Ali Serdar Gözen

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.

Laparoscopic Techniques for Removal of Renal and Ureteral Calculi

BACKGROUND AND PURPOSE Although most ureteral and renal stones are managed using endourologic techniques or shockwave lithotripsy in daily clinical practice, stone surgery has not completely disappeared. The increasing experience with laparoscopy in urology poses the question of whether urolithiasis may be an indication for laparoscopy. MATERIALS AND METHODS A review of the literature was conducted to point out the indications and techniques of laparoscopic stone surgery. RESULTS Indications for stone surgery are anatomic abnormalities, such as horseshoe kidneys, malrotated kidneys, or ectopic kidneys; symptomatic stones in diverticula of the renal pelvis; and extremely large stones, especially in children; or concomitant open or laparoscopic surgery. After failure of endourologic stone removal or shockwave lithotripsy, stone surgery may be a second option. In experienced hands, most procedures can be performed laparoscopically, either using a retroperitoneal or a transperitoneal approach. Accurate planning and imaging before surgery is mandatory. Intracorporeal ultrasonography or combined laparoscopic and endourologic techniques may be useful in difficult cases. Functional outcomes and complication rates of the laparoscopic approach are comparable to those of open surgery. The benefits of laparoscopy are lower postoperative morbidity, shorter hospitalization, shorter convalescence time, and better cosmetic results. CONCLUSIONS Laparoscopic removal of renal and ureteral calculi plays a role in special cases of urolithiasis. In experienced hands, it can be performed safely and efficiently and may therefore replace open stone surgery in most indications.

Role of laparoscopy in reconstructive surgery.

Purpose of review Despite increasing laparoscopic expertise in reconstructive surgery, open procedures still represent the gold standard. Robot-assisted techniques increasingly replace laparoscopy. However, laparoscopy is also developing: by improvement of ergonomics, new instruments, and techniques further reducing access trauma. We evaluated the actual role of laparoscopy focusing on main indications of urologic reconstructive surgery. Recent findings We analysed the current literature (PubMed/Medline) concerning indications, perioperative results, complications, and long-term outcome of laparoscopy for pyeloplasty, ureteral reimplantation, stone surgery, management of vesico-vaginal fistula, sacrocolpopexy (including evidence level). For all indications, laparoscopy provides the advantages of less postoperative pain, blood loss, shorter convalescence, and minimal disfigurement. However, it requires expertise with endoscopic suturing. Most experience (N > 1000) exists with laparoscopic pyeloplasty and sacrocolpopexy which can be considered as valuable options (IIB). Concerning ureteral reimplantation and repair of vesico-vaginal fistula, only a limited number of cases were reported (N < 150) (III). Laparoscopic stone surgery may gain importance particularly in developing countries. Robot-assistance will definitively increase the application of laparoscopic techniques providing optimal ergonomics, whereas the role of single-port surgery will be limited. Summary Laparoscopy will increasingly be used for reconstructive urologic surgery. This trend will be supported by the widespread use of the DaVinci device.

Analysis of three different vesicourethral anastomotic techniques in laparoscopic radical prostatectomy.

ObjectivesThe vesicourethral anastomosis is critical to the outcome of laparoscopic radical prostatectomy (LRP). We retrospectively compared a recently introduced running suture with existing interrupted techniques.Materials and methodsA total of 600 patients undergoing LRP at our institution were reviewed. Each group consisted of 200 patients. Group 1 (intracorporeal-single-knot-running suture) was compared to cohorts in whom the anastomosis was created by interrupted suturing, with (group 2) or without (group 3) a previously placed 6 o’clock suture. Intraoperative data and cystographic evaluation were collected prospectively. Detailed analysis of the location of extravasation was correlated with duration of leak. At a median follow up of 26 months, continence and stricture rates were assessed.ResultsThe groups were statistically similar with respect to age, prostate volumes and pre-operative PSA. Numbers of patients undergoing lymphadenectomy and/or nerve-sparing procedures were also similar between groups. The median time for anastomosis was significantly shorter for group 1 (15.3 min) compared to group 2 (23.5 min) and group 3 (27.7 min) (P < 0.000.1). This was reflected in the overall operative times [group 1; 155.4 min, group 2; 185.6 min and group 3; 202.2 min (P = 0.03)]. Subjective assessment suggested that tension to the anastamosis was present in fewer patients in group 1 (3.5%) compared to group 2 (17%) and group 3 (9.5%) (P = 0.001). There was no significant difference in the continence or stricture rate between the three groups.ConclusionsThe continuous anastomotic suture reduced the operative time and tension to the anastomosis. However, the long term continence and stricture rates were unaffected by anastomotic technique.

Laparoscopic Radical Prostatectomy in Clinical T1a and T1b Prostate Cancer : Oncologic and Functional Outcomes-A Matched-Pair Analysis

OBJECTIVES To evaluate the effect of previous transurethral resection of the prostate (TURP) on surgical, functional, and oncologic outcomes after laparoscopic radical prostatectomy. METHODS From a series of 2100 patients undergoing laparoscopic radical prostatectomy, we compared the intraoperative complications and functional and oncologic outcomes for 55 patients who had been diagnosed with prostate carcinoma on previous TURP (group 1), with those of 55 matched patients who had not undergone previous prostate surgery (group 2). The patients were match-paired for age, operating surgeon, procedure type (eg, nerve-sparing, lymph node dissection), anastamotic technique, pathologic stage, and Gleason score. The minimal duration of follow-up was 24 months. RESULTS Both groups were similar with respect to patient age and pathologic stage. Of those with Stage cT1a and cT1b, 83.6% had a clinically significant tumor, with a mean tumor volume of 1.7 cm(3) for those with Stage cT1a and 2.4 cm(3) for those with Stage cT1b. The positive surgical margin rate was 14.5% and 16.3% for groups 1 and 2, respectively. Biochemical recurrence developed in 12.7% and 11% of patients in groups 1 and 2, respectively. Neither outcome was significantly different between the 2 groups. The long-term continence rates were similar; however, previous TURP was associated with a lower continence rate (49.1%) at 3 months compared with 61.8% for group 2 (P = .01). A nerve-sparing technique was used in 54% of group 1 patients. No significant difference was found in the potency rates between the 2 groups at 12 months. CONCLUSIONS Laparoscopic radical prostatectomy after TURP is a challenging, but oncologically safe, procedure. The interval to total continence was delayed, but the potency rates remain unchanged.

Is Type 2 Diabetes Mellitus a Predictive Factor for Incontinence After Laparoscopic Radical Prostatectomy? A Matched Pair and Multivariate Analysis

PURPOSE We evaluated the effect of diabetes mellitus on incontinence after laparoscopic radical prostatectomy. MATERIALS AND METHODS From a series of 2,071 patients 135 with type 2 diabetes mellitus undergoing laparoscopic radical prostatectomy without radiotherapy and with a minimum followup of 24 months were identified. These patients were randomly matched with 135 nondiabetic controls for age, body mass index, preoperative prostate specific antigen, clinical stage, neoadjuvant hormonal therapy, prostate volume, previous surgery, surgeon skills, surgical approach, presence of bladder neck sparing, lymphadenectomy, technique of urethrovesical anastomosis and attempted nerve sparing surgery. RESULTS Using multivariate analysis age, diabetes mellitus and duration of diabetes mellitus were independent factors for post-prostatectomy incontinence in the whole group. Early continence (0 to 3 months) was observed in 43.7% of patients with diabetes and in 57.8% of nondiabetic controls which was statistically significant (p = 0.02). The rates of continence in patients with diabetes mellitus for 5 or more years at 3, 12 and 24-month evaluations were less than those in patients with diabetes mellitus for less than 5 years, and the difference was statistically significant (36% vs 50%, p = 0.001; 63.9% vs 82.4%, p = 0.02; 91.8% vs 98.6%, p = 0.03, respectively). CONCLUSIONS Patients with type 2 diabetes mellitus need longer to recover continence than nondiabetics after laparoscopic radical prostatectomy. However, type II diabetes mellitus did not affect overall return to continence. Patients with diabetes mellitus for 5 or more years have an almost 5 times increased risk of post-prostatectomy incontinence compared to those with diabetes mellitus for less than 5 years. Diabetic patients should be counseled for the potential negative impact of diabetes mellitus on the recovery of continence after laparoscopic radical prostatectomy.

Comparison of laparoscopic closure of the bladder with barbed polyglyconate versus polyglactin suture material in the pig bladder model: an experimental in vitro study.

PURPOSE The objective of this randomized in-vitro study was to compare the suturation time, integrity, and quality of the bladder closure in fresh cadaver pig bladders performed with barbed polyglyconate sutures vs polyglactin 910 sutures in running and interrupted fashion. MATERIALS AND METHODS Forty-eight pig bladders, each weighing from 120 to 150 g, were randomly divided into three groups: Group 1 (interrupted polyglactin 910 suture group), group 2 (running polyglactin 910 suture group), and group 3 (running barbed polyglyconate suture group). The bladder defects were closed laparoscopically, and the suturation times were noted. Two surgeons evaluated the integrity of each bladder closure. A cystometry was performed, and the filling and leak pressures were noted. A Kruskal-Wallis variance analysis test was used to compare the results of the three groups, and P<0.05 was considered significant. RESULTS There was a statistically significant difference between the mean suturation times of three groups: Group 1, 15.2 minutes; group 2, 9.14 minutes; and group 3, 7.13 minutes (P<0.05). Mean bladder capacity at the time of leakage was 276.2, 353.8, and 419.7 mL for groups 1, 2, and 3, respectively, and the difference was statistically significant (P<0.05). CONCLUSION For the first time, we demonstrated laparoscopic knotless closure of bladder defects using the barbed polyglyconate suture material in an experimental in-vitro model. Closing the pig bladder with running knotless barbed suture provides a more effective and faster watertight bladder closure than traditional polyglactin 910 suture material.

Surgical navigation in urology: European perspective.

Purpose of review Use of virtual reality to navigate open and endoscopic surgery has significantly evolved during the last decade. Current status of seven most interesting projects inside the European Association of Urology section of uro-technology is summarized with review of literature. Recent findings Marker-based endoscopic tracking during laparoscopic radical prostatectomy using high-definition technology reduces positive margins. Marker-based endoscopic tracking during laparoscopic partial nephrectomy by mechanical overlay of three-dimensional-segmented virtual anatomy is helpful during planning of trocar placement and dissection of renal hilum. Marker-based, iPAD-assisted puncture of renal collecting system shows more benefit for trainees with reduction of radiation exposure. Three-dimensional laser-assisted puncture of renal collecting system using Uro-Dyna-CT realized in an ex-vivo model enables minimal radiation time. Electromagnetic tracking for puncture of renal collecting system using a sensor at the tip of ureteral catheter worked in an in-vivo model of porcine ureter and kidney. Attitude tracking for ultrasound-guided puncture of renal tumours by accelerometer reduces the puncture error from 4.7 to 1.8 mm. Feasibility of electromagnetic and optical tracking with the da Vinci telemanipulator was shown in vitro as well as using in-vivo model of oesophagectomy. Target registration error was 11.2 mm because of soft-tissue deformation. Summary Intraoperative navigation is helpful during percutaneous puncture collecting system and biopsy of renal tumour using various tracking techniques. Early clinical studies demonstrate advantages of marker-based navigation during laparoscopic radical prostatectomy and partial nephrectomy. Combination of different tracking techniques may further improve this interesting addition to video-assisted surgery.

Principles and initial experience of a new device for dissection and hemostasis.

Electrosurgery is a commonly used technology in laparoscopy. Electrosurgical devices are being used in many medical subdisciplines in order to coagulate, cut, and ablate tissue and to produce hemostasis. The latest advance in electrosurgery is the introduction of novel simultaneous hemostatic sealing and cutting bipolar devices that minimize force by delivering energy as high current and low voltage output. One of these systems is the Gyrus Plasma Trissector (GPT), (Gyrus Group PLC, Gyrus International, Ltd.UK), a novel radiofrequency (RF) system based on bipolar technology, which consists of a proprietary PlasmaKinetic (PK) generator and specific instruments, designed as a system. The instrument consists of a 17 mm long gold‐coated curved jaw with a ceramic insulated cutting element. The PK system uses high‐powered pulsed bipolar energy to produce a plasmakinetic field around the working elements and is designed to operate at temperatures that allow effective tissue dissection but result in minimal collateral damage and adherence to tissue. The GPT was used with the Gyrus G400 WorkStation generator in laparoscopic radical prostatectomies (LRP). Our initial experience with this novel bipolar device demonstrates it to be safe and effective in dissection and hemostasis. The GPT permits us to act quickly when bloody fields are present, improves coagulation, reduces or eliminates sticking, seals large vessels such as dorsal vein complex (DVC) and allows secure grasping and dissecting of tissue. The urologist is familiar with electrosurgery, as we have become comfortable using GPT to dissect, cut, and coagulate tissue. We feel that the GPT can be used in a variety of laparoscopic procedures in urology.

In vivo Porcine Model for Practicing Retrograde Intrarenal Surgery

Objectives: To examine the feasibility of retrograde intrarenal surgery (RIRS) in a porcine model. Materials and Methods: Female pigs (n = 3) were placed in a dorsal lithotomy position under general anesthesia, and stone material was inserted into the renal pelvis of the pigs. The bladder was entered with a cystoscope, and a 0.038-inch hydrophilic guidewire was passed into the renal pelvis. Following successful placement of the guidewire, a ureteral access sheath (9.5/11.5 Fr) was placed to allow for optimal visualization. A 7.5-Fr flexible ureteroscope (Karl Storz Flex-X2) and a 200-μm laser fiber were used for lithotripsy. When basketing was deemed necessary, zero-tipped nitinol stone baskets were used. Trainees then practiced all these manipulations on the model. Results: Urologists with moderate experience in advanced endourologic surgery were trained using this model. However, there were some surgical difficulties due to the urinary system anatomy of the pig. Intravaginal location of the urethra, bladder neck location of the ureters, tight ureteric orifices, tortuous ureters, longitudinally elongated renal pelvis, narrow infundibulopelvic angle and shallow calices made the passage of the instruments and maneuverability of the flexible ureteroscope more difficult than in a human model. Conclusions: Despite some difficulties, our porcine model was very effective, because all the trainees successfully practiced the RIRS manipulations on this model.