Mehmet Zeynel Keskin has a total of 169 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Is Cystolitholapaxy Sufficient in Patients With Bladder Stones Secondary to Benign Prostatic Obstruction?

    by Mert Hamza Özbilen, Mahmut Can Karabacak, Taylan Tığlı, Mehmet Yoldaş, Ümit Uysal, Mehmet Zeynel Keskin, Gökhan Koç, Zafer Gökhan Gürbüz

    Background: To question the necessity of simultaneous benign prostatic obstruction (BPO) intervention with cystolitholapaxy in patients with bladder stone (BS) due to BPO and to investigate the factors predicting secondary intervention. Methods: A total of 235 male patients over 40 years of age who underwent cystolitholapaxy, had a follow‐up period longer than 12 months, and were thought to have BS secondary to BPO were included in the study. Results: A total of 190 patients who did not require additional intervention were defined as Group 1, and 45 patients who required secondary intervention were defined as Group 2. Secondary surgical intervention was required at a rate of 19.5% with an average follow‐up of 49 months. Mean peak urine flow rate ( Q max ) was 11 m/s in Group 1 and 8.6 m/s in Group 2 ( p < 0.001), postvoid residual urine volume (PVR) was 85.5 mL in Group 1 and 115.3 mL in Group 2 ( p < 0.001), International Prostate Symptoms Score (IPSS) was 16.7 in Group 1 and 21.7 in Group 2 ( p < 0.001). Total prostate volume (TPV) ( p = 0.015) and serum prostate‐specific antigen (PSA) ( p = 0.005) were also significantly higher in Group 2. In the multivariable Cox proportional hazards regression analysis of factors predicting secondary intervention in patients undergoing cystolitholapaxy, low Q max (hazard ratio (HR) = 0.905, 95% confidence interval (CI): 0.821–0.997, p = 0.043), high PVR (HR = 1.014, 95% CI: 1.007–1.022, p < 0.001), high IPSS (HR = 1.178, 95% CI: 1.106–1.255, p < 0.001) and high PSA (HR = 1.086, 95% CI: 1.000–1.178, p = 0.05) were found to be predictors. Conclusions: In patients with BS secondary to BPO, performing cystolitholapaxy offers a high likelihood of avoiding secondary intervention. Low Q max , high PVR, high IPSS, and high PSA are indicators of a higher risk of secondary intervention in the preoperative period. Therefore, in a patient‐centered approach, these predictors should be taken into account when deciding whether BPO surgery is necessary in addition to cystolitholapaxy.

  • Open Access

    Comparison of three-lobe and en-bloc techniques during the holmium laser enucleation of the prostate learning curve: a prospective, multicenter, cohort study

    by Ozgur Kazan, Yusuf Arikan, Adnan Basaran, Mehmet Zeynel Keskin, Burak Tüfekci, Ilkin Hamid-Zada, Asif Yildirim

    SUMMARY OBJECTIVE: The aim of this study was to compare the safety and effectiveness of the three-lobe and en-bloc techniques during the learning curve of holmium laser enucleation of the prostate. METHODS: We conducted a prospective, parallel-group, multicenter study that included patients who underwent holmium laser enucleation of the prostate between February and December 2024 at two tertiary urology departments. Patients with prostate volumes ≥80 cm3 scheduled for holmium laser enucleation of the prostate were alternately assigned (1:1) to either the three-lobe or en-bloc technique. Exclusion criteria included use of anticoagulants, prostate biopsy within the previous month, diagnosis of prostate cancer, or a history of pelvic surgery or radiotherapy associated with overactive bladder symptoms. The study evaluated the performance of a single surgeon at each center using either the three-lobe or en-bloc technique during their holmium laser enucleation of the prostate learning curve. Primary outcomes were enucleation time/efficiency and complications. Secondary outcomes included postoperative incontinence and functional outcomes. RESULTS: A total of 116 patients were enrolled in the study, with 60 in the three-lobe group and 56 in the en-bloc group. Patients in the en-bloc group were older than those in the three-lobe group (69.4 vs. 64.9 years, p=0.001). Body mass index and performance scores were comparable between groups. The mean prostate volume was 83.5 cm3 in the three-lobe group and 81.3 cm3 in the en-bloc group (p=0.732). No significant differences were observed in prostate volume or Prostate-Specific Antigen density. Short-term complication rates and postoperative urinary incontinence were similar between techniques. Operative and enucleation times were significantly shorter in the en-bloc group compared to the three-lobe group (86.1 vs. 107.4 min, p=0.042; 56.7 vs. 72.9 min, p=0.001, respectively). However, enucleation and morcellation efficiencies did not differ significantly. Other intraoperative parameters, as well as postoperative functional outcomes and uroflowmetry measurements, were comparable between the groups. CONCLUSION: The en-bloc technique demonstrated comparable safety and functional outcomes to the three-lobe technique but offered significantly shorter operative and enucleation times during the holmium laser enucleation of the prostate learning curve.

  • Open Access

    Relationship of Pelvimetric Diameters with Peroperative Outcomes, Complications, and Surgical Success in Patients Undergoing Perineal Radical Prostatectomy

    by Deniz Noyan Özlü, Yusuf Arıkan, Yavuz Onur Danacıoğlu, Ayşegül Öz Özcan, Büşra Emir, Hakan Polat, Mehmet Zeynel Keskin, Ali İhsan Taşçı

    Background: This study investigates the effect of pelvimetric measurements on intraoperative and postoperative outcomes in the open perineal radical prostatectomy procedure. Methods: Distance of the ischial spines (ISD), angle of symphysis pubis (ASP), angle of symphysis pubisseminal vesicles (ASS), distance between the prostate apex and anus (DAA), distance between seminal vesicles and anus (DSA), distance of pelvic outlet (DPO) measurements were determined in multiparametric magnetic resonance imaging. The effects of these pelvimetric measurements on perioperative factors were analyzed. Results: A total of 71 patients were included. Distance of the ischial spines was 9.0 Å} 0.82 mm, DPO 8.2 Å} 0.86 cm, DAA 4.8 Å} 1.2 cm, DSA 7.8 Å} 1.3 cm, ASP 63.7 Å} 7.2 degrees and ASS 44.9 Å} 6.5 degrees. It was found that a 1-cm increase in the ISD value resulted in a decrease of 9.19 minutes in the operation duration, a 1-cm increase in the DSA value caused an increase of 4.55 minutes in the operation duration, and a 1-cm increase in the ASS value caused a decrease of 0.76 minutes in the operation duration. A 1-cm increase in ASP resulted in 6.5 cm3 less blood loss and 1 unit increase in ASS resulted in 15.15 cm3 less blood loss. A 1-cm increase in ISD decreased anastomosis time by 1.7 minutes, whereas a 1-cm increase in DAA increased to 1.03 minutes. In the postoperative pathologic findings of the patients after radical prostatectomy, Gleason score 3 + 4 was the most common finding with 56.3%. Seminal vesicle invasion positivity was observed in 2 (2.8%) and extraprostatic invasion positivity in 18 (25.4%). Conclusion: Six parameters were examined with pelvimetric measurements had particular effects on operation duration, blood loss, anastomosis time, and complication development. Cite this article as: Arıkan Y, Danacıoğlu YO, Özcan A., et al. Relationship of pelvimetric diameters with peroperative outcomes, complications, and surgical success in patients undergoing perineal radical prostatectomy. Eurasian J Med. 2025, 57(4), 0877, doi:10.5152/eurasianjmed.2025.25877.

  • Relationship of Muscle Mass Based on Psoas Muscle Index and Skeletal Muscle Index with Recurrence and Mortality Risk in Localized Renal Cell Carcinoma: A Comprehensive Retrospective Analysis

    by Yusuf Arıkan, Deniz Noyan Özlü, Büşra Emir, Hakan Polat, Mehmet Zeynel Keskin

    Objective: We aimed to determine the relationship between the Psoas Muscle Index (PMI) and Skeletal Muscle Index (SMI) and the risk of recurrence and mortality in patients with localized Renal Cell Carcinoma (RCC). Material and Methods: SMI and PMI values were obtained from non-contrast computed tomography (NCCT) measurements on slices at the L3 level, normalized by height. Available survival data, including overall survival (OS) and recurrence-free survival (RFS), were collected at postoperative follow-up. Disease recurrence was defined as radiological evidence of disease on computed tomography (CT), magnetic resonance imaging, or bone scan. Results: In the ROC analysis, the optimal cut-off value for PMI was ≤ 5.1 cm²/m² and ≤ 3.1 cm²/m² in male and female patients, while the cut-off value for SMI was ≤ 44 cm²/m² and ≤ 30 cm²/m² in male and female patients. In multivariate analyses, female gender, recurrence, clinical T stage ≥ T3b, pathological T stage ≥T3b, and sarcopenia according to PMI and SMI were independent predictors of worse OS and RFS (p < 0.001). In Kaplan-Meier analysis, OS in patients with and without sarcopenia was 74 vs 85 months (p < 0.001), respectively. RFS were shorter in patients with sarcopenia (PMI: 76 vs 84, SMI: 74 vs 85 months, both p < 0.001) Conclusion: In patients with localized RCC, sarcopenia was associated with earlier recurrence, shorter OS, and RFS. Patients with sarcopenia had a worse prognosis in preoperative staging.


  • Open Access

    Comparison of Supine and Prone Positions in PCNL Operations Performed in Isolated Kidney Upper Pole Access

    by Yusuf Arıkan, Serhat Beyan, Ömer Koraş, Mert Guroglu, Büşra Emir, Ferhat Demirci, Yavuz Danacıoğlu, Mehmet Zeynel Keskin

    Background: Renal stones larger than 2 cm in the upper pelvical system are usually managed with Percutaneous Nephro-lithotomy (PCNL) operation, but there are unclear as to which position should be used. In our study, we aimed to compare the preoperative-peroperative and postoperative data of patients who underwent PCNL with isolated renal upper pole access in supine and prone position. Materials and Methods: The study included 20 Supine PCNL and 45 Prone PCNL cases who underwent isolated renal upper pole access for renal calculi. Age, gender, body mass index (BMI) were evaluated from demographic data. Radiological findings such as stone-skin distance, stone density, stone size and volume were recorded. Total operation time, access time and fluoroscopy time were recorded from peroperative data. In the postoperative period, the duration of hospital stay and complications according to Clavien Dindo classification were recorded. Non-contrast computed tomography was performed at the 1st postoperative month and the stone-free status of the patients was evaluated. Results: There was no statistical difference in demographic data in terms of age, gender, BMI, ASA scores in both groups. The total operation time was 75.95±28.7 min in supine PCNL group and 92.48±23.4 min in prone PCNL group (p2 complications are less common in prone PCNL for renal upper pole calculi.


  • Open Access

    Comparison of active surveillance vs. partial nephrectomy results in small renal masses

    by Yusuf Arikan, Serhat Beyan, Cemre Kuscuoglu, Büsra Emir, Mehmet Zeynel Keskin, Yusuf Ozlem Ilbey

    Aim: Incidentally diagnosed renal cancers have increased with the increase in imaging modalities. Incidentally diagnosed masses are smaller in size and there are conflicts in the management of these 3,259 masses. Active surveillance (AS) and surgery are the treatment options. In our study, we aimed to compare the data of patients who underwent these two methods. Methods: The data of 34 patients who underwent AS and 89 patients who underwent surgery were retrospectively analyzed. AS patients were defined as Group 1 and surgical patients as Group 2. Treatment options were determined according to tumor characteristics, patient age, comorbidities, and surgical risks. The Eastern Cooperative Oncology Group (ECOG) performance score and the Charlson Comorbidity Index (CCI) were used to assess comorbidity in each patient. AS patients were offered surgical treatment when their tumors reached > 4 cm in maximal diameter or had rapid tumor growth rates. Results: The mean patient age was 74.06 ± 6.78 in Group 1 and 58.82 ± 7.60 in Group 2 (P < 0.001). The ECOG performance score was > 1 in all patients in Group 1, while the rate of ECOG > 1 was 59.6% in Group 2 (P < 0.001). CCI was 8.09 ± 0.75 in Group 1 and 3.94 ± 1.14 in Group 2 (P < 0.001). Mortality rates developed in 10 (29.4%) patients in Group 1 and 3 (3.4%) patients in Group 2. Regarding 5- and 10-year cancer-specific survival (CSS), the 5-year survival rate was 81.1% in Group 1 and 97.7% in Group 2, and the 10-year CSS was 63.2% in Group 1 and 89.5% in Group 2, which was statistically higher in Group 2 (P : 0.0022). Conclusion: Although AS has worse outcomes than surgery in terms of CSS, it is a recommended option for patients with older age and poor performance scores.

  • The effect of varicocelectomy on intracytoplasmic sperm injection pregnancy success in patients with severe oligospermia and varicocele

    by Yusuf Arıkan, Abdurrahman Hamdi İnAn, Mert Güroğlu, Mehmet Zeynel Keskin

    OBJECTIVES: There is still controversy about the necessity of varicocelectomy in infertile men with severe oligospermia if varicocelectomy is additionally available and Intracytoplasmic Sperm Injection (ICSI) is planned. This study will investigate the effect of varicocelectomy on ICSI success in varicocele patients with severe oligospermia. MATERIAL and METHODS: The data of 60 patients with varicocelectomy before ICSI (Group 1) and 32 patients without varicocelectomy before ICSI (Group 2) were compared. Patient and partner age, hormone levels and sperm parameters from demographic data, hormone levels and sperm parameters from laboratory tests, and scrotal Doppler ultrasonography results radiologically were compared. After ICSI, clinical pregnancy rates, miscarriage rates and live birth rates were evaluated. RESULTS: There was a significant increase in sperm count and motility in Group 1 patients after varicocelectomy surgery. When the preoperative and postoperative sperm parameters of the patients in Group 1 were compared with those in Group 2, it was found that there was no difference before the varicocelectomy , while only sperm count was statistically affected after the surgery. Clinical pregnancy was observed in 44 patients (73.3%) in Group 1 and 21 patients (65.6%) in Group 2 and there was no statistical difference between the groups (p: 0.321). Miscarriage was observed in 11 patients (25%) in Group 1 and 7 patients (33.3%) in Group 2 (p: 0.128). Live birth was observed in 33 patients (55%) in Group 1 and 14 patients (43.7%) in Group 2 and was statistically higher in Group 1 (p: 0.026). CONCLUSION: In varicocelectomy patients with severe oligospermia, varicocelectomy before ICSI does not affect clinical pregnancy and miscarriage rates, but causes an increase in live birth rates. Keywords: intracytoplasmic sperm injection, varicocelectomy, severe oligospermia, pregnancy rate

  • Prognostic Significance of the Controlling Nutritional Status (CONUT) Score in Patients with Muscle-Invasive Bladder Cancer after Radical Cystectomy

    by Cem Yucel, Enes Dumanli, Mahmut Can Karabacak, Esat Kaan Akbay, Mehmet Yoldas, Uygar Micoogullari, Yusuf Ozlem Ilbey, Mehmet Zeynel Keskin

    Purpose: To assess the impact of the The Controlling Nutritional Status (CONUT) score, an indicator of nutritional status, on the survival and prognosis after radical cystectomy. Materials and Methods: The medical records of patients who underwent consecutive radical cystectomy operations with the diagnosis of muscle-invasive bladder cancer at our clinic were retrospectively examined. The patients were separated into two groups based on the cut-off CONUT score which was derived using the receiver operating characteristic (ROC) curve. The group with a CONUT score >= 3 was categorized as high CONUT, whereas the group with a CONUT score < 3 was categorized as low CONUT. The groups were compaired according to oncological outcomes and survival risk factors. Results: Cancer-specific survival (CSS) and overall survival (OS) were statistically significantly lower in the High CONUT group compared to the Low CONUT group (p < 0.001, p = 0.024, respectively). Age (HR: 1.02, 95% CI: 1.006-1.04, p = 0.011) and CONUT score (HR: 3.92, 95% CI: 2.66-5.77, p < 0.001) were revealed to be independent prognostic variables in the multivariate analysis for OS. Conclusion: The CONUT score was found to be an independent predictor of survival in patients with muscle-invasive bladder cancer in this study.


  • Komplike Olmayan Üriner Sistem Enfeksiyonlarında Lokal Antibiyotik Direncinin Çok Merkezli Taranması: 37 Merkezden 1850 Hasta

    by Ahmet Emre Cinislioğlu, Nazan Cinislioğlu, Metin İsHak Öztürk, Fatih Akkaş, Tugay Aksakallı, Mustafa Kemal Atilla, Gökhan Atış, Hasan Rıza Aydın, Uğur Balcı, Ömer Bayrak, et al.

    Study demonstrated that antibiotic resistance in the treatment of uncomplicated urinary tract infections varies by geographical region. We believe this comprehensive, national prospective study will provide valuable insights for clinicians planning empirical treatment for uncomplicated urinary tract infections.


  • Open Access

    Factors Affecting Biochemical Recurrence After Radical Prostatectomy and Validity of CAPRA Score in Predicting Biochemical Recurrence

    by Yusuf Arıkan, Berat Aydın Enginler, Enes Dumanli, Deniz Noyan Özlü, Büşra Emir, Mehmet Zeynel Keskin

    Objective: Biochemical recurrence (BCR) after prostate cancer (PCa) treatment is undesirable. It is important to inform a patient about BCR in preoperative evaluation. We aimed to demonstrate the effectiveness of the (The Prostate Cancer Risk Assessment) CAPRA score used to predict this situation in our study. Material and Methods: The study included 348 patients who underwent Radical Prostatectony (RP) for localized PCa. Demographic, preoperative and postoperative data were collected. CAPRA score based on preoperative total PSA value, Gleason Score, clinical T stage, percentage of positive biopsy cores and age was calculated using these data. BCR was defined as a total PSA value >0.2 ng/dL for two consecutive times after RP. Follow-up periods, recurrence status and time of recurrence were recorded. Results: BCR positivity was detected in 60 (17.2%) of 348 patients. In univariate analyses, PSA level, lesion volume on MRI, ISUP grade, D’Amico risk classification, Seminal vesicule invasion (SVI) and CAPRA score were statistically significant in the groups. In multivariate analyses, PSA level, Neutrophile Lymphocyte Ratio, lesion dimension, intermediate risk according to D’amico classification, Extraprostatic extension (EPE) showed differences between both groups. The probability of biochemical progression-free in CAPRA risk groups shows a significant decrease in the probability of biochemical progression-free in the long term as risk increases in CAPRA risk groups: 91.4% in the low-risk group, 77.8% in the intermediate-risk group and only 61.7% in the high-risk group at 80-month follow-up. Conclusion: CAPRA scoring system should be supported by MpMRI findings and a new nomogram should be developed with these findings.