Incorporation of Integra in tissue defects: a pilot study in the rat model.

Integra has been shown to be very useful in accelerating the growth of neodermis. It has found extensive use in case of burns as a primary dressing immediately after a burn, after release of contractures and following scar revision. It has been used to achieve cover after the debridement of extensive infective processes involving the skin. Encouraged by these results we have assessed the application of Integra to augment and/or patch defects of the urinary bladder, diaphragm and the abdominal wall in the rat model. This was a pilot study and involved the incorporation of Integra in the diaphragm, the urinary bladder (extramucosal) and the muscle layer of the abdominal wall. Eight adult Wistar rats were given general anaesthesia and Integra was implanted with absorbable sutures at the sites mentioned. The omentum was hitched to the collagen matrix surface to revascularise the graft. The silicone was left in situ. The operative period was covered with antibiotics. The anaesthesia was then reversed. Postoperatively the rats were given analgesia and feeds started immediately. The rats were sacrificed after 3 weeks. The abdominal cavity was examined for adhesions. The Integra implant along with adjacent tissue was harvested and examined histologically. There were no visible intra-abdominal adhesions. The histology revealed good degree of neovascularisation and fibrosis in and adjacent to the implant. This was comparable to the changes seen in the skin. This pilot study has shown that implanting Integra invokes a similar response in deeper tissues and it can develop neovascularisation from the omentum. Hence, this could find some application in treating congenital conditions such as diaphragmatic hernias, abdominal wall defects and for bladders requiring augmentation. Our initial results are quite encouraging and we feel that this field should be further explored.

Dose response relationship between adriamycin and birth defects in a rat model of VATER association.

BACKGROUND/PURPOSE: The aim of this study was to reproduce the animal model of esophageal atresia and the VATER association. The purpose was a dose response analysis of Adriamycin teratogenicity in the rat and comparison of these anomalies with the human VATER association. METHODS: Twenty time-mated Sprague-Dawley rats received intraperitoneal Adriamycin (dose range, 0 to 2.5 mg/kg/d) for 4 consecutive gestational days E6 to E9. The embryos were harvested on day E21, inspected, weighed, and dissected with a binocular dissecting microscope. Statistical analysis was performed with exact chi2. RESULTS: Threshold doses of 1.25 and 1.5 mg/kg/d Adriamycin produced renal and gastrointestinal anomalies, respectively (exact chi2, P < .00001). In doses below 1.25 mg/kg/d Adriamycin, no anomalies were seen, and in above-threshold doses, the frequency of anomalies rose sharply as the dose increased. At 2.25 mg/kg/d of Adriamycin all embryos were abnormal, and Adriamycin at 2.5 mg/kg/d led to resorption of all embryos. CONCLUSIONS: Adriamycin induced esophageal atresia, and VATER in the rat is a reproducible model that has many similarities to the VATER anomalies in the human. There is a relationship between dose and the frequency as well as severity of anomalies. Further studies of this model are likely to provide information relevant to the understanding of this human congenital disease.

Fine needle aspiration biopsy in children.

BACKGROUND: Fine needle biopsy (FNB) in children has been slow to gain acceptance compared with the use of the technique in adults where it is regarded as standard clinical practice in screening significant lymphadenopathy and suspicious masses. We report our early experience with FNB in the paediatric population. METHODS: Fifty-two biopsies were performed between June 1991 and June 1993. The age of the children ranged from 6 months to 14 years (median 2 years, mean 5 years). RESULTS: A definite diagnosis on cytology alone was obtained in 67%. The pathologist was certain of malignant or nonmalignant potential in 79% (67% benign and 12% malignant) and unsure in 21% (17% benign and 4% malignant). There were no false positive or false negative diagnoses of malignancy. Surgical excision or biopsy was performed in 33%. Fine needle biopsy assisted in planning surgery in 12%. Surgery was necessary for a definite diagnosis in 21% and FNB assisted 42% of the patients to avoid surgery altogether. CONCLUSIONS: Fine needle biopsy is simple, minimally invasive and useful in the evaluation of children with suspicious lymph nodes and masses.

Scar formation after breast-conserving surgery for cancer. Sir Charles Gairdner Hospital Breast Cancer Group.

A study of surgery for breast cancer was performed to examine the influence of haematoma formation and radiotherapy on the development of mammographically detected scars. Fifty-nine women undergoing lumpectomy and radiotherapy were studied. Sixteen had mammographic scars 12 months after surgery. There was a correlation between postoperative haematoma formation and scarring (P = 0.03) but not between tumour size and scarring. The type of radiation therapy did not influence scar formation.