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Stephen D W Beck

Publications and source records attributed to Stephen D W Beck.

4 recordsLinked to original sources
PubMed2002

Multilayered small intestinal submucosa is inferior to autologous bowel for laparoscopic bladder augmentation.

PURPOSE: Bladder augmentation is most commonly performed with ileum. However, porcine small intestinal submucosa has been reported as a substitute for bowel for incorporation into the urinary tract. We assessed the feasibility and long-term 12-month results of laparoscopic bladder augmentation with ileum or multilayered small intestinal submucosa (Cook Biotech, Spencer, Indiana) in a porcine model. MATERIALS AND METHODS: We performed laparoscopically assisted hemicystectomy and bladder augmentation in 24 female Yucatan mini-pigs using an ileal segment (12) or multilayered small intestinal submucosa (12). The followup protocol included anesthetic bladder capacity, renal ultrasonography and serum chemistry. At 3, 6 and 12 months, respectively, 4 animals per group were scheduled for sacrifice and pathological analysis. RESULTS: Despite longer anastomotic time in the multilayered small intestinal submucosa group (120 versus 91 minutes, p = 0.026) total operative time was similar in the 2 groups. In each group bladder capacity increased with time but by 12 months bladder capacity was significantly better in the bowel than in the small intestinal submucosa group (825 versus 431 cc, p = 0.016). At 3 months pathological evaluation revealed that the multilayered regenerated bladder patch had shrunken and by 6 months it was replaced by dense calcified scar tissue. Long-term 6 and 12-month bladder capacity in the small intestinal submucosa group was the result of the regeneration of native bladder with exclusion of the whole multilayered patch in the majority of cases. CONCLUSIONS: Laparoscopic bladder augmentation using multilayered small intestinal submucosa produced functional and pathological results inferior to those of bowel at 12-month followup in a porcine model.

Animals↗
PubMed2002

Teratoma in the orchiectomy specimen and volume of metastasis are predictors of retroperitoneal teratoma in post-chemotherapy nonseminomatous testis cancer.

PURPOSE: Patients who require post-chemotherapy retroperitoneal lymph node dissection after induction chemotherapy for metastatic testis cancer derive therapeutic benefit from resection of teratoma but resection of necrosis is not beneficial. We determine if the absence of teratoma in the orchiectomy specimen is a reliable predictor of the absence of teratoma in the retroperitoneum at post-chemotherapy retroperitoneal lymph node dissection. MATERIALS AND METHODS: A retrospective review of the Indiana University testis cancer data base was performed. A total of 644 patients who underwent retroperitoneal lymph node dissection after induction chemotherapy only were selected for study. The presence or absence of teratoma in the orchiectomy specimen and volume of retroperitoneal tumor were analyzed as predictors of retroperitoneal teratoma at post-chemotherapy retroperitoneal lymph node dissection. RESULTS: Of the patients with teratoma in the orchiectomy specimen 85.6% had an element of teratoma in the retroperitoneum, and of those without teratomatous elements in the orchiectomy specimen 48% had teratoma in the retroperitoneum (p <0.00001). Increasing volumes of retroperitoneal tumor were associated with a higher probability of discovering teratoma at post-chemotherapy retroperitoneal lymph node dissection. CONCLUSIONS: The absence of teratoma in the orchiectomy specimen does not reliably predict the absence of teratoma in the surgical specimen at post-chemotherapy retroperitoneal lymph node dissection. Post-chemotherapy surgery is indicated if retroperitoneal tumor remains after chemotherapy irrespective of the presence or absence of teratoma in the orchiectomy specimen.

Chemotherapy, Adjuvant↗
PubMed2002

Endoloop-assisted laparoscopic partial nephrectomy.

PURPOSE: To determine the safety and feasibility of Endoloop-assisted laparoscopic partial nephrectomy in a large-animal model. MATERIALS AND METHODS: Twelve female Yucatan mini-pigs underwent either left (N = 6) or right (N = 6) transperitoneal laparoscopic lower-pole nephrectomy following cinching of a 1-0 Vicryl suture loop (Endoloop) proximal to the resected lower pole until ischemic discoloration was achieved. The ischemic lower pole was excised with Endo-scissors and the lower pole removed using a laparoscopic bag. Follow-up involved evaluation under anesthesia with retrograde pyelography and intravenous urography and subsequent sacrifice for pathologic evaluation at 3 (N = 4), 14 (N = 4), or 60 (N = 4) days. RESULTS: All procedures were completed successfully. In two cases, the Endoloop slipped off the retained parenchyma. Both problems were corrected immediately with no sequelae. At sacrifice, all upper-pole renal segments functioned, as shown by urography, and no urinomas or abscesses were found. In one animal, there was moderate hydronephrosis presumably secondary to ureteral scarring, and in another, mild extravasation was demonstrated on the retrograde pyelogram. CONCLUSION: We were able to perform laparoscopic partial nephrectomy with the Endoloop safely and effectively in the current model. Modification of the Endoloop to allow more controlled pressure application may allow clinical application of this method for polar laparoscopic partial nephrectomy.

Animals↗