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Dive into the research topics where Andreas J. Gross is active.

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Featured researches published by Andreas J. Gross.


European Urology | 2013

Complications and Early Postoperative Outcome in 1080 Patients After Thulium Vapoenucleation of the Prostate: Results at a Single Institution

Andreas J. Gross; Christopher Netsch; Sophie Knipper; Jasmin Hölzel; Thorsten Bach

BACKGROUND Thulium vapoenucleation of the prostate (ThuVEP) has been introduced as a minimally invasive treatment for benign prostatic obstruction (BPO). OBJECTIVE To analyze immediate outcomes and the institutional learning curve of ThuVEP, and to report its standardized complication rates, using the modified Clavien classification system (CCS) to grade perioperative complication rates. DESIGN, SETTINGS, AND PARTICIPANTS A prospective evaluation of 1080 patients undergoing ThuVEP from January 2007 until May 2012 at our institution. INTERVENTION ThuVEP was performed using the 2-μm, continuous-wave, thulium:yttrium-aluminum-garnet laser. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Preoperative status, surgical details, and immediate outcome were recorded for each patient. Perioperative complications were classified according to the modified CCS. RESULTS AND LIMITATIONS Median prostate size was 51 ml (interquartile range [IQR]: 36-78.7). Median operation time was 56 min (IQR: 40-80), and median enucleation time was 32.5 min (IQR: 22-50). Median catheterization time was 2 d (IQR: 2-2); median length of hospital stay was 4 d (IQR: 3-5). Median resected tissue weight was 30 g (IQR: 16.00-51.25). Incidental carcinoma of the prostate was detected in 59 (5.5%) patients. Median maximum urinary flow rate (8.9 vs 18.4 ml/s) and postvoid residual urine volume (120 vs 20 ml) changed significantly (p<0.001). Minor complications occurred in 24.6% of the patients (Clavien 1: 20.8%; Clavien 2: 3.8%). Early reinterventions were necessary in 6.6% of the patients (Clavien 3a: 0.6%; Clavien 3b: 6%). One Clavien 4 complication occurred (0.09%). The overall complication rates decreased significantly over time due to decreasing Clavien 1, 2, and 3b events. The major limitations of the study are the prospective, unicentric study design, the lack of a control group, and that only short-term data were documented on morbidity and efficacy of the ThuVEP procedure. CONCLUSIONS ThuVEP is a safe and effective procedure for the treatment of symptomatic BPO, with low perioperative morbidity.


World Journal of Urology | 2007

Oncological and functional results of open, robot-assisted and laparoscopic radical prostatectomy: does surgical approach and surgical experience matter?

Thomas R. W. Herrmann; Robert Rabenalt; J.-U. Stolzenburg; Evangelos Liatsikos; Florian Imkamp; Hossein Tezval; Andreas J. Gross; Udo Jonas; M. Burchardt

The treatment of prostate cancer has undergone a fundamental change in the last decade. New surgical and nonsurgical minimal invasive methods have evolved. As the methodology of the different treatments is commonly known to urologists, this article focuses on oncological and functional outcome of open retropubic (ORP), trans- or extraperitoneal endoscopical (LRP), and robot-assisted radical prostatectomy (RALP), based on personal experience and review of the literature. A MEDLINE search was performed to review the literature on LRP and RALP between 1982 and 2007 with special emphasis on oncological and functional results, technical considerations, comparison of LRP and RALP to ORP, laparoscopic training, historical aspects, and cost-efficiency of the techniques. Based on diligent training and proctoring programs, a continuous dissemination of laparoscopic techniques takes place. There is a trend towards the extraperitoneal access in most of the minimal invasive programs at least in the European community. Mid-term outcomes of LRP and short-term outcomes of RALP achieved equivalence to open surgery with regards to complications, oncologic and functional results. Distinct advantages of LRP include less postoperative pain, lower transfusion rates, shorter convalescence, and better cosmetics. In contrast to RALP, LRP reaches cost-equivalence with open surgery in selected centers. LRP and RALP reproduce the short-term results of open surgery while providing the advantages of a minimal access. Video-assisted teaching improves the transfer of anatomical knowledge and technical knowhow, but the discussion about the longer learning curve for laparoscopy handling remains. The future will show if European centers adopt the use of robots comparable to the United States.


Journal of Endourology | 2008

Working tools in flexible ureterorenoscopy--influence on flow and deflection: what does matter?

Thorsten Bach; B. Geavlete; Thomas R. W. Herrmann; Andreas J. Gross

INTRODUCTION Flexible renoscopes offer access to almost all points within the collecting system. For stone workup, excellent visualization is mandatory. Therefore, irrigation flow is of critical importance. The aim of this study was to evaluate the effect of tools and probes on deflection angle and irrigation flow volume in the latest generation of flexible renoscopes. METHODS Five flexible renoscopes [Wolf (Viper), Storz (FlexX(2)), ACMI (DUR-8 Elite, DUR-D), Olympus (URF-P5)] were tested. Deflection angle, lowest diameter of the bent tip, and flow rates were measured. Recorded parameters were deflection angle and flow rate of the empty and loaded scopes. A laser probe (273 mum), biopsy forceps (2.4-3.0 French), and tipless nitinol baskets (1.5-2.4 French) were tested. RESULTS Deflection has no influence on flow rate. The size of the basket has no influence on the maximum angle of deflection. Introducing the laser fiber or the biopsy forceps leads to relevant loss of deflection (laser fiber: 4.44%-10.21%; biopsy forceps: 30.7%-57.8%). The inner diameter of the bent tip increases with introduction of a laser fiber (+1 to 3 mm) or the biopsy forceps (+13 to 34 mm). Flow rates are dependent on the size of the tool used. Loss of irrigation volume varies from 62.24% (1.5 French) to 99.1% (3.0 French). The use of a laser fiber leads to a decrease in irrigation volume of 53.7%. CONCLUSION Irrigation flow, loss of deflection, and intraoperative visualization are dependent on the working tool used. The provided data, in awareness of the patients anatomy, help to select scopes, probes, and tools correctly for successful ureterorenoscopy.


The Journal of Urology | 2011

Thulium:YAG Vapoenucleation in Large Volume Prostates

Thorsten Bach; C. Netsch; Laura Pohlmann; Thomas R. W. Herrmann; Andreas J. Gross

PURPOSE Tm:YAG vapoenucleation was introduced as a minimally invasive treatment in patients with benign prostatic obstruction. The efficiency and safety of Tm:YAG vapoenucleation must still be confirmed in large volume prostates to prove the size independence of this promising treatment option. We evaluated the safety and efficiency of Tm:YAG vapoenucleation in patients with a prostate volume of 80 cc or greater and benign prostatic obstruction during a 12-month followup. MATERIALS AND METHODS Included in this trial were 90 consecutive patients undergoing 90 W Tm:YAG vapoenucleation. Vapoenucleation was done using the 2 μm continuous wave Tm:YAG laser combined with a mechanical tissue morcellator. We analyzed patient demographic, perioperative and 12-month followup data. Complications were assessed. RESULTS Mean preoperative prostate volume was 108.6 cc (range 80 to 200), mean International Prostate Symptom Score was 23.5 (range 8 to 35) and mean quality of life score was 4.3 (range 1 to 6). There was an 86% reduction (range 67% to 99%) in prostate volume on transrectal ultrasound by 12 months and an 88% decrease (range 58% to 100%) in prostate specific antigen. International Index of Erectile Function score remained stable. Peak urinary flow rate, International Prostate Symptom Score and quality of life improved significantly (p <0.001), as did post-void residual urine. The overall complication rate was manageable. Two patients required blood transfusion and 10 experienced early postoperative stress incontinence. During followup 7% of patients had symptomatic urinary tract infection and 2 had persistent grade I stress urinary incontinence. The reoperation rate due to urethral stricture was 1.8% during the 12-month followup. CONCLUSIONS Tm:YAG vapoenucleation is a safe, effective and size independent treatment option for benign prostatic obstruction. As shown by reductions in transrectal ultrasound prostate volume and prostate specific antigen, complete removal of the adenoma can be achieved by this procedure.


BJUI | 2009

Thulium:yttrium-aluminium-garnet laser prostatectomy in men with refractory urinary retention

Thorsten Bach; Thomas R. W. Herrmann; Axel Haecker; Maurice Stephan Michel; Andreas J. Gross

To evaluate the feasibility and efficacy of thulium:yttrium‐aluminium‐garnet (YAG) laser prostatectomy in patients with an indwelling transurethral catheter due to recurrent urinary retention secondary to benign prostatic obstruction.


World Journal of Urology | 2011

Current evidence for transurethral laser therapy of non-muscle invasive bladder cancer

Mario W. Kramer; Thorsten Bach; Mathias Wolters; Florian Imkamp; Andreas J. Gross; Markus A. Kuczyk; Axel S. Merseburger; Thomas R. W. Herrmann

IntroductionBladder cancer is the second most common malignancy of urologic tumors. Back in 1976, lasers were added to the endourological armetarium for bladder tumor treatment. Despite nowadays’ standard procedure for staging and treating non-muscle invasive bladder tumor by transurethral resection of bladder tumors (TURB) via a wire loop, laser resection techniques for bladder tumor came back in focus with the introduction of Ho:YAG and not to mention recently Tm:YAG lasers. This review aims to display the current evidence for these techniques.Materials and methodsThroughout April 2010, MEDLINE and the Cochrane central register of controlled trials were searched previously for the following terms: “Laser, resection, ablation, coagulation, Nd:YAG Neodym, HoYAG: Holmium, Tm:YAG Thulium and transitional carcinoma, bladder, intravesical.”ResultsEleven articles on Ho:YAG and 7 on Tm:YAG were identified. Searches by Cochrane online library resulted in no available manuscripts.ConclusionToday, Nd:YAG does not play any role in treatment of lower urinary tract transitional cell carcinoma. Ho:YAG and Tm:YAG seem to offer alternatives in the treatment of bladder cancer, but still to prove their potential in larger prospective randomized controlled studies with long-term follow-up. Future expectations will show whether en bloc resection of tumors are preferable to the traditional “incise and scatter” resection technique, in which is contrary to all oncological surgical principles. For the primary targets, here are within first-time clearance of disease, in addition to low in-fields and out-of-fields recurrence rates.


BJUI | 2010

70 vs 120 W thulium:yttrium‐aluminium‐garnet 2 µm continuous‐wave laser for the treatment of benign prostatic hyperplasia: a systematic ex‐vivo evaluation

Thorsten Bach; Nina Huck; Felix Wezel; Axel Häcker; Andreas J. Gross; Maurice Stephan Michel

Study Type – Aetiology (case series)
Level of Evidence 4


World Journal of Urology | 2007

History of lasers

Andreas J. Gross; T. R. W. Herrmann

The developments of laser technology from the cradle of modern physics in 1900 by Planck to its latest medical boundaries is an exciting example of how basic physics finds its way into clinical practice. This article merits the protagonists and their contribution to the steps in this development. The competition between the different research groups finally led to the award of the Nobel Prize to Townes, Basov and Prokhorov in 1964 for the scientific basis on quantum electronics, which led to the construction of oscillators and amplifiers based on the laser-maser principle. Forty-three years after Einstein’s first theories Maiman introduced the first ruby laser for commercial use. This marked the key step for the laser application and pioneered fruitful cooperations between basic and clinical science. The pioneers of lasers in clinical urology were Parsons in 1966 with studies in canine bladders and Mulvany 1968 with experiments in calculi fragmentation. The central technological component for the triumphal procession of lasers in urology is the endoscope. Therefore lasers are currently widely used, being the tool of choice in some areas, such as endoscopical lithotriptic stone treatment or endoluminal organ-preserving tumor ablation. Furthermore they show promising treatment alternatives for the treatment of benign prostate hyperplasia.


Journal of Endourology | 2013

Does imaging modality used for percutaneous renal access make a difference? A matched case analysis.

Sero Andonian; C. Scoffone; Michael K. Louie; Andreas J. Gross; Magnus Grabe; Francisco Pedro Juan Daels; Hemendra N. Shah; Jean de la Rosette

OBJECTIVE To assess perioperative outcomes of percutaneous nephrolithotomy (PCNL) using ultrasound or fluoroscopic guidance for percutaneous access. METHODS A prospectively collected international Clinical Research Office of the Endourological Society (CROES) database containing 5806 patients treated with PCNL was used for the study. Patients were divided into two groups based on the methods of percutaneous access: ultrasound versus fluoroscopy. Patient characteristics, operative data, and postoperative outcomes were compared. RESULTS Percutaneous access was obtained using ultrasound guidance only in 453 patients (13.7%) and fluoroscopic guidance only in 2853 patients (86.3%). Comparisons were performed on a matched sample with 453 patients in each group. Frequency and pattern of Clavien complications did not differ between groups (p=0.333). However, postoperative hemorrhage and transfusions were significantly higher in the fluoroscopy group: 6.0 v 13.1% (p=0.001) and 3.8 v 11.1% (p=0.001), respectively. The mean access sheath size was significantly greater in the fluoroscopy group (22.6 v 29.5F; p<0.001). Multivariate analysis showed that when compared with an access sheath ≤ 18F, larger access sheaths of 24-26F were associated with 3.04 times increased odds of bleeding and access sheaths of 27-30F were associated with 4.91 times increased odds of bleeding (p<0.05). Multiple renal punctures were associated with a 2.6 odds of bleeding. There were no significant differences in stone-free rates classified by the imaging method used to check treatment success. However, mean hospitalization was significantly longer in the ultrasound group (5.3 v 3.5 days; p<0.001). CONCLUSIONS On univariate analysis, fluoroscopic-guided percutaneous access was found to be associated with a higher incidence of hemorrhage. However, on multivariate analysis, this was found to be related to a greater access sheath size (≥ 27F) and multiple punctures. Prospective randomized trials are needed to clarify this issue.


Urology | 2012

Impact of Preoperative Ureteral Stenting on Stone-free Rates of Ureteroscopy for Nephroureterolithiasis: A Matched-paired Analysis of 286 Patients

Christopher Netsch; Sophie Knipper; Thorsten Bach; Thomas R. W. Herrmann; Andreas J. Gross

OBJECTIVE To determine the effect of preoperative ureteral stenting on success rates of ureteroscopy (URS) for nephroureterolithiasis. MATERIALS AND METHODS We retrospectively evaluated patients who underwent URS for nephroureterolithiasis without preoperative indwelling ureteral stents. These patients were matched according to age, sex, body mass index, and stone side, size, site, and number of stones per patient, with patients who had been prestented before URS. Patient data, stone-free rates (SFRs), and complications were compared. RESULTS The study included 286 patients (143 stented vs 143 nonstented). The mean stone size was 5.69 ± 3 mm. The mean number of stones per patient was 1.35 ± 0.7. The overall SFR after 1 URS procedure was 90.9% and higher in prestented than in nonstented patients (95.1% vs 86.7%, P ≤ .013). For ureteral stones, the SFR was 99% in prestented and 90% in nonstented patients (P ≤ .0048). The SFR did not differ between the groups for ureteral stones <5 mm, but was higher in prestented than in nonstented patients for ureteral calculi ≥ 5 mm (98.2% vs 83.3%, P ≤ .0105). For urinary calculi ≥ 5 mm, the overall SFR was higher in prestented than in nonstented patients (93.3 vs 78.3%, P ≤ .0054). Perioperative complications occurred in 27 patients (9.4%; Clavien I, 6.6%; Clavien IIIb, 2.8%) without differences between the groups. CONCLUSION URS is a safe and efficacious procedure for the treatment of nephroureterolithiasis. Preoperative ureteral stent placement is associated with higher SFRs compared with nonstented patients for urinary calculi ≥ 5 mm. Nonstented patients with urinary calculi ≥ 5 mm should be informed about the risk for a second-look URS procedure.

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Thomas Herrmann

University Hospital Heidelberg

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Udo Nagele

University of Tübingen

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