Significant complications following minimally invasive office-based treatments for BPH: experience from a tertiary care center

Introduction: Minimally invasive treatments (MITs) for benign prostatic hypertrophy are effective treatments in properly selected patients. Despite being minimally invasive, significant complications can still arise. The objective of this study is to describe a tertiary care center experience with complications arising from MITs for benign prostatic hyper-trophy. Patients and Methods: A retrospective chart review was done from January 2007 to August 2008 to identify patients who developed stress incontinence or a urethral stricture after undergoing a MIT for benign prostatic hyper-trophy. Results: Three patients were identified as experiencing a complication. All 3 patients had undergone a prior transurethral microwave thermotherapy procedure at 9, 14, and 13 months prior to presentation. No patients had prior pelvic radiation, bladder or urethral trauma. No patients had prostate cancer. Patient ages were 61, 71, and 90 years. One patient developed a urethral stricture without incontinence. The other 2 patients developed both stress incontinence as well as urethral strictures. Conclusions: MITs for benign prostatic hypertrophy are effective treatments in properly selected patients. Despite being minimally invasive, significant complications can still arise. Proper training and good surgical technique are required to minimize and avoid complications

The management of genitourinary fistula in the third millennium

BACKGROUND: A vesicovaginal fistula (VVF) is an abnormal fistulous tract between the bladder and vagina, causing continuous loss of urine via the vagina. VVF is a relatively uncommon condition, but there is a drastically higher prevalence in the developing world. Furthermore, iatrogenic postoperative VVF is most common in developed countries, compared to mainly obstetric trauma in developing countries. In this review we focus on the development of current management techniques for VVF. METHODS: Medline was searched to identify articles related to urogenital fistulae, including VVF. Based on these reports we focus on the aetiology, clinical presentation, diagnosis and management of VVF. This in-depth review includes the optimal surgical timing, different surgical approaches (including minimally invasive techniques such as laparoscopic and robotic surgery), recommendations for postoperative care, surgical complications, and the need for further research in the use of robotic surgery to treat this condition. RESULTS: In all, 60 articles were identified and included in this review; eight were related to the aetiology, 12 to diagnosis, and 40 to the management of VVF. A thorough evaluation of VVF is imperative for planning the repair. Although the surgeonís experience typically influences the surgical approach, special situations will dictate the best approach. CONCLUSION: The treatment of genitourinary fistulae with robotic assistance continues to develop, but further research is necessary to fully understand the use of this technology

Multiscale Analysis of Fracture of Carbon Nanotubes Embedded in Composites

Abstract. Due to the enormous difference in the scales involved in correlating the macroscopic prop-erties with the micro- and nano-physical mechanisms of carbon nanotube-reinforced composites, mul-tiscale mechanics analysis is of considerable interest. A hybrid atomistic/continuum mechanics method is established in the present paper to study the deformation and fracture behaviors of carbon nanotu-bes (CNTs) in composites. The unit cell containing a CNT embedded in a matrix is divided in three regions, which are simulated by the atomic-potential method, the continuum method based on the modified Cauchy–Born rule, and the classical continuum mechanics, respectively. The effect of CNT interaction is taken into account via the Mori–Tanaka effective field method of micromechanics. This method not only can predict the formation of Stone–Wales (5-7-7-5) defects, but also simulate the subsequent deformation and fracture process of CNTs. It is found that the critical strain of defect nucleation in a CNT is sensitive to its chiral angle but not to its diameter. The critical strain of Stone–Wales defect formation of zigzag CNTs is nearly twice that of armchair CNTs. Due to the constraint effect of matrix, the CNTs embedded in a composite are easier to fracture in compari-son with those not embedded. With the increase in the Young’s modulus of the matrix, the critical breaking strain of CNTs decreases