Comparison of a novel endoscope holder and traditional camera assistant for laparoscopic simple nephrectomy in a porcine model.

PURPOSE: To establish the feasibility of single-surgeon laparoscopy with application of a novel endoscope-holder device and to compare this technique with traditional assistant-driven laparoscopic camera control. MATERIALS AND METHODS: Bilateral simple nephrectomies were performed in six pigs. On one side, the operating surgeon employed the "scope holder" and performed the surgery without a laparoscopic assistant. On the contralateral side, an experienced camera operator was responsible for control of the laparoscopic field of vision in the traditional manner. The time required for hilar ligation and complete renal mobilization was documented. Pigs were sacrificed immediately after the procedure. RESULTS: The mean operative times for scope-holder and camera person-assisted nephrectomy were 20.7 minutes and 19.3 minutes, respectively. The time to hilar ligation in the scope-holder and camera-operator-assisted cohorts was 13 and 14.5 minutes, respectively. There were no significant differences in operative times or blood loss in the two groups. The operative surgeon perceived some increase in shoulder and neck pain with use of the scope holder. CONCLUSIONS: This novel device provides a means for the operative surgeon to safely perform a laparoscopic nephrectomy alone without significantly increasing operative time or morbidity.

Comparison of renal ablation with cryotherapy, dry radiofrequency, and saline augmented radiofrequency in a porcine model.

BACKGROUND: Needle ablative therapy has recently generated a lot of interest in the urologic community. We compare renal lesions produced in a porcine model using three forms of needle ablative energy: cryoablation (CR), dry radiofrequency (RF), and saline augmented radiofrequency (SARF). STUDY DESIGN: In 10 farm pigs, under ultrasonographic guidance, 40 laparoscopic renal lesions were produced: 825-mm CR lesions were produced with 2.4-mm cryoprobes (Endocare Inc, Irvine, CA), after 1-mL preinfusions of 14.6% saline, 12 SARF lesions were created with 22-gauge needles (2 mL/minute 14.6% saline, 50 W 510 kHz RF for 60 seconds), 12 RF lesions were created with a 2-cm array LeVeen electrode and an RF2000 generator using impedance limited 30 to 60 W double activations (Radiotherapeutics Corp, Mountain View, CA), and 8 RF lesions were produced using 22-gauge needles and double 10 W activations with the RF2000 generator. Eight animals were sacrificed after 1 week for acute pathology. An additional two animals were sacrificed at 8 weeks to provide chronic pathology results for the LeVeen dry RF and SARF modalities. RESULTS: CR produced a regular 18- to 22-mm zone of complete necrosis bordered by a 1.5- to 2.5-mm zone of partial necrosis. Acutely, LeVeen RF and single-needle RF produced lesions 25 to 45 mm and 6 to 10 mm wide, respectively. Acutely, SARF produced irregular cone-shaped lesions 15 to 31 mm wide. Only one of eight acute LeVeen RF lesions showed complete necrosis; none of the four 8-week LeVeen RF lesions displayed complete necrosis. Two of the four 8-week SARF lesions displayed complete necrosis. The remainder of the LeVeen RF, single-needle RF, and SARF lesions showed early, indeterminate tubular damage with relative glomerular sparing and bands of complete necrosis (0.5 to 1.5 mm) and inflammation (0.5 to 2 mm) at the periphery. Only CR could be consistently monitored with laparoscopic ultrasonography. CONCLUSIONS: Renal cryoablation produces well-defined, completely necrotic lesions that can be monitored reliably with ultrasonography. Longer followup may be required to characterize the full extent of renal necrosis produced by RF, but in the short run, none of the RF modalities reliably produced 100% necrosis in all cases.

Assessment of optimal balloon size for rupture of the ureteropelvic junction and mid-ureter in a porcine model.

PURPOSE: Balloon dilation potentially represents a safer and simpler technique for the treatment of ureteropelvic junction (UPJ) obstruction and ureteral strictures. Using a porcine model, we sought to establish the optimal balloon size for endoballoon rupture of the UPJ and ureter. MATERIALS AND METHODS: The efficacy of endoballoon rupture of the proximal and middle ureter with 24F, 30F, and 36F balloon catheters was compared in 19 female minipigs. At the proximal ureter, the effect of the rate of dilation also was evaluated for each balloon size. Extravasation of methylene blue-stained contrast material was assessed with retrograde pyelograms and direct laparoscopic vision. After acute sacrifice, the dilated segments were evaluated histologically with hematoxylin and eosin and Masson's trichrome staining. RESULTS: At the proximal ureter, free extravasation of contrast was observed in 61% of the rapid inflation and 72% of the slow inflation trials; contained extravasation was noted in 28% of the rapid inflation and 17% of the slow inflation trials. Except for two of the 24F slow inflation trials, all of the proximal ureteral trials produced at least one full-thickness tear into the periureteral fat. Grossly, the tears appeared linear with various lengths and no consistent orientation. Rapid inflation and increasing balloon size tended to produce a ureterotomy with less damage to the ureter surrounding the tear. At the mid-ureter, none of the balloon sizes consistently produced a transmural tear. CONCLUSIONS: Rapid dilation and use of a 36F balloon capable of maintaining a low profile after inflation may result in a cleaner proximal ureterotomy with less distortion of the untorn neighboring proximal ureter. Both 36F and 30F balloons consistently produced a full-thickness proximal ureterotomy in normal porcine tissue. For mid-ureteral strictures, balloon dilation to even 36F may fail to create a suitable ureterotomy. However, it must be noted that dysplastic or scarred tissue may respond differently to dilation than the more elastic normal porcine tissues used in this study.

Laparoscopic renal ablation: an in vitro comparison of currently available electrical tissue morcellators.

OBJECTIVES: Morcellation with the Cook high-speed electrical laparoscopic (HSEL) morcellator in an impermeable nylon/plastic sack (LapSac) has remained unchanged since its inception nearly one decade ago. Sack deployment and specimen entrapment remain relatively difficult, and morcellation with this device is expensive and relatively slow. As such, in an effort to facilitate specimen entrapment and morcellation, we adapted two currently available electrical morcellators (the Steiner gynecologic morcellator and the electrical prostate morcellator [EPM]) for renal morcellation and compared them with the HSEL morcellator. METHODS: All morcellation was performed through a simulated abdominal wall under direct laparoscopic vision. Ten porcine kidneys were ablated with each of the following techniques: HSEL morcellation in a LapSac; HSEL morcellation in a fluid-filled LapSac; Steiner morcellation in an insufflated Endocatch sack; and EPM morcellation in a fluid-filled Endocatch sack. A modified laparoscopic trocar was constructed and used for the Steiner and EPM morcellation. The time to complete morcellation, morcellation product size, and entrapment sack integrity were evaluated for each technique. Cost data for each morcellator are also presented. RESULTS: The mean morcellation time for the Steiner, HSEL dry, HSEL wet, and EPM morcellation was 6.0, 15.9, 14.7, and 26.0 minutes, respectively. The mean fragment size for these morcellators was 2.97, 0.65, 0.62, and 0.013 g, respectively. A single entrapment sack perforation was documented in a LapSac during routine HSEL morcellation. CONCLUSIONS: Renal morcellation with all three morcellators is feasible. The Steiner morcellator combined with an Endocatch resulted in more rapid morcellation and larger morcellation products.

Laparoscopic nephropexy: long-term follow-up--Washington University experience.

BACKGROUND AND PURPOSE: Recently, laparoscopy has been reported as a minimally invasive approach for performing nephropexy in patients with symptomatic nephroptosis. Herein, we report our long-term follow-up of patients undergoing laparoscopic nephropexy for this indication. PATIENTS AND METHODS: Fourteen women presenting with right flank pain and radiologically documented nephroptosis underwent transperitoneal laparoscopic nephropexy. The hospital data were evaluated for operative time, time to oral intake, time to ambulation, amount of parenteral analgesics, and hospital stay. Pain analog scores and postoperative questionnaires were used to assess the long-term postoperative recovery of the patients. RESULTS: The average operative time was 4.1 hours (range 2.5-6.5 hours). The patients resumed oral intake an average of 16.5 hours (range 15-48 hours) postoperatively. Analgesic requirements averaged 37 mg of morphine sulfate equivalent (range 15-80 mg of morphine equivalent). The average hospital stay was 2.6 days (range 2-5 days). The average follow-up time for the 14 patients was 3.3 years, with an average 80% improvement in their pain (range 56%-100%). On average, the patients resumed their usual activities 6 weeks postoperatively (range 1-12 weeks). CONCLUSION: Nephropexy can be safely and effectively accomplished laparoscopically, with durable radiographic and clinical resolution of the signs and symptoms.