Biomedical subjects

Can Obek

Publications and source records attributed to Can Obek.

9 recordsLinked to original sources

PubMed2006

Hypoechoic space formation with periprostatic nerve block: myth or reality?

INTRODUCTION: The most efficacious and commonly applied anesthetic technique for prostate biopsy is periprostatic block. In a previous publication, the creation of a 'hypoechoic space' at the injection site was described. This was reported to be a routine and essential part of the technique in various subsequent series. We were interested in assessing the incidence of the formation of such a hypoechoic area, and more importantly, whether it had any impact on pain management. MATERIALS AND METHODS: One hundred and eleven consecutive patients were prospectively evaluated. Local anesthetic consisted of 2.5 ml of 2% lidocaine for each side of the prostate. Infiltration was done within the neurovascular space at the base of the prostate just lateral to the junction between the prostate and the seminal vesicle. The creation of a hypoechoic nodule was recorded in three categories: no formation, unilateral or bilateral formation. Three groups were compared regarding the intensity of pain using a numeric analog scale. RESULTS: No hypoechoic area was formed in 30 (27%) patients. A unilateral nodule was created in 40 (36%), and a bilateral nodule was seen in 41 (37%) patients. The median pain scores were 3.3, 2.5 and 1.3 for the no hypoechoic wheal, unilateral and bilateral wheal groups, respectively (p<0.0001). CONCLUSION: Our results suggest that the creation of a hypoechoic space with anesthetic infiltration for prostate biopsy is indeed an important aspect of the technique with regard to pain control; however, it may not be accomplished in every case.

Aged↗

PubMed2005

Robotic versus conventional laparoscopic skill acquisition: implications for training.

BACKGROUND AND PURPOSE: Despite the growing interest in surgical robotics, very little study has been done regarding the acquisition of the skills needed to perform robotic surgery safely. The purpose of this study was to determine whether skills are transferred between conventional laparoscopy and robotically assisted surgery. SUBJECTS AND METHODS: Intracorporeal knot tying was used for evaluating laparoscopic skills for time and error performance. Twenty medical students without any laparoscopic experience were randomized into two groups. Group A initially performed knot tying with conventional laparoscopic instruments, were trained with the daVinci Robotic System, and then performed knot tying with conventional laparoscopy. Group B performed knot tying with robotics, trained with standard laparoscopy, and completed post-training knot tying with robotics. Pretraining and post-training tasks were videotaped and analyzed using a detailed scoring system by one independent referee, who was blinded to the subjects' experience. RESULTS: Pre-training knot tying was faster with robotics (4.4 v 9.9 minutes; P < 0.001). The mean composite scores were 27.4 for group A and 57.4 for group B (P = 0.09), and the error scores were 57.1 and 42.1 (P = 0.29), respectively. Post-training time for knot completion decreased to 6.7 minutes and 3.4 minutes for groups A and B, respectively. Composite scores increased significantly, from 27.4 to 66.1 for group A and 57.4 to 81.8 for group B. Error scores decreased to 32.9 for group A (P = 0.1) and 16.2 in group B (P = 0.02). CONCLUSIONS: There appears to be reciprocal transfer of skills between conventional laparoscopy and robotically assisted surgery. However, this transference is incomplete. Our results suggest that training with either technique or conventional laparoscopy is superior to training with robotics alone.

Clinical Competence↗

PubMed2004

A simple position to provide better imaging of upper ureteral stones close to the crista iliaca during extracorporeal shock wave lithotripsy using the Siemens Lithostar.

OBJECTIVE: The fluoroscopic image from the second plan (oblique) tube of an upper ureteral stone close to the crista iliaca may be superimposed on the pelvic bones during SWL using the Siemens Lithostar with the patient in the prone position. This creates difficulty in imaging and targeting of the stone and can necessitate using ureteral catheters before treatment and/or intravenous contrast injection during SWL. We describe a very simple, yet effective method for easier visualization of the stone under this circumstance. METHODS: Between March 1992 and February 2003, we treated 1561 patients with ureteral stones by SWL with the Siemens Lithostar. The stones were localized in the upper ureter in 841. The image of the stone from the second plan (oblique) tube was superimposed on the pelvic bones in 221 in whom visualization of the stone was hardly possible with the standard prone position. By simply rotating the patient 180 degrees on the table, the superimposition of the image of the stone on the pelvic bone was obviated. This resulted in easier and better imaging of the stone during SWL. It also allowed for a clear and superior image to the treating physician during SWL. The energy and shock waves, utilization of anesthesia, number of treatment sessions, auxiliary measures, and complications were noted. Stone load was recorded in square centimeters (cm(2)). Patients were evaluated by intravenous urogram or KUB and ultrasonography when stone-free or CIRF (nonobstructive and noninfectious insignificant fragments < or =4mm) status was noted at the fluoroscopic control 2 to 4 weeks after the last session. Final CIRF decision was made 10-12 weeks after the last session. SWL was regarded as failure if no fragmentation was noted after the 3rd session. Therapy was continued if fragmentation was noted. RESULTS: The median age was 40 (range 5-85). The mean stone burden was 0.8 (range 0.24-2.9) cm(2). No indwelling ureteral stents were placed in any patients before and during treatment. The mean number of shock waves and energy used for the entire patient population was 2007 and 17.5kV, respectively. The median and average treatment session was 1 and 1.7, respectively. A total of 196 patients (89%) were rendered stone-free. Clinically insignificant residual fragments were present in 18 (8%). SWL was unsuccessful in 7 (3%) patients. These stones were removed by ureterorenoscopy. Intravenous contrast administration was not used to facilitate stone targeting during SWL. Anesthesia, in the form of analgesic sedation, was used in 7 (3%) patients. We did not observe any complications and adverse effects. CONCLUSIONS: The technique described hereby does not have an affect on coupling; it only provides a superior image of the stone to the treating physician. We advocate its application in all patients with upper ureteral stones close to the crista iliaca when the fluoroscopic image of the stone from the second plan (oblique) tube is superimposed on pelvic bones during SWL in prone position.

Adolescent↗

PubMed2004

The effect of prostate cancer and antiandrogenic therapy on lipid peroxidation and antioxidant systems.

In living organism, excessive free radicals or oxidative damage which occur as a result of deficient antioxidant defensive mechanisms by the effect of endogenous and exogenous factors, influences especially developmental steps of chemically induced cancers. In our study, plasma malondialdehyde level (MDA) as an indicator of lipid peroxidation, erythrocyte glutathione (GSH) level as an indicator of antioxidant state, glutathione reductase (GSH-Red), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) as an antioxidant enzymes and plasma vitamin E level were detected in patients with prostate cancer (21 males; age, 69.4 +/- 4.8 years) before and after three months of antiandrogenic therapy with goserelin acetate as luteinizing hormone releasing hormone (LHRH) analogue. Healthy people evaluated as a control group (20 males; age, 63.7 +/- 3.9). Erythrocyte GSH levels, the activities of GSH-Red and GSH-Px and plasma vitamin E levels were found significantly low in patients with prostate cancer when compared with the healthy subjects (p < 0.01, p < 0.05, p < or = 0.001 and p < or = 0.001 respectively). Plasma MDA level and erythrocyte GST activity of patient group were significantly higher than the levels of control group (p < or = 0.001 and p < or = 0.001 respectively). After antiandrogenic therapy erythrocyte GSH level, GSH-Red, GSH-Px activity and plasma vitamin E level were found unchanged. Significant decrease in plasma MDA level and significant increase in erythrocyte GST activity were detected in patient group (p < 0.05 and p < or = 0.01 respectively). The study has revealed the shift in the oxidant-antioxidant balance towards oxidative state in patients with metastatic prostate cancer. Our results showed that antiandrogenic therapy increased in GST activity, decreased in lipid peroxidation.

Aged↗

PubMed2004

Comparison of 3 different methods of anesthesia before transrectal prostate biopsy: a prospective randomized trial.

PURPOSE: Periprostatic nerve block (PNB) is the most common anesthesia technique used before prostate biopsy. However, needle punctures for anesthetic infiltration may be painful and cause higher infectious complications. We assessed whether addition of rectal lidocaine gel would improve its efficacy. We also investigated the efficacy and safety of tramadol, a codeine derivative, as a noninvasive method. MATERIALS AND METHODS: A total of 300 patients who underwent prostate biopsies were randomized into 4 groups of controls, PNB, perianal/intrarectal lidocaine gel plus PNB and tramadol. Pain was assessed with a numeric analog scale. RESULTS: Each group consisted of 75 patients, and there was a statistically significant difference among pain scores (p = 0.001). Mean pain scores were 4.63 for controls, 2.57 for PNB, 2.03 for infiltration plus gel group and 3.11 for tramadol. Pain and discomfort were least in PNB plus gel arm. The difference of pain score between PNB alone and tramadol group did not reach statistical significance. Infectious complications were higher in the combination group, whereas there were no complications with tramadol. CONCLUSIONS: Any form of analgesia/anesthesia was superior to none. The combination of PNB plus gel provided significantly better analgesia compared to PNB alone or tramadol. If this can be duplicated in other trials, the combination may be accepted as the new gold standard of anesthesia for prostate biopsy. The efficacy of tramadol was similar to that of PNB, and was free of complications. Therefore, tramadol may have a role before prostate biopsy, which needs to be explored.

Aged↗

PubMed2003

Outcome of nephron-sparing surgery: elective versus imperative indications.

INTRODUCTION: The increase in the detection of renal tumors incidentally in earlier stages has enhanced the enthusiasm for nephron-sparing surgery (NSS). PATIENTS AND METHODS: We performed NSS in 76 patients (53 male, 23 female) with a mean age 52.3 between December 1988 and September 2001. Patients were sub-classified into 2 groups as elective or imperative indication group. They were compared regarding surgical technique, time of surgery, pathological analysis, complications, and disease free status. RESULTS: Elective indication group (group I) with a normal contralateral kidney consisted of 50 patients, whereas there were 26 patients in the imperative indication group (group II). Tumors were incidentally detected in 63%; 74% in group I and 42% in group II. Although the mean diameter of the tumor was slightly higher in group II (39.1 vs. 36.3 mm), this difference did not reach statistical significance (p > 0.05). The partial nephrectomy was performed more frequently compared to enucleation in group I (90 vs. 69%, p = 0.050). However, the mean operation time as well as the mean clamping time did not differ significantly between the two groups (p > 0.05). In the histological evaluation tumors were benign in 16 (21%) and malignant in 60 patients. All of the patients but one with renal cell carcinoma had stage T1-T2 disease. Major complications were observed in 14 (18%) and 12 were from group II. Complication rate was significantly higher in group II (p = 0.000). Of 60 patients with renal cell carcinoma, 2 died of unrelated causes. One patient died with multiple visceral metastases. One patient was lost to follow-up. In the remaining 56 patients with a mean follow-up of 37.1 months (1-152), local recurrence or distant metastases were not detected. Serum creatinine levels have remained almost the same compared to preoperative levels (1.2 +/- 0.6 vs. 1.5 +/- 0.9). Overall and cancer-specific survivals were 100 and 100% in group I, 85 and 95% in group II, and 94 and 98% for the entire patient population, respectively. CONCLUSION: NSS is an effective and reliable treatment in low stage renal tumors. It prevents unnecessary nephrectomy in benign lesions that could not be diagnosed preoperatively. However, the patients who underwent NSS with elective indication outcome with better results, compared to those with imperative indication.

Carcinoma, Renal Cell↗

PubMed2002

Spontaneous ureteral rupture: is immediate surgical intervention always necessary? Presentation of four cases and review of the literature.

PURPOSE: We report our experience with spontaneous ureteral rupture (SUR) managed conservatively. CASE REPORTS: Data on three men and one woman 53 to 89 years old (mean age 73) with SUR were retrospectively evaluated. The common complaint was sudden-onset abdominal and concomitant flank pain. On physical examination, all patients had abdominal tenderness and pain with costovertebral angle tenderness on the associated side. One patient had rheumatoid arthritis treated with corticosteroids, and one had carcinoma of the prostate. All patients had urinary extravasation on CT scans. Two patients had ureteral obstruction by stones, and another had bladder outlet obstruction secondary to prostate cancer. Interestingly, irrespective of the obstruction level, the rupture was near the ureteropelvic junction in all patients. The symptoms regressed within hours after basket catheterization and ureteral stent placement in one patient and close follow-up and supportive treatment in three patients. In two patients, disappearance of extravasation and reabsorption of perirenal fluid were confirmed by second- and third-day CT scans. The patients were followed for a mean of 17 (range 14-21) months without any problems. CONCLUSIONS: We believe that SUR cases are more frequent than reported. It is the authors' opinion that if the clinical scenario is suspected in the acute phase and investigated by appropriate radiologic techniques, many more SUR cases will be diagnosed. Careful monitoring with supportive measures may be curative in the majority of the patients, obviating a surgical intervention.

Acute Disease↗

PubMed2002

Is periprostatic local anesthesia for transrectal ultrasound guided prostate biopsy associated with increased infectious or hemorrhagic complications? A prospective randomized trial.

PURPOSE: Periprostatic local anesthesia for prostate biopsy requires 2 or more extra needle punctures and injection of the local anesthetic through the highly colonized rectum. To our knowledge we report the first prospective randomized trial to assess the infectious or hemorrhagic complications associated with this method. MATERIALS AND METHODS: A total of 100 consecutive patients with sterile urine cultures underwent transrectal ultrasound guided prostate biopsy. They were randomized to receive a periprostatic nerve block or no anesthesia. Patients were evaluated for the amount of rectal and urethral bleeding, and symptoms and signs of infection after biopsy. RESULTS: The amount of urethral bleeding was slight and similar in the 2 groups. Rectal bleeding was significantly less in the patients who received anesthesia. High fever (greater than 37.8C) was more frequent in the nerve block group and 2 patients in this group required rehospitalization. Bacteriuria in post-biopsy urine cultures was significantly more common in the anesthesia group. CONCLUSIONS: Our results suggest that periprostatic local anesthesia for prostate biopsy does not increase the risk of urethral bleeding. It is associated with a decreased incidence of rectal bleeding, presumably due to decreased patient discomfort. The incidence of bacteriuria was significantly higher in the anesthesia group. High fever and hospitalization due to infectious complications were also more common in the local anesthesia group, although not statistically significant. Prospective randomized trials seem warranted to determine the optimum antibiotic prophylaxis regimen in patients undergoing biopsy with a periprostatic nerve block.

Aged↗

PubMedDate not supplied

Methylguanine DNA methyl transferase activities, glutathione s transferase and nitric oxide in bladder cancer patients.

Tumor formation is a multistep process that can be divided in to the stages of tumor initiation, promotion, and progression. DNA repair protein; MGMT is a key suicide enzyme that repairs the mispairing base methylguanine, which is induced in DNA as a minor lesion. The glutathione S transferases (GSTs) are a family of enzymes that are important to protect against alkylating agents. Nitric oxide, contributes to the regulation of tumor angiogenesis. A substantial body of experimental evidence supports the hypothesis that tumor angiogenesis is fundamental for the growth and metastasis of solid tumors. We measured the activities of GST, MGMT, and levels of NO3-/NO2- in the leukocytes from patients with bladder carcinoma and healthy controls and activities of MGMT in the tissue from patients with bladder carcinoma and adjacent normal tissue in bladder. Both GST and tissue MGMT activites were significantly increased in the patient group. There was no significant difference between controls and patients for MGMT activity in peripheral blood leukocytes (PBL). Nitrate/nitrite levels in PBL, there was no significant difference between controls and patients. Nitrate/nitrite levels were increased in G2-G3 tumors. In conclusion, we determined high concentrations of nitrite in leukocytes are suspected alkylation damage by induction nitrosamine. Increased DNA alkylation damage may lead the stimulation of MGMT and GST.

Aged↗