Tobias S. Köhler
Mayo Clinic
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Featured researches published by Tobias S. Köhler.
Journal of Assisted Reproduction and Genetics | 2011
Tobias S. Köhler; Laxmi A. Kondapalli; Amul Shah; Sarah Chan; Teresa K. Woodruff; Robert E. Brannigan
PurposeDiminished reproductive capacity is a devastating consequence of life-sparing therapies for childhood malignancy. In 2006, the American Society of Clinical Oncology (ASCO) published fertility preservation recommendations (ASCOR) emphasizing the importance of early discussion and intervention for fertility preservation strategies. Using the Survey for Preservation of Adolescent REproduction (SPARE), we sought to determine fertility preservation attitudes and practice patterns post-ASCOR from pediatric oncology specialists nationwide.Materials and methodsThe SPARE survey consists of 22 questions assessing pediatric oncology specialists’ attitudes and practice patterns toward fertility preservation. Broad perspectives on fertility preservation, including a willingness to discuss fertility, knowledge of current fertility preservation methods and awareness of ASCOR, were assessed.ResultsThe majority of respondents acknowledged that fertility threats are a major concern for them and agreed that all pubertal cancer patients should be offered a fertility consultation, but only 46% reported they refer male pubertal cancer patients to a fertility specialist prior to cancer treatment >50% of the time, and only 12% reported they refer female pubertal cancer patients to a fertility specialist prior to cancer treatment > 50% of the time. While 44% of respondents were familiar with the 2006 ASCOR, only 39% of those utilized them to guide decision-making in greater than half of their patients.ConclusionOur study demonstrates pediatric oncologists’ motivation to preserve fertility in pediatric cancer patients; however, barriers to both gamete cryopreservation and referral to fertility specialists persist. Female pubertal patients are referred to fertility preservation specialists with much less frequency than are male pubertal patients, highlighting a disparity.
European Urology | 2009
Tobias S. Köhler; Kevin T. McVary
CONTEXT The relationship between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) and the potential interplay of phosphodiesterase type 5 inhibitors (PDE5-I) have clinical implications for both patient screening and treatment. OBJECTIVE To describe the current literature assessing the LUTS-ED relationship and the role of PDE5-I from both a basic science and clinical intervention perspective. EVIDENCE ACQUISITION We focused on data recently published (1990-2008) describing epidemiologic and mechanistic manuscripts of the LUTS-ED relationship with emphasis on papers involving PDE5-I-particularly those using level 1 evidence clinical trials. Base key words used included BPH, LUTS, ED, and phosphodiesterase inhibitors in combination with such secondary key words as nitric oxide, autonomic hyperactivity, Rho-kinase, atherosclerosis, and mechanism. We abstracted >200 articles and reviewed >100. EVIDENCE SYNTHESIS The large overlap of elderly men with both LUTS and ED likely stems from a cause-and-effect relationship. Thus far, four proposed mechanisms attempt to explain the relationship between LUTS and ED. Multiple studies showing that PDE5-I improved LUTS have been performed. Understanding the role of PDE5-I in the LUTS and ED relationship affects patient screening and treatment but also raises further research questions. CONCLUSIONS The future use of phosphodiesterase inhibitors as either prophylaxis or as a primary treatment for LUTS looms as a possibility and may not be limited to men.
Journal of the American College of Cardiology | 2012
Jason H. Rogers; Irwin Goldstein; David E. Kandzari; Tobias S. Köhler; Curtiss T. Stinis; Paula J. Wagner; Jeffrey J. Popma; Michael R. Jaff; Krishna J. Rocha-Singh
OBJECTIVES This study sought to evaluate the safety and feasibility of zotarolimus-eluting stent implantation in focal atherosclerotic lesions of the internal pudendal arteries among men with erectile dysfunction (ED) and a suboptimal response to phosphodiesterase-5 inhibitors. BACKGROUND ED, a common condition, is often mediated by atherosclerosis. Current treatment options are limited. METHODS Male subjects with atherosclerotic ED and a suboptimal response to phosphodiesterase-5 inhibitors were enrolled in this prospective, multicenter, single-armed safety and feasibility trial. A novel combination of clinical, duplex ultrasound, and invasive angiographic factors were used to determine eligibility for stent therapy. The primary safety endpoint was any major adverse event 30 days after the procedure. The primary feasibility end point was improvement in the International Index of Erectile Function (Erectile Dysfunction Domain) score ≥ 4 points in ≥ 50% of subjects at 3 months. We report 6-month follow-up results, including duplex ultrasound and angiography. RESULTS Forty-five lesions were treated with stents in 30 subjects. Procedural success was 100% with no major adverse events through follow-up. The primary feasibility endpoint at 6 months was achieved by 59.3% of intention-to-treat subjects (95% confidence interval: 38.8% to 77.6%) and 69.6% of per-protocol subjects (95% confidence interval: 47.1% to 86.8%). Duplex ultrasound peak systolic velocity of the cavernosal arteries increased from baseline by 14.4 ± 10.7 cm/s at 30 days and 22.5 ± 23.7 cm/s at 6 months. Angiographic binary restenosis (≥ 50% lumen diameter stenosis) was reported in 11 (34.4%) of 32 lesions. CONCLUSIONS Among patients with ED and limited response with pharmacologic therapy, percutaneous stent revascularization of the internal pudendal artery is feasible and is associated with clinically meaningful improvement in both subjective and objective measures of erectile function.
The Journal of Urology | 2012
Kunj R. Sheth; Vidit Sharma; Brian T. Helfand; John Cashy; Kristin Smith; Jason C. Hedges; Tobias S. Köhler; Teresa K. Woodruff; Robert E. Brannigan
PURPOSE Survival to reproductive age among men with cancer has steadily increased and yet cancer therapy and cancer itself may carry the risk of infertility. Since 2006, we have used a formalized fertility preservation program with expedited fertility care at our institution. We assessed the impact of this program by comparing the frequency of sperm cryopreservation and patient characteristics before and after its implementation. MATERIALS AND METHODS Men 18 to 55 years old diagnosed with cancer at our institution from 2002 to 2010 were included in our study. We retrospectively reviewed patient charts to identify those who were offered and subsequently used fertility preservation services before and after program formalization. RESULTS From 2002 to 2010 at our institution 4,818 men 18 to 55 years old were diagnosed with cancer, of whom 411 were offered fertility preservation consultation and 249 underwent sperm cryopreservation. Since program implementation, the annual number of men receiving fertility preservation consultation and undergoing sperm cryopreservation increased by 2.4 and 2.7-fold, respectively, while the total number diagnosed with cancer remained fairly constant. Upon substratifying patients into the more conventional reproductive age range of 18 to 40 years 23.4% of all men with cancer in this group were offered consultation before formalization vs 43.3% after formalization (p <0.05). The overall sperm use and discard rates were 8.4% and 14.8%, respectively. CONCLUSIONS A formalized institutional fertility preservation program significantly increased the overall number and percent of male patients with cancer who received fertility preservation consultation and pursued sperm cryopreservation. These increases were seen in men with all types of cancer and across all demographics assessed at our institution.
The Journal of Sexual Medicine | 2016
Laurence A. Levine; Edgardo Becher; Anthony J Bella; William O. Brant; Tobias S. Köhler; Juan I. Martínez-Salamanca; Landon Trost; Allen F. Morey
INTRODUCTION Penile prosthesis implantation has emerged as a definitive treatment to restore sexual function to the motivated man with erectile dysfunction. Substantial improvements in the design of inflatable devices have been made since they first became available more than four decades ago. AIM To review the history of the penile prosthesis, the indications, preoperative evaluation, and patient and partner satisfaction. The current approaches to addressing intra- and postoperative complications, provide an understanding of prosthesis infection, and placement of these devices will be reviewed. METHODS A committee of worldwide experts in this field was assembled during the 2015 International Consultation on Sexual Medicine (ICSM) and performed a systematic review of the peer-reviewed published medical literature pertaining to penile prosthesis. Particular attention was given to higher level trials when available. Recommendations are based upon the Oxford Criteria. MAIN OUTCOME MEASURES Unfortunately there is limited level 1 and 2 evidence, and where expert opinion was utilized, the decision was unanimous within the committee with a goal of presenting a clinically relevant guideline pertaining to penile prostheses. RESULTS Penile prosthesis has undergone an evolution over the past 40 years resulting in a more effective and reliable treatment for advanced erectile dysfunction not responding to less invasive methods including oral treatment with PDE5 inhibitors, vacuum erection device, and intracorporal injection therapy. It should be considered an appropriate treatment option for the man who wishes to restore erectile function and who understands the potential risk of mechanical failure and infection, both of which are less common now as a result of improvements made in device design as well as surgical protocols adhered to in the operating room. Patients must be clearly informed of the risks associated with penile prosthesis including mechanical failure, infection, shortening of the penis, change in sensation and configuration of the penis, as well as injury to local structures. Intraoperative complications are unusual but do occur and can usually be addressed intraoperatively to allow placement of the device at the time of initial surgery. Postoperative complications may also be addressed when they occur but may require more advanced reconstructive surgical techniques. Men with Peyronies disease, corporal fibrosis due to infection, trauma, prior prosthesis explantation, priapism, and men who have undergone construction of a neophallus may require additional advanced maneuvers to obtain optimum results with a penile prosthesis. CONCLUSION Penile prosthesis remains as an important, viable, and effective treatment for male erectile dysfunction that does not respond to other less invasive approaches or when these approaches are contraindicated or not acceptable to the patient. These devices provide the patient with the ability to engage in penetrative sexual activity without interfering with urination, ejaculation, sensation, or orgasm. Although mechanical failure can occur, the current devices are more reliable as a result of design modifications. Infection remains the most dreaded complication but since the introduction of antibiotic and hydrophilic coatings, infection is less common. Overall, patient and partner satisfaction appear to be reasonably high when a penile prosthesis is used to restore erectile function.
The Journal of Sexual Medicine | 2009
Tobias S. Köhler; Joshua K. Modder; James M. Dupree; Nicol C. Bush; Kevin T. McVary
INTRODUCTION Managing isolated scrotal pump erosion or infection in patients with inflatable penile prosthesis (IPP) is a challenging problem. We describe our malleable implant substitution technique to address this problem. AIM The aim of this study was to describe and assess the outcomes of the malleable implant substitution technique. METHODS In this retrospective case series, six patients underwent removal of the infected and/or eroded scrotal pump, and replacement of the entire IPP with a malleable prosthesis. This procedure was only performed in men in the absence of penile pain on palpation or overwhelming sepsis. The procedure utilized components of the Mulcahy washout protocol with loose scrotal wound approximation and drains as necessary. MAIN OUTCOME MEASURES The main outcome is a recurrent infection rate and prosthesis functionality of the malleable implant substitution technique. RESULTS All six men who underwent the procedure have done well and remain infection-free. Two men have undergone conversion from a malleable prosthesis back to IPP. Three are considering conversion to an IPP as they are satisfied with their current malleable prosthesis function. One man had a distal erosion of the malleable prosthesis that necessitated complete removal. CONCLUSIONS We believe the malleable implant substitution technique provides an excellent option for management of isolated scrotal pump erosion or infection and prevents the problems associated with the other common management strategies.
Urology | 2013
Jeremy T. Choy; H. Joseph Wiser; Stephen W. Bell; John Cashy; Robert E. Brannigan; Tobias S. Köhler
OBJECTIVE To evaluate the presence of spermatogenesis in orchiectomy specimens of patients with testicular cancer to determine possible predictors of success with oncologic testicular sperm extraction of the cancerous testis at orchiectomy. MATERIALS AND METHODS We retrospectively reviewed the pathology reports and slides from 83 men who underwent radical orchiectomy for testicular cancer at 2 institutions from 1999 to 2010. The presence or absence of spermatogenesis in each specimen was determined. Data on tumor histopathologic type, serum tumor markers, and tumor size were also obtained and analyzed to detect any associations with the presence of spermatogenesis. RESULTS The 83 specimens included 41 pure seminomas, 36 nonseminomatous and mixed germ cell tumors, and 6 benign lesions. Overall, spermatogenesis was detected in 48 of 77 (62%) cancerous specimens. Spermatogenesis was present in 22 of 41 (54%) pure seminomas and 26 of 36 (72%) nonseminomatous and mixed germ cell tumors, with no significant difference found between the 2 subtypes (P = .11). No association was found between tumor marker levels and the presence of spermatogenesis. A logistic regression model revealed a statistically significant inverse relationship between tumor size and spermatogenesis presence (P = .004). CONCLUSION At orchiectomy, most cancerous testes contained active spermatogenesis and, thus, represent a viable source for sperm cryopreservation with oncologic testicular sperm extraction. A small tumor size proved to be a positive prognostic indicator for the presence of spermatogenesis, although a larger tumor size did not preclude the presence of spermatogenesis.
Urologic Clinics of North America | 2009
Tobias S. Köhler; Anees Fazili; Robert E. Brannigan
Vasectomy is widely regarded as a safe method of contraception, but over the years there have been many reports suggesting putative health risks associated with the procedure. Concerns over the possible association of vasectomy with a number of medical conditions, including cardiovascular disease, testicular cancer, prostate cancer, psychologic distress, and a variety of immune complex-mediated disease processes have been reported. Most recently, a manuscript from the neurology literature has described an association between vasectomy and primary progressive aphasia, a rare variety of frontotemporal dementia. This article reviews the literature surrounding each of these purported health concerns. Because the ultimate findings have important ramifications for both informed consent of vasectomy patients and for public health, the reported health risks in question should be critically evaluated.
International Braz J Urol | 2008
Tobias S. Köhler; Mitchell Yadven; Ankur M. Manvar; Nathan Liu; Manoj Monga
PURPOSE Catheter-based medical devices are an important component of the urologic armamentarium. To our knowledge, there is no population-based data regarding normal male urethral length. We evaluated the length of the urethra in men with normal genitourinary anatomy undergoing either Foley catheter removal or standard cystoscopy. MATERIALS AND METHODS Male urethral length was obtained in 109 men. After study permission was obtained, the subjects penis was placed on a gentle stretch and the catheter was marked at the tip of the penis. The catheter was then removed and the distance from the mark to the beginning of the re-inflated balloon was measured. Alternatively, urethral length was measured at the time of cystoscopy, on removal of the cystoscope. Data on age, weight, and height was obtained in patients when possible. RESULTS The mean urethral length was 22.3 cm with a standard deviation of 2.4 cm. Urethral length varied between 15 cm and 29 cm. No statistically significant correlation was found between urethral length and height, weight, body mass index (BMI), or age. CONCLUSIONS Literature documenting the length of the normal male adult urethra is scarce. Our data adds to basic anatomic information of the male urethra and may be used to optimize genitourinary device design.
The Journal of Sexual Medicine | 2010
Hannah H. Alphs; Neema Navai; Tobias S. Köhler; Kevin T. McVary
INTRODUCTION Penile vascular abnormalities occur in a high proportion of patients with Peyronies disease (PD). Penile duplex ultrasonography (PDU) and dynamic infusion cavernosometry and cavernosography (DICC) are tools that can be used to help tailor individualized treatment for patients undergoing surgical intervention for their PD. However, precisely which parameters can be used to predict those patients with PD at risk for developing erectile dysfunction (ED) after intervention without inflatable penile prosthesis (IPP) has not been previously elucidated. AIM To evaluate preoperative vascular parameters that predispose PD patients for developing ED after intervention without IPP. METHODS Twenty-six patients receiving surgical intervention for their PD at a single center were retrospectively identified. Of these, 11 (42.3%) opted for primary repair without placement of an IPP. Three (27.2%) of these 11 patients went on to develop ED postoperatively. MAIN OUTCOME MEASURES We compared various demographic, PDU, and DICC parameters between patients who did and did not fail primary repair of their PD. RESULTS Mean age and follow-up of patients who went on to develop ED after repair of PD without IPP were not significantly different (P < 0.05). Resistive index (RI) and end diastolic volume were significantly different between these two groups (P < 0.05), while peak systolic volume, flow to maintain, and pressure decay were not significantly different. An RI cutoff of <0.80 was found to identify all patients who would later develop ED and fail primary repair without IPP. CONCLUSIONS Penile vascular assessment can aid in counseling patients about their risk of developing delayed ED after primary repair of PD. In our cohort of patients, PDU provided preoperative risk stratification for postoperative erectile dysfunction in men undergoing Peyronies repair without IPP. We propose the prospective study of an RI cutoff to identify patients at risk of failing primary PD repair without IPP.