Influence of body mass index, surgical approach and lymphadenectomy on the development of symptomatic lymphoceles after radical prostatectomy.

PURPOSE: Identification of factors influencing lymphocele formation requiring intervention after radical prostatectomy. METHODS: 302 patients undergoing radical retropubic prostatectomy (RRP, n = 174) or transperitoneal robot-assisted laparoscopic prostatectomy (RALP, n = 128) by the same surgeon were retrospectively reviewed. Incidence of symptomatic lymphoceles (SLC) was compared with clinical and pathological data (contingency analyses, Wilcoxon-Kruskal-Wallis test). RESULTS: Sixteen patients (5.3%) developed SLC. SLC occurred significantly more frequently after RRP compared to RALP (8.0 vs. 0.8%, p = 0.0008). Patients with SLC had more lymph nodes (LN) removed median (17 vs. 13, p = 0.009) and a significantly lower BMI (median 24.4 vs. 26.4, p = 0.0008). Presence of LN metastases (n = 18 patients, 6.0%) showed no statistical impact on SLC. In a multivariate analysis surgical method, the number of resected LN and the BMI remained independent predictors of SLC formation. CONCLUSIONS: The lower incidence of SLC after RALP compared to RRP probably results from peritoneal drainage of lymphatic fluid. The correlation of removed LN and SLC might be explained by increased injury of lymphatic vessels during more extended LN dissection. Why patients with lower BMI are more prone to develop SLC still remains unclear. However, early postoperative mobilization in nonobese patients might be a contributing factor.

[Post-chemotherapy laparoscopic retroperitoneal lymph node dissection in low volume residual germ cell cancer: a technique to reduce morbidity]. / Laparoskopisch retroperitoneale Lymphadenektomie bei Low-volume-Keimzelltumoren nach Chemotherapie : Ein Verfahren zur Verringerung der Morbidität.

PURPOSE: Retroperitoneal lymph node dissection (RPLND) is the most appropriate method for the detection of residual tumor tissue and mature teratoma after chemotherapy in patients with advanced nonseminomatous (NSGCT) or seminomatous (SGCT) germ cell tumors in clinical stage II-III. Open surgical procedures are associated with higher morbidity rates and laparoscopic RPLND offers a minimally invasive procedure with equivalent oncological safety and low morbidity. METHODS: In 39 patients laparoscopic RPLND (L-RPLND) after platinum-based chemotherapy for clinical stage IIa-III NSGCT was performed unilaterally as well as bilaterally by two surgeons. Patients with retroperitoneal residual tumor >1 cm and normalization of tumor markers after chemotherapy were included. Bilateral L-RPLND was performed with complete contralateral nerve sparing while the decision for ipsilateral nerve preservation was based on the volume of the residual mass in the respective standard field. RESULTS: The L-RPLND was completed in all patients without conversion. Median operation time was 248 min (range 95-397 min) and mean hospitalization time was 5 days (range 3-14 days). Furthermore, there was no difference in recurrence rate of the disease (p=0.45) between patients with unilateral or bilateral dissection. The postoperative ejaculatory function was normal in 37 out of 39 patients. The median follow-up period was 18.5 months (range 3-38 months) and 3 out of 39 patients developed recurrence (7.69 %). CONCLUSIONS: Post-chemotherapy L-RPLND is feasible with a lower complication rate and an adequate oncological safety and functional outcome. Due to the complexity of L-RPLND the procedure remains limited to institutions with extensive laparoscopic experience.

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.

[Robotic laparoscopic cystectomy: on the way to a standard procedure?]. / Die Roboter-assistierte laparoskopische Zystektomie: Auf dem Weg zu einem Standard-Verfahren?

INTRODUCTION: Radical cystectomy is considered the standard treatment for muscle-invasive bladder cancer. Minimally invasive techniques - especially robot-assisted techniques (RARC) - are being increasingly employed for this indication. Herein, we evaluate the current status of RARC and its acceptance in the urological community. RESULTS: The field of RARC is steadily increasing particularly due to an extremely short learning curve for surgeons with previous experience in robot-assisted radical prostatectomy. Lymph node yield has been shown to be adequate in several independent studies, being comparable to that of the open approach. Urinary diversion is most frequently done extracorporeally while several groups have commited themselves to intracorporeal techniques and have already shown excellent results. The perioperative outcome data compare favourably to those of open cystectomy. Short-term and interim oncological data are promising while a final long-term assessment is still lacking. CONCLUSIONS: RARC completed by appropriate urinary diversion is gaining relevance in academic institutions worldwide. The relatively wide availability of the robotic system will further add to this development. Secondary to the final assessment of its oncological efficacy RARC has the potential to become a standard treatment of muscle-invasive bladder cancer since its perioperative efficacy is excellent.

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.

Increased expression of connexin 43 in the overactive neurogenic detrusor.

PURPOSE: The cellular mechanisms involved in unstable uncontrolled detrusor contractions in the human bladder remain unknown. One hypothesis, based on electron microscopical observations and animal studies, is that gap junctions are present in the human detrusor and are increased in patients with detrusor overactivity. Thus intercellular electrical coupling between adjacent detrusor cells would be increased allowing electrical activity to spead more easily within the detrusor muscle mass and more readily generate significant contractions. The aim of this study was to prove this hypothesis. MATERIAL AND METHODS: Detrusor biopsies have been obtained from videourodynamically evaluated patients with neurogenic detrusor overactivity (NDO) (n = 19) [group I] and from patients with stress urinary incontinence (SUI) with stable, non-obstructed detrusors (n = 5) [group II] serving as controls. Specimens were fixed, paraffin embedded, sectioned, stained with a monoclonal connexin 43 antibody and evaluated by two blinded examiners using a semiquantitative scale. Connexin 43 mRNA levels were evaluated using quantitative RT-PCR with primers for connexin 43 and for 18S rRNA. The results were correlated with the patients' groups. RESULTS: Connexin 43 could be identified in cross sections of every detrusor biopsy. In all biopsies from patients with NDO a widespread presence of connexin 43 staining was observed, whereas only a limited presence of connexin 43 staining was observed in the specimen from patients with SUI. Connexin 43 mRNA levels within the detrusor were 3.7 fold higher in the NDO group than in the SUI group (p = 0.017). CONCLUSIONS: A limited amount of gap junctions seems to be present in every detrusor independently from its urodynamic stability or instability. But there is a significant increase in connexin 43 protein and RNA levels in patients with neurogenic detrusor overactivity underlining their role in intercellular electrical coupling.