Long-term outcome of non-antireflux robotic-assisted laparoscopic ureter reimplantation in ureteral obstruction

PURPOSE

Although robotic-assisted laparoscopic ureter reimplantation (RALUR) is a recognized alternative to open and laparoscopic ureter reimplantation in treating distal ureteral obstruction, there are limited data on long-term efficacy and safety outcomes of non-antireflux RALUR. We assessed patients undergoing RALUR, evaluating operative, functional and safety determinants.

MATERIALS AND METHODS

All consecutive patients undergoing non-antireflux RALUR between April 2015 and January 2020 were included in this retrospective cohort study. The primary outcome endpoint was recurrent distal ureteral obstruction.

RESULTS

Mean follow-up was 41.3 months (CI 95%, 33.3-49.2). Among the 26 included patients, none developed recurrent distal ureteral obstruction. Kidney function in terms of serum creatinine level (72.0 vs. 71.0 µmol/L, p=0.988) and glomerular filtration rate (92.0 vs. 91.0 mL/min, p=0.831) was stable between the preoperative period and the last follow-up. Renal pelvis dilatation decreased significantly postoperatively, from grade 2 to grade 0 (p<0.001). Most patients (73.1%) remained free from any clinical symptoms of reflux during the follow-up. The rate of postoperative complications (Clavien-Dindo grade ≥II) was 23.1%. All complications resolved without sequelae. No recurring urinary tract infections were reported.

CONCLUSIONS

Non-antireflux RALUR appears to be safe and effective in the management of distal ureteral obstruction. There was no recurrent ureteral obstruction after RALUR in our cohort during a mean follow-up of more than 3 years. Non-antireflux reimplantation did not seem to have any notable impact on renal function during the follow-up period.

Indication for Active Surveillance in the Era of MRI-Targeted Prostate Biopsies

INTRODUCTION

Active surveillance (AS) strategies were established to avoid overtreatment of low-risk prostate cancer (PCa) patients. Low tumor volume represents one indication criteria; however, applying this criterion after MRI-targeted prostate biopsies may lead to overestimation of tumor volume; wherefore, patients suitable for AS would be exposed to the risk of overtreatment.

METHODS

This retrospective analysis included 318 patients in which PCa was detected by MRI-TRUS fusion prostate biopsy. Classic and extended indication for AS included Gleason 6 and Gleason 3 + 4 cancer, respectively. We assessed the effect of targeted biopsies and temporary rating strategies on eligibility for AS and developed new "composite" algorithms to more accurately assess eligibility for AS.

RESULTS

Forty-four (13.8%) and 60 (18.9%) of the 318 patients qualified for AS according to "classic" and "extended" criteria, respectively. Application of the "composite 1" definition led to AS eligibility of 52 of 248 patients (20.97%) in the classic and of 77 of 248 patients (31.05%) in the "extended" group.

CONCLUSIONS

We could demonstrate that classic algorithms led to ineligibility of patients for AS. We propose a new rating algorithm to improve tumor assessment for a more accurate indication for AS.

Dynamics of Urinary Calprotectin after Renal Ischaemia

Background: Urinary calprotectin has been identified as a promising biomarker for acute kidney injury. To date, however, the time-dependent changes of this parameter during acute kidney injury remain elusive. The aim of the present work was to define the time-course of urinary calprotectin secretion after ischaemia/reperfusion-induced kidney injury in comparison to neutrophil gelatinase—associated lipocalin, thereby monitoring the extent of tubular damage in nephron sparing surgery for kidney tumours. Methods: The study population consisted of 42 patients. Thirty-two patients underwent either open or endoscopic nephron sparing surgery for kidney tumours. During the surgery, the renal arterial pedicle was clamped with a median ischaemic time of 13 minutes (interquartile range, 4.5–20.3 minutes) in 26 patients. Ten retro-peritoneoscopic living donor nephrectomy patients and 6 nephron sparing surgery patients in whom the renal artery was not clamped served as controls. Urinary calprotectin and neutrophil gelatinase—associated lipocalin concentrations were repeatedly measured by enzyme-linked immunosorbent assay and assessed according to renal function parameters. Results: Urinary concentrations of calprotectin and neutrophil gelatinase—associated lipocalin increased significantly after ischaemia/reperfusion injury, whereas concentrations remained unchanged after nephron sparing surgery without ischaemia/reperfusion injury and after kidney donation. Calprotectin and neutrophil gelatinase—associated lipocalin levels were significantly increased 2 and 8 hours, respectively, post-ischaemia. Both proteins reached maximal concentrations after 48 hours, followed by a subsequent persistent decrease. Maximal neutrophil gelatinase—associated lipocalin and calprotectin concentrations were 9-fold and 69-fold higher than their respective baseline values. The glomerular filtration rate was only transiently impaired at the first post-operative day after ischaemia/reperfusion injury (p = 0.049). Conclusion: Calprotectin and neutrophil gelatinase—associated lipocalin can be used to monitor clinical and sub-clinical tubular damage after nephron sparing surgery for kidney tumours. Urinary calprotectin concentrations start rising within 2 hours after ischaemia/reperfusion-induced kidney injury.

Expression of histone deacetylases 1, 2 and 3 in histological subtypes of testicular germ cell tumours

In this study we aimed to evaluate the protein expression of class I histone deacetylases (HDAC) in testicular germ cell tumours (GCT) and to analyse differences between the histological subtypes of testicular GCT. 325 testicular GCT were included in a tissue microarray with each histological subtype of the tumour being separately represented on this array. Expression of class I HDAC isoforms 1, 2 and 3 was assessed by immunohistochemistry. While HDAC2 and 3 were highly expressed in all histological subtypes of GCT, HDAC1 was almost consistently expressed at lower levels. We observed significant differences in the expression of the respective HDACs between seminoma and non-seminoma GCT tissue components. Interestingly, choriocarcinomas showed generally high expression values for all three class I HDAC isoforms. Relevant correlations with clinicopathological parameters could not be demonstrated. Contrasting published findings on other tumour entities, no immediate practical diagnostic or prognostic value for HDAC1-3 in GCT could be inferred. However, the high expression levels might still be indicative for a treatment response to HDAC inhibitors which ought to be evaluated in further studies.

Transurethral injection therapy with dextranomer/hyaluronic acid copolymer (Deflux) for treatment of secondary vesicoureteral reflux after renal transplantation

BACKGROUND AND PURPOSE

Secondary vesicoureteral reflux (SVUR) after renal transplantation may cause recurrent urinary-tract infections (UTI) and loss of renal function. There are only a few reports on the endoscopic treatment of SVUR by transurethral injection therapy. This is the first report of transurethral injection of dextranomer/hyaluronic acid copolymer (Deflux; Q-Med Scandinavia, Uppsala, Sweden) to relieve SVUR after renal transplantation.

PATIENTS AND METHODS

Between November 2003 and October 2005, four women were treated for SVUR with transurethral injections of dextranomer/hyaluronic acid copolymer. All patients had deterioration of renal function attributable to SVUR, recurrent UTI, or both. The mean follow-up was 29 months (range 16-38 months).

RESULTS

Initially, SVUR was corrected in all patients. Recurrent SVUR made a second treatment necessary in two patients. Three patients had no signs of SVUR 15, 27, and 36 months after the treatment. Renal function remained stable in these patients, and two were free of UTI. One of the patients who received two Deflux injections developed a filiform stenosis of the distal ureter, which was corrected by ureteropyeloplasty with the native ureter.

CONCLUSION

Transurethral injection therapy with Deflux is a minimally invasive treatment option for patients with SVUR after renal transplantation. A second treatment seems to be necessary in some cases. Complications such as ureteral obstruction may occur.

Destabilization of chromosome 9 in transitional cell carcinoma of the urinary bladder

The most frequent genetic alteration in transitional cell carcinoma of the urinary bladder (TCC) is loss of chromosome 9 which targets CDKN2A on 9p. The targets on 9q are not confirmed. Here, 81 advanced TCC specimens were investigated for loss of heterozygosity (LOH) and homozygous deletions (HD) on chromosome 9q using multiplex analysis of microsatellite markers. 41/81 tumours (51%) showed LOH on 9q, with LOH at all markers in 33 cases. Eight partial losses involved three regions in 9q12, 9q22.3, and 9q33- 9q34. No mutations were identified in the candidate tumour suppressor gene DBCCR1 in three tumours showing restricted LOH at 9q32-33. 22% of the specimens had HD at CDKN2A, but no HD was found on 9q. Two tumours had lost 9p only and five 9q only. 9q LOH was not related to tumour grade or stage and present or absent with equal frequency in recurrent TCC. LOH on 9q correlated with the extent of genome-wide hypomethylation (P < 0.0001) which extended into satellite sequences located in 9q12 juxtacentromeric heterochromatin. While the high frequency of chromosome 9q loss in TCC may reflect destabilization of the chromosome related to hypomethylation of repetitive DNA, the data are compatible with the existence of tumour suppressor genes on this chromosome arm.

Polymorphic methyl group metabolism genes in patients with transitional cell carcinoma of the urinary bladder

Because polymorphisms in the methyl group metabolism genes methylene-tetrahydrofolate reductase (MTHFR), methionine synthase (MS), and cystathione beta-synthetase (CBS) affect plasma homocysteine levels and intracellular concentrations of S-adenosylmethionine (SAM), they modify the susceptibility to cardiovascular diseases and cancer. Specifically, genome-wide decreased DNA methylation ('hypomethylation') in human cancers might be a consequence of decreased SAM levels. Because hypomethylation is particularly prevalent in transitional cell carcinoma of the urinary bladder (TCC), the genotype distributions for the two each most prevalent MTHFR, MS, and CBS alleles were compared between 165 TCC patients and 150 population controls. The distributions of the MTHFR 677A/V and the MS 919G/D alleles were not significantly different between cancer patients and controls, even after stratification according to age, gender, tumor stage or grade. The CBS 844INS68 allele was slightly less frequent in TCC patients than in controls (q=0.07 versus 0.10), but was rarer among males in both groups. Among the TCC patients, this gender difference was highly significant (Mantel-Haenszel and chi(2)-test P=0.007). No significant difference between TCC patients and controls was found for any combined genotype. Likewise, the extent of DNA hypomethylation determined in 62 carcinoma specimens was not related to the respective genotypes. Thus, on their own, the MTHFR, MS and CBS genotypes do not appear to act upon susceptibility to TCC or influence the extent of DNA hypomethylation in this cancer.

DNA methylation and the mechanisms of CDKN2A inactivation in transitional cell carcinoma of the urinary bladder

Alterations of the CDKN2A locus on chromosome 9p21 encoding the p16INK4A cell cycle regulator and the p14ARF1 p53 activator proteins are frequently found in bladder cancer. Here, we present an analysis of 86 transitional cell carcinomas (TCC) to elucidate the mechanisms responsible for inactivation of this locus. Multiplex quantitative PCR analysis for five microsatellites around the locus showed that 34 tumors (39%) had loss of heterozygosity (LOH) generally encompassing the entire region. Of these, 17 tumors (20%) carried homozygous deletions of at least one CDKN2A exon and of flanking microsatellites, as detected by quantitative PCR. Analysis by restriction enzyme PCR and methylation-specific PCR showed that only three specimens, each with LOH across 9p21, had bona fide hypermethylation of the CDKN2A exon 1alpha CpG-island in the remaining allele. Like most other specimens, these three specimens displayed substantial genome-wide hypomethylation of DNA as reflected in the methylation status of LINE L1 sequences. The extent of DNA hypomethylation was significantly more pronounced in TCC with LOH and/or homozygous deletions at 9p21 than in those without (26% and 28%, respectively, on average, versus 11%, p < 0.0015). No association of LOH or homozygous deletions at 9p21 with tumor stage or grade was found. The data indicate that DNA hypermethylation may be rare in TCC and that deletions are the most important mechanism for inactivation of the CDKN2A locus. The predominance of allelic loss may be explained by its correlation with genome-wide DNA hypomethylation, which is thought to favor chromosomal instability and illegitimate recombination.