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

OBJECTIVE: 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. SUBJECTS AND METHODS: A two part 24-question survey was disseminated to 1000 urology residents, fellows and attending physicians. The first part of the questionnaire assessed the respondents' demographics and education about ESI; the second part evaluated the respondent's knowledge of surgical energy methods and ESI, and was stratified into nine basic- and six advanced-knowledge questions. RESULTS: In all, 136 people (13.6%) viewed the survey and it was completed by 63 (6.3%). Respondents comprised 27 (43%) attending physicians, 14 (22%) minimally-invasive urology fellows and 22 (35%) urology residents. Among participants, 41 (64%) had received no formal didactic training on ESI, and a further 14% of respondents' didactic experience was limited to one lecture. Of the respondents, 70% said that monopolar energy was the mode most often used in surgery. Overall, the participants correctly answered 41% of the questions. Of the nine questions classified as 'basic' knowledge, respondents correctly answered 49%. Of the six questions classified as 'advanced' knowledge, 29% were answered correctly. The highest percentage score was obtained by the attending urologists, with a mean (range) score of 41 (29-86)%, followed by the fellows, with a mean score of 39.5 (29-57)%, and then the residents, at 34 (14-64)%. CONCLUSION: Despite widespread and growing use of ESI, there is currently minimal formal training on energy modes and current energy devices being provided to urological surgeons. Both practising and training urologists have a limited understanding of surgical energy modes and of existing ESI.

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.

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.

Kidney cancer ablative therapy: indications and patient selection.

The increased application of radiographic imaging has paralleled a simultaneous increase in the detection of incidental and asymptomatic renal neoplasms. The reference standard for treating small renal tumors includes open and laparoscopic partial nephrectomy. The primary objectives of ablative renal procedures are to duplicate the excellent oncologic outcomes of partial nephrectomy while decreasing patient morbidity and shortening hospitalization and overall convalescence. Ablation, with cryotherapy or radiofrequency probes, offers the advantages of minimally invasive surgery, but with a significantly lower complication rate than laparoscopic partial nephrectomy. Ablation now represents a major change in surgical thinking as tumors are ablated and left in situ. This article reviews the status of the two ablative modalities currently available for clinical application, cryoablation and radiofrequency ablation.

Cryoablation and radiofrequency for kidney tumor.

The detection of incidental and asymptomatic renal cortical neoplasms has concomitantly increased with radiographic imaging use. The gold standard for treating small renal tumors includes open and laparoscopic partial nephrectomy. Ablative renal procedures intend to duplicate the excellent oncologic outcomes of partial nephrectomy, while decreasing complications and shortening hospitalization time and convalescence. Only short and medium-term data are available, but ablation with cryotherapy or radiofrequency probes may achieve these goals. Ablation also offers the advantages of a minimally invasive surgical approach, with a significantly lower complication rate than partial nephrectomy. Ablated lesions are typically left in situ. Leaving potentially malignant tissues in place, albeit in a nonviable condition, certainly represents a major change in surgical thinking processes. This article reviews the status of cryoablation and radiofrequency ablation, the two ablative modalities currently available for clinical application.

An evidence-based review of medical and surgical treatments of genital warts.

Genital human papillomavirus (HPV) infection is the most common sexually transmitted disease. Each year 1 million new cases of genital warts are diagnosed, two thirds of which are in women. The estimated prevalence rate in the US population is 15 percent. HPV infects keratinocytes. Such infection can manifest clinically as warts. Treatment options for genital warts are numerous, well established, and effective. Topical treatments include podophyllin resin, imiquimod, trichloroacetic acid, and podophyllotoxin. Surgical or destructive therapies include carbon dioxide laser, surgical excision, loop excision, cryotherapy, and electrodessication. Interferon can be injected locally or administered systemically to treat genital warts. Evidence of efficacy in the treatment of genital warts is drawn from randomized blind-controlled trials, prospective studies, and retrospective cohort studies. Evidence of efficacy appears to be good, but more head-to-head studies and comparisons of combination therapies versus monotherapy need to be done. Treatment of choice depends on the number, size, and location of lesions. There is little certainty that any approach is more effective than another, however costs differ. It would seem that the first line destructive treatment is cryotherapy, but surgery and electrodesiccation are more effective. The first line topical treatments appear to be podophyllotoxin and imiquimod. Interferon is too expensive and trichloracetic acid is too inconsistent to be recommended as primary treatment. It is unclear if combinations of therapies are more effective than monotherapy. Side effect profile, cost, effectiveness and convenience (ability to attend physician's office or to undertake protracted home treatment) define the choice of therapy.

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.

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.

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.

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 LigaSure's 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 Trisector's mean full thickness and superficial lateral energy damage were 6.3 mm and 7.0 mm, respectively, whereas the Ligasure's 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-C5's 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.

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.

Physiological fatigue of smooth muscle contractions in rat urinary bladder.

OBJECTIVE: To characterize the physiological fatigue in bladder smooth muscles that can occur within 60 s of stimulation, which is closer to the duration of normal voiding. MATERIALS AND METHODS: Longitudinal and transverse strips of rat bladder were used; the muscles were mounted in an in vitro multi-muscle chamber, and the decline in contractile tension recorded during continuous electrical stimulation at frequencies of 5-30 Hz for 60 s. The effect of muscle length on fatigue was assessed by monitoring the decline in tension during 30 Hz stimulation at rest length, and at 60% and 100% stretched lengths of the bladder strips. To assess some of the factors involved in the development of fatigue, tension responses of fatigued muscles were monitored on exposure to 80 mm potassium or 1 microm bethanechol. RESULTS: In both longitudinal and transverse bladder strips stimulated at 30 Hz, peak contractile tension declined to 50% of original after approximately 33 s, and to 30% after 60 s of stimulation. After 10 s rest, 60% of the original tension was recovered. Increasing the frequency of fatigue stimulation from 5 to 30 Hz significantly increased the extent of the decline in tension and reduced the time to a 50% decrease in tension. Stretching the bladder strips from rest length to 100% stretched length significantly reduced the extent of tension decline and increased the time to a 50% decrease in tension. Exposure of fatigued muscles to high potassium or bethanechol generated more tension than electrical stimulation. CONCLUSION: Contractile fatigue occurs in both longitudinal and transverse strips of the bladder smooth muscles within the duration of normal voiding. Increasing the frequency of stimulation from 5 to 30 Hz increased the degree and rate of fatigue. Stretching the bladder strips from rest length by 60-100% reduced the degree and rate of fatigue. Bladder fatigue may be caused by decreased depolarization of the smooth muscle membranes, reduced release of acetylcholine from presynaptic nerve terminals, or by other yet undetermined mechanisms.