Dogu Teber

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 radical prostatectomy: functional and oncological outcomes.

Purpose of review Laparoscopic radical prostatectomy has become an accepted alternative to open surgery, however data on the functional and oncological outcome are still lacking. In this study we present an analysis based on a survey of the current literature and the first 500 patients treated with the Heilbronn technique. Additionally, we compare the results of laparoscopy with those of open radical prostatectomy. Recent findings We conducted an extensive MEDLINE search of laparoscopic and open radical prostatectomy from 1999 through 2003, focusing on the last 3 years. The articles as well as our own results were analyzed with respect to continence, potency, positive margins, prostatic specific antigen failure, and clinical progression. No significant differences were found between the laparoscopic and open approach with respect to overall continence at 12 months (60-94% versus 61-98%) or at 3 months (51-63% versus 62-69%), varying from 4.1% at pT2, 12% at pT3 to 19% at pT4 stages. We found no significant differences between the two techniques in the recovery of potency (34-67% versus 31-79%), if one excludes the selected series of Walsh with a mean age of 57 years. Furthermore, we did not detect any significant differences in positive margins and short-term prostatic specific antigen recurrence (3 years). Summary At centers of expertise, laparoscopic radical prostatectomy is able to provide similar functional and oncological results as its open counterpart, however with the advantages of minimally invasive surgery.

Bipolar transurethral resection of the prostate ‐ technical modifications and early clinical experience

The purpose of the study was to update the current modifications of transurethral resection of the prostate (TURP) using bipolar high frequency current and to report on our first own clinical experience. Based on a Medline search covering the period from January 2000 to September 2006 and our clinical experience with three different devices (VISTA‐ACMI, Gyrus, Storz), the technical basis of these modifications was described. In addition, an analysis of the actual outcome (handling, complications, morbidity) of bipolar TURP (n = 124) compared to a parallel series of monopolar TURP (N = 148) was carried out. Recently, five different modifications of bipolar resection devices (ACMI, Gyrus, Olympus, Storz, Wolf) have been introduced. Experimental and clinical data were available for four of these modifications (VISTA‐ACMI, Gyrus, Olympus, Storz). The devices differ in terms of modification of the passive electrode (two loops, single loop, resectoscope sheath). Bipolar technology allows the use of 0.9% sodium chloride (instead of glycine) as irrigant. In all bipolar devices, a slight prolongation was noted for initiation of the cut, with the VISTA showing the poorest cutting behaviour. Finest apical dissection could be performed with the Storz device. Phase III‐studies comparing bipolar and monopolar TURP showed advantages for bipolar concerning the rate of TUR‐syndrome/fluid absorption, bleeding, catheter time, whereas the resection speed was similar. In two studies using two different devices (Gyrus, Olympus) a higher rate of urethral strictures was detected. We conclude that TURP still represents the reference standard in the management of benign prostatic hyperplasia. Initial data suggest that bipolar technology is safe and effective. It may offer some advantages with respect to the reduction of TUR‐syndrome, less conductive trauma (i.e. tissue charring), cheaper irrigation solution, and a shorter catheter time. In addition to already existing phase III‐studies, larger randomized mulit‐institutional trials will have to substantiate these advantages.

Complications of laparoscopic pyeloplasty

ObjectivesWith the development of new video-endoscopic techniques like endopyelotomy, laparoscopy and retroperitoneoscopy the treatment of UPJO has become less invasive. The complications and learning curve of laparoscopic pyeloplasty are presented together with recommendations for adequate management.Materials and methodsBased on the personal experience with 189 cases of retroperitoneoscopic pyeloplasty, a literature review (PubMed) was performed focussing on complication and success rates of the procedure. Intraoperative incidents were analysed using the Satava-classification, postoperative complications according to the Clavien-classification. The meta-analysis focussed on the experience of the 3 largest and 2 smaller series representing a cohort of 601 patients.ResultsIntraoperative incidents ranged from 2.0 to 2.3% in large series, mostly without consequences for the patient including ligation of lower pole artery, loss of needle, hyperkapnia, cutting of DJ-stent, colonic injury, and port site bleeding. The conversion rate was mainly due to inability to access UPJ or to accomplish the anastomosis ranging between 0.5 and 5.5%. Postoperative complications occured between 12.9 and 15.8% in large series. A total of 5.4–10% represented Grade III-complications, such as urine leakage, haematoma, colonic lesion, and stone formation. Recurrent UPJ-stenosis requiring reintervention was seen in 3.5–4.8%. In all three large series, complications were part of the learning curve.ConclusionLaparoscopic pyeloplasty has been proven safe and effective with comparable results to open surgery. The experience of pioneering centres with incidence and management of complications will be used by next generations of laparoscopic urologic surgeons to shorten their learning curve.

iPad-assisted percutaneous access to the kidney using marker-based navigation: initial clinical experience.

of T1 tumours. In support of this, AQP3 has been shown to play an emerging role in other malignancies such as gastric adenocarcinoma. Moreover, abnormalities of chromosome 9p, where the AQP3 gene is located, are also commonplace in TCC, adding extra evidence for a role for AQP3. Taken together, this is the first description of a potential role for AQP3 in bladder cancer. Despite the very limited number of samples, our findings are a solid platform for further studies comprising adequate numbers of tumours of all grades and stages as well as considering cancer progression and survival to appropriately elucidate the role of AQP3 in TCC.

Augmented reality visualization during laparoscopic radical prostatectomy.

PURPOSE We present an augmented reality (AR) navigation system that conveys virtual organ models generated from transrectal ultrasonography (TRUS) onto a real laparoscopic video during radical prostatectomy. By providing this additional information about the actual anatomy, we can support surgeons in their working decisions. This work reports the systems first in-vivo application. MATERIALS AND METHODS The system uses custom-developed needles with colored heads that are inserted into the prostate as soon as the organ surface is uncovered. These navigation aids are once segmented in three-dimensional (3D) TRUS data that is acquired right after the placement of the needles and then continuously tracked in the laparoscopic video images by the surgical navigation system. The navigation system traces the navigation aids in real time and computes a registration between TRUS image and laparoscopic video based on the two-dimensional-three dimensional (2D-3D) point correspondences. With this registration, the system correctly superimposes TRUS-based 3D information on an additional AR monitor placed next to the normal laparoscopic screen. Surgical navigation guidance took place until the prostate was removed from the rectal wall. Finally, the navigation aids were removed together with the specimen inside the specimen bag. RESULTS The initial human in-vivo application of the surgical navigation system was successful. No complications occurred, the prostate was removed together with the navigation aids, and the system supported the surgeons as intended with an AR visualization in real time. In case of tissue deformations, changes in the spatial configuration of the navigation aids are detected, which preserves the system from erroneous navigation visualization. CONCLUSIONS Feasibility of the navigation system was shown in the first in-vivo application. TRUS information could be superimposed via AR in real time. To show the benefit for the patient, results obtained from a larger number of trials are needed.

Complications in 2200 Consecutive Laparoscopic Radical Prostatectomies: Standardised Evaluation and Analysis of Learning Curves

BACKGROUND Laparoscopic radical prostatectomy (LRP) represents an established treatment modality for localised prostate cancer. OBJECTIVE To report standardised complication rates for LRP, evaluate the development of complication rates over time, and show changes within the learning curves of laparoscopic surgeons. DESIGN, SETTING, AND PARTICIPANTS We conducted a standardised analysis of 2200 consecutive patients who underwent LRP between 1999 and 2008 at a single institution. INTERVENTION LRP was performed using a transperitoneal (n=871) or extraperitoneal (n=1329) retrograde Heilbronn technique. Five surgeons operated on 96% of the patients. MEASUREMENTS Complications were classified according to the modified Clavien system. Total complication rates and changes over time were analysed. Three generations of surgeons were defined for evaluation of learning curves. RESULTS AND LIMITATIONS Minor complications occurred in 21.7% of patients (Clavien 1: 6.8%; Clavien 2: 14.9%); anaemia requiring transfusion (10.4%) dominated. Early reinterventions were necessary in 6.7% of patients (Clavien 3a: 3.6%; Clavien 3b: 1.5%; Clavien 4a: 1.5%; Clavien 4b: 0.1%). Late Clavien 3b complications occurred in 4.7% of patients-most of them anastomotic strictures. Mortality was 0.1% (Clavien 5). There was a significant decrease in overall complication rates over time, resulting predominantly from decreasing Clavien 1-2 events. Learning curves of third-generation surgeons plateaued earlier compared to the first generation (250 vs 700 cases). The limitation of this study is that data concerning comorbidity were not included. CONCLUSIONS LRP is a safe procedure characterised by an acceptable profile of complications. Specifically, few major complications are reported. According to the complication rates, the learning curve of third-generation surgeons is significantly shorter compared to first- and second-generation surgeons.

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.

Laparoscopic radical nephrectomy: the new gold standard surgical treatment for localized renal cell carcinoma.

We will try to demonstrate that laparoscopic radical nephrectomy could be the new gold standard treatment for renal cell carcinoma with the aid of the current reports exploring the advantages and disadvantages of laparoscopic radical nephrectom overopen surgery. Reported perioperative outcomes like operating time, blood loss, postoperative analgesia requirement, and length of hospital stay and duration of convalescence had been found to be in favor of laparoscopic radical nephrectomy. Some technical issues like approach of laparoscopic technique (Transperitoneal versus retroperitoneal laparoscopic nephrectomy), removal of dissected specimen and need for lymph node dissection had been also discussed in detail in this review. Besides, oncological safety of laparoscopic radical nephrectomy had been explored. The overall five-year disease free survival rates of laparoscopic radical nephrectomy in recent series were found to be over 90%. All of the series including the present one at least confirmed the oncological efficacy of LRN as compared with open surgical approach. The contemporary review of the literature documents clearly demonstrated the perioperative benefits of laparoscopy compared to the open approach. Nevertheless, the development, however, more safe and reliable technique in laparoscopy is necessary for tumor extraction. Recent studies confirmed the long-term similar cancer control results of laparoscopic radical nephrectomy with open surgery. Despite some technical modifications by the different groups, it can be stated that laparoscopic radical nephrectomy is the new gold standard treatment modality for patients with localized renal cell carcinoma.

Robotics and telesurgery – an update on their position in laparoscopic radical prostatectomy

Laparoscopy is handicapped by the reduction of the range of motion from six to only four degrees of freedom. In complicated cases (i.e. radical prostatectomy), there is often a crossing of the hands of surgeon and assistant. Finally, standard laparoscopes allow only 2D‐vision. This has a major impact on technically difficult reconstructive procedures such as laparoscopic radical prostatectomy. Solutions include the understanding of the geometry of laparoscopy, but also newly developed surgical robots. During the last five years, there has been an increasing development and experience with robotics in urology. This article reviews the actual results focussing on the benefits and problems of robotics in laparoscopic radical prostatectomy. Own experiences with robot‐assisted surgery include more than 1200 laparoscopic radical prostatectomies using a voice‐controlled camera‐arm (AESOP) as well as six telesurgical interventions with the da Vinci‐system. Substantial experimental studies have been performed focussing on the geometry of laparoscopy and new training concepts such as perfused pelvitrainers and models for simulation of urethrovesical anastomosis. The recent literature on robotics in urology has been reviewed based on a MEDLINE/PUBMED research. The geometry of laparoscopy includes the angles between the instruments which have to be in a range of 25° to 45°; the angles between the instrument and the working plane that should not exceed 55°; and the bi‐planar angle between the shaft of the needle holder and the needle which has to be adapted according to the anatomical situation in range of 90° to 110°. 3‐D‐systems have not yet proved to be effective due to handling problems such as shutter glasses, video helmets or reduced brightness. At the moment, there are only two robotic surgical systems (AESOP, da Vinci) in clinical use, of which only the da Vinci provides stereovision and all six degrees of freedom (DOF).To date, more than 3000 laparoscopic radical prostatectomies have been performed worldwide at 92 centres with this system. The main advantage of the system represents the translation of open surgical skills to laparoscopy. Despite recent development of basic tools (e.g. bipolar forceps) for the da Vinci robot, investment and maintenance costs still represent the major problem of the device. Additionally, the device does not provide any haptic sense (i.e. tactile feedback). Robotic surgery represents a turning point of surgical research. However, broad use of robotic systems is limited mainly because of the high investment and running costs. Interestingly, more than in the field of cardiac surgery, there seems to be a need for telemanipulators in urology, mainly to reduce the learning curve of standard laparoscopy. However, new training concepts used in combination with mono‐tasking computerized robots (AESOP) have proved their efficacy associated with a significant cost reduction.