Sanket Chauhan

Publications (29) View all

• Article: Retrograde Versus Antegrade Nerve Sparing During Robot-assisted Radical Prostatectomy: Which Is Better for Achieving Early Functional Recovery?

  Young Hwii Ko, Rafael F Coelho, Ananthakrishnan Sivaraman, Oscar Schatloff, Sanket Chauhan, Haidar M Abdul-Muhsin, Rair Jose Valero Carrion, Kenneth J Palmer, Jun Cheon, Vipul R Patel
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  ABSTRACT: BACKGROUND: Although the retrograde approach to nerve sparing (NS) aimed at maximizing NS during robot-assisted radical prostatectomy (RARP) has been described, its significant benefits compared to the antegrade approach have not yet been investigated. OBJECTIVE: To evaluate the impact of NS approaches on perioperative, pathologic, and functional outcomes. DESIGN, SETTING, AND PARTICIPANTS: Five hundred one potent (Sexual Health Inventory for Men [SHIM] score >21) men underwent bilateral full NS and were followed up for a minimum of 1 yr. After propensity score matching, 344 patients were selected and were then categorized into two groups. SURGICAL PROCEDURE: RARP with antegrade NS (n=172) or RARP with retrograde NS (n=172). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Functional outcomes were assessed using validated questionnaires. Multivariable logistic regression models were applied. RESULTS AND LIMITATIONS: Positive margin rates were similar (11.1% vs 6.9%; p=0.192), and no correlation with the NS approach was found on regression analysis. At 3, 6, and 9 mo, the potency rate was significantly higher in the retrograde approach (65% vs 80.8% and 72.1% vs 90.1% and 85.3% vs 92.9%, respectively). The multivariable model indicated that the NS approach was an independent predictor for potency recovery at 3, 6, and 9 mo, along with age, gland size, and hyperlipidemia. After adjusting for these predictors, the hazard ratio (HR) for the retrograde relative to the antegrade approach was 2.462 (95% confidence interval [CI], 1.482-4.089; p=0.001) at 3, 4.024 (95% CI, 2.171-7.457; p<0.001) at 6, and 2.145 (95% CI, 1.019-4.514; p=0.044) at 9 mo. Regarding continence, the recovery rates at each time point and the mean time to regaining it were similar, and the method of NS had no effect on multivariable analysis. The absence of randomization is a major limitation of this study. CONCLUSIONS: In patients with normal erectile function who underwent bilateral full NS, a retrograde NS approach facilitated early recovery of potency compared to that with an antegrade NS approach without compromising cancer control.
  European urology 09/2012; · 7.67 Impact Factor
• Article: History of robotic surgery

  Satyam Kalan, Sanket Chauhan, Rafael F. Coelho, Marcelo A. Orvieto, Ignacio R. Camacho, Kenneth J. Palmer, Vipul R. Patel
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  ABSTRACT: Robotic surgery is one of the most advanced forms of Minimally Invasive Surgery. Although the application of robotic technology to surgical robotics started some 20years ago, the earliest work in robotics and automation can be traced back to 400 BC. Some of the early pioneers include Archytas of Arentum, Leonardo da Vinci, Gianello Toriano, and Pierre Jaquet-Droz, and we owe to these philosophers and scientists the fact that we can offer the benefit of minimal invasion in surgery. The purpose of this review is to give a brief description of the evolution of robotic surgery from its early history to present-day surgical robotics. KeywordsHistory of robotics-Unimate-PROBOT-ROBODOC-ZEUS-AESOP
  Journal of Robotic Surgery 04/2012; 4(3):141-147.
• Article: Anatomic grading of nerve sparing during robot-assisted radical prostatectomy.

  Oscar Schatloff, Sanket Chauhan, Ananthakrishnan Sivaraman, Darian Kameh, Kenneth J Palmer, Vipul R Patel
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  ABSTRACT: Because of the lack of intraoperative visual cues, the amount of nerve sparing (NS) intended by the surgeon does not always correspond to what is actually performed during surgery. Describe a standardized NS grading system based on intraoperative visual cues. A total of 133 consecutive patients who underwent robot-assisted radical prostatectomy (RARP) by a single surgeon were evaluated. The surgeon intraoperatively graded the NS independently for either side as follows: 1=no NS; 2=<50% NS; 3=50% NS; 4=75% NS; 5= ≥ 95% NS. RARP; detailed description of a five-point NS grading system. The area of residual nerve tissue on prostatectomy specimens was compared with the intraoperative NS score (NSS). The rate of positive surgical margins (PSMs) according to the NSS is also reported. In all, 52.6% of operated sides (140 of 266 sides) had NSS 5, 30.1% (80 of 266) had NSS 4, 2.3% (6 of 266) had NSS 3, 13.2% (35 of 266) had NSS 2, and 1.9% (5 of 266) had NSS 1. The area of residual nerve tissue was significantly different among the different NSSs: median area (interquartile range) for NSS 5: 0.5 (0-2) mm(2); for NSS 4: 3 (0-8) mm(2); for NSS 3: 13 (7-23) mm(2); for NSS 2: 14 (8-24) mm(2); and for NSS 1: 57 (56-165) mm(2) (p<0.001). Overall, 9.02% of the patients (12 of 133 patients) had a PSM, with 8.3% (9 of 108) for pT2 and 12% (3 of 25) for pT3. Side-specific PSMs according to NSS were 3.6% (5 of 140) for NSS 5, 7.5% (6 of 80) for NSS 4, 16.7% (1 of 6) for NSS 3, 5.7% (2 of 35) for NSS 2, and 0% (0 of 5) for NSS 1. A limitation of our study is that the key anatomic landmarks are not recognizable in every case, and this technique might not be easy to perform during the early learning curve. We believe that the visual cues exposed in this article will help surgeons achieve more consistent NS during RARP.
  European urology 04/2012; 61(4):796-802. · 7.67 Impact Factor
• Article: The role of the prostatic vasculature as a landmark for nerve sparing during robot-assisted radical prostatectomy.

  Vipul R Patel, Oscar Schatloff, Sanket Chauhan, Ananthakrishnan Sivaraman, Rair Valero, Rafael F Coelho, Bernardo Rocco, Kenneth J Palmer, Darian Kameh
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  ABSTRACT: Macroscopic landmarks are lacking to identify the cavernosal nerves (CNs) during radical prostatectomy. The prostatic and capsular arteries run along the lateral border of the prostate and could help identify the location of the CNs during robot-assisted radical prostatectomy (RARP). Describe the visual cues that have helped us achieve consistent nerve sparing (NS) during RARP, placing special emphasis on the usefulness of the prostatic vasculature (PV). Retrospective video analysis of 133 consecutive patients who underwent RARP in a single institution between January and February 2011. NS was performed using a retrograde, antegrade, or combined approach. A landmark artery (LA) was identified running on the lateral border of the prostate corresponding to either a prostatic or capsular artery. NS was classified as either medial or lateral to the LA. The area of residual nerve tissue on surgical specimens was measured to compare the amount of NS between the groups. We could identify an LA in 73.3% (195 of 266) of the operated sides. The area of residual nerve tissue was significantly different whether the NS was performed medial (between the LA and the prostate) or lateral to the LA (between the LA and pelvic side wall): median (interquartile range) of 0 (0-3) mm2 versus14 (9-25) mm2; p<0.001, respectively. The PV is an identifiable landmark during NS. Fine tailoring on the medial border of an LA can consistently result in a complete or almost complete NS, whereas performing the NS on its lateral border results in several degrees of incomplete NS.
  European urology 03/2012; 61(3):571-6. · 7.67 Impact Factor
• Article: Cavernosal nerve preservation during robot-assisted radical prostatectomy is a graded rather than an all-or-none phenomenon: objective demonstration by assessment of residual nerve tissue on surgical specimens.

  Oscar Schatloff, Sanket Chauhan, Darian Kameh, Rair Valero, Young H Ko, Ananthakrishnan Sivaraman, Rafael F Coelho, Jeff Marquinez, Kenneth J Palmer, Vipul R Patel
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  ABSTRACT: To demonstrate the existence of different degrees of nerve sparing (NS) (graded NS) by comparing the surgeon's intent of NS with the residual nerve tissue on prostatectomy specimens. We performed a prospective study of 133 consecutive patients who underwent robot-assisted radical prostatectomy in January and February of 2011. The surgeon graded the amount of NS intraoperatively independently for either side as follows: 1, no NS; 2, <50% NS; 3, 50% NS; 4, 75% NS; and 5, ≥ 95% NS. A pathologist who was unaware of the surgeon's score measured the area of residual nerve tissue on the posterolateral surface of the prostate. A greater NS score correlated significantly with a decreasing area of residual nerve tissue on the prostatectomy specimens (P < .001). Overall, the area of residual nerve tissue on the prostatectomy specimens was significantly different among the NS groups (P < .001). On specific intergroup analysis, significant differences were found in the area of residual nerve tissue on the prostatectomy specimens between the greater NS groups: NS score 3 versus 4, median 13 mm(2) (interquartile range [IQR] 7-23) versus 3 mm(2) (IQR 0-8; P = .01); NS score 4 versus 5, median 3 mm(2) (IQR 0-8) versus 0.5 mm(2) (IQR 0-2; P = .001). Subjective NS classification using the surgeon's intraoperative perception correlated significantly with the area of residual nerve tissue on the prostatectomy specimens determined by the pathologist. It is possible to intentionally tailor the amount of NS performed at surgery. This finding demonstrates that NS is a graded rather than an all-or-none phenomenon that can even go beyond the traditional concept of complete, partial, or no NS.
  Urology 03/2012; 79(3):596-600. · 2.43 Impact Factor