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Dive into the research topics where Denys Montandon is active.

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Featured researches published by Denys Montandon.


Lancet Infectious Diseases | 2005

Infection in breast implants

Brigitte Pittet; Denys Montandon; Didier Pittet

Infection is the leading cause of morbidity that occurs after breast implantation and complicates 2.0-2.5% of interventions in most case series. Two-thirds of infections develop within the acute post-operative period, whereas some infections may develop years or even decades after surgery. Infection rates are higher after breast reconstruction and subsequent implantation than after breast augmentation. Risk factors for infection associated with breast implantation have not been carefully assessed in prospective studies with long-term follow-up. Surgical technique and the patients underlying condition are the most important determinants. In particular, breast reconstruction after mastectomy and radiotherapy for cancer is associated with a higher risk for infection. The origin of infection in women with implants remains difficult to determine, but potential sources include a contaminated implant, contaminated saline, the surgery itself or the surgical environment, the patients skin or mammary ducts, or, as suggested by many reports, seeding of the implant from remote infection sites. Late infection usually results from secondary bacteraemia or an invasive procedure at a location other than breasts. Diagnostic and management strategies are proposed and the value of peri-operative surgical prophylaxis is revisited. The current hypothesis of the possible role of low-grade or subclinical infection in the origin of capsular contracture is also reviewed.


Gene Therapy | 2001

Delivery of FGF-2 but not VEGF by encapsulated genetically engineered myoblasts improves survival and vascularization in a model of acute skin flap ischemia

Christopher Rinsch; Pierre Dominique Quinodoz; Brigitte Pittet; Navid Alizadeh; Danielle Baetens; Denys Montandon; Patrick Aebischer; Michael S. Pepper

Stimulating angiogenesis by gene transfer approaches offers the hope of treating tissue ischemia which is untreatable by currently practiced techniques of vessel grafting and bypass surgery. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (FGF-2) are potent angiogenic molecules, making them ideal candidates for novel gene transfer protocols designed to promote new blood vessel growth. In this study, an ex vivo gene therapy approach utilizing cell encapsulation was employed to deliver VEGF and FGF-2 in a continuous and localized manner. C2C12 myoblasts were genetically engineered to secrete VEGF121, VEGF165 and FGF-2. These cell lines were encapsulated in hollow microporous polymer membranes for transplantation in vivo. Therapeutic efficacy was evaluated in a model of acute skin flap ischemia. Capsules were positioned under the distal, ischemic region of the flap. Control flaps showed 50% necrosis at 1 week. Capsules releasing either form of VEGF had no effect on flap survival, but induced a modest increase in distal vascular supply. Delivery of FGF-2 significantly improved flap survival, reducing necrosis to 34.2% (P < 0.001). Flap vascularization was significantly increased by FGF-2 (P < 0.01), with numerous vessels, many of which had a large lumen diameter, growing in the proximity of the implanted capsules. These results demonstrate that FGF-2, delivered from encapsulated cells, is more efficacious than either VEGF121 or VEGF165 in treating acute skin ischemia and improving skin flap survival. Furthermore, these data attest to the applicability of cell encapsulation for the delivery of angiogenic factors for the treatment and prevention of tissue ischemia.


Lancet Infectious Diseases | 2003

Noma: an “infectious” disease of unknown aetiology

Denise Baratti-Mayer; Brigitte Pittet; Denys Montandon; Ignacio Bolivar; Jacques-Etienne Bornand; Stéphane Hugonnet; Alexandre René Jaquinet; Jacques Schrenzel; Didier Pittet

Noma (cancrum oris) is a devastating gangrenous disease that leads to severe tissue destruction in the face and is associated with high morbidity and mortality. It is seen almost exclusively in young children living in remote areas of less developed countries, particularly in Africa. The exact prevalence of the disease is unknown, but a conservative estimate is that 770000 people are currently affected by noma sequelae. The cause remains unknown, but a combination of several elements of a plausible aetiology has been identified: malnutrition, a compromised immune system, poor oral hygiene and a lesion of the gingival mucosal barrier, and an unidentified bacterial factor acting as a trigger for the disease. This review discusses the epidemiology, clinical features, current understanding of the pathophysiology, and treatment of the acute phase and sequelae requiring reconstructive surgery. Noma may be preventable if recognised at an early stage. Further research is needed to identify more exactly the causative agents.


Plastic and Reconstructive Surgery | 1991

The reversed fasciosubcutaneous flap in the leg.

Raphaël Gumener; A. Zbrodowski; Denys Montandon

A reversed fasciosubcutaneous tissue flap in the leg is described. This distally based flap is vascularized by the perforating cutaneous branches of the peroneal and tibialis posterior arteries. It must carry all its subcutaneous tissue. A study on the vascularization of the subcutaneous tissue reveals the predominance of the vascular network in this layer with regard to the dermal or fascial plane. The dermal vascular network at the donor site is sufficient to let the skin survive without its underlying subcutaneous vascular support. The flap can reach the malleolar and heel region. The advantages of this technique are (1) easy dissection, (2) preservation of the major vascular pedicles of the lower limb, (3) skin preservation at the donor site, thus preserving the shape of the limb, and (4) versatility (it is supple and can adapt to every surface, and it can be grafted on the deep or the superficial side). The addition of this technique to the armamentarium of the reconstructive surgeon has proved to be very useful in repairing soft-tissue defects in the lower limb. Often it can replace the classical fasciocutaneous flap or even a free flap.


Plastic and Reconstructive Surgery | 1991

THE SURGICAL TREATMENT OF NOMA

Denys Montandon; Catherine Lehmann; Nicolas Chami

Noma is a gangrenous stomatitis affecting children from developing countries. It may leave dreadful mutilations around the mouth, with amputation of the lips, cheek, nose, lids, maxilla, palate, or mandibula. Reconstruction should take into account the size of the defect, the presence of trismus or constriction of the mandible, the age of the child, and the childs general condition. During the last 3 years, eight patients were treated at the Unit of Plastic and Reconstructive Surgery of the Hôpital Cantonal Universitaire. Except in one case, tracheostomy was avoided, thanks to intranasal intubation by fibroscopy. These children, aged 2 to 9 years, underwent 31 general anesthesias and complex reconstructive procedures, including latissimus dorsi musculocutaneous pedunculated and free flaps, cranial flaps with galea, cranial bone and skin grafts, and retroauricular temporal skin flaps. All patients were able to return to Africa with dramatic functional and cosmetic improvements. However, satisfactory mouth opening and mandibular function were not always obtained.


Annals of Plastic Surgery | 1986

Subcutaneous tissue in the scalp: anatomical, physiological, and clinical study.

Felix Marty; Denys Montandon; Rapha l Gumener; A. Zbrodowski

The galea aponeurotica has been used by various surgeons either as a supporting sheet or as a blood carrier for bringing flaps to various areas of the face. In this study, we first reviewed the anatomy of the scalp vascularization by means of cadaver injections. The arteries and veins are mainly located in the galea and numerous anastomotic vessels are present over the vertex. The physiology of this vascularization has been studied by percutaneous Po2 registration after occlusion of various vessels by means of a tourniquet placed around the head. The superficial temporal arteries have been found to be the most important vessels for designing flaps over the head. On the basis of these experiments, several patients have been operated upon. The possibility of using a skin island from the retroauricular region based on subcutaneous tissue only is described.


Annals of Plastic Surgery | 1991

Sensibility and cutaneous reinnervation after breast reconstruction with musculocutaneous flaps

Lehmann C; Gumener R; Denys Montandon

Sensibility and sensory reinnervation were investigated in 19 patients who underwent, after mastectomy, a breast reconstruction using myocutaneous flaps. A comparative study in reinnervation of the flaps has been performed either after surgery with a latissimus dorsi flap with prosthesis or after surgery with a simple or double pedicle transverse rectus abdominal flap. Ten patients with latissimus dorsi flaps and 9 patients with transverse rectus abdominal flaps were tested. The tests included stimulation with touch, pressure, pin prick, and temperature. The patients were also interviewed regarding their impressions, a subjective sensibihty. These results show that the recovery of sensibility by patients who underwent surgery with the transverse rectus abdominal flap technique is superior, objectively and subjectively.


British Journal of Plastic Surgery | 1984

The use of subcutaneous tissue flaps in the repair of soft tissue defects of the forearm and hand: an experimental and clinical study of a new technique

Felix Marty; Denys Montandon; Raphaël Gumener; A. Zbrodowski

Abstract This paper records our experience with a new technique of providing cover for soft tissue defects of the upper extremity using flaps consisting of subcutaneous tissue only and relying on the arterial anastomotic network of this tissue layer to sustain its vascularisation. The experimental basis of this technique is described in detail and two illustrations of the clinical use of this technique are given. The main advantages of this type of flap are its ready availability from the local tissues, its elasticity, the absence of functional and aesthetic disturbance at the donor site and the preservation of the natural contour of the limb.


Wound Repair and Regeneration | 1996

Covering by a flap induces apoptosis of granulation tissue myofibroblasts and vascular cells.

Stefania Garbin; Brigitte Pittet; Denys Montandon; Giulio Gabbiani; Alexis Desmoulière

It has recently been shown that during the healing of an open wound, apoptosis mediates the decrease in cellularity during the transition between granulation tissue and scar. Because reduced contraction and a decrease in the number of fibroblastic cells have been described in wounds covered with a successful skin graft, we hypothesized that apoptosis could be responsible for these phenomena. Using in situ labeling of fragmented DNA, immunohistochemistry for α‐smooth muscle actin, and electron microscopy, we have studied in rats the evolution of 10‐day‐old wound tissue covered with a total skin flap (containing epidermis, dermis, and the cutaneous muscle). In 10‐day‐old wound tissue, few apoptotic vascular cells and rare apoptotic myofibroblasts were present; the number of apoptotic cells increased slightly 72 hours later. In wounds covered with total skin flaps, the number of apoptotic vascular and myofibroblastic cells increased drastically 6 hours after flap application with a maximum at 24 and 48 hours, respectively. A decrease of apoptotic cell number was noted at 72 hours; at this time, the size of the granulation tissue was greatly reduced and showed extracellular matrix remodeling. Total flaps were more efficient in the induction of granulation tissue cell apoptosis compared with dermo‐epidermal flaps. Moreover, the control application of full‐thickness skin autografts, which were not viable 7 days later, did not induce apoptosis 24 hours after implantation. Our results indicate that covering granulation tissue with a skin flap results in a massive apoptotic process, possibly by means of a (some) locally released substance(s).


Journal of Craniofacial Surgery | 1998

Nasal reconstruction in children: a review of 29 patients

Brigitte Pittet; Denys Montandon

SUMMARYAcquired large nasal defects are much more common in adulthood than in childhood because of the frequency of skin tumors after a certain age. However, from their experience in treating a number of children with sequelae of noma and burns, the authors have collected a series of 17 total and 12 partial nasal reconstructions in children aged 1 to 15 years. After reviewing the various methods used for recreating the lining, the support, and the skin cover in the whole series, three cases are reported in detail. A 1-year-old patient received a tempororetroauricular flap after total amputation of the nose and was observed for 17 years. Another patient, who was burned as a baby, underwent reconstruction at age 10 with a deltopectoral flap and was observed for 7 years. The third patient underwent total nose reconstruction at age 12 with an Indian forehead flap. From their experience, the authors conclude that, for psychosocial reasons, nasal reconstruction should be started early, despite possible reoperation at a later age. The best results are certainly obtained at the end of growth or at least after the age of 12. Adjacent bone or soft tissue defects further enhance the difficult challenge of restoring a satisfactory aesthetic appearance in these children.

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