Faculty Bibliography

OBJECTIVE To assess a prototype ureteric 'buoy' stent with a 10 F upper body tapering to a 3F tail, developed to potentially reduce stent-related irritative symptoms while providing an adequate mould for healing after endopyelotomy. MATERIALS AND METHODS Eighteen Yucatan minipigs had the stent placed either into the intact ureter (phase I) or after Acucise proximal endoureterotomy (phase II). Buoy stents were compared to 10/7 F endopyelotomy stents and to standard 7 F stents in phases I and II, respectively. The pigs were assessed for vesico-ureteric reflux, hydronephrosis and infection, before stent insertion and at harvest. Stents were weighed before and after placement and the removal force was measured. Pressure/flow studies, antegrade nephrostograms and specimens for histopathology from the renal pelvis, ureter and vesico-ureteric junction (VUJ) were obtained at harvest. RESULTS Thirteen minipigs survived the entire study. Ureteric flow with the stents in situ was better for buoy stents than for 10/7 F stents (P < 0.005). Ureteric flow after endoureterotomy and subsequent stent removal was similar for buoy stents and standard 7 F stents. None of the stents refluxed. There was no difference between stents in removal force, weight change or incidence of hydronephrosis. At 1 and 12 weeks, buoy stents tended to produce lower histopathological alteration scores than control stents, especially at the VUJ (phase I, 2.0 vs 3.9, P = 0.092; phase II, 0.6 vs 1.7, P = 0.18). CONCLUSIONS The novel buoy stents are easily placed and removed via the urethra. They can cause less VUJ inflammation than standard stents while allowing for adequate ureteric flow and healing after proximal endoureterotomy.

INTRODUCTION: Bowel injury is an uncommon, although potentially devastating, intraoperative laparoscopic complication. Questions have been raised about the possible use of a tissue adhesive to repair injured bowel. We compared glued repair and sutured repair of both large bowel (LB) and small bowel (SB) electrosurgical injuries in a rabbit model. METHODS: Pneumoperitoneum was obtained, and four laparoscopic ports were placed in each of 48 New Zealand rabbits. The hook electrode was used in a specified manner to create an equal number of uniform full-thickness injuries to either the SB or the LB. Laparoscopic repair was performed with a 3-0 silk Lembert suture (LS), fibrin glue (FG), or BioGlue (BG), or repair was not performed (i.e., no repair, NR); the animals were monitored for 3 weeks. Adverse clinical outcomes and findings at laparotomy were recorded. Pathologic assessment included an objective scaled evaluation of the intensity of the inflammatory response and degree of healing. RESULTS: In the SB injury group, deteriorating clinical condition necessitated early euthanasia in one animal repaired with FG, one animal repaired with BG, and two animals with NR. LS repair animals had no adverse clinical outcomes. The LB injury group had no adverse clinical outcomes regardless of the method of repair, including the control group. Of the animals that survived for 3 weeks, the animals repaired with BG had more intraabdominal adhesions (100%) than LS (33%), FG (55%), and NR (50%) (p = 0.001). The pathologic assessment revealed that BG induced a more intense inflammatory response (p < 0.05). CONCLUSION: In the rabbit, suture repair of an electrosurgical SB injury appears to have improved outcomes when compared with a glued repair. In contrast, LB injury responded well to any form of treatment. The data suggest that suture is superior to biological glues when dealing with a laparoscopic electrosurgical bowel injury.

PURPOSE: Sealing the lymphatic vessels during abdominal and pelvic surgery is important to prevent the leakage of lymphatic fluid and its resultant sequelae. To our knowledge we compared for the first time the quality of lymphatic sealing by each of 4 commonly used laparoscopic dissection devices. MATERIALS AND METHODS: A total of 12 domestic pigs were used to test dissecting devices, including monopolar scissors (Ethicon Endo-Surgery, Cincinnati, Ohio), Harmonic ACE Scalpel, LigaSure V, EnSeal and Trissector. A midline incision was made from mid sternum to umbilicus, the diaphragm was divided and the porcine thoracic duct was isolated. In all animals each device was used to seal an area of the duct and each seal was placed at least 2 cm from the prior seal. In group 1 the thoracic duct of 6 pigs was cannulated with a 5Fr catheter and the seal was subjected to burst pressure testing using a burst pressure measuring device (Cole-Parmer, Vernon Hills, Illinois). In the 6 pigs in group 2 each seal was immediately sent for histopathological evaluation. Specimens were given a score for the extent of cautery damage, including 0-none, 1-minimal, 2-moderate, 3-severe and 4-extreme. RESULTS: A total of 64 seals were created, of which 35 were subjected to burst pressure testing. Mean size of the thoracic duct was 2.6 mm. No acute seal failures were observed with any bipolar device or the harmonic shears. However, 2 immediate failures (33%) were seen with monopolar scissors. Mean burst pressure for monopolar scissors, Harmonic ACE Scalpel, LigaSure V, EnSeal and Trissector was 46 (range 0 to 165), 540 (range 175 to 795), 258 (range 75 to 435), 453 (range 255 to 825) and 379 mm Hg (range 175 to 605), respectively (p <0.05). Trissector, Harmonic ACE Scalpel and EnSeal generated seals with significantly higher burst pressure than that of monopolar scissors (p <0.05). Histopathological evaluation revealed that LigaSure caused less thermal damage than Trissector and EnSeal (p <0.05). CONCLUSIONS: Each device tested except monopolar scissors consistently produced a supraphysiological seal and should be suitable for sealing lymphatic vessels during laparoscopic surgery.

BACKGROUND AND PURPOSE: There have been several reports of rhabdomyolysis occurring after prolonged laparoscopic procedures in the flank position. Accordingly, we evaluated interface pressures between the skin and three commonly used operating room table surfaces. The aim of our study was to determine if pressure changes could be related to body mass index (BMI), sex, position, and/or the table surface material. PATIENTS AND METHODS: Ten men and 10 women were grouped according to BMI <25 or >or=25, with five participants in each group. Subjects were placed in the left lateral decubitus position with the operating table flat, half flexed, fully flexed, half flexed with the kidney rest elevated, and fully flexed with the kidney rest elevated. Interface pressures were recorded, using an X-Sensor pressure sensing mat, for 5-minute periods in each of the described positions on each surface. RESULTS: Sex and BMI were statistically significant predictors of increased pressures (P= 0.0042 and 0.0402, respectively). The parameter estimate for the difference between men and women was 4.63 mm Hg (P= 0.0002), and the difference for BMI >or= 25 compared with <25 was also significant (P < 0.0209). Full table flexion (50-degree) produced significantly higher pressures than both flat (P= 0.0001) and the half-flexed (25-degree) position (P < 0.0001). Positions with the kidney rest elevated were associated with significantly higher pressures than without elevation (P < 0.0001). With regard to the surface used, egg crate provided lower pressures than gel pads (P= 0.0117). CONCLUSION: Women have significantly lower interface pressures when compared with men. BMI >or= 25 also increases interface pressures. The use of the kidney rest is associated with markedly increased pressure; use of a half-flexed position is preferable to a full-flexed position. These data have implications for patient positioning and identification of persons at risk for rhabdomyolysis during laparoscopic renal surgery.

PURPOSE: Laparoscopic partial/wedge nephrectomy, similar to laparoscopic radical prostatectomy, is a technically challenging procedure that is performed by a limited number of expert laparoscopic surgeons. The incorporation of a robotic surgical interface has dramatically increased the use of minimally invasive pelvic surgery such that robotic laparoscopic radical prostatectomy is commonly performed even by laparoscopically naive surgeons. This analysis compares the outcomes of our initial experience with robot-assisted laparoscopic partial nephrectomy (RLPN) performed by an experienced open surgeon to that of standard laparoscopic partial nephrectomy (LPN) performed by two experienced laparoscopic surgeons. PATIENTS AND METHODS: We reviewed the medical records of 11 consecutive patients who underwent 12 standard LPNs (EMM, RVC) (one patient had two unilateral tumors) and 10 consecutive patients (representing the first 11 of such robotic procedures performed at our institution) who underwent 11 RLPNs (one patient had bilateral tumors managed in an asynchronous manner) (DKO). RESULTS: The mean tumor size was 2.3 cm (range 1.7-6.2 cm) for LPN and 3.1 cm (range 2.5-4 cm) for RLPN. The mean total procedure time was 289.5 minutes (range 145-369 min) for LPN and 228.7 minutes (range 98-375 min) for RLPN (P=0.102). The mean estimated blood loss was 198 mL (range 75-500 mL) for LPN v 115 mL (25-300 mL) for RLPN (P=0.169). The mean warm ischemia time was 35.3 minutes (range 15-49 min) in the LPN group and 32.1 minutes (range 30-45 minutes) in the RLPN group (P=0.501). CONCLUSIONS: Introducing a robotic interface for laparoscopic partial/wedge resection allowed a fellowship-trained urologic oncologist with limited reconstructive laparoscopic experience to achieve results comparable to those for laparoscopic partial/wedge resection performed by experienced laparoscopic surgeons. In this regard, the learning curve appears truncated, similar to that with robot-assisted laparoscopic prostatectomy.

PURPOSE OF REVIEW: Concurrent with the rise of laparoscopic radical nephrectomy as the gold standard for managing renal cell carcinoma, awareness has increased regarding the value of nephron-sparing surgery, even in the presence of a normal contralateral kidney. Therefore, whereas fewer radical nephrectomies will be performed for T1a tumors, there is a move towards handling more advanced pathology laparoscopically; that is, very large tumors, T3b disease, and limited lymph-node involvement. This review will highlight the long-term outcomes and recent developments in laparoscopic radical nephrectomy reported over the past year. RECENT FINDINGS: There were several papers reiterating the excellent long-term outcomes of laparoscopic radical nephrectomy in the form of retrospective comparisons with cohorts of patients undergoing open radical nephrectomy. None of these studies demonstrated any differences in 5-year cancer-specific or overall survival. Surgeons continue to expand upon the current technique and indications. SUMMARY: Long-term studies repeatedly support the superiority of laparoscopic radical nephrectomy over open radical nephrectomy for the majority of renal cell cancers due to equivalent oncologic control, low morbidity and shorter convalescence time. Experienced surgeons are able to manage more advanced pathologies laparoscopically without compromising cancer control or patient safety.

PURPOSE: We compared healing after laparoscopic cystotomy using fibrin glue, sutures, or a combination to determine whether fibrin glue can obviate the need for sutures and whether there is any detriment when glue is used in the presence of sutures. MATERIALS AND METHODS: In 24 Yorkshire pigs, a 3.5 cm vertical cystotomy was created laparoscopically and repaired as follows: Group 1--no closure; group 2--fibrin glue closure; group 3--suture repair; group 4--combined fibrin glue and suture repair. All animals had a Foley catheter for 1 week. In each group, three animals were harvested at 1 week (acute) and three animals were harvested at 6 weeks (chronic). RESULTS: Acute: Group 1--all pigs had an unhealed defect that leaked when evaluated by cystography. Groups 2, 3, 4--mean leak pressures were 80, 97, and 60 cm H(2)O (P = 0.36), respectively. Mean bladder capacity was not significantly different between groups. Chronic: No leakage seen on a cystogram at 1 week; at 6 weeks, bladders were filled at > or =95 to 100 cm H(2)O without leakage. Histologically, there was more inflammation in the acute group v chronic group pigs. In the acute group pigs repaired with glue or suture + glue, there was more inflammation and less epithelial continuity than in the suture alone group. At 6 weeks, there was no difference between groups. CONCLUSION: Fibrin glue provoked an intense inflammatory response that might have delayed healing acutely, resulting in a lower burst pressure in both scenarios in which it was used (i.e., alone or in combination with sutures). However, by 6 weeks, there did not seem to be any difference between groups either clinically or histopathologically.