Osamu Ukimura

Laparoscopic partial nephrectomy in solitary kidney

PURPOSE We report our experience with LPN for tumor in a solitary kidney. MATERIALS AND METHODS Of 430 patients undergoing LPN since February 1999 at our institution 22 (5%) underwent LPN for tumor in a solitary kidney, as performed by a single surgeon. The laparoscopic technique that we used duplicated open principles, including hilar clamping, cold cut tumor excision and sutured renal reconstruction. RESULTS Mean tumor size was 3.6 cm (range 1.4 to 8.3, median 3 cm), median blood loss was 200 cc (range 50 to 500), warm ischemia time was 29 minutes (range 14 to 55), total operative time was 3.3 hours (range 2.2 to 4.5) and hospital stay was 2.8 days (range 1.3 to 12). Two cases (9%) were electively converted to open surgery. Pathological findings confirmed renal cell carcinoma in 16 patients (73%) with negative surgical margins in all those with LPN. Major complications occurred in 3 patients (15%) and minor complications developed in 7 (32%). Median preoperative and postoperative serum creatinine (1.2 and 1.5 mg/dl) and estimated glomerular filtration rate (67.5 and 50 ml per minute per 1.73 m2) reflected a change of 33% and 27%, respectively, which appeared proportionate to the median amount of kidney parenchyma excised (23%). One patient (4.5%) required temporary hemodialysis. At a median followup of 2.5 years (range 0.5 to 4.5) cancer specific and overall survival was 100% and 91%, respectively. No patient with LPN had local or port site recurrence, or metastatic disease. CONCLUSIONS LPN can be performed efficaciously and safely in select patients with tumor in a solitary kidney. To our knowledge we present the largest series in the literature. Advanced laparoscopic experience and expertise are necessary in this high risk population.

Real-Time Transrectal Ultrasound Guidance During Laparoscopic Radical Prostatectomy: Impact on Surgical Margins

PURPOSE We evaluated whether intraoperative real-time TRUS navigation during LRP can decrease the incidence of positive surgical margins. MATERIALS AND METHODS Since March 2001, 294 patients with clinically organ confined prostate cancer undergoing LRP have been retrospectively divided into 2 groups, including group 1-217 who underwent LRP without TRUS from March 2001 to February 2003 and group 2-77 who have undergone LRP with TRUS since March 2003. Various baseline parameters were similar between the groups. Before March 2001 the senior surgeon had already performed more than 50 cases of LRP, thus, gaining reasonable familiarity with the technique. RESULTS Compared to group 1, group 2 had a significantly decreased rate of positive surgical margins in patients with pT3 disease (57% vs 18%, p = 0.002). Positive margin rates also decreased in our overall experience (29% vs 9%, p = 0.0002). Intraoperative TRUS correctly predicted pT2 and pT3 disease in 85% and 86% of patients, respectively. Of the 54 TRUS visualized hypoechoic lesions at sites corresponding to biopsy proven cancer extracapsular extension was suspected in 31, leading to a real-time recommendation of calibrated wider, site specific dissection to achieve negative surgical margins. CONCLUSIONS Intraoperative TRUS monitoring during LRP allows individualized, precise dissection tailored to the specific prostate contour anatomy, thus, compensating for the muted tactile feedback of laparoscopy. In what is to our knowledge the initial experience real-time TRUS guidance significantly decreased the incidence of positive surgical margins during LRP. In the future this concept of rectum based, intraoperative real-time navigation may facilitate a more sophisticated performance of radical prostatectomy.

Flexible Robotic Retrograde Renoscopy: Description of Novel Robotic Device and Preliminary Laboratory Experience

OBJECTIVES To describe a novel flexible robotic system for performing retrograde intrarenal surgery. METHODS Remote robotic flexible ureterorenoscopy was performed bilaterally in 5 acute swine (10 kidneys). A novel 14F robotic catheter system, which manipulated a passive optical fiberscope mounted on a remote catheter manipulator was used. The technical feasibility, efficiency, and reproducibility of accessing all calices were assessed. Additionally, laser lithotripsy of calculi and laser ablation of renal papillae were performed. RESULTS The robotic catheter system could be introduced de novo in eight ureters; two ureters required balloon dilation. The ureteroscope could be successfully manipulated remotely into 83 (98%) of the 85 calices. The time required to inspect all calices within a given kidney decreased with experience from 15 minutes in the first kidney to 49 seconds in the last (mean 4.6 minutes). On a visual analog scale (1, worst to 10, best), the reproducibility of caliceal access was rated at 8, and instrument tip stability was rated at 10. A renal pelvic perforation constituted the solitary complication. Histologic examination of the ureter showed changes consistent with acute dilation without areas of necrosis. CONCLUSIONS A novel robotic catheter system is described for performing retrograde ureterorenoscopy. The potential advantages compared with conventional manual flexible ureterorenoscopy include an increased range of motion, instrument stability, and improved ergonomics. Ongoing refinement is likely to expand the role of this technology in retrograde intrarenal surgery in the near future.

Real-Time Transrectal Ultrasound Guidance During Nerve Sparing Laparoscopic Radical Prostatectomy: Pictorial Essay

PURPOSE We report that real-time TRUS can visualize prostate/periprostatic anatomy and provide intraoperative navigation during nerve sparing LRP. Real-time TRUS navigation during radical prostatectomy, whether open or laparoscopic, is a novel application about which little is known. MATERIALS AND METHODS Transperitoneal LRP with TRUS guidance has been performed in 77 consecutive men since March 2003. Gray-scale ultrasound (7.5 MHz) and power Doppler ultrasound were used. Real-time TRUS monitoring was performed preoperatively, intraoperatively and immediately postoperatively. Emphasis was placed on identifying the neurovascular bundles, defining the prostate apex contour and evaluating the location and extent of any hypoechoic cancer nodules. RESULTS Intraoperative TRUS navigation appeared to be helpful for certain specific technical aspects of LRP, including 1) the identification of hypoechoic prostate cancer nodules, 2) precision during lateral pedicle transection and neurovascular bundle release, 3) calibrated, wider dissection at the site of suspected extracapsular extension of cancer nodules to achieve negative margins, 4) tailored dissection according to the individual prostate apex and (5) facilitation of posterior bladder neck transection for the novice. Real-time TRUS monitoring of the location of the laparoscopic scissors tip (hyperechoic spot) in regard to the safe dissection plane at the concerned anatomical site was feasible. Blood flow in the neurovascular bundles before, during and after nerve sparing LRP was documented. CONCLUSIONS Real-time rectum based monitoring such as TRUS navigation has the potential to enhance intraoperative surgical precision during LRP. A pictorial essay highlighting the various aspects of intraoperative TRUS is presented.

Third Prize: Synchronized Real-Time Ultrasonography and Three-Dimensional Computed Tomography Scan Navigation During Percutaneous Renal Cryoablation in a Porcine Model

AIM To investigate the accuracy of percutaneous cryoablation for kidney tumors performed under combined real-time ultrasonography (US) and three-dimensional (3D) CT scan navigation in a porcine model. MATERIALS AND METHODS After percutaneously injecting 2 to 6 tumor mimic lesions in 11 pigs, a CT scan was performed and digital data were saved into a navigation system (Real-Time Virtual Sonography [RVS]) that allows 3D reconstruction and synchronization with real-time US images. The cryoprobe was guided percutaneously into the kidney tumor mimic, and ice ball formation was monitored continuously during cryoablation using the RVS system. Kidneys were harvested and sent for gross pathologic and histopathologic analysis at days 0, 15, and 30 postoperatively. RESULTS Thirty-five renal tumor mimics were created and treated by percutaneous cryotherapy; tumor mimic locations were as follows: 16 tumors (46%) in the lower pole, 14 (40%) in the central region, and 5 (14%) in the upper pole. Eleven tumor mimics (31%) were intraparenchymal, and 24 (69%) subcapsular. The synchronization between the CT scan 3D reconstructed images and real-time US was successful in all cases. The mean tumor size was 2 cm (range, 1.2-4 cm). Mean cryonecrosis size was 3.3, 3.7, and 2.8 cm at days 0, 15, and 30, respectively. Three (8.5%) positive margins were found on the macroscopic and microscopic analysis. CONCLUSIONS RVS imaging system synchronizing real-time US with preoperative CT scan is a feasible and safe technique for percutaneous probe ablation of kidney tumors.

Efficacy of a Novel Device for Assessment of Autonomic Sensory Function in the Rat Bladder

PURPOSE We developed and tested the efficacy of an implantable bladder device which, when combined with the Neurometer, can be used to assess fiber specific afferent bladder sensation in the rat. MATERIALS AND METHODS We developed an implantable bladder device that applies selective nerve fiber stimuli (250 Hz for small myelinated Adelta fibers and 5 Hz for unmyelinated C fibers) to the bladder mucosa in the rat to determine bladder sensory perception threshold values. We performed 3 experiments in 55 female Sprague-Dawley rats to examine the effects of our device on voiding habits, assess the interobserver reliability of the sensory perception threshold and determine the effects of intravesical administration of resiniferatoxin (Sigma) and lidocaine on the sensory perception threshold. RESULTS Sensory perception threshold values obtained by 2 blinded, independent observers were not different from each other (p = 0.41). Sensory perception threshold values obtained at the 2 stimulation frequencies remained constant for at least 3 weeks after device implantation. A significant increase in sensory perception threshold values after resiniferatoxin instillation was noted at a stimulus frequency of 5 Hz (p = 0.02), whereas intravesical lidocaine led to an immediate increase in the sensory perception threshold at 250 and 5 Hz. Device implantation led to an early decreased voided volume and increased frequency of voids, although these parameters returned to normal after 4 days. CONCLUSIONS Assessment of bladder afferent sensation with our newly developed device is feasible in rats. It provides sensory perception thresholds that appear to be fiber-type selective for autonomic bladder afferent nerves.

Management of the En Bloc Distal Ureter and Bladder Cuff During Retroperitoneoscopic Radical Nephroureterectomy

Radical nephroureterectomy with resection of the en bloc distal ureter and bladder cuff is the gold standard treatment option for most patients with upper urinary tract transitional cell carcinoma (TCC). Recurrence at the distal ureter and/or peiureteral bladder mucosa in the presence of ipsilateral upper urinary tract urothelial carcinoma has clinical significance. This procedure involves radical nephrectomy and en bloc distal ureterectomy with 2- to 3-cm-diameter bladder cuff, with special care to prevent urine spillage. We describe here our pure laparoscopic technique using two suprapubic transvesical ports, with cystoscopic secured detachment and ligation of the en bloc bladder cuff and juxtavesical ureter. This laparoscopic technique duplicates established principles of open radical nephroureterectomy.