Experimental and Clinical Studies Investigating the Efficacy of Distal Anastomosis with Patch Plasty in Bypass Operations with Expanded Polytetrafluoroethylene Grafts

Purpose: We investigated the efficiency of distal anastomosis with patch plasty (DAPP), both experimentally and clinically. Methods: In our experimental study, dogs were divided into two groups: a control group in which anastomosis was performed without DAPP (n = 7), and a DAPP group in which DAPP was performed at the distal anastomosis (n = 7). In our clinical study, 169 femoropopliteal bypasses were divided into three groups and analyzed. In one group, the saphenous vein was used (SVG group, n = 65); in one group, an expanded polytetrafluoroethylene (ePTFE) graft was used without DAPP (ePTFE group, n = 64); and in one group, an ePTFE graft was used with DAPP (DAPP group, n = 40). Results: In the experimental study, the ratio between the area of thrombus adherence and the entire area of the intraluminal surface of the graft, defined as the thrombus covering ratio, was 48.9% in the control group and 30.2% in the DAPP group. The ratio in the DAPP group was significantly lower than that in the control group. In the clinical study, although there were no significant differences among the three groups in cumulative patency rates of the femoral above-knee popliteal arterial bypasses, the patency in the DAPP group was excellent. The cumulative patency rates of the femoral below-knee popliteal arterial bypasses in the ePTFE group were significantly lower than those in the other two groups. Conclusion: There results suggest that the addition of DAPP may achieve excellent graft patency. Received: February 14, 2002 /Accepted: November 19, 2002 Reprint requests to: K. Dairaku     

Multicentric Malignant Melanoma in a Giant Melanocytic Congenital Nevus 20 Years After Dermabrasion in Adulthood

BACKGROUND: Dermabrasion is one approach to the treatment of treating giant melanocytic congenital nevi. Treatment is recommended to reduce the risk of spontaneous malignant transformation of giant nevi into malignant melanomas that usually occur in childhood. OBJECTIVE: To describe the development of a multicentric malignant melanoma in a giant melanocytic congenital nevus after dermabrasion. METHODS: We report about a 46-year-old male patient who developed a multicentric malignant melanoma in a giant melanocytic congenital nevus. The nevus was located on his left shoulder extending to his neck and chest. Previously, dermabrasion of the nevus was performed twice at the ages of 26 and 28. RESULTS: To our knowledge, this is the first report of malignant transformation of a giant nevus into a multicentric malignant melanoma diagnosed 20 years after the procedure of dermabrasion. CONCLUSION: We conclude that a close follow-up of such patients is mandatory.     

Estimation of stature using fragmentary femora in indigenous South Africans

Intact long bones of the upper and lower extremities have been used in the derivation of regression equations for the estimation of stature in different population groups. These bones are sometimes presented to forensic anthropologists in different states of fragmentation thereby making the derived equations unusable. This has necessitated the need to assess the usefulness of measurements of fragments of long bones (e.g., femur) in the estimation of stature. While few studies have reported such equations, which are population and sex specific, it was the aim of this study to derive equations based on measurements of commonly preserved fragments of the femur for the indigenous South African population group. A total of 100 complete skeletons, equally distributed by sex, were obtained from the Raymond A. Dart collection of human skeletons. Stature was estimated for each of the skeleton using the Fully's method (Fully in Ann Med Leg 35:266-273, 1956). Regression equation for the estimation of stature and maximum length of the femur were derived from six measurements of the femur. The standard error of estimate for regression equations for stature estimation (3.72-4.38) was slightly higher than that presented for intact femur. This study confirms the usefulness of fragments of the femur of indigenous South Africans in the estimation of stature.     

Application of stem cells in bone repair

Bone has the ability to repair minor injuries through remodeling. However, when the host source of osteoprogenitors is compromised at the defect site, one effective treatment may be cell-based therapy, as it replenishes the area of bone loss with cells possessing osteogenic potential. This review is a concise comparison of different types of stem cells that have the potential to be used in tissue-engineered scaffolds for bone repair. The clinical use of mesenchymal stem or stromal cells isolated from the bone marrow for treating various diseases has been well documented. However, the scarcity of these cells prompts the search for alternative sources of multipotential cells such as amniotic fluid stem cells and umbilical cord perivascular cells. Embryonic stem cells are another controversial source of cells with osteogenic potential. These cells have the ability to differentiate into all cell types of the adult body. Issues such as the use of human embryos and the risk of contamination from animal-derived culture components continue to prevent the therapeutic use of ESCs. As a result, abundant research has been carried out to design defined culture conditions for culturing ESCs, and alternative strategies such as the generation of induced pluripotent stem cells are being developed to eliminate the need for using embryos for cell derivation. In addition to the cell source, the ability to control stem cell differentiation into functional bone and the choice of biomaterial are also paramount objectives that are being examined in research and clinical trials.     

Could <Superscript>99m</Superscript>Tc-glucarate be used to evaluate tumour necrosis?

PURPOSE: The aim of this study was to determine whether (99m)Tc-glucarate ((99m)Tc-GLA) is a powerful and discriminant tumour necrosis marker. MATERIALS AND METHODS: The induction of apoptosis and secondary necrosis (by a chemotherapeutic agent) and necrosis (by intense hyperthermia) was studied on an in vitro and in vivo leukaemic cell line model (U937). The percentage of apoptosis/necrosis in vitro was determined by flow cytometry after staining cells with annexin-V-fluorescein/propidium iodide. The uptake of (99m)Tc-GLA was studied after treatments that produce an optimal of necrosis cells or apoptotic cells. Three populations of interest: viable, apoptotic and necrotic cells were sorted by flow cytometry. The uptake and the intracellular distribution of (99m)Tc-GLA on each population have been studied. We also investigated the influence of necrosis on (99m)Tc-GLA uptake in a model of U937 xenografts in nude mice. RESULTS: The accumulation of (99m)Tc-GLA in untreated and apoptotic cells was lower than in necrotic cells. Cell sorting discriminated each cellular population and showed a 14% accumulation in necrotic cells and no more than a 3% in apoptotic cells. In apoptotic and viable cells, (99m)Tc-GLA is distributed between the cytosolic/membrane and the nucleus fractions. In necrotic cells, (99m)Tc-GLA is mainly found in the nucleus fraction. In vivo investigations showed a higher (99m)Tc-GLA uptake in necrotic tumour than in apoptotic and control ones. CONCLUSIONS: (99m)Tc-GLA may be a useful agent to specifically evaluate tumour necrosis and may be helpful for the follow-up of patients with cancer.     

Computer-aided detection of pulmonary embolism: Influence on radiologists’ detection performance with respect to vessel segments

The purpose was to assess the sensitivity of a CAD software prototype for the detection of pulmonary embolism in MDCT chest examinations with regard to vessel level and to assess the influence on radiologists' detection performance. Forty-three patients with suspected PE were included in this retrospective study. MDCT chest examinations with a standard PE protocol were acquired at a 16-slice MDCT. All patient data were read by three radiologists (R1, R2, R3), and all thrombi were marked. A CAD prototype software was applied to all datasets, and each finding of the software was analyzed with regard to vessel level. The standard of reference was assessed in a consensus read. Sensitivity for the radiologists and CAD software was assessed. Thirty-three patients were positive for PE, with a total of 215 thrombi. The mean overall sensitivity for the CAD software alone was 83% (specificity, 80%). Radiologist sensitivity was 77% = R3, 82% = R2, and R1 = 87%. With the aid of the CAD software, sensitivities increased to 98% (R1), 93% (R2), and 92% (R3) (p<0.0001). CAD performance at the lobar level was 87%, at the segmental 90% and at the subsegmental 77%. With the use of CAD for PE, the detection performance of radiologists can be improved.     

Imaging findings of complications affecting the upper extremity in intravenous drug users: featured cases

Infections generally occur in intravenous drug abuse (IVDA) patients, most commonly affecting the spine and proximal joints. Numerous serious musculoskeletal complications of IVDA may involve the upper extremity, however. Soft-tissue complications in the upper extremity of IVDA patients include cellulitis, ulceration, abscess, pyomyositis, septic bursitis, tenosynovitis, and necrotizing fasciitis. Foreign bodies in soft tissue due to needle fragments are common findings. Primary bone and joint IVDA complications include osteomyelitis (acute and chronic) and septic arthritis. Other IVDA complications in the upper extremity affecting blood vessels and lymphatics include hematoma, arterial aneurysm and pseudoaneurysm, thrombosis, thrombophlebitis, "puffy hand" syndrome, and lymphadenopathy. These complications usually present as urgent issues requiring prompt and accurate evaluation in the acute setting. Diagnostic imaging not only aids in making the correct diagnosis but also permits precise definition of the location and extent of these abnormalities. We review the imaging findings and illustrate a wide range of disabling and even life-threatening complications affecting the upper extremity of IVDA patients that require early diagnosis for optimal outcome.     

<Superscript>18</Superscript>F-FDG PET for the lymph node staging of non-small cell lung cancer in a tuberculosis-endemic country: <Emphasis Type="Italic">Is dual time point imaging worth the effort?</Emphasis>

PURPOSE: This study was to compare (18)F-FDG positron emission tomography (PET) with thoracic contrast-enhanced CT (CECT) in the ability of lymph node (LN) staging non-small cell lung cancer (NSCLC) in a tuberculosis-prevalent country. The usefulness of dual time point PET imaging (DTPI) in NSCLC nodal staging was also evaluated. METHODS: We reviewed 96 NSCLC patients (mean age, 65.3 +/- 11.7 years) who had received PET studies before their surgery. DTPI were performed on 37 patients (mean age, 64.8 +/- 12.2 years) who received an additional scan of thorax 3 h after tracer injection. The accuracies of nodal staging by CECT and PET were evaluated according to final histopathology of hilar and mediastinal LN resected by surgery. RESULTS: The accuracy for nodal staging by CECT was 65.6% and that by PET was 82.3% (p < 0.05). Six patients were over-staged and 11 were under-staged by PET. Tuberculosis (n = 3, 50%) were mostly responsible for false-positive, while small tumor foci (n = 7, 63.6%) were mostly accountable for false-negative. For the 37 patients with DTPI, 45 min standardized uptake value (SUV) and 3 h SUV for negative LNs are significantly lower than those for positive LNs (p < 0.0001). Nevertheless, the retention index (RI) showed no significant difference between these two groups. CONCLUSIONS: Our study demonstrates that PET is more accurate than CECT in LN staging NSCLC patients in Taiwan where TB is still prevalent. Semi-quantitative SUV method or DTPI with RI does not result in better diagnostic accuracy than visual analysis of PET images.     

Aortic injury with chance fracture in a child

To present the findings in a 10-year-old male with a Chance fracture and associated aortic vascular injury and review of the literature on the subject. We reviewed the clinical and imaging findings in a patient who was in a serious motor vehicle accident, sustaining a Chance fracture of the lumbar spine and associated aortic and common iliac vessel injury. We also accomplished a literature review. Evidence of an associated aortic injury was available on the initial computed tomography (CT) study, but the findings were more exquisitely demonstrated on reconstructed studies of the lumbar spine. Our literature review indicated that aortic injury associated with Chance fracture is relatively rare and often overlooked. Abdominal aortic injury although rare, can occur with Chance fractures. With the now present sophisticated CT imaging in most Emergency Rooms it is possible to obtain exquisite reconstructed images of all organ systems including the vascular tree. The images may provide enough details so that further delineation of any given problem may not be necessary.     

The effect of overlapping on the primary stability of osteochondral grafts in mosaicplasty

Our goal was to determine the primary stability of overlapping osteochondral grafts used in mosaicplasty by studying the effect of overlapping in an ex vivo model. Osteochondral grafts, 10 mm in diameter, were transplanted from the trochlea of cow femurs to the weight-bearing area of the lateral femoral condyle with 0, 15, or 30% overlap. The grafts were pushed in with a probe at a rate of 2 mm/min, and load (N)-displacement (mm) curves were recorded. In Group I (control, 0% overlap), insertion 1 and 2 mm below the cartilage level could be reached at 572.3 +/- 273.6 and 999.3 +/- 427.6 N, respectively. In Group II (15% overlap), insertion 1 and 2 mm below the cartilage level could be reached at 263.6 +/- 91.7 and 746.6 +/- 88.0 N, respectively. In Group III (30% overlap), insertion 1 and 2 mm below the cartilage level could be reached at 179.4 +/- 31.2 and 657.0 +/- 106.5 N, respectively. The loads that were necessary to produce a 1-mm dent in the grafts were significantly different between Groups I and II and Groups I and III (p < 0.05). These results suggest that stability may be reduced by graft overlapping in mosaicplasty surgery. The results of this ex vivo animal study contribute to a more complete understanding of the primary stability of osteochondral grafts in an overlapping position as well as postoperative protocols.