Publications by authors named "Stefan Siemer"

Article Synopsis
  • Conversions from robot-assisted partial nephrectomy to more invasive surgeries happen in about 1-5% of cases, and this study looks at what could predict these conversions.
  • The research analyzed 2,549 patients operated on by 25 surgeons, finding a 3.5% conversion rate linked to factors like older age, higher BMI, tumor size, and the surgeon’s experience.
  • The study concludes that both patient characteristics and surgical expertise significantly impact the likelihood of conversion, suggesting that better training could enhance outcomes and allow for more kidney-sparing procedures.
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Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by the presence of proliferative lesions throughout the body. Management of TSC is challenging because patients have a multifaceted systemic illness with prominent neurological and developmental impact as well as potentially severe kidney, heart and lung phenotypes; however, every organ system can be involved. Adequate care for patients with TSC requires a coordinated effort involving a multidisciplinary team of clinicians and support staff.

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Background: The first robot-assisted kidney transplantation (RAKT) was conducted in 2010, and the first time in Germany in 2016. As more than 5 years have passed, current evidence, technological developments and the latest (German) experience are presented.

Objectives: The current evidence and experience of RAKT was investigated from an international and German perspective.

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Despite perioperative advantages, robot-assisted surgery is associated with high costs. However, the lower morbidity of robotic surgery could lead to a lower nursing workload and cost savings. In this comparative cost analysis of open retroperitoneal versus robot-assisted transperitoneal partial nephrectomies (PN), these possible cost savings, including other cost factors, were quantified.

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Lymphoceles (LC) occur in up to 60% after robot-assisted radical prostatectomy (RARP) and pelvic lymphadenectomy (PLND). In 2-10%, they are symptomatic and may cause complications and require treatment. Data on risk factors for the formation of lymphoceles after RARP and PNLD remain sparse in the urologic literature and are inconclusive to date.

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Background: Little is known regarding functional outcomes after robot-assisted radical cystectomy (RARC) and intracorporeal neobladder (ICNB) reconstruction.

Objective: To report on urinary continence (UC) and erectile function (EF) at 12 mo after RARC and ICNB reconstruction and investigate predictors of these outcomes.

Design, Setting, And Participants: We used data from a multi-institutional database of patients who underwent RARC and ICNB reconstruction for bladder cancer.

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Background: Robot-assisted partial nephrectomy (RAPN) is a challenging procedure that is influenced by a multitude of factors.

Objective: To assess the impact of prior surgical experience on perioperative outcomes in RAPN.

Design Setting And Participants: In this retrospective multicenter study, results for 2548 RAPNs performed by 25 surgeons at eight robotic referral centers were analyzed.

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Purpose: The purpose of this study was to investigate the effect of a surgically constructed bilateral peritoneal flap (PIF) as an adjunct to robot-assisted radical prostatectomy (RARP) and pelvic lymph node dissection (PLND) on the incidence of lymphoceles.

Materials And Methods: A total of 530 men with localized prostate cancer underwent a RARP with bilateral extended standardized PLND in a prospective randomized controlled trial. In group A, a PIF was created by suturing the margins of the bladder peritoneum to the ipsilateral endopelvic fascia at 2 points on each side.

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Background: Even though robot-assisted operations have evolved to a standard procedure in surgery, they are underrepresented in the curriculum of current medical students.

Objectives: We present our experience and findings in Germany's first elective "Robot-assisted surgery" at a urological department for undergraduate medical students.

Materials And Methods: Ten undergraduates in their final years were taught the theoretical basics and practical skills in robot-assisted surgery within six lessons each lasting 2 h, including the opportunity to observe a live robot-assisted surgery.

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Background: Follow-up during Active Surveillance (AS) may result in psychological burden and discomfort due to the constant clinical monitoring. Therefore, successful implementation of AS is to some extent a challenge for the patient and the caregiver.

Materials And Methods: In this monocentric study, we analyzed the reasons for termination of AS and the rate of the postoperative adverse pathology (AP) in patients who underwent deferred radical prostatectomy (RP) after AS.

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(1) Background: about 10% of Wilms Tumor (WT) patients have a malformation or cancer predisposition syndrome (CPS) with causative germline genetic or epigenetic variants. Knowledge on CPS is essential for genetic counselling. (2) Methods: this retrospective analysis focused on 2927 consecutive patients with WTs registered between 1989 and 2017 in the SIOP/GPOH studies.

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Twenty years have passed since the first reports on robot-assisted kidney tumor surgery in 2001. However, robotic surgery has not spread to all German urologic departments yet. Hence, one has to question whether robot-assisted kidney tumor surgery can be considered a standard today.

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Purpose: Radical nephroureterectomy is the gold standard of treatment for high-risk non-metastatic urothelial carcinoma of the upper urinary tract. However, the optimal surgical approach remains a controversial debate. This study compared the perioperative and oncological outcomes of open and robot-assisted radical nephroureterectomies.

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Data on robotic retroperitoneal lymph node dissection (R-RPLND) for metastatic testicular germ cell tumours (mTGCTs) are scarce and the use of R-RPLND itself is still under debate. The aim of our study was to evaluate the indications, feasibility and outcomes of R-RPLND, with special emphasis on differences between primary R-RPLND (pR-RPLND) and post-chemotherapeutic R-RPLND (pcR-RPLND) in mTGCTs. We retrospectively analysed the data of patients who underwent R-RPLND for mTGCT between November 2013 and September 2019 in two centres in Germany.

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Background: Most comparisons of robot-assisted (RARC) versus open radical cystectomy (ORC) for urothelial carcinoma do not factor the inherent stage selection bias or surgical experience.

Methods: We compared the perioperative outcomes of 229 RARC and 335 ORC at a single tertiary referral centre with propensity score matching and multiple regression models, when controlling for tumour and patient characteristics, surgeon's experience and type of urinary diversion.

Results: RARC had less major complications (19.

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Purpose: Salvage lymph node dissection is a rescue treatment for patients with nodal recurrence after radical prostatectomy. Very limited data are available on robotic salvage lymph node dissection. Our purpose was to investigate perioperative and oncological outcomes of robotic salvage lymph node dissection in a large monocentric series.

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Purpose: A number of observational clinical studies suggest that prior primary tumor treatment favorably influences the course of metastatic prostate cancer (PCa), but its mechanisms of action are still speculative. Here, we describe the long-lasting sensitivity to various forms of androgen deprivation in patients after radical prostatectomy (RP) for locally advanced PCa as one potential mechanism.

Methods: A consecutive series of 115 radical prostatectomies after inductive therapy for T4 prostate cancer was re-analyzed, and long-term survival, as well as recurrence patterns and responses to different forms of hormonal manipulation, were assessed.

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Priapism as a sign of a severe hematological disease is a rare event, which has to be considered as both a urological and a hematological emergency that requires immediate treatment. This article describes a clinical case of priapism as the first clinical manifestation of a hitherto undiagnosed chronic myeloid leukemia (CML) and discusses the results of a literature review on this topic.

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Background: Most comparisons between robot-assisted partial nephrectomy (RAPN) and open partial nephrectomy (OPN) indicate the superiority of RAPN, but the learning curve is often not considered.

Methods: All consecutive partial nephrectomies from the very first RAPN at a single tertiary referral centre (n = 818, 500 RAPN vs. 313 OPN) were retrospectively analyzed.

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Background: Minimally invasive donor nephrectomy (DN) is considered the gold standard, but the role of robot-assisted surgery is still controversial.

Objectives: The first 50 robot-assisted DN (RDN) of a urologic transplant department in Germany were retrospectively analyzed.

Materials And Methods: Patient characteristics as well as intra- and postoperative surgical parameters were obtained.

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Background: Robot-assisted partial nephrectomy (RAPN) has become widely accepted, but its different underlying types of learning curves have not been comparatively analyzed to date. This study aimed to determine and compare the impact that the learning curve of the department, the console surgeon, and the bedside assistant as well as patient-related factors has on the perioperative outcomes of RAPN.

Methods: The study retrospectively analyzed 500 consecutive transperitoneal RAPNs (2007-2018) performed in a tertiary referral center by 7 surgeons and 37 bedside assistants.

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Living kidney donation is the best treatment for end-stage renal disease, however, the best surgical approach for minimally-invasive donor nephrectomy (DN) is still a matter of debate. This bi-centric study aimed to retrospectively compare perioperative outcomes and postoperative kidney function after 257 transperitoneal DNs including 52 robot-assisted (RDN) and 205 laparoscopic DNs (LDN). As primary outcomes, the intraoperative (operating time, warm ischemia time (WIT), major complications) and postoperative (length of stay, complications) results were compared.

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