ümit Yıldırım

Dr. ümit Yıldırım


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 April 2023 in Asian Journal of Urology
Verified
Journal Article
Open access
RGRasim Güzel
Rasim Güzel
ÜYümit Yıldırım
ümit Yıldırım
KSKemal Sarica
Kemal Sarica
Pediatric urolithiasis has been more common over the past 20 years, and urologists have unique challenges in managing it surgically because this particular demographic is recognized as one of the high-risk categories for stone recurrence. Given this reality, care focuses on maintaining renal function, achieving total stone-free status, and most importantly avoiding stone recurrences. In this presented article, we aimed to make a comprehensive review of the current minimally invasive treatment of pediatric kidney stone disease. We evaluated the results of 74 studies following a comprehensive PubMed search till February 2023. This article was written by making use of current urology guidelines. Considering the reported occurrence of metabolic issues in up to 50% of cases in addition to the anatomic anomalies (about 30% of cases), the treatment of pediatric urolithiasis necessitates a full metabolic and urological examination on an individual basis. Timely management of metabolic imbalances and obstructive diseases is necessary. In addition to encouraging proper fluid consumption, it is advisable to improve urine volume and consider using medical therapeutics to raise urinary citrate levels. The location, content, and size of the stone(s), the morphology of the collecting system, the presence of urinary tract infection, as well as the presence of any obstruction, should all be taken into consideration while deciding on the best surgical procedure. All modern endourological methods are now used in the safe and efficient care of pediatric urolithiasis as a consequence of the obvious advancements in instrument technology and expanding expertise derived from adult patients. Other minimally invasive procedures, such as ureterorenoscopy and percutaneous nephrolithotomy, require more expertise and can be successfully applied with careful management for an excellent stone-free rate with minimal morbidity. Of these procedures, shock wave lithotripsy is still the first choice in the majority of cases with upper tract calculi. Open surgery will still be the therapy of choice for pediatric patients with complicated and big stones as well as anatomical anomalies.

19 April 2025 in Urolithiasis
Verified
Journal Article
Open access
PDF file
ÜYümit Yıldırım
ümit Yıldırım
MUMehmet Uslu
Mehmet Uslu
MEMehmet Ezer
Mehmet Ezer
ÇEÇağlayan Erdoğdu
Çağlayan Erdoğdu
RKRamazan Kocaaslan
Ramazan Kocaaslan
KSKemal Sarıca
Kemal Sarıca
This study compares the efficacy and safety of two techniques for flexible ureteroscopy (FURS) in managing 2–3 cm lower pole renal stones: the use of flexible and navigable access sheath (FANS) versus direct in-scope suction (DISS) without an access sheath. A retrospective analysis of 60 patients undergoing FURS for lower pole renal stones was conducted between March 2023 and January 2025. Group 1 ( n = 32) underwent FANS-assisted procedures, while Group 2 ( n = 28) underwent sheathless FURS with DISS. Stone-free rates (SFR) were assessed with non-contrast computed tomography (NCCT) after four weeks. Operative time, peri- and postoperative complications, and hospitalization duration were also compared. The mean operative time was significantly shorter in the FANS group (71.8 ± 11.5 min) compared to the DISS group (79.1 ± 11.7 min, p = 0.026). The difference between the SFRs obtained in the FANS group (62.5%) and the DISS group (46.4%) after the first session was not statistically significant ( p = 0.162). After the second session, SFRs were also comparable (87.5% vs. 82.1%, p = 0.412) (Residual stones < 4 mm were considered stone-free). Completely stone-free rates (CSFR), defined as the absence of residual fragments after the first session were 43.7% in the FANS group and 32.1% in the DISS group ( p = 0.256), while after the second session, these rates increased to 84.3% and 75%, respectively ( p = 0.280). Postoperative fever rates (9.3% vs. 10.7%, p = 0.598) and hospitalization duration (2.5 ± 1.3 vs. 2.6 ± 1.4 days, p = 0.819) were similar. Both techniques achieved high overall SFRs for large lower pole stones in a staged manner. However, FANS was associated with a shorter operative time. While DISS eliminates the need for an access sheath, its longer operative time may be a limitation. Larger studies are needed to further evaluate these techniques.

1 January 2024 in Revista da Associação Médica Brasileira
Verified
Journal Article
Open access
PDF file
MUMehmet Uslu
Mehmet Uslu
ÜYümit Yıldırım
ümit Yıldırım
MEMehmet Ezer
Mehmet Ezer
ÖAÖmer Erkam Arslan
Ömer Erkam Arslan
HYHikmet Yaşar
Hikmet Yaşar
KSKemal Sarıca
Kemal Sarıca
OBJECTIVE: The aim of this study was to compare the success and complication rates of retrograde intrarenal surgery for lower calyceal renal stones performed with novel tip-bendable suction ureteral access sheaths and standard ureteral access sheaths.

26 December 2022 in Urolithiasis
Verified
Journal Article
Closed access
PDF file
ÜYümit Yıldırım
ümit Yıldırım
MEMehmet Ezer
Mehmet Ezer
MUMehmet Uslu
Mehmet Uslu
RGRasim Güzel
Rasim Güzel
KSKemal Sarıca
Kemal Sarıca

22 October 2022 in Andrologia
Verified
Journal Article
Closed access
ÜYümit Yıldırım
ümit Yıldırım
MKMuammer Karakayalı
Muammer Karakayalı
MUMehmet Uslu
Mehmet Uslu
MEMehmet Ezer
Mehmet Ezer
IEIsmet Bilger Erihan
Ismet Bilger Erihan
IRIbrahim Rencüzoğulları
Ibrahim Rencüzoğulları
By the beginning of this study in 2019, it was known that hypertension is a risk factor for erectile dysfunction, and also, there are circadian changes that occur in blood pressure. Further, non-dipping hypertension is known to be linked to poor cardiac outcomes and erectile functions, so the research described in this article was initiated with an aim to explore the potential relationship between erectile dysfunction and circadian patterns of newly diagnosed hypertension. Between April 2019 and May 2022, 583 patients aged 30-70 years were diagnosed with erectile dysfunction (ED) in our outpatient clinic. Applying our exclusion criteria to 583 patients, a group of 371 patients left with us; these patients were referred to the cardiology clinic for hypertension evaluation with consecutive ambulatory blood pressure monitoring (ABPM). Data were collected for the study prospectively. Of the 371 patients evaluated with ABPM, 125 had newly diagnosed hypertension (mean BP ≥135/85 mmHg in ABPM). These patients were divided into two groups according to the pattern of hypertension identified in ABPM: dippers (Group D) and non-dippers (Group ND). They were then compared using clinical and laboratory findings, including erectile function scores. While the number of patients in the ND group was 83, the number in the D group was 42. In the ND group, the mean age was higher (59 ± 10 vs. 54 ± 12, p = 0.0024). IIEF-5 (international index of erectile function) scores were determined to be significantly lower in the ND group (14.4 ± 4.9 vs. 11.5 ± 4.6, p = 0.001). Also, serum creatinine levels were higher in Group ND than in D (0.96 ± 0.12 vs. 1 ± 0.15, p = 0.001). In our multivariate analysis, IIEF-5 scores (OR: 0.880, 95% CI: 0.811-0.955; p = 0.002) and serum creatinine levels (OR: 1027, 95% CI: 1003-1052; p = 0.025) were found to be independent risk factors of non-dipper HT. The cut-off value of the IIEF-5 score for non-dipper HT in a ROC curve analysis was 13.5 with 64.3% sensitivity and 66.1% specificity (area under curve value: 0.673 [95% CI: 0.573-0.772, p < 0.001]). This study showed that, in patients with ED, the non-dipper pattern was associated with poorer erectile function when HT was newly diagnosed. We also found that the severity of erectile dysfunction is an independent marker for non-dipper HT.