Search PubMed⌕ Search

Biomedical subjects

W M Swartz

Publications and source records attributed to W M Swartz.

At least 37 records · Page 2Linked to original sources
PubMed1988

The critical relationship between free radicals and degrees of ischemia: evidence for tissue intolerance of marginal perfusion.

UNLABELLED: Skin-flap ischemia has been associated with the presence of free radicals. In this study, two enzyme systems involved in free-radical metabolism were used to compare a distal skin flap to a skin graft. Forty-two rats were divided into several test groups. A 10 X 3 cm dorsal rat flap was used, and tissue biopsies for xanthine oxidase and malonyldialdehyde (MDA) were obtained 2.5, 5.5, and 8.5 cm from the base of the flap at the hours given. In group I (control), the flap was outlined but not elevated, and biopsies were obtained. In group II, the flap was elevated, and biopsies were obtained at 6 hours. In group III, the flap was elevated, the distal 4 X 3 cm was amputated and replaced as a full-thickness skin graft, and biopsies were obtained at 6 hours. In group IV, the flap was elevated, and biopsies were obtained at 12 hours. In group V, the flap was treated as in group III, and biopsies were obtained at 12 hours. In group VI, the flap was elevated, and biopsies were obtained at 24 hours. In group VII, the flap was treated as in group III, and biopsies were obtained at 24 hours. RESULTS: Xanthine oxidase was significantly higher in all distal biopsies compared to proximal biopsies. Xanthine oxidase also increased with time. Malonyldialdehyde increased over time as well as with distance from the flap base. Distal flap biopsies at 24 hours had greatly increased levels of malonyldialdehyde compared to skin grafts (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1988

The "double barrel" free vascularized fibular bone graft.

A further modification of the free vascularized fibular bone graft is described in which a transverse osteotomy is made from the anterolateral aspect of the fibular shaft just distal to the entry of the nutrient artery. This produces two vascularized bone struts that may be folded parallel to each other but that remain connected by the periosteum and muscle cuff surrounding the peroneal artery and vein. The proximal strut is vascularized by both a periosteal and an endosteal blood supply, whereas the distal strut is vascularized by a periosteal blood supply alone. This so-called "double barrel" free vascularized fibular graft has been employed in three patients with segmental bone defects of the distal femur and in one patient with adjacent bony defects of the radius and ulna.

Adult↗
PubMed1988

Extensive and complex defects of the scalp, middle third of the face, and palate: the role of microsurgical reconstruction.

Twenty-one patients with gigantic defects of the scalp and middle third of the face and palate following excision of neglected or recurrent tumors, burns, and infections have undergone microsurgical reconstruction. Wide resection of the middle third of the face, orbit, and palate requires "complex" three-dimensional volume reconstruction, whereas extensive defects of the scalp and skull (exceeding 80 cm2) require coverage of the larger surface area soft-tissue defect and the exposed brain and dura. The latissimus dorsi free-muscle flap and split-thickness skin graft have become our methods of choice for extensive scalp and skull defects. The latissimus dorsi musculocutaneous free flap is preferable for reconstruction of complex palatal and external skin and orbital defects of the middle third of the face. Microsurgical free-tissue transfer reliably frees the oncologic surgeon from the constraints imposed by conventional reconstructive techniques and may therefore allow improved curative or at least palliative resection of these extensive tumors.

Adult↗
PubMed1987

Pyoderma gangrenosum with myelofibrosis.

Pyoderma gangrenosum is a papulovesicular skin disorder commonly associated with underlying systemic disease, but rarely with the myeloproliferative syndromes. A case of rapidly progressive pyoderma is cited in a 77-year-old white man who had no other evidence of disease aside from macrocytic anemia. Bone marrow biopsy revealed proliferation of fibroblasts and a dense reticulin network consistent with myelofibrosis. Response of the pyoderma to steroid therapy was dramatic. Although pyoderma gangrenosum is more commonly associated with inflammatory bowel disease and rheumatoid arthritis, this is the fifth reported case of its coexistence with idiopathic myelofibrosis.

Aged↗
PubMed1987

Microsurgery for macrodefects: microvascular free-tissue transfer for massive defects of the head and neck.

Despite defect location and the fear of creating complex massive defects, coverage of large areas of soft tissue loss, with or without exposed calvaria, dura, and brain, can be reconstructed reliably with microvascular free tissue transfer. This technique permits separation of the oronasopharynyx from the intracranial contents, coverage of dural grafts, restoration of composite tissue loss, and achievement of superior aesthetic results in a single stage. When choosing vascular anastomotic sites, free-flap transfer permits a greater latitude in flap orientation, tailoring, and inset than is possible when using fixed pedicled rotation flaps. When confronted with a deeply invasive or gigantic malignancy, a multidisciplinary team approach is optimal. The risk associated with sophisticated ablative and reconstructive operative procedures is justified when dealing with potentially curable lesions. The success of these extensive procedures is related not only to the functional result and the aesthetic appearance, but most importantly to the resultant quality of life they allow.

Adult↗
PubMed1987

The gluteus maximus muscle: experimental and clinical considerations relevant to reconstruction in ambulatory patients.

The gluteus maximus muscle and other haemodynamically related structures have been used for the reconstruction of significant defects in the perineum, sacrum, lumbar area and hip in 35 patients. The preservation of muscle function was achieved in all of 20 ambulatory patients and documented by gait analysis, muscle strength testing and EMG studies. Dye injection studies of the first perforating artery, inferior gluteal artery and superior gluteal artery led to the design of new flaps based on this arterial system. They include: medial advancements with extension above the sacrum, lateral advancements, lower gluteus advancements, the tensor fasciae latae gluteal extension and modifications of the gluteal thigh flap. These findings significantly increase our ability to close difficult wounds within the perineal, sacral, lumbar and trochanteric regions.

Adult↗
PubMed1987

Augmentation of skin flap survival with allopurinol.

Although allopurinol is primarily known as an effective medication for gout, it has been shown to enhance tissue survival in a wide range of ischemic conditions. The study reported here investigated the effects of allopurinol on flap survival in a dorsal rat model. In a preliminary study, animals were given varying doses of allopurinol (0 to 400 mg per kilogram). A clinically efficacious dose was established upon conclusion of the test period by laboratory determinations and necropsy data. Other animals were divided into 3 groups: 1 (saline control), N = 11; 2 (50 mg per kilogram of allopurinol daily), N = 10; 3 (100 mg per kilogram of allopurinol qd), N = 11. Flaps were raised and necrosis assessed at 8 days. Flaps treated with allopurinol 100 mg per kilogram had significantly better survival than the controls (p less than 0.001) and 50 mg per kilogram (p less than 0.01). Allopurinol 50 mg per kilogram had no effect on flap survival.

Allopurinol↗
PubMed1987

Distally based vastus lateralis muscle flap for coverage of wounds about the knee.

The blood supply to the vastus lateralis muscle has been evaluated by dye injection techniques in fresh cadaver dissections. The main dominant blood supply is the descending branch of the lateral femoral circumflex artery. Vascular contributions from distal perforators of the superficial femoral artery, the superior geniculate artery, fill the main vascular pedicle in a retrograde fashion. Latex staining is observed consistently in the proximal third of the muscle. Five patients are presented in whom the distally based vastus lateralis muscle flap was successfully used to cover defects above the knee. Superficial muscle necrosis is a complication of this operation but has not precluded its usefulness. It is anticipated that this flap will be useful in the armamentarium of reconstructive surgeons treating such problematic patients.

Adolescent↗
PubMed1987

Free jejunal transfer for reconstruction of the laryngopharynx.

Reconstruction of the laryngopharynx and cervical esophagus presents difficult problems. We embarked on a program using free jejunal transfer for such reconstruction. Thirty-two patients have been evaluated, with a mean follow-up of 16.7 months. Thirty-four transfers were undertaken--14 as primary repair and 20 after the failure of alternate methods. Twenty-six patients were able to achieve oral feeding. There was one immediate and one delayed failure of the graft. Twelve fistulas developed, seven of which healed spontaneously in less than 2 weeks. Four patients experienced complications related to the microvascular anastomosis which required repair. Six patients had significant dysphagia; four of these had side-to-end distal anastomosis. This technique had been abandoned and improvement resulted. We conclude that free jejunal transfer is an expeditious, safe, and reliable method of reconstruction for patients who require total laryngopharyngectomy.

Adult↗
PubMed1986

Deferoxamine increases skin flap survival: additional evidence of free radical involvement in ischaemic flap surgery.

This study presents further evidence of free radical involvement in skin flap necrosis in a dorsal rat flap model. Rats receiving deferoxamine, a free radical scavenger and iron chelator had significantly less necrosis (p less than 0.001) than saline treated rats. In a separate experiment, tissue determinations for malonyldialdehyde (MDA) were consistent with the survival results in showing a significant decrease in MDA in all biopsy sites (p less than 0.05 or less), indicative of reduced lipoperoxidation in the deferoxamine treated rats.

Animals↗
PubMed1986

Invasive squamous cell carcinoma of the carpus: malignant transformation of epidermis dysplasia verruciformis.

Epidermodysplasia verruciformis is a rare disease that is characterized by the eruption of wartlike skin lesions. There is a high incidence of malignant transformation of these lesions, especially in areas exposed to the sun, such as the face or the dorsum of the hands. We present a case that demonstrates many aspects of this disease entity, which ultimately required amputation of the hand because of invasive squamous cell carcinoma of the carpal bones.

Amputation, Surgical↗
PubMed1986

Clinical applications of free temporoparietal flaps in hand reconstruction.

Vascularized temporoparietal fascia can be used to cover deficits up to 14.0 X 12.0 cm in the hand or fingers. The tissue is thin, pliable, and has a smooth gliding surface advantageous to tendon function. Through scalp incisions, with meticulous yet straightforward dissection, this fascia can be isolated as a vascular island based on the superficial temporal artery system. Vessels are large and the anatomy is constant. Technique and clinical applications are discussed in detail.

Acute Disease↗
PubMed1986

The influence of dexamethasone on the regrowth of surgically removed fat.

We investigated the interaction between long-term dexamethasone administration and lipectomy on regional fat deposits in the rat. Seven-week-old Sprague-Dawley rats (N = 24) were divided into 3 test groups. Group 1 (control) received 0.5 ml/kg of saline intramuscularly daily; group 2, 1 microgram dexamethasone intramuscularly; group 3, 5 micrograms dexamethasone intramuscularly. At week 9 a lipectomy of 4 regional fat deposits on the right side of the animal was done: inguinal, epididymal, interscapular, and perirenal. Injections continued for an additional 27 weeks, at which time a lipectomy was done removing left-sided depots in addition to any "regrown fat" on the previously dissected right side. Several conclusions can be made. First, rats receiving 5 micrograms/kg reaccumulated more fat than the controls in the inguinal, perirenal, and interscapular depots. Second, fat cell size in this model greatly influenced the ultimate size of each depot. Third, fat depots vary in their response to steroids and lipectomy because of local and systemic factors.

Adipose Tissue↗