[Immuno-oncological therapeutic options in high-risk non-muscle invasive bladder cancer]

High-risk nonmuscle invasive bladder cancer (HR NMIBC) is an immunological malignancy. The standard therapy for HR NMIBC is based on transurethral bladder tumor resection with adjuvant Bacillus Calmette Guérin (BCG) instillation therapy. To prevent progression in case of BCG-refractory disease, early radical cystectomy is considered the therapy of choice according to the German S3 guidelines. With the advent of checkpoint inhibitors for the treatment of metastatic urological malignancies, a novel option for bladder preservation has been introduced for the treatment of HR NMIBC. The currently available data do not allow a meaningful conclusion on the long-term efficacy of PD-(L)1 (programmed cell death [ligand] 1) inhibitors due to the relatively short duration of oncological follow-up. Yet, it can be expected that checkpoint inhibitors will change the treatment algorithm of HR NMIBC in the next few years. Promising studies have been initiated to test the combination of local and systemic immunomodulation in terms of response and toxicity.

Adherence to the EAU guideline recommendations for systemic chemotherapy in penile cancer: results of the E-PROPS study group survey

OBJECTIVES

To validate the adherence of urologists to chemotherapy recommendations given in the EAU guidelines on PeCa. The European Association of Urology (EAU) guidelines on penile cancer (PeCa) are predominantly based on retrospective studies with low level of evidence.

MATERIALS AND METHODS

A 14-item-survey addressing general issues of PeCa treatment was developed and sent to 45 European hospitals. 557 urologists participated in the survey of which 43.5%, 19.3%, and 37.2% were in-training, certified, and in leading positions, respectively. Median response rate among participating departments was 85.7% (IQR 75-94%). Three of 14 questions addressed clinical decisions on neoadjuvant, adjuvant, and palliative chemotherapy. Survey results were analyzed by bootstrap-adjusted multivariate logistic-regression-analysis to identify predictors for chemotherapy recommendations consistent with the guidelines.

RESULTS

Neoadjuvant, adjuvant, and palliative chemotherapy was recommended according to EAU guidelines in 21%, 26%, and 48%, respectively. For neoadjuvant chemotherapy, urologists holding leading positions or performing chemotherapy were more likely to recommend guideline-consistent treatment (OR 1.85 and 1.92 with p_(bootstrap) = 0.007 and 0.003, respectively). Supporting resources (i.e., guidelines, textbooks) were used by 23% of survey participants and significantly improved consistency between treatment recommendations and Guideline recommendations in all chemotherapy settings (p_(bootstrap) = 0.010-0.001). Department size and university center status were no significant predictors for all three endpoints.

CONCLUSIONS

In this study, we found a very low rate of adherence to the EAU guidelines on systemic treatment for PeCa. Further investigations are needed to clarify whether this missing adherence is a consequence of limited individual knowledge level or of the low grade of guideline recommendations.

EAU-ESMO consensus statements on the management of advanced and variant bladder cancer-an international collaborative multi-stakeholder effort: under the auspices of the EAU and ESMO Guidelines Committees†

BACKGROUND

Although guidelines exist for advanced and variant bladder cancer management, evidence is limited/conflicting in some areas and the optimal approach remains controversial.

OBJECTIVE

To bring together a large multidisciplinary group of experts to develop consensus statements on controversial topics in bladder cancer management.

DESIGN

A steering committee compiled proposed statements regarding advanced and variant bladder cancer management which were assessed by 113 experts in a Delphi survey. Statements not reaching consensus were reviewed; those prioritised were revised by a panel of 45 experts before voting during a consensus conference.

SETTING

Online Delphi survey and consensus conference.

PARTICIPANTS

The European Association of Urology (EAU), the European Society for Medical Oncology (ESMO), experts in bladder cancer management.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Statements were ranked by experts according to their level of agreement: 1-3 (disagree), 4-6 (equivocal), 7-9 (agree). A priori (level 1) consensus was defined as ≥70% agreement and ≤15% disagreement, or vice versa. In the Delphi survey, a second analysis was restricted to stakeholder group(s) considered to have adequate expertise relating to each statement (to achieve level 2 consensus).

RESULTS AND LIMITATIONS

Overall, 116 statements were included in the Delphi survey. Of these, 33 (28%) statements achieved level 1 consensus and 49 (42%) statements achieved level 1 or 2 consensus. At the consensus conference, 22 of 27 (81%) statements achieved consensus. These consensus statements provide further guidance across a broad range of topics, including the management of variant histologies, the role/limitations of prognostic biomarkers in clinical decision making, bladder preservation strategies, modern radiotherapy techniques, the management of oligometastatic disease and the evolving role of checkpoint inhibitor therapy in metastatic disease.

CONCLUSIONS

These consensus statements provide further guidance on controversial topics in advanced and variant bladder cancer management until a time where further evidence is available to guide our approach.

[Molecular tumor board-urothelial cancer]

BACKGROUND

Molecular tumor boards (MTB) are becoming more common. There are several molecular alterations in urothelial cancer a molecular tumor board can potentially rely on.

OBJECTIVES

The aim is to specify molecular alterations and their correlations with different clinical endpoints and to highlight potential questions addressed to a MTB for urothelial cancer.

MATERIALS AND METHODS

Descriptive review of the literature based on PubMed.

RESULTS

The landscape of molecular alterations in urothelial cancer is heterogeneous. Thus, recent biomarker research has been focusing on biomarker panels and classifiers instead of single biomarkers. Recently, molecular subtypes of urothelial cancer have been identified and correlated with different clinical endpoints. Furthermore, circulating tumor cells and tumor DNA are under investigation as potential biomarkers. In addition to treatment response and prognosis, molecular markers are also needed to improve clinical staging prior to radical cystectomy or for proper patient selection for neoadjuvant chemotherapy. Erdafitinib is the first targeted therapy (fibroblast growth factor receptor [FGFR] alteration) in urothelial cancer that was recently approved (in the USA).

CONCLUSIONS

Due to the lack of external validation, none of the identified biomarkers is currently established in clinical routine. In addition, there is no single driver mutation in urothelial cancer that facilitates the development of biomarkers and targeted therapies.

Laparoscopic radical nephrectomy with inferior vena cava thrombectomy: highlight of key surgical steps

Objective:

Vascular involvement in the form of renal vein (RV) or inferior vena cava (IVC) thrombus can be seen in 4-10% of patients presented with RCC. In patients without presence of metastasis, surgical treatment in the form of radical nephrectomy remains the treatment of choice with 5-year survival rates of 45-70%. Open surgery is still the first treatment option of choice at the moment for RCC patients with IVC thrombus.

Materials and Methods:

In our study, we are reporting a case of patient with RCC and level I IVC thrombus treated with laparoscopy. Our patient is a 72 years old man with underlying co-morbidity of hypertension and chronic kidney disease (CKD) presented with right-sided RCC. The CT scan done showed a large right renal upper pole tumor measuring 8.4x5.2cm with level I IVC thrombus (Figure-1). There were no regional lymphadenopathy and the staging scans were negative.

Results:

The operative time was 124 minutes and blood loss was minimal. The patient was progressed to diet on POD 1 with bowel movement on POD 2. There was no significant change in the pre and post-operative glomerular filtration rate (GFR). The surgical drain was removed on POD2. The patient was discharged well on POD 5. There were no perioperative complications. The pathology was pT3bN0M0 Fuhrman grade II clear cell RCC.

Conclusions:

As a conclusion, laparoscopic radical nephrectomy and IVC thrombectomy is a complex and technically demanding surgery. With advancement of surgical skills as well as technology, more cases of minimally invasive laparoscopic radical nephrectomy and IVC thrombectomy can performed to improve the perioperative outcomes of carefully selected patients in a high volume center.

[Elective organ and function preservation in ureter and renal pelvis tumors]

With the technical innovations of smaller, flexible ureteroscopes, color-filtered imaging, and endoscopic laser technology, organ-preserving treatment for upper urinary tract transitional cell carcinoma has become feasible. While in the past, radical nephroureterectomy was the sole gold standard approach for the treatment of upper urinary tract tumors, the endoscopic approach is no longer restricted to only patients with the imperative indication of kidney preservation. Initial clinical results have demonstrated oncologic efficacy of endoscopic management or segmental ureteral resection. However, careful preoperative risk-assessment and close endoscopic follow-up are mandatory.

Impact of perioperative chemotherapy on survival in patients with advanced primary urethral cancer: results of the international collaboration on primary urethral carcinoma

BACKGROUND

To investigate the impact of perioperative chemo(radio)therapy in advanced primary urethral carcinoma (PUC).

PATIENTS AND METHODS

A series of 124 patients (86 men, 38 women) were diagnosed with and underwent surgery for PUC in 10 referral centers between 1993 and 2012. Kaplan-Meier analysis with log-rank testing was used to investigate the impact of perioperative chemo(radio)therapy on overall survival (OS). The median follow-up was 21 months (mean: 32 months; interquartile range: 5-48).

RESULTS

Neoadjuvant chemotherapy (NAC), neoadjuvant chemoradiotherapy (N-CRT) plus adjuvant chemotherapy (ACH), and ACH was delivered in 12 (31%), 6 (15%) and 21 (54%) of these patients, respectively. Receipt of NAC/N-CRT was associated with clinically node-positive disease (cN+; P = 0.033) and lower utilization of cystectomy at surgery (P = 0.015). The objective response rate to NAC and N-CRT was 25% and 33%, respectively. The 3-year OS for patients with objective response to neoadjuvant treatment (complete/partial response) was 100% and 58.3% for those with stable or progressive disease (P = 0.30). Of the 26 patients staged ≥cT3 and/or cN+ disease, 16 (62%) received perioperative chemo(radio)therapy and 10 upfront surgery without perioperative chemotherapy (38%). The 3-year OS for this locally advanced subset of patients (≥cT3 and/or cN+) who received NAC (N = 5), N-CRT (N = 3), surgery-only (N = 10) and surgery plus ACH (N = 8) was 100%, 100%, 50% and 20%, respectively (P = 0.016). Among these 26 patients, receipt of neoadjuvant treatment was significantly associated with improved 3-year relapse-free survival (RFS) (P = 0.022) and OS (P = 0.022). Proximal tumor location correlated with inferior 3-year RFS and OS (P = 0.056/0.005).

CONCLUSION

In this series, patients who received NAC/N-CRT for cT3 and/or cN+ PUC appeared to demonstrate improved survival compared with those who underwent upfront surgery with or without ACH.

[Transurethral resection of bladder tumors: management of complications]

As a frequent endourological procedure, transurethral resection of bladder tumors (TURB) represents a major field of activity for urological surgeons. Although TURB represents an endoscopic training procedure for urology residents, there are clear requirements for the quality of the surgical procedure as such. The knowledge of possible complications and their management are essential for urologists active in the clinical field. Bleeding complications, bladder perforation, infections and injuries to the ureteral orifice are the most frequently observed complications. This article summarizes the essential risks and complications as well as the corresponding preventive and therapeutic measures.

[Treatment of invasive bladder cancer: robot-assisted radical cystectomy and intracorporeal urinary diversion]

PURPOSE

Robot-assisted radical cystectomy (RARC) and intracorporeal urinary diversion are only performed in a few centers of excellence worldwide. Functional and oncologic outcomes are comparable. We report on our experience with RARC and intracorporeal diversion.

PATIENTS AND METHODS

We retrospectively identified 86 RARCs in 72 men and 14 women (mean age 69.7 years). All patients underwent robot-assisted radical cystectomy and pelvic lymphadenectomy followed by intracorporeal urinary diversion using ileal conduit or neobladder. Of the 86 patients, 24 patients (28%) underwent intracorporeal ileal conduit and 62 patients (72%) underwent intracorporeal neobladder formation. A Studer pouch was created in all who underwent intracorporeal neobladder diversion. Cancer specific survival (CSS) and overall survival (OS) are reported.

RESULTS

The mean operative time was 418.9 min (range 205-690 min) and blood loss was 380 ml (range 100-1000 ml). The mean hospital stay was 17.5 days (range 5-62 days). All the surgeries were completed with no open conversions. Minor complications (grade I and II) were reported in 23 patients, while major complications (grade III and above) were reported in 21 patients. The mean nodal yield was 20.3 (range 0-46). Positive margins were found in in 8%. The average follow-up was 31.5 months (range 3-52 months). Continence could be achieved in 88% of patients who received an intracorporeal neobladder. The cancer-specific survival (CSS) and overall survival (OS) were 80% and 70%, respectively.

CONCLUSION

RARC with intracorporeal diversion seems to be safe and reproducible in tertiary centers with robotic expertise. Operative times are acceptable and complications as well as functional and oncologic outcomes are comparable. Further standardization of RARC with intracorporeal diversion may lead to a wider adoption of the approach.

Cost effective laparoendoscopic single-site surgery with a reusable platform

The authors found that laparoendoscopic single-site surgery with a reusable platform was feasible for various urologic entities, yielding favorable cosmetic and functional results.

Background and Objectives:

Many disposable platforms have been applied in laparoendoscopic single-site surgery (LESS). Besides technical issues, cost is one of the limiting factors for its widespread acceptance. The current study describes the first completely reusable LESS-platform.

Methods:

We performed LESS-procedures in 52 patients including nephrectomy (18), adrenalectomy (2), partial nephrectomy (3), pyeloplasty (4), renal cyst ablation (4), pelvic lymphadenectomy (15), and lymphocele ablation (6). All procedures were conducted using a novel reusable single-port device (X-Cone, Karl-Storz) with a simplified set of instruments. We obtained perioperative and demographic data, including a visual analogue pain scale (VAS), and a complication reporting system based on Clavien grading.

Results:

Mean age was 50.04 y. Conversion to standard laparoscopy was necessary in 3 cases and addition of a needlescopic instrument in 6 cases. There was no open conversion. Intra- and postoperative complications occurred in 3 (Clavien II in 2 and III in 1) cases. Mean operative time was 110, 90, and 89 min, and hospital stay was 4.9, 3.1, and 3.6 d for nephrectomy, pelvic lymphadenectomy, and pyeloplasty, respectively. Mean VAS was 2.13, 1.07, and 1.5 while blood loss was 81.3 mL, 25.67 mL, and 17.5 mL, respectively. Mean lymph node yield was 15 (range, 8 to 21).

Conclusions:

A completely reusable LESS-platform is applicable to various uses in urology, yielding favorable functional and cosmetic results. Reusable materials are useful to reduce the cost of LESS, further increasing its acceptance. LESS with a completely reusable platform is more cost effective than standard laparoscopy.

[Laparoendoscopic single-site surgery in urology using reusable systems]

PURPOSE

Many disposable platforms have been available for laparoendoscopic single-site surgery (LESS) for a long time. Besides technical challenges cost remains the limiting factor for the widespread use of LESS. We present our experiences with the first completely reusable LESS platform.

METHODS

We performed LESS procedures in 52 patients, including nephrectomy (n=18), adrenalectomy (2), partial nephrectomy (3), pyeloplasty (4), renal cyst ablation (4), pelvic lymphadenectomy (15) and lymphocele ablation (6). All procedures were carried out using a novel reusable single-port device (X-ConeR, Karl-Storz) with a simplified combination of standard and preformed instruments. Perioperative and demographic data including a visual analogue pain scale (VAS) were obtained. Complications were recorded using the Clavien classification.

RESULTS

The mean age of the patients was 50.04 years. Conversion to standard laparoscopy was necessary in 3 cases and the additional use of a 3 mm needle instrument in 6 cases. There were no open conversions. Intraoperative and postoperative complications occurred in 3 (Clavien II in 2 and III in 1) cases. Mean operating time was 110, 90, and 89 min and hospital stay was 4.9, 3.1 and 3.6 days for nephrectomy, pelvic lymphadenectomy, and pyeloplasty, respectively. The mean VAS was 2.13, 1.07 and 1.5 while blood loss was 81.3 ml, 25.67 ml and 17.5 ml, respectively.

CONCLUSIONS

The LESS technique with a completely reusable platform is applicable to various indications in urology yielding favorable functional and cosmetic results. This novel simplified combination of instruments facilitates handling and shortens the learning curve. Reusable materials may help to reduce cost leading to a wider acceptance of LESS.

Development of a porcine animal model for urethral stricture repair using autologous urothelial cells

OBJECTIVE

To present a versatile large animal model for endoscopic stricture repair using autologous urothelial cells.

MATERIALS AND METHODS

12 male minipigs were used. An artificial stricture model was established using suture-ligation, thermo-coagulation and internal urethrotomy. A vesicostomy served for urinary diversion. Stricture formation was confirmed radiologically and histologically. Autologous urothelial cells were harvested from bladder washings, cultivated and labeled. Internal urethrotomy was done in all, and the cultivated cells were injected into the urethrotomy wound. All animals were sacrificed after 4 or 8 weeks. Immunohistology was done to confirm the presence of autologous urothelial cells within the reconstituted urethra.

RESULTS

Stricture formation was verified with all three methods. Histologically, no significant differences in the severity of stricture development could be observed with regard to the method used. The autologous urothelial cells in the area of the urethrotomy could be detected in the urothelium and the corpus spongiosum until 8 weeks after re-implantation.

CONCLUSIONS

We created a reliable and reproducible porcine model for artificial urethral strictures. Autologous urothelial cells can be implanted into an artificial stricture after urethrotomy. These cells retain their epithelial phenotype and are integrated in the resident urothelium. Further comparative studies are needed to ultimately determine a superior efficacy of this novel approach.

Evidence for PTEN-independent Akt activation and Akt-independent p27(Kip1) expression in advanced bladder cancer

In the treatment of advanced bladder cancer (BC), attention has recently focused on small molecule therapy concerning EGFR and the downstream Akt signalling pathway. Cellular deregulation processes are poorly understood, and biological determinants for the selection of therapy and monitoring are currently not available. The proteins PTEN, p-Akt and p27(Kip1) are suggested to be potentially significant biomarkers of Akt signalling. In this study, we investigated the expression of these proteins in advanced BC. PTEN, p-Akt and p27(Kip1) expression was determined immunohistochemically in 86 T2-4 BC specimens using a tissue microarray technique. Staining was documented with regard to intensity, cellular frequency and a multiplied staining score. Staining characteristics of the three proteins were correlated by regression analysis with the parameters of tumour stage and grade. A positive correlation was observed in the expression scores of PTEN and p-Akt, p-Akt and p27(Kip1) as well as PTEN and p27(Kip1) (p<0.02 for all combinations). The positive correlation between PTEN and p-Akt resulted mainly due to the strong correlation of PTEN intensity with p-Akt (p=0.0003 and p=0.0006 to p-Akt frequency and intensity, respectively). A positive correlation between p-Akt and p27(Kip1) was noted for p-Akt frequency as well as intensity (p<0.05 for all combinations). The positive correlation between PTEN and p27(Kip1) resulted due to the correlation of PTEN intensity alone with p27(Kip1) (p<0.03 for p27(Kip1) frequency and intensity), whereas no significance was noted for PTEN frequency. No correlation was found between T or G and expression of the proteins. However, activation of Akt in BC is known to occur independently of PTEN protein loss and appears not to cause a decrease of p27(Kip1). However, a direct regulatory impact of PTEN on p27(Kip1) was found. PTEN intensity, rather than frequency, appears to be a superior biomarker. These results may provide information to support research into protein profiling-predicted targeted therapy for BC. Correlations to benign urothelium, superficial BC specimens and follow-up data remain to be investigated.

[Benefits and risks of orthotopic neobladder reconstruction in female patients]

Orthotopic neobladder reconstruction is an established treatment option in female patients undergoing radical cystectomy for invasive bladder cancer. Long-term results have proven its oncological safety and functional efficacy in both organ-confined and locally advanced disease. The use of nerve-sparing procedures has the potential to further improve the functional results in terms of postoperative continence and sexual function as long as we adhere to basic oncological principles. One important contraindication for performing neobladder reconstruction in female patients with bladder cancer is a positive urethral margin at radical cystectomy. In this respect, frozen section analysis is associated with a high sensitivity and specificity for the detection of positive urethral margins. The risk of urethral recurrence at 5 years in patients with negative urethral margins at cystectomy is ≤ 1 % and may become clinically apparent as inguinal lymphadenopathy due to changes of the lymphatic drainge after neobladder reconstruction. The 5-year recurrence-free survival after neobladder reconstruction in female patients with organ-confined bladder cancer ranges between 63 and 75 %. In female patients with locally advanced node-negative disease (≥ pT3a-4a, pN0) who underwent an orthotopic neobladder the recurrence free survival at 5 years is 71 % and so does not significantly differ from that of female patients with node-positive disease treated with an cutaneous diversion. Whether robotic cystectomy has the potential to further improve the functional outcome after neobladder reconstruction in female patients and achieve oncological long-term results comparable to those of open series is still under investigation should further be evaluated in prospective trials.

[The importance of lymphadenectomy for muscle invasive transitional cell carcinoma of the human bladder - a review of the literature]

INTRODUCTION

The extent of the lymphadenectomy (LAE) as well as the appearance of lymph node metastasis are important prognostic factors in the treatment of the muscle invasive transitional cell carcinoma of the bladder (TCC). However there is still the need to discuss the dimension of the LAE.

MATERIAL AND METHODS

Pubmed was searched with regard to guidelines for the treatment of muscle invasive TCC. In particular, operation techniques, the appearance of lymph node metastasis, lymph node mapping, histopathological and radiological detection methods, as well as the risk of positive lymph nodes were analysed.

RESULTS

The confirmation of lymph node metastasis is associated with a poorer outcome. Besides knowledge of metastasis pathways, an extensive and careful pathological reprocessing is one cornerstone of the procedure. Molecular markers seem to support the detection of micrometastasis. The extended LAE is associated with a better long-term survival rate compared to the limited LAE. New operation techniques such as laparoscopic or robot-assisted cystectomy are associated with lower peri- and postoperative morbidity, but the extended LAE is more challenging using these techniques. There are no long-term results available yet for these methods. Most data regarding lymphadenectomy and survival rate are based on retrospective studies thus decreasing the level of evidence.

CONCLUSION

An extended LAE shows retrospectively a better outcome in patients with lymph node metastasis in TCC. Therefore an extended LAE should be performed in patients with muscle invasive TCC. New methods for detecting lymph node metastasis are elevating the confirmation rate.

Long-term biochemical evaluation of the androgen receptor pathway in males with disorders of sex development

PURPOSE

Disorders of sex (DSD) development represent a serious condition. Most of the underlying mechanisms remain unclear. Disturbances within the androgen receptor (AR) pathway frequently account for 46 XY-DSDs. The individual gender-related outcome often is unsatisfactory. We present a long-term AR gene-mutation-associated follow-up in a group of 46 XY-DSD patients.

METHODS

Twenty patients (46 XY) who underwent genitoplasty in infancy or early childhood were retrospectively identified. Median follow-up after surgery was 16 years. All were undervirilized at initial presentation. Thirteen had female gender assignment, and 7 were raised as males. A genital skin biopsy and subsequent fibroblast cultures were done. The specific binding of dihydrotestosterone, the thermostability of the receptor hormone complex, and 5-α-reductase activity were measured. AR gene mutations were detected by direct sequencing. The individual outcome was correlated with specific AR mutations.

RESULTS

AR point mutations were detected in 12, 7 were previously unknown. There was no specific androgen binding in 3, reduced affinity in 9, and normal binding in 8 patients. 5-α-Reductase activity was normal in 15, reduced in 4 and completely absent in 1 patient.

CONCLUSIONS

Retrospective evaluation revealed previously unknown and established AR gene mutations being associated with a distinct long-term outcome. Identification of the molecular mechanisms causing DSD will likely improve timely diagnosis and therapy. Exact characterization of AR activation and function may offer a treatment modality in affected patients. These data may allow us to give prognostic estimations on the individual outcome adding objective criteria for gender assignment in 46 XY-DSD patients.

[Minimally invasive percutaneous treatment of lower pole stones with a diameter of 8 to 15 millimeters]

PURPOSE

The optimal treatment options for lower pole stones with a diameter below 15 mm are controversially discussed. Extracorporeal shock wave lithotripsy (ESWL) is non-invasive but is hampered by low stone-free rates and a significant retreatment rate. Flexible ureterorenoscopy (URS) has been demonstrated to have high stone-free rates but the treatment costs - consisting of OR time, repair costs and expenditure for laser fibers, guide wires and stone baskets - as well as low stone-free rates with increasing stone size render this procedure highly expensive. Minimally invasive percutaneous litholapaxy (MIP) has shown low morbidity and high efficacy in the treatment of nephrolithiasis. The goal of this study was to investigate the efficacy and -safety of MIP for the treatment of small lower pole stones.

PATIENTS AND METHOD

The charts of 29 patients who were treated with MIP were reviewed and clinical data like OR time, drop in haemoglobin, complication rate, stone-free rate and duration of hospital stay were collected.

RESULTS

28 of 29 patients were primarily stone-free; one had to undergo additional flexible URS to become stone-free. All procedures were undertaken with only one access, no severe complications occurred; none of the patients had to be transfused.

CONCLUSIONS

The MIP concept has a low complication rate and has been shown to be safe and effective in previous studies. We demonstrate that the feasibility and efficacy justify the percutaneous approach also for small lower pole stones.

Neuronal activation in the nucleus of the solitary tract following jejunal lipopolysaccharide in the rat

INTRODUCTION

Inflammation during systemic lipopolysaccharide (LPS) seems to be modulated by the CNS via afferent and efferent vagal pathways. We hypothesized that similar to systemic inflammation, local LPS in the gut lumen may also activate central neurons and aimed to identify potential molecular mechanisms.

METHODS

Male Wistar rats were equipped with an exteriorized canula in the proximal jejunum. LPS or vehicle were administered into the jejunum (10 mg ml(-1)). For further study of molecular mechanisms, LPS or vehicle were administered systemically (1 mg kg(-1)). Brain stem activation was quantified by Fos-immunohistochemistry in the vagal nucleus of the solitary tract (NTS) and the Area postrema which is exposed to systemic circulation. Serum LPS concentrations were also determined.

RESULTS

Jejunal LPS exposure entailed 91+/-12 (n=7) Fos-positive neurons in the NTS compared to 39+/-9 in controls (n=6; p<0.01), while serum LPS concentrations and Fos-positive neurons in the Area postrema were not different. Systemic LPS triggered 150+/-25 (n=6) and vehicle 52+/-6 Fos-positive neurons (n=7; p<0.01). The Fos count after systemic LPS was reduced to 99+/-30 following pretreatment with the cyclooxygenase inhibitor Naproxen (10 mg kg(-1); p>0.05 versus vehicle controls) and increased to 242+/-66 following the iNOS-inhibitor Aminoguanidine (15 mg kg(-1); p<0.01). In the Area postrema, 97+/-17 (n=6) neurons were counted in animals pretreated with systemic LPS compared to 14+/-4 in controls (n=7, p<0.001).

CONCLUSIONS

Central neuronal activation following inflammation after systemic LPS is modulated by cyclooxygenase and NO pathways. Local exposure to bacterial LPS in the gut lumen activates the NTS which may set the stage for efferent vagal modulation of intestinal inflammation.