Anatomic foveal reconstruction of the triangular fibrocartilage complex with a tendon graft

An acute injury to the triangular fibrocartilage complex (TFCC) with avulsion of the foveal attachment can produce distal radioulnar joint (DRUJ) instability. The avulsed TFCC is translated distally so the footprint will be bathed in synovial fluid from the DRUJ and will become covered in synovitis. If the TFCC fails to heal to the footprint, then persistent instability can occur. The authors describe a surgical technique indicated for the treatment of persistent instability of the DRUJ due to foveal detachment of the TFCC. The procedure utilizes a loop of palmaris longus tendon graft passed through the ulnar aspect of the TFCC and into an osseous tunnel in the distal ulna to reconstruct the foveal attachment. This technique provides stability of the distal ulna to the radius and carpus. We recommend this procedure for chronic instability of the DRUJ due to TFCC avulsion, but recommend that suture repair remain the treatment of choice for acute instability. An arthroscopic assessment includes the trampoline test, hook test, and reverse hook test. DRUJ ballottement under arthroscopic vision details the direction of instability, the functional tear pattern, and unmasks concealed tears. If the reverse hook test demonstrates a functional instability between the TFCC and the radius, then a foveal reconstruction is contraindicated, and a reconstruction that stabilizes the radial and ulnar aspects of the TFCC is required. The foveal reconstruction technique has the advantage of providing a robust anatomically based reconstruction of the TFCC to the fovea, which stabilizes the DRUJ and the ulnocarpal sag.

Mid-term results of aortic root replacement using a self-assembled biological composite graft.

OBJECTIVES To report the mid-term results of aortic root replacement using a self-assembled biological composite graft, consisting of a vascular tube graft and a stented tissue valve. METHODS Between January 2005 and December 2011, 201 consecutive patients [median age 66 (interquartile range, IQR, 55-77) years, 31 female patients (15.4%), median logistic EuroSCORE 10 (IQR 6.8-23.2)] underwent aortic root replacement using a stented tissue valve for the following indications: annulo-aortic ectasia or ascending aortic aneurysm with aortic valve disease in 162 (76.8%) patients, active infective endocarditis in 18 (9.0%) and acute aortic dissection Stanford type A in 21 (10.4%). All patients underwent clinical and echocardiographic follow-up. We analysed survival and valve-related events. RESULTS The overall in-hospital mortality rate was 4.5%. One- and 5-year cardiac-related mortality rates were 3 and 6%, and overall survival was 95 ± 1.5 and 75 ± 3.6%, respectively. The rate of freedom from structural valve failure was 99% and 97 ± 0.4% at the 1- and 5-year follow-up, respectively. The incidence rates of prosthetic valve endocarditis were 3 and 4%, respectively. During a median follow-up of 28 (IQR 14-51) months, only 2 (1%) patients required valve-related redo surgery due to prosthetic valvular endocarditis and none suffered from thromboembolic events. One percent of patients showed structural valve deterioration without any clinical symptoms; none of the patients suffered greater than mild aortic regurgitation. CONCLUSIONS Aortic root replacement using a self-assembled biological composite graft is an interesting option. Haemodynamic results are excellent, with freedom from structured valve failure. Need for reoperation is extremely low, but long-term results are necessary to prove the durability of this concept.

Antioxidant supplementation attenuates oxidative stress in patients undergoing coronary artery bypass graft surgery.

Ischemia-reperfusion has been reported to be associated with augmented oxidative stress in the course of surgery, which might be causally involved in the onset of atrial fibrillation (AF), the most common arrhythmia after cardiac surgery. We hypothesized that supplementation of antioxidants and n-3 polyunsaturated fatty acids (n-3 PUFAs) might lower the incidence of AF following coronary artery bypass graft (CABG) surgery. In the present study, by monitoring oxidative stress in the course of CABG surgery, we analyzed the efficacy of vitamins (ascorbic acid and α-tocopherol) and/or n-3 PUFAs (eicosapentaenoic acid and docosahexaenoic acid). Subjects (n = 75) were divided into 4 subgroups: control, vitamins, n-3 PUFAs, and a combination of vitamins and n-3 PUFAs. Fluorescent techniques were used to measure the antioxidative capacity, i.e. ability to inhibit oxidation. Total peroxides, endogenous peroxidase activity, and antibodies against oxidized LDL (oLAb) were used as serum oxidative stress biomarkers. Post-operative increase in oxidative stress was associated with the consumption of antioxidants and a simultaneous onset of AF. This was confirmed through an increased peroxide level and a decreased oLAb titer in control and n-3 PUFAs groups, indicating the binding of antibodies to oxidative modified epitopes. In both subgroups that were supplemented with vitamins, total peroxides decreased, and the maintenance of a constant IgG antibody titer was facilitated. However, treatment with vitamins or n-3 PUFAs was inefficient with respect to AF onset and its duration. We conclude that the administration of vitamins attenuates post-operative oxidative stress in the course of CABG surgery.

Healing of localized gingival recessions treated with coronally advanced flap alone or combined with either a resorbable collagen matrix or subepithelial connective tissue graft: A preclinical study.

OBJECTIVES To histologically evaluate the effectiveness of a porcine derived collagen matrix (CM) and a subepithelial connective tissue graft (CTG) for coverage of localized gingival recessions. MATERIALS AND METHODS Chronic single Miller Class I-like recessions were created at the buccal at the canines and at the third and fourth premolars in the upper and lower jaws of six beagle dogs. The defects were randomly treated with (1) coronally advanced flap surgery (CAF) + CM, (2) CAF + CTG, or (3) CAF alone. At 12 weeks, histometric measurements were made, e.g., between a reference point (N) - and the gingival margin (GM) - and the outer contour of the adjacent soft tissue (gingival thickness [GT]). RESULTS The postoperative healing was uneventful in all animals. No complications such as allergic reactions, abscesses or infections were noted throughout the entire study period. All three treatments resulted in coverage of localized gingival recessions. The histological analysis failed to identify any residues of CM or CTG. The histometric measurements revealed comparable outcomes for N-GM and GT values for all three groups (CAF + CM: 1.04 ± 0.69 mm/0.68 ± 0.33 mm; CAF + CTG: 1.15 ± 1.12 mm/0.76 ± 0.37 mm; CAF: 1.43 ± 0.45 mm/0.79 ± 0.24 mm). CONCLUSIONS In the used defect model, the application of CTG or CM in conjunction with CAF did not have an advantage over the use of CAF alone. CLINICAL RELEVANCE The use of CAF alone is a valuable option for the treatment localized Miller Class I recessions.

Effect of bone graft density on in vitro cell behavior with enamel matrix derivative

OBJECTIVES Bone replacement grafting materials play an important role in regenerative dentistry. Despite a large array of tested bone-grafting materials, little information is available comparing the effects of bone graft density on in vitro cell behavior. Therefore, the aim of the present study is to compare the effects of cells seeded on bone grafts at low and high density in vitro for osteoblast adhesion, proliferation, and differentiation. MATERIALS AND METHODS The response of osteoblasts to the presence of a growth factor (enamel matrix derivative, (EMD)) in combination with low (8 mg per well) or high (100 mg per well) bone grafts (BG; natural bone mineral, Bio-Oss®) density, was studied and compared for osteoblast cell adhesion, proliferation, and differentiation as assessed by real-time PCR. Standard tissue culture plastic was used as a control with and without EMD. RESULTS The present study demonstrates that in vitro testing of bone-grafting materials is largely influenced by bone graft seeding density. Osteoblast adhesion was up to 50 % lower when cells were seeded on high-density BG when compared to low-density BG and control tissue culture plastic. Furthermore, proliferation was affected in a similar manner whereby cell proliferation on high-density BG (100 mg/well) was significantly increased when compared to that on low-density BG (8 mg/well). In contrast, cell differentiation was significantly increased on high-density BG as assessed by real-time PCR for markers collagen 1 (Col 1), alkaline phosphatase (ALP), and osteocalcin (OC) as well as alizarin red staining. The effects of EMD on osteoblast adhesion, proliferation, and differentiation further demonstrated that the bone graft seeding density largely controls in vitro results. EMD significantly increased cell attachment only on high-density BG, whereas EMD was able to further stimulate cell proliferation and differentiation of osteoblasts on control culture plastic and low-density BG when compared to high-density BG. CONCLUSION The results from the present study demonstrate that the in vitro conditions largely influence cell behavior of osteoblasts seeded on bone grafts and in vitro testing. CLINICAL RELEVANCE These results also illustrate the necessity for careful selection of bone graft seeding density to optimize in vitro testing and provide the clinician with a more accurate description of the osteopromotive potential of bone grafts.

Supplemental cardioplegia immediately before graft implantation may improve early post-transplantation outcome

Gebiet: Chirurgie Abstract: Background: Preservation of cardiac grafts for transplantation is not standardized and most centers use a single administration of crystalloid solution at the time of harvesting. We investigated possible benefits of an additional dose of cardioplegia dispensed immediately before implantation. – – Methods: Consecutive adult cardiac transplantations (2005?2012) were reviewed. Hearts were harvested following a standard protocol (Celsior 2L, 4?8°C). In 2008, 100 ml crys-talloid cardioplegic solution was added and administered immediately before implanta-tion. Univariate and logistic regression analyses were used to investigate risk factors for post-operative graft failure and mid-term outcome. – – Results: A total of 81 patients, 44 standard (?Cardio???) vs. 37 with additional cardiople-gia (?CardioC?) were analyzed. Recipients and donors were comparable in both groups. CardioC patients demonstrated a reduced need for defibrillation (24 vs. 48%, p D0.03), post-operative ratio of CK-MB/CK (10.1_3.9 vs. 13.3_4.2%, p D0.001), intubation time (2.0_1.6 vs. 7.2_11.5 days, p D0.05), and ICU stay (3.9_2.1 vs. 8.5_7.8 days, p D0.001). Actuarial survival was reduced when graft ischemic time was >180 min in Cardio?? but not in CardioC patients (p D0.033). Organ ischemic time >180 min (OR: 5.48, CI: 1.08?27.75), donor female gender (OR: 5.84, CI: 1.13?33.01), and recipient/donor age >60 (OR: 6.33, CI: 0.86?46.75), but not the additional cardioplegia or the observation period appeared independent predictors of post-operative acute graft failure. – – Conclusion: An additional dose of cardioplegia administered immediately before implan-tation may be a simple way to improve early and late outcome of cardiac transplantation, especially in situations of prolonged graft ischemia.A large, ideally multicentric, randomized study is desirable to verify this preliminary observation.

Reconstruction of Chronic Foveal TFCC Tears with an Autologous Tendon Graft

Background A triangular fibrocartilage complex (TFCC) injury can produce distal radioulnar joint (DRUJ) instability. If the foveal attachment is avulsed, it translates distally. The footprint is separated from its origin and will become covered in synovitis, preventing healing. The authors describe a surgical technique for the treatment of instability of the DRUJ due to chronic foveal detachment of the TFCC. Technique The procedure utilizes a loop of autologous palmaris longus tendon graft passed through the ulnar aspect of the TFCC and through an osseous tunnel in the distal ulna to reconstruct the fovel attachment. Patients and Methods We report on nine patients with a mean age of 42. Median follow-up was 13 months. Results The median pain scores measured were reduced from 8 to 3 postoperatively, and all had a stable DRUJ. Conclusions This technique provides stability of the distal ulna to the radius and carpus, with potential for biologic healing through osseous integration. It is a robust, anatomically based reconstruction of the TFCC to the fovea that stabilizes the DRUJ and the ulnar-carpal sag.

Human graft-derived mesenchymal stromal cells potently suppress alloreactive T-cell responses

After organ transplantation, recipient T cells contribute to graft rejection. Mesenchymal stromal cells from the bone marrow (BM-MSCs) are known to suppress allogeneic T-cell responses, suggesting a possible clinical application of MSCs in organ transplantation. Human liver grafts harbor resident populations of MSCs (L-MSCs). We aimed to determine the immunosuppressive effects of these graft-derived MSCs on allogeneic T-cell responses and to compare these with the effects of BM-MSCs. BM-MSCs were harvested from aspirates and L-MSCs from liver graft perfusates. We cultured them for 21 days and compared their suppressive effects with the effects of BM-MSCs on allogeneic T-cell responses. Proliferation, cytotoxic degranulation, and interferon-gamma production of alloreactive T cells were more potently suppressed by L-MSCs than BM-MSCs. Suppression was mediated by both cell-cell contact and secreted factors. In addition, L-MSCs showed ex vivo a higher expression of PD-L1 than BM-MSCs, which was associated with inhibition of T-cell proliferation and cytotoxic degranulation in vitro. Blocking PD-L1 partly abrogated the inhibition of cytotoxic degranulation by L-MSCs. In addition, blocking indoleamine 2,3-dioxygenase partly abrogated the inhibitive effects of L-MSCs, but not BM-MSCs, on T-cell proliferation. In conclusion, liver graft-derived MSC suppression of allogeneic T-cell responses is stronger than BM-MSCs, which may be related to in situ priming and mobilization from the graft. These graft-derived MSCs may therefore be relevant in transplantation by promoting allohyporesponsiveness.

Graft preservation solutions in cardiovascular surgery.

Vein grafts are still the most commonly used graft material in cardiovascular surgery and much effort has been spent in recent years on investigating the optimal harvesting technique. One other related topic of similar importance remained more or less an incidental one. The storage solutions of vein grafts following procurement and prior to implantation are, despite their assumed impact, a relatively neglected theme. There is no doubt that the endothelium plays a key role in long-term patency of vein grafts, but the effects of the different storage solutions on the endothelium remain unclear : In a review of the literature, we could find 20 specific papers that addressed the question, of which the currently available preservation solutions are superior, harmless, damaging or ineffective. The focus lies on saline and autologous whole blood. Besides these two storage media, novel or alternative solutions have been investigated with surprising findings. In addition, a few words will be spent on potential alternatives and novel solutions on the market. As there is currently no randomized clinical trial regarding saline versus autologous whole blood available, this review compares all previous studies and methods of analysis to provide a certain level of evidence on this topic. In summary, saline has negative effects on the endothelial layers and therefore may compromise graft patency. Related factors, such as distension pressure, may outbalance the initial benefit of autologous whole blood or storage solutions and intensify the harmful effects of warm saline. In addition, there is no uniform consent on the superiority of autologous whole blood for vein graft storage. This may open the door to alternatives such as the University of Wisconsin solution or one of the specific designed storage solutions like TiProtec™ or Somaluthion™. Whether these preservation solutions are superior or advantageous remains the subject of further studies.