China
Africa
Explore chapters and articles related to this topic
Reconstruction of skull base defects
Published in Jyotirmay S. Hegde, Hemanth Vamanshankar, CSF Rhinorrhea, 2020
Hemanth Vamanshankar, Jyotirmay S Hegde
Human acellular dermis grafts are popular in head and neck reconstructions, because compared to autologous tissues they do not require time for graft harvesting, and their propensity for shrinkage is low. They are relatively cheap and easy to use. Crusting, however, can be a problem with these grafts in the postoperative phase.
Biological reactions to reconstructive materials
Published in Steven J. Kronowitz, John R. Benson, Maurizio B. Nava, Oncoplastic and Reconstructive Management of the Breast, 2020
Steven J. Kronowitz, John R. Benson, Maurizio B. Nava
Histologic studies of implanted porcine small intestinal submucosa derived ECM have shown that it is entirely degraded and replaced by functional host tissue during a process of constructive remodeling.14 However, the extent to which thicker acellular dermis is similarly degraded and replaced varies. Furthermore, what constitutes complete ADM remodeling in breast reconstruction is not yet well-defined.16 Histologic evaluation of both human and porcine dermal matrices in a rat abdominal wall model showed incomplete cellular penetration of the full thickness of the material, more than 1-year post-implantation,17 whereas other studies have reported significant cellular infiltration of ADM at earlier time points.18
Secondary cleft surgery
Published in John Dudley Langdon, Mohan Francis Patel, Robert Andrew Ord, Peter Brennan, Operative Oral and Maxillofacial Surgery, 2017
The palatal re-repair, raising the original hard palatal flaps and if necessary performing a functional revision of the soft palate, is most useful in most circumstances (Figure 68.9). For large fistulae, acellular dermis can be useful as an additional layer and might facilitate healing in the eventuality of dehiscence.Incisions are made in the mucosa around the fistula and it is turned in towards the nasal side to allow creation of a nasal layer (wound edges everted and sutures tied to nasal side).A two-flap or von Langenbeck palatoplasty is performed on the remaining hard palate mucosa, scoring or release is performed laterally and around the neurovascular bundle as needed.Acellular dermis can be interposed and secured between the oral and nasal flaps as needed.The flaps are sutured in the midline (Figure 68.9e through h).
Aqueous Drainage Device Erosion: A Review of Rates, Risks, Prevention, and Repair
Published in Seminars in Ophthalmology, 2018
The surgical management of tube erosion often poses a challenge, especially since it can beassociated with repeat erosions. Each subsequent repair becomes more difficult, as healthy conjunctiva is required to cover the eroded area. There have been a variety of different surgical approaches to repair, all with the basic principle of undermining the surrounding conjunctiva, placing a patch graft over the tube, and closing over with healthy conjunctiva and tenons, much the way the initial implant is covered. Some have hypothesized that it may be beneficial to use a different type of patch graft than the initial surgery in case the dissolution of the graft was secondary to an immunologic response to the material.13 Additionally, in some cases, repositioning of the tube to the pars plana is advocated to reduce anterior friction.58 Traditionally, the patch grafts used for repair are similar to what is used for primary tube insertions. Kalenak described his success with donor acellular dermis graft in 30 cases, which has not been described in primary tube implantation thus far.56
Simultaneous ipsilateral transconjunctival repair of upper and lower eyelid retraction in thyroid-associated ophthalmopathy
Published in Orbit, 2019
Nahyoung Grace Lee, Larissa Habib, Jonathan Hall, Suzanne K. Freitag
Surgical correction of lower eyelid retraction usually requires a posterior spacer graft to lengthen the vertical height of the tarsus. Autogenous materials such as hard palate and ear cartilage are commonly used as graft sources; however, there can be significant donor site morbidity and chronic ocular surface discomfort and abnormal secretions.2 Malhotra et al. describe using a tarsal graft fashioned into two parallel vertical struts as support for the lower eyelid.3 Homologous grafts, such as human cadaveric acellular dermis and Tutoplast® sclera, carry a risk of infectious disease transmission and tend to be associated with unpredictable absorption.4 For instance, AlloDerm has been shown to resorb by greater than 50% at 6 months.5
Posterior lamellar reconstruction: a comprehensive review of the literature
Published in Orbit, 2019
Alessandra Fin, Fabrizio De Biasio, Paolo Lanzetta, Sebastiano Mura, Anna Tarantini, Pier Camillo Parodi
A porcine acellular dermis, Permacol was first used to reconstruct the posterior lamella by Peter and Kumar in 2013.105 This substitute tissue was chosen for its strength, rigidity, and robustness; it proved to be well incorporated by the body and to serve as a matrix for tissue ingrowth. Nonetheless, the rate and occurrence of resorption was found to be unpredictable. Indeed, Livia Teo noted significant graft shrinkage in the in-vivo rat model.106 Like acellular human dermis, resorption and shrinkage is likely to be due to dehydration and insufficient exposure to vascular tissue. Permacol grafts should therefore be oversized with respect to the defect.