Kidney Stones

Reviewing the Literature

RIU0282_08-12.qxd 8/12/06 3:08 PM Page 170 Kidney Stones continued to 6 weekly double-blinded intravesical instillations of either BCG or placebo and followed for a total of 34 weeks. The response rate for the primary outcome (patient-reported global response questionnaire) was 12% for placebo and 21% for BCG (P
.06). The BCG safety profile in IC patients was acceptable. Unfortunately the response rate was low, and this modality of therapy could not be recommended for general use in IC patients. Intravesical Resiniferatoxin for the Treatment of Interstitial Cystitis: A Randomized, DoubleBlind, Placebo Controlled Trial Payne CK, Mosbaugh PG, Forrest JB, et al. J Urol. 2005;173:1590-1594. Interest in using vanilloid compounds for intravesical therapy in IC is based on mechanisms of pain development (C-fiber hypersensitivity) and evidence from a number of clinical pilot studies. RTX is an ultra-potent analogue of capsaicin that is believed to be safer and more effective (in terms of desensitizing bladder afferents). An ICOS-funded multicenter study group performed a randomized, doubleblind, placebo-controlled study in 163 IC patients to determine the safety and efficacy (primary outcome measured was the Global Response Assessment, similar to the outcome tool used in the BCG trial) of various doses of intravesical RTX compared with placebo. RTX did not improve overall symptoms, pain, urgency, frequency, nocturia, or average void volume during 12 weeks’ follow-up. This study demonstrated that a single administration of RTX was not effective in patients with IC. Effective therapy for IC remains elusive. Studies funded by the National Institutes of Health that are presently enrolling patients include evaluation of neuromodulation (amitriptyline) in early-diagnosed disease, immunomodulation (mycophenolate mofetil HCl [CellCept]) in late treatment-refractory disease, physical therapy, and psychosocial intervention. Kidney Stones educing urinary oxalate excretion in calcium oxalate stone formers with enteric hyperoxaluria might be difficult to accomplish. Dietary modifications, such as reduced fat and oxalate consumption, have been combined with the administration of calcium supplements and bile sequestrants like cholestyramine. However, patients might not be compliant with such regimens, and even if so, outcomes might not always be effective. R Use of a Probiotic to Decrease Hyperoxaluria Lieske JC, Goldfarb DS, De Simone C, Regner C. Kidney Int. 2005;68:1244-1249. Lieske and colleagues performed a study in which a lactic acid bacterial preparation, Oxadrop (Seaford Pharmaceuticals, Mississauga, Ontario, Canada), was administered on a daily basis for 3 months in 10 calcium oxalate stone formers with enteric hyperoxaluria due to a variety of gastrointestinal disorders causing chronic fat malabsorption. The dose of this probiotic preparation was increased each month. Twenty-four urine specimens were collected before the intervention, during each month of the intervention, and 1 month later. Mean oxalate excretion decreased by 19% at 1 month, 24% at 2 months, and returned to near baseline level at 3 months. A reduction in the supersaturation of calcium oxalate also occurred. There were no adverse events. The administration of this probiotic preparation promoted a reduction in urinary oxalate excretion and supersaturation of calcium oxalate in a group of stone formers afflicted with enteric hyperoxaluria. More than 50% of the urinary oxalate pool is derived from dietary sources. Therefore, gastrointestinal oxalate absorption has a profound influence on urinary oxalate excretion and consequently calcium oxalate supersaturation. Patients with enteric hyperoxaluria absorb oxalate more readily, and the aforementioned measures have been A lactic acid bacterial preparation was administered on a daily basis for 3 months in 10 calcium oxalate stone formers with enteric hyperoxaluria. Probiotic Therapy for Hyperoxaluria Reviewed by Dean G. Assimos, MD Department of Urology, Wake Forest University School of Medicine, Winston-Salem, NC [Rev Urol. 2006;8(3):170-171] © 2006 MedReviews, LLC 170 VOL. 8 NO. 3 2006 REVIEWS IN UROLOGY used to attenuate this response. The results of this study suggest that probiotic therapy might have beneficial effects in this group of patients. However, a number of issues need to be considered. First, the reduction in urinary oxalate excretion was only modest. Second, dietary RIU0282_08-12.qxd 8/12/06 3:08 PM Page 171 Fertility oxalate intake was not tightly controlled: the patients were only instructed to reduce the consumption of foods containing high levels of oxalate. Third, the highest dose did not result in a reduction of oxalate excretion. The latter might be due to these bacteria having an impact on oxalate-degrading bacteria already residing in the fecal flora, such as Oxalobacter formigenes. Nevertheless, these results are encouraging, and more carefully designed studies are needed to determine the efficacy of probiotic therapy for this patient group and other types of hyperoxaluria. Preliminary reports suggest that those with other types of hyperoxaluria might benefit from probiotic therapy. Campieri and colleagues1 previously demonstrated that the administration of Oxadrop to calcium oxalate stone formers with idiopathic hyperoxaluria produced a significant reduction in oxalate excretion. Hoppe and associates2 reported that the administration of an Oxalobacter formigenes preparation to a small group of patients with primary hyperoxaluria resulted in a significant reduction in oxalate excretion in some individuals. the probability of finding sperm in NOA patients. These samplings can be done by 2 methods: 1) TESE (testicular sperm extraction), which is actually a surgical biopsy of the testis; or 2) TESA (testicular sperm aspiration), which is performed by sticking a needle in the testis and aspirating fluid and tissue with negative pressure. Sperm extraction is being performed more and more by non-urologists (called andrologists) who are actually either internists or obstetrician-gynecologists. It stands to reason that these non-urologists prefer TESA, given that they are not surgically trained. There has always been debate, however, as to which procedure is “better” at obtaining sperm for successful intracytoplasmic sperm injection. Comparison of Efficacy of Two Techniques for Testicular Sperm Retrieval in Nonobstructive Azoospermia: Multifocal Testicular Sperm Extraction Versus Multifocal Testicular Sperm Aspiration Hauser R, Yogev L, Paz G, et al. J Androl. 2006;27:28-33. References 1. 2. Campieri C, Campieri M, Bertuzzi V, et al. Reduction of oxaluria after an oral dose of lactic acid bacteria at high concentration. Kidney Int. 2001;68: 1097-1105. Hoppe B, von Unruh G, Laube N, et al. Oxalate degrading bacteria: new treatment option for patients with primary and secondary hyperoxaluria. Urol Res. 2005;33:372-375. To better answer this dilemma, Hauser and colleagues from Tel Aviv, Israel, compared the results of TESE with The investigators found that TESE was markedly superior to TESA at obtaining sperm and in terms of the quantity and subsequent motility of the sperm found. Fertility TESA or TESE: Which Is Better for Sperm Extraction? Reviewed by Jacob Rajfer, MD Department of Urology, The David Geffen School of Medicine at UCLA, Los Angeles, and Division of Urology, Harbor-UCLA Medical Center, Torrence, CA [Rev Urol. 2006;8(3):171-172] © 2006 MedReviews, LLC any azoospermic patients with nonobstructive azoospermia (NOA) might be candidates for sperm aspiration as part of their in vitro fertilization procedure. Because sperm might be present in some but not all parts of the testes of such men, multiple samplings of the testicular tissue are usually performed to increase M those from TESA in the same testis of NOA patients. Three samples by TESE and by TESA were taken in each testis, and the results were compared. The investigators found that TESE was markedly superior to TESA at obtaining sperm and in terms of the quantity and subsequent motility of the sperm found. This meant that there was a better chance of cryopreservation of sperm obtained by TESE rather than TESA. The import of this is that such cryopreserved sperm can be used in subsequent cycles rather than the patient having to go through another TESE or TESA procedure. One of the “complaints” about TESE by non-urologists is that general anesthesia is necessary for such a procedure. This is not necessarily true: it can be done safely and comfortably with a cord block, as we perform it at the University of California, Los Angeles. Therefore, according to Hauser and colleagues’ data, it seems that TESE is the preferred method of sperm aspiration in men with NOA. VOL. 8 NO. 3 2006 REVIEWS IN UROLOGY 171