Evaluation of the MMI Symani® robotic microsurgical system for coronary-bypass anastomoses in a cadaveric porcine model.

The MMI Symani® is a recently approved robotic microsurgical system for surgical procedures in adults. The system enables the surgeon to create microanastomoses. Clinical applications so far include lymphatic vessels surgery and the creation of special flap plastics. The use of the system in coronary arteries has not yet been assessed. The aim of this preclinical study was to evaluate the applicability of the Symani® surgical system in the creation of coronary anastomoses a cadaveric porcine model. A total of 12 anastomoses were performed by three senior cardiovascular surgeons on the left main coronary artery of three porcine hearts. Artificial bypasses (diameter 1 mm) were performed to the left main trunk. The anastomoses were performed with the Symani® surgical system. Evaluation included procedure times and anastomosis leakage. All anastomoses could be successfully performed. The procedure time decreased due to the learning curve between the first anastomosis 47:28 ± 5:30 min and the last anastomosis 22:37 ± 3:25 min. The final evaluation of the anastomoses showed excellent results with low leakage. The quality of the anastomosis also improved in relation to the increasing learning curve. The Symani® surgical system could be used to create coronary anastomoses in an acceptable time frame and without technical failures. Hence, the system appears feasible for conventional coronary surgery. Further studies in animal models are mandatory prior to clinical application.

A technical feasibility study on adaptation of a microsurgical robotic system to an intraoperative complication management in dental implantology: perforated Schneiderian membrane repair using Symani® Surgical System.

The aim of the current study was to test the technical and clinical feasibility of a robotic system and investigate its potential in the surgical repair of perforated Schneiderian membranes using an ex-vivo porcine model. Eight pig heads were operated conventionally via a surgical loop and eight pig heads with the surgical robot "Symani® Surgical System" (Medical Microinstruments, Inc., Pisa, Italy). On each specimen, the Schneiderian membrane was incised over a length of 0.7 mm resembling a perforation. Operation time, the maximum sinusoidal pressure, the course of the pressure and the filling volume were measured. Additionally, adaptation of the wound edges has been detected via scanning electron microscopy. There were no significant differences for the pressure maximum (p = 0.528), for the time until the pressure maximum was reached (p = 0.528), or for the maximum filling volume (p = 0.674). The time needed for the suturing of the membrane via robotic surgery was significantly longer (p < 0.001). However, the scanning electron microscope revealed a better adaptation of the wound edges with robotic surgery. The technical feasibility of robot-assisted suturing of Schneiderian membrane laceration using the robotic system has been confirmed for the first time. No differences considering the pressure resistance compared to the conventional repair could be observed, but advantages in wound adaptation could be found with an electron microscope. Regarding the material and training costs and limited indications spectrum, robotic surgery systems still might not present financially feasible options in the daily dental practice yet.

Organic Bone Matrix Component Type I and V Collagen Are Not Destructed in Bisphosphonate-Associated Osteonecrosis of the Jaws.

Background and objectives: The investigation of the pathophysiology behind medication-related osteonecrosis (MRONJ) of the jaw mostly focuses on alterations in osteoclast and osteoblast cell activity, but changes in the organic and inorganic bone matrix have rarely been studied. The aim of this study was to investigate whether collagen, the main organic component of extracellular bone matrix, is destructed in osteonecrosis of the jaw secondary to antiresorptive medication. Material and methods: Bone samples of patients with MRONJ (n = 15, control group n = 3) were demineralized, and collagen fragments were separated from intact collagen pellets by ultrafiltration. The quantification of mature collagen cross-links hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) in pellets and ultrafiltrates was performed by high-performance liquid chromatography (HPLC). The detection of hydroxyproline (Hyp) was carried out using a spectrophotometric assay. In addition, collagen chains were analyzed by sodium dodecylsulfate-polyacrylamide gel (SDS-PAGE). Results: The results revealed significantly higher concentrations of HP, LP and Hyp in pellet samples. In addition, there were no significant differences between samples from MRONJ patients and those of the control group. These results were paralleled by SDS- PAGE. Conclusion: These findings suggest that MRONJ does not involve the destruction of type I and V collagen molecules, in contrast to previously reported destruction by osteoradionecrosis.

Learning Curve and Comparison of Dynamic Implant Placement Accuracy Using a Navigation System in Young Professionals.

The aim of the current study was to evaluate the learning curve and accuracy of implant placement by young professionals using a dynamic computer-assisted surgical system for dental implant placement. Ten students tried to place eight implants with a dynamic surgical system in predefined positions on two consecutive weekends, resulting in 160 implant placements in total. Postoperatively, the positions of the implants were scanned with an intraoral scanner and compared for deviations at the entry point, the apex, as well as angular deviations to the master model. The mean values of all measurements improved; statistical significance was found for the changes in the angle as well as for the position of the implants to the apex (p < 0.001). Furthermore, the young professionals indicated subjective improvement in handling the dynamic surgery system. Navigated surgical dental implant placement can be learned quickly and can support young professionals in everyday clinical practice, especially in difficult anatomic situations.

Robot-assisted scaffold implantation and two-stage flap raising of the greater omentum for reconstruction of the facial skeleton: Description of a novel technique.

BACKGROUND: Bone regeneration in the greater omentum is a promising strategy in facial skeleton reconstruction. This feasibility-study aims to perform robot-assisted scaffold implantation and second-stage flap raising. METHODS: Firstly, scaffolds were implanted into the greater omentum using the da Vinci Xi surgical system or conventional technique in five miniature pigs, respectively. After 3 months a free flap including the gastrocolic vascular pedicle was harvested and procedures were evaluated. RESULTS: The average operation time was 59.2 min for open surgery and 73.8 min for robot-assisted surgery. The average incision length of open surgery was 11.6 cm. Both techniques led to successful scaffold implantation without any complication. In all cases the scaffolds were integrated as intended and resulted in bone formation. CONCLUSIONS: Current study demonstrated that the implantation of scaffolds into the greater omentum and flap harvesting using da Vinci Xi surgical system is a promising minimally-invasive approach in regenerative surgery.

Changes in hormones of the thyroid axis after tracheostomy and their influence on regeneration in patients with head and neck cancer: A prospective study.

This prospective study aimed to compare and evaluate changes in hormones of the thyroid axis affected by tracheostomy due to surgical treatment in patients with oral cancer. The patients were evaluated with regard to serum levels of the thyroid axis - free T3/triiodothyronine (fT3) and free T4/thyroxine (fT4), as well as thyroid-stimulating hormone (TSH) - at fixed perioperative time points: during the tumor staging about 1 week before operation, immediately before and within 6 h after operation, 2 days after operation, and about 10 days after operation. Additionally, data on the patients' characteristics (age, gender), relevant secondary diagnoses, duration of ventilation in the intensive care unit, and perioperative complications were obtained and analyzed. In total, 51 patients with an average age of 68.29 years (±11.82) were included. Analyses of thyroid hormones directly before and after tracheostomy showed a significant postoperative decrease in circulating TSH (p = 0.005) and fT3 (p < 0.001), whilst a significant increase in fT4 values (p < 0.001) was found. Nine patients showed perioperative complications, such as infection, emphysema, or requiring a revision operation. Eleven patients were diagnosed with a cardiac problem or suffered from agitation after operation. Within the limitations of the study it seems that hormonal changes following tracheostomy in critically ill patients should be monitored and thyroid hormone adjustment should be taken into account because the latter might lead to lower mortality and morbidity during hospitalization in these patients. CLINICAL TRIAL REGISTRATION NUMBER: DRKS00023942.

Robotic infant surgery with 3 mm instruments: a study in piglets of less than 10 kg body weight.

No data exist concerning the appication of a new robotic system with 3 mm instruments (Senhance®, Transenterix) in infants and small children. Therefore, the aim of this study was to test the system for its feasibility, performance and safety of robotic pediatric abdominal and thoracic surgery in piglets simulating infants with a body weight lower than 10 kg. 34 procedures (from explorative laparoscopy to thoracoscopic esophageal repair) were performed in 12 piglets with a median age of 23 (interquartile range: 12-28) days and a median body weight of 6.9 (6.1-7.3) kg. The Senhance® robotic system was used with 3 mm instruments, a 10 mm 3D 0° or 30° videoscope and advanced energy devices, the setup consisted of the master console and three separate arms. The amount, size, and position of the applied ports, their distance as well as the distance between the three operator arms of the robot, external and internal collisions, and complications of the procedures were recorded and analyzed. We were able to perform all planned surgical procedures with 3 mm robotic instruments in piglets with a median body weight of less than 7 kg. We encountered two non-robot associated complications (bleeding from the inferior caval and hepatic vein) which led to termination of the live procedures. Technical limitations were the reaction time and speed of robotic camera movement with eye tracking, the excessive bending of the 3 mm instruments and intermittent need of re-calibration of the fulcrum point. Robotic newborn and infant surgery appears technically feasible with the Senhance® system. Software adjustments for camera movement and sensitivity of the fulcrum point calibration algorithm to adjust for the increased compliance of the abdominal wall of infants, therefore reducing the bending of the instruments, need to be implemented by the manufacturer as a result of our study. To further evaluate the Senhance® system, prospective trials comparing it to open, laparoscopic and other robotic systems are needed.

Microbiological Characteristics and Surgical Management of Animal-Bite-Related Oral & Maxillofacial Injuries: A Single Center's Experience.

The objective of the current study is to retrospectively evaluate animal-bite injuries and to gain insight into the epidemiology, accident consequences and treatment concept of these accidents in oral and maxillofacial surgery. Data of patients, who were admitted January 2015 and April 2021, were retrospectively evaluated regarding the patients' characteristics (age, gender), facial distribution of substance defects/partial amputations, duration of hospitalization, operation treatments and antibiotic treatments. Data of 75 patients were included. Patients were bitten by dogs (n = 69.92%), cats (n = 4) and horses (n = 2). Lower eyelid/cheek complex was the most affected region (n = 37, 32.74%). Most of the patients between 0 and 3 years had to be operated on under general anesthesia (p = 0.011), while most of the adults could be operated on under local anesthesia (p = 0.007). In the age group 0-12 years, 30 patients (68%) were operated on under general anesthesia. Ampicillin/Sulbactam (48%) was the antibiotic most used. Antibiotics were adjusted after wound swabs in case of wound infections or critical wound conditions. This means that resistant antibiotics were stopped, and sensitive antibiotics were used. Structured surgical and antibiotic management of animal-bite wounds in the maxillofacial region is the most important factor for medical care to avoid long-term aesthetic consequences. Public health actions and policies under the leadership of an interdisciplinary committee could improve primary wound management, healing outcome and information status in the general population.

Clinicopathological Risk Factors for Contralateral Lymph Node Metastases in Intraoral Squamous Cell Carcinoma: A Study of 331 Cases.

The current study aimed to examine the effects of clinicopathological factors, including the region, midline involvement, T classification, histological grade, and differentiation of the tumor on the rate of contralateral lymph node metastasis for oral squamous cell carcinoma and to assess their effects on survival rates. A total of 331 patients with intraoral squamous cell carcinomas were included. The influence of tumor location, T status, midline involvement, tumor grading, and the infiltration depth of the tumor on the pattern of metastasis was evaluated. Additionally, the effect of contralateral metastases on the prognosis was examined. Metastases of the contralateral side occurred most frequently in squamous cell carcinomas of the palate and floor of the mouth. Furthermore, tumors with a high T status resulted in significantly higher rates of contralateral metastases. Similarly, the midline involvement, tumor grading, existing ipsilateral metastases, and the infiltration depth of the tumor had a highly significant influence on the development of lymph node metastases on the opposite side. Oral squamous cell carcinomas require a patient-specific decision. There is an ongoing need for further prospective studies to confirm the validity of the prognostic factors described herein.

A retrospective analysis of the surgical outcomes of different free vascularized flaps used for the reconstruction of the maxillofacial region: Hand-sewn microvascular anastomosis vs anastomotic coupler device.

The aim of the study was to assess the surgical outcomes following venous anastomosis with a coupling device and hand-sewn anastomosis in the reconstruction of the maxillofacial region. The study sample was recruited from patients who underwent reconstructive surgeries between January 2011 and November 2016. Tumor type, recipient veins, distribution of flap type, flap survival rates and anastomosis associated complications requiring a flap revision were documented. The follow-up period was four years. In total, 236 patients were included in this study, in which 201 reconstructions were performed via microsurgical venous coupling device (82.04%), whereas hand sewn anastomosis was used in 44 patients (17.96%). Postoperative complications regarding the anastomosis technique revealed that venous coupler devices showed significantly lower complications (4,97%) compared to hand sewn anastomosis (11,36%) (p < 0.05). Within the limitations of the current study, it can be concluded that the coupler system does appear to have advantages over conventional hand-sewn venous anastomosis and should be preferred when possible.

A clinical study on the 6-year outcomes of immediately loaded three implants for completely edentulous mandibles: "the all-on-3 concept".

The objective of the current study was to demonstrate the 6-year clinical and radiological treatment outcomes of the technique performed by immediately loading of three implants (single straight in the mid-line and two tilted distal implants) for the management of total edentulous mandibles and introduce a simple decision matrix for selection of the most appropriate protocol in cases with insufficient length of the interforaminal area. Re-assessments were performed over a total observation period of 6 years after surgery via measurement of bone resorption around implants, bleeding on probing, plaque accumulation, periodontal probing depth, bite force measurements and oral health impact profile. A total of 29 patients (45% women and 55% men) with a mean age of 65 ± 6 years enrolled in the study. 14 patients received an acryl-based bridge as definitive prosthetic restoration and 15 patients received a ceramic-based restoration. Both during the immediate loading phase and during the 6-year follow-up, there was no implantation loss. Regardless of the implant position, all implants showed continuous bone loss over the observation time. The bone loss around dental implants during observation period was only maximum 1.0 ± 1 mm and it remained well within the limits for 'success' according to the 2007 Pisa consensus (< 2 mm). The plaque index showed no significant fluctuations between the implant positions and the individual examination times. The approach described herein might help the surgeon by avoiding unnecessary loss of bone strength, selecting implant sites, and establishing the biomechanical advantage of increased A-P spread for immediate function.

Antigen-induced arthritis of the temporomandibular joint via repeated injections of bovine serum albumin in domestic pigs.

Rheumatoid arthritis (RA) is a chronic inflammatory disease and the temporomandibular joint (TMJ) is affected in up to 50%, resulting in pain, limited mouth opening and dental malocclusion. The outcome of conservative and surgical therapies is unsatisfying in many cases. The purpose of this study was to establish a large animal model of antigen-induced arthritis (AIA) of the TMJ that enables the investigation of the pathogenesis of RA and the evaluation of new therapies. In five domestic pigs, systemic immunization was performed via consecutive intramuscular injections of bovine serum albumin (BSA). Then, AIA was induced via the application of BSA into the TMJ. Injection with saline served as the control. After ten weeks, the joints and adjacent tissues were harvested for histological analysis and cytokine quantification. The changes observed in the AIA specimens included severe synovial inflammation, cartilage-specific glycosaminoglycan content loss, and cartilage surface and discus alterations as well as the formation of chondrocyte clusters. Protein analyses of the synovia showed enhanced levels of IL-1ß, IL-6, TNFα and VEGF. A porcine model of immunologic arthritis of the TMJ was successfully established. This model may be used in future studies to investigate the underlying pathogenesis of RA and new therapeutic strategies.

Bone tissue engineering in the greater omentum is enhanced by a periosteal transplant in a miniature pig model.

AIM: Reconstruction of bone defects with autologous grafts has certain disadvantages. The aim of this study is to introduce a new type of living bioreactor for engineering of bone flaps and to evaluate the effect of different barrier membranes. MATERIALS & METHODS: Scaffolds loaded with bone morphogenetic proteins and bone marrow aspirate wrapped with either a collagen membrane or a periosteal flap were implanted in the greater omentum of miniature pigs. RESULTS: Both histological and radiographic evaluation showed proven bone formation and increased density after 8 and 16 weeks, with an enhanced effect of the periosteal transplant. CONCLUSION: The greater omentum is a suitable bioreactor for bone tissue engineering. Endocultivation is both an innovative and promising approach in regenerative medicine.

An experimental study on antitumoral effects of KI-21-3, a synthetic fragment of antimicrobial peptide LL-37, on oral squamous cell carcinoma.

PURPOSE: The aim of this study was to investigate the oncolytic properties of KI-21-3, a shortened fragment of LL-37, against oral squamous cell carcinoma (OSCC) in an animal model. MATERIALS AND METHODS: Twelve athymic nude mice were divided into a therapy and a control group of six animals each. In both groups, SCC-4 cells were administered extraorally into the floor of the mouth in order to create an OSCC model. In the study group, KI-21-3 was applied intravenously during the 8th and 9th weeks. The subjects in the control group were injected with phosphate buffered saline solution in the same manner. During an examination period of 12 weeks, weight control was performed twice a week. Tumor growth was further controlled volumetrically via ultrasonography once a week with regular intervals. Following sacrifice, ablated tumoral tissues were immunohistochemically evaluated in order to determine the proliferation and apoptotic properties. RESULTS: The mean tumor weight in the AMP group was 0.0236 ± 0.023 g, which was 30% lower than the control group with the mean value of 0.01651 ± 0.012 g. In the control group, the approximate number of the proliferating cells per visualized field was fourfold higher compared to the therapy group. Moreover, in the control group, the number of apoptotic cells per visualized field was significantly lower compared to the therapy group. CONCLUSION: KI-21-3 showed considerable oncolytic properties on SCC-4 carcinoma cells via antiproliferative and caspase-3 apoptotic pathway. Further investigations are necessary to clarify the dose-dependent effects of this agent.

Cytotoxic and inflammatory effects of alendronate and zolendronate on human osteoblasts, gingival fibroblasts and osteosarcoma cells.

OBJECTIVE: The aim of this paper was to assess the effects of zoledronate (ZOL) and alendronate (FOS) on apoptotic behavior and gene expression of pro- and inflammatory cytokines of three cell types (human osteoblasts, human gingival fibroblasts and human osteogenic sarcoma cell lines) during a period of 4 weeks. MATERIAL AND METHODS: Cell viability and proliferation was assessed via cell proliferation test (MTT), fluorescence diacetate analysis (FDA). Expression of inflammatory cytokines was investigated by using polymerase chain reaction. RESULTS: The proliferation and cell vitality of osteoblasts and fibroblasts were negatively affected in a dose dependent manner under ZOL and FOS administration. Osteosarcoma cells showed an increase in proliferation under lower doses of BP. ZOL had a significantly higher cytotoxic effect compared with FOS on osteoblasts and fibroblasts. ZOL increased the production of IL-6 in all cell types, whereas FOS only in osteosarcoma cell, which happened in dose dependent manner. Bisphosphonates could result in increase of IL-1ß expression of fibroblasts. An increase of IL-12 was observed at higher doses of ZOL administration among osteoblasts and FOS administration in osteosarcoma cells. CONCLUSION: ZOL and FOS could encourage cytotoxic and inflammatory reactions.

* Endocultivation of Scaffolds with Recombinant Human Bone Morphogenetic Protein-2 and VEGF165 in the Omentum Majus in a Rabbit Model.

The reconstruction of defects in the mandible are still challenging. Despite several adequate microvascular bone reconstruction techniques, there is a need for ectopic bone endocultivation without drawbacks by donor-site morbidity. The omentum majus is described as a good vascularized fleece with undifferentiated cells with potential for bone culturing. In the omentum majus of six rabbits, two hydroxyapatite blocks were incorporated for 12 weeks each. The blocks were prepared with recombinant human bone morphogenetic protein-2 (rhBMP-2) or VEGF165 + rhBMP-2 and wrapped into the omentum. For ectopic bone endocultivation observation computed tomography (CT) scans were performed, and fluorescence markers were applied. After harvesting the block, histological sections were performed with hematoxylin and eosin and toluidine blue staining. In the CT scans, the Hounsfield units of the blocks increased within the trail. In some sections, new bone formation was observed within the hydroxyapatite blocks, however, the histological staining showed soft-tissue invasion only, no gross bone formation was observed. The ectopic bone endocultivation in the omentum majus is technically a good approach. An adequate mixture of osteoinductive proteins is still missing.

Man as a Living Bioreactor: Prefabrication of a Custom Vascularized Bone Graft in the Gastrocolic Omentum.

Reconstruction of critical-size jaw defects still remains challenging. The standard treatment today is transplantation of autologous bone grafts, which is associated with high donor-site morbidity and unsatisfactory outcomes. We aimed to reconstruct a mandibular discontinuity defect after ablative surgery using the gastrocolic omentum as a bioreactor for heterotopic ossification. Three-dimensional computed tomography data were used to produce an ideal virtual replacement for the mandibular defect. A titanium mesh cage was filled with bone mineral blocks, infiltrated with 12 mg of recombinant human bone morphogenetic protein 2, and enriched with bone marrow aspirate. The scaffold was implanted into the gastrocolic omentum, and 3 months later, a free flap was harvested to reconstruct the mandibular defect. In vivo single photon emission computed tomography/computed tomography revealed bone remodeling and mineralization inside the mandibular transplant during prefabrication and after transplantation. Reconstruction was possible without any further modifications of the graft. A histological evaluation revealed that large sections of the Bio-Oss material were covered with osteoid matrix 3 months after transplantation. The quality of life of the patient significantly increased with acquisition of the ability to masticate and the improvement in pronunciation and aesthetics. Heterotopic bone induction to form a mandibular replacement inside the gastrocolic omentum is possible in human subjects. Heterotopic prefabrication is associated with many advantages, like allowing a reduced operative burden compared with conventional techniques and good three-dimensional outcomes.

Impact of body mass index, gender, and smoking on thickness of free soft tissue flaps used for orofacial reconstruction.

Donor-site selection may play an important role in the reconstruction of large orofacial defects. The thickness and structure of transplanted tissue has to fit those of the recipient site to achieve a satisfactory outcome. To evaluate the thickness of free flaps that are frequently used for orofacial reconstruction and its association with body mass index (BMI), gender, and smoking, a prospective study was conducted. A total of 122 volunteers were included in the study, and their data regarding BMI, gender, and tobacco use were documented. Ultrasonography was used to evaluate the thickness of the radial and ulnar forearm flaps (RFFF and UFFF, respectively), the scapular and parascapular flaps (SF and PSF, respectively), the anterolateral thigh flap (ALT), and the free fibular flap (FF). Correlation and regression analysis were performed to assess any relationship among parameters and to investigate their effect on flap thickness. The UFFF showed the lowest thickness (0.65 ± 0.16 cm), followed by the RFFF (0.83 ± 0.20 cm). The FF showed a comparable thickness (0.82 ± 0.26 cm), followed by the SF (0.99 ± 0.13 cm) and the PSF (1 ± 0.14 cm). The ALT flap displayed the greatest thickness (1.42 ± 0.42 cm) and correlated especially with BMI and gender, whereas the UFFF was the thinnest with relatively constant values, regardless of potential influential factors.

Ankyloglossia superior syndrome: case report and review of publications.

Ankyloglossia superior syndrome is a rare malformation that consists of a fibrous or osseous connection between the tip of the tongue and the hard palate, and additional congenital anomalies such as cleft palate, gastrointestinal malformations, and deformed limbs. We present the case of a 5-year-old boy with ankyloglossia superior syndrome that comprised the complete complex malformation. We reviewed previous publications and summarise the different theories of its genesis.