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Dive into the research topics where John J. Knoedler is active.

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Featured researches published by John J. Knoedler.


The Journal of Urology | 2012

Does Partial Cystectomy Compromise Oncologic Outcomes for Patients with Bladder Cancer Compared to Radical Cystectomy? A Matched Case-Control Analysis

John J. Knoedler; Stephen A. Boorjian; Simon P. Kim; Christopher J. Weight; Prabin Thapa; Robert F. Tarrell; John C. Cheville; Igor Frank

PURPOSE To our knowledge long-term oncologic outcomes following partial cystectomy for urothelial carcinoma remain to be defined. We evaluated patterns of recurrence and survival among matched patients treated with partial vs radical cystectomy for bladder cancer. MATERIALS AND METHODS We identified 86 patients who underwent partial cystectomy for pT1-4N0-1Mx urothelial carcinoma between 1980 and 2006 at our institution. They were matched 1:2 to patients undergoing radical cystectomy based on age, gender, pathological T stage and receipt of neoadjuvant chemotherapy. Survival was estimated using Kaplan-Meier analysis and compared with the log rank test. RESULTS Median postoperative followup was 6.2 years (range 0 to 27). No difference was noted for 10-year distant recurrence-free survival (61% vs 66%, p = 0.63) or cancer specific survival (58% vs 63%, p = 0.67) between patients treated with partial and radical cystectomy, respectively. Interestingly, 4 of 86 patients (5%) who underwent partial cystectomy showed extravesical pelvic tumor recurrence postoperatively vs 29 of 167 (17%) who underwent radical cystectomy (p = 0.004). In addition, 33 of 86 patients (38%) were diagnosed with intravesical recurrence of tumor after partial cystectomy and 16 of 86 (19%) initially treated with partial cystectomy ultimately underwent radical cystectomy. CONCLUSIONS Our matched analysis demonstrated no difference in metastasis-free or cancer specific survival between select patients undergoing partial cystectomy and those undergoing radical cystectomy. Nevertheless, patients treated with partial cystectomy remain at risk for intravesical recurrence and, thus, they should be counseled and surveilled accordingly.


Mayo Clinic Proceedings | 2015

Stone Composition Among First-Time Symptomatic Kidney Stone Formers in the Community

Prince Singh; Felicity T. Enders; Lisa E. Vaughan; Eric J. Bergstralh; John J. Knoedler; Amy E. Krambeck; John C. Lieske; Andrew D. Rule

OBJECTIVE To determine the variation in kidney stone composition and its association with risk factors and recurrence among first-time stone formers in the general population. PATIENTS AND METHODS Medical records were manually reviewed and validated for symptomatic kidney stone episodes among Olmsted County, Minnesota, residents from January 1, 1984, through December 31, 2012. Clinical and laboratory characteristics and the risk of symptomatic recurrence were compared between stone compositions. RESULTS There were 2961 validated first-time symptomatic kidney stone formers. Stone composition analysis was obtained in 1508 (51%) at the first episode. Stone formers were divided into the following mutually exclusive groups: any brushite (0.9%), any struvite (0.9%), any uric acid (4.8%), and majority calcium oxalate (76%) or majority hydroxyapatite (18%). Stone composition varied with clinical characteristics. A multivariable model had a 69% probability of correctly estimating stone composition but assuming calcium oxalate monohydrate stone was correct 65% of the time. Symptomatic recurrence at 10 years was approximately 50% for brushite, struvite, and uric acid but approximately 30% for calcium oxalate and hydroxyapatite stones (P<.001). Recurrence was similar across different proportions of calcium oxalate and hydroxyapatite (P for trend=.10). However, among calcium oxalate stones, 10-year recurrence rate ranged from 38% for 100% calcium oxalate dihydrate to 26% for 100% calcium oxalate monohydrate (P for trend=.007). CONCLUSION Calcium stones are more common (93.5% of stone formers) than has been previously reported. Although clinical and laboratory factors associate with the stone composition, they are of limited utility for estimating stone composition. Rarer stone compositions are more likely to recur.


Current Opinion in Urology | 2015

Organ-sparing surgery in urology: partial cystectomy.

John J. Knoedler; Igor Frank

Purpose of review While radical cystectomy continues to be the gold standard for surgical management of muscle invasive bladder cancer, there has been a renewed interest in partial cystectomy as a viable treatment alternative. The purpose of this review is to summarize and discuss the recent literature regarding partial cystectomy for bladder cancer. Recent findings Utilization of partial cystectomy has remained stable, at a rate of 7–10% of all cystectomies performed nationally. Additionally, recent population-based series as well as single institution cohorts have found that partial cystectomy did not compromise survival when compared to radical cystectomy. While patients may recur, those with organ-confined disease had no difference in survival following salvage cystectomy when compared to primary radical cystectomy. Current data indicate 14% of patients experience an in-hospital complication, which is a marked decrease compared to radical cystectomy. Finally, innovations in surgical technique, such as robotics, as well as the inclusion of partial cystectomy into trimodal therapy, offer exciting new frontiers in bladder cancer treatment. Summary Once maligned, partial cystectomy now represents a standard-of-care option for management of bladder cancer. Although additional research is needed to clarify patient selection and outcomes, partial cystectomy is an important treatment option for appropriately selected patients.


Prostate Cancer and Prostatic Diseases | 2014

The association of tumor volume with mortality following radical prostatectomy.

John J. Knoedler; R.J. Karnes; Robert Houston Thompson; Laureano J. Rangel; Erik J. Bergstralh; Stephen A. Boorjian

Background:Data regarding the prognostic significance of tumor volume (TV) in prostate cancer are conflicting. Herein, we evaluated the association of TV with prostate cancer mortality following radical prostatectomy (RP), and assessed the additive prognostic value of TV to an established predictive model.Methods:We identified 13 687 patients who underwent RP without preoperative therapy between 1987 and 2009. TV was estimated using the prolate ellipsoid formula. Survival was estimated using the Kaplan–Meier method and compared with the log-rank test. Cox proportional hazard regression models were used to evaluate the association of TV with mortality. The ability of TV to enhance the performance of an established prognostic model (Mayo Clinic GPSM (Gleason, PSA, seminal vesicle and margin status) score) was assessed using the c-index.Results:Median TV was 1.57 cm3 (interquartile range (IQR) 0.48–4.19). Increasing TV was associated with significantly higher risks of seminal vesicle invasion (hazard ratio (HR) 1.58; P<0.0001), positive surgical margins (HR 1.28; P<0.0001) and lymph node involvement (HR 1.26; P<0.0001). Median postoperative follow-up was 9.4 years (IQR 5.0–14.5). Patient grouping into quartiles according to TV resulted in a significant stratification of outcome, as the 15-year cancer-specific survival by TV quartile was 99%, 98%, 95% and 88%, respectively (P<0.0001). Moreover, on multivariate analysis, greater TV remained associated with significantly increased risks of systemic progression (HR 1.27; P<0.0001), death from prostate cancer (HR 1.29; P<0.0001) and all-cause mortality (HR 1.05; P<0.0001). Meanwhile, addition of TV to the GPSM score increased the c-index for the model’s prediction of prostate cancer mortality from 0.803 to 0.822.Conclusions:TV is associated with survival following RP, and enhances, although modestly, the performance of an established prediction model. As such, TV warrants continued assessment in risk stratification tools.


BJUI | 2016

Intravesical gemcitabine in combination with mitomycin C as salvage treatment in recurrent non-muscle-invasive bladder cancer.

Patrick A. Cockerill; John J. Knoedler; Igor Frank; Robert F. Tarrell; R.J. Karnes

To evaluate oncological outcomes after combination intravesical therapy with gemcitabine (GC) and mitomycin C (MMC) in the setting of recurrent non‐muscle‐invasive bladder cancer (NMIBC) after failure of previous intravesical therapy.


The Journal of Urology | 2014

Thiazide Diuretic Prophylaxis for Kidney Stones and the Risk of Diabetes Mellitus

Prince Singh; John J. Knoedler; Amy E. Krambeck; John C. Lieske; Eric J. Bergstralh; Andrew D. Rule

PURPOSE Thiazide diuretics used to treat hypertension are associated with a modest risk of diabetes mellitus. It is unknown if there is a similar risk with kidney stone prevention. MATERIALS AND METHODS We identified and validated incident stone formers in Olmsted County, Minnesota from 1984 to 2011 with manual review of medical records using the Rochester Epidemiology Project. The risk of diabetes mellitus after thiazide therapy was evaluated with and without multivariate adjustment for hypertension, age, gender, race, family history of stones, body mass index and number of stone events. RESULTS Among 2,350 incident stone formers with a median followup of 10 years, 332 (14%) were treated with thiazide diuretics at some point after the first stone event and 84 (3.6%) received the thiazide diuretic only for kidney stone prevention. Stone formers who received thiazide diuretics were more likely to be older, have hypertension, have higher body mass index and have more stone events. The incidence of diabetes mellitus at 10 years after the first stone event was 9.2% in the group that received thiazide diuretics vs 4.2% in those who did not (HR 2.91; 95% CI 2.02, 4.20). After multivariate adjustment the risk of diabetes mellitus was attenuated (HR 1.20; 95% CI 0.78, 1.83). The risk of diabetes mellitus among those receiving thiazide diuretics solely for kidney stones was further attenuated (multivariate adjusted HR 0.80; 95% CI 0.28, 2.23). CONCLUSIONS Thiazide diuretic use for kidney stone prophylaxis was not associated with a high risk of diabetes mellitus. Larger studies are needed to determine if there is a modest risk of diabetes mellitus with thiazide diuretics.


BJUI | 2013

Population-based comparison of laparoscopic and open pyeloplasty in paediatric pelvi-ureretic junction obstruction

John J. Knoedler; Leona C. Han; Candace F. Granberg; Stephen A. Kramer; George K. Chow; Matthew T. Gettman; Brittany Kimball; James P. Moriarty; Simon P. Kim; Douglas A. Husmann

To describe the extent of use and in‐hospital outcomes of open and laparoscopic pyeloplasty for paediatric pelvi‐ureteric junction (PUJ) obstruction in the USA.


BJUI | 2014

Urothelial carcinoma involving the prostate: the association of revised tumour stage and coexistent bladder cancer with survival after radical cystectomy

John J. Knoedler; Stephen A. Boorjian; Matthew K. Tollefson; John C. Cheville; Prabin Thapa; Robert F. Tarrell; Igor Frank

To evaluate survival among patients with urothelial carcinoma (UC) within the prostate in order to assess the impact of depth of tumour invasion as well as the importance of a concurrent bladder tumour.


Clinical Journal of The American Society of Nephrology | 2017

Risk of Hypertension among First-Time Symptomatic Kidney Stone Formers

Wonngarm Kittanamongkolchai; Kristin C. Mara; Ramila A. Mehta; Lisa E. Vaughan; Aleksandar Denic; John J. Knoedler; Felicity T. Enders; John C. Lieske; Andrew D. Rule

BACKGROUND AND OBJECTIVES Prior work has suggested a higher risk of hypertension in kidney stone formers but lacked disease validation and adjustment for potential confounders. Certain types of stone formers may also be at higher risk of hypertension. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS In our study, incident symptomatic stone formers in Olmsted County from 2000 to 2011 were manually validated by chart review and age and sex matched to Olmsted County controls. We followed up patients through November 20, 2015. Hypertension was also validated by manual chart review, and the risk of hypertension in stone formers compared with controls was assessed both univariately and after adjusting for comorbidities. The risk of hypertension among different subtypes of stone formers was also evaluated. RESULTS Among 3023 coded stone formers from 2000 to 2011, a total of 1515 were validated and matched to 1515 controls (mean age was 45 years old, and 56% were men). After excluding those with baseline hypertension (20% of stone formers and 18% of controls), 154 stone formers and 110 controls developed hypertension. Median follow-up time was 7.8 years in stone formers and 9.6 years in controls. Stone formers were found to have a higher risk of hypertension compared with controls (hazard ratio, 1.50; 95% confidence interval, 1.18 to 1.92), even after adjusting for age, sex, body mass index, serum creatinine, CKD, diabetes, gout, coronary artery disease, dyslipidemia, tobacco use, and alcohol abuse (hazard ratio, 1.58; 95% confidence interval, 1.12 to 2.21). Results were similar after excluding patients who were ever on a thiazide diuretic (hazard ratio, 1.65; 95% confidence interval, 1.16 to 2.38). Stone composition, radiographic stone burden, number of subsequent stone events, and stone removal surgeries were not associated with hypertension (P>0.05 for all). CONCLUSIONS The risk of hypertension was higher after the first symptomatic kidney stone event. However, kidney stone severity, type, and treatment did not associate with hypertension.


Urology | 2017

Same-Session Bilateral Ureteroscopy: Safety and Outcomes

Johann P. Ingimarsson; Marcelino E. Rivera; John J. Knoedler; Amy E. Krambeck

OBJECTIVE To assess the complications and outcomes associated with same-session bilateral ureteroscopy in a tertiary referral center, as same-session bilateral ureteroscopy for stone disease has been critiqued for the theoretical risk of injury to both ureters with subsequent risk to renal function. METHODS We retrospectively reviewed all cases of bilateral ureteroscopy performed for urolithiasis by a single surgeon at out institution between 2009 and 2014. These were compared to a prospective unilateral ureteroscopy database. RESULTS There were 117 same-session bilateral ureteroscopic procedures performed in 113 patients totaling 234 ureteroscopies. A flexible ureteroscope was used in 228 ureters (97.4%), and 6 (2.6%) were semirigid only. Ureteral dilators were required in 8 (6.8%) cases. Pre-stenting was performed in 23 (19.6%) patients. Short-term complications were observed following 19 (16.2%) procedures, including 11 (9.4%) Clavien I, 4 (3.4%) Clavien II, and 4 (3.4%) Clavien III. Of the 84 (71.8%) patients who completed a 6-week follow-up, there were no long-term complications. Stone-free rates were 91.4% for patients imaged with abdominal x-ray and ultrasound, and 84.2% for those imaged with computed tomography scans. Neither complications nor re-admissions were significantly different in the unilateral group. Median length of follow-up for the entire cohort was 2.8 years (range 0-7 years). CONCLUSION Bilateral ureteroscopy can be performed safely with short-term complications, consistent with published literature. We found no long-term complications and high stone-free rates. Bilateral ureteroscopy in a single procedure represents a viable standard of care for patients with bilateral stone disease.

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