Computer-assisted detection versus conventional colonoscopy for proximal colonic lesions: a multicenter, randomized, tandem-colonoscopy study.

BACKGROUND AND AIMS: Computer-assisted detection (CADe) is a promising technologic advance that enhances adenoma detection during colonoscopy. However, the role of CADe in reducing missed colonic lesions is uncertain. The aim of this study was to determine the miss rates of proximal colonic lesions by CADe and conventional colonoscopy. METHODS: This was a prospective, multicenter, randomized, tandem-colonoscopy study conducted in 3 Asian centers. Patients were randomized to receive CADe or conventional white-light colonoscopy during the first withdrawal of the proximal colon (cecum to splenic flexure), immediately followed by tandem examination of the proximal colon with white light in both groups. The primary outcome was adenoma/polyp miss rate, which was defined as any adenoma/polyp detected during the second examination. RESULTS: Of 223 patients (48.6% men; median age, 63 years) enrolled, 7 patients did not have tandem examination, leaving 108 patients in each group. There was no difference in the miss rate for proximal adenomas (CADe vs conventional: 20.0% vs 14.0%, P = .07) and polyps (26.7% vs 19.6%, P = .06). The CADe group, however, had significantly higher proximal polyp (58.0% vs 46.7%, P = .03) and adenoma (44.7% vs 34.6%, P = .04) detection rates than the conventional group. The mean number of proximal polyps and adenomas detected per patient during the first examination was also significantly higher in the CADe group (polyp: 1.20 vs .86, P = .03; adenoma, .91 vs .61, P = .03). Subgroup analysis showed that CADe enhanced proximal adenoma detection in patients with fair bowel preparation, shorter withdrawal time, and endoscopists with lower adenoma detection rate. CONCLUSIONS: This multicenter trial from Asia confirmed that CADe can further enhance proximal adenoma and polyp detection but may not be able to reduce the number of missed proximal colonic lesions. (Clinical trial registration number: NCT04294355.).

Robotic Natural Orifice Transluminal Endoscopic Surgery Hysterectomy and Salpingo-Oophorectomy in a Porcine Model.

Purpose. The emergence of robotic-assisted surgical techniques has gained significant indications in terms of reduced trauma, shortened recovery, and higher patients' satisfaction. However, limitations by present surgical robotic systems used in natural orifice transluminal endoscopic surgery (NOTES) gynecology still exists, such as arm collisions, countertraction, instrument dexterity, and, in particular, space confinement due to the narrow pelvic anatomy. The current study evaluated the use of a miniaturized single-site surgical robotic system and its feasibility in performing robotic NOTES gynecological procedures using a live porcine animal model. Methods. Using a transrectal approach, the fully internalized robotic arms were deployed in a reverse configuration to access the lower pelvic cavity of the animals to perform NOTES gynecological procedures. Results. Robotic-assisted transrectal gynecological procedures were successfully performed using the new robotic system. A hemi-hysterectomy with unilateral salpingo-oophorectomy was completed in the first animal and a total hysterectomy with bilateral salpingo-oophorectomy in the second animal with an average docking time of 22.5 minutes and console time of 63 minutes and 58 minutes, respectively. The overall blood loss for each procedure was estimated to be <20 mL per animal with no intraoperative complications. Conclusions. The reverse configuration of the miniaturized surgical robotic system has demonstrated its capability to provide a potential solution to maintain clear visualization of the surgical field, optimal triangulation, and dexterity robotic NOTES gynecological procedures within the deep confined space of the pelvic cavity.

Feasibility study of a single-use balloon-assisted robotic colonoscope in healthy volunteers.

Background and study aims Despite its widespread adoption, colonoscope still has its limitations. Advancement is often limited by the looping of colon. The isolation of SARS-CoV-2 in stool raises concern for the risk of disease transmission. A single-use robotic colonoscope, the NISInspire-C System, that features a balloon-suction anchorage mechanism was developed to address these. Methods The NISInspire-C balloons are designed to provide anchorage for straightening of the colon during advancement. Angulation at the bending section is tendon-wire driven by servo mechanisms integrated into a robotic control console. This was a pilot, prospective trial to evaluate the safety and feasibility of this system. Healthy volunteers underwent examination with the NISInspire-C, followed by the conventional colonoscope. The procedure time, cecal intubation rates (CIR), complications, and level of pain were measured. Results A total of 19 subjects underwent the examination. The cecal intubation rate was 89.5 % (17/19) and the overall time-to-cecum was 26.3 minutes (SD: 17.9 mins). There were no procedure-related complications. Polyps were detected in seven of 19 (36.8 %) subjects during the NISInspire-C procedure. Three more subjects were found to have adenomatous polyps with the conventional colonoscope. There was minimal variation in level of pain during the procedures with the two colonoscopes. Conclusion The single-use robotic colonoscope NISInspire-C is a safe and feasible alternative to the conventional colonoscope. Further technical refinement is needed to improve the CIR. This study was limited by its small sample size.

New insights on missed colonic lesions during colonoscopy through artificial intelligence-assisted real-time detection (with video).

BACKGROUND AND AIMS: Meta-analysis shows that up to 26% of adenomas could be missed during colonoscopy. We investigated whether the use of artificial intelligence (AI)-assisted real-time detection could provide new insights into mechanisms underlying missed lesions during colonoscopy. METHODS: A validated real-time deep-learning AI model for the detection of colonic polyps was first tested in videos of tandem colonoscopy of the proximal colon for missed lesions. The real-time AI model was then prospectively validated in a total colonoscopy in which the endoscopist was blinded to real-time AI findings. Segmental unblinding of the AI findings were provided, and the colonic segment was then re-examined when missed lesions were detected by AI but not the endoscopist. All polyps were removed for histologic examination as the criterion standard. RESULTS: Sixty-five videos of tandem examination of the proximal colon were reviewed by AI. AI detected 79.1% (19/24) of missed proximal adenomas in the video of the first-pass examination. In 52 prospective colonoscopies, real-time AI detection detected at least 1 missed adenoma in 14 patients (26.9%) and increased the total number of adenomas detected by 23.6%. Multivariable analysis showed that a missed adenoma(s) was more likely when there were multiple polyps (adjusted odds ratio, 1.05; 95% confidence interval, 1.02-1.09; P < .0001) or colonoscopy was performed by less-experienced endoscopists (adjusted odds ratio, 1.30; 95% confidence interval, 1.05-1.62; P = .02). CONCLUSIONS: Our findings provide new insights on the prominent role of human factors, including inexperience and distraction, on missed colonic lesions. With the use of real-time AI assistance, up to 80% of missed adenomas could be prevented. (Clinical trial registration number: NCT04227795.).

Emerging next-generation robotic colonoscopy systems towards painless colonoscopy.

Advances in the field of robotics have allowed modern technology to be integrated into medicine and that can minimize patients suffering from the side effects that are inherent to procedures for improving their quality of life. Conventional devices that are used for colonoscopies are rigid and require a high level of expertise from endoscopists to perform the procedure. Advances in robot-assisted colonoscopic systems now produce softer, more slender, automated designs that no longer require the operator to use forceful pushing to advance the colonoscope inside the colon, reducing risks to the patient of perforation and pain. It is challenging to reprocess these scopes for reuse as the materials used can be damaged during decontamination, leading to the possible risks of cross-infection by pathogenic microorganisms when reused by patients. An ideal solution is to eliminate these contamination risks to patients by adopting sterile, single-use scopes straight from the manufacturer's package to the patient. With this idea in mind, emerging developments that push the boundaries in this area will benefit patients and encourage the public to participate in and adhere better to colonoscopy screening to reduce the development of colorectal cancer. Thus, in light of these concerns and challenges, to encourage patients undergoing colorectal screening to comply with colonoscopy procedures that they are less invasive, changes in the design and materials are necessary. One of the more promising technological advances in this area is the advent of robotic colonoscopy.

Robotic-Assisted Transrectal Cholecystectomy in a Porcine Model.

Background. With increasing experience and technological advancement in surgical instruments, surgeons have explored the feasibility of single-incision laparoscopic surgery and natural orifice transluminal endoscopic surgery (NOTES). These techniques aim to further reduce surgical trauma, but are not popular due to their inherent pitfalls including clashing of instruments, lack of counter traction, lengthy operating time, and so on. A novel surgical robotic system was designed to overcome the limitations of the existing technologies. Animal trials were conducted to demonstrate its feasibility in performing robotic-assisted transrectal cholecystectomy in a porcine model. Method. The Novel surgical robotic system is a high dexterity, single access port surgical robotic system that enables surgeons to carry out single-port surgical procedure or NOTES. The proposed system's main features include the ability to perform intraabdominal and pelvic surgeries via natural orifices like the vagina or rectum. The system is equipped with multiple miniaturized (16 mm diameter) internally motorized robotic arms, each with a minimum of 7 degrees of freedom, a dual in vivo camera system, a cannula, and an external swivel system. Results. Robotic-assisted transrectal cholecystectomy was successfully performed in 3 adult male pigs. The estimated blood loss was <10 mL in all 3 cases. There were no intraoperative complications. The system provided good dexterity and clear vision. Conclusions. The trial demonstrated that the system can provide the surgeon a stable platform with adequate spacing for the transrectal insertion of robotic arms, 3-dimensional vision, and enhanced dexterity in performing NOTES cholecystectomy.

Nonparametric Online Learning Control for Soft Continuum Robot: An Enabling Technique for Effective Endoscopic Navigation.

Bioinspired robotic structures comprising soft actuation units have attracted increasing research interest. Taking advantage of its inherent compliance, soft robots can assure safe interaction with external environments, provided that precise and effective manipulation could be achieved. Endoscopy is a typical application. However, previous model-based control approaches often require simplified geometric assumptions on the soft manipulator, but which could be very inaccurate in the presence of unmodeled external interaction forces. In this study, we propose a generic control framework based on nonparametric and online, as well as local, training to learn the inverse model directly, without prior knowledge of the robot's structural parameters. Detailed experimental evaluation was conducted on a soft robot prototype with control redundancy, performing trajectory tracking in dynamically constrained environments. Advanced element formulation of finite element analysis is employed to initialize the control policy, hence eliminating the need for random exploration in the robot's workspace. The proposed control framework enabled a soft fluid-driven continuum robot to follow a 3D trajectory precisely, even under dynamic external disturbance. Such enhanced control accuracy and adaptability would facilitate effective endoscopic navigation in complex and changing environments.

Minimally Invasive Management for Vesicoureteral Reflux in Infants and Young Children.

Minimally invasive ureteral reimplantation is an attractive and useful tool in the armamentarium for the management of complicated vesicoureteral reflux (VUR). Subureteric dextranomer/hyaluronic acid injection, laparoscopic extravesical ureteric reimplantation and pneumovesicoscopic intravesical ureteral reimplantation with or without robotic assistance are established minimally invasive approaches to management of VUR. The high cost and the limited availability of robotics have restricted accessibility to these approaches. Laparoscopic and/or robotic ureteral reimplantation continues to evolve and will have a significant bearing on the management of complicated VUR in infants and young children.

Short-Term Changes in Postoperative Cognitive Function in Children Aged 5 to 12 Years Undergoing General Anesthesia: A Cohort Study.

Due to the neurotoxicity effects of general anesthesia (GA) and sedatives found in animal studies, there is a general recommendation to avoid nonurgent surgical procedures requiring anesthesia in children younger than 3 years of age. The aim of this study was to determine the incidence of anesthesia-related postoperative cognitive dysfunction (POCD) on the first day (Day 1) and at 6 weeks after elective noncardiac surgery in school-age children.This was a prospective cohort study of 118 children undergoing GA and 126 age-matched controls of school children aged 5 to 12 years. All children were given a panel of 4 neuropsychological assessments (Hong Kong List Learning for verbal memory, Visual Matching for processing speed, Visual Memory, and General Comprehension Skill from the Hong Kong Wechsler Intelligence Scale for Children). The primary outcome was the incidence of POCD on Day 1 and at 6 weeks after surgery. POCD was defined as when at least 2 of the 4 cognitive function tests showed individual Z-scores ≤-1.96 or a combined Z-score ≤-1.96.Using the combined Z-score definition, the incidence of POCD in the GA group on Day 1 and at 6 weeks were 5.1% (95% confidence interval [CI]: 2.1-10.3) and 3.4% (95% CI: 1.1-8.0), respectively. No POCD was found using the other definition. The incidences of decline and improvement in neuropsychological tests were similar between groups over time except for a higher risk in visual matching impairment in the anesthesia group (11.9%) versus control group (1.6%) on Day 1 (P < 0.01). The adjusted relative risk ratio of postoperative cognitive decline to improvement between groups on Day 1 and at 6 weeks were 0.85 (95% CI: 0.10-7.05) and 0.45 (95% CI: 0.04-4.84), respectively. The observed risk of POCD is assumed to apply to current drugs and techniques used in GA.In conclusion, the incidence of POCD was low. GA was associated with a transient effect on visual matching. When using the widely accepted Z-score definitions and relative risk ratio methodology, we found no anesthesia-related POCD per se in school-age children.

Chinese medicine and the surgeon.

The surgeon aims at a direct, complete removal of the pathology. In spite of the modern advancements of imaging facilities and precision instrumentations, unsatisfactory results and recurrences are not uncommon. This paper provides a general review of the four specific areas in surgery that would benefit from Chinese medicine. Extensive searches were made on four surgical areas based on available English language journals, viz. low-back pain, chronic ulcers, renal calculus, and enuresis in children, in the past 10 years. The quoted communications are mainly related to clinical evidences, while a smaller number of crucial laboratory reports are also included. Low-back pain, a most frequent orthopaedic problem, would benefit from acupuncture treatment. Chronic leg ulcers could achieve better results of healing using herbal supplements. Problems of renal stones, besides the conventional methods of removal, could be further supplemented with herbal drinks that aim at prevention of recurrences. Enuresis in children, an untreatable common condition, may respond well to acupuncture. Surgeons should keep an open mind. In case of difficulties, they could seriously consider options of traditional treatment.

Functional brainstem changes in response to bladder function alteration elicited by surgical reduction in bladder capacity: a functional magnetic resonance imaging study.

PURPOSE: Our previous results revealed a positive correlation between bladder dysfunction and cortical arousals in children with enuresis. This finding implied an interrelationship between bladder dysfunction and brainstem dysfunction. Thus, we used an animal model to characterize brainstem functional changes in response to altered bladder function. MATERIALS AND METHODS: Adult male New Zealand rabbits weighing 3.0 to 3.5 kg underwent surgical bladder volume reduction (12) or sham operation (12). We performed conventional fill cystometry and brainstem functional magnetic resonance imaging in each group 4 weeks postoperatively. During scanning bladder stimulation was provided by bladder filling up to 70% of maximum capacity. We then compared brainstem activation area(s). RESULTS: Results revealed voiding dysfunction in animals with altered bladder function. Bladder function was markedly altered in the reduced bladder volume vs the sham operated group, mainly as significantly increased maximum voiding detrusor pressure (mean ± 1 SD 24.4 ± 7.0 vs 0.16.5 ± 7.2 cm water, p <0.05) and markedly decreased cystometric bladder volume (mean 35.3 ± 8.2 vs 71.6 ± 12.9 ml, p <0.05). Functional magnetic resonance imaging results revealed activation of 2 brainstem regions, including in 1) the ventrolateral periaqueductal gray and 2) the dorsolateral pons, in response to bladder distention. Activation in the ventrolateral periaqueductal gray was significantly decreased in the reduced bladder vs the sham operated group with a corresponding decrease in signal size (25% vs 83.3%, signal size 0.7 ± 1.4 vs 3.3 ± 2.1 mm(2)). There was no significant difference in activation of the dorsolateral pons between the groups (83.3% vs 91.7%, signal size 3.7 ± 2.4 vs 0.4.7 ± 3.0 mm(2)). CONCLUSIONS: Functional derangement in brainstem micturition centers can be evoked by bladder dysfunction. In response to bladder dysfunction the ventrolateral periaqueductal gray shows deactivation during bladder distention, suggesting that it has an important role in bladder dysfunction biofeedback.

Dynamic ultrasound study on urinary bladder in infants with antenatally detected fetal hydronephrosis.

UNLABELLED: To evaluate bladder function in infants with antenatally diagnosed hydronephrosis (ANH) using dynamic ultrasound protocol. Forty consecutive male infants (mean, 0.25 y) with ANH and 33 age-matched normal controls (mean, 0.49 y) were recruited. Anteroposterior (AP) diameter of renal pelvis (RP) and hydronephrosis index [HI = anteroposterior diameter of RP of kidney divided by urinary bladder volume (BV)] were calculated. Maximum BV (MaxBV) was determined just before voiding. Residual volume (RV) and bladder wall thickness (BWT) were measured after spontaneous voiding. Thirty-one infants (77.5%) showed persistently dilated RP postnatally in which 12 (39%) showed significantly high HI. In general, ANH infants had smaller MaxBV (30.71 versus 52.45 mL), larger residual volume (2.47 versus 1.93 mL), and larger BWT (4.4 versus 3.7 mm) than normal (p < 0.05, Mann-Whitney test). Infants with abnormally high HI had significantly more disturbed bladder parameters [smaller MaxBV (23.33 versus 33.49 mL) and larger BWT (4.67 versus 3.79 mm)] than the normal HI group (p < 0.05, Mann-Whitney test). Abnormal functional bladder parameters were evident in ANH infants. We postulated that immature function in the pelviureteric junction was associated with bladder dysfunction in these infants. Dynamic ultrasound protocol might help to understand the underlying pathophysiology of urinary system in ANH infants. ABBREVIATIONS: :

Bladder reduction surgery accelerates the appearance of spontaneous voiding in neonatal rats.

PURPOSE: Patients with nocturnal enuresis may have small functional bladder capacity or altered bladder fullness sensation. We determined whether reducing bladder volume would affect the central inhibition of voiding that is normally present between birth and 2 weeks of life in neonatal rats. MATERIALS AND METHODS: One and 3-week-old Sprague-Dawley rats underwent 50% bladder volume reduction by suture closure of the bladder dome. T8-T10 spinal cord injury was done in select animals. Latency of the perigenital-bladder reflex, spontaneous voiding onset and body weight were measured. Cystometry using urethane anesthesia, and measurements of in vitro spontaneous and KCl evoked contractions were done. RESULTS: Bladder reduction surgery led to the immediate appearance of spontaneous voiding in 1-week-old rats. Cystometry at 2 weeks showed voiding contractions in rats with bladder reduction, which was abolished by acute T8-T10 spinalization. Voiding contractions were not seen in animals with sham surgery or concurrent T8-T10 spinalization and bladder reduction. The perigenital-bladder reflex, somatic growth, spontaneous bladder contractions and bladder contractility were not affected by bladder reduction. Bladder capacity at 9 weeks was significantly larger in animals that underwent bladder reduction at 1 week than in sham treated animals (540 vs 256 microl, p = 0.04) but not in animals that underwent bladder reduction at 3 weeks. CONCLUSIONS: Bladder reduction removes the central inhibition of spontaneous voiding in neonatal rats. This suggests that decreased neonatal bladder capacity may alter how the brain regulates the bladder.

Duodenal ulcers dominate acute upper gastrointestinal tract bleeding in childhood: a 10-year experience from Hong Kong.

OBJECTIVE: Systematic reports on acute upper gastrointestinal bleeding in children/adolescents are scanty. The aim of this study is to analyze its presentation, pathology and outcome in Hong Kong. METHODS: A retrospective review of the hospital database for admissions up to the age of 18 years with signs of acute upper gastrointestinal bleeding between 1 June 1996 and 31 May 2006. RESULTS: During the 10-year period 76 patients (55 boys) were admitted with signs of upper gastrointestinal bleeding. The median age was 13.5 (range 0.25-18) years. Melena and hematemesis were by far the most frequent presentations. Medication was implicated in 16 cases (21%) as the possible cause for the bleeding. Endoscopic findings were a duodenal ulcer in 57 (75%) patients (50 boys) and a gastric ulcer in eight (10.5%). Helicobacter pylori infection was identified in 42 (55%) patients, of which 38 were found in duodenal ulcer patients. Eleven patients (14.5%) had interventions to achieve hemostasis: six epinephrine spray only, three thermal probe and two vessel ligation. After a median follow-up time of 3.5 years six patients had a recurrent duodenal ulcer. Three patients died of unrelated illnesses. CONCLUSION: Acute upper gastrointestinal tract bleeding in children and adolescents in Hong Kong is dominated by a duodenal ulcer in 75% of the patients. Acute bleeding is more frequent in boys (boy to girl ratio 2.6:1). Medication is a predisposing factor in 20% of the bleedings. Six patients (8%) have recurrent duodenal ulcers.

Characteristics of the bladder in infants with urinary tract infections: an ultrasound study.

BACKGROUND: Patients with urinary tract infection (UTI) are known to have impaired bladder function as demonstrated by urodynamic (UD) studies. UD is rarely performed in infants. OBJECTIVE: To evaluate bladder function in infants with UTI using a dynamic US protocol. Maximal bladder volume (MaxBV), residual volume (RV) and bladder wall thickness (BWT) were measured and compared with values from normal controls. MATERIALS AND METHODS: A total of 57 consecutive infants (47 males, 10 females; mean age 0.48+/-0.30 years) with proven UTI, and 63 age-matched normal controls (37 males, 26 females; mean age 0.47+/-0.37 years) were recruited. MaxBV was determined just before voiding, and RV and BWT were measured after spontaneous voiding. RESULTS: Infants with UTI had smaller MaxBV (34.89 vs. 42.91 ml), larger RV (3.46 vs. 1.51 ml) and greater BWT (4.21 vs. 3.68 mm) than normal infants (P<0.05, Mann-Whitney test). CONCLUSION: Smaller bladder volume, larger residual volume and thicker bladder wall in infants with UTI can be explained by bladder instability, hypercontractility and infection-induced oedema of the bladder wall during UTI. The US measurement of bladder parameters might serve as an objective guide for clinical diagnosis and allow objective evaluation of bladder function during posttreatment follow-up.

Sonic Hedgehog mediator Gli2 regulates bladder mesenchymal patterning.

PURPOSE: Congenital bladder anomalies are a major challenge to pediatric urologists. Understanding the mechanism of bladder development is crucial for advancing patient treatment. Current evidence suggests that Shh (R&D Systems) is an epithelial signal regulating bladder development, although the mechanism of the regulation is still unclear. We examined the regulation of bladder mesenchymal development. MATERIALS AND METHODS: Mutation analysis, immunohistochemistry, immunoblot, in situ hybridization, and primary cell culture and transfection were performed. The mesenchyma proximal to the epithelium was defined as the inner zone and that distal to the epithelium was defined as the outer zone. RESULTS: We found that the Shh transcriptional factor Gli2 and the Shh target gene Bmp4 (R&D Systems) were expressed in the inner mesenchymal zone of the bladder, where active cell proliferation was observed. In Gli2(-/-) bladder primary mesenchymal cell cultures transfection with adenoviruses expressing DeltaNGli2, a constitutionally active form of Gli2, up-regulated Bmp4 expression and promoted cell proliferation. In the outer mesenchymal zone, where Gli2 and Bmp4 expression was not detectable, smooth muscle alpha-actin was expressed. In Gli2(-/-) embryo bladders Bmp4 expression in the inner zone was lost and ectopic smooth muscle was detected in the inner mesenchymal zone. Exogenous Bmp4 (10 ng/ml) in primary smooth muscle cell culture repressed smooth muscle differentiation and repression was partially rescued by the Bmp4 antagonist Noggin (R&D Systems) (300 ng/ml). CONCLUSIONS: Our data suggests that the Shh transcriptional factor Gli2 regulates radial patterning of the bladder mesenchyma.

A population-based study of Helicobacter pylori infection in Chinese children resident in Hong Kong: prevalence and potential risk factors.

BACKGROUND: Data of Helicobacter pylori prevalence in children and its risk factors provide clues to the health authority to estimate burden of H. pylori-associated diseases usually encountered in adulthood and facilitate healthcare planning. MATERIALS AND METHODS: A cross-sectional population-based study was conducted in Chinese children in elementary and high schools. Schools were selected from all three major areas of Hong Kong. H. pylori infection was defined by a positive (13)C-urea breath test. Study subjects were stratified into six age groups for estimation of prevalence. Potential risk factors were analyzed from data of self-administered questionnaires. RESULTS: A total of 2480 children (aged 6-19, male: 47.3%) participated in the study. Overall, 324 (13.1%) were positive for H. pylori. There was no difference in prevalence between sexes, and no statistical trend in the prevalence across the six age groups. Multivariate logistic regression identified lack of formal education of mother (OR = 2.43, 95%CI 1.36-4.34), family history of gastric cancer (OR = 2.19, 95%CI 1.09-4.41), and household member > 5 (OR = 1.57, 95%CI 1.12-2.19) to be positively associated with H. pylori infection in our children. CONCLUSIONS: The H. pylori prevalence of Hong Kong children is comparable to the data of developed countries. The association with family history of gastric cancer justifies further study to investigate the cost-benefit of community screening program for such children to decrease the incidence of gastric cancer in adulthood.

Laparoscopic-assisted excision of sacrococcygeal teratoma in children.

BACKGROUND: Sacrococcygeal teratoma (SCT) is one of the most common tumors encountered in the neonatal period. Traditionally, a large abdominal incision is required for the combined abdominal perineal approach for the complete resection of type II-IV tumors. In this paper, we report our experience of using the combined laparoscopic perineal approach in treating these tumors. METHODS: Between November 2000 and September 2004, 4 patients with SCT were treated by the combined approach. The operation was started with the laparoscopic mobilization of the pelvic part of the tumor, followed by the completion excision and tumor retrieval through the perineal route. RESULTS: The operation was successfully completed in all patients, with a mean operative time of 279 minutes. There was no complication related to the laparoscopic dissection. Postoperative recovery was uneventful in all patients, except in 1 with a minor wound problem. At a median follow-up of 46.5 months, there was no recurrence encountered in all these patients and the cosmetic result was excellent. Functional outcome was satisfactory, except in the patient with spinal metastases. CONCLUSION: The combined laparoscopic and perineal approach provides a safe, excellent access in removing type II-IV SCT in infants.

Fetoscopy under gas amniodistension: pressure-dependent influence of helium vs nitrous oxide on fetal goats.

PURPOSE: Recently, gas amniodistension has been advocated for fetoscopic surgery to employ ergonomics similar to laparoscopy. However, neither the optimal type of gas nor its physiological influence on the fetus have been clearly outlined yet. This study investigates the impact of helium (HE) vs nitrous oxide (N2O) on fetal goats during fetoscopy. METHODS: We insufflated either HE or N2O in 12 pregnant goats (15 fetuses; HE = 7, N2O = 8), then increased the pressures from 0, 4, 7, to 10 mm Hg in 30-minute intervals and recorded the fetal and maternal vital parameters. Finally, whole-body computed tomography to asses for intracorporeal gas was performed. RESULTS: All fetuses survived. Mean fetal vital signs showed no significant differences between HE or N2O at specific pressure levels. In detail, HE/N2O at 0 vs 10 mm Hg caused a fetal temperature decrease (32.9 degrees C/33.2 degrees C vs 32 degrees C/32.5 degrees C), heart rate increase in the N2O group (100/102 vs 102/121 beats per minute), and no significant change in arterial pressure (45.8/48.3 vs 53.7/46.7 mm Hg). The PO2 was adequate (3.7/3.3 vs 3.7/2.9 kPa), whereas the pH remained unchanged (7.4/7.3 vs 7.3/7.3). However, fetal pCO2 was elevated in the N2O group before insufflation (5.5/7.2 vs 6.8/8.0 kPa) owing to maternal hypoventilation (maternal PCO2: 4.9/5.8 vs 5.0/5.4 kPa), correction of which was slower in the fetus than in the maternal animal. Computed tomography ruled out intracorporeal gas accumulation. CONCLUSION: Neither HE nor N2O impose significant physiological harm for the fetus. Heating of the gas and maternal anesthesia seem essential. Considering the potential teratogenicity of N2O, however, HE could be the favorable environment for fetoscopic procedures under gas amniodistension.

Dynamic MR assessment of the anorectal angle and puborectalis muscle in pediatric patients with anismus: technique and feasibility.

PURPOSE: To assess the feasibility of dynamic breath-hold MRI for evaluating changes in the anorectal angle and movements of the pelvic-floor musculature (puborectalis) during resting and straining states in pediatric patients presenting with anismus. MATERIALS AND METHODS: Six pediatric patients (7-13 years old) with chronic constipation and manometric evidence of anismus were assessed by dynamic breath-hold MRI. Changes in the anorectal angle, the degree of pelvic-floor descent, and the thickness and length of the puborectalis muscles were measured during rest and straining. The findings were compared with those obtained in six age- and sex-matched controls. RESULTS: The children with anismus had a smaller anorectal angle during straining, and the angle decreased from rest to defecation. The puborectalis also became paradoxically shortened and thickened during straining in the anismus group. There were significant differences between the two groups in terms of the change of degree of the anorectal angle, and the thickness and length of the puborectalis muscle during straining. CONCLUSION: Fast dynamic MRI is feasible for evaluating pelvic-floor movement in pediatric patients. Preliminary results suggest that children with anismus have a smaller anorectal angle and a different puborectalis configuration compared to controls.