Use of 3-dimensional printing technology and silicone modeling in surgical simulation: development and face validation in pediatric laparoscopic pyeloplasty.

OBJECTIVES: Pediatric laparoscopy poses unique training challenges owing to smaller workspaces, finer sutures used, and potentially more delicate tissues that require increased surgical dexterity when compared with adult analogs. We describe the development and face validation of a pediatric pyeloplasty simulator using a low-cost laparoscopic dry-laboratory model developed with 3-dimensional (3D) printing and silicone modeling. DESIGN AND SETTING: The organs (the kidney, renal pelvis, and ureter) were created in a 3-step process where molds were created with 3D modeling software, printed with a Spectrum Z510 3D printer, and cast with Dragon Skin 30 silicone rubber. The model was secured in a laparoscopy box trainer. A pilot study was conducted at a Canadian Urological Association meeting. A total of 24 pediatric urology fellows and 3 experienced faculty members then assessed our skills module during a minimally invasive surgery training course. Participants had 60 minutes to perform a right-side pyeloplasty using laparoscopic tools and 5-0 VICRYL suture. Face validity was demonstrated on a 5-point Likert scale. PARTICIPANTS AND RESULTS: The dry-laboratory model consists of a kidney, a replaceable dilated renal pelvis and ureter with an obstructed ureteropelvic junction, and an overlying peritoneum with an inscribed fundamentals of laparoscopic surgery pattern-cutting exercise. During initial validation at the Canadian Urological Association, participants rated (out of 5) 4.75 ± 0.29 for overall impression, 4.50 ± 0.41 for realism, and 4.38 ± 0.48 for handling. During the minimally invasive surgery course, 22 of 24 fellows and all the faculty members completed the scoring. Usability was rated 4 or 5 by 14 participants (overall, 3.6 ± 1.22 by novices and 3.7 ± 0.58 by experts), indicating that they would use the model in their own training and teaching. Esthetically, the model was rated 3.5 ± 0.74 (novices) and 3.3 ± 0.58 (experts). CONCLUSIONS: We developed a pediatric pyeloplasty simulator by applying a low-cost reusable model for laparoscopic training and skills acquisition. The model's usability, realism, and feel are good, it can be imaged under common modalities, and it shows promise as an educational tool.

Fused video and ultrasound images for minimally invasive partial nephrectomy: a phantom study.

The shift to minimally invasive abdominal surgery has increased reliance on image guidance during surgical procedures. However, these images are most often presented independently, increasing the cognitive workload for the surgeon and potentially increasing procedure time. When warm ischemia of an organ is involved, time is an important factor to consider. To address these limitations, we present a more intuitive visualization that combines images in a common augmented reality environment. In this paper, we assess surgeon performance under the guidance of the conventional visualization system and our fusion system using a phantom study that mimics the tumour resection of partial nephrectomy. The RMS error between the fused images was 2.43mm, which is sufficient for our purposes. A faster planning time for the resection was achieved using our fusion visualization system. This result is a positive step towards decreasing risks associated with long procedure times in minimally invasive abdominal interventions.

Daily treatment with esomeprazole is superior to that taken on-demand for maintenance of healed erosive oesophagitis.

BACKGROUND: On-demand therapy with esomeprazole is effective for long-term treatment of non-erosive gastro-oesophageal reflux disease, but it has not been evaluated in erosive gastro-oesophageal reflux disease. AIMS: To compare endoscopic and symptomatic remission over a 6-month period when patients with healed erosive gastro-oesophageal reflux disease are treated with esomeprazole 20 mg, either once daily or on-demand. METHODS: Patients with verified erosive reflux oesophagitis of Los Angeles grades A-D were enrolled. Following 4-8 weeks treatment with esomeprazole 40 mg daily, those who were endoscopically healed and had symptom control during the last week were randomized to maintenance therapy for 6 months with esomeprazole 20 mg, taken either once daily or on-demand. RESULTS: Of 539 enrolled patients, 494 (91%) were healed at 8 weeks and 477 were randomized to maintenance therapy with esomeprazole 20 mg, 243 once daily and 234 on-demand. After once daily treatment, 81% of patients were still in remission at 6 months, compared with only 58% who took on-demand treatment (P < 0.0001). A difference in remission was found irrespective of baseline grade of oesophagitis, but it was more pronounced for the more severe grades. There was no difference in overall symptomatic remission between the two treatments, although heartburn was significantly more prevalent in the on-demand group. CONCLUSIONS: Once daily esomeprazole 20 mg was better than that taken on-demand for maintaining healed erosive oesophagitis, regardless of baseline Los Angeles grade.

Body mass and reflux oesophagitis: an oestrogen-dependent association?

BACKGROUND: There is widespread belief that obesity is associated with gastro-oesophageal reflux disease, but the scientific evidence is weak and contradictory. Our aim is to evaluate the relation between body mass and reflux oesophagitis. METHODS: A population-based case-control study of endoscopically verified case subjects with reflux oesophagitis, and of randomly selected, control subjects matched for age, sex and area of residence. Subjects were classified within three body mass index (BMI) categories: BMI <25 (normal in the WHO classification), BMI 25-30 (overweight) and BMI >30 (obese). Odds ratios (OR) with 95% confidence intervals (CI) were the measures of association. RESULTS: Of 179 matched case-control pairs included in the study, 71 pairs were female. In males, no association between overweight and/or obesity and the risk of reflux oesophagitis was found. In females, there was a strong association between increasing BMI and the risk of reflux oesophagitis, with an OR of 2.9 (95% CI: 1.1-7.6) in the BMI 25-30 group and 14.6 (95% CI: 2.6-80.9) in the BMI >30 group (P value for trend = 0.0007). The association between obesity and oesophagitis was further strengthened by the use of oestrogen replacement medication. CONCLUSIONS: The study discloses a strong and dose-dependent association between body mass and reflux oesophagitis in women as opposed to no association among men. This association might be caused by increased oestrogen activity in overweight and obese females.

Effect of budesonide enema on remission and relapse rate in distal ulcerative colitis and proctitis.

BACKGROUND: Glucocorticosteroid enemas are equally effective as 5-ASA enemas in the treatment of active distal ulcerative colitis (UC). With the introduction of budesonide, the risk of systemic side effects may be reduced. We investigated whether budesonide enema, 2 mg/100 ml, administered twice daily (b.i.d.) could increase the remission rate in comparison with the once daily (o.d.) standard regimen. Furthermore, we evaluated whether 2 mg budesonide enema, given twice weekly, could have a relapse preventing effect. METHODS: 149 patients with active distal UC were treated in a controlled, double-blind multicentre study with two parallel groups: placebo enema in the morning and budesonide enema in the evening (i.e. 2 mg/day) or budesonide enema b.i.d. (i.e. 4 mg/day) until remission (absence of clinical symptoms and endoscopic healing) or at most 8 weeks. Patients in remission were randomized to either budesonide enema or placebo enema twice weekly for 24 weeks or until relapse. RESULTS: The remission rates at 4 weeks were 33% for o.d. and 41% for b.i.d. regimens (NS) and correspondingly 51% and 54% at 8 weeks (NS). The b.i.d. group had an increased frequency of impaired adrenal function, 32% versus 4.8% (P = 0.001). The relapse rates during maintenance treatment with budesonide enema and placebo were 15% versus 24% after 8 weeks, 31% versus 27% after 16 weeks and 41% versus 51% after 24 weeks (NS). CONCLUSION: Budesonide enema 2 mg o.d. appears to be the optimal dosage in active distal UC. We could not show that budesonide enema twice weekly is sufficient to maintain remission.

Lansoprazole and omeprazole in the prevention of relapse of reflux oesophagitis: a long-term comparative study.

BACKGROUND: Proton pump inhibitors are superior to H2-receptor antagonists in the prevention of relapse of oesophagitis, but few data directly compare the relative efficacies of lansoprazole and omeprazole in preventing oesophagitis relapse over a prolonged period. METHODS: Patients with healed Grade II, III or IV oesophagitis were treated with lansoprazole 30 mg o.d. or omeprazole 20 mg o.d. for 48 weeks. Endoscopy and symptom assessment were performed after 12. 24 and 48 weeks of treatment and an additional symptom assessment 36 weeks after starting treatment. RESULTS: Intention-to-treat analysis included 248 patients (lansoprazole n = 126, omeprazole n = 122). Comparison of time to endoscopic and/or symptomatic relapse revealed no difference between the treatments. There was no significant difference between treatments with respect to the proportion of patients in whom endoscopic and/or symptomatic relapse was reported (lansoprazole 12/126 (9.5%), omeprazole 11/122 (9.0%)). No difference between the treatments in either the number or severity of adverse events was reported. CONCLUSIONS: Continuous treatment with either lansoprazole 30 mg or omeprazole 20 mg is effective in preventing the relapse of oesophagitis over a 48-week period in a majority of patients. Both treatments exhibit a similar side-effect profile.

Gastro-oesophageal reflux symptoms--clinical findings and effect of ranitidine treatment.

BACKGROUND: This study was performed to study the demography, effect of treatment with ranitidine and relapse pattern in patients with reflux symptoms. METHODS: Patients with reflux symptoms were examined by endoscopy and included in a double-blind, comparative trial of placebo and ranitidine 150 mg b.i.d. for two weeks. At two weeks satisfied patients continued the same treatment. Non-satisfied patients were randomised to ranitidine 150 mg b.i.d. or q.i.d for another two weeks. After four weeks medication was stopped and satisfied patients were followed for 24 weeks. No further endoscopy was performed. RESULTS: Four hundred and twenty-seven patients were randomised. At two weeks there was no significant difference between placebo and ranitidine, regarding the proportion of patients with complete relief from symptoms or satisfied with treatment. Ranitidine was superior to placebo in improving symptoms at two weeks. Ranitidine, 150 mg q.i.d. offered no additional advantage in weeks three to four over prolonging treatment with 150 mg b.i.d. after the first two weeks. Patients with oesophagitis at inclusion relapsed more than those with symptoms only, 67% compared with 52%, (p = 0.013). CONCLUSIONS: The effect of ranitidine was marginal compared to placebo. The relapse rate was high after treatment stopped.

The effect of cisapride in maintaining symptomatic remission in patients with gastro-oesophageal reflux disease.

BACKGROUND: Successful treatment of gastro-oesophageal reflux disease (GORD) has traditionally been assessed as healing of reflux oesophagitis, which may not be relevant in patients with moderate disease. In these patients symptom relief and patient satisfaction with therapy are of fundamental importance. Cisapride has well-documented prokinetic effects and may be well suited for long-term therapy of GORD, but its effectiveness in purely symptomatic treatment is unknown. We therefore compared two dosage regimens of cisapride with placebo over a period of 6 months in patients with evidence of gastrooesophageal reflux, initially treated with antisecretory medication, with regard to maintaining symptom relief and satisfaction with treatment. METHODS: Five hundred and thirty-five patients with reflux oesophagitis grade 1 (n = 293) or 2 (n = 124) or with no reflux oesophagitis but pathologic 24-h pH-metry (n = 118) achieved satisfactory symptom relief with an H2-receptor antagonist or proton pump inhibitor within 4-8 weeks. In a double-blind randomized, parallel-group study, they were then treated with cisapride, 20 mg at night or 20 mg twice daily, or placebo and followed up for a maximum period of 6 months. Relapse was defined as dissatisfaction with therapy or an average consumption of more than two antacid tablets a day. RESULTS: Median time to relapse was 63 days for cisapride, 20 mg twice daily; 59 days for cisapride, 20 mg at night; and 49 days for placebo. Time to relapse was not significantly different (P = 0.09). Presence and grade of oesophagitis at base line, type of therapy before randomization, and pattern of non-reflux symptoms at base line did not influence these findings significantly. CONCLUSION: The study indicates that cisapride is of limited value in maintenance therapy of GORD in patients in whom symptom relief has been accomplished with potent antisecretory medication. This 'step-down' approach to therapy seems disadvantageous in the long-term therapy of GORD.

Prevention of peptic ulcer and dyspeptic symptoms with omeprazole in patients receiving continuous non-steroidal anti-inflammatory drug therapy. A Nordic multicentre study.

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) are known to cause gastroduodenal lesions and dyspeptic symptoms. METHODS: Patients with a history of dyspepsia or uncomplicated peptic ulcer disease and with a need for continuous NSAID treatment were randomized to receive either 20 mg omeprazole once daily or placebo. Gastroduodenal ulcers, erosions, and dyspeptic symptoms were evaluated after 1 and 3 months. RESULTS: During a 3-month study period 4.7% (4 of 85) of omeprazole-treated patients developed peptic ulcer, compared with 16.7% (15 of 90) of patients treated with placebo. This prophylactic effect of omeprazole was sustained independently of previous peptic ulcer history or Helicobacter pylori status. Development of dyspeptic symptoms requiring active treatment, either alone or in combination with ulcer(s) or erosions, occurred in 15.3% (15 of 85) of patients treated with omeprazole and 35.6% of those who received placebo. CONCLUSIONS: Omeprazole, 20 mg once daily, provides effective prophylactic therapy in patients at risk of developing NSAID-associated peptic ulcers or dyspeptic symptoms.

Lansoprazole versus omeprazole in active duodenal ulcer. A double-blind, randomized, comparative study.

BACKGROUND: Lansoprazole is a new substituted benzimidazole that inhibits the H+,K(+)-adenosine triphosphatase in the parietal cell and, like the first developed proton pump inhibitor omeprazole, gives a strong inhibition of gastric acid output. METHODS: In this double-blind randomized comparative study patients with active duodenal ulcers were treated with either 30 mg lansoprazole or 20 mg omeprazole in the morning. All demographic data in the two treatment groups were comparable. RESULTS: A total of 279 patients entered the study. There was no difference in healing rates between the groups either after 2 weeks (86.2% for lansoprazole and 82.1% for omeprazole) or after 4 weeks (97.1% and 96.2%). No patient ceased treatment owing to side effects. CONCLUSIONS: Both lansoprazole and omeprazole generate very high healing rates and good symptom relief in active duodenal ulcer. Side effects are few and mild.

Omeprazole or ranitidine in long-term treatment of reflux esophagitis. The Scandinavian Clinics for United Research Group.

BACKGROUND/AIMS: Patients with reflux esophagitis have rapid relapses after treatment withdrawal. This study was designed to investigate the relapse rate of symptomatic esophagitis during maintenance treatment with omeprazole or ranitidine. METHODS: Patients with endoscopically verified acute erosive or ulcerative esophagitis were initially treated with 20-40 mg omeprazole daily for 8-12 weeks. After healing, the patients were randomized to maintenance treatment with omeprazole (20 or 10 mg each morning) or ranitidine (150 mg twice daily). Control endoscopy was performed at the end of the healing phase and after 12 months of maintenance treatment or symptomatic relapse. RESULTS: Of 426 initially treated patients, 392 were healed and entered the maintenance study. The months of maintenance treatment with 20 mg omeprazole once daily (n = 131), 10 mg omeprazole once daily (n = 133), and 150 mg ranitidine twice daily (n = 128) were 72%, 62%, and 45%, respectively. Both the 10- and 20-mg doses of omeprazole were significantly better than the dose of ranitidine (P < 0.001 and P < 0.005, respectively). There was no significant difference between the 10- and 20-mg doses of omeprazole (P = 0.06). CONCLUSIONS: Maintenance treatment with omeprazole (20 or 10 mg once daily) is superior to ranitidine (150 mg twice daily) in keeping patients with erosive reflux esophagitis in remission over a 12-month period.

Lansoprazole versus omeprazole in short-term treatment of reflux oesophagitis. Results of a Scandinavian multicentre trial.

To evaluate the therapeutic potential of the newly developed proton pump inhibitor lansoprazole in patients with reflux oesophagitis, we performed a double-blind randomized clinical trial comparing 20 mg omeprazole and 30 mg lansoprazole, involving 229 patients at 9 Scandinavian hospitals. The treatment period was 4 or 8 weeks, and main efficacy variables were healing of endoscopic changes, relief of reflux symptoms, and occurrence of adverse events. No significant difference in terms of healing was found, either after 4 or after 8 weeks' treatment. Patients receiving lansoprazole experienced a greater improvement in heartburn after 4 weeks (p = 0.03), and there was a similar trend for acid regurgitation. Lansoprazole was found to be an effective and safe alternative to omeprazole in short-term treatment of moderate reflux oesophagitis.

Effect of cisapride on relapse of reflux oesophagitis, healed with an antisecretory drug.

Maintenance treatment with cisapride was evaluated in 298 patients in whom reflux oesophagitis had been healed with antisecretory drugs. Initially, 34% of the patients had grade-I oesophagitis, 33% had grade II, and 33% had grade III. The patients were treated with 20 mg cisapride twice daily or placebo for 6 months or until endoscopic relapse was shown if this occurred earlier. Survival analysis showed that cisapride significantly prolonged the time to endoscopic relapse in grade-I patients (P = 0.02). The intergroup difference in symptomatic relapse in all patients was also significant (P = 0.010). The effect of cisapride was less clearcut in grade II or III, and/or in patients healed with omeprazole. Factors associated with early relapse were placebo therapy, prior omeprazole therapy, duration of pre-trial symptomatic period, and initial endoscopic severity grade. Adverse experiences were limited; diarrhoea was reported by 9% of the cisapride patients.

Two and four weeks' treatment for duodenal ulcer. Symptom relief and clinical remission comparing omeprazole and ranitidine. Scandinavian Clinics for United Research.

In a Swedish-Norwegian multicentre study patients with endoscopically verified duodenal ulcers (greater than 5 mm) were randomized to 2 or 4 weeks of treatment with either 20 mg omeprazole once daily or 300 mg ranitidine once daily. The aim was to evaluate 2 and 4 weeks' treatment with regard to symptomatic improvement during treatment, relapse after treatment, and safety of the two drugs. Endoscopy was not performed to check healing at the end of treatment. Instead the patients were instructed to contact the investigator in the event of recurrence of symptoms for renewed endoscopy. Follow-up was ended 10 weeks after stopping active treatment. Altogether 450 patients were evaluated at 17 centres. The symptomatic improvement during treatment was good in all groups, with significantly better reductions of daytime pain and heartburn in omeprazole-treated patients. Symptomatic relapse was commonest in the 2-week ranitidine group (57%), significantly more than in the 2-week omeprazole group (31%) (p less than 0.003). In the 4-week groups relapse rates were 34% (ranitidine) and 39% (omeprazole) (NS). It is suggested that in the short-term treatment of acute duodenal ulcer 20 mg omeprazole once daily is most rationally used in a 2- to 4-week regimen, whereas 300 mg ranitidine once daily should not be used for less than 4 weeks.

Sucralfate versus placebo in reflux esophagitis. A double-blind multicenter study.

The healing capacity and symptom relief were studied in 138 patients with symptomatic endoscopically verified reflux esophagitis treated with sucralfate (n = 69) or placebo (n = 69), 1 g four times daily (granules suspended in half a glass of water), for at most up to 12 weeks. The reflux esophagitis (modified Savary-Miller scale) was distributed with 71 patients having grade 1, 39 patients having grade 2 or 3, and 28 patients having grade 4. All patients were told to follow the antireflux regimen. Antacid tablets were supplied, to be used only for the relief of severe pain, and were counted. The esophageal lesions were completely healed in 42% (sucralfate) and 35% (placebo) after 6 weeks of treatment (NS). Corresponding cumulative healing rates at 12 weeks of treatment were 54% and 41% (NS), respectively. The symptom improvement, however, was significantly better in the sucralfate group after 3 weeks of treatment. The results indicate a symptomatic benefit of sucralfate in reflux esophagitis.

Relapse rate of healed duodenal, prepyloric, and gastric ulcers treated either with sucralfate or cimetidine.

A multicenter double-blind study was designed to compare the relapse rates of peptic ulcers after initial healing with a cytoprotective agent and a histamine (H2)-receptor antagonist. Patients with endoscopically verified prepyloric or duodenal ulcers were treated with cimetidine 400 mg twice daily or sucralfate 1 g four times daily for a maximum of eight weeks; gastric ulcers were treated for up to 12 weeks. Patients with healed ulcers were followed up to 12 months, during which time anti-ulcer medication was not permitted. Control endoscopy was performed two to four and nine to 11 months after healing and at the time of symptomatic relapse. A total of 258 patients were followed for 12 months; of these, 143 had been previously treated with cimetidine and 115 had been treated with sucralfate. The relapse rates and the median time to relapse did not differ between the two groups. After 12 months, 71 percent of the previously cimetidine-treated patients and 68 percent of the sucralfate-treated patients had experienced a relapse. Smoking significantly increased the relapse rate and shortened the time to relapse in the total study population and among cimetidine-treated patients; it had no such effect in the sucralfate-treated group.

Recurrent ulcer after treatment with cimetidine or sucralfate.

The recurrence of peptic ulcer disease after successful treatment with 400 mg cimetidine twice daily or 1 g sucralfate four times daily was investigated in a double-blind, 1-year follow-up study. Endoscopy was performed if ulcer symptoms recurred and 2-4 and 9-11 months after endoscopically confirmed healing of the initial ulcer. No anti-ulcer medication was permitted during the follow-up period. The recurrence rates were 71% in the cimetidine group (n = 143) and 68% in the sucralfate group (n = 115) (p greater than 0.3). The rate of asymptomatic ulcer relapse was 26% in the cimetidine and 23% in the sucralfate group (p greater than 0.4). The time to relapse did not differ between the treatment groups (p greater than 0.3). In the cimetidine group smokers had a higher 12-month recurrence rate than non-smokers, 83% compared with 58% (p less than 0.01). The corresponding figures in the sucralfate group were 76% and 57% (p = 0.057). The median time to recurrence in the cimetidine-treated group was 17 weeks among smokers, compared to 43 weeks among non-smokers (p less than 0.001). In the sucralfate-treated group the median time to recurrence was 23 weeks among smokers and 32 weeks among non-smokers (p greater than 0.3). Pre-study use of non-steroidal anti-inflammatory drugs and the time to healing of the initial ulcer did not influence the relapse rates in either of the treatment groups.

Geographic differences in the prevalence and distribution of large-bowel polyps--colonoscopic findings.

The large-bowel polyp pattern in two widely separated geographic regions of Sweden, Bollnäs in the central part and Trelleborg in the south, was studied prospectively by colonoscopic polypectomy. In Bollnäs 11.8% of 1,153 patients had neoplastic, and 3.8% hyperplastic, polyps. In Trelleborg 29% of 1,040 patients had neoplastic, and 17.3% hyperplastic, polyps. Furthermore, the Trelleborg patients had, on average, more polyps per patients than their Bollnäs counterparts: 2.0 versus 1.5 neoplastic, and 2.1 versus 1.7 hyperplastic, polyps. There was a marked difference in the anatomic location of the polyps between the two regions: in Trelleborg 55.4% of the neoplastic, and 40.5% of the hyperplastic polyps were distributed above the rectosigmoid, compared with 20.9% and 26.4%, respectively, in Bollnäs. The findings offer an explanation of the fact that the incidence of colorectal carcinoma in the Malmö region, close to the Trelleborg area, is the highest in Sweden.