Daniel S. Lehman

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.

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 Evaluation of Periureteral Botulinum Toxin Type A Injection for Ureteral Stent Pain Reduction

PURPOSE The use of ureteral stents for ureteral obstruction and after ureteroscopy can result in substantial deterioration in patient quality of life due to pain, frequency and urgency. We postulated that many stent related symptoms may be related to detrusor muscle spasm in and around the intramural ureter, and evaluated the effect of botulinum toxin type A (Botox) in patients with indwelling stents after ureteroscopy. MATERIALS AND METHODS A total of 51 patients between December 2007 and March 2009 were enrolled in an institutional review board approved, prospective, randomized, single-blind study comparing botulinum toxin type A injection at a concentration of 10 U/ml to 3 locations around the ureteral orifice (30) vs no injection after unilateral ureteral stent insertion (21). Pain and urinary symptoms after stent placement were evaluated through the Ureteral Stent Symptom Questionnaire, which was completed on postoperative day 7. In addition, patients were required to maintain a log of narcotic use after stent placement until removal. The Wilcoxon rank sum and Fisher exact tests were used for nonparametric and categorical data, respectively, with p <or=0.05 considered significant. RESULTS No complications or adverse events occurred in this study. There was a significant decrease in the reported postoperative pain score between the botulinum toxin type A and control group at 3.4 vs 6.0 (p = 0.02). Postoperative narcotic use was also significantly less in the botulinum toxin type A group at 7.7 pills during an average of 2.7 days vs 24.7 in an average of 7.0 days in control patients (p = 0.03). With respect to postoperative lower urinary tract symptoms there was no significant difference between cohorts using the individual index scores within the Ureteral Stent Symptom Questionnaire. Stent related emergency room visits were reported by 1 patient treated in the botulinum toxin type A group vs 2 in the control group. CONCLUSIONS Periureteral botulinum toxin type A injection improves ureteral stent tolerability by significantly decreasing postoperative pain and narcotic requirements. Improvement in irritative symptoms was not observed.

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.

Prospective Comparison of Flexible Fiberoptic and Digital Cystoscopes

OBJECTIVES To compare the optics, performance, and durability of digital (DC) and fiberoptic (FC) cystoscopes. METHODS In an office setting, we randomly assigned staff urologists to 1 of the 4 cystoscopes, the Gyrus-ACMI ICN-0564 (AD), Gyrus-ACMI ACN-2 (AF), Olympus CYF-V2 EndoEYE Cysto-Nephro Videoscope (OD), Olympus CYF-5 Cysto-Fiberscope (OF), to perform diagnostic or surveillance cystoscopy and stent removal. The documented metrics included a subjective surgeon assessment of cystoscope optics and function characteristics on a 10-point scale (1, poor to 10, excellent). The measurement of the upward and downward cystoscope deflection and damage and repairs were all documented. RESULTS A total of 1022 cases were performed. The DC and FC were used 690 and 332 times, respectively. Two repairs (0.2%) were documented (1 AF and 1 AD); both resulted directly from incorrect cystoscope handling/cleaning. The mean operative time per case for the DC and FC was 4.5 and 4.6 minutes, respectively (P = .66). The mean surgeon optical ranking for the DC and FC was 8.4 and 7.8, respectively (P = .0076). The mean surgeon deflection ranking for the DC and FC was 8.6 and 8.0, respectively (P = .0001). The mean surgeon retroflex deflection ranking for the DC and FC was 8.4 and 7.8, respectively (P = .001). The mean overall cystoscope score surgeon ranking for the DC and FC was 8.6 and 7.9, respectively (P = .0001). CONCLUSIONS In the office setting, with proper care, FCs and DCs are durable for office applications. Overall, surgeons significantly preferred the DCs as demonstrated by discrepancies in both use and differences in the subjective metrics.

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.

Minimally Invasive Management of Upper Tract Malignancies: Renal Cell and Transitional Cell Carcinoma

This article focuses on the laparoscopic approaches to radical and partial nephrectomy for the managment of renal cell carcinoma and on the laparoscopic and endoscopic approaches for treating upper tract urothelial carcimoma. An in-depth discussion of treatment for transitional cell carcinoma is also presented.

Erythropoietin-induced optimization of renal function after warm ischemia.

BACKGROUND AND PURPOSE Recent preclinical data have indicated that erythropoietin (Epo) can protect organs from ischemic damage. We evaluated the ability of Epo to protect the kidney from the effects of ischemia. METHODS Thirty dogs underwent a laparoscopic nephrectomy and were allowed to recover for 2 weeks. The dogs were then divided into five groups. Animals in groups 1 and 2 underwent 1.5 hours of abdominal insufflation with placebo (saline) injection (group 1) or Epo injection (group 2) before; groups 3 to 5 underwent 1 hour of laparoscopic renal artery clamping after placebo injection (group 3), Epo injection (group 4), or mannitol injection (group 5). Serum evaluations and 24-hour urine collections were performed weekly. After 28 days, the animals were sacrificed. Statistical analysis was performed with the Kruskal-Wallis test. RESULTS After recovery from the initial nephrectomy, all dogs had similar serum hematocrit and creatinine levels. Hematocrit was not significantly affected by Epo administration at any time point. Immediately after the second surgery, dogs that underwent renal artery clamping (groups 3-5) had significantly lower 24-hour urine creatinine levels than those that were not clamped (groups 1-2). After 4 weeks of recovery, the dogs that had received Epo before ischemia (group 4) had recovered significantly more renal function than the dogs that received placebo or mannitol before ischemia (urine creatinine level = Epo 149.1 mg/dL v placebo 70.7 mg/dL v mannitol 80.7 mg/dL). At sacrifice, microalbuminuria was also significantly less in dogs receiving Epo before ischemia than their mannitol or placebo counterparts. CONCLUSION The current study demonstrates that administering Epo before warm ischemia can improve the recovery of renal function after ischemia better than placebo or mannitol.

An assessment of urologists' training and knowledge of energy-based surgical devices

To assess surgeons’ training and current understanding of existing energy‐based surgical instrumentation (ESI), we disseminated an online questionnaire to urology residents, fellows and attending urologists.