Faruk Yencilek

Augmented reality: a new tool to improve surgical accuracy during laparoscopic partial nephrectomy? Preliminary in vitro and in vivo results.

BACKGROUND Use of an augmented reality (AR)-based soft tissue navigation system in urologic laparoscopic surgery is an evolving technique. OBJECTIVE To evaluate a novel soft tissue navigation system developed to enhance the surgeons perception and to provide decision-making guidance directly before initiation of kidney resection for laparoscopic partial nephrectomy (LPN). DESIGN, SETTING, AND PARTICIPANTS Custom-designed navigation aids, a mobile C-arm capable of cone-beam imaging, and a standard personal computer were used. The feasibility and reproducibility of inside-out tracking principles were evaluated in a porcine model with an artificially created intraparenchymal tumor in vitro. The same algorithm was then incorporated into clinical practice during LPN. INTERVENTIONS Evaluation of a fully automated inside-out tracking system was repeated in exactly the same way for 10 different porcine renal units. Additionally, 10 patients underwent retroperitoneal LPNs under manual AR guidance by one surgeon. MEASUREMENTS The navigation errors and image-acquisition times were determined in vitro. The mean operative time, time to locate the tumor, and positive surgical margin were assessed in vivo. RESULTS AND LIMITATIONS The system was able to navigate and superpose the virtually created images and real-time images with an error margin of only 0.5 mm, and fully automated initial image acquisition took 40 ms. The mean operative time was 165 min (range: 135-195 min), and mean time to locate the tumor was 20 min (range: 13-27 min). None of the cases required conversion to open surgery. Definitive histology revealed tumor-free margins in all 10 cases. CONCLUSIONS This novel AR tracking system proved to be functional with a reasonable margin of error and image-to-image registration time. Mounting the pre- or intraoperative imaging properties on real-time videoendoscopic images in a real-time manner will simplify and increase the precision of laparoscopic procedures.

Diffusion-weighted imaging of the renal and adrenal lesions.

Objectives: The purpose of this study was to calculate the apparent diffusion coefficient (ADC) values of different renal and adrenal lesions to evaluate the ability of diffusion-weighted imaging in characterizing masses and determining malignancy. Methods: A total of 52 patients consisting of 67 renal lesions and 28 patients with 33 adrenal lesions in addition to 50 healthy controls with normal kidneys were enrolled in the study. Diffusion-weighted imaging was performed with b factors of 0, 500, and 1000 s/mm2, and the ADCs of the normal kidney and renal and adrenal lesions were calculated. Results: The mean (SD) ADCs of the renal cortex and medulla of the control group were 2.08 (0.22) × 10−3 and 1.94 (0.18) × 10−3 mm2/s, respectively. Focal renal lesions were as follows: simple cysts (2.94 [0.20] × 10−3 mm2/s), hemorrhagic cysts (1.71 [0.38] × 10−3 mm2/s), angiomyolipomas (1.40 [0.21] × 10−3 mm2/s), renal cell carcinomas (1.06 [0.39] × 10−3 mm2/s), metastases (1.50 [0.13] × 10−3 mm2/s), and hydronephrosis (1.54 [0.25] × 10−3 mm2/s). The mean ADCs of all these pathologies were significantly different when compared with normal parenchyma. Diffusion-weighted imaging was also able to differentiate angiomyolipomas and hemorrhagic cysts from renal cell carcinomas. Adrenal lesions were subgrouped as adenomas (1.41 [0.27] × M10−3 mm2/s), nonadenomatous solid masses (1.08 [0.28] × 10−3 mm2/s), and cysts (2.82 [0.24] × 10−3 mm2/s). The mean ADCs of adenomas were significantly different when compared with nonadenomatous solid masses and cysts. Conclusions: Our findings show that ADC measurement has a potential ability to differentiate benign and malignant focal renal and adrenal lesions with the guidance of conventional sequences. When used alone, diffusion-weighted imaging may lead to misdiagnoses due to overlapping ADCs of the lesions.

Role of overweight status on stone-forming risk factors in children: a prospective study.

OBJECTIVES To evaluate the possible role of being overweight on stone-forming risk factors in children. METHODS A total of 94 children (43 boys and 51 girls, male/female ratio 1:1.8) who were taking no medication or dietary modifications before treatment were included in the study. After a detailed stone disease history, the systolic and diastolic blood pressures were precisely measured and recorded for all patients. The body mass index, 24-hour urine values, and serum stone-forming risk parameters were evaluated in 44 overweight (17 boys and 27 girls; group 1) and 50 normal (26 boys and 24 girls; group 2) children. The results of each group were compared using the Wilcoxon rank sum test. RESULTS The evaluation of the stone-forming risk factors in both groups revealed that the overweight status might be responsible for the increased excretion of these substances in such children. Most of the children in group 1 demonstrated hypocitraturia and hyperoxaluria (9/44, 20.5%) compared with the patients in group 2. Although the mean urinary oxalate level was 0.74 +/- 0.81 mg/kg/24 h for boys and 0.69 +/- 0.72 mg/kg/24 h for girls in group 1, relatively lower values were noted in group 2 (0.42 +/- 0.52 and 0.45 +/- 0.57 mg/kg/24 h for the boys and girls, respectively). Similarly, the children in group 1 had elevated mean urinary calcium and lower citrate excretion compared with the group 2 patients. CONCLUSIONS Overweight status in children might be associated with an elevated risk of stone formation in both sexes owing to the alterations in urine composition. Obese children could be more prone to stone formation, and they should be evaluated and followed up for this aspect.

Vardenafil Reduces Testicular Damage Following Ischemia/Reperfusion Injury in Rats

We investigated the effect of intraperitoneal vardenafil (1 mg/kg) administration during an ischemic period in a rat model of testicular torsion/detorsion (T/D). Twenty‐one adult Wistar rats were equally randomized into a control group, a T/D group and a vardenafil group. The control group was designed to collect basal values for biochemical and histopathological parameters. The T/D group underwent testicular torsion for 1 hour. The vardenafil group received vardenafil (1mg/kg) intraperitoneally at 30 minutes after torsion. All rats were sacrificed 4 hours after reperfusion to evaluate the tissue levels of malondialdehyde and total antioxidant status. Germ cell apoptosis was evaluated using the apoptosis protease activating factor 1 antibody in all groups. The expressions of endothelial nitric oxide synthase (NOS) and inducible NOS were also assessed in both testes of all rats. The malondialdehyde levels in the T/D group were significantly higher than in the control and vardenafil groups. There were also significant decreases in total antioxidant status in the T/D group compared with the control and vardenafil groups. Vardenafil treatment significantly reduced apoptosis protease activating factor 1, endothelial NOS and inducible NOS levels in the vardenafil group compared with the T/D group. Administration of 1 mg/kg vardenafil during testicular torsion decreased ischemia/reperfusion cellular damage. Our results indicate that the reduction in oxidative stress by vardenafil may play a major role in its cytoprotective effects.

Diagnostic utility of DTI in prostate cancer

PURPOSE The aim of this study was to compare the diffusion tensor parameters of prostate cancer, prostatitis and normal prostate tissue. MATERIALS AND METHODS A total of 25 patients with the suspicion of prostate cancer were included in the study. MRI was performed with 3 T system (Intera Achieva, Philips Medical Systems, The Netherlands). T2 TSE and DTI with ss-EPI were obtained in each subject. TRUS-guided prostate biopsy was performed after the MRI examination. Images were analyzed by two radiologists using a special software system. ROIs were drawn according to biopsy zones which are apex, midgland, base and central zone on each sides of the gland. FA and ADC values in areas of cancer, chronic prostatitis and normal prostate tissue were compared using Students t-test. RESULTS Histopathological analysis revealed carcinoma in 68, chronic prostatitis in 67 and was reported as normal in 65 zones. The mean FA of cancerous tissue was significantly higher (p<0.01) than the FA of chronic prostatitis and normal gland. The mean ADC of cancerous tissue was found to be significantly lower (p<0.01), compared with non-cancerous tissue. CONCLUSION Decreased ADC and increased FA are compatible with the hypercellular nature of prostate tumors. These differences may increase the accuracy of MRI in the detection of carcinoma and to differentiate between cancer and prostatitis.

Treatment of Ureteral Calculi with Semirigid Ureteroscopy: Where Should We Stop?

Objectives: To evaluate the efficacy of semirigid ureteroscopy in the management of ureteral stones located in different parts of the ureter. Methods: 1,503 patients were treated with semirigid ureteroscopy. All ureteral stones were either removed only by a basket catheter or disintegrated by pneumatic lithotripsy. Success rates, auxiliary procedures, complication rates and operation time were comparatively evaluated according to stone location. Results: Overall, mean stone size and age were 12.1 ± 3.7 mm and 43.2 ± 9.72 years, respectively. While 1,416 patients (94.2%) were completely stone-free, the procedure was unsuccessful in 87 cases (5.8%). The success rate was relatively low in the proximal ureter (71.7%) when compared with the mid (94.8%) and distal ureter (98.9%) (p = 0.021). Mean operation time was 25.4 ± 11.7 min. Longer duration of operation and higher complication rate were found in proximal ureteral calculi. Stone migration to the kidney and hematuria were the main reasons of failure in the proximal ureter and ureteral stenting was needed for 56.4% of patients with upper ureteral stone. Conclusions: Semirigid ureteroscopy can be the treatment of choice in lower and midureteral stones. However, it is an invasive and less successful treatment modality for proximal ureteral stones with relatively high complication rates.

Factors affecting sexual function in premenopausal age women with type 2 diabetes: a comprehensive study

OBJECTIVE To compare the factors affecting sexual function in premenopausal women with type 2 diabetes using the female sexual function index (FSFI). DESIGN Cross-sectional study. SETTING Premenopausal women with type 2 diabetes and healthy volunteers in an academic research environment. PATIENT(S) Sixty-two type 2 diabetic women were compared with 50 controls. The FSFI scores of the patients were compared according to age, duration of diabetes, marriage, socioeconomic status, parity, menstruation regularity, body mass index (BMI), and smoking. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Female sexual function index scores. RESULT(S) The mean FSFI score in diabetics was lower than in controls. Menstrual irregularity and duration of diabetes affected female sexual function unlike age, BMI, socioeconomic status, duration of marriage, or parity. Regularly menstruating women had higher FSFI scores (27.1 ± 6.7) than irregularly menstruating women (20.7 ± 7.4). Type 2 diabetics were divided into three groups according to duration of diabetes. The women having diabetes longer than 10 years had the worse sexual function. Also, smoking affected inversely female sexual well being. CONCLUSION(S) Menstrual disturbance, smoking, and longer duration of diabetes (more than 10 years) impair FSFI scores in premenopausal women with type 2 diabetes.

The Evaluation of Saphenofemoral Insufficiency in Primary Adult Varicocele

The aim of this study was to evaluate the possible relationship between varicocele and saphenofemoral insufficiency in patients diagnosed with primary varicocele. A total of 70 patients with the primary diagnosis of varicocele were included into the study. A total of 30 age-matched healthy adults were also included in the study as a control group. Varicocele was diagnosed by palpation and observation of each spermatic cord in standing position before and during a valsalva maneuver. Additionally, scrotal Doppler and lower extremity venous Doppler ultrasonography were performed. Patients who were with spermatic varicose vein larger than 3.0 mm were included in the study group as a varicocele patient. At the lower extremity venous Doppler ultrasonography, a retrograde flow lasting longer than 0.5 seconds during normal breathing or at the valsalva maneuver was considered to be meaningful for saphenofemoral junction insufficiency. Thirty-six (51.35%) patients had insufficiency in saphenofemoral junction in the study group (6 [8.5%] bilateral, 30 [42.85%] unilateral) whereas 8 (26.6%) had insufficiency in the control group (2 [6.6%] bilateral, 6 [20%] unilateral insufficiency). The patients with primary varicocele had a statistically significant (P = .02) higher rate of venous insufficiency in their saphenofemoral junctions when compared with the control group. In the present study, the rate of saphenofemoral insufficiency has been found to be statistically higher in patients with primary varicocele compared with healthy men. Depending on the common presence of valvular insufficiency, we believe that the presence of varicocele should be investigated in the young population suffering from saphenofemoral junction insufficiency.

Emergent stenting after uncomplicated ureteroscopy: evaluation of 23 patients.

OBJECTIVES To evaluate the causes of emergent stent placement during the postoperative early period after uncomplicated ureteroscopy in 23 patients. METHODS Of 276 uncomplicated ureteroscopy procedures performed for the management of ureteral calculi, double-J stent placement was necessary on an emergent basis in 23 patients because of intolerable colic pain and extreme patient discomfort. All stents were inserted within 24 hours after the procedure. RESULTS Of the 23 patients requiring emergent stent placement, 14 were men and 9 were women. The stones had been located in the lower ureter in 11, mid-ureter in 6, and upper ureter in 6 patients. All patients had undergone an uncomplicated procedure with no complication evident either during or immediately after ureteroscopic stone management. The intraoperative findings for the 23 patients revealed extensive edema formation, unrecognized small stones embedded in the edematous ureteral wall, unpassed small fragments gathered at the orifice, obstructing blood clots, and kinking of the ureter. A retrospective evaluation of the operative CD recordings and radiographic findings clearly showed that a longer operative time, repeated access, management of a large stone, impacted calculi with ureteral wall edema, a mildly narrowed ureteral segment, ignored caliceal small calculi, and a recent history of urinary tract infection contributed to the need for postoperative intervention. CONCLUSIONS Ureteral catheterization, at least in the form of overnight stent placement, might prevent the formation of transient ureteral obstruction, with resultant postoperative patient discomfort and colic pain evident in selected cases.

Role of Papaverine Hydrochloride Administration in Patients With Intractable Renal Colic: Randomized Prospective Trial

OBJECTIVES To evaluate the therapeutic effect of papaverine hydrochloride in the treatment of patients with renal colic pain unresponsive to conventional treatment. METHODS From March 2007 to January 2008, a total of 561 patients with severe renal colic pain due to a ureteral stone were treated with conventional agents (hyoscine-N-butylbromide and diclofenac sodium) in the emergency and urology departments. Of these 561 patients, 110, with no response to the treatment and persistent severe pain, were randomized into 3 groups for additional treatment. The patients in group 1 (n = 37) received intravenous hyoscine-N-butylbromide, those in group 2 (n = 37) received papaverine hydrochloride, and those in group 3 (n = 36) received pethidine. Before and after treatment, all patients completed a visual analog scale (VAS) questionnaire, with a scale of 0 (no pain) to 10 (maximal complaint), to measure their subjective pain. The mean VAS score of each group was compared with that of the other groups. RESULTS The pretreatment mean VAS scores of all 3 groups were not significantly different statistically from each other (4.02 +/- 1.20, 4.36 +/- 1.97, and 4.27 +/- 1.50; P > .05). However, after treatment, the mean VAS scores of the patients treated with papaverine (0.93 +/- 0.29) and pethidine (0.81 +/- 0.38) were significantly different from those of the hycosine group (3.67 +/- 2.21; P < .001). However, the mean VAS scores of groups 2 and 3 were comparable (P = .67). Unlike opioids, no papaverine-related severe side effects were observed. CONCLUSIONS Our results indicate that papaverine hydrochloride can used in an effective manner in the management of renal colic pain in patients unresponsive to commonly used conventional agents.