Lee E. Edstrom

Thrombosis of microvascular anastomoses in traumatized vessels : fibrin versus platelets

Thrombosis is the end result of two closely interrelated processes: the coagulation cascade and the platelet aggregation process. To determine their relative contribution, we used pharmacologic agents that selectively block each process. The specific effect of each pharmacologic agent on either fibrin deposition or platelet activity was confirmed morphologically by scanning electron microscopy and was substantiated with ADP-induced platelet aggregation and blood clotting time determinations. Forty-two rats had both femoral arteries subjected to a standardized crush-avulsion injury. A total of 84 femoral microvascular anastomoses were subsequently performed. None of the 24 control anastomoses treated with saline remained patent, whereas 6 of 24 of the anastomoses treated with dazmagrel (a selective thromboxane synthetase and platelet aggregation inhibitor), 2.5 mg/ kg IV, remained patent and 18 of 24 of those treated with a single dose of heparin, 200 U/kg IV, remained patent. All 12 anastomoses treated with both drugs remained patent but developed a 33 percent hematoma rate. We conclude that in this microvascular model, fibrin mesh deposition is a more significant factor than platelet aggregation in the pathogenesis of occlusional thrombosis within traumatized arteries. Its temporary inhibition with a single dose of heparin yielded a 75 percent improvement in patency rate.

The efficacy of systemic antibiotics in the treatment of granulating wounds

Abstract The efficacy of systemic antibiotics in the treatment of granulating wounds has been evaluated. A reproducible laboratory animal model on a chronic granulating wound has been developed and used to evaluate the ability of systemically administered antibiotics to decrease the bacterial flora in the wound. No significant reduction in bacteria was found. This appears to be due to the absence of the antibiotic in the granulation tissue. It is suggested that the fibrin base of a granulating wound may prevent adequate antibiotic penetration into the wound. From this study, therefore, it is suggested that systemic antibiotics have no role in attempting to decrease the bacterial count in a granulating wound.

Buccal mucosal grafts for urethral reconstruction

OBJECTIVES Patients requiring urethral reconstruction but who have a paucity of usable genital tissue present a considerable technical challenge. Herein we report the experience of three centers in the use of buccal mucosa for urethral replacement. METHODS From 1991 to 1996, 22 urethral reconstructions were completed using a graft of buccal mucosa. Eighteen of 22 patients had previously failed hypospadias repairs, while three had bulbar urethral stricture and one had penile carcinoma. Grafts were taken from either the inner cheek or the lower lip, and seven were used as a combined graft. Onlay grafts were used in 6 cases and tubularized grafts in 16 cases. RESULTS Two patients developed complications at the donor site. Nine of 22 patients had complications of the urethroplasty-two had meatal stenosis, four developed a urethral fistula, and three developed urethral stricture. All complications have been managed successfully to date. CONCLUSIONS Buccal mucosa is an excellent source of graft material for urethral replacement in complex urethroplasties. It is readily available, in abundant supply, and has physical properties beneficial to free graft survival.

The fetal cleft palate: I. Characterization of a congenital model.

Any animal model of a human congenital anomaly established by iatrogenic methods involving intrauterine fetal manipulation has limited clinical applicability. A congenital model that more closely simulates the etiopathogenesis of a human anomaly may provide data that can more readily be extrapolated to that anomaly and, therefore, be used in diagnostic and management strategies. The present work provides a description and characterization of a congenital model of cleft palate in the goat. Palatal shelf closure normally occurs at approximately day 38 of gestation in the caprine species. Sixteen pregnant goats were gavaged twice daily during gestational days 32 through 41 [term, 145 days] with a plant slurry of Nicotiana glauca containing the piperidine alkaloid teratogen anabasine. Gross analysis and measurement of fetal clefts were performed at 60, 70, and 85 days gestation (four fetuses were studied at each time point). Seventeen clefted kids were sacrificed at specific intervals after birth (2 weeks, and 1, 3, and 6 months); after skull debridement and preparation, they were compared with 12 unclefted control kids. Complete clefting of the secondary palate occurred in 97 percent of the fetuses. In all cases, the cleft extended from the posterior aspect of the alveolar ridge to the uvula; the majority of these clefts were bilateral, with complete detachment of the vomer. Morphologically, these clefts were similar to human clefts. Eighteen percent of clefted newborn kids demonstrated gross maxillary hypoplasia and midfacial retrusion at birth with a relative Class III malocclusion. Direct measurement of the congenital caprine skulls confirmed these findings. The incidence of midfacial growth abnormalities in these clefted animals raises questions regarding the etiopathogenesis of facial dysmorphology that is unrelated to scarring of the maxilla. This congenital cleft palate model is currently being used to explore these questions and others related to craniofacial growth and palatal function after in utero repair.

Hypoplasia of the latissimus dorsi muscle complicating breast reconstruction in Poland's syndrome.

Polands syndrome includes anomalies of the breast, thorax, and upper extremity. Unilateral hypoplasia of the breast and pectoral muscle are seen most frequently, and the resulting problem of breast reconstruction must be addressed. The latissimus dorsi myocutaneous flap is one of the most useful reconstructive tools in this situation. A case is presented of Polands syndrome with hypoplasia of the latissimus dorsi muscle-an abnormality not generally associated with Polands syndrome. The latissimus dorsi muscle should be carefully evaluated preoperatively in such patients, to make sure it is adequate for reconstructing the absent breast and pectoral muscle.

The fetal cleft palate: II. Scarless healing after in utero repair of a congenital model.

The role of fetal surgery in the treatment of non-life-threatening congenital anomalies remains a source of much debate. Before such undertakings can be justified, models must be established that closely resemble the respective human anomalies, and the feasibility and safety of these in utero procedures must be demonstrated. The authors recently described and characterized a congenital model of cleft palate in the goat. The present work demonstrates the methodology they developed to successfully repair these congenital cleft palates in utero, and it shows palatal healing and development after repair. A surgically created cleft model was developed for comparative purposes. Palatal shelf closure normally occurs at approximately day 38 of gestation in the caprine species. Six pregnant goats were gavaged twice daily during gestational days 32 to 41 (term, 145 days) with a plant slurry of Nicotiana glauca containing the piperidine alkaloid anabasine; the 12 fetuses had complete congenital clefts of the secondary palate. Repair of the congenital clefts was performed at 85 days of gestation using a modified von Langenbeck technique employing lateral relaxing incisions with elevation and midline approximation of full-thickness, bilateral, mucoperiosteal palatal flaps followed by single-layer closure. Six congenitally clefted fetuses underwent in utero repair, six remained as unrepaired controls. Twelve normal fetuses underwent surgical cleft creation by excision of a 20 x 3 mm full-thickness midline section of the secondary palate extending from the alveolus to the uvula, at 85 days of gestation. Six surgically clefted fetuses underwent concurrent repair of the cleft at that time; six clefted fetuses remained as unrepaired controls. At 2 weeks of age, no congenitally or surgically created clefts repaired in utero demonstrated gross or histologic evidence of scar formation. A slight indentation at the site of repair was the only remaining evidence of a cleft. At 6 months of age, normal palatal architecture, including that of mucosal, muscular, and glandular elements, was seen grossly and histologically. Cross-section through the mid-portion of the repaired congenitally clefted palates demonstrated reconstitution of a bilaminar palate, with distinct oral and nasal mucosal layers, after single-layer repair. In utero cleft palate repair is technically feasible and results in scarless healing of the mucoperiosteum and velum. The present work represents the first in utero repair of a congenital cleft palate model in any species. The use of a congenital cleft palate model that can be consistently reproduced with high predictability and little variation represents the ideal experimental situation. It provides an opportunity to manipulate specific variables, assess the influence of each change on the outcome and, subsequently, extrapolate such findings to the clinical arena with a greater degree of relevance.

Split-thickness plantar skin grafts for coverage in the hand and digits*

The instep of the foot is an excellent donor site for split-thickness skin grafts to cover soft tissue defects of the palm and digits. The technique is described and three illustrative clinical cases are presented. The unique, specialized characteristics of plantar skin are described, emphasizing similarities to palmar skin. The indications for this technique are hyperpigmentation, hair growth, ulceration, hyperkeratosis, marginal scarring, or recurrent breakdown of a preexisting graft, but we have also employed it for primary reconstructions in selected circumstances. The instep graft provides ideal color and texture match and long durability for a palmar graft, with the added advantage of an inconspicuous donor site.

A Method For The Evaluation Of Minor Degrees Of Breast Asymmetry

We have found the study of split-and-reversed photographs useful in the preoperative evaluation of patients presenting for corrective surgery of the breasts. It puts double emphasis on minor asymmetries, and can be used as an objective tool in planning procedures to correct these, and in evaluating the results. Asymmetry in volume is, however, less readily demonstrated by this technique than is asymmetry of shape.

Effect of ischemic skin flap elevation on tissue and plasma thromboxane A2 and prostacyclin production: modification by thromboxane synthetase inhibition.

The circulating prostaglandins have been implicated as mediators of microcirculatory derangements in skin and skin-muscle flaps. The study described here investigated the roles of thromboxane A2 and prostacyclin, measured as thromboxane B2 (TxB2) and prostaglandin 6-keto-F1a (PGF1a), in ischemic skin flaps, and the effects of thromboxane synthetase inhibition on flap blood flow and survival. A canine ventral island flap model was used to measure the appearance of TxB2 and PGF1a in the central arterial and venous plasma, and in the tissue and venous effluent of acutely raised flaps; with and without pretreatment with the specific thromboxane A2 synthetase inhibitor UK38485. Prostaglandin levels change significantly during flap elevation, and can be modified beneficially by thromboxane A2 synthetase inhibition, causing dramatic increases in flap blood flow and survival, as predicted by intravital dye penetration. The results presented in this article suggest that the manipulation of these compounds may provide a method of producing a pharmacological delay phenomenon and perhaps even allow effective intervention in the failing flap.

The Diabetic Foot: An Alternative Approach to Major Amputation

Of the complications of diabetes mellitus, none is more devastating than gangrene of the foot and the threat of leg amputation. The pathophysiology of vascular insufficiency, neurotrophic changes, and infection leading to this gangrene have been reviewed. Based on this pathophysiology, an approach for conservative surgery of the diabetic foot has been outlined. Using known principles of wound healing and the management of soft tissue infection, obviously necrotic or infected tissue is debrided and the wound managed conservatively. The use of debriding adjuncts such as the pulsating jet lavage, topical antibacterials, and biologic dressings are suggested to control the infection so that the wounds can be closed with either skin grafts or local flaps. This method can result in salvage of many feet and the maintenance of biped ambulation since the outlook for the diabetic with a major amputation is markedly different from the nondiabetic amputee.