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Mani Menon

Publications and source records attributed to Mani Menon.

At least 37 records · Page 2Linked to original sources
PubMed2005

Laparoscopic radical prostatectomy: conventional and robotic.

By 2015, prostate cancer will become the most commonly diagnosed cancer in men. Radical prostatectomy reduces disease-specific mortality in patients with localized prostate cancer; however, the invasiveness of surgery and its resultant side effects cause many men to seek other treatments. In 2000, laparoscopic radical prostatectomy emerged as a minimally invasive alternative to open surgery; it has been refined recently by the addition of robotic technology. To examine the outcomes of robotic radical prostatectomy and compare them with those from open and conventional laparoscopic radical prostatectomy, we prospectively collected baseline demographic data on all patients undergoing surgery for prostate cancer over a 4-year period at our center. Urinary function and sexual function were evaluated using standardized criteria as well as a questionnaire preoperatively and at 1, 3, 6, 12, and 18 months after their procedure. Operative and postoperative outcomes were compared using values for open radical prostatectomy as the reference standard. A total of 100 men underwent open radical prostatectomy with conventional laparoscopic radical prostatectomy (n = 50) and robotic radical prostatectomy (n = 500). The odds ratios for operative times, blood loss, postoperative pain, complications, and median times to urinary continence and resumption of sexual activity all were lower for robotic than for open or laparoscopic radical prostatectomy. It appears safe to conclude that conventional laparoscopic radical prostatectomy is a reasonable alternative to open radical prostatectomy in the surgical treatment of patients with clinically localized prostate cancer. The incorporation of robotics may result in even better surgical outcomes than conventional laparoscopy. However, the surgical robot is expensive; few centers have access to the technology and even fewer have expertise in the technique. For robotic radical prostatectomy to become the standard of care for the treatment of localized prostate cancer will require economies of cost, dissemination of surgical expertise, and data from randomized trials.

Humans↗
PubMed2005

Robotic radical prostatectomy with preservation of the prostatic fascia: a feasibility study.

OBJECTIVES: To describe a feasibility study of our ability to preserve the prostatic fascia in men undergoing robotic radical prostatectomy. The prostate is covered anterolaterally by prostatic fascia, also called lateral pelvic fascia or the parietal layer of endopelvic fascia. The prostatic fascia is rich in vessels, nerves, and smooth muscle. We hypothesized that preservation of this fascial layer may result in improved postoperative potency. METHODS: The technique was first attempted in 15 men undergoing radical cystoprostatectomy, in which accidental entry to the prostatic tissue is not critical. Thereafter, it was performed in 6 impotent men undergoing robotic radical prostatectomy. The fascia was excised and stained for prostate-specific antigen and neural and muscle tissue. The technique was then performed in 35 potent men (Sexual Health Inventory for Men score greater than 21) undergoing robotic radical prostatectomy. Postoperative potency was evaluated with a self-administered questionnaire (Sexual Health Inventory for Men). RESULTS: Under the magnification of the da Vinci robotic system, and also shown histologically, the prostatic fascia is a multifascial layer of fibrovascular tissue, covering the anterolateral aspect of the prostate. It stains positive for smooth muscle and nerves, but negative for prostate-specific antigen. The amount of neural tissue in the fascia is variable, but never exceeds that in the neurovascular bundle. At 12 months of follow-up, 34 (97%) of 35 men undergoing fascia-preserving robotic radical prostatectomy had erections strong enough for vaginal penetration, and 30 (86%) had normal erections (Sexual Health Inventory for Men greater than 21). CONCLUSIONS: Preservation of the prostatic fascia is safe and feasible, without compromising the surgical margins, and allows enhanced preservation of neural tissue during robotic prostatectomy with an apparent improvement in potency.

Fascia↗
PubMed2005

Comparison of two-dimensional and three-dimensional suturing: is there a difference in a robotic surgery setting?

BACKGROUND AND PURPOSE: Robotic surgery allows three-dimensional (3D) viewing of tissues. We compared two-dimensional (2D) and 3D suturing drills using the daVinci surgical system to determine if the latter is advantageous. MATERIALS AND METHODS: Twenty-eight anastomotic drills were completed by seven surgeons using the daVinci robot. Three surgeons had considerable (>6 months) robotic experience, and four had none. Drills were performed randomly in both dimensional modes in a blinded fashion. Drill 1 was an interrupted four stitch and drill 2 a running closure. All tasks were kept uniform. We recorded time to completion, difficulty, and accuracy. The drills were evaluated by two independent reviewers for accuracy and major errors (i.e., broken suture, torn graft). RESULTS: The average operative time per drill in two dimensions was 13.1 minutes (range 6.9-21.9 minutes) and in three dimensions was 8.5 minutes (range 4.7-12.8 minutes) (P<0.001). Drill 1 was 6.1 minutes faster in three dimensions (mean 9.2 minutes; P<0.01), and drill 2 was 2.9 minutes faster (mean 7.8 minutes; P=0.03). Both advanced and novice groups were faster in 3D (P<0.01). There were two major errors in the 3D performances and 5 in the 2D exercises (P<0.05). The participants correctly identified the dimensional mode 92.9% of the time (P<0.01). CONCLUSION: The anastomosis was completed 65% faster using 3D with equal, if not greater, accuracy. Drill 1 was improved to a greater degree than drill 2, suggesting most benefit of 3D views during knot tying. Use of three dimensions outperformed two dimensions in both groups. Surgeons can immediately benefit from 3D viewing during robotic surgery.

Anastomosis, Surgical↗
PubMed2005

Perioperative complications of robotic radical prostatectomy after the learning curve.

PURPOSE: We assessed the incidence of and analyzed factors that contributed to perioperative complications in patients undergoing robotic radical prostatectomy, that is Vattikuti Institute prostatectomy (VIP), at our institution. MATERIALS AND METHODS: We recorded operative and postoperative data on 300 consecutive patients who underwent VIP at our institution during a 1-year period. All operations were performed by 1 of 2 surgeons (MM or JOP). We reviewed the complications seen in these patients. RESULTS: There was no operative mortality and no case was converted to open surgery. A total of 269 (89.7%) patients were considered to have an ideal postoperative course, ie they were discharged home within 48 hours with no unscheduled office visits or complications. There were 14 unscheduled postoperative visits (4.7%) for transient urinary retention after early catheter removal (13) or hematuria (1). There were 17 complications, of which 16 (5.3%) were related to surgery and 1 was related to anesthesia. A total of 11 complications (3.7%) were minor (grade I) and 5 (1.7%) were major (grade II). Of them 3 (1%) patients required reoperation. There were no grade III or IV complications. CONCLUSIONS: In our hands VIP is a safe operation with an overall complication rate of 5.3%, a major complication rate of less than 2% and a surgical re-intervention rate of 1%.

Adult↗
PubMed2005

Potency following robotic radical prostatectomy: a questionnaire based analysis of outcomes after conventional nerve sparing and prostatic fascia sparing techniques.

PURPOSE: Anatomical nerve sparing radical prostatectomy provides excellent cancer control, although the recovery of sexual function is variable. We recently described a technique to preserve the prostatic fascia (veil of Aphrodite) that appears to enhance the quality of nerve preservation during robotic prostatectomy. In January 2003 we initiated a prospective study comparing patients undergoing prostatic fascia preservation with those undergoing conventional nerve sparing robotic radical prostatectomy. We report results at 12 months of followup MATERIALS AND METHODS: From January to August 2003, 58 potent men with a Sexual Health Inventory for Men score (SHIM) of greater than 21 without phosphodiesterase 5 inhibitors underwent Vattikuti Institute prostatectomy, including 35 with preservation of the prostatic fascia (study) and 23 with conventional nerve sparing (control). Potency was assessed with self-administered SHIM questionnaires 12 months after surgery. The primary end point was achievement of erections strong enough for penetration with or without oral medications. The secondary end point was the ability to achieve normal erections (SHIM greater than 21) with and without medications. RESULTS: At 12 months of followup 17 of 23 control (74%) and 34 of 35 study (97%) patients achieved erections strong enough for intercourse (p = 0.002). Four control (17%) and 18 study (51%) patients achieved normal erections (SHIM greater than 21) without medication (p <0.0001). Six control (26%) and 30 study (86%) patients achieved normal erections with or without phosphodiesterase 5 inhibitors (p <0.0001). CONCLUSIONS: Potency rates after radical prostatectomy vary with the measure used to define potency. Irrespective of the definition used patients undergoing prostatic fascia preserving radical prostatectomy have significantly better potency outcomes than patients undergoing conventional nerve sparing robotic prostatectomy at 12 months of followup.

Aged↗
PubMed2005

Racial differences in serum prostate-specific antigen (PSA) doubling time, histopathological variables and long-term PSA recurrence between African-American and white American men undergoing radical prostatectomy for clinically localized prostate cancer.

OBJECTIVE: To determine if there are significant differences in biochemical characteristics, biopsy variables, histopathological data, and rates of prostate-specific antigen (PSA) recurrence between African-American (AA) and white American (WA) men undergoing radical prostatectomy (RP), as AA men are twice as likely to die from prostate cancer than their white counterparts. PATIENTS AND METHODS: We established a cohort of 1058 patients (402 AA, 646 WA) who had RP and were followed for PSA recurrence. Age, race, serum PSA, biopsy Gleason score, clinical stage, pathological stage, and PSA recurrence data were available for the cohort. The chi-square test of proportions and t-tests were used to assess basic associations with race, and log-rank tests and Cox regression models for time to PSA recurrence. Forward stepwise variable selection was used to assess the effect on the risk of PSA recurrence for race, adjusted by the other variables added one at a time. RESULTS: The AA men had higher baseline PSA levels, more high-grade prostatic intraepithelial neoplasia (HGPIN) in the biopsy, and more HGPIN in the pathology specimen than WA men. The AA men also had a shorter mean (sd) PSA doubling time before RP, at 4.2 (4.7) vs 5.2 (5.9) years. However, race was not an independent predictor of PSA recurrence (P = 0.225). Important predictors for PSA recurrence in a multivariable model were biopsy HGPIN (P < 0.014), unilateral vs bilateral cancer (P < 0.006), pathology Gleason score and positive margin status (both P < 0.001). CONCLUSIONS: This study indicates that while there are racial differences in baseline serum PSA and incidence of HGPIN, race is not an independent risk factor for PSA recurrence. Rather, other variables such as pathology Gleason score, bilateral cancers, HGPIN and margin positivity are independently associated with PSA recurrence. The PSA doubling time after recurrence may also be important, leading to the increased mortality of AA men with prostate cancer.

Black or African American↗
PubMed2005

Vitamin E therapy prevents hyperoxaluria-induced calcium oxalate crystal deposition in the kidney by improving renal tissue antioxidant status.

OBJECTIVE: To determine whether vitamin E prevents hyperoxaluria-induced stone formation, using a new animal model of calcium oxalate stone disease, as our previous in- vitro and in-vivo studies showed that oxalate and hyperoxaluria induce free-radical generation, which results in peroxidative injury to renal tubular cells. MATERIALS AND METHODS: Ethylene glycol (EG) was administered at 150 mg/day by gavage for 3 weeks to rats fed on diets with adequate (group 1), excess (group 2) or deficient (group 3) vitamin E. Several indicators of peroxidation, free radicals and enzymatic activity were then assessed. RESULTS: EG treatment in group 1 lead to increased lipid peroxidation, protein thiol, excretion of urinary enzymes, oxalate and decreases in urinary calcium, antioxidant enzymes and altered glutathione redox balance. Although renal function was not altered, there was increased water intake, urine volume and lowered urinary pH in these rats. These changes were more intense, with extensive calcium-oxalate crystal deposition, in rats in group 3, and prevented in rats in group 2, except for urinary oxalate levels, which remained high. Histopathological examination showed that there was no deposition of calcium oxalate crystals in rats in group 2. CONCLUSION: This is the first study to demonstrate in-vivo evidence that hyperoxaluria-induced peroxidative injury induces individual calcium oxalate crystal attachment in the renal tubules. In addition, excess vitamin E completely prevented calcium oxalate deposition, by preventing peroxidative injury and restoring renal tissue antioxidants and glutathione redox balance. Therefore, vitamin E therapy might provide protection against the deposition of calcium oxalate stones in the kidney of humans.

Animals↗
PubMed2005

Factors contributing to the racial differences in prostate cancer mortality.

OBJECTIVE: To analyse, in a retrospective cohort study, differences in rates of surgical treatment for prostate cancer between African-Americans and White Americans, and to evaluate the extent to which these differences are associated with disparities in survival rates between these groups. PATIENTS AND METHODS: Clinical, pathological, and demographic data from 4279 men diagnosed with clinically localized prostate cancer between 1980 and 1997 were used. The variables assessed included age, disease stage, tumour grade, comorbidities, treatment method, and socio-economic status (SES). Kaplan-Meier survival curves were generated and compared using log-rank tests. The Cox proportional hazards method was used for analyses involving adjustments for potential confounding factors. RESULTS: The surgical treatment rate was 17% for African-American and 28% for White patients (P < 0.001). In those patients treated conservatively or by radiation therapy, both crude and cancer-specific survival rates were lower for African-Americans than for Whites (P < 0.001). However, for patients undergoing surgery, differences in survival between African-Americans and Whites were not statistically significant. According to our models, SES explained 50% and surgical treatment rates approximately 34% of the differences in survival between African-Americans and Whites. CONCLUSIONS: This analysis suggests that the lower prostate cancer survival rates for the African-Americans in the present population can be largely explained by differences in SES and lower surgical treatment rates. Efforts to increase awareness of treatment options among African-American patients may be a way of improving survival in this group.

Black or African American↗
PubMed2005

Robotic-assisted anatomic radical prostatectomy: technical difficulties due to a large median lobe.

The case of a robot-assisted laparoscopic radical prostatectomy in a patient with a 143-gram prostate with a large median lobe is reported. The aim of the study was to delineate the difficulties and concern when confronted with such a situation. The technical difficulties, possible preventive methods, correction and management are discussed briefly with the hope of aiding urologists when performing radical prostatectomy in patients with large median lobe prostates.

Adenocarcinoma↗
PubMed2004

Molecular mechanism of oxalate-induced free radical production and glutathione redox imbalance in renal epithelial cells: effect of antioxidants.

BACKGROUND: Peroxidation of renal cells is a critical event in the nucleation and formation of calcium oxalate crystals under hyperoxaluric conditions. We previously demonstrated that oxalate-induced peroxidative injury is one of the major mechanisms in promoting crystal attachment to renal epithelial cells. METHODS: In this study we have demonstrated that the mechanism of oxalate-induced peroxidative injury is through the induction of TGF-beta1 and glutathione (GSH) redox imbalance in LLC-PK1 cells. RESULTS: LLC-PK1, renal epithelial cells exposed to oxalate had significantly higher reactive oxygen species (ROS) production; higher TGF-beta1 levels, as measured by ELISA (1.89 +/- 0.035 fold increase) or Western blot (1.65 +/- 0.01 fold increase); increased malondialdehyde formation; increased LDH release, and loss of cell viability. In addition, oxalate exposure significantly decreased GSH content, glutathione reductase, glucose-6-phosphate dehydrogenase activities, and increased oxidized GSH content. Treatment with vitamin E, neutralizing anti-TGF-beta antibody, or diphenylene iodium, an inhibitor of NAD(P)H oxidase, significantly inhibited oxalate-induced ROS production and prevented peroxidative injury and cytolysis. Vitamin E, catalase, or desferoxamine treatment also significantly restored the oxalate-induced cellular GSH redox status toward the control level, and vitamin E treatment significantly attenuated the oxalate-mediated increase in TGF-beta1 protein in cultured LLC-PK1 cells. CONCLUSIONS: This is the first study to demonstrate that the mechanism of oxalate-induced free radical production in renal tubular epithelial cells is through the activation of NAD(P)H oxidase via cytokine TGF-beta1 induction. These results also provide direct evidence that antioxidant therapy might prevent calcium oxalate nucleation and kidney stone formation by preventing oxalate-mediated peroxidative injury and GSH redox imbalance.

Antioxidants↗
PubMed2004

Effect of a short CAG (glutamine) repeat on human androgen receptor function.

BACKGROUND: The human androgen receptor (AR) gene contains an uninterrupted CAG repeat that is polymorphic in length in the general population (range, 11-31 CAG's; median, 21). The CAG repeat encodes a glutamine repeat in the N-terminal transactivation domain of the AR protein. We previously reported that a 17-CAG AR gene was much more common in a cohort of men with prostate cancer (8.5%) than in the general European American population (1.3%). This suggested that a 17-CAG repeat may have pathophysiological consequences. The goal of the present study was to directly test the hypothesis that a 17-CAG repeat might uniquely affect androgen action in human prostate cancer cells. METHODS: DU145 cells, lacking endogenous AR, were transiently transfected with an AR expression plasmid (with a CAG repeat ranging in length from 14 to 25) and an androgen-responsive reporter plasmid (PSA-luciferase). RESULTS: We found a significant effect of CAG repeat length on AR protein levels per unit amount of DNA transfected (one-way ANOVA, P = 0.02), indicating the need to express transactivation data per unit amount of AR protein. CAG17 AR had 40% more transactivation activity per unit amount of AR protein than CAG21 AR (P < 0.01). CONCLUSIONS: Thus, an AR with a 17-CAG repeat may mediate more efficacious growth stimulation of androgen-dependent prostate epithelial cells, and thereby increase the risk that prostate cancer cells develop more efficiently into a clinically significant cancer.

Blotting, Western↗
PubMed2004

Robot-assisted radical cystectomy and urinary diversion in female patients: technique with preservation of the uterus and vagina.

BACKGROUND: After performing more than 500 robotic radical prostatectomy and robotic radical cystoprostatectomy in men, we attempted to develop the technique of robot-assisted radical cystectomy in women. This article describes two techniques of robot-assisted radical cystectomy for women, conventional and with preservation of the uterus and vagina. To the best of our knowledge, this is the first case series of robot-assisted radical cystectomy and urinary diversion in women. STUDY DESIGN: Robot-assisted radical cystectomy was undertaken in three female patients with transitional cell carcinoma of the urinary bladder. The operation was performed with the conventional anterior approach in one patient and with a new technique in two patients, which allows preservation of urethra, uterus, vagina, and both ovaries. As planned, the radical cystectomy was done robotically, using the da Vinci Surgical System (Intuitive Surgical). The bladder was entrapped in an Endocatch bag and removed through a small subumbilical incision. Urinary reconstruction was performed extracorporeally after exteriorizing the bowel through the incision used for retrieving the specimen. In two patients, the reconstructed pouch was placed in the pelvis and the abdominal incision was closed. Urethroneovesical anastomosis was done robotically, using a technique described previously for men. RESULTS: The average operating time for the robotic radical cystectomy was 160 minutes and the mean operating times for ileal conduit and orthotopic neobladder were 130 minutes and 180 minutes, respectively. The mean blood loss was less than 100 mL. The mean number of lymph nodes removed was 12 (range 3 to 21). Surgical margins were free of tumor in all three patients. CONCLUSIONS: This approach incorporates advantages of minimally invasive and open surgery. Performing the radical cystectomy with the robot allows precise and rapid removal of the bladder with minimal blood loss. Extracorporeal reconstruction of the urinary tract reduces operative time at this stage of evolution of laparoscopic and robotic instrumentation. In the future, with the development of technology, instrumentation, and with additional refinement of our technique, the entire procedure may be done completely intracorporeally with equal efficiency.

Aged↗
PubMed2004

Robotic radical cystectomy and urinary diversion in the management of bladder cancer.

The authors have explored the versatility of the da Vinci robot for pelvic surgery to develop the technique of robotic radical cystectomy in conjunction with the Urology and Nephrology Center in Mansoura, Egypt, a world leader in conventional (open) cystectomy. This approach, which is designed to minimize the time required for surgery, is a sandwich technique in which the cystectomy and the neobladder-urethral anastomosis are performed with robotic assistance and the urinary diversion is performed extracorporeally. This article reviews the published literature and details the authors' current technique of robotic radical cystectomy and urinary diversion.

Cystectomy↗
PubMed2004

Nuances in the optimum placement of ports in pelvic and upper urinary tract surgery using the da Vinci robot.

This article shares the authors' experience in optimizing patient setup, port placement, and installation of the robot in various urologic procedures using the da Vinci robotic system. The authors give a general description on patient positioning, port placement, and installation of the robot with respect to the individual operations, followed by an explanation of important nuances, general principles, and caveats gained through experience.

Humans↗
PubMed2004

Vattikuti Institute prostatectomy, a technique of robotic radical prostatectomy for management of localized carcinoma of the prostate: experience of over 1100 cases.

Advances in surgical techniques, technology, and surgeons' skills have allowed robot-assisted radical prostatectomy to be an option in the management of organ-confined prostate cancer. The goals of the VIP technique are to cure cancer, preserve urinary continence, preserve potency, and decrease morbidity, along with the benefits of a minimally invasive surgery and excellent cosmesis. VIP is nearly equal to traditional retro-pubic prostatectomy, with certain outstanding advantages.

Equipment Design↗
PubMed2004

Surgical robotics and laparoscopic training drills.

PURPOSE: We investigated the impact of robotics on surgical skills by comparing traditional laparoscopy with the da Vinci Surgical System in the performance of various laparoscopic training drills. SUBJECTS AND METHODS: Twenty-one surgeons performed eight timed drills of increasing difficulty with a laparoscopic trainer and the da Vinci Surgical System (Intuitive Surgical Sunnyvale, CA). The mean time to drill completion, drill time variance, and statistical analysis were performed. Surgeons were also questioned about their perception of the robotic technology following completion of the drill series. RESULTS: The mean time required to complete the first drill was 69 seconds with laparoscopy and 57 seconds with the robotic system. The mean times for drill two were 67 seconds with laparoscopy and 44 seconds with robotics; for drill three, the times were 88 seconds for laparoscopy and 61 seconds for robotics, and for drill four, 186 seconds with laparoscopy and 71 seconds with robotics. Only the first drill failed to show a statistically significant difference between the laparoscopic and robotic groups. CONCLUSIONS: The robotic system allowed surgeons to complete drills faster than traditional laparoscopy. Novice laparoscopic surgeons performed three of the four drills faster robotically than did expert laparoscopic surgeons. These findings may indicate that the attributes of the robotic system level the playing field between surgeons of different skill levels. The next generation of surgeons must focus on this evolving technology and its application in the operating room of the future.

Education, Medical, Continuing↗
PubMed2004

Vattikuti Institute prostatectomy: a technique of robotic radical prostatectomy: experience in more than 1000 cases.

The Vattikuti Institute prostatectomy (VIP), a robotic radical prostatectomy approach, was conceived, designed, and refined with the goal of finding the most surgeon-friendly technique while minimizing patient morbidity and continuing to follow the standards of open radical prostatectomy. In this approach, the entire procedure is performed extraperitoneally after the ports have been placed transperitoneally and the bladder is dissected off the anterior abdominal wall. The evolution of the VIP is an amalgam of knowledge gained from the different procedures and recreated mixing in the technical nuances of robotic assistance. The procedure has been modified further from what we began with to obtain better outcomes. In our experience, robotic assistance, with its virtues of wristed movements, three-dimensional magnified vision, and filtered movements, allowed us to adjudicate a better operation with good oncologic and functional outcomes. It is also associated with decreased morbidity and earlier convalescence with excellent cosmesis. It is an ideal choice of the treatment at our center for localized cancer of prostate. Herein, the technique is described, detailing the different steps.

Humans↗