Biomedical subjects

Daniel J Scott

Publications and source records attributed to Daniel J Scott.

15 recordsLinked to original sources

PubMed2006

Laparoscopic skills laboratories: current assessment and a call for resident training standards.

BACKGROUND: Numerous protocols for laparoscopic skills training using simulator-based laboratories have proven effective. However, little is known about the availability and uniformity of such facilities. The purpose of this study was to evaluate the prevalence, utilization, and costs of skills laboratories currently in use. METHODS: A survey was mailed to 253 general surgery program directors to determine the perceived value, prevalence, equipment, types of training, supervision, and costs of the labs. RESULTS: One hundred sixty-two (64%) programs completed the survey. Eighty-eight percent of responders consider skills labs effective in improving operating room performance; however, only 55% have skills labs. Of 89 programs with skills labs, 99% have videotrainer equipment (mean 3.8 trainers per lab, range 1 to 15); 46% have virtual reality trainer equipment (mean 1.7 trainers per lab, range 1 to 7). Eighty-two percent of programs teach basic skills using a variety of tasks (Rosser/Southwestern stations, MIST-VR, MISTELS, department-created); 96% teach suturing (intracorporeal, extracorporeal, suture devices). On average, residents train 0.8 hours per week (range 0 to 6). Training is mandatory in 55% and supervised in 73% of the programs. The mean development cost was 133,000 dollars (range 300 dollars to 1,000,000 dollars). CONCLUSIONS: While a large majority of program directors consider skills labs important, 45% of programs have no such facilities. Moreover, significant variability of equipment and training practices exist in currently available labs. Strategies are needed for more widespread implementation of skills labs, and standards should be developed to facilitate uniform adoption of validated curricula that reliably maximize training efficiency and educational benefit.

Clinical Competence↗

PubMed2006

Intensive continuing medical education course training on simulators results in proficiency for laparoscopic suturing.

BACKGROUND: The purpose of this study was to determine the feasibility and effectiveness of implementing a validated suturing curriculum as a free-standing continuing medical education (CME) course. METHODS: Eighteen participants (9 practicing surgeons, 9 surgery residents) attended a 4-hour laparoscopic suturing CME course. After viewing an instructional videotape all participants had their baseline performance measured on a fundamentals of laparoscopic surgery-type videotrainer suture model. Participants then practiced on the model with active instruction from 6 proctors until a previously reported proficiency level was achieved or until the course ended. Performance was scored objectively based on time and errors. Precourse and postcourse questionnaires were collected. RESULTS: Participants trained for 2.6 +/- .8 hours and performed 37 +/- 11 repetitions. Although no participant was proficient at baseline, 72% achieved the proficiency level by the end of the course. Participants showed 44% improvement in objective scores and 34% improvement according to subjective self-rating. CONCLUSIONS: Although 4 hours may be insufficient for some trainees, an intensive half-day CME course is feasible and effective in significantly improving performance and allowing the majority of participants to achieve proficiency.

Adult↗

PubMed2006

Proficiency maintenance: impact of ongoing simulator training on laparoscopic skill retention.

BACKGROUND: Proficiency-based training in laparoscopic suturing and knot tying translates to the operating room, but little is known about the durability of acquired skill. The purpose of this study was to determine the effect of maintenance training on skill retention after demonstration of proficiency. STUDY DESIGN: Medical students (n=18) with no previous laparoscopic or simulator experience were enrolled in an IRB-approved randomized controlled trial. All subjects trained to proficiency (score of 512, based on time and errors) on a previously validated suturing model (Fundamentals of Laparoscopic Surgery videotrainer). Subjects were then randomized to a control group, which received no additional training, and an ongoing training group, which trained again to proficiency at 1 and 3 months (immediately after testing). Simulator testing was repeated at 2 weeks, 1 month, 3 months, and 6 months after initial training. No subject had interval operative experience. RESULTS: Both groups demonstrated excellent skill retention during followup; performance scores, reported as means+/-SD, were 488+/-57 versus 482+/-55 at 2 weeks (p=ns), 483+/-81 versus 491+/-64 at 1 month (p=ns), 467+/-75 versus 470+/-67 at 3 months (p=ns), and 462+/-62 versus 492+/-43 at 6 months (p=0.02) for the control versus ongoing training groups, respectively. At 6 months, the ongoing training group showed better skill retention (95% versus 90%; p=0.02) and a trend for achieving the proficiency level (33% versus 18%; p=0.2) more often than the control group. CONCLUSIONS: Although proficiency-based training results in excellent skill retention, ongoing training substantially enhances performance and minimizes skill loss. Curricula should incorporate training that fosters maintenance of proficiency.

Adult↗

PubMed2005

Developing and testing competency levels for laparoscopic skills training.

HYPOTHESIS: Expert levels can be developed for use as training end points for a basic video-trainer skills curriculum, and the levels developed will be suitable for training. DESIGN: Fifty subjects with minimal prior simulator exposure were enrolled using an institutional review board-approved protocol. As a measure of baseline performance, medical students (n = 11) and surgery residents (n = 39) completed 3 trials on each of 5 validated video-trainer tasks. Four board-certified surgeons established as laparoscopic experts (with more than 250 basic and more than 50 advanced cases) performed 11 trials on each of the 5 tasks. The mean score was determined and outliers (>2 SDs) were trimmed; the trimmed mean was used as the competency level. Baseline performance of each subject was compared with the competency level for each task. SETTING: All research was performed in a laparoscopic skills training and simulation laboratory. PARTICIPANTS: Medical students, surgical residents, and board-certified surgeons. MAIN OUTCOME MEASURES: Expert scores based on completion time and the number of subjects achieving these scores at baseline testing. RESULTS: For all tasks combined, the competency level was reached by 6% of subjects by the third trial; 73% of these subjects were chief residents, and none were medical students. CONCLUSIONS: These data suggest that the competency level is suitably challenging for novices but is achievable for subjects with more experience. Implementation of this performance criterion may allow trainees to reliably achieve maximal benefit while minimizing unnecessary training.

Clinical Competence↗

PubMed2005

Robotic Laparoscopic Fundoplication.

Gastroesophageal reflux disease is a very common disorder, and both medical and surgical treatments have shown outstanding results. Whereas proton pump inhibitors are the mainstay of treatment, laparoscopic fundoplication has become a very attractive alternative due to its efficacy and low morbidity. There are defined patient categories that may benefit more from laparoscopy than medical therapy, but a conclusive comparison between the two is lacking. Robotic laparoscopic fundoplication can be performed safely without increased morbidity. Potential advantages include enhanced precision, improved dexterity, and remote telesurgical applications. Disadvantages include increased cost and prolonged operative times. Further studies and more long-term outcome data are needed to fully evaluate the procedure. Robotic surgery is currently in its infancy and not cost effective but has a very promising future. With further development of automatization and miniaturization features, robotic surgery may prove more efficient than conventional laparoscopy.

Journal Article↗

PubMed2005

Simulator training for laparoscopic suturing using performance goals translates to the operating room.

BACKGROUND: The purpose of this study was to develop a performance-based laparoscopic suturing curriculum using simulators and to test the effectiveness (transferability) of the curriculum. STUDY DESIGN: Surgical residents (PGY1 to PGY5, n = 17) proficient in basic skills, but with minimal laparoscopic suturing experience, were enrolled in an IRB-approved, randomized controlled protocol. Subjects viewed an instructional video and were pretested on a live porcine laparoscopic Nissen fundoplication model by placing three gastrogastric sutures tied in an intracorporeal fashion. A blinded rater objectively scored each knot based on a previously published formula (600 minus completion time [sec] minus penalties for accuracy and knot integrity errors). Subjects were stratified according to pretest scores and randomized. The trained group practiced on a videotrainer suturing model until an expert-derived proficiency score (512) was achieved on 12 attempts. The control group received no training. Both the trained and control groups were posttested on the porcine Nissen model. RESULTS: For the training group, mean time to demonstrate simulator proficiency was 151 minutes (range 107 to 224 minutes) and mean number of attempts was 37 (range 24 to 51 attempts). Both the trained and control groups demonstrated significant improvement in overall score from baseline. But the trained group performed significantly better than the control group at posttesting (389 +/- 70 versus 217 +/- 140, p < 0.001), confirming curriculum effectiveness. CONCLUSIONS: These data suggest that training to a predetermined expert level on a videotrainer suture model provides trainees with skills that translate into improved operative performance. Such curricula should be further developed and implemented as a means of ensuring proficiency.

Adult↗

PubMed2005

Multicenter construct validity for southwestern laparoscopic videotrainer stations.

BACKGROUND: The "Southwestern" videotrainer stations have demonstrated concurrent validity (transferability to the operating room). The purpose of this study was to evaluate the Southwestern stations for construct validity (the ability to discriminate between subjects at different levels of experience). MATERIALS AND METHODS: From two surgical training programs, Institutional Review Board approved protocol data were collected from 142 subjects, including novice (medical students and R1, n = 66), intermediate (R2-R4, n = 67), and advanced (R5 and expert surgeons, n = 9) groups. All participants performed three repetitions on each of five stations. Completion time was scored for each task. Laparoscopic experience was determined from residency case log databases and from expert surgeon personal case logs. Results for the three groups were compared using one-way ANOVA, including relevant pair-wise comparisons. Correlations between number of laparoscopic cases performed and task scores were determined by Pearson's and Spearman's rho-correlation coefficients. RESULTS: The mean number of laparoscopic cases performed prior to completing the five tasks was 0 for novices, 9 for intermediates, and 431 for the advanced group. Significant differences (P < 0.001) were noted between groups for all five tasks and composite score. Task scores and composite scores significantly correlated with laparoscopic experience (P < 0.01). CONCLUSION: These data suggest that differences in laparoscopic ability are detected by performance on the videotrainer; thus, construct validity is demonstrated. Moreover, scores accurately reflect laparoscopic experience. Further validation may allow such simulators to be used for testing and credentialing purposes.

Adult↗

PubMed2005

Skill retention following proficiency-based laparoscopic simulator training.

BACKGROUND: Proficiency-based curricula using both virtual reality (VR) and videotrainer (VT) simulators have proven to be efficient and maximally effective, but little is known about the retention of acquired skills. The purpose of this study was to assess skill retention after completion of a validated laparoscopic skills curriculum. METHODS: Surgery residents (n=14) with no previous VR or VT experience were enrolled in an Institutional Review Board-approved protocol and sequentially practiced 12 Minimally Invasive Surgical Trainer-VR and 5 VT tasks until proficiency levels were achieved. One VR (manipulate diathermy) and 1 VT (bean drop) tasks were selected for assessment at baseline, after training completion (posttest), and at retention. RESULTS: All residents completed the curriculum. Posttest assessment occurred at 13.2 +/- 11.8 days and retention assessment at 7.0 +/- 4.0 months. After an early performance decrement at posttest (17%-45%), the acquired skill was maintained up to the end of the follow-up period. For VR, scores were 81.5 +/- 23.5 at baseline, 33.3 +/- 1.8 at proficiency, 48.4 +/- 9.2 at posttest, and 48.4 +/- 11.8 at retention. For VT, scores were 49.4 +/- 12.5 at baseline, 22.0 +/- 1.4 at proficiency, 25.6 +/- 3.6 at posttest, and 26.4 +/- 4.2 at retention. Skill retention was better for VT, compared with VR (P < .02). The extent of skill deterioration did not correlate with training duration or resident level. CONCLUSIONS: Although residents do not retain all acquired skills (more so for VR than for VT) according to simulator assessment, proficiency-based training on simulators results in durable skills. Additional studies are warranted to further optimize curriculum design, investigate simulator differences, and establish training methods that improve skill retention.

Adult↗

PubMed2005

Determining standards for laparoscopic proficiency using virtual reality.

Laparoscopic training using virtual reality has proven effective, but rates of skill acquisition vary widely. We hypothesize that training to predetermined expert levels may more efficiently establish proficiency. Our purpose was to determine expert levels for performance-based training. Four surgeons established as laparoscopic experts performed 11 repetitions of 12 tasks. One surgeon (EXP-1) had extensive Minimally Invasive Surgical Trainer-Virtual Reality (MIST VR) exposure and formal laparoscopic fellowship training. Trimmed mean scores for each were determined as expert levels. A composite score (EXP-C) was defined as the average of all four expert levels. Thirty-seven surgery residents without prior MIST VR exposure and two research residents with extensive MIST VR exposure completed three repetitions of each task to determine baseline performance. Scores for EXP-1 and EXP-C were plotted against the best score of each participant. On average, the EXP-C level was reached or exceeded by 7 of the 37 (19%) residents. In contrast, the EXP-1 level was reached or exceeded by 1 of 37 (3%) residents and both research residents on all tasks. These data suggest the EXP-C level may be too lenient, whereas the EXP-1 level is more challenging and should result in adequate skill acquisition. Such standards should be further developed and integrated into surgical education.

Clinical Competence↗

PubMed2005

Restricted expression of LGR8 in intralaminar thalamic nuclei of rat brain suggests a role in sensorimotor systems.

LGR8 was recently identified as a cognate receptor for insulin-like peptide-3 (INSL3), and INSL3-LGR8 signaling is best known for its role in testis descent during development. LGR8 mRNA has been detected in various human tissues including brain, but the regional and cellular distribution of LGR8 expression in the mammalian central nervous system is unknown. Therefore, in this study we investigated the presence and localization of LGR8 mRNA in rat brain using reverse transcription-polymerase chain reaction and in situ hybridization histochemistry. Results revealed a distinct distribution of LGR8 in forebrain, with transcripts principally restricted to the posterior thalamus and highest densities detected in the parafascicular nucleus of both adult and developing rats. Unexpectedly, INSL3 mRNA was not detected in brain by similar methods, but preliminary electrophysiologic studies of parafascicular neurons revealed that INSL3 altered their activity. These findings suggest that LGR8 signaling may be involved in sensorimotor control in the rat and perhaps other species, particularly via actions on parafascicular neurons that project to basal ganglia and are depleted in Parkinson's disease.

Aging↗

PubMed2005

Detection, localization, and action of the INSL3 receptor, LGR8, in rat kidney.

Recent molecular and pharmacologic studies have identified LGR8, a member of the leucine-rich repeat-containing G-protein-coupled receptor family, as a cognate receptor for insulin-like peptide-3 (INSL3). LGR8 mRNA has been detected in various tissues, but the precise roles of these INSL3-LGR8 systems are unknown. In this study we first investigated the presence and cellular localization of LGR8 mRNA in both adult and developing rat kidney and subsequently examined the possible role of INSL3-LGR8 signaling in cultured mesangial cells. LGR8 mRNA was detected in the kidney by polymerase chain reaction and localized by in situ hybridization in mature glomerular mesangial cells within the renal cortex, with highest levels detected at embryonic day 18 and lowest levels in adult kidney. Synthetic INSL3 inhibited the proliferation of mesangial cells in primary culture, indicating the presence of functional LGR8 on these cells. These findings suggest that INSL3/LGR8 signaling may be involved in the genesis and/or developmental maturation of renal glomeruli and in the regulation of mesangial cell density in the adult kidney.

Aging↗

PubMed2004

Laparoscopic virtual reality training: are 30 repetitions enough?

BACKGROUND: Current literature suggests that novices reach a plateau after two to seven trials when training on the MIST VR laparoscopic virtual reality system. We hypothesize that significant benefit may be gained through additional training. MATERIALS AND METHODS: Second-year medical students (n = 12) voluntarily enrolled under an IRB-approved protocol for MIST VR training. All subjects completed pre- and posttraining questionnaires and performed 30 repetitions of 12 tasks. Performance data were automatically recorded for each trial. Learning curves for each task were generated by fitting spline curves to the mean overall scores for each repetition. Scores were assessed for plateaus by repeated measures, slope, and best score. RESULTS: On average, subjects completed training in 7.1 h. (range, 5.9-9.2). Two to seven performance plateaus were identified for each of the 12 MIST VR tasks. Initial plateaus were found for all tasks by the 8th repetition; however, ultimate plateaus were not reached until 21-29 repetitions. Overall best score was reached between 20 and 30 repetitions and occurred beyond the ultimate plateau for 9 tasks. CONCLUSIONS: These data indicate that a lengthy learning curve exists for novices and may be seen throughout 30 repetitions and possibly beyond. Performance plateaus may not reliably determine training endpoints. We conclude that a significant and variable amount of training may be required to achieve maximal benefit. Neither a predetermined training duration nor an arbitrary number of repetitions may be adequate to ensure laparoscopic proficiency following simulator training. Standards which define performance-based endpoints should be established.

Adult↗

PubMed2003

Laparoscopic totally extraperitoneal versus Lichtenstein herniorrhaphy: cost comparison at teaching hospitals.

Laparoscopic hernia repair is safe and effective and may result in less postoperative pain and faster recuperation compared with traditional open hernia repairs. Controversy exists as to the increased cost associated with laparoscopic repairs. The purpose of this study was to quantify and compare the cost of the totally extraperitoneal (TEP) laparoscopic repair and the tension-free Lichtenstein repair at teaching hospitals. The records of consecutive TEP (n = 28) and Lichtenstein (n = 28) repairs performed at Parkland Memorial Hospital and Zale-Lipshy University Hospital were reviewed. A detailed cost analysis was performed. Total patient charge (5,509 US dollars vs. 3,999 US dollars) and total cost (2,861 US dollars vs. 2,009 US dollars) were higher for TEP versus Lichtenstein repairs, respectively (P < 0.05). Operative time and complications were similar for both groups. Return to full activity (15 vs. 34 days) was faster for TEP versus Lichtenstein repairs, respectively (P < 0.05). Of 9 patients in the TEP group who had previously undergone an open hernia repair, 8 (89%) preferred the laparoscopic approach. The laparoscopic TEP repair costs 852 US dollars more than the Lichtenstein repair. The TEP repair results in faster recuperation. Patient preference and faster recuperation may offset the increased cost associated with laparoscopic hernia repair.

Adult↗

PubMed2002

Do preoperative finger pressures predict early arterial steal in hemodialysis access patients? A prospective analysis.

BACKGROUND: Hand ischemia resulting from arterial steal is a serious complication in patients undergoing hemodialysis access, but specific risk factors for steal remain in dispute. The purpose of this study was to determine whether plethysmographically derived finger pressures (FPs) or digital-brachial indices (DBIs) are predictive of symptomatic arterial steal. METHODS: We prospectively studied 72 patients (37 men, 35 women; mean age, 57 +/- 10 years) who were undergoing brachial artery-based hemodialysis access. All patients had complete pre- and postoperative hand examinations and FP determinations. Surgeons were blinded to preoperative FP results. RESULTS: Prosthetic graft was used in 60 patients (6-mm polytetrafluoroethylene [PTFE] in 50, tapered PTFE in 10), and brachial-based arteriovenous fistulas were created in 12. Fourteen (19%) patients developed arterial steal symptoms. The mean preoperative FP was significantly lower in steal patients than in those without steal (131 +/- 27 vs 151 +/- 31 mm Hg, P <.03). Nine (64%) of the patients with steal had DBIs <1.0, compared to 18 (31%) of the patients without steal (P =.02). However, there was no absolute FP or DBI threshold below which steal was inevitable. The occurrence of steal was attributed to proximal arterial stenoses in seven, to distal arterial disease in five, and was unknown in two. When comparing the 14 patients who developed steal to the 58 who did not, we noted that a higher proportion of steal patients had coronary artery disease (57% vs 17%, P =.005). Steal was more likely to develop in patients with arteriovenous fistulas than in patients with prosthetic grafts (43% vs 14%, P =.009). There were no significant differences in demographic factors, atherosclerotic risks (diabetes, smoking, hypertension, dyslipidemia), prevalence of peripheral vascular disease, cerebrovascular disease, shunt location, tapered vs straight graft, or number of prior grafts placed. CONCLUSIONS: These data indicate that preoperative FPs are lower in patients who develop steal syndrome after hemodialysis access. Patients with preoperative DBIs <1.0 are more likely to develop steal, but there is no DBI threshold below which steal is inevitable. Steal is more likely in patients undergoing brachial-based arteriovenous fistulas than in those receiving prosthetic grafts.

Aged↗

PubMedDate not supplied

Laparoscopic marsupialization of a giant posttraumatic splenic cyst.

BACKGROUND AND OBJECTIVE: Nonparasitic cysts are rare clinical lesions of the spleen. Causes include congenital malformations and trauma. Historically, management has entailed partial or total splenectomy using an open approach. Recently, laparoscopic approaches have been developed. In this report, we describe laparoscopic marsupialization of a giant splenic cyst (diameter > 15 cm). METHODS: A 25-year-old African-American man presented with a 9-month history of early satiety, constipation, and left upper quadrant pain. Additionally, he reported blunt trauma to the abdomen 2 years earlier. Physical examination revealed a large, fixed, nontender left upper quadrant mass. Computed tomography scan confirmed a simple cyst within the spleen, measuring 20 x 25 cm. Echinococcus and Entamoeba histolytica serologies were negative. Laparoscopic exploration was performed. Four liters of brown fluid were aspirated and intraoperative cytology confirmed a nonparasitic cyst. The cyst wall was excised and the cavity was packed with omentum. RESULTS: The patient's recovery was uneventful, and he was discharged to home tolerating a regular diet on postoperative day 3. At 6-month follow-up, the patient was asymptomatic and showed no evidence of recurrence. CONCLUSION: Nonparasitic splenic cysts are rare lesions. Laparoscopic marsupialization is safe and effective for giant nonparasitic splenic cysts and should be considered the treatment of choice.

Abdominal Injuries↗