Courtney K. Phillips

Robot Assisted Laparoscopic Partial Nephrectomy: Initial Experience

PURPOSE Advances in laparoscopy have made laparoscopic partial nephrectomy a technically feasible procedure but it remains challenging to even experienced laparoscopists. We hypothesized that robotic assisted laparoscopic partial nephrectomy may make this procedure more efficacious than the standard laparoscopic approach. MATERIALS AND METHODS Ten patients with a mean age of 58 years and mean tumor size of 2.0 cm underwent robotic assisted laparoscopic partial nephrectomy and another 10 with a mean age of 61 years and mean tumor size of 2.18 cm underwent laparoscopic partial nephrectomy, as performed by a team of 2 surgeons (MS and ST) between May 2002 and January 2004. Demographic data, intraoperative parameters and postoperative data were compared between the 2 groups. RESULTS There were no significant differences in patient demographics between the 2 groups. Intraoperative data and postoperative outcomes were statistically similar. In the 10 patients who underwent robotic assisted laparoscopic partial nephrectomy there were 2 intraoperative complications. There was 1 conversion in the laparoscopic partial nephrectomy group. CONCLUSIONS Robotic assisted laparoscopic partial nephrectomy is a safe and feasible procedure in patients with small exophytic masses. The robotic approach to laparoscopic partial nephrectomy does not offer any clinical advantage over conventional laparoscopic nephrectomy.

Tissue Response to Surgical Energy Devices

OBJECTIVES There is little data available on the effects of energy-based surgical devices (ESD) on tissues other than arteries and veins. As such, we quantified the lateral thermal damage associated with contemporary ESD: the Harmonic ACE, a prototype bipolar device known as the Gyrus Trisector, the Harmonic LCS-C5, and the LigaSure V. METHODS We divided 24 domestic pigs into 4 groups, 1 group for each ESD tested. Segments of bladder, stomach, small bowel, colon, ureter, peritoneum, arteries, and veins were exposed to each ESD. The tissues were stained with hematoxylin and eosin and evaluated by an experienced pathologist to quantitate the lateral energy spread associated with each device. We measured blade temperatures of each device using the IR-Flex thermal camera. RESULTS The Trisector developed the lowest mean blade temperature (97.84 degrees F), whereas the LigaSures was the second lowest (103.14 degrees F). The ACE and LCS-C5 created the highest blade temperatures, measuring 220.5 degrees F and 205.6 degrees F, respectively. The Trisectors mean full thickness and superficial lateral energy damage were 6.3 mm and 7.0 mm, respectively, whereas the Ligasures was 4.5 mm and 5.9 mm, respectively. For the ACE, however, mean full thickness and superficial energy spread were 2.4 mm and 2.8 mm, respectively, whereas the LCS-C5s were 3.1 mm and 4.3 mm, respectively. CONCLUSIONS The Harmonic ACE and LCS-C5 produced the least thermal damage in the tissues tested. ESD-associated tissue energy damage is not directly related to blade temperature, but is likely the result of several factors including blade temperature, transection time, tissue properties, and the vascularity of each transected tissue.

A matched‐cohort comparison of laparoscopic cryoablation and laparoscopic partial nephrectomy for treating renal masses

To compare the surgical outcomes of elderly patients with renal masses treated with laparoscopic partial nephrectomy (LPN) or laparoscopic cryoablation (LCA).

First Prize (Tie): Laparoscopic Renal Cryoablation: Efficacy and Complications for Larger Renal Masses

BACKGROUND AND PURPOSE In expanding our indications for cryoablation of renal cortical neoplasms, there was an increased morbidity with laparoscopic cryoablation. As such, we evaluated our single institution experience with laparoscopic renal cryoablation for complications and oncologic effectiveness as a function of tumor size. MATERIALS AND METHODS We retrospectively evaluated our prospectively established urologic oncology database and identified 44 laparoscopic cryoablation procedures performed for the management of 51 renal masses. Measured parameters included patient age, tumor size and location, estimated blood loss, complications, and recurrences. Patients were stratified into two groups. In group 1, the patients presented with a maximum tumor diameter less than 3.0 cm. Group 2 patients had a maximum tumor diameter of 3.0 cm or larger. RESULTS Group 1 included 30 tumors in 23 patients, and group 2 had 21 tumors in 21 patients. The mean tumor size for groups 1 and 2 were 1.8 cm (range 0.7 to 2.8 cm) and 4.0 cm (range 3.0 to 7.5 cm), respectively (P < 0.0001). The average patient age for group 1 was 70.2 and group 2 was 77.6 years (P = 0.04). The mean American Society of Anesthesiologists score was 1.8 and 2.1 for groups 1 and 2, respectively (P = 0.06). There were no complications in group 1. Group 2 had 13 (62%) complications, including two mortalities. The most common complication was blood transfusions at 38%. With a mean follow-up of 9 months, there were no recurrences in group 1. With a mean follow-up of 11 months, there was a single (4.8%) recurrence in group 2. Biopsy histopathology revealed renal cell carcinoma variants in 46.7% in group 1 and 66.7% in group 2, respectively (P = 0.079). CONCLUSION Renal cryoablation of renal cortical neoplasms smaller than 3.0 cm is effective and safe. Our initial experience, however, demonstrates that cryoablation of larger renal masses may be associated with increased morbidity.

Prospective Randomized Comparison of a Combined Ultrasonic and Pneumatic Lithotrite with a Standard Ultrasonic Lithotrite for Percutaneous Nephrolithotomy

PURPOSE To compare the efficiency and cost effectiveness of a combined pneumatic and ultrasonic lithotrite (Lithoclast Ultra) and a standard ultrasonic lithotrite, (LUS-1) during percutaneous nephrolithotomy. MATERIALS AND METHODS In a prospective randomized trial, 30 patients undergoing percutaneous nephrolithotomy (PCNL) were randomized to PCNL with either the combined pneumatic and ultrasonic lithotrite (PUL) or a standard ultrasonic lithotrite (SUL). Patient demographics, stone composition, location, pre- and post-operative stone burden, fragmentation rates, and device failures were compared. RESULTS There were 13 patients in the PUL group and 17 patients in the SUL group. Stone burden and location were equal. Overall, 64% of the PUL group had hard stones (defined as stones that were either pure or a mixture of cystine [3], calcium oxalate monohydrate [CaOxMono; 2], and calcium phosphate [CaPO4; 2]), and four had soft stones (3 struvite and 1 uric acid [UA]). In the SUL group, there were eight hard stones (5 CaOxMono and 3 CaPO4), and six soft stones (4 calcium oxalate dihydrate [CaOxDi] and 2 UA) (P = 0.51). Stone composition data were unavailable for five patients. Fragmentation time for the PAL was 37 minutes versus 31.5 minutes for the SUL (P = 0.22). Stone retrieval and mean operative times were similar for both groups. There were a total of three (23.1%) device-related problems in the PUL group, and eight (47%) in the SUL group. There was one (7.7%) device malfunction in the PUL group due to probe fracture. There were two (11.7%) device failures in the SUL group; one failure required the device to be reset every 30 minutes, and the second was an electrical failure. Suction tubing obstruction occurred twice (15.3%) in the PUL group and 35.3% in the SU group (P = 0.35). The stone-free rates for the PUL and SUL were 46% and 66.7%, respectively (P = 0.26). CONCLUSION Although the PUL was more costly, stone ablation and clearance rates were similar for both the combined pneumatic and ultrasonic device and the standard ultrasonic device. When stratified with respect to stone composition, the PUL was more efficient for harder stones, and the SUL was more efficient for softer stones.

Risk factors associated with renal parenchymal fracture during laparoscopic cryoablation

To assess the risk factors for haemorrhage and renal fracture associated with renal cryoablation.

Pilot study evaluating ureteric physiological changes with a novel ‘ribbon stent’ design using electromyographic and giant magnetoresistive sensors

To test a novel ‘ribbon stent’ (RS) design using an extraluminal bipolar electromyographic (EMG) and giant magnetoresistive (GMR) sensor system to characterize ureteric responses.

Lasers in the upper urinary tract for non-stone disease

Though the most common use for lasers in the genitourinary tract is for urolithiasis, a number of other urologic conditions can be treated with lasers because of their unique ablative, destructive and hemostatic properties. This paper reviews the advantages and disadvantages of laser technology for a number of non-stone indications.

Evaluation of a Novel Temperature-Sensitive Polymer for Temporary Ureteral Occlusion

PURPOSE Proximal stone migration during ureteroscopic procedures increases operative time and risk. This study was designed to evaluate the ability of a new temperature-sensitive polymer to prevent proximal stone migration during ureteroscopic procedures. MATERIALS AND METHODS Porcine urinary systems were harvested en bloc. The volume of gel needed to occlude the ureter, time to achieve a solid state, length of ureter filled, and pressure needed to dislodge the gel from the ureter were recorded. Radio opacity of the polymer was evaluated. Endoscopic laser lithotripsy was the performed after deploying the urologic polymer, and, after gel application and stone manipulation, all ureters were examined for histologic changes. RESULTS At 36.7 degrees C, 0.5 mL and 1 mL of polymer sufficiently occluded the ureter. Both amounts solidified in 25 to 40 seconds. The mean length of ureter occluded was 56.3 mm, and the mean pressure needed to dislodge the polymer was 159.2 mm Hg. The polymer was radiopaque and did not cause histologic alterations in the ureter. Proximal migration of stone fragments was not observed during any of the procedures performed. CONCLUSIONS Our in vitro study indicates that this radiopaque, thermosensitive polymer is able to transiently occlude the ureter without damaging the urothelium while withstanding the pressure of ureteroscopic irrigation, stone motion, and laser energy.

The effect of intraluminal content on the bursting strength of vessels ligated with the harmonic ACE and LigaSure V.

PURPOSE Energy-based surgical devices (ESDs) are critical for maintaining hemostasis during laparoscopy; however, there are no studies that have evaluated the function of ESDs under different physiologic conditions. We evaluated the effect of intraluminal vessel content on bursting pressure (BP) after ligation with two ESDs: the Harmonic ACE and the LigaSure V. MATERIALS AND METHODS Bursting trials were performed on the vasculature of 24 pigs. Blood vessels were distended with blood of different hematocrit concentrations or an albumin solution of varying protein content. The vessel size and BP of each vessel was recorded after ligation with each ESD. RESULTS In arteries 0 to 3 mm and veins 0 to 3 mm in size ligated with the Harmonic ACE or the LigaSure V, there were significantly elevated vessel BPs with supraphysiologic intraluminal hematocrits. In arteries and veins ligated with the Harmonic ACE, increasing albumin concentrations also led to increasing BPs, though these maximal BPs were lower than those obtained with supraphysiologic hematocrit levels. Increasing albumin concentrations did not increase the BP of the LigaSure V. Within the ranges tested, there was no decrease in vessel BP associated with anemia. CONCLUSION In small vessels, a supraphysiologic hematocrit increased the BP of both arteries and veins when using the Harmonic ACE or the LigaSure V. With the devices tested, anemia did not seem to affect BP. While factors such as intraluminal protein concentration may play a role with ultrasonic energy devices, the mechanism of the increased BP remains unclear. Better understanding of ESDs will help in the design of future devices.