Eşref Oğuz Güven

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.

Protective effects of tadalafil on experimental spinal cord injury in rats

Tadalafil is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Nitric oxide (NO) functions as a retrograde neurotransmitter in the spinal cord, and postsynaptic structures respond to NO by producing cGMP. The concentrations of cGMP in the spinal cord are controlled by the actions of PDE. The aim of the study was to evaluate and compare the effects of the use of both methylprednisolone and tadalafil on serum and tissue concentrations of NO, malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity, and tissue glutathione peroxidase (GSH-Px) activity in rats with spinal cord injury (SCI). SCI was induced in Wistar albino rats by dropping a 10 g rod from a 5.0 cm height at T8-10. The 28 rats were randomly divided into four equal groups: tadalafil, methylprednisolone, non-treatment and sham groups. Rats were neurologically tested at 24 hours after trauma. At the end of the experiment, blood samples were collected and spinal cord tissue samples were harvested for biochemical evaluation. The tissue level of NO was increased in the tadalafil group compared with the non-treatment and methylprednisolone groups (p<0.05). The tissue levels of SOD and GSH-Px did not differ between the groups. Serum levels of NO were higher in the tadalafil group than in the non-treatment group (p<0.05). The increase in serum SOD levels was greater in the tadalafil group than the methylprednisolone group. Serum MDA levels in the tadalafil and methylprednisolone groups tended to be lower than in the non-treatment group (p>0.05). Tissue MDA levels in the tadalafil and methylprednisolone groups tended to be lower than in the non-treatment group and sham groups (p>0.05). Although there was no difference in neurological outcome scores between the tadalafil, methylprednisolone and non-treatment groups (p>0.05), the animals in the tadalafil and methylprednisolone groups tended to have better scores than the non-treatment group. Thus, tadalafil appears to be beneficial in reducing the effects of injury to the spinal cord by increasing tissue levels of NO and serum activity of SOD.

Robotic and imaging in urological surgery.

Purpose of review New imaging modalities and tissue navigation systems, which are adoptable to minimally invasive robotic urological surgical systems and prone to make the procedures more precise and easy, are reviewed. Recent findings Image-guided surgery as the general name of combining information of imaging modalities with real-time surgery has already found a place in open and minimally invasive procedures. Soft tissue navigation is a complex type of computer-assisted surgery for soft tissue interventions. Robotic surgery has advantages of superior degrees of freedom and three-dimensional stereotactic user interface. A combination of surgical robotics with image-assisted surgery and soft tissue navigation may offer advantages of more precise anatomical target localization and dissection with minimal damage to the tissue. Solving the problem of organ shift and as a result, unpredictable changing of intraoperative anatomy soft tissue navigation has the potential to increase the precision of minimally invasive robotic surgery. Summary Apart from less invasiveness, the concomitant use of minimal invasive robotic systems with soft tissue navigation enhances surgical precision. However, at present, abdominal navigation systems are in experimental use and not perfect enough for daily surgical routine.

Transitional cell carcinoma of the clitoris: direct implantation or metastasis

Transitional cell carcinoma (TCC) of the bladder is the seventh most frequent cancer of women. The possible mechanisms of local tumor recurrence are seeding and multicentricity. Distant metastases are most frequently as a result of vascular or lymphatic spread and to a lesser extent by seeding of the tumor cells with urine or transurethral instrumentation. We report a clitoral metastasis of a TCC of the bladder, which is a very unexpected and extremely rare site for metatstasis and discuss whether the possible mechanism is vascular spreading or direct seeding. To our knowledge this is the third case in the literature.

Hereditary Behavior of Varicocele

The inheritance of varicoceles and the potential transmission to first-degree relatives has rarely been investigated. In the present study, we examined the first-degree relatives of men with known varicocele to reveal the familial risk for varicocele. Of the patients with clinical varicocele who presented with infertility, testicular pain, or asymmetrical swelling of the scrotum between June 1, 2008 and May 31, 2009, 49 agreed to have their available first-degree relatives contacted for screening of varicoceles (n = 66). A cohort of 100 consecutive men who applied to the department of internal medicine between 2008 and 2009 for checkup procedure without a history of subfertility or a varicocele were used as a control population. Of the 92 first-degree relatives contacted, 66 (71.7%) decided to participate in this study. Of these 66 men, 21 (33.9%) had a palpable varicocele on physical examination. Compared with a control population (12%), the prevalence of palpable varicocele in the first-degree relatives of patients with known varicocele (33.9%) was approximately 3-fold greater (P < .005). Among the first-degree relatives, 4 (21.1%) of 19 fathers and 17 (36.2%) of 47 brothers had palpable varicocele. As a conclusion, a significant increase in varicocele prevalence is present in the first-degree relatives of men with known varicoceles. Patients should be counseled about this increased risk in male relatives of patients.

Malign Priapism Secondary to Renal Cell Carcinoma Provoked Paraneoplastic Leukemoid Reaction: Report of The First Case

Malign priapism (MP) is described due to tumoral invasion or metastasis to the penil corporeal tissue. Paraneoplastic leukemoid reaction (PLR) is reported in nearly all solid tumor types as a paraneoplastic syndrome. It is a reactive leukocytosis where white blood cell(WBC) count exceeds 50x10/L without evidence of leukemia. 3-8% of all priapism cases are caused by malignancy.We present a case of MP, showed up secondary to a PLR which was provoked firstly by the primary renal malignancy and it was again induced four years after by its lung metastasis.To our knowledge, this is the first case in the literature. We’d like to emphesize that there were no evidents of invasion or metastasis to corpus cavernosum. PLR can also give rise to priapism attacks and this may be the first symptom of a malignant condition.