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Dive into the research topics where Darren Katz is active.

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Featured researches published by Darren Katz.


The Journal of Urology | 2009

Tumor size is associated with malignant potential in renal cell carcinoma cases.

R. Houston Thompson; Jordan M. Kurta; Matthew Kaag; Satish K. Tickoo; Shilajit Kundu; Darren Katz; Lucas Nogueira; Victor E. Reuter; Paul Russo

PURPOSE We evaluated our experience with renal cortical tumors to determine whether tumor size is associated with malignant histology and/or nuclear grade. MATERIALS AND METHODS We identified 2,675 patients treated surgically at our institution for renal cell carcinoma or a benign tumor between 1989 and 2007. Histological subtype and tumor size were obtained from our kidney cancer database and logistic regression analysis was performed. RESULTS Of the 2,675 tumors 311 (12%) were benign and 2,364 (88%) were renal cell carcinoma. The OR for the association of malignancy with tumor size was 1.16 (95% CI 1.11-1.22, p <0.001), indicating that each 1 cm increase in tumor size was associated with a 16% increase in the odds of malignancy. The incidence of benign tumors decreased from 38% for tumors less than 1 cm to 7% for tumors 7 cm or greater. In patients with clear cell renal cell carcinoma each 1 cm increase in tumor size increased the odds of high grade disease (Fuhrman grade 3-4) compared with low grade disease (Fuhrman grade 1-2) by 25% (OR 1.25, 95% CI 1.21-1.30, p <0.001). In this subset the incidence of high grade lesions increased from 0% for tumors less than 1 cm to 59% for tumors greater than 7 cm. CONCLUSIONS Our results confirm previous observations suggesting that the risks of malignancy and high grade tumors increase with tumor size. Patients with small renal masses are at low risk for harboring a high grade clear cell malignancy, which may be useful during initial consultation.


BJUI | 2012

Outcomes of clomiphene citrate treatment in young hypogonadal men

Darren Katz; Omar Nabulsi; Raanan Tal; John P. Mulhall

Study Type – Therapy (case series)


BJUI | 2012

Clomiphene citrate is safe and effective for long-term management of hypogonadism

Daniel J. Moskovic; Darren Katz; Ardavan Akhavan; Kelly Park; John P. Mulhall

Study Type – Therapy (population cohort)


Urology | 2010

Extended Pelvic Lymph Node Dissection in Robotic-assisted Radical Prostatectomy: Surgical Technique and Initial Experience

David S. Yee; Darren Katz; Guilherme Godoy; Lucas Nogueira; Kian Tai Chong; Matthew Kaag; Jonathan A. Coleman

OBJECTIVES To describe, and show in the accompanying video segments, a technique for extended pelvic lymph node dissection (ePLND) in robotic-assisted radical prostatectomy (RARP) and report our clinicopathologic and perioperative outcomes. The extent of pelvic lymphadenectomy during radical prostatectomy has not been standardized. However, evidence demonstrates that an ePLND yields a greater number of positive nodes. METHODS A total of 32 patients with clinically localized prostate cancer underwent RARP with ePLND by a single surgeon (J.C.) between January and August 2008. The template for the ePLND included the obturator, hypogastric, external iliac, and common iliac lymph nodes up to the bifurcation of the aorta. Systematic review and grading of adverse events were performed. RESULTS The median number of lymph nodes retrieved was 18 (interquartile range [IQR] 12-28). Four patients (12.5%) had lymph node metastases. Of the 4 patients with lymph node metastases, 1 patient (25%) had the involved lymph node exclusively in the common iliac region. Median operative time for the ePLND was 72 minutes (IQR 66-86). Median hospital length of stay was 2.0 days (IQR 2.0-2.8). Graded complications included 13 grade 1 events and 1 grade 2 event, with 1 grade 1 event being considered related to ePLND. No clinically presenting lymphoceles or thrombotic events were encountered. CONCLUSIONS An ePLND during RARP is technically feasible and appears to have minimal morbidity. It produces a high lymph node yield and may result in improved pathologic staging.


Urology | 2010

Focal treatment or observation of prostate cancer: pretreatment accuracy of transrectal ultrasound biopsy and T2-weighted MRI.

Lucas Nogueira; Liang Wang; Samson W. Fine; Rodrigo Pinochet; Jordan M. Kurta; Darren Katz; Caroline Savage; Angel M. Cronin; Hedvig Hricak; Peter T. Scardino; Oguz Akin; Jonathan A. Coleman

OBJECTIVES To test the hypothesis that men with prostate cancer (PCA) and preoperative disease features considered favorable for focal treatment would be accurately characterized with transrectal biopsy and prostate magnetic resonance imaging (MRI) by performing a retrospective analysis of a selected cohort of such patients treated with radical prostatectomy (RP). METHODS A total of 202 patients with PCA who had preoperative MRI and low-risk biopsy criteria (no Gleason grade 4/5, 1 involved core, < 2 mm, PSA density < or = 0.10, clinical stage < or = T2a) were included in the study. Indolent RP pathology was defined as no Gleason 4/5, organ confined, tumor volume < 0.5 mL, and negative surgical margins. MRI ability to locate and determine the tumor extent was assessed. RESULTS After RP, 101 men (50%) had nonindolent cancer. Multifocal and bilateral tumors were present in 81% and 68% of patients, respectively. MRI indicated extensive disease in 16 (8%). MRI sensitivity to locate PCA ranged from 2% to 20%, and specificity from 91% to 95%. On univariate analysis, MRI evidence of extracapsular extension (P = .027) and extensive disease (P = .001) were associated with nonindolent cancer. On multivariate analysis, only the latter remained as significant predictor (P = .0018). CONCLUSIONS Transrectal biopsy identified men with indolent tumors favorable for focal treatment in 50% of cases. MRI findings of extracapsular extension and extensive tumor involving more than half of the gland are associated with unfavorable features, and may be useful in excluding patients from focal treatment. According to these data, endorectal MRI is not sufficient to localize small tumors for focal treatment.


The Journal of Sexual Medicine | 2010

Chronology of erectile function in patients with early functional erections following radical prostatectomy

Darren Katz; Nelson Bennett; Jason Stasi; James A. Eastham; Bertrand Guillonneau; Peter T. Scardino; John P. Mulhall

INTRODUCTION The association between erectile dysfunction (ED) and radical prostatectomy (RP) is well established. It is our clinical experience that some men who have functional erections in the days to weeks after RP go on to lose erectile function (EF) after the first 3 months postsurgery. AIM To assess EF over a 12-month period in patients with functional erections at 3 months following RP. METHODS As part of a large prospective quality-of-life (QOL) study of men undergoing RP at our institution, EF is measured postoperatively at regular time intervals using serial administration of the International Index of Erectile Function (IIEF) questionnaire. For study inclusion, patients had to have functional erections (a score 4 or 5 on IIEF question 3) at the third postoperative month, and have at least 12 months of follow-up. MAIN OUTCOME MEASURES Assessment of EF and phosphodiesterase type 5 inhibitor (PDE5i) use at 3, 6, and 12 months after RP. RESULTS At 3 months, 76 of 482 patients (16%) had functional erections. Between 3 to 6 months postoperatively, 20% of men deteriorated in their functional status. Of these men, 91% had functional erections at 1 year. Comparing patients who did not require PDE5i to obtain a functional erection at 3 months with those who did, the EF outcomes were superior at 6 months (80% vs. 72%, P = 0.74) and 12 months (100% vs. 88%, P = 0.33). CONCLUSION The recovery of functional erections in the early postoperative phase, especially without the need for PDE5i, is a good prognostic indicator for EF at 12 months. However, a distinct cohort of men lose functional erections within 6 months after surgery. It is important to inform patients of this possibility, as it has an impact on their QOL and, potentially, on their compliance with post-RP therapy for ED.


Urology | 2010

Critical Evaluation of Perioperative Complications in Laparoscopic Partial Nephrectomy

Lucas Nogueira; Darren Katz; Rodrigo Pinochet; Guilherme Godoy; Jordan M. Kurta; Caroline Savage; Angel M. Cronin; Bertrand Guillonneau; Karim Touijer; Jonathan A. Coleman

OBJECTIVES To analyze our experience with laparoscopic partial nephrectomy (LPN) to detail postoperative adverse events and identify factors that may contribute to adverse surgical outcomes. Complications from LPN result from a variety of factors, both technical and inherent. METHODS Single-center review of 144 consecutive LPN (4 surgeons) performed between November 2002 and January 2008 was conducted. Identified complications were graded using standard reporting criteria. Univariate and multivariate statistical analysis of variables and their association with complication event and blood loss was performed. RESULTS A total of 39 complications occurred in 29 (20%) cases. Of these, 20 (51%) were urologic and 19 (49%) were nonurologic. Individual adverse events by grade were as follows: grade I, 6 (15.4%); grade II, 19 (48.7%), grade III, 11 (28.2%), and grade IV, 3 (7.7%). No grade V complications occurred. The median tumor size and ischemia time were 2.7 cm and 35 minutes, respectively. Univariate analysis identified increased American Society of Anesthesiologists risk score (odds ratio 2.99, 95% confidence interval [CI] 1.28, 6.94) and ischemia time (odds ratio 1.31; 95% CI 1.00, 1.71) as associated with complication risk. On multivariate analysis, longer ischemia time was associated with increased estimated blood loss (95% CI 3, 57; P = .03). Hospital readmission and reintervention was required in 15 (10.4%) and 9 (6.2%) patients, respectively. CONCLUSIONS Complications from LPN occur in a meaningful proportion of procedures although the majority does not require reintervention and half are not urologic. Increasing ischemia time and American Society of Anesthesiologists score are associated with risk for unfavorable surgical outcomes.


The Journal of Sexual Medicine | 2012

Perioperative Prevention of Penile Prosthesis Infection: Practice Patterns among Surgeons of SMSNA and ISSM

Darren Katz; Doron S. Stember; Christian J. Nelson; John P. Mulhall

INTRODUCTION Anecdotally, there is great variation in the use of strategies to prevent postoperative penile implant infection. AIM To evaluate the perioperative practice patterns of surgeons who insert penile prostheses focusing on their respective infection control routines. METHOD An anonymous Web-based survey was sent to members of the Sexual Medicine Society of North America (SMSNA) and the International Society of Sexual Medicine (ISSM). MAIN OUTCOME MEASURES Thirty-nine questions were asked pertaining to the strategies used during the pre-, intra-, and postoperative phases of penile implant surgery to prevent infection. RESULTS One hundred twenty-nine surgeons responded to the survey (SMSNA 84; ISSM 45). Most surgeons considered themselves sexual medicine specialists. More SMSNA respondents had inserted >100 prosthesis (SMSNA 69%, ISSM 50%). Routine urine culture is not performed by 40% and 50% of SMSNA and ISSM members, respectively. Similar percentages of surgeons from each society request a daily preoperative antimicrobial scrub. About two-thirds of ISSM members use razors for the preoperative shave compared with one-third of SMSNA members. Most ISSM surgeons preferred povidone-iodine for hand and skin preparation while most SMSNA surgeons chose this only for skin preparation. Two-thirds of SMSNA members prepared the skin for at least 10 minutes compared with 34% of ISSM surgeons. There were considerable differences in all aspects of antibiotic usage not only between members of both societies but also among individual members of each society. Most surgeons prefer not to place a drain (SMSNA 70%, ISSM 81%). Discharge timing differs between the two groups. CONCLUSIONS There is great variation in perioperative strategies utilized to prevent penile implant infections including some key differences between surgeons from SMSNA and ISSM. It is unknown if these variations result in changes in the postoperative infection rate; however, the study data may assist in the formation of practice guidelines and form the basis of future prospective studies.


The Journal of Urology | 2011

Routine Drain Placement After Partial Nephrectomy is Not Always Necessary

Guilherme Godoy; Darren Katz; Ari Adamy; Joseph E. Jamal; Melanie Bernstein; Paul Russo

PURPOSE To our knowledge the benefit of routine drainage after partial nephrectomy has never been investigated, although a drain after partial nephrectomy can be associated with morbidity. We report our initial experience with omitting the drain in select cases of superficial renal cortical tumors. MATERIALS AND METHODS From a surgery database we identified 512 consecutive open partial nephrectomies performed by a single surgeon between January 2005 and May 2009 using standardized technique. The study group included 75 evaluable patients (14.6%) who did not have a drain placed. Clinical data, surgical information, histological type and postoperative complications within 90 days of the procedure using the modified Clavien system were included in analysis. RESULTS Median patient age was 64 years (IQR 49, 70) and 56.8% of the patients were male. Median tumor size was 2.0 cm (IQR 1.5, 3.0) and more than 70% were malignant. A total of 38 patients (50.7%) underwent renal artery clamping and cold ischemia with a median clamp time of 30 minutes. The overall complication rate was 13.3% (10 patients). In 4 patients (5.3%) complications were related to an absent drain, including grade I urinary leak, grade II perirenal collection, grade III urinoma requiring percutaneous drainage and grade III urinary leak with urosepsis, respectively. No deaths occurred in this cohort. CONCLUSIONS Omitting drainage after partial nephrectomy in a select group of patients without collecting system entry is feasible and safe. The decision to place a drain after partial nephrectomy for small renal cortical tumors must be made intraoperatively and should be tailored to each case.


BJUI | 2010

Lymph node dissection during robotic-assisted laparoscopic prostatectomy: comparison of lymph node yield and clinical outcomes when including common iliac nodes with standard template dissection

Darren Katz; David S. Yee; Guilherme Godoy; Lucas Nogueira; Kian Tai Chong; Jonathan A. Coleman

Study Type – Therapy (case series)
Level of Evidence 4

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John P. Mulhall

Memorial Sloan Kettering Cancer Center

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Lucas Nogueira

Memorial Sloan Kettering Cancer Center

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Bertrand Guillonneau

Memorial Sloan Kettering Cancer Center

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Guilherme Godoy

Baylor College of Medicine

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Jonathan A. Coleman

Memorial Sloan Kettering Cancer Center

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Karim Touijer

Memorial Sloan Kettering Cancer Center

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Clarisse R. Mazzola

Memorial Sloan Kettering Cancer Center

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Peter T. Scardino

Memorial Sloan Kettering Cancer Center

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Rodrigo Pinochet

Memorial Sloan Kettering Cancer Center

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