Immediate effect of kidney cryoablation on renal arterial structure in a porcine model studied by imaging cryomicrotome.

PURPOSE: Injury to blood microvessels has a crucial role in effective cryoablation for renal masses. We visualized vascular injury induced by a clinically applied cryoablation instrument and established a microvascular diameter threshold for vascular damage. MATERIALS AND METHODS: In 5 anesthetized pigs 1 kidney each was exposed and 3, 17 gauge cryoneedles were inserted in 1 pole. Tissue was exposed to freezing for 2 x 10 minutes with a 10-minute thaw between freezes. After nephrectomy the arteries were injected with fluorescence dyed casting material and the kidney was frozen to -20C and cut in 40 to 60 micron slices in the imaging cryomicrotome, where fluorescent images of the cutting plane of the bulk were obtained. This resulted in a 3-dimensional image of the arterial tree that was segmented, resulting in unbranched vessel segments. Histograms were constructed with the total segment length per diameter bin plotted as function of diameter. RESULTS: The ablated zone was sharply demarcated on fluorescent and normal light images. Mean +/- SD diameter at the peak of the histogram from control areas was 152.4 +/- 5.3 micron. Compared to control areas the peak diameter of ablated areas was shifted to a larger diameter by an average of 25.4 +/- 2.6 micron. CONCLUSIONS: Immediate renal cryoablation injury destroys arteries smaller than 180 micron. Branching structures of larger arteries remain anatomically intact and connected to vascular structures in surrounding tissue.

Clinical update on testicular microlithiasis.

PURPOSE OF REVIEW: Testicular microlithiasis becomes a greater interdisciplinary issue among urologists, andrologists, gynecologists dedicated to reproductive medicine, pediatricians, radiologists and pathologists. Proposed management ranges from benign neglect, instructing self-examination over follow-up once, regular biannual follow-up including ultrasonography to bilateral testicular biopsy to rule out possible concomitant unclassified intratubular germ cell neoplasia (ITGCN) or future development of testicular cancer. The aim of this review is to present an overview of the current dilemma and summarize management trends based on the most recent data. RECENT FINDINGS: Testicular microlithiasis is not a premalignant condition but may accompany ITGCN or testicular cancer. The importance of ruling out ITGCN with testicular biopsy in high-risk men, such as in those with bilateral testicular microlithiasis, infertility, cryptorchidism, atrophic testes or contralateral testicular cancer, has been recently advocated. SUMMARY: Despite greater awareness of testicular microlithiasis, a clear definition is currently missing and the etiology is still obscure. This causes confusion in management and follow-up. Self-examination alone or in combination with testicular ultrasonography has been advised. Recently, a single set of biopsies in selected, high-risk groups has been proposed to rule out ITGCN without a need for further investigations apart from self-examination. However, the cost-effectiveness of such a strategy needs to be evaluated.

International and Multi-institutional Assessment of Factors Associated With Performance and Quality of Lymph Node Dissection During Radical Nephrectomy.

OBJECTIVE: To determine factors associated with performance and quality of lymph node dissection during radical nephrectomy. MATERIALS AND METHODS: Using an International Data Registry, we performed multilevel logistic regression to determine the association of surgical approach (open surgery vs minimally invasive surgery), institutional experience (low, moderate, and high tertiles), and institutional preference (minimally invasive surgery, balanced, and open surgery tertiles) with the performance of lymph node dissection in subgroups by clinical stage and nodal status. RESULTS: Among 1,742 patients undergoing radical nephrectomy, 312 (18%) underwent lymph node dissection, which was associated with stage (28% for ≥cT2 vs 9.3% for cT1), and nodal status (68% for ≥cN1 vs 13% for cN0). Open surgery was significantly associated with performing lymph node dissection in all subgroups. Institutional experience and institutional preference had no association with performing lymph node dissection in the ≥cN1 group. The number of nodes removed was greater for open surgery (mean 5.9) vs minimally invasive surgery (mean 3.4); this held true even when stratified by stage and nodal status. CONCLUSION: In this large dataset, open surgical radical nephrectomy is associated with more frequent performance and higher quality of lymph node dissection, which may owe to selection bias but also could reflect technical concerns. In the patient population in whom lymph node dissection is recommended (≥cN1), this is not explained by institutional experience or preference. Lymph node dissection may be under-utilized for ≥cN1 disease and over-utilized for cN0 disease, at least according to practice guidelines.

The performance of 17-gauge cryoprobes in vitro.

In cryosurgery it is crucial that the performance of cryoprobes is predictable and constant. In this study we tested the intra- and interneedle variation between 17-gauge cryoprobes in two homogeneous mediums. Also, a multiprobe setup was tested. Cryoprobe performance was defined as the time it takes one cryoprobe to lower the temperature from 0 to -20 degrees C as measured by four thermosensors each at 3 mm distance from the cryoprobe. In agar eight cryoprobes were tested during six freeze cycles, and in gel four cryoprobes during four freeze cycles; each freeze cycle in a different cup of agar or gel. Using more accurate 'bare' thermosensors three cryoprobes were tested in gel during two freeze cycles. A multiprobe configuration with four cryoprobes was tested during two freeze cycles in both agar and gel. Statistical analyses were done using ANOVA for repeated measures. There was no significant intraneedle variation, whereas both in agar and gel there was a significant interneedle variation (p<0.05). Mean performance in gel was better than in agar (p<0.001). Also, there was a significant variation between the four thermosensors (p<0.001). Using bare thermosensors mean performance was 2.7 times faster compared to measurements by regular thermosensors (p<0.001). In a multiprobe configuration, overall performance seems less variable and more reproducible compared to a single cryoprobe. In conclusion, the performance of cryoprobes differs depending on the medium and measuring device used. Cryoprobes deliver reproducible freeze cycles, although there is variation between different cryoprobes. In a multiprobe configuration performance seems less variable.

Quality of life and perceived pain after laparoscopic-assisted renal cryoablation.

PURPOSE: Assessing changes in quality of life (QoL) and perceived pain after laparoscopic-assisted cryoablation (LAC) of renal tumors. PATIENTS AND METHODS: Data for 57 patients who were treated with LAC were prospectively collected. QoL, divided into various domains, and postoperative pain were assessed using the Medical Outcome Study 36-item Short Form Health Survey (SF-36), the European Organization for Research and Treatment of Cancer QLQ-C30 (EORTC-QLQ-C30), and Visual Analog Scale (VAS). Assessment was performed at baseline and at different time intervals until 1 year after LAC. Using a repeated measures analysis of variance, the influence of the following parameters was evaluated: Time of assessment, age, comorbidity, the occurrence of a complication, and tumor histology. RESULTS: SF-36: At baseline, only general health perceptions scored lower compared with the general population. Time of assessment and a complication did not affect QoL. Comorbidity and age >70 years led to a significantly lower QoL. Tumor histology affected general health perceptions. EORTC-QLQ-C30: Time of assessment affected 7 of 15 domains because of lower scores after 2 weeks. Age and comorbidity each negatively influenced five domains. A complication increased three symptoms scores and lowered general health status. Tumor histology significantly altered role functioning. VAS: VAS reached a peak 1 day after LAC, then quickly declined. Patients >70 years had significant higher VAS. CONCLUSIONS: QoL of patients who were treated with LAC showed a decrease 2 weeks after surgery but normalized to baseline within 3 months. Age and comorbidities especially affected QoL negatively. The VAS showed a peak 1 day after LAC and then quickly declined.

The diagnostic yield of immediate postcryoablation biopsies of small renal masses.

AIM: To evaluate the diagnostic feasibility and reproducibility of immediate postcryoablation biopsies of small renal masses. MATERIALS AND METHODS: Between December 2006 and July 2007, 21 intraoperative pre- and postcryoablation (18-gauge core) biopsies of renal masses were obtained. Evaluation of the biopsies by the institutional uropathologist was followed by a blind assessment by two other uropathologists. Tumor subtype and Fuhrman grade were determined by the three pathologists, while biopsy timing (before or after cryoablation) was only assessed by the two blinded pathologists. The diagnostic yield of the pre- and postcryoablation biopsies and interobserver agreement were calculated. RESULTS: The mean size of the 21 cryoablated tumors was 2.8 cm. No significant bleeding occurred after any biopsy. Of the precryoablation biopsies 75-81% was correctly labeled as precryo, and 48% of the postcryoablation biopsies as postcryo. The diagnostic yield of the three pathologists for precryo biopsies ranged between 67% and 71%, and for postcryo biopsies between 48% and 71% (not statistically different). When combining both types of biopsies, the overall diagnostic yield was 81% for all pathologists. The interobserver agreement was "almost perfect" (kappa = 0.902) for precryo biopsies and "substantial" (kappa = 0.514) for postcryo biopsies. CONCLUSION: This study shows that it is feasible to obtain histopathological diagnoses from postcryoablation biopsies with a diagnostic yield and interobserver agreement similar to precryoablation biopsies.