Observational study of medical marijuana as a treatment for treatment-resistant epilepsies.

OBJECTIVES: Medical cannabis formulations with cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) are widely used to treat epilepsy. We studied the safety and efficacy of two formulations. METHODS: We prospectively observed 29 subjects (12 to 46 years old) with treatment-resistant epilepsies (11 Lennox-Gastaut syndrome; 15 with focal or multifocal epilepsy; three generalized epilepsy) were treated with medical cannabis (1THC:20CBD and/or 1THC:50CBD; maximum of 6 mg THC/day) for ≥24 weeks. The primary outcome was change in convulsive seizure frequency from the pre-treatment baseline to the stable optimal dose phase. RESULTS: There were no significant differences during treatment on stable maximal doses for convulsive seizure frequency, seizure duration, postictal duration, or use of rescue medications compared to baseline. No benefits were seen for behavioral disorders or sleep duration; there was a trend for more frequent bowel movements compared to baseline. Ten adverse events occurred in 6/29 patients, all were transient and most unrelated to study medication. No serious adverse events were related to study medication. INTERPRETATION: Our prospective observational study of two high-CBD/low-THC formulations found no evidence of efficacy in reducing seizures, seizure duration, postictal duration, or rescue medication use. Behavioral disorders or sleep duration was unchanged. Study medication was generally well tolerated. The doses of CBD used were lower than prior studies. Randomized trials with larger cohorts are needed, but we found no evidence of efficacy for two CBD:THC products in treating epilepsy, sleep, or behavior in our population.

Influence of diabetes on plasma pharmacokinetics and brain bioavailability of grape polyphenols and their phase II metabolites in the Zucker diabetic fatty rat.

SCOPE: The effect of diabetes on the pharmacokinetics, bioavailability and brain distribution of grape polyphenols and select metabolites was studied in the Zucker diabetic fatty (ZDF) rat model. METHODS AND RESULTS: (ZDF) rats and their lean controls (LN) were dosed with a Standardized Grape Polyphenol (SGP) Mixture consisting of grape seed extract, Concord grape juice and resveratrol (RES) by oral gavage for 10 days. An 8-h pharmacokinetic study was performed. After 24 h, a second dose of SGP was administered and 1 h later animals were sacrificed and brain tissue was harvested. Plasma, urine, and brain tissue were analyzed for grape polyphenols. ZDF rats exhibited significantly diminished Cmax for all catechin, epicatechin, quercetin and resveratrol conjugated metabolites. Bioavailability was significantly lower in ZDF rats for methylated flavan-3-ol, RES, and quercetin metabolites. Significantly lower levels of metabolites of RES, quercetin, and flavan-3-ols were found in brains of ZDF rats. There was no significant difference between ZDF and LN in anthocyanins in plasma and no anthocyanins were detectable in brain extracts. ZDF rats showed significantly higher urinary excretion for all polyphenols. CONCLUSION: Diabetes may alter the overall bioavailability of some polyphenols in plasma and brain in part due to higher urinary clearance.

Non-Operative Management of Paget-Schroetter Syndrome: A Single-Center Experience.

OBJECTIVE: The preponderance of existing literature for the treatment of Paget-Schroetter syndrome (PSS) advocates clot lysis followed by thoracic outlet decompression (TOD). We postulate that long-term anticoagulation has equal outcomes to more invasive and costly surgical intervention, and review our experience with non-operative management of PSS. METHODS: A retrospective review was conducted, examining patients between 1994-2014. Forty patients were identified with PSS, and 27 of these patients had sufficient follow-up for this analysis. Charts were reviewed for details of clinical presentation, disease course, interventions, duration of oral anticoagulation, ultrasound reports, and symptoms at long-term follow-up. RESULTS: With a mean follow-up of 54.3 months, 23/27 patients (85%) were asymptomatic after non-operative therapy. In this cohort, 16/27 patients (59%) underwent catheter-directed thrombolysis. Average treatment course with oral anticoagulation was 8.6 months. Four patients (15%) remained symptomatic at follow-up. Two patients (7%) underwent thoracic outlet decompression at another institution, with good results. At least partial recanalization of vessels was documented in 25/27 patients (93%), although recanalization did not correlate with symptoms at long-term follow-up. CONCLUSIONS: Based upon equivalent functional results, non-operative management appears to offer similar outcomes for some patients with PSS. We propose a patient-tailored approach to the treatment of PSS, in which patients presenting acutely undergo catheter-directed thrombolysis, followed by a 6-12 month course of oral anticoagulation. Persistent symptoms, recurrent disease, lengthy duration of symptoms prior to diagnosis, and identifiable structural abnormalities may be factors predictive of poor outcomes after non-operative intervention.

The evidence for nonoperative management of visceral artery dissections: a single-center experience.

BACKGROUND: Spontaneous isolated visceral artery dissection is an uncommon condition encountered by clinicians. Presentation may vary from asymptomatic to acute intestinal ischemia, although a clear natural history has yet to be elucidated. No consensus exists on how best to manage these patients in the absence of true intestinal ischemia; however, much of the literature suggests that intervention is required. We present our institution's experience with 10 patients, both symptomatic and asymptomatic, all but 1 of whom was managed medically. METHODS: From September 2009 to August 2013, 10 patients presented to our institution with celiac or mesenteric artery dissection. We retrospectively reviewed these patients' clinical presentation, treatment, and follow-up. RESULTS: The mean age of the patients was 61.5 ± 10.3 (standard deviation [SD]) years (range, 41-77 years), and the mean follow-up period was 14.7 ± 11.6 (SD) months (range, 1-31 months). Four (40%) patients had abdominal pain and no ischemic changes of the bowel. There were 1 type I, 6 type II, 2 type III, and 1 type IV dissections according to Sakamoto classification. Treatments included observation without anticoagulation treatment in 8 patients (80%), anticoagulation treatment in 1 patient (10%), and endovascular stenting in 1 patient (10%) with unremitting abdominal pain. Anticoagulation was used in the 1 symptomatic patient with radiographic evidence of associated thrombus. The disease stabilized in all patients during follow-up. CONCLUSIONS: Most authors tend to advocate an endovascular or even operative repair for these processes. In our experience, most of these patients have a self-limited course of symptoms or their dissections are found incidentally. We believe that the results of conservative management in our cohort of patients support the conservative approach over the once recommended operative repair.

Outcomes of combined somatosensory evoked potential, motor evoked potential, and electroencephalography monitoring during carotid endarterectomy.

BACKGROUND: While much has been written about multiple methods of neuromonitoring during carotid endarterectomy (CEA), there has been relatively little discussion of the use of triple monitoring via somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) in conjunction with electroencephalography (EEG). Our objective was to evaluate the rate of detection and prevention of neurologic events by multinerve SEP, MEP, and EEG in patients undergoing CEA while under general anesthesia. METHODS: A prospective study of 181 consecutive patients undergoing CEA between June 2005 and September 2010 was reviewed. Intraoperative changes, including a 50% reduction in the amplitude of SEP waveforms, loss of MEP, and/or a 50% change in EEG frequency were noted as indications for shunting. This was correlated with the actual use of intraoperative shunting and postoperative neurologic sequelae at both 24 hours and 30 days. Median and tibial nerve SEPs and MEPs were also correlated. RESULTS: Eleven patients (6%) experienced intraoperative monitoring changes (SEP: 11/11; MEP: 6/11). Five of 11 patients with MEP/SEP changes underwent shunting, while the other 6 had normalization with the elevation of their blood pressure. Of the 11 patients that had neurophysiologic changes, 54% (6/11) were patients with symptomatic disease. No patients had significant EEG changes. The total shunt rate was 2.7% (5/181). No postoperative neurologic sequelae were noted. CONCLUSION: The ratio of shunting at 2.7% is equal to the lowest rates reported in the awake patient literature. Interestingly, the predicted synergy of multimodality monitoring cannot be directly attributed to an increased specificity resulting from the addition of SEP and MEP to EEG, because no patients had EEG changes. In addition, in today's cost-conscious world of health care, our results do not justify implementing this particular technique of neuromonitoring across the board-but it is apparent that the combination of these 3 modalities is both safe and effective with potential applications in symptomatic patients.

Towards neuronal organoids: a method for long-term culturing of high-density hippocampal neurons.

One of the goals in neuroscience is to obtain tractable laboratory cultures that closely recapitulate in vivo systems while still providing ease of use in the lab. Because neurons can exist in the body over a lifetime, long-term culture systems are necessary so as to closely mimic the physiological conditions under laboratory culture conditions. Ideally, such a neuronal organoid culture would contain multiple cell types, be highly differentiated, and have a high density of interconnected cells. However, before these types of cultures can be created, certain problems associated with long-term neuronal culturing must be addressed. We sought to develop a new protocol which may further prolong the duration and integrity of E18 rat hippocampal cultures. We have developed a protocol that allows for culturing of E18 hippocampal neurons at high densities for more than 120 days. These cultured hippocampal neurons are (i) well differentiated with high numbers of synapses, (ii) anchored securely to their substrate, (iii) have high levels of functional connectivity, and (iv) form dense multi-layered cellular networks. We propose that our culture methodology is likely to be effective for multiple neuronal subtypes-particularly those that can be grown in Neurobasal/B27 media. This methodology presents new avenues for long-term functional studies in neurons.

Reevaluation of the evolutionary events within recA/RAD51 phylogeny.

BACKGROUND: The recA/RAD51 gene family encodes a diverse set of recombinase proteins that affect homologous recombination, DNA-repair, and genome stability. The recA gene family is expressed across all three domains of life - Eubacteria, Archaea, and Eukaryotes - and even in some viruses. To date, efforts to resolve the deep evolutionary origins of this ancient protein family have been hindered by the high sequence divergence between paralogous groups (i.e. ~30% average pairwise identity). RESULTS: Through large taxon sampling and the use of a phylogenetic algorithm designed for inferring evolutionary events in highly divergent paralogs, we obtained a robust, parsimonious and more refined phylogenetic history of the recA/RAD51 superfamily. CONCLUSIONS: In summary, our model for the evolution of recA/RAD51 family provides a better understanding of the ancient origin of recA proteins and the multiple events that lead to the diversification of recA homologs in eukaryotes, including the discovery of additional RAD51 sub-families.

Statins reduce neurologic injury in asymptomatic carotid endarterectomy patients.

BACKGROUND AND PURPOSE: Statins are neuroprotective in a variety of experimental models of cerebral injury. We sought to determine whether patients taking statins before asymptomatic carotid endarterectomy exhibit a lower incidence of neurological injury (clinical stroke and cognitive dysfunction). METHODS: A total of 328 patients with asymptomatic carotid stenosis scheduled for elective carotid endarterectomy consented to participate in this observational study of perioperative neurological injury. RESULTS: Patients taking statins had a lower incidence of clinical stroke (0.0% vs 3.1%; P=0.02) and cognitive dysfunction (11.0% vs 20.2%; P=0.03). In a multivariate regression model, statin use was significantly associated with decreased odds of cognitive dysfunction (odds ratio, 0.51 [95% CI, 0.27-0.96]; P=0.04). CONCLUSIONS: Preoperative statin use was associated with less neurological injury after asymptomatic carotid endarterectomy. These observations suggest that it may be possible to further reduce the perioperative morbidity of carotid endarterectomy. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00597883.

Endoleaks with the AneuRx graft: a longer-term, single-center study.

PURPOSE: To report the frequency of endoleaks after endovascular aneurysm repair (EVAR) with the AneuRx graft. MATERIAL AND METHODS: The study group included 121 consecutive patients treated with the first-generation AneuRx graft before December 2005, which ensured a potential minimum follow-up of 5 years. RESULTS: Thirty-seven patients (31%) had 45 different endoleaks at varying times in their follow-up. There were 18 type I endoleaks (15%), 56% of which developed more than 5 years after EVAR. All 12 type Ia endoleaks were associated with dilation of the neck of the aneurysm by a mean of 8.5 mm at a median follow-up of 4 years. Ten of the 12 type Ia endoleaks were judged to have very favorable necks for EVAR. Five additional patients being followed had documented neck dilation and/or migration without evidence of endoleak or aneurysm enlargement. All type II endoleaks were noted in the first 2 years, and one persisted untreated for 9 years. CONCLUSIONS: Type I endoleaks continue to appear over time, and 56% occurred at 5 years or later after EVAR. All were associated with dilation at the attachment site, and all type Ia endoleaks had migration. As type Ia endoleaks may not always be amenable to endovascular repair, EVAR should be considered a less attractive option for some patients whose life expectancy is predicted to exceed 10 years.

The effect of percutaneous intervention on wound healing in patients with mixed arterial venous disease.

BACKGROUND: Open venous ulcers in patients with combined arterial and venous insufficiency are notoriously hard to treat. Patients with an ankle-brachial index (ABI) of 0.5-0.8 have been shown to heal poorly. Because adequate compression therapy is contraindicated in patients with an ABI of <0.7, we decided to undertake an aggressive approach of percutaneous revascularization for these patients. METHODS: A total of 27 patients with clinical and duplex scan evidence of chronic venous insufficiency, active leg ulcers, and impaired arterial perfusion (ABI: <0.7) were treated using a protocol that required performing percutaneous revascularization before ambulatory compression therapy. The patients were followed at 2-week intervals (average) before and after revascularization. Wound measurements and time to complete closure were also recorded. RESULTS: The results of the patients were compared with their own previous wound healing trajectories. Additionally, their healing rate was compared with previously published rates of impaired arterial perfusion venous wound closure; 25% closure at 10 weeks, 50% at 19 weeks. At enrollment, the average ABI and wound sizes were 0.56 and 12 cm(2), respectively. On average, the wounds had remained open for 17 weeks. After the intervention, the average ABI was 0.97, average time taken to complete closure was 10 weeks, closure rate at 10 weeks was 75%, and absolute closure rate was 100%. CONCLUSION: Although previous studies have shown that closure of mixed arterial venous ulcers occur without arterial intervention, attaining a near normal ABI allows for timelier wound closure. Therefore, we advocate an aggressive approach of percutaneous revascularization in this population.

Type II endoleaks involving an accessory renal artery and the inferior mesenteric artery.

Two patients are described with type II endoleaks involving an accessory renal artery and the inferior mesenteric artery. One patient was successfully embolized via the translumbar route. The other continues to be observed; the endoleak is expected to close spontaneously because both the inflow and outflow are significantly compromised.

Vacuum-assisted closure instill as a method of sterilizing massive venous stasis wounds prior to split thickness skin graft placement.

Patients with massive venous stasis ulcers that have very high bacterial burdens represent some of the most difficult wounds to manage. The vacuum-assisted closure (VAC) device is known to optimise wound bed preparation; however, these patients have too high a bacterial burden for simple VAC application to facilitate this function. We present the application of the VAC with instillation of dilute Dakins solution as a way of bacterial eradication in these patients. Five patients with venous stasis ulcers greater than 200 cm(2) that were colonised with greater than 10(5) bacteria were treated with the VAC instill for 10 days with 12.5% Dakins solution, instilled for 10 minutes every hour. Two patients had multi-drug-resistant pseudomonas, three with MRSA. All the five had negative quantitative cultures, prior to split thickness skin graft with 100% take and complete healing at 1 year. Adequate delivery of bactericidal agents to the infected tissue can be very difficult, especially while promoting tissue growth. By providing a single delivery system for a bactericidal agent for a short period of time followed by a growth stimulating therapy, the VAC instill provides a unique combination that appears to maximise wound bed preparation.

Laparoscopic single-site surgery for placement of adjustable gastric band--a series of 22 cases.

BACKGROUND: We present a series of 22 patients who underwent laparoendoscopic single-site (LESS) surgery for placement of an adjustable gastric band at a U.S. university hospital. METHODS: From December 2007 to December 2008, LESS surgery, through a transumbilical incision, to place an adjustable gastric band was performed on 22 patients under institutional review board approval. Multiple ports were placed through a single incision in the umbilicus to allow for liver retraction, visualization, and the working instruments. None of the critical steps of the standard pars flaccida technique were altered. RESULTS: A total of 22 patients were carefully selected and included 20 women and 2 men, with an age range of 18-67 years (mean 42). The mean body mass index was 42 kg/m(2) (range 35-45). The exclusion criteria included hepatomegaly, central obesity, previous abdominal surgery, and super-obesity. The mean operative time was 84 minutes (range 53-111). All patients were discharged home within the 23-hour admission, and no perioperative complications were noted. In addition, no wound-related complications developed. One patient required conversion to conventional laparoscopy. No intraoperative or postoperative complications occurred. CONCLUSION: In our experience, LESS surgery for adjustable gastric band placement shows this technique to be both feasible and safe in selected patients to date. Although technical limitations exist that will be improved on, additional studies are needed to compare LESS surgery for placement of an adjustable gastric band with traditional laparoscopic techniques.

Bacterial burden and wound outcomes as influenced by negative pressure wound therapy .

UNLABELLED:  Abstract: Negative pressure wound therapy (NPWT) has consistently shown significant clinical benefits in wound healing, but the mechanisms are not fully elucidated. While a reduction in bacterial burden is one possible contributor, studies have shown mixed results in this regard. The present study used a porcine infected wound model to test the effect of NPWT on bacterial burden. METHODS: Infected wounds (Pseudomonas aeruginosa, coagulase negative Staphylococcus, and Bacteroides fragilis) in a porcine model were treated with V.A.C.® therapy with the standard GranuFoam™ dressing, V.A.C. therapy with the GranuFoam Silver® dressing, or moist gauze for a period of 7 days with three dressing changes. Quantitative and semiquantitative bacterial cultures, histological samples, and digital photographs were taken at dressing changes. RESULTS: The wounds continued to show gross and microscopic improvement when treated with standard NPWT and NPWT with silver compared to moist wound care controls. However, the bacterial burden in all wounds continued to increase and broadened to include local skin flora, which had been absent immediately after wounding. These increases in bacteria were not affected by the use of silver dressings. CONCLUSION: Negative pressure wound therapy with either standard NPWT foam or silver NPWT foam produced significant improvements in local wound appearance. This occurred despite a persistently high level of bacterial infection; thus, the improvement in healing of these infected wounds cannot be explained by a change in the bacterial burden. .

Single-incision laparoscopic cholecystectomy using a flexible endoscope.

OBJECTIVE: To describe our experience with a single-incision laparoscopic cholecystectomy (SILC) performed using a flexible endoscope as the means of visualization and surgical dissection. The use of flexible endoscopy in intra-abdominal surgery has never been described. DESIGN: Prospective observational case series. PATIENTS: Eleven patients with symptomatic cholelithiasis were selected based on age, clinical presentation, body habitus, and history of previous abdominal surgery. Patients with acute or chronic cholecystitis were excluded. RESULTS: All procedures were completed laparoscopically via the single umbilical incision without the need to convert to an open operation and without introduction of any additional laparoscopic instruments or trocars. The mean operative time was 149.5 minutes (range, 99-240 minutes). The mean length of hospital stay was 0.36 days. There were no associated intraoperative or postoperative complications. CONCLUSIONS: In our experience, SILC performed with a flexible endoscope is feasible and safe. Further studies are needed to determine its advantages in reference to postoperative pain and complication rate in juxtaposition with the current standard laparoscopic cholecystectomy.

Analysis of patient cost for recombinant human platelet-derived growth factor therapy as the first-line treatment of the insured patient with a diabetic foot ulcer.

INTRODUCTION: The 2-year cost of a new diabetic foot ulcer (DFU) is estimated to be $27,987. These costs are thought to be secondary to hospitalization, amputation, and the duration of care. Treatments that accelerate rapid and complete healing of DFUs reduce the need for hospitalization, thus reducing the costs of care. One of the therapies previously shown to lead to more rapid and complete wound healing of DFUs is recombinant human platelet-derived growth factor (rhPDGF). Many centers, however, do not initiate rhPDGF therapy, based on patient cost issues. Therefore, many centers reserve a potentially cost-saving therapy as a second- or third-line therapy. The goal of the authors' analysis was to examine the actual cost to patients of a policy of initiating rhPDGF as the initial therapy for appropriately debrided DFUs. METHODS: A 12-month retrospective analysis of all patients presenting to a tertiary care referral wound practice with the diagnosis of DFUs was performed. The algorithm the authors followed specified that all wounds of patients with an ankle brachial index of greater than 0.7 and a diagnosis of DFUs (that were not enrolled in a research protocol) were debrided widely (ie, all wounds were debrided sharply with a 45-degree bevel on the border and the bases of the wounds were sharply debrided to a clean granular base), provided off-loading, and initiated on rhPDGF at the patients' first center visit. The patient payer mix and average cost-per-patient per year were analyzed, and the average number of tubes of rhPDGF was recorded. RESULTS: There were 121 patients with the diagnosis of DFUs, representing 766 visits. A total of 187 tubes of rhPDGF were prescribed for these 121 patients over the course of 12 months. There was an average use of 1.54 tubes per patient. The primary payer mix was Medicare, 44%; Medicaid, 27%; and private-payer mix, 29%, representing 10 companies. The average patient cost per tube was $28, the average cost for Medicare was $25 (many with secondary payers, as data predate 2006 Medicare D), Medicaid was $2, and private insurance was $71. Therefore, the average patient cost per course of therapy was $42. DISCUSSION: The average cost to patients with prescription benefits for a course of rhPDGF therapy, over a diverse and representative patient mix, is less than $50 in an inner-city tertiary care facility. Thus, patient cost alone should not provide a barrier to initiating active therapy in the form of rhPDGF to the patient presenting with a DFU. This early initiation could potentially lead to lower overall health costs by improving wound-healing outcomes.

Neuropsychological dysfunction in the absence of structural evidence for cerebral ischemia after uncomplicated carotid endarterectomy.

OBJECTIVE: Neurocognitive dysfunction has been shown to occur in roughly 25% of patients undergoing carotid endarterectomy (CEA). Despite this, little is known about the mechanism of this injury. Recently, several groups have shown that new diffusion weighted imaging (DWI)-positive lesions are seen in 20% of patients undergoing CEA. We investigated to what degree neurocognitive dysfunction was associated with new DWI lesions. METHODS: Thirty-four consecutive patients undergoing CEA were subjected to pre- and postoperative cognitive evaluation with a battery of neuropsychological tests. Postoperative magnetic resonance imaging was performed in all patients within 24 hours of surgery. Lesions that showed high signal on DWI and restricted diffusion on apparent diffusion coefficient maps but no abnormal high signal on the fluid-attenuated inversion recovery images were considered hyperacute. RESULTS: Cognitive dysfunction was seen in eight (24%) patients. New hyperacute DWI lesions were seen in three (9%). Only one (13%) of the patients with cognitive dysfunction had a new DWI lesion. Two thirds of the new DWI lesions occurred in the absence of cognitive deterioration. Patients with cognitive dysfunction had significantly longer carotid cross-clamp times. CONCLUSION: Neurocognitive dysfunction after CEA does not seem to be associated with new DWI positive lesions.

The LapSim: a learning environment for both experts and novices.

BACKGROUND: Simulated environments present challenges to both clinical experts and novices in laparoscopic surgery. Experts and novices may have different expectations when confronted with a novel simulated environment. The LapSim is a computer-based virtual reality laparoscopic trainer. Our aim was to analyze the performance of experienced basic laparoscopists and novices during their first exposure to the LapSim Basic Skill set and Dissection module. METHODS: Experienced basic laparoscopists (n=16) were defined as attending surgeons and chief residents who performed >30 laparoscopic cholecystectomies. Novices (n=13) were surgical residents with minimal laparoscopic experience. None of the subjects had used a computer-based laparoscopic simulator in the past. Subjects were given one practice session on the LapSim tutorial and dissection module and were supervised throughout the testing. Instrument motion, completion time, and errors were recorded by the LapSim. A Performance Score (PS) was calculated using the sum of total errors and time to task completion. A Relative Efficiency Score (RES) was calculated using the sum of the path lengths and angular path lengths for each hand expressed as a ratio of the subject's score to the worst score achieved among the subjects. All groups were compared using the Kruskal-Wallis and Mann-Whitney U-test. RESULTS: Novices achieved better PS and/or RES in Instrument Navigation, Suturing, and Dissection (p<0.05). There was no difference in the PS and RES between experts and novices in the remaining skills. CONCLUSION: Novices tended to have better performance compared to the experienced basic laparoscopists during their first exposure to the LapSim Basic Skill set and Dissection module.

A novel drill set for the enhancement and assessment of robotic surgical performance.

BACKGROUND: There currently exist several training modules to improve performance during video-assisted surgery. The unique characteristics of robotic surgery make these platforms an inadequate environment for the development and assessment of robotic surgical performance. METHODS: Expert surgeons (n=4) (>50 clinical robotic procedures and >2 years of clinical robotic experience) were compared to novice surgeons (n=17) (<5 clinical cases and limited laboratory experience) using the da Vinci Surgical System. Seven drills were designed to simulate clinical robotic surgical tasks. Performance score was calculated by the equation Time to Completion + (minor error) x 5 + (major error) x 10. The Robotic Learning Curve (RLC) was expressed as a trend line of the performance scores corresponding to each repeated drill. RESULTS: Performance scores for experts were better than novices in all 7 drills (p<0.05). The RLC for novices reflected an improvement in scores (p<0.05). In contrast, experts demonstrated a flat RLC for 6 drills and an improvement in one drill (p=0.027). CONCLUSION: This new drill set provides a framework for performance assessment during robotic surgery. The inclusion of particular drills and their role in training robotic surgeons of the future awaits larger validation studies.