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Biomedical subjects

Gottfried Wechselberger

Publications and source records attributed to Gottfried Wechselberger.

At least 37 records · Page 2Linked to original sources
PubMed2004

Capsule induction technique in a rat model for bladder wall replacement: an overview.

The search for a reliable technique for functional genitourinary tissue replacement remains a challenging task. The most recent advances in cell biology and tissue engineering have utilized various avascular and acellular collagen scaffolds with or without seeded cells. These techniques, however, are frequently complicated by tissue necrosis, contracture and resorption due to limited vascularization. We employed a new three-stage, evolving animal model with stage I optimizing the culture delivery vehicle, stage II employing a seeded vascularized capsule flap, and stage III adding a contractile matrix in the form of pedicled gracilis muscle prelaminated with autologous, in vitro-expanded urothelial cells to reconstruct an entire supratrigonal bladder-wall defect in rats.Specimens stained with hematoxylin and eosin (H&E), alpha(1)-actin staining, and a specific immunohistochemical staining (AE(1)&AE(3)-anticytoceratin monoclonal antibody stain) showed a continuous, multilayered, functioning urothelial lining along the transposed prelaminated gracilis flap in the animals of the final-stage experiment. Successful urinary reconstruction requires a contractile neoreservoir resistant to resorption over time and a stable, protective urothelial lining. We demonstrated that a gracilis muscle flap can be seeded with autologous cultured urothelial cells suspended in fibrin glue. This prelaminated flap can be safely transposed onto its pedicle and become successfully integrated into the remaining bladder wall, demonstrating urothelial lining and the potential to contract. Further studies in larger animals with urodynamic assessment is warranted to determine if this type of bladder-wall replacement technique is suitable for urinary reconstruction in humans.

Animals↗
PubMed2004

The transverse myocutaneous gracilis free flap: a valuable tissue source in autologous breast reconstruction.

The transverse myocutaneous gracilis free flap with a transverse orientation of the skin paddle in the proximal third of the medial thigh region allows the taking, in selected patients, of a moderate amount of tissue for autologous breast reconstruction. The donor-site morbidity is similar to that of a classic medial thigh lift. The indication for this flap in autologous breast reconstruction and the surgical technique will be discussed in this article. From August of 2002 to March of 2003, 10 patients underwent autologous breast reconstruction with 12 transverse myocutaneous gracilis free flaps. The patients' ages ranged from 26 to 48 years (median, 40 years). Of those, two BRCA-positive women received bilateral breast reconstructions after prophylactic skin-sparing mastectomy, and eight patients received immediate breast reconstruction after skin-sparing mastectomy in early-stage breast cancer. Mean follow-up of the 10 patients was 5 months (range, 1 to 9 months). We had no free-flap failure. Four patients had small areas of ischemic skin necrosis related to very thin preparation of the skin envelope after skin-sparing mastectomy without altering the final aesthetic results. Cosmetic evaluation of the reconstructed breasts and thigh donor site by two plastic surgeons showed good results in nine patients and fair results in one patient. There was no functional donor-site morbidity caused by harvesting the gracilis flap. The transverse myocutaneous gracilis flap is a valuable alternative for immediate autologous breast reconstruction after skin-sparing mastectomy in patients with small and medium-sized breasts and inadequate soft-tissue bulk at the lower abdomen and gluteal region.

Adult↗
PubMed2004

Microsurgical repair of the sural nerve after nerve biopsy to avoid associated sensory morbidity: a preliminary report.

OBJECTIVE: The purpose of this article is to report our preliminary results regarding microsurgical repair of the sural nerve after nerve biopsy, in an attempt to reduce the well-described sensory morbidity and neuroma formation. METHODS: Three patients with a suspected diagnosis of peripheral neuropathy underwent sural nerve biopsies to establish definitive diagnoses. A 10-mm segment of the sural nerve was resected with local anesthesia. After harvesting of the specimen, the proximal and distal nerve stumps were carefully mobilized and united with epineural suture techniques, under a surgical microscope. Sensory evaluations (assessing the presence of hypesthesia/dysesthesia or pain) of the lateral aspect of the foot, in regions designated Areas 1, 2, and 3, were performed before and 6 and 12 months after the biopsies. A visual analog scale was used for pain estimation. RESULTS: The biopsy material was sufficient for histopathological examinations in all cases, leading to conclusive diagnoses (vasculitis in two cases and amyloidosis in one case). The early post-biopsy hypesthesia, which was present for 4 to 8 weeks, improved to preoperative levels as early as 6 months after the nerve repair. Sensory evaluations performed at 6- and 12-month follow-up times demonstrated that none of the patients complained of pain at the biopsy site or distally in the area innervated by the sural nerve. Ultrasonography performed at the 12-month follow-up examination revealed normal sural nerve morphological features, with no neuroma formation, comparable to findings for the contralateral site. CONCLUSION: Microsurgical repair of the sural nerve after biopsy can eliminate or reduce sensory disturbances such as paraesthesia, hypesthesia, and dysesthesia distal to the biopsy site, in the distribution of the sensory innervation of the sural nerve, and can prevent painful neuroma formation. To our knowledge, this article is the first in the literature to report on microsurgical repair of the sural nerve after nerve biopsy. Decreased side effects suggest that this technique can become a standard procedure after sural nerve biopsy, which is commonly required to establish the diagnosis of various diseases, such as peripheral nerve pathological conditions, vasculitis, and amyloidosis. More cases should be analyzed, however, to explore the usefulness of the technique and the reliability of sural nerve biopsy samples in attempts to obtain conclusive diagnoses.

Aged↗
PubMed2003

Unilateral blepharochalasis.

Unilateral blepharochalasis is an extremely rare disorder with an unknown etiology and pathogenesis. The authors present a 22-year old patient in whom a right-sided skin overhang of the upper eyelid caused visual field impairment. The condition was corrected by a standard blepharoplasty. The histological examination suggested a localised anomaly of the lymphatic system and an almost complete absence of elastic fibres as the causative agent.

Adult↗
PubMed2003

[Elephantiasis of the thoracic wall within the scope of von Recklinghausen neurofibromatosis, case report].

Neurofibromas are benign tumors arising from neuroectodermal tissues. They may occur as solitary lesions, or multiple, in which case they are referred to as neurofibromatosis, or von Recklinghausen's disease. We report about a 17-year-old patient with neurofibromatous elephantiasis located in the lateral aspect of the left hemithorax. CT showed massive chest wall infiltration and retroperitoneal tumor growth, but no abnormalities of the cranium. Our surgical treatment consisted of a two-stage, palliative tumor debulking and defect coverage with a splitthickness skin graft. The operative and postoperative course was uneventful.

Adolescent↗
PubMed2003

Gracilis muscle split into two free flaps.

A case is presented in which the gracilis muscle was transversely split into two free flaps for coverage of two separate defects in a patient with a multi-segment fracture of the metatarsal bones and the ankle joint.

Adult↗
PubMed2003

Modified free paraumbilical perforator flap: the next logical step in breast reconstruction.

The free paraumbilical perforator flap that was developed with only the perforator penetrating the rectus abdominis muscle seems nearly ideal from the donor-site perspective, because it reduces morbidity virtually to that of an abdominoplasty. However, it requires "supermicrosurgery" skills for suturing of vessels with diameters of 0.7 mm or less, making the procedure technically demanding and risky. Another significant disadvantage of that technique is that the flap has very short vascular pedicles. To overcome the disadvantages of the free paraumbilical perforator flap, a minor modification in flap harvesting that improves the vessel size and length is described. Results for a total of 15 patients who underwent breast reconstruction with modified free paraumbilical perforator flaps are presented, and the advantages and disadvantages of this flap are discussed.

Adult↗
PubMed2003

Improved dorsal random-pattern skin flap survival in rats with a topically applied combination of nonivamide and nicoboxil.

The effects of a topically applied combination of nonivamide and nicoboxil in improving skin perfusion and preventing distal flap necrosis were tested in a random-pattern dorsal skin flap model. Forty male Wistar rats were randomized into two groups (n = 20), and a standardized dorsal random-pattern skin flap was raised on each rat. Animals in the experimental group were treated with the topically applied drug combination four times per day for 6 days, whereas in the control group only a placebo ointment was applied each time. Skin flap viability was evaluated on day 7, and the extent of skin flap necrosis was compared between the two groups. The topically applied combination of nonivamide and nicoboxil resulted in a statistically significant decrease in skin flap necrosis, compared with the control group (mean percentage of skin flap necrosis in the nonivamide/nicoboxil-treated group, 22.6 +/- 6.0 percent; control group, 36.8 +/- 4.3 percent; p< 0.05). The topical combination of nonivamide and nicoboxil was effective in reducing ischemic necrosis in failing random-pattern skin flaps in this rat model. The results of this study suggest that such a topical drug application might have significant effects in the reduction of ischemic necrosis in the distal parts of skin flaps, and this treatment might also have applications as prophylactic therapy for risky skin flaps.

Administration, Topical↗
PubMed2003

Inframammary fold reconstruction with a deepithelialized skin flap.

Sagging of the remaining breast behind the inframammary fold after breast reduction or breast augmentation may necessitate revisional surgery. The authors achieved inframammary fold reconstruction by reconstruction of the inframammary crease ligament through a deepithelialized skin flap that is anchored to the periosteum of the fifth or sixth rib. They present their simple and safe technique.

Female↗
PubMed2002

One-stage breast reduction and nipple-areolar reconstruction.

The authors present an easily designed and accomplished technique of one-stage reduction mammaplasty and nipple-areolar reconstruction for patients with large or medium-size breasts and for patients missing the nipple-areolar complex. The technique has low inherent risks, and the symmetry of the breast is maintained to the maximum. In addition to the cosmetic improvement, using this technique benefits the patient further by avoiding postoperative corrections or adjustments.

Female↗
PubMed2002

Successful transplantation of three tissue-engineered cell types using capsule induction technique and fibrin glue as a delivery vehicle.

Recent advances in cell biology and tissue engineering have used various delivery vehicles for transplanting varying cell cultures with limited success. These techniques are frequently complicated by tissue necrosis, infection, and resorption. The purpose of this study was to investigate whether urothelium cells, tracheal epithelial cells, and preadipocytes cultured in vitro could be successfully transplanted onto a prefabricated capsule surface by using fibrin glue as a delivery vehicle, with the ultimate goal for use in reconstruction. In the first step of the animal study, tissue specimens (bladder urothelium, tracheal epithelial cells, epididymal fat pad) were harvested for in vitro cell culturing, and a silicone block was implanted subcutaneously or within the anterior rectus sheath to induce capsule formation. After 6 to 10 days, when primary cultures were confluent, the animals were re-anesthetized, the newly formed capsule pouches were incised, and the suspensions of cultured urothelia cells (n = 40), tracheal epithelial cells (n = 32), and preadipocytes (n = 40) were implanted onto the capsule surface in two groups, one using standard culture medium as a delivery vehicle and the second using fibrin glue. Histologic sections were taken, and different histomorphologic studies were performed according to tissue type. Consistently in all animals, a highly vascularized capsule was induced by the silicon material. In all animals in which the authors used fibrin glue as a delivery vehicle, they could demonstrate a successful reimplantation of cultured urothelium cells, tracheal epithelial cells, or preadipocytes. Their animal studies showed that capsule induction in combination with fibrin glue as a delivery vehicle is a successful model for transplantation of different in vivo cultured tissue types.

Adipocytes↗