In vivo tracking of adipose tissue grafts with cadmium-telluride quantum dots.

BACKGROUND: Fat grafting, or lipofilling, represent frequent clinically used entities. The fate of these transplants is still not predictable, whereas only few animal models are available for further research. Quantum dots (QDs) are semiconductor nanocrystals which can be conveniently tracked in vivo due to photoluminescence. METHODS: Fat grafts in cluster form were labeled with cadmium-telluride (CdTe)-QD 770 and transplanted subcutaneously in a murine in vivo model. Photoluminescence levels were serially followed in vivo. RESULTS: Tracing of fat grafts was possible for 50 days with CdTe-QD 770. The remaining photoluminescence was 4.9%±2.5% for the QDs marked fat grafts after 30 days and 4.2%± 1.7% after 50 days. There was no significant correlation in the relative course of the tracking signal, when vital fat transplants were compared to non-vital graft controls. CONCLUSIONS: For the first-time fat grafts were tracked in vivo with CdTe-QDs. CdTe-QDs could offer a new option for in vivo tracking of fat grafts for at least 50 days, but do not document vitality of the grafts.

Cadmium Telluride Quantum Dots as a Fluorescence Marker for Adipose Tissue Grafts.

Plastic and reconstructive surgeons increasingly apply adipose tissue grafting in a clinical setting, although the anticipation of graft survival is insecure. There are only few tools for tracking transplanted fat grafts in vivo.Murine adipose tissue clusters were incubated with negatively charged, mercaptoproprionic acid-coated cadmium telluride quantum dots (QDs) emitting in the dark red or near infrared. The intracellular localization of QDs was studied by confocal laser scanning microscopy.As a result, the adipose tissue clusters showed a proportional increase in fluorescence with increasing concentrations (1, 10, 16, 30, 50 nM) of cadmium telluride QDs. Laser scanning microscopy demonstrated a membrane bound localization of QDs. Vacuoles and cell nuclei of adipocytes were spared by QDs. We conclude that QDs were for the first time proven intracellular in adult adipocytes and demonstrate a strong fluorescence signal. Therefore, they may play an essential role for in vivo tracking of fat grafts.

Microsurgical Lymphatic Vessel Transplantation.

BACKGROUND: Lymphedema often arises after a regional interruption during cancer treatment, for example after lymph node resection the axilla or the groin. Lymphatic vessels as vascular grafts may overcome these lymphatic gaps. METHOD: Experiments in rats and dogs were performed for developing this method. Volume measurements, lymphoscintigraphies, proof of patency by MRI and radiology as well as quality of life studies were performed in patients. RESULTS: Long-term follow-up studies revealed significantly reduced volumes, significant improvement of lymphatic outflow shown by lymphoscintigraphy, long-term patency of the grafts for more than 10 years, and improved quality of life after surgery compared with the situation with conservative treatment before surgery. CONCLUSION: Vascular grafts using the patients own lymphatic vessels are able to successfully reconstruct a locally interrupted lymphatic pathway.

Primary lymphedema of the lower limb: the clinical utility of single photon emission computed tomography/CT.

OBJECTIVE: The aim of this prospective study was to determine whether the additional use of the single photon emission computed tomography/CT (SPECT/CT) technique improves the diagnostic value of planar lymphoscintigraphy in patients presenting with primary lymph edema of the lower limb. MATERIALS AND METHODS: For a defined period of three years (April 2011-April 2014) a total of 34 consecutive patients (28 females; age range, 27-83 years) presenting with swelling of the leg(s) suspicious of (uni- or bilateral, proximal or distal) primary lymphedema were prospectively examined by planar lymphoscintigraphy (lower limbs, n = 67) and the tomographic SPECT/CT technique (anatomical sides, n = 65). RESULTS: In comparison to pathological planar scintigraphic findings, the addition of SPECT/CT provided relevant additional information regarding the presence of dermal backflow (86%), the anatomical extent of lymphatic disorders (64%), the presence or absence of lymph nodes (46%), and the visualization of lymph vessels (4%). CONCLUSION: As an adjunct to planar lymphoscintigraphy, SPECT/CT specifies the anatomical correlation of lymphatic disorders and thus improves assessment of the extent of pathology due to the particular advantages of tomographic separation of overlapping sources. The interpretation of scintigraphic data benefits not only in baseline diagnosis, but also in physiotherapeutical and microsurgical treatments of primary lymphedema.

Correction of asymmetric pectus excavatum using a virtually designed silicone implant.

BACKGROUND: An extended asymmetric funnel chest deformity with the breast gland located in the thoracic mold can lead to a fictitious aplasia of the breast. The authors termed this condition "pseudo-Amazon syndrome" because the breast tissue and the pectoralis muscle are fully developed. METHODS: This report presents a detailed technical approach to the fabrication of a precise-fitting custom-made silicone implant. The design of the implant was achieved using a computed tomography (CT) data set and rapid prototyping. The volumes of the "hidden" and the normal breasts measured preoperatively by processing the CT data were similar. These volumes were compared with the breast volumes measured by three-dimensional photography 4 years postoperatively to assess the predictability of the volume congruency. The silicone implant was surgically placed in the epicostal plane and extended almost over the right hemithorax. RESULTS: The implantation was performed without the necessity of further trimming. Both the surgeon and the patient rated the aesthetic and functional long-term result as good in terms of symmetry and the possibility of exercise without restrictions. The final breast volume of the surgically treated side was 95 % of the volume of the normal contralateral breast. CONCLUSION: The described method reduces the operation time and the operative trauma by primary implant fit. However, the method is rather elaborate and the production process is expensive. This in turn reduces the generation of proceeds to a minimum. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

MR lymphangiography at 3.0 T: correlation with lymphoscintigraphy.

PURPOSE: To prospectively compare findings of magnetic resonance (MR) lymphangiography with those of lymphoscintigraphy, evaluate the pattern and delay of lymphatic drainage, compare typical findings, and investigate discrepancies between the techniques. MATERIALS AND METHODS: This prospective study was performed according to the Declaration of Helsinki and was approved by the local ethics committee. Thirty consecutive patients with uni- or bilateral lymphedema and lymph vessel transplants of the lower extremities were examined with 3.0-T fat-saturated three-dimensional gradient-echo MR after gadopentetate dimeglumine injection. Results of all examinations were correlated with corresponding results of lymphoscintigraphy examinations. Results of both techniques were separately reviewed in consensus by a radiologist and a nuclear physician, who rated delay and pattern of drainage, number of enhancing levels, and quality of conspicuity of the depiction of lymph nodes and lymph vessels. Sensitivity and specificity were calculated by using combined results of both techniques and clinical presentation findings as reference standard. Correlation was calculated with weighted k coefficients. RESULTS: Weak lymphatic drainage at lymphoscintigraphy correlated with lymphangiectasia at MR lymphangiography (13 of 33 affected extremities). Lymph vessels were clearly visualized with MR lymphangiography (five of 24 affected extremities), while they were not detectable with lymphoscintigraphy. Depiction of inguinal lymph nodes was clearer with lymphoscintigraphy (five of 60 extremities). Correlation of both techniques was excellent for delay (κ=0.93) and pattern (κ=0.84) of drainage, good for depiction of lymph nodes (κ=0.67) and number of enhancing levels (κ=0.77), and moderate for depiction of lymph vessels (κ=0.50). Sensitivity and specificity for delay and pattern of drainage were concordant, whereas MR lymphangiography showed a higher sensitivity for lymph vessel abnormalities (100% vs 79%) and lower specificity for lymph node abnormalities (78% vs 100%). CONCLUSION: Imaging findings of MR lymphangiography and lymphoscintigraphy show a clear concordance. With lymphoscintigraphy, better visualization of inguinal lymph nodes was achieved, whereas with MR lymphangiography, better depiction of lymph vessels and morphologic features of lymph vessel abnormalities were achieved.

MR-lymphangiography at 3.0 T--a feasibility study.

The purpose of this study was to establish and evaluate contrast-enhanced MR-lymphangiography (MRL) at 3.0 T for detection and visualization of abnormalities of the peripheral lymphatic system. Sixteen patients were examined with a highly resolved isotropic T1w-3D-GRE-(FLASH) sequence (TR 3.76 ms/TE 1.45 ms/FA 30 degrees /voxel-size 0.8 x 0.8 x 0.8 mm(3)) at 3T after intracutaneous injection of gadolinium-diethylene-triamine-pentaacetic-acid. Two radiologists evaluated overall image quality, contrast between lymph vessels and background tissue, venous contamination, visualized levels, and fat-saturation-homogeneity on 3D maximum-intensity projections. Overall image quality was good to excellent, and all examinations were diagnostic except one, where contrast medium was injected subcutaneously instead of intracutaneously. Overall image quality was good to excellent in 12/16 cases, depiction of lymph vessels was good to excellent in 15/16 cases. Venous contamination was always present, but diagnostically problematical in only one case. Instant lymphatic drainage was observed in unaffected extremities, reaching the pelvic level after approximately 10 min. Lymphatic drainage was considerably delayed in lymphedematous extremities. Ectatic lymph vessels, entrapment, and diffuse drainage of contrast medium correlated with impaired lymphatic drainage. In conclusion, MRL at 3.0 T provides very high spatial resolution and anatomical detail of normal and abnormal peripheral lymph vessels. MRL may thus become a valuable tool for microsurgical treatment planning and monitoring.

Technique and proof of patency of microsurgical lympho-lymphonodular anastomoses: a study in the rat model.

BACKGROUND: Lymphedemas due to local lymphatic blocks can be treated by microsurgical transplantation or transposition of lymphatic vessels. Here, the anastomoses are usually made end-to-end between lymphatics, but occasionally appropriate lymphatic recipient vessels are missing. In such cases, reconstructing lymph drainage by connection to a lymph node could be another technical option. The purpose of this study was to examine the patency rate of such lympho-lymphonodular anastomoses in an experimental animal model. METHODS: Male Sprague-Dawley rats were anesthetized, and the retroperitoneum was exposed. Patent blue dye was injected into the left foot to stain lymphatic structures. In group A (n = 8), the left lumbar trunk was cut centrally, the distal part was turned over to the right lumbar lymph node, and a microsurgical lympho-lymphonodular anastomosis was performed. In group B (n = 8), the left lumbar trunk was cut. After 8 weeks, the lumbar region was surgically re-explored, and the lymphatic drainage was examined by injection of Patent blue dye into the left lumbar lymph node. RESULTS: In 8/8 animals of group A, patent transposed lymphatics were found. The patency of the anastomosis was proven directly by observation of blue dye transit and indirectly by observation of blue staining of the right lumbar lymph node. In 6/8 animals of group B, no lymphatic connection to the right lumbar lymphatic system was observed. CONCLUSIONS: This is the first report of the microsurgical technique and the proof of patency of lympho-lymphonodular anastomoses. The novel animal model for testing the patency of transposed lymphatics is discussed.

Microvascular anastomosis in an optical cavity: is it possible?

Microsurgery is one of the highly interesting surgical procedures that can be performed using different applications and in different specialties, including plastic surgery. The endoscope is a popular instrument used in many fields, including plastic surgery. Although the operating microscope is still a must for microsurgical performance, microsurgery could be performed, depending on the experiences and facilities, by using other visual-assisting equipment. From this point of view, the authors tried to find less costly and more widespread equipment suitable for performing microsurgery that can, furthermore, be applied in special situations and indications, such as operating in an optical cavity. The authors investigated this issue with the endoscope. In this experimental project, the authors performed vascular microsurgical anastomoses of the rats' femoral vessels to create an optical cavity in a prefabricated skin retraction model in the groin area of 10 Sprague-Dawley male rats. The microsurgical anastomoses of the femoral vessels and nerves were performed easily in a reasonable time, without recorded difficulties, and with maximum physical and visual comfort for the surgeon. The authors spent a mean time of 28.1, 27.3, and 19.2 minutes for the arterial, venous, and neural anastomoses, respectively. In this group of animals, 90 percent vascular patency and 100 percent accurate neural anastomoses were recorded. The advantage the authors noted was that this new technique of operating in the field of microsurgery, with its feasibility and difficulties, would be a point of research and application for the young generations of microsurgeons.

Endoscope-assisted lymphatic microanastomoses: concept, results, expectations, and applications.

Autologous lymph-vessel transplantation is one of the microsurgical procedures that should be performed with good magnification and visualization of the fine lymphatic vessels. It is the preferable surgical intervention in the authors' institute for patients with secondary lymphedema. Although this technique has been performed under the operating microscope, in this study, the authors have experimentally investigated the possibility of performance of lymphatic vessel anastomoses of the rat thoracic duct with the visual assistance of the endoscope, and compared it with the conventional operating microscope, not for its replacement, but as an alternative operating tool which may be preferred in certain situations. There were minimal technical differences between the microscope and the endoscope; however, they have recorded significantly shorter operating time and lymphatic vessel preparation time by using the endoscope. The endoscope seems to be a promising new tool in performing microsurgery, with more ease in handling and more physical comfort for the surgeon.

Microscopic vs. endoscopic assisted harvesting and transplantation of free groin flaps: a comparative experimental study in the rat model.

Advances in video technology can now permit the surgeon to view a microsurgical field on a video monitor without the necessity of physically looking through the microscope eyepieces. In this project, we investigated the possibility of the performance of rat groin free-flap harvesting and transplantation with the visual assistance of the endoscope, and compared it with the conventional operating microscope, not for its replacement but as an alternative operating tool that may be preferred by a younger generation of microsurgeons or in certain operative and financial situations. Although there were not many technical differences between the microscope and the endoscope, we recorded significantly shorter operative, harvesting, and transplantation times by using the endoscope. The endoscope seems to be a promising new tool in performing microsurgery, with better handling and greater physical comfort for the surgeon. It is reliable, time-efficient, and cost-effective.