Jae-Wook Chung

Risk factors for the development of urethrocutaneous fistula after hypospadias repair: a retrospective study.

Purpose The purpose of this study was to investigate the risk factors for urethrocutaneous fistula development after hypospadias repair. Materials and Methods Between January 1990 and May 2010, 348 patients underwent hypospadias repair. This study included 294 patients who were followed up for more than 6 months. Potential risk factors for the development of fistula after operation included age, location of hypospadias, type of hypospadias repair, suture materials and methods, methods and duration of catheterization, combined congenital urologic disorders, timing of presentation and repair of fistula, and location of fistula. Data were analyzed retrospectively. Binary logistic regression analysis was used for univariate and multivariate analysis. Results Out of 294 patients, 63 patients (21.4%, 63/294) developed urethrocutaneous fistulas after hypospadias repair. In the univariate analysis, fistula formation was statistically related with type of hypospadias and type of hypospadias repair. In the multivariate analysis with stratification by hypospadias site, however, only the location of hypospadias was a significant independent risk factor in urethrocutaneous fistula development after hypospadias repair (p<0.001). Conclusions Our results suggest that the risk of developing urethrocutaneous fistula after hypospadias repair is associated with the location of hypospadias (more proximal-type hypospadias). Type of hypospadias repair, suture materials, suture techniques, and number of other combined urologic disorders were not related to the development of urethrocutaneous fistulas.

Comparison of 5 Different Rat Models to Establish a Standard Animal Model for Research Into Interstitial Cystitis

Purpose We evaluated 5 different rat models using different agents in order to establish a standard animal model for interstitial cystitis (IC) in terms of the functional and pathologic characteristics of the bladder. Methods Five IC models were generated in 8-week-old female Sprague-Dawley rats via transurethral instillation of 0.1M hydrogen chloride (HCl) or 3% acetic acid (AA), intraperitoneal injection of cyclophosphamide (CYP) or lipopolysaccharide (LPS), or subcutaneous injection of uroplakin II (UPK2). After generating the IC models, conscious cystometry was performed on days 3, 7, and 14. All rats were euthanized on day 14 and their bladders were obtained for histological and pro-inflammatory-related gene expression analysis. Results In the cystometric analysis, all experimental groups showed significantly decreased intercontraction intervals compared with the control group on day 3, but only the LPS and UPK groups maintained significantly shorter intercontraction intervals than the control group on day 14. The histological analysis revealed that areas with severe urothelial erosion (HCl, AA, and UPK) and hyperplasia (CYP and LPS), particularly in the UPK-treated bladders, showed a markedly increased infiltration of toluidine blue-stained mast cells and increased tissue fibrosis. In addition, significantly elevated expression of interleukin-1b, interleukin-6, myeloperoxidase, monocyte chemotactic protein 1, and Toll-like receptors 2 and 4 was observed in the UPK group compared to the other groups. Conclusions Among the 5 different agents, the injection of UPK generated the most effective IC animal model, showing consequent urothelial barrier loss, inflammatory reaction, tissue fibrosis stimulation, and persistent hyperactive bladder.

Clinical Significance of Subclassification of Papillary Renal Cell Carcinoma: Comparison of Clinicopathologic Parameters and Oncologic Outcomes Between Papillary Histologic Subtypes 1 and 2 Using the Korean Renal Cell Carcinoma Database

Micro‐Abstract The aim of the present study was to investigate the clinical significance of the subclassification of papillary renal cell carcinoma (pRCC) in a multi‐institutional study of 274 Korean patients with pRCC. Type 2 pRCC displayed more aggressive clinicopathologic characteristics; however, no significant differences in prognosis were found between types 1 and 2 pRCC. Among patients with pRCC, the pathologic T stage was the only prognosticator. Introduction: The aims of the present study were to compare the clinicopathologic characteristics between type 1 and type 2 papillary renal cell carcinoma (pRCC) and to evaluate the effect of the subclassification of pRCC on the oncologic outcomes after surgery. Materials and Methods: The records of 274 patients with pRCC in the Korean renal cell carcinoma (KORCC) database were included for evaluation. Of the 274 patients, 118 had type 1 pRCC and 156 had type 2 pRCC. The patient characteristics, including clinicopathologic parameters, were investigated, and the oncologic outcomes were evaluated. Results: The mean patient age was significantly older in the type 2 pRCC group. Compared with type 1 pRCC tumors, type 2 pRCC tumors were more often localized to the renal hilum (P = .030). Patients with type 2 pRCC had a greater incidence of Fuhrman grade 3 and 4 tumors than those with type 1 pRCC (78.8% vs. 22.8; P < .001). Tumor necrosis and capsular invasion were more frequently found in type 2 pRCC (P = .008 and P = .007, respectively). At a mean follow‐up period of 38.0 months (interquartile range, 11.8‐57.3 months), the subclassification of pRCC did not influence the prognosis of patients with pRCC. Conclusion: From the information available in the KORCC database, we identified significant differences in clinicopathologic variables, including age, Fuhrman grade, tumor location, tumor necrosis, and capsular invasion between type 1 and 2 pRCC. Although type 2 pRCC had more aggressive clinicopathologic characteristics, subclassification of pRCC did not affect the oncologic outcomes.

In Vivo Validation Model of a Novel Anti-Inflammatory Scaffold in Interleukin-10 Knockout Mouse

BACKGROUND:We fabricated anti-inflammatory scaffold using Mg(OH)2-incorporated polylactic acid-polyglycolic acid copolymer (MH-PLGA). To demonstrate the anti-inflammatory effects of the MH-PLGA scaffold, an animal model should be sensitive to inflammatory responses. The interleukin-10 knockout (IL-10 KO) mouse is a widely used bowel disease model for evaluating inflammatory responses, however, few studies have evaluated this mouse for the anti-inflammatory scaffold.METHODS:To compare the sensitivity of the inflammatory reaction, the PLGA scaffold was implanted into IL-10 KO and C57BL/6 mouse kidneys. Morphology, histology, immunohistochemistry, and gene expression analyses were carried out at weeks 1, 4, 8, and 12. The anti-inflammatory effect and renal regeneration potency of the MH-PLGA scaffold was also compared to those of PLGA in IL-10 KO mice.RESULTS:The PLGA scaffold-implanted IL-10 KO mice showed kidneys relatively shrunken by fibrosis, significantly increased inflammatory cell infiltration, high levels of acidic debris residue, more frequent CD8-, C-reactive protein-, and ectodysplasin A-positive cells, and higher expression of pro-inflammatory and fibrotic factors compared to the control group. The MH-PLGA scaffold group showed lower expression of pro-inflammatory and fibrotic factors, low immune cell infiltration, and significantly higher expression of anti-inflammatory factors and renal differentiation related genes compared to the PLGA scaffold group.CONCLUSION:These results indicate that the MH-PLGA scaffold had anti-inflammatory effects and high renal regeneration potency. Therefore, IL-10 KO mice are a suitable animal model for in vivo validation of novel anti-inflammatory scaffolds.

A Novel Dorsal Slit Approached Non-Ischemic Partial Nephrectomy Method for a Renal Tissue Regeneration in a Mouse Model

BACKGROUND:Kidney ischemia–reperfusion (IR) via laparotomy is a conventional method for kidney surgery in a mouse model. However, IR, an invasive procedure, can cause serious acute and chronic complications through apoptotic and inflammatory pathways. To avoid these adverse responses, a Non-IR and dorsal slit approach was designed for kidney surgery.METHODS:Animals were divided into three groups, 1) sham-operated control; 2) IR, Kidney IR via laparotomy; and 3) Non-IR, Non-IR and dorsal slit. The effects of Non-IR method on renal surgery outcomes were verified with respect to animal viability, renal function, apoptosis, inflammation, fibrosis, renal regeneration, and systemic response using histology, immunohistochemistry, real-time polymerase chain reaction, serum chemistry, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and Masson’s trichrome staining.RESULTS:The Non-IR group showed 100% viability with mild elevation of serum blood urea nitrogen and creatinine values at day 1 after surgery, whereas the IR group showed 20% viability and lethal functional abnormality. Histologically, renal tubule epithelial cell injury was evident on day 1 in the IR group, and cellular apoptosis enhanced TUNEL-positive cell number and Fas/caspase-3 and KIM-1/NGAL expression. Inflammation and fibrosis were high in the IR group, with enhanced CD4/CD8-positive T cell infiltration, inflammatory cytokine secretion, and Masson’s trichrome stain-positive cell numbers. The Non-IR group showed a suitable microenvironment for renal regeneration with enhanced host cell migration, reduced immune cell influx, and increased expression of renal differentiation-related genes and anti-inflammatory cytokines. The local renal IR influenced distal organ apoptosis and inflammation by releasing circulating pro-inflammatory cytokines.CONCLUSION:The Non-IR and dorsal slit method for kidney surgery in a mouse model can be an alternative surgical approach for researchers without adverse reactions such as apoptosis, inflammation, fibrosis, functional impairment, and systemic reactions.

Clinical characteristics of postoperative febrile urinary tract infections after ureteroscopic lithotripsy

Purpose Ureteroscopic lithotripsy (URS) is gaining popularity for the management of ureteral stones and even renal stones, with high efficacy and minimal invasiveness. Although this procedure is known to be safe and to have a low complication rate, febrile urinary tract infection (UTI) after URS is not rare. Therefore, we aimed to analyze the risk factors and causative pathogens of febrile UTI after URS. Materials and Methods Between January 2013 and June 2015, 304 patients underwent URS for ureteral or renal stones. The rate of postoperative febrile UTI and the causative pathogens were verified, and the risk factors for postoperative febrile UTI were analyzed using logistic regression analysis. Results Of 304 patients, postoperative febrile UTI occurred in 43 patients (14.1%). Of them, pathogens were cultured in blood or urine in 19 patients (44.2%), and definite pathogens were not identified in 24 patients (55.8%). In patients with an identified pathogen, Pseudomonas aeruginosa had the highest incidence. Multivariate analysis showed that the operation time (p<0.001) was an independent risk factor for febrile UTI after URS. The cut-off value of operation time for increased risk of febrile UTI was 70 minutes. Conclusions Overall, febrile UTI after URS occurred in 14.1% of patients, and the operation time was an independent predictive factor for this complication. Considering that more than 83.7% of febrile UTIs after URS were not controlled with fluoroquinolones, it may be more appropriate to use higher-level antibiotics for treatment, even in cases with unidentified pathogens.

Impact of preoperative thrombocytosis on prognosis after surgical treatment in pathological T1 and T2 renal cell carcinoma: results of a multi-institutional comprehensive study

BACKGROUND The prognostic significance of preoperative thrombocytosis (TC) in renal cell carcinoma (RCC) is not without some debate. The aim of the present multi-institutional study was to determine the association of preoperative TC with the clinicopathological features and prognosis of localized RCC patients who underwent surgery in a large cohort. METHODS A study involving 8 institutions, and 4,376 patients with pT1 and pT2 RCC from the Korean renal cell carcinoma (KORCC) database, was conducted. TC was defined as a platelet count ≥400,000/μL. Patients were divided into 2 groups based on the presence of preoperative TC. Clinicopathological variables and survival rates were compared between the 2 groups. RESULTS Out of the 4,376 patients in the study, 106 (2.4%) had preoperative TC. Compared to patients without TC, these patients had a lower body mass index. Additionally, these patients had more advanced stage tumors with a higher Fuhrman grade, and higher incidence of symptoms at the time of diagnosis. Kaplan-Meier curves revealed that patients with TC had a significantly lower rate of recurrence-free survival (RFS). Furthermore, a lower rate of overall survival (OS) was exhibited amongst patients with TC. Multivariate analysis revealed that TC was an independent prognostic factor in terms of the RFS and OS. CONCLUSIONS TC appeared to be an important prognostic determinant in localized RCC. Furthermore, preoperative platelet count may be clinically useful for risk stratification of patients with surgically treated localized RCC.Background The prognostic significance of preoperative thrombocytosis (TC) in renal cell carcinoma (RCC) is not without some debate. The aim of the present multi-institutional study was to determine the association of preoperative TC with the clinicopathological features and prognosis of localized RCC patients who underwent surgery in a large cohort. Methods A study involving 8 institutions, and 4,376 patients with pT1 and pT2 RCC from the Korean renal cell carcinoma (KORCC) database, was conducted. TC was defined as a platelet count ≥400,000/μL. Patients were divided into 2 groups based on the presence of preoperative TC. Clinicopathological variables and survival rates were compared between the 2 groups. Results Out of the 4,376 patients in the study, 106 (2.4%) had preoperative TC. Compared to patients without TC, these patients had a lower body mass index. Additionally, these patients had more advanced stage tumors with a higher Fuhrman grade, and higher incidence of symptoms at the time of diagnosis. Kaplan-Meier curves revealed that patients with TC had a significantly lower rate of recurrence-free survival (RFS). Furthermore, a lower rate of overall survival (OS) was exhibited amongst patients with TC. Multivariate analysis revealed that TC was an independent prognostic factor in terms of the RFS and OS. Conclusions TC appeared to be an important prognostic determinant in localized RCC. Furthermore, preoperative platelet count may be clinically useful for risk stratification of patients with surgically treated localized RCC.