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Re: BioGlue Iceball Stabilization to Minimize the Risk of Hemorrhage During Laparoscopic Renal Cryoablation
84
LAPAROSCOPY/NEW TECHNOLOGY
for survival through univariate and multivariable Cox regression analysis. Results and Limitations: Tumour location was renal pelvis in 317 cases (52%), ureter in 185 cases (30%), and multifocal in 107 cases (18%). Compared to renal pelvic and ureteral tumours, multifocal tumours were more likely to be associated with advanced stages (pT3/pT4; 39%, 30%, and 54%, respectively; p⬍0.001) and high-grade disease (53%, 56%, and 76%, respectively; p⬍0.001). On multivariable analysis, tumour location was an independent prognostic factor for cancer-specific death, disease recurrence, and metastasis (p⬍0.05). The 5-yr cancer-specific death-free survival probability was 86.8% for renal pelvic tumours, 68.9% for ureteral tumours, and 56.8% for multifocal tumours (p⬍0.001). The retrospective design of this study was its main limitation. Conclusions: Ureteral and multifocal tumours had a worse prognosis than renal pelvic tumours. These findings are not in line with recently published data and should be investigated in a prospective assessment to obtain a definitive statement regarding this matter. Editorial Comment: The authors compare prognosis among cancers of the upper tract localized to the renal pelvis or ureter and those that are multifocal. Comparison of recurrence (bladder and contralateral kidney), metastasis and cancer specific survival showed that the ureteral tumors and those that were multifocal had a significantly worse prognosis than renal pelvic tumors. It is noteworthy that stage and grade distribution of ureteral and renal pelvic tumors was not greatly different, but multifocal tumors tended more often to be high grade and locally advanced. It is also noteworthy that on multivariate analysis only multifocal tumors carried a greater risk of death than renal pelvic tumors. Stage remained the strongest predictor. The observations of this study may have implications in selecting candidates for neoadjuvant therapy. Given the recent demonstration of a potential role for chemotherapy before nephroureterectomy (while glomerular filtration rate is maximized), this information may be useful in selecting candidates for therapy. Samir S. Taneja, M.D.
Laparoscopy/New Technology Re: BioGlue Iceball Stabilization to Minimize the Risk of Hemorrhage During Laparoscopic Renal Cryoablation A. C. Mues, J. A. Graversen, M. D. Truesdale, C. Casazza and J. Landman Department of Urology, University of California, Irvine, California Urology 2011; 78: 353–356.
Objective: To evaluate the application of a BioGlue adhesive shell to minimize iceball fracture. Iceball fracture and hemorrhage is common with laparoscopic cryoablation (LCA) of larger (⬎4 cm) renal tumors. Methods: Twenty large iceballs were created in porcine kidneys using 3 cryoablation probes in a nonsurvival study. Each kidney underwent an upper and lower pole ablation. One pole in each kidney was covered with 5 mL of BioGlue and the opposite pole served as a control. A double freeze-thaw cycle was performed (10 minutes freeze and 5 minutes active thaw) in both renal poles simultaneously. The probes were removed and the sites were monitored for 20 minutes under direct vision. Fracture length (mm), severity of fracture depth, severity of bleeding (absent, mild, moderate, severe), and estimated blood loss (EBL) (mL) were recorded. Results: In the control group, the mean fracture length was 1.9 mm (range, 0 –3 mm). Blood loss was absent in 10%, mild in 60%, and moderate in 30% of ablations. The mean EBL was 20.5 mL (range, 0 –50 mL). For the BioGlue ablations, there were no parenchymal fractures. Blood loss was mild in 30% and absent in 70% of sites with an average EBL of 5 mL (range, 0 –20). Two bleeding sites occurred as a result of subcapsular
LAPAROSCOPY/NEW TECHNOLOGY
85
hematomas caused by initial probe placement. Conclusions: BioGlue application minimized the frequency and magnitude of renal fracture. EBL was lower with BioGlue application and most sites demonstrated no postablation bleeding. Further clinical study of the BioGlue shell should be performed to confirm these results. Editorial Comment: The most common and frightening complication associated with laparoscopic renal tumor cryoablation is tumor fracture and hemorrhage immediately after ablation. Interestingly this complication occurs less frequently after percutaneous cryoablation, with the authors hypothesizing that the uninterrupted surrounding perinephric fat and Gerota’s fascia provide a protective tamponade effect after thawing. To regain this anatomical advantage, the authors applied BioGlue® surgical adhesive over the cryoablation zone in a porcine model to create an adhesive shell that mimicked the effect of surrounding tissue support of the ablative iceball. The technique worked to reduce the frequency and magnitude of renal fractures. Whether this original idea will succeed clinically remains to be determined. One concern is that in the rare cases of incomplete tumor ablation I wonder if the subsequent fibrotic shell will further increase the difficulty of any salvage procedure. Jeffrey A. Cadeddu, M.D.
Re: Perioperative, Oncologic, and Functional Outcomes of Laparoscopic Renal Cryoablation and Open Partial Nephrectomy: A Matched Pair Analysis T. Klatte, J. Mauermann, G. Heinz-Peer, M. Waldert, P. Weibl, H. C. Klingler and M. Remzi Department of Urology, Medical University of Vienna, Vienna, Austria J Endourol 2011; 25: 991–997.
Purpose: To directly compare perioperative, oncologic, and functional outcomes of laparoscopic renal cryoablation and open partial nephrectomy using a matched pair analysis. Patients and Methods: A total of 41 patients who underwent laparoscopic cryoablation for an incidental, solid clinical T1aN0M0 renal tumor were matched with 82 patients who received partial nephrectomy in cold ischemia, using optimal matching based on propensity scores, which were created on the basis of preoperative aspects and dimensions used for an anatomic classification of renal tumors (PADUA) score, preoperative glomerular filtration rate, age-adjusted Charlson comorbidity index, and sex. Median follow-up was 33.6 months. Results: No differences in the overall incidence of complications (cryoablation, 20%; partial nephrectomy, 17%; P⫽0.739) and grade of complications (P⫽0.424) were observed. After cryoablation, local recurrence developed in four patients with renal-cell carcinoma (n⫽35) after a median duration of 14 months (range 6 –18 mos), but none after partial nephrectomy. The 3-year recurrence-free survival probabilities after laparoscopic renal cryoablation vs open partial nephrectomy were 83% vs 100%, respectively (P⫽0.015). The average decrease of estimated glomerular filtration rate during follow-up was 7.8⫾3.1 mL/min/1.73 m2 after laparoscopic cryoablation and 9.8⫾2.3 mL/min/1.73 m2 after open partial nephrectomy, which was not statistically significant (P⫽0.602). Conclusions: Perioperative complications and renal functional outcomes of laparoscopic cryoablation and open partial nephrectomy are similar; however, laparoscopic cryoablation confers a substantially higher local recurrence risk of about 17% after 3 years. Therefore, laparoscopic renal cryoablation should be reserved for high-risk patients with decreased life expectancy. Careful patient counseling is advocated. Study limitations include the small sample size, the lack of randomization, and the short follow-up.
LAPAROSCOPY/NEW TECHNOLOGY
for survival through univariate and multivariable Cox regression analysis. Results and Limitations: Tumour location was renal pelvis in 317 cases (52%), ureter in 185 cases (30%), and multifocal in 107 cases (18%). Compared to renal pelvic and ureteral tumours, multifocal tumours were more likely to be associated with advanced stages (pT3/pT4; 39%, 30%, and 54%, respectively; p⬍0.001) and high-grade disease (53%, 56%, and 76%, respectively; p⬍0.001). On multivariable analysis, tumour location was an independent prognostic factor for cancer-specific death, disease recurrence, and metastasis (p⬍0.05). The 5-yr cancer-specific death-free survival probability was 86.8% for renal pelvic tumours, 68.9% for ureteral tumours, and 56.8% for multifocal tumours (p⬍0.001). The retrospective design of this study was its main limitation. Conclusions: Ureteral and multifocal tumours had a worse prognosis than renal pelvic tumours. These findings are not in line with recently published data and should be investigated in a prospective assessment to obtain a definitive statement regarding this matter. Editorial Comment: The authors compare prognosis among cancers of the upper tract localized to the renal pelvis or ureter and those that are multifocal. Comparison of recurrence (bladder and contralateral kidney), metastasis and cancer specific survival showed that the ureteral tumors and those that were multifocal had a significantly worse prognosis than renal pelvic tumors. It is noteworthy that stage and grade distribution of ureteral and renal pelvic tumors was not greatly different, but multifocal tumors tended more often to be high grade and locally advanced. It is also noteworthy that on multivariate analysis only multifocal tumors carried a greater risk of death than renal pelvic tumors. Stage remained the strongest predictor. The observations of this study may have implications in selecting candidates for neoadjuvant therapy. Given the recent demonstration of a potential role for chemotherapy before nephroureterectomy (while glomerular filtration rate is maximized), this information may be useful in selecting candidates for therapy. Samir S. Taneja, M.D.
Laparoscopy/New Technology Re: BioGlue Iceball Stabilization to Minimize the Risk of Hemorrhage During Laparoscopic Renal Cryoablation A. C. Mues, J. A. Graversen, M. D. Truesdale, C. Casazza and J. Landman Department of Urology, University of California, Irvine, California Urology 2011; 78: 353–356.
Objective: To evaluate the application of a BioGlue adhesive shell to minimize iceball fracture. Iceball fracture and hemorrhage is common with laparoscopic cryoablation (LCA) of larger (⬎4 cm) renal tumors. Methods: Twenty large iceballs were created in porcine kidneys using 3 cryoablation probes in a nonsurvival study. Each kidney underwent an upper and lower pole ablation. One pole in each kidney was covered with 5 mL of BioGlue and the opposite pole served as a control. A double freeze-thaw cycle was performed (10 minutes freeze and 5 minutes active thaw) in both renal poles simultaneously. The probes were removed and the sites were monitored for 20 minutes under direct vision. Fracture length (mm), severity of fracture depth, severity of bleeding (absent, mild, moderate, severe), and estimated blood loss (EBL) (mL) were recorded. Results: In the control group, the mean fracture length was 1.9 mm (range, 0 –3 mm). Blood loss was absent in 10%, mild in 60%, and moderate in 30% of ablations. The mean EBL was 20.5 mL (range, 0 –50 mL). For the BioGlue ablations, there were no parenchymal fractures. Blood loss was mild in 30% and absent in 70% of sites with an average EBL of 5 mL (range, 0 –20). Two bleeding sites occurred as a result of subcapsular
LAPAROSCOPY/NEW TECHNOLOGY
85
hematomas caused by initial probe placement. Conclusions: BioGlue application minimized the frequency and magnitude of renal fracture. EBL was lower with BioGlue application and most sites demonstrated no postablation bleeding. Further clinical study of the BioGlue shell should be performed to confirm these results. Editorial Comment: The most common and frightening complication associated with laparoscopic renal tumor cryoablation is tumor fracture and hemorrhage immediately after ablation. Interestingly this complication occurs less frequently after percutaneous cryoablation, with the authors hypothesizing that the uninterrupted surrounding perinephric fat and Gerota’s fascia provide a protective tamponade effect after thawing. To regain this anatomical advantage, the authors applied BioGlue® surgical adhesive over the cryoablation zone in a porcine model to create an adhesive shell that mimicked the effect of surrounding tissue support of the ablative iceball. The technique worked to reduce the frequency and magnitude of renal fractures. Whether this original idea will succeed clinically remains to be determined. One concern is that in the rare cases of incomplete tumor ablation I wonder if the subsequent fibrotic shell will further increase the difficulty of any salvage procedure. Jeffrey A. Cadeddu, M.D.
Re: Perioperative, Oncologic, and Functional Outcomes of Laparoscopic Renal Cryoablation and Open Partial Nephrectomy: A Matched Pair Analysis T. Klatte, J. Mauermann, G. Heinz-Peer, M. Waldert, P. Weibl, H. C. Klingler and M. Remzi Department of Urology, Medical University of Vienna, Vienna, Austria J Endourol 2011; 25: 991–997.
Purpose: To directly compare perioperative, oncologic, and functional outcomes of laparoscopic renal cryoablation and open partial nephrectomy using a matched pair analysis. Patients and Methods: A total of 41 patients who underwent laparoscopic cryoablation for an incidental, solid clinical T1aN0M0 renal tumor were matched with 82 patients who received partial nephrectomy in cold ischemia, using optimal matching based on propensity scores, which were created on the basis of preoperative aspects and dimensions used for an anatomic classification of renal tumors (PADUA) score, preoperative glomerular filtration rate, age-adjusted Charlson comorbidity index, and sex. Median follow-up was 33.6 months. Results: No differences in the overall incidence of complications (cryoablation, 20%; partial nephrectomy, 17%; P⫽0.739) and grade of complications (P⫽0.424) were observed. After cryoablation, local recurrence developed in four patients with renal-cell carcinoma (n⫽35) after a median duration of 14 months (range 6 –18 mos), but none after partial nephrectomy. The 3-year recurrence-free survival probabilities after laparoscopic renal cryoablation vs open partial nephrectomy were 83% vs 100%, respectively (P⫽0.015). The average decrease of estimated glomerular filtration rate during follow-up was 7.8⫾3.1 mL/min/1.73 m2 after laparoscopic cryoablation and 9.8⫾2.3 mL/min/1.73 m2 after open partial nephrectomy, which was not statistically significant (P⫽0.602). Conclusions: Perioperative complications and renal functional outcomes of laparoscopic cryoablation and open partial nephrectomy are similar; however, laparoscopic cryoablation confers a substantially higher local recurrence risk of about 17% after 3 years. Therefore, laparoscopic renal cryoablation should be reserved for high-risk patients with decreased life expectancy. Careful patient counseling is advocated. Study limitations include the small sample size, the lack of randomization, and the short follow-up.