Dynamic Maxillary Sinus Changes of Facial Vascularized Composite Allotransplants.

SUMMARY: Skin is one of the target tissues of rejection in face transplants and, because of its easy accessibility, has become the gold standard in the diagnosis of rejection. The allograft contains deeper tissues where rejection can occur, but samples cannot be obtained because of difficult access. Deep tissue changes were monitored on computed tomographic scans of the midface in six face transplant recipients with the help of image segmentation. The maxillary sinus was identified as a dynamic anatomical compartment. Observed changes in volume of the aeration relative to the opacification (aeration coefficient) of the maxillary sinus were quantified with the help of image segmentation. Changes in the aeration coefficient as a surrogate of mucosal swelling were quantified and related to time, treatment, and skin rejection grade. Lower aeration coefficients were found only in patients with transplanted maxillary sinus mucosa. Pathologic changes were not observed in face transplant recipients with a native maxillary sinus. The data show that the aeration coefficient was significantly lower at the time of biopsy-proven allograft rejection. Neither mechanical, nor infectious, nor medication side effects sufficiently explain the findings presented herein. The authors' findings are important to consider for clinical management of face transplant patients who receive parts of the sinonasal tract. The authors identify a potential radiologic biomarker of deep tissue allograft rejection. In the future, the proposed methodology might prove useful in monitoring deeper dynamic tissue changes in vascularized composite allografts and might help in designing patient-specific, individualized treatment strategies.

No-Touch Saphenous Vein Harvesting May Improve Further the Patency of Saphenous Vein Composite Grafts: Early Outcomes and 1-Year Angiographic Results.

BACKGROUND: Harvesting technique and surgical strategy may affect patency rates of saphenous vein (SV) grafts in coronary artery bypass graft surgery (CABG). We evaluated early clinical outcomes and 1-year graft patency rates of SV grafts that were harvested with a no-touch technique and used as composite grafts. METHODS: Three hundred sixty-eight patients who underwent off-pump CABG using SV composite grafts based on the left internal thoracic artery were studied. The results of 103 patients who received SV grafts harvested with a "no-touch" technique (group NT) were compared with the results of 265 patients who received SV grafts harvested with a "minimal manipulation" technique (group MM). A propensity score-matched analysis was also performed to minimize differences in preoperative and intraoperative variables (n = 98 in each group). Early clinical outcomes and early and 1-year postoperative angiographic results were compared. RESULTS: No differences in early mortality or postoperative complications were observed between the two groups. Early postoperative (1.6 ± 2.2 days) angiography demonstrated a significantly higher patency rate of SV grafts in group NT than in group MM before and after propensity score matching (before, 100% versus 97.2%, p = 0.002; after, 100% versus 97.7%, p = 0.003). One-year postoperative (13.0 ± 2.5 months) angiography also showed a higher patency rate of SV grafts in group NT than in group MM before and after propensity score matching (before, 97.4% versus 92.4%, p = 0.024; after, 97.3% versus 92.6%, p = 0.051). CONCLUSIONS: The SV grafts harvested with a no-touch technique further improved the early and 1-year patency of SV composite grafts. Midterm and long-term angiographic follow-up may be warranted to demonstrate the superiority of no-touch SV composite grafts.

A murine model of orthotopic periorbital subunit transplantation.

BACKGROUND: Conventional reconstructive methods fail to achieve satisfactory results in total eyelid defect cases. Vascularized composite tissue allotransplantation might provide both good appearance and function for these patients. We developed an orthotopic periorbital transplantation model in rats to facilitate further experimentation in this field. METHODS: In anatomical studies, the vascular distribution to and innervation of the periorbital unit were identified and recorded. Then, according to the anatomical studies, eight orthotopic transplantations and two transplantations with pedicle ligation were performed. The posterior facial vein and the external carotid artery were selected as the graft pedicles, while the temporal and upper zygomatic facial nerves were used for graft innervation. All transplanted eyelids were assessed daily. Micro-CT scanning and hematoxylin and eosin staining of the grafts were performed 60 days after the operation. RESULTS: In total, 90% of recipients tolerated the operation well. All grafts without pedicle ligation survived, and new hair growth was observed. The position of the eyelid was maintained, and eyelid function was partially restored. In the recipients with graft pedicle ligation, the grafts became necrotic and mummified within four to five days. Micro-CT of the surviving grafts showed a good blood supply, and histological staining revealed normal morphology. CONCLUSIONS: A periorbital subunit orthotopic transplantation model was established, which might facilitate future eyelid allotransplantation-related experimentation.

Reflectance confocal microscopy as a useful diagnostic tool for monitoring of skin containing vascularized composite allograft rejection: A preliminary study on rats.

Vascularized composite allografts can undergo immune-mediated rejection, and skin biopsies are needed for monitoring of the transplant. However it is an invasive method, and requires processing time and pathological assessment. The purpose of this study is to use a new noninvasive monitoring method of the reflectance confocal microscopy (RCM) to determine severity of the allograft rejection on rats. Five groin flap allotransplantation were performed between 10 male Sprague-Dawley rats. Immunosuppressive therapy with cyclosporine A was given to the recipients during 10 days after surgery and was ended at the 10th postoperative days to allow acute transplant rejection. Following cessation of CsA, concomitant RCM evaluation and skin biopsy was performed every other day from each animal until total rejection of the allograft. Complete rejection of the allograft took nearly about 10 days and 4 or 5 RCM evaluation and skin biopsy was performed from each rat during this period. A total of 17 specimens were evaluated. A scoring system was developed based on the RCM findings. Skin biopsies were evaluated according to the Banff 2007 working classification criteria. RCM evaluation revealed epidermal irregularity and collagen destruction, however mild perivascular inflammation and degeneration of the basal epidermal layer were observed in early and late rejection period respectively with histopathologic evaluation. High correlation was found between the RCM scores and histopathologic grading. The RCM may be the useful tool to reduce the need for skin biopsy for monitoring of the skin containing vascularized composite allograft.

Assessment of vascular function of hand allografts.

BACKGROUND: Insufficiency of blood vessels supplying a limb allograft may lead to loss of the extremity. Thus, a regular evaluation of perfusion of transplants seems a reasonable approach. The purpose of the present study was assessment of allograft perfusion by means of non-invasive methods. MATERIAL/METHODS: Six hand allografts transplanted in 5 patients were included in the study group. The transplant procedure occurred on average 45 months before. The study group comprised 2 allografts at forearm level, 2 transplants of the arm, and 1 bilateral transplant of the forearm. Parameters of blood flow using Doppler ultrasonography, impedance plethysmography, Doppler measurement of segmental pressures, optical pulse oscillography (OPO), and thermography were performed in all participants. RESULTS: DUS revealed increased resistive index in ulnar arteries of transplant hands compared to native hands and an altered blood supply was confirmed by IP. Flow-mediated dilatation within the transplanted extremity was abnormal in most patients and was inversely correlated with number of episodes of acute rejection. Analysis of oscillographic spectrum revealed flattening of the dicrotic notch in transplant hands. A tendency for lower temperature of the skin of transplanted hands compared to native extremities was also observed. CONCLUSIONS: In asymptomatic patients after limb transplantation, non-invasive methods disclosed discreet abnormalities of graft perfusion. Thus, regular measurement of perfusion parameters using these methods appears to be a promising approach to detect early and potentially reversible disturbances of blood supply. Further observational studies are required to determine its clinical significance.

Analysis of the morphologic differences of the second toe and digits of the hand, and evaluation of potential surgical intervention to minimize the differences using computer-aided design technology.

BACKGROUND: Toe "narrow neck" augmentation and pulp-plasty are two aesthetic surgical refinements that are performed to minimize the visual differences between the transferred toe and digit following a second toe-to-hand transfer. To improve the aesthetic refinements in a second toe transfer, the authors investigated the real shape of the flap and factors affecting the flap design using computer-aided design technology. METHODS: The plaster models of the right first through fourth digits and right second toes from 20 volunteers were scanned by spiral computer tomography to obtain three-dimensional reconstruction data. Computer-aided design software was used to analyze the data and simulate narrow neck augmentation and pulp-plasty. Next, the three-dimensional shapes of the transferred and excised flaps were created by Boolean calculation. RESULTS: The simulated transferred flaps were classified into two types in terms of their shape: crab claw and cross. The simulated excised pulp flaps could also be divided into two types-water drop and elliptic. There were individual variations and gender differences in the second toe morphology that resulted in different flap shapes. The flap shapes in narrow neck augmentation and pulp-plasty were determined using the location of the palmar protruding part and contour of the distal margin of the toe tip, respectively. CONCLUSIONS: Accurate three-dimensional shapes of the flap could be obtained by computer-aided design, and there were individual variations and gender differences. The authors suggest that the affected factors should be considered, and computer-aided design could be used to improve the accuracy of flap design before surgery.

The clinical and radiological evaluation of the use of an allograft-prosthesis composite in the treatment of proximal femoral giant cell tumours.

Giant cell tumour is the most common aggressive benign tumour of the musculoskeletal system and has a high rate of local recurrence. When it occurs in proximity to the hip, reconstruction of the joint is a challenge. Options for reconstruction after wide resection include the use of a megaprosthesis or an allograft-prosthesis composite. We performed a clinical and radiological study to evaluate the functional results of a proximal femoral allograft-prosthesis composite in the treatment of proximal femoral giant cell tumour after wide resection. This was an observational study, between 2006 and 2012, of 18 patients with a mean age of 32 years (28 to 42) and a mean follow-up of 54 months (18 to 79). We achieved excellent outcomes using Harris Hip Score in 13 patients and a good outcome in five. All allografts united. There were no complications such as infection, failure, fracture or resorption of the graft, or recurrent tumour. Resection and reconstruction of giant cell tumours with proximal femoral allograft-prosthesis composite is a better option than using a prosthesis considering preservation of bone stock and excellent restoration of function. A good result requires demanding bone banking techniques, effective measures to prevent infection and stability at the allograft-host junction.

Computer-assisted zygoma reconstruction with vascularized iliac crest bone graft.

BACKGROUND: The reconstruction of zygoma is a challenge with regard to aesthetic and reconstructive demands. METHODS: Pre-operative CT data were imported into specific surgical planning software. The mirror-imaging technique was used. A surgical guide transferred the virtual surgery plan to the operation site, whereby it fitted uniquely to the iliac donor site. A postoperative CT scan was obtained for comparing the actual postoperative graft position and shape with the pre-operative virtual simulation. RESULTS: A mean difference of 0.71 mm (SD ± 1.42) for the shape analysis and 3.53 mm (SD ± 3.14) for the graft position was determined. The calculation of the closest point distance showed a surface deviation of < 2 mm for the shape analysis with 83.6% of values and for the graft position with 35.7% of values. CONCLUSION: Virtual surgical planning is a suitable method for zygoma reconstruction with vascularized iliac crest bone graft, with good accuracy for restoring the three-dimensional anatomy.