Perforator flaps: evolution,classification, and applications

In this article, the authors review the literature regarding perforator flaps. Musculocutaneous perforator flaps have evolved from musculocutaneous flaps and offer several distinct advantages. By sparing muscle tissue, thus reducing donor site morbidity and functional loss, perforator flaps are indicated for a number of clinical problems. The versatility of the perforator flap makes it ideal for the reconstruction of three-dimensional defects such as breast reconstruction or as a thin flap for resurfacing shallow wounds when bulk is considered a disadvantage. The authors review the historical development of the perforator flap and discuss the advantages and disadvantages of perforator flaps compared with free and pedicled musculocutaneous flaps. The nomenclature traditionally used for perforator flaps is confusing and lacks a standardized anatomic basis. The authors present a method to describe all perforator flaps according to their artery of origin.     

Development and validation of new model for microvascular transplantation of epiphyseal plate allografts with minimal adjoining epiphyseal and metaphyseal bone

A model for the free allograft microvascular transplantation of rabbit proximal tibial epiphyseal plate allografts was developed, validated, and tested in an in vivo animal model. Transplants contained the minimum amount of adjacent epiphyseal and metaphyseal bone compatible with preservation of the epiphyseal-plate vascular supply, as determined by corrosion casting. Perfusion to this graft was evaluated quantitatively using radioactive microspheres, and qualitatively using India-ink injection. Female New Zealand White rabbits at 12 weeks of age were utilized. Vascularized transplantation of epiphyseal plate allografts was performed either into a defect of matched size in the iliac crest or into a soft-tissue pocket without bone contact. Cyclosporine A immunosuppression (CSA) was administered daily for 6 weeks. Two control groups underwent identical surgical procedures, but had no postoperative immunosuppression. Epiphyseal plates both with and without bone contact, in rabbits immunosuppressed postoperatively with CSA, demonstrated longitudinal growth and preserved viability as determined by positive bromodeoxyuridine uptake. Control epiphyseal plates transferred without postoperative immunosuppression were uniformly nonviable. This new model has value as a basis for further studies into the clinical applicability of isolated epiphyseal-plate transplants.     

Role of thrombolysis in free-flap salvage

Approximately 5 percent of microvascular free-tissue transfers fail; often this is due to microvascular or peri-anastomotic thrombosis. Various reports have advocated the use of thrombolytics for salvage of these flaps, although clinical evidence supporting this approach is sparse. The authors attempted to review their own and other published results and present an algorithm for the use of thrombolytics in the management of failing free flaps. A retrospective review of 590 free flaps, revealed 71 (12 percent) requiring re-exploration for impending flap failure, determined by standard clinical indicators. Forty-four (62 percent) were found to have pedicle thrombosis and 20 (28 percent) received thrombolysis with streptokinase or urokinase. All 44 flaps were grouped by final outcome and thrombolytic use for comparison. In 24 (55 percent) of the flaps with evidence of thrombosis, the use of thrombolytics was felt to be inappropriate or unnecessary; 13 (54 percent) of these were salvaged. Twenty flaps, however, did receive thrombolysis and 6 (30 percent) of these were salvaged. There was no statistically significant difference among groups with respect to preoperative risk factors, age, gender, flap type, and site of anastomotic thrombosis. There was a twofold higher use of vein grafts in the failed vs. salvaged flaps (36 percent vs. 15.7 percent), and no flaps with vessel grafts were salvaged with thrombolytics. Despite the fact that all flaps were re-explored within 3 hr of a problem being detected, the mean time from the initial operation to re-exploration was significantly higher in flaps that did not respond to thrombolytics (63. 8 vs. 32.8 hr, respectively, p=0.0457). Also, the mean time to re-exploration was significantly higher in the salvaged flaps receiving thrombolysis vs. those that did not (32.8 vs. 22.3 hr, respectively, p=0.0264). While early detection and re-exploration are crucial for salvaging failing free flaps, those flaps unresponsive to other standard interventions may benefit from the selective use of thrombolytics.     

Validation and reproducibility of computerised cell-viability analysis of tissue slices

Background

The identification of live cells using membrane integrity dyes has become a frequently used technique, especially with articular cartilage and chondrocytes in situ where tissue slices are used to assess cell recovery as a function of location. The development of a reproducible computerised method of cell evaluation would eliminate many variables associated with manual counting and significantly reduce the amount of time required to evaluate experimental results.

Methods

To validate a custom computerised counting program, intra-person and inter-person cell counts of nine human evaluators (three groups – unskilled, novice, and experienced) were compared with repeated pixel counts of the custom program on 15 digitised images (in triplicate) of chondrocytes in situ stained with fluorescent dyes.

Results

Results indicated increased reproducibility with increased experience within evaluators [Intraclass Correlation Coefficient (ICC) range = 0.67 (unskilled) to 0.99 (experienced)] and between evaluators [ICC = 0.47 (unskilled), 0.85 (novice), 0.93 (experienced)]. The computer program had perfect reproducibility (ICC = 1.0). There was a significant relationship between the average of the experienced evaluators results and the custom program results (ICC = 0.77).

Conclusions

This study demonstrated that increased experience in cell counting resulted in increased reproducibility both within and between human evaluators but confirmed that the computer program was the most reproducible. There was a good correlation between the intact cell recovery determined by the computer program and the experienced human evaluators. The results of this study showed that the computer counting program was a reproducible tool to evaluate intact cell recovery after use of membrane integrity dyes on chondrocytes in situ. This and the significant decrease in the time used to count the cells by the computer program advocate its use in future studies because it has significant advantages.

     

Resurfacing of the nasopharynx after nasopharyngectomy using a free radial forearm flap

BACKGROUND: Nasopharyngectomy is emerging as an important treatment option for salvaging locally recurrent nasopharyngeal carcinoma (NPC). After nasopharyngectomy, resurfacing the nasopharynx and covering the internal carotid artery is important to minimize the risk of infection, osteoradionecrosis, and carotid rupture. Previous authors have advocated the use of free grafts of skin and mucosa for this purpose but have also described significant rates of partial and total graft failure. METHODS: We believe that the best and most reliable way to resurface the nasopharynx is with vascularized tissue, and our preference is for the use of a free radial forearm flap. To illustrate our approach, we present two patients who underwent nasopharyngectomy by means of a maxillary swing approach and who had resurfacing of the surgical defect with a free radial forearm flap. RESULTS: Both patients had complete en bloc resection of tumor followed by the insetting of a free radial forearm flap to reline the surgical defect. Both flaps remained completely viable, and both patients achieved successful resurfacing of the entire nasopharynx. The morbidity of surgery was minimal, and there were no perioperative complications. On assessment 1 year later, the free radial forearm flap continues to reline the entire neonasopharynx, and the long-term functional recovery after surgery is excellent. CONCLUSION: Resurfacing the nasopharynx after nasopharyngectomy with a free radial forearm flap aids healing and minimizes the risk of complications. The morbidity of surgery is minimal and the functional recovery is excellent.     

Epidermal cyst of the breast: Detection in a screening programme

Two cases of epidermal cyst of the breast, a rare benign condition, were detected during a 3-year period in a mammographic screening programme, from 57 954 screening examinations. It is not uncommon for epidermal cysts to be initially misdiagnosed. The mammographic, ultrasound and histological features are presented. It is recommended that these lesions be resected because they possibly have malignant potential.     

Family factors affecting child development.

In a large, geographically defined population of children a number of family factors in addition to social class, determined by the father''s occupation, were recorded by health visitors and school nurses with routine responsibility for these children. The quality of the children in normal schools was assessed in terms of nonverbal IQ and height at the ages of 5 and 10 years, and of behavior as reported by the teacher at the age of 10 years. By analysis of variance the sum of the independent effects of the other family factors greatly outweighed that of occupational social class, except in the case of the IQ at 10 years. The most important of the other family factors was the quality of the mother''s care of her child during the first 3 years of life.