Psychomotor skills assessment by motion analysis in minimally invasive surgery on an animal organ.

BACKGROUND: A high level of psychomotor skills is required to perform minimally invasive surgery (MIS) safely. To be able to measure these skills is important in the assessment of surgeons, as it enables constructive feedback during training. The aim of this study was to test the validity of an objective and automatic assessment method using motion analysis during a laparoscopic procedure on an animal organ. MATERIAL AND METHODS: Experienced surgeons in laparoscopy (experts) and medical students (novices) performed a cholecystectomy on a porcine liver box model. The motions of the surgical tools were acquired and analyzed by 11 different motion-related metrics, i.e., a total of 19 metrics as eight of them were measured separately for each hand. We identified for which of the metrics the experts outperformed the novices. RESULTS: In total, two experts and 28 novices were included. The experts achieved significantly better results for 13 of the 19 instrument motion metrics. CONCLUSIONS: Expert performance is characterized by a low time to complete the cholecystectomy, high bimanual dexterity (instrument coordination), a limited amount of movement and low measurement of motion smoothness of the dissection instrument, and relatively high usage of the grasper to optimize tissue positioning for dissection.

Lack of transfer of skills after virtual reality simulator training with haptic feedback.

BACKGROUND AND OBJECTIVE: Virtual reality (VR) simulators enrich surgical training and offer training possibilities outside of the operating room (OR). In this study, we created a criterion-based training program on a VR simulator with haptic feedback and tested it by comparing the performances of a simulator group against a control group. MATERIAL AND METHODS: Medical students with no experience in laparoscopy were randomly assigned to a simulator group or a control group. In the simulator group, the candidates trained until they reached predefined criteria on the LapSim® VR simulator (Surgical Science AB, Göteborg, Sweden) with haptic feedback (XitactTM IHP, Mentice AB, Göteborg, Sweden). All candidates performed a cholecystectomy on a porcine organ model in a box trainer (the clinical setting). The performances were video rated by two surgeons blinded to subject training status. RESULTS: In total, 30 students performed the cholecystectomy and had their videos rated (N = 16 simulator group, N = 14 control group). The control group achieved better video rating scores than the simulator group (p < .05). CONCLUSIONS: The criterion-based training program did not transfer skills to the clinical setting. Poor mechanical performance of the simulated haptic feedback is believed to have resulted in a negative training effect.

The effect of duodenojejunostomy and sleeve gastrectomy on type 2 diabetes mellitus and gastrin secretion in Goto-Kakizaki rats.

BACKGROUND: Bariatric surgery is a highly effective treatment of type 2 diabetes in patients with morbid obesity. The weight-loss independent improvement of glycemic control observed after these procedures has led to the discussion whether bariatric surgery can be introduced as treatment for type 2 diabetes in patients with a body mass index < 35 kg/m(2). We have studied the effects of two bariatric procedures on type 2 diabetes and on gastrointestinal hormone secretion in a lean diabetic animal model. METHODS: Male Goto-Kakizaki rats, 17-18 weeks old, were randomized into three groups: duodenojejunostomy (DJ), sleeve gastrectomy (SG), or sham operation. During 36 postoperative weeks we evaluated body weight, fasting blood glucose, glucose tolerance, insulin, HbA1c, glucagon-like peptide 1, cholesterol parameters, triglycerides, total ghrelin, and gastrin. RESULTS: Oral glucose tolerance was significantly improved for both DJ and SG at four weeks after surgery (p < 0.05). At the 34th postoperative week, SG had significantly lower area under the curve during oral glucose tolerance test compared to sham (p = 0.007). SG had significantly lower HbA1c compared to sham at 12 weeks; (mean ± SEM) 4.3 ± 0.1 % versus 5.2 ± 0.3 % (p < 0.05) and compared to both DJ and sham 34 weeks after surgery [median (75 %;25 %)] 5.2 (6.0; 4.3) % versus 7.0 (7.5; 6.7) % and 7.3 (7.6; 6.7) % (p = 0.009). Serum gastrin levels were markedly elevated for SG compared to DJ and sham; 188.0 (318.0; 121.0) versus 77.5 (114.0; 58.0) and 68.0 (90.0; 59.5) pmol/L (p = 0.004) at six weeks and 192.0 (587.8; 110.8) versus 65.5 (77.0; 59.0) and 69.5 (113.0; 55.5) (p = 0.001) 36 weeks after surgery. CONCLUSION: Sleeve gastrectomy induces hypergastrinemia, lowers HbA1c, and improves glycemic control in Goto-Kakizaki rats. Sleeve gastrectomy is superior to duodenojejunostomy as treatment of type 2 diabetes mellitus in this animal model.

To perform operative procedures in an optimized local atmosphere: can it reduce post-operative adhesion formation?

BACKGROUND: Adhesion formation is a major problem following abdominal surgery as it creates a considerable economic burden in addition to an increased risk for complications. In the present study, an effort was made to reduce post-operative adhesion formation by creating an artificial atmosphere within and around the abdominal cavity during an open surgical procedure. METHODS: 82 Wistar male rats (Clr:WI) (200 gr, 7 weeks) were randomized into two groups. The abdominal cavity of the control group was exposed to the normal atmosphere of the operating-theatre during surgery (21% O2, 21 °C, 40-47% relative humidity (RH)), while the abdominal cavity of the study group was exposed to an artificial atmosphere during surgery (3-6% O2, >75% CO2, 95-100% RH, 37 °C). Adhesion induction consisted of a laparotomy along linea-alba, four lesions in the anterior abdominal-wall, blood from the tail vein dripped inside the abdominal cavity and exposure to the atmosphere around the wound by use of self-retaining retractors. In addition, a liquid-sample for quantitative bacteriologic cultivation and bacterial load (CFU/ml) calculation was taken just before closure. After 3 weeks the abdominal cavity was scored for the extent, tenacity and severity of adhesions before the rats were euthanized. The two-sample-Wilcoxon-rank-sum test was used in the analysis. RESULTS: Highly significant differences in postoperative total adhesion score, extent-, severity- and tenacity-score were found (P < 0.01). No differences were found between the two groups regarding mean bacterial load (P > 0.05). CONCLUSIONS: The rats exposed to the warmed and humidified artificial atmosphere consisting of more than 75% carbon dioxide and 3-4% oxygen during surgery had more severe and more post-operative adhesions compared to the rats that were exposed to the ambient air during surgery.

Urinary incontinence and risk of functional decline in older women: data from the Norwegian HUNT-study.

BACKGROUND: The main objective of the present study was to determine whether UI is an independent predictor of ADL decline and IADL decline in elderly women. We also aimed to find out whether incontinent subjects were at higher risk of needing help from formal home care or home nursing care during 11 year follow-up. METHODS: A prospective cohort study conducted as part of the North-Trøndelag Health Study 2 and 3. Women aged 70-80 years when participating in the HUNT 2 study, who also participated in the HUNT 3 study, were included in this study. Analyses on self-reported urinary incontinence at baseline and functional decline during a11-year period were performed for incontinent and continent subjects. RESULTS: Baseline prevalence of urinary incontinence was 24%. At on average eleven year follow up, logistic regression analysis showed a significant association between incontinence and decline in activities of daily living (ADL) (OR =2.37, 95% CI =1.01-5.58) (P=0.04). No association between urinary incontinence and instrumental activities of daily living (IADL) in incontinent women compared with continent women was found (OR=1.18, CI=.75-1.86) (P=.46). Data were adjusted for ADL, IADL and co morbid conditions at baseline. No significant differences in need of more help from formal home care and home nursing care between continent and incontinent women were found after 11 years of follow-up. CONCLUSIONS: Urinary incontinence is an important factor associated with functional decline in women aged 70-80 years living in their own homes. At eleven years of follow up, no significant differences in need of more help from formal home care and home nursing care between continent and incontinent women were found.

A study of psychomotor skills in minimally invasive surgery: what differentiates expert and nonexpert performance.

BACKGROUND: A high level of psychomotor skills is required to perform minimally invasive surgery (MIS) safely. To assure high quality of skills, it is important to be able to measure and assess these skills. For that, it is necessary to determine aspects that indicate the difference between performances at various levels of proficiency. Measurement and assessment of skills in MIS are best done in an automatic and objective way. The goal of this study was to investigate a set of nine motion-related metrics for their relevance to assess psychomotor skills in MIS during the performance of a labyrinth task. METHODS: Thirty-two surgeons and medical students were divided into three groups according to their level of experience in MIS; experts (>500 MIS procedures), intermediates (31-500 MIS), and novices (no experience in MIS). The participants performed the labyrinth task in the D-box Basic simulator (D-Box Medical, Lier, Norway). The task required bimanual maneuvering and threading a needle through a labyrinth of 10 holes. Nine motion-related metrics were used to assess the MIS skills of each participant. RESULTS: Experts (n = 7) and intermediates (n = 14) performed significantly better than the novices (n = 11) in terms of time and parameters measuring the amount of instrument movement. The experts had significantly better bimanual dexterity, which indicated that they made more simultaneous movements of the two instruments compared to the intermediates and novices. The experts also performed the task with a shorter instrument path length with the nondominant hand than the intermediates. CONCLUSIONS: The surgeon's performance in MIS can be distinguished from a novice by metrics such as time and path length. An experienced surgeon in MIS can be differentiated from a less experienced one by the higher ability to control the instrument in the nondominant hand and the higher degree of simultaneous (coordinated) movements of the two instruments.

Limitations of haptic feedback devices on construct validity of the LapSim® virtual reality simulator.

BACKGROUND: Surgeons performing laparoscopy need a high degree of psychomotor skills, which can be trained and assessed on virtual reality (VR) simulators. VR simulators simulate the surgical environment and assess psychomotor skills according to predefined parameters. This study aimed to validate a proficiency-based training setup that consisted of two tasks with predefined threshold values and handles with haptic feedback on the LapSim(®) VR simulator. The two tasks have been found to have construct validity in previous studies using handles without haptic feedback. METHODS: The participants were divided into three groups: novices (0-50 laparoscopic procedures), intermediates (51-300 laparoscopic procedures), and experts (more than 300 procedures). It was assumed that psychomotor skills increase with experience. All participants conducted the tasks lifting and grasping and fine dissection 20 times each. Validity of the training setup was investigated by comparing the number of times each participant passed a predefined threshold level for a set of 19 parameters. RESULTS: Construct validity was established for one parameter; "misses on right side" on the lifting and grasping task, whereas the other 18 parameters did not show construct validity. CONCLUSION: The setup employed in this study failed to establish construct validity for more than one parameter. This indicates that the simulation of haptic feedback influences the training performance on laparoscopic simulators and is an important part of validating a training setup. A haptic device should generate haptic sensations in a realistic manner, without introducing frictional forces that are not inherent to laparoscopy.

Efficacy and safety of transgastric closure in natural orifice transluminal endoscopic surgery using the OTSC system and T-bar sutures: a survival study in a porcine model.

BACKGROUND: In natural orifice transluminal endoscopic surgery (NOTES), procedures are performed with an endoscope passed through a natural orifice. One of the most important factors that will determine the future of transgastric NOTES is obtaining a reliable closure of the access site. The aim of this study was to determine the efficacy and safety of transgastric closure using the over-the-scope clip (OTSC) system or T-bar sutures. METHODS: We performed a survival study that included 15 pigs. A standardized transgastric approach to the peritoneal cavity and a peritoneoscopy were performed. The gastrotomy was closed using the OTSC system or T-bar sutures. The gastrotomy closure was tested for leaks with the methylene blue test. All animals were observed for 2 weeks before they were sacrificed and necropsy was performed. Histopathological examination of tissue samples retrieved from the access sites was performed. RESULTS: There were no perioperative complications. The methylene blue test did not demonstrate any leakage of fluid. Necropsy after 2 weeks confirmed completeness of gastric closure in all animals with full-thickness healing and no spillage of gastric contents into the peritoneal cavity. No differences between the OTSC system and T-bar sutures were observed. CONCLUSION: We observed no differences between the efficacy and safety of the OTSC system and those of T-bar sutures used in closing gastric incisions in NOTES. Both methods are safe and effective.

Pad per day usage, urinary incontinence and urinary tract infections in nursing home residents.

BACKGROUND: many elderly suffer from urinary incontinence and use absorbent pads. Pad use per day (PPD) is a frequently used measure of urinary incontinence. Nursing home residents are often dependent on help from nursing staff to change pads. This study was performed in order to determine whether PPD is a reliable method to quantify urinary incontinence in nursing home residents. Furthermore, the association between urinary tract infections (UTIs), PPD and fluid intake was studied. METHODS: data were retrieved from a multicentre, prospective surveillance among nursing home residents. Data on the use of absorbent pads, fluid intake and incontinence volumes were collected during 48 h. During a 1-year follow-up period, data on UTIs were collected. RESULTS: in this study, 153 residents were included, of whom 118 (77%) used absorbent pads. Residents who used absorbent pads were at increased risk of developing UTIs compared to residents who did not use pads (41 vs 11%; P = 0.001). Daily fluid intake was not associated with UTIs (P = 0.46). The number of pad changes showed no correlation with the risk of developing UTIs (P = 0.62). Patients with a given PPD presented a wide range of incontinence volumes. CONCLUSION: the use of absorbent pads is associated with an increased risk of developing UTIs. PPD and daily fluid intake are not correlated with the risk of developing UTIs. PPD is an unreliable measure of urinary incontinence in nursing home residents.

[Surgery without scars]. / Operasjoner uten arr.

In Natural Orifice Transluminal Endoscopic Surgery (NOTES), the procedures are performed through natural body openings, such as the mouth, vagina, urtehra and anus. By avoiding skin incisions, it is possible to prevent scars, hernias and wound infections. NOTES in humans should at this point in time only be performed within approved clinical studies.

Survival after laparoscopic surgery versus open surgery for colon cancer: long-term outcome of a randomised clinical trial.

BACKGROUND: Laparoscopic surgery for colon cancer has been proven safe, but debate continues over whether the available long-term survival data justify implementation of laparoscopic techniques in surgery for colon cancer. The aim of the COlon cancer Laparoscopic or Open Resection (COLOR) trial was to compare 3-year disease-free survival and overall survival after laparoscopic and open resection of solitary colon cancer. METHODS: Between March 7, 1997, and March 6, 2003, patients recruited from 29 European hospitals with a solitary cancer of the right or left colon and a body-mass index up to 30 kg/m(2) were randomly assigned to either laparoscopic or open surgery as curative treatment in this non-inferiority randomised trial. Disease-free survival at 3 years after surgery was the primary outcome, with a prespecified non-inferiority boundary at 7% difference between groups. Secondary outcomes were short-term morbidity and mortality, number of positive resection margins, local recurrence, port-site or wound-site recurrence, and blood loss during surgery. Neither patients nor health-care providers were blinded to patient groupings. Analysis was by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT00387842. FINDINGS: During the recruitment period, 1248 patients were randomly assigned to either open surgery (n=621) or laparoscopic surgery (n=627). 172 were excluded after randomisation, mainly because of the presence of distant metastases or benign disease, leaving 1076 patients eligible for analysis (542 assigned open surgery and 534 assigned laparoscopic surgery). Median follow-up was 53 months (range 0.03-60). Positive resection margins, number of lymph nodes removed, and morbidity and mortality were similar in both groups. The combined 3-year disease-free survival for all stages was 74.2% (95% CI 70.4-78.0) in the laparoscopic group and 76.2% (72.6-79.8) in the open-surgery group (p=0.70 by log-rank test); the difference in disease-free survival after 3 years was 2.0% (95% CI -3.2 to 7.2). The hazard ratio (HR) for disease-free survival (open vs laparoscopic surgery) was 0.92 (95% CI 0.74-1.15). The combined 3-year overall survival for all stages was 81.8% (78.4-85.1) in the laparoscopic group and 84.2% (81.1-87.3) in the open-surgery group (p=0.45 by log-rank test); the difference in overall survival after 3 years was 2.4% (95% CI -2.1 to 7.0; HR 0.95 [0.74-1.22]). INTERPRETATION: Our trial could not rule out a difference in disease-free survival at 3 years in favour of open colectomy because the upper limit of the 95% CI for the difference just exceeded the predetermined non-inferiority boundary of 7%. However, the difference in disease-free survival between groups was small and, we believe, clinically acceptable, justifying the implementation of laparoscopic surgery into daily practice. Further studies should address whether laparoscopic surgery is superior to open surgery in this setting.

Long-term outcome of laparoscopic surgery for colorectal cancer: a cochrane systematic review of randomised controlled trials.

BACKGROUND: The aim of this systematic review is to evaluate long-term outcome of laparoscopically assisted versus open surgery for non-metastasised colorectal cancer. METHODS: Cochrane library, EMBASE, Pub med and CancerLit were searched for published and unpublished randomised controlled trials. RevMan 4.2 was used for statistical analysis. RESULTS: Twelve trials (3346 patients) reported long-term outcome and were included in the current analyses. No significant differences were found between laparoscopic and open surgery in the occurrence of incisional hernias or the number of reoperations for adhesions (p=0.32 and 0.30, respectively). Port-site metastases and wound recurrences were rare and no differences in occurrence after laparoscopic and open surgery were observed (p=0.16). Cancer-related mortality at maximum follow-up was similar after laparoscopic and open surgery (p=0.15 and 0.16 for colon and rectal cancer, respectively). No significant difference in tumour recurrence after laparoscopic and open surgery for colon cancer was observed (3 RCTs, hazard ratio for tumour recurrence in the laparoscopic group 0.86; 95% CI 0.70-1.08). In colon cancer patients, no significant differences in overall mortality were found (2 RCTs, hazard ratio for overall mortality after laparoscopic surgery 0.86; 95% CI 0.86-1.07). CONCLUSIONS: Laparoscopic resection of carcinoma of the colon is associated with a long-term outcome that is similar to that after open colectomy. Laparoscopic surgery for cancer of the upper rectum is feasible, but more randomised trials need to be conducted to assess long-term outcome.

Residual urine as a risk factor for lower urinary tract infection: a 1-year follow-up study in nursing homes.

OBJECTIVES: To determine whether postvoid urine is a risk factor for the development of lower urinary tract infections (UTIs) in nursing home residents. DESIGN: Prospective surveillance with a follow-up period of 1 year. SETTING: Six Norwegian nursing homes. PARTICIPANTS: One hundred fifty nursing home residents. METHODS: Postvoid residual (PVR) urine volumes were measured using a portable ultrasound. UTIs were registered prospectively for 1 year. RESULTS: Ninety-eight residents (65.3%) had a PVR less than 100 mL, and 52 (34.7%) had a PVR of 100 mL or greater. During the follow-up period, 51 residents (34.0%) developed one or more UTIs. The prevalence of UTI in women was higher than in men (40.4% vs 19.6%; P=.02). There was no significant difference in mean PVR between residents who did and did not develop a UTI (79 vs 97 mL, P=.26). PVR of 100 mL or greater was not associated with greater risk of developing a UTI (P=.59). CONCLUSION: High PVR is common in nursing home residents. No association between PVR and UTI was found.

[Laparoscopic surgery for colorectal cancer]. / Laparoskopi ved kolorektal kreft.

BACKGROUND: It has been possible to perform colorectal operations for cancer with a laparoscopic approach for several years, but most operations are still performed by laparotomy. A systematic overview of randomized studies that compare the two techniques is presented. MATERIAL AND METHODS: Pubmed and Embase were systematically searched for relevant randomized clinical trials. RESULTS: 11 randomized clinical trials were identified. Most trials showed that laparoscopic surgery for colorectal cancer was associated with significantly longer operating time (8/11), significantly less intraoperative blood loss (5/7) and a shorter hospital stay (8/10) than open surgery. There were significantly fewer complications after laparoscopic surgery in four of 11 studies. None of the studies showed any significant differences in mortality (6/6). Survival after colon cancer surgery was reported in five studies. In one case, improved disease-free survival after laparoscopic surgery was found whereas the other four showed no significant differences. Two of these studies also included rectal cancer but did not report separate data for these patients. One study that included 28 patients found no difference in cancer-related survival after laparoscopic and open surgery for rectal cancer. INTERPRETATION: Laparoscopic surgery is an acceptable alternative to open surgery in patients with colon cancer. The procedure can be offered to patients in hospitals where experienced laparoscopic surgeons are available. In rectal cancer surgery, evidence is scarce and results from large randomized trials have to be awaited.

Laparoscopic surgery versus open surgery for colon cancer: short-term outcomes of a randomised trial.

BACKGROUND: The safety and short-term benefits of laparoscopic colectomy for cancer remain debatable. The multicentre COLOR (COlon cancer Laparoscopic or Open Resection) trial was done to assess the safety and benefit of laparoscopic resection compared with open resection for curative treatment of patients with cancer of the right or left colon. METHODS: 627 patients were randomly assigned to laparoscopic surgery and 621 patients to open surgery. The primary endpoint was cancer-free survival 3 years after surgery. Secondary outcomes were short-term morbidity and mortality, number of positive resection margins, local recurrence, port-site or wound-site recurrence, metastasis, overall survival, and blood loss during surgery. Analysis was by intention to treat. Here, clinical characteristics, operative findings, and postoperative outcome are reported. FINDINGS: Patients assigned laparoscopic resection had less blood loss compared with those assigned open resection (median 100 mL [range 0-2700] vs 175 mL [0-2000], p<0.0001), although laparoscopic surgery lasted 30 min longer than did open surgery (p<0.0001). Conversion to open surgery was needed for 91 (17%) patients undergoing the laparoscopic procedure. Radicality of resection as assessed by number of removed lymph nodes and length of resected oral and aboral bowel did not differ between groups. Laparoscopic colectomy was associated with earlier recovery of bowel function (p<0.0001), need for fewer analgesics, and with a shorter hospital stay (p<0.0001) compared with open colectomy. Morbidity and mortality 28 days after colectomy did not differ between groups. INTERPRETATION: Laparoscopic surgery can be used for safe and radical resection of cancer in the right, left, and sigmoid colon.