumours is not only responsible for sestamibi uptake and retention.

Evaluation of skeletal muscle metabolism and response to erythropoietin treatment in patients with chronic renal failure using 99Tcm-sestamibi leg scintigraphy.

It is well known that uraemia affects skeletal muscle metabolism. This has been attributed to a variety of causes, including anaemia, vitamin D, carnitine deficiency and hyperparathyroidism. The aim of this study was to ascertain whether 99Tcm-sestamibi leg scintigraphy is useful in the evaluation of skeletal muscle metabolism and the monitoring of treatment response in uraemic myopathy. Forty patients with chronic renal failure and 24 normal controls underwent examination. Fifteen patients with chronic renal failure received erythropoietin treatment. 99Tcm-sestamibi leg scintigraphy was performed in all subjects and in 15 patients after therapy. The calf-to-ankle uptake ratio was calculated by semi-quantitative analysis and normalized to lean body mass. The normalized uptake ratios were significantly different between patients and controls. After erythropoietin therapy, there was a significant increase in the normalized uptake ratios compared with pre-therapy. Our results suggest that 99Tcm-sestamibi leg scintigraphy is useful in the assessment of muscle metabolic abnormalities and the effect of treatment in uraemic myopathy.

The incidence of recurrence and hypothyroidism after radioiodine treatment in patients with hyperthyroidism in Trakya, a mild iodine deficiency area, during the period 1991–2003

ObjectiveThe purpose of this retrospective study was to evaluate the incidence of recurrence and the success of radioiodine treatment (RIT) in the Trakya region of Turkey, an area with mild iodine deficiency, and to compare the effect of dose regimen selection (fixed (FD) or calculated dose (CD)) on treatment success.Material and MethodsThe study sample included 148 patients (40 male, median age 50) treated with radioiodine between the years 1991-2003. Patients were categorized into three diagnostic groups: Graves’ disease (GD) (n = 65), solitary toxic adenoma (TA) (n = 29), and toxic multinodular hyperthyroidism (TMH) (n = 54), and each divided into two subgroups according to treatment method; the first group was treated with a FD of 370 MBq (10 mCi), and the second with CD.ResultsThe largest group was GD (44%), followed by TMH (36%). Median duration of follow-up was 28 months (range 6-147). FD was given to 52.7% of all patients and CD was given to 47.3%. There was a partial difference in the dose regimen between all groups, but did not reach statistically significant levels (FD vs. CD: 65%–35%; 38%–62%; 46%–54%; GD, TA, TMH respectively, p > 0.05). Total cure rate in FD and CD was 46 (59%) and 37 (52.9%), respectively. The rates of hypothyroidism for GD, TA, and TMH groups were 28 (43.1%), 6 (20.7%) and 16 (29.6%), respectively. The incidence of hypothyroidism did not vary significantly between any groups (p > 0.05). At the end of the follow-up period, a total of 104 patients (70.3%) were treated successfully. There was no significant difference in the cure rate between any groups (p > 0.05).ConclusionsThe treatment success in all groups and subgroups did not differ significantly between FD and CD. Our lower cure rate than in previous studies may be related to iodine deficiency. Higher doses of radioiodine may be required to increase final treatment success in endemic goiter areas. If this true, dosimetry and calculated dose regimen would be required in all groups of patients instead of an FD concept. However, our findings should be verified in larger series of patients, with longer follow-up period, and urinary iodine concentration measurements.

Lumbosacral transitional vertebral articulation: evaluation by planar and SPECT bone scintigraphy.

It has been suggested that low back pain (LBP) may arise from lumbosacral transitional vertebral articulation (LSTVA) itself. It is known that bone scintigraphy is a valuable tool for the recognition of pain arising from bone and articular diseases. Therefore we aimed to show planar and SPECT bone scintigraphic findings of LSTVA and compare them with the LBP and X-ray findings. Twenty-eight patients (aged 20-63 years) in whom LSTVA had been identified radiographically were evaluated with planar bone scintigraphy, utilizing 99mTc methylene diphosphonate; and single photon emission computed tomography (SPECT) bone scintigraphy. Eighteen patients had LBP whereas 10 had not. There were 25 type IIA, one type IIB and two type IIIA LSTV articulation. On planar images, normal or non-focal minimally increased uptake superimposed on the upper sacroiliac joint was seen in patients without degenerative changes regardless of LBP whereas SPECT showed non-focal mild increased uptake on the area medial to the upper sacroiliac joint. Planar scans showed normal to non-focal mild, and mild-to-moderately increased uptake whereas SPECT demonstrated focal mild-to-moderately and markedly increased uptake in patients with degenerative changes without LBP and with LBP, respectively. The X-ray results showed an association of LBP degenerative changes, and the SPECT results showed a focal, markedly increased, uptake. We conclude that this focal, markedly increased, uptake may show the metabolically active degenerative changes of LSTV articulation and may help to reveal the pain arising from LSTVA. Therefore we propose that bone scintigraphy may be considered for the evaluation of patients with LBP thought to arise from LSTV articulation.

99mTc-sestamibi muscle scintigraphy to assess the response to neuromuscular electrical stimulation of normal quadriceps femoris muscle.

ObjectivesNeuromuscular electrical stimulation (NMES) is widely used for improving muscle strength by simultaneous contraction in the prevention of muscle atrophy. Although there exist many clinical methods for evaluating the therapeutic response of muscles,99mTc-sestamibi which is a skeletal muscle perfusion and metabolism agent has not previously been used for this purpose. The aim of our work was to ascertain whether99mTc-sestamibi muscle scintigraphy is useful in the monitoring of therapeutic response to NMES in healthy women.MethodsThe study included 16 women aged between 21 and 45, with a mean age of 32.7±6.4. Both quadriceps femoris muscles (QFM) of each patient were studied. After randomization to remove the effect of the dominant side, one QFM of each patient was subjected to the NMES procedure for a period of 20 days. NMES was performed with an alternating biphasic rectangular current, from a computed electrical stimulator daily for 23 minutes. After measurement of skinfold thickness over the thigh, pre- and post-NMES girth measurements were assessed in centimeters. Sixty minutes after injections of 555 MBq99mTc-sestamibi, static images of the thigh were obtained for 5 minutes. The thigh-to-knee uptake ratio was calculated by semiquantitative analysis and normalized to body surface area (NUR=normalized uptake ratio).ResultsThe difference between the pre and post NMES NUR values was significant (1.76±0.31 versus 2.25±0.38, p=0.0000). The percentage (%) increase in NUR values also well correlated with the % increase in thigh girth measurements (r=0.89, p=0.0000).ConclusionThese results indicated that99mTc-sestamibi muscle scintigraphy as a new tool may be useful in evaluating therapeutic response to NMES.