Simple method of designing a bilobed flap

In the present study, we devised a new method of designing bilobed flaps. This method makes the flap easy to draw and has the merits of diffusing the tension on the flap and minimizing the dog-ear. We used this flap in 16 patients with face and head skin defects and obtained good results.     

Umbilical transposition in TRAM flap: a simple horizontal translocation

A simple method of umbilical repositioning by incising the anterior rectus sheath and rectus abdominis muscle is reported for cases of unilateral abdominal wall plication during the TRAM flap operation. This method keeps the umbilicus stable and nonstenotic, and it avoids hypertrophic scars, which result from other techniques such as direct suturing of the stalk to the skin. Although this method might weaken contralateral muscle activity, the patients we operated on maintained their ability to perform sit-ups, and no periumbilical weakening was noticed.     

Conchal transposition flap for postburn ear deformities

Severe thermal injuries to the external ear often lead to extensive loss of peripheral structures such as helix and lobule but frequently spare the more central parts of the ear, even though they may be grossly deformed by scar contracture. The use of spared conchal structures as a transposition flap in combination with remodeling of the residual auricle and release of surrounding scar when indicated has been a useful technique in the reconstruction of a frequently occurring type of postburn ear deformity. Twenty-four ears have been reconstructed in 18 patients over the past 5 years using a conchal transposition flap. The residual concha with its overlying skin can be transposed superiorly, based on a very narrow pedicle in the area of the crus helicis. The raw central area remaining is then resurfaced with a split-thickness skin graft. This technique maximally utilizes the unique remaining auricular elements and can provide a satisfactory reconstruction in selected patients without resorting to more complex and extensive procedures. There have been no significant complications in this series, and patient acceptance of the results has been excellent.     

Assembly of a strong promoter following IS911 circularization and the role of circles in transposition.

When supplied with high levels of the IS911-encoded transposase, IS911-based transposons can excise as circles in which the right and left terminal inverted repeats are abutted. Formation of the circle junction is shown here to create a promoter, p(junc), which is significantly stronger than the indigenous promoter, pIRL, and is also capable of driving expression of the IS911 transposition proteins. High transposase expression from the circular transposon may promote use of the circle as an integration substrate. The results demonstrate that IS911 circles are highly efficient substrates for insertion into a target molecule in vivo. Insertion leads to the disassembly of p(junc) and thus to a lower level of synthesis of the transposition proteins. The observation that normal levels of IS911 transposition proteins supplied by wild-type copies of IS911 are also capable of generating transposon circles, albeit at a low level, reinforces the idea that the transposon circles might form part of the natural transposition cycle of IS911. These observations form the elements of a feedback control mechanism and have been incorporated into a model describing one possible pathway of IS911 transposition.     

Vicious circles: a mechanism for yeast aging

The past year has confirmed the great potential of the yeast Saccharomyces cerevisiae as a model to study aging. Ground breaking papers have revealed similarities between aging in yeast and in mammals, and have identified genetic instability of the ribosomal DNA array as the first known cause of aging in yeast cells.     

Prefabricated vascularized bone flap: a tissue transformation technique for bone reconstruction

In this study, an attempt was made to transform a muscle vascularized pedicle raised on host vessels into a vascularized bone flap, using recombinant human bone morphogenetic protein 2 (rhBMP-2). The purpose of this study was to produce new bone vascularized in nature to increase the survival rate of the subsequently grafted bone and to fabricate the newly formed bone into the desired shape. Silicone molds in the shape of a rat mandible were used to deliver rat bone matrix impregnated with or without rhBMP-2. A muscle pedicle the same size as the mold was raised on the saphenous vessels in the rat thigh and then sandwiched in the center of the silicone molds. The molds were sliced in half and each section was filled with rat bone matrix that was impregnated either with 25 microg of rhBMP-2 for the experimental group or with diluting material alone for the control group. The sandwiched flaps were then secured by tying them to the adjacent muscles and were harvested at 2 and 4 weeks after surgery. Three and six rats were used in the control and experimental groups at each time point, respectively. Bone formation was assessed in the ex vivo specimens by macroscopic, radiologic, and histologic evaluation. Macroscopically, the continuation of the vascular pedicle was clearly visible for both the control and experimental muscle flaps. However, no evidence of muscle-tissue transformation was observed in the control flaps, whereas all the flaps treated with rhBMP-2 produced new bone that replicated the shape of the mold exactly and had saphenous vessels supplying the newly formed bone. This study demonstrates that this experimental model has the potential to be therapeutically applied for effective bone reconstruction.     

Nipple reconstruction using the C-V flap technique: a long-term evaluation

Numerous procedures are available for nipple reconstruction with no true universal favorite. This study presents long-term follow-up data for nipple reconstruction using the C-V flap technique. Patients were identified by searching the Breast Reconstruction Database, and they were asked to return for a follow-up visit. All those who underwent nipple reconstruction using the C-V flap technique between January of 1992 and December of 1996 were reviewed in an attempt to conduct a long-term follow-up evaluation. The response was poor, and 11 patients participated in the study and returned for follow-up. They all completed a questionnaire, which focused on patient satisfaction using a visual analogue scale. Nipple measurements were taken with a caliper and compared with the opposite breast for symmetry. Fourteen nipple reconstructions were evaluated in 11 patients with an average follow-up of 5.3 years. All patients had undergone transverse rectus abdominis musculocutaneous (TRAM) flap reconstructions. Patient satisfaction was 42 percent with nipple projection, 62 percent with pigmentation, and 26 percent with sensation. Overall patient satisfaction with the procedure was 81 percent. Average nipple projection of the reconstructed nipple was 3.77 mm and was not statistically different when compared with the opposite nipple. Long-term subjective evaluation of the C-V flap technique does report a loss in nipple projection; however, overall patient satisfaction at 5.3 years is good, as is the ability to restore symmetry with the opposite breast.     

Uvular transposition: a new method of cleft palate repair

This prospective study was done to determine whether a new cleft palate repair utilizing uvular transposition improved speech outcome as measured objectively by a speech pathologist. In the uvular transposition procedure, the palate was lengthened with tissue from the uvula by a double-opposing Z-plasty; an intravelar veloplasty was performed, and two-thirds of the mass of the uvula was transposed to the nasal surface of the soft palate. This procedure facilitates velopharyngeal closure by significantly lengthening the palate, anatomically reconstructing the muscles of the palate, and decreasing the palatal excursion necessary to achieve closure. Sixty-two children with a cleft palate were treated with this procedure performed by the senior surgeon between the years of 1988 and 1995. These children were then enrolled in cleft lip and palate clinic at age 2 to 3 years and blindly evaluated yearly by a single speech pathologist who specialized in pediatric speech pathology. Postoperative clinical follow-up ranged from 36 to 112 months (mean, 56.8 months). Perceptual nasal emission was found to be normal in 59 of the 62 patients (95 percent). Nasometry was performed in all 62 of these patients, and the mean score was 15.7 percent, well within the accepted normal range of 25 or less at our institution. Only two of these children (3 percent) required a pharyngeal flap for velopharyngeal insufficiency. These findings suggest that the uvula transposition cleft palate repair may result in good normalization of speech with negligible rates of velopharyngeal insufficiency.     

Development of a technique for the complete correction of transposition of great vessels]

Complete transposition of the great arteries is one of the most common cardiovascular anomalies. Several surgical methods of treatment have been proposed. Arterial repair theoretically seems a better option since it does not introduce any additional intra cardiac anomaly and it restores the left ventricle to its natival systemic function. The rationale for neonatal arterial repair lies on fetal and neonatal cardiopulmonary physiology. The left ventricle has to eject immediately after surgery a normal cardiac output at systemic pressure in the aorta. This is the case in the neonatal period, because during fetal life pulmonary artery and aortic pressure are equal. For simple TGA, after birth, with the fall in pulmonary vascular resistances and constriction of the ductus arteriosus, pulmonary artery and left ventricular pressures drop dramatically to less than one third (1/3) of systemic pressure. As a result, the left ventricle is not stimulated for growth adaptation and becomes a thin ventricle less contractile and more compliant. However, there is little doubt that during the first 2 to 4 post-natal weeks, the left ventricle is still suitable to sustain a systemic workload. Between april 1984 and april 1992, four hundred and twenty six (426) consecutive neonates underwent an arterial switch operation for various forms of transposition: with 34 hospital deaths. The mean age at operation was 13 days and the mean weight was 3.2 kg. Among patients with TGA-VSD and coarctation, 14 underwent a single stage repair through mid sternotomy. Actuarial survival rates were: 89% for TGA-IVS at 5 years, 90% for TGA-VSD, 85.3% for TGA-VSD and coarctation at 3 years.(ABSTRACT TRUNCATED AT 250 WORDS)