Transvenous renal biopsy in an ex vivo swine kidney model: a comparison of five devices.

PURPOSE: To compare the efficacy of end-cut and side-cut devices in transvenous renal biopsies of ex vivo swine kidneys and to examine the use of the swine kidney as an animal model in this setting. MATERIALS AND METHODS: Biopsy specimens of ex vivo swine kidneys were obtained after selective renal vein cannulation with use of five separate biopsy devices (Quick-Core 16 gauge and 18 gauge, Colapinto 16 gauge, Mansfield biopsy forceps, Flexi-Temno 16 gauge). Biopsy specimens were defined as the material obtained from three separate passes at a given site, with 30 biopsy specimens obtained per device. Capsular perforation was examined for each pass. A blinded pathologist recorded the presence of tissue and the number of glomeruli present for each pass. A diagnostic biopsy was defined as six or more glomeruli obtained. RESULTS: The median number of glomeruli obtained for each device per biopsy was Colapinto 0.0 (range, 0-13), Mansfield 0.0 (range, 0-19), Flexi-Temno 2.0 (range, 0-13), 18-gauge Quick-Core 8.5 (range, 0-30), and 16-gauge Quick-Core 16.0 (range, 0-52). The Quick-Core 16-gauge and 18-gauge devices obtained diagnostically adequate biopsy specimens 83% and 77% of the time, respectively, compared to 20% or less for the other devices. CONCLUSION: The Quick-Core 16-gauge and 18-gauge side-cut biopsy devices are the most efficacious for obtaining diagnostic quality biopsy specimens in the ex vivo swine kidney model.

Chondroblastoma of the foot.

A total of 322 cases of chondroblastoma were referred to the Armed Forces Institute of Pathology between 1960 and 1990. Ten additional cases of chondroblastoma were treated at Walter Reed Army Medical Center between 1985 and 1993. Forty-two of these involved the foot, two of which were treated at Walter Reed Army Medical Center. Patients with chondroblastoma of the foot were male in 35 (81%) cases, with a mean age of 25.5 years, which was significantly different from the mean age of 17.3 years in patients with chondroblastoma of the long bones (P < 0.0001). Chondroblastoma of the foot is most commonly found in the posterior subchondral areas of the talus and calcaneus as well as in the calcaneal apophysis. Radiographically, the lesion was associated with an articular surface or apophyseal area in all cases and appeared radiolucent, with little to no matrix production. The margins were generally well defined. Cystic features were noted grossly and histologically in 24 (57%) specimens, a feature seen in only 21% of all chondroblastomas overall. Treatment consists of thorough curetting and bone grafting with good oncologic and functional results.