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Dive into the research topics where Mike M. Nguyen is active.

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Featured researches published by Mike M. Nguyen.


BJUI | 2008

Robotic and laparoscopic partial nephrectomy : a matched-pair comparison from a high-volume centre

Monish Aron; Phillipe Koenig; Jihad H. Kaouk; Mike M. Nguyen; Mihir M. Desai; Inderbir S. Gill

To evaluate the relative merits of robotically assisted partial nephrectomy (RPN), using a matched‐pair analysis, with laparoscopic PN (LPN).


BJUI | 2008

Early continence outcomes of posterior musculofascial plate reconstruction during robotic and laparoscopic prostatectomy

Mike M. Nguyen; Kazumi Kamoi; Robert J. Stein; Monish Aron; Jason Hafron; Burak Turna; Robert P. Myers; Inderbir S. Gill

Associate Editor


The Journal of Urology | 2009

Effect of Renal Cancer Size on the Prevalence of Metastasis at Diagnosis and Mortality

Mike M. Nguyen; Inderbir S. Gill

PURPOSE We determined the relationship between the prevalence of metastasis at presentation and cancer specific mortality with tumor size in renal cancer cases using a large cancer database. MATERIALS AND METHODS The Surveillance, Epidemiology and End Results data set was analyzed for renal tumors diagnosed from 1998 to 2003. A total of 24,253 patients were included. The prevalence of metastasis and cancer specific survival as a function of tumor size were evaluated using linear and nonlinear curve fitting methods. Metastatic cases with tumors 2.5 cm or less were individually reconfirmed case by case for accuracy. RESULTS Increasing tumor size correlated with a higher prevalence of metastasis at diagnosis (range 1.4% for tumors 1 cm or less to 50.9% for tumors greater than 15 cm). Five-year cancer specific mortality in treated patients was also closely related to tumor size (range 3.5% for tumors 1 cm or less to 50.9% for tumors greater than 15 cm). In each instance the relationship was sigmoidal rather than linear and it was best modeled using a quadratic function. The most rapid increase in the prevalence of metastasis and mortality was noted for tumors 4 to 12 cm. In treated patients with tumors 1 cm or less, 1.1 to 2, 2.1 to 3 and 3.1 to 4 the prevalence of metastasis at diagnosis was 1.4%, 2.5%, 4.7% and 7.4%, and the 5-year cancer specific mortality rate was 3.5%, 3.8%, 4.1% and 5.3%, respectively. CONCLUSIONS In cases of renal cancer the prevalence of metastasis at presentation and 5-year cancer specific mortality increase in a nonlinear sigmoidal relationship with tumor size.


The Journal of Urology | 2015

Radical Prostatectomy or External Beam Radiation Therapy vs No Local Therapy for Survival Benefit in Metastatic Prostate Cancer: A SEER-Medicare Analysis

Raj Satkunasivam; Andre Kim; Mihir M. Desai; Mike M. Nguyen; David I. Quinn; Leslie Ballas; Juan Pablo Lewinger; Mariana C. Stern; Ann S. Hamilton; Monish Aron; Inderbir S. Gill

PURPOSE We assessed survival after radical prostatectomy, intensity modulated radiation therapy or conformal radiation therapy vs no local therapy for metastatic prostate cancer adjusting for patient comorbidity, androgen deprivation therapy and other factors. MATERIALS AND METHODS We identified men 66 years old or older with metastatic prostate cancer treated with radical prostatectomy, intensity modulated radiation therapy, conformal radiation therapy or no local therapy in the SEER-Medicare linked database from 2004 to 2009. Multivariable Cox proportional hazards models before and after inverse propensity score weighting were used to assess all cause and prostate cancer specific mortality. Competing risk regression analysis was done to assess prostate cancer specific mortality. RESULTS Of 4,069 men with metastatic prostate cancer radical prostatectomy in 47, intensity modulated radiation therapy in 88 and conformal radiation therapy in 107 were selected as local therapy vs no local therapy in 3,827. Radical prostatectomy was associated with a 52% decrease (HR 0.48, 95% CI 0.27-0.85) in the risk of prostate cancer specific mortality after adjusting for sociodemographics, primary tumor characteristics, comorbidity, androgen deprivation therapy and bone radiation within 6 months of diagnosis. Intensity modulated radiation therapy was associated with a 62% decrease (HR 0.38, 95% CI 0.24-0.61) in the risk of prostate specific cancer specific mortality. Conformal radiation therapy was not associated with improved survival compared to no local therapy. Propensity score weighting yielded comparable results. Competing risk analysis revealed a 42% and 57% decrease (SHR 0.58, 95% CI 0.35-0.95 and SHR 0.43, 95% CI 0.27-0.68, respectively) in the risk of prostate cancer specific mortality for radical prostatectomy and intensity modulated radiation therapy. CONCLUSIONS Local therapy with radical prostatectomy and intensity modulated radiation therapy but not with conformal radiation therapy was associated with a survival benefit in men with metastatic prostate cancer. This finding warrants prospective evaluation in clinical trials.


Current Opinion in Urology | 2008

Laparoscopic radical adrenalectomy for cancer: long-term outcomes.

Lipika R McCauley; Mike M. Nguyen

Purpose of review Laparoscopic adrenalectomy for malignant adrenal masses has been controversial because of initial reports of high rates of local recurrence and carcinomatosis. With additional experience, improved outcomes have been reported. We evaluate the contemporary role of laparoscopy in treating adrenal malignancies. Recent findings Several contemporary reports now demonstrate that laparoscopic adrenalectomy for primary adrenal malignancy can provide oncologic outcomes equivalent to open surgery without an increased risk of carcinomatosis or port site recurrence. Although long-term survival of 47 months with no recurrence has been reported, the underlying aggressiveness of this tumor has contributed to a 39.6% rate of recurrence for the 48 contemporary cases reviewed in this article. This compares favorably to open series that report a similar or higher recurrence rate. When utilized for the treatment of solitary metastases to the adrenal gland, laparoscopic adrenalectomy provides equivalent oncologic outcomes to open adrenalectomy. Summary Laparoscopic adrenalectomy for malignancy can be performed in appropriately selected cases with equal oncologic outcomes to open approaches while providing advantages in patient morbidity. Caution must be taken to avoid tumor entry or spillage because of the potential for local recurrence, port site recurrence, and carcinomatosis that can occur with these aggressive tumors.


The Journal of Urology | 2009

Laparoscopic Assisted Ileal Ureter: Technique, Outcomes and Comparison to the Open Procedure

Robert J. Stein; Burak Turna; Neil S. Patel; Christopher J. Weight; Mike M. Nguyen; Gaurang Shah; Monish Aron; Amr Fergany; Inderbir S. Gill; Mihir M. Desai

PURPOSE Ureteral replacement with interposition of a bowel segment has traditionally required a large incision with substantial associated morbidity and prolonged time to convalescence. During the last 7 years a technique for laparoscopic assisted ileal interposition has evolved that mimics our open approach. We present a comparative analysis of functional and perioperative outcomes between patients undergoing laparoscopic or open ileal ureter replacement at our institution. MATERIALS AND METHODS A search of all procedures from 1980 to the present revealed 7 patients undergoing laparoscopic and 7 undergoing open ileal interposition. Functional and perioperative data from these patients are compared, and a detailed description of technique for the laparoscopic procedure is presented. RESULTS Narcotic analgesic use in morphine equivalents (median 38.9 vs 322.2 mg, p = 0.035) and time to convalescence (median 4 vs 5.5 weeks, p = 0.03) were significantly less in the laparoscopic group. A trend toward shorter hospital stay (median 5 vs 8 days, p = 0.101) was also noted in patients in the laparoscopic group. There was no evidence of anastomotic stricture for patients in either group at last followup. CONCLUSIONS Despite the small number of subjects involved a significant advantage was noted for postoperative recovery after laparoscopic compared to open ileal interposition. A detailed understanding of this complicated procedure can help prevent inherent pitfalls.


The Journal of Urology | 2012

Factors Influencing Fluid Intake Behavior Among Kidney Stone Formers

Lipika R. McCauley; Anthony J. Dyer; Karen Stern; Thomas Hicks; Mike M. Nguyen

PURPOSE We determined factors influencing the behavior of patients with kidney stones in the prevention of recurrent stones. MATERIALS AND METHODS Patients with stones from an academic and a community practice were recruited for key informant interviews and focus groups. Groups were guided based on the framework of the health belief model. Content analysis was done on transcriptions using qualitative data analysis software. RESULTS Key informant interviews were completed with 16 patients and with a total of 29 subjects in 5 focus groups. Content analysis revealed that patients were highly motivated to prevent stones. The minimum level of perceived benefit for adopting the behavior change varied among patients and the behaviors proposed. An important strategy to increase fluid intake was insuring availability with containers. Patients were more consistently confident in the ability to increase fluid, in contrast to ingesting medicine or changing the diet. While barriers to increasing fluid were multifactorial among individuals, the barriers aligned into 3 progressive stages that were associated with distinct patient characteristics. Stage 1 barriers included not knowing the benefits of fluid or not remembering to drink. Stage 2 barriers included disliking the taste of water, lack of thirst and lack of availability. Stage 3 barriers included the need to void frequently and related workplace disruptions. CONCLUSIONS Patients with kidney stones are highly motivated to prevent recurrence and were more amenable to fluid intake change than to another dietary or pharmaceutical intervention. Barriers preventing fluid intake success aligned into 3 progressive stages. Tailoring fluid intake counseling based on patient stage may improve fluid intake behavior.


Journal of Endourology | 2008

Laparoscopic pyeloplasty with concomitant pyelolithotomy: technique and outcomes.

Robert J. Stein; Burak Turna; Mike M. Nguyen; Monish Aron; Jason Hafron; Inderbir S. Gill; Jihad H. Kaouk; Mihir M. Desai

BACKGROUND AND PURPOSE Coexisting renal calculus disease may pose technical challenges in the surgical management of ureteropelvic junction obstruction. We report our experience with laparoscopic pyelolithotomy at the time of laparoscopic pyeloplasty and compare outcome data with a cohort of patients undergoing laparoscopic pyeloplasty without coexistent stone disease. PATIENTS AND METHODS We reviewed data on 117 patients undergoing laparoscopic pyeloplasty in the last 3 years at our institution. Fifteen (10.6%) patients underwent concomitant ipsilateral pyelolithotomy at the time of laparoscopic pyeloplasty. Laparoscopic graspers alone were used in 11 (73.3%) patients, flexible nephroscopy in 2 (13.3%) patients, and laparoscopic irrigation in 2 (13.3%) patients for renal stone removal. Patients in the group undergoing pyelolithotomy were compared with 15 matched patients undergoing laparoscopic pyeloplasty without concomitant calculus disease. Preoperative, intraoperative, and postoperative parameters were compared between the groups. RESULTS Overall stone-free rate after laparoscopic pyelolithotomy was 80%. Mean operative time was 174 minutes nu 170 minutes for the pyelolithotomy nu control group, respectively (P = 0.81). CONCLUSIONS Laparoscopic pyelolithotomy, primarily using laparoscopic graspers, is an efficient procedure with associated high stone-free rates without significant increase in operative time or morbidity. Intraoperative flexible nephroscopy may be necessary only occasionally for stone retrieval.


Urology | 2008

Laparoscopic Transperitoneal Radical Prostatectomy in Renal Transplant Recipients: A Review of Three Cases

Anil A. Thomas; Mike M. Nguyen; Inderbir S. Gill

OBJECTIVES To report our experience with laparoscopic radical prostatectomy for the treatment of localized prostate carcinoma in 3 renal transplant recipients. METHODS We retrospectively identified all patients who had undergone laparoscopic prostatectomy for clinically localized prostate cancer between 1999 and 2006 at our institution (n = 1067). Of these patients, 3 were renal transplant recipients (dual cadaveric renal transplant, simultaneous pancreas kidney transplant, and a cadaveric renal transplant that had failed owing to chronic rejection by the time of surgery). We reviewed all available clinicopathological data. RESULTS All three patients underwent successful laparoscopic radical prostatectomy without major complications. The average operative time was 237 minutes (range, 180 to 290 minutes) with a mean estimated blood loss of 425 mL (range, 75 to 1000 mL). No changes in renal graft function, measured by serum creatinine, were noted. Pathological outcomes revealed negative surgical margins with organ-confined disease in each case. All three patients tolerated the procedure well and had an average hospital stay of 3.3 days (range, 2 to 5 days). CONCLUSIONS The data from our 3 patients suggest that laparoscopic radical prostatectomy is a technically feasible and safe treatment of localized prostate cancer in renal transplant recipients.


Urology | 2010

Coded Tumor Size May Be Unreliable for Small Metastatic Renal Cancers in the Surveillance, Epidemiology, and End Results Dataset

Mike M. Nguyen; Inderbir S. Gill

OBJECTIVES To report a weakness in the April 2006 release of the Surveillance, Epidemiology, and End Results (SEER) dataset, in which the primary tumor size of small (< 1.8 cm) metastatic renal cancers was often incorrectly coded into the dataset from the measurement as listed in the patients chart. METHODS In the SEER dataset, 167 patients with tumor size < or = 2.5 cm had metastatic disease at presentation in 1998-2003. Each patients chart was individually re-examined by SEER registries to determine the correct primary tumor size. This confirmed data were compared with the coded tumor size in the SEER dataset. RESULTS Of the 167 re-examined cases, 2 had incorrect histology and 6 could not be verified. Of the remaining 159 cases, 87 (55%) were correctly coded for primary tumor size while 72 (45%) were incorrect. The error rate decreased with increasing size; for tumors < or = 1 cm, > 1-2 cm, and > 2-2.5 cm, error rates were 88%, 53%, and 6.8%, respectively (P < .001). A breakpoint in error rate occurred between tumor sizes < 1.8 cm (78%) and > or = 1.8 cm (10%) (P < .001). Most errors (72%) were miscoded by a factor of 10. Analysis of the latest April 2009 release suggests that most corrections have been incorporated into the public access dataset. CONCLUSIONS Coded primary tumor sizes in the April 2006 release SEER dataset for metastatic renal tumors < 1.8 cm from 1998 to 2003 were often inaccurate. Verification of tumor size in this subset was essential to insure data accuracy and quality of research. Researchers should recognize potential limitations of population-based cancer registries.

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Inderbir S. Gill

University of Southern California

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Monish Aron

University of Southern California

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Jason Hafron

Memorial Sloan Kettering Cancer Center

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Mihir M. Desai

University of Southern California

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Troy Gianduzzo

University of Queensland

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