Lars Enochsson

Visuospatial skills and computer game experience influence the performance of virtual endoscopy

Advanced medical simulators have been introduced to facilitate surgical and endoscopic training and thereby improve patient safety. Residents trained in the Procedicus Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) laparoscopic simulator perform laparoscopic cholecystectomy safer and faster than a control group. Little has been reported regarding whether factors like gender, computer experience, and visuospatial tests can predict the performance with a medical simulator. Our aim was to investigate whether such factors influence the performance of simulated gastroscopy. Seventeen medical students were asked about computer gaming experiences. Before virtual endoscopy, they performed the visuospatial test PicCOr, which discriminates the ability of the tested person to create a three-dimensional image from a two-dimensional presentation. Each student performed one gastroscopy (level 1, case 1) in the GI Mentor II, Simbionix, and several variables related to performance were registered. Percentage of time spent with a clear view in the endoscope correlated well with the performance on the PicSOr test (r = 0.56, P < 0.001). Efficiency of screening also correlated with PicSOr (r = 0.23, P < 0.05). In students with computer gaming experience, the efficiency of screening increased (33.6% +- 3.1% versus 22.6% +- 2.8%, P < 0.05) and the duration of the examination decreased by 1.5 minutes (P < 0.05). A similar trend was seen in men compared with women. The visuospatial test PicSOr predicts the results with the endoscopic simulator GI Mentor II. Two-dimensional image experience, as in computer games, also seems to affect the outcome.

Intraoperative endoscopic retrograde cholangiopancreatography (ERCP) to remove common bile duct stones during routine laparoscopic cholecystectomy does not prolong hospitalization: a 2-year experience

Background: There is still some controversy regarding the optimal timing and best method for the removal of common bile duct stones (CBDS). Intraoperative endoscopic retrograde cholangiopancreaticography (IO-ERCP) is an alternative method that should be considered for this procedure. The aim of our study was to investigate the clinical outcome of a single-step procedure (IO-ERCP) to remove CBDS, thereby combining two existing high-volume clinical modalities—i.e., laparoscopic cholecystectomy (LC) and ERCP. Methods: Between January 2000 and December 2001, 674 patients, 192 male and 482 female, underwent cholecystectomy at our hospital. Therewere 612 LC (90.8%), 37 converted procedures (5.5%), and 25 open operations (3.7%). In 592 of the patients, (87.8%) intraoperative cholangiography (IOC) was performed. In 34 (5.7%) of those who had and IOC, an IO-ERCP was performed. While the surgeon waited for the endoscopist, care was taken to introduce a thin guidewire through the lOC catheter and pass it through the sphincter of Oddi, out into the duodenum. This complementary procedure greatly facilitated the subsequent cannulation of the bile ducts. Results: The cannulation frequency of the CBD was 100%. Common bile duct stones were successfully extracted in 93.5%. Endoscopic sphincterotomy (EST), followed by the insertion of a plastic endoprosthesis, was performed in two patients with remaining stones. The CBD of these two patients was cleared by postoperative ERCP. None of the patients developed postoperative pancreatitis. The operating time was prolonged as compared with the time for LC (192 vs 110 mins; p < 0.05). The length of hospitalization for IO-ERCP patients did not differ from that for patients undergoing cholecystectomy alone (2.6 vs 2.1. days; NS). Conclusions: The study suggests that elective IO-ERCP is a safe and efficient method for removing CBDS that has a low risk of inducing postoperative pancreatitis and does not prolong postoperative hospitalization. This technique enables perioperative extraction of CBDS without open or laparoscopic surgical exploration of the CBD and can be used safely in a routine clinical setting.

Nationwide, population-based data from 11,074 ERCP procedures from the Swedish Registry for Gallstone Surgery and ERCP

BACKGROUND The Swedish Registry for Gallstone Surgery and ERCP (GallRiks) is the first nationwide Web-based quality registry for gallstone surgery and ERCP in the world. In this article we report data from 11,074 ERCPs performed in 2007 and 2008. OBJECTIVE The aim of this study is to present outcomes, safety data, and success rates of ERCPs performed in Sweden. DESIGN Data gathering from a medical record database. PATIENTS This study reviewed 11,074 ERCPs performed in 2007 and 2008. METHODS In GallRiks, data concerning surgery performed for gallstone disease as well as all ERCPs are recorded. The registry is approved by the Swedish Surgical Society and is based on an Internet platform with online data registration. The online program includes 30-day follow-up information as well as the opportunity to retrieve electronic reports on demand. The present data represent 76% of all ERCPs performed in Sweden in 2007 and 95% of those performed in 2008. The database also has been validated, indicating a complete match between the medical records and the database in 97.3% of ERCP cases. MAIN OUTCOME MEASUREMENTS Cannulation success and perioperative and postoperative complications. RESULTS A successful bile duct cannulation was achieved in 92% of the ERCPs performed. The presence of common bile duct stones was the predominant finding and was seen in 36.8% of examinations. Perioperative and postoperative complication rates were 2.5% and 9.8%, respectively. The rate of ERCP-induced pancreatitis was 2.7%, and the total 30-day mortality rate in the database was 5.9% but varied significantly among the different diagnostic groups. The indications for ERCP differed between high-volume and low-volume centers, indicating an adequate referral pattern of complex cases in Sweden. LIMITATIONS GallRiks registration is voluntary and thus not 100%. This makes selection bias a possibility. CONCLUSION ERCP is widely used at Swedish hospitals, with acceptable cannulation success rates and perioperative and postoperative complication rates similar to established standards. GallRiks is a population-based nationwide registry with good data validity and high inclusion rates regarding ERCPs.

Effects of intraluminal pressure on regional blood flow in obstructed and unobstructed small intestines in the rat

Small bowel circulation in the rat was studied with the microsphere technique before and after 10 minutes of elevated intraintestinal pressure. A distal small bowel loop consisting of 10 vascular arcades was used. The specimens were inflated with nitrogen gas. Regional blood flow in both obstructed and unobstructed small bowels was significantly diminished by an intraintestinal pressure of 40 mm Hg. A pressure of 20 mm Hg impaired circulation only in the obstructed small intestine, whereas the unobstructed intestine did not show a similar decrease. These findings suggest that moderate intraluminal pressures can imply a potential hazard to the vulnerable capillary bed of an obstructed intestine. Hence, it is suggested that intraoperative decompression should be performed to avoid this postoperative threat to bowel viability.

The Swedish Registry of Gallstone Surgery and Endoscopic Retrograde Cholangiopancreatography (GallRiks) A Nationwide Registry for Quality Assurance of Gallstone Surgery

OBJECTIVES To describe the process of initiating and organizing a nationwide validated web-based quality registry of gallstone surgery and endoscopic retrograde cholangiopancreatography (ERCP) and to present some clinical data and the impact the registry has had on the clinical treatment of gallstones. DESIGN Observational, population-based registry study. SETTING Data from the nationwide Swedish Registry of Gallstone Surgery and ERCP (GallRiks). PATIENTS From May 1, 2005, to December 31, 2011, 63 685 cholecystectomies (laparoscopic and open) and 37 860 ERCPs have been prospectively registered in GallRiks. INTERVENTIONS Cholecystectomies, laparoscopic or conventional, as well as ERCP in a population-based setting. MAIN OUTCOME MEASURES Registrations of all cholecystectomies and ERCPs are performed online by the surgeon or endoscopist. Thirty-day follow-up of both gallstone surgery and ERCP is mandatory, as is an additional 6-month follow-up of the cholecystectomies. Scores on the 36-Item Short Form Health Survey are registered preoperatively and 6 months postoperatively in elective cholecystectomies at selected units. RESULTS The 30-day overall complication rate is 6.1% in elective cholecystectomy, 11.2% in urgent cholecystectomy, and 12.0% following ERCP. The use of antibiotic and thromboembolic prophylaxis in elective laparoscopic cholecystectomy in Sweden has decreased by 8.7% and 17.8% (2006-2011), respectively, mainly owing to presentation of GallRiks data both at meetings and published in peer-reviewed publications. The large database has also enabled several research projects, including one demonstrating that the intention to perform intraoperative cholangiography reduced the risk of death after cholecystectomy. The database has reached greater than 90% national coverage and is continuously validated. CONCLUSIONS GallRiks is a validated national quality registry for gallstone surgery and ERCP, serving as a base for audit of gallstone disease treatment. It also provides a database for clinical research.

Endoscopic Sphincterotomy and Risk of Malignancy in the Bile Ducts, Liver, and Pancreas

BACKGROUND & AIMS After endoscopic sphincterotomy (ES), an elevated long-term risk of cholangiocarcinoma has been reported. However, large population-based studies testing this hypothesis are lacking. The aim of this study was to evaluate the risk in a large population-based cohort. METHODS Data concerning all patients having had an inpatient endoscopic retrograde cholangiopancreatography (ERCP) were collected from the Swedish Hospital Discharge Register. Incident cases of malignancy were identified through linkage to the Swedish Cancer Registry. Patients with a diagnosis of malignancy before or within 2 years of the ERCP were excluded. The cohort was followed to a diagnosis of malignancy, censoring as a result of death, emigration, or end of follow-up. The risk of malignancy was calculated as standardized incidence ratio (SIR) compared with the general population, inherently adjusting for age, gender, and year of entry. RESULTS A total of 27,708 patients undergoing ERCP from 1976 through 2003 for benign disease were included in the cohort. ES was performed in 11,617 of these. The risk of malignancy in the bile ducts alone and in the bile ducts, liver, and pancreas together was significantly elevated in the total cohort (SIR, 3.3; 95% confidence interval, 2.3-4.5), irrespective of whether an ES was performed. The risk of malignancy diminished with increasing follow-up time. Patients ever having had a cholecystectomy had a significantly lower risk of the studied malignancies. CONCLUSIONS The risk of malignancy in the bile ducts, liver, or pancreas is elevated after ERCP in benign disease. However, ES does not seem to affect this risk.

Chronically Administered Islet Amyloid Polypeptide in Rats Serves as an Adiposity Inhibitor and Regulates Energy Homeostasis

Aims/Hypothesis: Islet amyloid polypeptide (IAPP) reduces food intake and body weight in laboratory animals. In addition, IAPP appears to regulate nutrient metabolism. In the present studies, we investigated the effect of chronic IAPP treatment on different aspects of energy homeostasis. Methods: IAPP was infused (25 pmol/kg/min) from subcutaneous osmotic pumps for 2–7 days. Rats in 2 saline-infused control groups were fed ad libitum (AF) or pair-fed (PF) against the IAPP-treated rats. Results: As expected, the IAPP infusion reduced food intake and body weight gain. In addition, the IAPP treatment decreased the epididymal fat pad (vs. PF rats, p < 0.05) and lowered circulating levels of triglycerides (vs. PF rats, p < 0.05), free fatty acids (vs. PF rats, p < 0.05), leptin (vs. both AF and PF rats, p < 0.05) and insulin (vs. AF rats, p < 0.05). In contrast, glucose and protein metabolism in the IAPP-treated rats was largely unchanged, as shown in results regarding serum glucose, glucose transport in skeletal muscle, blood urea nitrogen, and glycogen and protein content in the liver and in skeletal muscle. Conclusion/Interpretation: In summary, chronic IAPP exposure led to a changed lipid metabolism, which was characterized by decreased adiposity, hypolipidemia and hypoleptinemia, and to unchanged glucose and protein homeostasis. These results were similar to those seen in rodents during chronic exposure to another satiety/adiposity regulator, leptin. In conclusion, chronically administered IAPP plays a role as a satiety and adiposity signal in rats, and helps regulate energy homeostasis.

Visuospatial abilities correlate with performance of senior endoscopy specialist in simulated colonoscopy

Visuospatial abilities have been demonstrated to predict the performance of medical students in simulated endoscopy. However, little has been reported whether differences in visuospatial abilities influence the performance of senior endoscopists or whether their vast endoscopy experience reduces the importance of these abilities. Eleven senior endoscopists were included in our study. Before the simulated endoscopies in GI Mentor II (gastroscopy: case 3, module 1 and colonoscopy: case 3, module 1), the endoscopists performed three visuospatial tests: (1) pictorial surface orientation (PicSOr), (2) card rotation, and (3) cube comparison tests that monitor the ability of the tested person to re-create a three-dimensional image from a two-dimensional presentation as well as mentally manipulate that re-created image. The results of the visuospatial tests were correlated to the performance parameters of the virtual-reality endoscopy simulator. The percent of time spent with clear view in the simulated colonoscopy correlated well with the performance in the visuospatial PicSOr (r= -0.75, P = 0.01), card rotation (r = 0.75, P = 0.01), and cube comparison (r = 0.79, P = 0.004) tests. The endoscopists who performed better in the visuospatial tests also were better at maintaining visualization of the colon lumen. Those who performed better in the PicSOr test formed fewer loops during colonoscopy (r = 0.60, P = 0.05). In the technically less demanding simulated gastroscopy, there were no such correlations. The visuospatial tests performed better in endoscopists not playing computer games. Good visuospatial ability correlates significantly with the performance of experienced endoscopists in a technically demanding simulated colonoscopy, but not in the less demanding simulated gastroscopy.

Rendezvous Cannulation Technique Reduces Post-ERCP Pancreatitis: A Prospective Nationwide Study of 12,718 ERCP Procedures

OBJECTIVES:The aim of this study was to investigate if intraoperative rendezvous cannulation reduces the risk of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) because there is no universal consensus on the optimal treatment of common bile duct stones.METHODS:We performed a nationwide case–control study, nested within the cohort of ERCP procedures reported to the Swedish Registry for Gallstone Surgery and ERCP (GallRiks), between 2007 and 2009. Data were collected prospectively from a web-based registry of ERCP procedures that includes variables such as patient characteristics, indication, cannulation technique, diagnostic findings, therapeutic measures, and complications. The primary outcome was PEP.RESULTS:The registry included 12,718 ERCP procedures performed on patients without a history of previous ERCP. The risk of PEP when using the rendezvous technique compared with those who were cannulated by conventional means was reduced from 3.6 to 2.2% (odds ratio (OR) 0.5, 95% confidence interval 0.2–0.9, P=0.02). Although a significant reduction there are overall relatively few cases with PEP and the calculated numbers needed to treat to avoid one case of PEP is as high as 71. Other factors associated with increased risk of PEP were young age, prolonged procedure time, and elective ERCP.CONCLUSIONS:Rendezvous bile duct cannulation during ERCP reduces the risk of PEP from 3.6 to 2.2% compared with conventional biliary cannulation.

Selective intraoperative cholangiography and risk of bile duct injury during cholecystectomy

Whether intraoperative cholangiography can prevent iatrogenic bile duct injury during cholecystectomy remains controversial.