Nonischemic Laparoscopic Partial Nephrectomy Using a Novel Wet Monopolar Device in a Porcine Model (original) (raw)
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Urology, 2001
Objectives. Laparoscopic partial nephrectomy (LPN) has generally been reserved for small exophytic lesions because of the limited hemostatic capabilities when excising large segments of renal parenchyma. To overcome this problem, we investigated a technique of laparoscopic reversible, regional hypoperfusion using a cable-tie to minimize blood loss and optimize exposure. Methods. Ten domestic pigs underwent LPN after securing a cable-tie around one pole of the kidney and tightening it until the distal parenchymal surface blanched completely. Eight large amputations involving the collecting system and eight smaller amputations excluding the collecting system were performed using laparoscopic scissors. Fibrin glue was applied to seal the cut surface prior to cable-tie removal. Four pigs (4 large and 4 small amputations) were killed immediately and methylene blue was injected retrograde into the ureter to identify collecting system leaks. The remaining 6 pigs (4 large and 4 small amputations) were killed 4 weeks later and retrograde urograms were performed to assess collecting system integrity. Results. Median cable-tie ischemia time was 15 minutes (range 7 to 48) and median blood loss was 30 mL (range 10 to 300). In each case, hemostasis was attained with fibrin glue. In the survival group, all 4 small amputations healed with a fibrotic scar. In the large amputation group, 1 animal died from urinary extravasation on postoperative day 4. The collecting systems of the remaining 3 pigs sealed completely. Conclusions. In the porcine model, cable-tie-assisted LPN provides an almost bloodless surgical field that facilitates rapid resection of large renal segments and hemostasis during a short ischemic period. We anticipate that this technique will broaden the clinical application of LPN. UROLOGY 57: 562-566, 2001.
Journal of Endourology, 2011
Purpose: To test the viability of a new device to obtain hemostasis during laparoscopic partial nephrectomy (LPN) without vascular clamping. Materials and Methods: We performed a comparative experimental study between a new radiofrequency (RF)assisted device consisting of a handheld instrument that simultaneously conducts coagulation and cutting tasks without hilar clamping vs a standard technique with hilar clamping. A porcine model was used (10 animals per group) with survival of 17 days. Results: The estimated blood loss with the new device was significantly lower than with the standard technique (15.5-23.7 vs 79.4-76.3 mL). Although transection time was longer with the new device (10.7-13.7 vs 2.1-1.2 min), the total operative time was significantly shorter (35.3-13.7 vs 60.2-10.5 min). Evidence of localized urinary extravasation (urinoma) was identical in both groups (five cases). The group subjected to the new device, however, showed a significantly higher number of cases of leakage after conducting the methylene-blue test: eight (80%) cases vs only one (11%) with the standard technique. Necrosis depth was significantly greater with the new device (6.6-0.9 vs < 1 mm). Conclusions: The experimental results suggest that the proposed RF-assisted device provides adequate hemostatic control during transection of the renal parenchyma without additional instruments or surgical maneuvers and could therefore be a valuable adjunct for LPN without vascular clamping. The device was unsuccessful in effectively sealing the collecting system.
Urology, 2003
To report a novel method of accomplishing laparoscopic lower pole partial nephrectomy in an acute porcine model using a bipolar needle electrode without the need for renal arterial occlusion.Six animals (12 renal units) underwent laparoscopic polar nephrectomy using the bipolar needle electrode. After complete laparoscopic mobilization of the lower pole of the kidney, the bipolar needle electrode was repeatedly inserted full-thickness into the renal parenchyma and applied transversely, creating regional ischemia to the entire lower pole without renal vascular occlusion. The specimen was then amputated using laparoscopic scissors.For the 12 laparoscopic partial nephrectomies, the mean operative time was 39 ± 30 minutes, and the mean blood loss was 90 ± 112 mL. Of the 12 cases, 10 (83%) were performed successfully with the bipolar needle electrocautery as the only source of hemostasis and without the need for ancillary hemostatic measures. Two of the procedures (17%) required temporary arterial control for hemostasis. For the successful procedures, the mean operative time was 29 ± 4 minutes, and the mean blood loss was 48 ± 11 mL. Histologic analysis of the specimens demonstrated coagulative necrosis between 2 and 4 mm from the line of the surgical incision.Bipolar needle electrocautery is a promising device that can be used to facilitate laparoscopic partial nephrectomy with minimal blood loss and without the need for renal arterial occlusion and warm ischemia. Additional studies are required to optimize the delivery parameters of this device.
Hemostatic laparoscopic partial nephrectomy: cable-tie compression
Urology, 2001
Objectives. Laparoscopic partial nephrectomy (LPN) has generally been reserved for small exophytic lesions because of the limited hemostatic capabilities when excising large segments of renal parenchyma. To overcome this problem, we investigated a technique of laparoscopic reversible, regional hypoperfusion using a cable-tie to minimize blood loss and optimize exposure. Methods. Ten domestic pigs underwent LPN after securing a cable-tie around one pole of the kidney and tightening it until the distal parenchymal surface blanched completely. Eight large amputations involving the collecting system and eight smaller amputations excluding the collecting system were performed using laparoscopic scissors. Fibrin glue was applied to seal the cut surface prior to cable-tie removal. Four pigs (4 large and 4 small amputations) were killed immediately and methylene blue was injected retrograde into the ureter to identify collecting system leaks. The remaining 6 pigs (4 large and 4 small amputations) were killed 4 weeks later and retrograde urograms were performed to assess collecting system integrity. Results. Median cable-tie ischemia time was 15 minutes (range 7 to 48) and median blood loss was 30 mL (range 10 to 300). In each case, hemostasis was attained with fibrin glue. In the survival group, all 4 small amputations healed with a fibrotic scar. In the large amputation group, 1 animal died from urinary extravasation on postoperative day 4. The collecting systems of the remaining 3 pigs sealed completely. Conclusions. In the porcine model, cable-tie-assisted LPN provides an almost bloodless surgical field that facilitates rapid resection of large renal segments and hemostasis during a short ischemic period. We anticipate that this technique will broaden the clinical application of LPN. UROLOGY 57: 562-566, 2001.
Partial renal resection by LaparoNewPro: in vivo open and laparoscopic study in an animal model
Minimally invasive therapy & allied technologies : MITAT : official journal of the Society for Minimally Invasive Therapy, 2017
The aim of this research project was to test an incremental bipolar radiofrequency generator with open and laparoscopic inline electrode probe for partial renal resection without vascular clamping. Sixteen polar resections with clamping and six without were performed in four pigs in the acute phase. Three pigs underwent laparoscopic polar resection and were live housed for ten days and reoperated to verify the presence of hematic and urinary collection and the condition of the renal edge. Five pigs underwent laparoscopic polar resection without clamping, and two of these were live housed and reoperated after ten days. Polar renal resection by our system (LaparoNewPro) turned out to be effective and safe, without cardio-respiratory complications or damage to the remaining parenchyma. Coagulation of the renal parenchyma before resection is effective and safe; at the reoperation, no complications were observed. The laparoscopic version of the probe is ergonomic and safe, with effective...
A laparoscopic HIFU probe for kidney ablation prior to partial nephrectomy
2001 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.01CH37263), 2001
In an effort to reduce the complications associated with nephrectomy, high intensity focused ultrasound (HIFU) has been used to selectively ablate renal tissue prior to partial nephrectomy. To this end, a hand-held HIFU laparoscopic probe (OD=11mm) was developed. The probe consists of two focused rectangular HIFU piezoceramic transducers for side and front firing configurations. The probe was fully characterized for electrical impedances, acoustic fields, and total acoustic power outputs for both side and front transducers. It was then tested in an in vivo animal experimental study in which 5 pigs were treated through a sterile HIFU open surgery procedure. A cross-sectional disk-shaped coagulative lesion was induced in the lower pole of the right kidney in each animal. The average treatment time for an ablated volume of 20cc was approximately 45 minutes. Histopathology results demonstrated contiguous well-delineated necrosed lesions extending from the kidney's pelvic system to the capsule. Moreover, the histology results suggested that the tissue ablation was obtained through both thermal and mechanical mechanisms. The overall results suggest that the cross-sectional necrosed tissue volume effectively reduces blood loss during partial nephrectomy.
Journal of Endourology, 2009
Introduction: Laparoscopic partial nephrectomy has emerged as a standard of care for small renal masses. Nevertheless, there remains concern over the potential for irreversible insult to the kidney as a result of exposure to warm ischemia. We aim to investigate the utility of selective segmental arterial clamping as a means to reduce the potential for ischemic damage to a solitary kidney during laparoscopic partial nephrectomy utilizing a porcine model. Materials and Methods: A total of 20 domestic swine were randomized into four equal groups. Each subject underwent laparoscopic radical nephrectomy to create the condition of a solitary kidney. On the contralateral side, a laparoscopic lower pole partial nephrectomy was performed, employing either selective or nonselective vascular clamping for either 60 or 90 minutes. Postoperatively, clinical status and serial serum studies were closely monitored for 1 week. Results: There were no intraoperative complications. The 90-minute nonselective clamping produced devastating effects, resulting in rapid deterioration into florid renal failure within 72 hours. The 60-minute nonselective clamping group experienced modest but significant rises in both blood urea nitrogen and creatinine. Both 60-and 90-minute selective clamping groups performed well, with no significant rises in creatinine over a 7-day period, and no instances of renal failure. Conclusions: Selective arterial clamping is a safe and feasible means of vascular control during laparoscopic partial nephrectomy. In the porcine model, selective clamping appears to improve functional outcomes during prolonged periods of warm ischemic insult. Prospective evaluation of the technique in humans is necessary to determine if selective arterial control confers long-term functional benefits in patients with limited renal reserve.
Journal of Endourology, 2008
Purpose: Advances in the field of surgery have recently developed a number of devices and materials to improve surgical hemostasis. The effects of one such device, saline-cooled monopolar radiofrequency electrocautery, has been well scrutinized in splenic and hepatic applications. Despite the utilization of this device in urologic surgery, the classification of the thermal effects has been poorly characterized to date. The purpose of this study was to discern the thermal characteristics of the device in the laparoscopic environment when used on renal parenchyma. Materials and Methods: After institutional approval, four domestic swine were randomized to receive laparoscopic renal lesions randomly generated by either saline-cooled (25 W with saline flow rate of 4 mL/min) or standard monopolar radiofrequency electrocautery. The energy source was applied for between 1 and 11 seconds for each device in order to create a total of 64 renal lesions. Each kidney was harvested and examined by a genitourinary pathologist blinded to the treatment interval. Results: The saline-cooled device provided a greater depth of coagulation effect compared to standard monopolar electrocautery at all points in time (P Ͻ 0.05). The diameter of the lesions created using salinecooled monopolar electrocautery was greater than those created with standard electrocautery (P Ͻ 0.05). Conclusions: The saline-cooled monopolar electrocautery provided an improved coagulation effect compared to standard electrocautery in the laparoscopic setting. Recognition of the time and resultant thermal consequences can help the laparoscopic surgeon plan surgical approaches for renal lesions and improve hemostasis.
European Urology, 2007
Objective: To test the hypothesis that a modified technique for renal parenchymal closure during laparoscopic partial nephrectomy (LPN) enables a significant reduction in warm ischaemia (WIT). Methods: Perioperative factors including WIT were prospectively recorded during 40 consecutive LPNs performed by a single experienced laparoscopist. In the first 20 (controls), renal parenchyma was closed by conventional technique (haemostasis and closure of the collecting system with interrupted sutures, then closure of the renal parenchyma over a Surgicel bolster before unclamping the renal artery). In the second consecutive 20 patients (group 1), a modified closure technique was used, which involved earlier arterial unclamping after two (group 1a) or one (group 1b) running suture on the tumour bed. Vascularised renal parenchyma was then closed over a surgical bolster. Results: All LPNs were performed successfully without conversion. WIT was significantly less in group 1 compared with the control group (27.2 AE 5 min vs. 13.7 AE 4 min, respectively; p < 0.01). WIT was 16.8 AE 3.6 vs. 10.3 AE 1.2 min in groups 1a and 1b (p < 0.01); no other significant differences were observed in perioperative factors. All specimens had negative tumour margins histologically. Major complications and haemoglobin reduction were lower in group 1 compared with the control group. Conclusions: The described technique is effective and allows a significant reduction of WIT, even in challenging cases, without increasing perioperative bleeding or morbidity. Its use therefore reduces the need for hypothermic techniques, and allows more time for careful tumour resection and renal reconstruction.