Biomedical subjects

Weechang Kang

Publications and source records attributed to Weechang Kang.

15 recordsLinked to original sources

PubMed2006

Long-term results and factors affecting patency after removal of nasolacrimal stents.

PURPOSE: To retrospectively evaluate the long-term patency and prognostic factors affecting patency after removal of nasolacrimal stents. MATERIALS AND METHODS: Lacrimal polyurethane stents were removed from 317 lacrimal drainage systems of 275 patients because the stent ceased to function, and immediate and maintained patency were determined with follow-up dacryocystography (DCG) after stent removal. Prognostic factors for patency after stent removal were evaluated by univariate and multivariate analyses for immediate patency and Kaplan-Meier survival analysis and multivariate analysis for maintained patency. RESULTS: All stents were successfully removed under fluoroscopic or endoscopic guidance. After stent removal, 243 lacrimal systems (77%) showed immediate patency. The size of the lacrimal sac was the same (65% of cases), widened (2%), or contracted (33%) after stent removal. The shape of the lacrimal sac was normal in 30% and irregular in 70% of cases after stent removal. Seven-day follow-up DCG was obtained in 169 cases, and maintained patency of the lacrimal system was confirmed on 7-day follow-up DCG in 125 cases. Epiphora recurred in 70 cases (56%) during the mean 8-month follow-up period (range, 1-48 months). The mean maintained patency period after stent removal was 15.7 +/- 2.1 months. The maintained patency rates were 41% at 1 year, 31% at 2 years, and 14% at 4 years after stent removal. Multivariate analysis showed that the size of the lacrimal sac (P < .001) was the only factor affecting immediate and maintained patency after stent removal. CONCLUSIONS: After stent removal in patients with nasolacrimal stent obstruction, the immediate patency rate was 77%; however, the rate of maintained patency decreased progressively with time. The major factor negatively affecting immediate and maintained patency after stent removal was contraction of the lacrimal sac at the time of stent removal.

Adolescent↗

PubMed2005

HGLM versus conditional estimators for the analysis of clustered binary data.

Clustered binary data arise frequently in medical research such as cross-over clinical trials and twin studies. For the analysis of such data either a random-effects model or a conditional likelihood approach can be used. In this paper, we compare numerically the random-effects model estimator and the conditional likelihood estimator and discuss their relative merits for the analysis of binary data.

Age Factors↗

PubMed2005

Low-dose and standard-dose unenhanced helical computed tomography for the assessment of acute renal colic: prospective comparative study.

PURPOSE: To compare the efficacy of low-dose and standard-dose computed tomography (CT) for the diagnosis of ureteral stones. MATERIAL AND METHODS: Unenhanced helical CT was performed with both a standard dose (260 mAs, pitch 1.5) and a low dose (50 mAs, pitch 1.5) in 121 patients suspected of having acute renal colic. The two studies were prospectively and independently interpreted for the presence and location of ureteral stones, abnormalities unrelated to stone disease, identification of secondary signs, i.e. hydronephrosis and perinephric stranding, and tissue rim sign. The standard-dose CT images were interpreted by one reviewer and the low-dose CT images independently by two reviewers unaware of the standard-dose CT findings. The findings of the standard and low-dose CT scans were compared with the exact McNemar test. Interobserver agreements were assessed with kappa analysis. The effective radiation doses resulting from two different protocols were calculated by means of commercially available software to which the Monte-Carlo phantom model was given. RESULTS: The sensitivity, specificity, and accuracy of standard-dose CT for detecting ureteral stones were 99%, 93%, and 98%, respectively, whereas for the two reviewers the sensitivity of low-dose CT was 93% and 95%, specificity 86%, and accuracy 92% and 94%. We found no significant differences between standard-dose and low-dose CT in the sensitivity and specificity for diagnosing ureter stones (P >0.05 for both). However, the sensitivity of low-dose CT for detection of 19 stones less than or equal to 2 mm in diameter was 79% and 68%, respectively, for the two reviewers. Low-dose CT was comparable to standard-dose CT in visualizing hydronephrosis and the tissue rim sign. Perinephric stranding was far less clear on low-dose CT. Low-dose CT had the same diagnostic performance as standard-dose CT in diagnosing alternative diseases. Interobserver agreement between the two low-dose CT reviewers in the diagnosis of ureter stones and alternative diseases, the identification of secondary signs, and tissue rim sign were high, with kappa values ranging from 0.769 to 0.968. On standard-dose CT scans, the calculated mean effective radiation dose was 7.30 mSv for males and 10.00 mSv for females. On low-dose CT scans, the calculated mean effective radiation dose was 1.40 mSv for males and 1.97 mSv for females. CONCLUSION: Compared with standard scans using 260 mAs, low-dose unenhanced helical CT using a reduced tube current of 50 mAs results in a concomitant decrease in the radiation dose of 81%. Although low-dose CT was limited in its ability to depict small-sized calculi less than or equal to 2 mm, it is still comparable to standard-dose CT for the diagnosis of ureter stones and alternative disease.

Acute Disease↗

PubMed2005

Comparison of temporary and permanent stent placement with concurrent radiation therapy in patients with esophageal carcinoma.

PURPOSE: To assess the clinical effectiveness of temporary metallic stent placement with concurrent radiation therapy in patients with esophageal carcinoma by comparing it with permanent stent placement with concurrent radiation therapy. MATERIALS AND METHODS: Covered retrievable expandable nitinol stents were placed in 47 patients with esophageal carcinoma 1 week before starting radiation therapy; the stents were electively removed 4 weeks after placement in 24 patients (group A), while not electively removed in the other 23 patients (group B). In cases of complications, the stents were also removed from patients in groups A and B. The dysphagia score, complications (severe pain, granulation tissue formation, stent migration, esophagorespiratory fistula, and hematemesis), tumor overgrowth/regrowth, reintervention rates, and dysphagia-progression-free and overall survival rates were compared in the two groups. RESULTS: Stent placement or removal was technically successful and well tolerated in all patients. The dysphagia score was significantly improved in both groups after stent placement (P < .01). Each of the stent-related complications was less in group A than in group B but there was no significant difference. However, the total number of patients with one or more than one complications and who needed related reinterventions was significantly less in group A than in group B (P = .042 and .030, respectively). Tumor overgrowth/regrowth and the total number of patients who required related reinterventions was not significantly different (P = 1.00 and .517, respectively). Dysphagia-progression-free and overall survival rates were significantly longer in group A than in group B (P = .005 and .001, respectively). CONCLUSION: Temporary placement of a covered retrievable expandable metallic stent with concurrent radiation therapy for patients with esophageal carcinoma is beneficial for reducing complications and related reinterventions and for increasing resultant survival rates compared with permanent esophageal stent placement.

Adult↗

PubMed2005

Scoring method for early prediction of neonatal chronic lung disease using modified respiratory parameters.

In our previous study, we have demonstrated that peak inspiratory pressure over birth weight (PIP/kg) and mean airway pressure over birth weight (MAP/kg) were more significant risk factors for the development of neonatal chronic lung disease (CLD) than PIP and MAP. We aimed to develop a scoring method using the modified respiratory variables (SMUMRV) to predict CLD at early postnatal period. From 1997 to 1999, a retrospective review was performed for 197 infants <1,500 g for the development of the SMUMRV based on statistical analysis. From 2000 to 2001, calculated scores on day 4, 7 and 10 of life were obtained prospectively for 107 infants <1,500 g. Predictive values and the area under the receiver operator characteristic curve (AUC) were determined and compared with the result of the previous regression model. Gestational age, birth weight, 5 min Apgar score, PIP/kg at 12 hr of age, fractional inspired oxygen (FiO2), MAP/kg, modified oxygenation index and ventilatory mode were selected as parameters of SMUMRV. No significant differences of AUCs were found between the SMUMRV and the Yoder model. It is likely that our scoring method provides reliable values for predicting the development of CLD in very low birth weight infants.

Analysis of Variance↗

PubMed2004

Hepatic venous congestion after living donor liver transplantation with right lobe graft: two-phase CT findings.

PURPOSE: To describe and determine clinical importance of two-phase computed tomographic (CT) findings of hepatic venous congestion after living donor liver transplantation (LDLT) with right lobe graft. MATERIALS AND METHODS: Forty-eight patients underwent two-phase (hepatic arterial phase and portal venous phase [PVP]) CT at 1, 2, and 4 weeks after LDLT. Images were evaluated for hepatic attenuation difference in areas of hepatic venous congestion, opacification of hepatic and peripheral portal veins in those areas, and changes in findings at follow-up CT. CT findings were correlated with serum bilirubin level. Fisher exact test and mixed model were applied. Histopathologic specimens were obtained in six patients. RESULTS: Thirty patients (62%) had attenuation difference in segments V and VIII of right lobe transplant at initial CT scanning. Opacification of hepatic or peripheral portal veins was seen in 17 (63%) and 27 (100%) hyperattenuating areas of congestion during PVP and in none and three (19%) of 16 hypoattenuating areas, respectively. At 4-week follow-up CT, attenuation difference decreased in volume in 11 of 16 patients with hypoattenuation during PVP. All 14 patients with hyperattenuation showed no change in volume, but attenuation difference had decreased or disappeared. Histopathologic specimens showed evidence of hepatic venous congestion in all six patients. Hypoattenuation was seen at PVP CT in all three patients with severe hepatic venous congestion at histopathologic examination. Serum bilirubin level was significantly different between patients with hypoattenuation and those with hyperattenuation during PVP (P =.035) and between patients with hypoattenuation and those without attenuation difference (P =.009). CONCLUSION: Areas possibly related to hepatic venous congestion after LDLT have variable attenuation at CT; decreased enhancement during PVP correlates with increased postoperative serum bilirubin level, which indicates severity of hepatic venous congestion.

Adult↗

PubMed2004

Reduction of tissue hyperplasia with a rhenium-188 mercaptoacetyltriglycine-3-filled balloon: preliminary study in a canine urethral model.

PURPOSE: To evaluate the efficacy of beta-radiation therapy with rhenium-188 mercaptoacetyltriglycine-3 (MAG(3))-filled balloons to reduce tissue hyperplasia secondary to stent placement in 18 canine urethras. MATERIALS AND METHODS: Eight dogs were treated with 188-Re MAG(3)-filled balloon dilation immediately after stent placement and were killed 4 weeks later (group I, n = 4) or 8 weeks later (group II, n = 4). Five dogs were treated with 188-Re MAG(3)-filled balloon dilation 2 weeks after stent placement and were killed 4 weeks after stent placement (group III). The remaining five dogs were treated with conventional balloon dilation immediately after stent placement and were killed 4 weeks later; these animals formed the control group (group IV). Retrograde urethrography (RUG) was performed during follow-up and three histologic parameters were investigated: the number of epithelial layers, papillary projection thickness, and degree of submucosal inflammatory cell infiltration. The areas inside and outside the ends of the stents were evaluated in each case after animal sacrifice. After testing statistical significance of data for RUG and histologic findings in the four study groups, the Mann-Whitney U test was used to compare groups I and II to determine delayed effects of irradiation, groups I and III to determine benefits of delayed irradiation, groups I and IV to determine efficacy of immediate irradiation for reducing tissue hyperplasia, and groups III and IV to determine efficacy of delayed irradiation for reducing tissue hyperplasia. RESULTS: There were no significant differences in the four study groups on RUG before animal sacrifice. Between groups I and II, group II showed significantly lower mean values in five of six histologic comparisons. Between groups I and III, group III showed significantly lower mean values in only papillary projection thickness inside the stent ends. Between groups I and IV, group I showed significantly lower mean values in all three histologic parameters outside the stent ends. Between groups III and IV, group III showed significantly lower mean values in only two histologic parameters (papillary projection thickness in the in-stent area and inflammatory cell infiltration outside the stent edges). CONCLUSION: beta-Irradiation with use of a 188-Re MAG(3)-filled balloon shows the potential to reduce tissue hyperplasia secondary to stent placement in a canine urethral model. Treatment with 188-Re MAG(3)-filled balloons at the time of stent placement shows not only favorable outcomes for reducing tissue hyperplasia but also improved delayed effects until 8 weeks.

Animals↗

PubMed2003

Concordance odds ratios and approximate rate ratios in longitudinal twin studies.

Odds ratios derived from probandwise concordance rates are usually interpreted as increased risks in twins. Though the odds ratios in case-control studies have been shown to reflect rate ratios, few studies focused on such relationships in twin studies. The authors derived an approximate formula for the ratios of person-time incidence rates after the random assignment of twins into index twins and co-twins, i.e., incidence rate ratios. The resulting rate ratio was estimated as the product of the concordance odds ratio and a term that reflect the follow-up duration and the average time to occurrence of disease. Odds ratios coincide with rate ratios when the average time to occurrence of disease is half the duration of follow-up, although in studies spanning several decades these two measures might be different. The authors illustrated that when the incidence rate is not constant over the follow-up period as in longitudinal twin studies, the conventional odds ratio should not be used as an estimator of rate ratio.

Case-Control Studies↗

PubMed2003

Value of supranormal function and renogram patterns on 99mTc-mercaptoacetyltriglycine scintigraphy in relation to the extent of hydronephrosis for predicting ureteropelvic junction obstruction in the newborn.

UNLABELLED: We investigated the value of supranormal function and renogram patterns on (99m)Tc-mercaptoacetyltriglycine ((99m)Tc-MAG3) scintigraphy in relation to the extent of hydronephrosis for predicting ureteropelvic junction (UPJ) obstruction in the newborn. METHODS: We studied 48 patients with prenatally diagnosed unilateral hydronephrosis that was confirmed on postnatal ultrasonography. The anteroposterior pelvic diameter (APPD) and the Society for Fetal Urology (SFU) grade were measured on 1-mo ultrasonography to assess the extent of hydronephrosis. Neonates with an APPD of or=55%) and renogram grades (1, not obstructive; 2, indeterminate; 3, obstructive; and 4, prolonged parenchymal transit) were determined on 1-mo (99m)Tc-MAG3 renography. Multivariate logistic regression analysis was performed to predict the presence of obstruction. RESULTS: Of the 48 kidneys with hydronephrosis, 19 were diagnosed as having UPJ obstruction. Twenty-nine kidneys were classified as having nonobstructive hydronephrosis. The APPD of the 19 kidneys with obstruction (24.3 +/- 9.2 mm) was significantly larger than that of the 29 kidneys without obstruction (17.5 +/- 11.2 mm; P < 0.05). The SFU grades of UPJ obstruction (2 with grade 3, 17 with grade 4) were also significantly higher than those without UPJ obstruction (grades 1-4 in 1, 6, 10, and 12 kidneys, respectively; P < 0.01). Supranormal function was present in 4 kidneys with UPJ obstruction but in none without obstruction (P < 0.001). (99m)Tc-MAG3 renography of the 19 obstructions showed grades 2, 3, and 4 renograms in 4, 8, and 7 patients, respectively. The 29 without obstruction revealed significantly lower grades (grades 1-4 in 10, 13, 5, and 1 patient, respectively; P < 0.001). Multivariate logistic regression analysis revealed that the addition of supranormal function or renogram grade in the model significantly increased the likelihood ratio in comparison with that of the SFU grade only (chi(2) = 7.73 and 9.99, respectively; P < 0.01). Of the 29 neonates with SFU grade 4, supranormal function or renogram >or= grade 4 had a positive predictive value of 90% (9/10). CONCLUSION: (99m)Tc-MAG3 renography at 1 mo after birth has a significant additive value in relation to the degree of hydronephrosis in predicting UPJ obstruction in patients with prenatally diagnosed unilateral hydronephrosis with normal function.

False Positive Reactions↗

PubMed2002

Pattern of retinal nerve fiber layer damage in Korean eyes with normal-tension glaucoma and hemifield visual field defect.

PURPOSE: To evaluate quantitatively the pattern of retinal nerve fiber layer (RNFL) damage in eyes with normal-tension glaucoma (NTG) with hemifield dominant visual field defects using scanning laser polarimetry. METHODS: Prospectively, 40 consecutive eyes from 40 patients with NTG and hemifield defect based on the findings of examination using the Humphrey Field Analyzer underwent RNFL thickness measurements. Twenty normal eyes from 20 subjects matched in age and refractive error formed a control group. RESULTS: Symmetry, calculated as the ratio of superior to inferior RNFL thickness, showed no statistically significant difference between the study group and the control group ( P=0.50). Overall, 27.5% (11/40 eyes) showed an "abnormal" symmetry index that indicated focal RNFL change. The affected ratio, calculated as the ratio of RNFL thickness in the quadrant corresponding to the hemifield of visual field defect to that of the temporal quadrant was significantly lower in the study group than in the control group ( P<0.0001). A similar finding was noted for the unaffected ratio. CONCLUSION: Despite strict selection of the eyes with visual field defect confined to one hemifield, a mixture of both focal and diffuse RNFL damage was noted, with a common occurrence of symmetrical RNFL thinning in both upper and lower quadrants based on scanning laser polarimetry.

Adult↗

PubMed2002

Plasminogen activator inhibitor-1 is an independent diagnostic marker as well as severity predictor of hepatic veno-occlusive disease after allogeneic bone marrow transplantation in adults conditioned with busulphan and cyclophosphamide.

We attempted to identify the diagnostic markers and severity predictors of hepatic veno-occlusive disease (VOD) in 115 adult patients who were uniformly conditioned with busulphan and cyclophosphamide and who underwent allogeneic bone marrow transplantation (BMT). A diagnosis of VOD was made according to clinical criteria. Severity of VOD was classified as mild, moderate or severe. Various haemostatic parameters were determined at five time points (d -7, 0, 7, 14 and 21). Using clinical and haemostatic parameters, we developed multivariate models to identify diagnostic markers as well as severity predictors of VOD. Of the 115 patients included in the study, 50 (43.5%) developed VOD. Twenty-nine had mild VOD, 13 moderate and 8 severe. Multiple logistic regression models showed that plasminogen activator inhibitor-1 (PAI-1) antigen (P = 0.029), percentage change of body weight (P = 0.001) and bilirubin (P < 0.001) were independent marker variables for the occurrence of VOD, and PAI-1 antigen (P = 0.030) and bilirubin (P = 0.049) were independent marker variables for the occurrence of severe VOD. Our study suggests that PAI-1 antigen can be used as a diagnostic marker as well as a severity predictor of VOD after allogeneic BMT.

Adolescent↗

PubMed2002

Knowledge of, attitudes toward, and experience of complementary and alternative medicine in Western medicine- and oriental medicine-trained physicians in Korea.

OBJECTIVES: We compared knowledge of, attitudes toward, and experience with complementary and alternative medicine (CAM) among Western medicine-trained doctors (WMDs) and Oriental medicine-trained doctors (OMDs). METHODS: In Korea, 502 WMDs and 500 OMDs were interviewed with a structured questionnaire. RESULTS: OMDs held more favorable attitudes toward CAM than did WMDs. OMDs possessed a deeper understanding of and greater experience with CAM. OMDs more readily endorsed health beliefs congruent with CAM. CONCLUSIONS: In the future, CAM can be more readily used by OMDs than by WMDs. Because evidence for the effectiveness of CAM remains sparse, more research is needed for the prudent use of CAM in Korea. An education and training system for potential CAM providers remains to be developed.

Adult↗

PubMed2002

Using relative cerebral blood flow and volume to evaluate the histopathologic grade of cerebral gliomas: preliminary results.

OBJECTIVE: Relative cerebral blood flow has rarely been studied as part of the preoperative assessment of tumor grade, although relative cerebral blood volume is known to be useful for this assessment. The purpose of our study was to determine the usefulness of relative cerebral blood flow in assessing the histopathologic grade of cerebral gliomas. SUBJECTS AND METHODS: MR imaging was performed in 17 patients with proven cerebral gliomas (11 high-grade gliomas and six low-grade gliomas), using a first-pass gadopentetate dimeglumine-enhanced T2-weighted echoplanar perfusion sequence. The perfusion data were deconvoluted with an arterial input function, using singular value decomposition to obtain a color map of relative cerebral blood volume and flow; the relative cerebral blood volume and flow ratios were expressed relative to values measured in the contralateral white matter. The Wilcoxon's rank sum test was performed to test the difference between the mean of the relative cerebral blood volume (or flow) ratio in high-grade gliomas and that in low-grade gliomas. Receiver operating characteristic curve analysis was used to evaluate the association between the relative cerebral blood volume (or flow) ratio and the grade of the glioma, as well as to calculate the relative cerebral blood volume and flow ratio cutoff value permitting discrimination between high- and low-grade gliomas. The correlation between relative cerebral blood volume and flow ratios was evaluated using Spearman's rank correlation analysis. We also made a qualitative assessment regarding the match or mismatch of areas of maximal contrast enhancement with the areas of highest color perfusion maps. RESULTS: The mean of the relative cerebral blood volume ratio was 4.91 in the high-grade gliomas and 2.00 in the low-grade gliomas. The mean relative cerebral blood flow ratio was 4.82 in the high-grade gliomas and 1.83 in the low-grade gliomas. A significant difference in each relative cerebral blood volume and flow ratio was found between the high- and low-grade gliomas (Wilcoxon's rank sum test, p < 0.05). Both the relative cerebral blood volume and flow ratios strongly matched the grade of the glioma, but the difference between the two areas was not significant (receiver operating characteristic curve analysis, p > 0.05). The desired cutoff value was 2.93 in the relative cerebral blood volume ratio and 3.57 in the relative cerebral blood flow ratio. Additionally, there was a strong correlation between the relative cerebral blood volume and flow ratios (Spearman's rank correlation coefficient = 0.762; p < 0.05). There was frequent mismatch (33%) between the qualitative assessment of the contrast-enhanced T1-weighted MR images and the perfusion maps. CONCLUSION: First-pass gadopentetate dimeglumine-enhanced T2-weighted echoplanar perfusion MR imaging is useful for the preoperative assessment of tumor grade. A relative cerebral blood flow ratio, in addition to a relative cerebral blood volume ratio, can be a useful tool in the evaluation of the histopathologic grade of cerebral gliomas.

Adolescent↗

PubMedDate not supplied

The quality of reconstructed 3D images in multidetector-row helical CT: experimental study involving scan parameters.

OBJECTIVE: To determine which multidetector-row helical CT scanning technique provides the best-quality reconstructed 3D images, and to assess differences in image quality according to the levels of the scanning parameters used. MATERIALS AND METHODS: Four objects with different surfaces and contours were scanned using multidetector-row helical CT at three detector-row collimations (1.25, 2.50, 5.00 mm), two pitches (3.0, 6.0), and three different degrees of overlap between the reconstructed slices (0%, 25%, 50%). Reconstructed 3D images of the resulting 72 sets of data were produced using volumetric rendering. The 72 images were graded on a scale from 1 (worst) to 5 (best) for each of four rating criteria, giving a mean score for each criterion and an overall mean score. Statistical analysis was used to assess differences in image quality according to scanning parameter levels. RESULTS: The mean score for each rating criterion, and the overall mean score, varied significantly according to the scanning parameter levels used. With regard to detector-row collimation and pitch, all levels of scanning parameters gave rise to significant differences, while in the degree of overlap of reconstructed slices, there were significant differences between overlap of 0% and of 50% in all levels of scanning parameters, and between overlap of 25% and of 50% in overall accuracy and overall mean score. Among the 18 scanning sequences, the highest score (4.94) was achieved with 1.25 mm detector-row collimation, 3.0 pitch, and 50% overlap between reconstructed slices. CONCLUSION: Comparison of the quality of reconstructed 3D images obtained using multidetector-row helical CT and various scanning techniques indicated that the 1.25 mm, 3.0, 50% scanning sequence was best. Quality improved as detector-row collimation decreased; as pitch was reduced from 6.0 to 3.0; and as overlap between reconstructed slices increased.

Humans↗

PubMedDate not supplied

Balloon sheaths for gastrointestinal guidance and access: a preliminary phantom study.

OBJECTIVE: We wanted to evaluate the feasibility and usefulness of a newly designed balloon sheath for gastrointestinal guidance and access by conducting a phantom study. MATERIALS AND METHODS: The newly designed balloon sheath consisted of an introducer sheath and a supporting balloon. A coil catheter was advanced over a guide wire into two gastroduodenal phantoms (one was with stricture and one was without stricture); group I was without a balloon sheath, group ll was with a deflated balloon sheath, and groups III and IV were with an inflated balloon and with the balloon in the fundus and body, respectively. Each test was performed for 2 minutes and it was repeated 10 times in each group by two researchers, and the positions reached by the catheter tip were recorded. RESULTS: Both researchers had better performances with both phantoms in order of group IV, III, II and I. In group IV, both researchers advanced the catheter tip through the fourth duodenal segment in both the phantoms. In group I, however, the catheter tip never reached the third duodenal segment in both the phantoms by both the researchers. The numeric values for the four study groups were significantly different for both the phantoms (p < 0.001). A significant difference was also found between group III and IV for both phantoms (p < 0.001). CONCLUSION: The balloon sheath seems to be feasible for clinical use, and it has good clinical potential for gastrointestinal guidance and access, particularly when the inflated balloon is placed in the gastric body.

Catheterization↗