[Topographic study of the parietal region for the elaboration of revascularized cranium vault autograft]. / Izuchenie topografo-anatomicheskikh osobennostei temennoi oblasti pri razrabotke revaskulyariziruemogo kostno-fastsial'nogo temennogo autotransplantata.

OBJECTIVE: Topographic and blood vessel architecture study of the parietal area and distal regional pool of the superficial temporal artery (STA) to assess the possibility of revascularized cranium vault bone autograft formation. MATERIAL AND METHODS: For the topographic and anatomical study, 30 non-fixed corpses (17 male and 13 female) were selected, the average age of which was 59±5 years. In the anamnesis and catamnesis, there were no indications of trauma or other pathology of the head and neck, including vascular. STA was contrasted with a non-radiocontrast dye (brilliant green) with the introduction of the dye into the STA with preliminary ligation of the frontal branch of the STA. The area of blood supply to soft tissue and bone structures was studied. The angioarchitectonics of the parietal region was studied, the feeding vessel of the studied flap was identified. RESULTS: The obtained anatomical landmarks for the collection of CPFP flap make it possible to form a flap with high accuracy and minimize the morbidity of the donor area.

How to ensure immediate and long-term good blood supply by the careful dissection of the marginal artery and supercharge with neck vessels in esophageal reconstruction with the colon segment interposition: 35 years of experience.

BACKGROUND: Colon interposition for total esophageal replacement cases represents one of the most challenging procedures in surgery. A retrospective study has been conducted and suggestions are proposed according to the analysis of 268 patients who underwent colon interposition for esophageal replacement. Complication rates and the duration of hospital stay were retrospectively analyzed. METHODS: A total of 268 patients were operated between 1984 and 2018. In group 1, 164 patients underwent colon interposition without supercharging with neck vessels and in group 2, 104 patients underwent colon interposition with supercharging. Data regarding flap loss, anastomotic leakage, the duration of hospital stay, and stricture formation in the long-term were statistically analyzed and compared between two groups. RESULTS: The success rate of reconstruction was 98,1% (161 of 164 patients) and 99% (103 of 104 patients) for group 1 and 2, respectively. Early complication (anastomotic leakage) rate was 4,9% in group 1 and 1% in group 2. The differences between two groups regarding flap loss and anastomotic leakage rates were not statistically significant (p = 0,495 and p = 0,077, respectively). The hospital stay was 26,3 days for patients without supercharging (group1) and 20,5 days for patients with supercharging (group 2). In group 1, 6,7% (11/164) of patients had narrowing at the junction of the pharynx and colon; however, in group 2, proximal anastomotic stricture formation was observed in only 1% (1/104) of the patients. The stricture rate was significantly lower in group 2 when compared to group 1 (p = 0,021). CONCLUSION: The careful dissection of the marginal artery and supercharging with neck vessels provide lower complication rates in colon interposition for esophageal reconstruction.

Near-infrared spectroscopy for monitoring free jejunal flap.

BACKGROUND: Although the free jejunal graft is commonly used for reconstruction after resection of a tumor of the pharynx or cervical esophagus, adequate monitoring for detecting graft failure is not available. We employed near-infrared spectroscopy to measure regional oxygen saturation (rSO2) in the graft. METHODS: In 25 consecutive cases who underwent reconstructive surgery using a free jejunal graft, the feasibility of postoperative rSO2 monitoring was examined along with the changes in rSO2 values following vascular clamping or reperfusion. RESULTS: No operative mortality occurred, and except for one case of subcutaneous hematoma that necessitated evacuation surgery, no complications related to surgery or graft failure occurred. Postoperative rSO2 monitoring was feasible for >50 hours in most cases. It mostly remained >55% with a stable hemoglobin index (HbI) which reflects tissue hemoglobin density. A marked increase in the HbI was noted in a patient with hematoma. Intraoperatively, the rSO2 of intact jejunal tissue was >60% in every case but dropped within a few minutes after arterial clamping because of decreased oxygenated hemoglobin concentration. With venous clamping, the HbI was elevated while the rSO2 remained unchanged or was slightly decreased. Upon graft reperfusion, the rSO2 rapidly recovered in all 18 cases because of the recovery of oxygenated hemoglobin concentrations. CONCLUSIONS: The near-infrared spectroscopic assessment sensitively and accurately reflected the condition of the jejunal graft. It appears to be a promising postoperative method for monitoring graft perfusion. An rSO2 value of 55% appears to be an adequate criterion for ischemia.

Talus Fractures: Evaluation and Treatment.

The talus is unique in having a tenuous vascular supply and 57% of its surface covered by articular cartilage. Fractures of the head, neck, or body regions have the potential to compromise nearby joints and impair vascular inflow, necessitating surgical treatment with stable internal fixation in many cases. The widely preferred approach for many talar neck and body fractures is a dual anterior incision technique to achieve an anatomic reduction, with the addition of a medial malleolar osteotomy as needed to visualize the posterior talar body. Percutaneous screw fixation has also demonstrated success in certain patterns. Despite this modern technique, osteonecrosis and osteoarthritis remain common complications. A variety of new treatments for these complications have been proposed, including vascularized autograft, talar replacement, total ankle arthroplasty, and improved salvage techniques, permitting some patients to return to a higher level of function than was previously possible. Despite these advances, functional outcomes remain poor in a subset of severely injured patients, making further research imperative.

Histopathological Findings of Failed Free Vascularized Fibular Grafting for Osteonecrosis of the Femoral Head after Long-Term Follow-Up.

PURPOSE: The aim of this study was to report the histopathology of failed free vascularized fibular grafting (FVFG) for osteonecrosis of the femoral head (ONFH) after a mean follow-up of 11.5 years (ranged from 10.6 to 14.2 years). METHODS: Six hips of 5 patients with a history of steroid use, aged 34-67 years, were in stage II of ONFH as classified by the Ficat and Arlet classification at the time of FVFG treatment. Grafting failure led to osteoarthritis of the hip joint during a mean of 11.5 years of follow-up. Femoral head specimens were first evaluated macroscopically. Bone specimens were sectioned into long strips, divided into necrotic, transitional, and healthy zones, and then prepared for nondecalcified and decalcified histopathological examination using hematoxylin and eosin (HE) staining, Goldner's trichrome staining, and immunofluorescence (IF) staining. RESULTS: Femoral head articular cartilage surfaces appeared thin, opaque, and partially cartilaginous missing, with gradual collapse detected in weight-bearing areas. The interface with the fibular graft showed well union, with no obvious gaps between graft and host bone, as observed macroscopically. The necrotic area was filled with fibular graft, cancellous bone, and cartilaginous or soft tissue invasion. Histopathology results revealed well integration between fibular graft and host bone, with thickened trabecular bone. Gaps occurred in transitional and healthy zones. In the necrotic zone, cartilaginous or soft tissue invasion occurred, while thin or missing articular cartilage exposed subchondral bone to hip joint surfaces. By IF counterstaining with CD-31 and α-SMA, blood vessel transplanted during fibular grafting could be clearly observed along the graft from healthy to necrotic zones. In the necrotic zone, blood vessels presented obviously and spread into the surrounding area of the graft tip. CONCLUSION: After FVFG procedure with a mean follow-up of 11.5 years, fibular grafts retained their integrity as viable, vascularized, cortical bone that fused well with host bone and formed thickened trabecular bone surrounding the surface of the graft. However, the revascularization of FVFG's blood vessels spreading from the tip of the fibular graft into subchondral area of necrotic lesion did not improve significantly in these failure cases. The local necrotic lesion failed to be repaired as healthy trabecular bone to buttress articular surface and was occupied by soft tissues.

Mechano-biological adaptation of the pulmonary artery exposed to systemic conditions.

Cardiac surgeries may expose pulmonary arterial tissue to systemic conditions, potentially resulting in failure of that tissue. Our goal was to quantitatively assess pulmonary artery adaptation due to changes in mechanical environment. In 17 sheep, we placed a pulmonary autograft in aortic position, with or without macroporous mesh reinforcement. It was exposed to systemic conditions for 6 months. All sheep underwent 3 ECG-gated MRI's. Explanted tissue was subjected to mechanical and histological analysis. Results showed progressive dilatation of the unreinforced autograft, while reinforced autografts stabilized after two months. Some unreinforced pulmonary autograft samples displayed more aorta-like mechanical behavior with increased collagen deposition. The mechanical behavior of reinforced autografts was dominated by the mesh. The decrease in media thickness and loss of vascular smooth muscle cells was more pronounced in reinforced than in unreinforced autografts. In conclusion, altering the mechanical environment of a pulmonary artery causes changes in its mechano-biological properties.

Varying Negative Pressure Wound Therapy Acute Effects on Human Split-Thickness Autografts.

Over 6.5 million people in the United States suffer from traumatic, burn, acute, and chronic wounds yearly. When reconstruction is required, split and full-thickness autografts are a first line of treatment intervention. Negative pressure wound therapy (NPWT) is gaining traction as an adjunct modality to improve graft survival, yet the specifics on what settings to apply topically over the graft is unsubstantiated and associated with morbidities. This study was performed in an effort to understand initial changes in wound and graft healing with a long-term goal of surface pressure optimization. Excess skin from elective procedures from six human subjects was trimmed to 0.012 inch in order represent a split-thickness autografts. These grafts were treated continuously with either -75 mm Hg (n = 4), -125 mm Hg (n = 4), or no pressure (n = 4) for 3 hours. Six skin grafts were treated with no sponge or pressure control (n = 6). RNAseq was performed on all treatment groups and compared with no pressure control. Significant gene expression changes with a subset focusing on inflammatory, cellular/extracellular matrix proliferation and angiogenic mediators and having greater than 2-fold were confirmed with immunohistochemistry staining. There are 95 significant gene transcription differences among all treatment groups. NPWT leads to significantly increased gene expression of FGFR1, ET-1, and 22 Keratin proteins. Between -75 and -125 mm Hg groups, there are 19 significant gene changes. Proinflammatory genes S100A8 and Tenacin C (TNC) demonstrate an 8.8- and 9.1-fold change, respectively, and is upregulated in -125 mm Hg group and downregulated in -75 mm Hg group. Fibrinogen genes fibrinogen gamma chain and fibrinogen alpha chain had respective log2-fold changes of -7.9 and -7.4 change between treatment groups and were downregulated in -125 mm Hg group and upregulated in -75 mm Hg group. There are varying effects of surface pressures on human split-thickness autografts during the imbibition time period. NPWT may improve cellular migration, proliferation, and angiogenesis over controls. Human skin grafts respond differently to -125 and -75 mm Hg within 3 hours of NPWT treatment. The results suggest -75 mm Hg leads to less inflammation and increased fibrinogen production compared with the -125 mm Hg group, at least initially. Reducing "time to heal" with NPWT is critical to successful outcomes and quality of life within young patients who often experience pain/discomfort when treated at the current standard pump settings. The results from this study and continued investigation may quickly translate to the clinical setting by finding the ideal pressure setting utilized in an effort to reduce NPWT length of treatment, improve patient comfort, satisfaction, and psychosocial well-being.

Shoulder arthrodesis using a vascularized scapular pillar graft: Cadaver study and surgical technique.

INTRODUCTION: Whether secondary to trauma, infection or tumor invasion, a complex reconstruction procedure is required after proximal humerus resection. Among the reconstruction options, there are few published reports of a vascularized scapular pillar graft being used. The goal of our study was to describe the surgical technique for shoulder arthrodesis using a vascularized scapular pillar based on an anatomical study of this graft. MATERIALS AND METHODS: This anatomical and surgical study involved both shoulders from seven separate cadavers (14 shoulders). Two shoulders were used for trials. Four shoulders were injected with latex to describe the vascularization of the composite scapular pillar graft. Five fresh shoulders were then used to define the optimal orientation of the osteotomy and rotation of the scapular pillar. Each vascularization element was then isolated and measured. The shoulder arthrodesis procedure using a composite scapular pillar graft was performed on three shoulders in order to describe the steps of this procedure. RESULTS: The angular branch of the thoracodorsal artery was 8.25±1.5 cm long and reached the lateral angle of the scapula 1.6±1.1 cm above its antero-inferior edge. The mean length of the circumflex scapular artery was 5.25±1 cm with 3 cm separating the inferior edge of the glenoid and the end of the artery in question. Optimal graft positioning was achieved with a glenoid osteotomy of the pillar that was horizontal in the frontal plane and angled 20° downward and forward in the sagittal plane. This resulted in the pillar being turned 240° medially (internal rotation). DISCUSSION: The latex injection study confirmed that the scapular pillar always has two vascularization sources: circumflex scapular artery and angular branch of the thoracodorsal artery. While there are anatomical variations, the scapular pillar shares its vascularization with the latissimus dorsi and teres major muscles. It can be preserved when transferring the graft for reconstruction. Our anatomical description of shoulder arthrodesis using this composite graft allows surgeons to anticipate potential technical and anatomical problems that could be encountered during this complex surgical procedure.

Platelet-Rich Plasma and Platelet-Rich Fibrin Enhance the Outcomes of Fat Grafting: A Comparative Study.

BACKGROUND: Autologous fat grafting is an efficient procedure in plastic surgery. However, its long-term tissue absorption is variable and technique-dependent. Platelet-rich plasma positively affects fat-grafting outcomes but still has shortcomings, and platelet-rich fibrin has been reported to have efficacy in fat transplantation. Here, we compared the effects of platelet-rich fibrin and platelet-rich plasma in fat grafting using histologic analysis. METHODS: Twenty rabbits were divided randomly into two groups. In each group, the groin region fat pads were cut into 1-mm granules. Platelet-rich fibrin-treated or platelet-rich plasma-treated fat granules were transplanted into one ear, whereas the contralateral ear was transplanted with normal saline-treated fat granules. Histologic characteristics and capillary density of grafted tissue were analyzed 12 weeks after fat grafting. RESULTS: The grafted fat in the platelet-rich fibrin-treated group showed higher tissue retention than that in the control group [weight retention, 19.57 percent (interquartile range, 13.87 to 29.93 percent) versus 9.04 percent (interquartile range, 6.16 to 16.80 percent), p < 0.05; and volume retention, 18.00 percent (interquartile range, 10.50 to 26.50 percent) versus 8.00 percent (interquartile range, 5.75 to 13.25 percent), p < 0.05] and higher neovascularized capillary density than that in the platelet-rich plasma-treated and control groups. The platelet-rich plasma-treated group showed higher vessel density without superior tissue retention compared with the control group. CONCLUSION: Platelet-rich fibrin increased tissue retention, quality, and vascularization of grafted fat compared with the control group and showed effects similar to those of platelet-rich plasma on tissue retention and histologic graft improvement.

Treatment for proximal pole scaphoid nonunion with capsular-based vascularized distal radius graft.

PURPOSE: We retrospectively reviewed the results of 89 patients with proximal pole scaphoid nonunion, 58 with avascular necrosis, treated with a capsular-based vascularized distal radius graft. METHODS: Seventy-one male and eighteen female patients with symptomatic nonunion at the proximal pole of the scaphoid were included in this study. No patient had a humpback deformity. In all patients, the vascularized bone graft was harvested from the dorsum of the distal radius and was attached to a capsular flap of the dorsal wrist capsule. After fixation of the scaphoid with a small cannulated screw, the graft was inserted press-fit into the scaphoid trough in the nonunion site. Supplementary fixation of the graft with a microsuture anchor into the scaphoid was used in 66 patients. RESULTS: At a mean time of 12.3 weeks (range 6-24) after surgery, solid union was achieved in 76 of 89 patients (49 of 58 with avascular necrosis). Eleven patients had persistent nonunion and two fibrous union as determined by CT scan. Sixty-six of the patients with solid bone union were completely pain free, and ten complained of slight pain with strenuous activities. No donor site morbidity was observed. CONCLUSIONS: The capsular-based vascularized bone graft from the distal radius is a reliable alternative technique for scaphoid nonunions. It is a simple and expedient harvesting technique without the need for a microsurgical anastomoses. The supplemental fixation with a microsuture anchor eliminates the risk of graft displacement.

MR angiogram confirms sustained blood flow in 1,2 ICSR artery of vascularized bone grafting in scaphoid nonunion treatment.

PURPOSE: To evaluate the functioning of 1,2 intercompartmental supraretinacular artery (ICSRA) in vascularized bone grafting (VBG) of scaphoid nonunions with avascular necrosis of proximal pole. MATERIALS AND METHODS: Fourteen patients with scaphoid nonunion were treated operatively with 1,2 ICSRA VBG. Viability of the pedicle artery was evaluated by MR angiography with intravenous contrast agent. RESULTS: In 13 out of 14 patients, the 1,2 ICSR artery was found to be patent and functional. Revascularization of scaphoid proximal pole was revealed in all cases, and nonunion healing was confirmed as well. CONCLUSION: 1,2 ICSRA VBG in scaphoid nonunion is an effective surgical technique. It combines the advantages of bone grafting and vascular supply via the transferred pedicle artery which seems to be functional postoperatively if a meticulous operative technique is used.

The Disturbed Function of Neutrophils at the Early Stage of Fat Grafting Impairs Long-Term Fat Graft Retention.

BACKGROUND: Fat grafting is a popular soft-tissue filler method; however, the mechanism of its survival and regeneration is still not fully understood. Neutrophils are the frontier inflammatory cells and closely associated with tissue regeneration. To understand the role of neutrophils in fat graft retention, we adopted neutrophil depletion and up-regulation models. METHODS: Mouse inguinal fat (approximately 200 mg) was transferred autologously. The anti-mouse Ly6G antibody and lipopolysaccharides were used in the mouse fat grafting model for neutrophil depletion or activation, respectively. We examined the blood and graft stromal vascular fraction by fluorescence-activated cell sorting in manipulation/control groups. Graft weight, vascularization, and secreted factors were also compared. RESULTS: There was a significant reduction/increase of neutrophil counts in the circulation and the transferred fat before day 7 with Ly6G antibody/lipopolysaccharides treatment. Early depletion of neutrophils resulted in incompetent angiogenesis and eventually a poor retention rate (27 ± 8 percent) compared with control (51 ± 10 percent; p < 0.05), whereas up-regulated neutrophils increased the inflammation and reactive oxygen species level, leading to tissue damage and poor retention rate (20 ± 9 percent) compared with control (51 ± 10 percent; p < 0.05). Enhanced macrophage infiltration could be found in both neutrophil depletion and up-regulation groups after week 4. CONCLUSIONS: Undisturbed neutrophil function is the key to initiating downstream responses of macrophage infiltration, stimulating vessel formation, and regulating inflammation level; thus, it exerts a great impact on the long-term retention rate. Disturbed neutrophil function, either enhanced or weakened, can lead to impaired fat graft retention.

Improvement in the Retention Rate of Transplanted Fat in Muscle by Denervation.

BACKGROUND: Improvement in the retention rate of transplanted fat is currently a topic of interest. The retention of transplanted fat relies heavily on the reestablishment of blood supply and the function of the adipose-derived stem cells (ADSCs), which may both be impeded by mechanical force. However, the effect of mechanical force on the retention of adipose implants remains unclear. OBJECTIVES: This study aimed to evaluate the effectiveness of immobilization on fat retention rate. METHODS: Immobilization was carried out by denervation of the hind limb of rats to reduce the mechanical force. Sprague-Dawley (SD) rats were used, and the two hind limbs were assigned at random to the immobilization side and the control side. On average, 0.4 mL of fat was injected into the bilateral muscle and subcutaneous space of the hind limb, and 6 rats were sacrificed at each time point. The outcome measures included the retention rate, the histologic evaluation, and the density of new vessels and proliferative ADSCs. RESULTS: For the muscle fat, the retention rate improved, and more proliferative ADSCs and new vessels were found in the immobilization group. The histologic evaluation between the two sides was of no statistical significance. For the fat in the subcutaneous space, no statistical difference was observed in all the outcome measures between the two sides. CONCLUSIONS: Regional immobilization of the recipient site by denervation can improve the retention of the fat graft in muscles owing to improved density of the new vessels and proliferative ADSCs.

Requirements for Successful Trachea Transplantation: A Study in the Rabbit Model.

BACKGROUND: Although creating a tracheal tube de novo might appear straightforward, the first clinical applications have shown that reconstruction of long-segment tracheal defects remains challenging. In this study, the authors aimed to refine the baseline requirements of successful trachea transplantation by means of three proof-of-concept models in the rabbit. METHODS: In each model, one characteristic of a perfect tracheal transplant was eliminated. The first model was developed to map out the immunologic response of vascularized allogenic trachea, transplanted without immunosuppression (n = 6). The second model studied (1) the need for wrapping the transplant with a highly vascularized flap and (2) the source of angiogenesis after autologous trachea transplantation (n = 18). In the third model, the authors examined the importance of an inner epithelial covering (n = 12). All models were compared to a control group of heterotopically transplanted vascularized autologous tracheae (n = 6). RESULTS: Embedded in an avascular matrix, allogenic chondrocytes were protected from an overt immune response. Orthotopic transplantation without additional external vascular wrap was successful in a well-vascularized environment. Nonetheless, an external vascular source was essential to maintain viability of the construct. Epithelial covering was necessary to prevent secondary healing. Epithelial migration from the anastomoses or graft was not sufficient to cover long-segment defects. CONCLUSIONS: These experiments provided ample evidence of the importance of baseline requirements when designing a tracheal transplant study. This study confirmed that different tracheal cell types possess different immunologic sensitivities. External revascularization, preferably in a two-stage procedure, and fast reepithelialization were both paramount to successful transplantation.

Induced Granulation Tissue but not Artificial Dermis Enhances Early Host-Graft Interactions in Full-Thickness Burn Wounds.

BACKGROUND: Cellular grafts used for skin repair require rapid integration with the host tissue to remain viable and especially to nourish the epidermal cells. Here, we evaluated the responses in the split-thickness skin grafts (STSGs) grafted on three differently treated wound beds: directly on excised wound bed (EX), on an artificial dermal template (DT) and on granulation tissue (GT) induced by cellulose sponge. METHODS: In ten burn patients, after excision, a test area was divided into three sections: One transplanted with STSG instantaneously and two sections had a pre-treatment for 2 weeks with either DT or a cellulose sponge inducing granulation tissue formation and thereafter grafted with STSGs. RESULTS: One week after grafting, the STSGs on GT demonstrated most endothelial CD31+ staining, largest average vessel diameters as well as most CD163+ staining of M2-like macrophages and most MIB1+ proliferating epidermal cells, suggesting an active regenerative environment. STSGs on DT had smallest vessel diameters and the least CD163+ macrophages. STSGs on EX had the least CD31+ cells and the least MIB1+ proliferating cells. After 3 months, this reactivity in STSGs had subsided, except increased dermal cell proliferation was observed in STSGs on EX. CONCLUSIONS: Results show that pre-treatment of wound bed and induction of granulation tissue formation can accelerate host-graft interaction by stimulating graft vasculature and inducing cell proliferation.

Early Macrophage Infiltration Improves Fat Graft Survival by Inducing Angiogenesis and Hematopoietic Stem Cell Recruitment.

BACKGROUND: Fat grafting is a popular soft-tissue filler method; however, its results are variable and technique-dependent. Macrophages are present in fat grafts and closely associated with tissue regeneration. The authors hypothesized that activation/depletion of early macrophages in transferred fat improves/impairs fat graft survival. METHODS: Mouse inguinal fat (approximately 150 mg) was transferred autologously. Fat grafting was first performed without other manipulations to obtain baseline information. Then, liposome-encapsulated clodronate and macrophage-colony stimulating factor were used in a mouse fat grafting model for local macrophage depletion or activation. The authors examined the graft stromal vascular fraction by fluorescence-activated cell sorting at 1, 2, 4, and 12 weeks after transplantation in manipulation and control groups. Graft weight, vascularization, and secreted factors were also compared. RESULTS: Early depletion of macrophages resulted in incompetent angiogenesis, feeble Sca-1/CD45 stem cell recruitment, and eventually a poor retention rate (34 ± 6 mg versus control 84 ± 15 mg; p = 0.006), whereas up-regulated macrophages allowed better angiogenesis and survival (117 ± 12 mg versus control, 84 ± 15 mg; p = 0.043). CONCLUSIONS: In fat grafting, macrophages and their polarization initiated changes in the levels of dominant secreted factors and influenced blood-derived stem cell infiltration, indicating that macrophages were crucial for tissue revascularization. The macrophage manipulation models described here show that graft macrophage number can profoundly influence graft survival.

The vascularization pattern of acellular nerve allografts after nerve repair in Sprague-Dawley rats.

OBJECTIVE: We have demonstrated that angiogenesis in acellular nerve allografts (ANAs) can promote neuroregeneration. The present study aimed to investigate the microvascular regeneration pattern of ANAs in Sprague-Dawley (SD) rats. METHODS: Sixty male SD rats were randomly divided into an autologous group and a rat acellular nerve allograft group (rANA), and 10-mm sciatic nerve defects were induced in these rats. On the 7th, 14th and 21st days after surgery, systemic perfusion with Evans Blue (EB) or lead oxide was performed on the rats through carotid intubation. Samples were then collected for gross observation, and the microvessels in the nerves were reconstructed through microscopic CT scans using MIMICS software. The vascular volume fraction (VF, %) and microvessel growth rate (V, mm/d) in both groups were then measured, and 1 month after surgery, NF-200 staining was performed to observe and compare the growth condition of the axons. RESULTS: Early post-operative perfusion with gelatin/EB showed EB permeation around the acellular nerve. Perfusion with gelatin/lead oxide showed that the blood vessels had grown into the allograft from both ends 7 days after the operation. Fourteen days after the operation, the microvessel growth rate of the autologous group was faster than that of the rANA group (0.39 ± 0.17 mm/d vs. 0.26 ± 0.14 mm/d, p < 0.05), and the vascular VF was also higher than that of the rANA group (8.92% ± 1.54% vs. 6.31% ± 1.21%, p < 0.05). Twenty-one days after the operation, the blood vessels at both ends of the allograft had connected to form a microvessel network. The growth rate was not significantly different between the two groups; however, the vascular VF of the autologous group was higher than that of the rANA group (12.18% ± 2.27% vs. 9.92% ± 0.84%, p < 0.05). One month after the operation, the NF-200 fluorescence (IOD) in the autologous group significantly increased compared with that of the rANA group (540,278 ± 17,424 vs. 473,310 ± 14,636, respectively, p < 0.05), suggesting that the results of the repair after nerve injury were significantly better in the autologous group than in the rANA group. CONCLUSION: Both the autologous nerve and ANAs rely on the permeation of tissue fluids to supply nutrients during the early stage, and microvessel growth mainly starts at both ends of the graft and enters the graft along the long axis. Compared to ANAs, the growth speed of revascularization in autologous nerve grafts was faster, leading to a better outcome in the autologous nerve group.

[Allogeneic transplants for biological reconstruction of bone defects]. / Allogene Transplantate für biologische Rekonstruktionen von Knochendefekten.

A combination of allogeneic and autologous bone transplants is frequently used for the biological reconstruction of bone defects. Autologous bone transplants can be used either in the form of structural or cancellous bone transplants. The osteogenic potential of autologous cancellous bone is well-known and is still the gold standard with respect to osteoinduction and remodelling. Structural transplants, such as fibular and tricortical iliac crest grafts can be transplanted either free, i.e. non-vascularized or vascularized with anastomosed vessels. Allogeneic bone transplants can be used in a spongiose or structural form. In revision endoprosthetics the use of allogeneic bone transplants has essentially been reduced to impaction grafting, due to the introduction of trabecular metal as a permanently stable substitute. Allogeneic transplants have been restricted due to 3D-printing and the associated individually adapted reconstruction. In individual cases combined reconstruction consisting of allograft and endoprosthesis provide the advantage of safe load transmission and permanent reconstruction by the endoprosthesis and the possibility of soft tissue insertion of the allograft.

Tissue blood flow to a pedicled jejunal autograft in the dog: A pilot study.

OBJECTIVE: To determine the viability of a pedicled jejunal autograft after ligation of up to 3 jejunal arteries. STUDY DESIGN: Prospective crossover study. ANIMALS: Three adult dogs. METHODS: Dogs were instrumented for measurement of hemodynamic parameters. Two segments of jejunum with 4 arcadial vessels were isolated from the abdomen in each dog. An individual ligature was secured around the 4th, 3rd, and 2nd jejunal artery. The 1st jejunal artery was maintained to serve as the sole blood supply to the pedicled segment of jejunum. Colored microspheres were used to evaluate the effect of each ligation on tissue blood flow. RESULTS: Mean arterial blood pressure (P = .709) and heart rate (P = .905) did not differ between ligation groups. Tissue blood flow to a pedicled segment of jejunum was unchanged after ligation of 3 jejunal arteries. CONCLUSION: Tissue blood flow of an isolated jejunal segment maintained in normal position remains unaffected, when supplied by a single jejunal artery, after ligation of up to 3 concurrent jejunal arteries.

Hepatic Artery Reconstruction With Autologous Inferior Mesenteric Artery Graft in Living Donor Liver Transplant Recipients.

INTRODUCTION: In living donor liver transplantation (LDLT), hepatic arterial continuity is crucial to avoid biliary leakage, biliary stricture, cholangitis, and graft and patient loss. Sometimes there exist factors making anastomosis difficult or even impossible. In these cases, a vascular graft may be needed to bridge the two arteries for revascularization. METHOD: Medical records of 297 patients who underwent LDLT between June 2000 and July 2016 at the Hepatopancreatobiliary Surgery and Liver Transplantation Unit of Dokuz Eylul University Hospital were reviewed retrospectively. Twenty-eight (9%) patients younger than the age of 18 were excluded from the study. The remaining 269 patients were included in the study. We analyzed data of patients who developed hepatic arterial complications during or after LDLT and underwent revascularization using autologous interposed inferior mesenteric artery (IMA) grafts. RESULTS: In 8 (2.9%) of the 269 patients who underwent LDLT and were included in the study, autologous interposed IMA grafts were used for the hepatic artery revascularization. All of the patients were males. Their mean age was 42 (range, 25-57). The mean duration of follow-up was 83.25 months (range, 3-144 months). One patient developed intraoperative hepatic arterial thrombosis (HAT) after autologus IMA reconstruction and this patient needed retransplantation. No arterial complications developed in the other 7 patients. CONCLUSION: Autologous interposed IMA graft could be used as an alternative vascular graft in hepatic artery revascularization to provide tension-free hepatic arterial continuity.